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BACKGROUND 
     The framing of a residential house with a pitched roof presents several problems well known to carpenters. One of these problems occurs in framing the end or gable of a pitched roof where vertical studs extend upwardly from a horizontal sill plate to the inclined rafter boards. Before assembling the studs with the sill and the rafters, both the sill and the rafters must be marked with lines indicating where each stud must be nailed in order for the stud to be perfectly plumb in its attachment between the sill and the rafter. 
     To accomplish this measuring and marking task in the past, a carpenter might use a common tape measure or perhaps a layout tool, or layout stick as it is commonly called, such as disclosed in the U.S. Pat. No. 3,169,320 to Currie. The layout tool of this patent has an elongated flat header plate and a plurality of shorter, flat branch plates. The branch plates are integral with the header plate, are spaced therealong, and extend outwardly from the header plate at right angles thereto. The discloses branch plates are at various spacings, specifically sixteen inches, twenty-four inches, thirty-two inches, and forty-eight inches from the endmost branch plate. 
     More commonly, the layout stick that is commercially available and used by many carpenters has these branch plates equally spaced along the header plate on either sixteen inch centers or twenty-four inch centers since these are the most common spacings of studs in residential construction. In any case, the branch plates of known layout sticks are integral with and in fixed space relation along the header plate. 
     In use of this well known layout stick, the carpenter first places the stick on the sill and marks it with lines indicating where the studs are to be nailed. Insofar as the rafters are concerned, however, the tool loses its utility since the stud marks on the rafter cannot be spaced the same distance apart as the marks on the sill. As will be understood, because of the rise of the roof, the spacing between adjacent studs as measured along the rafter, i.e. the hypotenuse of the triangle, will be slightly greater than the spacing between adjacent studs as measured along the sill, i.e. the base of the triangle. For example, if the studs are spaced along the sill on sixteen inch centers, and if for example the rise of the roof is three inches, the studs must be spaced along the rafter on sixteen and one eighth inch centers. The carpenter must therefor calculate this difference and then use another tool, i.e., a tape measure, to mark the rafters. Apart from the inconvenience, this procedure is prone to error in having to make a calculation after marking the sill and then in having to use a different tool to mark the rafters. 
     SUMMARY 
     A construction tool and method for its use in laying out stud marks are provided. The tool is adjustable and is especially suited for laying out stud marks on a rafter of a pitched roof so as to be aligned with the corresponding stud marks on a sill beneath the rafter. The tool includes an elongated measuring member; stud-marking members attached to the measuring member in spaced, transverse relation therealong, at least one of the marking members being adjustable along the measuring member; measurement indicia on the measuring member that enables the spacing between the marking members to be set; and conversion indicia on one or more of the members that sets forth the relationship among various roof rises and stud spacings on sills and rafters. The method involves laying out markings on the sill and rafter boards with the tool including the steps of placing the layout tool along a first of the boards, e.g., either a sill or a rafter, with the marking members in a first predetermined spaced relation to each other depending on the desired spacing between marks to be made along the first board; marking the first board with marks at the locations of each of the marking members; adjusting the spacing between the marking members to a second predetermined spaced relation to each other depending on the desired spacing between marks to be made along the second board; and marking the second board, e.g., either the sill or the rafter depending on which board was first marked. with marks at the adjusted locations of each of the marking members. 
     An object of this invention is to provide an adjustable layout tool and a method for its use in laying out stud marks in a building construction. 
     Another object is to facilitate laying out stud marks on sills and rafters of a building with a pitched roof. 
     An additional object is to minimize the time required to layout stud marks on sill and rafter boards and other construction elements. 
     A further object is to provide a single adjustable tool for making stud marks on inclined rafters that match corresponding stud marks on the sill under the rafters. 
     Another object is to provide a single tool for measuring and marking sill and rafter boards that allows either board to be marked first and that is quickly adjustable to mark the other board second. 
     An additional object is to enable sills and rafters and other construction elements to be simultaneously laid out by using different adjustable layout tools as provided by the subject invention, each tool being adjusted for the specific measurements required. 
