The current invention relates to pneumatic tire inflation. More particularly, the invention relates to at self-inflating pneumatic tire having a compression layer disposed between a tire casing and tire tread.
One of the most efficient pumping designs for self-inflating tires for bicycles is to put the lumen outside of the tread of the tire and centered in the middle of the tire. With this design, the hard, stiff tire compresses the pumping mechanism against the hard pavement. This design is very efficient because most of the load on the wheel presses down on the pavement and therefore on the pumping mechanism. However with this type of design, there are several problems such as the tire ride quality is compromised because the pumping mechanism has a high ridge along the riding surface of the tire and therefore is prone to tracking or can be easily torn, ripped, damaged by elements on the riding surface. A further problem is low durability of the pumping mechanism due to thin wall thickness of the pumping mechanism, and current tire manufacturing processes do not lend themselves to high precision features, such as a pumping mechanism, withstanding the injection molding and vulcanization cycles.
What is needed is a self-inflating pneumatic tire having the compression mechanism disposed between the tire casing and tire tread.
To address the needs in the art, self-inflating tire is provided that includes a pneumatic tire having a tread, and a casing, where the tread includes an outer riding surface, where the casing includes an inner inflation surface, and an elastic inflation lumen disposed between the casing and the tread, where the inflation lumen has at least one air through-port.
On one aspect of the invention, the at least one air through-port includes an input port, an output port, or an input/output port (I/O port).
In another aspect of the invention, the inflation lumen includes a closed-end inflation lumen that spans along at least a portion of a circumference of the pneumatic tire.
According to a further aspect of the invention, the inflation lumen includes an open-end inflation lumen that spans along a circumference of the pneumatic tire.
In one aspect of the invention, the tread includes a channel, where the inflation lumen is disposed in the channel.
In yet another aspect of the invention, the pumping mechanism is configured to a tire according to a tubeless tire, or a tubed tire.
According to another aspect, the invention further includes a compression layer that is disposed in a position that includes between the inflation lumen and the tread, or between the casing and the inflation lumen, where the compression layer includes an actuator, where the actuator has a cross-section having a base and a converging tip, where the converging tip abuts an outer surface of the inflation lumen, where the compression layer has a length that spans along at least a portion of a circumference of a pneumatic tire. In one aspect, the actuator includes at least one ridge feature on the converging tip that is transverse to the compression layer length. In another aspect, the compression layer includes an interlocking actuator, where the interlocking actuator has a female actuator disposed on a first side of the inflation lumen and a male actuator disposed on a second side of the inflation lumen, where the first side is opposite the second side, where the interlocking actuator is configured to impart a surrounding-force directed to maintain alignment between the inflation lumen and the actuator. In a further aspect, the compression layer includes a lower hardness than a hardness of the tread.
According to one aspect of the invention, the inflation lumen is disposed along at least a portion of a circumference of the pneumatic tire.
In another aspect the invention further includes an inflation lumen protection layer disposed between the inflation lumen and the tread.
In a further aspect of the invention, the inflation lumen includes a block shape cross-section, where the block shape cross-section has a channel forming the lumen.
According to one aspect, the invention further includes a valve, where the valve includes a membrane valve, a 3-way valve, or a 2-way valve. In one aspect, the current embodiment further includes a connector tubing disposed between the lumen and the valve. In one aspect, the connector tubing includes an accumulator, where the accumulator stores a volume of air between the lumen and the valve. In a further aspect, the valve is connected to an inner tube, where the inner tube connection includes a controller connected between the inflation lumen and the valve of the inner tube.
According to one aspect, the invention further includes a valve and an actuator pressure governor, where the actuator pressure governor has an adjustable air input/output port.
In another aspect, the invention further includes a controller that includes a removable controller, an adjustable pressure controller, or a fixed pressure controller. In one aspect, the controller is disposed in a location inside an inner tube.
The invention provides a self-inflating tire system and a pressure regulation system for self-inflating bicycle tires, which controls the air pressure in the system. The self-inflating tire system uses mechanical energy from the rolling and deformation of the tire to push air into the tire. Once the desired pressure is reached the pressure regulation system stops the system from pumping.
According to one embodiment, the pumping mechanism is manufactured separately from the tire, where the pumping mechanism includes a compression lumen and control system, where the tire is designed with features for accepting the pumping mechanism. In this embodiment, the pumping mechanism is designed to be integrated into the tire to provide a uniform riding surface having sufficient rubber on the riding surface to protect the pumping mechanism from harm for the designed tire life. In this embodiment, the pumping mechanism includes a lumen within a polymer or rubber bulk layer, where the compression lumen is disposed circumferentially to an outer surface of a tire casing, yet embedded with or beneath the tire tread. In this example, the compression lumen is incorporated with the tire tread according to vulcanization, adhesion, extrusion, or molding technologies.
