Wear insert and retainer

Abstract

The present invention provides an apparatus for use on a milling or mining drum that is durable and robust, yet easily serviceable. The apparatus can include a base portion adapted to be mounted to the mining drum and a wear insert removably attachable within an opening of the base portion. The opening of the base portion preferably has a first seat at an upper end and a second seat at a lower end. The wear insert includes a surface configured to engage with the first seat and a bore for receiving a cutter bit. A retainer is provided having a threaded portion to threadably engage with the threaded portion of either the wear insert or the cutter bit. The retainer can have a flange dimension to engage with the second seat. The cutter bit preferably includes a hardened tip.

1 . An apparatus for use on a portion of a milling or mining drum, adapted to be rotated in a cutting direction about a cylindrical axis defined by said drum, the apparatus comprising:
 a base portion adapted to be mounted to said drum, comprising an upper surface and a lower surface, and an opening having a first seat proximate the upper surface;   a wear insert engageable with the base portion opening, the wear insert comprising an interior bore to receive at least one cutter bit, a gripping surface situated proximate the upper surface of the base portion, a middle portion dimensioned to be received in the base portion opening, a flange extending from the gripping surface to the middle portion and to engage frictionally with the first seat of the base portion, and a threaded portion extending from the middle potion away from said gripping surface; and   a retainer having a threaded portion threadably engageable with the threaded portion of the wear insert.   
   
   
       2 . The apparatus of  claim 1 , wherein the interior bore includes a first portion having a cross-sectional area and a second portion having a cross-sectional area less than the cross-sectional area of the first portion to define a flange within said interior bore. 
   
   
       3 . The apparatus of  claim 1 , wherein the interior bore includes a step ring attached to the surface of the interior bore, the step ring having an outer edge with a cross-sectional area substantially similar to the cross-sectional area of the interior bore and an inner edge with a cross-sectional area less than a cross-sectional area of the outer edge, the inner edge having a lower portion including a chamfered edge. 
   
   
       4 . The apparatus of  claim 1 , wherein the first seat of the base portion has a conical shape. 
   
   
       5 . The apparatus of  claim 1 , wherein the flange of the wear insert has a conical shape. 
   
   
       6 . The apparatus of  claim 1 , wherein the base portion opening further includes a second seat proximate the lower surface of the base portion, and the retainer includes a flange frictionally engageable with the second seat. 
   
   
       7 . The apparatus of  claim 6 , wherein the second seat of the base portion opening has a conical shape, and the retainer flange is disposed along an upper edge of said retainer, the retainer flange having a conical shape. 
   
   
       8 . The apparatus of  claim 7 , wherein the first seat of the base portion has a conical shape, and the flange of the wear insert has a conical shape, wherein the conical shape of said first seat and said wear insert flange is tapered at an angle in the range between 10 degrees to about 70 degrees. 
   
   
       9 . The apparatus of  claim 1 , wherein the cutter bit includes a flange, and the interior bore includes a conical seat proximate the upper surface of the base portion to engage frictionally with said flange of the cutter bit. 
   
   
       10 . The apparatus of  claim 1 , wherein the wear insert further includes a lower surface and an upper surface with a length defined therebetween, the lower surface of the wear insert extending beyond the lower surface of the base portion. 
   
   
       11 . The apparatus of  claim 1 , wherein the retainer further includes a gripping surface to permit rotatably engagement and disengagement of the threaded portion of the retainer from the threaded portion of the wear insert, the gripping surface of the retainer being accessible from the lower surface of the base portion. 
   
   
       12 . The apparatus of  claim 1 , further comprising an expandable cylindrical sleeve disposed within the interior bore of the wear insert to engage frictionally the cutter bit within the interior bore of the wear insert to prevent the cutter bit from translating longitudinally. 
   
   
       13 . The apparatus of  claim 12 , wherein the interior bore of the wear insert includes a protrusion to engage with a portion of the expandable sleeve to prevent rotatable movement of the expandable sleeve within said interior bore. 
   
   
       14 . An apparatus for use on a portion of a milling or mining drum, adapted to be rotated in a cutting direction about a cylindrical axis defined by said drum, the apparatus comprising:
 a base portion adapted to be mounted to said drum, comprising an upper surface and a lower surface, and an opening extending between the upper surface and the lower surface of the base portion, the opening having a first seat proximate the upper surface;   a wear insert engageable with the base portion opening, the wear insert comprising an interior bore to receive at least one cutter bit, a first portion proximate the upper surface of the base portion having a threaded portion, a second portion proximate the lower surface of the base portion having a threaded portion, and a middle portion dimensioned to be received in the base portion opening extending between the first and second portions,   an upper retainer having a gripping surface and a threaded portion threadably engageable with the threaded portion of the first portion of the wear insert, the gripping surface being configured to be rotated to engage and disengage the threaded portion of the upper retainer from the threaded portion of the first portion of the wear insert; and   a lower retainer having a gripping surface and a threaded portion threadably engageable with the threaded portion of the second portion of the wear insert to prevent the wear insert from translating longitudinally within the base portion, the gripping surface being configured to be rotated to engage and disengage the threaded portion of the lower retainer from the threaded portion of the second portion of the wear insert from the lower surface of the base portion.   
   
   
       15 . The apparatus of  claim 14 , wherein the upper retainer includes a flange extending from the gripping surface, the upper retainer flange to engage frictionally with the first seat of the base portion opening, and the base portion opening includes a second seat proximate the lower surface of the base portion, the lower retainer including a flange to engage frictionally with said second seat. 
   
   
       16 . The apparatus of  claim 14 , further comprising an expandable cylindrical sleeve disposed within the interior bore of the wear insert to engage frictionally the cutter bit within the interior bore of the wear insert to prevent the cutter bit from translating longitudinally. 
   
   
       17 . An apparatus for use on a portion of a milling or mining drum, adapted to be rotated in a cutting direction about a cylindrical axis defined by said drum, the apparatus comprising:
 a base portion adapted to be mounted to said drum, comprising an upper surface and a lower surface, and an opening having a first seat proximate the upper surface;   an insert engageable with the base portion opening, the insert comprising an interior bore to receive at least one cutter bit and an exterior surface, the cutter bit having a cutting tip, a shank extending therefrom, and a threaded portion, said shank having a transition disposed between the tip and the threaded portion, a portion of the exterior surface facing the base portion dimensioned to be received in the first seat of the base portion opening, a portion of the insert interior bore sized and shaped to engage securably with said transition of the cutter bit; and   a retainer having a threaded portion to threadably engage with the threaded portion of the cutter bit.   
   
   
       18 . The apparatus of  claim 17 , wherein the transition tapers between a first cross-sectional area adjacent the tip and a second cross-sectional area of the shank. 
   
   
       19 . The apparatus of  claim 18 , wherein the transition tapers at a Morris taper. 
   
   
       20 . The apparatus of  claim 17 , wherein the transition has a polygonal shape, said transition having a cross-sectional area greater than a cross-sectional area of the shank.