Mixed unlocking coupler for heavy-construction machine

Abstract

The invention concerns a coupler comprising a cam ( 211 ) for locking a tool ( 100 ) with the coupler ( 200 ), characterized in that the cam ( 211 ) comprises for bringing the cam into a locking position, an articulation ( 213 ) with a connecting rod ( 209 ) itself connected through a bearing ( 206 ) to a piston ( 209 ) mobile in a bore ( 203 ) of the coupler body ( 200 ), said piston being subjected to the action of a spring ( 208 ), a chamber ( 220 ), opening on to a conduit ( 223 ), being formed by the piston ( 205 ) and the base of the bore ( 203 ), and means ( 215 ) for being connected to an unlocking object for applying an unlocking torque on the cam.

1 . A coupler comprising:
 means for attachment to an arm of a heavy construction machine,   hooks for supporting a beam of an implement,   a cam rotatably mounted on a coupler body and arranged to come into contact with a bearing face of the implement in at least one position for locking the implement with the coupler,   
     wherein:
 the cam is driven toward its locked position by means of a spring in compression between a stop device mounted in a bore of the coupler body and a first face of a piston that can move in said bore, the spring pushing the piston connected, via a first articulation, to a connecting rod also linked to the cam via a second articulation, 
 a chamber is formed by the piston and a bottom of the bore opened by a supply duct, the piston comprising a peripheral groove, 
 the cam comprises means of connection with an unlocking object which makes it possible to apply an unlocking torque to the cam. 
 
   
   
       2 . The coupler as claimed in  claim 1 , wherein a seal being placed in the peripheral groove of the piston, means for delivering pressurized liquid into the chamber are connected via a connector to the supply duct in order to act on a second face of the piston opposite to the first face subjected to an action of the spring and to push the connecting rod driving the cam from the locked position to an unlocked position, in order to achieve a hydraulic unlocking of the coupler. 
   
   
       3 . The coupler as claimed in  claim 1 , wherein an unlocking object is a key interacting with the cam and comprising a lever to which an unlocking force is applied in order to apply an unlocking torque and rotate the cam toward an unlocked position, compressing the spring pressing between the piston and the stop by means of the force transmitted via the connecting rod in order to manually unlock the coupler. 
   
   
       4 . The coupler as claimed in  claim 3 , wherein a plug closes the supply duct, the piston being mounted without seal in the bore and comprising a drill hole or a longitudinal groove leading into the peripheral groove and placing the chamber in communication with a portion of the bore containing the spring. 
   
   
       5 . The coupler as claimed in  claim 1 , wherein the cam comprises on the one hand a surface of revolution along its axis of rotation, placed about a shaft held in bearings of the coupler body, the cam comprising on the other hand a contact surface designed to interact with a bearing face of the implement, the contact surface of the cam having an eccentric profile, on a plane perpendicular to its axis of rotation, whose radius substantially increases in an opposite direction (D 1 ) from locking. 
   
   
       6 . The coupler as claimed in  claim 1 , wherein the hooks and the coupler body are made from one and the same machined cast part. 
   
   
       7 . The coupler as claimed in  claim 1 , wherein the articulations between the connecting rod and the piston, between the connecting rod and the cam and between the cam and the coupler are achieved by means of materials lubricated for life. 
   
   
       8 . The coupler as claimed in  claim 1 , wherein a cover resting on the coupler and on a flat lateral face of the cam, perpendicular to an axis of rotation of the cam, closes off in a sealed manner a space comprising the connecting rod, the spring, and a portion in which the articulation between the connecting rod and the cam takes place. 
   
   
       9 . The coupler as claimed in  claim 1 , wherein the coupler comprises at least a second bore, a second piston, a second spring, a second supply duct and a second connecting rod in order to achieve a dual control of the cam.