GB808342A - Apparatus for the manufacture of pneumatic tyres - Google Patents

Abstract

808,342. Tyre building. DUNLOP RUBBER CO. Ltd. Jan. 18, 1956 [Feb. 1, 1955], No. 2903/55. Class 144 (1). An apparatus for winding pneumatic tyre cord-reinforcements of the form described in Specification 808,341 comprises a continuously rotatable former having an outer peripheral winding surface, and a thread guide for the cord located adjacent the winding surface for reciprocation transversely thereof a plurality of times for each revolution of the former at a predetermined speed or speeds relative to the speed of rotation of the former. Figs. 1-3 show a cylindrical-surfaced former 4 mounted on a frame 1 for rotation by a motor 2 which drives also, through gearing 5, 5a and a universal shaft 6, a rotary cam 7 controlling, through a mechanism 8, the reciprocation of cord guide 9 axially of the former 4. The cam 7 is mounted on the frame 1 for adjustment normally to the former surface, and has an outer peripheral, continuous, constant angle, helical cam groove in which reciprocates a cam follower 15. The follower 15 is slidably keyed in a cross member 14 of a cam frame 10b which is pivoted on the cam axis, Fig. 2, for adjustment thereof to accommodate formers of different diameters. A pivot 15b on the cam follower is engaged in a longitudinal slot 16 in one end of a link member 17 which is pivoted intermediate its ends, by means of a slot 22, on a pin 21 adjustably clamped in a slot 23 in the frame 10b. The other end of the link 17 has a slot 20 to receive a pivot 19b of a slide 19 which is slidably keyed in a cross member 18 overhanging the former. The slide 19 carries the cord guide 9 comprising a support 24 for a bracket 26 in which is journalled a castoring shaft 29 disposed radially of, and spring urged towards the former. The shaft 29 carries at one end a grooved, freely rotatable guide pulley 32, which is mounted in offset relation so that it will automatically castor, by rotation of shaft 29, to the correct angle and direction of lay. The pivot 21 is secured in desired position in the slot 22 according to the width of the winding desired, and the pivots 15b, 19b and 21 may be either locked in position in their respective slots 16, 20 and 23 or allowed to slide therein, according to the nature of the winding desired. For straight winding, the pivot 21 is locked in its associated slot 23, and pivots 15b, 19b are left free to slide ; for sinusoidal winding pivot 19b is locked in its slot 20, and pivots 21 and 15b are slidable in their respective slots 23, 16, and for cycloidal winding pivot 16b is locked, and pivots 21 and 19b are slidable. The relative speeds of rotation of the cam and former are adjusted to provide the desired number of complete reciprocations of the guide pulley 33 across the former surface for each near-complete revolution of the former, the said number of reciprocations determining the angle of lay of the cord. If a winding path of stepped nature is desired, the constant angle cam is replaced by one providing for different linear speeds of reciprocation of the guide pulley at different parts of its stroke. Figs. 7, 10 and 11 show an apparatus for use with a former 36 having a centrally crowned winding surface 36a, and employing a rotary cam 42 the groove of which is designed to provide a curved winding path. As in the previous embodiment, the cam drives a follower 44 which is slidably keyed in a guide bar 47 and is slidably engaged, or clamped, in a slot 49 in one end of a link 50. The link 50 has a fixed intermediate pivot which is adjustably clamped in a slot 53 in a frame member 54, and has a slot 57 at its other end to engage slidably, or be clamped to, a pivot 56 on a bar 58 slidably guided in a channel 59 extending parallel with the former axis. The bar 58 carries a bracket 60 on which is journalled a lever hub 65 in which is slidably keyed a guide shaft 63. The shaft 63 slidably carries a spring- loaded bracket 88 on which is mounted a freely rotatable guide pulley 93. Rotation of the shaft 63 to align the pulley 93 with the desired angle of cord lay is effected by a lever 82 carried by the lever hub 65 and supporting a roller 83 movable in one or other of two cam slots 86, 87 in a pair of frame bars 84, 85, the slots being shaped to rotate the shaft 63 in accordance with the changes in winding angle dictated by the rotary cam 42. The lever hub 65 carries also a pinion 69 geared to a rack 73 intermediate the ends 74 of a double-ended solenoid plunger which co-operates, at each end of the traverse of the pulley 93, with a solenoid 76 (or 77). Each solenoid is operated by a micro-switch actuated by a pin 30 (or 81) on the bracket 60 to move the rack 73 at each end of the traverse and thereby cause rotation of the lever hub 65 both to align the pulley with the return direction of lay and to swing the roller 83 from one to the other of the cam slots 86, 87. Reciprocation of the shaft 63 within the lever hub 65, to keep the pulley 93 in contact with the winding surface, is effected by a. spring-loaded swinging arm 99 pivotally mounted at one end on a frame member 104, and pivotally supporting at its other end a member 97 carrying a thrust housing 95 in which the upper end of shaft 63 is journalled, the said other end of the arm 99 carrying also a follower 100 which engages a cam surface 101 shaped to conform with the contour of the winding surface 36a. In alternative arrangements, the traverse of the guide pulley across the winding surface may be effected by a motorcontrolled screw-drive arrangement, or by an hydraulic piston and cylinder arrangement, instead of the above cam mechanisms. Also, angular adjustment of the guide pulley during its traverse may be effected by a solenoid and plunger mounted on the guide pulley bracket, instead of the free castoring, or cam-operated arrangements above.