Background of the Invention Field of the Invention

The present invention relates to devices for covering rooftops, and to methods of producing such devices. Description of the Related Art

Figures 1 and 2 illustrate one type of roofing shingle 20 that is commonly used today. The shingle 20 includes a first portion 22 (commonly referred to in the industry as a "tab") and a second portion 24 (commonly referred to in the industry as a "dragon's tooth" or "tooth"). The first portion 22 is substantially rectangular, and forms a lower layer of the shingle 20. The second portion 24 is shaped substantially as a rectangle having a plurality of cutouts 26 (Figure 1) along a lower edge 28 thereof. The cutouts 26 define a plurality of flaps 30 located between adjacent cutouts 26. The flaps 30 and cutouts 26 are of approximately equal width, and each is shaped substantially as a trapezoid, with the flaps 30 being widest along their lower edges 28. Approximately the lower half of the second portion 24 overlaps the first portion 22, such that the lower edge 28 (Figure 1) of the second portion 24 aligns with a lower edge 32 (Figure 1) of the first portion 22, as shown in Figure 2. Trapezoidally shaped segments 34 of the first portion 22 are visible through the cutouts 26, with the flaps 30 covering the first portion 22 between adjacent cutouts 26. Above the cutouts 26, the tab 22 and tooth 24 define a rectangular region 36 (Figure 2) in which the tooth 24 completely overlaps the tab 22.

Each of the portions 22, 24 may comprise, for example, a fiberglass membrane that is coated with asphalt tar and sprinkled with sand. During the manufacturing process, adhesive (not shown) is applied to a back surface of the tooth 24 and/or to a front surface of the tab 22. The adhesive is applied over the asphalt tar and sand. The tooth 24 is positioned over the tab 22 such that the lower edge 32 of the tab 22 aligns with the lower edge 28 of the tooth 24, as shown in Figure 2. The adhesive, which is commonly an asphalt-based glue such as SBS rubber, secures the tooth 24 and tab 22 to one another. The adhesive may be applied in the overlapping rectangular region 36, as well as in the areas where the flaps 30 overlap the tab 22.

Many consumers prefer two-piece shingles, because they provide a pleasing appearance that is similar to wood shingles. However, one problem common to two-piece shingles is separation of the tooth 24 from the tab 22. Such separation is most common in geographic areas that have warmer climates. The warmer temperatures cause the asphalt tar to become soft, thereby enabling the tab 22 to slide downward away from the tooth 24 under the influence of gravity on a slanted roof. Even when relatively strong adhesives are used to secure the tooth 24 and tab 22 to one another, softening of the asphalt tar still may allow for separation, because the

adhesive only secures the sand on the tooth 24 to the sand on the tab 22. Accordingly, softening of the asphalt tar enables the sand to separate from the fiberglass membranes of the tooth 24 and tab 22. This separation can occur regardless of how strong the adhesive is. When such separation occurs, it can lead to shingle failure and a leaky roof.

Fastening members, such as nails and staples, are most commonly used to secure shingles to roof surfaces. With two-piece shingles, such as those illustrated in Figures 1 and 2, the fastening members are preferably driven through the overlapping region 36 of each shingle 20. The fastening members thus reinforce the adhesive and restrain separation of the tooth 24 from the tab 22. Unfortunately, laborers who install shingles frequently fail to drive the fastening members through the overlapping region 36 of each shingle 20. These laborers are sometimes low-skilled and/or under time pressure to complete a job. They may drive the fastening members through the tooth 24 only. Thus, the fastening members do not penetrate the tab 22. As the asphalt tar softens, the tab 22 can disadvantageously slide down the roof away from the tooth 24, leading to roof failure. Accordingly, many two-piece shingles that are produced today do not last as long as their manufacturers and consumers would like. A two-piece shingle that is better able to restrain separation of the tab from the tooth, even in very warm climates, would be of substantial benefit to shingle manufacturers, homeowners and other consumers of roofing shingles.

