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Having disclosed my invention, what I claim as new and to be secured by
Letters Patent of the United States is:
1. An agricultural tractor comprising at least one power take-off shaft, at
least four front ground wheels and at least four rear ground wheels, each
of said ground wheels including a low-pressure, low profile tire, each
said ground wheel having a diameter of approximately 1.3 meters and
providing a relatively large area in continuous contact with the ground,
and an engine of at least fifty kilowatts of available power for driving
at least four of said ground wheels, the tracks followed by said four
wheels being substantially non-coinciding during the tractor's
straight-ahead travel, the tracks followed by two of said front wheels
being substantially contiguous and substantially non-overlapping with the
tracks followed by two of said front wheels so that the soil structure
underlying said tracks remains intact without adverse effects on
subsequent plant growth.
2. A tractor as claimed in claim 1, in which the total width of said
tractor at the wheels is about three meters.
3. A tractor as claimed in claim 1, in which said wheels are arranged in
two groups, and said engine is located between said two groups.
4. A tractor as claimed in claim 3, in which there is a power take-off
shaft both at the front and at the rear of the tractor.
5. A tractor as claimed in claim 4, comprising lifting devices which are
respectively at the front and at the rear of the tractor.
6. A tractor as claimed in claim 5, in which said wheels are provided with
low-pressure tires and are mounted on a beam extending transversely of the
intended direction of operative travel of the tractor.
7. A tractor as claimed in claim 6, in which at least part of one of said
lifting devices is pivotally connected to said beam.
8. A tractor as claimed in claim 6 wherein said wheels mounted on said beam
comprise two pairs, each said pair of said wheels being mounted on said
beam by means of a respective carrier disposed between the wheels of each
said pair.
9. A tractor as claimed in claim 8, in which said wheels mounted on each
said carrier are rotatable independently of each other.
10. A tractor as claimed in claim 1, wherein said wheels comprise front and
rear wheels, the rear wheels of said wheels being ground driven and the
front wheels of said wheels being steerable and drivable by said engine.
11. A tractor as claimed in claim 10 wherein said front wheels as a group
are turnable with respect to said rear wheels as a group about a
horizontal axis parallel to the tractor's usual direction of forward
travel and centered with respect to each said group of wheels.
12. A tractor as claimed in claim 11, comprising a change-speed mechanism
for said engine for driving said front wheels, in which the weight of said
engine is carried at least in substantial part and the weight of said
change-speed mechanism is carried primarily by said front wheels.
13. A tractor as claimed in claim 12, in which a lifting device is disposed
between two of said rear wheels.
14. A tractor as claimed in claim 13, in which a driver's cab is provided
which extends forwardly to a position above said front wheels.
15. A tractor as claimed in claim 14, in which means is provided for
carrying fuel whereby the weight of the fuel is carried at least in
substantial part by said front wheels.
16. A tractor as claimed in claim 10, in which at least two of said wheels
drivable by said engine are pivotable about a king pin through about
150.degree..
17. An agricultural tractor comprising a frame, an engine carried by said
frame, at least two ground driven wheels at one end of the tractor and at
least two wheels drivable by said engine at the other end, and steering
means which is so constructed and arranged that said latter two wheels are
pivotable about a king pin through about 150.degree., the tracks of said
ground wheels when the tractor is driven straight ahead being
substantially contiguous and substantially not over-lapping, the weight of
the tractor borne by said wheels distributed substantially uniformly over
the total width of said tracks.
18. A tractor as claimed in claim 17, in which said king pin is upwardly
and rearwardly inclined with respect to the tractor's intended direction
of operative travel.
19. A tractor as claimed in claim 18, in which said king pin is in a fixed
position with respect to said engine.
20. A tractor as claimed in claim 17, in which said wheels are provided
with low-pressure tires.
21. A tractor as claimed in claim 20, in which all of said wheels have
substantially the same diameter.
22. An agricultural tractor comprising a frame, a driving engine mounted on
said frame, four forward wheels, and two king pins having respective axes
of rotation which are each fixed with respect to said engine, said
plurality of wheels being steerable about said king pins, and the distance
between said engine and at least one of said king pins being substantially
equal to the diameter of one of said wheels which is a front wheel.
23. A tractor as claimed in claim 22, in which the distance between said
engine and the rotary axis of a wheel of the tractor which is ground
driven and a rear wheel is substantially equal to the diameter of said
ground driven wheel.
24. A tractor as claimed in claim 23, in which said engine is disposed
approximately midway between said front and rear wheels.
25. A tractor as claimed in claim 24, in which said engine and said king
pins are mounted on a frame part which is pivotable about an axis
extending lengthwise of the tractor with respect to said rear wheels.
26. A tractor as claimed in claim 22, comprising a change-speed gear box
including a differential gear, said king pins being mounted from said gear
box, said plurality of wheels being front side-by-side wheels.
27. A tractor as claimed in claim 26 in which the position of said king
pins is fixed with respect to said gear box.
