Improvements in or relating to building drums for manufacturing pneumatic tyres

摘要

951,402. Tyre building drums. PNEUMATIQUES & CAOUTCHOUC MANUFACTURE KLEBER COLOMBES. June 27, 1960 [June 25, 1959], No. 22447/60. Heading B7C. A tyre building drum consisting of circular end members 1 and 3 joined by a collapsible but axially inextensible tubular bladder 4 has spherically curved flanges 5 on the end members. These flanges serve during use of the drum, as a support for the tyre beads and, when the drum is collapsed, to allow its periphery to lie on an imaginary sphere 5a (Fig. 2) to facilitate removal of the tyre band 10. The bladder, whose axial extensibility is ensured by metal or fabric reinforcing elements 4a embedded in its rubber or like body, is secured to the end members by clamping between them and said flanges 5. These flanges have air holes 8 to facilitate removal of the tyre band, the interior of the bladder has ribs or grooves 11 to facilitate its collapse and the interior of the bladder may be pressurized or exhausted by way of a bore 7 in its supporting shaft 2 which opens into the drum at 7a. The drum collapses and expands by movement of end member 3 along shaft 2, which movement may be effected solely by pressure or vacuum applied to bore 7.