Axle oscillation adjustment means

An improved tractor axle oscillation limiter of the type projecting upwardly on the axle structure to engage a fixed bolster on the tractor. The device includes a base having a first top abutment surface, and a mounted member securable to the base in working position with a second top abutment surface positioned above the first. The mounted member is preferably also securable to the base in a storage position.

FIELD OF THE INVENTION 
This invention is related generally to axle mounts and supports for 
tractors and, more particularly, to axle oscillation limiting devices. 
BACKGROUND OF THE INVENTION 
A substantial angle of oscillation of an axle, such as the front axle of a 
tractor, is usually desirable to provide good vehicle stability on rough 
ground. When the terrain is quite irregular oscillation of such tractor 
axle allows the tractor wheels to remain infirm contact with the ground to 
give the tractor good support. 
It is necessary, of course, to limit the angle of axle oscillation such 
that the tractor tires do not contact portions of the tractor body. 
Tractors, therefore, have axle stops on their axle housings, and abutment 
members (sometimes called "bolsters") in fixed position above their axles 
to be engaged by the axle stops as the axle pivots well away from its 
normal horizontal orientation. 
While a substantial angle of axle oscillation is desirable for stability, 
in some cases it is desirable to restrict the maximum angle of 
oscillation. For any given set of tractor wheels and tires, a further 
restriction in the maximum angle of axle oscillation increases the maximum 
turning angle which is achievable before the tractor tires hit the body of 
the tractor. That is, limiting the angle of axle oscillation shortens the 
turning radius of the tractor, making it more maneuverable. 
Tractor maneuverability is very important in a number of tractor uses. For 
example, feed lot work requires substantial maneuverability in a situation 
in which instability due to uneven ground is rarely a problem. Therefore, 
restriction of the angle of axle oscillation is highly desirable. 
In some cases the use of large front wheels and tires on a tractor is 
desirable. For example, when a tractor has a mechanical front-wheel drive 
larger wheels and tires are highly desirable. When the axle pivots, larger 
tires tend to hit the tractor body more easily, that is, during smaller 
turns. Therefore, greater restriction of the angle of maximum axle 
oscillation tends to allow the use of tractor tires which are either 
greater in diameter or wider in tread width, or both. 
Given the number of tasks for which tractors are used, it is sometimes 
desirable to change the maximum angle of axle oscillation to adapt the 
tractor to the immediate task. In some cases this means increasing the 
maximum angle of axle oscillation and in other cases it means decreasing 
such maximum angle. 
Various devices have been used in the past to limit and in some cases 
change the angle of axle oscillation. The prior art includes limiting 
means of various kinds, including those disclosed in the following 
patents: U.S. Pat. Nos. 1,765,764 (Jett); 4,500,113 (Law); 3,805,908 
(Thompson); and 2,560,144 (Vorhees). The prior art also includes the use 
of crude devices, such as bolts holding a series of washers, to further 
restrict the angle of axle oscillation. 
While various axle oscillations stop means have been disclosed in the prior 
art, there is a need for an accessible, easily installable and easily 
adjustable device for further limiting the maximum angle of axle 
oscillation in tractors. 
OBJECT OF THE INVENTION 
It is an object of this invention to provide an axle oscillation adjustment 
means overcoming some problems and shortcomings of the prior art. 
Another object of this invention is to provide a tractor oscillation 
limiter which is easy to install and easy to remove and adjust. 
Another object of this invention is to provide an auxiliary stop means for 
limiting the extent of axle oscillation which may be kept readily 
accessible for easy installation when further oscillation limitation is 
desirable. 
Another object of this invention is to provide an axle oscillation 
adjustment means readily adjustable to accommodate the conversion of a 
tractor into a mechanical front drive tractor. 
These and other important objects will be apparent from the descriptions of 
this invention which follow. 
