Adapter for circular saw to cut-off saw
BACKGROUND OF THE INVENTION 
     In the past cut-off or &#34;chop&#34; saws have been employed for conveniently clamping bar stock, rods or the like for cutting off ends of material. Such saws have been of a specialized style and conventionally are of an integrated nature employing an adjustable clamp for the material to be cut and a hinged circular saw equipped with an abrasive blade for cutting metal. The saw is specially designed for use in the integrated cut-off saw and is not adapted for general use. 
     The afore-mentioned cut-off or &#34;chop&#34; saws, while effective, are of specialized employment for cut-off use and of considerable expense. 
     While conventional less expensive portable circular saws having the standard flat support base which is slidably positioned on top of the work piece may be employed to cut-off pieces from lengths of bar stock and the like, the use is awkward. A separate clamp or vise for the stock material should be employed and the set-up is awkward and time consuming. 
     SUMMARY OF THE INVENTION 
     By means of the instant invention, there has been provided an adapter for converting a conventional portable flat base circular saw to a cut-off or so-called &#34;chop saw&#34;. 
     The adapter is portable and has a flat base which may be supported on a flat work support such as a table or the like. The base is provided with an adjustable vise like clamp for firmly securing lengths of bar stock, rods or the like in a position to be cut-off by a circular saw. 
     A circular saw clamp is employed to support the saw for pivotable swinging movement from a rest position to a working or cut-off position. The clamp is connected by a hinge to the adapter base to accommodate the swinging movement. 
     A deep throat or groove in the clamp is used to support and clamp the conventional flat slide base of the circular saw wherein an end of the saw base is received within the groove. Thumb screws are employed to lock the saw base in the throat of the clamp. 
     The afore-mentioned clamp structure readily receives various types of conventional portable circular saws to provide a versatility in use for the saw and simple adaptation to cut-off or chop saw use. The conversion is simply effected in a minimum of time and expense. The saw may be interchanged with various types of blades as is usual and fitted with a standard abrasive blade for cut-off of metal as desired. 
     The above features are objects of this invention. Further objects will appear in the detailed description which follows and will be further apparent to those skilled in the art. 
     For the purpose of illustration of this invention, preferred embodiments thereof are shown in the accompanying drawing. It is to be understood that the drawing is for purpose of description only and that the invention is not limited thereto. 
    
    
     IN THE DRAWING 
     FIG. 1 is a top plan view of the adapter; 
     FIG. 2 is a view in side elevation taken from the right side of FIG. 1 showing a fragmentary portion of a circular saw in the rest position; 
     FIG. 3 is a view partly broken away in section similar to FIG. 2 but showing the circular saw clamped to the adapter in the cut-off position; 
     FIG. 4 is a view in side elevation showing a clamped circular saw in the cut-off position of FIG. 3 from the left side. 
    
    
     DESCRIPTION OF THE INVENTION 
     The adapter of this invention is generally indicated by the reference numeral 10 in FIGS. 1 through 4. A circular saw 12 is shown clamped to the adapter in FIGS. 2, 3 and 4. 
     The circular saw is of conventional construction employing a standard flat slide plate 14 having a bevelled front edge or toe 16. The saw supports a motor 15 and a circular blade 18 which may be an abrasive blade for metal cutting or interchanged if desired with a toothed blade for wood-cutting. A standard safety shield 20 having a handle 22 for opening the moveable shield 23 is provided along with a saw handle 24. The above features are standard in such portable electric circular saws and form no part of this invention, per se. These features, however, interfit with the structure of the adapter as will be described hereinbelow. 
     The adapter is comprised of a flat base 26 having side walls 28 of substantial height to position the circular saw blade in the finished cutting action substantially above a work table upon which the base is supported. The base may be made of steel for ruggedness, stability and weight and provided with a bottom pad 29 of rubber or the like for protection of support surfaces and resistance to movement. A top surface 30 of the base supports a work piece vise or clamp 32. 
