Abstract:
An all-in-one combination layout tool is provided for marking center lines for spacing studs, marking rip lines, marking cut lines for roof rafters and staircase stringers, and other purposes. The tool comprises a rectangular base plate, an elongate locator bar with a rounded pivot corner, and two connectors to connect the locator bar to the base plate in a variety of configurations. The base plate includes multiple “pivot” points for pivotally connecting the locator bar, two strategically-placed arcuate slots for marking or making angle cuts, and two strategically placed parallel slots for configuring the tool to mark or make rip cuts. Angle markings are provided on two adjacent edges of the base plate, and 1/16-inch markings are provided on the opposite adjacent edges. The base plate is planar and has no enlarged flange or lip that would hinder its use in laying out staircase stringers.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to layout tools, and more particularly to so-called “squaring” tools for marking cut lines on workpieces. 
     BACKGROUND OF THE INVENTION 
     There are several different types of layout tools that have been designed to assist carpenters in framing and construction of roof rafters, staircase stringers, spacing studs, marking rip lines, and the like. Carpenters often use framing squares for laying out staircase stringers and spacing studs. Perhaps the most famous tool for laying out roof rafters is the Swanson Speed Square offered by the Swanson Tool Co. of Frankfort, Ill. The speed square is shaped like a right-angle triangle with an enlarged lip or flange extending along one of the legs of the triangle. 
     The enlarged lip or flange of the speed square is a critical part of the speed square, for the speed square is positioned on a workpiece by pressing the speed square&#39;s lip against the workpiece straight edge. But the enlarged lip or flange makes the speed square, without an awkward accessory, unsuitable for laying out staircase stringers. Swanson Tool Co. offers a “Big 12 Speed Square” that combines an accessory that it refers to as a “layout bar” with a triangular speed square, for use in laying out staircase stringers. The layout bar, however, is not used to angularly align the speed square against a stringer. Rather, the layout bar simply adds a lip along the other “leg” of the right-angle triangle so that the speed square can be used to layout staircase stringers. Not only are two connectors required to connect the layout bar to the speed square, but also two separate “stop pegs” are required to configure the tool for laying out stringers. This particular product, in the inventor&#39;s opinion, is awkward, difficult, and time-consuming to use. 
     SUMMARY OF THE INVENTION 
     The inventor has developed an all-in-one combination layout tool that combines and extends the functions of a so-called “speed square” and a “framing square.” It is easy to use and configure for different purposes, including marking center lines for spacing studs, marking rip lines, and marking cut lines for roof rafters and staircase stringers. It is also easier to mark accurate and consistent cut lines with this new layout tool than with prior art devices. 
     The tool comprises a rectangular base plate, an elongate locator bar with a rounded pivot corner, and just two connectors to connect the locator bar to the base plate in a variety of configurations. The base plate includes multiple “pivot” points for pivotally connecting the locator bar, two strategically-placed arcuate slots for marking or making angle cuts, and two strategically placed parallel slots for configuring the tool to mark or make rip cuts. Angle markings are provided on two adjacent edges of the base plate, and 1/16-inch markings are provided on the opposite adjacent edges. The base plate is planar and has no enlarged flange or lip that would hinder its use in laying out staircase stringers. 
     The locator bar is far more useful than the so-called “layout bar” of the “Big 12 Speed Square.” For one thing, the locator bar can function by itself as a ruler, straight edge, or gauge. Second, the locator bar&#39;s “measuring edge” replaces the need for a “lip” on base plate. Either a rounded pivot corner, or the entire “measuring edge” of the locator bar is pressed against a workpiece straight edge in order to position the layout tool for marking or making cut lines. Third, the locator bar can be locked into a selected angular position for very accurate and stable positioning of the layout tool against a workpiece. When configured this way, the layout tool is so stable that it can be used directly as a saw guide - eliminating in many cases the need to mark a cut line. With the tool&#39;s locator bar locked into a fixed angular position with respect to the base plate, the tool can be placed against a workpiece while a circular saw is moved against an edge of the base plate, making an accurate angular cut. Fourth, the locator bar can be oriented to mark not only selected cut angles, but also staircase stringer “rise” and “run” cut lines. Fifth, the locator bar can be positioned parallel to the longitudinal edge of the base plate, for easy marking or cutting of “rip” lines. Sixth, the locator bar is longer than the either the width or length dimensions of the base plate. This allows the layout tool to be configured as either an 8-inch by 16-inch framing square or as a 12-inch by 16-inch framing square. 
