Abstract:
A hole saw assembly including a boss adapted to hold a hole saw and having a plurality of connecting shafts. The shafts rotationally engage a driving means and longitudinally engage a locking member that locks the boss, driving means and the locking member together. This is achieved by the driving means and the locking member having co-axially aligned cutouts allowing for the insertion of the shafts. The locking member is moveable between two positions in one the cutouts engaging the shafts and in the other allowing for free longitudinal movement of the shafts.

Description:
FEDERALLY-REFERENCE TO RELATED APPLICATIONS  
         [0001]    Not Applicable.  
         SEQUENCE LISTING OR PROGRAM  
         [0002]    Not Applicable.  
         PRIORITY  
         [0003]    This application claims the benefit of an Australian Application Number: 2003902866, filed Jun. 6, 2003, which is incorporated herein in its entirety by reference.  
         BACKGROUND OF THE INVENTION  
         [0004]    1. Field of Invention  
           [0005]    The present invention relates to an improved hole-saw assembly and in particular, to a unique means of releasably locking a hole saw to a mandrel.  
           [0006]    2. Background of the Invention  
           [0007]    Hole-saws typically consist of a flat base, which provides support for a cylindrically shaped member protruding therefrom that includes cutting teeth at its circular end. The base is generally locked by a drill mandrel and includes a central bore through which a pilot drill, also locked by the mandrel, may pass.  
           [0008]    The current applicant is the owner of various Australian and International Patent applications dealing with the quick and easy mounting and demounting of a hole-saw to a drill mandrel, and also of various connection means between a hole-saw and a mandrel. For example, International ApplicationPCT/AU02/01296 entitled ‘An improved hole-saw assembly’, the contents of which are incorporated by referenced herein, discloses the use of a hole-saw base including two shafts adapted to extend through the drill mandrel that are then locked by a locking member that moves between two positions. Typically the movement is a rotational one, the member being a rotatable annulus. Thus in one position the hole saw base is locked to the mandrel and in the other it is not, enabling the hole saw base and thus the hole saw to be easily and quickly removable from the mandrel.  
           [0009]    Although the above hole saw assembly works well, in some instances different ways other than rotational motion of locking the hole saw to the mandrel may be preferred. Further in some instances it would be preferred if the locking mechanism was shielded to avoid contamination by dirt and other material.  
           [0010]    It is therefore an object of the present invention to provide for a hole saw assembly including a locking means that overcomes at least some of the above-mentioned problems or provides the public with a useful alternative.  
         SUMMARY OF THE INVENTION  
         [0011]    Therefore in one form of the invention there is proposed a hole-saw assembly including:  
           [0012]    a hole-saw having at one end a plurality of cutting teeth and at the other end two shafts;  
           [0013]    a mandrel coaxially aligned with said hole-saw and including a body having two bores therethrough coaxially aligned with said shafts;  
           [0014]    a locking member forming part of said mandrel and including two cutouts, said locking member moveable from a first to a second position, wherein in said first position said locking member cutouts are aligned with said bores and said shafts allowing said shafts to be freely insertable and removable and in said second position said cutouts being misaligned thereby locking said shafts to said mandrel.  
           [0015]    In preference said locking member is biased to said second position. This is typically achieved by the use of a spring.  
           [0016]    In preference said locking member movement is a sliding movement across said mandrel.  
           [0017]    In preference said assembly includes a base from which therein extend the two shafts said base including a mounting means for mounting of a hole-saw thereon. Of course, the base may have two mounting means to accommodate two hole saw of different diameter.  
           [0018]    In preference said hole-saw includes a threaded inner bore adapted to engage a threaded outer projection extending from said base.  
           [0019]    In preference said shafts include a flute adjacent said outer end and a cap on said outer end, the cap having an inner surface adapted to engage the locking member when said locking member is in said second position to thereby lock the shafts from longitudinal movement from the locking member.  
           [0020]    In preference said hole-saw assembly includes a drill-bit mounted on said mandrel, said drill-bit extending through and beyond said hole-saw.  
           [0021]    In preference said cutouts are holes. Thus the locking member includes holes disposed within the member.  
