Patent Description:
Non-pneumatic tires are those that do not require air or other fluid for their inflation for use. Some non-pneumatic tires have a plurality of spokes arranged circumferentially around and attached to a hub. On their opposite end, the spokes are attached to a shear band. To build the spoke components of the non-pneumatic tire, it is known to combine together uncured sections of the spoke to form a green, uncured spoke which is subsequently cured through use of a mold and heat. One such method of producing a green, uncured spoke is shown and described in application <CIT>. In this method, a flat fixture is provided and various uncured spoke components are supplied onto this fixture. A pick and place device such, such as a pivoting end effector, can be used to pick the uncured spoke components up from a supply conveyor or other transport means and place the picked up components onto the flat fixture. Once the desired number of components have been assembled onto the flat fixture, the end effector can pick them up and move them to a second form, that is not flat, onto which a nose component of the spoke rests. The end effector can fold the variously assembled uncured components around and onto the nose component. This assembly can then be lifted by the end effector off of the second form and then placed onto a conveyor or otherwise transported to a mold for curing. Although capable of assembling a green, uncured spoke, additional methods of making a multi-component green, uncured spoke are desired. As such, there remains room for variation and improvement within the art. In order to solve these problems, the present invention provides a method to assemble an uncured spoke according to independent claim <NUM>. The dependent claims relate to advantageous embodiments.

The use of identical or similar reference numerals in different figures denotes identical or similar features.

Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, and not meant as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield still a third embodiment. It is intended that the present invention include these and other modifications and variations.

The present invention provides for a method of manufacturing a spoke <NUM> used in the construction of a non-pneumatic tire <NUM>. The spoke <NUM> formed via the method is an uncured spoke that is subsequently moved to a mold. In the mold, heat and pressure is applied to the spoke <NUM> for curing, and the cured spoke is subsequently assembled with the other components of the non-pneumatic tire <NUM>. The method of producing the uncured spoke <NUM> utilizes a complexing process in which components making up the spoke <NUM> are continuously fed and joined together. Components making up the spoke are folded and pressure is applied via rollers, and once certain components are assembled a desired width of the sub-assembly is cut to a length that represents the final depth size of the spoke. An end effector can also be used to add additional components to this spoke sub-assembly, and folding via rollers on the end effector can complete the uncured spoke assembly process. It is to be understood that as used herein, an uncured spoke can be referred to as a green spoke and that these two terms are interchangeable and refer to the spoke before molding with the application of heat and pressure.

<FIG> shows a non-pneumatic tire <NUM>. The non-pneumatic tire <NUM> has an axis <NUM> at its center, and the radial direction extends from the axis <NUM>. Tread is located on the outer exterior of a shear band <NUM> and extends all the way around the non-pneumatic tire <NUM> in the circumferential direction. The shear band <NUM> is located inward in the radial direction from the tread and likewise extends <NUM> degrees around the axis <NUM> in the circumferential direction. A series of spokes <NUM> engage the shear band <NUM> and extend inward in the radial direction from the shear band <NUM> to a hub <NUM> of the non-pneumatic tire <NUM>. Any number of spokes <NUM> can be present, and their cross-sectional shape can be different from that shown. In some instances, between <NUM>-<NUM> spokes <NUM> are present in the non-pneumatic tire <NUM>. The hub <NUM> is located inward from the spokes <NUM> in the radial direction and can be mounted onto a wheel of the vehicle. The spokes <NUM> at the top of the non-pneumatic tire <NUM> are in tension, and the spokes <NUM> at the bottom are in compression as the non-pneumatic tire <NUM> rests on the ground and as the non-pneumatic tire <NUM> turns in normal operation of the vehicle.

