Abstract:
A system for venting a tire mold includes a tire mold having an interior region and an exterior region. The interior region is defined by a surface having a non-smooth portion that defines a pattern. The interior and exterior regions of the tire mold are in fluid connection with each other via at least one conduit extending from the exterior region to the non-smooth portion of the surface defining the interior region. The system further includes a vent insert at least partially disposed inside the at least one conduit. The vent insert has a non-smooth face that corresponds to the pattern defined by the non-smooth surface of the surface of the interior region.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to U.S. Provisional Patent Application No. 62/095,450, filed on Dec. 22, 2014, the disclosure of which is incorporated by reference herein in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present disclosure relates to venting structures for tire molds. More particularly, the present disclosure relates to a venting structure for a non-smooth portion of a sidewall-forming region of a tire mold. 
       BACKGROUND 
       [0003]    During the curing cycle of a tire manufacturing process, air may become trapped between a green tire and a mold cavity when a tire molding press is closed. This trapped air can cause “lightness” in the cured tire. One known method for evacuating this trapped air is through the use of vents. Vents are added in the mold and bead rings to bleed the air during the curing process. The vents may be directly drilled through the mold or bead rings, or a hole may be drilled through the mold or bead ring and a preformed insert is placed in the hole, thereby forming a vent. 
         [0004]    During air evacuation, the elastomeric tire material may flow into the vents, creating projections on the surface of the tire known as sprues. Vent inserts may be employed to alter the air flow around the vents and prevent sprues from forming. 
       SUMMARY 
       [0005]    In one embodiment, a tire mold includes an interior surface having a non-smooth portion defined by at least one mold surface element selected from the group consisting of a raised surface and a recessed surface. The tire mold further includes a conduit extending from an opening in the non-smooth portion to an exterior of the tire mold. The tire mold also includes a vent insert located at least partially inside of the conduit. The vent insert has a face that is substantially flush with the tire mold interior surface. The face includes at least one face surface element selected from the group consisting of a raised surface and a recessed surface. The at least one face surface element corresponds to the at least one mold surface element. 
         [0006]    In another embodiment, a system for venting a tire mold includes a tire mold having an interior region and an exterior region. The interior region is defined by a surface having a non-smooth portion that defines a pattern. The interior and exterior regions of the tire mold are in fluid connection with each other via at least one conduit extending from the exterior region to the non-smooth portion of the surface defining the interior region. The system further includes a vent insert at least partially disposed inside the at least one conduit. The vent insert has a non-smooth face that corresponds to the pattern defined by the non-smooth surface of the surface of the interior region. 
         [0007]    In yet another embodiment, a tire mold includes an interior region and an exterior region. The interior and exterior regions of the tire mold are connected via at least one conduit extending from the exterior region to the interior region. The interior region is defined by an interior surface including a sidewall forming portion having multiple elevations. The at least one conduit has an opening in the sidewall forming portion of the interior surface. The tire mold further includes at least one vent insert having a face. At least a portion of the at least one vent insert is located inside the at least one conduit. The face has multiple elevations corresponding to the multiple elevations of the sidewall forming portion of the interior surface of the tire mold. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0008]    In the accompanying drawings, structures are illustrated that, together with the detailed description provided below, describe exemplary embodiments of the claimed invention. Like elements are identified with the same reference numerals. It should be understood that elements shown as a single component may be replaced with multiple components, and elements shown as multiple components may be replaced with a single component. The drawings are not to scale and the proportion of certain elements may be exaggerated for the purpose of illustration. 
