GB336050A - Radial arm drilling or tapping machine with all change gears centralized in head - Google Patents

Abstract

336,050. Cincinnati Bickford Tool Co., and Klausmeyer, D. C. Aug. 23, 1929. Drilling-machines.-In a radial- - arm drilling and tapping machine the charge speed gears for driving the spindle are all located in the drill-head and are arranged on three parallel axes to give a range of twenty four speeds in steps of three, two, two and two. The first two sets of gears, giving three and two speeds respectively, may be made removable so that these six speed changes may be performed by a variable speed motor. When all the speed changes are performed by gearing in the drill-head a constant-speed shaft 1 mounted on the radial arm drives a first shaft a, Fig. 1, in one direction or the other through one of a pair of oppositely rotating bevel gears x. A second shaft b is driven from the shaft a through one of the gear pairs AA<1>, BB<1> or CC<1>, and the shaft b drives a third shaft c, co-axial with the shaft a, through either of the gear pairs DD<1> or EE<1>. The shaft c carries a second double gear FG which drives a fourth shaft d, co-axial with the shaft b, through either of the gears F<1>, G<1>. The drill spindle 11 is splined within a sleeve 10 on which is splined a gear H and the spindle may be rotated either by the gears F<1>, H or by a pinion I on the shaft d and a gear I<1> loose on the sleeve 10 but capable of engagement with the gear H by means of an internally toothed ring H'. The gears Hand FG are displaced axially by hand-operated levers 32, 31 respectively which carry notched segments g co-operating with spring-pressed detents 35. The gears E<1>, D<1> and ABC are displaced axially by a shaft 15, Figs, 1 and 2, the former by axial movement of the shaft and the latter by rotary movement. A rack 16, Figs. 2 and 3, secured to the shaft engages a toothed segment on a bell-crank lever 17, pivoted at 18 and having a yoke 19 engaging the gear E<1>, D<1>, while an arm 21 secured to the shaft carries a yoke 22 engaging the gear ABC. A notched segment 24 on the lever 21 co-operates with a spring-pressed detent 25. A hand lever 26 pivoted to the shaft at 27 carries a roller 28. engaging an arcuate groove w in a bracket 29 on the head so that motion of the lever along the groove will rotate the shaft and motion about the axis of the roller will move the shaft axially. An indicator o rides over two arcuate scales m, n placed at the extreme limits of its movement along the axis of the shaft 15. When the first six speeds are supplied by the motor which drives the shaft 1, the shafts a, b, c are removed and replaced by a single shaft carrying the gears F, G only and extending down to the bearing f<1>, the hand lever 26 and connected mechanism also being removed. The gears A, B, C may be arranged in a different order from that shown in Fig. 1 so that the maximum speed is obtained with the indicator o at the position 1, Fig. 8, and the minimum speed at the position 6, in order to prevent abrupt changes of speed in going from one position to the next.