Patent ID: 6824334
Filing Date: 2004-11-30
Classification: B23B,Y10T

Abstract:
A rectilinearly reciprocating driving assembly for driving a plurality of mandrels, comprising a sliding carriage supporting a plurality of mandrels, arranged in an adjoining relationship parallel to a driving direction of said carriage, said assembly comprising releasable holding means for removably holding, at a withdrawn position, individual mandrels, and driving means for driving said individual mandrels, said driving means being actuated as the mandrel is arranged at an advanced position, a worm screw engaging with said carriage and being driven by a feeding motor coupled to a fixed construction supporting said carriage, said carriage slidably supporting a plurality of adjoining mandrels which can slide along sliding directions substantially parallel to a carriage driving direction, said mandrels being driven by fixed stroke pneumatic selecting cylinders having cylinder sliding rods, said cylinders being designed for locking said rods at their end of stroke positions, the mandrels to be used being selected by causing said pneumatic cylinders to be fed-forward, each preselected cylinder causing a corresponding slidable supporting element to move along guides of said mandrels, to cause selected mandrels to frontward project from non-selected mandrels, said mandrels being independently driven by brushless electric motors, said assembly selectively driving all said brushless electric motors or some of said brushless electric motors with respect to selected mandrels while holding in a rest condition unused mandrels, said carriage being driven by a worm screw in turn driven by a motor reducing unit supported by a shoulder, said worm screw engaging with a corresponding female thread formed on a rear surface of said carriage, said mandrels sliding on supporting bushes rigid with said carriage and adapted to be locked, by a tooth element and a counter-tooth element to a fixed wall to which said motor-reducing unit is applied, and wherein said fixed wall comprises a hole in which is engaged said worm screw, a hook element coupled to said fixed wall and engaging with a clamping spike element having a tooth shaped end portion.