Patent Publication Number: US-6655941-B1

Title: Central mechanism for a tire vulcanizer

Description:
This application is a divisional of application Ser. No. 08/657,287, filed on Jun. 4, 1996, now U.S. Pat. No. 6,062,837 issued May 16, 2000, the entire contents of which are hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION AND RELATED ART STATEMENT 
     The present invention relates to a central mechanism for a tire vulcanizer, which uses a both-end open type bladder. 
     A conventional tire vulcanizer is described with reference to FIG.  6 . Reference numeral  50  denotes a bladder,  51  denotes a lower ring,  51   a  denotes an internally threaded portion provided on the lower inside peripheral surface of the lower ring  51 , and  52  denotes a lower bead ring fixed to the lower ring  51 . The lower part of the bladder  50  is held by the lower ring  51  and the lower bead ring  52 . 
     Reference numeral  53  denotes a housing,  53   a  denotes an externally threaded portion provided on the upper outside peripheral surface of the housing  53 , and  54  denotes O-ring grooves provided on the aforementioned outside peripheral surface of the housing  53 . The externally threaded portion  53   a  provided on the upper outside peripheral surface of the housing  53  is threadedly engaged with the internally threaded portion  51   a  provided on the lower inside peripheral surface of the lower ring  51 , so that the housing  53  is detachably fixed to the lower ring  51 . 
     A post  55  is provided in the housing  53  in such a manner as to be capable of moving vertically. At the upper part of the post  55  are provided an upper ring (not shown) for holding the upper part of the bladder  50  and an upper clamp ring (not shown). The upper ring and the post  55  are bolted to each other, and the lower end of the post  55  is connected to a piston of a fluid pressure cylinder, so that when the fluid pressure cylinder is operated in the extending direction, a bladder assembly (a bladder assembly consisting of the bladder  50 , the lower ring  51 , the lower bead ring  52 , the upper ring, and the upper clamp ring) is elevated. 
     At this time, the lower ring  51  is rotated about five to six turns together with the bladder  50  by man power so that the lower ring  51  is removed from the housing  53 , by which the bladder  50  and the O-rings in the O-ring grooves  54 , which are expendables, are replaced. 
     On the conventional tire vulcanizer shown in FIG. 6, when the bladder  50  and the O-rings are replaced, an operator must remove the housing  53  by rotating the lower ring  51  about five to six turns together with the bladder  50  in a high-temperature atmosphere. Therefore, not only the replacement of the bladder  50  and O-rings requires much time, but also hard work is forced upon the operator in a high-temperature atmosphere, which imposes an excessive burden on the operator. 
     Also, since the replacement of the bladder  50  and O-rings requires much time as described above, the productivity is decreased, and radiation loss is increased. 
     To overcome these problems, the applicant of this invention has already proposed a tire vulcanizer shown in FIGS. 7 and 8 (Japanese Patent Provisional Publication No. 01-047511 (047511/1989)). 
     With this tire vulcanizer, after the vulcanization of a tire is completed, a piston rod  136   a  of a fluid pressure cylinder  136  is operated in the extending direction to turn a Y-shaped lever  133  clockwise around a rotation axis  132 , by which a lever  135  and a fluid pressure cylinder  123 , and a housing  115 , a piston rod  123   a , a rod  116 , a bladder assembly  105  to  113 , and each vulcanizing medium inflow/outflow pipe  114  are elevated to separate a lower bead ring  110  of the bladder assembly  105  to  113  from a lower mold  104 . 
     Next, piston rod  139   a  of a fluid pressure cylinder  139  for each stopper  141  is operated in the extending direction to move each stopper  141  to a position just under each nut  127 . 
     Then, the piston rod  136   a  of the fluid pressure cylinder  136  is operated in the retracting direction to turn the Y-shaped lever  133  counterclockwise around the rotation axis  132 , by which the lever  135  and the fluid pressure cylinder  123 , and the housing  115 , the piston rod  123   a , the rod  116 , the bladder assembly  105  to  113 , and each vulcanizing medium inflow/outflow pipe  114  are lowered to make each nut  127  abut against each stopper  141 . 