     Furthermore, the rectangular shape of the base plate facilitates accurate angle markings and cut lines along four different edges, and more specifically, along two sets of parallel edges. As illustrated in the accompanying drawings, this configuration provides a number of advantages over prior art tools. One significant advantage is that it the tool does not have to be reconfigured to layout a staircase stringer. Based on the inventor&#39;s own experience, it dramatically reduces the time needed to layout staircase stringers—by as much as 90%. It also enables the tool to mark angle cuts from between 0 and 180 degrees, without flipping the tool. 
     Part of what makes the present invention so innovative and remarkable is its elegant simplicity. It comprises only a few different parts and is easy to use. But despite its simplicity, the present invention provides numerous advantages over more awkward prior art tools. Those of ordinary skill in the art will appreciate these and other improvements described further below in the detailed description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a drawing of one embodiment of the components of the layout tool. 
         FIG. 2  illustrates the layout tool pivoted on a workpiece at a selected pivot angle to mark a cut line. 
         FIG. 3  illustrates the layout tool pivoted on the workpiece to mark a second cut line having an angle to the perpendicular equal to a second selected pivot angle. 
         FIG. 4  illustrates the layout tool of  FIG. 3  to mark a third cut line having an angle equal to 90 degrees minus the second selected pivot angle. 
         FIG. 5  illustrates the layout tool with its locator bar locked in position to facilitate more accurate angle markings. 
         FIG. 6  illustrates the layout tool with its locator bar anchored at a second pivot point to facilitate accurate but larger angle markings. 
         FIG. 7  illustrates the layout tool with its locator bar configured for laying out a staircase stringer. 
         FIGS. 8   a  through  8   d  illustrate the layout tool of  FIG. 7  rotated into positions for laying out the ends of the staircase stringer. 
         FIG. 9  illustrates the layout tool with its locator bar configured to mark rip lines. 
         FIG. 10  illustrates the layout tool with its locator bar configured to form an 8-inch by 16-inch framing square. 
         FIG. 11  illustrates the layout tool with its locator bar configured to form a 12-inch by 16-inch framing square. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates the components of one embodiment of the layout tool  10 . Layout tool  10  comprises a rectangular base plate  20 , an elongate locator bar  50 , two shaft connectors  85  (for example, bolts), and two flange nuts  90 . The base plate  20  and locator bar  50  are preferably made of a sturdy, lightweight material, such as aluminum or plastic, for ease of carrying. The locator bar  50  is operable to be pivotally and removably attached to the base plate  20  in a multitude of configurations. The different possible configurations, together with the strategic placement of angular and distance markings on the base plate  20  and the locator bar  50 , serve a wide variety of layout needs. 
     The elongate locator bar  50  measures 1 inch wide by 16 inches long by 3/16 inches thick. It has a latitudinal (i.e., minor-axis) alignment edge  52 , a right latitudinal edge  53 , a straight measuring edge  55  (also referred to as a “layout edge”), and a longitudinal (i.e., major-axis) alignment edge  59  opposite the measuring edge  55 . Regularly-spaced English-unit distance markings  58 , the smallest of which are 1/16 th  of an inch, are inscribed adjacent both the measuring edge  55  and the proximal longitudinal edge  59 . The locator bar  50  includes an arrow  61  and the textual inscription  62  “measure edge” to assist users in the proper assembly and configuration of the layout tool  10 . 
     The locator bar  50  includes a round pivot hole  51  located near the bar&#39;s latitudinal alignment edge  52  and centered on the ½-inch mark. The hole  51  is provided to receive a shaft connector  85  to pivotally attach the locator bar  50  to one of four holes  31 - 34  of the base plate  20 . Accordingly, the hole  51  has a diameter slightly greater than the diameter of the shafts  86  of the connectors  85 . 
     The locator bar  50  has four corners, all of which are right-angled except for rounded corner  54 . Rounded corner  54  has a radius of ½ inch that extends in a clockwise direction from the midpoint of the latitudinal alignment edge  52  to the ½-inch mark on the measuring edge  55 . When two connectors  85  secure the locator bar  50  to the rectangular base plate  20  as shown in  FIG. 2 , the rounded corner  54  provides a pivoting edge for pivoting the layout tool  10  against the straight edge  115  of a workpiece  100 . 