The spoke <NUM> is shown in <FIG> and includes a pair of legs with feet at ends of the spoke <NUM>. The central body of the spoke <NUM> has a generally triangular shaped cross-section and is referred to as a nose. The spoke <NUM> shown is the uncured, green spoke <NUM> produced from the disclosed method and is made out of multiple components. Each one of these components can include different materials, or can have the same materials in different amount or in the same amount. Rubber, fiberglass, urethane, polyurethane and other materials may be present in the components used to assemble the spoke <NUM>. The components of the spoke <NUM> include a first panel <NUM> and a second panel <NUM> that make up the legs of the spoke <NUM>. The first panel <NUM> has the first foot <NUM> on one end and a first foot layer <NUM> at least partially surrounds the first foot <NUM>. The second panel <NUM> in turn has a second foot <NUM> on one end and a second foot layer <NUM> at least partially surrounds this second foot <NUM>. A nose <NUM> is present under the spoke <NUM> and engages along a majority of its length both of the panels <NUM>, <NUM>. On an opposite of the spoke <NUM> from the nose <NUM>, a first nose layer <NUM> is present and engages both panels <NUM>, <NUM> along its length. A second nose layer <NUM> is laid on top of the first nose layer <NUM> and has ends that fold under the nose <NUM> and engage the panels <NUM>, <NUM>. It is to be understood that the shape and size of the spoke <NUM> formed by the process can be varied in accordance with different exemplary embodiments, and that a variety of spoke <NUM> configurations are possible. The spoke <NUM> extends from a first end to a second end, to achieve a width <NUM> of the spoke <NUM>, and may have an extension from end to end greater than, less than, or the same as the height of the spoke <NUM>.

The process of constructing the spoke <NUM> includes a number of stations that supply, complex and otherwise process the material and subassemblies into the final form of the green spoke <NUM>. <FIG> and <FIG> show stations that make up the first stages of the assembly process with <FIG> being a top view and <FIG> being a side view of <FIG>. Foot layer unwinding station <NUM> is shown and includes one or more bobbins onto which material making up the first and second foot layers <NUM>, <NUM> is wound. Although described as being supplied on bobbins, it is to be understood that the various components used in the construction of the spoke <NUM> could also be supplied to the machinery conducting the assembly process via extrusion. A panel unwinding station <NUM> is also present and includes a bobbin onto which a panel <NUM> is wound. A primary conveyor <NUM> is present and is downstream from both stations <NUM>, <NUM> and has a belt that moves in the machine direction. The primary conveyor <NUM> could be a belt, rollers, a combination of belts and rollers, or any other mechanism capable of moving the components downstream. The foot layer unwinding station <NUM> and the panel unwinding station <NUM> are in line with the primary conveyor <NUM>. The figures include a length direction <NUM> and a perpendicular width direction <NUM>. The length direction <NUM> may be referred to as the machine direction and is the direction the materials and components travel for complexing. The width direction <NUM> can be thought of as the side direction.

The first and second foot layers <NUM>, <NUM> are routed from the foot layer unwinding station <NUM> to the primary conveyor <NUM> with a required amount of spacing between them in the width direction <NUM>. Mechanical guides can be used to control the position of the first and second foot layers <NUM>, <NUM> on the primary conveyor <NUM>, and pressure rollers are applied to the first and second foot layers <NUM>, <NUM> to avoid slippage between them and the primary conveyor <NUM>. The panel <NUM> is supplied from the panel unwinding station <NUM> to the primary conveyor <NUM>, and dynamic centering is used to ensure proper positioning of the panel <NUM> with respect to the primary conveyor <NUM>. A foot layer and panel complexing station <NUM> is present on the primary conveyor <NUM>. The foot panel <NUM> is complexed on the primary conveyor <NUM> over the first and second foot layers <NUM>, <NUM> and a pressure roller is applied to push these components <NUM>, <NUM>, <NUM> together at the foot layer and panel complexing station <NUM>. The various green spoke components that are assembled via the disclosed process have a natural stickiness/tackiness to them so that they will exhibit some amount of adhesion even though they are not cured. Pressure applied to the sticky components will further enhance their adhesion with one another. As such, the components can be pushed together and may remain attached via their natural tackiness throughout the build process. The subassembly of the first and second foot layers <NUM>, <NUM> with the panel <NUM> is illustrated with reference to <FIG>.

