GB216852A - Improvements in and connected with gear generating machines - Google Patents

Abstract

216,852. Lees-Bradner Co., (Assignees of Schurr, C. H.). May 28, 1923, [Convention date]. Gear-cutting.-In a gear-generating machine of the type in which the relative rolling is produced by a motion compounded of rotary and rectilinear motions such as is described in Specification. 187,663, a pair of grinding-wheels are mounted beneath the work-spindle. and are adapted forfinishing two gear faces simultaneously. The frame 1 is provided with lugs 8 forming bearings for the pivots of a supplemental swinging frame 3 which carries a slide 61 having bearings for the spindle 64 carrying the blank A. The blapk spindle comprises two sections 64<a> and 64<b>, secured together by a bolt 66<a> which draws the tapered end of the outer portion into a conical recess in the inner portion, this construction facilitating the changing of the blank. The outer end of the blank spindle is steadied by a centre 75 mounted in a bracket 71 adjustably secured to the overhanging arm 69. The grinding-wheels B are mounted in bearings in tubular members 39 which are integral with plates 38 adjustably secured to slides 35 vertically adjustable on guides 34. Angular movement is imparted to the plates 38 to set the tools to the desired pressure angle by means of worm gearing 46 and axial adjustment of the spindles is effected from wheels 50. The tools are driven from separate electromotors 41 which counterbalance the weight of the tools and their casings 45. Trimming-mechanisms 146 having diamonds 46<a> are provided to true the grinding-wheels when required. The rolling of the blank past the tools is effected by means of an electromotor 14, which drives through gears 16 a shaft 9<1> in alignment with the pivotal axis of the frame 3. The shaft 9<1> carries a splined worm 30 which drives a worm 28 carrying an adjustable crank-pin 31 which through a connecting rod 32 oscillates an arm 33 which carries a spring plunger coacting with holes in an index wheel 55 secured to the blank spindle. Simultaneously with the oscillating movement of the blank, the required linear movement is imparted to the slide 61 by flexible-band mechanism comprising four alternately arranged tapes 96, 96a, secured at one end to tensioning rods 113 mounted in blocks 109 vertically adjustable on standards 107. The tapes are passed round a sector 95 surrounding the blank spindle and having the same diameter as the blank pitch circle, the ends of the tapes extending round a plate 102 and being clamped by a bar 104 secured by screws. The construction is such that the spindle 64 may be rotated relatively to the sector 95 to index the blank. The indexing-mechanism may be of the type described in Specification 197,652 or, as shown, indexing may be effected manually by withdrawing the plunger 53 from the index disc during the idle return movement of the slide 61 and allowing it to engage the next successive hole. During the return movement the frame 3 is swung upwardly to lift the blank clear of the tools by means of a cam 23 on a shaft 21 driven through worm gearing 19 from the shaft 9<1>. Lathe and like centres.-The centre 75 supporting the outer end of the blank spindle is protected against water and grit by means of a sleeve 76 which is pressed by a spring 77 against a shoulder on the reduced spindle end 67<b>.