Abstract:
An apparatus for spreading the bead of a pneumatic tire from a rim has a double acting piston and cylinder assembly that moves to an extended spread position and a retracted position. The piston and cylinder assembly has a cylinder, a piston slideably disposed in the cylinder and a piston rod connected to the cylinder. A first jaw connected to the piston rod is adapted to engage the rim supporting the tire. A second jaw is secured to the cylinder for engagement with the bead of the tire. A rod and tube guide structure connected to the first jaw in the cylinder maintains the jaws in longitudinal alignment during the extension and contraction of the piston and cylinder assembly. A control valve mounted on the cylinder has a pair of valving members interconnected with a pivoted beam so that the valving members function together to selectively move the jaws to an expanded spreading position and a retracted position.

Description:
This application is a continuation-in-part of U.S. application Ser. No. 342,446 filed Apr. 24, 1989. 
    
    
     FIELD OF INVENTION 
     The invention relates to spreading devices for pneumatic tires. The devices operate to spread the beads of the tires and hold the tires in spread positions to facilitate inspection and repair of the inside of the tires. 
     BACKGROUND OF INVENTION 
     Tubeless pneumatic tires are normally mounted on rims secured to axles of vehicles. When the tires are punctured or cut repairs are required to restore the tires to operating condition. The tires must be spread from the rims to provide access to the interior of the tires so that work persons can inspect and perform necessary repairs. Mechanical devices operated with air cylinders are used to break the beads of tires from rims. An example of a tire bead releaser tool for vehicle tires is disclosed in U.S. Pat. No. 2,775,290 issued to C. C. Mondaro on Dec. 25, 1956. Once the beads are separated from the rims one of the beads must move away from the rims to permit inspection and repair. The beads must be retained in the spread positions for inspection and repair of the tires. Mechanical tire spreaders are used to hold open tire beads to allow inspection and servicing of tires. These spreaders have brackets and arms that are moved apart to spread the beads of vehicle tires. The tire spreader of the invention is an improvement over prior tire spreading devices. 
     SUMMARY OF INVENTION 
     The invention relates to an apparatus to spread a pneumatic tire bead away from a rim and hold the tire in a spread position to enable a work person to inspect and repair the inside of the tire. The apparatus is also used to spread opposite beads of a tire. The apparatus has a linear actuator having relatively moveable members supporting jaws that engage the rim and a tire bead to spread one side wall of the tire away from the rim and hold the tire in a spread position. The apparatus is portable and useable for field service tire repairs. 
     The preferred embodiment of the tire spreader has a piston and cylinder assembly that includes a piston rod slidably mounted in a cylinder. A front jaw is mounted on the piston rod. A rear jaw is mounted on the cylinder. A linear guide structure connected to the front jaw and cylinder maintains the jaws in alignment with each other. An air control valve incorporated into a handle is mounted on the cylinder to control the expansion, holding, and contraction of the piston rod relative to the cylinder. The control valve has a pair of valving members to selectively control flow of air to and from opposite ends of the cylinder and trap air within the cylinder. When the front jaw is in engagement with the rim of the tire the rear jaw engages a bead of the tire. Upon expansion the piston and cylinder assembly the tire is spread and held in a spread position to provided access for servicing and repair of the tire. When the piston and cylinder assembly is retracted the tire spreader can be removed from the tire and rim. 
     The tire spreader is useable with different size tires and readily handled and operated with a single work person. The tire spreader operates to hold the tire in a spread position so that the work person can inspect and service the inside of the tire. After the tire has been repaired, the tire spreader is contracted and removed from the tire. The tire is then remounted on the rim and inflated with air. 
     The invention includes a control valve assembly for regulating the flow of fluid, such as air under pressure, to opposite chambers of a double acting piston and cylinder assembly. The control valve has a body with space generally parallel first and second bores. Valve members are moveably located in the bores for selective movement between open and closed positions. Each valve member has a first spool for controlling the flow of fluid to one of the chambers of the piston and cylinder assembly and a second spool for controlling the flow of fluid out of the other chamber of the piston and cylinder assembly when fluid under pressure is supplied to the one of the chambers. Seals located in the bores cooperate with the spools to control the flow of fluid through the bores. The fluid under pressure acting on the valve members operates to automatically return the valve members to their closed positions without external force or springs. The body has a fluid inlet port open to the first bore adapted to be connected to a supply of fluid under pressure. A passage in the body connects the first bore with the second bore to allow fluid under pressure to flow from the first bore to the second bore. A first fluid outlet port open to the first bore is adapted to be connected with a tube or like means that carries the fluid under pressure to and from one chamber of the piston and cylinder assembly. A second fluid outlet port in the body open to the second bore is adapted to be connected to a tube having a passage for carrying fluid under pressure to and from the other chamber of the piston and cylinder assembly. 