     Yet another object is to reduce error in making stud marks on the rafters of a pitched roof so that they exactly match corresponding stud marks on the sill from which the studs extend upwardly to the rafters. 
     An additional object is to provide a tool that can easily be adjusted for making stud marks on the rafters of a pitched roof after having made stud marks on a sill so that the marks on the rafters will match those on the sill and so that the studs that support the rafters from the sill will be perfectly plumb. 
     Still another object is to facilitate the adjustment of a layout tool for making matched stud marks on a sill and rafters of a pitched roof in accordance with the rise of the roof. 
     A still further object is to provide an adjustable layout tool for laying out stud marks that is durable in construction, dependable to use, economical to manufacture, and compatible with tools commonly used by carpenters for the intended purposes. 
     A feature of the subject tool is that it is magnetically attracted to the steel framing members to facilitate its use in marking stud locations. 
     These and other objects, features and advantages of the present invention will become apparent upon reference to the following description, accompanying drawings, and appended claims. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of the adjustable layout tool of the present invention shown in its retracted or closed position. 
     FIG. 2 is a plan view of the adjustable layout tool shown in FIG. 1 but with one of the end stud-marking arms in its fully extended or open position. 
     FIG. 3 is a side elevation of the tool shown in FIG. 1, looking at the tool as if it were rotated ninety degrees on its longitudinal axis from the position shown in FIG.  1 . 
     FIG. 4 is a somewhat enlarged transverse section taken on line  4 — 4  in FIG.  3 . 
     FIG. 5 is a somewhat enlarged end elevation of the subject tool looking at the tool from the right end of either FIG. 1,  2  or  3 . 
     FIG. 6 is a somewhat enlarged fragmentary plan view of the central portion of the subject tool showing the one of the end stud-marking arms in a partially extended or open position and also showing measurement indicia on the measuring bar and conversion indicia on the center stud-marking arm. 
     FIG. 7 is a diagram giving an example of sill rafter, and roof rise relationships set forth in the conversion indicia shown in FIG.  6 . 
     FIG. 8 is an isometric view of a sill and rafter and interconnecting studs in a building construction and showing how the subject adustable layout tool is positioned for making stud marks along the sill and rafter. 
    
    
     DETAILED DESCRIPTION 
     With reference to FIGS. 1,  2 , and  3 , the adjustable layout tool or stick is generally identified by the number  20 . The tool is preferably made of metal, such as aluminum, but may be made of other materials such as a durable hard plastic. The tool includes a elongated measuring bar  22  having a center portion  24  that is channel-shaped in cross section, as shown in FIGS. 4 and 5, and terminates in opposite end edges  26 . The measuring bar also includes opposite end portions  28  of flat stock that extend endwardly from the end edges of the center potion and are of a somewhat reduced width as compared with the width of the center portion. A measurement indicia or scale  30 , such as an English measurement scale with inch markings, is placed on the top face of each end portion  28 , as shown on the right side of the tool in FIGS. 2 and 6. A metric scale could equally as well be used. It will be understood that the left end portion  28 , not fully shown in FIGS. 1 and 2, is of the same width dimension and has the same measurement indicia or scale as the right end portion shown in FIG.  2 . This measurement indicia or scale will be described in more detail as the description proceeds, but it is here noted that the indicia or scale  30  as well as the other indicia set forth below may be applied to the tool  20  in various ways not involved with the present invention, that is, by inscribing or etching into the metal, by adhesive label, by imprinting or engraving, or by any other suitable method. 
