Abstract:
A precision electronic combination square having two elongated blades engaged to a head at perpendicular angles along two side surfaces. A digital display depicts the position of one or both blades as they translate relative to the head through the employment of a magnetic positioning system. An electronic switch allows the user to zero the relative position at any point and initiate a new measurement of travel of the blades.

Description:
[0001]    This application claims the benefit of U.S. Provisional Patent application No. 60/785,475 filed Mar. 24, 2006. The present invention relates to an improvement in the field of combination squares used by carpenters and machinists, artisans, handymen and the like. The combination square is one of the oldest and most commonly used hand tools used by a wide variety of tradesmen. The basic tool is used to achieve a precise 90-degree angle, a precise 45-degree angle, and a sliding blade with a measurement scale that is in most cases twelve inches long. A bubble-leveling vial is adjacent to one of the flat sides. 
     
    
     FIELD OF THE INVENTION 
     Background of the Invention 
       [0002]    The combination square as known today was first disclosed by Laroy Sunderland Starrett in U.S. Pat. No. 282,583 in 1883. The Starrett combination square has a bubble vial set in the body for leveling or plumbing surfaces. The body is locked in place by means of a thumbscrew. Although there have been many patents issued to revised concepts of the combination square, most tradesmen use a combination square very similar to the initial one patented by Laroy Southerland Starrett. 
         [0003]    Squares used by craftsmen come in a number of varieties including L-shaped framing squares, triangular speed squares, and combination squares, among others. Each square, while performing the same basic function, generally has some advantage over others for particular applications. 
         [0004]    For example, a framing square, which generally consists of a long blade and a short blade is useful for marking wide boards, checking the square sides of sheet stock, and laying out framing elements such as rafter or stringers with a scale imprinted on the blades for measurements and angular calculations. A speed square is in the shape of a right triangle and has a flange along its base which can be butted against the workpiece edge allowing the user to rapidly draw a square or 45 degree line. A combination square which includes a shorter handle-like leg, often referred to as a head, that slidably receives a blade, is useful in laying out fine detail work and transferring distances and is often used by machinists and tool and die makers. The head has fences at 90 and 45 degrees that allow the user to quickly transfer a distance accurately and hold it while a line is drawn with a scribe or pencil. Often, the head is provided with a leveling bubble. 
         [0005]    The device herein described and disclosed features an improved electronic combination square comprising an elongated blade constructed preferably of a non-magnetic material. An elongated conductor strip constructed of a magnetic material is attached longitudinally into a recessed top surface of the blade. A head has two ninety-degree angle sides and two forty-five degree angle sides constructed of a non-magnetic material. The head will slide to any position along the blades over the conductor strip from either of the two ninety degree angle sides. A fixing means is provided for locking the head to the blade from either of the two ninety degree angle sides. A component in the head provides a means for actuating a signal magnetically relative to the position of the head on the conductor strip in the blade. An assembly in the head is also provided as a means for outputting a visual representation of a dimension measured by the head in accordance with the signal received from the signal-actuating component. Of course other means to track and visually represent the travel of the blades relative to the head can be used and are anticipated; however, the current preferred mode of operation uses magneticly activated components since such a reading device is not subject to damage from dirt, grime, and dust, normally associated with cutting and forming components during measurements. 
       REFERENCES SITED 
       [0006]    More recently, U.S. Pat. No. 6,785,976 of Michael Morehouse presented a combination square comprising a blade and a head defining a slot in which said blade is at least partially received, said blade extending generally perpendicular to said head, wherein said head is divided into a first portion and a second portion, said first portion defining said slot, wherein said first and second portions are pivotally joined in each other by a pivot assembly, said pivot assembly defining an axis that extends parallel to said blade, whereby said second portion may be rotated about said axis. 
         [0007]    This patent describes a conventional combination square where the blade is adjusted by the means of loosening a thumb locking screw and moving the blade by holding the head in one hand and the blade in the other. It is difficult to get the blade in a precise location in this manner. In addition, the measurements must be read from the scale on the blade with reference to one of the flat sides of the head. This combination square has no electronic means to present precise digital measurements, and it cannot be zeroed out at any point along the travel path of the blade to give intermittent measurements within the center of the blade surface. 
         [0008]    U.S. Pat. No. 6,553,677 of Manny Szumer describes a combination square including a body with two opposing members, each having a plurality of straight-edged surfaces, and a clamping element adapted to clamp the opposing members together, the opposing members defining a recess therebetween for receiving therein a rule member. 