Summary of the Invention

The preferred embodiments of the present shingles and methods of producing shingles have several features, no single one of which is solely responsible for their desirable attributes. Without limiting the scope ^" of these shingles and methods as expressed by the claims that follow, their more prominent features will now be discussed briefly. After considering this discussion, and particularly after reading the section entitled "Detailed Description of the Preferred Embodiments," one will understand how the features of the preferred embodiments provide advantages, which include a very high resistance to separation of the tab and tooth portions of the shingle, and an ability to manufacture shingles at very high line speeds.

One embodiment of the present shingles and methods of producing shingles comprises a shingle adapted to be secured to a rooftop to prevent moisture from penetrating the rooftop. The shingle comprises a first relatively larger portion, and a second relatively smaller portion partially overlapping the first portion, thereby defining an overlapping region. At least one aperture extends through both portions in the overlapping region, and a fastening member extends through the at least one aperture.

Another embodiment of the present shingles and methods of producing shingles comprises apparatus for producing shingles. The apparatus comprises a strip of shingles, a first drum including puncturing apparatus and a second drum including injecting apparatus. The

second drum is spaced from the first drum and positioned such that longitudinal axes of the drums are substantially parallel. The drums are adapted to receive the strip along outer surfaces thereof.

Another embodiment of the present shingles and methods of producing shingles comprises a method of producing shingles. The method comprises the step of providing at least one shingle having a tab portion, a tooth portion and an overlapping region in which the tab portion and tooth portion overlap. The method comprises the steps of puncturing at least one shingle in the overlapping region to thereby produce an aperture, and inserting a fastening member into the aperture to thereby secure the tab portion to the tooth portion.

Another embodiment of the present shingles and methods of producing shingles comprises apparatus for producing shingles. The apparatus comprises a strip of shingles, an outer drum, a first drum and a second drum. The first drum includes puncturing apparatus, and the second drum includes injecting apparatus. The second drum is spaced from the first drum and positioned such that longitudinal axes of the drums are substantially parallel. The outer drum is adapted to contact the strip along an outer surface thereof. The first drum is adapted to puncture the strip as it passes by the outer drum. The second drum is adapted to inject a fastening member into the strip as it passes by the outer drum.

Brief Description of the Drawings

The preferred embodiments of the present shingles and methods of producing shingles, illustrating their features, will now be discussed in detail. These embodiments depict the novel and non-obvious shingles and methods shown in the accompanying drawings, which are for illustrative purposes only. These drawings include the following figures, in which like numerals indicate like parts:

Figure 1 is a top perspective, exploded view of a prior art shingle;

Figure 2 is a top perspective view of the shingle of Figure 1;

Figure 3 is a top perspective, exploded view of one embodiment of the present shingles;

Figure 4 is a top perspective view of the shingle of Figure 3;

Figure 5 is a cross-sectional view of the shingle of Figure 4, taken along the line 5-5;

Figure 6 is a side elevational view of one embodiment of apparatus for producing the shingle of Figure 3;

Figure 7 is a detail side elevational view of a strip of shingles that are arranged end-to- end, taken along the line 7-7 in Figure 6;

Figure 8 is a detail view of the apparatus of Figure 6, taken along the line 8-8;

Figure 9 is a detail side elevational view of the apparatus of Figure 6, taken along the line 9-9;

Figure 10 is a detail side elevational view of the apparatus of Figure 6, taken along the line 10-10;

Figure 11 is a detail side elevational view of the apparatus of Figure 6, taken along the line 11-11;

Figure 12 is a detail side elevational view of the apparatus of Figure 6, taken along the line 12-12;

Figure 13 is a side elevational view of another embodiment of apparatus for producing the shingle of Figure 3; and

Figure 14 is a detail side elevational view of an alternative embodiment of apparatus for performing puncturing and injecting steps.

