Patent Publication Number: US-6708417-B1

Title: Large panel sheathing square

Description:
FIELD OF THE INVENTION 
     The present invention relates to tools for building panels, and in particular, to a layout tool for use in establishing gable, hip/valley and radial cuts on large panel sheathing material. 
     BACKGROUND OF THE INVENTION 
     In the construction of residential or commercial buildings, large planar sheets or materials, such as plywood or composites, are used for wall and roof sheathing. The panels are available in standard sizes, typically 4 feet in width and 8 foot in length. On site many of the panels can be installed without cutting. Where side walls merge with roof lines, i.e. gables, and adjoining roof sections intersect, i.e. hips and valleys, the panels must be cut to size for proper fitting and continuity. 
     The prevalent technique is for the worker to determine one length of the finished panel and determine the other length from standard tables. A fine is drawn between the markings and the panel cut accordingly. Similar techniques are used for both the wall panel and roofing panel layouts and cutting. The task is time consuming and prone to error, particularly for non-skilled workers. 
     In an effort to reduce the manual and cognitive aspects of large panel construction, a number of layout tools have been proposed. In one approach as disclosed in U.S. Pat. No. 6,199,288 to Gregory an elongated bar is provided with a first pin at a terminal end and a second pin slidable within an elongated slot. The second pin is referenced to pitch legends adjacent the slot to thereby establish the hypotenuse dimension and cutting line when the pins are positioned on opposite sides of the panel. Inasmuch as the width of the panel is variable in normal production, the pin-to-pin layout can result in incorrect layout inclinations. Also, the tool is usable only with full size panels, and does not assist in laying out end panels where the required cut is across less than the full panel width. A similar two-pin layout tool is disclosed in U.S. Pat. Nos. 6,266,889 and 6,147,797 to Boyce. 
     Other layout tools having capabilities for making beveled cuts have been directed toward dimensional lumber applications, such as rafter, joists, miters and the like 2X. Typical carpenter&#39;s squares carrying pitch designations and tables, as disclosed in U.S. Pat. No. 1,196,519 to Caylor, provide at best short length markings that thereafter must be manually extended with supplemental straight edges for use with large panels. This presents the possibility of geometrically increasing errors in the initial layout when translated to larger panels. Similar difficulties are presented in the dimensional lumber layout tools as disclosed in U.S. Pat. Nos. 622,569 to Van Namee and 6,408,529 to Hodges. 
     SUMMARY OF THE INVENTION 
     The present invention provides a large panel sheathing tool for laying out beveled, transverse, and circular cuts for directly marking large building panels without the need for supplemental equipment. The sheathing tool comprises an elongated rectangular scale, having a length in excess of the width of a standard panel, carrying a T-bar disposed transverse to the front and rear surfaces thereof with a width the same as the width of the scale. The T-bar, in addition to accurately prescribing normal transverse cuts, provides a pair of pivot points when positioned against an edge of the panel. One surface of the scale includes indicia lines prescribing gable pitches referenced to one of the pivot points. When the designated pitch indicia is aligned with the opposite side of the panel an accurately positioned straight edge extends continuously across the panel for marking the desired cut. The other surface of the scale includes indicia lines referenced to the other pivot point and prescribes hip and valley pitches. The indicia lines extend across the surface and may also be used for making the desired layouts on partial panels. Additionally, the scale includes linear indicia for determining the pivot location for the cut as well as conventional measurements. The scale is further provided with a longitudinal series of holes referenced to the linear indicia and an integral pencil holder at the T-bar. The layout tool may be pivotally attached at a select hole of the desired radius and the scale rotated thereabout to layout circular cuts. Mirror image indicia may be provided for permitting direct layout of reverse inclinations on the panel. Thus, a unitary tool may be used for all the cuts required on large panel material, using continuous surfaces for marking and without the need for moving parts or supplemental equipment. The resultant simplicity and versatility increases productivity and allows lesser skilled workers to accurately layout and cut the large panels. 
     Accordingly, it is an object of the present invention to provide a tool for marking and making a variety of cuts in large sheathing panels. 
     Another object of the invention is to provide a layout tool for making gable, hip/valley, transverse, and radial cuts in roofing panels. 
