Improvements in or relating to horizontal boring facing and milling machine

摘要

812,611. Boring; facing and milling machines. BULLARD CO. Sept. 14, 1955 [Sept. 24, 1954], No. 26292/55. Class 83 (3). A horizontal boring, facing and milling machine comprises a base, a column attached to the base, a head movable vertically on the column, a spindle in the head, a saddle carrying a table on the base, a rear post carrying a vertically adjustable rear post head, a combined main change-speed gear-box and feed gear-box located within the column, and driving connections between the main gear-box and spindle, between the main gear-box and feed gear-box, and between the feed gear-box and head, saddle and rear post head. The machine comprises a bed B, Fig. 1, fitted with levels 56 and levelling screws 55. A main column C has guideways for the vertically slidable headstock H. The latter carries a spindle S1 movable axially by hand and power means. An outboard bearing 296 for the spindle is power adjusted vertically, in unison with the movement of the headstock H, and slides along guides 294, 295, Fig. 14, in an auxiliary column P1. This column is slidable along the bed guideways 54, and clamped in adjusted position by handles 290, 291. The screw 299 which moves the outboard bearing through a nut 300, is driven from a splined shaft 249 which also rotates the screw 251, Fig. 1, for the headstock H. The bed B also supports a saddle S movable along the ways 54, and carrying a transversely movable work-table T. A pendant P is supported to be near the operator and is provided with a number of interlocked switching devices to control all the movements of which the machine is capable. This pendant forms the subject-matter of Specification 812,612. Driving and feed gearing.-The driving-gears are mounted at the base of the column C and within the column. A pulley 105, Fig. 4, is driven from a motor (not shown) fitted with a brake, and rotates a primary driving shaft 104. This is connected through trains of gears and slidable dog clutches to give twenty-four speed changes to an output shaft 130. The latter drives, through bevel gears and a vertical splined shaft 140, gearing in the headstock H for rotating the spindle 61. A back gear drive is provided in the headstock for doubling the number of speeds at which the spindle may be rotated. The drive from vertical shaft 140 passes by pinions 141, 142 to a parallel stub shaft, and thence by bevel gears 144, 145 to a sleeve 146, Fig. 5, having a splined connection with a shaft 147. The main spindle drive is then through gears 156, 157. Alternatively, by fluid pressure delivered through a pipe 161, a piston 158 within sleeve 146 is moved to the right, and splined shaft 147, to which the piston is rotatably connected, is also moved. The forward bearing 148 for shaft 147 is carried in a sleeve 154 which is slidable within a casing 155. Movement of the shaft 147 to the right disengages the gear 156 and engages clutch dogs 149 with co-operating dogs 150 on a freely rotatable sleeve 151 carrying a gear 152. The latter meshes with a wheel 163 keyed to the spindle to complete the " back-gear " drive. Spindle feed and traverse.-The spindle 61, Fig. 6, is splined within a driving sleeve 62 and has its inner end rotatably connected to a nutsupporting member 65. A nut 69, offset from the spindle axis, is secured in the member 65, and engages a screw 71 driven from a shaft 76 which is mounted in a sleeve 77. The spindle may be rapidly traversed by moving the sleeve through rack-and-pinion gearing from a hand wheel 84, but a fluid-operated clutch in this gear enables the rack-and-pinion gears to be locked when the spindle is to be given a fine-feed by power means or from another handle 85. The latter, when pressed in to engage the clutch 86, drives the shaft 76 through gears 87, 88, and thus rotates the screw 71 through gearing 73, 72. Power feed is transmitted to the spindle screw- and-nut mechanism from a vertical splined shaft 83 driving a transverse shaft 80 in the headstock through bevel gearing, and driving the shaft 76 through further bevels 78, 79. Sliding gears and dog-clutch mechanisms for sixteen forward and reverse feed speeds are housed in a casing 165, Fig. 4, interchangeably secured on top of the housing Hs for the main drive gearing. In order that the feed ratio may be related to the spindle rotation, a first drive to the feed gearing is taken from a gear 202, Fig. 6, on the spindle 61, which drives through pinion 203 and bevel gears a splined vertical shaft 207. This shaft is connected through a cross shaft 209, Fig. 4, and further bevel gearing in the base of the column, to drive a shaft 211 and an input shaft 164 of the feed gearing. A second drive for rapid traverse movements is taken directly from the main drive gearing to spur gears 214-219, which latter gear is mounted on input shaft 164. The gear 219 meshes with a gear 220 on a stub shaft, and through gears 222-224, 225, 226, the last of which is on an output shaft 200. A further train and reverse gear is provided so that output shafts 194, 200 may be driven at a rapid traverse rate of speed in both directions. These output shafts may also be driven at feed speeds, as previously described, from the input shaft 164, these speeds being in " inches per revolution " of the spindle. A third variation may be effected by shifting clutches 234, 213 to the left, when the direct drive from the main gearing passes through the speed change gearing of the feedbox, giving "inches per minute " feeds at the output shafts. The output shafts 194, 200, Fig. 10, drive duplicate shafts 242, 232 respectively in parallel therewith, and these are connected to form vertically disposed drive shafts 235-238, Figs. 4 and 10, through bevel gears. Feed &c. drives are transmitted from these shafts through further bevel gears and shafting as follows: (a) from shaft 235 to the splined vertical shaft 83 for power feed of the spindle 61; (b) from shaft 236 to feed screw 259, Figs. 13 and 14, for saddle movement. (Hand operation of saddle is effected by rotating wheel 305, Fig. 14, which acts as a pinion co-operating with the screw 259 corresponding to a rack); (c) from shaft 237 to threaded vertical shaft 251 for raising and lowering headstock and outboard bearing; (d) from shafts 238 to a nut 273, Fig. 13, co-operating with a screw 269 secured to the transverse slide 266 for moving the latter. Clutch-actuating mechanism.-All the clutches in the main drive and feed gearing for speed changing, other than those referred to specifically above, are moved by rods such as 311, 313, 352, Fig. 4, brought to the right to connect with rods of hydraulically actuated pistons, e.g. 318, 354 arranged in banks in a bracket B1 at the rear of the column C. These pistons are actuated by solenoids, and are similar to the arrangement described in Specification 797,883.