     The subject tool  20  (FIGS. 1,  2 ,  3 , and  5 ) also includes a center stud-marking arm  40  of flat stock, as best seen in FIG.  3 . The center stud-marking arm is preferably welded to the center portion  24  of the measuring bar  22  equidistantly between the end edges  26  and in right angular relationship to the center portion. Alternatively but less desirably, the center arm could be fastened to the center portion with suitable fasteners. Moreover, although a fixed right angular relationship between the center arm and the center portion is preferred, the connection between this arm and center portion might be adjustable as by a pivoted connection with a fastener to fix its position, although this is also less desirable. As shown in FIGS. 1 and 2, the center arm has longer and shorter wings that extend in both directions from the center portion, the longer wing being about twice the length of the shorter wing. Furthermore, the center stud-marking arm has straight edges  41  that are in right angular relationship to the center portion of the measuring bar  22 . The reason for these different dimensions will be subsequently explained. 
     The tool  20  also includes end stud-marking arms  50  (FIGS. 1-3,  5  and  6 ) of flat stock and of the same size and shape as the center arm  40 . Elongated channel-shaped mounting bars  52  connect the end stud-marking arms  50  to the measuring bar in a manner and relationship to be described. More specifically, the mounting bars have the same channel-shaped cross-section as the center portions  24  of the measuring bar  22  and have flanges spaced apart slightly greater than the width of the end portions  28 . The mounting bars individually telescopically fit over the end portions  28  of the measuring bar so that the webs of the mounting bars slidably overlay the measurement indicia  30  on the top faces of the end portions  28  and so that the flanges of the bars slidably embrace the sides of the end portions  28 . As such, the mounting bars have end edges  54 , that are in opposed relation to the end edges  26  of the center portions  24 , and outer mounting ends  56 . 
     The end stud-marking arms  50  (FIGS. 1-3,  5  and  6 ) are individually secured, preferably by welding, to the outer ends  56  of the mounting bars  52  and in right angular relationship to their respective mounting bars and thus to the measuring bar  22  as assembled. Alternatively but less desirably, each end arm could be fastened to the end of its bar with suitable fasteners, as described with the center arm  40  and the center portion  24 . Again, although a fixed right angular relationship between each end arm and its mounting bar is preferred, the connection between each arm and bar might be adjustable, such as by a pivoted connector with a fastener to fix its position, although this is also less desirable. Each end marking arm is structurally identical to the center marking arm and is mounted on the mounting bar in spaced, parallel, coplanar relation with the center arm and so that each end arm has longer and shorter wings that extend in both directions from the center portion, in the same directions and with the same lengths as the center marking arm. Furthermore, each end stud-marking arm has straight edges  51  that are in right angular relationship to the measuring and mounting bars and parallel to the straight edges  41 . 
     In addition, each marking arm  40  and  50  (FIGS. 1 and 2) has a width equal to the narrower width of the cross section of the typical stud or framing member used in building construction in the United States, namely, a two-by-four, so that in the disclosed embodiment, this width is nominally two inches, although slightly less to correspond with finished lumber. Further, as mentioned, each marking arm has longer and shorter wings. The lengths of these wings correspond respectively to the wider and narrower dimensions of the cross section of the studs typically used. The invention is, of course, not limited to the particular dimensions or measurement system set forth above, and such dimensions may be adjusted to suit the framing member for which the marking is being made. The principle of having the marking members sized to fit the framing member on which the tool  20  is mostly to be used is incorporated in the preferred embodiment of this invention. 
     Each mounting bar  52  (FIGS. 1 and 2) is of substantially the same length as its respective end portion  28  of the measuring bar  22 . Thus when the end edge  26  of each center portion  24  and the end edge  54  of its adjacent mounting bar  52  are in engagement, the extreme outer end of the corresponding end portion  28  is coterminus with its adjacent outer end  56  of the mounting bar. The web of each mounting bar has an elongated slot  58  that extends longitudinally of its mounting bar throughout a substantial length thereof and that overlies the top face of its associated end portion. Bolts  60  are secured to the top faces of the end portions  28  of the measuring bar  22  and have threaded shanks extending outwardly from the bar and through the slots. Wing nuts  62  are threaded on the shanks of the bolts and are threadable down into tight engagement with the webs of the mounting bars  52  so that the mounting bars can be held in the selected positions along the measuring bar to which they are adjusted. 
