Patent GB-777130-A (GB)
Title: Improvements in or relating to the manufacture of pneumatic tyres
IPC: B29D30/28
Filed: 1954-08-30
Abstract: 777,130. Tyre building machines. CONTINENTAL GUMMI-WERKE AKT.-GES. Aug. 30, 1954 [Oct. 23, 1953], No. 25153/54. Class 144 (1). In a machine for building tyres by tensioning the edge portions of a carcaseweb band 11 about an annular former A by means of pairs of grippers 12, 13 which grip the said edge portions, the grippers are arranged at one side only of the former 4 to operate on one side edge ot the carcase band at a time, the annular former being turned over for subsequent operation of the grippers on the other edge portion. As shown the former 4 is removably mounted on the end of a vertical support 3 which is controlled, for axial sliding movement within a support tube 2 by a piston and cylinder 5. The tube 2 is carried by a pedestal 1 to which are pivoted at 16 pairs of radially outer and inner gripper levers 15, 14 which respectively support at their outer ends elastic gripper bands 12, 13. The two bands 12, 13 are pretensioned so as to tend to move radially inwardly, such movement being resisted by a spider 18 carrying rollers 20 which bear on inclined surfaces of the levers 14, and the spacing between the bands 12, 13 is controlled by pneumatic or hydraulic piston devices 17 associated with each pair of levers 15, 14. Slidably arranged on a column 7 upstanding from the pedestal 1 is a control cam 9 which is connected by a cable 10 to the former support 3 so that it follows the movements of the annular former. The surface of the cam 9 is followed by a feeler 24 carried at the end of a link 33 which has a pin and slot connection with the cam 9 and a pivotal connection (not shown) with the end of a lever 23. Lever 23 is pivoted at its other end to the pedestal and is connected to one of the levers 15 by a pivoted link member 22. Movement of the feeler 24 along the cam surface 9 on downward movement thereof actuates means controlling a piston and cylinder arrangement 19 which effects movement of the spider 18 to allow radial movement of the gripper bands 12, 13. In operation a carcase band 11 is applied to the former 4 and held thereon by a hollow-section clamping sleeve 25 having a pressure actuated inner peripheral membrane 25<SP>11</SP>. The former support 3 is then lowered by operation of the cylinder 5 until the edge 11<SP>1</SP> of the band 11 is disposed between the gripper bands 12, 13 which are opened and then closed to gripping position by appropriate operation of the devices 17. Continued lowering or axial movement of the drum causes the feeler 24 to follow the cam 9 whereupon the cylinder 19 is operated to lower the spider 18 and allow radially inward movement of the gripper bands, the relative movements of the former 4 and gripper bands resulting in the gripped edge of the carcase band traversing a path 27 which is determined by the shape of the cam 9 and terminates at the point where a correspondingly shaped surface of the gripper band 12 abuts the curved surface of the former 4. At this point a bell-crank extension 28 of each lever 15 abuts a stop 29. on a ring 30 so that further radially inward movement of the gripper 12 is prevented and the carcase band edge thereby released on continued radially inward movement of the lever 14 and band 13, Fig. 6. The former 4 is then raised, removed and.reversed on the support 3 so that the other edge 11<SP>11</SP> of the band 11 can be engaged by the grippers 12, 13, now in their starting position. Since the path of movement 27 of the grippers has a portion which lies radially inwards of the terminal point abutting the former, the abutment ring 30 is rotatable on the pedestal 1 and has recesses 31 therein to allow passage of the lever extensions 28, the ring 30 being rotated automatically near the end of the gripper movement to bring the abutments 29 into operative position.