is described during the injection phase the screw translation drive 38 is operated to move the screw forward in the barrel assembly 30 an injection force is directed from the translation drive 38 to the reciprocating screw body 164 and to the melt of material located in front of the reciprocating screw a reactive injection force is directed back through the accumulator 64 to the first barrel coupler 46 including linkage members to the first cradle coupler 152 to the first and second carriage actuator housings 170 172 to the drive mount 54 and to the screw translation drive assembly 30 the second barrel portion is isolated from the axial reactive injection force referring now to fig2 when the nozzle 62 includes a semispherical tip 90 see fig6 the first stop 156 and the second stop 158 are not required operation of the carriage actuator 42 moves the carriage assembly 34 and barrel assembly 30 towards the stationary platen 16 unit the semispherical tip 90 engages the sprue bushing the carriage actuator 42 is further operated to create the axial carriage force the axial carriage force is directed through the first carriage actuator 56 and the second carriage actuator 58 to the carriage assembly 34 the carriage assembly 34 further directs the axial carriage force through the first carriage coupler 152 to the first axial force linkage member 96 the first barrel coupler 46 the accumulator 64 and the nozzle 62 the first barrel portion distributes axial carriage force.