SUMMARY OF THE INVENTION 
This invention is an improved tractor axle oscillation limiter of the type 
including an upwardly-projecting stop on the tractor axle structure 
positioned to engage a bolster located in a fixed position on the tractor 
above the axle. The invention overcomes some deficiencies in oscillation 
stops of the prior art by providing an easily accessible and easily 
mountable pair of auxiliary stop structures to impose a further limitation 
on the maximum angle of possible axle oscillation, particularly a tractor 
front axle. 
As in the prior art, a stop is located on either side of the center of the 
axle as a part of or on top of the axle structure. Each of the two stops 
on a tractor axle limits axle oscillation in one direction about the 
midpoint of the axle. 
Each stop of this invention has two principal members--a base which is 
fixed with respect to the main axle structure, and an auxiliary member (or 
"mounted member") which is removably securable to the base. 
The base, which is preferably integrally formed with the axle housing, has 
a first top abutment surface configured and positioned to engage its 
counterpart bolster in fixed position on the tractor above the axle. The 
mounted member has a second top abutment surface which is also configured 
to engage the bolster. When the mounted member is secured to the base in a 
working position, the second top abutment surface is above the first top 
abutment surface, positioned for bolster engagement such that it restricts 
oscillation of the axle more than the first abutment surface. 
The mounted member is preferably secured to the base by screw means 
extending through the mounted member and having a distal end contacting 
the base. This allows easy attachment and detachment of the mounted member 
with respect to the base. 
The mounted member preferably includes a recess which nonrotatably receives 
a nut or other female threaded member and the screw means includes a male 
threaded member (bolt) extending through the mounted member and through 
the female threaded member to a point of contact with the base. As the 
bolt is tightened, the spreading between the female threaded member and 
the distal end of the bolt provides clamping contact with the base. 
In highly preferred embodiments, the mounted member, in addition to being 
securable to the base in a working position, is securable to the base in a 
storage position. In such storage position, the second abutment surface is 
positioned away from the first abutment surface to expose the first 
abutment surface for contact with the bolster. Thus, when the mounted 
member is not being used to restrict the angle of oscillation of the axle, 
it may be stored in a position in which it is readily accessible for use 
by simple detachment and remounting to the base in its working position. 
The mounted member preferably includes at least a pair of holes through it 
for receiving the screw means, one for securing the mounted member in the 
working position and the other for securing the mounted member in the 
storage position. Each such hole also preferably includes a recess to 
nonrotatably receive a female threaded member (nut) as described above. It 
has been found that a simple one-screw clamping attachment is quite 
adequate for mounting the mounted member to the base in either the storage 
position or the working position. 
The base and the mounted member of the stop means are preferably configured 
in a manner facilitating clamping engagement of the mounted member to the 
base, and also preferably facilitating the dual-position engagement 
previously described. 
The base, which as noted is preferably integrally formed with the axle 
housing, preferably includes a substantially horizontal portion and a 
substantially vertical portion. The horizontal portion forms the first 
abutment surface on its top and also has a bottom surface spaced above the 
main portion of the axle housing. The vertical portion extends from the 
main portion of the axle housing structure to the bottom surface of the 
horizontal portion. The horizontal portion and the vertical portion 
preferably have coplanar inward edges which form a T-shaped surface. 
The mounted member is slotted for insertion onto such T-shaped inward 
edges. The mounted member preferably has horizontal and vertical slots 
which cross each other to receive such T-shaped edges. 
More specifically, the mounted member includes major and minor 
vertically-offset portions forming a horizontal slot in which the 
horizontal portion of the base is received when the mounted member is 
secured to the base in the working position. The major vertically-offset 
portion forms the second abutment surface. 
The mounted member further includes a vertical slot dividing each of the 
major and minor vertically offset portions into two arms. When the mounted 
member is secured in its working position, the two arms of the minor 
offset portion extend on either side of the vertical portion of the base 
at a position just below the bottom surface of the horizontal portion of 
the base. When the mounted member is secured in its storage position, the 
two arms of the major offset portion extend on either side of the vertical 
portion of the base at the same position. The vertical slot divides the 
second abutment surface into two portions, preferably mirror images of 
each other. 