           [0022]    In preference said locking member is a semi-circle including an inner edge, said cutouts defined on said inner edge.  
           [0023]    In preference said locking member includes two split-rings biased towards each other and defining said cutouts therein between, each of the split rings movable to a second position in opposing directions to thereby allow for the removal of said shafts. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]    The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several implementations of the invention and, together with the description, serve to explain the advantages and principles of the invention. In the drawings,  
         [0025]    [0025]FIG. 1 is an exploded isometric view of a hole-saw assembly embodying the present invention and including a slidable locking member;  
         [0026]    [0026]FIG. 2 is a top view of the hole saw assembly illustrating the locking member of FIG. 1 in a locked position;  
         [0027]    [0027]FIG. 3 is a top view of the assembly as in FIG. 2 but when in an unlocked position;  
         [0028]    [0028]FIG. 4 is a top view of a hole saw assembly illustrating an alternate configuration of a locked locking member;  
         [0029]    [0029]FIG. 5 is a top view of the assembly of FIG. 4 but when in an unlocked configuration;  
         [0030]    [0030]FIG. 6 is a perspective exploded view of the hole saw assembly of FIGS. 4 and 5;  
         [0031]    [0031]FIG. 7 is a perspective view of the assembly of FIG. 6 but when in an engaged configuration;  
         [0032]    [0032]FIG. 8 is a top view of yet another embodiment of a locking member used in a hole saw assembly and when in a locked configuration;  
         [0033]    [0033]FIG. 9 is a top view of the assembly of FIG. 6 but when in an unlocked configuration;  
         [0034]    [0034]FIG. 10 is a side and cross-sectional view of the assembly of FIGS. 6 and 7;  
         [0035]    [0035]FIG. 11 is a perspective view of a hole saw assembly using a locking member as in FIGS. 8-10;  
         [0036]    [0036]FIG. 12 is a partial exploded perspective view of the hole saw assembly of FIGS. 8-11;  
         [0037]    [0037]FIG. 13 is a top view of yet another embodiment of a locking member used in a hole saw assembly and when in a locked configuration; and  
         [0038]    [0038]FIG. 14 is a perspective view the locking member as per the present invention when used to mechanically couple and alternate item, such as a garden hose;  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0039]    The following detailed description of the invention refers to the accompanying drawings. Although the description includes exemplary embodiments, other embodiments are possible, and changes may be made to the embodiments described without departing from the spirit and scope of the invention. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts.  
         [0040]    [0040]FIG. 1 illustrates a hole saw assembly  10  including a threaded base  12  adapted for a hole saw to be screwed thereto, a drill bit  14 , mandrel  16  and locking member  18 .  
         [0041]    Extending adjacent the edge of the base  12  and in an opposite direction to drill bit  14  are two identical and spaced apart shafts  20 . However it is to be understood that although it is advantageous to have two shafts, only one is required.  
         [0042]    Each shaft  20  includes column  22  extending from the base  12  and including a tapered outer end  24  adjacent to which is a groove  26 . The columns are adapted to be inserted into co-axial bores  28 , the depth of the bores  28  such that when the shafts  20  are inserted into the mandrel  16 , the groove  26  and the tapered end  24  of each shaft protruding beyond the mandrel  16 .  
         [0043]    Locking member  18  is located on top of the mandrel  16  and includes a central aperture  30  through which passes mandrel shaft  32  that is typically inserted into a drill or the like to provide the rotational driving force. Locking member  18  also has two co-axial bores  34  into which pass the tapered ends  24  and groove  26  of each shaft  20 . The depth of bores  34  is such that the underside flute  36  of the tapered ends  24  (defined by groove  26 ) extend above the top surface  38  of the member  18 .  
