Patent GB-277686-A (GB)
Title: Improved machine for building chafing strips for tyre beads
IPC: B29D30/38
Filed: 1927-09-16
Abstract: 277,686. Goodyear Tire & Rubber Co., (Assignees of Kirk, R. S.). Sept. 16, 1926, [Convention date]. Tyre covers, making.-A machine for making chafing strips for pneumatic tyres comprises continuously operated means for supplying a plurality of continuous bands of fabric to a device for measuring and cutting the fabric into lengths. Rubbers strips are supplied to the fabric bands before the cutting operation is effected, from a device which is adapted to unwind a fabric roll in which the strips are carried. This device includes means for disengaging the unvulcanized rubber strip from the fabric carrier. The machine consists of several mechanical units, including the means for supplying the fabric bands, means for supplying the rubber strips, and means for superimposing the various bands and strips, measuring them and partially severing the completed chafing strip at the correct intervals. The framework of the machine comprises vertical angle irons 21 with horizontal members 23 - - 25, Fig. 1, provided with a series of rollers 27, having guides 28<a>, 28b near the end rollers. A book of bias cut bands of fabric is arranged below each of the members 23, - - 25, the ends of the bands being joined by operators to form a continuous band. Two, three, or more bands may be used. Each band is drawn over the rollers by individual feed rollers 31 - - 33, Fig. 2, driven at the same speed, and against which the band is held by spring pressed rollers 41. The rollers 31 - - - 33 are expansible and adjustable so as to enable the rate of feed to be adjusted and the bands to be kept taut. The body of each roller comprises two half-cylinders 54, 55, Fig. 12, which may be adjusted towards or away from each other by means of a bolt with left- and righthanded threads screwing into tapped holes therein. The rubber strips 60, Fig. 2, are guided to the rollers 31 - - 33 by means of rollers 61 - - 63. The various strips are brought into alignment by means of guides 65. Each guide consists of a slotted plate 67, Fig. 10, having parallel end members 68, 69 to which is secured a narrow metal strip 71 spaced from the plate 67. The band of material passes between rollers 72, 73, and is kept against the end member 69 by a leaf spring 74, one end of which is secured to a bar 76, while the free end extends through a slot 75 in the guide. The bar 76 may be moved across the guide by means of a screw 78 passing through a collar 77 and provided with a knob 79. A pin 81 integral with the end member 69 is adapted to fit seamed openings 82, Fig. 5, in the casting 91 forming the front frame of the machine. The guide 65 is adjusted in position by a set screw 83, its lateral position being fixed by a collar 84, Fig. 10. The measuring, cutting, and pressing portion of the machine comprises three castings 91, 92, 93 Fig. 4, and a differential mechanism 94. The mechanism is driven bv a belt 96 engaging a sprocket 97 keyed to a shaft 98. A pinion 99 on this shaft drives a gear 101 keyed to a shaft 102, Fig 3. A sprocket 106 and a pinion 104 are keyed to the shaft 102, the former driving a large sprocket 108 by means of a chain, and the. latter driving a gear 111 keyed to a shaft 112. The sprocket 108 is keyed, to a shaft carrying sprockets 117, 118, 119 which drive the auxiliary elements, such as the supply rollers 31, 32, 33, and the rubber-strip removing device described belcw. Fig. 2 shows the disposition of the chains 121, 122, 123 which drive the rollers 31, 32, 33. The shaft 112, Fig. 3, forms one axle of the differential mechanism 94. The front end of the shaft 112 extends to the frcnt of the machine and carries a steel collar 131, Fig. 4, which serves as a measuring roller for one of the bands 29, Fig. 2. A second collar 135, Fig. 5, is keyed to a shaft 134 which is rotated by gearing from the shaft 112. Below the rollers 131, 135 is another pair of shafts 137, 138 provided with rollers 137a, 138<a>, the roller 138a having a helical knife blade 139. The shaft 138, Fig. 6, is journaled in the framing of the machine, while the shaft 137 is journaled in a casting 141 which is supported on the shaft 138 but free to rotate thereon. Adjustable springs 143, 144 bear on the casting 141 and keep the roller 137<a> against the roller 131. A bifurcated member 148 is bolted to the casting 141 and carries a roller 149 engaging a cam 151 which causes the arm 148 to oscillate and the shaft 137 to pivot about the shaft 138. The rear end of the shaft 137 carries a gear 153 meshing with a gear on the shaft 112. The teeth of these gears are deep enough to keep in mesh during lateral movement of the shaft 137. Adjacent each of the measuring rollers 131, 135, 137<a>, Fig. 5, an idle roller 156 is mounted on a lever and pressed against the measuring roller by a spring. The guides 65 are adjusted to feed the strips of fabric and rubber between the rollers 156 and the measuring rollers. A