permit the workpiece 174 to be moved away from the apparatus 12 without interference therewith the assembly of the dual action apparatus 12 of the present invention is very straightforward the top and bottom pistons 16 and 18 are inserted into their respective upper and lower piston guides 48 and 50 and the alignment blocks 26 and 28 are then bolted into position locking the pistons in their respective piston guides the pinion gear 34 and its accompanying pinion shaft 38 is then installed in the housing block 14 with its teeth engaging with the teeth at the right hand extent of the rack gear 68 on the top piston 16 and at the lefthand extent of the rack gear 68 on the bottom piston 18 the gear plug 32 is then installed to prevent lateral displacement of the pinion gear 34 the cushion probes 72 and proximity sensors 92 are attached to the end cap 20 then the end cap is attached to the end of the housing block 14 finally the pivot mounts are attached to the housing block 14 in the operation of the apparatus 12 the top and bottom pistons 16 and 18 are moved by the application of fluid pressure into one or both of the upper and lower piston guides 48 or 50 which produces a force on the associated top or bottom piston 16 or 18 the fluid pressure can be pneumatic or air pressure which is readily available in most industrial locations alternatively the top and bottom pistons 16 and 18 can be moved by a hydraulic pressure while the illustrative embodiments of the invention have been described in considerable detail for the purpose of setting forth practical operative.