Tooth adaptor

A tooth adaptor, which is welded upon the cutting edge surface portion of an earth moving bucket, is provided with oppositely extending lateral wings. The weld extends along the rear edges of the wings and the peripheral edge of the adaptor rearwardly of the wings, wherein the weld is protected by the wings.

This invention relates to replaceable tooth adaptors for earth moving 
buckets such as backhoe buckets, clamshell buckets and loader buckets. 
Most conventional replaceable tooth adaptors are constructed to engage the 
cutting edge of the loader or other earth moving bucket both above and 
below the cutting edge and are held in place by welding or by bolts. When 
a smooth floor is required on the bucket, the adaptor is welded to the 
bucket at the top only leaving the bottom of the bucket flush. 
One major disadvantage with such arrangements is that the weld attaching 
the adaptor to the bucket tends to commence tearing at the forward 
extremity of the weld where the weld is often thin in section due to weld 
run off and due to the fact that the weld must remain clear of the cutting 
edge to avoid stress concentrations and thermal shock in this area. 
It is the object of the invention to provide an improved tooth adaptor 
which at least to a large extent overcomes the above disadvantage. 
The invention therefore provides a replaceable tooth adaptor for an earth 
moving bucket comprising an adaptor body having means, such as a socket or 
spigot, for supporting a replaceable tooth or point, said body having 
oppositely extending lateral wings adjacent the front end of the body. 
The provision of lateral wings on the adaptor body enables the adaptor to 
be secured to a bucket by welding around the body and behind the wings. 
Since the wings are in use near the front of the adaptor the securement of 
the adaptor to the bucket is substantially strengthened by the build up of 
weld metal at the front edge of the bucket between the wings and the 
bucket. Unlike the prior art described above, this weld is protected 
against abrasion by the wings. Thus, not only is the weld less likely to 
tear than the prior art but is likely to have a longer life due to its 
protection against abrasion.

A conventional adaptor A supporting a replaceable point P is shown somewhat 
schematically in FIG. 1 of the drawings. It will be noted that the adaptor 
A is formed to engage the cutting edge E of the bucket B both above and 
below. The adaptor A is attached to the bucket by bolts or by welding in 
the usual manner. 
FIG. 2 of the drawings shows another prior art adaptor construction in 
which the adaptor A is attached to the bucket B by welding at the top 
surface only leaving the underside of the replaceable tooth or point P 
generally flush with the bottom of the cutting edge of the bucket. 
The general configuration of the weld W attaching the adaptor of FIG. 2 to 
the bucket is shown in FIG. 3. It is usual for the weld to be thin at the 
leading edges L of the weld W for the reasons referred to above and as a 
result the forces encountered during the use of the bucket B tend to tear 
the adaptor A away from the bucket B at the leading edge L of the weld W. 
FIGS. 4 and 5 of the drawings show an adaptor embodying the present 
invention and as will be clear from these Figures, the improved adaptor 10 
has oppositely extending lateral wings 12 adjacent its front or leading 
end, these wings 12 being formed as integral castings with the remainder 
of the body 14 of the adaptor 10. In the form shown in the drawings, the 
wings 12 have a smoothly rounded leading face 16, a flat trailing face 18 
and a flat support surface 20 which rests in use on the cutting edge E of 
the bucket B. The wings 12 taper generally uniformly from their connection 
to the adaptor body 14 and this in combination with the smoothly rounded 
leading face 16 reduces to a minimum any resistance that may be created by 
the wings 12. 
The adaptor body 14 is attached to the bucket B by means of a weld 22 in 
the area shown in FIGS. 4 and 5. As shown most clearly in FIG. 4, there is 
a build-up 24 of weld metal 22 behind each wing 12 extending generally 
perpendicularly to the body 14 of the adaptor 10 and transversely of the 
line of working movement of the bucket B. This weld metal build-up 24 is 
additional to the usual weld metal around the perimeter of the adaptor 
body 14 and substantially strengthens the attachment of the adaptor 10 to 
the bucket B. Furthermore, the additional weld metal 24 is protected 
against abrasion in use by means of the wings 12. 
The adaptor body 14 is formed with a socket (not shown) in the usual manner 
to receive the replaceable tooth P and a pin or the like 26 is used to 
hold the tooth P in position. Alternatively, the adaptor body 14 may be 
formed with a spigot which is received within a socket in the tooth P. 
While one particular configuration of adaptor body and wings has been 
described herein, it will be appreciated that other configurations may be 
used without departing from the essence of the present invention. 
Similarly, while the wings in the preferred embodiment are integrally cast 
with the adaptor body, it may be possible to form the wings separately and 
attach them to the body either by welding or by some other attachment 
means. Of course, the formation of the body and wings as an integral 
casting is preferred for obvious reasons. Furthermore, while the wings are 
shown as extending generally perpendicularly from the adaptor body, there 
may be some advantage in having the wings extend at some other acute angle 
to the adaptor body.