A foot unwinding station <NUM> is downstream from the foot layer and panel complexing station <NUM>. The foot unwinding station <NUM> is positioned perpendicular to the length direction <NUM>. The foot unwinding station <NUM> includes bobbins onto which the first foot <NUM> and the second foot <NUM> are wound. The feet <NUM>, <NUM> are unwound from the foot unwinding station <NUM> and transported in the width direction <NUM> to the primary conveyor <NUM>. Upon approach to the primary conveyor one or more rollers or other mechanical guides are employed to turn the transport direction of the feet <NUM>, <NUM> from the width direction <NUM> to the length direction <NUM>. Dynamic centering is used to ensure proper positioning of the feet <NUM>, <NUM> relative to the edges of the panel <NUM>. As described herein, the term "dynamic centering" is positioning of the component in the process using mechanical or visual means to determine positioning and then using mechanical means such as roller to properly position the component. A foot complexing station <NUM> is present downstream from the foot layer and panel complexing station <NUM> to complex the feet <NUM>, <NUM> with the subassembly of the panel <NUM> and foot layers <NUM>, <NUM>. At the foot complexing station <NUM>, the feet <NUM>, <NUM> are placed onto the panel <NUM> and this subassembly is shown in <FIG>. After placement of the feet <NUM>, <NUM> or simultaneously therewith, the process at the foot complexing station <NUM> also functions to turn up the foot layers <NUM>, <NUM>. This turn up is shown with reference to <FIG>. In this regard, the first foot layer <NUM> remains engaged to the bottom of the panel <NUM>, but is wrapped up and covers a portion of the first foot <NUM>. Similarly, the second foot layer <NUM> remains in engagement with the panel <NUM> and is wrapped up and covers a portion of the second foot <NUM>. A series of rollers is used at the foot complexing station <NUM> to accomplish turn up of the first and second foot layers <NUM>, <NUM>. Pressure rollers may be used to push the feet <NUM>, <NUM> against the panel <NUM>, and pushing the first and second foot layers <NUM>, <NUM> against the feet <NUM>, <NUM>, to ensure a connection stronger than that achieved by just placement onto the panel <NUM> with the natural tackiness. Up to this point in the assembly process, the panel <NUM> is a single piece and is not slit into two pieces and extends in the width direction <NUM> continuously from the first foot/layer <NUM>, <NUM> to the second foot/layer <NUM>, <NUM>.

<FIG> shows one manner of effecting the turn up as disclosed. Here, rollers <NUM> push down onto the panel <NUM> and the feet <NUM>, <NUM> to keep them in position for the turn up. Wedges <NUM> one either side of the subassembly in the width direction <NUM> can engage the first foot layer <NUM> and the second foot layer <NUM> to initially lift them up off of the surface of the primary conveyor <NUM>. As the subassembly moves downstream in the length direction <NUM>, a series of rollers <NUM> engage the layers <NUM>, <NUM> in sequence and function to turn them up onto the feet <NUM>, <NUM>. Additional arrangements of folding the first and second foot layers <NUM>, <NUM> are possible in other embodiments.

<FIG> and <FIG> show downstream portions of the assembly process from that previously described with <FIG> being a top view of the side view of <FIG>. After the turn up to achieve the subassembly of <FIG>, a cutter <NUM> is employed to cut this subassembly down the length of the subassembly such that the cutter <NUM> creates a cut in the length direction <NUM>. The cutter <NUM> may be a laser cutter and can be present just off of the end of the primary conveyor <NUM>. A space may exist in the length direction <NUM> between the primary conveyor <NUM> and a secondary conveyor <NUM> that is downstream in the machine direction from the primary conveyor <NUM>. The secondary conveyor <NUM> at the cutter <NUM> is not a belt. Rollers can be used to hold down the subassembly at the cutter <NUM> so that the cutter splits the subassembly into two separate pieces. A wedge profile partition is present to separate the two pieces of the cut subassembly in the width direction <NUM> as the subassembly moves downstream in the length direction <NUM>. Guiding rollers on either side are used to support the cut subassembly and move it to the desired width position. Multi-directional rollers <NUM> are present at the wedge profile partition to allow the cut subassembly to move in both the length direction <NUM> and the width direction <NUM>. Multi-direction rollers <NUM> have rollers that allow movement/rolling in both length and width <NUM>, <NUM> directions. The multi-directional rollers <NUM> thus afford movement in these two directions so that material thereon can be moved not just length <NUM> wise but also width <NUM> wise. The multi-directional rollers <NUM> are present at the wedge profile partition such that they share some of the same locations in the length direction <NUM>.

