Abstract:
A cutting system and method of use for manually cutting rigid foam insulation panels; the present cutting system is operated manually and requires no electric power whatsoever; the cutting system includes a fully adjustable carriage assembly whereon a cutting blade is mounted for traversing the limits of its working surface; the cutting system provides a measuring scale having graduated indicia inscribed thereon for conveniently changing blade settings to accommodate different foam panel dimensions; the cutting system produces a uniformly accurate cut surface comparable to a factory-made surface without damaging the foil moisture barrier on the rigid foam panel; the cutting system completely eliminates the health and safety hazards created by airborne foam particulates that are produced by powered cutting of such rigid foam materials and thereby provides an environmentally-friendly building practice; and the present cutting system is completely portable enabling its setup and use at any construction site or location.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This patent application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Patent Application No. 61/274,174 filed Aug. 11, 2009, entitled Rigid Foam Insulation Cutting System and Method of Use. 
     
    
     BACKGROUND OF INVENTION 
       [0002]    1. Field of Invention 
         [0003]    The present invention relates to rigid foam insulation panels and, more particularly, to a method and apparatus for cutting such rigid foam insulation panels. 
         [0004]    Rigid foam insulation panels are widely used in the building trade to provide an additional layer of insulation in the construction of new homes and commercial buildings. Typically, such rigid foam panels are used as a replacement for fiberglass batting and are cut to fit between wall studs. Sheets of rigid foam are also installed on the sides of houses being constructed, remodeled or repaired to provide additional insulation to the exterior walls. Such foam panels provide good thermal resistance and often add structural strength to the building. Since such rigid foam insulation panels are well known to those skilled in the art further detailed discussion of the same is not deemed necessary. 
         [0005]    A problem is encountered in cutting rigid foam insulation panels on the construction site. Such foam panels are typically provided in four-by-eight foot sheets and are often cut manually by the use of a utility knife and a straight edge. Using this method the foam panel is partially cut to a limited depth at the desired dimension and, thereafter, manually snapped along the superficial cut. However, this technique produces an uneven cut surface and quickly dulls the utility knife blade after repeated use resulting in damage to the foil moisture barrier which is typically adhered to the surface of the foam panel. 
         [0006]    Alternatively, circular saw or a table saw powered by an electric motor is utilized to cut the rigid foam panels, but this technique produces a substantial amount of airborne foam insulation particulates, which pose a health hazard to the user or to anyone in the vicinity. 
         [0007]    2. Background Art 
         [0008]    There are prior art patents that are available in the field of the present invention and their discussion follows. One method for cutting rigid foam panels employed in the past has involved the use of electrically heated wires which are drawn through the foam material to cause severing of the cellular material. For example, U. S. Pat. No. 3,786,701 discloses a Device for Cutting Urethane Foam comprising a carriage adapted to advance a slab of urethane material through a cutter assembly including groups of elongated cutting wires which are heated and oscillated longitudinally to clean the wires as the material is advanced through the device. However, the melted foam material inevitably builds up on the hot cutting wires preventing a satisfactory cut of the foam material. The oscillatory drive mechanism is powered by a conventional drive transmission means such as a belt and pulley arrangement connected to a drive motor, which has all the electromechanical complexities of such a powered system and the related maintenance problems as well. 
         [0009]    Another method of producing boards of cellular material involves the use of blade cutting equipment. For example, U. S. Pat. No. 3,242,779 discloses a Reciprocal Saw for Cellular Resinous Bodies which is a multiple blade machine capable of sawing a foam block into a plurality of boards during a single pass of the machine. Generally, such a reciprocal saw apparatus involves a number of problems including the ability to change blades and blade settings readily and the maintenance of a conventional motor and drive mechanism. 
         [0010]    Thus, the present invention has been developed to resolve these problems and other shortcomings of the prior art. 
