Replaceable Wear Tooth Assembly

Abstract

An improved tooth 21 and tooth holder 22 assembly for use with a digging implement such as a post hole digger has a first retention member 23 and a second retention member 24 each of which can be used in isolation or in combination. The first retention member 23 comprises a nylon plug having opposed serrated teeth 25 and which is pushed into an opening in the tooth holder 22 . The tooth contains rigid profiles 26 and when the tooth is pushed into the tooth holder, the serrations and profiles mesh together to positively retain the tooth within the tooth holder. The second retention means 24 comprises a resilient pin. The tooth and the tooth holder have a positive and negative wedge type shape which allows the tooth to be attached in one orientation only.

We claim: 
     
         1 . A replaceable tooth assembly for an auger, the assembly comprising a tooth, a tooth holder, a first retention member to retain the tooth in the holder and a separate second retention member to retain the tooth in the holder,
 the first retention member adapted to be mounted to the holder and comprising a plurality of resilient members,   the tooth comprising a plurality of rigid profiles adapted to engage with the resilient members to retain the tooth to the holder,   the second retention member comprising a removable pin,   whereby the first retaining member locks the tooth by forcing the resilient members into engagement with the rigid profiles on the tooth.   
     
     
         2 . An assembly according to  claim 1 , wherein the tooth comprises a front portion and a rear portion with a leading edge of the tooth located on the front portion. 
     
     
         3 . An assembly according to  claim 2 , wherein the front portion of the tooth is rectangular when viewed in plan and tapered when viewed in side elevation from a thicker rear portion to a thinner leading edge. 
     
     
         4 . An assembly according to  claim 2 , wherein the rear portion of the tooth is bifurcated when viewed in plan and comprises a first leg portion and a second leg portion. 
     
     
         5 . An assembly according to  claim 4 , wherein the leg portions include the rigid profiles adapted to engage with the resilient member to retain the tooth to the tooth holder. 
     
     
         6 . An assembly according to  claim 5 , wherein the rigid profiles are located on inner walls of each leg portion. 
     
     
         7 . An assembly according to  claim 2 , wherein the rear portion includes a configuration comprising at least one abutment or wedge to allow the tooth to be inserted into the holder in only one orientation. 
     
     
         8 . An assembly according to  claim 4 , wherein the rear portion includes a pin retainer to enable a retaining pin to hold the tooth in the tooth holder. 
     
     
         9 . An assembly according to  claim 8 , wherein the pin retainer comprises a semicircular recess adapted to locate approximately half the circumference of the retaining pin. 
     
     
         10 . An assembly according to  claim 9 , wherein the recess is located on one of the leg portions. 
     
     
         11 . An assembly according to  claim 1  in combination with an auger wherein the tooth holder is permanently fixed to the auger. 
     
     
         12 . An assembly according to  claim 1 , wherein the tooth holder comprises a solid rear wall, and a top wall and a bottom wall extending from the rear wall. 
     
     
         13 . An assembly according to  claim 12 , wherein the top wall and the bottom wall are typically spaced apart by a distance sufficient to enable a rear portion of a tooth to be positioned between the top wall and the bottom wall. 
     
     
         14 . An assembly according to  claim 13 , wherein one wall of the tooth holder includes an abutment or step or wedge type configuration adjacent a rear portion of the wall to ensure that the tooth is correctly orientated in the tooth holder. 
     
     
         15 . An assembly according to  claim 12 , wherein the tooth holder has an internal wall extending between the top wall and the bottom wall. 
     
     
         16 . An assembly according to  claim 15 , wherein an opening is provided through the internal wall for locating the first retention member. 
     
     
         17 . An assembly according to  claim 16 , wherein the opening is keyhole shaped. 
     
     
         18 . An assembly according to  claim 1 , wherein the tooth holder includes a knockout recess to assist in removal of the tooth. 
     
     
         19 . An assembly according to  claim 1  wherein the tooth holder includes at least one opening to accommodate a second retention member. 
     
     
         20 . An assembly according to  claim 1  including a plurality of resilient members to assist in holding the tooth in the tooth holder. 
     
     
         21 . A removable tooth for a replaceable tooth assembly for an auger, the tooth adapted to be attached to a tooth holder, the tooth comprising a leading edge adapted for ground engagement and a rear portion adapted for insertion into the tooth holder, the rear portion being bifurcated and comprising a first leg portion and a second leg portion, at least one leg portion comprising rigid profiles adapted to engage with resilient members on a retaining member to retain the tooth to the holder.