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BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to gauges and jigs that are used during the installation of railing spindles to create uniform spaces between those elements. More particularly, the present invention relates to gauges and jigs for railing spindles that can be selectively adjusted in size. 
     2. Description of the Prior Art 
     There are many exposed elevated structures, such as stairs, decks, balconies and the like, that are protected with railing systems. A typical railing system contains one or two horizontal rails. The space between the railings, or the railing and the floor, is filled with vertical railing spindles. The purpose of the railing system is to provide a barrier that would prevent a person from accidently falling off the edge of the elevated structure. 
     Many different municipalities have adapted standardized building codes that set specifications for the length and spacing of railing spindles in a railing system. A commonly adapted building code requires that railing spindles be spaced no more than four inches apart. Accordingly, when a carpenter builds a railing system, care is taken not to space the railing spindles too far apart, else the railing system will fail inspection from the municipality building inspector. 
     When building railing systems, carpenters commonly cut a piece of wood to the size desired for the railing spindle spacing. The cut piece of wood is then used as a gauge during the installation of the railing spindles. Although a cut piece of wood works as a spacing gauge, it does have its disadvantages. First, a cut piece of wood is not adjustable. Accordingly, different pieces of wood must be cut at different times if there are designed variations in the layout of the railing spindles. A second disadvantage is that a cut block of wood is not self supporting. Accordingly, a carpenter must manipulate both the block of wood and the railing spindles during the installation process. A third disadvantage of a cut block of wood is that it provides no indication as to whether or not a railing spindle is vertically straight. Rather, the cut block of wood only spaces a railing spindle a predetermined distance from the previous railing spindle. If the previous railing spindle is warped or otherwise not straight, this error is transferred to the next railing spindle through the use of the cut block of wood. Consequently, each railing spindle must be checked with a level and corrected after the cut block of wood is used. This requires a carpenter to manipulate the railing, the cut block and a level in properly positioning each railing spindle. 
     In the prior art, spindle spacing devices have been developed that improve upon the cut block of wood. Such prior art devices embody adjustments that allow the spacing device to be adjusted to different spacing dimensions. Such prior art spacing devices are exemplified by U.S. Pat. No. 5,491,905 to Jablonski, entitled Apparatus For Accurately Spacing Railing Spindles. However, such prior art spacing devices are time consuming to install. Furthermore, such prior art spacing devices often gauge from the previous railing spindle. Accordingly, if any railing spindle is warped, that error can be transmitted to subsequent railing spindles. A carpenter must therefore still check each railing spindle with a level during construction to ensure each railing spindle is straight. 
     A need therefore exists in the art of railing spindle spacers for a device that is adjustable, easy to install, self supporting, and eliminates the need for the use of a level. These needs are met by the present invention as is described and claimed below. 
     SUMMARY OF THE INVENTION 
     The present invention is a gauge device for spacing railing spindles or other parallel building elements used in construction. The gauge device is a generally rectangular assembly having two long edges that are spaced a predetermined distance apart. An adjustment mechanism is embodied within the rectangular assembly for selectively varying the predetermined distance between the two long edges across a range of distances. An indicator is coupled to the adjustment mechanism for indicating the predetermined distance between the two long edges maintained by the adjustment mechanism. Optional level bubbles are provided within the device to provide an indication as to when the long side edges are in a true vertical and/or horizontal orientation. 
     The gauge device is used by placing the gauge device between parallel building elements during construction, The gauge device ensures that the building elements are properly spaced and are aligned in the vertical. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a better understanding of the present invention, reference is made to the following description of exemplary embodiments thereof, considered in conjunction with the accompanying drawings, in which: 
     FIG. 1 is a front view of an exemplary embodiment of the present invention gauge device shown in use between railing spindles in a railing assembly; 
     FIG. 2 is an exploded perspective view of the embodiment of the present invention shown in FIG. 1; and 
     FIG. 3 is a front view of an alternate embodiment of a gauge device in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Although the present invention gauge device can be used to space most any parallel construction elements, such as fence rails, framing studs, joists and the like, the present invention gauge device is especially well suited for use in installing railing spindles in a railing system. Accordingly, by way of example, the present invention gauge device will be described in an application where parallel railing spindles are being installed. 
     Referring to FIG. 1, a segment of a typical railing system  10  is shown. The railing system  10  has a top rail  12  and a bottom rail  14 . Railing spindles  16  are installed between the top rail  12  and the bottom rail  14 . The railing spindles  16  are installed in a vertical orientation, wherein each of the vertical rails  16  are parallel. 
     In the shown railing system, the top rail  12  is angled and the bottom rail  14  lays in the horizontal. This segment of railing is used to illustrate the versatility of the present invention gauge device  20  by showing that the rails in the railing system  10  need not be parallel for its use. 
