Abstract:
The auxiliary hand grip attaches to a conventional rasp to provide the user with an additional grip, allowing the user to better control the rasp when used to reconfigure a hoof. The auxiliary hand grip has a plate affixed to a socket element, the socket element extending along an axis and the plate extending substantially normal to the axis. The socket has inner surfaces spaced to accept a distal end extension of the rasp, and is aligned with the rasp so as to align the axis of the auxiliary hand grip with a longitudinal axis of the rasp. Clamping elements such as set screws extending through the socket serve to affix the auxiliary hand grip onto the distal end extension of the rasp.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention provides an auxiliary grip that attaches to a rasp such as used for contouring the hooves of horses to provide the user increased control of the rasp. 
       BACKGROUND OF THE INVENTION 
       [0002]    Rasps that are employed for contouring the hooves of horses have a longitudinal axis, a distal end extension, and a proximal end extension. The proximal end extension is configured to be readily mounted in any of various currently available handles, such handles having a handle axis that is aligned with the rasp axis when the handle is mounted onto the proximal end extension. The distal end extension is typically bounded by an extension upper surface and an extension lower surface which are each substantially planar and have a distal end extension width W, these surfaces being parallel to each other and separated to define a distal end extension thickness t. Both the distal end and the proximal end extensions generally have smooth surfaces so that the rasp can be gripped by the user&#39;s hands without requiring handles to be installed. In general, a central region between the extensions is rectangular in cross section, having four raised surfaces forming the abrading surfaces of the rasp. These abrading surfaces are used to contour the hooves of horses that are being prepared for re-shoeing. 
         [0003]    A variety of proximal end handles are currently available to allow the user to provide power strokes to abrade the hoof surface and reconfigure it. The control of the stroke can be enhanced if the distal end of the rasp can be controlled to avoid wandering during the power strokes. Currently, this control is frequently supplied by gripping the distal end extension. While it is helpful in controlling movement of the rasp, the ability to grip the distal end extension is limited to finger contact and frequently results in the fingers being engaged with one or more of the abrading surfaces of the rasp. This problem has been addressed, in part, my providing a polymer cover into which the distal end extension slips; when in place, the cover also covers part of the raised abrasive surfaces to allow firmer gripping of the distal end extension by the fingers and to protect the fingers from accidental contact with the abrading surfaces. These covers reduce the discomfort that can result from gripping the distal end extension by eliminating the user contact the roughened section of the rasp, and allowing the finger tips of the user to be more securely engaged with respect to the rasp. However, the control of the distal end of the rasp is still controlled by fingertip contact which does not provide particularly positive control. 
       SUMMARY OF THE INVENTION 
       [0004]    The auxiliary hand grip of the present invention provides a grip configured to allow the user to wrap the fingers about the auxiliary hand grip as well as to allow the grip to be engaged by a portion of the palm of the hand; such engagement allows the user to more firmly engage the distal end extension, thereby providing better control of the rasp against torsional loads introduced when using the rasp to reconfigure a hoof and allowing the user to grasp the distal end of the rasp with various hand and finger positions to apply force as desired. Furthermore, the increased engagement allows the user to apply a pulling force with the hand engaging the distal end extension, allowing the user to perform power strokes while resting the hand engaging the conventional handle mounted to the proximal end extension. 
         [0005]    The auxiliary hand grip has a auxiliary hand grip axis and a plate bounded by a peripheral edge disposed about the distal grip axis. This plate extends substantially normal to the auxiliary hand grip axis. 
         [0006]    Attached to the plate is a socket element having a socket upper surface and a socket lower surface which extend parallel to each other and to the grip axis. The socket upper and lower surfaces are spaced apart by a socket depth D that is at least as great as the extension thickness t of the distal end extension so as to accommodate at least a portion of the distal end engaged in the socket. The socket element can be formed as a rectangular tube having a tube passage bounded by a passage upper surface and a passage lower surface, which serve as the socket upper and lower surfaces, and passage side surfaces. The tube passage is aligned with the auxiliary hand grip axis. The tube passage is configured to accommodate the rasp distal end extension such that one of the extension upper surface and the extension lower surface can be placed in slidable contact with one of the passage upper surface and the passage lower surface. 
         [0007]    Means for aligning the auxiliary hand grip axis with the rasp axis when inserting the distal end extension into engagement with the socket element can be provided to assure that, when the one of the extension upper or lower surfaces is in slidable contact with the corresponding socket surface, the axes are aligned. When the socket element is formed by a rectangular tube, the separation of side surfaces of the resulting rectangular passage can be closely matched to the distal end extension width W of the of the rasp to provide this means. In any case, for greatest stability, the socket surfaces can be separated such that the socket depth D is only slightly greater than the extension thickness t such that both the upper and lower surfaces are slidably engaged. 
