Abstract:
The present invention relates to an apparatus that cuts sheet metal, and more specifically, cut seamed sheet metal materials at user-specified angles. The present invention is capable of operation by a single person, is portable, easy to manufacture, use, adjust, and maintain, and in one embodiment utilizes a serrated blade capable of moving in a guillotine motion.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to an apparatus that cuts sheet metal, and more specifically a portable sheet metal cutting apparatus which cuts corrugated sheet metal at a plurality of cut angles.  
         BACKGROUND OF THE INVENTION  
         [0002]    Many commercial and residential buildings and structures use sheet metal for siding, structural framing, and roofing (hereinafter “sheet metal”) because of its low expense, ease of installation, and reduced maintenance. Sheet metal is usually delivered to a construction site in long un-cut rectangular shaped sheets. The contractor then must cut at least one end to accommodate the angle of the roof, for example. This task is extremely time consuming and thus expensive depending on the shape and complexity of the wall or roof on which the siding or roofing material is being installed.  
           [0003]    Many types of sheet metal cutters are known in the art, the most common being a sheet metal hand shear. Hand shears are rudimentary cutting devices incapable of making precision cuts and are ineffective for use with large materials. In addition, sheet metal materials often incorporate corrugations, ribs, seams, or channels (hereinafter “corrugations”) into their design to add stiffness and strength to the panel or to act as an interlocking means between two adjacent panels. The difficulty and time required to cut such materials make hand shears impractical, especially on large construction projects.  
           [0004]    Other commercial grade sheet metal cutting apparatus are known in the art to cut sheet metal panels. These larger tools traditionally use two cutting blades, one stationary and one capable of motion. Some devices act like a hand shear, cutting from one edge of the panel to the other, and others act like a guillotine, thus cutting through an entire sheet metal panel at substantially one time. The shear cutters generally consist of a base wherein the stationary blade is integrated and a movable blade that is hinged on one end to the base and that is equipped with a handle on the opposite end. The sheet metal panel is cut by closing the handle thereby bringing the two blades together. Alternatively, the movable blade is actuated such that the entire blade comes in contact with the sheet approximately the same time, to shear the sheet metal material like a guillotine.  
           [0005]    There are different types of movable blades, including straight and serrated. Straight blades have numerous drawbacks when used to cut corrugated sheet metal panels. First, when incorporated in a shear type apparatus, which cuts from one end to the other, the sheet material may move or deform undesirably as the blade is brought across a peak or valley of a corrugation. In a guillotine cutter, a straight blade may tend to bend the sheet before it is cut, thereby deforming the crests of the corrugations, which may force post-cutting reworks to the material which is time consuming and inherently expensive. Thus, it is common practice to use serrated edges to evenly pierce the peaks and valleys of a corrugated sheet metal panel which results in a cleaner cut.  
           [0006]    Furthermore, sheet metal panels often are required to be cut at an angle in order to be installed. In addition, angled cutters usually require a means for holding the sheet metal panel in place while it is being cut. Unfortunately, some of the holding and cutting means are unsuitable for cutting corrugated material at an angle, because there is not enough clearance between blade pairs for a corrugated piece of sheet metal to fit. Alternatively, some cutters have sufficient clearance for certain types of corrugation shapes, but they are unsuitable for other types. Further, some stationary blades are designed to conform with the corrugation profile, but they may not be suited for other types of corrugation shapes, and thus may hinder angled cutting. In addition, some angled cutter blades are limited since they are specifically designed for use with certain corrugation shapes because their serrations are incorporated on a limited portion of the blade. Furthermore, some devices are designed to cut at a limited number of specific angles, i.e. 45 degrees. Finally, some tools may in fact be capable of cutting corrugated sheet metal panels at a multitude of angles, but adjusting from one angle to another is time consuming and may require more than one laborer.  
