Abstract: A storage conveyer for workpieces is movable between selected locations to carry work pieces from one machine to another whilst maintaining the integrity of a batch. An endless chain is wound in a double helix configuration, each helix being supported on a respective driven shaft and an idler shaft. The chain carries pallets for supporting workpieces. The pallets are stepped through a loading location under the control of the manual worker and through a load/unload location where they are accessible to a robot machine, which may be given control of the chain drive. Location is at a lower position and extends out of the helical chain run to provide access for the robot machine.