         [0044]    The locking member includes a biasing means or spring  40  held in cavity  42  that forces the bores  34  to be misaligned with the shafts, the locking member then engaging the shafts by sliding into part of the groove  26 , as illustrated in FIG. 2. In use, the user inserts shafts  20  though mandrel  16  and into bores  34  of the locking member  18 . The tapered end  24  of the shafts  22  act against the spring  40  forcing the locking member bores  34  to be in aligned with the shafts  22  (FIG. 3) enabling the shafts to enter the bores  34 . However, as soon as the tapered ends  24  pass beyond the outer surface  38  of the locking member  18 , it snaps back into its biased position. This causes the underside flute  36  to now rest on the top surface  38  preventing the shafts from disengaging the member  18 . Quite obviously, the central hole  30  has to be somewhat enlarged to allow for this sideways movement. Further the locking member  18  is retained in position by the use of appropriate means such as circlip  44  engaging groove  46  on shaft  32 .  
         [0045]    The release the assembly, one simply needs to grab hold of the locking member  18  and slide it sideways until the bores  34  of the member  18  are aligned with the shafts allowing them to be withdrawn from the member  18  and mandrel  16 . To assist in the sliding motion the member  18  may include parallel and oppositely spaced protrusions  48 .  
         [0046]    Illustrated in FIGS.  4  to  7  is an alternate embodiment of a locking member  50 . The locking member has effectively been halved to be now a half-toroid or a half-ring structure. The member  50  includes three circular cutouts  52 ,  54  and  56 , cutouts  50  and  52  accommodating the shafts  20  whilst cutout  56  the mandrel shaft  32 . The half-ring  50  is biased by spring  58  into a locking position and is held in place by a cover  60  including a top surface  62  and skirt  64 , the skirt being of varying diameter to assist in gripping the cover. A projection  66  attached to half-ring  50  enables it to be moved for operation of the half-ring, cover  62  including a slit  66  to accommodate for this movement. Thus the reader will appreciate that in the biased or locked position, the half-ring upper surface engages the underside  36  of the tapered ends by sliding into the groove  26  of each shaft. In this embodiment, and mainly for illustrative purposes, the drill bit  14  is shown attached to the mandrel rather than to the base to which is attached the hole saw.  
         [0047]    In an alternate embodiment and as illustrated in FIGS.  8  to  12  the locking member includes two split rings that are hinged to be operable in clamp type configuration. Thus two split rings  68  and  70  are rotatably fixed around pivot pins  72  and  74  respectively at an adjacent end. The rings are slightly spaced apart by a distance equal to the diameter of the groove  26  of shafts  20  so that when in the locked position the inner edges  76  and  78  of the two splint rings  68  and  70  are effectively parallel. The split rings are biased in this position by the use of a spring  80 . To disengage the split rings from the shafts  20  a tapered pin  82  is pushed into the gap between the split rings at their free ends. This causes the split ring to open up pivoting around pivots  72  and  74 . The reader should appreciate that since the slit rings open wider at their free ends, the size of the shaft cutouts  84  and  86  (FIG. 9) at the pivoted ends is somewhat larger than the cutouts  88  and  90  at their free ends.  
         [0048]    In an alternate configuration of the split ring arrangement as illustrated in FIG. 13 there could indeed be two split-rings  92  and  94  that are biased together with springs  96  and  98  and that otherwise operate the same as the locking members above.  
         [0049]    To open up the locking member two tapered pins  100  and  102  are forced in between the ends of each split ring  92  and  94 .  
         [0050]    The reader should now appreciate the advantages of the present invention by the use of a locking member that moves or slides so as to lock a part having a specially configured shaft. Although the above description has revolved around the locking and releasing of a hole saw assembly the present invention may very well be used in numerous other applications. As illustrated in FIG. 14, the above invention may be used to couple two hoses. Thus first hose  104  includes a shaft  106  including a groove  108  and a tapered front  110  including sealing ring  112 . The shaft  104  is adapted to be inserted into a female socket  114  including a first member  116  that engages the seal  112  to ensure that the coupling does not leak. A second slidable locking member  118  that is operable by side button  120  is configured so that in its biased position its upper surface engages the underside  122  defined by groove  108  preventing the shaft from disengaging the female member I  14 .hose  104  to a slidable locking member  116 . Since the first member includes a central bore it allows hose  104  to be fluidly connected top hose  124 . By operating button  120 , the two are caused to be disengaged.  
         [0051]    Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.