Patent GB-271990-A (GB)
Title: Improvements relating to apparatus for and process of manufacturing laminated sheet material
IPC: H01B3/04
Filed: 1926-04-09
Abstract: 271,990. Allis-Chalmers Manufacturing Co., Furnas, W. C., and Rusch, E. C. April 9, 1926. Making compound fabrics.-Apparatus for producing laminated sheet material comprises a travelling-band conveyer, means for supplying a web of fabric to the conveyer, means for supplying fluent binding material in a layer on the web, means for superposing a second web, and means for distributing the binder below the second web comprising a device for stroking the superposed web in a direction having a component transverse to the edge of the web and to the direction of travel of the conveyer. The stroking device preferably strokes the sheet from the centre in two directions each having components both opposite and transverse to the direction of travel of the sheet, and the means for supplying binder includes a conduit with a discharge orifice or orifices moved to and fro across the material. The apparatus is described as applied to the manufacture of laminated sheet material for electrical insulation comprising sheet or flake mica enclosed between sheets of tissue paper. The apparatus comprises an endless belt 4, Fig. 2, carried on rollers 5, 5<a>, at the ends and supported intermediately. The conveyer belt preferably consists of bars or plates 6, Fig. 4, carried by chains 7 driven by sprockets on the shafts of the rollers 5, 5<a>, Fig. 2, which are driven by a motor 8. A roll 12 of sheet fabric such as tissue paper is carried under the frame of the machine, and the paper web passes therefrom over the roller 5 and is laid on the conveyer belt. As the paper travels, flakes 16, Fig. 1, of insulating material such as sheet or flake mica are laid thereon so as to overlap and cover the whole surface of the paper. An insulating fluent binder is deposited on the mica, in such quantity as to pass through between the flakes, from a vessel 18, Fig. 2, by means of a flexible conduit comprising articulated pipes 19, 20 rotatably connected by a joint 23. The pipe 20 has branches 201, 202, Fig. 1, each provided with a double nozzle 21. The pipe 20 is swung across the conveyer by mechanism which includes a lever 25 having a forked end 26, a bar 28 engaging with the lever 25 and reciprocated by means of a slotted cam disc 32 rotated through gearing 34 by a rod 36 from the motor 8. The binder is preferably discharged in the form of spray, or of dust when a powdered material is used. After passing the nozzles 21, the paper is drawn over a metallic plate 38, and a covering sheet of tissue paper fed from a roll 40 over guiding rolls 41, 42 is deposited on the material. The material then comes under the influence of a smoothing device which removes wrinkles from the paper, spreads the binder uniformly between the layers and forces out the excess. The smoothing device consists of one or more rotating brushes 45, 46, Fig. 1, arranged transversely of the travelling fabric and rotating in such a direction as to exert a brushing or smoothing effect towards the edge of the material. The outer ends of the brushes are mounted in bearings 47 and the inner ends in bearings 48, and the brushes are geared together and rotated by gearing from the shaft 36. The brushes may be wholly or partly enclosed in an enclosure of sheet metal. Each brush may comprise a central shaft and a sectional stock divided longitudinally and held on the shaft by bolts so as to permit easy removal and renewal. The bristles are soft and preferably disposed in helical rows. The material passes from the brushes into an enclosure 54 in which is disposed a heating element H consisting of steam pipes or electric resistances for the purpose of evaporating the solvent of the binder, or, when a powdered binder is used, of softening the latter to cause adhesion. The upper part of the enclosure 54 is provided with a removable cover-plate 56 and is preferably open at the rear and lower sides to permit the entrance of a current of air, a discharge funnel 57 with an exhaust fan 59 being provided. The flnished material is taken up on a roll 55 which is driven from the shaft of the roll 5<a> through a clutch arranged to slip so that the material is held in taut condition during winding. The required tension is obtained by means of a friction roll 61, the mounting of the latter including an adjustable spring device. The mounting of the feed roll 40 preferably includes a shaft 63 rotatably mounted in a support carried on the upper side of the frame and provided with arms 64 secured to the ends of the shafts. The ends of the arms are provided with slots 65, 67, the roll 40 being disposed in the slots 65 and secured therein. As the roll 40 is exhausted, a reserve roll 68 can be swung into position after removing a locking pin from the arm 64. The feed roll 12 may be mounted in the same manner. A rod or roller 71 is carried by one or more pivoted arms 72, the rod or the arms 72 being loaded by a weight or spring so that the rod 71 bears on the paper fed from the roll 40. In case of breaking of the paper, the rod 71 drops, operating a switch 73, which operates a bell or signal 74, and may also actuate a no-voltage release to stop the motor 8.