Corner guard system having a replaceable corner tooth

A corner tooth assembly is provided on the corner of an implement for protection thereof from wear during use. It is necessary to provide a tight fit between the corner tooth and the corner portion of the implement so that unnecessary movement of the corner tooth on the corner portion is avoided while at the same time not subjecting the corner tooth to undue stresses during initial installation of the corner tooth on the implement. The present corner tooth assembly includes a corner portion integrally connected to the implement with first and second load transferring pads defined on a leading edge thereof and first and second holes defined therein and a corner tooth adapted for releasable connection to the corner portion. A trailing end portion of the corner tooth has a load transferring portion including first and second load transferring surfaces adapted when installed to mate with the first and second load transferring pads of the corner portion and a single upright side portion with first and second holes therein operative when assembled to mate with respective first and second holes of the corner portion on an implement. By having the first and second load transferring surfaces mate with the first and second load transferring pads of the corner portion and the corner tooth being secured to the corner portion by a biasing means, a tight connection is made between the corner tooth and the corner portion.

TECHNICAL FIELD 
This invention relates generally to a replaceable corner tooth for a corner 
guard system and more particularly to the structure of the replaceable 
corner tooth and its relationship with the implement on which it is 
mounted. 
BACKGROUND ART 
Various types of corner guard systems have been utilized in the past to 
protect the corner of an implement such as a loader bucket. These corner 
guard systems normally include a replaceable corner tooth that is expected 
to withstand relatively large working forces during normal operation. The 
releasable corner tooth may be of the unitooth type in which the portion 
that engages the ground and the portion that is secured to the implement 
are one and the same or it may be the type in which an adapter is secured 
to the implement while a replaceable tip is secured to the leading end of 
the adapter and is operative to engage the ground. Most of these designs 
are releasably secured to the implement by one or more bolts and have load 
transferring pads arranged on the replaceable corner tooth such that 
forces can be transmitted therethrough to the implement. It is desirable 
to have a simple design but to also insure that the optimum conditions are 
maintained in transferring the forces from the leading end of the tip into 
the implement itself. It is also desirable that the replaceable corner 
tooth be securely connected to the implement and not be allowed to move 
during operation. It has been found in some past designs that since the 
elements that form the corner of the implement are welded one to the other 
that it is difficult to hold reasonable tolerances between the bottom of 
the implement and the holes that are used to secure the corner tooth to 
the implement. Therefore, in this type of design, it is beneficial not to 
have areas on the replaceable corner tooth that transfer loads directly to 
the bottom of the hardened cutting edge. 
Another problem that has been experienced with some of the previous designs 
is that in order to effectively transfer the loads from the leading edge 
of the tip into the implement, the replaceable corner tooth becomes very 
complicated and extremely difficult to manufacture by conventional forging 
processes. U.S. Pat. Nos. 4,007,550 issued Feb. 15, 1977 to V. A. Stepe; 
4,071,967 issued Feb. 7, 1978 to G. R. Klett; and 4,182,057 issued Jan. 8, 
1980 to G. R. Klett and J. A. Thies, each being assigned to the assignee 
of the subject invention, teach a replaceable corner tooth that provides 
means to transfer loads from the leading edge of the tip into the 
implement and further provides a means to releasably secure the adapter to 
the implement. However, they each suffer from common problems. More 
specifically, each of the corner adapters have an outside vertical portion 
and an inner strap that interact to sandwich a portion of the corner of 
the implement and must be secured by a bolt or other fastening means. 
