Patent GB-787483-A (GB)
Title: Improvements in and relating to grinding machines
IPC: B24D15/08
Filed: 1955-07-22
Abstract: 787,483. Grinding. ZALEWSKI, W. July 3, 1956 [July 22, 1955], No. 21356/55. Class 60. A machine for grinding tools and other workpieces comprises a vertically-adjustable column 17, Fig. 2, upstanding from a base 11 and carrying at its upper end a horizontally-adjustable electric motor 34 fitted with a grinding wheel 40 on its horizontally-extending shaft 35, and the workpiece is carried on a slide 82, Fig. 1, movable on parallel supporting bars 78 on a table 75 indexable about a vertical axis on a main table 47 which can slide on either a single bar 48 or two such bars carried by the base ; adjustable spring means are provided for moving the table 47 with its superstructure towards the grinding wheel for the feed stroke. The column 17 is slidable in an upstanding sleeve 16 on the base 11 by a screw 23 which engages in a crossweb 22 in the column and is driven through bevel gearing 24, 27 by a hand-operated shaft 28. The electric motor 34 is carried by a table 33 slidable on ways 32 on the top of the column 17, movement of the table being effected by a hand-operated shaft 38 carrying a pinion 37 meshing with a rack 36 on the table. The wheel 40 is clamped on a shaft 99 having a splittubular extension 46 supported in a ball bearing 42 and clamped on the motor shaft 35. While the axis of the motor shaft 35 is normally at right angles to the directon of movement of the table 47, the motor base may be mounted so that it can be pivotally adjusted about a vertical axis. The table 47, which is in the form of an inverted shallow tray, is shown in Fig. 3 as being slidable on two bars 48, 50 extending from front to back of the machine (or at an angle to this direction) and clamped in bearings on the base 11 ; the ends of the bars engage slidably, and with or without the interposition of ball bearings, in sleeves 53 clamped in the side flanges of the table. Two hand-operated spindles 57, 58 are rotatably mounted in the table 47 for respectively controlling the tension of a helical spring 59 urging the table towards the grinding wheel for the feed stroke and the position of a stop 68 arranged to co-operate with a fixed stop 69 for limiting the movement of the table in this direction ; the table can be returned from this position to its initial position by a handoperated cam acting through a lever 74 on a pin 70 which is slidable in the stop 69 and engages the stop 68. Other spring means of a single or compound nature may be used in place of the helical spring 57, and such means may be supplemented by a freely-hanging weight or a chain or lever. The upper surface of the table 47 is formed as a circular bed plate for mounting the indexable table 75 which carries the bars 78 for the slidable support of the slide 82 ; four saddles 84, Fig. 8, on the slide have bearing rollers 85 riding on the bars 78 and the undersides of the bars are engaged by rollers 86 carried by spring-urged pins 88 from the slide. Movement of the slide between limits set by stops 91, Fig. 1, on the slide and adjustablymounted stops 89 on bars 90 carried by the table 75 is effected by a hand-operated pinion 80 which engages a rack 81 on the underside of the slide and can be withdrawn from such engagement in order to enable the slide to be pushed along the bars 78; a friction-wheel drive may replace the rack-and-pinion drive, if desired. Laterally-extending plates 92 are provided on the slide 82 for the purpose of protecting the upper open portion of the table 75. The upper face of the slide 82 provides a bed surface for an indexable table 94 carrying a pair of horizontal guides 95 on which are clamped a headstock 96 and tailstock 97; driving means may be provided on the table 94 for continuously rotating or indexing the workpiece. The various tables and slides may be made of aluminium or a light alloy. The workpiece can be moved longitudinally during or after the feed motion of the main tables and be rotated during or subsequent to this feed motion and/or longitudinal movement.