           [0009]      FIG. 1  is a side view of an exemplary tire; 
           [0010]      FIG. 2  is a partial cross-section of a tire mold; 
           [0011]      FIG. 3A  is a front view of a portion of a tire mold and one embodiment of a vent insert; 
           [0012]      FIG. 3B  is a partial cross-section of the tire mold and vent insert of  FIG. 3A ; 
           [0013]      FIG. 4A  is a front view of a portion of a tire mold and an alternative embodiment of a vent insert; 
           [0014]      FIG. 4B  is a partial cross-section of the tire mold and vent insert of  FIG. 4A ; 
           [0015]      FIG. 5A  is a front view of a portion of a tire mold and another alternative embodiment of a vent insert; 
           [0016]      FIG. 5B  is a partial cross-section of the tire mold and vent insert of  FIG. 5A ; 
           [0017]      FIG. 6A  is a front view of a portion of a tire mold and yet another alternative embodiment of a vent insert; 
           [0018]      FIG. 6B  is a partial cross-section of the tire mold and vent insert of  FIG. 6A ; 
           [0019]      FIG. 7A  is a front view of a portion of a tire mold and still another alternative embodiment of a vent insert; and 
           [0020]      FIG. 7B  is a partial cross-section of the tire mold and vent insert of  FIG. 7A . 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    Directions are stated herein with reference to the tire mold. For example “interior,” “inside,” or “inner” refers to a direction or area towards the center cavity of a tire mold. The terms “exterior,” “outside,” or “outer” refer to a direction or area generally outside of the tire mold. 
         [0022]      FIG. 1  illustrates a side view of an exemplary tire  100 . The tire includes a sidewall  110  that includes both smooth portions and non-smooth portions. Non-smooth portions include serrations  120 , which may also be referred to as notches, hatching, or cross-hatching. Serrations in a tire are defined by a series of projections, a series of recesses, or a series of alternating projections and recesses. Serrations may be defined by straight lines, curved lines, or a combination of straight and curved lines. The lines may cross each other or maintain separation. 
         [0023]    Non-smooth portions also include grooves  130  or other recesses in the sidewall  110 , as well as ribs  140  or other projections in the sidewall  110 . Some non-smooth portions may form indicia, such as lettering  150 . Other indicia include numbers and other symbols, such as logos. The indicia may be formed by recesses, projections, or a combination of recesses and projections. Alternatively, the indicia may be a smooth portion of a sidewall that is outlined by surrounding serrations. 
         [0024]    Each of the above-described non-smooth portions forms a pattern. As used herein, “pattern” includes repeating series of elements, such as a repeating series of serrations, and also includes a single element. For example, a single, circumferential rib may be described as a pattern. 
         [0025]      FIG. 2  illustrates a partial cross-section of an exemplary tire mold  200  that may be used to form the tire  100  of  FIG. 1  or other tires. In the illustrated embodiment, the tire mold  200  includes an interior portion  210  defined by an interior surface  220 , and an exterior surface  230 . The interior surface  220  may take any shape suitable for forming tires. The tire mold  200  further includes a plurality of through holes (such as the illustrated through hole  240 ) extending from the interior surface  220  to the exterior surface  230 . In one known embodiment, the through holes have a diameter of about 0.092 inches (0.23 centimeters). In other embodiments, the through holes may have diameters ranging from 0.050 inches (0.13 centimeters) to 0.25 inches (0.64 centimeters). 
         [0026]    In the illustrated embodiment, each through hole  240  includes a counter-bore  250  extending outwardly from the interior surface  220 . Together, the through hole  240  and the counter-bore  250  form a conduit for venting air from the interior  210  of the tire mold  200  to the exterior of the tire mold  200 . The conduit may take any form, but here is depicted as cylindrical. An opening permits fluid communication between the interior  210  of the tire mold  200  and exterior. Other venting structures known in the art may be used without departing from the scope of the present disclosure. 
         [0027]    The counter-bore  250  forms an opening in the interior surface  220  and receives a vent insert  300 . The vent insert  300  may be employed to alter air flow around the openings of the conduit and prevent sprues from forming. Because the interior surface  220  includes curves and contours, each vent insert  300  may include a face that is similarly curved or contoured. 
