Patent GB-552116-A (GB)
Title: Improvements in or relating to tire building apparatus
IPC: B29D30/28
Filed: 1941-03-18
Abstract: 552,116. Tyre-making machines. FIRESTONE TIRE & RUBBER CO. March 18, 1941, No. 3719. Convention date, July 17, 1940. [Class 144 (i)] A tyre-making machine of the type wherein the parts which form the tyre, such as the under-bead layers, over-bead layers, chafer strips, tread reinforcement and tread strips are delivered flat sequentially from a storage rack to a rotating drum and are then pressed thereon by tools and the edges shaped, known as the flat-band method, has ply turn-up devcies comprising a non-rotatable folding tool and a rotatable pressing tool and means moving these tools in timed succession into engagement with the work. The drum 35, Figs. 1 and 8, is of the known type, adapted to be expanded and contracted by operation of a brake-drum 38 causing relative rotation between a sleeve 36 and a spindle 26 passing through the sleeve and on one end of which the drum is mounted. The spindle is driven through chain-and-sprocket gear 28, 28, from a motor 32, and normally the sleeve 36 rotates with the spindle for either direction of rotation, but, on application of the brake, the expanding and contracting gear causes the drum to'expand or contract. The ends of the drum are recessed and the bead rings are placed in proper order of sequence upon the under-tyre layers in these recesses by means of bead-placing rings 45, 46. The ring 45 is slidably mounted upon the sleeve 36 and is slid to and from the drum by means of a piston rod 51 working in a cylinder 52, a rubber cushion 54 being interposed at the end of the piston rod to prevent shock on retraction of the ring. The ring 46 is adjustably mounted at the end of a bent lever 57 pivoted at its lower end to an adjustable pivot 68 and intermediate of its length at 58 to a sleeve 59 adapted to be reciprocated by a piston-rod 64 operated in timed sequence by a cylinder 65. Underbead plies 125, Fig: 18, are first drawn on to the drum from a storage rack and their ends secured; the edges of the plies are then pressed into the end grooves of the drum, the beads applied, and the edges further bent around the outsides of the. beads; the upperbead plies 223, and chafer strips 224 are then applied and also the tread-strengthening strips 225 and tread strip 226 and the whole is pressed together on the drum; the edges of the upper-bead plies are then pressed outwardly around the edges of the lower bead plies, the drum is collapsed and the tyre removed. The edges of the under-bead plies are pressed into the drum recesses. by stitching-tools 99, Figs. 4 and 5, carried by compound slides 75, 77 so that the tools can be moved inwardly of and along the drum. Each compound slide carries a turntable 79 and pivotally mounted between ears 81 thereon is a guide structure 82 carrying at its upper end on a pivot 86, a bell-crank lever 87 one arm of which is'attached by links 88 to the piston of a cylinder 90, while the other arm carries a rod 92 to which are fixed upper and lower rollers 96, 95 respectively, around which the stitching tool 99 runs. The tool is moved to: wards and away from the drum for operation on the edges of the strips by operation of the cylinder 90, a slipper 93 guiding the lower end of the rod 92 between the plates of the guide structure 82 and the rake of the tools with respect to the edge of the drum is adjusted by a screw 84. After the first stitching operation, the beads 126 are applied and the edges of the outer plies are bent upwardly about the beads. For this purpose a fixed shaped tool 124 and a rotary tool 129, Fig. 9, are carried in an adjustable manner, to act sequentially on the tyre edge, by a rod 120 projecting from one flat face of a toothed segment 112 which is operated by a rack 114 from a cylinder 109 to raise the tools which are spring retracted. The fixed-shaped tool first operates to press the edge well into the recess and about the bead and the rotary tool is then pushed forward to turn the edge up about the bead, by the end of its shaft 136 being actuated by a head 141a of a lever 141 actuated through a pin and slot connection by the piston of a cylinder 108; the lever 141 is spring retracted. The sequence of operations so far described is controlled electrically from a switch box 152, Fig. 3, with buttons 153, 154 to control the direction of rotation of the drum, but a second switch box 155 is provided containing switches whereby the several operations may be controlled manually. The rate of approach of the stitching tool 124 toward the drum is variable and is controlled by means of toggles in'valves 158, 159 and an operating block 161, Fig. 1, attached to the piston rod 114 of the cylinder 109, and the exhaust valve 160 of the cylinder 108 is controlled by a block 162 also attached to this piston rod which is controlled by a timing device (not shown), so that the movement of the rotary tool by the cylinder 108 is controlled from the cylinder 109. After the bead