Abstract:
A chipping hammer for removing oxidation and slag from a welding bead, usually an arc welding bead, wherein the hammer includes a long lasting narrow replaceable chipping point economically formed by a hardened nail. Easily operated attachment means removably maintain the point on the hammer head.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention pertains to manually held chip hammers for removing oxidation and slag from a welding site wherein the hammer includes an easily replaceable point.  
         DESCRIPTION OF THE RELATED ART  
         [0002]    Chip hammers are a necessary tool for those performing arc welding. A slag forms over the welding bead, and if additional weld passes are to be taken, the slag must be first removed by a chip hammer to provide a bare metal surface for subsequent welding operations.  
           [0003]    A conventional welding chip hammer includes an elongated head mounted on the end of a handle. One end of the hammer head is usually in the form of a chisel, and the other end of the hammer head is ground to a point. The pointed end is necessary as it permits the hammer to be effective in close quarters and to strike small portions of the slag to be removed. However, because the slag is very hard and roughly surfaced, the chip hammer pointed end quickly dulls and must be resharpened by grinding the hammer head. Continuous regrinding or resharpening the pointed hammer head end is time consuming and depletes the mass of the hammer head periodically requiring discarding of the chip hammer for replacement by an entirely new hammer including head and handle.  
           [0004]    Accordingly, conventional weld chip hammers create an expensive non-obvious cost in arc welding operations due to the time required to grind and resharpen hammer head points, and as dull points do not effectively remove many types of slag configurations, defective welds may result from dull chip hammer points.  
           [0005]    Heretofore, the aforedescribed problem with respect to welding chip hammer pointed ends has not been successfully solved.  
         OBJECTS OF THE INVENTION  
         [0006]    It is an object of the invention to provide an inexpensive welding chip hammer having a replaceable sharp point eliminating the necessity to regrind or discard welding chip hammers because of dull points.  
           [0007]    Another object of the invention is to provide a welding chip hammer having a replaceable sharp point wherein the point is formed of an inexpensive commercially available hardened nail, and the practice of the invention substantially reduces welding costs arising from dull welding chip hammers.  
         SUMMARY OF THE INVENTION  
         [0008]    A welding chip hammer in accord with the invention includes the usual elongated hammer head having a chisel configuration at one end, and a point at the other. A handle stem is connected to the head intermediate its ends and a handle grip is attached to the outer end of the stem. In this sense, the general configuration of a chip hammer in accord with the invention corresponds with a conventional chip hammer, and no new skills need to be developed in using the chip hammer constructed in accord with the inventive concepts.  
           [0009]    The chip hammer of the invention departs from conventional construction in that the non-chisel end of the head is provided with attachment means by which a sharp replaceable point may be quickly affixed to the hammer head end by the use of conventional tools and ordinary mechanical skills.  
           [0010]    The replaceable chip hammer point attachment means includes a blind threaded hole formed in the hammer end usually coaxial with the hammer head axis. The threaded hole terminates in a closed end. Two embodiments of attachment means within the inventive concepts are illustrated. In one embodiment, a stud is threaded into the head threaded hole. In the other embodiment, a fitting is threaded into the hole for maintaining the point in position.  
           [0011]    The point removably attached to the hammer head end is preferably in the form of a conventional hardened nail having a head defining a shoulder at one end, and a pointed end at the other. Such a hardened nail, usually of approximately two inches in length, is readily available at most hardware stores as the same are used to be driven into concrete by hammer or explosive charge. Such nails have a high strength, and are capable of maintaining a sharp point over long periods of time when used to engage arc welding slag.  
           [0012]    In one embodiment, a threaded cap is mounted on a threaded stub screwed into the head hole and the cap has a hole therein wherein the pointed end of the nail is inserted through the cap hole, and the cap maintains the nail headed end against the stud outer end, which defines an anvil surface to limit nail movement toward the hammer head. Preferably, an annular washer of a resilient construction is located within the cap about the nail to align the nail within the cap prior to tightening of the cap, and give additional lateral support to the nail.  
