Conveyor facility

Claim 1

A conveyor facility comprising: a frame defining an article transportation surface; an endless flexible drive element continuously movable during operation, said drive element including upper and lower parts oriented generally parallel to said article support surface; a plurality of control elements each rotatably supported on a shaft between said upper and lower parts of said drive element, resilient means individually supporting each of said control elements for vertical movement in response to changes in conveyor operation between transport and accumulation each of said control elements including a first circumferential part concentric with said shaft and a second circumferential part at a shorter distance from said shaft than said first circumferential part; and lift means beneath the lower part, the lift means being normally lowered to retracted position and responsive to removal of an article movement restraint for selectively and temporarily shifting said lower part of said continuously movable drive element upwardly into engagement with said first circumferential parts of said control elements when said control elements are stationary and the restraint is removed to cause said control elements to rotate, said lift means lowering said lower part to disengage said control element when their rotation has been reinstated.