Patent Publication Number: US-6341427-B1

Title: Window casing installation tool

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention pertains generally to tools used in building construction. More specifically, an easy-to-use hand-held tool enables rapid and precise location and installation of casing about windows or doors during installation. 
     2. Description of the Related Art 
     In the construction of buildings, it is common practice to frame portals such as window openings and doorways with lumber or other structural components. For the purposes of this disclosure, framing will be understood to maintain spacing and provide structural integrity, the framing often extending between an interior surface of a building structure and an exterior surface. Into the framing, a prefabricated door or window may be mounted and rigidly supported relatively quickly and reliably. 
     Because windows and doors can not be specified to an exact size, but instead will vary in dimension somewhat due to tolerances and other factors, and because further shimming may be required for leveling, the framing material is preferred to have a slightly larger opening than the window or door&#39;s outer perimeter. The resulting gap between rough framing and door or window jamb may be relatively large and quite unsightly. Various caulking and insulation may be applied into the gap to improve energy efficiency and building comfort, but this caulk and insulation only further add to the unsightly appearance in the vicinity of the rough framing and jamb. In view of the limitations regarding rough framing and materials adjacent the jamb, it would make little sense to spend the time necessary in preparation and cutting of wall board to be perfectly precise. To save time and to greatly simplify effort, wall board is only rough cut to the approximate dimension of the opening, and may also have an uneven edge. In summary then, the junctions between framing lumber, window and door jambs, and wall boards are quite unsightly. 
     To improve the otherwise unsightly appearance of an opening, it is common practice to finish the opening with decorative trim pieces that conceal the uneven edges, gaps, caulking and insulation. These decorative trim pieces, for the purposes of this disclosure and also commonly in the trade, are referred to as casing. Casing, usually fabricated from wood, is finished on three sides, while the fourth side will be concealed from view and so is commonly left unfinished. For the purposes of this disclosure, casing will not be limited to wood, but is instead defined herein to include plastics, metals and other materials provided for use as decorative trim about a portal. Where casing intersects or joins to form a right angle with a perpendicular casing piece, the intersection is most commonly cut diagonally, so that each casing is cut at a forty-five degree angle to the long side of the trim. The diagonal cut offers an improved appearance, while further insuring coverage and concealment of underlying seams and other unsightly details. 
     Because of the more desirable diagonal cut and the need for a well-fit, highly finished appearance, the preparation of casing for portals is quite difficult and undesirably time consuming. Windows are particularly difficult, since all four casing pieces must align perfectly, though doors also require two well-finished intersections and well spaced reveal about three surfaces. In the prior art, there are a limited number of methods and tools available to address this very old problem. 
     Among the earliest tools used for the installation of casing are rules and squares. These devices are first used to mark the desired location of each component, to next measure from the marks the dimensions that would be necessary, and then to mark raw material for cutting. Once the raw materials are marked, they are cut and placed. As it might appear, there are many opportunities for error and deviation from the exact dimensions using rules and squares. For example, measurement from marks is rarely more accurate than within a thirty-second of an inch, and may deviate by a sixteenth or more, depending upon the skill of the carpenter. Cutting is generally less precise than the measurement, due to kerfs, smoothness or roughness of the kerf, and other similar factors. Final placement will also vary, depending upon the viewing angle of the carpenter. For example, the original mark may have been drawn from a view looking to the right over the rule or square, while placement may occur looking over the casing from the left. This optical variation may be as great as the other possible variants. Finally, during the installation, the carpenter must prevent the casing from moving, which can also be very difficult. 
     While the deviations between measurement, cut and placement may cancel each other in some instances, in other instances these deviations will be additive. That is, if each individual deviation was one-sixteenth of an inch, the resulting total deviation may be one-quarter of an inch. For many applications in carpentry this deviation may not adversely affect the appearance or quality of the work. However, with casing such as used around windows or doors, where the junctions are at forty-five degree angles, these deviations become quite pronounced. Further complicating the issue is the need, with windows, to form four such junctions around the window. All too often, the intersections may be tight at one edge of the trim, such as the inside perimeter, but then be fully separated by the amount of the deviation at the other edge, such as the outer perimeter, resulting in a visual emphasis of the deviation. Unfortunately, the deviation may not be easily taken up at some other location, since all four corners must align at the same forty-five degree angle. This can lead to a frustrating and time-consuming removal of the casing and additional sawing to bring the individual trim pieces to a more exact fit. 
