Patent Publication Number: US-2010116396-A1

Title: Pneumatic sealing ring having an inner tube and expandable liner for a tube-type tire

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to pneumatic sealing ring including an inner tube and an expandable liner extending in surrounding engagement thereover to be used with a tube-type tire and rim so that the tube-type tire will operate without a conventional inner tube and as if it were tubeless. 
     2. Background Art 
     A conventional tube-type tire is commonly known to have an inner tube associated therewith. A primary disadvantage of such a tube-type tire is that the rubber material of the inner tube is subject to pinching during use. Such a pinch may result in a tear and, ultimately, a pinch flat, whereby to place the tire out of service or in need of repair. The tools that are commonly used when a new tube-type tire is installed can also cause a pinch in the inner tube and the resulting damage to the tire. 
     In this same regard, the inner tube associated with the conventional tube-type tire is characteristically large, bulky and correspondingly heavy. These characteristics are not well suited for achieving the high performance that is required by racing vehicles on which such a tube-type tire may be used. In fact, such conventional tube-type tires can contribute to significant poundage when mounted on a wheel which is likely to reduce speed and increase energy (e.g., fuel) consumption. 
     Therefore, what is desirable is a tube-type tire that can be used by high performance (e.g., racing) vehicles but has the characteristics of a tubeless tire so as to avoid the shortcomings that have heretofor been associated with conventional tube-type tires. 
     SUMMARY OF THE INVENTION 
     In general terms, a pneumatic sealing ring is disclosed for use with a tube-type tire and rim so that the tube-type tire will operate without a conventional inner tube and as if it were tubeless. The pneumatic sealing ring is adapted to create an efficient seal within a main tire section of the tire. In this regard, the rim includes a generally flat shelf which lies between an upwardly turned vertical lip and a downwardly turned arcuate beadwell. The main tire section has a relatively large volume air chamber at the interior thereof. The pneumatic sealing ring includes a thin inner tube having a relatively small volume air chamber, whereby the inner tube is incapable of providing run flat support. The air chamber of the inner tube of the sealing ring is inflated to a pressure that is at least twice the pressure to which the air chamber of the main tire section is inflated to ensure a proper sealing effect of the pneumatic sealing ring against the inside of the main tire section. 
     The main tire section is seated upon the shelf of the rim, and the inner tube of the pneumatic sealing ring is seated upon the beadwell of the rim such that the air chamber of the main tire section is isolated from the rim. The sealing ring also includes an outer liner that is disposed in surrounding engagement over the inner tube. The liner is manufactured from a resilient material that is adapted to expand in response to the air chamber of the inner tube being inflated. Flexible casing cords run around the liner to provide structural reinforcement when the liner is expanded. The outer liner of the pneumatic sealing ring is moved into sealing engagement with the main tire section of the tire as the air chamber of the inner tube is inflated. To this end, one or more sealing rings project outwardly from the side walls of the outer liner to form an efficient seal with the main tire section and force the main tire section against the vertical lip of the rim. A centering lip projects downwardly from each side wall to be seated against the beadwell of the rim and thereby enable the liner to be self-centering over and around the inner tube. 
     The liner of the pneumatic sealing ring is covered by an optional rigid (e.g., plastic) shield. The shield provides a protective wall that safeguards the inner tube of the sealing ring lying below the liner from sharp objects within the air chamber of the main tire section. A series of deflectors project upwardly from the shield and into the air chamber of the main tire section. The deflectors are shaped to deflect thorns, and the like, that might cause damage to the inner tube. 
     In accordance with an alternate embodiment of the pneumatic sealing ring, a hollow threaded rim lock bolt extends through the tire rim, past the inner tube, and through the expandable outer liner to communicate with the air chamber of the main tire section so as to establish a passage through which the air chamber is inflated. The rim lock bolt runs through a deflector that is preferably manufactured from rubber. The deflector is located between the outer liner of the sealing ring and the rim to compress a section of the inner tube and thereby permit the rim lock bolt to pass outside the inner tube and unobstructed through the sealing ring to the air chamber of the main tire section. A rim lock nut is coupled to one end of the rim lock bolt outside the rim. A rim lock plate is coupled to the opposite end of the rim lock bolt within the air chamber of the main tire section. As the rim lock nut is tightened down against the rim, the rim lock plate is correspondingly pulled into sealing engagement against the main tire section to prevent the main tire section from spinning on the rim in response to the torque that is developed by the motor of a motorcycle. 