           [0007]    Even though there are tools that are capable of cutting sheet metal panels at various angles, they are not capable of one-man operation. Some devices are large and require external power to perform the cutting operation, while others require two or more people to operate. In addition, larger, complex tools are more likely to malfunction and require complicated maintenance or repair.  
           [0008]    Portability is another major concern for building contractors. The more portable a cutting apparatus, the more time and costs are saved. Some shears in use are large and impractical, while others are not portable and thus need to be delivered to a job site with a large truck. Alternatively, sheet metal panels may be cut off-site and delivered, which causes problems with respect to last minute design changes by a contractor, or incorrectly cut sheet metal panels being delivered. Ideally, sheet metal panels are cut as needed on-site to fit specific locations and minimize scrap.  
           [0009]    Thus there is a long felt need in the field of sheet metal installation for a portable and cost effective cutting apparatus that can support and cut various types of corrugated, ribbed, seamed, and flat sheet metal material at preferred angles and that is further easy to adjust, use, and maintain.  
         SUMMARY OF THE INVENTION  
         [0010]    It is thus one aspect of the present invention to provide a portable, cost effective sheet metal cutter which can be easily adapted for use with various types of sheet metal materials. More specifically, the apparatus is adapted for cutting sheet metals employing various types of corrugation profiles, sizes, and shapes and which can be cut at an angle without time consuming adjustments to the blades.  
           [0011]    It is another aspect of the present invention to provide a sheet metal cutting apparatus which is capable of making guillotine-type cuts that cause less deformation to the panel and are mechanically easier to perform by hand. In one embodiment, a movable blade works in conjunction with a stationary blade situated on the opposite side of the pre-cut sheet metal panel to aid the guillotine blade to perform a cleaner cut.  
           [0012]    It is another aspect of the present invention to provide a sheet metal cutting apparatus that is equipped with a movable blade which is serrated to facilitate clean cuts on various types of sheet metal materials. In one embodiment, the movable blade consists of a single serrated blade or a plurality of smaller blades that extend over the entire cutting area that together form a serrated edge. Serrated blades are designed to pierce the peaks and valleys of corrugations evenly, thereby minimizing bending and other deformations of the panel. Alternatively, for cutting panels with seams, a serrated blade will ensure a crest of the seam is cut at the same instance the flat portion of the sheet is cut, thereby yielding a cleaner cut. In addition, serrated blades are more suited for various profiles of panels so that the blade may not have to be removed to accommodate different corrugation shapes. For example, a blade with sufficient serrations will be able to cut a widely spaced round corrugation or a narrowly spaced hat-type corrugation without a blade change, because the majority of the corrugations will be pierced in the preferred fashion. As mentioned above, in one embodiment, a stationary blade is used to aid in the cutting operation. Some prior designs have used interchangeable stationary blades that match the corrugation contour of the pre-cut sheet metal panel. Alternatively, adjustable corrugation support blocks are used to aid in the cutting operation. The use of serrated blades eliminates the requirement for these measures, and therefore adds robustness to the design, and cost savings to the cutting process.  
           [0013]    It is yet another aspect of the present invention to provide a sheet metal cutting apparatus that is capable of holding a pre-cut sheet metal panel such that it can be cut at a multiplicity of desired angles. Prior designs of cutters were limited in the sizes and profiles of corrugations which could be cut at an angle. In one embodiment of the present invention, dies that interface with the sheet metal panel&#39;s edges and sheet metal panel guides are employed to restrain the metal panels that employ edge seams. The profile dies are selectively interconnected to die brackets and are easily adjusted or interchanged to fit various seam shapes and are capable of being used at a plurality of cut angles. The profile dies are designed so that a pre-cut panel can be set into the dies and to the desired angle before the cut is made without time consuming replacement of the dies. The combination of easily adjustable profile dies and panel guides provide the user with a multitude of cutting options while firmly securing the sheet metal panel. In addition, the relative angle between the cutting blade and the longitudinal axis of the sheet metal panel is capable of being altered between 45 to 90 degrees, where a 90 degree cut would be perpendicular to the longitudinal axis of the panel. Changes to the cut angle are made by loosening readily accessible fasteners, adjusting the panel guides and the profile dies, pivoting the cutting blade, and tightening the fasteners. Alterations to the cut angle can be completed while the panel is installed between the blades and in the guide, thereby permitting the user to more accurately set an angle without repeated removal and replacement of the sheet metal panel. Also, the profile dies can be reversed in order to cut angles between 90 to 135 degrees. This feature would be used when the panel needed to be cut to a point, such as for siding installation at a roof&#39;s apex, for example.  
