Abstract:
A multi-task protractor apparatus having the capabilities of a rotating protractor, adjustable triangle, ruler, miniature leveler, framing square and roof angle finder is disclosed. The multi-task protractor accurately measures angles and slopes and provides two straight edges for constructing angles and triangles.

Description:
FIELD OF THE INVENTION 
   This invention relates to a rotating protractor apparatus having the capabilities of a rotating protractor, adjustable triangle, ruler, miniature leveler, framing square and roof angle finder. The rotating protractor accurately measures angles and slopes and provides two straight edges for drawing lines. 
   BACKGROUND OF THE INVENTION 
   Architects, engineers, layout draftsmen, manufacturing engineering, field engineers, students and others require the use of protractors, triangle construction equipment, framing squares and the like almost daily in their activities. This results in the requirement to carry one or more rulers, a square, a protractor, a level, and the like. Since it is inconvenient to carry all of these tools a continuing effort has been directed to development of a single tool which can supply all of these functions. 
   SUMMARY OF THE INVENTION 
   According to the present invention, the above mentioned functions are all accomplished by the use of a multi-task protractor comprising: a ruler of a selected length, having a first edge and a second edge, a first side and a second side, a length and a width, a first connector opening, at least one second connector opening and at least one leveling vial; a rotatable arm having a first and a second end, a first and a second side, a first arm connector opening near the first end of the rotatable arm and a second arm connector opening and being connected to the ruler by a first connector connecting the first connector opening and the first arm connector opening for rotation about the first connector or positioning in selected fixed orientations relative to the ruler and the first connector; and, a protractor comprising a 180 degree arc having an arc inside and an arc outside, a first and a second end, a passageway extending around the 180 degree arc between the arc inside and the arc outside and at least one set of graduations on at least one side of the protractor, the protractor being connected to the ruler and to the rotatable arm by at least one of a second connector connecting at least one of the plurality of second connector openings, and the passageway and a third connector in the second arm connector opening to enable sliding and rotationable movement of the protractor relative to the rotatable arm and to enable positioning the protractor in selected fixed positions relative to the ruler and the rotatable arm. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic diagram of an embodiment of the multi-task protractor of the present invention; 
       FIG. 2  is a larger scale view of the protractor shown in  FIG. 1 ; 
       FIG. 3  is an end view taken at line AA of  FIG. 1  of the multi-task protractor; 
       FIG. 4  is a schematic diagram of an embodiment of the multi-task protractor positioned to construct a triangle having a 45 degree angle; 
       FIG. 5  is a schematic diagram of an embodiment of the multi-task protractor of the present invention positioned to measure the slope of a roof relative to a wall joining the roof; 
       FIG. 6  is a schematic diagram of an embodiment of the multi-task protractor of the present invention positioned to measure the slope of a roof; and, 
       FIG. 7  is a schematic diagram of an embodiment of the multi-task protractor of the present invention in its collapsed position so that its rotatable arm is positioned on the ruler. 
   

   DESCRIPTION OF PREFERRED EMBODIMENTS 
   In the discussion of the Figures, the same numbers will be used throughout to refer to the same or similar components. 
   In  FIG. 1  an embodiment  10  of the multi-task protractor of the present invention is shown. The multi-task protractor comprises a ruler  12  having a first edge  14  and a second edge  16 . The ruler also has a length  18 , a width  20  and a longitudinal axis  22 . English marking units  24  are shown positioned on first edge  14  of the ruler with metric marking units  26  being shown on second edge  16  of the ruler. Obviously a different choice of units or units in a different location could be used if desired. Ruler  12  has a first side  28  and a second side  30  and also includes leveling vials  32 ,  34  and  36 . The leveling vials are positioned to enable the positioning of the ruler in an upright position, a horizontal position or a 45 degree angle position. 