       SUMMARY OF THE INVENTION 
       [0011]    Accordingly, the present invention provides a cutting system and method of use for manually cutting rigid foam insulation panels. The present cutting system requires no electric power, which completely eliminates airborne foam particulates produced by powered cutting, and permits the use thereof at any location or construction site. Advantageously, the present cutting system includes a cutting blade that produces a uniformly accurate, cut surface without damaging the foil moisture barrier on the foam insulation panel. In addition, the present cutting system is fully adjustable to accommodate four by eight foot sheets of rigid foam insulation of different thicknesses (i.e. up to two inches) in a single pass of the cutting blade. 
         [0012]    There has thus been outlined, rather broadly, the important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. 
         [0013]    Those skilled in the art will appreciate that the concept upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods, and systems for carrying out the purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
         [0014]    Other features and technical advantages of the present invention will become apparent from a study of the following description and the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The novel features of the present invention are set forth in the appended claims. The invention itself, however, as well as other features and advantages thereof will be best understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures, wherein: 
           [0016]      FIG. 1  is a front perspective view of the present rigid foam insulation cutting system; 
           [0017]      FIG. 2A  is a rear perspective view of the present rigid foam insulation cutting system; 
           [0018]      FIG. 2B  is an enlarged perspective view of a portion of  FIG. 2A  showing further details thereof; 
           [0019]      FIG. 3  is a front elevation view of the present cutting system showing details of the carriage assembly; 
           [0020]      FIG. 4A  is a side elevation view of a cutting blade of the present invention; 
           [0021]      FIG. 4B  is a cross-sectional view taken along section line  4 B- 4 B of  FIG. 4A  showing further details of the cutting blade of  FIG. 4A ; 
           [0022]      FIG. 4C  is an enlarged, partial cross-sectional view of a portion of the cutting blade shown in  FIG. 4B  showing further details thereof; and 
           [0023]      FIG. 5  is a front perspective view of the present cutting system showing a rigid foam panel being cut therein. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0024]    With further reference to the drawings there is shown therein a rigid foam insulation cutting system in accordance with the present invention, indicated generally at  10  and illustrated in  FIG. 1 . 
         [0025]    The present cutting system includes a base plate or table  12  whereon a pair of horizontally opposed angle brackets or fences  14 ,  16  are attached such that vertical members  14   a,    16   a  of each fence  14 ,  16  are disposed in perpendicular relation to table  12  and such that each vertical member  14   a,    16   a  is parallel to the other. Fences  14 ,  16  are also disposed in parallel relation to blade  35  and function to guide a lateral edge of foam panel  50  ( FIG. 5 ) to produce a straight cut during operation as explained hereinafter in further detail. 
         [0026]    In an alternative construction of the present invention (not illustrated), the cutting system  10  is fabricated with a single fence  14  and still retains its essential function. For example, fence  16  can be omitted from the present cutting system to reduce manufacturing costs and vertical post  20  attached directly to table  12  by weldment or other fasteners. 
         [0027]    In the embodiment shown in  FIG. 1 , table  12  and fences  14 ,  16  are constructed from aluminum sheet and aluminum right angle stock respectively and secured by weldment or fasteners in the positions shown. Other materials such as laminated wood or engineered plastics are suitable for the fabrication of table  12  and fences  14 ,  16 . 
         [0028]    A plurality of elongated panel glide members  15  are provided for installation on table  12  extending from front to back across the table  12  as shown in  FIG. 1 . Glides  15  function to support a rigid foam panel  50  ( FIG. 5 ) or a portion thereof slightly above an upper surface of table  12  providing clearance for blade  35  during the cutting operation. It can be seen that a pair of such glides  15  are disposed on either side of blade  35  and another pair of glides  15  are positioned adjacent to each fence  14 ,  16  in the standard setup of the present cutting system  10 . In the embodiment shown guides  15  are constructed of wood and configured for sliding attachment to the front and rear edges  12   b,    12   c  of table  12 . Of course, other suitable materials such as laminated wood or engineered plastics may be utilized to fabricate glides  15 . 
