Abstract:
An apparatus for applying a sheet of flexible material to a cylindrical body is disclosed. The apparatus includes an applier frame segment movably mounted on a supporting frame member, a servo arm rotatably connected to said applier frame segment for retracting and extending said applier frame segment towards and away from cylindrical body. The invention provides in a second aspect a method of applying a sheet of elastomer to a cylindrical body comprising the steps of: providing an applier frame movably mounted to a frame assembly, providing the sheet of elastomer to the applier frame, pivoting the applier frame upwards and moving the applier frame towards the cylindrical body, locating the applier frame in an inclined position adjacent the cylindrical body, applying the sheet of elastomer to the cylindrical body, and then retracting the applier frame to its starting position.

Description:
[0001]    This application claims the benefit of, and incorporates by reference, U.S. Provisional Application No. 60/876,325 filed Dec. 21, 2006. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates generally to the applying of tire sheet components such as plies or inner liners directly onto a cylindrical body such as a tire building drum and to cutting the tire component prior to application to the cylindrical body. 
       BACKGROUND OF THE INVENTION 
       [0003]    Tire ply or other rubber components are often applied to a tire building drum with a conveyor type device often referred to as an applier. Prior art appliers typically utilize a conveyor type belt to precisely apply the tire component onto the tire building drum. It is important to precisely control the application of the tire component onto the drum, and is particularly of concern for the tail end of the component. It is also important that the component be applied quickly and efficiently as possible. The applier must also retract sufficiently from the drum to provide clearance for other mechanisms and functions. Further, prior art appliers typically require a separate drive and adjustment mechanism in order to make applier adjustable to different sizes of tire building drums. 
         [0004]    The tire ply or other rubber components are typically cut on a separate machine using an anvil, thus requiring additional machinery and control systems. The presence of the anvil can create ball-ups in the stock as well as lateral guiding problems especially in cases where the stock is cut at an angle. 
         [0005]    Thus it is desired to provide a more advanced applier having a cutter mechanism, which overcomes the disadvantages of the prior art. 
       SUMMARY OF THE INVENTION 
       [0006]    The invention provides in a first aspect an apparatus for applying a sheet of flexible material to a cylindrical body. The apparatus includes an applier frame segment movably mounted on a supporting frame member, a servo arm rotatably connected to said applier frame segment for retracting and extending said applier frame segment towards and away from cylindrical body. 
         [0007]    The invention provides in a second aspect a method of applying a sheet of elastomer to a cylindrical body comprising the steps of: providing an applier frame movably mounted to a frame assembly, providing the sheet of elastomer to the applier frame, pivoting the applier frame upwards and moving the applier frame towards the cylindrical body, locating the applier frame in an inclined position adjacent the cylindrical body, applying the sheet of elastomer to the cylindrical body, and then retracting the applier frame to its starting position. 
       DEFINITIONS 
       [0008]    “Aspect Ratio” means the ratio of a tire&#39;s section height to its section width. 
         [0009]    “Axial” and “axially” means the lines or directions that are parallel to the axis of rotation of the tire. 
         [0010]    “Bead” or “Bead Core” means generally that part of the tire comprising an annular tensile member, the radially inner beads are associated with holding the tire to the rim being wrapped by ply cords and shaped, with or without other reinforcement elements such as flippers, chippers, apexes or fillers, toe guards and chafers. 
         [0011]    “Belt Structure” or “Reinforcing Belts” means at least two annular layers or plies of parallel cords, woven or unwoven, underlying the tread, unanchored to the bead, and having both left and right cord angles in the range from 17° to 27° with respect to the equatorial plane of the tire. 
         [0012]    “Bias Ply Tire” means that the reinforcing cords in the carcass ply extend diagonally across the tire from bead-to-bead at about 25-65° angle with respect to the equatorial plane of the tire, the ply cords running at opposite angles in alternate layers 
         [0013]    “Breakers” or “Tire Breakers” means the same as belt or belt structure or reinforcement belts. 
         [0014]    “Carcass” means a laminate of tire ply material and other tire components cut to length suitable for splicing, or already spliced, into a cylindrical or toroidal shape. Additional components may be added to the carcass prior to its being vulcanized to create the molded tire. 
         [0015]    “Circumferential” means lines or directions extending along the perimeter of the surface of the annular tread perpendicular to the axial direction; it can also refer to the direction of the sets of adjacent circular curves whose radii define the axial curvature of the tread as viewed in cross section. 