     A first longitudinal slot  56  extends through the middle of the locator bar  50  from approximately from the 2-inch mark to the 10-inch mark. A second longitudinal slot  57  extends through the middle of the locator bar  50  from approximately from the 11½-inch mark to the 13½-inch mark. Both longitudinal slots  56  and  57  are provided to receive another shaft connector  85  to lock the locator bar  50 , at a second point, to the base plate  20 . Accordingly, both longitudinal slots  56  and  57  have a width slightly greater than the diameter of the shafts  86  of the connectors  85 . 
     The base plate  20  measures 8 inches wide by 12 inches long by 3/16 inches thick. The base plate  20  has a front face  18 , a back face  19 , proximal left corner  21 , a proximal right corner  22 , a distal left corner  23 , a distal right corner  24 , a left latitudinal (i.e., minor-axis) edge  26 , a right latitudinal edge  27 , a proximal longitudinal (i.e., major-axis) edge  28 , and a distal longitudinal edge  29 . 
     Regularly-spaced English-unit distance markings, the smallest of which are 1/16 th  of an inch, are inscribed adjacent the left latitudinal edge  26  and the proximal longitudinal edge  28 . This perpendicular set of distance markings serves many construction purposes, most especially the layout of a staircase stringer (illustrated in  FIG. 7 ). For staircase stringer configurations, a selected one of the distance markings along the left latitudinal edge  26  may serve as a “rise” length reference point, and a selected one of the distance markings along the proximal longitudinal edge  28  may serve as a “run” length reference point. Although not shown in the drawings, the base plate  20  may optionally have the inscriptions “rise” and “run” next to these corresponding sets of rise and run markings to illustrate this particular intended use. 
     Four round holes  31 ,  32 ,  33 , and  34  are located near each of the corners  21 - 24  of the base plate  20 . The holes  31 ,  32 ,  33 , and  34 , which are provided to receive a shaft connector  85  attaching the locator bar  50  to the base plate  20 , serve as selectable pivot points for pivotally connecting the locator bar  20  to the base plate  20 . Accordingly, the holes  31 ,  32 ,  33 , and  34  have diameters slightly greater than the diameter of the shafts  86  of the connectors  85 . 
     Angle markings, starting from 0 degrees at a point one inch above the proximal right corner  22  to about 31 degrees at the distal right corner  24 , are inscribed along the right latitudinal edge  27 . More angle markings, from about 31 degrees at the distal right corner  24  to 90 degrees at the distal left corner  23 , are inscribed along the distal longitudinal edge  29 . These angle markings are useful in marking cut lines when the layout tool  10  is pivoted about pivot point  31 , as shown in  FIGS. 2-5 . Each of the angle markings is angularly oriented so that when the layout tool  10  is pivoted about pivot point  31  against the straight edge  115  of a workpiece  100 , the angle marking corresponding to the selected pivot angle lines up with the workpiece edge  115 . 
     Two elongated arcuate slots  36  and  37 , each having common rafter slope markings  41  and hip-valley rafter slope markings  42 , extend through the base plate  20 . The markings represent the number of inches of rise per foot of run that an appropriately cut and assembled common rafter or hip-valley rafter is supposed to have. The markings facilitate orientations of the layout tool  10  to mark the appropriate rafter cuts. The arc of slot  37  has a 6-inch radius centered about 3 inches from the pivot point  31 . The inside edge of slot  37  is concave with respect to pivot point  31  and is spaced from the pivot point  31  between about 6 inches at its closest point and about 9 inches at its farthest point. 
     The arc of slot  36  has a 9-inch radius. The inside edge of slot  36  is concave with respect to pivot point  33  and is spaced from the pivot point  33  between about 9 inches at its closest point and about 10 inches at its farthest point. The outside edge of slot  36  is convex with respect to and extends fairly close to, and along a long portion of, the proximal longitudinal edge  28  of the base plate  20 . The orientation of slot  36  is deliberate, for, as illustrated in  FIG. 7 , it facilitates staircase-stringer configurations of the locator bar  50  with respect to the base plate  20 . 