     Other more specialized tools have been developed to help with the installation of casings. For example, Erickson in U.S. Pat. No. 2,473,639, the contents incorporated herein by reference, illustrates a tool for marking a doorjamb to show where the door casing should be placed. Like rulers and squares, the Erickson gauge is quite helpful in marking the proper location for the casing. However, as also required with rulers and squares, the measurements must still be taken from those markings and the cuts made from the measurements, and then the casing applied as best as possible in alignment with the markings. Since the Erickson device leaves a scribe in the doorjamb, it is critical that the casing cover the marking as well, which may be fairly difficult to do consistently at a construction site. 
     More recently, Bear in U.S. Pat. No. 5,349,758, the contents incorporated herein by reference, illustrates a more complex square capable of performing marking in a fashion similar to the Erickson device. In the Bear patent, a pencil may be inserted into one of a number of preselected holes, and the square slid along a door or window jamb to draw a line. While the pencil is an improvement over the scribe of the Erickson device, there is still a need to mark the entire jamb, and subsequently measure and cut the material, and finally very carefully align the material to the marks and secure the material thereto. Furthermore, the Bear square is rather large and unwieldy, making it undesirable to store and transport, and more difficult to use at the construction site than would be preferred. 
     Born in U.S. Pat. No. 3,293,764, also incorporated herein by reference, provides a construction gauge that clamps into doorways and windows, to assist with placement and also, in one embodiment, cutting of window and doorway casing. A spring clamp holds the gauge on both sides of the opening, and edges are provided for a predetermined offset. In one embodiment, a forty-five degree angle is also provided which ensures accurate placement of casing. Nevertheless, while the Born patent offers many advantages, there still remain several limitations. First, because the Born gauge is spring mounted, several gauges are required to be placed, prior to installing any casing. This adds to the purchase price and requires the carpenter to carry more tools, which is undesirable. Additionally, several different types of gauges are required to be used, varying depending upon how many trim strips have been placed. Furthermore, because the gauge is clamped into the wall, it is not possible for the carpenter to guide the casing into alignment throughout the installation. In other words, as a carpenter begins to nail casing to jamb, a nail may undesirably draw the casing one direction or another, leading to a slight angular offset. Unless the carpenter continually looks away from the casing to the ends where the gauges are located, after each nail has been driven home, the carpenter will not know this offset has occurred. By the time the carpenter reaches an end where the gauge is located, the casing may be completely destroyed and worthless. As is known, casing once nailed is usually not worth re-use. Between the different, although similar, types of gauges required to install a single window or door, and the concurrent risk of wasted trim and carpenter&#39;s time, the Born invention is not as beneficial to those in the trade as is desired. 
     Waltrip, Jr. et al in U.S. Pat. No. 4,989,336; Costelloe in U.S. Pat. No. 5,604,988; and Brumley in U.S. Pat. No. 5,737,844 are also incorporated herein by reference. Each disclose various hand-held gauges which are disclosed as having utility in the installation of casings. More recently, air guns have also been developed that enable a carpenter to, with only one hand controlling the gun, drive nails into lumber quickly and efficiently. Rather than having to hold the nail and hammer, which in the past typically required both hands, the air gun allows a carpenter one hand free for holding or adjusting the work which is being nailed. 
     In spite of the many beneficial advancements in the art, there continues to be a need for a small and portable tool which will assist a carpenter in the otherwise difficult installation of window and door casing. 
