Abstract:
An adaptor shank for SDS format pneumatic hammer/drill guns, the adaptor shank having a drill bit receiving end with drill bit locking means and an SDS format end for locking engagement with SDS format pneumatic hammer/drill gun, thereby allowing the drill bit alone to be discarded and replaced upon wear or breakage.

Description:
RELATED APPLICATIONS 
       [0001]    Applicant claims the benefit of provisional application 60/930,666, filed May 18, 2007. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to an adaptor for SDS format pneumatic hammer/drill guns for accommodating a replaceable drill bit and snap on driver for rapid drilling of bores in concrete or masonry and the installation of concrete screws therein. 
         [0004]    2. Description of the Prior Art 
         [0005]    Pneumatic hammer/drill guns commonly come in one of two formats for securing the drill or driver in the pneumatic hammer/drill gun. One format is the conventional chuck format and the other is the SDS format. The present invention relates to the SDS format only. 
         [0006]    As will be described in detail hereafter, the SDS format comprises a shank, one end of which has two opposed aligned grooves positioned at 180 degrees to each other on the shank. Disposed in 180 degree relationship with each other between these alignment grooves are two opposed arcuate recessed indents. The alignment grooves serve to align the shank as it is inserted into the pneumatic hammer/drill gun and the two opposed recessed indents are engaged by internal fingers or appendages within the pneumatic hammer/drill gun to retain the shank. 
         [0007]    In the prior art, in the SDS format, the shank and drill bit were of one piece construction. Therefore, when the drill bit wore down or broke or snapped, the drill bit and shank as a one piece construction had to be discarded. Due to the fact that the combination shank and drill bit were machined as one piece, this resulted in the loss of an expensive piece of equipment. It would therefore be desirable if the shank and the drill bit were of two piece construction so that the drill bit, being the relatively inexpensive piece of equipment, could be replaced quickly and easily should it become worn or broken. 
         [0008]    Applicant&#39;s invention relates to an adaptor shank and separate drill bit with locking mechanism which allows only the drill bit to be discarded upon wear or breakage while retaining the adaptor shank for further use with a replaceable drill bit. 
       OBJECTS OF THE INVENTION 
       [0009]    An object of the present invention is to provide a novel improved SDS format adaptor which allows for the rapid drilling of bores and subsequent installation of concrete and masonry screws. 
         [0010]    A still further object of the present invention is to provide a novel improved SDS format adaptor shank and drill bit, of two piece construction with a locking means for the rapid drilling of bores for the installation of concrete or masonry screws. 
         [0011]    A still further object of the present invention relates to a novel SDS format adaptor shank and drill bit which allows for only the drill bit to be discarded if broken or worn. 
         [0012]    A still further object of the present invention is to provide for an improved SDS format shank and drill bit of two piece construction in which the adaptor shank can adapt to the use of a drive sleeve with driver for the insertion of concrete or masonry screws. 
       SUMMARY OF THE INVENTION 
       [0013]    An adaptor shank for SDS format pneumatic hammer/drill guns, the adaptor shank having a drill bit receiving end with drill bit locking means and an SDS format end for locking engagement with SDS format pneumatic hammer/drill gun, thereby allowing the drill bit alone to be discarded and replaced upon wear or breakage. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    These and other objects of the present invention will become apparent, particularly when taken in light of the following illustrations wherein: 
           [0015]      FIGS. 1 and 2  are perspective views of an SDS shank and drill bit of the prior art; 
           [0016]      FIG. 3  is a cross sectional side view of a sleeve and fastener driver; 
           [0017]      FIG. 4  is a top view of the adaptor shank of the present invention with drill bit; 
           [0018]      FIG. 5  is a partial cutaway view of the adaptor shank of  FIG. 6  taken along Plane  5 - 5 ; and 
           [0019]      FIG. 6  is a side exploded view of the adaptor shank of the present invention and drill bit. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]      FIGS. 1 and 2  are prior art perspective views of an SDS shank and drill bit  10 . The SDS shank portion  12  and the drill bit  14  are of one piece construction being milled from a single piece of steel which presents the problem which Applicant seeks to solve. In the prior art format, if the drill bit becomes worn or breaks, the one piece shank portion and the drill bit must be discarded even though the shank portion is not damaged. 
         [0021]    The shank portion  12  has a first end  16  which is milled to provide for two opposed recessed grooves  18  and  20  which extend axially from first end  16  toward drill bit portion  14 . The recessed grooves  18  and  20  are in 180 degree relationship to each other. Formed on opposing sides of first end  16  of shank portion  12  and between recessed grooves  18  and  20  are a pair of recessed arcuate indents  22  and  24  which are formed distal proximate from first end  16  of shank portion  12 . 
         [0022]    In the SDS format for pneumatic hammer/drill guns, it is this shank portion  12  which is insertably engaged within the pneumatic hammer gun or pneumatic drill gun, recessed grooves  18  and  20  serving as a guide for the insertion and recessed indents  22  and  24  engaging internal fingers of the pneumatic drill gun or pneumatic hammer gun to secure the shank portion  12  to the pneumatic drill gun or pneumatic hammer gun and thus also secure the drill bit portion  14 , it being of one piece construction with the shank portion  12 . The pneumatic drill gun or pneumatic hammer gun operates in a reciprocating hammer-like motion which due to its internal mechanicals and gearing, imparts a rotational force to the SDS shank and drill bit. 
