Method of manufacturing enhanced teeth of dipper bucket of shovel

Abstract

A process of manufacturing a tooth of a dipper bucket of a shovel is disclosed. The tooth has a larger joining portion coupled to the dipper bucket and a sharp portion. The process comprises cooling the molded tooth in a furnace at about 920° C., suddenly cooling the tooth in a fluid contained in the furnace, heating the tooth at about 460° C., slowly cooling the tooth in the air, supporting the tooth in the furnace with the joining portion immersed in the fluid and the sharp portion exposed in the air, and producing the finished tooth. The teeth are less brittle and more ductile while having a sufficient hardness. The teeth can dig further into earth for increasing load of the dipper bucket per shovel.

1 . A process of manufacturing a tooth of a dipper bucket of a shovel, the tooth having a larger joining portion coupled to the dipper bucket and a sharp portion, the process comprising the steps of: 
 (a) cooling the molded tooth in a furnace at a first temperature;    (b) suddenly cooling the tooth in a fluid contained in the furnace;    (c) heating the tooth at a second temperature;    (d) slowly cooling the tooth in the air;    (e) supporting the tooth in the furnace with the joining portion immersed in the fluid and the sharp portion exposed in the air; and    (f) producing the finished tooth.    
     
     
         2 . The process of  claim 1 , wherein the furnace is an electric furnace.  
     
     
         3 . The process of  claim 1 , wherein the first temperature is about 920° C.  
     
     
         4 . The process of  claim 1 , wherein the fluid is oily.  
     
     
         5 . The process of  claim 1 , wherein the second temperature is about 460° C.  
     
     
         6 . The process of  claim 1 , wherein the fluid at a bottom of the furnace has a temperature about 560° C. and the fluid at its surface has a temperature about 460° C.  
     
     
         7 . The process of  claim 1 , wherein the joining portion has a hardness number from about 35 to about 46 as expressed in HRC and the sharp portion has a hardness number from about 46 to about 48 as expressed in HRC.