Patent GB-560809-A (GB)
Title: Improvements in grinding machines
IPC: B24B5/06
Filed: 1941-08-08
Abstract: 560,809. Grinding machines; hydraulic machines; rectilinear bearings. BRYANT CHUCKING GRINDER CO. Aug. 8, 1941, No. 10116. Convention date, Nov. 9, 1940. [Class 60] [Also in Groups XXIX and XXXIV] In a grinding machine, the tool carriage is rockably supported on and reciprocable along an axis ex - tending towards a work support with the angular position of the carriage adjustable during the reciprocation, the tool being above the axis. In the machine shown in Fig. 2, wheels 150, 153, for grinding the interior and end of a work-piece mounted in a rotary chuck 42, are mounted in brackets 1520, 155 on a base, 157 which can slide on a carriage 158. The wheel-spindles 151, 154 are belt driven from a motor 194, mounted on the carriage, the belts 191, 192 passing over adjustable tightening - pulleys carried by slides 187, 188 which are adjustable on inclined ways on the carriage. A support 40, Figs. 2 and 5, carrying the chuck 42 and a reversible, hydraulic driving-motor 50 therefor, is angularly adjustable in arcuate guides 35, 36 on a table 5 which runs on tracks on the bed. The carriage can rock on a cylinder 159, Fig. 5, which is mounted in shoes 181 on the base 1 and is movable longitudinally in either direction to traverse the carriage. The carriage is provided with a ribbed hood 184 for directing debris away from the cylinder. The carriage may be provided also with another hood 182. The carriage is provided at the rear with a straight or shaped templet 205, Fig. 4, which rides on a pivoted block 200 on a stationary bracket 204, and controls the angular position of the carriage and grinding-wheels during traverse thereof. The templet is mounted on a pivot 206 and is formed with a bevelled upper-edge co-operating with bevelled slides 214 which are adjustable, to vary the inclination of the templet by means of threaded rods 217 extending to the front of the machine. Adjustment of the templet determines whether a cylindrical or tapered internal hole is ground by the wheel 151. To provide an additional feed-control for the grinding-wheels, the templet may ride on a block or roller carried by a plunger which is adjusted vertically by a screw-and-nut mechanism geared to an operating hand-wheel. In an alternative construction, the templet is adjustably mounted on the base and co-operates with an adjustable roller on the carriage. The Specification as open to inspection under Sect. 91 describes also the following constructions :-Traverse of the carriage is positively limited by an adjustable stop-device comprising a longitudinally adjustable bar 261, Fig. 21 (Cancelled), on the carriage and a co-operating micrometer-stop 281 on the base. The bar is formed with teeth 262 for engaging a spring- urged plunger 264. When the bar is turned by means of a finger-piece 274, the plunger is released to permit of adjustment of the bar. The plunger 264 can be held in released position by a catch 267. The stop 281 is threaded on to a plug 282 on a rod 280, and is retained in fine-adjustment position by a spring-plunger 283. The rod 280 is in threaded engagement with a nut 290 which is revoluble, to adjust the rod, by means of a worm 294 operated by a hand-wheel 295. Instead of adjusting the bar 261 by steps, any desired adjustment can be effected by turning the bar and inserting a selected gauge-rod between a shoulder 263a on the bar, and a socket 301 on the carriage. The bar 261 may be replaced by a bar which can be turned to bring any one of a circumferential set of adjustable stop-plugs thereon into engagement with the socket 301. The stop-plugs are threaded into a head on the bar, and are locked by tightening a split part of the head. The carriage is formed with apertures for receiving the idle stop-plugs. The table 5 is provided with pairs of ballbearings 6, 7, Fig. 8 (Cancelled), consisting of blocks mounted on pivots 15, 20 on the table and formed with tracks for balls 11. The bearings 6 run on the top of the track 3, and the bearings 7 run on horizontal and vertical walls 19, 18 on the track 4. Side-play is prevented by rollers 8 mounted on spring-urged levers 22. For adjusting the inclination of the table, and consequently the position of the work-axis, the pivots 15 have eccentric parts supporting the bearings 6 and are provided with adjusting-arms. The table is provided with feed-mechanism comprising a screw 62 mounted on the table and co-operating with a nut 61 mounted on the base 2 and provided with a worm 63 co-operating with a worm 65 provided with a hand-wheel 81. The screw is normally locked by co-operation of a wormwheel 71 thereon with a worm 72. The table is fed automatically by co-operation of a ratchet-ring 89 on the hand-wheel 81 with a pawl on a bell-crank 86 operated by a hydraulic plunger 95. An adjustable knock-off device for the pawl is carried by a ring which is mounted in the hand-wheel 81 and is geared to an adjusting-knob 94. The