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Title: Tire building drum
Claims: What is claimed is: 1. A tire building drum comprising: a main tire building drum including a plurality of first main arcuate segments circumferentially spaced apart from each other and a plurality of second main arcuate segments each of which is interposed between said first arcuate segments to define said main tire building drum in the form of a cylindrical shape with said first main arcuate segments for holding a circumferential central portion of a composite annular tire member; a pair of auxiliary tire building drums partially engageable with the radially inner surfaces of the opposite end portions of said main tire building drum to axially be slidable toward and away from the equatorial plane of said main tire building drum, each auxiliary tire building drum including a plurality of first auxiliary arcuate segments disposed opposingly to said first main arcuate segments and a plurality of second auxiliary arcuate segments disposed opposingly to said second main arcuate segments to define said auxiliary tire building drum in the form of a cylindrical shape with said first auxiliary segments for holding axial opposite end portions of said composite annular tire member; a rotary shaft carrying thereon said main and auxiliary tire building drums for rotation of said main and auxiliary tire building drums; first diameter control means for expanding and collapsing said first main and auxiliary arcuate segments between a collapsed state and an ultimately expanded state through a partially expanded state; second diameter control means for expanding and collapsing said second main and auxiliary arcuate segments between said collapsed state and said ultimately expanded state; and a pair of slide means for axially sliding said auxiliary tire building drums towards and away from the equatorial plane of said main tire building drum. 2. A tire building drum as set forth in claim 1, which further comprises a main hub member having a circular plate portion and axial annular side extensions extending from the opposite sides of said plate portion, said main hub member being formed with an axial bore fitted with said rotary shaft to be rotated with said rotary shaft, and a pair of auxiliary hub member each of which has an axial bore axially slidably engaged with said respective extension of said main hub member and to be rotatable with said respective extension of said main hub member, and in which said first and second main arcuate segments of said main tire building drum are radially movably supported by said circular plate portion of said main hub member and said first and second auxiliary arcuate segments of each of said auxiliary tire building drum are radially movable supported by each of said extensions of said auxiliary hub member so that said auxiliary tire building drums are axially movable toward and away from the equatorial plane of said main tire building drum. 3. A tire building drum as set forth in claim 2, in which said first diameter control means includes a plurality of main double-acting actuators circumferentially equiangularly assembled in said circular plate portion of said main hub member for radially moving said first main arcuate segments toward and away from said rotary shaft to be maintained between said collapsed state and said ultimately expanded state through said partially expanded state, and in a plurality of auxiliary double-acting actuator circumferentially equiangularly assembled in each of said auxiliary hub members for radially moving said first auxiliary arcuate segments toward and away from said rotary shaft to be maintained between said collapsed state and said ultimately expanded state through said partially expanded state; said second diameter control means includes a plurality of main single-acting actuators each of which is assembled in the circular plate portion of said main hub member to be disposed between said main double-acting actuators for radially moving said second main arcuate segments toward and away from said rotary shaft to be maintained between said collapsed state and said ultimately expanded state, and a plurality of auxiliary single-acting actuators each of which is assembled in each of said the auxiliary hub members to be disposed between said auxiliary double-acting actuators for radially moving and second auxiliary arcuate segments toward and away from said rotary shaft to be maintained between said collapsed state and said ultimately expanded state. 4. A tire building drum as set forth in claim 3, in which each of said main double-acting actuators comprises a main fluid-operated cylinder assembly including a cylinder radially extending toward said first main arcuate segment and having an inner projection projected inwardly of said cylinder at its radially outer end, a secure piston radially slidably accommodated in said cylinder and having a radially outer end connected to said inner periphery of said first main arcuate segment and radially inner end with an outwardly projected outer projection to be engageable with said inner projection of said cylinder, said secure piston being formed with a recess radially extending from said radially inner end toward said first main arcuate segment and opened at said radially inner end, a tubular fluid passage member having a radially inner end connected to said radially inner portion of said cylinder to define a radially inner confined chamber connected to a first fluid pressure passage and a radially outer end with an outwardly projected annular projection to be accommodated in said recess of said secure piston, said tubular fluid passage member having therein a radial bore connecting said recess of said secure piston and said radially inner chamber and an outer diameter smaller than the inner diameter of said cylinder to define an annular chamber connected to second fluid pressure passage, and an annular free piston radially slidably accommodated in said annular chamber and having a radially outer end to be engageable with the radially inner surface of said projection of said tubular fluid passage member and a radially inner end with an outwardly projected annular projection to be slidably engaged with said inner wall of said annular chamber so that a fluid under pressure is introduced into said annular chamber through said second fluid pressure passage to radially outwardly move said secure piston until the radially outer end of said free piston is engaged with the radially inner surface of said projection of said tubular fluid passage member to expand said first main arcuate segment to said partially expanded state from said collapsed state and the fluid under pressure is thereafter introduced into said radially inner chamber through said first fluid pressure passage and permitted to enter said recess of said secure piston through said radial bore of said fluid passage member to radially outwardly move said secure piston until said outer projection of said secure piston is engaged with said inner projection of said cylinder to expand said first main arcuate segment to said ultimately expanded state from said partially expanded state. 