Tires building machine with rigid radially expansible drum

• US 4,614,562 A
• Filed: 08/13/1984
• Issued: 09/30/1986
• Est. Priority Date: 08/13/1984
• Status: Expired due to Fees

• Current Assignee: Uniroyal Goodrich Licensing Services Incorporated
• Original Assignee: Goodrich Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Jones, Robert F.
• Primary Examiner(s): Kimlin, Edward
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/639,763
• Time in Patent Office: 778 Days
• Field of Search: 156/414-420, 156/394.1, 156/398, 156/400, 156/402, 156/403, 156/408-410
• US Class Current: 156/420
• CPC Class Codes: B29D 2030/3257 using pressing rollers
• CPC Class Codes: B29D 30/247 Arrangements for the first stage only, e.g. means for radially expanding the drum to lock the beads B29D30/245 takes precedence
• CPC Class Codes: B29D 30/32 Fitting the bead-rings or bead-cores; Folding the textile layers around the rings or cores

Abstract

A simple two-stage process is disclosed for economic mass production of premium-quality heavy-duty belted tubeless and tube-type radial truck tires of various sizes using standard 30-year-old semi-automatic tire building machines heretofore used in the manufacture of bias-ply tires by the flat-band process. The old automatic machines are modified at minimal cost to receive a unique rigid expansible drum which is radially expanded 35% or more during the first-stage tire building operation. The drum may be adjusted to make tires of various widths and diameters and has a series of closely spaced radially movable segments defining a rigid segmental open-ended externally cylindrical shell having an annular rubber cover on which a complete green tire carcass is built prior to application of the belts and the tread at the second-stage machine.

The shell has rigid beveled shoulders at the ends of the drum which are inclined at an angle of from 40° to 50° relative to the drum axis and which are shaped to facilitate high-speed production, and to permit effective use of the ply turn-up tools and stitching means normally used on such automatic tire building machines with open-ended cylindrical drums. The rubber-covered shell expands radially in a precisely controlled manner in response to rotation of the drum, and it maintains uniform cord spacing and prevents the formation of wrinkles and air pockets during the ply down and ply turn-up operations. The unique drum facilitates accurate positioning of the wire beads and more precise control of bead-to-bead cord lengths and provides an ideal support during the stitching operations at the drum shoulders so as to improve tire quality and uniformity.

Claims

1. In a tire building machine designed for mass production of green bias tires by the flat-band process having a motor-driven cantilever shaft;

an externally cylindrical open-ended tire building drum mounted on said shaft;

bead setting means, ply turn-up means and tread stitching means engageable with said drum; and

automatic control means associated with said bead setting means, said turn-up means and said tread stitching means for effecting a predetermined sequence of operations during building of a green tire;

the improvement wherein

(a) said tire building drum has an expansible open-ended circumferentially discontinuous cylindrical shell formed of the upper surfaces of each of a series of closely spaced axially elongated rigid segments with rigid beveled shoulders which extend circumferentially discontinuously and has an annular sheath of elastic material sheathing said shell to provide an elastomeric cylindrical building surface, said sheath extending the full length of the drum and having thickened annular portions conforming to the drum'"'"'s beveled shoulders;

(b) said segments are mounted on a central supporting means for simultaneous radial outward movement to increase the drum diameter at least 35 percent while maintaining said upper surfaces as a discontinuous cylindrical surface and to extend axially outwardly from said supporting means in cantilever fashion with said rigid beveled shoulders extending axially outwardly at opposite ends of the drum, each segment having an inclined end portion providing an integral flange at one of the drum shoulders upon which the ends of the carcass are coextensively laid by said radial outward movement;

(c) actuating means are provided for causing each segment to move radially in unison with the other segments during drum rotation to maintain the cylindrical shape of the shell and conformation of said sheath to the shape of said rigid beveled shoulders;

(d) each bead setting means moves a wire bead ring against the carcass ply material at the end of the drum and places the bead ring against the ends of the segments radially inwardly of said rigid beveled shoulders; and

,

(e) said automatic control means causes the ply turn-up means to turn the outer portions of the tire carcass material up over the bead rings and to press said portions against the carcass material on the beveled shoulders.

2. The improvement according to claim 1 wherein said machine has motor-driven ply turn-up means including freely rotatable stitching rolls and arms for swinging the rolls into and out of engagement with the drum shoulders at both ends of the drum.

3. The improvement according to claim 1 wherein the beveled shoulders formed by the thickened end portions of said cover are inclined at an angle of from about 40°

to about 50°

relative to the drum axis.

4. The improvement according to claim 1 wherein said actuating means includes an actuating member mounted to move axially on the drum shaft and means for moving the segments radially in response to axial movement of said actuating member.

5. The improvement according to claim 1 wherein an externally threaded sleeve is mounted on the end portion of said cantilever shaft, an internally threaded actuating member is mounted on said sleeve, means are provided for temporarily engaging said actuating member to resist rotation thereof to cause said member to move axially a predetermined distance in response to drum rotation, and means are provided for moving the segments radially in response to axial movement of said actuating member.

6. The improvement according to claim 1 wherein the segments of said cylindrical shell are mounted on a series of regularly circumferentially spaced radial arms, each having an axially elongated plate which supports a pair of said segments in axially aligned positions, and means are provided for rapid adjustment of the axial length of said shell and the radial length of said arms.

7. The improvement according to claim 5 wherein a torque tube is mounted on the outer bead setting means in axial alignment with said cantilever shaft and has a central opening to receive and guide said externally threaded sleeve and a head portion engageable with said actuating member to stop rotation thereof, and means are provided for moving said tube axially into and out of engagement with said actuating member.