worm 72 is mounted on a lever which can be raised by means of a knob 77 to permit of quick operation of the screw 62 by means of a hand-wheel 70. The screw can be operated slowly by turning the knob. To provide for quick return of the table, the screw 62a, Fig. 13 (Cancelled) may be splined to a rod 100 which is mounted in the table and is provided with a collar 101 abutting on the screw. The arrangement enables the table to be moved forwards independently of the screw. The movement may be effected by a piston 106 which is connected to a collar 113 engaging a pin 111 on the table, and works in a cylinder 105 having feed and discharge pipes 115, 116. A stationary rod 160, Fig. 5 (Cancelled), passing through collars 167, 171 in the cylinder 159 is formed with a piston 161 and ports 165, 166 so arranged that when pressure-liquid is supplied to a pipe 175 or 180, the cylinder and carriage 158 are moved towards the left or right and discharge occurs through the pipe 180 or 175 respectively. A hydraulic circuit for the cylinder 159 that traverses the grinding- wheel carriage 158 comprises, as shown in Fig. 31 (Cancelled), manually operated and shut-off valves 359, 360 in a casing 358, and reversing and pilot valves 356, 355 in a casing 3540. The valve 355 is provided with a rack 405 engaging a pinion 406 on a valve 400. When the valves are in the position shown, a pump 351 supplies liquid through a pipe 352, around the valve 356, through a passage 371 in the valve 355, and a pipe 374, and the valve 356 is held in the right-hand position. Liquid is thereby enabled to flow through a pipe 375, around the valves 360, 359 and through the pipe 175, and the cylinder 159 and carriage 158 are traversed towards the left. The cylinder discharges through the pipe 180, around the valves 359, 360, 356, 355, through pipes 393, 398, pipes 413, 414, a valve 415, and a pipe 419. The speed of the cylinder and carriage is regulated by a manually adjustable valve 394 having a throttle-port 396 arranged between the pipes 393, 398. When the carriage reaches the end of its stroke, an adjustable dog 430 thereon rocks the valve 400, the valve 355 is shifted initially by the gear 405, 406 and is thrown leftwards by hydraulic pressure on a shoulder 3551. Thereupon, liquid flows through passages 435, 437 and a pipe 439, and the valve 356 is moved leftwards. The valve discharges through the pipe 374, passages 373, 371, and pipes 444, 419. The valve permits liquid to flow through pipes 352, 385, 180 and the cylinder and carriage are traversed rightwards. The cylinder discharges through the pipe 175,- around the valves 359, 360, 356, 353, and through valves 394, 400, 415 and pipes 393, 398, 413, 414, 419. At the end of the traverse, an adjustable dog 448 on the carriage rocks the valve 400, and the valve 355 is shifted by the gear 405, 406 and is then thrown rightwards by hydraulic pressure on a shoulder 3550. Thereupon, the above-described circuit is re-established, and the carriage is traversed leftwards. The valve 400 is movable axially into any of four positions by means of a hand-lever geared thereto, Fig. 31 (cancelled) showing the valve in the normal or " grinding " position. When the valve is moved into the second or " trueing " position, the valve is out of the path of the dog 448, and the rightwards traverse is extended to permit trueing of the grinding-wheels. Before the extended part of the traverse, the valve 416 is rocked by an adjustable dog 465, the pipe 413 is cut off, the cylinder discharge passes through an adjustable throttle-valve 421, the valve 400, and pipe 414, and the carriage is slowed down. At the end of the traverse, an adjustable dog 449 rocks the valve. 400, and the carriage returns at normal speed. When the valve 400 is moved into the third or " stop " position the pipes 375, 385, and consequently the pipes 175, 180, are placed in communication, the cylinder stops, and the carriage can be moved freely by hand, or under control of the valve 359. When a hand-lever 475 is moved leftwards, the valve is moved rightwards, liquid flows through the pipes 357, 175, and the cylinder and carriage are traversed leftwards, discharge occurring through pipes 180,499. Simultaneously, liquid flows through a passage 500, the valve 360 is moved rightwards, and the automatic traverse-mechanism is cut off. Similarly, when the hand-lever is moved rightwards, the valve 359 establishes a circuit for traversing the cylinder and carriage rightwards. For causing the speed of traverse to depend on the displacement of the handlever, the valve-part 495 controlling the port 496 of the pipe 357 is formed with tapered ends. In the fourth or " fast " position of the valve 400, the discharge circuit of the cylinder includes a pipe 426 which is not restricted by the throttlevalve 394. Moreover, the valve is out of the path of the dog 449, and an unrestricted rightwards traverse of the cylinder and carriage is permitted. The cylinder 96 of the plunger 95 for operating the feed-screw 62 of t