Patent GB-1142190-A (GB)
Title: Machine for applying a coating material to a workpiece
IPC: A43D11/00
Filed: 1968-02-23
Abstract: 1,142,190. Coating apparatus. J. S. KAMBORIAN. 23 Feb., 1968 [13 March, 1967], No. 8939/68. Heading B2L. Apparatus for applying to a predetermined area of a workpiece a stiffening coating of predetermined cross section comprises a worksupporting mask having an opening corresponding in slope to said area, a resilient deformable pad located above the mask for holding the workpiece thereon, a framework located above the pad and having an inner periphery complementary in shape to the mask opening, means for drawing the portion of the pad located above the mask opening and lying within said inner periphery upwardly into the framework to form a hollow portion having a cross section conforming to said predetermined cross section, means for maintaining the portion of the workpiece lying above the mask opening in contact with the surface of said hollow portion, and means for filling the space within the mask opening with coating material. A workpiece thus coated may be either a stiffener for the heel portion of a shoe, or a stiffened toe portion of a shoe. A fixed frame 10 supports a tank 12 having heating coils for maintaining thermoplastic coating material therein in molten condition. An air motor 14 is pivoted at 16 to frame 10, and has a piston rod 18 pivoted at 20 to one end of a frame 24, the other end of which is pivoted at 26 to frame 10. A depending bar 36, rigid with frame 24, carries a block 38 which is submerged in the coating material and has a horizontal bore 40 closed at both ends. One end of bore 40 communicates with a horizontal tube 42 rigid with block 38. The other end of bore 40 communicates with one end of a bore 48 in a horizontal rod 86 rigid with block 38. The closed end of bore 48 is formed with radial ports 92. An air motor 32, rigid with frame 24, has a piston rod 34 connected by a depending bar 50 with a tube 52 which is slidable on tube 42 and is provided at its outer end with a ball valve (58). A rod 64, journalled on frame 24, is in screwthreaded engagement with a block 70 slidable on piston rod 34. Rod 64 may be turned by a knob 72 for varying the position of block 70, engagement of which with a nut 270 on piston rod 34 thereby determines the stroke of motor 32. An air motor 74, rigid with frame 24, has a piston rod 76 rigid with a frame 78 slidably mounted on frame 24. An applicator 98, rigid with frame 78 and provided with a heating coil 272, is formed with a slot 110 bounded on one side by a sharp scraping work-engaging edge 108. A depending member 96 connects applicator 98 with a tube 88 which is slidable on rod 86 and is closed at its ends with plugs 90. A bore 114, formed in member 96, is provided with a ball valve 126 and communicates with slot 110 and also with the interior of tube 88 via an aperture 112 formed therein. A structure 134, pivoted intermediately at 132 on frame 78, carries at one end a roller 136 positioned adjacent applicator 98. A spring 138 biases roller 136 upwardly and a screw 140, carried by the other end of structure 134, into engagement with frame 78. A frame 144, secured to frame 10 above frame 78 has a rectangular opening closed by a thin flexible mask 150 which is held'in position by clamps 152 and is formed with an opening 154 shaped to the required coated area of. a workpiece. The latter may be pressed against mask 150 by a rubber pad 190 comprised in a work holder 173. Pad 190 is secured to longitudinal bars 184, 188 and lateral bars (182), (186) of holder 173, said bars being rigid with a plate 172 at the edges of the latter. Inwardly-positioned longitudinal bars 208, 210 slidably support end blocks 220 having shaped inner surfaces. Lugs 224, rigid with the respective blocks 220, are in screw-threaded engagement with a rod 222, rotation of which serves to shift the blocks 220 towards or away from one another. The area enclosed by the bars 208, 210 and the blocks 220 is complementary to the opening 154. A rigid plate 196, embedded centrally in pad 190, is rigid with a tube 200 which communicates through an aperture in plate 196 with a slot 198 formed in the outer surface of pad 190, and is connected to a vacuum line 204. Tightening of a nut 206, screwed upon tube 200 and in engagament with plate 172, serves to draw pad 190 into the space bounded by the bars 208, 210 and the blocks 220. Ears 170, rigid with plate 172, are pivoted at 169 to respective arms 168 rigid with a shaft journalled on frame 144. Respective links 176 are pivoted at 180 to the ears 170 and at 178 to arms 174 rigid with shaft 164. An arm 162, rigid with shaft 164, is pivoted to the piston rod 160 of an air motor 156 pivoted at 158 to frame 70. Slidable workpositioning fingers 234 are rigid with a vertical flange 236 biased by a spring 244 against an arm 246 rigid with shaft 164. In operation, when the piston rods of all the air motors are retracted, a workpiece is laid upon masks 150 in abutment with the fingers 234. Suction is then applied to line 204 and the motors are operated for advancing their respective piston rods. Motor 14 thereby raises frame 24 to engage applicator 98 and roller 136 with mask 150. Motor 156 lowers pad 190 into engagement with the workpiece, arm 246 initially shifting fingers 234 outwards against the bias of spring 244, when the portion of the workpiece overlying opening 154 will be drawn by suction against the upwardly curving surface of pad 190. Motor 32 shifts tube 52 to telescope upon tube 42, whereby ball valve (58) closes and coating material in tube 52 is pumped via bores 40, 48, tube 88 and bore 114, past the open ball valve 126, and through the slot 110. Motor 74 simultaneously shifts frame 78 rightwards, whereby coating material issuing from slot 110 passes through opening 154 to fill the space between mask 150 and the upwardly-curved surface of the workpiece, the material in said space subsequently hardening. Roller 136 engages mask 150 in advance of applicator 98 to prevent buckling of mask 150. The piston rods are then retracted, rod 160 being retracted further to carry work holder 173 to the position shown in chain lines, in which pad 190, to which the coated workpiece is still held by suction, faces upwardly. When the suction is shut off the workpiece drops on to a moving conveyor.