Welding apparatus

A welding apparatus for welding plastic battery covers to plastic battery jars to form a closed container, said apparatus comprising a frame, a work zone having loading, welding and unloading stations, means for moving said battery covers and battery jars to be welded together from said loading station to said welding station, means for moving welded battery covers and battery jars from said welding station to said unloading station, welding means for heating portions of said battery covers and battery jars, clamping means for heating portions of said battery covers and battery jars, clamping means for positioning and controlling the relationship between said battery covers and battery jars during welding, drive means for operating the apparatus and control means for activating the drive means in a predetermined sequence, the improvement which comprises means for pressing against the interface between the battery cover and battery jar during welding thereof wherein said means includes a plurality of presser feet individually disposed on said apparatus along each side of said container formed by said battery cover and battery jar, means for moving each presser foot in a vertical direction including a pair of brackets disposed on said apparatus, said brackets having a horizontal portion and a vertical portion, said vertical portion having a vertical bore therethrough, a shaft slidably disposed in said bore, a manifold attached to the lower end of said shaft and movable therewith, pneumatic means attached to the upper end of the shaft for moving same in a vertical direction, said presser foot being operatively associated with said manifold and moveable vertically therewith and means for moving each presser foot in a horizontal direction.