         [0009]    This patent describes a very unconventional combination square with unique capabilities, but it also requires loosening by the means of a nut and moving the blades by hand, and has no means to present visually readable precise measurements. 
         [0010]    U.S. Pat. No. 5,446,969 of Robert Terenzoni teaches of a combination square and multi-purpose hand tool that can be utilized as a large number of hand tools including a square, bevel square, stud and ceiling strapping spacer, clamp, caliper, string tender, and scribe. A first L shaped member includes a blade portion and a handle portion. A second member is pivotally and slidably coupled to the blade portion of the first member. Individual member dimensions such as the overall length of the first member, the maximum extended length of the second member along the first member, and the width of the blade portion of the first member are pre-established at selected lengths and widths to provide pre-determined fabrications for the present multi-purpose hand tool such as a stud spacer, ceiling strapping spacer, and string tender. 
         [0011]    This patent teaches of a hand tool with a wide variety of unique features that can be utilized by craftsmen, but does not offer the precise electronic measurement and capabilities and reporting of the Precision Electronic Combination Square described within this patent. 
         [0012]    While the prior patents and prior art of commercially available combination squares have been successful to a certain extent, it is nonetheless clear that substantial room exists for affecting an advance in the art, which overcomes these shortcomings in a practical and efficient manner. 
       THE OBJECTS OF THE INVENTION 
       [0013]    It is a general object of this invention to make a precision instrument out of the conventional combination square. 
         [0014]    A further object of the invention is to create a combination square with an electronic digital readout. 
         [0015]    Another object of this invention is to create a combination square which unlike prior devices can be zeroed out at any point along travel of the blade surface. 
         [0016]    Another object of the invention is to create a combination square with a secondary blade engageable at ninety degrees to the primary blade. 
         [0017]    Yet another object of this invention is to create a combination square with one or more fine adjustment thumbwheels. 
         [0018]    A further object of this invention is to create an alternate embodiment with two separate electronic digital readouts. 
         [0019]    Still another object of the invention is to create an alternate embodiment that can be zeroed out in two separate X and Y axes. 
         [0020]    A final object of this invention is to make the conventional combination square a state of the art precision hand tool that can be used by a wide variety of craftsmen. 
         [0021]    In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent construction insofar as they do not depart from the spirit and scope of the present invention. 
       SUMMARY OF THE INVENTION 
       [0022]    The preferred embodiment of the precision combination square consists of an improved precision electronic combination square comprising an elongated primary blade constructed of a non-magnetic material with an elongated conductor strip constructed of a magnetic material that is attached longitudinally into a recess on the front surface of the blade. The elongated primary blade slides within a groove in the first working surface with a conventional locking mechanism and a position clamping screw. A secondary elongated blade slides within a groove in the second working surface and is held in position by the means of a similar conventional locking mechanism and a position clamping screw. 
         [0023]    The head structure has a first working surface and a second working surface that are at a precise ninety-degree angle to each other. An additional forty-five degree angle working surface is adjacent to the first working surface. In a particularly preferred embodiment, the head structure is constructed of a non-magnetic material and will engage and slide to any position along either the elongated primary blade or the elongated secondary blade. An electronic component in the head provides an electronic means to ascertain a lateral translation measurement, in either direction, of the blade relative to the head for a determination and visual display of such a distance. Currently such means for translation measurement is provided by a means for actuating a signal magnetically relative to the position of the head on the conductor strip in the elongated primary blade and for communicating that position to a means for visual display in the desired degree of distance measurement, of the dimension measured by the head in accordance with the signal received from the signal-actuating component. The system will work in either metric or U.S. customary units. The electronic components may be either a capacitive sensing system or inductive sensing system and still fall within the scope of the particularly preferred mode of this invention. Of course other electronic means for translation measurement of the blade relative to the head can be employed, such as LED or laser reflection from a measurement indicator on the blade, or other electronic means to measure the traverse of the blade relative to the head. However, the current preferred mode uses magnetic operation of a reading device and strip having the acceptable components therein to provide the feedback as to lateral translation in either direction relative to the head. 
         [0024]    With either of these electronic systems, the precision combination square herein disclosed has the unique capability of being able to zero out anywhere along the elongated primary blade for precise measurement adjustments. With conventional instruments, mathematical calculations must be done with reference to the end of the blade to establish differences in head positions to obtain the zero position. This cumbersome error-prone problem is eliminated with the disclosed device which is enabled to go to the zero position at any point along the primary blade. 
