Patent GB-892538-A (GB)
Title: Improvements in or relating to tyre building machines
IPC: B29D30/32
Filed: 1958-10-28
Abstract: 892,538. Tyre building machines. CONTINENTAL GUMMI WERKE A.G. Oct. 28, 1958 [Nov. 2, 1957], No. 34509/58. Class 144(1). In a tyre building machine wherein an annular series of pairs of grippers 23, 24 are disposed adjacent one end only of a tyre-building drum 7 on a rotary shaft 6 to seize the ply edges 38<SP>1</SP> overhanging that end of the drum and apply said edges under tension against the drum shoulders, such application of the ply edges 38<SP>1</SP> is effected by axial movement of the drum towards the grippers 23, 24 coupled with radially inward movement of the grippers which ease their hold on the ply edges 38<SP>1</SP> during such movement to ensure a complete fold-free application of the ply edges in one uniform movement. As shown, the drum shaft 6 is journalled cantilever fashion in bearings 4, 5 in frame members 2, 3 and carries a rigid plate 9 secured against axial displacement thereon. The plate 9 is fixed to the piston-rod 14 of an hydraulic motor 10 which is mounted on the frame 3 and is operable to move the plate 9, and thereby the shaft 6 and drum 7, axially relative to the frame 2, 3. The extent and speed of such movement is controlled by means of an hydraulic buffer 16 the piston 14 of which engages the plate 9 and the pressure-fluid supply of which is controlled by a valve 18. The valve 18 is operable by a push-rod 22 which is cammed by the periphery of the plate 9 on movement of the shaft 6 and drum 7 towards the frame to restrict the exhaust of pressure-fluid from the buffer 16 and thereby slow the movement of the shaft 6. The pairs of grippers 23, 24 are pivoted to the frame member 2 and the outer and inner grippers of each pair are respectively interconnected by rubber rings 25, 26 which tend to urge the grippers radially inwardly about their frame pivots. Each pair has an hydraulic jack 28 fixed to the outer gripper 23 and operable to move the associated inner gripper 24 to open or closed position, and the inner gripper 24 of each pair has a ramp 33 on its under-surface engaging a roller 30 on the periphery of a spider 31 slidably mounted on the shaft 6. The spider 31 is movable along the shaft 6 by an hydraulic motor 32 mounted on the frame 2 whereby movement of the grippers about their pivots is effected. A bead carrier ring 35 is also slidably mounted on the shaft 6 and is displaceable therealong by an hydraulic motor 37. In operation, with the apparatus in the position shown in Fig. 1, the spider 31 and jacks 28 are operated to close the grippers in a horizontal position and clamp the ply edges 38<SP>1</SP> therebetween, the spacing of the grippers from the drum end being determined by the buffer stop 14, 16. The valve 20 is then operated to permit escape of pressure-fluid from the buffer 16 via the valve 18 so that the motor 10 overcomes the buffer piston 14 and draws the drum 7 towards the grippers. Simultaneously the spider motor 32 is depressurized to retract the spider and allow radially inward movement of both grippers until such movement of the outer grippers 23 is stopped by engagement of bolt stops 27 on the grippers 23 with the bead carrier ring 35, Fig. 4. During this movement of the grippers, the plate 9 operates the push-rod 22 to restrict the exhaust of pressure-fluid from the buffer 16 and thereby reduce the speed of movement of the drum 7 towards the grippers. When the grippers reach the position shown in Fig. 4, the jacks 28 are operated to permit continued radially inward movement of the grippers 24 whereby the bands 25, 26 open slowly to release the edges 38<SP>1</SP> whilst the drum continues its axial movement so that the ply edges are pressed by the band 25 against the drum shoulders, Fig. 6. Thereafter, the movement of the drum 7 is rapidly reversed by the motor 10, and the motor 32 is operated to move the grippers 24 radially outwardly, the jacks 28 being set to permit such movement. The motor 37 is then operated to move the carrier 35 to position the bead ring 36 against the ply edges 38<SP>1</SP> on the drum shoulders, Fig. 8, the carrier 35 at the same time moving the drum towards the end of the shaft 6 to force the bead ring 36 and ply edges over a garter-spring 44 which effects axially outward projection of the ply ends through the bead ring 36. The carrier 35 is then withdrawn followed by retraction of the hub 31 and operation of the jacks 28 to move the inner grippers 24 radially inwardly, the drum 7 moving back on the shaft 7 to surround the garter-spring 44, Fig. 9. Then the hub 31 is advanced and the jacks 28 operated to move the grippers 24 radially outwardly, the shaft 6 simultaneously being moved by the motor 10 in the direction of arrow 43 so that the band 26, which may have rollers 45 on its leading edge, turns and stitches the projecting ply edges 381 back around the drum shoulders, Fig. 10. The drum 7 is then removed from and reversed on the shaft 6 for a repeat cycle on the ply edges at the other end of the drum.