Abstract:
The gage has a body made of flat plate which has a reference edge. Another edge is a gage edge which is angular and defines a sharp apex away from the gage edge. A foot is slidable along the gage edge to rotate the gage body around the sharp apex pivot. Indicia indicate the angle at different foot positions.

Description:
FIELD OF THE INVENTION 
     This invention is directed to an angle setting and measurement gage, which is a 2-piece structure which can be set to accurately define and measure angles and particularly small angles. 
     BACKGROUND OF THE INVENTION 
     In the trades and crafts, such as metal working and wood working, it becomes necessary to set two parts in a very accurate angular position. Existing protractors do not have the required accuracy. At present, one manner in which precise angles are set is to employ precision angular gage blocks. The artisan must stack many of these dedicated angular blocks together to achieve the desired angles. Another method is to use sine bars. These very precise bars are used in conjunction with linear gage blocks. The artisan is required to employ trigonometric calculations to achieve the desired angle of the sine bar. Either of these methods of measuring or setting an angle becomes very time-consuming. In addition, the accurate gage blocks required are quite expensive. The same kind of system is used in both the setting of the angle and the measuring of an existing angle. The measurement works in the opposite manner, with the assembly of accurate gage bars to the angle presented by existing parts. Either the setting of an angle or measuring an angle is time-consuming by employing the present-day gage blocks. 
     It is helpful to provide a gage which can be easily used to set an angle or measure the angle between existing parts, with the angle measurement being done with great accuracy, even at small angles. 
     SUMMARY OF THE INVENTION 
     In order to aid in the understanding of this invention, it can be stated in essentially summary form that it is directed to an angle setting and measurement gage which has a body which is conveniently configured as a flat plate. The body has a reference edge and a base edge. The base edge has an apex which serves as a contact pivot on a supporting surface. A foot of known height is positioned under the base edge away from the apex to define a triangle. The height of the foot defines the opposite side; the distance from the apex to the top of the foot along the base edge defines the hypotenuse; while the distance from the apex to the bottom of the foot along the supporting surface defines the adjacent. Thus, the positioning of the foot along the base edge controls the angle of the reference edge with respect to the supporting surface. The body may have several reference edges, which have a known fixed angle with respect to each other. 
     It is, thus, a purpose and advantage of this invention to provide an angle setting and measurement gage which is economic of construction, easy to use and which can accurately set and measure angles. 
     It is another purpose and advantage of this invention to provide an angle setting and measurement gage which is of simple construction so that it can be accurately manufactured to provide accuracy in the gage. 
     It is another purpose and advantage of this invention to provide an angle setting and measurement gage which is particularly useful in setting small angles on a scroll saw or table saw. 
     Other purposes and advantages of this invention will be noted from the study of the following portion of the preferred embodiment and the attached claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side-elevational view of the angle setting and measurement gage of this invention, shown employed on a scroll saw, the table of which is taken in section. 
     FIG. 2 is a left end view thereof. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The gage  10 , seen in FIGS. 1 and 2, comprises a body  12  and a foot  14 . The body  12  can be made of metal or polymer (plastic) plate of substantially uniform thickness. It has a top reference edge  16  and end reference edge  18 . In the preferred embodiment, these two reference edges are at a right angle with respect to each other. The back edge  20  may be a reference edge, in which case it is preferably parallel to the end reference edge  18 . The bottom edge of the plate has a gage edge  22  and a clearance edge  24 . Between them is a sharp apex  26 . 
     The foot  14  is a rod initially formed as a right circular cylinder  28 , and it is machined with two flats  30  and  32 . The top flat defines an indicator point  34 . The bottom flat  32  defines a contact point  36 . As seen in FIG. 2, the foot  14  has a notch  38  therein into which the gage edge of the body  12  is engaged. The notch  38  has a bottom  40  which is a known distance above the contact point  36 . Clamp screw  42  is threaded into the end of the circular cylinder  28  and enters into the notch  38  so that tightening the screw clamps the foot surface  40  onto the bottom edge of the body. Since the foot  14  is long in the lateral direction of the body  12 , the gage has 3-point support that ensures stability when the gage is placed on the flat top surface  44  of saw table  46 . 
     The foot  14  has a particular dimension between its contact point  36  and the bottom  40  of the notch, which is the “opposite” side of the triangle. Thus, when the foot is placed at a particular position along the length of the gage edge  22 , the top reference edge  16  is parallel to the top surface  44  of the table. At this point, there is a zero indicia  48  on the body. The indicator point  34  serves as a witness line to indicate when the foot is properly positioned for the zero angle position. Since the end reference surface  18  is at a right angle to the top reference surface  16 , the end reference surface  18  is at a right angle with respect to the top surface  44  of the table. 
     The foot can be unclamped from the zero position and moved toward the apex  26 . This raises the left end of the body  12 . Through trigonometry, knowing the height of the notch bottom  40  above the contact point  36  (the “opposite” side) and knowing the distance from the sharp apex  26  to the indicator point  34  (the “adjacent” side), other angles can be calculated. For example, one-half degree indicia at witness line  50  is shown. Additional increasing angle notations, each with their corresponding witness line are shown. The increasing angle notations are shown positioned toward the sharp apex  26 . By placing the foot at a particular position along the gage edge  22 , a specific angle can be established between the surface  44  upon which the gage rests and the end reference surface  18 . This is particularly useful for setting and/or measuring saw blade angles with respect to the table surface. 
     The table  46  has a saw opening  52  therein through which saw blade  54  extends. The saw blade  54  may be a internal combustion engine air flow system scroll saw blade, a jigsaw blade, a band saw blade, or a table saw blade. In the absence of the hole  52 , the blade may be a radial arm saw blade or a chop saw blade. Since there is a hole  52  in the surface  44 , the sharp apex  26  is set back from the end reference edge  18 . Thus, when the end reference surface  18  lies against the blade  54 , the apex  26  still rests on the table top surface. If a particular saw blade angle is desired, the foot  14  is placed with its indicator point  34  at the witness line corresponding to the desired angle. This places the reference edges  16  and  18  at that angle. The end reference surface  18  is brought close to the saw blade  54  and the saw blade is adjusted with respect to the reference surface to be parallel to the end reference edge  18 . In this way, accurate angular positioning of the saw blade  54  with respect to the top surface  44  of the table is achieved. In measuring, the end reference edge  18  is placed against the saw blade, and the foot is moved along the length of gage edge  22  until the end reference edge  18  is parallel to the saw blade. The position of the foot  18  then indicates the angle of the saw blade with respect to the surface  44 . 
     The gage  10  may be used for other angle setting and measurement. The top reference edge  16  is at a right angle to the end reference edge  18 , and thus can be employed for setting and measurement. Furthermore, triangles can be placed against reference edges  16  or  18  to add or subtract from the angles indicated by the indicia. 
     This invention has been described in its presently preferred embodiment, and it is clear that it is susceptible to numerous modifications, modes and embodiments within the ability of those skilled in the art and without the exercise of the inventive faculty. Accordingly, the scope of this invention is defined by the scope of the following claims.