Coupler

Abstract

A coupler ( 10 ) for securely attaching an accessory to an excavator arm of an excavator. The coupler ( 10 ) comprises a first half ( 16 ) for connecting to the excavator arm and a second half ( 18 ) for connecting to the accessory. The second half comprises a front jaw with a movable front latch associated therewith, the front latch having a latching position and a non-latching position, and being for latching one of two attachment pins of the accessory within the front jaw when it is in its latching position. The second half also has a rear latch, the rear latch having a retracted position and an advanced position, and being for engaging a second of the attachment pins when it is in its advanced position. The second half also has a trigger member mounted for movement relative to the frame, the trigger member being arranged for movable interaction with both the front latch and the rear latch so as to move, respectively, the front latch between its latching position and its non-latching position and the rear latch between its advanced position and its retracted position.

1 . A coupler for attaching an accessory to an excavator arm of an excavator, the coupler comprising a frame with a first half for connecting to the excavator arm and a second half for connecting to the accessory, the second half comprising:
 a front jaw with a movable front latch associated therewith, the front latch having a latching position and a non-latching position, and being for latching one of two attachment pins of the accessory within the front jaw when it is in its latching position;   a rear latch, the rear latch having a retracted position and an advanced position, and being for engaging a second of the attachment pins when it is in its advanced position; and   a trigger member mounted for movement relative to the frame, the trigger member being arranged for movable interaction with both the front latch and the rear latch so as to move, respectively, the front latch between its latching position and its non-latching position and the rear latch between its advanced position and its retracted position.   
     
     
         2 . The coupler of  claim 1 , wherein the trigger member is pivotally mounted relative to the frame. 
     
     
         3 . The coupler of  claim 1 , wherein the coupler additionally comprises a rear jaw associated with the rear latch, and the rear latch at least partially closes its associated rear jaw when in its advanced position. 
     
     
         4 . The coupler of  claim 1 , wherein the front latch is pivotable between its latching position and its non-latching position. 
     
     
         5 . The coupler of  claim 1 , wherein the rear latch is permanently biased towards its advanced position. 
     
     
         6 . The coupler of  claim 1 , wherein either the front latch is biased towards its latching position by gravity when the coupler is oriented such that the first half is above the second half, or the front latch is permanently biased towards its latching position by a spring. 
     
     
         7 . The coupler of  claim 1 , wherein the front latch is bifurcated, and has two pivot pins, each being coaxial and extending in a lateral direction relative to the frame of the coupler. 
     
     
         8 . The coupler of  claim 1 , wherein the front latch has a blocking member extending therefrom, the blocking member being arranged to locate in front of an end of the rear latch when the rear latch is in its advanced position and simultaneously the front latch is in its latching position. 
     
     
         9 . The coupler of  claim 1 , wherein the trigger member comprises at least three protruding surfaces—a first protruding surface for interacting with the front latch, a second protruding surface for interacting with the rear latch, and a third protruding surface for interacting with a pin of the accessory. 
     
     
         10 . The coupler of  claim 1 , wherein the rear latch has an upstanding flange thereon, the flange having an end or surface for interaction with the trigger member. 
     
     
         11 . The coupler of  claim 1 , wherein interaction between the trigger member and the two latches causes the trigger member to move those latches when itself is moved, the interaction being such that there is at least one transitional resistance point. 
     
     
         12 . The coupler of  claim 11 , wherein to move the second latch from the retracted position to an advanced position, at least one of the transitional resistance points has to be overcome, whereupon the movement of the latches into their advanced or latching positions occurs under the impulse of the mechanism as a whole. 
     
     
         13 . The coupler of  claim 12 , wherein the impulse of the mechanism as a whole is driven at least in part by one or more of a spring bias for the rear latch and a spring bias for the front latch. 
     
     
         14 . The coupler of  claim 11 , wherein at least one of the transitional resistance points is provided by providing a flat or flattened portion on an end of a protruding surface of the trigger member. 
     
     
         15 . The coupler of  claim 11 , wherein at least one of the transitional resistance points is provided by providing a concavity on the trigger member into which a concave surface of one of the latches latch can selectively rest. 
     
     
         16 . The coupler of  claim 1 , wherein the trigger member has a hole in it for receiving a latch disengagement bar therein, whereby, with the latch disengagement bar, the trigger member can be forced to move, thereby interacting with the two latches. 
     
     
         17 . The coupler of  claim 1 , wherein the front latch is pivotably mounted to the frame at a position lying more rearward than a pivot point of the trigger member. 
     
     
         18 . The coupler of  claim 1 , wherein the front latch is biased into its latching position by a spring that is positioned generally above the trigger member. 
     
     
         19 . The coupler of  claim 1 , wherein the front latch has one or more arms adopting the general shape of an M, with two upper peaks, two dropping ends and a dipping middle, and a blocking member for selectively blocking retraction of the rear latch from an advanced position into a retracted position in which a pin cannot be disengaged from the coupler is formed on, or is attached to, the dipping middle of the one or more arms. 
     
     
         20 . The coupler of  claim 19 , wherein the trigger member interacts with the front latch in an inside of an upper peak thereof.