     The arcuate slots  36  and  37  each have a width slightly greater than the diameter of the shafts  86  of connectors  85 , so that the shafts  86  can be inserted up through the slots  56  and  57  of the locator bar  50  and up through the slots  36  and  37  of the base plate  20 , and then engaged by the flange nuts  90 , to lock the locator bar  50 , at a selected orientation, against the base plate  20 . 
     The common rafter slope markings  41  and hip-valley rafter slope markings  42  are angularly oriented so that the locator bar  50 , when affixed to the corresponding pivot point  31  or  33 , can be pivoted so that it&#39;s measuring edge  55  lines up with a selected common rafter slope marking  41  or hip-valley rafter slope marking  42  (as shown in  FIGS. 5 and 6 ). Also, when the layout tool  10  is pivoted about pivot point  31  against the straight edge  115  of a workpiece  100  as shown in  FIG. 2 , the appropriate common rafter slope marking  41  or hip-valley rafter slope marking  42  lines up with the workpiece edge  115 . 
     The arc of slot  37  facilitates locking configurations of the locator bar  50  with respect to the base plate  20  (when anchored at hole  31 ) that range from about 3 degrees when the locator bar  50  is locked to the base plate  20  at the most proximal point available on the slot  37  to about 53 degrees when the locator bar  50  is locked to the base plate  20  at the most distal point available on the slot  37 . The common rafter slope markings  41  of slot  37  extend from the value 1 to 12, which represents a range of rise/run slopes of between 1 inch of rise per foot of run to 12 inches of rise per foot of run. The hip-valley rafter slope markings  42  of slot  37  extend from 1 to 17, which represents a range of rise/run slopes of between 1 inch of rise per foot of run to 17 inches of rise per foot of run. 
     Slot  36  is provided for two purposes. The first purpose of slot  36  is to enable the locator bar  20  to be locked to the base plate  50  in a wide range of positions for laying out staircase stringers (see  FIG. 7 ). The second purpose of slot  36  is to facilitate the marking of a wider array of angles than is possible with slot  37  (see  FIG. 6 ). The arc of slot  36  facilitates locking configurations of the locator bar  50  with respect to the base plate  20  (when anchored at hole  33  as shown in  FIG. 6 ) that range from about 4 degrees from the left latitudinal edge  26  when the locator bar  50  is locked to the base plate  20  at the left-most point available on the slot  36  to about 63 degrees when the locator bar  50  is locked to the base plate  20  at the right-most point available on the slot  36 . To put it another way, the second elongated arcuate slot  36  facilitates a range of locked angular orientations of the locator bar  50  with respect to the base plate  20  that spans more than 45 degrees. The common rafter slope markings  41  of slot  36  extend from the value 1 to 21. The hip-valley rafter slope markings  42  of slot  37  extend from 1 to 30. 
     A latitudinal L-slot  38  extends for about 4½ inches proximate and parallel to the left latitudinal edge  26 . Another latitudinal straight slot  39  extends about 4½ inches proximate and parallel to the right latitudinal edge  27 . The slots  38  and  39  each have a width slightly greater than the diameter of the shafts  86  of connectors  85 , so that the shafts  86  can be inserted through the slots  56  and  57  of the locator bar  50  and through the slots  38  and  39  of the base plate  20 , and then engaged by the flange nuts  90 , to lock the locator bar  50  parallel to and at a selected distance from the proximal longitudinal edge  28  of the base plate  20 . The slots  38  and  39  also have regularly spaced, coordinated alignment markings  43  and  44 , the smallest of which are 1/16 th  of an inch, inscribed against their inside edges. These coordinated alignment markings  43  and  44  facilitate the parallel positioning of the locator bar  50  against the base plate  20 , as shown in  FIG. 9 , so that the locator tool  10  can be used to mark rip lines in a workpiece  100 . 
     Latitudinal slot  38  includes a longitudinal, approximately 1-inch extension  45  for staircase stringer configurations of the layout tool  10 . The longitudinal extension  45  enables the locator bar  50  to be positioned so that its measuring edge  55  intersects both the 8-inch distance mark on the left latitudinal edge  26  and the 12-inch distance mark on the proximal longitudinal edge  28  of the base plate  20 . 