secondary pressure roller 161, Fig. 5, having a rubber body and a fabric surface is mounted on a lever and pressed against the roller 137<a> by a spring, and an adjustable set screw engages the lever to limit the downward movement of the roller 161 when the roller 137<a> is moved downwardly. The strips of rubber and fabric are joined between rollers 131 and 137a, and subsequently pass between rollers 137<a> and 161. To facilitate the separation of the overlapping stepped ends of adjoining strips, periodical oscillatory motion is imparted to the roller 137<a> during which it moves away from the rollers 131, 161, thus interrupting the pressing. The cutting members are operated at definite predetermined intervals by timing mechanism which includes the differential gear 94, Fig. 3. Normally and during the intervals when the cutting roller 138a is inoperative motion is transmitted from the shaft 112 to the shaft 175 through the pinions 178. A brake drum 187, Fig. 7, and a gear 189, Fig. 3, are keyed to the shaft 175. A member 191, Fig. 9, is mounted on the casing so as to be rotatable concentrically with the shaft 175, and carries intermeshing pinions 192, 193, the former of which meshes with the gear 188. The member 191 is secured in position by bolts 194 passing through slots in the casing 92. The pinion 193 meshes with an interchangeable timing gear 197 bolted to a face plats 198 secured to a shaft 199 which is journaled in the framing and in a bracket 201, Fig. 3, secured to the differential casing 94. A counting device 203 is driven from the shaft 199. A cam 206, Fig. 7, having a stepped contour is secured to the shaft 199, and actuates a pawl 207 which in turn actuates brake shoes 221 through a rod 216 and a bell-crank lever 218. The brake shoes 221 engage the drum 187 on the shaft 175 when the pawl 207 is in the position shown. A cam 231, Fig. 8, having a trip-plate 232 bolted thereto is freely mounted on a collar 228 secured to the shaft 199, a small amount of relative rotation being allowed against the action of a spring disposed between lugs on the cams and collar. A bell-crank 238 is pivoted to the frame 92 and actuated by the cam 231 with which it is held in engagement by a spring. The lower arm 238<a> of the bell-crank engages at intervals a cam 246 secured to the shaft 184 and carrying a tripplate 247. The elongated portion of the tripplate 247 momentarily engages the extended portion of the trip-plate 232 during each revolution of the shaft 184. A further cam similar to the cam 206 is secured to the shaft 184 and engaged by a spring pressed pawl which prevents rebound or reversal of the shaft 184. One end of the shaft 184 carries a hollow pinion 256, Fig. 3, which rotates on a collar projecting from the frame 93 and meshes with a gear 257, Fig. 6, keyed to the shaft 138, and with a gear 258 keyed to the shaft 152 and engages the roller shaft 259 through gears 258, 260, these shafts carrying rollers 261, 262, Fig. 3, respectively having knife blades. The cam 151, Fig. 6. is keyed to the shaft 152 and engages the roller 149, imparting intermittent pivotal movement to the casting 141 which carries the measuring roller 137<a>, Fig. 5. The rubber-strip removing device comprises a frame portion 270, Fig. 1, travelling on wheels on tracks 272, with a casting 274, Fig. 14, and a bracket 276. Shafts 277, 278, Figs. 12 and 14, arc mounted in long journals in the casting 274, the projecting parts of the shafts being of rectangular section. The front ends of the shafts fit loosely in a U-shaped member 279, Fig. 12, pivoted to the frame 270 and normally held in engagement with the ends of the shafts by a latch. The rear ends of the shafts 277, 278 are provided with brake pulleys 282, Fig. 14, over which pass leather bands to which are fixed weights 284. The latter are also supported by cords passing over pulleys 287 secured to a shaft 288 provided with a hand lever 290 and a latch 291 whereby the brake bands may be applied to or released from the pulleys 282. Power is supplied by the chain 123, Fig. 12, to a sprocket 123a on a splined shaft 124, Fig. 13, journaled in the main frame of the machine. A two-part collar 292 carrying rollers whose peripheries engage in the splines of the shaft carries a sleeve 301 to which is secured a sprocket 302. The sleeve 301 passes through a journal bracket 303 attached to the bracket 276, and through a second journal bracket 304 secured to the bracket 303, the sprocket 302 being located between the two brackets. A sprocket 312, Fig. 14, and a pinion 313 are rotatably mounted on a shaft 310, and are adapted to be engaged by means of serrations thereon with a collar 314, Fig. 13, slidably keyed to the shaft 310, and actuated through levers by a rod 319 extending to the front of the machine. This clutch mechanism is also connected to an electrical circuit reversing switch. Parallel to the rear part of the shaft 310 is a short shaft 326, Fig. 14, driven by the chain 309 through a sprocket 327. A pinion 328 on this shaft meshes with the pi