           [0014]    It is another aspect of the present invention to provide a sheet metal cutting apparatus that is portable and operable by a single person to decrease construction cost and man power needs. In one embodiment, the entire assembly is compact and light weight. The blade actuation handle is capable of supporting the entire weight of the apparatus, and maybe used as a means of transportation from one building site to another. In addition, the cutting mechanism employs rack and pinion gears that, along with the leverage provided by the blade handle, provide enough mechanical energy to the blade so the apparatus can be operated by a single user. These advantages will translate to savings to the contractor because fewer skilled laborers will be required to complete the task. Alternatively, one skilled in the art can apprieciate that the cutting operation and apparatus can easily be automated, for example with a motor that controls the blade movement.  
           [0015]    It is yet another aspect of the present invention to provide a sheet metal cutting apparatus that is easy to maintain and repair. In one embodiment, a protective shield surrounds a blade and associated blade articulation components to provide protection to the user, prevent damage to the components, and to provide some barrier to dust and other debris. The protective shield may be removed thereby exposing the inner workings of the apparatus. Once opened maintenance activities such as inspection, fastener replacement, cleaning, lubrication, and blade replacement can be performed.  
           [0016]    It is still yet another aspect of the present invention to provide a sheet metal panel cutting apparatus that is safe to operate and will reduce construction costs as well. In one embodiment, a handle is used to actuate the blade from its up position to its cutting position. When the blade is up, the handle is oriented on the side of the pre-cut sheet metal panel that will be used after the cut is made. The user can make the required angle and securing adjustments safely because the majority of the blade will be retracted into a protective shield. Once the panel is at the desired cutting angle and secured, the handle must be rotated substantially 180 degrees around the protective shield to the exit or scrap side of the apparatus to actuate the blade into and through the cut position. Therefore, if the user were to accidentally lean on the handle during preliminary adjustments, the blade would not be actuated and potentially cause an injury.  
           [0017]    It is yet another aspect of the present invention to provide a sheet metal cutting apparatus that is constructed from common materials, and thus less expensive. More specifically, the majority of the components of the present invention are manufactured with steel, aluminum, or any other substantially rigid material. In addition, the majority of the components may be made of extruded material as in “L” beams, and commonly known fasteners. Basically, very few components have to be custom made, and any machining operations are minimal. Therefore, part manufacturing, replacement, and repair are inexpensive.  
           [0018]    As can be appreciated by one skilled in the art, the present invention may be constructed in different sizes and thus may be adapted for use for any type of cutting operations. Furthermore, the protective shield can be adapted for the display of advertisements, such as the contractors name, and safety warnings.  
