This invention relates to an accumulation system for driverless vehicles of the type which are propelled along a track by frictional contact between a drive wheel and a rotating drive shaft. In particular, this invention relates to the deceleration and accumulation of a number of driverless vehicles along a track without the need for direct cooperation between one vehicle and a fixed cam on the rear end of an adjacent vehicle. This invention may also be utilized to cause the vehicle to reverse its direction of motion along the track.
An accumulation system for driverless vehicles is shown in U.S. Pat. No. 3,818,837 and includes a speed control device or tail which is attached to the rear end of the vehicle for cooperation with a drive control member on the front end of the next adjacent vehicle. The speed control device is typically in the form of a cam. The contact between the tail on one vehicle and the drive control member on an adjacent vehicle on the track causes the trailing vehicle to accumulate or stop adjacent to the forward vehicle. Release of the forward vehicle will also cause a corresponding release of the trailing vehicle. The cam on the tail is contoured such that the change in speed of the trailing vehicle is effectuated gradually.