GB1419793A - Grinding machine - Google Patents

Abstract

1419793 Grinding CINCINNATI MILACKON-HEALD CORP 21 March 1973 [27 March 1972] 13649/73 Heading B3D A grinding machine for generating a surface of revolution on a workpiece comprises a workhead mounted in a base 11 for rotating the workpiece about the axis of the surface of revolution, a wheelhead for rotating an abrasive wheel about its axis, a feed box 16 containing electrical circuitry for controlling relative movement of the workhead and wheelhead both parallel to and perpendicular to the axis of the surface of revolution in accordance with predetermined grinding parameters to produce a grinding cycle, the circuitry having adjustable elements for setting the parameters, a first circuit board insertable in the feed box to render the adjustable elements operative, and a second circuit board insertable in the feed box to render the adjustable elements inoperative and to substitute in the electrical circuitry fixed elements in place of the adjustable elements. The second circuit board is insertable in the feed box in place of the first circuit board so that the electrical circuitry is rendered inaccessible and the adjustable elements always accessible whether operative or inoperative. When the second circuit board is inserted an operator cannot vary the parameters set into the machine. The workhead is disposed under a cover 13 having a window 14 and is slidable transversely in the base by an hydraulic cylinder. The wheelhead is driven by a motor 15 and has a spindle carrying the abrasive wheel. The wheelhead is movable longitudinally by an hydraulic cylinder and has an iscillator for effecting short reciprocations of the wheel during grinding. Cross feed is effected at controlled force by an hydraulic cylinder and at a controlled rate by pulses delivered to a stepping motor. The adjusting elements are accessible on a control panel 17, Fig. 2 of the box 16 and may be of the potentiometer type, e.g. finishing time element 22, rough spark-out element 20, or of the digital switch type, e.g. new wheel compensation element 18, and first and second size reductions elements 31, 32. The electrical circuitry is in the form of a number of circuit boards one or more of which control each of the functions of the machine. Each function is indicated on a sequence board 50, Fig. 34, having indicator lamps 52 adjacent locator plates 53 which list the circuit board or boards operative for each function of the machine. In the event of failure of any one function, an operator can observe from the lamps which function is defective and, from the plates 53, the circuit board or boards at fault which are easily replaced. When the first circuit board 39, Fig. 4, is inserted in the machine, the various adjusting elements, 29, 30, 31, 32, 24, 33 and 25 can be adjusted by a "set-up" operator to determine the various parameters of the machine cycle. The board 39 can be replaced by a circuit board 39<SP>1</SP>, Fig. 7, having sets of resistors and diodes for connection in decades to match the values of the adjusting elements which, although accessable, are inoperative so that the normal operator of the machine cannot adjust the parameters of the machine. In another circuit boards 39 ALT, Fig. 33, jumpers are used to connect the resistances and diodes in accordance with a binary number system.