         [0028]    In one embodiment, the counter bore  250  and the vent insert  300  are substantially cylindrical. The vent insert  300  includes both a large diameter portion and a small diameter portion. In one embodiment, the large diameter is 0.125 inches (0.318 centimeters) and the small diameter is 0.062 inches (0.16 centimeters). In other embodiments, the large diameter ranges from 0.060 inches (0.15 centimeters) to 0.25 inches (0.64 centimeters) and the small diameter ranges from 0.030 inches (0.075 centimeters) to 0.125 inches (0.318 centimeters). In an alternative embodiment (not shown), the vent insert has a single diameter. In other alternative embodiments, the conduits and inserts have non-cylindrical shapes. 
         [0029]    The diameter and length of the counter-bore  250  is dimensioned to accommodate the vent insert  300 . In one embodiment, the diameter of the counter-bore  250  is 0.003 inches (0.008 centimeters) smaller than the largest diameter of the insert  300  to provide a light press fit of the insert  300 . In alternative embodiments, the diameter of the counter-bore  250  is equal to or larger than the largest diameter of the insert  300 . In such embodiments, the insert  300  can be held in place by one or more pins, adhesive, or other attachment means. In one known embodiment, each counter-bore  250  has a diameter of about 0.122 inches (0.310 centimeters). In other embodiments, the counter-bores may have diameters ranging from 0.060 inches (0.15 centimeters) to 0.25 inches (0.64 centimeters). In an alternative embodiment (not shown), the mold  200  does not include a counter-bore, and instead the entire through hole is sized to accommodate the vent insert. 
         [0030]      FIGS. 3A and 3B  illustrate a partial front view and a partial cross-section, respectively, of a portion of the tire mold  200  and one embodiment of the vent insert  300   a . The vent insert  300   a  includes a large diameter portion  310  with a face  320  that is substantially flush with the interior surface  220  of the tire mold  200 . In an alternative embodiment (not shown), the face of the vent insert extends into the interior region of the tire mold. In another alternative embodiment (not shown), the vent insert is recessed such that the face of the vent insert is inside the conduit. 
         [0031]    The vent insert  300   a  has a plurality of spiral channels  330  on the large diameter portion  310 . Spiral channels  330  run continuously from the face  320  of the vent insert  300   a  along a portion of a length of the vent insert  300   a . Each spiral channel  330  defines an intake opening along the face  320  of the vent insert  300   a , as can be seen in  FIG. 3A . In other embodiments, the spiral channels may be replaced with straight channels. Any number of channels may be employed. Additionally, other types of vent inserts may be used without departing from the scope of the present disclosure, including but not limited to spring vents, drill vents, micro vents, or sinter vents. 
         [0032]    The vent insert  300   a  is a sprueless-type vent insert that allows gas from the interior  210  of the tire mold  200  to vent to an exterior of tire mold  200 , reducing or preventing the formation of tire sprues. When tire material is injected into the tire mold  200 , the air inside the tire mold  200  is displaced. The displaced air is forced into the intake openings through the channels  330  of the vent insert  300   a  in the counter bore  250 . The air then travels along the large diameter portion  310  and the small diameter portion  340  of the vent insert  300   a  and out the through hole  240  until reaching the exterior of the tire mold  200 . The shape and size of the intake openings, reducing or preventing the formation of tire sprues when tire material comes into contact with the interior surface  220  and the face  320 . 
         [0033]    In the illustrated embodiment, the vent insert  300   a  includes a plurality of raised surfaces, or projections  350   a  from the face  320  that extend into the interior  210  of the tire mold  200 . The face  320  and the projections  350   a  form multiple elevations. The projections  350   a  extend from a peak, to a lower elevation. In the illustrated embodiment, the lower elevation is the same elevation as the face  320  of the vent insert  350   a . In an alternative embodiment (not shown), the lower elevation is higher than the elevation of the face. In another alternative embodiment (not shown), the lower elevation is lower than the elevation of the face, such that the face has both projections and recesses. 