     At this time, the lowering of each vulcanizing medium inflow/outflow pipe  114  and the bladder assembly  105  to  113  ceases, but the lowering of other parts, that is, the lever  135  and the fluid pressure cylinder  123 , and the housing  115  and the bladder assembly  105  to  113  continues. Therefore, each belleville spring  128  is pressed by a flange  123   c  of the fluid pressure cylinder  123 , and a head  114   a  of the vulcanizing medium inflow/outflow pipe  114  is separated from an engagement hole  109   a  formed in a lower ring  109  of the bladder assembly  105  to  113 . 
     When this state is reached, a bolt  126 , which detachably fixes an upper ring  106  of the bladder assembly  105  to  113  to a rod  116 , is removed. 
     Then, the bladder assembly  105  to  113  is rotated in the direction of arrow (F) (counterclockwise) in FIG. 8 in the range of the engagement hole  109   a  around the center axis of the tire vulcanizer by man power, so that the head  114   a  of each vulcanizing medium inflow/outflow pipe  114  is positioned at the large-diameter hole portion of the engagement hole  109   a . Reference character L in FIG. 8 denotes a lock position, and UL denotes an unlock position. 
     Next, the bladder assembly  105  to  113  is pulled out upward. 
     After the old bladder is replaced with a new one, the bladder assembly  105  is mounted by reversing the above procedure, by which the preparation for tire vulcanization is completed. 
     On this tire vulcanizer, although the amount of rotation is significantly reduced, the lower ring must be rotated together with the bladder. Therefore, the frictional resistance of O-ring, which is inserted between the lower ring and the housing, is high, so that there remains a problem of hard work being forced upon the operator in a high-temperature atmosphere. 
     OBJECT AND SUMMARY OF THE INVENTION 
     The present invention was made to solve the above problems. Accordingly, an object of the present invention is to provide a central mechanism for a tire vulcanizer, which can significantly shorten the work time for replacing a bladder, which is an expendable. 
     To achieve the above object, the present invention provides a central mechanism for a tire vulcanizer, which uses a both-end open type bladder, comprising: a plurality of clamp rods slidably inserted into a housing to the lower part of which a post cylinder for vertically expanding and contracting a bladder assembly is assembled; a claw mechanism for detachably engaging the upper end portion of the clamp rod with the lower ring of the bladder assembly; and driving means for vertically moving and turning the clamp rod. 
     The central mechanism for a tire vulcanizer in accordance with the present invention, which is constructed as described above, is operated as described below. After a tire has been vulcanized (a bladder is expanded), the clamp rod is elevated to elevate a lower ring and separate it from the housing. After that, the clamp rod is turned so that a claw of the claw mechanism between the lower ring and the clamp rod can pass through. Then, a pin fixing a post to an upper ring is pulled out, and the bladder assembly is hung and carried out of the vulcanizer to replace the bladder and O-rings. After the bladder and other parts have been replaced, the bladder assembly is hung and mounted to the vulcanizer so that the hole for the claw mechanism of the lower ring is aligned with the upper end of the clamp rod. At this time, when the claw of the claw mechanism passes through, the lower ring is supported by the elevated clamp rod, and the lower ring and a supply/discharge opening of the housing is aligned with each other. After the mounting of the bladder assembly is completed, the pin is inserted in the upper ring and the post by reversing the above procedure to connect them to each other. The clamp rod is turned in the reverse direction to engage the claw of the claw mechanism. Then, the clamp rod is lowered to seat the lower ring on the housing, by which the preparation for vulcanizing tire is completed. 
