GB923620A - A boring head for precision boring - Google Patents

Abstract

923,620. Boring machine details. LUDWIGSBURGER MASCHINENBAU G.m.b.H. Oct. 27, 1961 [Oct. 28, 1960], No. 38589/61. Class 83 (3). A boring head comprises a spindle 17 rotated by a motor-driven belt and pulley 19, 18, a boring spindle 26 coupled to spindle 17 at 22, a tool-holder 40 having a roughing tool 43 and a finishing tool 44 secured to a pivot-pin 36, and means for pivoting the tools in directions A, B to vary the diameter of hole to be cut. Toolholder 40 has a forked end 46 which is integrally formed with an arm 50 which projects into spindle 26, and a similar counter-balancing arm 52 is pivotally carried by pin 36. The arms are normally held apart by a spring-urged cone 56, which seats in recesses 63, 64, in the arms and are moved together by wedges 71, 72, which engage bearing members 77, 78, carried in grooves 73, 75, in the arms. As the arms move together, arm 50 moves clockwise as shown in Fig. 1, and tool-holder 40 moves in direction B, thus increasing the cutting diameter of tool 44, and when wedges 71, 72 are moved to the right, spring 68 moves cone 56, thus pivoting the tool-holder in the direction A, to adjust the cutting diameter of tool 43. Wedges 71, 72 are integral with a guide 70 connected to an hydraulic piston 88 by a piston-rod 90, the piston being slidable in a cylinder 83, and the movement to the right, Fig. 1, of the piston, is limited by an adjustable stop 96. Stop 96 is screwed into a worm-wheel 98 and is non- rotatably held by a screw 99, and worm-wheel 98 is rotated to adjust the stop by a hand wheel 110 connected to a spindle 112 which carries a worm, the adjustment being indicated by a pointer 118. A boring machine is shown, Fig. 4, wherein the boring head is driven by an electric motor 124, and worm-wheel 98 is actuated by a servomotor 126. A workpiece 133 is held in an axially slidable work-holder 130, and a gauging device 140 is axially movable relative to the workpiece. In operation, after the roughing and finishing operations have been completed, gauge 140 is pushed into the bored hole, and if the bore is smaller than required, a current pulse is applied to a relay 143 through a timing device and the servomotor 126 adjusts the stop 96, thus adjusting the tool-holder to increase the size of the bore.