Patent GB-334036-A (GB)
Title: Improvements relating to lathes or other machine tools
IPC: B23Q5/26
Filed: 1929-08-08
Abstract: 334,036. Triggs, W. W., (Sundstrand Machine Tool Co.). Aug. 8, 1929. Lathes.-A lathe or like machine having a sliding support and a rotary support for the tool and work has a fluid pressure feed for the sliding support and mechanically operated means driven from the rotary support for determining the speed at which the feed can take place over predetermined portions of the traverse. In an automatic lathe the bed 1 has front ways 6 for the saddle 5 which carries a cross slide 7 and rear ways 9 for a cross slide 10. The headstock spindle 3 is driven by worm gearing 19, change gearing 15, a shaft 11 and a clutch 13 from a constantly driven pulley 12, and sprocket on the pulley serving to drive the pump 43a for the fluid pressure feed through a chain 57 and a shaft 58. The pump delivers fluid by a pipe 43 to a rotary control valve 34 and thence by branch pipes 47<a>, 47<b> and 47<c> to cylinders 21, 26, and 30 respectively, arranged to feed the saddle 5, cross slide 7 and cross slide 10. The piston rod 22 of the cylinder 21 is screwed and adjustably secured to the saddle by a nut 23, Fig. 1, whilst the other piston rods 27, 31, Fig. 2, are also screwed and are adjustable in their pistons on rotation of hand wheels 29, 33. Fluid returns to the valve 34 by branch pipes 49a, 49<b>, and 49<c> and thence to a sump 54 by ,a pipe 55. A rod 74, adjustably secured to the saddle by a nut 75, Fig. 1, carries a rack 73 engaging a pinion 72 loosely mounted on a shaft 70 and a spring pawl in the shaft engages the interior of the pinion so as to limit the speed of the pinion and the saddle to that of the shaft in the feeding direction but permit the saddle to be returned freely by the fluid pressure. The shaft 70 is driven by a worm wheel 69, change gearing 67 and a chain 63 from the headstock spindle' 3. The speed at which the cross slide 10 is fed during cutting is limited by a wedge 84, Fig. 2, engaging a roller 83 on the slide and actuated by a rack thereon meshing with a pinion 89 on a shaft 86 which is connected by a pinion 87, Fig. 1, to a rack 88 secured to the saddle 5. The automatic operation of the machine is described in which the following cycle takes place : (1) " in " feed of the cross slide 7 at a rapid rate to the cutting position, (2) traverse of the saddle 5 at a slow cutting speed, (3) " in " feed of the cross slide 10, first at a rapid rate and then at a slow cutting speed and (4) return of the slides to their inoperative positions and stoppage of the machine. To commence the cycle the valve 34 is actuated by a hand lever 39 to admit fluid to all three cylinders, whereupon the slide 7 is fed rapidly in until the piston engages the end of the cylinder 26 and the slide 10 is fed rapidly until its roller 83 engages the wedge 84, On throwing in the clutch 13 by means of a hand lever 105 connected to a pinion 107, Fig. 2, (which may if desired be performed simultaneously with the actuation of the valve 34), the headstock spindle 3 and the shaft 70 are rotated, thus allowing the saddle to be fed and causing the wedge 84 to be retracted. On completion of the cutting operation an adjustable dog 93, Fig. 5, on a disc 91 secured to the pinion 72, engages a rod 42 to move the valve 34 to the reverse position and return the slides rapidly. The rod 42 is telescopic and contains springs 96 which, in conjunction with notches on the rod and a spring plunger 42<a>, allow the valve to be thrown over suddenly. As the disc 91 is reversely rotated a second adjustable dog 93<a> thereon engages a spring end 98 on the rod 42 to move the valve 34 to the neutral position when the pistons are at the rear ends of their cylinders. Simultaneously with the reversal of the valve 34 by the dog 93 a cam 110, Fig. 2, on the shaft 86 engages a link 111 connected to the clutch lever 105 and thereby stops the rotation of the headstock spindle and the shaft 70.