     In a central mechanism for a tire vulcanizer in accordance with the present invention, after a tire has been vulcanized (a bladder is expanded), the clamp rod is elevated to elevate the lower ring and separate it from the housing. After that, the clamp rod is turned so that the claw of the claw mechanism between the lower ring and the clamp rod can pass through. Then, the pin fixing the post to the upper ring is pulled out, and the bladder assembly is hung and carried out of the vulcanizer to replace the bladder and O-rings. After the bladder and other parts have been replaced, the bladder assembly is hung and mounted to the vulcanizer so that the hole for the claw mechanism of the lower ring is aligned with the upper end of the clamp rod. At this time, when the claw of the claw mechanism passes through, the lower ring is supported by the elevated clamp rod, and the lower ring and a supply/discharge opening of the housing is aligned with each other. After the mounting of the bladder assembly is completed, the pin is inserted in the upper ring and the post by reversing the above procedure to connect them to each other. The clamp rod is turned in the reverse direction to engage the claw of the claw mechanism. Then, the clamp rod is lowered to seat the lower ring on the housing, by which the preparation for vulcanizing tire is completed. Therefore, when the bladder and other parts are replaced, the manual work which must be done by the operator is only the insertion and withdrawal of the pin fixing the post to the upper ring and the attachment and removal of lifting equipment, so that the manual turning work of the lower ring, which has so far been most dangerous and required much time, can be eliminated. Thereupon, the work time for replacing a bladder, which is an expendable, can be shortened significantly. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a longitudinal side sectional view showing one embodiment of a central mechanism for a tire vulcanizer in accordance with the present invention; 
     FIG. 2 is a longitudinal side sectional view of the central mechanism for a tire vulcanizer; 
     FIG. 3 is a side view along the line C—C of FIGS. 1 and 2; 
     FIG. 4 is an enlarged longitudinal side sectional view of the arrow B portion of FIGS. 1 and 2; 
     FIG. 5 is a plan view along the line D—D of FIG. 4; 
     FIG. 6 is a longitudinal side sectional view of a conventional central mechanism for a tire vulcanizer; 
     FIG. 7 is a longitudinal side sectional view showing another example of conventional central mechanism for a tire vulcanizer; and 
     FIG. 8 is a transverse plan view along the line E—E of FIG.  7 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     A central mechanism for a tire vulcanizer in accordance with the present invention will be described with reference to one embodiment shown in FIGS. 1 to  5 . FIGS. 1 and 2 are longitudinal side sectional views taken along the center line A—A of the central mechanism for a tire vulcanizer. In these figures, the members composing the tire vulcanizer, such as an upper mold and a beam for attaching the upper mold, are omitted. The right-hand and left-hand portions of the centerline A—A in FIG.  1  and the left-hand portion of the centerline A—A in FIG. 2 have a different phase. 
     Reference numeral  1  denotes a base for a tire vulcanizer,  3  denotes a lower platen fixed to the base  1  via a heat insulating plate  2 ,  4  denotes a lower mold bolted to the lower platen  3 , reference character T denotes a tire being vulcanized, and B denotes a bladder. 
     Reference numeral  7  denotes a lower ring, and  6  denotes a lower bead ring bolted to the lower ring  7 . The lower end portion of the bladder B is held by the lower ring  7  and the lower bead ring  6 . This lower bead ring  6  can be fitted into a central concave portion of the lower mold  4 , forming a part of the tire mold. 
     Reference numeral  10  denotes an upper ring, and  11  denotes an upper bead ring bolted to the upper ring  10 . The upper end portion of the bladder B is held by the upper ring  10  and the upper bead ring  11 . This upper bead ring  11  can be fitted into a central concave portion of the upper mold (not shown), forming a part of the tire mold. 
     The lower ring  7 , the lower bead ring  6 , the bladder B, the upper ring  10 , and the upper bead ring  11  composes a bladder assembly. This bladder assembly is assembled in advance outside the tire vulcanizer and carried into the vulcanizer. In this embodiment, however, a lower nozzle  8  for supplying/discharging a vulcanizing medium (a heating medium and/or a pressurizing medium), described later, is bolted to the lower ring  7 , and an upper nozzle  9  to the upper ring  10 . 
