DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS OF THE INVENTION

[0020] Referring now to the drawings, specifically FIG. 1 thereof, there is shown a multi-layer laminate roofing shingle 2 having a first sheet 4 having a first marginal edge 18, an intermediate sheet 6 having a second marginal edge 16, and a bottom sheet 8 having a third marginal edge 20. As shown in FIG. 1, first sheet 4 has a defined width (L), intermediate sheet 6 is about ⅔ the width of the first sheet 4, and bottom sheet 8 is about ⅓ the width of the first sheet 4. Preferably the ⅓ and ⅔ dimensions are maximum dimensions, so as to optimize stacking as described below. Additionally, one skilled in the art appreciates that “about ⅓” and “about ⅔” could be any dimension such that the ⅔ dimension is less than a full underlay and greater than a half underlay; and that the ⅓ dimension is less than a half underlay, and the addition of the two dimensions is less than or equal to one (e.g. about {fraction (4/9)} and {fraction (5/9)}). One skilled in the art appreciates that the dimensions may be less than described in this paragraph, such that the nesting occurs as described, but ideally the layers are nearly completely supported in the package as illustrated in FIG. 2 (with ⅓ and ⅔ underlays), so as to avoid damage to the layers during shipment and handling.

[0021] The sheets 4, 6 and 8 are arranged so that marginal edges 16, 18 and 20 substantially coincide with one another. The sheets 4, 6 and 8 are preferably affixed to one another by an adhesive that is applied in the shingle manufacturing process discussed below between each pair of sheets {fraction (4/6)}, and {fraction (6/8)}. The sheets 4, 6 and 8 are then laminated to assure adhesion of the sheets to one another. Additionally, if any of the layers is not coated with granules, an adjacent asphalt coated sheet may provide sufficient adhesive, while the asphalt is in a non-solidified state.

[0022] In a preferred embodiment, the roofing shingle 2 preferably has tabs 26, 28 which define cut-out portions 21. As shown in FIG. 1, cut-out portion 21 is shown to one layer in depth with the intermediate sheet 6 being exposed. Intermediate sheet 6 extends beyond the length of the cut-out portions 21 so as to provide positive aesthetic qualities to the shingle. The style of the tabs may be a “dragon tooth” design or may be square cut tab, a standard three-tab design or any other interlocking pattern design. The number of tabs may vary but typically there are three tabs per shingle, with the shingle typically having and an overall length of about 3 feet. Preferably, roofing shingle 2 may be either a fiberglass asphalt shingle or an organic felt asphalt shingle.

[0023] Turning now to FIG. 3, the cutting and laminating apparatus 30 for manufacturing the shingles of the present invention is shown. Before being directed to the cutting and laminating apparatus 30, a continuous sheet of asphalt roofing material is prepared using any standard method and apparatus known in the art to manufacture roofing shingles. In FIG. 3, one manufacturing line is shown. It should be noted that two lines can be used, as shown in U.S. Pat. No. 5,102,487 which is herein incorporated by reference.

[0024] The mat or substrates is payed out from a roll (not shown) as continuous sheet 41. The mat can be any type of material known for use in reinforcing roofing shingles, such as a web, scrim or felt of fibrous materials such as mineral fibers, cellulose fibers, rag fibers, mixtures of mineral and synthetic fibers, or the like. Preferably, the mat is a nonwoven web of glass fibers.

[0025] The sheet is passed through a coater (not shown) where a coating is applied to the sheet. The coating can be applied in any suitable manner. Typically, the sheet is submerged in a supply of hot, molten coating to completely cover the sheet with the tacky coating. However, in other embodiments, the coating can be sprayed on, rolled on, or applied to the sheet by other means.

[0026] The term “coating” means any type of material suitable for coating roofing shingles. Usually, the coating includes a bituminous material such as an asphalt, tar, pitch, or a mixture thereof. The asphalt can be either a manufactured asphalt produced by refining petroleum or a naturally occurring asphalt. The coating can also include various additives and/or modifiers, such as inorganic fillers or mineral stabilizers, organic materials such as polymers, recycled streams, or ground tire rubber.

[0027] The hot coated sheet is passed beneath one or more granule applicators that discharge protective surface granules onto the top of the sheet. The sheet is passed around a drum that presses the granules into the hot, tacky coating and inverts the sheet sufficiently for any non-adhering granules to fall into a hopper (not shown) for recycling. The sheet is then passed between a pair of press rolls that further press the granules into the sheet and then is passed through a conventional cooling apparatus.