    
    
     DESCRIPTION OF DRAWING 
     FIG. 1 is a side elevational view of the tire spreader of the invention in the retracted position; 
     FIG. 2 is a perspective view of a vehicle tire spread apart with the tire spreader of FIG. 1; 
     FIG. 3 is a foreshortened side elevational view of the tire spreader of FIG. 1 in the expanded position; 
     FIG. 4 is a front elevational view of the tire spreader of FIG. 1; 
     FIG. 5 is a rear elevational view of the tire spreader of FIG. 1; 
     FIG. 6 is a top plan view of the tire spreader of FIG. 1; 
     FIG. 7 is a sectional view taken along line 7--7 of FIG. 6; 
     FIG. 8 is an enlarged sectional view taken along line 8--8 of FIG. 7; 
     FIG. 9 is an enlarged sectional taken along line 9--9 of FIG. 8 showing the air control valve in the hold position; 
     FIG. 10 is a sectional view taken along line 10--10 of FIG. 9; 
     FIG. 11 is a sectional view similar to FIG. 10 showing the air control valve in the jaw spread position; 
     FIG. 12 is a sectional view similar to FIG. 10 showing the air control valve in the jaw contract position; and 
     FIG. 13 is a sectional view similar to FIG. 10 showing the air control valve in the valve storage position. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
     Referring to the drawing there is shown in FIGS. 1 and 2 the tire spreader of the invention indicated generally at 10 for spreading a bead 102 of a tire 101 away from a rim 103 and hold bead 102 in a spread position. Spreader 10 is also useable to separate the beads and side walls of a conventional pneumatic tire for inspection and repair by a work person. Tire spreader 10 has a linear extendible and contractible apparatus, shown as a piston and cylinder assembly 11. Piston 29 is an elongated cylindrical member having a forward end that is attached to a front jaw 12. A rear jaw 13 in general longitudinal alignment with front jaw 12 is attached to cylinder 23. Front jaw 12 has a downwardly and forwardly directed lip 14. Rear jaw 13 has a downwardly and rearwardly directed lip 16 in general horizontal alignment with lip 14. A generally horizontal hand grip 17 is secured to the mid portion of the top of cylinder 23. An inverted U-shaped handle 18 is secured to the top of the forward end of cylinder 23 to facilitate manual handling of tire spreader 10. Grip 17 surrounds an air control valve 19, shown in FIG. 7, that is operable to selectively supply and axhaust air under pressure from opposite ends of cylinder 23. Valve 19 has a pair of actuators 21 and 22 that are manually operable to control the flow of air to and from the opposite ends of cylinder 23, as hereinafter described. 
     As shown in FIG. 7, cylinder 23 has a closed end 24 closing a first chamber 26. A generally cup shaped piston 27 carrying annular seals 28 is slideably located within cylinder 23. An elongated tubular piston rod 29 attached to piston 27 extends through a sleeve or collar 31 at the rod end of cylinder 23. An annular seal 32 is interpossed between collar 31 and the inner surface of cylinder 23 to enclose a second chamber 30 whereby piston and cylinder assembly 11 has a double acting function. Collar 31 is retained in assembled relation with cylinder 23 with a snap ring 33 positioned in an annular groove 34 in the inner surface of cylinder 23. 
     Front jaw 12 has a rearwardly directed neck 36 attached to the downwardly directed jaw portion that terminates in lip 14. An upwardly directed ear 37 attached to neck 36 is secured to the forward or outer end of piston rod 29 so that front jaw 12 moves with piston rod 29 relative to cylinder 23. The linear longitudinal movement of jaw 12 is maintained with a linear guide rod 38 secured to the rear portion of neck 36. Guide rod 38 is slideably located in a linear tube 39 secured by welds or the like to a bottom linear portion of cylinder 23. Tube 39, as seen in FIG. 8, projects through a opening 42 in the upper end of rear jaw 13. Rod 38 and tube 39 comprise a guide assembly for jaw 12 that prevents rotation of jaw 12 relative to jaw 13 during relative movement of the jaws 12 and 13. 
     Rear jaw 13 has a generally U-shaped upper end 43 welded to a circumferential portion of cylinder 23 thereby fixing rear jaw 13 to cylinder 23. Jaw 13 has opposite side edges that diverge outwardly and downwardly toward lip 16. Jaw 13 projects downwardly and has a length that is substantially the same as the length of jaw 12. 
