Patent GB-238249-A (GB)
Title: Improvements in or relating to grinding or abrading machines
IPC: B24B5/06
Filed: 1925-08-07
Abstract: 238,249. Micro Machine Co., (Assignees of Yerk, H. H., and Baumberger, W. J.). Aug. 7, 1924, [Convention date]. Round holes, enlarging and trueing.-An internal grinding machine comprises a base A having a bed B thereon upon which is a grinding-spindle carrying head C the work being supported by a holder F mounted on a reciprocating table G carrying reversing stops 1. The head has bearings 5 in which a rotating spindle carrier 6 is journaled the carrier having an eccentric bore with conical ends receiving a sleeve 7 supporting eccentrically a spindle 11. The sleeve 7 is adjusted, to vary the eccentricity of the spindle, by worm gearing 14, 15 and is locked in position by a conical sleeve 9 and a nut 10. The spindle carries at one end a grinding-wheel 11<a> and at the other end a pulley 12. The spindle and the table G are driven by an electric motor 18, which drives through a clutch 20, a shaft 21. The spindle 11 is driven from the shaft 21, through a telescopic shaft 49, 50, universal joints 51, 52 a shaft. 45 carrying a pulley 46, and a belt 47. In order to allow the driving shaft 45 to follow the eccentric movement of the spindle 11, the shaft 45 is carried by an arm 37 guided to move vertically by rollers 40, 41, 43<a> upon a frame 26 which moves horizontally on a fixed frame D and is guided and supported by rollers 27. 29, 31, 32, 34, 35, the arm 37 being mounted on the spindle 11 by a ball bearing 38 and carrying a tightener 48 for the belt 47. In order to adapt the machine to the use of different grinding-wheels and to the grinding of various sizes of cylinders, change speed gearing is employed to obtain the correct speed of orbital movement of the grinding-wheel and the correct movement of the work table per revolution of the wheel, means also being provided whereby with any setting of the change gear, an alteration in speed of the revolution of the spindle is accompanied by a proportional change in the speed of the table. The gearing is driven from the shaft 21 through two reversely arranged cone pulleys 53, 54 on parallel axes, the pulley 54 being driven from the pulley 53 by a belt which is movable along the pulleys; the sleeve 6 and work traverse are both driven from the pulley 54. The belt is shifted by a yoke 62 connected to cable 64, which runs over guide pulleys and comes out at the front of the machine, where it is moved by a handle 71 set by a scale 73. The sleeve 6 is driven by gearing 16, 78 from a countershaft 77, which is driven by a belt 75 from a pulley 74 on the shaft of the pulley 54. The table is driven from the shaft by belts 80, 84 and through gears 93, 94 in a box 4, the speed changes being obtained by a sliding key 97 moved by a circular rack 106 and a pinion 107 actuated by a handle 110; the table is driven from the gear box through a pinion 105a driven through worm gearing 104 from a shaft 95 carrying the gears 94; reversal of the table is brought about by the stops 1 thereon which move a lever 3, operating the usual bevel gearing 86 carried by a shaft which is driven by the belt 84. The table may be moved manually through bevel gears 111, 112 by a handwheel 4<a>. Liquid may be supplied through a pipe 120 to a pipe 121 passing through the spindle 11.