Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF THE INVENTION
. . . _ . . _
(1) Field of the Invention:
. . .
~HIS INVENTION relates to a tractor self-propelled
implement vehicle or the like (hereinafter called "a tractor").
The invention is also directed to a power-module which can be
used with such tractors or implements.
(2) Descrlption of the Prior Art:
.
Ihe conventional tractor has been in use in the same
general configuration for many years and in principle has
been confined to one module incorporating the chassis,
engine, transmission and operator's platform, the module being
supported on four or more wheels, of which generally 2 or 4
are driven. The evolution of the tractor was based on horse
drawn equipment through to the "iron horse" with implements,
attachments and harvesters, the tractor taking over the role
of the horse(s) as the means of motive power.
While no one will deny that the tractor has been a
marked improvement over the horse in terms of productivity,
expense, running costs and ease of use, the conventional
tractor has limitations in many aspects and some of the more
important are listed as follows:
ta) It has only one three-point linkage assembly at the
rear.
(b) It requires a headland to turn about, the size of the
headland depending on whether the implement is attached
to the tllree-point linkage or to the draw bar.
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(c) ~s the implement is generally trailed, the operator
must drive looking forward to steer and rearward to
control the operation of the implement.
(d) In certain applications, e.g. harvesting, separate
operators are required for the tractor and implement.
(e) It is inefficient at low speeds as the engine speed, and
therefore the torque and power output, is low with the
possibility of the engine stalling. In addition the
output speed of any drive to any implement (eOg. by the
power-take-off (P.T.O.)) is not independent of the
engine speed.
(f) It has not been possible to o~fer both high clearance
and low clearance facilities on the one tractor.
(g) The extent of variations in the track, e.g. to suit row
crops, has been limited, and the wheel-base has been
fixed.
(h) It is liable to roll over either under load or when
travelling on steep terrain.
(i~ The number of attachments which can be fitted in one
operation is limited. ~-
(i) It is not adapted for ~uick disassembly and "walk out"
from one implement for fitting to another for a second
operation.
(k) It has not been convertable to an independent trans-
25- porter and cannot provide the facility of a transporter
e.g. during harvesting a crop.
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(l) It is not readily adaptable to the fitting of
implements within its wheelbase.
(m) It is not able to provide a forward speed which is slow
enough to suit specific operations, e.g. mushroom
compost turning.
(n) It has not been suitable as a mobile workshop with the
facility to supply drive to a number of independent
pieces of machinery and equipment and is not connectable
to both the mechanical and/or hydraulic drive of
commercially available equipment without the requirement
for auxiliary power being generated by further attach-
ments on the tractor or equipment.
(o) It has not provided an alternative range and power and
type of engine for a single tractor.
(p) It has not always offered a high gear ratio for road
transport and a low gear ratio for field work.
(q) It has not provided the facility to tip a transporter
bin inside the four wheels or to high clear with such
a bin.
(r~ It has not provided the option of four wheel drive
which may be fitted to a standard unit after delivery
or for independent drive to the four wheels.
(s) It has not been adaptable to be packed down into a
small volume module for transportation.
(t) It has not provided an all-purpose tractor powered by
an all-hydrostatic power system.
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SUM~RY OF THE INVEN~ION
It is an object of the present invention which can
overcome one or more of the above failings of conventional
tractors.
It is a preferred object that a tractor of the
present invention is relatively simple to manufacture and
operate.
It is a further preferred object of the present
invention to provide a suitable power module for the tractor.
1~ Other preferred objects of the present invention
will become apparen~ from the following description.
In one aspect the present invention resides in a
tractor including;
a frame;
an engine mounted on said frame;
at least one drive wheel supporting said frame;
transmission means operatively connecting said
engine and said drive wheeli
a-t least one boom pivotally connected to said
~O frame and extending in a direction away from said frame;
means for pivotally moving said boom towards or
away from the longitudinal axis of said frame;
means on said boom to permit a farming implement
to be secured thereto; and -
a ground engaging wheel supporting said boom.
Preferably the frame is rectangular and the boomsare pivotally connected to the corners of the frame. Alter-
natively a sub-frame may be pivotally connected to the frame
and the booms pivotally connected to the sub-frame. Preferably
the pivotal movement of each boom is controlled by a hydraulic
ram. The transmission means may include a hydraulic pump driven
by the engine and a pair of hyaraulic motors, one in the hub of
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each drive wheel. Alternatively, the transmission may
include a gearbox and difLerential or other suitable drive
means.
The ground engaging wheels on the booms may be castor
wheels or may be steered. IE required, these wheels may also
be provided with hydrostatic motors to provide Eour wheel
drive ( 4WD).
To enable the track of the tractor to be varied, the
booms may be swung in or out and the drive wheels may be
mounted on slidably mounted axles. The axle housings may be
movable to enable the clearance of the tractor to be raised or
lowered.
Tool attachment means, e.g. hitches, brackets, three-
point linkage or the like, may be mounted on the frame, sub~
frame and/or the booms.
BRIEF DESCRIPTION OF TIE SF.VE'RAL VIEWS OF THE DRAWING5
~o enable the invention to be fully understood, a
preferred embodiment will now be described with re~erence to
the accompanying drawings, in which:
FIG. 1 is a side of the tractor, with a portion broken
away for clarity; and
FIG. 2 is a pian view of the tractor showing the hooms
swung in (solid lines) and swung out (dashed lines).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
_ . _ ,
The power module lO of the tractor has a peripheral frame
ll. A petrol or diesel engine driving a hydraulic pump is
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mounted inside the engine cover 12. A fuel tank and hydraulic
oil tank is also mounted on the frame (not shown). An
operator's seat 13 is mounted at one side of the operator's
platform 14 and the operator is provided with operating
controls 15. A canopy 16, supported on posts 17, and side
covers 18 are ~rovided to protect the operator on the platform
14. ~Q~
Each drive wheel 19, fitted with a pneumatic ~q~ 20,
has a hydraulic motor 21 connected to its hub 22 in driving
arrangement. The motors 21 are connected to the hydraulic pump
via hydraulic lines 23. The supply of fluid from the pump to
each motor 21 is controlled by the operator via control levers
15. Each motor 21 is mounted on one end of a stub axle 24
which is slidably mounted in a box-section axle housing 25.
