SECOND STAGE TIRE BUILDING MACHINE AND METHOD

Abstract: An improved second stage tire building machine (10) including a first station (16) for receiving and supporting a first stage tire carcass; a second station (24) axially offset from the first station (16) for assembling a breaker and tread cylinder; a servicer (38) for feeding breaker strip material to the second station (24) to form a breaker cylinder; a tread conveyor (48) for feeding tread material to the second station (24) over the breaker cylinder to form a breaker and tread cylinder; a stitcher to stitch the tread material and the breaker material to the carcass; a transfer ring (36) to transport the breaker and tread cylinder from the second station (24) onto the periphery of a carcass at the first station (16) for the assembly of a green tire and to then transport a green tire to an intermediate location; a robot (52) to transport a carcass to the first station (16) and a green tire from the transfer ring (36); and control means (46) to coordinate the movement of the servicer (38), tread conveyor (48), transfer ring (36) and robot (52) in a continuous and automatic cycle of operation.

Description: BACKGROUND OF THE INVENTION Field of the Invention This invention relates to a tire building machine and, more particularly, to a continuous and automatic second stage tire building machine and to its method of operation. Description of the Background Art Pneumatic tires of the bias type are generally built commercially in a "flat band" and subsequently expanded to the toroid shape in a curing mold. While building such tires, the strip material including the tread strips are applied directly over a laminated tire carcass while in a flat band orientation. Conversely, pneumatic tires of the radial type are generally built commercially by the "toroid" method. This method requires a first stage tire building machine for constructing the carcass in a flat band configuration and a second stage tire building machine for constructing the breaker and tread strips and applying them to the carcass. At the second stage machine, the carcass is supported on a first drum where it is expanded into a toroid shape. The tread and breaker strips are separately built on a second drum and then transferred onto the periphery of the supported carcass to form the green tire ready for vulcanization. Various approaches to continuous and automatic tire building machines and their components are disclosed in the literature. Note for example, U.S. Patent Numbers 1,700,526 to Brey; 3,756,882 to Vila; 3,844,871 to Habert; 4,134,783 to Appleby; 4,197,155 to Hursell; 4,230,517 to Enders; 4,268,330 to Komatsu and 4,443,290 to Loeffler. The invention starts from a tire building machine as disclosed in EP-A-0242689. This machine as well as other known constructions does not achieve the objective of a tire building machine which is continuous and automatic, efficient, rapid and economical in its operation. As illustrated by the great number of prior patents as well as commercial devices, efforts are continuously being made in an attempt to improve tire building machines and methods to render them more effective, rapid and economical. None of these previous efforts, however, provides the benefits attendant with the present invention. Additionally, prior tire building machines do not suggest the present inventive combination of method steps and component elements arranged and configured as disclosed and claimed herein. The present invention achieves its intended purposes, objects and advantages over the prior art devices through a new, useful and unobvious combination of component elements, with the use of a minimum number of functioning parts, at a reasonable cost to manufacture, and by employing only readily available materials. Therefore, it is an object of this invention to provide an improved tire building machine including a first station for receiving and supporting a first stage tire carcass; a second station axially offset from the first station for assembling a breaker and tread cylinder; a servicer for feeding breaker strip material to the second station to form a breaker cylinder; a tread conveyor for feeding tread strip material to the second station over the breaker cylinder to form a breaker and tread cylinder; a transfer device to transport the breaker and tread cylinder from the second station onto the periphery of a carcass at the first station for the assembly of a green tire and to then transport a green tire to an intermediate location; a robot to transport a carcass to the first station and a green tire from the transfer ring; and control means to coordinate the movement of the servicer, conveyor, transfer ring and robot in a continuous and automatic cycle of operation. It is a further object of the invention to provide an improved method of fabricating a green tire from a carcass on a second stage tire building system including providing a first rotatable drum for receiving and supporting a method of fabricating a green tire from a carcass on a second stage tire building system including providing a first rotatable drum for receiving and supporting a first stage tire carcass; providing a second rotatable drum axially offset from the first drum for assembling a breaker and tread cylinder; feeding breaker material to the second drum to form a breaker cylinder; feeding tread material to the second drum over the breaker cylinder to form a breaker and tread cylinder; stitching the tread material and the breaker material to the carcass; transporting, by a transfer ring, the breaker and tread cylinder from the second drum onto the periphery of the carcass at the first drum for the assembly of the green tire and then transporting the green tire to an intermediate location; transporting, by a robot, the carcass to the first station and a green tire from the transfer ring; and coordinating the movement of the breaker material, the tread material, the transfer ring and the robot by a controller in a continuous and automatic cycle of operation. It is yet an additional object of the invention to continuously and automatically move components to and through a second stage tire building machine. Lastly, it is an object of the present invention to build tires on a second stage tire building machine more efficiently, rapidly and economically. The foregoing has outlined some of the more pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings. SUMMARY OF THE INVENTION The invention is defined by the appended claims with a specific embodiment shown in the attached drawings. For the purpose of summarizing the invention, the invention may be incorporated into a tire building machine including a first station for receiving and supporting a first stage tire carcass; a second station axially offset from the first station for assembling a breaker and tread cylinder; a servicer for feeding breaker strip material to the second station to form a breaker cylinder; a tread conveyor for feeding tread strip material to the second station over the breaker cylinder to form a breaker and tread cylinder; a transfer ring to transport the breaker and tread cylinder; a transfer device to transport the breakeer and tread cylinder from the second station onto the periphery of a carcass at the first station for the assembly of a green tire and to then transport a green tire from the first staton to an intermediate location; a robot to transport a carcass to the first station and a green tire from the transfer ring; and