     Referring to FIG. 2 in conjunction with FIG. 1, it can be seen that the gauge device  20  has two flat side edges  22 ,  24 . The side edges  22 ,  24  are spaced apart by a predetermined distance D 1 . However, the distance D 1  between the side edges  22 ,  24  is selectively adjustable within a predetermined range. In the shown application, the gauge device  20  is being used to install railing spindles  16  (FIG.  1 ). As such, the desired range of adjustment for the predetermined distance D 1  is between two inches and four inches. However, if the gauge device  20  were being used to install framing studs, the desired range of adjustment for the predetermined distance D 1  would preferably be between fourteen inches and twenty four inches. 
     In the shown embodiment, each of the side edges  22 ,  24  of the gauge device  20  is attached to a spanning body element  25 ,  26 , wherein each spanning body element  25 ,  26  attaches to the middle of its side edge  22 ,  24  at a perpendicular. The first spanning body element  25  embodies three level bubbles  27 ,  28 ,  29 . One level bubble  27  is disposed near the top of the first spanning body element  25 . One bubble  28  is disposed near the bottom of the first spanning body element  25 . Lastly, one level bubble  29  is disposed near the center of the first spanning body element  25 . In the shown embodiment, the top and bottom level bubbles  27 ,  28  are horizontal level bubbles and the middle level bubble  29  is a vertical level bubble. 
     The presence of the level bubbles  27 ,  28 ,  29  in the gauge device  20  enables the gauge device  20  to act as both a spacing gauge and a level when used in the installation of a railing spindle  16  (FIG.  1 ). As a new railing spindle is placed against a side edge of the gauge device  20 , a carpenter can instantly see if that railing spindle is aligned in the vertical. If the new railing spindle is not vertical, it can be checked and corrected using the gauge device  20 . The vertical bubble  29  in the gauge device, enables the gauge device to be used as a standard level when the railings and other horizontal elements are installed. 
     The first spanning body element  25  is generally U-shaped, wherein the first spanning body element  25  has two parallel extending walls  31 ,  33  (FIG.  2 ). The two parallel extending walls  31 ,  33  define an open slot  35  (FIG. 2) that runs the length of the first spanning body element  25 . 
     A second spanning body element  26  extends from the second edge  24  of the gauge device  20 . The second spanning body element  26  is sized to fit between the two parallel extending walls  31 ,  33  of the first spanning body element  25  on the opposite side of the gauge device  20 . The degree of penetration of the second spanning body  26  into the first spanning body element  25  determines the distance D 1  between the two side edges  22 ,  24 . In the shown embodiment, the degree of penetration of the second spanning body element  26  into the first spanning body element  25  is controlled through the use of locking bolts. Two adjustment slots  30  are formed in the first spanning body element  26 . The adjustment slots  30  are open on the edge of the first spanning body element  25  that faces the second spanning body element  26 . 
     Locking bolts  34  extend from the second spanning body element  26 . The bolts  34  are engaged by butterfly locking nuts  36  that can be manually tightened and loosened. As the first spanning body element  25  passes over the second spanning body element  26 , the locking bolts  34  on the second spanning body element  26  pass into the adjustment slots  30  of the first spanning body element  25 . Once a desired degree of penetration is obtained, the butterfly nuts  36  are tightened, thereby locking the first spanning body element  25  and the second spanning body element  26  into a fixed orientation. 
     The degree of penetration between the first spanning body element  25  and the second spanning body element  26  determines the distance D 1  between the opposing flat side edges of the gauge device  20 . Numeric indicia  41  are provided along the edge of the adjustment slots  30  in the first spanning body element  25 . As the first spanning body element  25  and the second spanning body element  26  engage, the edge of the second spanning body element  26  aligns with one of the numeric indicia  41 . The numeric indicia  41  are scaled to provide an accurate indication as to the width of the gauge device  20  depending upon which of the numeric indicia  41  the edge of the second spanning body element  26  aligns. Thus, if the edge of the second spanning body element  26  aligns with the numeric indicia “3”, as viewed through an adjustment slot, it can be determined that the distance D 1  between the side edges  22 ,  24  of the gauge device  20  is three inches. 
     In FIG. 2, optional guide shanks  40  are shown extending from the bottom of the locking bolts  34 . The guide shanks  40  are sized to engage the adjustment slots  30  formed in the first spanning body element  25 . The presence of the guide shanks  40  in the adjustment slots  30  maintains the first spanning body element  25  in a parallel orientation with respect to the second spanning body element  26  as the two spanning body elements  25 ,  26  are moved in relation to one another. 
     With returning reference to both FIG.  1  and FIG. 2, it can be seen that level reliefs  44  are formed in the second spanning body element  26 . The level reliefs  44  on the second spanning body element  26  align with the level bubbles  27 ,  28 ,  29  in the first spanning body element  25 . A second set of level reliefs  45  are also formed in the second extending wall of the first spanning body element  25 . The second set of level reliefs also align with the level bubbles  27 ,  28 ,  29 . Accordingly, when the first spanning body element  25  and the second spanning body element  26  overlap, the various level bubbles  27 ,  28 ,  29  can still be seen from both sides of the gauge device  20 . 
