Patent GB-587697-A (GB)
Title: Improved means for varying the length of stroke of a reciprocating spindle in a gear shaping machine or other machine tools
IPC: F16K31/32
Filed: 1944-11-23
Abstract: 587,697. Mechanism for converting rotary into reciprocating motion. FELLOWS GEAR SHAPER CO. Nov. 23, 1944, No. 23331. Convention date, Nov. 1, 1943. [Class 80 (i)] [Also in Group XXII] In a machine tool such as a gear shaping machine, having a reciprocating tool or work carrier, the carrier is actuated by an oscillating link whose pivot is adjustable, whilst the machine is operating, relatively to the driven and driving arms thereof so that the stroke of the carrier may be progressively variable. The machine, Figs, 1 and 2, which is similar in construction to that described in Specification 516,480, [Group XXII], has the work W mounted on a spindle 12 which is rotated in synchronism with the cutter spindle 15, for generating the tooth profile, from a motor 17 by mechanism as described in the above Specification. The cutter spindle 15 is reciprocated in a saddle 14, to provide the cutting strokes, by an annular rack 21 and a lever 20 pivoted at 19 and hinged at 22 to a link 23. The link is oscillated by a connecting rod 24 hinged thereto at 25 and actuated by a crank 26 on a shaft 27 driven by a belt 29 from the motor 17. The pivot 32 about which the link 23 oscillates is carried by a rocker 31 in which the link is slidable and the pivot is mounted in a slide 33 which may be adjusted whilst the machine is in motion to vary the distances of the link hinges 22, 25 from the pivot and hence vary the length of the stroke of the tool spindle 15. Adjustment of the slide 33 against the action of a spring 42 may be effected by a cam 39 engaging a bearing strip 41 on the slide and driven by gearing 44. . . . . 52 from a gear 53 which rotates the work spindle 12. The throw of the crank 26 may be adjustable to give further adjustments of stroke to the spindle 15, and the latter may carry the work instead of the cutter, or the reciprocation may be imparted to the spindle 12. As shown the plane containing the pivots 22, 25, 32 is normal to the axis of spindle 15 so that stroke adjustments due to movement of slide 33 will alter the extent of reciprocation equally in both directions about the mean position, but the plane of the pivots may be arranged perpendicular to the spindle when the latter is at either end of its stroke so that stroke adjustments will be unsymmetrical about the mid-point. In a modification the slide 33, Fig. 7, carrying the pivot 32a for the rocker 31a, is adjustable by an axially stationary screw 61 rotatable manually or by gearing 64, and the connecting rod 24a of the crank 26a is pivoted to the rocker at 25a intermediate of the pivot 32a and a roller 68 by which the rocker actuates the lever 19. In a further modification the slide 33, Fig. 10, adjustable by the screw 61 carries the pivot 32b for the rocker 31b and both the lever 19 and the connecting rod 24b engage flanges 69, 70 on the rocker through rollers 68, 71 respectively, or the roller 71 might be located between the pivot 32b and the roller 68. The connecting rod 24b slides through a guide block 72 mounted on a fixed pivot 73.