Detailed Description of the Preferred Embodiments

Figures 3-5 illustrate one embodiment of the present shingles 40. Like the prior art shingle 20 above, the present shingle 40 includes a first portion 42 (a "tab") and a second portion 44 (a "tooth"). In the illustrated embodiment, the first portion 42 is substantially rectangular, and forms a lower layer of the shingle 40. The second portion 44 is shaped substantially as a rectangle having a plurality of cutouts 46 (Figure 3) along a lower edge 48 thereof. The cutouts 46 define a plurality of flaps 50 located between adjacent cutouts 46. In the illustrated embodiment, the flaps 50 and cutouts 46 are of approximately equal width, and each is shaped substantially as a trapezoid, with the flaps 50 being widest along their lower edges 48. Those of skill in the art will appreciate that the cutouts 46 and flaps 50 need not be of approximately equal size, and that either or both could be shaped differently from a trapezoid.

In the illustrated embodiment, approximately the lower half of the second portion 44 overlaps the first portion 42, such that a lower edge 52 (Figure 3) of the first portion 42 aligns with the lower edge 48 (Figure 3) of the second portion 44, as illustrated in Figure 4. Trapezoidally shaped segments 54 of the first portion 42 are visible through the cutouts 46, with the flaps 50 covering the first portion 42 between adjacent cutouts 46. The shape of the segments 54 is dependent upon the shape of the cutouts 46, and need not be trapezoidal. The cutouts 46 and segments 54 could, for example, be rectangular or any other shape. Above the cutouts 46, the tab 42 and tooth 44 define a rectangular region 56 (Figure 4) in which the tooth 44 completely overlaps the tab 42.

For clarity, the figures herein illustrate only a segment of the width of the shingle 40. Side edges of the shingle 40 are represented by wavy lines that indicate that the shingle 40 may extend beyond the wavy lines. In one embodiment, side edges of the shingle 40 are substantially straight. In one embodiment, the shingle 40 has a width that is substantially greater than its height. For example, in one embodiment the shingle 40 may measure approximately twelve inches by approximately thirty-nine inches.

Each of the first and second portions 42, 44 may comprise, for example, a membrane that is coated with a sticky substance and sprinkled with a particulate material. The sticky substance and particulate material coat at least a substantial portion of a front surface of each membrane. In one embodiment the membrane may comprise fiberglass, the sticky substance may comprise asphalt tar, and the particulate material may comprise sand.

With reference to Figures 3 and 4, in the rectangular overlapping region 56 of each, the tooth 44 and the tab 42 each include at least one aperture 58. The aperture(s) 58 on the tooth 44 align with the aperture(s) 58 on the tab 42, and each receives a fastening member 60 that secures the tooth 44 and tab 42 to one another. In the illustrated embodiment, the fastening member 60 comprises a rivet 60. However, those of skill in the art will appreciate that the fastening member 60 could embody alternative shapes that may or may not resemble a rivet.

With reference to Figure 5, which illustrates a detailed cross-sectional view of one rivet 60 and its respective aperture 58, the rivet 60 includes a central shaft portion 62 and spaced end cap portions 64. In the illustrated embodiment, the shaft portion 62 is substantially conical, and matches the cross-sectional shape of the aperture 58. Also, in the illustrated embodiment, the end cap portions 64 are substantially disk-shaped. The conical shape of the aperture 58 and shaft portion 62, and the disk shape of the end cap portions 64 is a result of the manufacturing process, which is described in more detail below. Those of skill in the art will appreciate that alternative manufacturing methods may produce apertures, shaft portions and end cap portions having different shapes. Moreover, the number of apertures 58 and rivets 60 in a single shingle 40, and the spacing therebetween, can vary widely depending upon the intended application of that shingle 40.

The diameter of each end cap portion 64 is greater than the diameter of the aperture 58 at either end thereof. Inner surfaces 66 of each end cap portion 64 abut outward facing surfaces 68 of the tooth 44 and tab 42. Interengagement of the end cap portions 64 and the outward facing surfaces 68 inhibits separation of the tooth 44 and tab 42 from one another.