     In a modification to the pneumatic sealing ring, a valve stem extends through the rim. An air port extends through the expandable outer liner to communicate with the air chamber of the main tire section. An air bypass hose is connected between the valve stem and the air port to establish a passage through which the air chamber of the main tire section is inflated. The air bypass hose runs around one side of the sealing ring so as to lie between the inner tube and the expandable liner thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a tube-type tire including the pneumatic sealing ring of this invention mounted on the rim of a spoke-type wheel of the kind commonly used by bicycles and motorcycles; 
         FIG. 2  is a cross-section taken along lines  2 - 2  of  FIG. 1  showing the pneumatic sealing ring isolating the air chamber of a main tire section of the tire from the rim on which the sealing ring is seated; 
         FIG. 3  is a cross-section showing the pneumatic sealing ring of  FIG. 2  with a modification including a deflector by which to enable a hollow rim lock bolt to be connected to a rim lock plate to prevent the main tire section of the tire from spinning on the rim; 
         FIG. 4  is a top view of the deflector and the rim lock bolt connected to the rim lock plate taken in the direction of reference arrow  4  of  FIG. 3 ; and 
         FIG. 5  shows an additional modification to the pneumatic sealing ring of  FIG. 2 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A first preferred embodiment for a pneumatic sealing ring  40  which forms the present invention for use with a tube-type tire  1  and a suitable rim  30  is described while referring to  FIGS. 1 and 2  of the drawings. The tube-type tire  1  includes an outer inflatable main tire section  3 . The pneumatic sealing ring  40  includes an inflatable inner tube  5  which extends circumferentially around the rim  30  inside the main tire section  3 . The main tire section  3  is typically manufactured from thick rubber. The inner tube  5  of sealing ring  40  is preferably manufactured from a relatively thin (e.g., butyl) rubber material or a similar membrane. The tire  1  to which the sealing ring  40  will be mated is ideally mounted on a metal rim  30  having a generally flat shelf  7  located between an upturned vertical lip  8  and a downturned arcuate beadwell  9 . 
     The main tire section  3  of the tube-type tire  1  is seated on the shelf  7  of the rim  30  so as to press against the vertical lip  8  thereof. The inner tube  5  of pneumatic sealing ring  40  is seated on the beadwell  9  of the rim  7 . The tire  1  and its rim  30  as herein described are particularly suitable for a spoke-type wheel (best shown in  FIG. 1 ) such as that usually required by a bicycle or a motorcycle. Accordingly, a set of spoke holes  11  are formed through the rim  30  at the beadwell  9  to receive respective spokes (designated  33  in  FIG. 1 ). However, it is to be understood that the tire  1  can be employed on the wheel of any vehicle where a tube-type tire is desirable. 
     The main tire section  3  has a relatively large volume air chamber  32  at the interior thereof that is inflated with air. The inner tube  5  of pneumatic sealing ring  40  has a smaller volume air chamber  34  that is also inflated with air. As an important feature of the sealing ring  40 , the inner tube  5  thereof is seated upon the rim  30  so as to isolate the air chamber  32  of main tire section  3  from the rim  30 . 
     The pneumatic sealing ring  40  includes an outer liner  10  to lay over and around the inner tube  5  and thereby separate the inner tube  5  from the main tire section  3  and its air chamber  32 . The air chamber  34  of the inner tube  5  is ideally inflated to a pressure of approximately 100 psi by way of an integral valve stem  36 . The main tire section  3  includes a valve stem (not shown) through which the air chamber  32  thereof is ideally inflated with air to a lower pressure of approximately 15-20 psi. While the precise pressures to which the air chambers  32  and  34  of the main tire section  3  and the inner tube  5  of the tube-type tire  1  are inflated may vary with application, the pressure to which the inner tube  5  is inflated must be at least twice the pressure to which the main tire section  3  is inflated to enable the pneumatic sealing ring  40  to generate a sufficiently strong sealing force against tire section  3  for a purpose that will soon be described. 
     The outer liner  10  of sealing ring  40  is preferably manufactured from a resilient (e.g., rubber) material that is adapted to expand when the air chamber  34  of the inner tube  5  is inflated. Casing cords  12  that are manufactured from an (e.g., aramid) fiber material run continuously around the liner  10  between opposing beads  18  to provide structural reinforcement and limit the expansion of the liner  10  in response to the inflation of the air chamber  34  of inner tube  5 . To this end, one or more sealing O-rings  14  are molded into each of the sidewalls of the liner  10 . The O-rings  14  extend outwardly from the liner  10  to be sealed against the inside of main tire section  3  when the air chamber  34  of inner tube  5  is inflated. A centering lip  16  projects downwardly from each of the opposite sidewalls of the liner  10  below the bead  18  thereof. The centering lips  16  are seated upon the beadwell  9  of rim  30  and enable the outer liner  10  to be self-centering in surrounding engagement around the inner tube  5  in order to provide a uniform sealing force against the main tire section  3 . 
