Tire building drum

Claim 2

A radially expansible and axially contractable tire building drum, for use in connection with the building of tire carcasses of high stiffness ply material having metallic wire reinforcing cords or cables incorporated therein, comprising: a. a rotatable shaft; b. a pair of cylindrical drum end sections arranged concentrically about said shaft and supported thereby for joint opposed axial reciprocal movement therealong, for joint rotational movement therewith, and for relative rotational movement between said drum end sections and said shaft, each of said drum end sections comprising a respective set of axially extending, circumferentially side-by-side, radially displaceable, cylindrical sector-shaped elements, and said drum end sections defining the bead locations for the carcasses to be built and having, when in their axially most separated locations and with their respective sets of said elements in their radially inwardmost positions, a minimum outer diameter sufficiently small to permit a pair of respective bead cores to be slipped axially onto said drum end sections and into surrounding relation to the end regions of the carcass ply material supported thereby; and c. mechanical camming means operative interconnected between said shaft and said elements of said drum end sections for selectively displacing said elements under a high unyielding force radially outwardly from the minimum outer diameter state of said drum end sections and retracting said elements radially inwardly back to said minimum diameter state, said camming means cOmprising axially extending, radially inwardly facing identical cam track means of gradually varying radial height on each of said elements, respective cam roller means bearing against said cam track means, means rotatably supporting said cam roller means, and screw thread actuating means connected with both said shaft and said supporting means for displacing the latter axially along said shaft and said elements upon relative rotational movement between said shaft and said supporting means so as to cause said cam roller means to ride over said cam track means, whereby upon a resultant movement of said cam roller means from the respective minimum height portions of said cam track means to the respective maximum height portions thereof said elements are displaced radially outwardly so as to cause the overlying end regions of the carcass ply material to be clamped hard against the respective surrounding bead cores.

Claim 3

A tire building drum as claimed in claim 1; said actuating means comprising a pair of externally threaded sleeves mounted on said shaft non-rotatably relative thereto, said supporting means comprising at least one internally threaded ring member threaded onto each of said sleeves and provided with means for inhibiting rotation of said ring members with said shaft, and said cam roller means comprising respective sets of cam rollers journalled on the outer peripheries of said ring members and corresponding in number and circumferential location to said elements and said cam track means thereof.

Claim 4

A tire building drum as claimed in claim 1; said actuating means comprising a pair of sleeves mounted on said shaft non-rotatably relative thereto, each of said sleeves being externally threaded in opposite senses over its two halves extending from the middle thereof to its opposite ends, said cam track means comprising a ridge on each of said elements defining two identical cam track portions in mirror image relation to each other and each substantially coextensive with a respective one of said oppositely threaded halves of the corresponding one of said sleeves, said supporting means comprising two pairs of internally threaded ring members, the two ring members of each pair being threaded each onto a respective one of said halves of the corresponding sleeve and being provided with means for inhibiting rotation of said ring members with said shaft, and said cam roller means comprising a plurality of sets of cam rollers journalled on the respective outer peripheries of said ring members and in circumferentially spaced relation thereabout, each set of cam rollers corresponding in number and circumferential location to said elements and the respective cam track portions thereof.

Claim 5

A tire building drum as claimed in claim 3; further comprising a respective set of circumferentially spaced linkages interconnecting each of said ring members with the individual elements of the associated one of said drum end sections.

Claim 6

A tire building drum as claimed in claim 1; said elements having identically located, substantially medial, transverse grooves in their radially outermost surfaces to define a continuous, circumferential, bead core-receiving groove on each of said drum end sections when the same are in said minimum diameter states thereof.

Claim 7

A tire building drum as claimed in claim 5; each of said elements being provided in its radially outermost surface with an axially oriented recess extending from one end of that element to said transverse groove thereof, a ply turn-up pusher bar slidably received in and extending the entire length of each of said recesses for movement into and out of overlying crossing relation to the associated transverse groove, and means yieldingly retaining each pusher bar out of such overlying crossing relation to the associated transverse groove.