     Furthermore, a magnetic strip  65  (FIGS. 1-5) is applied to the outside surfaces of the flanges of the center portions  24  of the measuring bar  22  and the flanges of the mounting bars  52 . In this way, when the tool  20  is used on steel studs, rafters, or other framing members, the tool will be attracted to and lay flat against the framing member and insure more reliable markings. 
     It will thus be understood that each mounting bar  52  (FIGS. 1 and 2) is telescopically, slidably adjustably attached to its respective end portion  28  of the measuring bar  22  for movement between a closed or retracted position (FIG.  1 ), with the adjacent end edges  26  and  54  in engagement, and a plurality of open or extended positions, one of which is shown in FIG. 2, wherein said adjacent end edges are in spaced relation to each other. Each mounting bar is movably adjustable independently of the other mounting bar, although in typical use both mounting bars are both adjusted inwardly by the same distance, or both adjusted outwardly by the same distance, as will be seen. In order to adjust the mounting bars on the measuring bar, the wing nuts  62  are loosened to permit the described sliding action. When the mounting bar or bars are in their desired closed or opened position, the corresponding wing nut or nuts are tightened thereby securing the mounting bar or bars in the desired positions. In general, it will be understood that adjustment of the mounting bars on the measuring bar effects an adjustment of the spacing between the center stud-marking arm  40  and the end stud marking arm or arms  50  in a manner to be more fully described hereinafter. 
     The center-to-center spacing (FIGS. 2 and 6) between the center arm  40  and either end arm  50  is indicated by the inch marking on the measurement scale  30  that is aligned with the end edge  54  of the respective mounting bar. When the mounting bars  52  are in their completely closed positions, as shown in FIG. 1, the spacing between the center arm and each end arm is the same and this spacing is shown by tool size indicia  70 , a single number, preferably located in two places on the center portion  24 , that is, adjacent to each end edge  26 . This number indicates the common, or at least the desired, center-to-center spacing between adjacent studs along the sill of a building. This number also indicates the minimum center to center spacing between adjacent marking arms of the tool  20 . As is well known the typical spacing between adjacent studs along the sill in US residential building construction is sixteen inches on center. Accordingly, in the disclosed preferred embodiment of the subject tool, the number “16” appears as the indicia  70 , and the size of the tool is a No. 16 for a sill stud spacing of sixteen inches on-center. 
     Moreover, the end edges  26  (FIGS. 2 and 6) and their indicia  70  are parts of the scales  30  in that the minimum spacing between each end and and the center arm is indicated by the indicia  70 , whereas greater spacings are indicated by the respective scale  30 . In other words, each end edge  26  is the minimum inch marking on its corresponding scale  30 . That is, each scale  30  actually begins with each end edge  26  and continues from left to right on the right side of the tool and from right to left on the left side of the tool, as the tool is seen in FIG.  2 . Thus, since the disclosed embodiment is a sixteen inch tool, each scale starts with inch markings representing sixteen inches and continues with major inch markings at “17”, followed by “18”, “19”, “20”, and so on to “24”, from left to right at the right end of the tool and from right to left at the left end of the tool, as seen in FIG.  2 . When the end edge  54  is at “17”, for example, the center-to-center spacing between adjacent stud-marking arms is  40 ,  50  is 17″, that is, one inch greater than in the closed position, and so on at each inch marking as the mounting bars  52  are moved outwardly on the end portions  28 . In between major inch markings, of course, the scale is divided in the same manner as a typical carpenter&#39;s rule or ruler so that wherever the end edge  54  is placed, the scale reads the center-to-center distance between the corresponding end arm and the center arm. Of course and as mentioned, although the English system is shown as the indicia, the metric system could be used. Moreover, the exact number of fractional divisions between the major measurement markings is optional and may be varied as desired. 
     The subject layout tool  20  (FIGS. 1,  2  and  6 ) also includes indicia  80  in the form of a conversion table preferably appearing on the center portion  24  of the measuring bar  22 . Because of the small scale of FIGS. 1 and 2, this table is generally represented by a rectangle just to indicate its position. On the other hand, FIG. 6 shows the conversion table in full detail. This table shows the relationship between various rises of a pitched roof and the center-to-center spacing between stud markings on the rafters of such a roof for a given on-center stud spacing on the corresponding sill. 
