GB1211900A - Automatically reversible drive unit for a screwcutting die head - Google Patents

Abstract

1,211,900. Automatically reversible drive units. GEORG. FISCHER A.G. 19 Sept., 1968 [22 Sept., 1967], No. 44549/68. Heading B3N. An automatically reversible drive unit for a screw-cutting die which is to be rotated in two directions and which has a displaceable part which is adapted to be axially movable comprises a rotatable housing 1 for the die head, two selectively engageable driving shafts 4 and (5), Fig. 3 (not shown) adapted to drive the housing via a gear-wheel 3 and control means which in a first position connect a drive from a motor 13 through a first driving shaft 4 by means of a clutch 8, 8a to the housing and after a specific displacement of the displaceable part disconnect driving shaft 4 and connect the drive through a second driving shaft (5) by means of a second clutch (9, 9a) to the housing and after the displaceable part returns to its initial position disconnect the second driving shaft. The control means comprises an eccentric lever 22 which when rotated moves pins 31 and 29 to the right. Pin 31 is connected to a fork 32, the movement causes the fork to engage the clutch 8, 8a and thus drive to the housing 1. The pin 31 is retained in this position by a spring loaded plunger (34), Fig. 2 (not shown), engaging in a recess 33. As the die head rotates the displaceable part moves a holding part 18 to the right causing a pin (20), Fig. 5 (not shown), to engage and lock pin 29 in position. Lever 22 can now be returned to its initial position. After a specific displacement of part 18 a pin (41) causes pin 34 to disengage itself from pin 31 whence spring 36 urges the pin to the left thus disengaging the clutch 8, 8a and thus the drive to the housing 1. Pin 42 and lever 43 are operated by pin 31 to move fork 44 which engages the clutch (9, 9a) whereby the direction of rotation of the drive to the housing is reversed. When part 18 is then returned to its initial position it disengages pin 20 from pin 29 which is spring urged to the left thus disengaging the clutch (9, 9a) and thus the drive to the housing. In case of incorrect manipulation of lever 22 a release knob (48) is provided which is adapted to disconnect pin 34 from pin 31 such that part 18 will be returned to its initial position. Specification 1,211,899 is referred to.