Patent GB-980490-A (GB)
Title: Making pneumatic tyres
Inventor: NOVIKOV GRIGORY VASIL EVICH
IPC: B29D30/34
Filed: 1963-10-04
Abstract: 980,490. Building pneumatic tyres. IAROSLAVSKY GOSUDARSTVENNY SHINNY ZAVOD. Oct. 4, 1963, No. 39264/63. Heading B7C. A machine for forming a tyre carcass comprises a rotary mandrel 9 and, at each end of the mandrel, a ply manipulating head consisting of a circular spring 3 carried on levers 44 each of which forms part of an articulated polygon and which are arranged to be moved by an annular piston 60 which is coaxial with the spring 3 and the mandrel 9 and is contained in a movable cylinder 28. Each lever 44 is pivotally connected to further levers 33 and 49, the free ends of which are pivotally connected to the piston 60. The levers 33 have branches which are pivoted to projections on the radially outer surface of the cylinder 28 by pins 34. Between the levers 33 are similarly pivoted to the cylinder 28 a series of levers 22 each of which carries a roller 40 at its free end and is provided with an abutment 42. The levers 22 are urged into the axial position shown in Fig. 2 against the action of an elastic band 38 by means of an annular pressing part 1. Extent of movement of the piston 60 and the cylinder 28 is adjustably limited. One of a number of metal beads 76 is supported on pins 24 at the end of the pressing part 1 adjacent the mandrel 9. In building a tyre carcass a band 77 of superposed layers of parallel cords is placed on the mandrel 9 which is then expanded. Rams 70 move the cylinder 28 towards the mandrel, the pressing part 1 remaining stationary so that the levers 22 move into the position shown in Fig. 15 while the levers 33 and the ring 3 lie inside the band 77. Compressed air is admitted to the cylinder 28 to advance the piston 60 and so move the ring 3 radially outwards until its diameter is equal to that of the mandrel. Rams 11 then advance the pressing part 1 towards the mandrel and so press the levers 22 against the band 77, the abutments 42 engaging the edge of the band. Air is released from the cylinder 28 while the pressing part 1 moves forward to completely surround the levers and to press the metal bead 76 against the band. The pressing part 1 is then withdrawn, while compressed air is fed into the cylinder 28 to expand the ring 3 and thus turn back the axially outer portion of the band 77 against the part of the band overlying the shoulder of the mandrel 9. The compressed air is released from the cylinder 28 and the pressing part 1 is moved against the turnedover portion of the band 77 and compressed air is admitted to a resilient ring 13 mounted on the pressing part 1 to press the band against the mandrel shoulder. The ring 13 is then deflated and the head returns to its original position. When the required number of bands have been shaped, a chafing strip is pressed against the partly formed carcass by admitting air to the cylinder 28 to expand the ring 3, and force the rollers 40 against the bead portion of the carcass as shown in Fig. 22. In a modification, intended for use when the layers of parallel cord are formed on the mandrel, the ply manipulating heads are provided with tubular casings arranged to be pressed by springs against the mandrel and to rotate with it.