     For a more detailed explanation of this conversion table  80  (FIG.  6 ), reference is also made to FIGS. 7 and 8 where a sill is indicated by the number  90 , a rafter by the number  92 , and vertical studs by the number  94 . In order for the studs to be erected in perfectly plumbed, vertical positions, as shown in FIG. 8, the center-to-center stud spacing on the rafter must be slightly greater than the center-to-center stud spacing on the sill. This relationship is a matter of triangulation as shown in FIG.  7 . As there illustrated, if the stud spacing on the sill is 16″ on-center, for example, the stud spacing on the rafter will be X″ on-center depending on the rise of the roof. As shown in FIG. 7, for a roof rise of 5, meaning five inches over a span of twelve inches, the stud spacing along the rafter, or X, equals 17¼″ on-center. 
     Since the conversion table  80  (FIGS. 6,  7  and  8 ) shows the relationship among rafter stud spacing and roof rise for a given sill stud spacing, the table is different for different sizes of tools  20 . In the preferred embodiment shown and described, the tool is a No. 16, thereby indicating a sill stud spacing of sixteen inches on-center, so the table  80  provides the correct rafter stud spacings for common roof rises for sixteen inch sill stud spacings. If the tool is for a different sill stud spacing, such as for example twenty-four inches on-center, then the scale  30  as well as the dimensions set forth in the conversion table  80  will be different from that illustrated in FIG.  6  and be related to the particular sill stud spacing of twenty-four inches on-center. Alternatively, the tool could be for multiple sizes, for example, a No. {fraction (16/24)}, and be supplied with multiple conversion tables, for example, one for sixteen inches on-center and one for twenty-four inches on-center, with the table  30  accommodating sill and rafter measurements for both sixteen inches and twenty four inches on center. 
     DESCRIPTION OF THE METHOD AND USE OF THE TOOL 
     The method of using the subject adjustable layout tool  20  for making markings on a sill  90  and rafter  92  of a building under construction or remodel is now described, with particular reference to FIGS. 6-8. For illustrative convenience, FIG. 8 is a combined figure intended to illustrate several different stages of the subject method both for new construction and remodeling. The figure shows both the erected finished assembly of a sill, rafter and studs and two of the subject tools in place. In contrast, especially for new construction, the subject tool would be used on the ground on the individual sill and rafter before these framing members are assembled with the studs, since the very purpose of the tool is to facilitate such assembly. For a remodel job, however, the tool may be used in more of the setting and manner shown in FIG.  8 . 
     Assuming that the sill  90  (FIG. 8) is to be marked first for studs  94  at sixteen inches on center, the tool  20  is adjusted to its retracted position, as shown in FIGS. 1,  3 , and  8 , and the wing-nuts  62  are tightened so that adjacent marking arms  40  and  50  are sixteen inches apart, center-to-center to use the specific example shown in the drawings. The tool is then placed along the sill, as shown in FIG. 8, so that the measuring bar  22  is along and in engagement with the side of the sill and so that the stud-marking arms  40  and  50  are lying on top of the sill. The longer wings of the marking arms overlay and extend the full width of the wider dimension of the sill. It will of course be understood that the tool is placed at one end of the sill at the location where the initial stud-markings are to be made. Stud marks, as indicated at  96 , are then scribed along both straight edges  41  of each marking arm on the sill thereby marking the outlines of the exact locations on the sill where the studs are to be placed and nailed. The tool is then picked up and moved to the next successive location and positioned against the sill in the same manner as shown in FIG.  8  and as described above, whereupon the successive stud marks are made along the straight edges  41 . In this manner, the tool is moved along the sill until stud marks have been made throughout as much of the length of the sill as is desired. 
