Patent GB-153863-A (GB)
Title: Improvements in and relating to automatic machine tools
IPC: B23B9/12
Filed: 1919-05-26
Abstract: 153,863. Marks, E. C. R., (Bullard Machine Tool Co.). May 26, 1919. Lathes.-In an automatic turret lathe having rotating work-tables such as 91, Fig. 2, in are. volving automatically-indexed carrier 24, and tool slides such as 130 moved towards and away from the work, such as described in Specification 154,947, the carrier 24 is indexed by means such as a forked arm 74 engaging the ends 76 of spindles 92 of the successive work-carriers. The operation of this indexing means is determined by means such as a controller 69 automatically released by the return of the last tool slide 130 to inoperative position. The carrier 24 has camoperated positive and frictional locking-devices,. and adjusting means for its bearings. Framings.-The parts are preferably mounted on a base 20, with enclosing plates 28 and a column 21 the lower part of which has the turret bearing, and the upper part the slides for the tool carriers 130, and a casing 31 for the operating mechanism. Driving machine spindle.-The spindles 92 have gears 93, which move into position to engage gears 94 as the turret is indexed. The gears 94 are splined to shafts 95, and raised by cams on the carrier 24, so shaped that as the work-holders come into position the pinions 94 slide into engagement with the wheels 93, under the influence of springs and gravity. Spindle mountings.-The spindles 92 are mounted in bearings 87, 88, clamped in place by screws 89, 90. Turrets.-The turret or carrier 24 has a conical bearing 22, and a ball thrust bearing 80 with a screw ring 82 for adjusting. The driving-mechanism is actuated from the main driving-spindle 32 through a clutch 57, 58 operated by a hand lever 52, or automatically by mechanism controlled by cams on the drum 66, then through shafts 42, 47, and a gear 49 carrying a clutch member 50, and loose on the shaft 51 which carries the portion of clutch member, fixed to the shaft 51 driving the turret rotating and locking mechanism, and coupled through the operation of a controller 69. Turret-rotating mechanism.-The controller 69, Fig. 6, is loose on the shaft 51 and has stops 120 engaging stops 123 on arms 44 carried by rock shafts 122 having also arms to engage sliding bars 126 with inclined ends 127 pushed inwards by stops on the tool slides 130 when they are raised to inoperative position. When the slides 130 are all raised, the controller 69 is free to rotate slightly under the influence of a spring 131 the other end of which is attached to that portion of the clutch fixed to the shaft 51. The movement of the controller 69 operates a bell crank lever 133 to cause a latch to couple the parts of the clutch 138, and thus operate the shaft 51 for one revolution, during which the stops 120 engage the levers 124 and re-set the arms 121 for reengaging the stops 120 and holding the controller 69 so that the clutch 50 is again disengaged. The revolution of the shaft 51 operates through gears 70, 71, a crank with a pin 77 carrying a lever' 74 with a forked end 75 engaging a spindle end 76. The other end of the lever 74 engages a pivoted slide 78, so that a single operation of the shaft 51 causes the indexing of the turret, and the return of the lever 74 to engage the end 76 of the next work-holder spindle. Turret locking mechanism.-The shaft 51 carries a cam 106 which operates a split, spring-controlled locking-pin 108 through a lever 103, and forces it against one of the adjustable pins 111 fixed in the turret. In addition to this positive lock, a cam 117 engages a lever 114 to press a pad 118 against the bearing-surface of the turret, to hold it firmly and eliminate all play in the bearing.