control means to coordinate the movement of the servicer, conveyor, transfer ring and robot in a continuous and automatic cycle of operation. The tire building machine further includes an input station adapted to support a carcass to be transported by the robot to the first station and an output station adapted to receive a green tire transported thereto by the robot. The control means is adapted to receive signals from the servicer and conveyor indicative of the length of the breaker and tread strips and to vary the speed of movement of the servicer and conveyor in response thereto. The control means is programmable by an operator. The machine further includes means associated with the conveyor belts for driving the belts as well as the conveyed material, and for inputting the control means as a function of conveyor belt and material location along the sheet feed path. In addition, for the purpose of summarizing the invention, the invention may be incorporated into a second stage tire building machine including a first station having a first rotatable drum for receiving and supporting a first stage tire carcass; an input station adapted to support the carcass to be transported to the first drum; a second station having a second rotatable drum axially aligned with and offset from the first rotatable drum for assembling a breaker and tread cylinder; a servicer for feeding breaker strip material to the second drum to form a breaker cylinder; a tread conveyor for feeding tread strip material to the second drum over the breaker cylinder to form a breaker and tread cylinder; a transfer ring to axially convey the breaker and tread cylinder from the second drum onto the periphery of the carcass supported on the first drum for the assembly of a green tire and to then transport the green tire to an intermediate location; stitching means to stitch the tread strip material and the breaker strip material to the carcass; a robot to transport the carcass to the first drum and the green tire from the transfer ring; an output station adapted to receive the green tire transported thereto by the robot; and programmable control means to coordinate the movement of the servicer, conveyor, transfer ring and robot in a continuous and automatic cycle of operation and to receive signals from the servicer and the camage indicative of the lengths of the breaker material and the tread material and, in response thereto, to vary the relative speed of movement between the second drum, the servicer and the conveyor. The tire building machine further includes positive drive means for the conveyor belts, such positive drive means including a toothed belt and toothed pulleys fopr the positive driving of the belt and conveyed material, and for the precise input of belt location to the control means. Lastly, for the purposes of summarizing the invention, the invention may be incorporated into a method of fabricating a green tire from a carcass on a second stage tire building system including providing a first rotatable drum for receiving and supporting a first stage tire carcass; providing a second rotatable drum axially offset from the first drum for assembling a breaker and tread cylinder; feeding breaker material to the second drum to form a breaker cylinder; feeding tread material to the second drum over the breaker cylinder to form a breaker and tread cylinder; transporting, by a transfer ring, the breaker and tread cylinder from the second drum onto the periphery of the carcass at the first drum for the assembly of the green tire and then transporting the green tire to an intermediate location; stitching the tread and breaker material to the carcass; transporting, by a robot, the carcass to the first station and a green tire from the transfer ring; and coordinating the movement of the breaker material, the tread material, the transfer ring and the robot by a controller in a continuous and automatic cycle of operation. The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying of designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which: Figure 1 is a perspective illustration of a second stage tire building machine constructed in accordance with the principles of the present invention. Figure 2 is an enlarged perspective illustration of the gripping portion of the robot as seen in Figure 1. Figures 3A and 3B are plan views of the gripping portion of the robot shown in Figure 2 illustrating the gripping fingers in alternate operational positions. Figures 4A and 4B are side elevational and plan views of the gripping portion of the robot as shown in Figures 2, 3A and 3B. Figures 5A-5H are illustrations of the first stage tire carcass and robot showing their movements from the input station to the first station of the tire building machine as shown in Figure 1. Figures 6A-6F are illustrations showing the sequential movement of breaker strips from the servicer to the collapsible drum. Figures 7A-7F are perspective illustrations showing the sequential movement of a breaker and tread cylinder from the collapsible drum to the first stage tire carcass. Figures 8A-8D are illustrations showing the movement of the stitcher upon the breaker and tread cylinder at the first station with Figure 8D illustration the stitched green tire placed upon the table of the output station. Figures 9A and 9B are side elevational views of the sheet feeding mechanisms of the servicer in various operational positions. Figures 10A-10C are perspective illustrations of the various components of the cutter and aligner mechanisms. Figures 11A-11E are front elevational views of the cutter mechanisms illustrating their sequential movement through a cycle of operation. Figures 12A and 12B are illustrations showing the mechanisms for feeding tread material to the collapsible drum over the breaker plies. Similar reference characters refer to similar parts through the several views of the drawings. DETAILED DESCRIPTION OF THE INVENTION Overview The second stage tire building machine 10 of the present invention is depicted in the attached drawings. It is comprised of a plurality of assemblies, subassemblies and components operable together for its purpose of converting a generally cylindrically shaped carcass 12 into a toroid-shaped green tire 14 ready for vulcanization. The machine includes a first or carcass drum assembly or station 16 formed of spaced flanges 18 adapted to receive and support the carcass 12. It functions to expand the carcass 12 into a toroid shape for the receipt of a breaker and tread cylinder 20 for the formation of the green tire. The machine also includes a second or breaker drum assembly or station 24 formed of a collapsible drum 26 rotatable about an axis aligned with, but axially offset from, the axis of the flanges 18 of the carcass drum assembly. The breaker drum is adapted to receive strips of breaker material 28 and 30 and a strip 32 of tread material and to position them in a superposed relationship to form the breaker and tread cylinder. The breaker and tread cylinder is then transported axially from the breaker drum assembly 24 to the carcass 12 at the carcass drum assembly 16 by a transport ring 36 which is axially shiftable between the two drum assemblies. A third assembly is the servicer assembly or station 38 which is adapted to convey breaker material along paths of travel from supply rolls 40 and 42, past cutter and tip aligner subassemblies 44, to the breaker drum 26. The conveying of the breaker material is at an appropriate speed and in