         [0034]    The projections  350   a  correspond to projections  260   a  of the interior surface  220  in a non-smooth portion of a tread forming surface of a tire mold  200 . Together, the projections  260   a  and  350   a  define serrations in a tire sidewall. The serrations may be part of any pattern in a sidewall, and may also form an outline of letters, numbers, symbols, or logos. 
         [0035]    The projections  350   a  of the vent insert  300   a  and the projections  260   a  of the tire mold  200  have triangular cross sections. In alternative embodiments (not shown), the projections are rectangular, trapezoidal, round, or have any geometric cross-section. 
         [0036]      FIGS. 4A and 4B  illustrate a partial front view and a partial cross-section, respectively, of a portion of the tire mold  200  and an alternative embodiment of the vent insert  300   b . The vent insert  300   b  is substantially the same as the vent insert  300   a  described above with respect to  FIGS. 3A and 3B  (including the alternative embodiments discussed therein) except for the differences described below. Like reference numerals are used for like elements. 
         [0037]    In the illustrated embodiment, the vent insert  300   b  includes a raised surface, or projection  350   b  from the face  320  that extends into the interior  210  of the tire mold  200 . The face  320  and the projection  350   b  form multiple elevations. The projection  350   b  corresponds to a projection  260   b  of the interior surface  220  in a non-smooth portion of a tread forming surface of a tire mold  200 . Together, the projections  260   b  and  350   b  define a recess in a tire sidewall. The recess that is formed may be part of any pattern in a sidewall, and may form a groove, letters, numbers, symbols, or logos. 
         [0038]    The projection  350   b  of the vent insert  300   b  and the projection  260   b  of the tire mold  200  both have trapezoidal cross sections. In alternative embodiments (not shown), the projections are rectangular, triangular, or have any geometric cross-section. 
         [0039]      FIGS. 5A and 5B  illustrate a partial front view and a partial cross-section, respectively, of a portion of the tire mold  200  and another alternative embodiment of the vent insert  300   c . The vent insert  300   c  is substantially the same as the vent inserts  300   a  and  300   b  described above with respect to  FIGS. 3A-4B  (including the alternative embodiments discussed therein) except for the differences described below. Like reference numerals are used for like elements. 
         [0040]    In the illustrated embodiment, the vent insert  300   c  includes a raised surface, or projection  350   c  from the face  320  that extends into the interior  210  of the tire mold  200 . The face  320  and the projection  350   c  form multiple elevations. The projection  350   c  corresponds to a projection  260   c  of the interior surface  220  in a non-smooth portion of a tread forming surface of a tire mold  200 . Together, the projection  260   c  and  350   c  define a recess in a tire sidewall. The recess that is formed may be part of any pattern in a sidewall, and may form a groove, letters, numbers, symbols, or logos. 
         [0041]    The projection  350   c  of the vent insert  300   c  and the projection  260   c  of the tire mold  200  each have a round cross section, defined by a single radius. In an alternative embodiment (not shown), the projections are curved but are defined by multiple radii. In another alternative embodiment (not shown), the projections are defined by a geometric curve, such as a parabola, an ellipse, or a hyperbola. 
         [0042]      FIGS. 6A and 6B  illustrate a partial front view and a partial cross-section, respectively, of a portion of the tire mold  200  and yet another alternative embodiment of the vent insert  300   d . The vent insert  300   d  is substantially the same as the vent inserts  300   a ,  300   b , and  300   c  described above with respect to  FIGS. 3A-5B  (including the alternative embodiments discussed therein) except for the differences described below. Like reference numerals are used for like elements. 
         [0043]    In the illustrated embodiment, the vent insert  300   d  includes a recessed surface  350   d  in the face  320 . The face  320  and the recess  350   d  form multiple elevations. The recess  350   b  corresponds to a recess  260   d  of the interior surface  220  in a non-smooth portion of a tread forming surface of a tire mold  200 . Together, the recesses  260   d  and  350   d  define a projection in a tire sidewall. The projection that is formed may be part of any pattern in a sidewall, and may form a rib, letters, numbers, symbols, or logos. 