         [0029]    Referring now to the embodiment shown in  FIG. 2A , a pair of vertically disposed posts  18 ,  20  are secured to fences  14 ,  16  respectively being attached thereto by fasteners  22  in perpendicular relation to table  12  as shown. Posts  18 ,  20  both include a lug member  18   a,    20   a  respectively attached thereto by weldment as more clearly shown in  FIG. 2B . Each lug member  18   a,    20   a  includes an internally threaded hole (not shown) formed therein to receive mating machine bolts  26 . Each post  18 ,  20  also includes a vertically disposed slot  18   b,    20   b  respectively formed therein ( FIG. 3 ) and located directly below lug members  18   a,    20   a.  In the embodiment shown posts  18 ,  20  are fabricated from right angle stock of a suitable material such as steel. 
         [0030]    Referring to  FIG. 3 , an elongated crossbar  24  extends across table  12  in generally parallel relation thereto and is mechanically attached at each end thereof to posts  18 ,  20  by machine bolts  27  ( FIG. 2A ) extending through slots  18   b,    20   b  and engaging mating nuts  29  ( FIG. 3 ) at a position proximate to machine bolts  26  as shown. Machine bolts  26  are advanced into threads within each lug member  18   a,    20   a  and into contact with crossbar  24  to function as stops thereby preventing any upward movement of the crossbar in operation. In the embodiment shown crossbar  24  is fabricated from square, tubular material such as steel. Crossbar  24  can be fabricated from other suitable material such as solid cylindrical stock or tubular cylindrical tubular stock. 
         [0031]    The present invention provides means for measuring a rigid foam panel  50  being cut with the cutting system  10  including, but not limited to, the following measuring means. In one embodiment of the present invention, a measuring scale  46  having graduated indicia  48  inscribed thereon extends across table  12  in proximity to crossbar  24  as shown in  FIG. 3 . Scale  46  is positioned at a location proximate to crossbar  24  as shown being attached to lug members  18   a ,  20   a  ( FIG. 2A ) to be conveniently viewed in the line-of-sight of the user. 
         [0032]    It will be understood that scale  46  is installed at a predetermined position in vertical alignment with an inner surface of fence  14  corresponding to a zero point on scale  46  for measurement purposes. Any conventional measuring scale  46  graduated in English or metric indicia  48  is sufficient for this purpose. 
         [0033]    It will be appreciated by those skilled in the art that various other measuring means including both metric and/or inch measurements may be adapted for use with the present invention. For example, other measuring means (not illustrated) such as those common to calipers utilizing a Vernier scale, a measuring means of the type having a small gear rack that drives a pointer on a circular dial or a measuring means having an electronic digital readout on which a dimension is displayed are well known to those skilled in the art and such measuring means are considered to be within the scope of the present invention. 
         [0034]    Referring again to  FIG. 3 , the present cutting system  10  includes an adjustable carriage assembly, indicated generally at  25 , whereon a cutting blade  35  is mounted for traversal along crossbar  24 . Carriage assembly  25  includes a truck member  28  which is fabricated from a length of square, tubular stock having an inside dimension which is sufficiently larger than the outside dimension of crossbar  24  to provide a sliding fit with the crossbar. Of course, truck member  28  may be constructed of a cylindrical tubular material to provide a sliding fit with a crossbar  24  fabricated alternatively from solid or tubular, cylindrical stock as described hereinabove. 
         [0035]    Still referring to  FIG. 3  a blade support  32  extends downwardly in perpendicular relation to truck member  28  and is attached thereto by weldment in the embodiment shown. Blade support  32  includes a blade mounting bolt  34  and mating nut  36  which is fitted with blade adapter bushings  38  to permit blade  35  to be installed thereon and to rotate freely on bolt  34  in operation. 
         [0036]    In an alternative construction (not illustrated), an optional, adjustable blade support  32  is configured to position blade  35  at any angle up to forty-five degrees (45°) relative to table  12  to produce angled cuts on a section of rigid foam panel  50  when desired. 
