Patent Abstract:
A shingle cutter that is portable and can be temporarily attached to and used on the roof with the roofing nails used on the job. The power for cutting results from the housing of the cutting wheel being manually drawn back towards the operator. The shingle cutter has a structural base and two vertical end walls that support a rectangular rack, which holds the cutting block. In one version the rack drives a pinion, which in turn drives the cutting wheel. In a second version, the cutting wheel is free to rotate as it is pulled through the shingle. The cutting block is constrained by rollers in contact with the top and bottom of the rectangular guide bar so that the cutting wheel moves to perform a shearing function with an abutting shear ledge mounted on the structural base.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/201,759, filed May 4, 2000. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the building construction tools, and particularly to a shingle cutter which permits the on-site cutting of roofing shingles using a one-man operated machine. 
     2. Description of Related Art 
     A number of mechanical cutters and trimmers for producing fiber glass and asphalt roof shingles in a desired shape have been constructed and marketed, but most roofers have relied on a utility knife for cutting shingles in view of the knife&#39;s portability and simplicity. 
     Some shingle cutters are designed to produce particular kinds and shapes of shingles that are used in well-defined and specialized circumstances. For example, U.S. Pat. No. 4,951,540, issued to Cross et al., discloses a shingle ridge cap cutter used for cutting uniform sections from roof shingles. This cutter comprises a frame along which a shingle is guided under a manually operated cutter holding two blades with cutting edges positioned downward so that the cut shingle resembles a trapezoid adjoined to a rectangle so that the base of the trapezoid and a side of the rectangle coincide. Similarly, U.S. Pat. No. 5,052,256, issued to Morrissey, discloses a shingle cutting apparatus that produces a trapezoid-on-rectangle shingle used on ridge caps. The Morrissey cutter has grooves in the base into which the blades can fit. 
     Other patents deal with manufacturing processes that have also been applied to small scale applications. For example, U.S. Pat. No. 5,165,314, issued to Paulson et al., discloses the use of a rotating slitting blade. This devise is used to cut sheets of corrugated paperboard. Similarly, U.S. Pat. No. 5,322,001, issued to Boda, discloses a paper cutter using circular blades. 
     Several shingle cutters use a pivotal cutting blade. For example, U.S. Pat. No. 5,249,495, issued to Renk, discloses a pivotal cutter blade and anvil upon which the blade is mounted ins cooperation. A fence rotates in the plane of the base, so that angular cuts on a shingle can be made. Similarly, U.S. Pat. No. 5,787,781, issued to Hile, discloses a shingle cutter for cutting a straight even line and has a straight cutting edge pivotally mounted on a side and corner of the base. There is a bearing and lock nut disposed on a threaded rod and this combination keeps the blade tight against a support member recessed in the base. The base can be attached to legs. 
     U.S. Pat. No. 5,644,963, issued to Fountas, discloses a guide with no cutting edge. 
     It is apparent that no device other than a utility knife has gained wide-spread popularity for cutting and trimming shingles at the spot where the shingles are to be installed. Most of the devices are too cumbersome to be relocated on the roof or they are used only to perform specialized tasks. Recent changes in the manufacture of shingles from a single layer to a multi-layer shingle has made the hand cutting of shingles even more difficult than in the past further necessitating a cutting device which is efficient, easily portable, usable in place on a roof, and easily operated by a workman located on a roof slope. 
     None of the above inventions and patents, taken either singly, or in combination, is seen to describe the instant invention as claimed. 
     SUMMARY OF THE INVENTION 
     The shingle cutter according to the present invention is used to cut a shingle to produce a shingle having a desired size and shape. The shingle cutter is portable and can be temporarily attached to and used on a roof. The power for cutting results from the housing of the cutting wheel being manually drawn back towards the operator. 