     As seen in FIGS. 5 and 7, a downwardly directed bracket 44 having a pair of holes 46 is secured to end plate 24. The holes are adapted to receive fasteners that attach an auxiliary jaw (not shown) to cylinder 23. In large tires the auxiliary jaw is used to increase the spread distance of the tire bead relative to the rim. 
     Referring to FIGS. 3, 6, and 7, handle 18 has a transverse generally horizontal hand grip 47 located adjacent the forward end of cylinder 23. A pair of downwardly and rearwardly directed legs 48 and 49 attached to opposite ends of hand grip 47 are secured to the cylinder 23 as seen in FIG. 6. 
     Handle 17 has an inverted U-shape body 51 that extends over an air control valve 19. The lower portions of body 51 are located in close relationship to the outer cylindrical surface of cylinder 23 to protect the sides of control valve 19. A rearwardly direct second hand grip 52 is joined to body 51 to permit tire spreader 10 to be handled with both hands of the work person. Hand grip 47 is oriented perpendicular to hand grip 52. Grip 47 is transverse to the longitudinal axis of cylinder 23. Grip 52 is parallel to the longitudinal axis of cylinder 23. 
     As shown in FIG. 7, an upwardly directed mounting bracket 53 is located within U-shape body 51 and secured thereto by welds or the like. Control valve 19 has a body or housing 54 that is attached to body 51 with a fastener such as a bolt 56. Bolt 56 is threaded into a threaded hole 57 in the body 51, as shown in FIGS. 10, 12 and 13. 
     As shown in FIG. 10, body 54 has a first upright bore 58 having a lower reduced diameter portion 59 extended to an inwardly directed annular shoulder 61 surrounding a lower open end 62. First bore 58 accommodates a first generally upright spool 63 and a second spool 64. A neck 66 connects spools 63 and 64. A second neck 67 secured to the upper end of spool 63 is attached to a cylindrical actuator body or member 68. A metal sleeve or channel bushing 69 located in bore 58 surrounds neck 67. Sleeve 69 has a side port 71 in alignment with a passage 72 in body 54 in communication with air supply pipe 88. An O-ring 73 located above sleeve 69 engages a cylinderical bearing 74 located in bore 58. Cylindrical actuator member 68 linearly slides on the inner surface of bearing 74 as it moves between its open and closed positions. A retaining ring 60 surrounding actuator member 68 holds bearing 74 in bore 58. A second O-ring located below sleeve 69 surrounds the spool 63. Another O-ring 78 surrounds the lower end of spool 63. A second metal sleeve or channel bushing 77 having a side port 75 is located between O-rings 76 and 78. Opening 75 is in alignment with a passage 132 leading to pipe 92. 
     A third metal sleeve or channel bushing 79 surrounds neck 66 and engages an O-ring 81 surrounding spool 64. Sleeve 79 has a side port 82 allowing air to flow from the inside of sleeve 79 and around sleeve 79 to a passage 106. A C-clip or retainer 83 is secured to the bottom of spool 64 to limit upward movement of actuator 21 caused by air under pressure acting on member 68. 
     Housing 54 has a second generally upright bore 101 having a lower reduced diameter bore portion 102. An inwardly directed shoulder 103 at the bottom of bore 101 surrounds a bottom opening 104. A generally upright upper spool 106 and a lower spool 107 are located in bore portion 102. The lower spool 107 projects through lower opening 104 in communication with atmosphere. A reduced diameter neck 108 connects spools 106 and 107. A cylindrical actuator body 109 is located in bore 101 above spool 106. A reduced diameter neck 111 connects spool 106 with the bottom or actuator body 109. An upper retaining ring 112 mounted on housing 54 surrounds actuator body 109. A lower retaining ring 113 mounted on spool 107 limits upward movement of actuator 22 relative to housing 54 cause by air under pressure acting on body 109. A first metal sleeve or channel bearing 114 located in bore 101 surrounds neck 111. Sleeve 114 has a side port 116 open to bore 101 and a transverse passage 117 leading to bore 58. An O-ring 118 is located above sleeve 114 and below a bearing 119 located in bore 101. Body 109 slides on bearing 119 during movement of actuator 22 between its open and closed positions. 
     A second metal sleeve or channel bearing 121 having a side port 122 aligned with a passage 123 leading to the lower portion of bore portion 59 is located in bore portion 102. A second passage 124 is open to pipe 97 and the bore portion 102 adjacent sleeve 121. An O-ring 126 surrounding spool 106 engages the bottom of sleeve 114. A second O-ring 127 around spool 106 engages the bottom of sleeve 121. A third sleeve or channel bearing 128 having a side port 129 aligned with a passage 131 in housing 154 is located about neck 108. Passage 131 is open to bore portion 59 adjacent sleeve 77. A second passage 132 in housing 54 connects bore section 59 with pipe 92 allowing air to evacuate from pipe 92 to atmosphere when actuator 22 has been moved to the in or open position. An O-ring 133 is interposed between the bottom of sleeve 128 and shoulder 103. O-ring 133 surrounds and is located in sealing engagement with the lower spool 107. 
