GB687027A - Underply turn down and stitching device for a tyre-building machine - Google Patents

Abstract

687,027. Tyre-building machines. NATIONAL RUBBER MACHINERY CO. Nov. 3, 1950, No. 26953/50. Class 144 (i). In a tyre-building machine, means for holding down the under-ply fabric U on the end portions of the flat surface of the building- drum D whilst the overhanging edge-portions are being folded down the ends of the drum, comprise a power-cylinder 18 pivoted on a fixed support with a pair of pistons which are actuated in succession; first, to move a stitcherroll up to the fabric on the drum and then, at a relatively slower speed, to move a turn-down roll over the edge-portion of the fabric. As shown, pairs of rolls 1, 2 are adjustable on a rock-shaft 3, the rolls 1 being carried on swinging arms 4 on the shaft and the rolls 2 on arms 12 fast on the shaft. When the rolls 1 contact the flat surface of the drum, further rocking of the shaft 3 advances the rolls 2 down the ends of the drum whilst pressure of the rolls 1 is increased by means of springs 9 fitted between lugs 8 on the arms 4 and lugs 6 fast on the shaft. The power-cylinder 18 is divided by a wall 22, the upper portion being fitted with a piston 19, the rod 20 of which is pivoted to a yoke 15 on the shaft 3 and the lower portion with a piston 23 whose rod 24 is pivoted at 25 to the fixed framing 16. In use, the rolls are rocked into initial operative position by actuation of the piston 19 which, at the end of its stroke, uncovers a terminal port in the cylinder-wall to direct a restricted flow of fluid between the partition 22 and piston 23. The assembly of cylinder 18 and piston 19 is thus advanced, at a slower rate, to move the rolls 2 down the ends of the drum.