           [0019]    Thus in one aspect of the present invention, a portable cutting apparatus adapted for cutting sheet metal panels at a preferred angle is provided which comprises:  
           [0020]    a frame adapted to receive the piece of sheet metal to be cut;  
           [0021]    an articulating handle operably interconnected to said frame;  
           [0022]    a blade in mechanical communication with said handle and capable of reciprocating travel within said frame, wherein when said handle is in a first upward position said blade is not in contact with the sheet metal panel, and when said handle is in a second downward position said blade is in contact with the sheet metal panel; and  
           [0023]    an adjustable holding means operably interconnected to said frame and adapted to selectively interconnect and hold the sheet of metal panel at a plurality of predetermined angles, wherein the sheet metal panel is secured such that said adjustable holding means is capable of retaining the sheet metal panel during a cutting operation to achieve a clean cut. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]    [0024]FIG. 1 is a perspective view of one embodiment of the present invention, wherein the protective shield is removed to identify the various components of the apparatus;  
         [0025]    [0025]FIG. 2 is a front elevation view of the embodiment of the invention shown in FIG. 1;  
         [0026]    [0026]FIG. 3 is a front elevation view of the embodiment of the present invention shown in FIG. 1, wherein the protective shield is installed and a sheet metal panel is installed in preparation of cutting;  
         [0027]    [0027]FIG. 4 is a detail view of the embodiment of the present invention shown in FIG. 3; and more specifically depicting a sheet metal panel secured with a profile die, an entry guide, and a clamp; and  
         [0028]    [0028]FIG. 5 is a top plan view of the embodiment of the present invention shown in FIG. 1 and depicting a sheet metal panel adapted to be cut at an angle larger than 90 degrees, wherein some components are omitted for clarity. 
     
    
     DETAILED DESCRIPTION  
       [0029]    Referring now to the drawings, FIGS.  1 - 5  depict an apparatus for cutting sheet metal panels, and which can be safely performed by one person. More specifically, in one embodiment of the present invention the apparatus is adapted to cut exterior siding seamed sheet metal panels at various angles by sliding the sheet metal panels through the apparatus under a movable blade. A plurality of fasteners and clamps, along with channels and guides that approximately match the profile of the panel&#39;s seams, hold the panel securely in place. Preferably, the channels are rotatable around a point which allow a user to set the sheet metal panel to a desired angle prior to cutting.  
         [0030]    Referring now to FIG. 1, one embodiment of the present invention is depicted with a protective shield removed for clarity. The angled cutting shear  4  functions generally by articulating a handle  7  that is interconnected to a shaft  9 . The shaft  9  is interconnected by bearings  11  to a frame  13 , which further includes a plurality of vertical members  15  and horizontal members  17  operably interconnected to a moveable base channel  19 , and interconnected to a fixed base channel  20 . A blade  21  rides in a channel  23  and is interconnected to the shaft via a pinion  25  and rack gear  27  system, such that the blade  21  can freely travel and reciprocate in a vertical direction between the frame members without interference when the handle  7  is actuated. Preferably, in one embodiment the vertical members  15  and the horizontal members  17  are constructed from steel, aluminum, or any other rigid material as appreciated by one skilled in the art. Further, the horizontal members  17  may be constructed from “L” beams and interconnected to the vertical members with bolts, welds, or other interconnecting methods. Also, the channel  23  between the frame  13  members is sufficiently spaced such that the blade  21  can travel freely yet not be constrained to affect the precision of a cut. In operation, the user articulates the blade  21  by starting with the handle  7  in the “blade up” position  28 A and transitioning the handle through to the “shear” position  28 B. This motion effectively drives the blade  21  downward through the sheet metal panel or other material.  
         [0031]    Referring now to FIG. 2, a front plan view of one embodiment of the present invention is shown with the protective shield removed for clarity. More specifically, the blade  21  is shown in greater detail. Preferably, the blade  21  is constructed from a plurality of smaller blade segments  21 A. Alternatively, the blade  21  may be constructed from a single piece of material. The blade segments  21 A, which include edges  29 , interface with a common blade plate  31  that is in turn interconnected to the rack gears  27 . In this embodiment, individual blade segments  21 A can be replaced easily without replacing the entire blade. In addition, a user may tailor the type and size of the blade segments  21 A for custom tasks. It should be noted, as in other guillotine metal cutters known in the art, the apparatus contains stationary blades  33  which straddle the articulating blade  21  and which are interconnected to a lower horizontal member  17  of the frame  13 . The stationary blades  33  perform an opposite cutting motion when the handle  7  is transitioned and the articulating blade  21  is forced down on the sheet metal panel so that both sides are cut concurrently to prevent deformation.  