     The pneumatic sealing ring  40  also includes an optional protective shield  20  that lies overtop the outer liner  10 . The shield  20  is ideally manufactured from a rigid material (e.g., plastic) and is intended to safeguard the liner  10  and the inner tube  5  lying thereunder from puncture wounds and similar damage. A series of deflectors  22  (only one of which being shown) project upwardly from the shield  20  for receipt within the air chamber  32  of the main tire section  3 . The deflectors  22  are (e.g., nipple) shaped so as to be able to deflect thorns and similar sharp objects away from the inner tube  5 . The deflectors  22  are ideally manufactured from rubber. 
     With the added benefit of the pneumatic sealing ring  40  herein disclosed, the tube-type tire  1  having a standard rim  30  will be able to operate without a conventional inner tube and as if it were a tubeless tire. That is to say, the inner tube  5  of sealing ring  40  having a small volume air chamber  34  is separated from the relatively large volume air chamber  32  of the main tire section  3  by means of the outer expandable liner  10 . Therefore, the main tire section  3  and the inner tube  5  enclose separate and distinct air chambers  32  and  34  within the tire  1  so as to form a dual air chamber tire. The inner tube  5  seats against the beadwell  9  of the rim  30  and extends circumferentially around the rim  30  so as to advantageously seal off (i.e., isolate) the air chamber  32  of main tire section  3  from the rim  30  and thereby eliminate the need for a conventional inner tube on a tube-type rim. 
     In this regard, because the air chamber  34  of the inner tube  5  of pneumatic sealing ring  5  is inflated to a much greater pressure than the air chamber  32  of the main tire section  3  of tire  1 , the inner tube will be capable of exerting a pushing or sealing force against the resilient liner  10 . By virtue of its sealing O-ring  14  and centering lips  16 , the outer expandable liner  10  of pneumatic sealing ring  40  will be automatically and evenly aligned between the main tire section  3  and the inner tube  5  to create an efficient seal against the inside of the main tire section  3  and thereby force the outside of the main tire section  3  against the vertical tip  8  of the rim  30  in response to an inflation of inner tube  5 . 
     It may also be appreciated that the inner tube  5  is considerably thinner, smaller in size and lighter in weight than the thicker main tire section  3  of the tube-type tire  1 . Hence, and unlike conventional tube-type tire and rim assemblies, the inner tube  5  of the pneumatic sealing ring  40  of this invention is substantially confined to the beadwell  9  of rim  30 . Because of its correspondingly small size relative to commercially available pneumatic inner liners, inserts, and the like, of the kind shown, for example, in U.S. Pat. Nos. 5,246,050 or 6,688,359, the resilient liner  10  herein disclosed will offer no run flat support in the event that the main tire section  3  should suffer a blowout. Moreover, because of the small size of my inner tube  5  within the outer liner  10 , such inner tube will not be susceptible to pinching and will require less frequent repair and replacement than that experienced by inner tubes in conventional tube-type tires. 
     It is contemplated that the pneumatic sealing ring  40  including the inner tube  5 , outer liner  10  and optional shield  20  will be sold as a unit (e.g., in kit form) to enable a retrofit of the main tire section  3  in the shop to produce a tire  1  having the benefits of this invention. In the alternative, the tire  1  can be sold as a finished assembly including the main tire section  3  and the sealing ring  40  mounted on the rim  30  as described above. 
       FIGS. 3 and 4  of the drawings show a pneumatic sealing ring  50  including a modification to the sealing ring  40  described above. The tube-type tire  1  and the rim  30  to which the sealing ring  50  is mated may be identical to those shown in  FIGS. 1 and 2  and, therefore, identical reference numerals will be used to identify identical components. Similar to sealing ring  40 , the pneumatic sealing ring  50  of  FIGS. 3 and 4  includes an inflatable inner tube  52  which extends circumferentially around the beadwell  9  of rim  30  inside the main tire section  3 . Like that described above, the sealing ring  50  has a relatively small volume air chamber  54  that is inflated to a relatively high pressure with respect to the relatively large volume air chamber  32  of the main tire section  3 . 