   Ruler  12  also includes holes  38  to hold connectors used to maintain a protractor  54  in position relative to ruler  12 . Holes  38  are positioned in ruler  12  at locations useful for positioning protractor  54  in a desired position. As shown in this embodiment, thumb screw nuts  40  with threaded bolts positioned through ruler  12  and a rotatable arm  42  are used to maintain rotatable arm  42 , ruler  12  and protractor  54  in desired orientation to each other. Rotatable arm  42  includes a first side  44 , a second side  46 , a measurement scale  47 , which may be of any suitable units, a width  48  and has a longitudinal axis  50 . Rotatable arm  42  is held in position relative to ruler  12  by a first connector  52  which comprises a thumb screw nut operably positioned on a threaded bolt penetrating ruler  12 . Clearly thumb screws or their equivalent are equally useful. Similarly, the threaded bolt could be positioned through ruler  12  or rigidly fixed in ruler  12  in openings  38  or the like. Such variations are well within the scope of the present invention. 
   Protractor  54  includes an arc inside  58 , an arc outside  60  and a passageway  56  which allows it to move relative to a second connector  62  positioned in rotatable arm  42  and a third connector  64  positioned in ruler  12 . As mentioned previously, these connectors are shown as threaded bolt fittings which are equipped with a thumb screw nut on each threaded bolt. When these thumbscrews are tightened, the protractor, rotary arm and ruler are locked in position. In this position, the rotary arm and ruler may function as a square or a level. Ruler  12  can function as a level with rotatable arm  42  in virtually any position so long as the position of rotatable arm  42  does not interfere with the leveling measurement. Protractor  54  further includes a passageway  56 , which enables sliding engagement with second and third connectors  62  and  64 , respectively. 
   Ruler  12  also includes a pair of arrows  86  which are useful to read selected angles on protractor  54 . These arrows may be etched, stamped or otherwise formed on ruler  12 . 
   Ruler  12  may be of any suitable material, such as wood, plastic, steel or wood covered with plastic, steel or other metallic sheathing and the like. Any material which provides suitable strength and stability can be used. Rotatable arm  42  can be formed of a similar material. Desirably protractor  54  may be formed of steel or other metallic material, plastic or the like. The scaling units on protractor  54  may be etched, stamped or otherwise formed on protractor  54 . 
   As shown in  FIG. 2 , protractor  54  in one embodiment includes a 0 to 180 degree scale  66  near arc outside  60  with 0 degrees at the left and a 180 to 0 degrees scale  68  with the 180 degrees at the left. In  FIG. 2 , protractor  54  also includes a 90 to 0 degrees scale  70  near passageway  56  with the 0 degrees being at the top of the arc. Further protractor  54  desirably includes a pitch scale  72  near arc inside  58 , which is useful in determining the slope of roofs and the like. As shown, protractor  54  has a width  74  and a diameter  76 . 
   In  FIG. 3 , an end view of the multi-task protractor of  FIG. 1  is shown. Thumbscrew nuts  40  forming first connector  52  and third connector  64  are shown. Connector  64  comprises a bolt which is amenable to tightening so that thumbscrew  40  can be tightened to maintain protractor  54  in a desired position relative to rotatable arm  42  and ruler  12 . 
   Ruler  12  may be a formed piece of metal having lips  82  at edges  14  and  16 . Connector  62  is shown having a head  78  which is flush with the back of rotatable arm  42 . Rotatable arm  82  also includes a support  84  positioned on its back side which enables it to be supported at the same level on its outer end as on ruler  12 . A second support  84 ′ may also be provided if desired as shown by dotted lines. 
   In  FIG. 4 , the multi-task protractor is shown in position to construct triangles of a given configuration. In the embodiments shown, by positioning a line along the edge of first side  44  of adjustable arm  42  and along the edge  14  of ruler  12 , a 45 degree angle is readily constructed. The multi-task protractor may then be removed and the ruler or the rotatable arm used to extend the two lines toward their junction and to extend the lines a desired distance from the junction so that the ends of the lines when joined by a third line between their ends form a triangle. 
   In  FIG. 5 , the multi-task protractor is shown positioned against a wall  68  to determine the slope of a roof  66 . The slope of the roof is read on scale  72  at arrow  86  and identifies to the user the slope of a roof  66 . While performing this measurement, it is also possible to confirm that the horizontal wall  90  is in fact horizontal with the appropriate vial. 