The subassembly after cutting by the cutter <NUM> and separation via the wedge, multi-directional roller <NUM> and guide rollers is shown with reference to <FIG>. As shown, the sub-assembly is now two separate pieces spaced completely from one another in the width direction <NUM>. This cutting separates the panel <NUM> into a first panel <NUM>, that engages the first foot <NUM> and the first foot layer <NUM>, and a second panel <NUM> that in turn engages the second foot <NUM> and the second foot layer <NUM>. No new material or components are added in this cutting process in which the subassembly is cut into two pieces. The separation at this point does not employ a secondary conveyor <NUM> with belts but instead includes rollers and an open area underneath. The cut subassembly may then be passed to the belt portion of the secondary conveyor <NUM>. As such, the primary conveyor <NUM> may be a belt at all points, and the secondary conveyor <NUM> may have a belt portion and a roller portion such that it is not a belt at all points.

A first nose layer unwinding station <NUM> is present downstream from the cutter <NUM> in the length direction <NUM>, and is positioned perpendicular to the secondary conveyor <NUM>. The first nose layer <NUM> is wound onto a bobbin at the first nose layer unwinding station <NUM> and is unwound and moves in the width direction <NUM> to the secondary conveyor <NUM>. The first nose layer <NUM> is turned <NUM> degrees from the width direction <NUM> to travel on the length direction <NUM> by way of rollers or other mechanical members. Dynamic centering is used to control the position of the first nose layer <NUM> relative to the surface of the secondary conveyor <NUM> or to the subassembly carried by the secondary conveyor <NUM>. Profiled pressure rollers can be used to complex the subassembly of <FIG> with the first nose layer <NUM> to thus apply the first nose layer <NUM> to the first panel <NUM> and second panel <NUM> at a first nose layer station <NUM>. <FIG> shows the subassembly at this stage of development in which the first nose layer <NUM> bridges the first and second panels <NUM>, <NUM> and engages both of them on a single side. The subassembly can now be thought of as being a single piece once the first nose layer <NUM> is applied thereto to reattach the pieces <NUM>, <NUM>. The first and second panels <NUM>, <NUM> can still be thought of as separate components instead of a single panel <NUM> at this point in the subassembly and moving forward.

A cutting station <NUM> is downstream from the first nose layer station <NUM> in the length direction <NUM>. The first and second panels <NUM>, <NUM> may include a plurality of fiberglass cables that are oriented so as to run in the width direction <NUM>. A vision system at the cutting station <NUM> below the surface of the secondary conveyor <NUM> monitors the first and second panels <NUM>, <NUM> and positions the cutter at the cutting station <NUM>, or controls the movement of the secondary conveyor <NUM> relative to the cutter, or both so that the cut to the first and second panels <NUM>, <NUM> occurs between two successive cables of the first and second panels <NUM>, <NUM>. The cutting station <NUM> functions to ensure first and second panel <NUM>, <NUM> monofilaments are aligned with one another and cut therebetween. If a blade is used to cut the first and second panels <NUM>, <NUM> then it may be sized relative to the monofilaments to allow it to find a position between them so that the monofilaments themselves are not cut, but instead the material between them are cut. Additionally or alternatively, positioning with the vision system may ensure the material between the monofilaments and not the monofilaments are cut. The cutter at the cutting station <NUM> may be a laser or may be a mechanical blade.

The subassembly is cut at the cutting station <NUM> so that the cut extends in the width direction <NUM> and not in the length direction <NUM>. A cut is made and the subassembly advanced in the length direction <NUM> and another cut in the width direction <NUM> is made as such a point that a desired width/length of the subassembly is obtained. It is to be understood that up until this point the subassembly is described in terms of a length moving forward. Now, cutting of the subassembly in the width direction <NUM> results in an amount of final subassembly product that has a particular resulting width. Thus the width of the final spoke <NUM> product does not have the same meaning as the width direction <NUM> of the machinery constructing the subassemblies of the final spoke <NUM> product.

