A coupler

Abstract

A coupler for coupling an implement having first and second parallel pins to the arm of a vehicle or machine. The coupler has a body for attaching to the vehicle or machine arm, a front first jaw fixed relative to the body for receiving the first implement pin, a movable rear second jaw facing away from the first jaw for receiving the second implement pin, an actuator to move the second jaw towards and away from the first jaw, and a locking member. The first jaw has a pronounced lip forward of a seat for the respective pin. The locking member is pivotable between a locking position in which a portion of the locking member protrudes into the opening of the first jaw, and an unlocked retracted position, about a pivot axis that is positioned forward of the lip of the first jaw.

1 . A coupler for coupling an implement having first and second spaced apart parallel pins, to the arm of a vehicle or machine, the coupler comprising:
 a body for attaching to the vehicle or machine arm;   a front first jaw fixed relative to the body, defining an opening and a first seat for receiving the first implement pin, and having a pronounced lip forward of the first seat, the lip protruding in a direction generally towards the body;   a locking member that is pivotable relative to the first jaw about a pivot that is positioned forward of the lip of the first jaw, the locking member pivoting between a locking position in which a portion of the locking member protrudes into the opening of the first jaw, and an unlocked position in which the locking member is substantially or wholly retracted from the opening of the first jaw;   a movable rear second jaw facing away from the first jaw, defining an opening and a second seat for receiving the second implement pin, the second jaw having an extension surface adjacent to the jaw opening and rear of the second seat; and   an actuator operable to selectively move the second jaw towards and away from the first jaw along a movement axis;   wherein the first jaw including the lip defines an entry direction of the first pin into the seat of the first jaw that is not parallel to the movement axis.   
     
     
         2 . A coupler as claimed in  claim 1 , wherein the movable second jaw is biased away from the first jaw. 
     
     
         3 . A coupler as claimed in  claim 2 , wherein the actuator is a hydraulic cylinder, and wherein a biasing member is arranged to bias the cylinder towards an extended position. 
     
     
         4 . A coupler as claimed in  claim 3 , wherein the biasing member comprises a die spring. 
     
     
         5 . A coupler as claimed in  any preceding claim , wherein the lip of the first jaw comprises a rear surface oriented at an angle of between about 25 degrees and about 35 degrees relative to the movement axis. 
     
     
         6 . A coupler as claimed in  any preceding claim , wherein the lip of the first jaw is shaped such that, in a vertical orientation of the coupler with the second jaw above the first jaw, weight forces from an implement secured in the coupler are at least partly supported by the lip. 
     
     
         7 . A coupler as claimed in in  any preceding claim , wherein engagement of the first jaw with an implement pin requires a change in direction of the motion of the first jaw or said implement pin, to clear the lip of the first jaw. 
     
     
         8 . A coupler as claimed in in  any preceding claim , wherein the locking member is shaped such that, in a vertical orientation of the coupler with the second jaw above the first jaw and the locking member in a locking position, weight forces from an implement secured in the coupler are at least partly supported by the locking member. 
     
     
         9 . A coupler as claimed in  claim 8 , wherein in a vertical orientation of the coupler with the second jaw above the first jaw and the locking member in a locking position, reaction force vectors provided by the locking member to support the first implement extend through the locking member pivot. 
     
     
         10 . A coupler as claimed in in  any preceding claim , wherein in a vertical orientation of the coupler with the second jaw above the first jaw and the locking member in a locking position, at least a major weight force from an implement secured in the coupler is supported by the locking member and the lip of the first jaw support. 
     
     
         11 . A coupler as claimed in  any preceding claim , wherein the locking member comprises a locking surface for contacting the first implement pin at a contact point, and wherein the contact point is substantially colinear with a centre of said pin and a pivot axis of the locking member. 
     
     
         12 . A coupler as claimed in  claim 11 , wherein the locking surface at the contact point is substantially perpendicular with an axis running between the centre of said pin and the locking member pivot axis. 
     
     
         13 . A coupler as claimed in  claim 12 , wherein the locking surface is substantially flat. 
     
     
         14 . A coupler as claimed in  any preceding claim , wherein the locking member is biased towards the locking position. 
     
     
         15 . A coupler as claimed in  claim 14 , comprising a leaf spring arranged to bias the locking member towards the locking position. 
     
     
         16 . A coupler as claimed in  claim 15 , wherein a first end of the leaf spring is anchored to the body, a second end of the leaf spring is anchored to the locking member, and wherein the leaf spring comprises a bent intermediate portion adjacent the locking member pin. 
     
     
         17 . A coupler as claimed in  any preceding claim , wherein the locking member comprises a cam surface; and wherein the movable jaw is provided on a movable member, the movable member being configured to engage the cam surface and thereby retract the locking member from its locking position as the movable jaw moves towards the first jaw. 
     
     
         18 . A coupler as claimed in  any preceding claim , wherein the extension surface of the second jaw is configured such that, in the event of a failure of the actuator resulting in slight movement of the second jaw towards the first jaw, the extension surface prevents rotation of an implement attached to the coupler by retaining the second pin in the second jaw. 
     
     
         19 . A coupler as claimed in  any preceding claim , wherein the extension surface of the second jaw is substantially flat and/or is substantially parallel to the movement axis.