Abstract:
A toolholder for securing a cutting tool used for mining and construction applications whereby the holder has a recessed groove to provide access to the underside of a flange on the cutting bit to promote removal of the cutting tool from the toolholder.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a toolholder for holding a cutting tool. More particularly, this invention relates to a toolholder for holding a cutting tool in which the toolholder has a recessed groove to expose a portion of the underside of a flange on the cutting tool to assist in the removal of the cutting tool from the toolholder. 
     2. Description of the Prior Art 
     Rotatable cutting tools in toolholders have been common in the mining and construction industry for many years. However, one difficulty with these cutting tools occurs when the cutting tool is damaged or worn out and must be removed from the toolholder for replacement. One method for removing such a cutting tool involves striking the rear of the tool through the holder bore. However, on many machines using such toolholders, access to the rear of the holder bore is limited. A second method for removing the cutting tool involves the use of a hydraulic cylinder and pressure device which utilizes a wrench that slides into a groove on the head of the tool which by striking, physically forces the cutting tool from the toolholder. Both of these methods are slow and require extra equipment. Furthermore, both of these methods require an operator with training and experience. 
     U.S. application Ser. No. 09/166,634, filed Oct. 5, 1998 entitled “Cutting Bit Support Member With Undercut Flange For Removal” is co-pending and directed to a sleeve or a block for holding a cutting tool whereby the sleeve or block has an undercut portion to ease removal of the sleeve from a toolholder or removal of the block from a holder. 
     U.S. Pat. No. 5,374,111 entitled “Extraction Undercut For Flange Bits” and assigned to Kennametal Inc., the assignee of the current application, is hereby incorporated by reference and addresses the use of a rotatable cutting tool having a flange with an undercut whereby the undercut may be employed in conjunction with a prying tool to remove the rotatable cutting tool from the toolholder. Although it is relatively common to employ some sort of prying tool to physically remove a cutting bit from a toolholder, and such an undercut makes the removal of the cutting bit easier, the amount of material removed from the flange to form the undercut in limited because the structural integrity of the flange must be maintained when the force of the prying tool is applied against the flange. 
     The inventors of the subject application, realizing the need for easier removal of cutting tools from toolholders without removing material from the cutting bit flange, have sought a solution. 
     SUMMARY OF THE INVENTION 
     The invention is directed toward a holder for retaining a cutting tool having a shank with an outside diameter and a tool mounting flange integral with the shank wherein the flange has a greater outside diameter than the shank outside diameter thereby defining a shoulder with a tool mounting surface. The holder comprises a body having a forward end and a cylindrical bore extending rearwardly therein along a longitudinal axis to define a bore wall and to receive the cutting tool shank at the forward end of the holder and a generally planar face on the body circumscribing the bore and extending radially away from the bore to an outer wall, wherein the planar face of the body may contact the tool mounting surface of the cutting tool. 
     A portion of the outer wall adjacent to the planar face is recessed to form an access groove thereby providing access for a removal tool to contact a portion of the tool mounting surface when the cutting tool is mounted within the holder. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of an assembled cutting tool and toolholder in accordance with the subject invention; 
     FIG. 2 is an exploded perspective view of the arrangement illustrated in FIG. 1; 
     FIG. 3 is a perspective view of only the toolholder illustrated in FIG. 2; 
     FIG. 4 is a side view of the cutting tool and toolholder illustrated in FIG. 1 with a partial cross section showing internal details; and 
     FIG. 5 is a side view of the cutting tool and toolholder taken along lines “ 5 — 5 ” in FIG.  4 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 illustrates a cutting tool  10 , which is secured within a toolholder  100 . The toolholder  100  is secured, for example, to a rotating drum (not shown) which may be used in mining or construction applications. 
     FIG. 2 illustrates an exploded perspective view of the same arrangement in FIG.  1 . The cutting tool  10  generally includes a working head  15 , having a head portion  20 , which may be conical, and a tip  25  comprising a material such as cemented carbide or other hard material generally known in the field of mining and construction. A shank  30  of the cutting tool  10  is mounted within a cylindrical bore  110  of the toolholder  100  and secured therein by a retainer clip  32 , which is recessed within a groove  34  in the shank  30 . The shank  30  has an outside diameter D 1  and a tool mounting flange  35 , which has a diameter D 2  that is greater than the shank outside diameter D 1  thereby defining a shoulder  40  with a tool mounting surface  45 . 
     The toolholder  100  is comprised of a body  105  having the cylindrical bore  110  extending from a forward end  115  rearwardly toward a rearward end  120  along a longitudinal axis L to define a bore wall  125  and to receive the cutting tool shank  30 . 
     The body  105  has a generally planar face  130  circumscribing the bore  110  at the forward end  115  extending radially away from the cylindrical bore  110  to an outer wall  135 . The planar face  130  of the body  105  may contact the tool mounting surface  45  of the cutting tool  10 . A portion of the outer wall  135 , adjacent to the planar face  130 , is recessed to form an access groove  140 . The access groove  140  provides access for a removal tool (not shown) to contact a portion of the tool mounting surface  45  and to assist in removing the cutting tool  10  from the toolholder  100 . The width of the access groove  140  at the outer wall  135  is less than the diameter of the bore  110 . 
     A typical removal tool would be a rod used as a punch. The rod is placed against the tool mounting surface  45  and then the rod is struck with a hammer to impart a force against the tool mounting surface  45  thereby displacing the cutting tool  10  from the toolholder  100 . 
     Although only a single groove  140  is needed for access by a removal tool, additional grooves may be included at different locations for providing different access points for the removal tool to contact the tool mounting surface  45  (FIG. 2) of the cutting tool  10 . As illustrated in FIG. 3, multiple portions of the outer wall  135  of the toolholder  100  may be recessed to form multiple access grooves  140 ,  142 ,  144 . 
     As shown in FIG. 3, the planar face  130  of the toolholder  100  has a width W and the groove  140  penetrates the planar face  130  to a depth of between 30-100% of the width W. Preferably, the groove penetrates the planar face  130  to a depth of a approximately 75% of the width W. 
     The access groove  140 , when viewed along its groove axis GA, is generally arcuate in shape, as illustrated in FIG.  3 . However, it should be appreciated that the groove may have many other shapes, including rectangular, when viewed along the same axis so long as access is provided to the tool mounting surface  45  of the cutting tool  10  to promote removal of the cutting tool  10 . 
     FIG. 4 illustrates a side view with a section removed showing details of the access groove  142  illustrated in FIG.  3 . The details of this groove  142  are identical to those of groove  140  which was previously discussed. 
     The access groove  142 , when viewed from the side as in FIG. 4, defines a groove axis GA along a surface  143  of the groove  142 . The groove axis GA forms a penetration angle A of between 20°-80° with the longitudinal axis L. A penetration angle A of 30° is preferred. 
     FIG. 5 shows a side view of the apparatus in FIG. 4 along arrows “ 5 — 5 ” in FIG.  4 . It should be noted that FIG. 5 is a full view and the portion removed in the sectional view in FIG. 4 has been restored. When looking at the side of the toolholder  100 , as seen in FIG. 5, the groove axis GA is defined by a line bisecting the groove  142 . The projection of the groove axis GA in FIG. 5 with the longitudinal axis L forms an orientation angle B which may be between 0°-30° and is preferably 30°. 
     The present invention may be carried out in other specific ways different from those herein set forth without departing from the spirit and the essential characteristics of the invention. The present embodiment is therefore to be considered in all respects as illustrative and not restricted and all changes coming within the meaning of the equivalency range of the appended claims are intended to be embraced therein.