Safety locking device

• US 20080067784A1
• Filed: 05/02/2007
• Published: 03/20/2008
• Est. Priority Date: 05/02/2006
• Status: Active Grant

• Current Assignee: Cascade Corporation
• Original Assignee: Wedgelock Equipment Limited
• Inventors: Calvert, David, Calvert, Matthew
• Granted Patent: US 7,828,070 B2
• Time in Patent Office: Days
• US Class Current: 280/507
• CPC Class Codes: E02F 3/3622 with a hook and a locking element acting on a pin
• CPC Class Codes: E02F 3/3645 with auto-engagement means for automatic snap-on of the tool coupler part
• CPC Class Codes: E02F 3/365 with redundant latching means, e.g. for safety purposes
• CPC Class Codes: E02F 3/3663 hydraulically-operated
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A safety locking device 18 for a quick hitch/coupler 10 of an earth working machine. The safety locking device 18 has a locking element 21 which is biased into a locking position to automatically lock a front pin of an implement when it is engaged in the hook 14 of the coupler 10. The safety locking device 18 has an hydraulic operable mechanism to move the locking element 21 to an unlocking position. The hydraulic supply to the safety locking device 18 is independent of the hydraulic supply to a locking mechanism 16 of the coupler 10.

Claims

1. A safety locking device for a quick hitch/coupler of an earth working machine, the safety locking device including a locking element biased into a locking position to lock a front pin in the hook of the quick hitch/coupler, the safety locking device further including an hydraulic operable mechanism to move the locking element to an unlocking position, said hydraulic mechanism including an hydraulic supply independent of the hydraulic supply to a locking mechanism of the quick hitch/coupler.

2. The device of claim 1 wherein the locking element is biased into the locking position by a spring.

3. The device of claim 2 wherein the bias spring is engaged on a shaft which rotatably mounts the locking element, the spring being in the form of a coil spring with one end thereof engaged with the locking element and a second end engaged with a fixture of or carried by the body.

4. The device of claim 3 wherein the locking element is a knuckle which is, in use, engageable with a pin of an implement to lock the pin in the coupler.

5. The device of claim 1 wherein the locking element is a knuckle which, in use, is engageable with a pin of an implement to lock the pin in the coupler.

6. The device of claim 5 wherein the knuckle is mounted to be rotatable about an axis of rotation.

7. The device of claim 5 wherein the knuckle is mounted for sliding movement.

8. The device of claim 6 wherein the hydraulic mechanism includes a linear actuator which is operatively engaged with the knuckle.

9. The device of claim 6 wherein the knuckle is mounted for rotation by a shaft.

10. The device of claim 9 wherein the hydraulic mechanism includes a linear actuator which is operatively engaged with an engagement element connected to the shaft.

11. The device of claim 10 wherein the engagement element is a lug which projects substantially transverse to a central axis of the shaft.

12. The device of claim 11 wherein the lug includes a substantially hook shape portion and with which the distal end of a piston rod of the linear actuator is engaged.

13. The device of claim 1 wherein the device is adapted to fit into a body of the quick hitch and form a part of the quick hitch into which a pin of an implement will, in use, be locked by the safety locking device.

14. A quick hitch/coupler of an earth working machine for the coupling thereto of an implement, the quick hitch/coupler including a safety locking device as claimed in claim 1.

15. The coupler of claim 14 wherein the coupler includes a ram for operating a locking mechanism the ram being coupled to a first hydraulic supply circuit for operation of the coupler and a second and separate hydraulic supply coupled to the safety locking device.

16. The coupler of claim 15 further including a switching arrangement which includes a rotary switch forming part of a solenoid driver circuit.

17. The coupler of claim 16 wherein the rotary switch is coupled to a first solenoid of the coupler locking mechanism and a second solenoid of the safety locking device for effecting controlled operation of the coupler ram and the hydraulic mechanism of the safety locking device.

18. The coupler of claim 17 further including visual and/or audible warning devices.