GB855043A - Device and process for correcting the pitch of threads arising in thread-rolling machines - Google Patents

Abstract

855,043. Rolling screw-threads. GROB, E. Oct. 8, 1958 [Oct. 9, 1957], No. 32156/58. Class 83 (4). In thread-rolling machines in which the threads are formed by profiled grooved rolls as the workpiece moves in an axial direction, any errors which occur in the thread pitch of the workpiece are corrected by alteration of the angle between the axes of the rolls and the axis of the workpiece. Each grooved roll 17 is mounted in a holder 16 on an arm 8 which is seated on a bushing 4 rotatable by a worm 6 operated by a hand wheel 7. At the end of the arm 8 is mounted an adjusting motor 11 which through a worm 12 and rocking lever 14 swivels the holder 16 about the axis 15 of the bushing 4 to correct errors in the thread pitch of the workpiece W. The correcting motions of the holders 16, 16<1> are positively coupled in opposite directions, e.g. by a sun wheel (not shown). The motor 11 is operated by an electrical control device (not shown) actuated by contacts 26 engaged by feelers 25 upon movement of a sprung template 19 secured to a thread gauge spindle 18 which is coupled to the workpiece and is shifted axially by amounts corresponding to the errors in the thread pitch thereof. In another form axially-inclined grooved rolls are seated in brackets which are swivel guided in holders by the adjusting motor through'worm gearing. The rolls are drawn in at one of their ends such that when the angle between the axes of work and rolls is increased the rolls produce a thread of larger pitch in the workpiece. In a modification a single contact feeler 37 is used to control the adjusting motor.