In the illustrated embodiment, the rivet 60 is constructed of a plastic, a nylon, a polyester or a polymer material. Those of skill in the art will appreciate that other materials could be used instead. However, the selected material is preferably compatible with the manufacturing environment and with the environment in which the rivet 60 will ultimately be deployed (such as atop a roof). Thus, factors such as the ambient temperature, the composition of the surrounding medium and any adjacent shingle materials, the presence of certain solvents and production speeds may be considered. Examples of other possible materials for the rivet 60 include polypropylene, metals (such as aluminum), metal alloys, other alloys, fiberglass or injectable adhesives.

Figure 6 illustrates one embodiment of apparatus 70 and methods for producing the present shingles 40. The apparatus 70 may be self contained, or it may be just one aspect of a larger apparatus (not shown) for producing shingles 40. rn either case, at the right-hand side of Figure 6, a continuous strip 72 of shingles 40 enters the apparatus 70. In one embodiment, the strip 72 may comprise shingles 40 that are oriented top-to-bottom. In another embodiment, the strip 72 may comprise shingles 40 that are oriented end-to-end, as illustrated in Figure 7. In this embodiment, the shingles 40 are configured such that from left to right the viewer sees one continuous tooth 44 layered upon one continuous tab 42. Of course, if the viewer were positioned on the opposite side of the strip, he or she would see the evenly spaced gaps between the flaps 50 (Figure 4). The thickness of the strip 72 in Figure 7 has been exaggerated for illustrative effect. The strip 72 is cut at a later step of the process to form individual shingles 40.

In the configuration of Figure 7, the width of the strip 72 (measured into the plane of the Figure 7) may correspond to the height of a single shingle 40. Alternatively, the width of the strip 72 may include multiple uncut shingle strips 72 that are positioned next to one another along an axis that extends perpendicular to the plane of the paper. In such wider configurations, the strip 72 may be cut longitudinally at a later step of the process to form several thinner strips 72 of shingles 40. Alternatively, the width of the strip 72 may include multiple independent shingle strips 72 that are positioned next to one another along an axis that extends perpendicular to the plane of the paper.

With reference to Figure 6, the strip 72 may pass over or under several rollers 74, or through several pairs of rollers 74. Some of these rollers 74 may be driven, and some may be passive. Some of them may be pinch rollers 74 that provide locomotive force to drive the strip 72 through the apparatus 70. For example, the pinch rollers 74 may be pairs of driven rollers 74 that squeeze the strip 72 from opposite surfaces. As the rollers 74 spin, they pull the strip 72 through a gap located in between the rollers 74.

As the shingle strip 72 passes through the larger apparatus and/or the apparatus 70, at various stages guides (not shown) may direct the strip 72 so that it follows a desired path. For example, the guides may be positioned to either side of the strip 72 to push it left or right (that is, into our out of the plane of the paper in Figure 6). The guides may be positioned in a trough (not shown) that traces the path of the strip 72 through the larger apparatus and/or the apparatus 70. The guides may include ceramic surfaces that are highly resistant to wear that may be caused by the passing shingle strip 72. The guides may desirably create a small amount of friction with the strip 72, so as not to slow the strip 72 as it passes through the larger apparatus and/or the apparatus 70.

With further reference to Figure 6, the strip 72 may pass through two pairs of rollers 74 before being fed onto, and passing over the top of, a first drum 76, or puncturing drum 76. In an

alternative configuration for the manufacturing apparatus 70, the shingle strip 72 may pass underneath the drum 76. Guides (not shown) may ensure that the strip 72 is positioned correctly along a longitudinal axis of the drum 76.

The first drum 76 includes a plurality of puncturing apparatus 78 (Figure 8). In one embodiment, the puncturing apparatus 78 are evenly spaced around the circumference of the drum 76. The puncturing apparatus 78 are thus adapted to puncture the strip 72 at evenly spaced intervals along the length of the strip 72. In one embodiment, the interval may measure anywhere from 3 inches to 18 inches. However, those of skill in the art will appreciate that other intervals are also feasible, and the intervals stated above are not limiting.