Holes (not shown) are provided in each stub axle 24 and its
respective axle housing 25 and bolts 26 are provided to secure
the axles at a desired track setting. As shown in the FIGS.
the drive wheels 19 lie inside the frame 11 of the power
module. The track can be further reduced by movi`ng the wheels
20 ~ towards each other. To increase the track, the stub axles 24
are reversed so that the wheels 19 lie outside the frame 11.
To facilitate this adjustmentj quick-disconnect couplings are
provided between the motors 21 and hydraulic lines 23.
To enable the clearance of the tractor to be raised and
lowered, each axle housing 25 is mounted on axle arm 26a,
pivotally mounted on frame 11 via a pivot pin 26b and held in
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position by bolts (not shown). As shown in FIG. 1~ the
tractor is in the high clearance mode.
A sub-frame 27 extends transversely of the tractor and
is pivotally connected to the Erame 11 via a pivot pin 28
Limit stops (not shown) control the relative angular movement
between the frame 11 and sub-frame 27.
The sub-frame 27 is terminated by a pair of L-shaped
brackets 29 at each end, the brackets 29 being spaced apart
and interconnected by a pivot pin 30.
A boom 31, having lateral flanges 32 at one end, is
pivotally mounted on each pivot pin 30 and is pivotally movable
between the positions shown in FIG. 2~ The pivotal movement of
each boom 31 is controlled by a hydraulic ram 33 pivotally
mounted on brackets 34, 35 on the sub-frame 27 and boom 31
respectively. The operation of the hydraulic rams 33 is
controlled by the operator.
A lateral beam 36 extends inwardly from the other end of
each boom 31 and is terminated by a plate 37. If required, a
beam (not shown) may be provided to be connected to the plates
37 when the bo¢ms 31 are swung inwardly (full lines) - this
beam can be provided, for example, with a hitch or a three-
point linkage. A castor wheel 38, having a pneumatic tyre 39,
is mounted on an axle 40 carried by parallel arms 41. An axle
- 42 fixed on plate 43 connecting the arms 41 is journalled in a
bearing 44 mounted on each lateral beam 36.
A plurality of implement attachment brackets 45 are
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fixed along each boom 31 and a tool mounting bar 46 is mounted
on the frame 11 between the driving wheels 19.
The operationof the tractor will now be described.
The engine drives the hydraulic pump which in turn
S drives the two hydraulic motors 21, and thereby drive wheels
19. By operation of the control levers 15, the operator can
c~ontrol the flow of hydraulic ~ to each motor 21. To turn
the tractor, e.g. left, the operator moves the control lever 15
to restrict the flow of hydraulic fluid to the left hand drive
motor. The le~t hand drive wheel slows or stops and the
tractor turns to the left, the axles 42 of the castor wheels
38 rotating in their respective bearings 44.
In normal operation, the booms 31 are swung inwardly as
shown in solid lines in FIG~ 2. To secure an implement between
the booms via attachment brackets ~5, the operator extends
hydraulic rams 33 to swing the booms outwardly tas shown in
dashed lines). He then reverses the tractor until the
implement is straddled by the tractor. He swin~s the booms
inwardly and connects the implement to the brackets 45.
For row crop work, or where additional stability is
required, the operator may swing the booms outwardly to a
desired track setting.
To obtain the desired track setting for the drive
wheels 19, he slides the stub axles 24 in axle housings 25
until the desired setting is obtained, and locks the stub axles
in posltion via bolts 26.
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Alternatively, or in addition, where a greater track
setting is required, the stub axles 24 are removed from their
housings 25 inserted from outside the frame (so that the
drive wheels lie Gutside frame 11).
For reduced ground clearance, the axle arms 26a are
pivoted about pivot pins 26b until the desired ground
clearance is achieved~
In rough terrain, any twisting forces on the tractor
are at least partly compensated for b~ the pivotal movement
between the frame 11 and sub-frame 27. (It will be
appreciated that in many applications, this pivotal movement
will not be required and so the sub-frame may be deleted and
the booms mounted directly onto the frame 11).
With the present arrangement, one or more implements
can be mounted between the booms, on tool mounting bar 46 or
on the beam (not shown) interconnecting the plates 37. ~his
ensures the tractor is extremely versatile and has the major
advantage that one or more implements can be mounted within
the wheel base of the tractor, a factor which is difficult or
almost impossible with most known tractors.
Where a hydrostatic drive arrangement as previously
described is employed, the tractor can be used with the castor
wheels 38 either leading or trailing, depending on which
direction of travel is most advantageous.
In addition, the operator's platform can be mounted, e.g~
on an extensivle boom on the frame 11 so that the operator can
275
be positioned over the implement or to one side (such as when
picking fruit from trees)O
Various changes and modifications may be made to the
arrangements described without departing from the scope of the
present invention. It will be understood, for example~ that a
track assembly or a pair of such assemblies may be used in
substitution for the drive wheels 19 of the power module 10.
The castor wheels 38 may be replaced by steerable and driven
wheels or track assemblies in a four wheel drive ~4WD)
configuration. The terms "drive wheel" and "ground engaging
wheel" used herein shall be taken to include "drive tracks"
and "ground engaging tracks".
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