     Reference numeral  12  denotes an external cylinder whose flange portion  12   a  is bolted to the inner peripheral portion of the lower platen  3 , and  13  denotes a housing whose central portion is inserted slidably (in such a manner as to be moved vertically) with a bush fixed to the inner periphery of the external cylinder  12  being used as a guide. At the upper end portion of the housing  13 , an upper flange  13 a is threadedly fixed, and at the lower end portion thereof, an integrated lower flange  13   b  is provided. A post cylinder  19  is bolted to the lower surface of the lower flange  13   b , and a bolted beam  20  is provided at the lower end of the post cylinder  19 . A piston rod of bead lift cylinder  21  is fixed to each end of the beam  20 . The bead lift cylinder  21  is hung from a bracket  5  bolted to the base  1  via a pin. When the bead lift cylinder  21  is operated, this movement is transmitted to the housing  13  via the post cylinder  19 , so that the housing  13  moves vertically. 
     Reference numeral  18  denotes a post slidably inserted in an inside hole of the housing  13 . The lower end of the post  18  is fixed to a piston rod of the post cylinder  19 . A publicly known packing is inserted between the post  18  and the upper flange  13   a . When the post cylinder  19  is operated, the post  18  is moved vertically. 
     At the central portion of the upper ring  10 , as shown in FIG. 3, a hole  10   a  into which the upper end portion of the post  18  can be inserted, a convex portion  10   b  for regulating the insertion length of the upper end portion of the post  18 , and a horizontal hole  10   c  are formed. A pin  22  is inserted into the hole  10   c  and a horizontal hole  18   a  formed at the upper end portion of the post  18 , and a coming-off preventive C-shaped retaining ring  23  is inserted into the one end portion of the pin  22 , by which the post  18  is fixed to the upper ring  10 . 
     For convenience of inserting the pin  22 , the hole  10   c  is formed as an elongated hole extending horizontally, and the lower surface of the pin  22  is formed into a plane shape. A handle ring  24  is inserted into the other end portion of the pin  22  and integrated with the same. 
     At the central portion of the lower ring  7 , as shown in FIGS. 4 and 5, a cylindrical surface, which can accommodate a cylindrical protrusion  13   c  formed on the upper surface of the upper flange  13   a  of the housing  13 , is formed. On the lower surface side of the lower ring  7  is formed a concave portion  7   b  into which a T-shaped head  14   a  formed at the upper end portion of a crank rod  14  is inserted. A plurality of clamp rods  14  are incorporated in the housing so as to be capable of being moved vertically and being turned. At the inlet of the concave portion  7   b , protrusions  7   c  are formed so that the T-shaped head  14   a  passes or is locked depending on the rotation angle of the clamp rod  14 , a claw mechanism being formed by the T-shaped head  14   a  and the protrusions  7   c . Reference numeral  28  denotes an O-ring for sealing the vulcanizing medium. 
     As illustrated in FIGS. 4 and 5, a distance between the protrusions  7   c  which is perpendicular to a first portion of the inlet defines a width of the first portion of the inlet. A distance parallel to and equal to the extent in a vertical direction of the protrusions defines a length of the first portion of the inlet. A second portion of the inlet is that portion that is free of the protrusions. The second portion is parallel to the first portion and a vertical axis of the T-shaped heads. The second portion having a width and length larger than the first portion also has a solid uninterrupted surface. When the T-shaped head is locked, it is in physical contact with an upper surface of the protrusions. 
     To a bracket  15  assembled to the housing  13  so as to be capable of being moved vertically is fixed a piston rod of an elevation cylinder  17  bolted to the lower flange  13   b  of the housing  13 . A rotary cylinder  16  is fixed to the bracket  15 , and an output shaft of the rotary cylinder  16  is keyed to the lower end portion of the clamp rod  14  so that the clamp rod  14  is moved vertically and turned by the operation of the cylinders  16  and  17 . 
