Abstract:
A tire apparatus ( 14 ) having nozzles ( 32 ) for directing air steams against layers ( 34 ) of uncured tire components applied to a tire building drum ( 19 ) for stitching and ejecting air from the layers.

Description:
TECHNICAL FIELD 
     This invention relates to a stitching apparatus for assembling uncured tire components such as plies on a tire building drum. Streams of air under pressure from nozzles positioned around the tire building drum stitch and eject air from under the tire components as the drum is rotated. 
     DISCLOSURE OF INVENTION 
     Stitching apparatus utilizing metal stitcher disks, such as those shown in U.S. Pat. No. 3,125,481 have been used to stitch tire tire components applied to a tire building drum. Improved apparatus to control the pressure applied by a stitcher disk is shown and described in U.S. Pat. No. 3,524,784. With these stitcher disks, the drum must be rotated a sufficient number of revolutions for the disks to traverse the distance between a position midway between the edges of the drum and the edges of the drum to press the tire components sufficiently to eject air and stitch the components together. Sufficient pressure must be applied to do the stitching, and at the same time, safeguards must be provided so that the green tire materials of the tire components are not distorted during this pressing action. Also, the moving parts on which the stitcher disks are mounted must be designed so that they can be adjusted for different size tires. Set up time is required which reduces time available for production time. The environment for the stitching rollers is not favorable and maintenance problems, such as failure of the roller bearings for the stitching rollers, are inherent with this type of stitching. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to an improved stitching apparatus for stitching and ejecting air from layers of tire components applied to the cylindrical surface of a tire building drum. This is done with substantially no moving parts requiring a minimum of maintenance. Also, the stitching is done without contacting the tire components, resulting in substantially no distortion of the components during the stitching operation. The cycle time is reduced because the squeezing action is provided with a minimum of revolutions of the drum. Substantially no set up time for different size tires is required, hence the same set up can be used for stitching different width tire components. 
     In accordance with one aspect of the invention, there is provided a stitching apparatus for use with a tire building drum which is rotated for wrapping successive layers of tire components around a cylindrical surface of the drum comprising a supporting structure, a manifold mounted on the structure adjacent the drum in communication with a source of air pressure, characterized by nozzles in communication with the manifold positioned for directing streams of air through the nozzles under pressure against the layers of tire components on the surface, and means to rotate the tire building drum to expose successive portions of the layers to the streams of air as the tire components are carried past the nozzles on the rotating drum so as to stitch and eject air from the tire components. 
     In accordance with another aspect of the invention, there is provided a method of building a tire on a rotatable tire building drum comprising wrapping successive layers of tire component around the drum characterized by directing streams of air under pressure against the layers of tire components to press the layers together and eject air from between the layers as the drum is rotated. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 is a view in perspective of a tire building drum having a tire component stitching manifold and air jets embodying the invention with parts being broken away. 
     FIG. 2 is a side elevation of the apparatus shown in FIG.  1 . 
     FIG. 3 is a sectional view taken along the line  3 — 3  in FIG. 2, showing the positions of the jets on the manifold. 
     FIG. 4 is a view like FIG. 2, showing the manifold in a retracted position. 
     FIG. 5 is a view of the drum taken along line  5 — 5  in FIG. 4 showing the V-shaped configuration of the nozzles over the layer of tire components in dot dot dash lines. 
     FIG. 6 is a view like FIG. 2 of a modification in which the nozzles are positioned to provide parallel streams of air impinging upon the layers of tire components. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1 and 2, a tire building drum  10  is shown which may be of a collapsible type mounted for rotation about a shaft  12 . A ply stitching apparatus  14  is positioned adjacent the drum  10  and has a supporting structure such as a beam  16  of steel or other rigid material for mounting on the floor of a tire plant. A manifold  18 , which may be a fabricated steel container, is mounted on hinges  20  fastened to the beam  16  to permit rotation from the position shown in FIGS. 1 and 2 to the retracted position shown in FIG. 4. A piston-cylinder assembly  22  is hingedly fastened to the beam  16  and manifold  18  for rocking the manifold  18  about the hinges  20 . A piston  24  of the assembly  22  may be double-acting and connected to controls for actuating the piston by hoses  26  and  28 . 