an appropriately timed sequence to effect the desired result of a continuous and repeatable breaker tread cylinder. The servicer assembly includes the framing support structures as well as the conveyor belts and control mechanisms 46 for effecting the appropriate conveying of the breaker material to the breaker drum. The control mechanisms include belts, pulleys and sensors to input a controller for determining material position and thus allow for the intended operation and control of the machine. A tread conveyor 48, operable in association with the servicer, functions for feeding precut strips 32 of tread material onto the surface of the superposed strips 28 and 30 of breaker material on the breaker drum 26. The machine also includes a robot assembly 52 for conveying the tire carcass 12 from a loading station 54 to the carcass drum assembly. The loading station includes a pre-inflator 56 where the carcass 12 is initially placed by an operator after being carried or otherwise transported from a first stage tire building machine, the place of carcass fabrication. The robot assembly 52 is also adapted to convey the carcass with the breaker and tread cylinder stitched thereto, the green tire 14 ready for vulcanization, to a final or inspection station whereat the operator may view and inspect the green tire and then carry or otherwise transport such green tire to the curing press for vulcanization. Also included within the machine is an operator programmable control assembly 46 for coordinating the operation of the various assemblies, subassemblies and components in their intended continuous and automatic cycle of operation with minimum operator involvement. Drum Assemblies The carcass drum assembly 16 includes a cantilevered member 60 with a free outboard end and an inboard end supported by the machine for rotation by suitable drive mechanisms. Adjacent to its outboard end are a pair of carcass-receiving flanges 18 of similar construction, an inboard flange and an outboard flange. Each flange is of a generally conical configuration for receiving the internal edges of a carcass 12. The carcass-receiving surface of each flange is provided with an elastomeric membrane 62 which communicates by internal conduits with a source of air under pressure whereby the membranes may be inflated to sufficiently increase in diameter to form an air-tight seal with a supported carcass. A further source of air under pressure is coupled with the interior of the carcass through a conduit in the member for the inflation of the carcass supported by the flanges. Such air flows are conventional. The flanges 18 are mounted on the cantilevered member or shaft 60 through a concentric shaft and the sleeve arrangement. The outboard flange supported by the shaft and inboard flange supported by the sleeve are axially shiftable by drive mechanisms toward and away from each other equally and oppositely. Movement toward each other is performed concurrently with the inflation of the carcass in order to convert the cylindrical carcass into a toroid shape. As a result of the construction and arrangement of the components of the carcass drum assembly, the supported carcass is deformed and inflated in order to receive a breaker and tread cylinder 20 brought into an encompassing position by the transfer ring. With the transfer ring 36 and the breaker and tread cylinder encircling the inflated carcass, the carcass is further inflated to contact the interior surface of the breaker and tread cylinder for adhesion therebetween. The transfer ring is expanded to release the breaker and tread cylinder. The transfer ring is then axially displaced toward the breaker drum to an intermediate location for exposing the periphery of the breaker and tread cylinder. Note Figures 7A through 7F for the sequence. A stitcher 64, located adjacent the flanges 18 and pivoted on arms 66, is then brought into contact with the periphery of the breaker and tread cylinder 20. Its opposed wheels 68 rotate, through the rotation of the carcass and breaker and tread cylinder, and are driven concurrently away from each other to stitch the breaker and tread cylinder onto the carcass, thereby forming the green tire ready for vulcanization in the curing press. Note Figures 8A, 8B and 8C. The breaker drum subassembly 24 includes a collapsible drum 26 rotatable about an axis which is coextensive with, but offset from, the axis of the flanges 18 of the carcass drum assembly 16. The breaker drum assembly includes a cantilevered shaft 72 with a free outboard end and an inboard end supported and driven by the machine. Its outboard end supports the collapsible breaker drum 26 which is located at an axially spaced interval from the carcass drum assembly. A motion imparting linkage arrangement is adapted to radially displace a plurality of segments 74, two opposite segments greater than 90 degrees and the other two segments less than 90 degrees, as shown in the preferred embodiment. The segments function to effectively expand and contract the breaker-supporting surface of the breaker drum. This action will allow a constructed breaker and tread cylinder to be supported by the breaker drum when the segments are expanded or removed therefrom by the transfer ring when the segments are contracted. Compare Figures 7A and 7C. The breaker drum 26 is adapted to be rotated through the shaft 72 whereby it will receive and support a first applied breaker strip 28 from the first conveyor 76 of the servicer assembly and a subsequently applied second breaker strip from another or second conveyor 78 of the servicer assembly. The first breaker strip will completely overlie the surface of the expanded breaker drum with no overlap or gap at its opposite ends. The second breaker strip is slightly longer than the first since it will overlie the first breaker strip on the breaker drum, also with no overlap or gap between its opposite ends. The breaker strips, when together on the breaker drum, form the breaker cylinder. The cutting of the breaker strips and their positioning onto the breaker drum is effected without operator involvement in a continuous and automatic cycle of operation. Overlying the second breaker strip is the tread strip 32, fed to the rotating breaker drum from the side thereof opposite the servicer. In operation and use, the breaker and tread strips are fed into superposed position onto the breaker drum to form the breaker and tread cylinder. The only operator involvement is the placing of the tread strip on its conveyor 48 and the hand stitching of the trailing edge of the tread strip for completion of the breaker and tread cylinder to be attached to the carcass. The transfer ring subassembly 36 includes a shiftable member 82 with a circular aperture 84 having an internal diameter greater than the external diameter of the breaker and tread cylinder. The aperture has its axis aligned with the axis of the carcass and breaker drum subassemblies for movement therebetween. Its lower end is supported on rails 86 for movement between its opposite end positions. A plurality of segments 88, eight in the disclosed preferred embodiment with arcuate interior surfaces, are adapted to move radially toward and away from the axis of the ring. Their open positions are radially removed from the axis of the ring, but they are movable radially interiorly to closed positions to grasp the breaker and tread cylinder. With the breaker and tread cylinder gripped by the transfer ring, the breaker drum is then collapsed to a reduced