Claim 8

A tire building drum as claimed in claim 1; further comprising an elastically radially expansible tubular diaphragm surrounding the space between said drum end sections and overlying the adjacent portions of the latter, said diaphragm being circumferentially secured at its opposite ends to said elements substantially medially thereof and defining, in the axially most separated state of said drum end sections, a portion of the cylindrical carcass building surface of the drum, and folding lever arm means arranged in said space within the confines of said diaphragm and having the folding junctures thereof disposed in the transverse plane of symmetry of the drum, said lever arm means being articulated to the respective opposed ones of said sector-shaped elements of said drum end sections, and said lever arm means being constructed and arranged, to have their radially outwardmost surfaces lying along a cylindrical locus in the axially most separated state of said drum end sections to provide a rigid support for said diaphragm in a position imparting a continuous cylindrical outer surface to the entire drum for carcass building purposes, and to have their folding junctures displaced in said plane of symmetry radially outwardly of said space upon relative approach of said drum end sections to each other for carcass shaping purposes.

Claim 9

A tire building drum as claimed in claim 7; said elements having respective identically located, substantially medial, transverse grooves in their radially outermost surfaces to define a continuous circumferential groove on each of said drum end sections when the same are in said minimum diameter states thereof, said diaphragm being secured to said elements substantially at the adjacent sides of said transverse grooves.

Claim 10

A tire building drum as claimed in claim 8; each of said elements being provided in its radially outermost surface with an axially oriented recess extending from the axially outermost end of that element to the respective transverse groove thereof, a respective ply turn-up pusher bar slidably received in each of said recesses for movement into and out of overlying crossing relation to said respective transverse groove, and means yieldingly retaining each pusher bar out of such overlying crossing relation to said respective transverse groove.

Claim 11

A tire building drum as claimed in claim 7; further comprising means for applying an elevated air pressure against the interior of a tire carcass to facilitate radial expansion thereof during a shaping operation, said pressure applying means comprising duct means communicating with the interior of said drum to enable application of said air pressure indirectly to the carcass via said diaphragm.

Claim 12

A tire building drum as claimed in claim 7; further comprising means for applying an elevated air pressure against the interior of a tire carcass to facilitate radial expansion thereof during a shaping operation, said pressure applying means comprising means defining at least one air passage through said diaphragm and duct means communicating with said air passage to enable application of said air pressure directly to the carcass and without inflation of said diaphragm.

