Patent GB-812612-A (GB)
Title: Improvements in pendant controls for horizontal boring facing and milling machines and like machine tools
IPC: B23Q1/00
Filed: 1955-09-14
Abstract: 812,612. Boring; facing and milling machines. BULLARD CO. Sept. 14, 1955 [Sept. 24, 1954], No. 33086/56. Divided out of 812,611. Class 83 (3). [Also in Group XXXVII] A control pendant for a horizontal boring, facing and milling machine comprises a housing, a rotatable shaft in said housing, switch-operating dogs fixed to a drum rotatable with the shaft, a number of switches within the housing, means within the housing for supporting the switches, means for moving the supporting means from a position where said switches co-operate with the dogs, to a position where they are unaffected by the dogs, means between the rotatable shaft and the sup orting means for preventing the rotation of the shaft until the switches are in the unaffected position, and two additional sets of switches, one set being arranged at each end of the drum carrying the dogs, with a lever for each set for controlling the rate and direction of movement of the head and table of the machine. The power actuation of the movable elements of the machine, such as the vertical movement of the head H, Fig. 1, the axial movement and speed changes of the spindle S<SP>1</SP>, and movement of the work-table T and its supporting saddle S, is effected by gearing and clutches forming the subject-matter of Specification 812,611. The clutches are actuated bv parallel rods connected to individual hydraulically operated solenoid-controlled piston mecha. nisms arranged in a bracket at the side of the machine. Some of the clutches require to be moved right and left of a neutral position, and other piston arrangements have no neutral position but only a complete left- or right-hand position. An example of piston and solenoidoperated valve for a neutral-position clutch control has a rod 310, Fig. 20, connected to the clutch-operating rod. The inner end of rod 310 is of reduced diameter and supports spaced discs 326, 327, between which is located a sleeve 328. Piston elements 329, 330 are slidably mounted on the sleeve, and additional sleeves 331, 332 within the cylinder 316 limit the movement of the pistons away from one another. Liquid under pressure is admitted through the common line 320 to an annular space 333, from whence it flows through a passage 334 to the space between the pistons to hold them separated. Solenoids 322, 322<SP>1</SP> control valves 338, 339, respectively, which in the positions shown connect the outside ends of the piston to exhaust passages 342, 346. The portions 341 of the valves are of smaller diameter than the portions 340 so that the valves tend to be held in the position shown in Fig. 20 until moved by the solenoids. Movement by the solenoid of the valve 338 to the left opens the disc 326 to pressure via passages 335, 343, and the clutch rod is moved to the right. Operation of solenoid 3221 similarly moves the rod to the left, and immediately the solenoids are released the clutch rod is returned to the middle or neutral position. All of the solenoids except one for hand-traverse of the spindle are controlled from the pendant P, Fig. 25, arranged adjacent the operator. The pendant comprises an elongated body member 453 having a number of compartments in which are located switch mechanism and safety interlocks for controlling the solenoids associated with the different motions of the machine. The upper compartment 454 includes levers 455, 456 for directionally controlling the movement of the head H, Fig. 1, and table T respectively. The head moves only in a vertical direction, so that corresponding movement of levers 455, 456, Fig. 25, control this movement at " feed " and " traverse " rates respectively. Similarly since the table T moves only horizontally, corresponding movement of the levers is used for " feed " and " traverse " of this member. If the gates 517, Fig. 31, for the levers are moved through forty-five degrees and the levers then moved diagonally, simultaneous movement of both table and head is then obtained. Associated with the compartment 454, Fig. 25, is a knurled knob 457 for pre-setting the rate of feed in either "inches per rev." or " inches per min.", depending on whether switch 458 is in the left or right-hand position. A similar compartment 459 with levers 460, 461, moving horizontally only, is provided for the switch mechanism controlling the saddle. A third compartment 453 is provided for power control of the spindle movement, and the lowest compartment is provided with a single lever 465 for controlling the rotation of the spindle. This compartment has a knob 466 for pre-setting the spindle speed, and a switch 467 for forward or reverse rotation of 'the spindle. A pair of switches 468 control clamping gear for the head when this has been set in the required positions. Hand levers 555, 580 are provided at the side of the pendant so that switch contacts may be lifted clear of their actuating buttons during pre-setting of the speeds by knobs 457, 466. Switch mechanism for the top compartment 454 will be described, that for the other compartments being similar. A plate 469, Fig. 28, having side portions or ears 470, 471 with bearings 472, 473, fits within compartment 454. The bearings support shafts 474, 475 respectively carrying pairs of gearwheels, the purpose of which is described below. Block-like elements 478, 479 are arranged on each side of the plate 469, and each of these carries four slidable cam members 484-487, Figs. 28 and 33. (The blocks are identical and block 478 only will be considered.) The cams 486, 487 are identical and of T-shaped crosssection. They include forward portions having openings for the reception of the spherical ends of pins 488, 489, Fig. 31, that extend from the spherical surface of a member 490 carrying the control handle 455, and the cams are thus moved in and out when the lever is moved in the gate member 5201. A similar action on the cams 484, 485, Fig. 33, is effected by movement of the lever in a direction at right angles. The cams operate switches such as 503, 514, through slidable vertical tappet members such as 501, 513. The switches and tappet members are supported by plates 499, 500 mounted on the top and bottom of the assembly. These plates are connected to racks 546-549, Fig. 28, which are connected by gearing with the handle 555 so that when this is raised, the plates 499, 500 and switches &c. are moved away from the assembly out of co-operating position with the cams 484 and switch dogs 523 on a drum 520. The latter is carried by a spindle 521 to which the knob 457 for setting the feed speeds is secured. A spring detent 522, Fig. 33, co-operates with recesses to retain the drum in indexed positions where the dogs 523, predeterminately located, co-operate with the required combination of clutch-actuating switches to give the required speed. Interlock arrangements are provided in the assembly to obviate unintentional operation of the movable members, or clashing of gear-changes &c. For example, the drum 520, Fig. 33, is provided with a ratchet wheel 557 which engages with the end of a screw 556 to prevent rotation of the control knob 457 when the plates 499, 500 are in the closed switchoperating position. Similarly these plates are prevented from being opened by the lever 555, Figs. 27 and 28, when any of the pendant control levers 455, 456, &c., are out of the central or neutral position. The main driving motor is provided with a brake which is automatically operated to stop the motor before a change of gears in the headstock can be made. Specification 797,883 also is referred to.