After the cutting station <NUM>, the belt of the secondary conveyor <NUM> ends downstream in the length direction <NUM> and the product is directed off of the belt of the secondary conveyor <NUM> to an indexing fixture <NUM>. The indexing fixture <NUM> can reciprocate backwards and forwards in the length direction <NUM>. The cut to width subassembly is placed onto the indexing fixture <NUM> and the indexing fixture <NUM> moves downstream in the length direction <NUM> so that a space exists between the indexing fixture <NUM>/cut subassembly and the upstream cutting station <NUM>/secondary conveyor <NUM> belt. Pressure rollers are used to ensure traction between the surface of the secondary conveyor <NUM> belt and the cut subassembly. After moving the cut subassembly a short distance in the length direction <NUM>, the indexing fixture <NUM> stops. The reason the indexing fixture <NUM> is moved away from the primary conveyor <NUM> and stopped is to create an empty space. Turning now momentarily to <FIG>, the end effector <NUM> has an end effector portion <NUM> that extends downward past the engagement surface <NUM> and the subassembly held by the end effector <NUM>. When the end effector <NUM> engages the subassembly on the indexing fixture <NUM>, this downward extending end effector portion <NUM> goes into the empty space just created by the indexing fixture <NUM> so that the subassembly can be grasped and held onto the engagement surface <NUM>. If this space by the indexing fixture <NUM> were not created, then the projecting end effector portion <NUM> would hit the primary conveyor <NUM>/secondary conveyor <NUM>/indexing fixture <NUM> and interference would result so that the subassembly would not be able to be grasped.

The process includes a second nose layer unwinding station <NUM> at which the second nose layer <NUM> is wound on a bobbin. The second nose layer <NUM> may be unwound from the bobbin and cut to a desired length which is longer than the width of the previously cut subassembly. The second nose layer unwinding station <NUM> and cutting posts for cutting the second nose layer <NUM> are perpendicular to the machine direction of the secondary conveyor <NUM>. A robot having an end effector <NUM> is located downstream of the indexing fixture <NUM> and retrieves the cut piece of second nose layer <NUM>. This picked up second nose layer <NUM> piece is transported to the cut subassembly and placed directly over the first nose layer <NUM> with ends extending beyond each side of the cut subassembly. <FIG> shows the second nose layer <NUM> positioned onto the first nose layer <NUM> with ends extending over the sides. The ends will sag a bit as the second nose layer <NUM> overlays the subassembly.

On an opposite side of the robot with the end effector <NUM> and likewise perpendicular to the direction of travel of the secondary conveyor <NUM> in the length direction <NUM> a nose unwinding station <NUM> is located. The nose <NUM> is unwound from a bobbin at the nose unwinding station <NUM> and can be cut to length by a cutting post. The cut nose <NUM> may be placed by a second robot or other mechanism onto a nose assembly fixture <NUM>. At this point in the assembly process, the robot with the end effector <NUM> may lift the subassembly shown in <FIG> and transport it to the nose assembly fixture <NUM>. The end effector <NUM> has an engagement surface <NUM> that can have suction cups or vacuum capability to grasp the subassembly and lift it from the secondary conveyor <NUM> or other surface for transport and to hold the subassembly thereon. The vacuum or other holding feature can be released to remove the held subassembly components from the engagement surface <NUM>.

Claim 1:
A method to assemble an uncured spoke (<NUM>), comprising:
providing a panel (<NUM>, <NUM>, <NUM>);
providing a first foot (<NUM>);
providing a second foot (<NUM>);
joining the first foot (<NUM>) and the second foot (<NUM>) onto the panel (<NUM>, <NUM>, <NUM>) such that the panel (<NUM>, <NUM>, <NUM>) extends continuously from the first foot (<NUM>) to the second foot (<NUM>), wherein the first foot (<NUM>) and the second foot (<NUM>) engage the panel (<NUM>, <NUM>, <NUM>);
joining a first foot layer (<NUM>) and a second foot layer (<NUM>) onto the panel (<NUM>, <NUM>, <NUM>);
characterized by
folding the first foot layer (<NUM>) onto the first foot (<NUM>), wherein the first foot layer (<NUM>) engages the panel (<NUM>, <NUM>, <NUM>) and wherein the first foot layer (<NUM>) engages the first foot (<NUM>); and
folding the second foot layer (<NUM>) onto the second foot (<NUM>), wherein the second foot layer (<NUM>) engages the panel (<NUM>, <NUM>, <NUM>) and wherein the second foot layer (<NUM>) engages the second foot (<NUM>).