Claim 13

A radially expansible and axially contractable tire building drum, for use in connection with the building of tire carcasses of high stiffness ply material having metallic wire reinforcing cords or cables incorporated therein, comprising: a. a rotatable shaft; b. first and second sleeves concentric with and axially splined to said shaft for longitudinal reciprocal movement therealong, each of said sleeves being externally threaded in opposite senses over the two halves thereof extending from its middle to its ends; c. first and second pairs of radial annular cross-heads each one of which is rotatably mounted on a respective one of said sleeves at a respective one of the opposite ends of the same and coaxially therewith, each of said cross-heads being provided with a plurality of circumferentially spaced radial slots, all of said slots in each of said cross-heads being in alignment with the corresponding slots in the other cross-heads; d. first and second sets of circumferentially spaCed tie rods rigidly interconnecting the respective cross-heads of said first and second pairs, said cross-heads of said first pair being provided with respective mutually aligned sets of openings spaced circumferentially of said cross-heads in an alternating sequence with said tie rods of said first set, said tie rods of second set being circumferentially staggered relative to said tie rods of said first set and having longitudinal extensions each passing slidably through the respective aligned ones of said openings in said cross-heads of said first pair to beyond the one of the latter remote from said second pair of cross-heads, said tie rods of said first set having longitudinal extensions beyond said one cross-head of said first pair, the two sets of longitudinal extensions being constructed and arranged for connection to push-pull drive means operatable to reciprocate said sets of tie rods along with the associated cross-heads and sleeves jointly but in opposite senses axially along said shaft selectively toward and away from each other; e. first and second radially split, cylindrical drum end sections arranged concentrically about said first and second sleeves, respectively, each of said drum end sections being constituted by a respective set of circumferentially side-by-side cylindrical sector-shaped elements bridging the gap between the associated pair of crossheads and having adjacent their opposite ends respective adjuncts slidably received in said radial slots of said associated cross-heads, each of said elements further having a radially inwardly facing, axially extending ridge contoured to provide twin cam tracks substantially coextensive, respectively, with the oppositely threaded halves of the associated sleeve and sloping toward each other from a maximum radial height at the opposite ends of that element to a minimum radial height in the medial region thereof, said elements further having respective identically located, substantially medial, transverse grooves in their radially outermost surfaces to define a continuous circumferential bead core-receiving groove on each of said drum end sections when the same is in its minimum diameter state by virtue of the respective set of said elements being in the radially inwardmost positions thereof relative to the associated pair of cross-heads, the minimum diameter of said drum end sections being sufficiently small to permit a pair of respective bead cores to be slipped axially onto said drum end sections and into surrounding relation to the end regions of the carcass ply material supported thereby; f. first and second pairs of internally threaded ring members threaded onto said first and second sleeves, respectively, each of said ring members riding on a respective one of said oppositely threaded halves of the associated sleeve, said first pair of ring members being provided with respective mutually aligned, circumferentially spaced openings slidably accomodating said tie rods of said first set and said longitudinal extensions of said tie rods of said second set, said second pair of ring members being provided with respective mutually aligned, circumferentially spaced openings slidably accommodating said tie rods of said second set; g. a respective plurality of cam rollers journalled in circumferentially spaced relation at the outer periphery of each of said ring members for rotation about respective axes disposed in a plane normal to the axis of said shaft, each of said rollers being in rolling surface contact with the associated cam track of the respective overlying sector-shaped element, whereby upon rotation of said shaft relative to said cross-heads in a predetermined sense, said ring members of each pair are moved along the respective sleeve away from each other to cause said drum end sections to expand radially under a high unyielding force as said rollers ride along said cam tracks from the minimum height portions to the maximum height portions thereof; h. a respective plurality of circumferentially spaCed pivotal linkages interconnecting each of said ring members with a respective portion of the associated overlying sector-shaped elements, whereby upon rotation of said shaft relative to said cross-heads in the opposite sense, said ring members of each pair are moved along the respective sleeve toward each other and said linkages cause said drum end sections to contract radially by drawing said elements radially inwardly as said rollers ride along said cam tracks from the maximum height portions to the minimum height portions thereof; i. an elastically radially expansible tubular diaphragm surrounding the space between said drum end sections and overlying the adjacent portions of the latter, said diaphragm being circumferentially secured at its opposite ends to the respective sets of said sector-shaped elements in the vicinity of the adjacent sides of said transverse grooves and defining, in the axially most separated state of said drum end sections, a portion of the cylindrical carcass building surface of the drum; j. a plurality of circumferentially spaced, longitudinally aligned pairs of lever arms of identical length arranged in said space within the confines of said diaphragm, said lever arms of each pair being disposed in a respective common axial plane of the drum and being articulated at their adjacent ends to one another in the transverse plane of symmetry of the drum and at their remote ends to the respective opposed ones of said sector-shaped elements of said first and second drum end sections, said lever arms being constructed and arranged, to have their radially outwardmost surfaces lying along a cylindrical locus in the axially most separated state of said drum end sections to provide a rigid support for said diaphragm in a position imparting a continuous cylindrical outer surface to the entire drum for carcass building purposes, and to have their common junctures displaced in said plane of symmetry radially outwardly of said space upon relative approach of said drum end sections to each other for carcass shaping purposes; and k. means for applying an elevated air pressure against the interior of a tire carcass to facilitate radial expansion thereof during a shaping operation.

