Patent GB-503431-A (GB)
Title: Toolhead for grinding machines or the like
IPC: B24B3/04
Filed: 1937-10-20
Abstract: 503,431. Grinding - machines. CHITTENDEN, W. N. Oct. 20, 1937, Nos. 28566 and 28567. Convention dates, Oct. 20, 1936 and Oct. 6, 1937. [Class 60] A machine for grinding or sharpening twist drills, milling cutters, &c. comprises a spindle 28; Figs. 1, 2 and 3, carrying the work-piece 31 by a chuck 30 and journalled in a housing 29 pivotally adjustable in a bracket 32 extending from a table 19, so as to permit pivotal adjustment of the spindle in a vertical plane. The table 19 is slidable longitudinally on a bed 12 under the control of screw-and-nut mechanism operated by a haridle 21 on the table. The bed 12 is universally adjustable in a horizontal plane, being adjustable longitudinally on a member 9 adjustable transversely on a turntable 4, the latter being angularly adjustable in a base 1 secured to the machine. Adjustable means are provided whereby longitudinal movement of the table on the bed produces rotation of the spindle, such means comprising a block 46 which is pivotally carried by a rack 45 slidable vertically in a casing 42 secured to the table 19 and which slidably engages a guide bar 48 having a trunnion 50 journalled in a cover member 51 secured to the bed 12. The inclination of the bar 48 is varied by a worm 53 engaging teeth on the trunnion 50. The rack 45 meshes with a pinion 44 secured in a transverse shaft to which is secured a gear 39 meshing with a gear 38 mounted loosely on the spindle 28. An indexing plate 59, normally clamped to the gear 38, has a series of apertures 61, a selected one of which can be engaged by a spring-pressed pin 64 carried by a member 63 clamped to the spindle 28. The tail end of the work-piece may be supported by a tailstock 24 adjustable along the table 19, such tailstock incorporating means 25 and 66 for longitudinal and vertical adjustments of its centre. Prior to grinding, and after the various adjustments of the bed 12 have been effected, a feeler 18 is adjusted along the bed into a position corresponding to the grinding wheel 2, and indexing adjustments of the spindle and angular adjustment of the bar 48 are effected so that, on operation of the handle 21, the feeler traverses the required path on the work-piece. An electric motor may be pivotally mounted on the head 29 so that a worm on its shaft may be brought into engagement with teeth on the plate 59. If the plate 59 is released from the gear 38, the spindle 28 may thus be rotated by the motor. To introduce a finer adjustment into the indexing arrangement, the member 63 may be loose on the spindle 28 and an adjacent member 68, Fig. 5, secured to the spindle, may carry a rotatable pin 72 which is capable of being locked by a screw 73 and which has an eccentric part engaging a radial slot in the member 63. The spindle 28 may be locked against rotation by means of a pin 75 slidably carried by the head 29 and engageable with one of the apertures 61 in the plate 59, the latter being released from the gear 38. As shown in Fig. 11, the handle 21 is secured to a screwed shaft 89 engaging a nut 93 which is journalled in a bracket 86 secured to the bed 12 and which is geared to a shaft 83 journalled in the bracket and carrying. a handle 80. On locking either shaft against rotation, rotation of the other shaft produces movement of the table 19.