GB747396A - Improvements relating to duplicating or printing machines - Google Patents

Abstract

747,396. Duplicating machines; sheet-teeding devices. FORD, Ltd., F. R., and FORD, R. M. Oct. 9, 1953 [Oct. 10, 1952], No. 25374/52. Class 100 (1). A printing or duplicating machine has, in combination with a sheet ,feeding device adapted to engage and displace the topmost sheet of a pile placed on a feed tray, guide members or fences 16, 17 adapted to be moved in unison to corresponding extents towards and away from the longitudinal centre of the feed tray by means of a translatorily displaceable control member 32, or a rotary knob which is operatively connected with the guide members through mechanism which by movement of the control member (or peripheral movement of the rotary knob) not substantially exceeding tne width or length (whichever is the greater) of the feed tray causes movement of the guide members from their extreme outer to their extreme inner positions. The feed tray is shown in Fig. 2 applied to a duplicating machine 10 having a roller feeding device 12 adapted to displace the top sheet of a pile resting on the tray, towards the printing couple. The guide members 16, 17 are mounted for transverse displacement on rectangular blocks 20, 21 slidably engaged in staggered slots 18, 19 and retained by attachment to elongated strips 22, 23, Figs. 5, 6, bearing against the underside of the feed tray. The strips 22, 23 are connected to move equally in opposite directions by chains 34 passing over pulleys 33. Strip 22 is connected by a link 38 to the control member which consists of a lever 30 pivoted at one end to the underside of the tray and provided with a handle 31 at the other. Movement of the handle will cause inward or outward displacement of the guide members. Flanges 24, 25 on the guide members are adapted to engage and locate the sides of the pile 55 resting on the tray. The engaging pressure of the guide membeis can readily be judged by the operator by estimating the resistance to motion of the operating handle 31. The mechanism may be retained in set position by its own inherent friction or separate friction retaining means may be provided. The feed tray is tiltable to allow the height of the pile to be kept substantially constant. Supporting brackets 46 carry a cross-shaft 49 on which the tray is mounted by brackets 48. The rearward end of the tray is supported on a rotatable eccentric 51 which may be turned by a knob 5 to lift the tray. The eccentric is retained in adjusted position by a pawl 54 and ratchet 53. Retaining elements may be provided fitting in slots 39 in the flanges of the guide members, these elements consisting of casings 41, Fig. 4; enclosing a block of sponge rubber which is compressed by insertion &c. into the slot to cause the end to bulge as at 45, and to engage the sides of the pile along a narrow line. Knobs 40 are provided on the casings 41. In an alternative arrangement, instead of using chains to connect the strips 22, 23 for equal and opposite movement, the strips may be formed on opposed edges with rack teeth and connected by meshing engagement with a central gear-wheel on a fixed axis.