     The upper nozzle  9  is formed with a plurality of heating medium supply openings  9   b  which are arranged at predetermined angles radially along the horizontal surface. At the lower surface side cylindrical portion  9   a  of the upper nozzle  9  is formed a cylindrical surface which can accommodate a cylindrical portion  8   b  of the lower nozzle  8 . When a tire is vulcanized, the cylindrical portion  8   b  of the lower nozzle  8  is inserted into the lower surface side cylindrical portion  9   a , so that a heating medium chamber  8   a  is formed, and the upper end of a passage  25  formed in the upper flange  13   a  of the housing  13  is opened. To the other end of the passage  25  is assembled one end of a pipe  26  which is connected to a heating medium source via a switching valve or the like. 
     The lower nozzle  8  is formed with a plurality of pressurizing medium supply openings  8   d  which are arranged at predetermined angles radially and at a predetermined angle of inclination with respect to the horizontal plane. The pressurizing medium supply openings  8   d  are open to a pressurizing medium chamber  8   c . The upper end of a passage  7   a  formed in the lower ring  7  is open to the pressurizing medium chamber  8   c . When the lower ring  7  seats on the upper flange  13   a , the lower end portion of the passage  7   a  communicates airtightly with the upper end portion of a passage  13   d  formed in the upper flange  13   a . To the lower end of the passage  13   d  is assembled one end of a pipe  27  which is connected to a pressurizing medium supply source via a switching valve or the like. Although similar vulcanizing medium discharging means is also provided, the illustration thereof is omitted. 
     Next, the operation of the central mechanism for a tire vulcanizer, which is shown in FIGS. 1 to  5 , will be described in detail. 
     In order to replace a bladder, the post cylinder  19  is first operated without a tire T to elevate the post  18 , by which the bladder B is expanded. Then, the elevation cylinder  17  is operated to slightly elevate the clamp rod  14 , by which the lower ring  7  is elevated from the upper flange  13   a . Next, the rotary cylinder  16  is operated to turn the clamp rod  14  in such a manner that the T-shaped head  14   a  passes between the protrusions  7   c . After the pin  22  is pulled out, the bladder assembly is hung and carried out of the vulcanizer with the aid of lifting equipment such as a fork lift to replace the bladder B. The O-ring  23 , the bead rings  6  and  11  are also replaced as necessary. 
     After the replacement of the bladder B and other parts is completed, the bladder assembly is hung and mounted on the vulcanizer by reversing the above procedure, and the upper end portion of the post  18  is inserted into the hole  10   a  in the upper ring  10 . The T-shaped head  14   a  of the clamp rod  14  is inserted into the concave portion  7   b  of the lower ring  7 , and then the pin  22  is inserted to fix the post  18  to the upper ring  10 . The rotary cylinder  16  is operated in the reverse direction so that the T-shaped head  14   a  on top of the clamp rod  14  is locked by the protrusions  7   c  of the lower ring  7 . 
     At this time, the outside peripheral cylindrical surface of the lower ring  7  and the central cylindrical portion outside peripheral surface of the upper flange  13   a  are aligned with each other, and the pressurizing medium passage  7   a  and the passage  13   d  of the upper flange  13   a  are aligned with each other, so that the elevation cylinder  17  is operated in the reverse direction to pull down the lower ring  7  so as to seat on the abutting surface of the upper flange  13   a , by which the replacement work of the bladder and other parts is completed. 
     When a tire is vulcanized, the post cylinder  19  and the bead lift cylinders  21  are operated to do work such as the extension of the bladder B and the peeling-off of the vulcanized tire from the lower mold  4  due to the rise in the lower bead ring  6  as in the case with the conventional central mechanism for the tire vulcanizer. 
     When the upper and lower molds are closed after the shaping is completed, the cylindrical portion  8   b  of the lower nozzle  8  is inserted into the cylindrical portion  9   a  of the upper nozzle  9  to form the heating medium chamber  8   a , so that the injection of heating medium from the heating medium supply openings  9   b  into the tire T becomes possible.