Patent GB-1418188-A (GB)
Title: Apparatus for supporting a length of sheeting at a working site
IPC: B65H20/06
Filed: 1973-04-26
Abstract: 1418188 Endless conveyer belts VICKERS Ltd 20 June 1974 [26 April 1973] .19987/73 Heading B8A Stencil sheet material from a roll 21 is fed around a cylindrical working site defined by a cylindrical cage 2 having four circular supporting ribs 3, by the action of an endless belt 1. The latter passes around on the interior surface of the cage 2, and around the outer surface of an idler pulley 6, to pass to the outside of the cage, around the outside of a cylindrical surface 7 concentric with the axis of the cage 2. The belt then passes around an idler pulley 6<SP>1</SP> to pass back to the interior of the cage 2 again. At each of its outer edges, the part of the belt 1 within the cage 2 is supported on respective circular drive bands 4, 4<SP>1</SP>. Each of the latter is carried by an annular member 5 (or 5<SP>1</SP>) coaxial with, and forming, an end cap to the cage 2. The edge of the belt 1 is engaged between the outer periphery of the band 4 and the inner peripheral surface of an annular member 8. The members 5 and 5<SP>1</SP> are driven by toothed belts 12, 121 respectively, from a drive shaft 130. Further belts 14, 14<SP>1</SP> (Fig. 4), disposed respectively around the members 5, 5<SP>1</SP>, do not pass around the entire periphery of the latter, but pass around a part of the circumference of each pulley 6, 6<SP>1</SP>, and around the outer surface of a roller 18. These belts and the belt 1 thus form nips into which the sheet 21 is fed. After passing around the cage 2 to which it is held by the action of suction applied through a circumferential series of apertures 19 formed in each of the ribs 3, it comes out between the pulley 6<SP>1</SP> and the roller 18, and is trimmed off by a guillotine 26. The width of the main part of the sheet 21 can be less than the distance between the belts 14, 14<SP>1</SP>, provided a sufficient length of the greater width is provided at the leading end of the sheet 21 to enable the sheet to reach the effective zone of the suction through the apertures 19. In a modification (Figs. 7 and 8, not shown) the belts 14, 14<SP>1</SP>, are circular and are disposed wholly around the members 5, 5<SP>1</SP>. In addition, a transparent endless sheet having a width which is less than that of the spacing between the belts 4, 4<SP>1</SP>, but greater than the spacing between the belts 14, 14<SP>1</SP>, is disposed on a track similar to that of the belts 14, 14<SP>1</SP>, of the previous embodiment. Instead of the roller 18 however, there are two spaced rollers (102), (102<SP>1</SP>). This arrangement permits the feeding of separate sheets of varying widths. The apparatus may be used to convey two separate webs (27), (27<SP>1</SP>) (Fig. 6, not shown) supplied either from a single roll or from separate rolls, as in the case of a stencil sheet having backing material. The belt may be cleaned by the action of brushes 28, supplied with solvent from a bath 29. The internal and external diameters of the belt 1 are chosen so that the joint of the belt is always located outside of the interior of the cage 2 when the belt stops. The belt may be stopped by the action of its drive motor being controlled by a photo-cell which is responsive to suitable marks on the belt.