In such preferred form, the mounted member preferably includes a pair of 
holes for receiving screw means to secure the mounted member to the base. 
One of such holes is through the minor offset portion for receiving a bolt 
such that its distal end engages the bottom surface of the horizontal 
member to secure the mounted member in the working position. The other 
hole, through one of the arms in the major offset portion, is for 
receiving a bolt (for example, the same bolt) such that its distal end 
engages the vertical portion of the base to secure the mounted member in 
the storage position. 
The first and second abutment surfaces are generally similar to one another 
(although the second abutment surface may be divided by a slot) and 
substantially-identically oriented at the point of their separate 
engagements with the bolster. More specifically, just as the abutment 
surface of certain axle stops of the prior art engage the bolster in full 
face-to face fashion in order to minimize surface wear, both the first and 
second abutment surfaces engage the bolster in face-to-face fashion. 
Such first and second abutment surfaces are preferably planar, that is, 
they have substantial flat portions. In such cases, the flat portions of 
the first and second abutment surfaces are angled with respect to each 
other when the mounted member is in its working position on the base. The 
angle between such two planes is equal to the angle of restriction of the 
oscillation imposed by the mounted member. For example, if the normal 
angle of oscillation of the axle is twelve degrees above horizontal when 
the mounted member is not in the working position, and six degrees when 
the mounted member is in the working position, then such angle between the 
flat portions of such first and second abutment surfaces would be 
approximately six degrees. 
Other abutment surface characteristics are possible. However, face-to-face 
engagement is highly preferred, whether such surfaces are curved or flat.

DETAILED DESCRIPTIONS OF PREFERRED EMBODIMENTS 
FIG. 1 shows a pair of axle oscillation stops 10 on a tractor front axle 
housing 12, one on either side of a gear housing 14 which forms a portion 
of axle housing 12. The tractor front axle structure also includes a pivot 
mount member 16 by which axle housing 12 is pivotably attached to the 
remainder of the tractor. Each of the oscillation stops 10 is positioned 
to abut a bolster 18 (see FIGS. 7 and 8), which is in fixed position on 
the tractor above axle housing 12, when the axle pivots too far about 
pivot mount member 16. 
Each oscillation stop 10 includes a base 20 and a mounted member 22. Base 
20 is removably mounted on base 20 in one of two different 
positions--either a working position (see FIG. 7) or a storage position 
(see FIG. 8). 
Base 20 is integrally formed with the main portion of front axle housing 12 
and projects upwardly from the main portion of front axle housing 12 to 
terminate in a first top abutment surface 24. Base 20 includes a 
horizontal portion 26 on which first top abutment surface 24 is formed, a 
vertical portion 28, and an outside portion 30. Horizontal portion 26 has 
a bottom surface 32 and vertical portion 28 extends from the main portion 
of axle housing 12 to bottom surface 32. Outside portion 30 also extends 
from the main portion of front axle housing 12 to horizontal portion 26 
and is connected to vertical portion 28 along its length. This structure, 
known in the prior art, provides good strength for base 20. 
Mounted member 22 has a second top abutment surface 23 which, when mounted 
member 22 is secured to the base in its working position, is positioned 
above first top abutment surface 24. Thus, when mounted member is in its 
working position second abutment surface 34 serves to restrict the maximum 
oscillation of the axle more than first abutment surface 24. 
As best illustrated in FIGS. 3-6, mounted member 22 includes major and 
minor vertically-offset portions 36 and 38, respectively. Major and minor 
offset portions 36 and 38 form a horizontal slot 40 therebetween into 
which horizontal portion 26 of base 20 is received when mounted member 22 
is secured to base 20 in its working position. Second top abutment surface 
34 is formed on major offset portion 36. 