     The shingle cutter has a structural base attached to two end upright pieces that support a rectangular rack or bar, upon which a cutting wheel housing moves in a sliding manner. In one embodiment, the teeth of the bottom edge of the rack engage the gear teeth of a pinion, which in turn engage a circle of gear teeth fixed with and concentric with the cutting wheel. In another embodiment, the cutting block is supported by a rectangular guide bar with no teeth on its bottom edge. The cutting wheel is rotatably mounted on an axle disposed in a cutting block housing which is slidable along the bar. In both embodiments, the cutting block housing slides along the rectangular bar on four rollers whose axes are perpendicular to and are held rigidly by the two cutting block housing plates. 
     Accordingly, it is a principal object of the invention to provide a device for producing an efficient and clean cut edge on roof shingles in order to produce custom cut roof shingles. 
     It is another object of the invention to provide a convenient and easy to operate mechanism for cutting shingles. 
     It is a further object of the invention to provide a shingle cutting mechanism that is transportable from job site to job site and from ground level to roof top of the building where roof work is being performed. The shingle cutter of the present invention can be temporarily attached to the roof by a slotted mounting tab. 
     Still another object of the invention is to provide a device for cutting shingles to produce a variety of shapes for a variety of roofing conditions. Another object of the invention is to accommodate recent changes in the manufacture of shingles from a single layer to a multiple layer. This has made the cutting of shingles more difficult. This change has created a need for a more efficient and easier method of cutting shingles. 
     It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes. 
     These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an environmental perspective view of a first embodiment of a shingle cutter according to the present invention. 
     FIG. 2 is a front perspective view of the first embodiment of the shingle cutter showing pivoting right and left fences being used to align a shingle for cutting a shingle at an angle. 
     FIG. 3A is a side elevation view of the first embodiment of the shingle cutter with part of the cutting block housing removed. 
     FIG. 3B is a detail view of the shingle cutter of FIG. 3A showing the pinion gear and cutting wheel and its driving gear adjusted so as to place the cutting wheel in a raised position. 
     FIG. 3C is a detail view of the shingle cutter of FIG. 3A showing the pinion gear and cutting wheel and its driving gear adjusted so as to place the cutting wheel in a lowered position. 
     FIG. 4 is a front perspective view of a second embodiment of the shingle cutter, featuring an alternative method using pegs for maintaining the shingle aligned in an angular position relative to the path of the cutting wheel. 
     FIG. 5 is a top view of the second embodiment of a shingle cutter according to the present invention. 
     FIG. 6 is a fragmented side perspective view of the second embodiment of the shingle cutter with part of the cutting block housing removed. 
    
    
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is directed to a roofing tool in the form of a shingle cutter. A first embodiment of the present invention is depicted in FIGS. 1-3 and is generally referenced by numeral  10 . 
     As generally illustrated in FIGS. 1-3, the shingle cutter  10  comprises a cutting block  26  that is mounted in a slidable manner on a rectangular rack  19 . The rectangular rack  19  is fixedly attached to a U-shaped frame which includes a structural base  14  and rear and forward walls  16 . The rectangular rack  19  is supported between the end walls  16  and spaced above a structural base  14  by a predetermined distance, the rack  19  being disposed in a plane normal to a plane in which the base  14  is disposed. The structural base  14  has a coplanar extension at a right angle to its length-wise dimension, hereinafter referred to as transverse base  17 . This transverse base  17  serves as a flat area for placing the shingle while it is being worked on. The forward edge of the transverse base  17  has two fences,  20  and  21 , that may be pivoted about pins  24  on the plane of the bases  17  and  14  and serve as a stop to prevent sliding of the shingle S during cutting. Although FIG. 1, for purposes of economy of illustration, depicts the operator cutting the shingle S in a direction moving away from the operator, the preferred method of operation is to position cutting block  26  at a point on rack  19  past the shingle S to be cut and then pull block  26  toward the operator I , thus cutting the shingle S. This is preferable in that fence  20  serves as a stop to avoid sliding of the shingle S. 
