GB591815A - Improvements in or relating to work rests of automatic screw making and similar machines - Google Patents

Abstract

591,815. Lathes. BROWN & SHARPE MANUFACTURING CO. Sept. 28, 1944, No. 18581. Convention date, Sept. 18, 1943. [Class 83 (iii)] Steady rests.-A work rest for automatic screw-making and like machines comprises rigid contact elements arranged to receive the thrust of the tool and located radially from the true axis of the rotating work by a fixed distance exactly equal to the bar stock radius, and yieldable contact means for pressing the bar stock against said rigid elements. The hollow spindle turret lathe to which the invention is applied is described in Specification 553,285 and comprises an automatic screw machine for the manufacture of small parts from bar stock, such as balance staffs for watches. A slide 12, Fig. 2, carrying a rocking tool-turret supporting member 14 has a holder 32 secured to its end nearest the machine head which is capable of a limited adjustment through the screws 34, 36. A hole 42 in this holder is brought into line with the spindle axis and is used in conjunction with a template for adjusting the work rest as referred to below. A recess on the inside face of this holder provides a clamping face for a back rest 40 having a right-angled recess with hard metal inserts 44, 46, and a spring arm 54 clamped thereto with a work-engaging end 52. The arm is adjustably secured by a bolt 58. The ends of the fixed and yieldable parts of the work steady are bevelled to facilitate entry of the stock. The back rest 40 is secured in the recess in the holder by a clamping plate 66 and bolt 64. Adjustment of the rest is achieved by the use of a template which is held in the chuck and comprises a shouldered rod the free end of which is equal in diameter to that of the stock bar to be used. Feed movement of the lever rest 14 is obtained through a roller on its outer end engaging an inclined plate which moves with a slide at right angles to the machine spindle.