   In the embodiment shown in  FIG. 6 , the multi-task protractor is used to take a measurement of the slope of a roof at an edge of the roof or the like. The angle of the roof is the same as the angle between the arrow  86  and the 0 degree measurement at the top of the protractor. Further, the slope of the roof is readily determined by reading the protractor at arrow  86 . 
   In  FIG. 7 , the rotary arm is shown in position over the top of ruler  12 . In this embodiment, openings  92  and  94  respectively permit the positioning of rotary arm  42  flat over ruler  12 . 
   In the use of the multi-task protractor, the embodiment shown in  FIG. 1  enables the measurement of angles. The embodiment shown in  FIG. 4  is desirable for constructing triangles or measuring angles. In all embodiments the ruler can function as a ruler. The levels permit the use of the multi-task protractor as a level. The embodiment shown in  FIG. 1  can serve as a square and the embodiment shown in  FIGS. 5 and 6  enable the determination of the slope of a roof easily and quickly. 
   As indicated previously, the rotating arm, the ruler and the protractor may be of any suitable material. Suitable materials may comprise wood, plastic, metal or combinations thereof. For instance, the protractor may comprise a metallic protractor with the scaling units etched on the protractor at the selected spots. The ruler and rotating arm may also be metallic or may be plastic or wood or plastic or metal-covered wood or the like. Any suitable material may be used provided it has the requisite strength and durability for use in the applications referred to herein. 
   Typically the ruler will be a 12 inch ruler with scaling in English and metric units. In this ruler base, there are typically three leveling vials. Desirably the rotating arm may be 8 inches long with a 6 inch measurement scale. The rotating arm is desirably attached to the base ruler by a brass knob or a thumbscrew connector. The rotating protractor will be attached to the ruler and the rotating arm with similar thumbscrew connectors. The ruler, protractor and rotating arm may have different or additional scaling units scribed on them as an alternative to those described above. 
   The multi-task protractor is a valuable combination of a protractor, adjustable triangle, ruler, level and framing square capable of determining or drawing certain measures, angles, slopes and the like. 
   This invention is useful to many technical professions, such as students, architects, engineers, draftsmen, estimators, artists and the like. It may also be used as a hand tool in the construction industry where carpenters, framers, metal sheet workers, roofers, etc. may use this tool to determine existing slopes and angles more efficiently than possible with any other tool. Further the use of the multi-task protractor enables the carrying of only a single tool for all these functions. 
   In many instances it may be desirable to provide a tool which also will provide a reciprocal angle. Particularly with reference to  FIG. 6 , please note that the angle θ is the same as the angle between arrow  86  and the top 0 degree point on protractor  54 . This reciprocal angle is desirable in many instances. If cuts are being made in rafters to form roof  66 , it is very desirable to know the θ angle. 
   This tool effectively combines six tools into one. The multi-task protractor combines a ruler, protractor, leveler, adjustable triangle, framing square and a roof angle finder. 
   For instance, the multi-task protractor may be used to give the user four measurements in one-step instead of only the two measurements achieved by the prior art. For instance, with respect to  FIG. 6 , the outside angle of 120 degrees can be read on the scale  66 , the reciprocal angle can be read on scale  68 , the adjacent angle can be read on scale  70  and the slope or pitch can be read on scale  72 . 
   The multi-task protractor has an adjustable triangle and the protractor can be used to construct or measure any angle from 0 to 180 degrees. To measure the angle, the rotating arm should be adjusted to the desired degree marked by the arrow indicated in the middle center of the ruler base. The outside measurement is the angle. The second measurement reads the reciprocal angle and the third measure determines the adjacent angle. The multi-task protractor can measure any hip, ridge and valley rafter cut in one step and in several ways as discussed above. 
   As demonstrated above, the multi-task protractor is an extremely efficient and effective tool useful for those in the construction industry and by others who have need of rulers, protractors and the like for construction of angles, measurement of slopes and the like. 
   While the present invention has been described by reference to certain of its preferred embodiments, it is pointed out that the embodiments described are illustrative rather than limiting in nature and that many variations and modifications are possible within the scope of the present invention. Many such variations and modifications may be considered obvious and desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments.