Patent GB-423333-A (GB)
Title: Improvement in end facing and centering machine
IPC: B23B49/04
Filed: 1934-03-13
Abstract: 423,333. End-facing and centring machines. JONES & LAMSON MACHINE CO., Springfield, Vermont, U.S.A.-(Assignees of Lovely, J. E. ; 25, Cherry Hill Street, Springfield, Vermont, U.S.A.) March 13, 1934, No. 7917. Convention date, March 24, 1933. [Class 83 (iii)] In a machine for preparing work for turning between centres, the work is mounted in a carriage which is moved first to pass the work between a pair of spaced rotary facing tools and then to locate the work between a pair of drills which perform the centre-drilling operation. The machine comprises a headstock 2 and tailstock 3 between which is mounted the work carrier consisting of two portions 4 mounted on a rocking bar 5. Each of the stocks carries an end-mill (6, 7) and a centre drill (8, 9), the work piece 200 gripped near each end by jaws 190, 191 of the work holder being moved laterally by rocking of the bar 5 first to pass between the end mills to face the ends and bring the work to the required length and then to bring the work axis into line with the centre drills for the centring operation. The tailstock is adjustable to determine the length of the work by a longitudinal screw operated by a hand crank. The end-facing tools 6, 7, are secured to ballbearing spindles 30, Fig. 11, the left hand spindle carrying a gear 33 driven from the drive pulley 60 through a friction clutch 61 shaft 40, change-speed gearing 42-47 spur gears 37, shaft 35 and pinion 34. The shaft 38 of this gearing is connected to a shaft 98 which drives the end mill at the other end of the machine through spur gearing. The change speed mechanism in the cutter driving train is actuated from a handle 53 moving over a quadrant 56. The friction clutch 61 is operated by a rock-shaft 69 actuated by a hand lever 90. The rock-shaft is also connected to a rod 73 forming part of automatic stop mechanism. A spring normally tends to move the clutch mechanism to disengaged position. The rod 73 is connected to the arm 80 of band brake mechanism 81 coacting with a drum driven from the mainshaft 4 through bevel gearing. The automatic stopping of the machine is controlled from the main cam shaft 127 through a lever 270, rod 274, rock-shafts 277, 280 and a latch coacting with the starting lever 90. When the latch lug is displaced by the stop cam, the handle 90 is released whereupon the spring actuates the rod 73 to disconnect the main driving clutch and apply the brake. The machine may also be stopped by tripping the handle 90 by manual operation of the rock-shaft 280. The centre drill at the headstock end is mounted on a spindle carried in ball bearings in a sleeve 102 which may be moved axially by gear segments 111, 113, Fig. 11. The spindle is driven from the shaft 35 through gears 104, 105. A stop collar 107 limits the axial movement of the spindle. The rock-shaft 114 is operated to feed the drill through arm 115 connected by a rod 117 to a rock-shaft 120 operated by a cam drum 125 carried by the main cam shaft. The tail stock centre drill is mounted similarly to the drill 8 and is moved axially by a rocking segment 133 on a shaft carrying an arm 137 connected by an adjustable link 142 to the arm 115. By this mechanism the centre drills 8, 9 driven in opposite directions are moved simultaneously into opposite ends of the work and then retracted therefrom. The milling tools are driven in the same direction, one being a right handed and the other a left handed cutter. Each part 4 of the work-holder comprises a pair of slides 170, 171, Fig. 16, carrying clamping jaws 190, 191 and operated by a right and left hand threaded spindle 172 driven by an electric motor 179 through a clutch 184 and worm gearing. By removing the motor and its driving mechanism the shaft 172 may be rotated directly by hand. The jaw 191 is bifurcated to receive the jaw 190 when small work pieces are to be clamped. The movements of the work-holder are effected by former cams 205 on a carriage 206 slidable on a pivoted track bar. The former cams coact with followers 212 secured to the parts 4 and are moved axially by cams 219, 220, on cam drum 127. The work is moved quickly up to the spacing tools and then slowly for the facing operation. It is then quickly returned to a position opposite the drills for drilling and for positioning a fresh work piece. For this purpose a two speed cam shaft drive controlled by cams on the shaft is provided. The high speed drive is derived from the shaft 83, Fig. 8, through bevel gearing 237 shaft 236, bevel gearing 234 and clutch 240, the clutch being operated by cams on the main cam shaft. The low speed drive, which is operative whenever the high speed clutch is disengaged, is derived from the shaft 35 through change gearing, vertical shaft 258, bevel gearing 257 and over-running clutch 256. This cam shaft driving gear is similar to that described in Specification 372,367. The high speed shaft 236 may drive a coolant pump 292.