[0028] As shown in FIG. 3, after the cooling process, the sheet 41 is fed into the apparatus 30, through a pattern cutter 37 consisting of a knife roll 38 and an anvil roll 35, traveling in the direction indicated by arrow 43. The knife roll 38 engages the continuous sheet 41 and divides it into continuous overlay strips 45, first underlay 46 and second underlay 47. The knife roll has two straight blades (not shown) that divide the underlay strips from the overlay strips, and a patterned blade (not shown) that cuts the overlay strip into two continuous overlay strips having a dragon tooth pattern of tabs and cutouts (as shown in FIG. 1) or a standard three tab design (as shown in FIG. 1a). The patterned blade can be changed to produce different pattern lengths. For example, the patterned blade may form one pattern for every revolution of the knife roll. In such a case, the length of the pattern can be varied by changing the circumference of the knife roll. The patterned blade can also be changed so that it forms more or less than one pattern for every revolution of the knife roll. Additionally, the cutter 37 may be divided, such that the underlay strips 46, 47 are cut by one or more rolls separate from a pattern cutter. Furthermore, one or more of the underlay strips 46, 47 need not come from the same sheet as the overlay 45, so that each layer may be optimized to provide desired properties. For example, sheet 6 or sheet 8 may be made form modified asphalt, or have a high strength mat, to provide additional strength properties. Alternatively, since bottom layer 8 is generally not visible except at edge 20, this layer may be made from a less costly material, such as seconds from a strip shingle process, or be made from a non-asphalt material.

[0029] The overlay 45 and underlays 46, 47 then proceed over alignment rollers 50, 51, 52. Overlay 45 passes over single rotating roller 45, which sits in an adhesive bath 32, which coats the bottom surface of overlay 45 with adhesive. Typically, a laminating adhesive is used. First underlay 46 proceeds under guiding rollers 51, 53 to adhesive bath 38 where adhesive is applied to the bottom surface of underlay 46. Alternatively, an extruder may be used to apply adhesive to the underlays. Second underlay 47 proceeds under guiding rollers 52 and 36 and comes into contact with first underlay 46 at combining rollers 40 where first underlay 46 and second underlay 47 are laminated together forming sheet 58. Sheet 58 comes into contact with overlay 45 at guiding roller 54. At this point, the adhesive applied to the bottom surface of overlay 45 adheres to the top surface of sheet 58. Sheet 58 is laminated to overlay 45 at combining rollers 39 and is directed to free loop rolls 55, 56. As shown in FIG. 3, the final multi-layer sheet 59 is moved to an end cutter 42. Additionally, the bottom underlay layer 8 may not include granules, as the top surface is not exposed in the embodiments shown here. Similarly, the middle layer 6 may not have granules in the area above the cutouts 21 (above the bottom underlay), and may not include granules in the areas under the tabs 26, 28. Alternatively, the layers may include a granule coating on the top of each of the underlays 46, 47, as well as granules provided on the bottom of one or more of the underlays 46, 47 and/or overlay 4, to provide additional thickness to the laminated shingle. All such non-visible granules could be a less expensive material known to one skilled in the art, so as to reduce the overall cost.

[0030] FIG. 2 illustrates roofing shingles of the present invention being packaged after they are formed by the cutting and laminating apparatus 30. Shingle 24 is overturned so that undersides 11, 13 and 15 of sheets 10, 12 and 14 face upward. Shingle 22 is stacked on top of overturned shingle 22 so that the underside 5 of bottom sheet 8 contacts underside 15 of first sheet 14, underside 7 of intermediate sheet 6 contacts underside 13 of intermediate sheet 12, and underside 9 of first sheet 4 contacts underside 11 of bottom sheet 10, and the underlay layers thus are packaged so that the ⅓ and ⅔ lengths of the respective underlay of adjacent sheets nest. The shingles may be stacked in palletized form, with two shingles 22, 24 in a given layer, with the next overlying layer of shingles being stacked thereon. Suitable apparatus for positioning and orienting moving webs is well-known in the art. Such apparatus could include, for example, guiding conveyor belts that move the webs into position and invert one of the webs.

[0031] Although not illustrated here, one skilled in the art appreciates that the intermediate underlayment 6 may include cutouts within he cutouts 21 of the overlay sheet 4. Similarly, the bottom edge of the tabs 26, 28, may not extend to the marginal edge 18 of the overlay 4, and thereby may expose a portion of an underlay layer for visual effect. Likewise, the middle layer 6 may have visible portions within the cutouts 21 that do not extend to the marginal edge 16, and thereby provide an additional visual effect. One skilled in the art appreciates that each of these alternative embodiments is considered to have marginal edges of the overlay and underlay sheets that substantially coincide, as is the case with normal variation in alignment of such layers in a typical manufacturing process. Likewise, the ends of each layer substantially coincide to provide for efficient packaging and handleability.

[0032] In a further alternative embodiment (not shown), the intermediate layer 6 may include cutouts above the bottom sheet 8 and above the tabs 26, 28. Preferably, the bottom layer 8 includes tabs (not shown) that extend under the portion above the ⅓L to the ⅔L portion and when adjacent shingles are nested as shown in FIG. 2, the bottom underlay tabs nest between the cutouts of the intermediate underlay. The shingle preferably includes nailing targets on the overlay (e.g. a paint drop) above the underlay tabs, to provide a nailing zone through each of the three layers. Such a design is shown in U.S. Pat. No. 6,044,608 which is herein incorporated by reference. Furthermore, although described with respect to a three-layered shingle, the principles of the present invention may be applied to a shingle having additional layers.

[0033] It is possible that changes in configurations to other than those shown could be used but that which is shown is preferred and typical. It is therefore understood that although the present invention has been specifically disclosed with the preferred embodiment and examples, modifications to the design concerning sizing and shape will be apparent to those skilled in the art and such modifications and variations are considered to be equivalent to and within the scope of the disclosed invention and the appended claims.