         [0016]    “Cord” means one of the reinforcement strands, including fibers, which are used to reinforce the plies. 
         [0017]    “Inner Liner” means the layer or layers of elastomer or other material that form the inside surface of a tubeless tire and that contain the inflating fluid within the tire. 
         [0018]    “Inserts” means the reinforcement typically used to reinforce the sidewalls of runflat-type tires; it also refers to the elastomeric insert that underlies the tread. 
         [0019]    “Ply” means a cord-reinforced layer of elastomer-coated, radially deployed or otherwise parallel cords. 
         [0020]    “Radial” and “radially” mean directions radially toward or away from the axis of rotation of the tire. 
         [0021]    “Radial Ply Structure” means the one or more carcass plies or which at least one ply has reinforcing cords oriented at an angle of between 65° and 90° with respect to the equatorial plane of the tire. 
         [0022]    “Radial Ply Tire” means a belted or circumferentially-restricted pneumatic tire in which the ply cords which extend from bead to bead are laid at cord angles between 65° and 90° with respect to the equatorial plane of the tire. 
         [0023]    “Sidewall” means a portion of a tire between the tread and the bead. 
         [0024]    “Laminate structure” means an unvulcanized structure made of one or more layers of tire or elastomer components such as the innerliner, sidewalls, and optional ply layer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    The invention will be described by way of example and with reference to the accompanying drawings in which: 
           [0026]      FIG. 1  is a perspective view of a tire applier of the present invention; 
           [0027]      FIG. 2  is a side view from the right hand side of  FIG. 1 ; 
           [0028]      FIG. 2A  is a side view of the applier in motion and approaching a tire building drum; 
           [0029]      FIG. 2B  is a side view of the applier in motion in contact with a tire building drum; 
           [0030]      FIG. 3  is an end view of the tire applier of  FIG. 2 ; 
           [0031]      FIG. 4  is a top view of the tire applier; 
           [0032]      FIG. 5  illustrates the adjustment feature of the tire applier front end with respect to different sizes of a tire building drum; 
           [0033]      FIG. 6  illustrates the forces on the tail end of the rubber component depending upon angle of inclination of the applier nose; 
           [0034]      FIG. 7  is a perspective view of a cutter mechanism shown together with the applier of  FIG. 1 ; 
           [0035]      FIG. 8  is a side view of the applier and cutter mechanism of  FIG. 7  prior to cutting the sheet component; 
           [0036]      FIG. 9  is a side view of the applier and cutter mechanism of  FIG. 7  during cutting of the sheet component; and 
           [0037]      FIG. 10  is a side view of the applier and cutter mechanism of  FIG. 7  during cutting of the sheet component. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0038]      FIGS. 1-4  illustrate a first embodiment of a tire component applier  10  of the present invention. The tire component may be in the form of a precut sheet and may comprise a tire liner, ply, or other component. If the tire component is ply having a plurality of parallel cords, the cords may be oriented for a bias or radial orientation. Alternatively, the tire component could be in other contoured or profiled forms such as a sidewall, chafer or chipper. 
         [0039]    As shown in  FIG. 1 , the tire applier  10  comprises a frame subassembly  20  having a plurality of support legs  22  which are mounted on support plates  24 . Cross bars  26 ,  28  provide structural support to frame  20 . Support plates  24  may be mounted to the floor or other support structure. 
         [0040]    Cross bar  28  is further provided with opposed, parallel rails  30  for slidably receiving guide members  32  of the upper frame  44 , so that the entire upper portion of the frame may slide on said rails  30  to allow for lateral adjustment (direction Z-Z). An actuator arm  40  is connected to the upper frame via plate  42  and slides the entire upper frame assembly  44  into a desired lateral position. The actuator arm may be for example, a ball screw. The lateral adjustment allows the applier to move in a direction parallel to the axis of the tire building drum. This allows for picking up and applying rubber components at various lateral applier positions. The rubber component may be guided either onto the applier or onto the drum if necessary. 
         [0041]    The tire applier  10  is also slidable in the X direction. The upper portion of the tire applier  10  further comprises a central support member  50  having opposed parallel ends  52 ,  54  joined by a central support shaft  51 . Ends  52 ,  54  are slidably mounted on opposed parallel rails  56  aligned for travel in the X-X direction. The applier conveyor  60  is also rotatably mounted to support shaft  51  which is supported by vertical supports  58  of the central support member  50 . The applier conveyor  60  can thus pivot about support shaft  51 , slide fore and aft on rails  56  towards tire building drum  70  and optionally slide laterally on rails  30  in the Z-Z direction. 
