Excavating teeth and other wear members have long been mounted along the digging edge of buckets and other excavating equipment to break up the ground and enhance the digging operation. As can be appreciated, the wear members used along the digging edge are often placed in harsh working conditions and are thus subjected to a high degree of wearing.
In order to minimize the size of the part needing frequent replacement, excavating teeth are ordinarily formed as a plurality of integrally connected parts. An excavating tooth usually comprises an adapter, a point, and a lock pin for securing the point to the adapter. The adapter has a rear mounting end which is configured for attachment to the digging edge of an excavator and a forwardly projecting nose for mounting the point. The point is a tapered member provided with a forward earth-penetrating end and a rearwardly opening socket adapted to be received over the adapter nose. Although the points wear out more frequently, the adapters are also subjected to wearing and periodic replacement. As can be appreciated, the adapters must not only be capable of being firmly secured to the excavator to prevent undesired loss of the tooth during use, but it is desirable that they also be capable of being readily removed and installed by operators in the field.
A number of different approaches have been developed for securing wear members, such as adapters, to the digging edge of a bucket. U.S. Pat. No. 4,577,423 to Hahn provides an example of an adapter that is welded to the lip of a bucket. As to be expected, welding functions to securely attach the adapter to the bucket. However, the replacement of welded adapters is typically performed at a shop rather than in the field. The time and difficulty required to remove and install such welded adapters has proven to be a significant deterrent.
U.S. Pat. No. 4,267,653 to Hahn et al. describes an example of a mechanically attached adapter. As shown in this patent, mechanically attached adapters are frequently held to a bucket by the combination of a C-shaped clamp and a wedge. The wedge must be fit very tightly between the clamp and the adapter in order to securely hold the adapter to the bucket. Typically, the wedge is inserted into the assembly by repeated blows with a heavy sledge hammer. As can be appreciated, this is an onerous and time-consuming task for field workers, especially to achieve the final inch of movement needed to mount the assembly. Further, the wedge even when tightly inserted often becomes loose under heavy loading, which thus risks loss of the tooth. Finally, these assemblies require a hole to be formed in the bucket lip, which reduces the lip's strength and integrity.
U.S. Pat. No. 5,088,214 to Jones discloses another arrangement for mechanically attaching a wear member to the lip of a bucket. According to this construction, the wear member is matingly slipped over a T-shaped boss that has been welded to the bucket lip. A rigid locking block is fit within an opening defined in the top of the wear member to prevent undesired removal of the wear member from the lip. While this construction avoids the formation of a hole in the bucket lip, it is not suitable for use in attaching all types of wear members to any kind of bucket. For instance, larger buckets provided with beveled lips tend to generate large forces on an adapter which could in some circumstances cause instability in the mounting assembly. Further, the assembly lacks means for eliminating looseness that may exist between the wear member and the boss.
USPTO Backgrounds
USPTO Backgrounds