Consequently, during assembly it is necessary for the bolt to be securely 
tightened in an attempt to insure that the member does not move with 
respect to the corner of the implement. Since a two strap design is 
utilized in the above-noted patents, it is necessary, because of loose 
tolerances, to provide sufficient clearance between the straps so that the 
corner tooth fits the implement corner under the worst tolerance 
conditions. The double strap design, with the required clearance, leaves a 
gap between the sides of the straps and the implement corner sandwiched 
therebetween. In order to provide a tight connection between the corner 
tooth and the implement corner, the gap has to be tightly closed by the 
fastening means (bolt). Many times the torque normally needed for a tight 
connection is partially or fully used to close the gap thus a "loose" 
connection results. Consequently, during normal working conditions, the 
corner tooth can easily move relative to the implement corner thus 
requiring the bolt to absorb any additional loads as opposed to the 
additional loads being shared by the bolt and the joint connection. The 
resulting "loose" connection causes wear in the load transfer pads and 
creates a lever action that works against the inside strap causing the 
strap to break. In the situations where the connection appears tight but 
is not tight due to the large amount of tightening torque used just to 
close the gap, additional tensile force applied to the bolt under 
operation may cause the bolt to stretch or yield thus again causing a 
"loose" connection. Furthermore, since the construction of these designs 
does not allow them to be produced by a forging process which provides 
stronger parts, it is normally necessary to produce them by a casting 
process. 
U.S. Pat. No. 3,967,398 issued July 6, 1976 to V. A. Stepe and assigned to 
the assignee of the subject invention illustrates a replaceable corner 
tooth that is bolted to the corner portion of the implement by only one 
side portion of the replaceable corner tooth but suffers from the problem 
that the construction of this design makes it practically impossible to 
produce by normal forging processes. Furthermore, the load transferring 
characteristics of this design are primarily introduced into the bolts 
without having additional load transferring means to carry either tensile 
or shear forces on the bolts. 
U.S. Pat. No. 4,047,312 issued Sept. 13, 1977 to V. A. Stepe and assigned 
to the assignee of the subject invention illustrates a design that is 
bolted both to the side of the implement and also to the bottom portion of 
the implement. This design also proves to be more difficult to manufacture 
and creates more of a problem to mate with the corner of the bucket when 
the components of the bucket corner are welded one to the other. The 
tolerances on the corner of the bucket are much more difficult to maintain 
when the components of the bucket corner are welded together. 
The present invention is directed to overcoming one or more of the problems 
as set forth above. 
DISCLOSURE OF THE INVENTION 
In one aspect of the present invention, a replaceable corner tooth assembly 
is provided and is adapted for use on an implement having a normal forward 
longitudinal direction of working movement, an upright sidewall member and 
a laterally disposed cutting edge connected to the upright sidewall 
member. The replaceable corner tooth assembly includes a corner portion 
adaptable for use as an integral member of the implement and at least a 
portion thereof being generally vertically oriented on the upright 
sidewall member of the implement. The corner portion has a leading edge, 
first and second load transferring pads defined on the leading edge and 
first and second holes defined therein. The assembly further includes a 
corner tooth having a leading end portion operative to engage the work and 
a trailing end portion integrally connected to the leading end portion and 
adapted for releasable connection to the corner portion. The trailing end 
portion has a bottom end portion, a single upright side portion connected 
to the bottom portion on one side thereof and has first and second holes 
defined therein operatively aligned when assembled with the first and 
second holes of the corner portion, a forward portion connected to the 
bottom portion and to the upright side portion to define a cavity 
therebetween which opens in a direction away from both the leading end 
portion and the upright side portion, and a load transferring portion 
which includes first and second load transferring surfaces defined on the 
forward portion and operative to mate with the respective first and second 
load transferring pads of the corner portion. 
In another aspect of the invention, a corner tooth is provided and adapted 
for use on an implement. The corner tooth includes a leading end portion 
operative to engage the work and a trailing end portion connected to the 
leading end portion and adapted for connecting the corner tooth to the 
implement when installed thereon. The trailing end portion also has a 
bottom portion, a single upright side portion connected to the bottom 
portion on one side thereof and has first and second holes defined 
therein, and a forward portion connected to the bottom portion and the 
upright side portion to define a cavity therebetween which opens away from 
both the leading end portion and the upright side portion. The forward 
portion defines a load transferring portion thereon and an extension of a 
plane that passes through the centers of the first and second holes in the 
single upright side portion passes through the load transferring portion 
of the forward portion. 
