Patent GB-434772-A (GB)
Title: Improvements in and relating to multi-spindle turret lathes
IPC: B23B13/06
Filed: 1935-04-06
Abstract: 434,772. Lathes. POPPENSIEKER, F., 39, Ubierring, Cologne, Germany. April 6, 1935, No. 10721. Convention date, Feb. 14. [Class 83 (iii)] In a multi-spindle work-turret lathe for bar stock the stock-supporting reel 5 is connected to the work turret 3 through a clutch which may be disengaged so that the stock-reel may be recharged with fresh bars 11 without stopping the machine as soon as the bars under operation have passed out of the stock-reel. The stockreel consists of end discs 7, 8 connected by a central bar 9 and fitted with guide tubes 10 for the stock-bars. A bar 12 secured to the workturret carries a disc 13 bored at 14, Fig. 6, to receive coupling-pins 15 slidably mounted in the disc 8. The pins are fitted with studs 21 engaging in cam slots in a disc member 19 through which the stock bars pass, thus locking the coupling. After all the bars have cleared the disc 19, the disc may be rotated to withdraw the pins and free the stock-reel by rotation of a hand-wheel 16 connected to the disc through gears 17, 18. When the coupling-pins have been withdrawn the member 9 is positioned so that its holes are out of register with the guide tubes and serves as a stop for the insertion of fresh bars. A green signal light 24 indicates the passing of the bars clear of the stock-reel. A projection 25 on the disc 13 operates through a link 27 a pawl carrying ring 28, Fig. 9, the return movement of which, effected by a spring, gives a one-tooth rotation to a ratchet wheel 34 for each complete revolution of the turret. The stock bars 11 at each indexing movement of the turret act through a lever 29 and link 30 to impart movement to a pawl-carrying ring 31 which is returned by a spring to impart an opposite one-tooth rotation to a ratchet wheel 37. The two ratchet wheels are connected to bevel gears 40, 41 engaging opposite sides of a planetary bevel gear 43, Fig. 9, carried by a cam disc 44 which is adjustably connected to a second cam disc 45. At each revolution of the turret the movement of ratchet wheel 34 causes the cam discs 44, 45 to rotate slightly, but at the next indexing movement they are turned back by movement of the ratchet wheel 37 caused by one of the stock bars. Further movement by the other stock bars is prevented by a projection 47 on the cam 45 engaging a stop 48. When the longest stock-bar has left the stockreel the lever 29 is no longer actuated and the cam disc 45 is then rotated by the wheel 34 until the projection 47 trips a latch lever 51 and disengages an arm 49, Fig. 13, which thereupon makes a contact 57, 58 and causes the green light 24 to be illuminated. Fresh bars may now be inserted while the lathe continues to run. After further predetermined rotation of the cam discs a projection 59 on cam 44 engages a cranked lever 60, Fig. 14, which then clears a stop 61 and is pulled down by a spring to make contacts 64, 65 and cause a red lamp 66 to be illuminated. This occurs when the bars are used up to a small remainder and the machine is then stopped for feeding the fresh bars to the chucks. The time lag between the green and the red lights, depending on the length of material required for one piece, is determined by relative adjustment of the cams 44, 45 which is facilitated by a graduated disc 71 secured to cam 45 and coacting with an index mark on a head 70 secured to cam 44. After feeding the fresh bars the operator resets the cams thus switching off both lights and resetting the levers 49, 60. In one form the cam shaft of the machine may be automatically stopped when the red light is switched on. For this purpose completion of the red light circuit energizes a magnet 77 which acts through a lever 78 to shift a bar 79 which is then rotated by a cam projection 81 to disengage a clutch 84 and stop the camshaft. Alternatively the lever 83 may actuate a switch to disconnect the main driving motor 87 or to disengage a main driving clutch. The stopping is timed to occur when the tools and work-stop are both withdrawn. After the machine is stopped the operator connects the stock-reel to the work-turret. The roller 94 of the feed lever is then withdrawn and one of the bars pushed up to the feed fingers by means of handle 88 and pusher 90. A weight 93 returns the pusher subsequently. The feed fingers are then engaged with the bar which is moved into working position by operating the handle 95. The machine is then run until at the next indexing step it is again stopped by cam 81 whereupon another bar is inserted and so on. The indicating lamps are then extinguished, thus de-energising magnet 77, the cam roller 94 is returned into the path of its cam and normal working is resumed. In a modification the stock reel is disconnected automatically. For this purpose the circuit of the green light actuates a magnet 96, Fig. 7, to cause a lever 97 to engage and lock the hand wheel 16. At the next indexing step the stock reel is disconnected from the work turret. The lever 97 is reset by hand to permit the reconnection of the stock reel and work turret. In order to feed the bars into the chucks in a semi-automatic manner, the switching on of the red light may be arranged to energize a magnet 109, Fig. 17, so as to move a bar 113 into the path of a cam 115 which rotates the bar and operates a switch 117 to arrest the main driving motor. This action also starts an auxiliary motor 118 driving a cam drum 119 which actuates a slide 120. This slide is first moved to the left to set an abutment arm 125 and position a stop arm 126 against a stop 127. The slide 120 then moves to the right carrying with it by a latch 128 a member 129 connected to a pusher 108 engaging a bar 11. When the bar engages the stop 125, this stop is automatically swung aside and the bars fed a further predetermined distance into working position until the pawl 128 encounters a stop 136 and disconnects the pusher from the slide 120. After one revolution of the cam drum the auxiliary motor is switched off and the main driving motor switched on. The lathe then runs till the next indexing movement and the bar-feeding cycle repeated according to the number of spindles. After the last cycle a cam 143 driven through reduction gearing from the cam 119 actuates a switch 144 to energize a magnet which withdraws the lever 114 from the cam 115 so that the machine runs on without interruption.