enclosing operation, the over bead plies, the chafer strips, the tread reinforcing ply, and the tread slab are then wound on the drum from the storage rack and the tread slabs are rolled simultaneously with the turning down of the fabric about the beads. The apparatus for rolling down the side walls is shown in Figs. 16 and 17, and comprises plain and toothed rollers 183, 184 with rounded perimeters, mounted to rotate on shafts 176 carried by a frame 171 with their inner ends 178 resiliently mounted in the frame. The frame is pivotally carried by a bracket 165 and is adapted to be reciprocated toward and away from the drum by a piston 170 of a cylinder 176, and the engagement of the-rollers with the side walls is progressive and toward the laterial margins of the tread slabs, and prevents bulging or buckling during the final rolling down by tread stitching devices. fhese devices are placed on the opposite side of the machine to the previous devices as shown in Fig. 18, and comprise rollers 216 mounted for axial movement along a shaft 212, the upper surface of which is screwed in reverse direction from the centre and engaged by nuts 215 on the rollers as these are pressed against the drum. This shaft is resiliently mounted in interconnected slide blocks 192 carried by guides 190 which are interconnected by a cross-piece 206; an angle plate 204 is rotatably mounted at its ends on the slides block and rests normally on an adjustable stop 208 fixed to the member 206. The slides are moved towards the drum by the piston 196 of a double acting cylinder 195 controlled by a foot valve 197, and as the rollers 216 press against the drum, the nuts 215 thereon engage the threads of the shaft and the rollers are moved outwardly from the centre over the tread band and finally bend over the edges of the upper plies. The cylinder 195 is then reversed and at the end of the withdrawal stroke, the angle bar 204 is titlted by the stop 208 to press the rollers and their nuts free of the upper surface of the reverse screwed shaft and the rollers are then brought back to central position by springs 219, the rollers sliding along the upper surface of the angle bar 204. The reversals of cylinders 195, 171 are automatically effected through toggle valves 229 and stops 230 and the subsequent final tucking over operation is also controlled by a stop 234 and electric switch 232. This operation is performed by rollers mounted on standards 238, Figs. 4, 6, 7, on the slides 77, and are adjustable with the slides, to and from the drum. Each standard is surmounted by a main slide 241 capable of actuation axially at an inclination to the end of the drum, by a double acting cylinder 242 controlled through a timing device and electric switch 232 referred to above. Mounted at one side of the main slide is a stitcher slide 244 which carries a lower resiliently mounted roller 249 in a holder 247, an intermediate roller 252 pivotally mounted on the end of an arm 253 which is pivoted resiliently to a block 254 so as to oscillate in a horizontal plane and an upper stitcher disk 264 also mounted to oscillate in a horizontal plane at the end of an arm 265 pivoted at 267. The intermediate stitcher roller is moved away from the drum at the first movement of the main slide by a cam plate 260 having a bevelled end which allows the tool to move inwardly in a lateral direction against the drum under the action of a spring 256. The upper stitching roller is moved lateral y against the drum to fold over the edges of the outer plies by the piston of a double acting cylinder 271 mounted on the slide 244. The cylinder is controlled by a toggleactuated valve 274 and pivoted stop 276 at the end of the forward movement of the main slide. The storage rack, Fig. 21, 23, 24 comprises a turntable 281 on a pivot 282 carried by an open frame 280 and has four fixed stations A, B, C, D, of which two A, B, are similar and diametrically opposite and carry supplies of under beads and overbead plies, while the stations C and D also diametrically opposite carry supplies of single treads and side wall slabs. The turntable is indexed and rotated by controlling gear under manual control and the stations are replenished in the positions remote from the drum. The station A, Fig. 24, contains rollers 289, 290 for the supply of under bead and overbead plies 125a, 125b respectively and these rollers are adapted to be driven by an endless belt 312 driven through chain and sprocket gearing from a motor 326 to wind on the supplies. For this purpose crank-arms 331 with rollers 337 are adapted to press the belt into the rims of the pulleys 289, 290 and the crank arms are actuated by solenoids 329, 330 at the off-positions of the stations by solenoids 329, 330 at the off-positions of the stations. Liners between the plies are wound and unwound from rollers 291, 292 driven by spring bands 301 from the winding on rollers and the tension of winding and unwinding is controlled by counterweighted brakes 303. The plies are drawn by the shaping drum thro