         [0008]    Clamping means are provided, which are associated with the socket element and serve to affix the socket element to the distal end extension of the rasp. Typically, such clamping means are provided by one or more threaded elements that can be tightened to clamp the socket element against a portion of the distal end extension. When the socket element is provided by a rectangular tube, it can be provided with at least one setscrew that threadably engages the rectangular tube to provide the clamping means. The at least one setscrew passes through a passage surface so as to be forcibly engagable with the distal end extension when the setscrew is threadably advanced. In a preferred embodiment, the setscrew(s) pass through the upper or lower surface of the rectangular passage. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0009]      FIG. 1  is a partially exploded isometric view of one embodiment of a auxiliary hand grip for a rasp, the grip having a plate and a rectangular tube attached thereto to provide a socket element. The grip is illustrated adjacent to a portion of a rasp which includes a rasp distal end extension, which is positioned to be inserted into a tube passage of the auxiliary hand grip. 
           [0010]      FIG. 2  is an isometric view of the auxiliary hand grip shown in  FIG. 1  with the rasp distal end extension inserted into the tube passage of the auxiliary hand grip and secured thereto by setscrews that threadably engage the rectangular tube. 
           [0011]      FIGS. 3 and 4  illustrate the auxiliary hand grip shown in  FIGS. 1 and 2  when employed to provide a grip for a rasp having a narrower width. To stabilize the narrower rasp, a pair of spacers are employed that fill the space between the edges of the distal end extension of the rasp and side surfaces of the tube passage.  FIG. 3  illustrates auxiliary hand grip prior to insertion of the rasp and spacers into the tube passage, while  FIG. 4  shows the auxiliary hand grip installed on the distal end extension of the rasp. 
           [0012]      FIG. 5  is an exploded isometric view that illustrates a auxiliary hand grip similar to that shown in  FIGS. 1-4 , but differing in the details of its construction. In this embodiment, the rectangular tube is formed by machining a block and is attached to the grip with screws. 
           [0013]      FIG. 6  is an isometric view of a more basic embodiment of a auxiliary hand grip, having a plate with a rectangular central section and a socket element formed by a U-shaped channel. The socket element is clamped onto the distal end extension of the rasp by bolts that serve both to close the sides of the socket element to provide stability and to clamp the socket element to the rasp. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]      FIG. 1  is a partially exploded isometric view of a auxiliary hand grip  10  for a rasp  12 , the auxiliary hand grip  10  forming one embodiment of the present invention. The auxiliary hand grip  10  is configured to engage a distal end extension  14  of the rasp  12 . This distal end extension  14  is bounded in part by an extension upper surface  16  and an extension lower surface  18 , each having an extension width W. These extension surfaces ( 16 ,  18 ) are parallel and spaced apart so as to provide an extension of thickness t. The rasp  12  has a longitudinal rasp axis  20 , about which the rasp  12  is symmetrically located. 
         [0015]    The auxiliary hand grip  10  has a plate  22  bounded by a peripheral edge  24  that is preferably symmetrically disposed about a auxiliary hand grip axis  26  that is normal to the plate  22 . Having the peripheral edge symmetrical allows the user to readily grasp the rasp  12  either upright in the orientation illustrated or inverted relative to the illustrated position so as to use either of the active surfaces of the rasp  12 . 
         [0016]    A rectangular tube  28  is attached to the plate  22  to serve as a socket element for engaging the rasp  12 . The rectangular tube  28  has a tube passage  30  extending along the auxiliary hand grip axis  26  and bounded by a passage upper surface  32  and a passage lower surface  34  spaced apart by a separation D, and a pair of passage side surfaces  36 . The size of the passage  30  is sufficiently large to accommodate the insertion of the rasp distal end extension  14  thereinto. 
         [0017]    Two set screws  38  are provided, which threadably engage threaded screw passages  40  provided in the rectangular tube  28  and provide clamping means to affix the socket element to the distal end extension  14  of the rasp  12 . In this embodiment, the screw passages  40  pass through the upper surface  32  of the tube passage  30  so as to forcibly engage the extension upper surface  16  when the distal end extension  14  is inserted into the tube passage  30  and the setscrews  38  are advanced in the screw passages  40 , as shown in  FIG. 2 . 
         [0018]    The plate  22  is formed with a planar central section  41 , which extends normal to the grip axis  26 , and a pair of plate wings  42  which are canted with respect to the auxiliary hand grip axis  26  so as to form a concave terminating free surface  44  of the plate  22 , as best shown in the sectioned view of  FIG. 2 ; while the plate could be formed with a continuous concave curve, providing the planar central section  41  facilitates attachment of the rectangular tube  28  thereto, such as by welding when the plate  22  and the rectangular tube are made from a suitable metal such as aluminum or brass. The plate wings  42  aid the user in gripping the auxiliary hand grip  10  so as to better stabilize the rasp  12  in service, and help to contour the plate  22  so as to be firmly grasped by the user in a variety of hand and finger positions. The ability to grasp the plate  22  is further enhanced by forming the peripheral edge  24  of the plate  22  such that the central section has bowed edges that create a width that decreases as it approaches the wings  42 , this taper in the edges continuing in the wings  42 . 
