Ground engaging ripper tips for earthmoving apparatus must be chosen in accordance with the particular job requirements in the interest of economy. High quality ripper tips made from expensive, highly wear resistant material are unnecessary and unduly expensive when ripping soft materials. However, soft or low resistance ripper tips utilized in hard ground applications would be destroyed rapidly, particularly at the extremely high friction temperatures encountered when such tips are used in connection with a high powered earthmover vehicle in a hard ground application.
In such a case, it is essential that the tips used exhibit good heat treatment characteristics, high strength, toughness and wear resistance at elevated temperatures, frequently as high as 1000.degree. F.
It is noted, however, that only the leading end or nose portion of the ripper tip which is directly exposed to the material being ripped reaches such elevated temperatures. The use, therefore, of expensive hard and wear resistant material for the entire tip would be uneconomical. In order to provide a tip having both the requisite high temperature wear requirements on the nose thereof and a tip which is economical to use and replace, multi-metallic fabrications have been utilized, with a leading portion of special hardened material for greater wear and strength and the remaining portions of softer, less resistant material.
Examples of prior art attempts to provide multi-metallic ripper tips and general purpose tooth members are found in U.S. Pat. No. 2,718,162 to Smith; U.S. Pat. No. 2,738,602 to Meeks; U.S. Pat. No. 2,739,395 to Stratton; U.S. Pat. No. 2,837,843 to Meshorer; U.S. Pat. No. 3,280,486 to Hackel; U.S. Pat. No. 3,309,801 to Ratkowski; and U.S. Pat. No. 3,453,756 to Schroeder.
USPTO Backgrounds
USPTO Backgrounds