diameter so that the transfer ring may contact, grasp and then axially shift the breaker and tread cylinder to a position over and encompassing the carcass. Note the sequence shown in Figures 7A through 7F. The carcass is then expanded to contact the breaker and tread cylinder for adherence therebetween. The transfer ring is then expanded to release the breaker and tread cylinder and then move to a location between the two drum assemblies during the final stitching of the green tire. Thereafter, the transfer ring is moved to encompass the stitched green tire through the contraction of its segments. The exhausting of the air from the green tire and the separation of the flanges releases the green tire from the carcass drum assembly. The transfer ring then moves the green tire to a location between the drum assemblies where it is picked up by the robot. The segments are then expanded and the transfer ring returned to the breaker drum assembly to pick up the next breaker and tread cylinder while the robot conveys the green tire to the inspection station. Servicer Assembly The servicer assembly 38 may be considered as comprising the structures of the material support subassembly 40 and 42, the breaker feed subassembly 76 and 78 for conveying the breaker material to the breaker drum, and the cutter and tip aligner subassembly 44 located along the path of travel of the breaker material for cutting the breaker material fed from a supply roll into strips and for feeding such strips to the breaker drum. The servicer assembly also functions in association with the tread feed subassembly 48 located adjacent to the breaker drum but remote from the servicer assembly for feeding previously cut strips of tread material to the breaker drum. The support subassembly includes a plurality of interconnected channel irons and other supporting hardware and frames for the breaker feed subassembly and the cutter and tip aligner subassembly. The support assembly defines a path of movement for the fed breaker material from the rolls 40 and 42 to the breaker drum 26 by the sheet feed subassembly 76 and 78. Two such rolls, two sheet feed subassemblies and two cutter and tip aligner subassemblies are disclosed in the preferred embodiment to accommodate a tire being fabricated of two individual strips of breaker material. Any number of breakers, either more or less, could be utilized with a corresponding number of rolls and sheet feed and cutter and tip aligner subassemblies and sheet feed paths. The support subassembly also includes conventional frames for a preliminary conveyor 92, one for each sheet feed subassembly. Each frame has spaced rollers 94 supporting an inclined belt 96 with an upper surface located to allow an operator to manually adhere or stitch the trailing edge of a prior fed roll with the leading edge of the next following roll to be fed. The breaker material is then adapted to festoon or sag at 98 downwardly from the output end of the preliminary conveyor. The festooning of the breaker material allows the material to be easily withdrawn by a subsequent conveyor from a driven, rotatable supply roll without excessive forces which might otherwise withdraw materials irregularly resulting in imprecise feeding of the breaker material. A sensor is located to determine the extent or length of the festooned loop and to increase or decrease the speed of the preliminary conveyor and feed roll appropriately for maintaining the length of the festooned material within pre-selected limits. A loop which is too short might result in imprecise feeding of the fed material along with the stretching of the material. Similarly, a loop which is too long might also result in stretching of the fed material due to its weight. A device appropriate for this sensing and controlling function is a Sonitrol sensor manufactured and sold by Waddington Electronics, Inc., a corporation of the State of Rhode Island. Thereafter, the material is fed upwardly to the inclined input end of the input conveyor 102 and across an essentially horizontal stretch, terminating at a cutter and tip aligner subassembly 44. Guide rollers 104, one of which is driven by a motor, support the belt of the input conveyor. Prior to the belt of the input conveyor belt, a series of parallel rollers 106 overlie a plate at its edges to align the material prior to its contact with the belt. A second series of parallel rollers 108, perpendicular to the rollers of the first series, maintains the fed material in proper alignment centered on the conveyor belt. The rollers of the first and second series are adjustable toward and away from each other and the longitudinal center line of the plate and belt to accommodate the feeding and centering of breaker material of different widths. Idler rollers extend entirely across the path of travel at the curve of the input conveyor. At the input end of each input conveyor there is located a width sensor. Each sensor extends across the entire sheet feed path for the precise determination of the fed breaker material width at any particular time. This information is fed to the machine controller or programmer in combination with the timing belt position information, as is described hereinafter, so that the width of the sheet material in the cutter and tip aligner will be known precisely at the time the cutting and tip alignment is to be effected. This allows the precise cutting and tip alignment as a function of the location and width of the breaker material having been moved from the width sensor to the cutting and tip aligner location. The cutter and tip aligner subassembly 44 is located between the output end of the input conveyor and the input end of the intermediate conveyor 112. The input and intermediate conveyors include conveyor belts 114 and 116 upon which the breaker material rests and moves. Supporting rollers 118, one of which is driven, support the ends of the belt of each of the intermediate and input conveyor. Each intermediate conveyor is supported on brackets 120 which are longitudinally reciprocable on slide rails 122 of the frames of the support assembly. An air cylinder 124 has its piston secured to the brackets for independently reciprocating each intermediate conveyor longitudinally along the sheet feed path. The various conveyor belts described herein are actually timing belts. They are each formed with internal toothed surfaces 126 cooperable with belt pulleys having drive teeth for the accurate movement of the belts with respect to their pulleys, as well as the conveyed material along with sheet feed path. This arrangement allows for the accurate positioning of the belts and material through the conveyor system. The output from the drive pulleys may then precisely provide input signals to the controller for the overall precise and accurate operation of the tire building machine. Beneath the belts of the input and intermediate conveyors is a series of magnets 128 and 130 adapted to attract the breaker material due to its steel cords. This attraction allows for a precise positioning of the breaker material as set by the rollers prior to the belts of the input conveyor. This attraction also allows for the precise movement of the breaker material along the path of travel as determined by the movement of the conveyor belts. Located adjacent to the output end of the intermediate conveyor is an output conveyor 134 also formed as a belt 136, with support rollers 138, one of which is driven, and with magnets 140 on the side of the belt remote