Patent GB-1064348-A (GB)
Title: Machine for grinding the cutting edge of a die
IPC: B24B19/20
Filed: 1965-06-08
Abstract: 1,064,348. Grinding. WALBERT EQUIPMENT CO. June 8, 1965 [June 29, 1964], No. 24229/65. Heading B3D. A machine for grinding the cutting edge of a die B of the type used for cutting openings in envelope material comprises a die support 34 mounted in a frame for oscillation about, and reciprocation along, a fixed axis relative to a template 84 carried by the frame and provided with a track 109 conforming to the shape of the cutting edge of the die, means on the frame for carrying a grinding element 47 in fixed relation to the template, and the die support having a part 110 to engage the track of the template during movement of the die support for controlling contact of the cutting edge of the die with the grinding element. The die support consists of a cylinder 34 mounted on a shaft 33 which is guided for reciprocating movement by balls 27 in longitudinal tracks in sleeves 25, in turn supported for oscillatory movement by balls 23 in races 21 mounted in bearing blocks 14 carried by cross-members 13, 14 of the frame. The cross-members are secured to front and rear guide rails (3, 4, Fig. 1), the front rail slidably receiving a slide (88), which can be accurately located in position by a threaded pin (126) in a block (125) secured to the rail and releasably secured in position by thumbscrews (137). The template (84) is troughshaped (Fig. 7) and has a forward flange (86) which is clamped in a slot in the slide (88) by thumb-screws (136) and a rearward flange (87) which is held by clamps (102) on the rear rail (4), the clamps being in the form of bell-crank levers operable by eccentrics controlled by a handle (108). The part 110 for engaging the track 109 of the template conslsts of a cylindrical member having portions of large and small diameter which are selectively engaged with the track according to whether the inside or outside of the cutter B is to be ground by adjustment along a rod 116 having a threaded portion (117, Figs. 5 and 9) engaging an arcuate shoe (112) received in an annular slot (111) in the cylinder. The shoe is retained in the slot by a plate (113) having an opening for the passage of the rod (116) and a slot (115) through which a screw (114) passes into the cylinder (34). The plate rotatably carries a screw (131) which engages threads (134) in a groove (135) and, when rotated, adjusts the plate, and hence, the shoe (112) and rod (116), relative to the cylinder to position the cutter B relative to the grinding element, the screw (114) then being tightened to clamp the plate to the cylinder. A post (41, Fig. 1) extends upwardly from the rear rail (4) and has a base (42) for a support (44) for a vertically adjustable slide (48) which is connected by a block to a plate (53). The upper end of the plate (53) is joined by a horizontal pivot (54) to a further plate (55) on which is a vertically adjustable plate (57) having a releasable clamp (61) for a motor (46) provided with a housing (73) for the spindle of the grinding element 47. The housing 73 is releasably secured to the lower end of the plate 53 by a clamp 79 whereby, when the clamp is released, the motor 46 can be moved about the pivot 54 to move the grinding element to an inoperative position. In operation, a cutter to be sharpened is removed, together with its saddle A, from the envelope making machine and mounted on the cylinder 34. The template corresponding to the shape of the cutter is mounted on the slide 88, the control rod 116 at this time being removed from the cylinder, and the template is secured to the slide by the thumb-screws (136, Fig. 1). The slide is then adjusted by means of the screw (126) so that the centre of the opening (119) of the template is aligned with the centre of the saddle, the saddle then being clamped in position by the thumb-screws (137) and the rear of the template clamped to the rail (4) by the clamps (102). The control lever 116 is replaced in the plate 113 with the follower 110 positioned so that its larger or smaller portion 121 or 122 is engaged with the track 109 according to whether the inner or outer side of the cutter is to be ground. The follower is adjusted with respect to the cutter by slackening the screw 114 holding the plate 113 to the cylinder 34 and rotating the screw 132, the screw 114 then being retightened. The grinding element is brought to the level of the cutter by adjustment of the hand wheel 52 and the control rod actuated so that the follower 110 follows the track 109. The grinding element may be withdrawn from the cutter by releasing the clamp 79 to permit the motor 46 to be swung about the pivot 54.