The problem of maintaining a tight fit between the replaceable corner tooth 
assembly and the implement while still maintaining an effective load 
transferring relationship between the replaceable corner tooth assembly 
and the implement is overcome by this subject invention since the single 
upright side portion of the corner tooth is secured to the upright side 
member of the implement by two bolts and does not require two side straps 
to sandwich the upright sidewall member therebetween. The subject 
replaceable corner tooth assembly provides load transferring surfaces on 
both the corner tooth and the upright sidewall member in such a 
relationship that the forces from the leading edge of the corner tooth are 
transferred into the implement without subjecting the bolts to unnecessary 
tensile or shear stresses. Furthermore, since the corner tooth is secured 
tightly to the implement, there is no repeated "hammering" of the corner 
tooth against the load transferring pads of the upright sidewall member 
which would normally cause deforming of the load transferring pads of the 
upright sidewall member.

BEST MODE FOR CARRYING OUT THE INVENTION 
Referring now to the drawings, and more particularly to FIGS. 1-3, a 
replaceable corner tooth assembly 10 is shown for use on an implement 12, 
which only a portion thereof is shown, having a normal forward 
longitudinal direction of working movement. The implement 12 has an 
upright sidewall member 14 and a laterally disposed cutting edge 16 
connected to the upright sidewall member 14. 
The corner tooth assembly 10 includes a corner portion 18 and a corner 
tooth 20. As clearly shown in FIGS. 1 and 2, the corner portion 18 is an 
integral member of the upright sidewall member 14 of the implement 12 and 
is secured thereto by welding. However, it is recognized that the corner 
portion 18 and the upright sidewall member 14 could be one piece but 
preferably the corner portion 18 is a separate member that is welded to 
the upright sidewall member 14. The corner portion 18 is generally 
vertically oriented on the upright sidewall member 14 of the implement 12 
as clearly shown in FIGS. 1 and 2. The corner portion 18 has a leading 
edge 22, first and second holes 24,26 defined therein, and first and 
second load transferring pads 28,30 defined on the leading edge 22. An 
acute angle is formed, as shown in FIG. 2, at the juncture of the load 
transferring pads 28,30. 
The corner tooth 20, as clearly shown in FIG. 1 includes an adapter 32, a 
replaceable tip 34, and a retaining assembly 36. The corner tooth 20 has a 
leading end portion 38 that is operative to engage the work and as 
illustrated in FIG. 1 includes the replaceable tip 34 and a nose portion 
40 of the adapter 32. The corner tooth 20 further includes a trailing end 
portion 42 integrally formed with at least part of the leading end portion 
38 and is adapted for releasable connection to the corner portion 18. 
The trailing end portion 42 has a bottom portion 44, a single upright side 
portion 46 connected to the bottom portion on one side thereof, and a 
forward portion 48 that is connected to the bottom portion 44 and to the 
upright side portion 46. A cavity 50 is defined within an area encompassed 
by the bottom portion 44, the forward portion 48, and the upright side 
portion 46 and opens in a direction away from both the leading end portion 
38 and the upright side portion 46. First and second holes 52,54 are 
defined in the single upright side portion. The trailing end portion 42 
also includes a load transferring portion 56 defined on the forward 
portion 48. The load transferring portion 56 includes first and second 
load transferring surfaces 58,60 which are operative to mate with the 
respective first and second load transferring pads 28,30 of the corner 
portion 18 that is secured to the upright sidewall member 14. An acute 
angle "A" is formed, as shown in FIG. 2, at the juncture of the load 
transferring surfaces 58,60 and has an acute angle equal in size to the 
acute angle formed by the juncture of the load transferring pads 28,30. 
As clearly shown in FIG. 2, the load transferring portion 56 is spaced from 
the bottom portion 44 of the corner tooth 20 so that when assembled the 
bottom portion 44 is free from enagement with any portion of the implement 
12. A plane 62 that passes through the centers of the first and second 
holes 52,54 of the single upright side portion 46 also passes through the 
load transferring portion 56 and the leading end portion 38. 
