Patent GB-394563-A (GB)
Title: Improvements in or relating to methods of and machines for abrading workpieces
IPC: B24B5/10
Filed: 1932-11-04
Abstract: 394,563. Grinding-machines. HEALD MACHINE CO., 10, New Bond Street, Worcester, Massachusetts, U.S.A.-(Assignees of Taylor, E. M., Quimby, R. A., and Lippard, R. M..; 10, New Bond Street, Worcester, Massachusetts, U.S.A.) Nov. 4, 1932, No. 31202. Convention date, July 19. [Class 60.] Round holes, enlarging and trueing.-An abrading-machine is provided with a cutting wheel and a polishing wheel on a single spindle which is continuously reciprocated axially, or the work itself may be reciprocated ; means are also provided for separating the wheels from the work in changing from one wheel to the other. The wheels 12, 13 or the work holder 6 are carried by a table 1 driven by hydraulic or other power, the reversal of motion being effected by adjustable dogs carried by the table and alternately engaging a reversing member 7 ; for the crossfeed between work and wheel, the head 2 is mounted on a cross-slide 8<1> actuated by a screw 8, cam 9, pawl 11 on an arm not shown, and a ratchet wheel on the screw 8. The reciprocations of the rough wheel 12 are controlled by dogs 14, 15 pivoted on a member 18 adjustable on the table 1, and those of the wheel 13 by dogs 16, 17 on an adjustable member 20. The dogs are actuated in pairs by a sliding bar 22, Figs. 2 and 5, which carries a rack 24 engaging with a pivoted segment 25. As the table 1 moves to the left, an arm 34 is tilted by a cam 36 and bears against a pin 31 so that the segment 25 turns counterclockwise and moves the bar 22 to the right, thus bringing a recess 38 over the dog 14 so that it falls, while dogs 16, 17 are held up out of action. The rough grinding continues under the control of dogs 14, 15 until the finished size is approximately reached ; the table is then given an extended movement to the right to bring the wheels under a dressing device 49, 50 which may be actuated by any suitable mechanism. The extended movement may be produced by a gauge or mechanism responsive to the crossfeed and energizing an electromagnet which elevates a lever 45, thereby raising the dog 14 and allowing the carriage to continue to move to the right until a dog 47 shifts the reversing lever 7. The back-off movement of the wheels radially from the work is effected by a cam 65, Fig. 10, on the back of the machine, and a pivoted arm 63 which lifts a pin 67 and turns a forked lever 68 and pin 70 on a bracket 57, thus shifting the cross-slide towards the front by means of screwed sleeves 52, 53, Fig. 12. A spring 61 returns the slide for the finishing process. Shifting of the table 1 to bring the finishing wheel 13 into action is effected during the extended movement to the right by the cam 36 engaging the arm 34 and turning the segment 25 clockwise to move the bar 22 to the left, thus bringing recesses 38, 42 over the dogs 16, 17 and lifting the dog 14. The table then reciprocates under the control of dogs 16, 17 until the workpiece is of the size desired ; a lever 71 is then raised by a gauge or the crossfeed movement and removes the dog 16 from action, and the table continues to move to the right into rest position.