Apparatus for dispensing comestibles having a reversible piston rod

Abstract

A battery-operated apparatus for dispensing comestibles has a housing to which a comestibles-receiving barrel is removably connected. A removable piston is nonrotatably slidable within the barrel and pushed through the barrel by a piston rod nonrotatably connected to the piston and slidably received within the housing. The piston rod has external screw threads over a substantial portion of its length which are engaged by internal threads of an encircling drive nut. A drive member rotatably mounted in the housing and having a through-bore for slidably receiving the piston rod is provided for rotating the drive nut. The piston rod and the drive nut constitute a reversible assembly so that, following use, the barrel and the piston may be removed from the housing for cleaning and the piston rod with the drive nut thereon may be removed from the housing, turned upside-down, and reinserted into the housing ready for another use. Portions of the piston rod are unthreaded to prevent overtravel, and resilient stop members on the piston rod push the drive nut onto the threaded portion of the piston rod at each end of its travel to assure a threaded connection when the piston rod is reversed.