     The most externally conspicuous features of the cutting block  26  are the lower portions of the cutting wheel  31 , the right  27  and left  29  cutting block housing panels, and the right and left cutting block handles  28 . Aside from the handles, the most noticeable features on the panels  27  and  29  are the holes that accommodate the threaded ends of wheel axles,  52 ,  66 , and  70  (shown in FIG.  3 ). A flat, elongated plate or shear ledge  32  is mounted on the structural base  14  such that one edge abuts the path of the cutting wheel  31 . The edge of the cutting wheel shear ledge  32  and the cutting wheel  31  coact in the same way each blade of a pair of scissors would cut or shear through a piece of material. 
     An elongated tab with a hole and slot  25  defined therein forms roof anchor  22 , which is used to anchor the shingle cutter to the roof by placing the hole portion of the hole and slot  25  of the tab  22  over the head of a nail attached to the roof and sliding the shaft of the nail into the slot. The roof anchor  22  is slidably mounted to the base  14  so that the anchor  22  can be retracted into a hollow space in the structural base  14  when the shingle cutter  10  is not in use. Two widened portions (not shown) on the end of the roof anchor  22  prevent the anchor from being pulled free of the shingle cutter  10 . The environmental perspective view of FIG. 1 shows an installer I cutting a shingle S by pulling the cutting block  26  by its handles,  28 . The shingle S is supported by the right  20  and left  21  pivotal fences as the cutting wheel  31  is drawn across the shingle S. 
     A second embodiment of the present invention is depicted in FIGS. 4-6 and is generally referenced by numeral  12 . 
     The second embodiment of the shingle cutter  12 , comprises the same or similar components as those of the shingle cutter  10  of the first embodiment. As shown in FIGS. 4-5, the shear ledge  132  may have a series of holes  62  into which shingle guiding pegs  63  are inserted. In the second embodiment, a fixed transverse back fence  61  is permanently fixed to the forward edge of the transverse base  17 . A cutter block bumper guard  23  projects from the forward end wall  16  in order to prevent the cutting block from bumping against the end wall  16  in both the first  10  and second  12  embodiments of the shingle cutter. 
     A side view of the cutting block  126  with the right panel  127  removed to show details of the cutting block  126  in FIG. 6 permits comparison of the first  10  and second  12  embodiments of the shingle cutter. Similar cutaway views are shown for the first embodiment in FIGS. 3A-3C. In both embodiments, the cutting block  26  or  126  is supported on the rack  19  or  119  by a plurality of roller wheels  45  which are rotatably mounted on axles  52 . Axles  52  are fixedly mounted to extend between plates  27  and  29  ( 127  and  129  in the second embodiment) and secured by axle nuts  37 . Each roller wheel  45  has a groove  56  or neck defined therein slightly greater than the thickness of the rack  19  or  119  so that the roller wheels  45  roll along the rack as the cutting block is pulled or pushed, the grooves  56  preventing lateral movement of the cutting block as it rolls along the rack. The roller wheels  45  may have a plurality of O-rings (not shown) disposed in the groove  56  to decrease rolling friction between the roller wheels  45  and the rack. The roller wheels  45  maintain the plates and in spaced apart relation. 
     AS shown in FIG. 3A, in a first embodiment the bottom edge of the rack has a plurality of gear teeth  51  defined therein which engage the gear teeth  65  of a pinion  64  which is rotatably mounted on axle  66 , which extends between plates  27  and  29  and is secured by nuts  35  (only one shown). Cutting wheel  31  is rotatably mounted on axle  70 , which is fixedly mounted between plates  27  and  29  and secured by nuts  33  (only one shown). The teeth of the pinion  64  engage the teeth of gear  71 , which is fixedly attached to cutting wheel  31 . Therefore, as the cutting block is pushed or pulled along rack  19 , pinion  64  drives gear  71 , causing cutting wheel  31  to rotate. 
