Patent GB-190624808-A (GB)
Title: Improvements in Automatic Screw Machines.
Inventor: LESTER HARRY BURDETT
Filed: 1906-11-05
Granted: 1907-05-02
Abstract: 24,808. Lester, H. B. Nov. 5. Lathes; screwing; chucks.-A lathe having a number of hollow spindles 16, mounted in a rotary head 19, is arranged so that the feedmechanism and chuck of only one spindle, or of the whole of them, may be operated at one time. The jaw part 34 of each chuck abuts against a chuck 21 which is adjusted longitudinally by means of a screw-cap 35. within the tube 21 being a split spring-ended feed-tube 22. The chuck-closing sleeve 36 is operated by a spring 37, a sliding collar 40, levers 39, a conical ended sliding sleeve 42, a non- rotating part 66 having a groove 67 with cam shaped edges, and two pins 64 in brackets 62 adjustably secured to a drum 54, the pins being depressed at the proper times by a cam-plate 68 fixed to the stationary casing 20. The collar 40 has set-screws passing through grooves in the spindle 16 and engaging bayonet-slots in the sleeve 36, which may therefore be withdrawn after being partly rotated. The drum 54 is rotated on the head 19 by worm gearing 55, 56, and by means of cam-plates 52, 53 reciprocates a bar 50, which in turn by gearing 49, 48, 47 reciprocates the tool carrier 44 in its support 46 and also the connected bar 31. This bar passes through the centre of the headstock and carries a fixed disk 30, a collar 29 capable of being secured by a screw 33 to the disk 30 in either of two angular positions, and a sliding sleeve 70 which by means of a key 71 is angularly adjusted simultaneously with the collar 29. In one position of the collar 29, five rollers 28 carried by it lie between flanges 25 of, and collars 26 on, sleeves 24 secured to the five feed-tubes 22 so that they are operated simultaneously ; but in the other position of the collar 29 a single roller 28 placed midway between two of the other rollers 28 engages one feed-tube, so that only one tube is operated at a time. The collars 26 are screwed along the sleeves 24 to adjust the feed, the rotation of each collar being shown by a pointer 32. In one position of the sleeve 70, a projection 74 on the part 66 of the chuck which is being opened and closed reciprocates the sleeve 70 and operates the remainder of the chucks ; but in the other position of the sleeve 70, the projection 74 simply slides through a slot 73, cut from the groove 72 to the end of the sleeve, without moving the sleeve or operating the remaining chucks. The spindles 16 carry pinions 82 gear ing with the internal teeth of a wheel 77, which is rotated on the head 19 by a wheel 80 and pulley 79 either directly or by means of pitch-chain gearing. The head 19 is rotated by means of the friction between the head and the wheel 77 and drum 54, whenever a roller carried' by a lever is withdrawn from a notch in the index-ring 83 either by hand or by a cam roller on the drum 54. The drum 54 drives a number of sets of gearing 105, 103,'and cam-plates 101 to feed and retract radially-disposed slides 93 fitted with knurling or other tools. The guides for these slides 93 are pivoted in the casing 20, and are angularly adjusted by set-screws and locked by screws 96. The tool-carrier 44 has a depending portion 108 embracing the rod 50 for steadying purposes, and recesses 107 for tools and for the passage of two threading-tool holders 109. While threading, these holders are positively rotated in the same direction as, but slower than the work spindles, by pins 122, 123 in wheels 111, 118, wheels 119, 120, 121, and the shaft 78. The tools are advanced to the work by lever arms 129 pivoted to the bar 31 ; these arms are turned into inoperative positions by pins 130 and oblique grooves in a plate 132 as soon as the tools have been started, the tools continuing to feed themselves on. At the end of the threading operation, the lock-nuts 133 engage the tubes 112 and move the pins 122, 123 out of gear, and the wheels 111 into contact with the friction wheel 114 driven by gearing 115, 116, and the threading-tools are rotated faster than, but in the same direction as the work spindles, and thus off the work. The pins 122, 123 are again engaged by the headed rods 134 connected with the bar 31 by a bracket 127. The wheels 111 are retained in either of their two positions by spring plungers 126 and bevelled flanges 125 on sleeves 124. The threading- dies may be so backed off as to allow of the simultaneous operation of a turning-tool on the work being threaded.