     SUMMARY OF THE INVENTION 
     In a first manifestation, the invention is a window casing installation tool for accurately aligning casing to first and second generally planar faces of a portal jamb. A first generally planar surface is provided on the tool for abutting with the first jamb face, and a second generally planar surface is provided on the tool for abutting with the second jamb face. A third generally planar surface is provided for abutting with the casing piece, and is spaced from the first tool surface by a predetermined reveal amount. A fourth generally planar surface abuts with the casing at the diagonal cut edge, extending at a one hundred and thirty-five degree angle from the third surface. The tool may be engaged with the portal jamb and casing engaged with third and fourth surfaces, to precisely and repeatedly locate casing relative to jamb. 
     In a second manifestation, the invention is a method for installing trim about a portal. The steps include: placing a guide against the jamb; moving the guide along the jamb until the guide engages a corner of the portal; abutting the trim against the guide; and fastening the trim relative to the portal. 
     In a third manifestation, the invention is a hand-held tool for accurately locating window casing during installation. First and second rectangular frames each surround a third frame. The third frame extends beyond the first and second frames along three faces of a rectangle. A protrusion on the third frame extends from what would otherwise be the fourth rectangular side in a triangular configuration, with one edge of the protrusion extending at a one hundred and thirty-five degree angle from one edge of the otherwise rectangular third frame. There is a central opening coextensive through each of the three frames through which a hand may pass and grasp the tool. The hand-held tool may be used to measure and locate a reveal using any of the three rectangular edges of the third frame in conjunction with an associated edge of either the first or second frame. The protrusion from the third frame may be used in conjunction with the other features of the invention to locate the end of a pre-cut casing strip adjacent a portal in all three dimensions. 
     OBJECTS OF THE INVENTION 
     A first object of the invention is to provide a relatively small hand held tool which will assist a carpenter in the installation of casing and other trim, without requiring substantial space for storage or being unwieldy at the job site. A second object of the invention is to enable the carpenter to securely grasp and manipulate the tool, allowing substantial force to be applied through the tool, as required. A further object of the invention is to include within the tool a predetermined measure of offset, also sometimes referred to as reveal, and also a predetermined forty-five degree angle for accurate placement of a single piece of casing adjacent a portal. Another object of the invention is to continuously ensure accurate placement during installation, by sliding the tool along a jamb surface, thereby enabling rapid installation using modern tools such as nailing guns. These and other objects are accomplished in the preferred embodiment, which will be better understood when considered in conjunction with the appended drawing figures. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates a preferred embodiment casing installation tool in accord with the invention, from a projected view. 
     FIG. 2 illustrates the preferred embodiment from a top plan view. 
     FIG. 3 illustrates the preferred embodiment from a side plan view . 
     FIG. 4 illustrates the use of the preferred embodiment in installing casing. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Casing installation tool  100  is designed from three layers of material, which may be formed as a unitary assembly or which may each be formed separately and then assembled together. The layers may be formed from a variety of materials, including plastics, metals, wood, or other material with little restriction. However, in the most preferred embodiment, a clear plastic such as Acrylic, Lucite, or polycarbonate offers added advantage where scribe marks, discussed herein below, are used, due to the inherent transparency of the material. Top and bottom layers  110  and  120  sandwich center layer  130 . Extending entirely through each of the three layers is a hole  116 , which in the preferred embodiment is rectangular, and sized to comfortably accept a person&#39;s hand. At the entrance to hole  116 , the edge  115  is beveled or slightly rounded, to improve comfort and ease of use. 
     Center layer  130  is designed to extend slightly beyond layers  110  and  120 , in the preferred embodiment by three-sixteenths of an inch on each of the three regular rectangular sides of layer  130 . More specifically, edge  131  extends three-sixteenths of an inch from edges  111  and  121 , while edge  132  extends three-sixteenths of an inch from edges  112  and  122 , and so forth. This is the preferred amount for set-back or reveal of window casing around the window jamb, though this distance may be varied depending upon the preferences of the tool designer or casing installer. In alternative embodiments, center layer  130  may extend by more or less amounts. Furthermore, different edges may be designed to different predetermined offsets. So, for example, while edge  132  extends by three-sixteenths, edge  131  in an alternative embodiment might only extend one-eighth of an inch. Each of the three sides might extend by different amounts, though, in the preferred embodiment tool designed primarily for window casing installation, three-sixteenths on each side allows the user to grasp and apply the tool from many different directions relative to the work and still get the prescribed distance. 
