GB418742A - Improvements in or relating to machines for grinding, polishing and similar treatment of work-pieces - Google Patents

Abstract

418,742. Centreless grinding. ROBLING, F., 145, Broekslootkade, Rijswijk, Holland. April 24, 1933, No. 11990. Convention date, April 23, 1932. [Class 60.] A machine for grinding or polishing straight or curved work pieces with a circular or non- circular cross-section has the work supported in at least three points of its circumference by means which rotate around the work, such means consisting either of tools only or of tools working in conjunction with one or more supporting members. In one form, two grinding discs a mounted on a rotary plate d cooperate with a steady roller b carried by a member A sliding in a sleeve i secured to the plate, the work c being shown as a curved rod of circular section. The plate d is mounted on a hollow shaft d' and is driven for the planetary movement of the wheels round the work by means of a gear e. Each grinding-spindle o is driven by toothed gearing m, n and shaft l from a gear k, one of which engages directly and the other indirectly through an idler w with a stationary gear j, the grinding wheels being thus rotated on their axes in opposite directions. Casings h enclosing the grinding wheel spindles and their driving gears m, n are secured to bushes mounted in sleeves g and carrying tooth segments u engaged by racks x adjustably mounted on a slide s. In order resiliently to force the tools and guide roller equally against the work piece, a rod r is constrained to move axially in the hollow shaft d<1> by means of a lever p weighted at v. The member r engages one arm of two bellcranks H, one of which is connected to the slide s to impart inward pressure to the grinding wheels and the other of which is connected through a slide s<1>, spindle z<1> and lever mechanism E, B to the member A carrying the guide roller which is thus pressed towards the work with the same force as the tools. The pressure between the tools and work may be adjusted during the working operation by varying the position of the weight v. Instead of the yieldable pressure on the work piece obtained by use of the weight v, the free end of the lever p may be rigidly guided for accurate adjustment of the wheels and guide roller. In order to adjust the grinding discs for work of different sizes the casings are adjusted by screws z which move the racks relatively to the slide s. The adjusting spindle z<1> is used for setting the guide roller b.