Patent GB-940643-A (GB)
Title: Machine tools
IPC: B23B13/00
Filed: 1961-01-09
Abstract: 940,643. Lathe details. WARNER & SWASEY CO. Jan. 9, 1961 [Jan. 26, 1960], No. 818/61. Headings B3B and B3T. [Also in Division F2] A single spindle automatic bar-machine comprises a headstock 4 supporting a rotatable workspindle 5 having a collet 26, Fig. 5, a reciprocating gripper 8 in the spindle, tool cross-slides 13, 14, an indexible multi-faced tool turret 9 slidable on guides 11, 12, a bar cut-off tool 60, Fig. 8, power means for sequentially moving the slides, and cut-off tool at rapid traverse, and feed rates, indexing and feeding the turret, and actuating the gripper, electrical control circuits including a limit switch operable to automatically terminate the machining cycle when the workpiece has been cut off, and to set up the machine for a new cycle, and means carried by the gripper, responsive to the disengagement of the gripper fingers from the stub end of the bar stock during retraction to operate the limit switch. Bar stock is loaded into a tube 16 which can be pivoted on a support 17, on to an arm 21 and the tube is clamped in line with spindle 5 by a clamp 19. Collet 26 in spindle 5, Fig. 5, is actuated by a fluid pressure actuated lever 35 pivoted to a bracket 36 carried by guides 11, 12, and the latter slidably supports a fluid pressure actuated head 37 which rotatably supports the tube 39, and resilient fingers 40 of the reciprocating gripper 8. An adaptor 41 may be secured to tube 39 to accommodate small diameter bars; in which case resilient fingers 40 are modified. Head 37 comprises an annular member 42<SP>1</SP>, Figs. 5 and 18, with a ring 45 attached thereto and a ring 46 urged to the left by springs 47. Tube 39 is rotatably supported within ring 46 by a bearing 42 and a switch actuating rod 53, Fig. 18, is engaged by a pin 57 secured in ring 46, the pin being slidable in a slot 58 in member 42<SP>1</SP>. A nut 55 on rod 53 is in non-actuating engagement with a switch EFLS, when the gripper is fully retracted and fingers 40 are gripping the bar and ring 45 of the head is contacting the right-hand end of ring 46, thus compressing springs 47. The gripper 8 is moved forward but ring 46 and tube 39 are initially held stationary due to fingers 40 gripping the work, and rod 53 is held stationary by pin 57 until member 42 engages the left-hand end of ring 46, whereupon the complete unit moves to feed the stock. When gripper 8 is retracted from its forward feeding position, Fig. 5, member 421 moves until ring 45 compresses springs 47 and engages the right-hand end of ring 46, whereupon the complete unit will be retracted, and nut 55 will again be in non- actuating engagement with switch EFLS. However, if the bar stock has been used up, and the gripper is retracted, fingers 40 will leave the bar and there will be no resistance to movement. Springs 47 will then move ring 46 away from ring 45 and rod 53 will be moved a further distance to the left so that when the gripper is fully retracted, switch EFLS will be actuated. This occurs prior to the completion of the machining of the last workpiece, and when these operations are completed, the sequence is stopped although the work spindle continues to rotate, and new bar stock is inserted, a switch CS, Fig. 2, is actuated manually, and the cycle starts again. Tool 60, Figs. 8, 10, is secured to a tool-holder 61, which is attached to a slide 62 mounted in a support 63. A roller 64 rotatable in a support 65 secured to slide 62, engages a spiral groove 66 in a toothed disc 67 keyed to a shaft 68 mounted for rotation in support 63 and a machine part 63<SP>1</SP>. Disc 67 is rotated by a pinion 72 keyed to a shaft 73 driven from spindle 5, such rotation causing tool 60 to move towards and away from the axis of spindle 5 to part off the work-pieces. Slide 62 is driven at rapid traverse and feed speeds which are proportional to the rotational speeds of spindle 5 through a gear-box, Fig. 7. Pinion shaft 73 is connected to a shaft 74 having an electrically operated brake COS mounted thereon, and a sleeve 75<SP>1</SP> rotatable on the shaft and having a gear 75 fixed thereto. Sleeve 75<SP>1</SP> is connected to one element 74<SP>1</SP> of a magnetic clutch rotatable on shaft 74 and the other clutch element 74<SP>11</SP> is