The present invention relates to a method for repairing axles, particularly large heavy duty axles for semitrailers and vehicles. The invention also provides assemblies and components for repairing axles.
Large heavy duty trailer axles such as those utilized for semitrailers, are typically one-piece units having spindles integrally formed at each end of a generally hollow axle. Often these spindles become worn, threads on the spindle ends become damaged, or the spindles may fracture or break. Since the spindles are integral with the axle, it is necessary to replace the entire unit of axle and spindles. Such units are expensive and difficult to replace. Accordingly, there is a need for a method of repairing spindles or end portions of trailer axles.
Prior artisans have attempted a wide array of techniques for repairing damaged axles. Although satisfactory in most respects, even the most attractive techniques have several disadvantages. U.S. Pat. No. 4,455,732 to Shiets describes a method for rebuilding vehicle axles. The method requires a jig and a boring machine to form a concentric cylindrical cavity within the axle undergoing repair. Thus, in order to begin repair of an axle, the boring machine and jig must be transported to the vehicle or trailer and damaged axle. After repair, the machine and jig are shipped back. Alternatively, if the boring machine and jig are not transported, the damaged axle must be removed from the vehicle and brought to the boring machine and jig. After repair, the axle is shipped back to the vehicle and re-installed. As will be appreciated, typical boring machines are relatively expensive and difficult to transport. Moreover, operating such boring machines requires considerable training and expertise, thereby further adding to the difficulty and expense in repairing an axle. Furthermore, it may be necessary to provide a particular jig depending upon the specific axle in need of repair. Thus, not only must an assortment of jigs be provided, but a determination must be made as to the proper jig for each repair job. This further contributes to the complexity of the repair process. Accordingly, there is a need for a method of repairing axles which does not require boring axle ends and therefore, does not require the use of a boring machine and jig and the difficulties associated therewith.
Another approach to repairing axles is described in U.S. Pat. No. 4,792,080 to Ferrari. In this approach, an axle end is repaired by removing the damaged end portion and butt welding a new replacement end portion on to the axle. Although this technique is relatively straightforward and avoids the use of a boring machine, it requires the use of an axle-specific jig. In view of the wide array of axle configurations, particularly in the field of large heavy duty axles for semitrailers, it is burdensome for a repair facility to stock all jigs. Furthermore, there exists a potential for failure of a butt welded axle. This potential is of even greater concern for axles utilized in high load applications such as in many semitrailers. Accordingly, there is a need for a technique for repairing axles which does not require a jig, and which avoids butt welding a replacement axle portion.
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USPTO Backgrounds