The subject invention relates to building construction equipment, and more particularly to a portable apparatus for cutting roofing shingles.
A number of cutting apparatuses designed to shear or trim roofing shingles have been constructed and marketed, but most roofers continue to rely upon utility knives and straight-edges for cutting shingles because of the ease the knives' portability and simplicity of use, as well as the ease and low cost of replacing dulled blades as compared to existing cutting apparatuses. Most existing apparatuses are cumbersome to move and provide inferior cutting results when contrasted with the utility knife. Therefore, there exists a need in the art for a portable shingle cutting apparatus which provides ease of portability and use, as well as shearing performance equivalent to or better than the cutting quality provided by utility knives.
In one embodiment, a cutting apparatus comprises a frame assembly including a support surface and a first cutting blade, wherein the support surface includes at least one key hole; a cutting arm assembly rotatably attached to the frame assembly, the cutting arm including a second cutting blade; and an alignment mechanism secured to the frame assembly and the cutting arm assembly.
In one aspect of the subject invention, the support surface is inscribed with numbers indicating angular degrees relative to the first cutting blade.
In another aspect of the subject invention, the cutting apparatus comprises a guide fence selectively attachable to the support surface through the at least one key hole, such that the position of the guide fence corresponds to an angular degree.
In still another aspect of the subject invention, the first cutting blade is selectively attachable to the frame assembly.
In a further aspect of the subject invention, the second cutting blade is selectively attachable to the cutting arm assembly.
In still a further aspect of the subject invention, the second cutting blade further comprises a blade alignment tab disposed between the cutting arm assembly and the frame assembly.
In yet another aspect of the subject invention, the cutting arm assembly comprises an arm assembly frame and an extendable handle member disposed therein.
In another aspect of the subject invention, the extendable handle member is axially reciprocating within the arm assembly frame.
In still another aspect of the subject invention, the support surface includes a handle aperture.
In a further aspect of the subject invention, the second cutting blade includes an arcuate cutting edge.
In another embodiment of the subject invention, a cutting apparatus comprises a frame assembly including a support surface and a first cutting blade; a cutting arm assembly rotatably attached to the frame assembly, the cutting arm including a second cutting blade; and an alignment mechanism secured to the frame assembly and the cutting arm assembly, wherein the alignment mechanism includes a plurality of biasing members.
In another aspect of the subject invention, the plurality of biasing members includes a first biasing member and a second biasing member.
In still another aspect of the subject invention, the first biasing member is positioned substantially perpendicular to the first cutting blade and the second biasing member is positioned substantially parallel to the first cutting blade.
In yet another aspect of the subject invention, the first biasing member and the second biasing member are arranged in different vertical planes.
In a further aspect of the subject invention, the first biasing member includes a bolt having a shaft, wherein the angle between the shaft and the first cutting blade is less than 90°.
In still a further aspect of the subject invention, the angle between the shaft and the first cutting blade is between 75° and 90°.
In yet another embodiment of the subject invention, a cutting apparatus comprises a frame assembly including a support surface and a first cutting blade, wherein the support surface includes at least one key hole; a cutting arm assembly rotatably attached to the frame assembly, the cutting arm including a second cutting blade; and an alignment mechanism secured to the frame assembly and the cutting arm assembly, wherein the alignment mechanism includes a plurality of biasing members.
In another aspect of the subject invention, a first biasing member is positioned substantially perpendicular to the first cutting blade and a second biasing member is positioned substantially parallel to the first cutting blade.
In still another aspect of the subject invention, a cutting apparatus further comprises a guide fence selectively attachable to the support surface through the at least one key hole, such that the position of the guide fence corresponds to an angle relative to the first cutting blade.
In yet another aspect of the subject invention, the second cutting blade includes an arcuate cutting edge.
An embodiment of a portable cutting apparatus, generally identified by reference numeral 10, is illustrated in the Figures. As shown in
As shown in
With continued reference to
As shown in
A stationary blade 40 may be selectively attached to the frame assembly 20 by one or more fasteners 42 as are known in the art. The stationary blade 40 may be made of hardened tool steel, however, any suitably hard material may be employed in construction of the stationary blade 40. In the event that the stationary blade 40 becomes dulled through repeated use, the stationary blade 40 may be removed and either replaced or sharpened.
