This invention relates to a flat-proof tire having particular application for use on a motorcycle wherein the interior of the tire is completely filled with an insert that is manufactured from a solid, resilient (e.g., closed cell foam) material. The tire insert is covered by a low friction (e.g., nylon) sleeve which minimizes friction and the heat that will be generated at the interface of the tire and the insert when the tire is subjected to road conditions and the insert moves within the tire.
It is known to locate a solid insert within the interior of a flat-proof tire so as to provide the tire with run flat support and thereby enable the tire to continue to operate after sustaining a puncture wound. It is also known that as the insert repeatedly expands and contracts in response to the road conditions to which the tire is subjected, friction and heat are produced at the interface of the tire and the insert which causes the insert to wear and deteriorate over time. The degradation of the insert can negatively affect the tire's performance and/or require that the insert be frequently replaced.
One solution by which to reduce the generation of heat caused by friction has been to bond the insert directly to the inside of the tire to limit the ability of the insert to move relative to the tire. However, this technique requires a time consuming bonding step and makes removal of the insert complicated. Another solution to minimize heat and insert deterioration is to cover the insert with a powder or a lubricant to reduce friction caused by the insert rubbing against the tire. However, such a powder or lubricant can be rubbed off leaving potential hot spots over the surface of the insert lying adjacent the tire.
What would therefore be desirable is an improved combination flat-proof tire and low friction insert that is located inside a tire and adapted to reduce surface-to-surface friction between the insert and the tire so as to advantageously minimize the generation of heat and the degradation of the insert as a result of road conditions and movement of the insert within the tire.
In general terms, an improved combination flat-proof tire and low friction tire insert are disclosed which is ideal for use on a motorcycle. The interior of the tire is completely filled with a donut-shaped insert that is manufactured from a resilient (e.g., closed cell foam) material and capable of moving relative to the tire. The insert is shaped to extend completely and continuously around the interior of the tire to provide the tire with run flat support and enable it to continue to operate with a puncture. The insert is surrounded by a low friction cover (i.e., a sleeve) that is preferably manufactured from a smooth textile (e.g., nylon) material. The low friction sleeve reduces the surface-to-surface friction that will be created at the interface between the insert and the tire as the insert expands and contracts in response to road conditions encountered during use. By virtue of the foregoing, less heat is generated at the interface of the insert and the tire whereby to slow the degradation of and the need to replace the insert. The preferred thickness of the low friction sleeve which surrounds the insert is at least 0.005 inches.
In an alternate embodiment for an improved combination flat-proof tire and low friction tire insert, the insert is formed from a plurality of resilient (e.g., closed cell foam) segments. The insert segments are arranged side-by-side one another so as to extend around the inside of the tire. A (e.g., plastic or rubber or foam) spacer is located between each successive pair of side-by-side aligned insert segments. The spacers and the resilient insert segments alternate with one another around the tire so that the insert segments are compressed and move independently of one another in response to road conditions. Depending upon the density and the hardness of the insert segments and the spacers, the tire can be customized so that the forces transmitted to the (e.g., motorcycle) rider are selectively controlled to change his feel of the road. A low friction (e.g., nylon) sleeve surrounds the insert to hold the insert segments and the spacers in their side-by-side alignment and reduce friction and the corresponding heat that is created at the interface of the insert and the tire as the insert segments contract and expand.
By way of a first modification, the size of the spacers which alternate with the resilient insert segments inside the low friction sleeve of the tire insert is chosen so that rectangular voids or air gaps are created between the tops of the spacers and the crown of the tire within which the insert is located. The particular size of the voids located above the spacers allows the rider's feel of the road through the tire to be selectively controlled.
By way of a second modification, a continuous plurality of resilient insert segments extend around the tire insert. In this case, a triangular (i.e., V-shaped) void or air gap is created at the interface of each pair of adjacent insert segments. The triangular voids are widest at their tops which lie below the crown of the tire within which the insert is located so that the rider's feel of the road through the tire can be selectively controlled depending upon the size of the voids.
A first preferred embodiment for an improved combination flat-proof tire and low friction tire insert is described while referring to
In accordance with the improvement herein disclosed, the resilient core 4 of the tire insert 3 is surrounded by a low friction cover (i.e., a sleeve) 5. In particular, the low friction sleeve 5 is ideally manufactured from a smooth (e.g., textile) material (e.g., nylon) that is capable of reducing the usual surface-to-surface friction that is typically created between a conventional insert and a tire when the insert expands and contracts as a result of road conditions to which the tire is subjected.
In the tire 1 shown in
Although the low friction cover for the tire insert 3 is shown in the drawings as being a single continuous sleeve 5, the cover may include a plurality of sleeves, one laying over the other. Each sleeve may surround part or all of the core 4. The number of sleeves and/or the thickness of each sleeve which surrounds the core 4 of insert 3 is determined by the dimensions of the tire 1 and the size of the core. However, for the purpose of avoiding failure (e.g., tears) when the tire is exposed to high impact forces, it has been found that the thickness of each sleeve 5 is preferably at least 0.005 inches.
Surrounding the core 4 with the low friction cover (i.e., sleeve) 5 herein disclosed increases the life of the insert and avoids the necessity for an early replacement thereof as might otherwise be required had the insert been uncovered or covered by a liquid lubricant or a powder which are prone to being rubbed off as a consequence of wear and time. The sleeve 5 may consist of a plurality of sections that are positioned over and around the core 4 of tire insert 3. In this case, one or more sections of the sleeve 5 can be removed from the insert 3 and replaced with a new section when needed. In the alternative, the sleeve can be a single piece that is wound or wrapped continuously around the core 4 and then sewn, bonded or sealed closed to create a cover lying thereover. In any case, the smooth low friction sleeve 5 is adapted to slide along the tire 1 as it rotates.
A second preferred embodiment for an improved combination flat-proof tire and low friction tire insert to be mounted on the rim of a wheel is described while referring to
A spacer 16 is located between each adjacent pair of the side-by-side aligned insert segments 14 of insert 10. Like the earlier described insert 3 of
By virtue of the plurality of spacers 16 that alternate with the resilient insert segments 14 within the insert 10 that extends completely and continuously around the inside of a tire, the insert segments 14 are able to move relative to and independently of one another around the tire. That is, the resilient insert segments 14 of the tire insert 10 can be compressed between opposing spacers 16 in response to road conditions. The compressive pressure to which the insert segments 14 will be subjected is dependent upon the density and hardness of the material from which the insert segments 14 and the spacers 16 are manufactured. The ability of the insert segments 14 of the tire insert 10 to be compressed and expand and move towards and away from one another around the tire enables the tire to be customized to correspondingly control the magnitude of the forces that will be transmitted from the tire to the (e.g., motorcycle) rider to selectively change his feel of the road through the tire while riding under different road conditions.
As in the case of the insert 3 which extends continuously around the tire 1 of
The resilient insert segments 34 and the spacers 36 which alternate around the insert 30 are positioned side-by-side one another. By virtue of the foregoing, one or more of the insert segments 34 and spacers 36 can be relatively easily removed and replaced to facilitate repair of the insert 30. A void 38 or air gap is located above each spacer 36 of the insert 30. Each void 38 lies between the top of a spacer 36 and the crown of the tire. In the example of
The segmented tire insert 30 of
A modification to the low friction insert shown in
As in the case of the inserts 3, 10 and 30 of