CA2014223C - Brake release mechanism for a spring applied vehicle park brake - Google Patents
Brake release mechanism for a spring applied vehicle park brakeInfo
- Publication number
- CA2014223C CA2014223C CA002014223A CA2014223A CA2014223C CA 2014223 C CA2014223 C CA 2014223C CA 002014223 A CA002014223 A CA 002014223A CA 2014223 A CA2014223 A CA 2014223A CA 2014223 C CA2014223 C CA 2014223C
- Authority
- CA
- Canada
- Prior art keywords
- brake
- hydraulic
- hook
- shuttle valve
- vehicle
- 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 - Fee Related
Links
- 239000012530 fluid Substances 0.000 claims abstract description 6
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
- B60T7/00—Brake-action initiating means
- B60T7/12—Brake-action initiating means for automatic initiation; for initiation not subject to will of driver or passenger
- B60T7/20—Brake-action initiating means for automatic initiation; for initiation not subject to will of driver or passenger specially for trailers, e.g. in case of uncoupling of or overrunning by trailer
-
- 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
- B60T11/00—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant
- B60T11/10—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant transmitting by fluid means, e.g. hydraulic
-
- 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)
- Valves And Accessory Devices For Braking Systems (AREA)
- Braking Systems And Boosters (AREA)
- Braking Arrangements (AREA)
Abstract
A brake release mechanism for a vehicle provided with a main retrieval hook is disclosed. The brake release mechanism comprises a hydraulic cylinder having its piston rod terminated in the form of a hook which is located within the main retrieval hook of the vehicle, a shuttle valve located in the main hydraulic line interconnecting the regular spring applied brake to a hydraulic pressure supply, and an auxiliary hydraulic line interconnecting the shuttle valve and the hydraulic cylinder for applying fluid pressure to the spring applied brake through the shuttle valve in case of loss of pressure from the regular hydraulic pressure supply. The above mechanism allows the hook of the piston rod to be engaged at the same time as the regular retrieval hook to disengage the brake while pulling on the stranded vehicle.
Description
201~1223 Brake Release Mec-h~n~sm for a 8pring Applied Vehi¢le Park Bra~e This invention relates to a brake release mechanism for a spring applied vehicle park brake.
In order to retrieve stranded vehicles, such as scoops from open stopes, it is necessary to release the spring applied park brakes. On these vehicles, the regular hydraulic system operating the wheel brakes bleeds down after thirty seconds of shut down and externally applied hydraulic pressure is required to back off the springs in the brake heads. It is known to provide a manual pump to apply hydraulic pressure to back off the springs in the brake heads as disclosed in U.S. Patent 4,195,716 issued April 1, 1980 . However, it is not possible to operate a manual pump from a remote location when a vehicle is stranded in a non-accessible area such as an open stope.
It is therefore the object of the present invention to provide a park brake release system which may be operated from a remote location.
The brake release mechanism in accordance with the present invention comprises a hydraulic cylinder having ~ its piston rod terminated in the form of a hook located within the main retrieval hook of the vehicle, a shuttle valve located in the hydraulic line interconnecting the ~,~
201~223 brake to the regular hydraulic pressure supply, and an auxiliary hydraulic line interconnecting the shuttle valve to the hydraulic cylinder for supplying hydraulic pressure to the brake through the shuttle valve in case of loss of pressure from the regular hydraulic pressure supply. The location of the hook of the piston rod of the hydraulic cylinder within the retrieval hook of the vehicle allows disengagement of the brake while pulling on the stranded vehicle.
A relief valve is preferably connected to the auxiliary hydraulic line for protection of the shuttle valve, the hydraulic line and the hydraulic cylinder.
The invention will now be disclosed, by way of example, with reference to a drawing illustrating a preferred embodiment.
Referring to the drawing, a hydraulic cylinder 10 is installed to the rear of a scoop 12 . A rod 14 is connected to the piston 16 of the cylinder and terminated in the form of a hook 18 which is located within the main retrieval hook 20 of the scoop. The rod end of the cylinder contains hydraulic fluid and the piston end is vented to atmosphere through breather 22. The regular spring loaded disc brake 24 is connected to a regular hydraulic pressure supply through a shuttle valve 26 and a manual break test valve 28 located in a regular hydraulic line 30. An auxiliary hydraulic line 32 is connected 201gl2~3 between the shuttle valve 26 and the hydraulic cylinder 10. A relief valve 34 is located in the auxiliary hydraulic line 32 to protect the shuttle valve, the hydraulic line and the hydraulic cylinder.
In operation, the retrieving scoop, which is normally remotely operated, will proceed to latch with a cable onto the main hook 20 of the stranded vehicle. As the retrieving scoop pulls back, the retrieval cable will catch on the hook 18 of the piston rod and the piston of the hydraulic cylinder will be forced to move, thus moving hydraulic fluid through shuttle valve 26 onto the calipers of the brake head to back off the springs of the brake, The pressure supplied by the hydraulic cylinder is set so as to be sufficient to hold off the brake. If the retrieval scoop should have a failure, or the retrieval cable was to fail, the springs in the brake head of the stranded vehicle would apply, forcing the hydraulic fluid back through shuttle valve 26, back to the hydraulic cylinder 10, allowing the brake to apply and the retrieval process could be repeated. This would eliminate any possibility of a runaway vehicle.
Although the invention has been disclosed with reference to a preferred embodiment, it is to be understood that it is not limited to such embodiment and that other alternatives are also envisaged within the scope of the following claims.