         [0032]    Referring now to FIGS. 3 and 4, a front elevation and front perspective view of one embodiment of the present invention is shown with the protective shield  35 , base members, and the sheet metal panel  40  in place to be cut at an angle. Once at the work site, the angle shear&#39;s  4  base channels  19  and  20  are preferably mounted to a base  36 , which may include riser blocks  36 A. The base and riser blocks are preferably constructed of wood, but other rigid materials may also be employed. It should be noted that at least one of the base interface bolts  37  is adapted to ride in an adjustment slot  38  to provide rotational freedom during initial adjustments.  
         [0033]    In operation, the handle  7  is moved to the front entry side of the apparatus (see FIG. 1, item  28 A) to provide a gap into which the sheet metal panel will be inserted. Setting the angle shear  4  to cut the sheet metal panel  40  of a particular profile to a specific angle may require adjustment of a base channel  19 , profile dies  39 , and an entry guide  41 . Initially, the correct profile die  39  must be selected that generally matches the profile of the seam  45 . Various profile dies  39  can be used, and in one embodiment, at least two unique profile dies are used. When installed, the panel&#39;s  40  seam  45  is seated in the panel interface portion  41 A of the entry guide  41 .  
         [0034]    Initially, to set a desired cutting angle, a pivot point  49  of the base channel  19  may require adjustment. The frame  13  is connected to a foot plate  53  which in turn is operably interconnected to an angle degree wheel  55  which is interconnected to the base channel  19  through the pivot point  49 . The relative angle of the frame  13  and the panel  40  is set by loosening the pivot fastener  49  and rotating the base channel  19  until the desired angle is achieved. The user may use an indication mark  61  that lines up with a plurality of incremental hash marks on the angle degree wheel  55  to accurately set the desired angle. As noted above, at least one bolt  37  that interfaces with the base  36  rides in a slot  38  that in turn allows the base channel  19  to rotate about the pivot point  49 .  
         [0035]    Subsequently, the profile dies  39  (which function as sheet metal panel securing means) are adjusted in relation to the shear blade edges  29 . Initially, the fasteners that hold a profile die bracket  64  need to be loosened in order for the bracket  64  to travel in a profile die track  67 . The panel  40  is then fed along the entry guide  41 A through the profile dies  39  until the cut plane is at the desired location on the panel  40 . A clamp  71 that interfaces with the panel  40  and holds it firmly against the entry guide  41 A is then engaged, in one embodiment, by a clamp handle  73 . Preferably, the profile die brackets  64  are adjusted such that the blade  21  points are positioned just inside a panel seam  45  before blade engagement. For example, for a “C” channel type seam profile, the distance between the nearest blade  21  point and the upper portion of the seam is preferably about 0.50 inches. This length can be verified by carefully actuating the handle  7  towards the shear position (see FIG. 1, item  28 B) but not far enough to actually contact the panel  40 . In order to make the required adjustments, the entry guide  41  is equipped with a plurality of holes  75  and fasteners  78 , or other operably interconnection mechanisms that allow the entry guide  41  to move relative to the base channel  19  as the panel is angulated. Finally, after the desired cut angle is set, the profile dies  39  preferably are moved to fit snugly against the seams  45  and all the adjustment fasteners tightened or locked.  
