GB1253211A - - Google Patents

Abstract

1,253,211. Work loading mechanisms; gear hobbing. PRECISION GEAR MACHINES & TOOLS Ltd. 14 Feb., 1969 [17 Jan., 1968], No. 2623/68. Headings B3B and B3K. A loading mechanism for a gear bobbing or like gear-cutting or finishing machine tool comprises a turret assembly 15 adapted to receive and store a plurality of workpieces 10, the turret being indexable to present successive workpieces to the headstock 11 of the machine and comprising also a drive adaptor member 20 for each workpiece whereby drive may be transmitted from the headstock to the workpiece presented thereto. In the machining position the workpiece 10, e.g. a cam-shaft on which a gear 13 is to be hobbed by a hobbing tool 14, is supported between headstock 11 and tailstock 12 and centred by a spring-loaded centre 76 and centre 77 the drive adaptor member 20 having serrations 73 corresponding in number to the teeth of the gear to be cut which engage corresponding serrations 74 on the top of a pillar 75 forming part of the headstock 11. The drive adaptor member 20 has also dissimilar protruding pegs 70, 71 which engage recesses in a flange 72 of the workpiece to locate it in a unique angular relationship to the adaptor member. The turret comprises end plates 16, 17 mounted on a sleeve 21 which forms with an enlarged portion 43 of a central index shaft 24 an hydraulic cylinder and piston arrangement whereby the turret assembly is reciprocable on the shaft 24 while being adapted to be indexed therewith by means of a pin 40 bracketed to the shaft. The shaft 24 is indexed by hydraulic means 30. Bushes 18, 19 are arranged in apertures in the end plates 16, 17 for supporting the workpieces and an upstanding pin 61 on a stationary turret frame end plate 28 serves to locate the turret in its various workpositions by engaging a series of locating bushes 60. The turret with its supporting frame may be pivotally mounted on the machine column so as to be pivotally movable to a position for replenishment with new workpieces and unloading of completed ones. A proximity switch may be arranged adjacent the turret to detect the absence or mispositioning of a workpiece or the presence of an already machined workpiece and to inhibit the operation of the index mechanism in response thereto.