     All of the markings shown on the front face  18  of the base plate  20  of  FIG. 1  are preferably reproduced, in mirror-image fashion, on the back face  19  of the base plate  20 . For example, regularly-spaced distance and angle markings would be inscribed adjacent the same edges on the front face  18  as they are on the back face  19 . Likewise, the markings shown on the front face of the locator bar  50  are preferably reproduced, in mirror-image fashion, on the back face of the locator bar  50 . 
       FIG. 2  illustrates a pencil  120  being used with a particular configuration of the layout tool  10  to mark a line  125  for a rafter angle cut on a workpiece  100  such as a piece of lumber. The locator bar  50  is mounted on the underside of the base plate  20 . A first shaft connector  85  (concealed from view, but with the corresponding flange nut  90  shown) has been inserted, from below, first through the hole  51  of the locator bar  50  and second through the hole  31  of the base plate  20 , and then engaged by a hand-tightened flange nut  90 . A second shaft connector  85  (also concealed from view, but with the corresponding flange nut  90  shown) has been inserted, from below, first through the slot  57  of the locator bar  50  and second through the hole  32  of the base plate  20 , and engaged by a hand-tightened flange nut  90 . 
     In this position, the proximal longitudinal edge  28  of the base plate  20  is aligned with the proximal longitudinal edge  59  of the locator bar  50 . Also, the latitudinal alignment edge  52  of the locator bar  50  is aligned with a left latitudinal edge  26  of the base plate  20 . 
     In  FIG. 2 , the layout tool  10  is positioned over the face of the workpiece  100 , with the curved, rounded corner  54  (hidden from view in  FIG. 2 ) of the locator bar  50  positioned against the straight edge  115  of the workpiece  100 .  FIG. 2  also illustrates how the slot  37  exposes the workpiece straight edge  115  to view. The layout tool  10  has been pivoted about the rounded corner  54  so that the common rafter slope marking  41  of the arcuate slot  37  having a value of “5” approximately lines up with the straight edge  115  of the workpiece  100 . As is well known in the industry, the common rafter slope value “5” corresponds to a “rise” of 5 inches per foot of “run.” (This also corresponds to an angle of about 22.62 degrees). Likewise, the angle marking  48  having a value of “22.5” degrees approximately lines up with the workpiece straight edge  115 . 
     With the layout tool  10  so positioned on and against the workpiece  100 , the left latitudinal edge  26  of the base plate  50  provides a guide for marking a line  125  or moving a saw at an angle corresponding to a selected common rafter marking  41  of the arcuate slot  37 . Namely, the angle  110  between the left latitudinal edge  26  and a perpendicular  105  to the workpiece straight edge  115  is about 22.5 degrees, which equates very approximately to a rise of 5 inches per every foot of run. Likewise, the angle  111  between the proximal longitudinal edge  28  and the workpiece straight edge  115  is about 22.5 degrees. 
       FIG. 3  illustrates the layout tool  10  pivoted on the workpiece  100  to mark a second cut line  126  having an angle  112  to the perpendicular  105  equal to a second selected pivot angle  49 . In  FIG. 3 , the layout tool  10  is positioned so that the angle markings on the distal longitudinal edge  29  of the layout tool  10 , corresponding with the second selected pivot angle  49 , lines up with workpiece straight edge  115 . 
       FIGS. 2-4  illustrate one of the significant advantages that the rectangular configuration of the base plate  20  has over prior art triangular speed squares.  FIGS. 2 and 3  illustrate how the left latitudinal edge  26  of the base plate  20  provides a guide for marking a line at an angle from the workpiece perpendicular  105 .  FIG. 4  illustrates how the distal longitudinal edge  29  of the base plate  20  can act as another guide for marking a third cut line  127  at an angle from the workpiece straight edge  115 . 
     The third cut line  127 , unlike the first and second cut lines  125  and  126 , extends at counterclockwise angle from the perpendicular  105 . Because the rectangular configuration of the base plate  20  provides two guides, perpendicular to each other, for marking lines on a workpiece, the layout tool  10  facilitates the marking of cut lines from an angle of 0 to 180 degrees without the necessity of flipping the layout tool  10 , as one would have to do to mark the same range of angles using a traditional triangular speed square. Eliminating the need to flip the tool  10  reduces confusion and errors and makes the process of marking and cutting lines easier, faster, and generally more accurate. 
