Patent GB-777842-A (GB)
Title: Apparatus for printing or coating
Inventor: HUEBNER WILLIAM CARL
IPC: B41M1/12
Filed: 1954-06-25
Abstract: <PICT:0777842/III/1> An apparatus for printing and casting upon receiving material in predetermined configurations comprises a hollow, rotatable cylinder having passages adapted to conduct a fluid from within the cylinder to the exterior surface, means for conducting a fluid into the cylinder, a stationary housing surrounding a portion of the periphery of the cylinder, means in the housing adapted to supply a fluid directly upon the exterior surface of the cylinder, means for guiding receiving material in a path closely adjacent a portion of the exterior surface of the cylinder and means for creating an electrostatic field of force extending through the receiving material and including a first electrode means within the cylinder and a second electrode means externally of the cylinder and spaced from the surface to effect transfer of the mingled fluids from the exterior of the cylinder to the receiving material.  A hollow cylinder 23 about which the sheet or web of material to be coated or printed passes is rotatably mounted in end supports.  An insulated tube 54 within the cylinder supports an electrode 55, two segments 57, 58 with bladelike projections 61 and a wiper 63 contacting the inner surface of a cylinder 43 coaxial with the cylinder 23.  The cylinders 23, 43 have spaced end closure members connected by a perforated annular boss on the closure of cylinder 43 which fits into a groove in the closure of cylinder 23 whereby a fluid introduced into a bore mounted in an end support and coaxial with the cylinders passes to the space between the closure members through the perforated boss to the space between the cylinders and through apertures connected by grooves to the outer surface of the cylinder 23.  The surface of the cylinder is covered by a narrow metal strip having protuberances on one side to space the strips and allow passage of fluid.  The cylinder is partly surrounded by longitudinal shields 78-81.  The shields 80, 81 have apertures 109 and 118 and all the shields have flanges secured to spaced upright members 82, 83.  The lower ends of members 82, 83 have sealing pads fitted into channel members connected by bolts to a top closure member 94 and separated from members 82 and 83 by springs whereby tightening the bolts raises the seals from the surface of the cylinder 23.  A conduit 95 communicates with the space between the members and with the surface of the cylinder.  Conduits 107, 116 which may each comprise a series of conduits communicate with the space between the shields which contain electrodes 165, 166.  The space between the shields 80, 81 and the cylinder contain electrodes 167, 171. The shields 80, 81 have clips 126 removably fitted with wipers 125.  The lower ends of shields 78, 80 are fitted to a member 90 having an inlet 111 to a bore 122 and a sealing pad for adjustable engagement with the surface of the cylinder 23.  The bore 112 communicates with a conduit 114 connected to a conduit 115 connected to a source for creating a partial pressure.  A similar member 91 is fitted to flanges at the other ends of the shields and a bore 120 has an inlet communicating with the surface of the cylinder and an outlet communicating with conduits 122, 124, the conduits 115, 124 may be interconnected.  The members 90, 91 have sealing pads similar to those previously described.  A cylinder 22 is rotatably mounted below the cylinder 20 and has an insulator 67 mounting an electrode 68 and an adjustably mounted shielding means comprising electromagnets 70, 71 with pole pieces 73, 74.  A wiping roller 127 is adjustably and removably mounted adjacent the roller 23.  The roller comprises a perforated surface fitted with a series of wipers 137 and a central member with a groove 142, and apertures 143.  Liquid retained by the wipers from the cylinder 23 is removed by air or other fluid under pressure which issues from the groove 142 from a conduit 130 supporting the roller and is withdrawn through conduits 154, 155 and 124.  The roller is surrounded by a shield connected to plates 150, 151, and having a part flexible connection with the tube 124. Electrodes 157 are provided on a bracket adjacent the cylinder 23 whereby a sheet or web of material to be printed or coated passing from a roller 156 over the cylinder 22 is precharged before passing round the cylinder 23.  Alternatively the web or sheet may be passed round rollers 160, 161 and pre-charged by electrodes 163 before passing round the roller 23.  A shield 77a is provided between the cylinders 22 and 161 to prevent escape of fluid.  The apparatus may be used for forming an image on a sheet or web by covering the cylinder 23 by a shell on the non image parts and introducing liquid to the surface of the cylinder through conduit 95.  A switching circuit connecting the electrodes is so arranged that electrodes 55, 68, are energized together with electrodes 171, 157.  The wiping means 125, 127 wipe liquid from the non-image surfaces.  To effect a uniform coating wipers 125 are removed and wiper 127 is displaced and an imperforate shell is used.  Liquid may be supplied to the interior of the cylinder through the end conduit and a solvent may be supplied through conduit 95 to the surface of the cylinder.  Alternatively the solvent may be supplied internally and the liquid externally.  In producing image formation by smoke, vapour or gaseous suspensions, wipers 125 are removed and wiper 127 from the surface of the cylinder 23. The circuit is operated to energize electrodes 163, 165, 166, 167, 57, 58, 171 and smoke is introduced by the conduit 107.  Fluid such as adhesive may be introduced internally of the cylinder with the wiper in position and with electrodes 157, 171, 55, 68 energized. Smoke may be introduced internally of the cylinder with no wipers in operation and electrodes 162, 167, 170, 57, 58 and contact 63 energized fluid may be introduced to the external surface of the cylinder.  Coating may be applied by introducing coating smoke or liquid through the conduit 107 only and a further liquid through the conduit 95.  Specification 618,512 and U.S.A. Specification 261,538,389 are referred to.