As illustrated in
The cutting blade 32 may be made of tool steel; however, any hard material capable of holding an edge for a period of time may be used in construction of the cutting blade. As a result of repeated use, the cutting blade 32 may become dulled, resulting in diminished shearing ability. In such an event, the plurality of fasteners 34 may be removed from the cutting blade 32, and the cutting blade 32 may be removed, sharpened, and re-secured to the arm assembly frame 31 by the fasteners 34. Alternately, the dulled cutting blade 32 may be replaced by a new cutting blade, which would be fastened to the arm assembly frame 31 in a similar manner as the dulled blade.
When transporting the cutting apparatus 10, it may be beneficial to insert the extendible handle 36 axially as deeply into the arm assembly frame 31 as possible in order to reduce the effective perimeter of the cutting apparatus 10 and to decrease the likelihood that the extendible handle 36 will inadvertently contact items in the ambient environment. To prevent the arm assembly 30 from moving while in transit, the arm assembly 30 may be lowered until the bottom of the assembly 30 contacts the top of the blade stop 29, at which point the corresponding blade lock apertures 48A and 48B are aligned. A lock retaining pin (not shown) may be then inserted through both of the apertures 48A, 48B to prevent the arm assembly 30 from being raised unintentionally or inadvertently. Once the cutting apparatus 10 is moved to its operational situs, the retaining pin may be removed and the arm assembly 30 may be raised without interference. In a further embodiment shown in
As depicted in
In addition to serving as a means for securing the arm assembly 30 to the frame assembly 20, the alignment mechanism 50 maintains the alignment and varies the interference between the cutting blade 32 and the stationary blade 40, permitting the cutting apparatus 10 to shear heavy duty materials such as roofing shingles. In prior art cutting devices, the alignment between the cutting blade and the stationary blade may be altered as a result of repeated use or other unforeseen circumstances. Such improper alignment may lead to deterioration of the quality of the cut edge of a shingle, thereby decreasing the aesthetic appearance of a roof if the poorly sheared shingles are installed. Alternatively, poorly sheared shingles may be discarded and replaced with properly sheared shingles, effectively increasing the material cost of roofing a building. Rather than shearing, loose or improperly aligned cutting devices may also fold the material to be sheared over the edge of the support surface, resulting in undesirably creased (and therefore, unusable) shingles.
Although apertures 58E and 59E are perpendicular, the angle α between extended bolt 58A and bolt 59A may be less than 90°, as extended bolt 58A may be constructed such that the shaft of the bolt is not perpendicular to the head of the bolt. For example, extended bolt 58A may be angled 3°, whereby angle α is 87°, although a range of angles between 75° and 90° is contemplated. To ensure that no difficulties exist when inserting extended bolt 58A through aperture 58E, the diameter of aperture 58E may be greater than the diameter of extended bolt 58A to accommodate the angle of extended bolt 58A. In operation, the angle of extended bolt 58A, in conjunction with extended bolt spring 58B, extended bolt washer 58C, and extended bolt nut 58D, serves to pull cutting blade 32 into proper alignment with stationary blade 40 for cutting. In the event that alignment of the cutting blade 32 and stationary blade 40 may be improper (as evidenced by poor shearing performance or folding of the material to be sheared), the alignment may be altered by either loosening or tightening nut 58D, which in turn decreases or increases the tension in spring 58B. In a similar manner, the alignment may be adjusted by loosening or tightening nut 59D, which similarly increases or decreases the tension in the spring 59B through which bolt 59A has been passed. When viewed as shown in
In an alternate embodiment, extended bolt 58A may be constructed such that the shaft of the bolt and the head of the bolt are perpendicular. In this embodiment, alignment block aperture 58E may be angled through block 52 such that the angle α between the shaft of extended bolt 58A and the shaft of bolt 59A may be less than 90°. For example, the alignment block aperture 58E may be angled such that angle α is 87°, although a range of angles between 75° and 90° is contemplated. Further this embodiment, an axially compressible washer may be inserted between bolt 58A and cutting arm assembly frame 31 to ensure contact between the bottom of the head of the bolt 58A and the cutting arm assembly frame 31.
The foregoing description of the preferred embodiments of the invention is by way of example only, and other variations of the above described embodiments are provided by the subject invention. The embodiments presented herein have been presented for purposes of illustration and are not intended to be exhaustive or limiting. Many variations and modifications are possible in light of the foregoing teaching.
This patent application is a continuation of U.S. Pat. No. 8,359,962, issued Jan. 29, 2013, which claims the benefit of and priority to U.S. Provisional Patent Application No. 61/013,126, filed Dec. 12, 2007, the disclosures of which are expressly incorporated by reference herein.