         [0036]    Referring now to FIG. 5, an alternative embodiment of the present invention is provided which is adapted to cut opposite angles of the panel  40 . More specifically, FIG. 5 depicts the adjustments to the profile dies  39  that may be required in order to cut opposite angles. For example, some applications may require the user to cut the panel  40  at opposite angles. More specifically, the panel  40  must be cut to a “point”, wherein a tip is provided between the edges of the panel  40  and not on the seams  45 . Alternatively, the panel  40  may be cut wherein the point is on the opposite seam  45 . To perform this operation, it is necessary to make some modifications to the apparatus. More specifically, since the profile dies  39  are tailored to allow cutting angles from 0 to 90 degrees, the profile dies  39  must be altered to cut angles from 90 to 135 degrees. Before the panel  40  is inserted, the left front profile die  39 A is switched with the right rear profile die  39 D and the right front profile die  39 B is switched with the left rear profile die  39 C. Next, the above-described steps are performed, except prior to tightening the fasteners, the entry guide  41  is rotated in the opposite direction to achieve opposite angled cuts. Alternatively, as can be appreciated by one skilled in the art, and depending on the seam shape, an opposite angle cut may be achieved by altering the profile dies, flipping the panel  40 , and cutting to achieve the desired resultant cut shape.  
         [0037]    Referring now to all the previously discussed figures, the cutting guillotine operation on the panel is generally described herein. The handle  7  is articulated from the entry side or “blade up” location  28 A of the angle shear  4  to the exit side or “shear” position  28 B. During articulation, the blade  21  will emerge from the protective shield  35 , initially pierce the panel  40 , and then shear with the blade edges  29 , all while the stationary blade  33  is shearing from the opposite direction. The handle  7  is then articulated back to its starting position, thereby retracting the blade  21  to a safe position for subsequent adjustments and cuts.  
         [0038]    To assist in the understanding of the present invention the following list of components and associated numbering found in the drawings is provided herein:  
         [0039]    # Component  
         [0040]    [0040] 4  Angle shear  
         [0041]    [0041] 7  Blade actuating handle  
         [0042]    [0042] 9  Shaft  
         [0043]    [0043] 11  Bearings  
         [0044]    [0044] 13  Frame  
         [0045]    [0045] 15  Vertical frame member  
         [0046]    [0046] 17  Horizontal frame member  
         [0047]    [0047] 19  Movable base channel  
         [0048]    [0048] 20  Stationary base channel  
         [0049]    [0049] 21  Articulating blade  
         [0050]    [0050] 21 A Blade segment  
         [0051]    [0051] 23  Blade channel  
         [0052]    [0052] 25  Pinion gear  
         [0053]    [0053] 27  Rack gear  
         [0054]    [0054] 28 A “Blade up” direction  
         [0055]    [0055] 28 B “Shear” position  
         [0056]    [0056] 29  Shear blade edge  
         [0057]    [0057] 31  Blade interface plate  
         [0058]    [0058] 33  Stationary blades  
         [0059]    [0059] 35  Protective shield  
         [0060]    [0060] 36  Base  
         [0061]    [0061] 36 A Base riser block  
         [0062]    [0062] 37  Bolt  
         [0063]    [0063] 38  Base channel adjustment slot  
         [0064]    [0064] 39  Profile die  
         [0065]    [0065] 39 A Left front profile die  
         [0066]    [0066] 39 B Right front profile die  
         [0067]    [0067] 39 C Left rear profile die  
         [0068]    [0068] 39 D Right rear profile die  
         [0069]    [0069] 40  Sheet metal panel  
         [0070]    [0070] 41  Entry guide  
         [0071]    [0071] 41 A Panel interface of entry guide  
         [0072]    [0072] 45  Panel seam  
         [0073]    [0073] 49  Base channel pivot point  
         [0074]    [0074] 53  Base channel foot plate  
         [0075]    [0075] 55  Degree wheel  
         [0076]    [0076] 61  Degree indication mark  
         [0077]    [0077] 64  Profile die bracket  
         [0078]    [0078] 67  Profile die bracket track  
         [0079]    [0079] 71  Holding clamp  
         [0080]    [0080] 73  Holding clamp handle  
         [0081]    [0081] 75  Entry guide adjustment holes  
         [0082]    [0082] 78  Entry guide adjustment fasteners.  
         [0083]    While various embodiments of the present invention have been described in detail, it is apparent that modifications and abdications of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and abdications are within the scope and spirit of the present invention, as set forth in the following claims.