           [0013]    In the other embodiment of the invention, a tubular threaded fitting receives the nail pointed end and is of a length sufficiently less than the nail length so that the nail point extends beyond the fitting. The diameter of the fitting thread is less than the diameter of the nail head wherein threading of the fitting into the hammer head threaded hole results in the nail head being firmly held against the bottom surface of the head threaded hole which defines an anvil surface preventing nail movement. The extension of the nail pointed end past the fitting makes the nail pointed end available for weld slag chipping purposes.  
           [0014]    Preferably, the hammer grip includes an interior hollow chamber having a closeable opening wherein spare points may be stored within the chip hammer grip for quick use at the welding site.  
           [0015]    A welding chip hammer constructed in accord with the invention provides an inexpensive welding tool capable of maintaining a sharp point during use, and it is to be appreciated that the objects and advantages of the invention have been achieved.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    The aforementioned objects and advantages of the invention will be appreciated from the following description and accompanying drawings wherein:  
         [0017]    [0017]FIG. 1 is an elevational view of one embodiment of the welding chip hammer of the invention,  
         [0018]    [0018]FIG. 2 is a plan sectional view as taken along Section  2 - 2  of FIG. 1,  
         [0019]    [0019]FIG. 3 is a detail elevational, partially sectioned, exploded view of the replaceable point structure as shown in FIGS. 1 and 2,  
         [0020]    [0020]FIG. 4 is a sectional view taken through the hammer grip along Section  4 - 4  of FIG. 1 illustrating spare points within the grip,  
         [0021]    [0021]FIG. 5 is an elevational view of another embodiment of a welding chip hammer including the concepts of the invention,  
         [0022]    [0022]FIG. 6 is a detail sectional elevational view of the attachment means of the embodiment of FIG. 5 as assembled,  
         [0023]    [0023]FIG. 7 is a detail, exploded, partially sectioned view of the attachment means of FIGS. 5 and 6, and  
         [0024]    [0024]FIG. 8 illustrates the grip shown in FIG. 5 having a chamber defined therein for spare nail points.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0025]    A chip hammer utilizing the concepts of the invention is shown in elevation in FIG. 1 wherein the head  10  is mounted upon a shank  12  having a hand grip  14  permitting the tool to be used in the normal hammer manner.  
         [0026]    The head  10 , at one end, includes the usual chisel-shaped end  16 , and the other end of the head constitutes the pointed end assembly  18 . As will appreciated, the pointed end  18  constitutes an assembly of several parts as later described.  
         [0027]    The head end at assembly  18  is squared off with respect to the length of the elongated head, and a threaded blind hole  20  is formed within the head end which receives a threaded stud  19 . The outer end of the threaded stud  19  is formed with a flat end surface  22 , FIG. 3, which serves as an anvil to absorb forces imposed upon the head by the tool point as later apparent.  
         [0028]    A cap  24  of a configuration similar to a conventional crown nut includes interior threads  26  so as to be threadable upon the outer end of stud  19 . The cap threads  26  are axially symmetrically aligned with the cap convex crown  28  which defines an interior concave chamber  30  and a hole  32  centrally extends through the crown  28  as will be apparent from FIG. 3. The cap  24  is provided with a hexagonal surface  34  whereby a wrench may be applied for tightening the cap upon the stud  19 .  
         [0029]    The tool point  36  is formed by a conventional nail, preferably of the hardened type such as a conventional concrete nail adapted to be driven into a wall or floor. The point  36  includes a shoulder or head end  38  and the usual pointed end  40 . An annular positioning ring  42  is located within the cap chamber  30 , and the ring  42  is preferably formed of polyurethane or other resilient material.  
