Patent GB-990431-A (GB)
Title: Improvements in and relating to grinding machines
IPC: B23Q7/16
Filed: 1962-10-04
Abstract: 990,431. Surface grinding machines. COMPAGNIE DES MEULES NORTON. Oct. 4, 1962 [Oct. 11, 1961], No. 37635/62. Heading B3D. A machine for grinding billets, bars and other workpieces comprises a grinding-wheel 3, Fig. 1, mounted on a pivoted arm 2, a carriage 5 reciprocable in relation to the grinding-wheel, one or more work tables 18, Fig. 2, which are carried by the carriage for vertical movement and, in the grinding position, are arranged to be flush with the flat upper surface 15 of the carriage so that a workpiece can be located against a stop disposed inwards of the edge of the carriage to provide a ledge 16a, and means for clamping the workpiece during grinding and ejecting it thereafter, the stop and ledge 16a being arranged to act during the lowering of the tables to index a workpiece to present a new face for grinding. The carriage 5, which is reciprocable on guides 9, 9a by a rack-and-pinion drive 12, 13, carries each table 18 for arcuate movement between its upper and lower positions by links 19 on a shaft 22 which is operable through a lever 23 by a pneumatic jack 26 and controlled by an hydraulic damper 28 through a further lever 24; the lower position of the tables may be set by an adjustable stop. The work clamping and ejecting means comprises one or more members having arms 34, 35, Fig. 4, on a shaft 36 which is mounted in the carriage 5 and operated through a lever 37 by a pneumatic jack 39. In the operation on a square-sectioned bar 43a, Fig. 5, the bar is fed down a shoot 17 on to the table 18 when the latter is in upper position flush with the upper surface 15 of the carriage 5 and the members 34, 35 are so actuated as to cause the arms 34 to press the bar against the stop 16 and position its upper face for grinding. After this operation the arms 34 are withdrawn and the table 18 is lowered; during the initial part of the movement of the table, the table and bar are caused to rise slightly by the links 19 and then, as the table descends, the bar is held back by the ledge 16a as shown in Fig. 7 until finally it drops down on to the table with its next side uppermost. Upward movement of the table is then followed by clamping by the arms 34 and repositioning of the bar for grinding. The arms 35 are swung to eject the bar when all its four sides have been ground. The grinding of each of the two opposite large sides of a rectangular bar is also effected with the table 18 in its upper position and the bar clamped by the arms 34 against the stop 16 but the narrower sides of the bar are ground with the table in a lower position and the bar clamped against the end face of the carriage 5, as shown in Fig. 13. The ledge 16a again serves, in conjunction with the lowering of the table, to tilt the bar from its flat to upstanding position (Fig. 13), such movement being completed by the action of the arms 34; movement of the bar from the position of Fig. 13 to a flat position is caused by a rapid clockwise movement of the arms 35. The shaft 36 mounting the arms 34, 35 serves as a torsion bar to effect uniform clamping even of warped bars.