from the breaker material being fed. The output conveyor, however, is a bottom-feed conveyor adapted to accurately lift the cut breaker strips through magnets from the intermediate portion of the conveyor for delivery onto the breaker drum. Each output conveyor 134 of the disclosed two conveyor systems is reciprocable with the intermediate conveyor 112 to which it is coupled. Each output conveyor has an articulated support structure whereby it is pivotable about a central roller 142 but only after its intermediate conveyor has been driven to its extended position. With the intermediate and output conveyors in an extended and pivoted position, the output end of the output conveyor is in close proximity to the breaker drum, a feeding location sufficiently close to the breaker drum to preclude operator involvement during the transfer of a fed strip of breaker material onto the breaker drum. Air cylinders 124 associated with each output conveyor effect the longitudinal movement of the intermediate and output conveyors while coordinated air cylinders 144 mounted on each intermediate and output conveyor effect the pivotal movement of the output ends of the output conveyors. Note particularly the lower conveyor of Figure 9A. An optical sensor 148 is mounted on a depending vertical support 150 to detect the leading as well as the trailing edges of the cut breaker strips. The sensing is done very accurately. The sensed output is fed to the controller 146 whereat the speed of the intermediate and output conveyor may be increased or decreased appropriately so that all cut breaker strips will be of a precise length to fully cover the entire circumference of the breaker drum with no gap or overlap. In the case of the second breaker strip, that it may fully cover the first breaker strip with no gap or overlap. The controller could also be programmed to vary the rotational speed of the drum to effect the same result. The upper conveyor of the servicer functions to deliver the first strip of breaker material of the upper conveyor onto the breaker drum. Thereafter the lower conveyor will feed a second strip of breaker material over the initially fed breaker material from the upper conveyor. The programming of the system is such that the leading edge of the lower conveyor may be placed on the upper breaker material at any rotational position with respect to the leading edge of the first strip of breaker material on the breaker drum. Figures 6A through 6F show the breaker strips being delivered. The edge sensor and a timing belt function together in a synergistic manner to measure the location of the breaker material, to track its movement and the cutting and tip alignment, all of which are correlated to the center line of the belt and material. The tread feeding subassembly 48 is located on the side of the breaker drum remote from the servicer assembly. It is formed of parallel end rails 154 and coupled parallel side rails 156 with rollers 158 spanning the space therebetween. The rollers constitute a tread strip conveyor 160 and are driven by a motor. The upper surfaces of the driven rollers define the tread strip feed path. The tread strip feed path extends from a supply of precut strips of tread material and terminates in close proximity to the breaker drum whereby the leading edge may be fed in timed sequence to the drum rotation for applying the tread strip to the superposed breaker strips on the breaker drum. An optical sensor is located above the tread feed path for measuring the length of each fed tread strip. Through the logic of the control assembly 46, the output of the sensor functions to vary the speed of movement of the tread strips being fed. In this manner the fed tread strip will form a complete cylinder around the breaker strips with no overlap or gap. The controller could also be programmed to vary the rotational speed of the drum to effect the same result. The side rails and rollers are supported by an assembly for automatically pivoting the entire tread feed subassembly about shaft 162 on a floor support and through a piston 164 to longitudinally raise and lower the output end of the tread strip conveyor. The subassembly thus moves between an operative position shown in Figure 12B with the output end raised and located adjacent to the breaker drum and an inoperative position shown in Figures 12A with the output end lowered and located away from the breaker drum. This movement allows the operator access to the breaker drum to stitch the trailing end of the tread stock for completing the breaker and tread subassembly when the output end is lowered and retracted. Cutter and Tip Aligner Subassembly Cutting is effected by two freely rotatable knives 168 and 170 that are independently activatable but concurrently positionable at an angle with respect to the material to be cut. Since breaker material normally has steel or other hard cords from edge to edge at a specific predetermined angle, the cutters move at the same angle as the cords to cut the breaker material between the cords. It is preferred that the breaker material be cut evenly by cutting from the center of the material outwardly to the edges. In this manner the disturbing of the material from its intended central positioning is minimized. The angle of the knives may be varied to correspond to the angle of the steel cords of the breaker material. If cutting breaker material with its cords offset at 23 degrees, for example, the operator would set the cutter track at 23 degrees, either electronically through the panel of the control assembly or mechanically. The breaker strip material is stopped through the stopping of the conveyor for the cutting operation. The actual cutting of the breaker strips is effected by a pair of coordinated rotary knives having sharp peripheral edges adapted to cooperate with a hard metal plate or anvil 172 on the opposite side of the breaker material to be cut. The anvil is a fixed plate located above the conveyor belts but beneath the breaker material in the region where the cutting occurs. It is fixedly secured by its side edges to the frame structure. The knives and anvil are commonly supported by side brackets through an upper support shaft 174, for varying the horizontal path of travel of the cutters to equal the angle of the cords in the breaker strip material to be cut. The rotary knives are each mounted on a knife supporting shaft 176 for free rotation during their cutting movement which is effected by the breaker material and anvil over which they roll. The knife-supporting shafts are, in turn, supported by side plates 178. The adjacent remote ends of the plates support the rotary knives while their opposite ends are mounted on plate-supporting shafts to effect the pivoting of the side plates and knives into and out of cutting contact with the breaker strips and anvil. The side plates with their knives are independently reciprocable longitudinally along a track 174 through a carriage assembly 180 supporting the side plates. In this manner, the knives are independently pivotable through pneumatic pistons 182 into and out of contact with the anvil and the breaker strip to be cut. The knives are also independently movable across the anvil and the breaker material to be cut through pistons 184. In operation and use, the knives are located in their raised position as shown in Figure 11A adjacent to each other over a central extent of the breaker strip to be cut. The breaker strip is stopped for the cutting thereof. Cutting begins with