Bucket tooth locking pin

Abstract

A system to attaching a tooth to a bucket shank comprises a ring seat in the shank having a cam. A locking ring having a corresponding cam is seated in the seat and has an interior channel bounded by shoulders. A locking pin of a dissimilar material to the ring includes a lobe sized to correspond to the channel. Once inserted through apertures in the tooth and the shank, the pin may be rotated to force the lobe over the shoulders and to be housed in the channel to securely hold the pin in place.

1 . A bucket tooth assembly comprising:
 a shank having an aperture extending therethrough;   said aperture comprising an enlarged portion forming a ring seat at one end of said aperture;   said ring seat being partly circular and further having a cam portion;   a tooth adapted to fit over said shank, said tooth having aligned apertures in opposed walls of said tooth;   a ring seatable in said ring seat, said ring having a cam portion corresponding to said cam portion of said ring seat;   an inner wall of said ring defining a recess;   a locking pin for extending through said aperture of said shank and at least one of said opposed apertures of said tooth;   said locking pin comprising a protrusion adapted to be retained in said recess when said locking pin disposed in said aperture of said shank and said at least one of said opposed apertures.   
     
     
         2 . The assembly of  claim 1  wherein said recess is a channel formed along said inner wall, said channel extending less than 360 degrees along said inner wall. 
     
     
         3 . The assembly of  claim 2  wherein said ring further comprises an axially oriented slot whose dimensions accommodate said protrusion. 
     
     
         4 . The assembly of  claim 3  wherein said slot extends to a portion of said inner wall to which said channel does not extend. 
     
     
         5 . A sub-assembly for a bucket tooth assembly comprising:
 a shank for receiving a bucket tooth thereon;   a ring seat in said shank and a ring shaped and sized to seat in said ring seat, the shapes of said ring seat and of said ring preventing rotation of said ring when the ring is seated in the ring seat; and,   a locking pin having an element that is selectively securable in a portion of said ring to prevent axial withdrawal of said locking pin from said ring.   
     
     
         6 . The sub-assembly of  claim 5  wherein said portion of said ring comprises a cavity. 
     
     
         7 . The sub-assembly of  claim 6  wherein said cavity comprises a channel along a portion of an inner wall of said ring and said element of said locking pin comprises a protrusion on a surface of said locking pin. 
     
     
         8 . A ring for use in a bucket tooth and shank assembly, said a ring having a generally circular shape with a portion that engages a surrounding surface so as to prevent said ring from rotating against said surface, and a cavity for receiving and preventing a portion of a locking pin from sliding axially out of engagement with said ring. 
     
     
         9 . The ring of  claim 8  wherein said portion of said ring is an eccentric portion thereof. 
     
     
         10 . The ring of  claim 8  or  9  wherein said cavity is a channel along a portion of an inner wall of said ring. 
     
     
         11 . A shank for a bucket tooth and shank assembly, said shank having an aperture extending therethrough, said aperture comprising an enlarged portion forming a ring seat at one end of said aperture wherein said ring seat is generally circular with an eccentric portion. 
     
     
         12 . A pin for use in a bucket tooth and shank assembly, said pin being generally cylindrical and having a frusto-spherical lobe on the surface thereof. 
     
     
         13 . A method for assembling a tooth to a bucket shank comprising:
 placing a ring in a ring seat on said bucket shank, said ring and said ring seat being respectively shaped to prevent rotation of said ring in said ring seat;   installing a bucket tooth over said shank; and,   inserting a generally cylindrical locking pin having a protrusion on the surface thereof into apertures in said tooth and said shank such that said protrusion engages and is retained by said ring against axial withdrawal of said pin from said engagement with said ring.   
     
     
         14 . The method of  claim 13  wherein said ring includes an axially extending slot of a size to accommodate movement of said protrusion along the slot, and a channel on an inner wall of said ring for retaining said protrusion against axial displacement, and wherein said step of inserting said pin comprises the steps of sliding said pin such that said protrusion moves axially along and within said slot, then rotating said pin so as to cause said protrusion to be located within said channel.