| 摘要 |
1387198 Actuating slides MACHINE TOOL DIVISIONAL SERVICES Ltd 27 Nov 1973 [4 Dec 1972] 55805/72 Heading B3B In a machine tool a slide 10 is slowed down from a rapid feed to a slower feed prior to stopping it by an arrangement comprising a screw 18 which is movable both axially and rotationally, a non-rotatable nut 12 engaged by the screw and acting as an abutment to arrest advance of the slide, a. spring 21 yieldably urging the screw 18 in the direction of advance of the slide 10 into engagement with a first abutment, e.g. a shoulder 23, engaging an abutment surface on the end of a sleeve 20, means for advancing the first abutment after contact of the slide 10 with the nut 12 to permit further advance of the slide, accompanied by advance of said first abutment, at a speed governed by the speed of advance of said first abutment, and a second and fixed abutment, e.g. surface 24, of a fixed collar 25, which coacts with the shoulder 23 of the screw 18 to prevent further advance of the screw and nut and therefore of the slide. In operation when the hydraulically driven slide engages the nut 12 a switch 17 is operated which controls a hydraulic cylinder 34 to engage clutch members 36, 39. A continuously rotating shaft 38 therefore drives gears 40, 29 to axially move the sleeve 20 by means of a screw thread drive 31 to allow the screw 18 to advance. Eventually the shoulder 23 engages the abutment surface 24 to stop further movement. Limit switches control the arrangement and a separate motor (51) (Fig. 5, not shown), re-sets the sleeve 20 back to a start position. The position of the nut 12 on the screw 18 is adjustable. |