Claim 14

A radially expansible and axially contractable tire building drum, for use in connection with the building of tire carcasses of high stiffness ply material having metallic wire reinforcing cords or cables incorporated therein, comprising: a. a rotatable shaft; b. first and second sleeves concentric with and axially splined to said shaft for longitudinal reciprocal movement therealong, each of said sleeves being externally threaded in opposite senses over the two halves thereof extending from its middle to its ends; c. first and second pairs of radial annular cross-heads each one of which is rotatably mounted on a respective one of said sleeves at a respective one of the opposite ends of the same and coaxially therewith, each of said cross-heads being provided with a plurality of circumferentially spaced radial slots, all of said slots in each of said cross-heads being in alignment with the corresponding slots in the other cross-heads; d. first and second sets of circumferentially spaCed tie rods rigidly interconnecting the respective cross-heads of said first and second pairs, said cross-heads of said first pair being provided with respective mutually aligned sets of openings spaced circumferentially of said cross-heads in an alternating sequence with said tie rods of said first set, said tie rods of second set being circumferentially staggered relative to said tie rods of said first set and having longitudinal extensions each passing slidably through the respective aligned ones of said openings in said cross-heads of said first pair to beyond the one of the latter remote from said second pair of cross-heads, said tie rods of said first set having longitudinal extensions beyond said one cross-head of said first pair, the two sets of longitudinal extensions being constructed and arranged for connection to push-pull drive means operatable to reciprocate said sets of tie rods along with the associated cross-heads and sleeves jointly but in opposite senses axially along said shaft selectively toward and away from each other; e. first and second radially split, cylindrical drum end sections arranged concentrically about said first and second sleeves, respectively, each of said drum end sections being constituted by a respective set of circumferentially side-by-side cylindrical sector-shaped elements bridging the gap between the associated pair of crossheads and having adjacent their opposite ends respective adjuncts slidably received in said radial slots of said associated cross-heads, each of said elements further having a radially inwardly facing, axially extending ridge contoured to provide twin cam tracks substantially coextensive, respectively, with the oppositely threaded halves of the associated sleeve and sloping toward each other from a maximum radial height at the opposite ends of that element to a minimum radial height in the medial region thereof, said elements further having respective identically located, substantially medial, transverse grooves in their radially outermost surfaces to define a continuous circumferential bead core-receiving groove on each of said drum end sections when the same is in its minimum diameter state by virtue of the respective set of said elements being in the radially inwardmost positions thereof relative to the associated pair of cross-heads, the minimum diameter of said drum end sections being sufficiently small to permit a pair of respective bead cores to be slipped axially onto said drum end sections and into surrounding relation to the end regions of the carcass ply material supported thereby; f. first and second pairs of internally threaded ring members threaded onto said first and second sleeves, respectively, each of said ring members riding on a respective one of said oppositely threaded halves of the associated sleeve, said first pair of ring members being provided with respective mutually aligned, circumferentially spaced openings slidably accomodating said tie rods of said first set and said longitudinal extensions of said tie rods of said second set, said second pair of ring members being provided with respective mutually aligned, circumferentially spaced openings slidably accommodating said tie rods of said second set; g. a respective plurality of cam rollers journalled in circumferentially spaced relation at the outer periphery of each of said ring members for rotation about respective axes disposed in a plane normal to the axis of said shaft, each of said rollers being in rolling surface contact with the associated cam track of the respective overlying sector-shaped element, whereby upon rotation of said shaft relative to said cross-heads in a predetermined sense, said ring members of each pair are moved along the respective sleeve away from each other to cause said drum end sections to expand radially under a high unyielding force as said rollers ride along said cam tracks from the minimum height portions to the maximum height portions thereof; h. a respective plurality of circumferentially spaCed pivotal linkages interconnecting each of said ring members with a respective portion of the associated overlying sector-shaped elements, whereby upon rotation of said shaft relative to said cross-heads in the opposite sense, said ring members of each pair are moved along the respective sleeve toward each other and said linkages cause said drum end sections to contract radially by drawing said elements radially inwardly as said rollers ride along said cam tracks from the maximum height portions to the minimum height portions thereof; i. an elastically radially expansible tubular diaphragm surrounding the space between said drum end sections and overlying the adjacent portions of the latter, said diaphragm being circumferentially secured at its opposite ends to the respective sets of said sector-shaped elements in the vicinity of the adjacent sides of said transverse grooves and defining, in the axially most separated state of said drum end sections, a portion of the cylindrical carcass building surface of the drum; j. a plurality of circumferentially spaced, longitudinally aligned pairs of lever arms of identical length arranged in said space within the confines of said diaphragm, said lever arms of each pair being disposed in a respective common axial plane of the drum and being articulated at their adjacent ends to one another in the transverse plane of symmetry of the drum and at their remote ends to the respective opposed ones of said sector-shaped elements of said first and second drum end sections, said lever arms being constructed and arranged, to have their radially outwardmost surfaces lying along a cylindrical locus in the axially most separated state of said drum end sections to provide a rigid support for said diaphragm in a position imparting a continuous cylindrical outer surface to the entire drum for carcass building purposes, and to have their common junctures displaced in said plane of symmetry radially outwardly of said space upon relative approach of said drum end sections to each other for carcass shaping purposes; and k. means for applying an elevated air pressure against the interior of a tire carcass to facilitate radial expansion thereof during a shaping operation.

Claim 15

A tire building drum as claimed in claim 12; each of said elements being provided in its radially outermost surface with an axially oriented recess extending from the axially outermost end of that element to the respective transverse groove thereof, a respective ply turn-up pusher bar slidably received in each of said recesses for movement into and out of overlying crossing relation to said respective transverse groove, and means yieldingly retaining each pusher bar out of such overlying crossing relation to said respective transverse groove.

Claim 16

A tire building drum as claimed in claim 12; said pressure applying means comprising duct means communicating with the interior of said drum to enable application of said air pressure indirectly to the carcass via said diaphragm.

Claim 17

A tire building drum as claimed in claim 12; said pressure applying means comprising means defining at least one air passage through said diaphragm, to enable application of said air pressure directly to the carcass and without inflation of said diaphragm.