     Also like that described above, the pneumatic sealing ring  50  includes an expandable outer liner  56  lying over and around the inner tube  52  so as to separate the inner tube  52  from the air chamber  32  of main tire section  3 . As with the flexible liner  10  of the sealing ring  40  of  FIG. 2 , the flexible liner  56  of pneumatic sealing ring  50  includes one or more sealing O-rings  58  that are molded into the sidewalls thereof and extend outwardly therefrom. Accordingly, the O-rings  58  will be sealed against the inside of the main tire section  3  when the air chamber  54  of inner tube  52  is inflated and the outer liner  56  is correspondingly expanded so that the air chamber  32  of main tire section  3  is isolated from the rim  30 . A centering lip  60 , which projects downwardly from each of the opposite sidewalls of the liner  56  below the beads  62  is seated upon the beadwell  9  of rim  30  to enable the liner  56  to be self-centering in surrounding engagement with the inner tube  52 . 
     In the embodiment of  FIGS. 3 and 4 , a stem (similar to that designated  36  in  FIG. 2 ) extends through the rim  30  and the inner tube  52  to enable the air chamber  54  to be inflated. A threaded hollow rim lock bolt  64  extends through the rim  30 , past the inner tube  52 , and into the main tire section  3  so as to communicate with the air chamber  32  thereof and provide a passage through which air chamber  32  can be inflated. A threaded rim lock nut  66  (of  FIG. 3 ) is rotated around one end of the threaded bolt  64  at a location outside the beadwell  9  of rim  30 . A rigid (e.g., metal) rim lock plate  68  having a threaded hole through the center thereof is rotated around the opposite end of the threaded bolt  64  within the air chamber  32  of main tire section  3 . Alternatively, the rim lock plate  68  can be welded around the bolt  64 . 
     As the rim lock nut  66  is rotated around the rim lock bolt  64  and tightened down against the beadwell  9  of rim  30 , the rim lock plate  68  is correspondingly pulled towards the outer liner  56  and tightened down against the main tire section  3 . By virtue of the foregoing, the rim lock plate  68  is forced into locking engagement against the inside of the main tire section  3 . The locking pressure of the rim lock plate  68  against the main tire section  3  advantageously prevents tire section  3  from spinning on the rim  30  as the tire  1  rides along a roadway. That is to say, it is known for the main tire section  3  to be subjected to a spinning force in response to the usual torque that is generated by the motor of a motorcycle or similar motorized vehicle on which the tire  1  has been mounted. 
     To enable the hollow rim lock bolt  64  to move unobstructed through the sealing ring  50  and past the inner tube  52  thereof so as to communicate with the air chamber  32  of the main tire section  3 , the bolt  64  is inserted through a deflector  74 . More particularly, the deflector  74  is preferably a block of rubber, or the like, that is located at one side of the inner tube  52  between the outer expandable liner  56  of sealing ring  50  and the beadwell  9  of rim  30 . The deflector  74  functions to apply a pushing force against the inner tube  52  so as to compress a section  52 - 1  (of  FIG. 4 ) thereof against the main tire section  3  so that the inner tube  52  will wrap around the deflector  74  so as not to interfere with the rim lock bolt  64  depending downwardly from the rim lock plate  68  and running through the sealing ring  50  at one side of the inner tube  52 . 
       FIG. 5  of the drawings shows the tube-type tire  1  including the main tire section  3  seated on the rim  30  in the manner of  FIG. 2 . By way of an additional modification to the sealing ring  40 , the pneumatic sealing ring  40 - 1  of  FIG. 5  includes an air bypass hose  78 . The air bypass hose  78  extends between a threaded valve stem  80  and the air chamber  32  of the main tire section  3 . The air bypass hose  78  bypasses air chamber  34  and enables the air chamber  32  to be inflated. In this case, another valve stem (such as that designated  36  in  FIG. 2 ) extends through the rim  30  to permit the air chamber  34  of inner tube  5  to be inflated. 
     One end of the air bypass hose  78  is connected to a valve  82  of the valve stem  80  outside inner tube  5 . The opposite end of the bypass hose  78  is connected to an air port  84  that is also located outside inner tube  5  and communicates with the air chamber  32  of main tire section  3  through the expandable outer liner  10  of the sealing ring  40 - 1 . The air port  84  is preferably bonded (e.g., vulcanized) to liner  78  to avoid a detachment. Accordingly, an air flow passage is established from the valve  82  of valve stem  80 , through the air bypass hose  78 , to air chamber  32  via air port  84 . 
     The air bypass hose  78  is disposed between the inner tube  5  and the outer liner  10  of pneumatic sealing ring  40 - 1  so as to travel outside the inner tube  5  and around one side of the sealing ring  40 - 1 . That is, the inner tube  5  and the outer flexible liner  10  located thereover are separated from one another by the run of the bypass hose  78  between the valve  82  of valve stem  80  and the air port  84  which communicates with air chamber  32 .