Automatic accumulating transfer mechanism

Claim 1

In a mechanical automatic accumulating transfer mechanism including a pair of parallel spaced support rails upon which a series of spaced workpieces or parts are slidably mounted in an automation line: longitudinally spaced pairs of support rollers below and inwardly of said rail; a pair of longitudinally extending spaced transfer bars reciprocally and guidably mounted on said rollers below said rails; power means joined to said transfer bars for causing reciprocal movement in unison of said transfer bars; a series of aligned dogs pivotally mounted upon said transfer bars and longitudinally spaced thereon at a distance corresponding to the distance between each of a series of work stations along said rails, said dogs being reciprocally movable continuously with said transfer bars between adjacent work stations, and said dogs each having a cam follower mounted thereon; each of said dogs having an upright workpiece-engaging position and an inclined inoperative workpiece-clearing position; a series of downwardly and rearwardly inclined workpiece detector cam arms, each pivotally mounted at a point forward of its balance point to one of its said support rails adjacent to respective ones of said stations, so as to be normally pivoted by gravity to a first position wherein the forward upper end of each of said arms is in a first elevated position placing it in the path of sliding movement of the workpieces, said workpiece detector arms being movable to a second, inoperative position when a workpiece at the corresponding work station cams said forward upper end thereof downwardly; a dog control cam mounted at the lower rearward end of each of said workpiece detector cam arms, said cam being so positioned as to lie in the reciprocating path of said dog cam follower of the next rearward dog when said workpiece detector cam arm is in said first position, and said cam lying out of the path of said dog cam follower when said workpiece detector cam arm lies in said second inoperative position; dog retracting means for placing said dogs in their inoperative position upon each rearward stroke of said transfer bars; and the existence of an empty work station placing the corresponding workpiece detector cam arm in said first position, whereby on the terminal portion of the rearward stroke of said transfer bars said dog control cam mounted on such workpiece detector cam arm cams said dog at the next adjacent rearward work station to its upright workpiece-engaging position.