The means of adjusting
and holding the tension
on the track assemblies
of all Allis-Chalmers,
Caterpillar, and
International Harvester
Tractors, was until 1951
accomplished by turning
an adjusting screw out
of an internally
threaded retainer. The
retainer is in most
cases fixed through a
recoil spring to the
track frame, and the
screw is connected to
the front idler wheel of
the tractor. As the
screw is turned the
idler is pushed forward
which results in a
tightening of the track
chain.
This
mechanical procedure of
adjusting tracks
requires an average time
of approximately one and
one half hours. The job
of adjusting tracks is
always difficult and in
most cases requires the
use of a large wrench
and lever bar, and the
time of two or more men.
Track adjustment is
required as a result of
track and roller wear
and is also required
when the condition of
the soil in which the
tractor is working
changes with the result
that the track tightens
or loosens.
When
the tracks are extremely
loose they climb the
sprocket teeth or idler
rim which frequently
results in a thrown
track, requiring several
hours to replace. As a
result of the work and
time required to adjust
the tracks they are
frequently allowed to
run without proper
adjustment which results
in excessive wear on the
tractor rollers, idlers,
sprockets and track
links. The tractor
manufacturers estimate
that improper track
adjustment accounts for
25 to 30% of the wear on
track parts.
Since the track system
represents one fifth of
the cost of the machine,
it is therefore very
essential that proper
care be taken at all
times, especially to the
track adjustment.
In
1951 a hydraulic means
of adjusting and holding
the tension on the
tracks of crawler
tractors was invented
and patented by Mr. Bill
Henderson of Pittsburg,
Texas, which eliminates
all of the work with the
large wrench and lever
bar. With this device it
is possible to adjust
the tracks on any size
tractor in two or three
minutes. This device,
called a HYDRA-JUSTER,
enables the operator to
both tighten and loosen
the track chain as
required without effort. |
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The tracks can be
adjusted simply by using
a hand grease gun. Track
tension is released by
opening a bleeder valve
located at the base of
the cylinder. An
adjusting force of
approximately 10,000 PSI
can be obtained with the
hand grease gun. This
multiplied by the area
of the piston gives an
adjusting force in
excess of 30,000 lbs.
even on the small
HYDRA-JUSTER.
As
stated above, adjustment
is achieved by adding
grease to the cylinder
chamber which in turn
forces the idler
forward. This grease
remains trapped in the
cylinder until the track
adjustment requires
changing. During tractor
operation the pressure
on the piston may exceed
one hundred tons as a
result of idler recoil.
However, no grease is
lost due to the design
of the special grease
holding seal. As grease
is a semi-solid and
cannot be compressed,
track adjustment always
remains the same.
The allowable track
adjustment when
HYDRA-JUSTERS are
installed is equal to or
greater than that
possible with the
original mechanical
adjusting screw.
HYDRA-JUSTERS have
been so widely accepted
that most tractor
manufacturers have been
forced to approve of the
hydraulic method of
track adjustment.
Hydraulic track
adjusters are now being
provided on a few of the
new tractors as standard
equipment. However, to
convert an existing
tractor to hydraulic
adjustment HYDRA-JUSTERS
usually costs less than
half the amount charged
for the tractor
manufacturer’s hydraulic
conversion. In some
cases HYDRA-JUSTERS cost
less than one-third the
price asked for the
manufacturer’s hydraulic
conversion.
Since
1951 we have
manufactured and sold
more than 1,230,000 sets
of HYDRA-JUSTERS which,
as you can see, proves
that the HYDRA-JUSTER is
a time-tested and field
proven product.
As HYDRA-JUSTERS are
tailor made to fit all
popular models of
Allis-Chalmers,
Caterpillars, and
International Harvester
Tractors, the
installation must of
necessity vary according
to the particular
tractor. Complete
instructions regarding
installation and proper
operation accompany all
shipments. |