the inner or longitudinally rearwardly moving knife 168 pivoting downward to pierce the breaker strip material between adjacent steel cords. Note Figure 11B. The lowered knife then begins movement inwardly or longitudinally rearwardly with respect to the material to initiate the cutting. The outer or longitudinally forwardly moving knife 170 moves along the track concurrently with the inner knife but in a raised position. Note Figure 11C. Thereafter, as shown in Figure 11D, the outer knife pivots downwardly into the cut in the breaker strip effected by the inner knife and then moves outward or longitudinally forward. The inner and outer knives are thus moving at a common speed, but in opposed directions, both knives traveling toward its adjacent edge and arriving at their edges at about the same time as shown in Figure 11E. Both knives then pivot to their raised positions after the cut has been completed and return to their rest positions adjacent to the longitudinal center line of the breaker strip material and conveyor belts. This mode of operation allows a precise cut, with the knives moving in opposite directions and arriving at the edges at the same time this minimizes the movement of the edges away from the longitudinal centerline. In practice it has been found that some movement of the edges of the breaker strip material will be laterally displaced during cutting. This is particularly true of the leading edge which is at an acute angle of, for example, 23 degrees from the longitudinal centerline of the material and conveyor belts in a preferred operative embodiment. Rather than attempt to preclude displacement of the leading edge as through clamps and magnets, it has been found easier to merely align such edge after the cut. This is effected by sets of rollers 188 located about parallel vertical axes on the sides of the cutter and anvil adjacent to the edges of the conveyor. Roller bearings are located on the support rods for the rollers to minimize frictional loss. A common plate 190 supporting the rollers adjacent to their upper edges is provided for supporting each set of rollers. The rollers will shift the leading edge back toward the longitudinal centerline a predetermined distance for the accurate realignment of the leading edge and the entire breaker strip. The primary force effecting realignment of the tip of the cut breaker material is a motor 192 to move a drive belt 194 on rollers 196. The roller-supporting plates are mounted on rotatable guides 198 secured to the drive belt for movement toward and away from the cut material but always parallel with the longitudinal center line of the fed material. The belt 194 is supported on rollers and move both the forward and rearward plates and their supported sets of rollers equally and oppositely to align the both edges of the cut breaker material at locations adjacent to their cuts. Parallelism is maintained through the primary guides and secondary guides being slidably received in parallel rods 202. The rods are pivotally secured to vertical side plates 204 movable on vertical axes 206 to a predetermined angle equal to the angle of breaker cut. Sensors 210 prior to the input conveyor belts sense the width of the breaker material to be cut and drive the motor for the plates and rollers 188 of the tip aligner 44 so that they will move outwardly from, and inwardly towards, the edges of the cut material to effect the trapping, squeezing and repositioning of the edges of the cut breaker material when in position between the rollers 188. The movement and extent of movement of the tip aligner rollers is effected through mechanisms as shown. Such movement is determined by the width of the material in the programmer as read by the width sensor and material location as determined by the timing belts and their output. Robot Assembly The robot 52 functions to move the carcass 12, previously constructed at the first stage tire building machine, not shown, from the pre-inflator 56 at the loading station 54, onto the flanges of the carcass drum. It then moves the carcass 12 with a breaker and tread cylinder thereon, the green tire 14, from the transfer ring 36 between the two drum assemblies, to an inspection station 212 for viewing by the operator. The inspection station is simply a table with an upper surface for supporting the green tire with its axis positioned vertically. The loading station 54, however, includes a table 214 having a conically shaped support 216 for retaining a carcass spaced from the table with its axis oriented vertically. Above the carcass is a sealing cone 218 movable into and out of contact with the upper edge of the carcass. An aperture through the center of the cone allows for the introduction of a short burst of air, from a source of compressed air, into the carcass sealed by the cones to return the carcass to its cylindrical orientation in the event that it has been deformed during storage. The robot 52 includes a flat rectangular plate 222 with an arcuate cutout 224 extending inwardly from the first or remote edge to form a semicircle with a radius slightly larger than the radius of the carcass when unexpanded. The second or near edge is supported by a motion imparting mechanism 226 for essentially universal movement. The motion imparting mechanism is, in turn, mounted to a vertical guide bar 230 for raising and lowering the plate by movement through an actuatable first drive carriage 232 in the Z meridian or vertically. The first drive carriage is mounted on a second drive carriage 234. The second drive carriage is actuatable to move a short horizontal guide bar 236 in the X meridian. The second drive carriage is movable upon a long horizontal guide bar 238 in the Y meridian, also horizontally. The three guide bars and two drive carriages function together from controller signals to impart the necessary three meridian horizontal and vertical movements to the robot plate and its arms in order to effect its intended functions. Signals from the controller also effect the opening and closing of the arms on the robot plate. Located on the plate on opposite sides of the cutout adjacent to the side edges are pairs of arms 242 pivotally secured to the plate by drive pins for moving the arms 244. The free ends of the arms are formed with curved flanges 246, or gripping surfaces, extending outwardly from the plate. The formed arms are generally movable concurrently between first open or separated positions where the arms are located remote from the cutout and second closed or adjacent positions where the arms are located to overlie the cutout. The flanges have smooth radially interior surfaces whereby they are moved inwardly to grasp the exterior of a carcass from a pre-inflator at the loading station and to move the grasped carcass onto the carcass drum. The exterior surfaces of the flanges of the arms are shaped to be inserted into an end of the green tire supported by the transfer ring between the carcass and breaker drums. When expanded, the robot grasps the green tire and transports it to an inspection station remote from the machine. The gripping of the carcass by the arms of the robot occurs at the circumferential edge of the carcass where the bead is located. The bead 250 is an inextensible cord and, as a result, the gripping will not stretch the carcass and will thereby ensure a more reliable gripping and retention of the gripped carcass by the arms. In operation and use, the plate 222 is initially held horizontally adjacent the pre-inflator