         [0042]    The applier conveyor  60  further comprises a belt  62  driven by internal rollers (not shown) and drive motor  63 . The applier conveyor  60  further includes a nose roller  64  located at the front of the applier and a rear roller  66  mounted on shaft  68 . The rear of the applier is located adjacent a feed conveyor  72  for feeding a sheet of ply or stock onto the applier. 
         [0043]    The shaft  68  on which the rear roller  66  of the applier conveyor belt is mounted also serves a second purpose. It is connected to a single servo arm  80  which is driven by a precision servo motor/reducer  90 . The servo arm rotates in the range of about 150 to about 200 degrees about point  82  in a clockwise direction. The applier is thus driven to and from the drum by this servo-controlled arm  80 .  FIG. 2  illustrates the applier in the retracted or initial position wherein the servo arm is at 0 degrees.  FIG. 2A  illustrates the applier approaching the drum wherein the servo arm has rotated about 90 degrees.  FIG. 2B  illustrates the applier nose in contact with the drum wherein the servo arm  80  has rotated about 170 degrees. The applier servo arm rotates counterclockwise to return the applier to its initial position. 
         [0044]    It is preferred that the center of gravity  65  of the conveyor  60  be located to the rear of the pivot point  59  of the applier conveyor. Thus the center of gravity  65  is located between the pivot point  59  and the rear  66  of the applier. Thus, the applier conveyor  60  is nearly balanced on top of a pivot shaft mount  58  mounted near the midpoint of the applier. The location of the sliding pivot point  59  just in front of the applier&#39;s center of gravity  64  is very helpful to overcome the inertial loads when the applier starts moving towards the drum. The moment arm of the weight of the applier also favorably assists the acceleration and deceleration of the servo arm when the moments about the sliding pivot point are considered. 
         [0045]    The applier further includes a stitcher roll  95  which helps adhere the component to the drum. This stitcher roller  95  is located beyond the tangency point of the applier to the drum to assure that the component has contacted the drum before contacting the stitcher roll. If the stitcher roller contacts the component before the component contacts the drum, the stitcher contributes to potential standing waves and component stretching and distortion. This stitcher roller may be made of soft foam or segmented disks in order to conform to component contours and distribute stitching pressures properly. The stitcher roller  95  is mounted upon a rotatable arm  97  positioned adjacent the front the applier. Actuator arm  100  rotates the stitcher roller forward into engagement with the tire building drum in order to stitch the applied component on the drum. 
       Cutter System 
       [0046]    As shown in  FIG. 7 , the invention may further comprise an optional cutting system  200  to cut the feed stock into a tire component of the desired length. The leading edge of the feed stock is advanced forward from a feed conveyor  72  to the applier conveyor  10  until the desired length is reached at the cutting line of the cutting system  200 . The cutting system  200  is positioned such that the cutting line is located over the gap between the rear applier roller  66  and the front roller  74  of the feed conveyor  72 . The gap between the rollers is approximately 1-2 inches, although it may vary. It is preferred that the feed roller  74  be smaller than the rear applier roller  66  so that a small gap distance may be utilized. This also helps facilitate the transfer of the leading edge of the stock from the feed conveyor onto the applier. Sensors mounted on or adjacent the applier conveyor belt  62  detect when the desired length of the feed stock to be cut has been reached, so that the cutting line of the feed stock is positioned correctly. After the feed stock has been positioned at the cutting line, one or more retractable hold down cylinders  120  are lowered to clamp the feed stock between the conveyor belts. Preferably two hold down cylinders  205  are used, and one is positioned over the end of the applier roller  66  near the centerline to clamp the feed stock while the other hold down cylinder is positioned over the end of the front roller  74  of the feed conveyor to likewise clamp the feed stock. The hold down cylinders  120  have two functions. First, the hold down cylinders function to clamp the feed stock to the conveyor belt and ensure that there is sufficient tension for the blade of the cutter to plunge through the feed stock. Second, as the cutting blades split and traverse away from each other, the hold down cylinders ensure that the blades do not pull the feed stock off center. 
