GB526523A - Improvements relating to change-speed gearing for machine tools - Google Patents

Abstract

526,523. Change-speed gearing. WARNER & SWASEY CO. March 18, 1939, No. 8735. Convention date. March 19, 1938. [Class 80 (ii)] A preselective control for change - speed gearing in the spindle or feed drive of a machine-tool such as a turret-lathe, comprises a pair of gapped profile-plates 64, 64a, Fig. 4, which are moved in one linear direction to preselect, and are closed together in another linear direction in the same plane to actuate three gear-shifter levers 52b, 54b. 58, controlling eight speeds. Preselection is effected by turning a hand-knob 63b, which, through pinions 63, 62, 61 and a rack, slides, along guides 60, a rectangular frame 59 carrying the profile-plates 64, 64a, which are thereby selectively positioned in relation to the interposed shifter-levers 52b &c. The profileplates 64, 64a are transversely slidable in the frame 59 and, to execute a change, are moved together inwardly over the shifter-levers 52b &c. by pulling down a handle 49, Fig. 3, a depending part 71 of which, through a bell-crank lever 69 and link 68, Fig. 4, rocks a pair of intermeshing toothed segments 67, the free ends of which are pivoted to bars 65 slidably longitudinally in the profile-plates 64, 64a, whereby the transverse movement only of the bars 65 is imparted to the profile-plates 64, 64a to execute the change. An additional pair of intermeshing toothed segments 66 assists in equalising the transverse movement of the respective profile-plates. The executive hand-lever 49, Fig. 3, is pivotally mounted in a tower 48, which, by horizontal movement of the lever 49, can be turned about a vertical axis in either direction for controlling forward and reverse main-clutches 22, 23, Fig. 2, through which the change-speed gear is driven. Such movement, without affecting the speedchanging part 71 of the lever, turns a spindle 48a on a cranked lower extension 48 of the tower 48, thereby operating a selector fork 45 of the forward and reverse clutches 22, 23. The speedchanging shifter - levers are concentrically pivoted, one, 58, being secured to an inner shaft 53, operating a shifter-fork through a lever 57 and link 56, whilst the other levers 52b. 54b are secured respectively to sleeves 52a, 54a, journalled on the shaft 53 and directly carrying shifter-forks 50, 54. The shifter-forks directly straddle the periphery of the gear wheels to be shifted. The change-speed and reversing gear is shown in Fig. 2, and comprises a driving shaft 20, having the clutches 22, 23 for driving a parallel shaft 27 forward or reversely. Twospeeds are imparted to a third shaft 35 by a sliding pair 31 on the second shaft 27. The third shaft 35 drives a pair of wheels 36 freely journalled on the the final driven spindle 19 and serving to drive a fourth shaft 41 at either of two speeds by means of a sliding pair 40 on that shaft. The fourth shaft 41 drives the final driven spindle at either of two ratios provided by a sliding pair 42. this arrangement yielding eight speeds in either direction.