     The third cut line  127  has an angle  113  to the perpendicular  105  equal to 90 degrees minus the second selected pivot angle  49 . Viewed another way, the third cut line  127  has an angle  114  to the workpiece straight edge  115  that is equal to the second selected pivot angle  49 . 
       FIGS. 2-4  also illustrate “free pivoting” configurations of the layout tool  10 . In each of those drawings, the layout tool  10  is configured to be freely pivoted about the round, curved corner  54  of the locator bar  50 , while the bar&#39;s longitudinal alignment edge  59  is aligned with the proximal longitudinal edge  28  of the base plate  20 . 
       FIGS. 5 and 6 , by contrast, illustrate “fixed layout angle” configurations of the layout tool  10 . In  FIGS. 5 and 6 , the locator bar  50  is locked to the base plate  20  at a selected angular position. These configurations are designed to position the measuring edge  55  of the locator bar  50  against the workpiece straight edge  115 , in order to facilitate more accurate angle markings or cuts along the distal longitudinal edge  29  and left latitudinal edge  26  of the base plate  20 . 
     In  FIG. 5 , the locator bar  50  is mounted on the underside of the base plate  20  at a pivot point centered at hole  31  of the base plate  20 . To configure the layout tool  10  as shown, a first shaft connector  85  is inserted, from below, through the hole  51  of the locator bar  50  and the hole  31  of the base plate  20 . The locator bar  50  is then pivoted to a selected angle marking along the right latitudinal edge  27  of the base plate  20  (or alternatively to a selected slope marking  41  or  42  along the arcuate slot  37 .  FIG. 5  illustrates how the slot  37  exposes the measuring edge  55  to view, so that it can be aligned with the appropriate slope marking  41  or  42 . A second shaft connector  85  is then inserted, from below, through the longitudinal slot  57  of the locator bar  50  and the arcuate slot  37  of the base plate  20 . Finally, both shaft connectors  85  are engaged by a hand-tightened flange nut  90 . 
     In  FIG. 5 , the layout tool  10  is positioned over the face of the workpiece  100 , with the measuring edge  55  of the locator bar  50  positioned against the workpiece straight edge  115 . While in this position, the tip of a pencil  120  is drawn against the left latitudinal edge  26  of the base plate  20  in order to draw an angle  116  from the perpendicular  105  that is either equal to the selected angle marking or that corresponds to the selected rafter slope marking. 
     In  FIG. 6 , the locator bar  50  is mounted on the underside of the base plate  20  at a second pivot point centered at hole  33  of the base plate  20 . FIG.  6 &#39;s fixed layout angle configuration facilitates larger angle markings than the configuration shown in  FIG. 5 . In  FIG. 6 , the locator bar  50  has been positioned for marking common rafter cuts to build a steep roof with a slope of 21 inches of rise per foot of run, or for marking hip-valley rafter cuts to build a roof with a slope of 30 inches of rise per foot of run. 
     To configure the layout tool  10  as shown in  FIG. 6 , the locator bar  50  is oriented so that its measuring edge  55  faces the distal right corner  24 . A first shaft connector  85  is inserted, from below, through the hole  51  of the locator bar  50  and the hole  33  of the base plate  20 . The locator bar  50  is pivoted to a selected slope marking  41  or  42  along the second arcuate slot  36 .  FIG. 6  illustrates how the slot  36  exposes the measuring edge  55  to view, so that it can be aligned with the appropriate slope marking  41  or  42 . A second shaft connector  85  is then inserted, from below, through the longitudinal slot  57  of the locator bar  50  and the arcuate slot  36  of the base plate  20 . Finally, both shaft connectors  85  are engaged by a hand-tightened flange nut  90 . 
     In  FIG. 6 , the layout tool  10  is positioned over the face of the workpiece  100 , with the measuring edge  55  of the locator bar  50  positioned against the workpiece straight edge  115 . While in this position, the tip of a pencil  120  is moved against the distal longitudinal edge  29  of the base plate  20  in order to draw a rafter cut line at an angle  117  from the perpendicular  105  that corresponds to the selected slope marking. 