     The vise is comprised of a stationary jaw 34 and an adjustable jaw 36 as best shown in FIGS. 1 through 3. The jaw 34 is formed of an upstanding haw fase 37 of an angle iron secured to the adapter base by bolts or the like. These bolts may be reset in threaded openings 40 to provide a greater vise opening as desired. 
     The adjustable jaw 36 is comprised of an upstanding jaw face 42 supported upon a pair of rails 44 and 46 which interfit with a stationary yoke 48 fixed to the base. The yoke has overhanging end portions 50 and 52 spaced above the top surface of the base and slidably receiving the rails. 
     In order to adjust the adjustable jaw 36, a threaded shaft 53 is received in a bearing 54 on the jaw. The threaded shaft is fitted through a threaded hole in the yoke and turned by a knob 56 at the free end of the shaft. As the shaft is rotated the adjustable jaw may be opened or closed with respect to the stationary jaw. 
     In order to support the circular saw, a hinged saw clamp 58 is employed. The saw clamp is comprised of a support member 60 connected to the base 26 by a hinge 62. A stop 64 abutts against the base in a rest position as shown in FIG. 2. 
     The support member 60 has a generally upstanding clamp portion 66 comprised of plates 68 and 70 spaced from one another to provide a deep throat or groove 72 which receives the bevelled toe 16 of the circular saw sliding support base. Thumb screws 74 and 76 are employed to lock or clamp the circular saw in the clamping groove. For further stability and support of the saw in the clamp, plate 68 extends substantially beyond the plate 70 in order to provide a rest support for the weight of the saw. Where a bevelled front edge or toe 16 is not employed with the flat slide plate (or is of minor extent) it will be understood that it will fit flat in substantially parallel relation within the clamp plates 68 and 70. In any case the clamp is employed at the front of the slide plate and performs equally well for the front end configuration. 
     The base is further provided with a spark deflector 78 to deflect sparks, sawdust and the like generated in the cutting operation of FIG. 3 downwardly. The deflector is open at the bottom and has a concave interior to direct the deflected material downwardly alongside the side wall of the base to which it is connected by flange 80. 
     USE 
     The circular saw adapter of this invention is very simply employed by placing the flat adapter upon a convenient flat work piece such as a table or the like. A conventional circular saw is then clamped to the hinged clamp by insertion of the bevelled flange-like toe 16 into the deep throat 72. The saw is positioned to line the saw blade a short distance from the side of the vise or clamp 32 of the adapter in general alignment with the deflector 78. The thumb screws 74 and 76 are then tightened to clamp the saw firmly in the groove or throat 72. 
     The saw, when not in the operative position of FIG. 3 may be rested in the rest or support position of FIG. 2 where the stop 64 abutts against the side of the adapter base. The center of gravity of the saw is positioned to the right of the hinge 64 to hold this position. 
     In use, the saw may be equipped with an abrasive blade for metal cutting or interchanged if desired with a toothed blade for wood-cutting. Such interchange is standard for the usual circular saw. 
     With the saw ready for use, or as a preliminary operation, a work piece to be cut such as that shown at 82 is clamped in the adapter vise 32. The saw is then grasped by the handle 24 and rotated counter-clockwise as shown in FIGS. 2 and 3 toward the work piece. The handle 22 of the blade shield is operated to open the shield or cover of the movable blade shield 23. The saw is then lowered to engage the saw blade 18 against the work piece 82 to be cut. The center of gravity of the saw is to the left of the hinge 62 as viewed in FIG. 3 and the weight of the saw aids the cutting operation. 
     When the cut-off operation is completed, the saw is returned to the stable rest position shown in FIG. 2. The work piece is readjusted in the vise and the cutting cycle above described may be completed. 
     The adapter as will be readily understood from the above description may be simply employed to convert a standard circular saw to a cut-off or chop saw. The adapter is portable and may be used in the field by support on any flat surface support or the like. It is rugged and through its relatively inexpensive cost and simplicity may be employed as a versatile adjunct with the standard circular saw. 
     Various changes and modifications may be made within this invention as will be apparent to those skilled in the art. Such changes and modifications are within the scope of this invention as defined in the claims appended hereto.