According to other aspects, the invention further includes a compression layer that is disposed in a position that includes between the inflation lumen and the tread, or between the casing and the inflation lumen, where the compression layer includes an actuator, where the actuator has a cross-section having a base and a converging tip, where the converging tip abuts an outer surface of the inflation lumen, where the compression layer has a length that spans along at least a portion of a circumference of pneumatic tire. In one aspect, the actuator includes at least one ridge feature on the converging tip that is transverse to the compression layer length. In another aspect, the compression layer includes an interlocking actuator, where the interlocking actuator has a female actuator disposed on a first side of the inflation lumen and a male actuator disposed on a second side of the inflation lumen, where the first side is opposite the second side, where the interlocking actuator is configure to impart a surrounding-force on the inflation lumen. In a further aspect, the compression layer includes a lower hardness than a hardness of the tire.
Turning now to the pumping mechanism, the current invention provides a pumping mechanism between the casing and the tread of the tire. Pneumatic tires such as bicycle tires carry their load through the tension of the fibers in the casing. This tension plus the surrounding materials create a stiff, but pliable region. The current invention places a pumping mechanism between the outer surface of the casing and the tread. The load imparted on the tire is transferred from the casing to the pumping mechanism, where the pumping mechanism compresses as the tire rolls on the ground surface. These dynamics causes the lumen to collapse and push air forward through the lumen and into the control system. As the wheel rotates, the load is removed from the pumping mechanism and the lumen rebounds to its original shape, where air is drawn in for the next pumping cycle.
Turning now to the figures,
According to the current invention, the inflation lumen 106 material includes any one of, or a combination of: natural rubber, synthetic rubber, high molecular weight, flexible polyvinyl chloride (PVC), standard flexible PVC, peroxide cured silicone, thermoplastic vulcanizate (TPV), and thermoplastic elastomer (TPE) Viton™ rubber.
According to the current invention, the compression layer 108 material includes any one of, or a combination of foamed natural rubber, foamed synthetic rubber, foamed thermoplastic PU, foamed polyurethane, open cell foam, and closed cell foam.
There are many benefits to this construction. For example, separate construction of the pumping mechanism 200 and tire allows much more complexity to be built into the tire assembly. Typically, tires go through a vulcanization process where high heat and pressure force the unformed, unvulcanized rubber into the shape and profile of the finished product.
Delicate elements such as the pumping mechanism 200 would otherwise have difficulty withstanding the high heat and pressure of the process without deformation.
Another advantage of the current invention is that the pumping mechanism 200 is uniform around the major circumference, or at least a portion of the circumference of the wheel; this maintains the uniform riding surface of the tire, resulting in a high quality of ride.
The compression layer with a raised surface and block lumen, such as in
In another embodiment of the invention the tread may have different layers of materials. For example different layers to indicate wear. This can be done through different layers of multicolor rubber. For example the color may start out black then go to yellow then to red. Other layered materials may include Kevlar or other reinforcement material to protect against puncture.
The inflation lumen 106 is an elastic and compressible tube which provides the spring force for drawing in air in the intake cycle. During the compression cycle, the inflation lumen 106 is compressed, which pushes the air through the system. To have a balanced and uniform wheel, it is desirable to have the inflation lumen 106 completely encircle the outside of casing 102 and beneath the tread 104. However, it can completely encircle the casing 102 or only partially encircle the casing 102. The inflation lumen 106 can also completely encircle the casing 102 but only be active for a portion of its length. For the closed-end inflation lumen 106, for example, the active section shown in the drawing only occupies 180-degrees. The other 180-degrees of the inflation lumen 106 would be of similar density and material so that there is no noticeable difference between the two sections for the rider.
The compression layer 108 and actuator tip 112 push on the inflation lumen 106 from one or more sides to cause it to compress. The actuator tip 112 may be a raised surface as shown in
An open-end pumping mechanism is shown in
Ideally, the pumping mechanism completely encircles the major diameter of the tire. This is beneficial because it preserves the uniform ride of the tire. It is possible, however, to limit the active section of the pumping mechanism. This would be desirable in high usage applications for example where the pumping mechanism has a pumping volume much greater than that required to offset air loss from diffusion. Bike sharing would be an example of this. In this case the active length of the pumping mechanism could be reduced to any fraction of the circumference, for example 120-degrees or 180-degrees of the tire major diameter. This would also reduce the incidence of puncture and increase reliability because a portion of the pumping mechanism would no longer be susceptible to puncture.
The current invention includes a closed-end pumping mechanism shown in
Essentially, the air in the inflation lumen 106 is compressed and pushed out of the inflation lumen 106 from the same end it entered the inflation lumen 106. This design significantly reduces the complexity of the pneumatic circuit because is it only requires one pneumatic passageway between the tire and the controller. Having only one passageway through the tire opens up great flexibility of the connection between the tire and the inner tube.
