Patent GB-960414-A (GB)
Title: Method of and machine for stencil-printing thick fabrics
Inventor: LECKIE THOMAS LIDDLE
IPC: B41F15/08
Filed: 1960-02-03
Abstract: 960,414. Stencil-printing machines. BRADFORD DYERS' ASSOCIATION Ltd. Jan. 26, 1961 [Feb. 3, 1960], No. 3878/60. Heading B6C. The step-by-step carpet stencil - printing machine shown comprises a brushing frame 1, Fig. 1, two main side frames 2 of uprights 3 and horizontal members 4 spaced apart from one another by a distance greater than the width of the carpet to be printed, an entry station 6 to the printing part of the machine, a perforated carpet support 5 spanning the frames 2 and providing eight printing stations defined by vertically movable screens S1-S8, Fig. 3, beneath colour boxes CB1-CB8 (CB shown in Fig. 12), a take-off station 7, a steaming vessel 8, Fig. 2, a washing apparatus 9 and a withdrawal and lapping mechanism 18. The carpet C is moved by engagement of the selvedges thereof by pins 13 upwardly projecting from endless chains 10 at each side of the machine. The chains pass round sprockets, two of which, 14, 15, are carried by shafts 16 and 17, Figs. 10 and 8, and the shaft 17 is intermittently driven. The machine is powered by a continuously running electric motor 19, Fig. 9, driving a shaft 20 carrying cams 22 co-operating with followers 23 controlling valves in pipes supplying hydraulic fluid to rams. Each of these rams reciprocates as the valves open and close, the ram movements being timed to actuate the various machine parts appropriately. Ram 24 drives the shaft 17 through a pawl 131 engaging a ratchet-wheel 132 fixed to a shaft 130 carrying at each side of the machine a gear-wheel 133 which meshes with a gear-wheel 134 rigid with the shaft 17. In the brushing frame 1 the carpet is guided by rollers 32 . . . 38 past a brush 48 which rotates in the mouth of a suction pipe 42 connected to a fan 39 so that fluff detached by the brush is drawn down the pipe to a collector. To prevent the carpet being brushed while it is stationary the brush is allowed to continuously rotate whilst the carpet is moved out of contact therewith by rocking levers 40 on which the rollers guides are swing- ingly mounted. Such movement is effected by hydraulic rams 43 controlled from the cams 22. Rollers 45, 46 guide the carpet on to the chains 10 and the roller 46, which carries pins to engage the carpet under surface, is adjustably braked by a belt brake 90 so as to longitudinally tension the carpet, the selvedges of which are forced on to the pins 13 of the chains by rollers 47. The support 5 is interrupted to receive nine freely rotatable pinned rollers 49 . . . 57, each of which is mounted in the side frames 2 between adjacent printing stations so that the upper surface of the support is tangential to the roller surface and the pins project above the support to engage the carpet. An end pinned roller 58 is positively driven from the shaft 17 and thus contributes to the longitudinal tensioning of the carpet. The means by which the carpet is engaged and intermittently moved are the subject of Specification 960,417. In travelling beneath each screen S the carpet slides over the support 5 comprising a metal table having perforations which allow suction to be applied to the underside of the carpet through the corresponding suction box SB1 . . .  SB8. The colouring matter is supplied to each screen S from a narrow bottomless colour box CB extending completely across the screen. Its narrow end walls are adjustable in height through devices 73 themselves secured to lifting rails 74. Each screen consists of gauge 75 stretched across the underside of a metal frame 76. Along the side edges the meshes in the gauze are closed whilst along the end edges the meshes are closed over an area at each end large enough to receive the complete colour box. The boxes and the mechanism by which they are carried are preferably constructed as disclosed in Specification 960,415. The colouring matter required for each box CB is supplied to that box from a container 80 by a pump 81 through a pipe 82 containing a manually adjusted valve 83 to distributers 84. An electrical probe 85 responsive to the liquid level is provided in each box and is electrically connected to control the operation of the pump 81. To avoid the risk of colouring matter escaping between the box and screen when they are lifted at the end of each printing operation, the screen is moved through a slightly greater distance than the box. All the screens S are carried by rails 77, one at each side. These rails are lifted vertically to allow the carpet to move whilst the rails 74 are vertically movable and horizontally reciprocable through apparatus comprising a plurality of rollers 91 carried by crank levers 92 pivoted to the frames 2 at 93 and pivotally connected at their lower ends with operating bars 94, one at each side. The two bars 94 are reciprocated horizontally through inclined rods 154 by a ram 25 when the colour boxes are to be raised. To reciprocate each colour box over the screen beneath it, the rails 74 are caused to slide over the rollers 91. Each is engaged by a sleeve 98 which forms a housing for a pivot pin 99 that enters one end of a connecting rod 150. The other end of this rod is pivotally connected to a crank 151 on a cross-shaft 152 rockable through a crank 153 by a ram 26, the ram movement being controlled through cams 22 so that each colour box makes one stroke each time the carpet is halted for printing. The risk of inaccurate printing is counteracted by applying positive pressure through the suction boxes to the underside of the carpet whenever it is moved (see Specification 960,416). The risk is also counteracted by the rollers 49 . . . 57 which ensure that the carpet centre does not lag behind the selvedges during printing. At the end of the printing the carpet runs over the pinned roller 58 in the take-off station 7 and forms a loop 181 which allows the carpet to move continuously through the vessel 8 and apparatus 9. The carpet enters the steaming vessel 8 through a slot 182, Fig. 14, and to ensure that the wet pile surface remains clear of the slot walls an air blast from a nozzle 183 forces the undersurface of the carpet against one wall of the slot. From the washing apparatus the carpet is lapped into a trolley 145 and conveyed to a drying apparatus. Alternatively it may be dried before being lapped. Specification 895,706 also is referred to.