         [0044]    The recess  350   d  of the vent insert  300   d  and the recess  260   d  of the tire mold  200  have trapezoidal cross sections. In alternative embodiments, the recesses are rectangular, triangular, or have any geometric cross-section. 
         [0045]      FIGS. 7A and 7B  illustrate a partial front view and a partial cross-section, respectively, of a portion of the tire mold  200  and still another alternative embodiment of the vent insert  300   e . The vent insert  300   e  is substantially the same as the vent inserts  300   a ,  300   b ,  300   c , and  300   d  described above with respect to  FIGS. 3A-6B  (including the alternative embodiments discussed therein) except for the differences described below. Like reference numerals are used for like elements. 
         [0046]    In the illustrated embodiment, the vent insert  300   e  includes a recess  350   e  in the face  320 . The face  320  and the recess  350   e  form multiple elevations. The recess  350   e  corresponds to a recess  260   e  of the interior surface  220  in a non-smooth portion of a tread forming surface of a tire mold  200 . Together, the recess  260   e  of the interior surface  220  of the tire mold and the recess  350   e  of the face  320  of the vent insert  300   e  define a projection in a tire sidewall. The formed projection may be part of any pattern in a sidewall, and may form a rib, letters, numbers, symbols, or logos. 
         [0047]    The recess  350   e  of the vent insert  300   e  and the recess  260   e  of the tire mold  200  each have a round cross section, defined by a single radius. In an alternative embodiment (not shown), the recesses are curved but are defined by multiple radii. In another alternative embodiment (not shown), each recess is defined by a geometric curve, such as a parabola, an ellipse, or a hyperbola. 
         [0048]    It should be understood that the embodiments illustrated in  FIGS. 3A-7B  are merely exemplary, and that other projections and recesses may be employed. For example, a vent insert may include a combination of both recesses and projections. 
         [0049]    While only vent inserts for non-smooth portions of a sidewall forming surface are shown, it should be understood that additional conduits and vent inserts may be employed in smooth portions of a sidewall forming surface. Such a vent insert would not include projections or recesses. 
         [0050]    Additionally, while the vent inserts are generally described as being used in a sidewall-forming portion of a tire mold, they may also be employed in a bead-forming portion or a shoulder forming portion of a tire mold. They may also be employed in the tread portion of a tire mold. 
         [0051]    In one embodiment, the tire mold  200  and vent inserts  300  are formed of the same material. Exemplary material includes steel, aluminum, and other metal. In an alternative embodiment, the tire mold is made of metal and the vent inserts  300  are made of thermoplastic. Thermoplastic may be easier to cut, mold, or otherwise shape to include the desired projections and recesses. In another alternative embodiment, vent inserts that are used in smooth portions of a sidewall-forming surface are constructed of metal, while vent inserts that are used in non-smooth portions of a sidewall forming surface are constructed of thermoplastic. 
         [0052]    To the extent that the term “includes” or “including” is used in the specification or the claims, it is intended to be inclusive in a manner similar to the term “comprising” as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “or” is employed (e.g., A or B) it is intended to mean “A or B or both.” When the applicants intend to indicate “only A or B but not both” then the term “only A or B but not both” will be employed. Thus, use of the term “or” herein is the inclusive, and not the exclusive use. See, Bryan A. Garner, A Dictionary of Modern Legal Usage 624 (2d. Ed. 1995). Also, to the extent that the terms “in” or “into” are used in the specification or the claims, it is intended to additionally mean “on” or “onto.” Furthermore, to the extent the term “connect” is used in the specification or claims, it is intended to mean not only “directly connected to,” but also “indirectly connected to” such as connected through another component or components. While the present application has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the application, in its broader aspects, is not limited to the specific details, the representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant&#39;s general inventive concept.