         [0025]    Further, a unique fine adjustment thumbwheel has been incorporated into the design of the precision combination square similar to the ones used on some precision calipers for fine adjustments of the elongated primary blade. On one preferred embodiment of the precision electronic combination square, the elongated secondary blade does not have the electronic components or the fine adjustment thumbwheel and is used to extend the length of the secondary working surface. The elongated secondary blade is held in position by the means of a second position clamping screw. 
         [0026]    An alternate preferred embodiment of the precision electronic combination square herein disclosed has a second electronic component engaged adjacent to the secondary working surface along with a second fine adjustment thumbwheel. The elongated secondary blade communicates with a second electronic means to ascertain a lateral translation measurement, in either direction, of the secondary blade relative to the head. In the current preferred mode, this means to ascertain lateral translation will incorporate the conductor strip constructed of a magnetic material attached longitudinally into a recess on the front surface similar to the elongated primary blade with an additional forty-five degree angle working surface that is adjacent to the second working surface. The incorporation of the second electronic component and elongated secondary blade with the magnetic strip will allow craftsmen to work precisely along both the X and Y axes of their work piece, and to zero out either at any point of translation of either the primary or secondary blades. 
         [0027]    With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, especially with regard to the electronic means of determining travel of the blade relative to the head since such technologies are constantly evolving. All equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]    The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of this invention. 
           [0029]      FIG. 1  depicts a side view of the precision combination square with a single electronic component for measuring and displaying lateral translation. 
           [0030]      FIG. 2  depicts a top view of the precision combination square with a single electronic component. 
           [0031]      FIG. 3  depicts a detail view of the fine adjustment thumbwheel mechanism. 
           [0032]      FIG. 4  depicts an alternate embodiment of the precision combination square with two electronic components for measuring translation of both a primary and secondary blade. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0033]    For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in conjunction with the accompanying drawings which are incorporated in and form a part of this specification, illustrate embodiments of the invention, and together with the description, serve to explain the principles of this invention. 
         [0034]    A first preferred embodiment of the precision combination square  10 A, shown in  FIG. 1  consists of an elongated primary blade  12  constructed of a non-magnetic material such as stainless steel or brass or plastic. Means for electronic determination and communication of translation distance of the blade  12  in the primary blade groove  20  is provided by an elongated conductor strip  14  constructed of a magnetic material conductor strip that is engaged longitudinally into a conductor strip recess  16  on the front surface  18  of the elongated primary blade  12 . Such material is conventionally formed in flexible strips of magnetic material that has alternating layers of magnetic material with alternating poles such as the flexible tape of model ZMX40M from Zetex Semiconductor. Other such magnetic material devices, as well as capacitive and inductive and optical systems for distance measurement are well known and commercially available and configurable to measure the translation of the blade  12 , in either direction in its engagement relative to the head  24 , and this application, of course, anticipates other electronic means to measure translation distance of travel of the blade  12  in either direction relative to the head  24 . 
         [0035]    The elongated primary blade  12  slides within a primary blade groove  20  in the first working surface  22  of the head structure  24 A with a conventional blade locking mechanism  26  and a position clamping screw  28 . A secondary elongated blade  30 A slides within a secondary blade groove  32  in the second working surface  34  and is held in position by the means of a similar conventional blade locking mechanism  26  and a second position clamping screw  36 . 
         [0036]    The head structure  24 A has a first working surface  22  and a second working surface  34  that are precisely at a ninety-degree angle to each other. An additional forty-five degree angle working surface  38 A is adjacent to the first working surface  22 . The head structure  24 A is constructed of a preferably non-magnetic material such as aluminum, stainless steel, or brass, and may be positioned along either the elongated primary blade  12  or the elongated secondary blade  30 A. A bubble leveling vile  40  is adjacent to the second working surface  34  on the upper portion  42 A of the head structure  24 A and provides a means to determine level positioning of the device. 
         [0037]    An electronic component  44 A providing means to read the translation of the primary blade  12  is located on the lower front surface  46  of the head structure  24 A. The electronic component  44 A is for actuating a signal magnetically relative to the position of the head structure  24 A with the conductor strip  14  on the elongated primary blade  12 , and outputting a signal to produce visual digital representation on the electronic digital reading screen  48  of a dimension of travel measured by the head structure  24 A in accordance with the signal received from the signal actuating component. The electronic component  44 A will work in either metric or U.S. customary units and may be adjusted by pressing the control button  50 . The electronic component  44 A, while currently employing magnetic means to determine distance of travel, may be either a capacitive sensing system or inductive sensing system and could also be optical and still fall within the scope of this invention. 
