GB143546A - Improvements in drilling-machines - Google Patents

Abstract

143,546. Bayrer, W. J. Dec. 18, 1916, [Convention date]. Drilling-machines; attachments for drilling. - In a belt-driven pillar drilling-machine, means are provided for rapidly adjusting the position of the guide-pulleys 98, 99, according to the belt tension desired and to the portion of the stepped cone pulley 12 it is desired to use. The pulley 98 is carried by a frame 105 pivoted between round-headed pins 100 on a slide 97, which also has a race to support the rollers 111 on the front of the bracket 105. The pulley 99 is carried by a bracket 116 pivoted vertically on the slide 97 and clamped in adjusted position by a set-screw. The slide 97 is adjusted on the support 24 by a rack 143 and pinion 142 actuated by a worm-wheel and worm 144, which may be rotated by a hand-wheel 154, or may move axially, against the pressure of a spring 151, to an extent limited by a collar 150, and a stop 161, which engages a stop 160 to prevent further rotation of the worm when the spring 151 is compressed to give the maximum desirable belt tension. The support 24 is adjusted vertically by rack and pinion operated by a handle 85, and so proportioned that each complete revolution of the handle shifts the support 24 a distance equal to the width of one 'step on the pulley 12, where it is then held. by a spring-controlled releasable stop 90. The weight of the spindle and sleeve 13 is counterbalanced by a weight 15 on a chain 16. The Specification as open to inspection under Sect. 91 (3) (a) describes also a high speed supplemental tool carrier, Fig. 1, driven by belts from a pulley on the spindle 14 through a parallel lay shaft. The positions of the guide pulley support 24 are indicated by a pointer co-operating with an index plate. A belt shifting device comprising a ring 173 and adjustable yoke 174, Fig. 3 (Cancelled) is mounted on a rod 170 moved transversely by a link 191, crank 190, shaft 184, bevel pinion 188, and sector 187 on a shaft 179 carrying pedals 180 the sector and bevel pinion being kept in mesh by a slot 182 which also acts as a stop to determine the extreme positions of the belt movement. The spindle 14 is carried on ball bearings and springs mounted between the upper thrust bearing and a collar 38 eliminate end play. Flanged oil-retaining caps are provided for the ball bearings of the pulley 12, spindle 14, pulleys 98, 99, shaft 8, and the sleeves 220, 214 of the high speed attachment. This subject-matter is not described in the Specification as accepted.