GB758443A - Improvements in or relating to boring heads - Google Patents

Abstract

758,443. Boring-heads. WILLETT, V. W. May 5, 1954 [Feb. 10, 1953], No. 3712/53. Class 83 (3). A boring-head of the brake-ring type comprises a gear reduction-train between the brake-ring and a tool-slide, and manually-operable gear selectors with means for effecting a quick return of the slide either independently, or through the gear-train. The tool-holding slide 21, Figs. 3 and 4, is guided in ways 29 in the body 19 and may be clamped during boring operations by a screw 68, Fig. 4. The slide is fed, for facing operations, by a screw 23, Fig. 3, which may be rotated through a socket-head 33, or by change-gearing described below. A shank 13 is secured to the body by screws 20, and a flange 12 integral with the shank, encloses an arcuate brake-piece 8 against a rotatable ring 2 provided with gear teeth on its inner end-face. A shoe 3 is secured by screws to the brakepiece 8 and a screw 10, Fig. 2, enables the shoe, brake-piece 8, and gear-ring 2 to be clamped together. When the shoe is held, either by hand or by a rod 11 engaging a fixed part' of the machine, the gear-ring is stationary relative to the remainder of the rotating toolhead. Diametrically-opposite gear-wheels 36, Fig. 3, on stub shafts 37, rotatable in the body 19, engage the gear-ring 2, and further gearwheels 43 on the stub-shafts may engage either a slidable wheel 40, Fig. 2, or a slidable wheel 41, thus giving forward or reverse rotation respectively to a shaft 38 on which the wheels 40, 41 are slidably keyed. These wheels may occupy a neutral mid-position as shown, in which no drive is transmitted, and are moved into engagement by a spindle 58, extending to an opening in the head, which has a pair of eccentric pins at its inner end engaging inclined slots in a slide-bar 55. The latter has notches which engage flanges 57 integral with the gearwheels 40, 41. The shaft 38 carries a worm 47 which engages a worm-wheel 48, Fig. 4, on a transverse shaft 51. A further worm 49 on this shaft drives a worm-wheel 50, Figs. 2 and 3, on a shaft 39 parallel to shaft 38. A slidable gear 42 on the latter shaft is engaged or disengaged from a pinion 34 on the feed-screw by a forked slide-bar 60 similar to that for sliding the gears 40, 41. The screw 23 may thus be hand-adjusted when the gear 42 is in the disengaged position. An adjustable stop-bar is provided for automatically sliding the gears 40, 41 into the neutral position. Different gear ratios in the feed drive may be provided for. Specifications 554,820, 633,465 and 758,488 are referred to.