and moved forward by the first drive carriage 232 with the plate located beneath the lower edge of the carcass. The pre-inflator provides an initial burst of air to the carcass to return the carcass to its essentially cylindrical shape. The retracted arms 244 are then pivoted inwardly toward the lower edge of the carcass for grasping it. The grasped carcass is then moved upwardly a slight extent to clear the lower cone of the pre-inflator. It is then horizontally withdrawn therefrom. The carcass and plate may then be inverted by the universal mechanism by rotary movement in an R meridian about an axis with the carcass depending from the horizontal plate to minimize deformation of the carcass during its movement. The movement is upwardly by the first drive carriage 232 and then horizontally in one or both meridians by the second drive carriage 234 above the carcass drum and the two guide bars. The network of two horizontal and one vertical guide rails define the path of movement of the robot as determined by the controller driving the two drive carriages. Note Figures 5A through 5F. The plate 222 is then held vertically with the carcass supported on a horizontal axis, parallel with, but offset from the axis of the carcass drum. The plate and carcass are then arcuately moved, plate side first, over the outboard flange of the carcass drum until the edges of the carcass overlie the outboard and inboard flanges. After the carcass has been let go, the flanges are pneumatically expanded radially into contact with the interior edges of the carcass for its support whereafter the arms of the robot are expanded and the plate lifted to allow for the inflation of the carcass through the introduction of air to the interior of the carcass concurrent with the axial movement of the flanges toward each other. This continues the carcass assumes a toroid shape. The sealing of the carcass is effected prior to bringing the flanges together. After the transfer ring 36 has moved a breaker and tread cylinder from the breaker drum 26 to encircle the carcass or the carcass drum, the carcass is further inflated to contact and adhere to the interior surface of the breaker and tread ring. At this point, the transfer ring 36 is expanded and axially shifted away to an intermediate location between the two drum assemblies so that a stitcher may secure the breaker and tread cylinder to the carcass thereby completing the green tire ready for vulcanization. The transfer ring 36 is then moved back to the green tire on the carcass drum whereat it is contracted to support the green tire while the air therein is depressurized. The transfer ring is then axially shifted to a location intermediate the carcass and breaker drums. The robot 52 is then moved with its plate 222 held vertically and its arms totally contracted so that the flanges of the arms are within one end of the green tire, that end facing the carcass drum. At this point the arms 244 are then expanded so that the exterior surfaces of the flanges of the robot grasp the green tire from its interior edge. The robot, with the green tire depending therefrom, is moved to the table 212 at the inspection station whereat the arms are contracted and the green tire deposited on the surface of table. The transfer ring 36 is then axially shifted for grasping the next breaker and tread cylinder in a continuing cycle of operation. When the transfer ring releases the green tire for being transported by the robot 52, the transfer ring 36 then begins moving toward the breaker and tread cylinder 20 while the robot 52 moves to pick up the next carcass 12 at the loading station in a continuing, automatic cycle of operation. The motors 252 for opening and closing the arms in a predetermined cycle of operation are all controlled automatically from the controller 46 at an operator station. A robot of this type is commercially available as a gantry type robot manufactured and sold by The C & D Machine & Engineering Company of Port Neches, Texas. The movement, sequence and timing of the robot may be modified by the operator. Controller Assembly and Method A controller assembly 46 dictates the operational events of the second stage tire building machine and the method of operation as described above including the carcass and breaker drum assemblies 24, the servicer assembly 38, the cutter and tip aligner assembly 44 and the robot assembly 52. The controller 46 is fully programmable by the operator through the control panel to vary the mode of operation of the various assemblies and component subassemblies and elements as may be desired to accommodate the fabrication of green tires of various characteristics from carcasses and breaker and tread strips of various characteristics. The controller 46 provides the operator with various timed windows of operation such as for bringing the carcass onto the pre-inflator at the input station 214 and for removing the green tire from the inspection or output station. A window of operation is meant to be a predetermined time period in the sequence of operation of the machine during which the operator must perform a particular task or step in the sequence of operations otherwise the machine will cease its next sequential function and stop its further functioning. Another window of operation is provided for placing a tread strip on the tread conveyor. In all other aspects, the controller drives the machine continuously and automatically without operator involvement. Inputs to the controller assembly 46 as set forth above include the breaker material width sensors 210 between the preliminary and input conveyors, the breaker strip length sensors 148, and the tread strip length sensor. Outputs from the controller assembly, as set forth above, include the drives for the preliminary conveyors and feed rolls, the breaker material conveyors, the tread material conveyor, the cutter and aligner subassembly, the drum assemblies, stitcher and robot. The method of operation basically involves the fabricating of a green tire 14 from a carcass 12 on a second stage tire building machine including the steps of providing a first inboard station for loading, shaping and stitching a first stage tire carcass, providing an outboard second station 24 axially offset from the first station for assembling a breaker and tread cylinder, feeding breaker strips to the second station, feeding a tread strip to the second station 24 for the completion of the breaker tread and cylinder, transporting the breaker and tread cylinder 20 from the second station 24 onto the periphery of the carcass 12 for the formation of a green tire 14 by a transfer ring 36 and then transporting the green tire 14 to an intermediate location to transport the carcass to the first station 16 and the green tire to a final location by a robot 52, and coordinating the movement of the breaker strip, tread strip, transfer ring and robot by a controller 46 in a continuous and automatic cycle of operation. The various sensors and control functions act together to synchronize the various component elements, subassemblies and assemblies of the machine. They also allow for the programmability of such functions to provide flexibility through the controller, all precisely determined by the precise measurements initiated with the toothed timing belts and the associated sensors. Further specifics involved in the method of operation are detailed more completely in the descriptions of the various assemblies, subassemblies and components as described above.

