Patent GB-537246-A (GB)
Title: Improvements in or relating to machines for finishing the surface of a cylindrical workpiece by abrasion
IPC: B24B35/00
Filed: 1939-12-13
Abstract: 537,246. Abrading cylindrical articles. CINCINNATI GRINDERS, Inc. Dec. 13 1939, No. 32169. Convention date, April 10. [Class 60] A machine for finishing the surface of a plain or stepped cylindrical article by abrasion comprises a work-carrying support oscillatable so as to oscillate the work about the work axes, and an abrading element rapidly vibrated in a direction axially of the work-piece. The various sides or facets of individual abrasive particles are thus utilized. The work-piece 34 is secured between a chuck 33 and a centre 35 which is pushed forward by a spring 46, Fig. 29, and retracted by hydraulic pressure under control of a pedal 162. The centre is locked in position in the tailstock 38 by a bevelled plunger 48 pressed forward by a spring and retracted by fluid pressure. The chuck is driven by a belt 83 from a shaft 81 driven through gearing both from a shaft 55 and from a shaft 57 which shafts are driven by seperate belts from a motor. The shaft 55 drives through bevel gear 58, 59 and spur gear 61, 62, a disc 63 carrying an adjustable crank pin 69 which through link 68 oscillates a bracket 70 about an axis 72. The bracket carries a pair of meshed gear wheels 76, 77, the latter of which is geared to a wheel 78 driving through bevel gear 79, 80 the shaft 81. An oscillatory movement is thus given to the chuck 33. The chuck is also continuously rotated from the shaft 57 by worm gear 85, 86 and spur gear 87, 88, the latter being mounted on the shaft 72 to which is keyed a wheel 90 meshing with a wheel 91 forming a couplet with the wheel 76. In a modified form, Fig. 19, the pulley 190 which corresponds with the pulley 82 of Fig. 3, is driven by bevel gear 189, 188, spur gear 187, 186, 185 and worm gear 184 from a shaft 183, which is splined to a shaft 181 driven by the motor. The gear 186 has an eccentric pin 191 which through a link 192 and adjustable yoke link 193 reciprocates the worm shaft 183. In a further form, Fig. 22, the motor drives through worm gear 200, 201, crank pin 202 and link 203 a gear 213 meshing with a gear 214 which is connected by over-running clutch elements 215 to a shaft 209 in one half revolution of the wheel 201, so as to drive through bevel gear 210, 211 the pulley 212. During the other half revolution of the wheel 201 the wheel 213 is reversed so that a wheel 207 is connected by over-running clutch 204 to the shaft 206, the wheel 207 meshing with a wheel 208 on the shaft 209 so as to reverse the movement of the pulley. The movements in opposite directions are at different rates due to the difference in ratios between the sets of inter-meshing gears 207, 208 and 213, 214. The abrasive tools 92 are secured in holders 94, Fig. 16; pressed by springs 96 towards the work and mounted in heads 95 which are provided with elongated slots 100 and are reciprocated axially of the work by eccentric pins 102 on shafts rotated by motors 105. The tool assemblies are carried by arms 107, Fig. 12, which are moved inwards by springs 113 and are held out of action by adjustable abutments 114 engaging cams 115 on a shaft 116 mounted on sleeves 108 on a cylinder 109, which is moved axially of the work by hydraulic pressure. The cylinder 109 carries an arm 142, Fig. 24, and stop rod 141, provided with stops 139, 140. As the cylinder moves upwards the stop 140 raises a valve 135 and so connects the conduit 132, through which pressure is forced by a pump 130, with passage 153 so as to raise valve 145. Fluid thus passes through passages 154 and 156 to the lower end of the piston 110 so as to lower the cylinder 109. When the stop 139 engages the valve 135 the parts are reversed and the cylinder raised again. The operation is stopped by the pedal 162 which pushes down a valve 161 so opening the pipe 133 to pipe 164. Fluid then passes up the pipe 165 to operate a piston 121 to rotate the camshaft 116 and so bring the tools out of contact with the work. At the same time the centre 35 is withdrawn by fluid passing through part 166 and cutting oil which is forced by pump 174 through pipe 175 and passage 176 in the tool is cut off by closing of valve 172. Tha tailstock 38 is adjustable by a hand wheel, bevel gear and screw on ways 39 of the column and is secured in position by bolts 42 and slides engaging T-slots 40 in the column. Springs steady the tailstock in position and facilitate adjustment when the nuts are loosened. The tool holders may be mounted on the chuck and used for finishing flat or cylindrical work.