28. A tractor as claimed in claim 27, in which transverse carrier members
are secured to the gear box, said transverse carrier members mounting said
king pins to said gear box.
29. A tractor as claimed in claim 28, in which each said transverse carrier
member is substantially fixed with respect to said frame.
30. a tractor as claimed in claim 29, comprising mounting and
power-take-off means for mounting and driving soil cultivating implements,
said wheels being provided with low-pressure and low profile tires.
31. An agricultural tractor comprising an engine, ground engaging wheels,
means mounting a plurality of soil cultivating implements and power
take-off shafts driving said soil cultivating implements, at least one of
said shafts rotating at a speed proportional to said engine's rpm and at
least a further said shaft rotating at a speed proportional to the
tractor's forward speed, and low-pressure low-profile tires mounted on all
of said wheels, at least one of said cultivating implements having
rotating members driven by said further shaft, said rotating members
having ground engaging parts which are rotated by said further shaft at a
peripheral speed of at least about that of said wheels and in the same
direction to exert tractive force on the tractor.
32. A tractor as claimed in claim 31, in which the profile of each said
tire has a height of about five centimeters.
33. A tractor as claimed in claim 32, in which the width of each said tire
is about forty centimeters.
34. A tractor as claimed in claim 33 in which the brake kilowatt power of
said engine is about sixty.
35. A tractor as claimed in claim 34, in which the tractor's overall weight
is not greater than about 3500 kilograms.
36. A tractor as claimed in claim 35, comprising power driven tillage
equipment at the tractor's front and also at its rear.
37. A tractor as claimed in claim 36, comprising a power driven rotary
tiller at the tractor's front and a seed drill mounted at the tractor's
rear. |
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Claims |
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Description |
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SUMMARY OF THE INVENTION
This invention relates to an agricultural tractor comprising an engine and
a plurality of ground wheels.
Known tractors are relatively heavy and the ground contact area is
relatively small, with the result that high ground pressures exist below
the tractor wheels, causing serious deterioration of the soil structure
damaging the growth of the plants.
According to one aspect of the present invention there is provided an
agricultural tractor comprising at least one power take-off shaft, at
least four ground wheels having a diameter of approximately 1.3 meters,
and an engine of at least fifty kilowatts for driving two of the wheels,
the tracks of the said four wheels being different from each other during
straight-ahead travel of the tractor.
Owing to the low ground pressure of the tractor relatively low power is
required for driving the tractor. Because there are many wheels, the
ground pressure is very low so that the tractor is particularly suitable
for soil cultivation in spring, in particular when the soil cultivating
implements are driven from one or more of the power take-off shafts.
According to another aspect of the present invention there is provided an
agricultural tractor comprising front and rear wheels, of which the rear
wheels are ground driven and the front wheels are steerable and drivable
by the engine.
According to a third aspect of the present invention there is provided an
agricultural tractor comprising ground driven wheels at one end and at
least two wheels drivable by the engine at the other end which are
pivotable about one or two king pins through about 150.degree..
According to a fourth aspect of the present invention there is provided an
agricultural tractor comprising a driving engine and a plurality of wheels
which are steerable about king pins which are in a fixed position with
respect to the engine.
According to a fifth aspect of the present invention there is provided an
agricultural tractor comprising a change-speed gear box including a
differential gear on which king pins bearing front wheels are mounted.
According to a sixth aspect of the present invention there is provided an
agricultural tractor comprising one or more power taken-off shafts for
driving soil cultivating implements, the tractor having low-pressure
low-profile tires.
For a better understanding of the present invention and to show how it may
be carried into effect, reference will now be made, by way of example, to
the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational side view of a tractor;
FIG. 2 is a plan view of the tractor of FIG. 1;
FIG. 3 is a front view of the tractor of FIGS. 1 and 2;
FIG. 4 is a side elevational view of the tractor of FIGS. 1 to 3 with
implements hitched to it;
FIG. 5 is a plan view of the tractor and implements of FIG. 4;
FIG. 6 is a plan view on an enlarged scale of a coupling between a lifting
device of the tractor and the implements; and
FIGS. 7 to 9 are side elevational views of three possible combinations of
the tractor of the preceding Figures with attached machines or implements.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The tractor shown in the Figures has a frame 1 mainly comprising a
horizontal, hollow tube 2 extending in the intended direction of operative
travel of the tractor, as indicated by an arrow A. The tube 2 is situated
at the bottom of the frame and is provided with two horizontal carriers 3
extending transversely of the direction A. The carriers 3 are spaced apart
from each other and their outer ends are fastened to upright cover plates
4 which are directed in the direction A and, as viewed from the side (FIG.
1) are rectangular. The upper edges of the cover plates are secured to the
lower edges of an H-shaped frame part 5, which is shown in plan in FIG. 2.