         [0030]    The tool pointed end  18  is assembled as will be appreciated from FIGS. 2 and 3. By orienting the parts as shown in exploded view FIG. 3, the point sharp end  40  may be inserted through the positioning ring  42  and the cap hole  32 . Upon complete insertion of the point head  38  into the cap  24 , the cap may be threaded upon the stud  19  and tightened thereon. Tightening of the cap causes the positioning ring  42  to engage the internal concave surface of cap chamber  30  forcing the point head  38  against the stud anvil surface  22  as shown in FIG. 2, to complete the assembly.  
         [0031]    When fully assembled as shown in FIG. 2, the point  36  is rigidly attached to the stud  19  of the tool head  10 , and as the preferred length of the point  36  is approximately one and one-half to two inches, a significant portion of the point  36  extends beyond the cap  24  whereby the point  36  may be used to chip slag from a welding site. The hardened nature of the point  36  permits the point to have a long wear life, and the point end  36  will retain its shape and sharpness much longer than points previously ground upon a head of a conventional welding chip hammer.  
         [0032]    Use of the positioning ring  42  is optional, and the assembly shown in FIG. 2 can be accomplished without use of the ring  42 . The ring helps to initially maintain the point  36  within the cap  24 , but if the ring  42  is omitted from the assembly, the point head  38  will directly engage the wall defining chamber  30  which maintains the head  38  against the stud end surface  22 .  
         [0033]    Preferably, a chamber  44  is defined within the grip  14 , FIG. 4, and a threaded removable plug  46  provides access to the chamber  44 . As shown in phantom lines, spare points  36  can be stored within the chamber  44 .  
         [0034]    Another embodiment of a welding chip hammer utilizing concepts of the invention is shown in FIGS.  5 - 8 . In this embodiment, components substantially identical to those described above are indicated by primed reference numerals.  
         [0035]    In the embodiment of FIG. 6, the hammer head  48  can be made from a conventional cold chisel having a chisel end  50 , and the pointed end assembly is represented at  52 . As shown in FIGS. 6 and 7, a threaded blind hole  54  is formed in the head end in a manner similar to the hole  20  of FIGS.  1 - 4 .  
         [0036]    A fitting  56 , of the type commonly used in hydraulic systems, includes a cylindrical bore  58 , exterior threads  60  and an abutment end  62  lying in a plane perpendicular to the longitudinal axis of the fitting  56 . The fitting  56  is provided with a hexagonal portion  63  whereby a wrench may be applied to the fitting for tightening thereof.  
         [0037]    The pointed end assembly  52  is assembled as will be apparent from FIGS. 6 and 7. The point  36 ′, preferably comprising a headed concrete nail, includes the head  38 ′ and the pointed end  40 ′. The diameter of the point  36 ′ is slightly less than the diameter of the fitting bore  58  wherein the point  36 ′ is received within the bore  58  as will be appreciated from FIG. 6. The fitting  56  is tightened into the blind threaded hole  54  and engages the point headed end  38 ′ forcing the point head against the bottom  54  of the threaded hole  20 ′ wherein the threaded hole end  54  constitutes the anvil surface for supporting the point  36 ′ during use. Of course, the diameter of the threaded portion of the  56  is slightly greater than the diameter of the point head  38 ′ to permit the assembly shown in FIG. 6. The embodiment of FIGS. 5 and 6 is a little less expensive to produce than the embodiment of FIGS.  1 - 3  as only two components are required.  
         [0038]    The tool handle grip  14 ′ is provided with a chamber  44 ′ having an access hole  66  which is closed by a removable plug  68  permitting extra points  36 ′ to be located within the chamber.  
         [0039]    From the above description, it will be appreciated that the invention permits a welding chip hammer to be economically manufactured having a replaceable point. Because the point constitutes a conventional hard concrete nail, such points are inexpensive, and yet very durable, and as the assembly procedure for either embodiment is simple, the replacement of points is well within the skill of an arc welder operator.  
         [0040]    It will be appreciated that various modifications to the inventive concepts may be apparent to those skilled in the art without departing from the spirit and scope of the invention.