     In certain circumstances, a carpenter may not want to manually hold the gauge device  20  in place. For that reason the gauge device  20  is self supporting. A hook element  48  is provided. The hook element  48  can be selectively attached or detached from the gauge device  20 . The hook element  48  is shaped to engage the upper rail of a railing system. Accordingly, by placing the hook element  48  on a railing and suspending the gauge device  20  from the hook element  48 , the gauge device  20  can be self supporting at any point below the top rail of a railing system. 
     In usage, it would be convenient if the gauge device  20  were to hang directly vertical from the hook element  48 . In order for that orientation to occur, the hook element  48  must engage the gauge device  20  at a point directly above the center of gravity for the gauge device  20 . This problem, however, is complicated by the fact that the center of gravity of the gauge device  20  changes as the width of the gauge device  20  is adjusted. 
     To compensate for the changing center of gravity, an angled slot  50  is formed near the top of both the first spanning body element  25  and the second spanning body element  26 . As the gauge device  20  is adjusted in width, the point of intersection between the two slots  50  changes. The slope of the two slots  50  is calculated so that the point of intersection between the two slots  50  always occurs directly above the center of gravity for the gauge device  20 . Accordingly, by engaging the hook element  48  with the angled slots  50 , the hook element  48  is always above the center of gravity for the gauge device  20  and the gauge device  20  lays in the vertical. 
     A handle  46  is attached to the face of the first spanning body element  25 . The handle  46  provides an object for the carpenter to grasp when manipulating the gauge device  20 . The handle  46  is preferably positioned proximate the center of gravity of the gauge device  20 , thereby enabling the gauge device  20  to be manipulated in a balanced manner with only one hand. However, as has already been described, the center of gravity of the gauge device  20  changes as the gauge device is adjusted. Accordingly, the handle  46  can be attached to the gauge device in the same manner as the hook element  48 . To compensate for the changing center of gravity, an angled slot  51  is formed in both the first spanning body element  25  and the second spanning body element  26  at points corresponding to the top and the bottom of the handle  46 . As the gauge device  20  is adjusted in width, the point of intersection between the two slots  51  changes. The slope of the two slots  51  is calculated so that the point of intersection between the two slots  51  always occurs directly above the center of gravity for the gauge device  20 . Accordingly, by engaging the handle  46  with the angled slots  51 , the handle  46  is always above the center of gravity for the gauge device  20 . 
     Referring now to FIG. 3, an alternate embodiment of the present invention is shown. In this embodiment, the gauge device  100  has a main body  102 . One side of the main body  102  terminates with a flat side edge  104 . The main body  102  also contains three level bubbles  106  that enable the gauge device to act as a level during the installation of railing spindles. 
     The gauge device  100  also has a second side edge  108  that can be moved in relation to the main body  102 . Accordingly, the distance D 2  between the two side edges  106 ,  108  can be selectively varied. The second side edge  108  is connected to a series of linkages  110 . The linkages  110  are pivotably connected to the main body  102  of the gauge device  100 . A control bar  112  connects to the ends of the linkages  110  opposite the second side edge  108 . As the control bar  112  moves up and down, the linkages  110  pivot around their pivot points and vary the distance between the second side edge  108  and the main body of the gauge device  100 . 
     A position indicator  114  extends from the control bar  112 . The position indicator  114  passes along a scale of numeric indicia  116  present on the main body  102  of the gauge device  100 . The numeric value pointed to by the position indicator  114  is indicative of the distance D 2  between the two side edges  104 ,  108  of the gauge device  100 . 
     A slot  118  is formed in the control bar  112 . A bolt  120  extends through the slot  118 . By tightening a nut  122  onto the bolt  120 , the position of the control bar  112  on the main body  102  of the gauge device  100  can be controlled. Accordingly, the distance D 2  between the opposite side edges  106 ,  108  of the gauge device  100  can also be selectively controlled. 
     It will be understood that the various figures described above illustrate only two preferred embodiments of the present invention. A person skilled in the art can therefore make numerous alterations and modifications to the shown embodiment utilizing functionally equivalent components to those shown and described. For example, there are numerous ways to vary the distance between the edges of the gauge device. Any such prior art length adjustment mechanism can be substituted for the elements described. All such modifications are intended to be included within the scope of the present invention as defined by the appended claims.

Summary:
A gauge device for spacing railing spindles or other parallel building elements used in construction. The gauge device is a generally rectangular assembly having two long edges that are spaced a predetermined distance apart. An adjustment mechanism is embodied within the rectangular assembly for selectively varying the predetermined distance between the two long edges across a range of distances. An indicator is coupled to the adjustment mechanism for indicating the predetermined distance between the two long edges maintained by the adjustment mechanism. Optional level bubbles are provided within the device to provide an indication as to when the long side edges were in a true vertical orientation. The gauge device is used by placing the gauge device between parallel building elements during construction, The gauge device ensures that the building elements are properly spaced and are aligned in the vertical.