Abstract: A drive mechanism for movement of a horizontal shelf in a vending machine includes first and second spaced apart rotatable sprockets. A continuous chain engages and extends around the first and second spaced apart sprockets. A plurality of brackets are attached to the continuous chain supported in a fixed angular relationship to the chain and at predetermined distances along the length of the chain for movement therewith upon rotation of the sprockets. Gear portions are affixed to the vending machine adjacent to and extending approximately 180.degree. around the first and second sprocket. A planetary idler gear is rotatably mounted on the bracket for engagement with the track gear portions. The planetary idler gear is sized for having a predetermined gear ratio with the track gear. A pinion idler gear is coaxially affixed for co-rotation with the planetary idler gear thereby forming an idler gear pair mounted to the bracket for rotation relative to the bracket.