         [0023]    The opposing end, the drill bit end  26  of the shank portion  12  is formed with a hexagonal circumferential surface  28  which is used to engage a sleeve  17  ( FIG. 3 ) which is slidably received over the drill bit portion  14  and end  15  and engages with the hexagonal surface  28 . The sleeve  17  typically contains a driver member  19  at its opposing end illustrated in  FIG. 3  as a hex drive. The driver member can consist of or comprise one of a variety of driver heads, such as a Phillips, screwdriver, Allen-head or the like. 
         [0024]    In operation, with the SDS format shank and drill bit  10  secured to the pneumatic hammer gun or pneumatic drill gun, the operator drills the concrete or masonry hole at the location desired. The operator then inserts the sleeve over the drill bit portion  14  so that a first end of the sleeve engages the hexagonal surface  28  to lock it in position and cause it to rotate with the SDS shank and drill bit under the operation of the pneumatic hammer gun or pneumatic drill gun. This allows the opposing end of the sleeve having the drive member (Phillips head, screw head, hex head or the like) to rotate similarly and engage a concrete or masonry screw to cause the screw to be engaged within the bore or hole which was just previously drilled. Upon positioning the concrete or masonry screw, the user would remove the sleeve and driver unit and commence to bore an additional hole in the concrete or masonry in the manner described. 
         [0025]    It is evident from the illustration of  FIGS. 1 and 2 , that the combination, one piece SDS format shank and drill bit  10  requires extensive and expensive machining. It therefore is an expensive item for the tradesman. Still further, when the drill bit portion  14  either wears or breaks so that it is no longer effectively usable, the tradesman or user must discard the entire piece, including the shank portion  12 . This must then be replaced by a duplicate which is another expense. It would therefore be desirable if the SDS shank format and the drill bit were of a two piece combination so that the tradesman or user would only have to replace the relatively inexpensive drill bit should it become worn or broken. 
         [0026]      FIG. 4  is a top view of an adaptor shank  40  of the present invention, together with a drill bit  42 .  FIG. 5  is a cross sectional view of the adaptor shank  40  of the present invention along Plane  5 - 5  of  FIG. 4 , and  FIG. 6  is a side, exploded view of the adaptor shank and drill bit of the present invention. The adaptor shank  40  of the present invention comprises an SDS format connection, which has formed therein, the opposed recessed grooves  18 A and  20 A and the opposed recessed indents  22 A and  24 A proximate first end  16 A identical to the SDS shank of the prior art. The body portion first end  16 A of the adaptor shank  40  is identical to the body portion of the prior art SDS shank with regards to diameter and circumference. The difference between the SDS shank and the adaptor shank lies at the drill bit engaging end  26 A. Drill bit engaging end  26 A is formed with hexagonal circumferential surface  28 A which function in the same manner as the hexagonal circumferential surface  28  of the prior art SDS shank  12  for engagement with a sleeve and driver. However, drill bit engaging end  26 A of adaptor shank  40  is formed with an axial bore  44  which extends into an expanded body portion or shoulder  46  of adaptor shank  40 . The expanded body portion  46  comprises a body portion which is of greater circumference and diameter than the body portion of adaptor shank  40  which is proximate to the shank engaging end  16 A. 
         [0027]    This expanded body portion or shoulder  46  allows for a radially threaded bore  48  extending from the outer circumference of the extended body portion or shoulder  46  perpendicular to the bore  44  formed in drill bit engaging end  26 A of adaptor shank  40 , the two bores  44  and  48  intersecting at 90 degree angles within the adaptor shank  40 . Bore  48  of extended body portion or shoulder  46  is for receipt of a threaded set screw  50 . Threaded set screw  50  when secured in bore  48  and rotated accordingly, will engage a flattened end portion  51  of a drill bit  42  in order to lock drill bit  42  within bore  44  and insure its rotation with the adaptor shank  40  under the influence of the pneumatic hammer gun or pneumatic drill gun. 
         [0028]    The engagement with the pneumatic hammer gun or pneumatic drill gun by adaptor shank  40  and drill bit  42  serves to operate in the same manner as that described with respect to the prior art. Upon completion of the drilling of a bore, a sleeve member and driver  17  can be inserted directly over the drill bit and lockingly engage the hexagonal surfaces  28 A such that the pneumatic hammer gun or pneumatic drill gun can be utilized to rotate a drive member at the end of the sleeve so as to insert and secure a concrete or masonry screw into the bore just previously drilled. The process itself can be repeated as desired. The advantage of the adaptor shank  40  and drill bit  42  is that when the drill bit  42  itself becomes worn, broken or chipped, the user or tradesman need only loosen the set screw  50  in extended body portion or shoulder  46  of adaptor shank  40  so as to be able to slidably remove the broken, worn or chipped drill bit and insert a replacement drill bit rotating it accordingly until the set screw  50  can be tightened to engage the flattened end portion  51  of the inserted end. There is no requirement that the adaptor shank  40  be separated from the pneumatic hammer gun or pneumatic drill gun and the user or tradesman can quickly and efficiently accomplish this drill bit replacement without significant downtime. 
         [0029]    While Applicant&#39;s novel contribution could be adapted to various sized pneumatic hammer guns and pneumatic drill guns, the Applicant&#39;s specific adaptation is to concrete and masonry screws and drill bits. As such, the adaptor shank as described herein would be dimensioned to receive three sixteenths concrete or masonry bits, which bits typically are utilized to install quarter inch concrete or masonry screws. 
         [0030]    Therefore, while the present invention has been disclosed with respect to the preferred embodiments thereof, it will be recognized by those of ordinary skill in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore manifestly intended that the invention be limited only by the claims and the equivalence thereof.