         [0038]    As noted earlier, employing such an electronic means to determine translation travel of the blade  12  relative to the head in its slidable engagement, the disclosed combination square  10 A has the unique capability of being able to zero out anywhere along the elongated primary blade  12 . This unique and useful function is provided by an electronic switch or zero button  52  which will cause the electronic component  44 A to reset to a distance of zero and to produce a signal to display a measurement of zero. This reset can be activated at any point of translation of the primary blade  12  relative to the head. Pressing the zero button  52  will thus zero the display, and thereafter translation of the primary blade  12  in either direction will be measured from the zero point. Thus, the zero button allows measurement of distance of translation in either direction of the primary blade  12  relative to the head and thus gives the user great convenience in measuring. The electronic component  44 A is turned on and off by pressing the on/off button  54  or could be equipped to automatically turn off after a defined period of time. The battery cover plate  56  is located in the lower right hand corner of the electronic component  44 A. A numerical scale of distance is formed on the front surface  18  as a back up translation measurement in case of failure of the electronic component or a dead battery and also as a visual double-check of the electronically calculated relative position. 
         [0039]    A unique fine adjustment thumbwheel  58 A has been incorporated into the design of the precision combination square  10 A. The fine adjustment thumbwheel  58 A has been incorporated into the design of the precision combination square  10 A for the purpose fine adjustments of the elongated primary blade  12 . It is especially important to place the thumbwheel  58 A as depicted in  FIG. 2 , the top view of the precision combination square  10 A, where the fine adjustment thumbwheel  58 A may be rotated to easily move the elongated primary blade  12  back and forth with the frictionally engaged roller  66  positioned in a recess between the parallel and adjacent roller-engaged thumbwheels  58 A. 
         [0040]      FIG. 3  depicts a detail view of the fine adjustment thumbwheel  58 A with the thumb rest  60 A held in place by the means of a screw  62 . Thumb rest  60 A has an arm  64  that retains centrally located roller  66  in a rotational engagement between the arm  64  and the top surface of the primary blade  12 . The arm  64  additionally provides a means to exert pressure on the central area roller  66  against the top surface  68  of the elongated primary blade  12 . Especially desirable is the two thumbwheels  58 A separated by a recess adapted to engage the arm  64 . The two thumbwheels  58 A with the gap therebetween, allow for an especially good connection between the surface of the user&#39;s thumb and the thumbwheel  58 A, as the soft tissue of the thumb will depress into the gap and around both thumbwheels  58 A. This allows for much more accurate rolling of the thumbwheel  58 A by the thumb and with less pressure thereon than would be required with a single surface thumbwheel. It must be fully understood at this time that a variety of configurations of fine adjustment thumbwheels  58 A to accomplish the task of translating the elongated primary blade  12  back and forth are anticipated and will be covered within the scope of this patent. However the depicted configuration is especially well adapted as noted. 
         [0041]    Additionally, on the first preferred embodiment of the precision electronic combination square  10 A, the elongated secondary blade  30 A does not have the magnetic conductive strip  14  and is basically used to extend the length of the second working surface  34  against which the device would engage to then obtain the desired measurement of translation of the primary blade  12  by translation thereof. The elongated secondary blade  30 A is held in position by the means of a second position clamping screw  36 . 
         [0042]    The alternate preferred embodiment of the precision electronic combination square  10 B shown in  FIG. 4  has a second electronic component unit  44 B engaged on the upper portion of the head structure  24 B adjacent to the second working surface  34  along with a second fine adjustment thumbwheel  58 B and a second thumb rest  60 B. The elongated secondary blade  30 B will incorporate the conductor strip  14  constructed of a magnetic material attached longitudinally into a conductor strip recess  16  on the blade front surface  18  similar to the elongated primary blade  12 . The incorporation of the second electronic component  44 B and elongated secondary blade  30 B with the conductor strip  14  will allow craftsmen to work precisely along the X and Y axes of their work piece, to measure translation of either blade in either direction, and to zero out either blade at any point in travel, in either direction. 
         [0043]    The precision combination square  10 A and  10 B shown in the drawings and described in detail herein disclose arrangements of elements of particular construction and configuration for illustrating preferred embodiments of structure and method of operation of the present invention. It is to be understood, however, that elements of different construction and configuration and other arrangements thereof, other than those illustrated and described may be employed for providing a precision combination square  10 A and  10 B in accordance with the spirit of this invention, and such changes, alternations and modifications as would occur to those skilled in the art are considered to be within the scope of this invention as broadly defined in the appended claims. 
         [0044]    Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.