Vulcanizing mould for pneumatic tyres and the like

Claim 1

A vulcanizing mould for pneumatic tires, comprising: a first plate positionable over one side of a tire to be vulcanized; a counter plate positionable over the opposite side of the tire and in opposed relationship to said first plate; said first plate carrying first ring means on the side thereof facing said counter plate; said first ring means having a generally truncated cone shaped surface that faces radially inwardly of the tire and that extends around the circumferential periphery of the tire when said first and counter plates are brought into engagement with the opposite sides of the tire; said counter plate engaging with a second ring means on the side thereof facing said first plate; said second ring means having a radially outwardly facing surface that engages and cooperates with said first ring surface, such that moving said first and said counter plates together shifts said second ring means radially inwardly; said second ring means being comprised of a plurality of segments, each of which is comprised of two separate elements; one of said segments elements being radially outward of the other radially inward element; all said outward elements having a respective outward surface and these element surfaces together defining said outwardly facing surface of said second ring means and all said outward elements also having clamping means for releasably clamping the respective said inward elements; each said inward element having clampable means that are securely but releasably clamped by said clamping means of said outward element, whereby said elements of each said segment are clamped together, and release of said clamping means permits easy removal of said inward element from said outward element; said clamping means comprising a clamping plate that is removably secured to said outward element of each of said segments; each said clamping plate including a first projection extending from said clamping plate toward said inward element; said inward element clampable means comprising a first groove for receiving said first projection and said first projection extending into said first groove; Said clamping plates being at one axial end of said second ring means; at the opposite axial end of said second ring means, asid outward element clamping means further comprising a second projection from each said outward element extending toward said inward element; said clampable means further comprising a second cooperating groove in each said inward element to receive a said second projection and said second projection extending into said second groove, whereby said outward and inward elements are securely locked together by means of said first and second projections extending into the respective said grooves; on the radially inward side of each said inward element is a profile for moulding the tread on the tire circumferential periphery; radial movement guide means on said second ring means and on said counter plate and in cooperative engagement with each other for guiding the radial motion of said second ring means segments that is caused by their cooperative engagement with said first ring means conical surface; cooperating guide elements connected with said second ring means for guiding motion of said second ring means relative to said first ring means and for retaining continuous engagement of said first ring means inward surface with said second ring means outward surface, thereby to cause radial shifting of said second ring means segments as said first and counter plates move.