     After the sill  90  (FIG. 8) has been marked with stud marks  96 , the tool is adjusted for marking the rafter  92 . For this purpose, reference is made to the conversion table  80  (FIG. 6) to determine what spacing is to be used between the studs  94  on the rafter for the particular roof involved. Assuming that the roof rise is known to be 5, the table shows that the rafter stud spacing must be 17¼″, so both wing nuts  62  (FIGS. 1,  2  and  6 ) are loosened and both mounting bars  52  are slid outwardly on the end portions  28  until the end edges  54  are aligned with the 17¼″ markings on the respective scales  30  whereby adjacent marking arms  40  and  50  are now 17¼″ apart center-to-center. The wing nuts  62  are then tightened so as to secure the mounting bars in their adjusted positions. 
     The tool  20  (FIG. 8) is then laid on the rafter  92  in the same manner as described above with regard to the sill  90 . Although the tool is shown in FIG. 8 upside down and against the rafter of an existing structure, it will be understood, as explained above, that for new construction, the rafter at this point is unassembled and still on the ground. Thus, for new construction, the rafter and tool of FIG. 8 should be visualized as inverted and in a horizontal attitude for marking purposes. For a remodel, however, the rafter and tool would be used as shown in FIG. 8, albeit without the studs  94  in place. Regardless of the orientation, the rafter is marked with lines such as at  98  along each marking edge  41  and  51 , just like the sill  90  as described above, except that now the tool has been adjusted to mark the stud locations at the exact spacing required on the rafter consistent with the sill markings and the roof rise. 
     After the sill  90  and rafter  92  (FIG. 8) have been marked with the stud marks  96  and  98 , the wall section, as  100 , can be assembled with the studs  94  extending between sill and the rafter. The studs are placed within corresponding marks made on the sill and the rafter and are nailed in place. When the wall is erected, the studs will be vertical and in perfectly plumbed relationship since with the subject tool  20 , the corresponding stud marks have been precisely made on both the sill and the rafter. 
     From the foregoing it will be understood that an adjustable layout tool and method have been shown and described that have several advantages. The tool and method facilitate laying out stud marks on sills and rafters of a building with a pitched roof while minimizing the time and tools to accomplish the task and while insuring greater accuracy of the stud locations. Because of its adjustability and ease of calculating stud spacings, either the sill or the rafter board can be marked first and the other marked second after quickly adjusting the tool so that the marks on the second board match the marks on the first board. Alternatively, the sills and rafters and other construction elements can be simultaneously laid out by using different adjustable layout tools, each tool being adjusted for the specific measurements required. In addition, the adjustable layout tool for laying out stud marks is durable in construction, dependable to use, economical to manufacture, and compatible with tools commonly used by carpenters for the intended purposes. Furthermore, when working with steel sills and rafters, the tool is magnetically attracted to the framing member to facilitate its use. 
     Although a preferred embodiment of the present invention has been shown and described, various modifications, substitutions and equivalents may be used therein without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.

Summary:
A construction tool and method for its use in laying out stud marks. The tool is adjustable and is especially suited for laying out stud marks on a rafter of a pitched roof so as to be aligned with the corresponding stud marks on a sill beneath the rafter. The tool includes an elongated measuring member; stud-marking members attached to the measuring member in spaced, transverse relation therealong, at least one of the marking members being adjustable along the measuring member; measurement indicia on the measuring member that enables the spacing between the marking members to be set; and conversion indicia on one or more of the members that sets forth the relationship among various roof rises and stud spacings on sills and rafters. The method involves laying out markings on the sill and rafter boards with the tool including the steps of placing the layout tool along a first of the boards, e.g., either a sill or a rafter, with the marking members in a first predetermined spaced relation to each other depending on the desired spacing between marks to be made along the first board; marking the first board with marks at the locations of each of the marking members; adjusting the spacing between the marking members to a second predetermined spaced relation to each other depending on the desired spacing between marks to be made along the second board; and marking the second board, e.g., either the sill or the rafter depending on which board was first marked, with marks at the adjusted locations of each of the marking members.