GB507012A - Improvements in and relating to apparatus for feeding and distributing sludgy materials - Google Patents

Abstract

507,012. Coating surfaces and webs; lost-motion coupling. BAKELITE, Ltd. Dec. 7, 1937, No. 33898. Convention date, Dec. 9, 1936. [Class 95] [Also in Groups VIII and XXIV] An apparatus for feeding and distributing sludgy material on to surfaces, e.g. for applying hydraulic cement to shingle tiles as in Specification 423,694, [Group X], comprises a hopper, a discharge roller forming part of the supporting surface for the material in the hopper and which carries the material from the hopper, a device for controlling the quantity of material carried from the hopper by the discharge roller and for trowelling the material while on that roller, and a bristle device for removing the trowelled material from the surface of the discharge roller and directing it by centrifugal action on to the surface to be coated. In the example the articles to be coated pass on a moving band 26 under two identical coating units. Each unit consists of a hopper 32 containing the sludgy composition, adjustable false ends 118 serving to restrict the effective size of the hopper if desired. The base of the hopper is formed of a discharge roller 50 consisting of hubs 52 and a tubular shell 54 bearing helical grooves 56. An adjustable rubber-surfaced gate roller 58 controls the rate of discharge of the composition and is driven by a chain from a sprocket 82 on the discharge roller, which in turn is driven by a motor 72 through reduction gearing 75 and a chain 74. The peripheral speed of the gate roller is less than that of the discharge roller so as to exert a wiping or trowelling action on the composition in the grooves of the discharge roller. The composition is removed from the discharge roller and thrown on to the surface to be coated by a rotary brush 108, preferably having cadmium-plated steel bristles. To prevent jamming when a large particle of composition is caught in the nip of the rollers, the gate roller drive is effected through a clutch which permits the gate roller to be driven by friction from the discharge roller for a limited fraction of a revolution. The gate roller 58 is fixed on a shaft 92 on which is mounted the driving sprocket 84 held in position by a collar 93. Two projections 94 on the sprocket co-operate with equivalent projections 100, provided with adjusting screws 102, on a clutch member 96 in the form of a hand wheel splined to the shaft by a key 98 which permits axial movement. The clutch member 96 is held in the driving position by a spring 104, a set screw 106 enabling the clutch to be held rigidly in or put of position as desired. When a large particle is caught in the nip of the rollers, the surface speed of the gate roller accelerates to that of the discharge roller, the pins 100 moving ahead of the driving pins 94. If this limited movement is insufficient to pass the particle, the operator disconnects the drive temporarily by pulling the hand wheel 96 axially, and if necessary gives the gate roller an oscillatory movement to discharge the particle.