In order to retrieve stranded vehicles, such as scoops from open stopes, it is necessary to release the spring applied park brakes. On these vehicles, the regular hydraulic system operating the wheel brakes bleeds down after thirty seconds of shut down and externally applied hydraulic pressure is required to back off the springs in the brake heads. It is known to provide a manual pump to apply hydraulic pressure to back off the springs in the brake heads as disclosed in U.S. Patent 4,195,716 issued April 1, 1980 . However, it is not possible to operate a manual pump from a remote location when a vehicle is stranded in a non-accessible area such as an open stope.
It is therefore the object of the present invention to provide a park brake release system which may be operated from a remote location.
The brake release mechanism in accordance with the present invention comprises a hydraulic cylinder having ~ its piston rod terminated in the form of a hook located within the main retrieval hook of the vehicle, a shuttle valve located in the hydraulic line interconnecting the ~,~
201~223 brake to the regular hydraulic pressure supply, and an auxiliary hydraulic line interconnecting the shuttle valve to the hydraulic cylinder for supplying hydraulic pressure to the brake through the shuttle valve in case of loss of pressure from the regular hydraulic pressure supply. The location of the hook of the piston rod of the hydraulic cylinder within the retrieval hook of the vehicle allows disengagement of the brake while pulling on the stranded vehicle.
A relief valve is preferably connected to the auxiliary hydraulic line for protection of the shuttle valve, the hydraulic line and the hydraulic cylinder.
The invention will now be disclosed, by way of example, with reference to a drawing illustrating a preferred embodiment.
Referring to the drawing, a hydraulic cylinder 10 is installed to the rear of a scoop 12 . A rod 14 is connected to the piston 16 of the cylinder and terminated in the form of a hook 18 which is located within the main retrieval hook 20 of the scoop. The rod end of the cylinder contains hydraulic fluid and the piston end is vented to atmosphere through breather 22. The regular spring loaded disc brake 24 is connected to a regular hydraulic pressure supply through a shuttle valve 26 and a manual break test valve 28 located in a regular hydraulic line 30. An auxiliary hydraulic line 32 is connected 201gl2~3 between the shuttle valve 26 and the hydraulic cylinder 10. A relief valve 34 is located in the auxiliary hydraulic line 32 to protect the shuttle valve, the hydraulic line and the hydraulic cylinder.
In operation, the retrieving scoop, which is normally remotely operated, will proceed to latch with a cable onto the main hook 20 of the stranded vehicle. As the retrieving scoop pulls back, the retrieval cable will catch on the hook 18 of the piston rod and the piston of the hydraulic cylinder will be forced to move, thus moving hydraulic fluid through shuttle valve 26 onto the calipers of the brake head to back off the springs of the brake, The pressure supplied by the hydraulic cylinder is set so as to be sufficient to hold off the brake. If the retrieval scoop should have a failure, or the retrieval cable was to fail, the springs in the brake head of the stranded vehicle would apply, forcing the hydraulic fluid back through shuttle valve 26, back to the hydraulic cylinder 10, allowing the brake to apply and the retrieval process could be repeated. This would eliminate any possibility of a runaway vehicle.
Although the invention has been disclosed with reference to a preferred embodiment, it is to be understood that it is not limited to such embodiment and that other alternatives are also envisaged within the scope of the following claims.
Claims (2)
1. A brake release mechanism for a vehicle provided with a main hook for retrieval when stranded, said vehicle having spring applied brakes which are releasable by hydraulic fluid pressure, comprising:
a) a hydraulic cylinder having its piston rod terminated in the form of a hook located within the main retrieval hook of the vehicle;
b) a shuttle valve located in a main hydraulic line interconnecting said brake to a regular hydraulic pressure supply, and c) an auxiliary hydraulic line interconnecting said shuttle valve and said hydraulic cylinder for applying fluid pressure to said brake through said shuttle valve in case of loss of pressure from said regular hydraulic pressure supply, whereby the hook of the piston rod may be engaged at the same time as the regular retrieval hook to disengage the brake while pulling on the stranded vehicle.
a) a hydraulic cylinder having its piston rod terminated in the form of a hook located within the main retrieval hook of the vehicle;
b) a shuttle valve located in a main hydraulic line interconnecting said brake to a regular hydraulic pressure supply, and c) an auxiliary hydraulic line interconnecting said shuttle valve and said hydraulic cylinder for applying fluid pressure to said brake through said shuttle valve in case of loss of pressure from said regular hydraulic pressure supply, whereby the hook of the piston rod may be engaged at the same time as the regular retrieval hook to disengage the brake while pulling on the stranded vehicle.
2. A brake release mechanism as defined in claim 1, further comprising a relief valve connected to said hydraulic line for protection of the shuttle valve, the hydraulic line and the hydraulic cylinder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002014223A CA2014223C (en) | 1990-04-09 | 1990-04-09 | Brake release mechanism for a spring applied vehicle park brake |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002014223A CA2014223C (en) | 1990-04-09 | 1990-04-09 | Brake release mechanism for a spring applied vehicle park brake |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2014223A1 CA2014223A1 (en) | 1991-10-09 |
| CA2014223C true CA2014223C (en) | 1995-09-12 |
Family
ID=4144723
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002014223A Expired - Fee Related CA2014223C (en) | 1990-04-09 | 1990-04-09 | Brake release mechanism for a spring applied vehicle park brake |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2014223C (en) |
-
1990
- 1990-04-09 CA CA002014223A patent/CA2014223C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CA2014223A1 (en) | 1991-10-09 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |