Patent ID: 6254331
Filing Date: 2001-07-03
Classification: E02F

Abstract:
A coupler connectable to the free end of a boom and to a boom attachment, for connecting the boom attachment to the free end of the boom, by use of a pair of parallel, spaced apart coupler pins on said attachment, said coupler comprising:a coupler frame including a forward end, a rearward end and a bottom plate, said bottom plate having a forward end slot extending through the bottom plate;a rear end hook structure connected to the frame below said bottom plate, said rear end hook structure including a rearwardly opening rear hook throat;a front end hook structure having a front hook throat end and an opposite pivot end, said pivot end being pivotally connected to said frame below said bottom plate, for pivotal movement of the front end hook structure between an up position in which the front hook throat opens forwardly, and a down position in which the front end hook structure and the front hook throat are angled downwardly from said bottom plate;a top hook on said front hook structure, said top hook extending upwardly from the front end hook structure through the forward end slot in the bottom plate when the front end hook structure is in its up position, said top hook including a top hook tine that is spaced above the bottom plate when the front hook structure is in its up position, to provide a top hook throat between the top hook tine and the bottom plate and further to provide a top cam surface;a lock member above said bottom plate, movable between a first position in which it is spaced rearwardly from said top hook throat and a second position in which a portion of the lock member is located in said top hook throat, between said top hook tine and the bottom plate, for locking the front hook structure in its up position,wherein said lock member is a swing arm having a first end portion that is pivotally attached to the coupler frame and a second end portion which includes the portion of the lock member that is within the top hook throat when the lock member is in its second position;a spring positioned to bias the lock member into its second positionwhereby said boom and coupler can be moved together to position the rear coupler pin of the attachment within the rear hook throat, and further to position the front coupler pin of the attachment within the front hook throat when the front hook structure is in its down position, and then the boom and coupler can be moved relative to the attachment to swing the front hook structure up into its up position and move the top hook into and through the forward end slot, so as to position the top hook tine and top hook throat above the bottom plate, and move the top cam against the lock member, to move the lock member from its second position towards its first position and allow a portion of the lock member to move into the top hook throat, said spring being positioned to then move the lock member back into its second position so that it will block downward movement of the front hook structure from its up position to its down position.