GB842489A - An impregnating machine for materials having low permeability - Google Patents

Abstract

<PICT:0842489/III/1> A machine for wetting and for impregnating with liquid materials wood fibre hardboards in plate, sheet or strip form, comprises, as shown, two pairs of impregnating rollers 4, 5 and 6, 7 and a pair of cleaning rollers 8, 9 located in sequence, the lower rollers being slightly displaced, in the direction of feed, from the upper rollers. The upper rollers, which are plain steel cylinders, are journalled in bearings rigid with the frame 1, and the lower rollers in bearings carried by swinging arms 34, which are pivoted to the frame at 35 and connected at their other ends to the pistons of pneumatic cylinders 65, which are pivoted on the frame 1. The sloping ends of the arms 34 abut against wedges 70 carried by rods 71 which may be adjusted axially by the rotation of worm wheels 73, threaded thereon, by worms on shafts 76 carrying hand-wheels 77. Each such shaft is connected to the corresponding one on the other side of the machine through a dogclutch which is disengaged by a lever 84 connected to a handle (not shown) when the hand-wheels 77 are to be operated, for varying the gap between the rollers independently of the pressure exerted by the pistons 65. The lower rollers 5 and 7 dip into constant-level water troughs 112, and each is formed by a cylindrical tube 36 (Fig. 7B) having an ebonite mantle 37 and an outer layer of rubber 38 having parallelopiped recesses 39 arranged in staggered rows with their long axes parallel with the axis of the cylinder. The roller 9 is similar, except that the outer rubber layer is smooth. The upper rollers are driven by chainand-sprocket gearing from an electric motor (not shown) and the lower rollers are friction-driven by spring-pressed rollers 40 which are driven by chains 43 trained around sprockets on the shafts of the upper rollers. Adjustable guides 12 are placed in front of the rollers to support the sheets, and a spring-pressed scraper 126 removes water etc. from the finishing roller 8. A control system is provided for adjusting the air-pressure in the cylinders 65.