5. A tire building drum as set forth in claim 3, in which each of said auxiliary double-acting actuator comprises an auxiliary fluid-operated cylinder assembly including a cylinder radially extending toward said first auxiliary arcuate segment and having an inner projection projected inwardly of said cylinder at its radially outer end, a secure piston radially slidably accommodated in said cylinder and having a radially outer end connected to said inner periphery of said first auxiliary arcuate segment and radially inner end with an outwardly projected outer projection to be engageable with said inner projection of said cylinder, said secure piston being formed with a recess radially extending from said radially inner end toward said first auxiliary arcuate segment and opened at said radial inner end, a tubular fluid passage member having a radially inner end connected to said radially inner portion of said cylinder to define a radially inner confined chamber connected to a third fluid pressure passage and a radially outer end with an outwardly projected annular projection to be accommodated in said recess of said secure piston, said tubular passage member having therein a radial bore connecting said recess of said secure piston and said radially inner chamber and an outer diameter smaller than the inner diameter of said cylinder to define an annular chamber connected to a second fluid pressure passage, and an annular free piston radially slidably accommodated in said annular chamber and having a radially outer end to be engageable with the radially inner surface of said projection of said tubular fluid passage member and a radially inner end with an outwardly projected annular projection to be slidably engaged with said inner wall of said annular chamber so that a fluid under pressure is introduced into said annular chamber through said second fluid pressure passage to radially outwardly move said secure piston until the radially outer end of said free piston is engaged with the radially inner surface of said projection of said tubular fluid passage member to expand said first auxiliary arcuate segment to said partially expanded state from said collapsed state and the fluid under pressure is thereafter introduced into said radially inner chamber through said third fluid passage and permitted to enter said recess of said secure piston through said radial bore of said fluid passage member to radially move and secure piston until said outer projection of said secure piston is engaged with said inner projection of said cylinder to expand said first auxiliary arcuate segment to said ultimately expanded state from said partially expanded state. 6. A tire building drum as set forth in claim 3, in which each of said main single-acting actuators comprises at least a main fluid-operated cylinder assembly including a cylinder radially extending toward said second main arcuate segment and having an inner projection projected inwardly of said cylinder at its radially outer end, a secure piston radially slidably accommodated in said cylinder having a radially outer end connection to said inner periphery of said second main arcuate segment and a radially inner end with an outwardly projected outer projection to be engageable with said arcuate projection of said cylinder, said cylinder being connected to a fourth fluid pressure passage so that a fluid under pressure is introduced into said cylinder through said fourth fluid pressure passage to radially outwardly move said secure piston until said outer projection of said secure piston is engaged with said inner projection of said cylinder to expand said second main arcuate segment to said ultimately expanded state from said collapsed state. 7. A tire building drum as set forth in claim 3, in which each of said auxiliary single-acting actuators comprises an auxiliary fluid-operated cylinder assembly including a cylinder radially extending toward said second auxiliary segment and having an inner projection projected inwardly of said cylinder at its radially outer end, a secure piston radially slidably accommodated in said cylinder having a radially outer end connected to said inner periphery of said second auxiliary segment and a radially inner end with an outwardly projected outer projection to be engageable with said arcuate projection of said cylinder, said cylinder being connected to a fourth fluid pressure passage so that a fluid under pressure is introduced into said cylinder through said fourth fluid pressure passage to radially outwardly move said secure piston until said outer projection of said secure piston is engaged with said inner projection of said cylinder to expand said second auxiliary arcuate segment to said ultimate expanded state from said collapsed state. 8. A tire building drum as set forth in claim 2, in which each of said slide means comprises an annular cylinder formed between said rotary shaft and said side extension of said main hub member to extend along said rotary shaft and having a pair of ports formed at its opposite ends and connected to a fluid pressure source, an annular piston accommodated in said annular cylinder slidably along said rotary shaft, an annular piston rod having one end connected to said annular piston, and an extension extending from said auxiliary hub member in parallel with said annular piston rod and having the remotest end connected to the other end of said piston rod so that each of said auxiliary hub member is caused to move toward and away from said hub member for moving each of said auxiliary tire building drum toward and away from the equatorial plane of said main tire building drum when said annular piston is actuated by alternatively introducing a fluid under pressure into said ports of said annular cylinder. 9. A tire building drum as set forth in claim 8, in which further comprises an tubular adjusting screw member having an outer surface with a thread being in threaded engagement with the inner surface of said extension of said auxiliary hub member and an inner surface with a thread opposite to said thread of said outer surface being in threaded engagement with the outer surface of said annular piston so that the width between said circular plate portion of said main hub member and said auxiliary hub member is caused to be adjustable by rotation of said tubular adjusting screw. 10. A tire building drum as set forth in claim 9, which further comprises a flapper ring connected to the outer end of said each adjusting screw member to form a semi-circular slit extending toward the axial line of the adjusting screw member, and an adjusting screw held in threaded engagement with said adjusting screw member to lock said adjusting screw member and the annular piston rod. 11. A tire building drum as set forth in claim 1, which further comprises an expansible annular diaphragm surrounding and placed on said first and second main arcuate segments of said main tire building drum to radially inwardly urge said main tire building drum toward said rotary shaft. 12. A tire building drum as set forth in claim 1, in which each of said second main arcuate segments having at least a ledge formed integral with and below its radially inner periphery and each of said second auxiliary arcuate segments having at least a ledge formed integral with and below its radially inner periphery, and which further comprising an endless coil spring surrounding and placed on each of said ledges of said second main and auxiliary arcuate segments to radially inwardly urge said second main and auxiliary segments toward said rotary shaft. Other info: Inventors: Suzuki, Masayoshi (Kodaira, JA) Ozaki, Kazuo (Higashiyamato, JA) Application Number: 568053 Filing Date: 1975-04-14 Publication_date: 1976-04-06 Assignee: Bridgestone Tire Company Limited (Tokyo, JA) Primary Class(es): 156/415 156/132, 156/417, 156/419 Other Classes: US Patent Ref:
Other Refs: Primary Examiner: Powell, William A. Assistant Examiner: Kittle, John E. Attorney: Haseltine, Lake & Waters |
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