         [0047]    As shown in  FIGS. 7 and 8 , the cutting mechanism  200  is mounted over the applier and feed conveyor on a support rail  210 . The cutting mechanism  200  further comprises a guide member  214  which is mounted across the feed stock. The guide member  214  is a support frame which houses the belt  224  which actuates the cutting means  220 . The cutting means  220  may be a divided blade having two sides  222   a, b  which split apart after the cutting means is plunged through the center of the feed stock. The blades preferably have a hooked end  215 . The cutting means is plunged through the feed stock, and then the belt  224  traverses the blades apart cutting the feed stock into sheets. The invention is not limited to a split blade, as other cutting means such as a single knife may also be used. Blades  222  or cutting means  220  rest upon a hot plate preferably spring loaded and heated to a temperature suitable for cutting ply stock. 
         [0048]    The cutting system has the capability of cutting ply with cord angled perpendicular to the conveyor belt longitudinal axis. In addition, the cutting system may cut the feed stock at an angle. For example, if the feed stock is ply having cords oriented within the range of 0 to about +/−45 degrees as measured from longitudinal axis of conveyor belt, the cutting system can cut at an angle with the cord and not through it. 
         [0049]    The cutting system  200  has actuators  230  such as a cylinder or ball screw which raise and lower blades  220   a, b  toward and away from the cutting line. If the ply is being cut at an angle, the cutting system can raise the blades during the cutting operation away from the conveyors and still continue to cut the feed stock. The blades are raised during cutting after the blades are traversed a few inches from the starting point as shown in  FIG. 10 . Raising the blades on the fly during cutting prevents the blades from interfering with the conveyors. 
       System Operation 
       [0050]    A sheet of ply, liner or other tire component stock is fed onto the rear end of the applier conveyor  60  via a feed conveyor or other device. The sheet of ply may be cut to length using the ply cutter as described above. The applier conveyor belt advances the cut sheet of ply to the front of the applier conveyor. The applier conveyor next approaches the tire building drum by rotating the servo-controlled arm  80  about point  82  in a clockwise manner. The applier conveyor rotates about pivot point  59  in a clockwise manner, thus lifting the nose of the applier upward. As the servo arm continues to rotates (90 degrees) clockwise, the applier conveyor pivots upward as shown in  FIG. 2A . Thus initially, the applier motion is mostly rotational about the sliding pivot point  59  at the start of the cycle. As the servo arm continues to rotate and approaches about 90 degrees, the motion of the applier is mostly in a linear direction as the applier slides forward on the rails  56 . As shown in  FIG. 2A , the nose of the applier is still raised at an angle. As the servo arm continues to rotate, the motion of the applier changes from linear to mostly rotational as the applier approaches the tire building drum. The fact that the center of gravity is behind the pivot point assists the operation of the applier by helping to decelerate the applier. As the front end of the applier approaches the drum, the applier is angled upwardly in an inclined position, typically in the range of about 5 to about 25 degrees ( FIG. 2B ). The fact that applier is angled upwardly (as opposed to being angled downwardly) when it comes to rest in the apply position at the drum increases the friction force (Ff) between the component and the applier belt during transfer to the drum, resulting in more control of the trailing edge of the stock as illustrated in  FIG. 6 . 
         [0051]    Next, the conveyor belt is then rotated, applying the leading edge of the sheet stock to the drum. After the leading edge of the sheet stock is applied to the drum, the roller actuator arm rotates the stitcher roller into engagement with the sheet stock on the drum. The roller and drum rotates to allow stitching of the sheet stock. The actuator arm then rotates the stitcher wheel out into its retracted position, and then the servo arm rotates from approximately about 180 degrees back to about 0 degrees (starting point) retracting the applier into the start or retracted position. 
         [0052]    The geometry and mechanics at work between the applier, the sliding pivot, and the servo-driven control arm make this an extremely fast and accurate applier which outperforms more traditional appliers. In summary, the applier offers a number of advantages as described above. It provides a very quick and controlled motion from the pick-up position to the apply position. It does not “beat itself up” or get knocked out of adjustment or alignment when operating at high speeds. It utilizes only one drive which provides for translation and also compensates for various drum diameters as opposed to prior art systems which have a separate drive and adjustment mechanism. This applier concept also eliminates relatively high maintenance linear drives and replaces them with one very robust and accurate motor/reducer drive. The posture of the applier in an uphill “inclined” orientation at the drum also offers improved control of the rubber component during application, especially the trailing edge. This is due to an increased friction force acting on the component. 
         [0053]    Variations in the present invention are possible in light of the description of it provided herein. While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. It is, therefore, to be understood that changes can be made in the particular embodiments described which will be within the full intended scope of the invention as defined by the following appended claims.