     As a visual aid to assist with proper placement, guiding and, where required, marking, small scribes  140 - 147  are provided in each major surface of layer  130 . Scribes  140 - 147  are placed adjacent each planar edge of layers  110  and  120 , and extend parallel therefrom. As a result, there is easy visual indication of alignment with edges on layer  10  or  120 , such as edges  112  or  121 . In addition, scribes  140 - 147  also provide a means for marking various points around an opening or portal, as desired, at the appropriate predetermined three-sixteenths of an inch offset. 
     A large angular extension  135  is provided that enables rapid marking, when desired, and, very importantly, also enables accurate placement of casing around a portal. Extending from edge  132  and at a one hundred and thirty-five degree angle thereto, is edge  136 . Ruler graduations may be provided along edge  136 , or along one or more portions of a major surface of extension  135 , such as shown by ruler scale  137  in the preferred embodiment. Ruler scale  137  enables tool  100  to serve a more diverse set of needs, including standard rule and marking functions. As noted, these or similar graduations may be provided along any of the surfaces of tool  100 , and in some cases will be desirable, though the marking of extension  135  provides extra synergism in these otherwise difficult to calculate angularly offset directions. 
     A small notch  138  may most preferably be provided at the end of extension  135 , which is preferably cut three-sixteenths of an inch. This small notch allows an installer to measure and position small or irregular components, or quickly measure a reveal without covering a large area. Most desirably, the juncture between edges  132  and  136  occurs at the same three-sixteenths of an inch from layers  110  and  120 . This way, when casing strip  250  is to be installed on wall  230  and jamb  210 , as shown in FIG. 4, there will be no error introduced in the placement. 
     The process of installing casing is simple and almost intuitive, even from installation of the very first casing strip. First, tool  100  is pressed against window jamb  210 , with, for this example, edge  122  pressed against jamb  210  and layer  130  with edge  132  overlapping jamb  210 . Tool  100  will be pressed into the corner between jamb  210  and jamb  220  by manually applying force to tool  100  in a direction as shown by line  150 , so that the two perpendicular jambs  210 ,  220  are both overlapped by layer  130 . Next, casing piece  250  will be slid into tight alignment with tool  100  and wall  230 . The shorter edge  252  of the two long edges of casing piece  250  may be abutted against edge  132 , and angled edge  256  of casing piece  250  is then abutted against edge  136 . This process of abutting casing piece  250  against both edge  132  and edge  136  ensures casing piece  250  is located accurately in all three dimensions, with wall  230 , edge  136  and edge  132  each forming a stop against which casing piece  250  may be held. Next a nail gun or other tool will be used to apply a first fastener to casing  250 . Once casing  250  is fixed relative to wall  230 , tool  100  may be rotated so that extension  135  is no longer engaged with casing  250 . Tool  100  may then be slid downwards, as indicated by arrow  152 , and nails or other fasteners may be inserted through casing  250  to further anchor casing  250  to wall  230  and jamb  210 . With the use of a nail gun, regardless of whether the gun actuation is electric, pneumatic, explosive, mechanical lost motion or other, and tool  100 , a single installer can slide tool  100  and simultaneously affix casing  250 , thereby ensuring proper placement throughout the entire installation. 
     While the foregoing details what is felt to be the preferred embodiment of the invention, as required by the statutes, no material limitations to the scope of the claimed invention is intended. While a limited number of alternative embodiments have been referenced herein, additional features and design alternatives will be obvious to one of ordinary skill in the art upon review of the present disclosure, and these alternatives are considered to be incorporated herein. For example, the invention is illustrated in the preferred embodiment as being constructed from three layers of material. The working surfaces of tool  100  only require two distinct parallel but offset edges, and so only two layers are required for a fully functional tool. Nevertheless, three layers are preferred, to allow tool  100  to be manipulated right or left handed, from any of a variety of directions, thereby ensuring the easiest use regardless of the handedness or other preference of each individual user. 
     Therefore, the scope of the invention not limited by the foregoing description, and is instead set forth and particularly described in the claims herein below.