       FIG. 7  illustrates the layout tool  10  with its locator bar  50  configured for laying out a staircase stringer  200 . As with  FIG. 6 , the locator bar  50  is locked to the base plate  20  at two points, one of them located at the left distal hole  33 . But in contrast to  FIG. 6 , FIG.  7 &#39;s configuration has the locator bar  50  oriented so that its measuring edge  55  faces the proximal left corner  21  of the base plate  20 . A first shaft connector  85  is inserted up through the longitudinal slot  57  of the locator bar  50  and the latitudinal L-slot  38  of the base plate  20 . A second shaft connector  85  is inserted up through the longitudinal slot  56  of the locator bar  50  and the arcuate slot  36  of the base plate  20 . Before the corresponding flange nuts  90  are tightened, the locator bar  50  is positioned so that its measuring edge  55  intersects the appropriate “rise” and “run” length reference points of the base plate  20 . Once the flange nuts  90  are tightened, the layout tool  10  is configured for laying out the staircase stringer  200 . 
     Once the layout tool  10  is in the proper staircase stringer configuration, the tool  10  is positioned over the face of the stringer  200 , with the measuring edge  55  of the locator bar  50  positioned against the straight edge  215  of the stringer  200 . “Rise” and “run” pencil markings  225  and  226  are then quickly made against the left latitudinal edge  26  and the proximal longitudinal edge  28  of the base plate  20 . After each set of rise and run pencil markings  225  and  226  is made, the layout tool  10  is quickly repositioned further down the stringer  200  to mark the next set of rise and run pencil markings  225  and  226 . 
       FIGS. 8   a  through  8   d  illustrate the layout tool  10  of  FIG. 7  rotated into positions for laying out the ends of the staircase stringer  200 . After the rise and run cut lines  225  and  226  are marked on the stringer  200 , the layout tool  10  can be used—without reconfiguration of the locator bar  50 —to mark the stringer plumb cut line  227  and the stringer level cut line  228 . The letters A, B, C, D, and E designate the positions and orientations of the layout tool  10  that enable these marks to be made. As a beginning reference point, position “A” illustrates the layout tool  10  being used to mark out the last “rise” line  225  of the stringer  200 . 
     To mark the stringer cut level line  228 , the layout tool  10  is simply translated from position “A” to the opposite side of the stringer  200 , as illustrated in position “B,” with the proximal longitudinal edge  59  of the locator bar  50  lying against the opposite edge  216  of the stringer  200 . The stringer cut level line  228  is then marked against the distal longitudinal edge  29  of the base plate  20 . If the cut level line  228  needs to be extended, then the layout tool  10  is rotated counterclockwise 90 degrees and moved to the right edge  217  of the stringer  200 , as illustrated in position “C,” with the proximal longitudinal edge  59  of the locator bar  50  lying against the right edge  217  of the stringer  200 . The extension of the cut level line  228  is then marked against the right latitudinal edge  27  of the base plate  20 . 
     To mark the stringer plumb cut line  227 , the layout tool  10  is translated from position “C” to position “D,” this time with the measuring edge  55  of the locator bar  50  lying against the left edge  218  of the stringer  200 . Alternatively, assuming that position “C” was not needed, the layout tool  10  is rotated counterclockwise 90 degrees from the position shown in position “A” or “B” and moved toward the left edge  218  of the stringer  200 . Either way, the stringer plumb cut line  227  is then marked against the proximal longitudinal edge  28  of the base plate  20 . If the stringer plumb cut line  227  needs to be extended, then the layout tool  10  can be translated (without rotation) from position “B” to position “E,” and the line  227  extended by marking against the right latitudinal edge  27  of the base plate  10 . 
       FIG. 9  illustrates the layout tool  10  with its locator bar  50  configured to mark rip lines  155  parallel to the workpiece straight edge  115 . Once again, the locator bar  50  is locked to the base plate  20  at two points. The locator bar  50  is oriented so that its measuring edge  55  faces the proximal longitudinal edge  28  of the base plate  20 . A first shaft connector  85  is inserted up through the longitudinal slot  57  of the locator bar  50  and the latitudinal L-slot  38  of the base plate  20 . A second shaft connector  85  is inserted up through the longitudinal slot  56  of the locator bar  50  and the latitudinal straight slot  39  of the base plate  20 . Before the corresponding flange nuts  90  are tightened, the locator bar  50  is positioned so that its measuring edge  55  is parallel with the proximal longitudinal edge  28  of the base plate  20 . The coordinated alignment markings  43  and  44  along slots  38  and  39  facilitate the parallel positioning of the locator bar  50  against the base plate  20 . Once the flange nuts  90  are tightened, the layout tool  10  is configured for marking rip lines. 