The elements of the three-way control valve can be located anywhere in the system. For example in the embodiment shown in
Another important aspect of the closed-end pumping mechanism is that it does not need to be unbalanced. The pumping mechanism may go completely around the tire or it may go partially around the tire. A pumping mechanism can be designed to completely encircle the tire and only have a portion of the pumping mechanism active. In this way the invention can be optimized for uniform ride, balance and ease of manufacturing while at the same time limiting the degrees or length of the active pumping mechanism. The inflation lumen 106 of the pumping mechanism 200 could be plugged, clamped, glued, terminated or use any other method to limit the length of the active pumping mechanism.
The pumping mechanism 200 can be similar in form to open-end designs in that it can be slightly stretched and then glued or vulcanized into place in the channel on the tire (see
Although the closed-end inflation lumen 106 design can be used for almost any self-inflating tire, the invention has been shown in the embodiment where the pumping mechanism 200 is located outside the casing 102 of the tire. The pumping mechanism 200 connects to the inner tube through a single port, which passes through the casing of the tire.
The inner tube contains a corresponding port so that the pneumatic connection between the inner tube and tire is made. In one embodiment the male connector is part of the pumping mechanism 200 and the female connector is part of the inner tube. In other embodiments the male/female connectors can be reversed. Having the male connector attached to the pumping mechanism 200 has the advantage of not introducing any raised elements outside of the casing and therefore potentially offers a smoother ride. In the case where the application is tubeless all of the same elements are included in the system only they are not packaged within an inner tube.
The current invention uses flexible tubing to join the different elements together. The overall flow of air through the system can be seen in
The tires used is this system can be manufactured on current equipment found in industry. That is to say they are of the same standard sizes and use the same construction methods. Because most of the high precision elements of the system are located in the pumping mechanism, the manufacturing processes for the tire remains mostly unchanged. In the embodiments where the tire has a channel to accept the pumping mechanism. The channel is approximately 5-20 mm wide. In certain embodiments, the pumping mechanism is adhered in its position in the between the casing and the tread either through vulcanization or adhesion.
One of the advantages of the system is that that self-inflating tire can be manufactured on existing industry equipment. Typically, in bicycle tire manufacturing the components of the tire including casing, bead and tread rubber are assembled and then placed in a mold for vulcanization. The heat and pressure from the mold force the rubber into its final shape and the raised edges and profile of the tread are formed. The typical vulcanization process would damage the pumping mechanism so the invention uses two methods to incorporate the pumping mechanism into the tire.
In the first method the casing of the tire and the tread are assembled and vulcanized independently of each other.
The second method of assembly is shown in
The self-inflating tire has one or more ports to pneumatically join the tire to the inner tube. The in this embodiment, the ports include a tire low-pressure port and a tire high-pressure port.
In one embodiment the tire ports have a fiber layer which strengthens the casing in the area where the port pushes through the casing. The fibers may be of nylon, cotton or any other load bearing material.
According to the invention, the design has at least one hole through the casing of the tire.
As described earlier, a check valve is located in the control module which is near the valve stem and away from the riding surface. It is desirable to have the check valve as close as possible to the end of the pumping mechanism, but this would bring it close to the riding surface which would expose the check valve to potential damage. High-pressure applications might favor a check valve closer to the end of the pumping mechanism. Embodiments where reliability or cost should be optimized, favor the check valve near the valve stem. The control module comprises a mechanism to control the pressure inside the chamber of the tire or inside the inner tube. The control module may be partially inside the inner tube or partially outside the inner tube. The control module may contain a check valve or it may not. The current invention works for tubeless tires as well as tires utilizing inner tubes
In the embodiments in
In the case where the embodiment uses an inner tube, the control module may be releasably attached to the inner tube. In one embodiment the inner tube has three ports. The first port connects the inner tube low-pressure port to the tire. The second port connects the inner tube high-pressure port to the tire. The third port connects the inner tube to the control module. In another embodiment the inner tube has two ports. The two-port embodiment is used with the closed-end pumping mechanism. The first port connects the inner tube to the tire. In this embodiment there is only one port connecting the inner tube and tire and the port acts as both the low-pressure and high-pressure port. The second port connects the inner tube to the control module.
The present invention has now been described in accordance with several exemplary embodiments, which are intended to be illustrative in all aspects, rather than restrictive. Thus, the present invention is capable of many variations in detailed implementation, which may be derived from the description contained herein by a person of ordinary skill in the art. All such variations are considered to be within the scope and spirit of the present invention as defined by the following claims and their legal equivalents.
This application claims priority from U.S. Provisional Patent Application 62/635,195 filed Feb. 26, 2018, which is incorporated herein by reference. This application claims priority from U.S. Provisional Patent Application 62/658,855 filed Apr. 17, 2018, which is incorporated herein by reference.
Number | Date | Country | |
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62635195 | Feb 2018 | US | |
62658855 | Apr 2018 | US |