         [0019]    The plate  22 , as configured and positioned, provides overhanging regions  46  above and below the rectangular tube  28 . These regions  46  each have a maximum depth d and provide surfaces which can be employed to engage a portion of the palm of a user in service, thereby serving to further stabilize the rasp  12  in service and allowing the user to forcibly apply the rasp  12  against a hoof by pulling the rasp with the hand engaging the auxiliary hand grip  10  or by pushing from the distal end. Having the auxiliary hand grip  10  so configured not only allows the hand to guide the rasp distal end extension  14 , but also to pull it forward with the hand thereby reducing the force needed to be applied to the proximal end extension with the other hand and thus allowing both hand so share in applying the motivating force to the rasp. 
         [0020]    To provide means for aligning the rasp axis  20  with the distal end axis  26  as the distal end extension  14  is inserted into the passage  30  of the tube  28 , it is preferred for the passage side surfaces  36  to have a separation essentially the same as or only slightly greater than the extension width W. It is also preferred for the tube passage  30  to have a passage length l that is less than an extension length L of the distal end extension  14 , thereby allowing a distal end terminal surface  48  (shown in  FIG. 1 ) of the rasp  12  to rest against the plate  22  when the distal end extension  14  is fully inserted into the tube passage  30 . 
         [0021]      FIGS. 3 and 4  illustrate a pair of spacers  50  that can be employed with the auxiliary hand grip  10  when used with a rasp  12 ′ having a somewhat narrower extension width W′ that is significantly less than the separation between the passage side surfaces  36 , which is essentially the same as the extension width W of the wider rasp  12  shown in  FIGS. 1 and 2 . The spacers  50  are provided with insertion hooks  52  that engage the distal end extension  14 ′ to maintain the spacers  50  engaged therewith as the distal end extension  14 ′ is inserted into the tube passage  30 . 
         [0022]    While the grip  10  shown in  FIGS. 1-4  can be readily formed by welding a length of suitably-sized rectangular tube stock onto a plate that is bent to provide a concave terminating surface, alternative fabrication techniques could be employed. As an example of such,  FIG. 5  illustrates a auxiliary hand grip  10 ′ which is functionally similar to the grip  10 , but differs in the details of its construction. In the grip  10 ′, a plate  22 ′ is affixed to a rectangular tube  28 ′ by screws  70  that pass through plate passages  72  in the plate  22 ′ and threadably engage recesses  74  formed in the rectangular tube  28 ′. To accommodate the recesses  74 , the rectangular tube  28 ′ is formed by machining a solid block of material to form a tube passage  30 ′ while leaving remaining a pair of corner blocks  76 , into which the recesses  74  are formed. 
         [0023]    When the rectangular tube  28 ′ is formed by machining, it may be desirable to form the tube passage  30 ′ off-center so as to provide a greater thickness t 1  on the side in which the screw passages  40 ′ are provided compared to the thickness t 2  of the other side to increase the depth of screw passages  40 ′ passing therethrough. 
         [0024]      FIG. 6  illustrates an alternative embodiment for a auxiliary hand grip  100  that may offer greater ease of fabrication, since it does not require that a rectangular tube be provided; however, may or may not have the self-aligning properties provided by the earlier described embodiment. The grip  100  has a plate  102  that is affixed to a socket element  104  that, in the grip  100 , is formed as a U-shaped channel that provides a pair of parallel socket plates  106  for engaging the distal end extension  14  of the rasp  12 . The socket plates  106  are each provided with a pair of bolt passages  108  through which clamp bolts  110  pass. The socket element  104  can be affixed to the distal end extension  14  by tightening the clamp bolts  110  by use of nuts  112 , the combined nuts bolts  110  and nuts  112  serving as clamping elements to bring the socket plates  106  into forcible engagement with the distal end extension  14  to affix the grip  100  thereto. 
         [0025]    The socket element  104  can be affixed to the plate  102  by suitable means, such as by being welded to a central section  114  of the plate  102 . Forming the socket element  104  as a U-shaped channel results in greater ease in affixing the socket plates  106  to the plate  102  than if the socket plates were provided as individual elements. However, because the socket element  104  has open sides that are closed only by the clamp bolts  110 , the sides of a socket  116  formed by these elements may not be stabilized sufficiently to provide means for positively aligning a grip axis  118  with the rasp axis  20 . However, if a bolt separation S between the clamp bolts  110  when installed in the bolt passage  108  is maintained at only slightly greater than the distal end width W, and a bolt spacing s from the plate  102  is sufficiently large to assure that the clamp bolts  110  are positioned to bracket side surfaces  120  of the rasp extension  14 , then the clamp bolts  110  will serve to, in part, align the grip axis  118  with the rasp axis  20 . 
         [0026]    While the novel features of the present invention have been described in terms of particular embodiments and preferred applications, it should be appreciated by one skilled in the art that substitution of materials and modification of details can be made without departing from the spirit of the invention.