Referring to FIG. 4, the corner tooth 20 is shown and differs from the 
corner tooth 20 shown in FIGS. 1-3 only in that the corner tooth 20 of 
FIG. 4 is of a "unitooth" design. In this arrangement, the leading end 
portion 38 is of a one-piece design as opposed to having the replaceable 
tip 34 and the nose portion 40 as illustrated in FIGS. 1-3. All other 
features of the trailing end portion 42 of the corner tooth 20, 
illustrated in FIG. 4, are the same as those set forth above for the 
corner tooth 20 illustrated in FIGS. 1-3. 
Referring to FIG. 5, an alternate embodiment of the corner tooth assembly 
10 is illustrated. In this embodiment, like elements will be illustrated 
by like numerals and modified elements are illustrated by like numerals 
with prime attached thereto. A corner portion 18' as clearly illustrated 
in FIG. 5 is L-shaped and includes a bottom portion 64 formed as an 
integral part of the corner portion 18'. When viewing the corner portion 
18 of FIG. 1 and the corner portion 18' of FIG. 5, it is clear that the 
only difference therebetween is that the corner portion 18' of FIG. 5 is a 
unitary L-shaped member that has no weld joints forming the "L" and that 
the corner portion 18 of FIG. 1 is welded at its bottom to the cutting 
edge 16. 
The corner tooth 20', of FIG. 5, is of the unitooth construction but it is 
recognized that it could be a two-piece design including an adapter with a 
replaceable tip as illustrated in FIG. 1 without departing from the 
essence of the invention. The corner tooth 20' is generally the same as 
the corner tooth 20 illustrated in FIG. 4 except the unitooth 20' of FIG. 
5 also includes an additional load transferring surface 66. The additional 
load transferring surface 66 is defined on the bottom portion 44 within 
the cavity 50 and is adapted to have load bearing contact with the bottom 
of the corner portion 18'. The additional load transferring surface 66 is 
located within the cavity 50 with respect to the load transferring portion 
56 by a plane 68 that is perpendicular to the bottom portion 44 and that 
intersects at least a part of both the load transferring portion 56 and 
the additional load transferring surface 66. All other features of the 
corner tooth 20' are the same as those set forth with respect to the 
preceding figures. 
As clearly illustrated in FIGS. 1, 2, 3 and 5, the corner tooth 20/20' is 
secured to the corner portion 18/18' by biasing means 70, such as nuts 71 
and bolts 72. 
INDUSTRIAL APPLICABILITY 
Working forces acting on the leading end portion 38 of the corner tooth 20 
may generally be divided into three categories. One being the forces 
acting on the corner tooth 20 generally parallel with but in opposite 
direction of the line of action of the implement 12. The second one being 
the vertical forces acting on the corner tooth 20 trying to force the tip 
up or down with respect to the implement. The third being the lateral 
force that is trying to move the corner tooth 20 to one side or the other 
with respect to the implement. Therefore, the corner tooth 20 must be able 
to overcome each of these forces while still being simple enough in 
construction to make the manufacturing thereof simple and economical to 
make. 
With particular reference to the corner tooth 20 illustrated in FIGS. 1-4, 
the single upright side portion 46 is positively secured to the corner 
portion 18 by the nuts and bolts 71,72. This connection insures a tight 
fit between the corner tooth 20 and the corner portion 18 so that the 
physical connection between the parts absorbs the forces instead of the 
forces being absorbed only by the bolts 72. Additionally, the engagement 
of the first and second load transferring surfaces 58,60 with the first 
and second load transferring pads 28,30 provides a mechanism to transfer 
various loads from the leading end portion 38 directly to the implement 12 
through the corner portion 18. All generally horizontal forces subjected 
to the leading end portion 38 are transferred to the implement 12 through 
the load transferring portion 56 and the first and second load 
transferring pads 28,30 while vertical forces acting upwardly are 
transferred to the first load transferring pad 28 by the first load 
transferring surface 58 and any vertical forces acting downwardly are 
transmitted to the second load transferring pad 30 by the second load 
transferring surface 60. This transferring of forces from the first and 
second load transferring surfaces 58,60 to the first and second load 
transferring pads 28,30 is more effectively transferred in view of the 
fact that the line of action of the forces is directed through a plane 
that intersects the load transferring portion 56 and the centers of the 
first and second holes 52,54 of the corner tooth 20. Furthermore, the load 
transferring abilities of the subject invention is enhanced if an 
extension of the plane 62 would also generally intersect at least a 
portion of the leading end portion 38. 