splined to the shaft. A gear 86 is fixed to shaft 74 and meshes with a pinion 85 on a shaft 77, and a two-gear cluster 76, 87, rotatable on this shaft meshes with gear 75, and a pinion 87<SP>1</SP> fixed on a shaft 88, which is driven from spindle 5 by gears 89, 90. Gear 87 has a stub-shaft on which a pinion 78 is free to rotate, and this pinion constantly meshes with a gear 79 formed on a sleeve 80 rotatable on shaft 77, and meshes with a gear 81 fixed to the housing 82. Sleeve 80 has an element 83 of a magnetic clutch splined thereto, the other element 84 of which is keyed to shaft 77. Slide 62 is driven for rapid traverse from spindle 5 through gears 90, 89, 87<SP>1</SP>, 87, 76, 75, and clutch 74<SP>1</SP>, 74<SP>11</SP> with clutch 83 disengaged, and is driven at its feed rate through gears 90, 89, 87<SP>1</SP>, 87, planet wheel 78 rotatable about fixed wheel 81, gear 79, clutch 83, and gears 85, 86, with clutch 74<SP>1</SP>, 74<SP>11</SP> disengaged. The gear ratios may be changed by substituting a smaller gear carried by gear 87 for gear 78 and gears 81, 79 are replaced by larger gears. Clutches 83, 74<SP>1</SP>, 74<SP>11</SP> and brake COS are controlled by a cam 92, Figs. 11, 12, driven by shaft 74 through gears 94, 95, which actuates switches CORTLS, COSLS, COFLS. Spindle 5, Fig. 13, is driven from a motor 102 through gearing 104 at any one of 10 speeds, selected by actuating fluid clutches. SC1- SC5, by solenoids SVA-SVC energized by limit switches, cross-slides 13, 14, are driven at one of three feed speeds from spindle 5 through a transmission 120, including fluid clutches FC1- FC5 operated by solenoids FVA-FVC actuated by limit switches, and at rapid traverse speeds by a reversible motor 127. Turret 9, having five tool supporting faces, is moved longitudinally by a cam 128 rotated in opposite directions to effect rapid traverse by motor 127, and rotated in one direction at a feed rate from transmission 120, with the shaft of motor 127 idling. The turret is indexed by a motor 133 actuated by a limit switch CDLS4, associated with a cam drum 132 and limit switches are actuated by a control drum 10 on the turret during indexing and feeding of the latter to initiate various machine operations. The collet is actuated by a valve controlled fluid pressure piston 150, Fig. 6, connected to lever 35 by a rod 153, and the reciprocating gripper 8 is actuated by a valve-controlled fluid-pressure piston 168 connected to head 37 by a rod 171. Bar stop 181, Fig. 1, may be pivotable on turret 9 in which case a piston 182 provides the pivoting movement. In operation switch M on control panel P, Fig. 2, is pressed to start main motor, 102, Fig. 13. Switches HP and C are pressed to open the collet, and switch B is pressed to move the reciprocating gripper to its forward position; a bar is loaded into the machine, switch HP is pressed to close the collet and switch B is pressed to retract the gripper, and then HP is released. Switches SS, SC are depressed to energize the selected solenoid SVA-SVC, Fig. 13, and slide 62 is rapidly traversed towards the stock by depressing and then releasing button CO to part off end of bar, whereupon COF is depressed to rapidly retract slide 62. The machine is now set for automatic operation and button CS is pressed to start motor 127 to rapidly traverse turret 9 until a solenoid FVAFVC is energized and turret 9 is fed at slow speed to machine the work. At end of forward travel, motor 127 is started to rapidly retract the turret, the latter being indexed at the end of the stroke. The turret is traversed forward and slide 62 is moved towards the stock, and the turret is slowed down, solenoid FVA &c., Fig. 13, is energized to stop the turret with bar stop 181, just clear of the work, and slide 62 is retracted. Solenoids SVA &c., Fig. 13, are deenergized, spindle 5 stops and the collet is opened. Gripper 8 moves the stock up to stop 181 and the collet is closed, whereupon the gripper is retracted and the turret is moved back rapidly, is indexed and the collet is opened. This sequence continues until the stock is used up whereupon gripper fingers 40 leave the bar and an alarm is actuated to indicate new stock is required. Button CS is pressed after loading new stock, and the automatic operation continues. Specification 653,706 is referred to.