Mounted member 22 also includes a vertical slot 42 which divides major 
offset portion 36 into two arms 44 and 46 and minor offset portion 38 into 
two arms 48 and 50. Arms 48 and 50 of minor offset portion 38 extend on 
either side of vertical portion 28 when mounted member 22 is secured in 
its working position, as illustrated in FIG. 7. Arms 44 and 46 of major 
offset portion 36 extend on either side of vertical portion 28 of base 20 
when mounted member 22 is secured in its storage position as illustrated 
in FIG. 8. 
Mounted member 22 is secured to base 20 in either the working position or 
the storage position by means of a single bolt and nut combination. 
As illustrated in FIGS. 3, 5, and 7, a pair of holes 52 extend vertically 
through arms 44 and 46 of minor offset portion 38. Arms 44 and 46 each 
have an inside surface 54 with a recess 56 to nonrotatably receive a nut 
58 (see FIG. 7), which is threadedly engaged with a bolt 60. Nut 58 is 
preferably a square nut and recess 56 is preferably of square 
configuration to receive nut 58 nonrotatably. To engage mounted member 22 
to base 20 in its working position, nut 58 is dropped into a recess 56 
either on arm 44 or on arm 56 and bolt 60 is threaded therethrough. As 
bolt 60 is tightened, the distal end 62 of bolt 60 contacts bottom surface 
32 of horizontal portion 26 of base 20. Further tightening clamps 
horizontal portion 26 between nut 58, the movement of which is restricted 
by recess 56, and major offset portion 36. In this way mounted member 22 
is held securely in its working position. 
Two bolt and nut combinations could be used, one through each of the arms 
44 and 46, but one is sufficient. However, a pair of holes 52 and recesses 
56 are preferably included so that mounted member 22 can be made in one 
form for either side of the axle, thus facilitating attachment to base 20 
in the easiest manner. 
Likewise, as illustrated in FIGS. 3, 4 and 8, a pair of holes 64 and 
corresponding recesses 66 extend horizontally through arms 48 and 50 of 
major offset portion 36. Recesses 66 are on the inside surfaces 68 of arms 
48 and 50. A bolt 70, shown in FIG. 8 and a nut (not shown) cooperate in 
the same manner as is described above with respect to bolt 60 and nut 58 
to clamp mounting member 22 in place against vertical portion 28 of base 
20. Only one bolt is used, but two pairs of holes 64 and recesses 66 are 
available for convenience and for use on either side of the axle midpoint. 
As best illustrated in FIG. 8, when mounted member 22 is in its storage 
position, second abutment surface 34 is well below horizontal portion 26, 
positioned well out of the way to fully expose first abutment surface 24 
for contact with bolster 18 as required. Storage at this position assures 
that mounted member 22 will be available and will be accessible when it is 
desirable to further restrict the oscillatory movement of front axle 
housing 12. 
First top abutment surface 24 is flat and second top abutment surface 34 is 
also flat. Second top abutment surface is divided into two portions by 
vertical slot 42 (see FIGS. 4 and 6). Nevertheless, when first and second 
abutment surfaces 24 and 34 are at the point of their separate engagements 
with bolster 18, they have substantial portions which are similar and 
identically-oriented so that they each engage bolster 18 in face-to-face 
fashion. 
As best illustrated in FIGS. 3, 7 and 8, second abutment surface 34 is 
angled with respect to first abutment surface 24. Such angle is equal to 
the further limitation in the angle of oscillation which is imposed by 
mounted member 22 when it is in its working position. 
Mounted member 22 may be moved from its storage position, illustrated in 
FIG. 8, to its working position, illustrated in FIG. 7, by loosening bolt 
70, slipping mounted member 22 off base 20, inverting mounted member 22, 
taking the nut which was removed from bolt 70 and inserting it in one of 
the recesses 56 and engaging the same bolt with it, sliding mounted member 
22 into full engagement with base 20, and tightening the bolt. Moving 
mounted member 22 from the working position to the storage position 
involves the same sorts of steps. 
While the principles of this invention have been described in connection 
with specific embodiments, it should be understood clearly that these 
descriptions are made only by way of example and are not intended to limit 
the scope of the invention.