Tire building drum and a method for shaping tire components on said tire building drum

Abstract

Disclosed is a tire building drum and a method for shaping tire components on the tire building drum, wherein the tire building drum has cover plates extending in the circumferential direction between each pair of directly adjacent turn-up arms to close gaps between the turn-up arms in the circumferential direction. The cover plates are arranged to remain at the first radius when the turn-up arms are moved from the level orientation towards the turned-up orientation.

1 . A tire building drum comprising a rotational axis that defines an axial direction of the tire building drum, wherein the tire building drum further comprises a bead holder extending in a circumferential direction around the rotational axis at a first axial position for holding a bead at said first axial position and an axially movable arm drive member extending circumferentially around the rotational axis at a second axial position spaced apart from the first axial position, wherein the tire building drum is provided with turn-up arms which are distributed circumferentially about the rotational axis for supporting tire components between the first axial position and the second axial position, wherein each one of the turn-up arms extends in a longitudinal direction from the arm drive member towards the bead holder and is hingably coupled to the arm drive member about a respective turn-up axis for turning up the tire components supported thereon around the bead at the bead holder as the arm drive member moves towards the bead holder, wherein the turn-up arms are hingable with respect to their respective hinge axes between a level orientation, in which the turn-up arms extend parallel to the axial direction, and a turned-up orientation, in which the turn-up arms extend under an oblique angle with respect to the axial direction from a first radius at the arm drive member towards a second, larger radius radially outside the bead holder, wherein the tire building drum comprises cover plates extending in the circumferential direction between each pair of directly adjacent turn-up arms to close gaps between the turn-up arms in the circumferential direction, wherein the cover plates are arranged to remain at the first radius when the turn-up arms are moved from the level orientation towards the turned-up orientation. 
     
     
         2 . The tire building drum according to  claim 1 , wherein the cover plates are fixed in a radial direction perpendicular to the rotational axis to the same base as the bead holder. 
     
     
         3 . The tire building drum according to  claim 1 , wherein the cover plates remain parallel to the rotational axis of the tire building drum when the turn-up arms are moved from the level orientation towards the turned-up orientation. 
     
     
         4 . The tire building drum according to  claim 1 , wherein the cover plates are slidable in the axial direction relative to the base. 
     
     
         5 . The tire building drum according to  claim 1 , wherein each turn-up arm comprises a proximal end that is hingably coupled to the arm drive member, a distal end that faces a bead holder and an elongate arm body extending between the proximal end and the distal end, wherein each turn-up arm further comprises a roller that is rotatably supported at the distal end, wherein each cover plate is slidable in the axial direction into a position in which the respective cover plate covers one of the rollers in the radial direction. 
     
     
         6 . The tire building drum according to  claim 5 , wherein each cover plate is slidable in the axial direction into a position in which the respective cover plate uncovers said one roller in the radial direction. 
     
     
         7 . The tire building drum according to  claim 1 , wherein the each cover plate is slidable in the axial direction within a range defined by an abutting part that abuts the base in the axial direction at each end of the range. 
     
     
         8 . The tire building drum according to  claim 1 , wherein the turn-up arms together form a circumferential surface for supporting tire components between the first axial position and the second axial position. 
     
     
         9 . The tire building drum according to  claim 1 , wherein the turn-up arms together form a part of a circumferential surface for supporting tire components between the first axial position and the second axial position. 
     
     
         10 . The tire building drum according to  claim 1 , wherein the turn-up arms are arranged on a circumferential surface for supporting tire components between the first axial position and the second axial position. 
     
     
         11 . A method for shaping tire components on a tire building drum according to  claim 1 , wherein the method comprises the steps of:
 moving the arm drive member in the axial direction towards the bead holder to move the turn-up arms from the level orientation towards the turned-up orientation, while the cover plates remain at the first radius.   
     
     
         12 . The method according to  claim 11 , wherein the cover plates remain parallel to the rotational axis of the tire building drum when the turn-up arms are moved from the level orientation towards the turned-up orientation. 
     
     
         13 . The method according to  claim 11 , wherein the method comprises the step of sliding the cover plates in the axial direction. 
     
     
         14 . The method according to  claim 11 , wherein each turn-up arm comprises a proximal end that is hingably coupled to the arm drive member, a distal end that faces a bead holder and an elongate arm body extending between the proximal end and the distal end, wherein each turn-up arm further comprises a roller that is rotatably supported at the distal end, wherein the method comprises the step of sliding each cover plate in the axial direction into a position in which the respective cover plate covers one of the rollers in the radial direction.