| 摘要 |
1,084,041. Feeding webs. NRM CORPORATION. Aug. 25, 1964 [Sept. 10, 1963], No. 34728/64. Heading B6B. [Also in Divison F2] A tyre fabric bias cutter is associated with a number of fabric-dispensing units operable selectively to supply fabric to the cutter, each unit being capable of rewinding unused fabric after a required amount has been dispensed to the cutter. The embodiment described comprises three units 1, 2, 3, Fig. 1, from either of which tyre fabric can be fed to a bias cutter 7 by intermittently-driven conveyers 5, 6, 23, or on which material can be rewound when sufficient material has been cut. Each unit comprises means for mounting a spindle 68, Fig. 2, carrying a. roll of fabric 4. interleaved with a protective liner web, and for mounting a second spindle 57 for receiving the liner as the fabric is fed to the cutter. One end of each of the spindles has a grooved part 58, Fig. 3, resting on two rollers 60 and the other end has a reduced cylindrical part resting on a roller 62 and a star-shaped drag brake 63, the latter being turned through 90 degrees when one face wears. The liner passes from the roll 4 to the spindle 57 via a fixed axis roller 140. The fabric F, however, passes around a roller 146, roller 140 and a roller 156 and then drops vertically past two rollers 189, 191 to the conveyer 5. A looping roller 190, described later, operates adjacent to the rollers 189, 191. The roller 146 is carried by a lever 147 actuated by a piston- and-cylinder 151 to hold the roller against the fabric roll 4, and the roller 156 is carried by pivoted arms 164. The roller 156 can be pivoted manually out of contact with the roller 140 for initially threading the webs and also automatically to relieve its pressure on the roll 140 if the fabric tension becomes excessive, the latter operation being effected by the action of the fabric F on a roller 175 mounted on a pivoted arm 177 carrying a cam 181 engaging the roller 156. A square section kicker bar 170 is journalled in the arms 164 and is rotated as the roller 156 rotates, and acts intermittently to flick the fabric F dropping from the roller 156 away from the rollers 140, 156. The spindles 57, 68 are driven from a motor 75, Fig. 1, which also drives a shaft 80 to which the drives of the other units are coupled. Clutch means shown in Fig. 4 are provided whereby it can be arranged that the spindle 68 pays out fabric while the spindle 57 winds up the liner, or the spindle 57 pays out the liner and the spindle 68 rewinds liner and fabric. These means include a clutch element 127 in one end of each spindle such as 57, which can be engaged by a coacting element 122 carried by a piston 130 movable by fluid pressure in a hollow shaft 95. The outer end of the shaft 95 carries an inner clutch drum 104 with an inflatable air bag 107 secured to it. The bag 107 has friction elements 108 to engage the interior of an outer clutch drum 98 to which a pinion 85 driven from the motor 75 is fixed. By applying high pressure air to the clutch system of the spindle 57 and low pressure air to the clutch system of the spindle 68, the spindle 57 is positively driven and the spindle 68 is braked. Reversing the air pressures causes the spindle 68 to be driven for rewinding and the spindle 57 to be braked. In the latter case, a photo-cell detector 186 causes the rewinding operation to be stopped when all the fabric has been rewound. The looping roller 190 is freely mounted on a spindle carrying pinions engaged with a rack attached to a piston-and-cylinder drive 196 and to fixed racks so that the roller 190 moves a much greater distance than the piston. Initially the roller 190 is at position 195, Fig. 2, and the fabric F passes in front of it and along: conveyers 5, 6,. 21 to the cutter 7 where its presence is sensed by a photo-electric cell 310. This causes operation of the cylinder 196 so as to move the roller 190 leftwards to form a loop in the fabric as it continues to leave the roll 4 while the conveyers. 5, 6, 23 are stationary during the cutting operation. During normal operation, the roller 190 moves between positions 311, 312, and'as the loop increases in size the speed of the motor is decreased and correspondingly the motor speed increases as the loop decreases. This is effected by a variable resistor the shaft of which has a pinion engaging the rack moving the roller 190. Cams on the resistor shaft operate two limit switches so as to lock the cutter if the loop is empty or to disengage the spindle clutches if the loop is completely full. The looping rollers of succeeding units are linked to that of the first unit so as to move in unison therewith. |