     FIG. 10 shows the valve in the hold position. The valve actuators 21 and 22 are in the up or closed positions wherein spools 63, 64, 106 and 107 are in sealing engagement with their associated O-rings thereby preventing air from being introduced to the cylinder and evacuated from the cylinder. The pressure of the air within sleeves 69 and 114 acting on bodies 68 and 109 force actuators 21 and 22 to the closed positions. 
     Referring to FIG. 11, valve assembly 19 is shown in the position wherein actuator 21 allows air under pressure to chamber 26 to extend spreader 10 and allows air to exhaust from chamber 30. The air under pressure from inlet pipe 88 flows through passage 72, port 71 through O-ring 76 and out through port 71 through passage 132 to pipe 92 leading to chamber 26. The flow of air is indicated by arrow 134. Air is exhausted from the opposite end of the cylinder via pipe 97, passage 124, around sleeve 121 and through passage 123 through port 82 and O-ring 81 and bottom openings 62 to atmosphere. The flow of exhaust air has shown by the broken line arrow 136. 
     Referring to FIG. 12, actuator 22 has been moved to the down or open position as indicated by arrow 137 to supply air under pressure to pipe 97 to retract piston 29 into cylinder 39 as shown in FIG. 7. Air is evacuated from chamber 26 via pipe 92. The air under pressure from pipe 88 flows through passage 92 around sleeve 69 through passage 117 into bore 101 surrounding sleeve 114. The air flows through O-ring 126, port 122, around sleeve 127, and through passage 124 into pipe 97 leading to chamber 30 as seen in FIG. 7. The flow path of the air is indicated by arrow 138. Exhaust air from pipe 92 flows through passage 132 around sleeve 77, through passage 131 and port 129, O-ring 133 and opening 104 to atmosphere. The flow path of the exhaust air is shown by the broken line arrow 139. 
     Referring to FIG. 13, there is shown valve assembly 19 in the storage or total exhaust position. Both valve actuators 21 and 22 have been moved to the down or open positions as indicated by the arrows 141 and 142. Valve actuator 21 allows the air from the chamber 30 of the piston and cylinder assembly to evacuate to atmosphere. Valve actuator 22 functions to allow air from the chamber 26 of the piston and cylinder assembly to evacuate to atmosphere. Thus, the piston and cylinder assembly 11 is relieved of air pressure during storage. The air in pipe 92 flows passage 132, around sleeve 77, through passage 131, through port 129 into sleeve 128, downwardly through O-ring 133 and outlet passage 104 to atmosphere. The air in pipe 97 flows through passage 124 around sleeve 121, through passage 123 and into sleeve 79 via port 82, down through O-ring 82 and outlet openings 62 to atmosphere. The flow path of the air is shown by the broken line arrow 144. 
     In use as shown in FIG. 2, tire spreader 10 is used to spread one of the beads 102 of the pneumatic tire from rim 103 after it has been separated from the rim. Rim 103 is secured to a support or holder 104 which retains the rim in its upright position. Front jaw 12 is placed in engagement with the lower edge of rim 103. Rear jaw 13 is placed inside tire bead 102. The operator utilizes hand grips 17 and 18 to manually place tire spreader 10 in its operative position relative to rim 103 and tire bead 102. Valve assembly 19 is connected to a source of air under pressure. Actuator 21 is operated to spread bead 102 from rim 103 by allowing air to expand the piston and cylinder assembly 11. When actuator 21 is released air is locked within piston and cylinder assembly 11 to hold the jaws in the open or expanded positions. The work person having acess to the interior of the tire can preform inspection and repair. The spreader 10 is removed from the tire and rim by moving actuator 22 to the in or open position whereby the air contracts te piston and cylinder assembly 11. 
     Spreader 10 can also be used to spread or separate opposite beads and side walls of a pneumatic tire. The jaws 12 and 13 are located in engagement with inside portions of the opposite beads. Expansion of the piston and cylinder assembly 11 spreads the beads to allow inspection and repair by the work person. The spreader 10 is removed from the tire by contracting the piston and cylinder assembly 11. 
     While there has been shown and described a preferred embodiment of the tire spreader of the invention is understood that changes in the structure, arrangement of structure and parts may be made by those skilled in the art without departing from the invention. The invention is defined in the following claims.