The drum 76 may also include puncturing apparatus 78 that are evenly spaced from one another in the direction of a longitudinal axis of the drum 76. The puncturing apparatus 78 are thus adapted to puncture the strip 72, or multiple strips 72, at evenly spaced intervals across the width of the drum 76. Such a drum would allow multiple strips 72 positioned side-by-side to travel over the drum 76 and be punctured at the same time.

In one embodiment, the puncturing apparatus 78 comprises a plurality of spikes 78, as illustrated in Figure 8. In the illustrated embodiment, the spikes 78 are substantially conically shaped. However, those of skill in the art will appreciate that the spikes 78 could have a variety of other shapes, such as cylindrical. The spikes 78 may be constructed of a relatively hard and tough material, for example, diamond, carbide, steel, ferrous or nonferrous alloys or ceramics. In still further embodiments, the puncturing apparatus 78 may comprise, for example, a water jet, an air jet, a laser cutter, or any other type of apparatus that is capable of puncturing, piercing or otherwise creating a hole in a shingle 40.

In the configuration of Figure 7, the circumferential spacing of the puncturing apparatus 78 is preferably set to whatever rivet spacing is desired. The shingle strip 72 is preferably positioned so that the puncturing apparatus 78 punctures each overlapping region 56 as shown in Figure 8. Figure 9 illustrates a close-up view of each overlapping region 56 after it has passed over the first drum 76 and been punctured. After the puncturing step, each overlapping region 56 includes one or more apertures 58 that pass through both the tooth 44 and the tab 42 of each shingle 40. Those of skill in the art will appreciate that the orientation of the tooth 44 and tab 42 may be reversed.

After passing over the first drum 76, the strip 72 may pass under one or more additional rollers 74, as shown in Figure 6. The rollers 74 may help to maintain tension in the strip 72. The strip 72 may then be fed onto, and pass over the top of, a second drum 80, or injecting drum 80. In an alternative configuration for the manufacturing apparatus 70, the shingle strip 72 may pass underneath the drum 80.

In the illustrated embodiment, the second drum 80 is substantially the same diameter as the first drum 76. For example, each drum 76, 80 may have a diameter of 6 feet. However, those of skill in the art will appreciate that the drums 76, 80 could have different diameters. The drums 76, 80 may also have substantially equal widths (measured perpendicular to the plane of Figure 6). For example, each drum 76, 80 may have a width of about twelve inches. However, those of skill in the art will appreciate that the drums 76, 80 could have different widths.

The second drum 80 includes a plurality of injecting apparatus 82, as illustrated in Figure 10. In one embodiment, the injecting apparatus 82 are evenly spaced around the circumference of the drum 80. The injecting apparatus 82 are thus adapted to inject rivets 60 into the strip 72 at evenly spaced intervals along the length of the strip 72. The spacing may be the same as that described above with respect to the first drum 76.

The second drum 80 may also include injecting apparatus 82 that are evenly spaced from one another in the direction of a longitudinal axis of the drum 80. The injecting apparatus 82 are thus adapted to inject rivets 60 into the strip 72, or multiple strips 72, at evenly spaced intervals along the width of the drum 80. Such a drum would allow multiple strips 72 positioned side-by- side to travel over the drum 80 and be injected at the same time.

In one embodiment, the injecting apparatus 82 comprises a plurality of injection nozzles 84, as illustrated in Figure 10. Figure 10 illustrates the configuration of the shingle strip 72 that is illustrated in Figure 7. The injection nozzles 84 may be, for example, pneumatically operated. In the illustrated embodiment, the injection nozzles 84 are positioned such that they abut an inside surface 86 of the drum 80. Holes (not shown) are preferably provided in the outer surface of the drum 80 at the location of each injection nozzle 84.

A fluid conduit 88 extends from each nozzle 84 to a central hub 90. Liquefied rivet material flows through the central hub 90, into the fluid conduits 88 and is expelled through the injection nozzles 84 and into the apertures 58 in the strip 72. In one embodiment, for example, the rivet material may begin as a solid that is placed in an extruder (not shown), melted and pumped through a melt pump (not shown) to the central hub 90. Pressure may be used to push the rivet material through any piping/conduits between the extruder and the injection nozzles 84. One or more photoelectric sensors may be used to control the opening and closing of the injection nozzles 84.

