Patent GB-892099-A (GB)
Title: Article decorating apparatus
IPC: B41F17/00
Filed: 1958-04-14
Abstract: 892,099. Printing on curved surfaces; stencilling- apparatus. HOMER LAUGHLIN CHINA CO. April 14, 1958 [June 20, 1957], No. 11759/58. Class 100(2) Article decorating apparatus comprises a turret rotatable on a horizonatal axis, elastic diaphragms mounted on the turret at circumferentially spaced points, means normally holding the turret stationary with a first diaphragm at its bottom, a colour-applying device adjacent the turret for applying a design to a second diaphragm on the turret above the level of the bottom diaphragm, an article-receiving chuck normally spaced from the turret, means for moving the chuck towards and away from the bottom diaphragm, means for inflating the bottom diaphragm to press it against an article on the chuck moved towards that diaphragm, means for moving the colour-applying device away from the turret, and means for rotating the turret while the colour-applying device and chuck are moved away from the turret, so as to move a colourcarrying diaphragm to the bottom of the turret. Printing on curved surfaces. The turret 10, Figs. 2 and 3, comprises four plates 12, Figs. 3 and 8, supported 90 degrees apart by spokes 13 from a shaft 9, Figs. 2, 3, 5 and 8. Each plate 12 carries two hollow circular boxes 86, Fig. 8, having air holes 87, and each box supports an elastic diaphragm 88. Each box is connected by a pipe 89 with an opening 90 in a flange 91 rigid on the shaft 9, which flange thus has four pairs of openings. Pressed against the flange by coil springs 92 is a non-rotatable collar 93 provided with a pair of openings at its top, bottom and front, with which the openings 90 register as the turret is indexed in 90 degree steps. The boxes 86 at the bottom are thereby connected to pipes 95, Figs. 2 and 8, leading to a common pipe 101 connected to a valve 102 having pipes 103, 104 leading to a source of air pressure and vacuum respectively. The boxes at the top are connected to a pipe 98, and the boxes in front to a similar pipe, leading to a common constant vacuum source. The shaft 9 carries a disc 30, Fig. 5, having notches 31 engaged by a bolt 33 urged upwards by air pressure in a cylinder 36 through a pivoted lever 34 so as to lock the turret against rotation. A table 66, Figs. 3 and 8, supports two chucks 67. Each chuck comprises a metal ring 78 welded to the table, and a ring 79 on which is mounted a flat plate 80 covered by a rubber pad 81. A suction pipe 82 extends through the table, plate and pad, and carries a suction cup 83. When a piece of ware, such as a dinner-plate 84, is placed on the chuck it is held thereon by suction applied through the pipe 82 only during traverse and decorating. The table 66 is carried on two levers 65 and a link 68, all pivoted to arms 69 mounted on a rock shaft 70. Air in cylinder 73 urges the table to the right, Fig. 3, to a position below the turret. In operation, with the table 66 in its lower and forward (left in Fig. 3) position, a piece of ware is placed on each chuck, and a button pressed to start an electric motor 46, Figs. 2 and 5, and bring on the vacuum to hold the ware securely. The motor 46 rotates through a chain 57 cam shafts 48, 61. Cams 59 on the shaft 48 allow the table 66 to move rearwardly, and cams 62 on the shaft 61 raise it so that the ware contacts the diaphragms 88, which at this time are pressed against the ware owing to a cam 110 on the shaft 48 actuating the valve 102 to admit compressed air to the boxes 86. The diaphragms have previously been impressed with a design by screen-printing, and the design is impressed on the ware. The valve is then reversed to draw the diaphragm against the boxes. After 350 degrees of rotation of the shaft 48, an arm thereon closes a switch to start a second electric motor 26, and after a complete rotation a second arm 50 opens a switch 51 to stop the motor 46. The motor 26, Fig. 5, through a chain 22 rotates a cam shaft 28 and the input of a Geneva mechanism 18. A cam on the shaft 28 swings up an arm 39 on a rocker shaft 40 carrying a pair of arms 41, Fig. 3, which raise a pair of vertical guide bars 42 travelling between rollers 43. A pin 44 on one of the bars 42 engages the lever 34 and withdraws the bolt 33, the output of the Geneva mechanism rotating the shaft 9 through 90 degrees. The bolt 33 having again moved upwards snaps into the next notch 31. An arm on the shaft 28 then opens a switch to stop the motor 26. Designs are printed on the diaphragms in the top position, inspected in the rear position, printed on to the ware at the bottom position, and wiped off the diaphragms at the front position. Stencilling-apparatus. The diaphragms to be printed on in their upper position are held against the boxes by suction from the pipe 98, Fig. 8. The stencil 112, Figs. 10 and 12, is secured to a frame 113 detachably secured to a metal frame 114 resting on a rectangular support 115 mounted on the guide bars 42, Fig. 3, the screen in its lower position resting on the diaphragms. The support 115 carries brackets 116, 117 in which is journalled a traversing screw 118 rotatable by a reversible electric motor 121. Surrounding the screw is a barrel 124 guided at each end by four circumferentially spaced rollers 127 engaging the flat crests of the screw threads. Mounted on the barrel is a bearing 126 in which is journalled a tapered roller 125 extending through an opening in the top of the barrel to engage the screw so that, as the screw is rotated the barrel is moved laterally. The barrel carries a bracket 132 supporting a plunger 133 which at either end of the barrel's traverse opens a limit switch 136 to stop the motor 121, a spring 135 allowing slight continued movement of the barrel. Secured to the band is an arm 128 extending across the frames and having at its free end a roller 129 running on the front of the support 115, and a pair of magnets 130 hold the roller against the support. The arm 128 carries two cylinders 143 in each of which is a piston 144 having a rod 145, flexible hoses 146, 147 communicating with the upper and lower end of the cylinder respectively leading through a valve 148, Fig. 2, to a source of air pressure. Rotatably mounted in the rods 145 are a pair of shafts 152 slidably mounted in opposite ends of a bar 153 having a pair of slots 154 through which project stems 155 on the shafts, so that the shafts can be pulled inwards against the action of a coil spring 156 to release them from the rods 145. The bar 153 supports a rubber squeegee 158, Figs. 12 and 13. When the squeegee assembly is raised, a roller 161 on the bar is engaged by a slotted cam 162 suspended from the arm 128 so that the squeegee assumes a vertical position, and on . descending contacts the screen behind the pool of colour. In operation, when the motor 46 is started, the screen is in its lower position and the squeegee raised. A cam 149 on the shaft 48 reverses the valve 148 to lower the squeegee, and a switch 137 or 138, according to which switch 136 was last opened, is closed by an arm 139 driven from the shaft 61, to start the motor 121, whereupon the squeegee traverses the screen to print on the diaphragms. After the motor 121 has stopped, the valve 148 is reversed and the squeegee raised. When the motor 26 starts, the guide bars 42 raise the entire screen-printing mechanism before the turret is rotated, and then lower it with two further diaphragms in position.