     A further object of the invention is to provide a layout tool which reduces the time and skill level required to layout and cut large standardized standard size sheathing panels used in residential and commercial construction. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The above and other objects and advantages of the present invention will become apparent upon reading the following detailed description taken in conjunction with the accompanying drawings in which: 
     FIG. 1 is a front perspective view of a large panel sheathing square in accordance with a preferred embodiment of the invention; 
     FIG. 2 is a rear perspective view of the sheathing square shown in FIG. 1; 
     FIG. 3 is a fragmentary front view of the sheathing square; 
     FIG. 4 is a fragmentary side view of the sheathing square; 
     FIG. 5 is a fragmentary rear view of the sheathing square; 
     FIG. 6 is an enlarged fragmentary front view of the T-bar handle of the sheathing square; 
     FIG. 7 is an enlarged fragmentary side view of the handle of FIG. 6; 
     FIG. 8 is an enlarged fragmentary rear view of the handle of FIG. 6; 
     FIG. 9 is an enlarged front perspective view of the handle end of the sheathing square; 
     FIG. 10 is an enlarged rear perspective view of the handle end of the sheathing square; 
     FIG. 11 is a plan view illustrating the use of the sheathing square in establishing a gable cut on full and partial panels; 
     FIG. 12 is a plan view illustrating the use of the sheathing square in establishing a radial cut on a panel; 
     FIG. 13 is an illustrative view of a structure showing the panels formed with the sheathing square; 
     FIG. 14 is a front view of a sheathing square in accordance with an embodiment of the invention; 
     FIG. 15 is a rear view of the sheathing square of FIG. 14; and 
     FIG. 16 is a fragmentary plan view illustrating the use of the sheathing square in establishing a beveled cut on dimensional lumber. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawings for the purpose of describing the preferred embodiment and not for limiting same, FIGS. 1 and 2 illustrate a large panel sheathing square or layout tool  10  for use in the layout of various cut on the large panels typically used in housing construction. The large panels are available in a standard size, generally rectangular 4 feet by 8 sheets and ranging in thickness from about ⅜ inch to ¾ inch. In addition to the layout of transverse and lateral cuts, the tool  10  as described below may be used for the quick, convenient layout of gable, hip and valley, and straight cuts, as well as the layout of circular cuts. 
     In a typical housing configuration, as shown in FIG. 13, the vertical walls will involve basically transverse and vertical cuts. For a gable  12 , gable cuts  22  in the vertical panels  23  take into account the angle of the gable roof  24 . If a gable window is provided, the panel must be appropriately marked and transversely cut  25 , and where a semicircular light  26  is provided, a circular cut  27  must be made. Similarly where the main roof  28  intersects the gable, a valley cut  28  takes into account both the main roof pitch and the gable roof pitch. 
     As shown additionally in FIGS. 3 through 10, each of the foregoing cuts is facilitated by the tool  10 , which comprises an elongated rectangular scale or blade  40  having T-bar handle  42 . The blade  40  is preferably formed of metal with a thickness of about ¼ inch. The blade has a length substantially greater than the length of the short side of the panel, which allows the various pitches for cuts to be made with a single line. A length of about 5½ to 6 feet is preferred. The blade has a width of about 4 inches, which provides sufficient length for indicia thereon to be aligned with the panel sides during layout. The blade  40  has parallel sides  44  and  46 , and a planar front surface  48  and a planar rear surface  50 . 
     The T-bar handle  42  extends mutually perpendicular to the surfaces  48 ,  50  and sides  44 ,  46 . Importantly, the handle  42  has sidewalls  43  having a width the same as the width of the blade  40 . The handle  42  includes a pair of L-shaped sections  52  secured, by mechanical fasteners or bonding, at the ends of the blade  40 . Each section  52  has a base leg  54  secured to the surfaces  48  or  50 , and front leg  56  perpendicular thereto. The front leg  56  has a planar guide surface  58  mutually perpendicular to the surfaces  48 ,  50  and the sides  44 ,  46 . The comers at the guide surface  58  and the side walls  43  at the sides  44 ,  46  establishes laterally spaced side pivot points  60 ,  62  for the layout measurements as described below. 
     A semicircular sleeve  64  is formed at the top of the front legs  56  and includes a semicircular opening  66  extending therethrough for receiving and holding a conventional carpenter&#39;s pencil  68  having a wedge shaped scribing lead  70 . 
