MARCHEPIED POUR TRACTEUR SERVANT A LA POSE DES RAILS

MOUNTING STEP ASSEMBLY FOR TRACK LAYING TRACTOR

Abrégé anglais

MOUNTING STEP ASSEMBLY FOR TRACK LAYING TRACTOR
Abstract of the Disclosure
A track laying tractor includes a mounting step located on
the track frame within a walled enclosure arranged to prevent
debris from dropping from the upper run of the track onto the
frame in the area of the step.

Revendications

The embodiments of the invention in which an exclusive
property or privilege is claimed are defined as follows:
1. In combination with a track laying tractor track assem-
bly including a fore-and-aft elongated track frame, drive and
idler elements rotatably mounted at opposite ends of the track
frame, a flexible endless track received about the drive and
idler elements and having upper and lower runs respectively
located vertically above and below the track frame and a mounting
step mounted on an upper surface of the track frame beneath the
upper run of the track, a step enclosure, comprising: first and
second upright end walls fixed to the track frame at respective
fore-and-aft spaced locations bordering the step and extending
outwardly at least as far as an outermost surface of the step;
and a further wall extending between and joined to the end walls
and extending downwardly and inwardly to the frame from a location
vertically above the outermost surface of the step.
2. In combination with a track laying tractor track assem-
bly including a fore-and-aft elongated track frame, drive and
idler elements rotatably mounted at opposite ends of the track
frame, a flexible endless track received about the drive and
idler elements and having upper and lower runs, respectively,
located vertically above and below the track frame and a mounting
step mounted on an upper surface of the track frame beneath an
upper run of the track, a step enclosure, comprising: a pair of
vertical triangular end walls mounted on the track frame at
opposite ends of the step in crosswise extending relationship to
the frame; said end walls having respective outer edges located
outwardly at least as far as the step and having respective upper
edges inclined downwardly and inwardly to the frame; and a down-
wardly and inwardly inclined wall extending between the end walls
and joined to the upper edges of the latter along the entire
length thereof.

Description

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1 MOUNTING STEP ASSEMBLY FOR TRACK LAYING TRACTOR
The present invention relates to mounting step assemblies
for vehicles and more particularly relates to mounting step
assemblies located on track frame of track laying tractors.
It is known to provide track laying tractors with step
assemblies for aiding an operator in climbing to and from operator
stations of the tractors, the step assemblies being secured to
the track frames of the tractors. These step assemblies are
normally located beneath the upper runs of the endless tracks of
the tractors. Therefore, whenever the tractors are operating in
conditions where adhesive materials such as mud and/or snow and
the like, it has been found that these materials are carried
above and deposited on the step area by the upper runs of the
tracks such as to make the steps entirely unuseable or dangerous
to use because of the slipperiness of the materials coating the
steps.
Summary of the Inve_tion
According to the present invention, there is provided an
improved mounting step assembly for use on track frames of track

laying tractors.
An object of the invention is to provide a step assembly
located on a track laying tractor track frame beneath the upper
run of an endless track encircling the frame and designed such as
to prevent materials carried by the upper run of the track from
falling onto and covering the step of the assembly.
A more specific object of the invention is to provide a
mounting step assembly for a track laying tractor including a
step fixed to the track frame and an outwardly opening shield
structure fixed to the track frame and disposed above and at


opposite ends of the step.
These and other objects will become apparent from a reading
of the ensuing description together with the appended drawings.


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1 Brief Description of the Drawings
Fig. 1 is a right side elevational view showing a crawler
tractor provided with a mounting step assembly constructed in
accordance with the principles of the present invention.
Fig. 2 is a right rear perspective view of a prior art
mounting step assembly.
Fig. 3 is a right rear perspective view of the mounting of
the present invention.
Description of the Preferred Embodiment
Referring now to Fig 1 of the drawing, therein is shown a
track laying tractor 10 including a main frame 12 supported by a
pair of track frame assemblies 14 (only one visible) located at
the opposite side thereof. Located forwardly on the frame 12 is
an engine compartment 16. An operator's station 18 is located on
the frame 12 behind the compartment 16.
The track assemblies 14 each includes a fore-and-aft elon-
gated track frame 20 having an idler wheel 22 mounted at the
forward end of the frame 20 for fore-and-aft movement and a drive
sprocket 24 supported by the frame 12 and disposed at the rear

end of the frame 20 in fore-and-aft alignment with the idler
wheel 22. An endless track 26 is disposed about the idler wheel
22 and drive sprocket 24 and includes upper and lower runs 28 and
30, respectively, disposed vertically above and below the frame
20. The frame 20 includes a housing 32 forming an upper portion
thereof and within which is located an idler wheel recoil mecha-
nism (not shown) connected between the frame 20 and the idler
wheel 22 and acting to resiliently bias the wheel 22 forwardly to
maintain proper tension in the track 26.
Fixed to the housing 32 in transverse alignment with an

operator access passage of the operator's station 18 is a mounting
step assembly 34. Specifically, the step assembly 34 includes a
U-shaped strap 35 having a fore-and-aft extending foot-engageable

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1 portion 36 joined at its opposite ends to front and rear parallel,
transversely extending legs. This much of the step assembly 34
is known in the prior art as illustrated in Fig. 2. Disposed in
partial covering relationship to the U-shaped strap is a shield
37 comprising triangular end plates 38 and 40 respectively engaged
with outer vertical surfaces of the ends of the U-shaped strap
35. The end plates 38 and 40 respectively include our edges 42
and 44, located coplanar with an outer surface of the foot-
engageable portion 36 of the strap 35 and downwardly and inwardly

inclined upper ends joined by a downwardly and inwardly inclined
plate 46 having an outer edge 48 located vertically above the
strap portion 36, the plates 38, 40 and 46 thus defining an
outwardly opening cavity 50 into which an operator's foot may be
inserted while engaging the strap portion 36 as the operator
mounts or dismounts from the vehicle. Further, it is noted that
the disposition of the plate 46 relative to the strap 36 results
in the area occupied by and inwardly of the strap 36 being kept
free of material which may be carried above and dropped upon the
step assembly 34 by the ~pper run 28 of the track 26.

The operation of the step assembly 34 is thought to be
understood from the foregoing description and for the sake of
brevity no further description of the operation is given.