     The manifold  18  has a drum face  30  for positioning adjacent the drum  10  in the operating position of the apparatus  14  shown in FIGS. 1,  2  and  3 . Nozzles  32  are mounted on the drum face in communication with an air chamber (not shown) within the manifold  18 . Preferably the nozzles  32  have passages extending in a radial direction A-B, A-C, A-D, A-E, A-F, A-G, providing radial streams of air for pressing layers of tire components  34  against the surface of the tire building drum  10 . In the position of the manifold  18 , shown in FIGS. 1,  2  and  3 , air under pressure may be communicated to the manifold  18  from a source of air pressure, such as a blower  36  mounted on the manifold. 
     The nozzles  32  are preferably in an overlapping relation and are positioned in a V-shaped configuration shown in FIG. 3 for impinging air under pressure on the layers  34  of tire components at positions shown in dot dot dash lines in FIG.  5 . 
     In operation the layers of tire components  34  are laid on the drum  10  by rotating the drum while a server applies the tire components, which may be of a length equal to the circumference of the drum with biased ends  38  and  40  being spliced at splice  42 . This operation is performed with the manifold  18  in the retracted position shown in FIG. 4 where the double-acting cylinder  24  is actuated to pull the manifold away from the drum  10 . After the layers of tire components  34  are applied to the drum  10 , the manifold  18  may be rotated into the operating position shown in FIGS. 1,  2  and  3  with the nozzles  32  facing the layers of tire components  34 . The drum  10  is then rotated in a clockwise direction as shown in FIGS. 1,  2  and  5 , and air under pressure is supplied to the manifold  18  so that streams of air in the direction of the passages A-B, A-C, A-D, A-E, A-F and A-G impinge upon the layers of tire components  34 . It can be seen from FIG.  2  and FIG. 5 that as the drum  10  rotates in the direction of the arrow Z, a first jet  32  at the position X shown in FIG. 5, at the apex of the V-shaped configuration will project a stream of air against the layers of tire components  34  at a position midway between the edges  44  and  46  of the drum  10  and in a direction AB as shown in FIG.  2 . Then as the drum rotates, streams from the other jets will impinge upon the layers  34  in directions AC, AD, AE, AF and AG at positions spaced further from the position X midway between the edges to eject air from between the layers of tire components  34  at the edges. The resulting curtain of air under pressure provides stitching and ejection of air without contacting the layers of tire components  34 . The stitching and ejection of air is applied to the full width of the layers of tire components  34  upon each revolution of the drum  10  and, therefore, the number of revolutions required for complete stitching does not depend upon movable rollers which require many revolutions to cover the width of the layers. 
     As shown in FIG. 1, the nozzles  32  are mounted to provide streams of air under pressure in a radial direction through passages A-B, A-C, A-D, A-E, A-F and A-G. However, in the modification shown in FIG. 6, where similar parts have been designated by the same numerals, but with the addition of the prime mark, the manifold  18 ′ has nozzles  48 , which are mounted on a drum face  50 , wherein the direction of the nozzle passages, A′H, A′I, A′J, A′K, A′L and A′M are in a parallel configuration with the ends of the nozzles being evenly spaced from the surface of the drum  10 ′. The nozzles  48  otherwise are positioned in a V-shaped configuration like that shown in the embodiment of FIGS. 1-5. The ends of the nozzles  48 , 48  are evenly spaced from the drum surface as are the nozzles  32 , 32  of the embodiment of FIGS. 1-5. 
     The invention has been described with reference to preferred embodiments. Obviously, modifications and alterations will occur to others upon a reading and understanding of this specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or equivalents thereof.