Patent GB-696460-A (GB)
Title: Improvements in profile grinding or polishing machines
IPC: B24B17/08
Filed: 1951-10-19
Abstract: 696,460. Grinding machines. RANSOMES, SIMS & JEFFERIES, Ltd., DYER, F. T., and REVETT, R. H. Oct. 17, 1952 [Oct. 19, 1951], No. 24494/51. Addition to 659,939. Class 60. [Also in Group XXIX] The grinding machine of the parent Specification is modified by arranging for the up-anddown tilting of the work table 34, Fig. 1, which is mounted on a traversing table 38 carried by a feed carriage 41, to be effected by means of pressure fluid supplied to and exhausted from hydraulic cylinders 303 under the control of a valve 311 which is operated by a cam bar 341 on the carriage 41 and has its casing so supported as to reciprocate with the traversing table and rise and fall correspondingly with the tilting of the work table 34. The latter table is pivoted on trunnions 36 on brackets 37 fixed to the table 38 which is reciprocated on the carriage 41 by a hydraulic cylinder, and the carriage 41 is movable on a base 65 by a hydraulic cylinder 300 as described in Specification 696,461. Two doubleacting hydraulic cylinders 303 pivoted on the brackets 37 have their piston rods 306 connected by levers with the trunnions 36, and pressure fluid is supplied to and exhausted from the opposite ends of the cylinders under control of the valve 311 to tilt the table 34 as desired. The casing 313, Fig. 5, of this valve is secured to a bracket 312 slidable in vertical guides on brackets carried by a bar 320 fixed between the brackets 37; as the table 34 tilts, the vertical position of the casing 313 is adjusted by links 323 connected between the casing and table. The piston valve 334 in the casing 313 has three pistons 335, 336, 337 controlling a pressure-fluid inlet port 327, exhaust ports 328, 329, and ports 330, 332 connected by pipes to opposite ends of the cylinders 303. A spring 338 presses the piston valve downwardly into engagement with an operating plunger 339 having a roller 340 running on the cam bar 341 which is supported by rods 342 passing through guides 343 in the feed carriage 41 and having rollers 344 running on rails 345. At the start of the right-hand movement of the table 38 in Fig. 1, the cam bar 341 gradually raises the piston valve 334 in its casing so as to uncover the supply port 327 and exhaust port 328 whereby pressure fluid passes to the upper ends of the cylinders 303 and is exhausted from their lower ends; the resultant downward tilting of the table 34 acts through the links 323 to raise the valve casing 313 so as to compensate for the rising of the piston valve, but the valve remains open to allow fluid pressure to continue the downward tilt of the table. When the table 38 reaches the end of its stroke, the piston valve'ceases to rise but the table 34 continues to tilt downwardly and so raise the casing 313 until the valve pistons 335, 336 close the ports 327, 328 to arrest the table in its downward position. During the return stroke of the table 38, the piston valve 334 moves downwardly to cause upward tilting of the table 34 and the casing 313 therefore moves downwardly. The degree of tilt of the table 34 can be varied, even during the operation of the machine, by mounting the support rods 342 for the cam bar 341 so that their lengths can be independently adjusted. The rails 345 on which the rods 342 travel may be removable so as to be exchangeable with others of different profile or inclination.