GB759484A - A new or improved machine for cutting sheet material into small pieces - Google Patents

Abstract

759,484. Severing by grinding GLENDINING, P. N. Nov. 27, 1953 [Dec. 5, 1952], No. 30995/52. Class 60 A machine for cutting sheets of hard material such as germanium into a series of parallel strips comprises a cutting wheel 6, Fig. 3, a work slide 5 movable in the direction of the axis of the cutting wheel on a main slide 4 which is itself reciprocable in a direction at right-angles to this direction under the action of a rotary cam drum 34, means for advancing the cutting wheel towards the work slide at the commencement of alternate strokes of the main slide and for withdrawing it at the end of each of such stroke, and means for indexing or traversing the work slide on the main slide to the extent required for the next cutting stroke and while the cutting wheel is withdrawn from the work slide. The main slide 4 is reciprocated on the machine bed 1, Figs. 3 and 5, by the cam drum 34 which is carried on a driven shaft 18 beneath the bed and has a helical slot 35 engaged by a roller 36 on a pin 38 depending from the slide; the pin is guided in a longitudinal slot 39 in the bed and the slot 35 is shaped to advance the slide at uniform speed during the cutting stroke and return it more rapidly. The stepped transverse movement or index of the work slide 5 on the slide 4 occurs after the return movement of the latter (while the cutting wheel is raised) and is effected by the engagement of a depending nut 59 on the work slide with a screw 58 which extends across and is journalled in the slide 4. The screw is intermittently rotated to index the work slide by a cam 40 on the shaft 18 acting through a one-way clutch 57. The clutch, which comprises an outer cylinder 70 rotatable over a core on one end of the screw 58, has a radially-projecting arm 62 whereby it is actuated once every revolution of the shaft 18 by a spring-pressed push rod 63 operated by the cam 40 through a lever 67; the cylinder 70 rotates upon upward movement of the push rod without driving the screw, but on its return rotation under spring action is clutched to the screw so that the work slide is indexed forward one step, the extent of this movement being determined by a stop screw co-operating with the arm 62. To permit the screw 58 to be turned by a hand wheel 84 in setting up the machine the one-way clutch 57 is arranged to drive the screw through a friction clutch 88. The cutting wheel 6 is in the form of a metal ring 7, Fig. 10, having embedded diamond, &c., particles and clamped between plates 8, 9 on a spindle 11 which is journalled in a housing 92 removably mounted in one arm 13 of a head 14 pivoted on a spindle 15 carried by a bracket 16, Figs: 3 and 5, upstanding from the machine bed; rotation of the spindle 11 is effected from a motor through a belt-and-pulley drive, one pulley 100 of which is carried on the spindle 15. The pivoted movement of the head 14 for lifting and lowering the cutting wheel at opposite ends of each cutting stroke is controlled by a cam 41 on the shaft 18 acting through a lever 43 on a spring-pressed push rod 46 which at its upper end engages a screw 47 in an arm 17 projecting from the head, a spring 49 providing for the lifting of the cutting wheel at the end of the cutting stroke; the screw 47 is adjustable to advance or retard the moment of operation of the push rod and its head 48 is graduated for co-operation with a pointer 54. The cam shaft 18 is driven from a motor through a hand-controlled friction clutch (Fig. 11, not shown) which is disposed on a spindle arranged parallel to the cam shaft and, when engaged, drives a gear 24 fixed on the latter shaft; the drive from the motor to the clutch is through a gear 20 rotatable on the cam shaft and meshing with a gear rotatable on the second spindle. A hand - wheel 103, Fig. 3, permits rotation of the cam shaft when setting up the machine. The machine is automatically stopped after the completion of a series of cutting strokes by the engagement of a switch 104 adjustably carried from the bed 1 with a button replaceably mounted on the work slide and of the desired axial length to stop the machine at the appropriate time. The sheet 107 to be cut is secured by shellac or pitch to a sheet 108 of glass or mica carried by a metal plate 109 which is mounted on spaced pins 110 upstanding from the work slide. If desired, a sheet may first be cut into parallel strips as described above and then, with its backing, turned through right-angles on the work slide for cutting into squares or rectangles.