To properly align the apertures 58 with the injection nozzles 84, a circumferential spacing of the injection nozzles 84 is preferably equal to a circumferential spacing of the puncturing apparatus 78 (though the drums 76, 80 need not have equal diameters). The second drum 80 is also preferably positioned such that a distance between the drums 76, 80 as measured along the path of travel of the strip 72 is a multiple of the circumferential spacing of the puncturing apparatus 78. Then, tension in the strip 72 ensures that the strip 72 always aligns

properly with the second drum 80 so that the rivets 60 are injected into the apertures 58. A timing belt (not shown) may ensure that the drums 76, 80 rotate in synchronicity with one another, or with other components of the apparatus, as desired.

After passing over the second drum 80 (Figure 6), the strip 72 passes through a pair of pinch rollers 74. With reference to Figures 11 and 12, prior to passing through the pinch rollers 74 the rivet 60 has a first end 94 shaped substantially as an arcuate dome with a relatively large diameter, and a second end 96 shaped substantially as a ball with a relatively small diameter. The shape of the rivet ends 94, 96 at this stage is a result of the injection process. The end nearest the nozzle 84 during injection forms the dome shape, and the opposite end forms the ball shape.

When the shingles 40 are installed atop a roof, the lower portions of shingles 40 in a first row overlap the upper portions of the shingles 40 in a second, adjacent, row. The shingles 40 in the first row may overlap the portions of a shingles 40 in the second row where the rivets 60 are located. Therefore, to provide a more functional and aesthetically pleasing roof, it is advantageous to flatten the ends 94, 96 of the rivets 60 as much as possible so that they do not cause the overlapping adjacent shingles 40 to protrude upwardly.

When the rivets 60 pass through the pinch rollers 74 (Figure 11), the rivet 60 material is still soft enough to easily undergo plastic deformation. The rollers 74 thus flatten the rivet ends 94, 96 into the configurations shown in Figure 12.

The manufacturing steps described above are advantageously capable of being integrated into a larger manufacturing process in which the production line is moving very quickly. In the illustrated embodiment, the steps of puncturing and riveting are performed on relatively large drums 76, 80 that rotate at an angular velocity that is proportional to the linear velocity of the shingle strip 72. Thus, while the steps of puncturing and riveting are performed, the apparatus that is performing those functions remains fixed relative to the shingle strip 72, providing a relatively large amount of time to perform these steps.

Whereas prior art shingles 20 glue the sand on the tooth 24 to the sand on the tab 22, as described above, the rivets 60 of the present shingles 40 advantageously extend through the membranes of the tooth 44 and tab 42, thereby locking these components together. Separation of the shingle components thus depends solely upon the rivets 60, rather than upon the asphalt tar, which has a relatively low melting temperature. Testing conducted by the inventor has shown the durability of the present shingles 40 and the ability of the rivets 60 to hold the tooth 44 and tab 42 together. In one test, one of the present shingles 40 was suspended from its tooth 44, such that the tab 42 hung freely and would have separated from the tooth 44 had it not been for the rivet 60 holding the two portions together. The shingle 40 was then placed in an oven set at about 120° F. The temperature was increased about 10° F every hour until the tab 42 separated from the tooth 44 and dropped off. The goal was to see if the rivet 60 could hold the two portions together up to

a temperature of about 220° F. When the oven temperature reached about 315° F, the test was stopped. The rivet 60 still firmly held the tooth 44 and tab 42 together. By contrast, a prior art shingle 20 with no rivet 60 subjected to the same test failed at about 160 ⁰ F.