     Once the layout tool  10  is in the proper rip-line-marking configuration, the tool  10  is positioned over the face of the workpiece  100 , with the measuring edge  55  of the locator bar  50  positioned against the straight edge  115  of the workpiece  100 . Rip lines  155  are easily and quickly made by moving the pencil  120  along the proximal longitudinal edge  28  of the base plate  20 , or by holding the pencil  120  against the edge  28  while sliding the base plate  20  along the workpiece  100 . 
     The layout tool  10  can also be configured as two differently-dimensioned right-angle framing tools (often referred to in the art as a “framing square”).  FIG. 10  illustrates the layout tool  10  with its locator bar  50  configured to form an 8-inch by 16-inch framing square. The configuration is identical to that shown in  FIGS. 2-4 , with the alignment edge  59  of the locator bar  50  aligned with the base plate&#39;s proximal longitudinal edge  28 .  FIG. 11  illustrates the layout tool  10  with its locator bar  50  configured to form a 12-inch by 16-inch framing square. Here, the locator bar  50  is connected to the base plate  20  at hole  31  by connector  85  and pivoted until its measuring edge  55  is aligned with the base plate&#39;s left latitudinal edge  26 . In the 12-inch by 16-inch configuration, in particular, the layout tool  10  facilitates the rapid laying out of the center points of studs that are to be separated either 12 or 16 inches apart. 
     Although not shown in the drawings, the locator bar  50  can be removed and separated from the base plate  20  and used as a gauge. 
     Although the foregoing specific details describe various embodiments of the invention, persons reasonably skilled in the art will recognize that various changes may be made in the details of the apparatus or method of this invention without departing from the spirit and scope of the invention as defined in the appended claims. 
     The present invention includes several independently meritorious inventive aspects and advantages. Unless compelled by the claim language itself, the claims should not be construed to be limited to structures that incorporate all of the inventive aspects, or enjoy all of the advantages, disclosed herein. 
     It is well established that the claims of the patent serve an important public notice function to potential competitors—enabling them to not only determine what is covered, but also what is not covered—by the patent. And a number of Federal Circuit decisions have emphasized the importance of discerning the patentee&#39;s intent—as expressed in the specification—in construing the claims of the patent. 
     It is my intent that the claims receive a liberal construction and be interpreted to uphold and not destroy the right of the inventor. It is my intent that the claim terms be construed in a charitable and common-sensical manner, in a manner that encompasses the embodiments disclosed in the specification and drawings without incorporating unrecited, unnecessary limitations. It is my intent that the claim terms be construed as broadly as practicable while preserving the validity of the claims. It is my intent that the claim terms be construed in a manner consistent with the context of the overall claim language and the specification, without importing extraneous limitations from the specification or other sources into the claims, and without confining the scope of the claims to the exact representations depicted in the specification or drawings. It is also my intent that not each and every term of the claim be systematically defined and rewritten. Claim terms and phrases should be construed only to the extent that it will provide helpful, clarifying guidance to the jury, or to the extent needed to resolve a legitimate, good faith dispute that is material to the questions of validity or infringement. Otherwise, simple claim terms and phrases should be presented to the jury without any potentially confusing and difficult-to-apply definitional construction. 
     It is also to be understood that the terminology employed in the Summary of the Invention and Detailed Description sections of this application is for the purpose of describing particular embodiments. Unless the context clearly demonstrates otherwise, is not intended to be limiting. In this specification and the appended claims, the singular forms “a,” “an” and “the” include plural references unless the context clearly dictates otherwise. Conversely, it is contemplated that the claims may be drafted to exclude any optional element or be further limited using exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements or by use of a “negative” limitation. It is also contemplated that any optional feature of the inventive variations described herein may be set forth and claimed independently, or in combination with any one or more of the features described herein. 
     The headquarters building of the World Intellectual Property Organization bears the following inscription: “Human genius is the source of all works of art and invention; these works are the guarantee of a life worthy of me; it is the duty of the State to ensure with diligence the protection of the arts and inventions.” It is my intent that the claims of this patent be construed—and ultimately enforced, if necessary—in a manner worthy of this mandate.