In order to insure a proper fit-up between the corner tooth 20 and the 
upright sidewall member 14, the bottom portion 44 of the corner tooth 20 
is spaced from the load transferring portion 56 a sufficient distance that 
when assembled the bottom portion 44 does not contact any portion of the 
implement 2. This is beneficial since the corner portion 18 is welded to 
the upright sidewall member 14 and the cutting edge 16. The tolerancing of 
welding the corner portion 18 in place and the bulkiness of the weld many 
times creates clearance problems and interferes with the ability of the 
nuts and bolts 71,72 to securely tighten the corner tooth 20 to the corner 
portion 18. As clearly shown in FIGS. 1 and 2, the cavity 50 provides 
ample clearance between any part of the implement 12 and the bottom 
portion 44 of the corner tooth 20. 
The nuts and bolts 71,72 effectively control all lateral forces subjected 
to the corner tooth 20. By having a tight joint connection between the 
corner tooth 20 and the corner portion 18, there is no undesirable 
movement of the corner tooth 20 with respect to the corner portion 18, 
thus generally eliminating any "hammering" type of impact loads from the 
first and second load transferring surfaces 58,60 to the respective first 
and second load transferring pads 28,30. Any unnecessary hammering type 
impact loads tend to prematurely destroy the intimate contact between the 
first and second load transferring surfaces 58,60 and the first and second 
load transferring pads 28,30. 
By having the juncture of the first and second load transferring surfaces 
58,60 form the acute angle "A" and the corresponding first and second load 
transferring pads 28,30 of the corner portion 18 having the same acute 
angle formed at its juncture, any horizontal forces coupled with any 
vertical forces are more effectively controlled by the mate-up of the load 
transferring surfaces 58,60 of the corner tooth 20 with the first and 
second load transferring pads 28,30 of the corner portion 18. 
Referring to FIG. 5, since the corner portion 18' is of an L-shaped 
configuration and the bottom portion of the "L" is an integral part of the 
corner portion 18' and does not have to be welded thereto, the concerns of 
the bulkiness of the weld and weld tolerances are no longer of serious 
consequence. Therefore, an additional load transferring pad 66 is located 
within the cavity 50 and when assembled is in intimate contact with the 
bottom portion 64 of the corner portion 18'. By having the additional load 
transferring surface 66 located generally under the load transferring 
portion 56 of the corner tooth 20', any and all upwardly induced vertical 
forces may be more effectively controlled without making the corner tooth 
20 more complicated to make. 
The replaceable corner tooth assembly 10, as set forth above, provides a 
corner system that insures the corner tooth 20/20' to be tightly fitted to 
the corner portion 18/18'. It also provides a load transferring portion 56 
on the corner tooth that mates with the corresponding pads 28,30 on the 
corner portion 18/18'. This mate-up effectively transfers the loads from 
the leading end portion 38 directly into the implement 12 while keeping 
the corner tooth 20/20' simple to manufacture and more economical to 
produce. By insuring a tight fit between the corner tooth 20/20' and the 
corner portion 18/18', less stresses are induced into the corner tooth and 
premature breakage of the corner tooth during use is substantially 
eliminated. 
Other aspects, objects and advantages of this invention can be obtained 
from a study of the drawings, the disclosure and the appended claims.