Claims: A method of fabricating a green tire from a carcass (12) on a second stage tire building system including: providing a first drum (16) for receiving and supporting a first stage tire carcass (12); providing a second drum (26) rotatable about a fixed horizontal axis axially offset from the first drum (16) for assembling a breaker and tread cylinder (20); feeding breaker material (28,30) to the second drum (26) to form a breaker cylinder; feeding tread material (32) to the second drum (26) over the breaker cylinder to form a breaker and tread cylinder (20); stitching the tread material (32) to the breaker material; transporting by a transfer ring (36), the breaker and tread cylinder (20) from the second drum (26) onto the periphery of the carcass (12) at the first drum (16) for the assembly of the green tire (14) and transporting the green tire (14) to an intermediate location; characterized by providing the first drum (16) being rotatable about a fixed horizontal axis; grasping by a robot (52), the external surface of the carcass (12) and transporting the carcass (12) onto the first drum (16) at the first station and then grasping the internal surface of a green tire (14) and transporting the green tire (14) from the transfer ring (36); and coordinating the movement of the breaker material (28,30), the tread material (32), the transfer ring (36) and the robot (52) by a controller (46) in a continuous and automatic cycle of operation. A tire building machine (10) including: a first station having a first tire building drum (16) rotatable about a horizontal axis for receiving and supporting a first stage tire carcass (12); a second station having a second axially fixed breaker and tread cylinder building drum (26) rotatable about a horizontal axis axially aligned and offset from the first drum (16) for assembling a breaker and tread cylinder (20); a servicer (38) for feeding breaker strip material (28,30) to the second drum (26) to form a breaker cylinder; a tread conveyor (48) for feeding tread strip material (32) to the second drum (26) over the breaker cylinder to form a breaker and tread cylinder (20); a transfer ring (36) to transport the breaker and tread cylinder (20) from the second drum (26) onto the periphery of a carcass (12) at the first drum (16) for the assembly of a green tire (14) and to then transport a green tire (14) from the first station to an intermediate location; characterized by the first station having a first axially fixed tire building drum (16); a robot (52) having a pair of arms (244) to grasp the external surface of a carcass (12) and transport the carcass (12) onto the first drum (16) and then to grasp the internal surface of a green tire (14) and transport the green tire (14) from the transfer ring (36); and by control means (46) to coordinate the movement of the servicer (38), conveyor (48), transfer ring (36) and robot (52) in a continuous and automatic cycle of operation. The tire building machine as set forth in claim 2 and further including an input station adapted to support a carcass (12) to be transported by the robot (52) to the first station. The tire building machine as set forth in claim 2 or 3 and further including an output station adapted to receive a green tire (14) transported thereto by the robot (52). The tire building machine as set forth in one of claims 2 - 4 wherein the control means (46) is adapted to receive signals from the servicer (38) indicative of the length of the breaker material (28,30) and, in response thereto, to vary the relative speed of movement between the servicer (38) and a rotating breaker material receiving drum (26) at the second station. The tire building machine as set forth in claim 5 wherein the control means (46) is adapted to receive signals from the conveyor (48) indicative of the length of the tread material (32) and, in response thereto, to vary the relative speed of movement between the conveyor (48) and the rotating tread material-receiving drum (26). The tire building machine as set forth in one of claims 2 - 6 wherein the control means (46) is programmable by an operator. The tire building machine as set forth in one of claims 2 - 7 and further including means associated with conveyor belts (114,116) for driving the belts (114,116) as well as tire conveyed material and for inputting the control means (46) as a function of the location of the conveyor belt (114,116) and conveyed material along the sheet feed path. A second stage tire building machine as set forth in one of claims 2 - 8, characterized by an input station (54) adapted to support the carcass (12) to be transported to the first drum (16); an output station adapted to receive the green tire (14) transported thereto by the robot (52); and programmable control means (46) to coordinate the movement of the servicer (38), tread conveyor (48), transfer ring (36) and robot (52) in a continuous and automatic cycle of operation and to receive signals from the servicer (38) and the tread conveyor (48) indicative of the lengths of the breaker material (28,30) and the tread material (32) and, in response thereto, to vary the relative speed of movement between both the second drum (26), the servicer (38) and the tread conveyor (48). The tire building machine as set forth in one of claims 2 - 9, and further including positive drive means for the conveyor belts (114,116), such positive drive means including a toothed belt (126) and toothed pulleys for the positive driving of the belt (114,116) and conveyed material and for the precise input of the belt (114,116) and material location to the control means (46).

Inventors: BAILEY, DAVID WILLIAM
Applicants: THE UNIROYAL GOODRICH TIRE COMPANY
Application year: 1989
Main classification: B29D30
IPC codes: B29D30