     As shown in FIG. 6, in a second embodiment the bottom edge of rack  119  is smooth and has no gear teeth. The second embodiment includes roller wheels  45  as described above, but pinion  64  and gear  71  are absent. Cutting wheel  131  is rotatable mounted on axle  70  and rotates by frictional engagement of the edge of the cutting wheel  131  with the shingle S or other workpiece. 
     Referring to FIGS. 3B and 3C, in either the first or second embodiment, the height of the cutting wheel  31  or  131  may be made adjustable as follows. The axle  70  may include a cylindrical hub  72  mounted between the ends of the axle  70 . The cutting wheel may be rotatably mounted on the hub  72 . The hub  72  may be eccentrically mounted on the axle  70 . The end of the axle  70  may have a fitting  73 , such as an Allen head, so that the axle  70  may be rotated in its mounting holes. This raises and lowers the cutting wheel to adjust for different shingle thickness and depth of cut. 
     In the first embodiment, in order to compensate for movement of cutting gear wheel movement as cutting wheel  31  is raised upwardly or lowered downwardly to accomplish differing depth cuts, it may be necessary to mount pinion gear  64  in a manner similar to cutting wheel  31  in order to maintain proper mesh of its gear teeth with cutting wheel gear  71  while maintaining proper mesh with the gear teeth  51  along the lower edge of rectangular rack  19 . The axle  66  may include a cylindrical hub  67  mounted between the ends of the axle  66 . The pinion gear may be rotatably mounted on the hub. The hub may be eccentrically mounted on the axle  66 . The end of the axle  66  may have a fitting, such as an Allen head  68 , so that the axle  66  may be rotated in its mounting holes. This allows adjustment of the pinion gear  64  to maintain proper mesh with the cutting wheel gear  71  as the cutting wheel  31  is raised or lowered. Alternatively, the gear teeth of pinion  64  and cutting wheel gear  71  may be so designed so as to allow adequate meshing of the gears as cutting wheel  31  and its gear  71  as it is raised or lowered within a limited range so as to effectively turn cutting wheel  31 . In the second embodiment there are no gears or pinion so that the cutting wheel may be raised or lowered as described above without the need to manipulate gears for adequate meshing since the second embodiment employs no gears for operation. 
     As generally illustrated in FIG. 2, in a first embodiment, the shingle cutter  10  is shown cutting a shingle S using one or both pivotal fences  20  and  21  in order to make an angular cut. The right fence  20  rotates about the right pivotal fence pivot pin  24  to provide a reference position on the right end of the shingle S. The left fence  21  rotates about the left pivotal fence pivot pin (not shown) to provide a reference position on the forward long side of a shingle S. The positions of the rotated fences are associated with the particular angle at which the shingle S is being cut as long as the given sides of the shingle S are flush with their corresponding pivotal fences  20  and  21 . 
     As illustrated in FIG. 4, in a second embodiment, the shingle cutter  12  is shown cutting a shingle S using the pegs  63  and the peg holes  62  along a segment of the cutting wheel shear ledge  132  to orient the shingle S in order to make an angular cut. In FIG. 4, part of the apparatus is cut away to reveal the forward-most peg  63  located in forward-most peg hole  62  between both sections of the back fence  61 . The holes bored to hold the peg second closest to the operator are so placed that the direction of the width of the shingle S relative to the cutting direction corresponds to a pre-determined angle. The line between the two pegs, which is parallel to the cutting line, is the hypotenuse of a right triangle of which the width of the shingle S represents a side. The distance between the positions of the pegs  63  is determined by the inverse of trigonometric functions for pre-determined angles. Although a multiplicity of peg holes  62  are illustrated in FIGS. 4 and 6, the preferred number of peg holes  62  is four, corresponding to standard angle cuts in the industry. A standard spring-loaded clamp(not shown) may be attached where convenient such as near the intersection of the shingle S and transverse base  17  to assist in holding in place shingle S against transverse base  17  while the cutting operation is performed. 
     It is to be understood that the present invention is not limited to the sole embodiments described above, but encompasses any and all embodiments within the scope of the following claims.

Technology Classification (CPC): 8