During testing of the present shingle 40, large amounts of the sticky substance melted and dropped away. However, because the rivet 60 engaged the more heat-resistant membranes of the shingle 40, melting of the sticky substance did not affect the grip of the rivet 60 on the tooth 44 or the tab 42. Because the rivet 60 firmly secures the tooth 44 and the tab 42 to one another, it is unnecessary to penetrate the overlapping region 56 with a fastening member (such as a nail or a staple) when the shingles 40 are installed atop a roof. With prior art shingles 20 it was advantageous to drive the fastening member through the overlapping region 36 and into the roof so that the fastening member would supplement the adhesive and more firmly secure that tooth 24 and tab 22 to one another. However, with the present shingles 40 the fastening member may be driven only through the tooth 24 or the tab 42 without affecting the expected lifespan of the shingle 40. The rivets 60 alone securely hold the tooth 44 and the tab 42 together without the need for any additional fastening members.

Figure 13 illustrates another embodiment of apparatus 100 and methods for producing the present shingles 40. Again, the apparatus 100 may be self contained, or it may be just one aspect of a larger apparatus (not shown) for producing shingles 40. In either case, at the right-hand side of Figure 13, a continuous strip 72 of shingles 40 enters the apparatus. The strip 72 may pass through a pair of rollers 74 before being fed onto, and passing over the top of, an outer drum 102. After passing over the outer drum 102, the strip 72 may pass through another pair of rollers 74. Guides (not shown) may ensure that the strip 72 is positioned correctly along a longitudinal axis of the drum 102.

First and second drums 104, 106 are positioned within the outer drum 102. In the illustrated embodiment, the first drum 104 is positioned at approximately 3 o'clock on the outer drum 102, and the second drum 106 is positioned at approximately 12 o'clock on the outer drum 102. However, those of ordinary skill in the art will appreciate that the first and second drums 104, 106 could be positioned at other locations within the outer drum 102, and that the first and second drums 104, 106 could be positioned outside the outer drum 102.

The first drum 104 includes puncturing apparatus (not shown), and is similar in configuration to the first drum 76 described above. The second drum 106 includes injecting apparatus (not shown), and is similar in configuration to the second drum 80 described above. Outer surfaces 108, 110 of the first and second drums 104, 106, respectively, may abut an inner surface 112 of the outer drum 102. The drums 102, 104, 106 preferably rotate at appropriate angular velocities so that as the drums 102, 104, 106 all rotate the outer surfaces 108, 110 of the

first and second drums 104, 106 do not slip with respect to the inner surface 112 of the outer drum 102.

The outer drum 102 includes a plurality of holes (not shown) in its surface. In one embodiment, the holes are evenly spaced around the circumference of the drum 102. The holes align with the puncturing apparatus and the injecting apparatus on the first and second drums 104, 106, respectively, as the drums 102, 104, 106 rotate. Thus, the puncturing and injecting steps described above with respect to the apparatus 70 and methods illustrated in Figure 6 take place at the surface of the outer drum 102 as the strip 72 passes over the drum 102.

Figure 14 illustrates an alternative embodiment of apparatus 120 for performing puncturing and injecting steps. In the illustrated embodiment, the puncturing and injecting tools comprise a single apparatus 120. The apparatus 120 includes an injection nozzle 122. A lumen 124 of the injection nozzle 122 houses a puncturing tool 126 that is selectively retractable. The apparatus 120 may be positioned on the inside of a drum 128, similarly to the injecting apparatus 82 described above. As the strip 72 passes over the drum 128, the puncturing tool 126 punctures the strip 72 to produce a hole 130, and the injection nozzle subsequently injects liquefied rivet 132 material into the hole 130.

Scope of the Invention

The above presents a description of the best mode contemplated for carrying out the present shingles and methods of producing shingles, and of the manner and process of making and using them, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which they pertain to make and use these shingles and methods. These shingles and methods are, however, susceptible to modifications and alternate constructions from those discussed above that are fully equivalent. Consequently, these shingles and methods are not limited to the particular embodiments disclosed. On the contrary, these shingles and methods cover all modifications and alternate constructions coming within the spirit and scope of the shingles and methods as generally expressed by the following claims, which particularly point out and distinctly claim the subject matter of the shingles and methods.