         [0037]    Still referring to  FIG. 3 , carriage assembly  25  is adapted for sliding movement along crossbar  24  as indicated by directional arrows  55  for traversal between posts  18 ,  20  during use. Carriage assembly  25  includes a setscrew  31  to lock it in position during the cutting procedure. In this manner blade  35  may be positioned at a width dimension “D” in relation to fence  14  corresponding to the width dimension of a rigid foam panel  50  ( FIG. 5 ) to be cut as explained hereinafter in further detail. 
         [0038]    In one embodiment blade  35  is symmetrically tapered in cross-section when viewed at its circumference along section line  4 B- 4 B as most clearly shown in  FIG. 4C . Blade  35  is manufactured from conventional hardened steel or other suitable material. It will be noted that in this configuration, blade  35  tends to maintain a sharp cutting edge as at  35   a  by repeated burnishing of blade  35  against the aluminum foil moisture barrier  50   a  of a rigid foam panel  50  during the cutting operation. 
         [0039]    In a method of use of the present invention, the cutting system  10  is assembled as shown in  FIG. 1  and mounted on a suitable stand, work bench or saw horses. Next, crossbar  24  is adjusted vertically within slots  18   b,    20   b  to a height “H” ( FIG. 3 ), which will allow adequate clearance between blade  35  and table  12  as at “C” and secured in position by tightening nuts  29  ( FIG. 3 ). Thereafter, machine bolts  26  are advanced downwardly through lugs  18   a,    20   a  into contact with crossbar  24  to stop position any upward deflection of the crossbar during use. 
         [0040]    Next, carriage assembly  25  is traversed along crossbar  24  to a position corresponding to a dimension “D” of a foam panel  50  to be cut ( FIG. 3 ). Blade  35  is visually aligned by the user with scale  46  to fine adjust carriage assembly  25  and the blade to the desired position. Thereafter, setscrew  31  is tightened to hold the carriage assembly  25  in the selected position on crossbar  24 . Next, glides  15  are arranged on either side of blade  35  and also adjacent to both fences  14 ,  16 . 
         [0041]    Thereafter, a rigid foam panel  50  to be cut is positioned on glides  15  and held against an inner surface of vertical member  14   a  of fence  14  to ensure a straight cut or kerf as at  60  parallel to the lateral edge of the foam panel. Next, foam panel  50  is manually advanced by the user into contact with blade  35  with sufficient pressure to pass between the inner surface of vertical member  14   a  and blade  35  cutting the panel to the selected dimension “D”. Advantageously, blade  35  passes through foam panel  50  providing a smooth, finished edge without tearing the foil moisture barrier  50   a,  which is adhered to the panel. Repeated cutting passes through the foil moisture barrier  50   a  has been observed to maintain the desired sharpness of blade  35  by burnishing the blade. This prevents tearing of the metallic foil moisture barrier  50   a  that is caused by the conventional practice of powered cutting of foam panels  50  with a circular saw or by the use of a utility knife. 
         [0042]    The procedure described hereinabove to cut foam panels  50  is typically repeated using the cutting system  10  to produce multiple, rigid foam boards of the same dimension “D” or, alternatively, carriage assembly  25  is reset utilizing scale  46  to position blade  35  at a different width dimension to produce foam boards of another size. 
         [0043]    Thus, the present invention provides a cutting system  10  and related method of use for manually cutting rigid foam insulation panels  50 . The present cutting system  10  requires no electric power, which completely eliminates airborne foam particulates produced by powered cutting and is completely portable, which permits the use of the present system at any construction site. The present cutting system  10  is fully adjustable to accommodate full sheets of rigid foam insulation of different thicknesses. 
         [0044]    Although not specifically illustrated in the drawings, it should be understood that additional equipment and structural components will be provided as necessary and that all of the components described above are arranged and supported in an appropriate fashion to form a complete and operative rigid foam insulation cutting system incorporating features of the present invention. 
         [0045]    Moreover, although illustrative embodiments of the invention have been described, a latitude of modification, change, and substitution is intended in the foregoing disclosure, and in certain instances some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of invention.