     The front surface  44  of the blade  40  is provided with linear indicia  72  and hip/valley indicia  74 . The linear indicia  72  delineate uniformly incremental distances from the guide surfaces for use in establishing and marking linear distances referenced thereto. The hip/valley indicia  74  are in the form of inclined transverse lines  76  extending across the front surface  46  and delineate conventional hip/valley pitches referenced to the pivot point  60  and opposite side of a standard panel. 
     The rear surface  46  of the blade  40  is provided with linear indicia  82 , gable indicia  84 , and secondary pitch indicia  86 . The linear indicia  72  delineate incremental distances from the guide surfaces  58  to use in establishing and marking linear distances referenced thereto. The gable indicia  84  are in the form of inclined transverse lines  88  extending across the rear surface  46  and delineate convention gable pitches referenced to the pivot point  62  and opposite side of a standard panel. The secondary pitch indicia  86  are referenced to the pivot point  60  and used for the layout of conventional pitches on short lengths of material, such as dimensional lumber. 
     A plurality of uniformly spaced series of transverse holes  90  are formed through the blade  40  and referenced to each linear indicia  72  and  84 . Each hole  90  represents an attachment point for determining a radius for a circular cut when appropriately attached to a panel. Inasmuch as the scribed line is located beyond the guide surface  58 , the resulting scribed line is a “heavy” with the circular cut interior thereof and thereby within normal building tolerances. 
     Referring to FIG. 11, for the layout of a gable cut, the worker establishes a layout mark  100  on one long side of a standard 4×8 sheathing panel  102  in accordance with standard practice. The tool  10  is then oriented with the T-bar handle  42  engaging the top side of the panel at the pivot point and the transverse line for the desired pitch on the gable indicia aligned at the layout mark  100  at the bottom side edge thus establishing the angularity for the selected pitch. The line is then scribed along the edge of the bar  40 , and thereafter the panel is cut with an appropriate tool. For partial panels as shown by the dashed lines  110 , the transverse line of the desired pitch is aligned with the mark  110  and the lower edge, and the cut line thereafter inscribed. Inasmuch as the transverse line extends entirely across the width of the bar, a sufficiently wide and clearly identified inscription is provided for alignment with the panel edge to permit a cut in the partial panel within accepted building tolerance. It will be appreciated that similar methodology may be employed for the layout of the hip and valley cuts. 
     Referring to FIG. 12, the radial cuts may be made on a panel  120  by marking a pivot point  122  thereon, attaching the blade  40  to the panel  120  a nail  124  at a hole representing desired radius, and rotating the blade  40  about the nail  124  to inscribe a radius on the panel with the marking point of the pencil. The tool is then removed and the radial cut performed with an appropriate tool. 
     Cut on smaller construction items such as dimensional lumber used in establishing the gables and panels may be laid out using the secondary indicia as shown in FIG.  16 . Therein the pivot point  60  of the T-bar handle  42  is located at a layout mark and rotated until the selected pitch of the secondary indicia  82  is aligned with the side of a construction component  132 , such as 2X lumber. A line is scribed along the side of the blade and the component cut in a conventional manner. 
     For the gable, hip and valley layouts as described above, it will be appreciated that the same are inclined toward the right side of the panel as illustrated in FIG.  11 . Where an inclination toward the left side of the panel is required, the sheet is reversed and the required layout proceeds from the reverse side of the sheet. FIGS. 14 and 15 illustrate another embodiment wherein the layout tool  150  is provided mirror image indicia for the layout. Therein, the front surface of the scale  40  includes a first pitch indicia  152  referenced to pivot point  60  as in the above described embodiment, and a second pitch indicia  154  referenced to the pivot point  62  for making bidirectional inclined hip/valley cut from the front surface of the panel. Similarly, the rear surface of the scale includes a first pitch indicia  162  referenced to pivot point  62  as in the first described embodiment and a second pitch indicia  164  referenced to the pivot point  60  for making bidirectional inclined gable cuts. Supplemental linear  166  may also be included in area of the pitch delineations. 
     In view of the foregoing, it will be appreciated that the layout tool  101  of the present invention can be used to accurately layout the gable, and hip/valley cuts used in construction on large panels, both full and partial sized. Moreover, radial cuts and dimensional lumber cuts can also be accomplished. 
     Having thus described a presently preferred embodiment of the present invention, it will now be appreciated that the objects of the invention have been fully achieved, and it will be understood by those skilled in the art that many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the present invention. The disclosures and description herein are intended to be illustrative and are not in any sense limiting of the invention, which is defined solely in accordance with the following claims.