Patent ID: 7032742

Claim:
A spiral accumulator apparatus for controlling the flow of articles, comprising: a support structure; an infeed conveyor mounted to the support structure and driven in a first direction to convey articles therealong in the first direction along a first path that is at least partially curved; an outfeed conveyor mounted to the support structure and driven in an opposite direction to convey articles therealong in the opposite direction along a second path that is at least partially curved; the infeed and outfeed conveyors being spaced apart and generally parallel along at least a portion of the first and second paths so as to define a space therebetween; a track mounted to the support structure along at least a portion of the space; a movable transport member disposed generally across and movable along the space on the track; an article transfer member carried by the transport member and operably disposed between the infeed and outfeed conveyors to transfer articles between the infeed conveyor and the outfeed conveyor; a transport member mover connected to the transport member, the transport member mover including an endless loop; and a differential drive mechanism located at a fixed position spaced from the transport member, the differential drive mechanism including an output portion for contacting and moving the transport member mover when a relative speed difference exists between the infeed and outfeed conveyors thereby causing the transport member to travel in the direction of the faster of the infeed and outfeed conveyors.