The frame part 5 has a relatively lightweight tubular construction, since
its main function is to support only a cab 6 (omitted in FIG. 2 for the
sake of clarity). As shown in FIG. 2, the frame part 5 comprises two tubes
7 located one on each side of the tractor and interconnected midway along
their length by a tube 8 which extends horizontally and transversely of
the direction A. The construction comprising the parts 1 to 8 is
symmetrical about the vertical, central, longitudinal plane of the
tractor, which is designated in FIG. 2 by reference numeral 9. The center
line of the main frame tube 2 is thus also located in the plane 9. FIG. 2
shows a driving engine 10 disposed to one side of the plane 9 and
supported by the carriers 3. At the rear of the engine 10 there is a
radiator. On the other side of the plane 9, there is a fuel tank 11 which
is supported by the carriers 3. Near the front end of the main frame tube
2 there are two rigid supports 12 which are fastened on the sides of the
tube 2 and slope upwardly and forwardly from the tube 2 at an angle of
about 45.degree.. The top ends of the supports 12 are fastened to the
underside of a housing 13 for a box or combined change speed and
differential gear, which, as shown in FIG. 1, is disposed mainly ahead of
the front end of the tube 2. The horizontal underside of the housing 13 is
approximately at the level of the top of the engine 10, which is situated,
as shown in FIG. 1, behind the housing 13. The output shaft of the engine
10 extends forwardly and is coupled with the input shaft of a gear wheel
transmission 14 accommodated in a rigid housing which slopes upwardly from
the engine towards the plane 9, as can be seen in FIG. 3. The directional
disposition of the housing of the gear wheel transmission 14 is prompted
because engine 10 is disposed to one side of the plane 9 and at the lowest
possible level with respect to the frame 1 with regard to the position of
the center of gravity of the tractor. The output shaft of the engine 10
drives a gear wheel 15 (FIG. 3), which drives a gear wheel 16 situated
obliquely above it. The gear wheel 16 drives a gear wheel 18 through the
intermediary of a gear wheel 17. The rotary axis of the gear wheel 18 lies
in the plane 9. The shaft of the gear wheel 18 emerges forwardly from the
housing of the gear wheel transmission 14, and is coupled with an input
shaft of the change-speed gear box 13. The gear wheel 16 is mounted on the
same shaft as a gear wheel 19. Through an intermediate gear wheel 20, the
gear wheel 19 drives a gear wheel 21, the rotary axis of which lies in the
plane 9 below the gear wheel 18. All of the gear wheels 15 to 21 are
mounted in the rigid housing which connects the engine with the
change-speed gear box 13. The rotary shaft of the gear wheel 21 projects
both to the front and to the rear from the housing of the gear box and is
integral with a drive shaft 22 journalled in a horizontal, bearing tube 23
lying in the plane 9 below the underside of the housing of the
change-speed gear box 13 (FIG. 1). The bearing tube 23 is disposed below
the change-speed gear box 13 and in front of the housing of the gear wheel
transmission 14. The rear end of the bearing tube 23 is rigidly secured to
the front of the housing of the gear wheel transmission 14 and is
connected by a support 24 to the underside of the gear box 13 at a
position ahead of the gear wheel transmission 14. The drive shaft 22
accommodated inside the bearing tube 23 projects from the pipe 23 both at
the front and the rear side of the housing of the gear wheel transmission
14 (FIG. 1). The front end of the H-shaped frame part 5 embraces the
housing of the change speed and differential gear box 13. As shown in FIG.
1, the tie beam 8 of the frame part 5 is situated a short distance behind
the front end of the tube 2.
To one side of the housing of the gear box 13 is fastened a drive casing 25
having an output shaft 26 directed to the rear. The mechanism accommodated
in the drive casing 25 and driving the output shaft 26 is coupled with an
output shaft of the mechanism in the gear box 13 so that the output shaft
26 can be driven with a rotary speed which is proportional to the travel
speed of the tractor. The drive shaft 22, however, is driven at a speed
which does not vary with the travel speed of the tractor, but is
proportional to the speed of rotation of the output shaft of the engine
10.
Three resilient mountings 27 of synthetic resin or rubber are arranged one
behind the other on the top of each of the two tubes 7 of the H-shaped
frame part 5 for supporting the tractor cab 6. The tractor cab 6
accommodates a driver's seat and steering means for the steerable wheels
which will be described more fully later, and also accommodates control
members for controlling drive to the wheels and preferably also for
connecting and disconnecting drive to the drive shaft 22 and the output
shaft 26 by means of clutches (not shown) situated respectively near the
drive shaft 22 at the housing of the gear wheel transmission 14 and in the
drive casing 25. As shown in FIG. 1, the cab 6 comprises sidewalls with
panes terminating at lower edges which lie on a boundary line 28 which
slopes upwardly towards the front so that the rear wall of the cab extends
only for a short distance above the frame part 5, this enabling the driver
to get a good view of the rear part of the tractor. The boundary line 28
terminates at the front a short distance above the top of the gear box 13
so that the driver also gets a good view through the front pane of the cab
6 of the front part of the tractor. As shown in FIG. 1, the front plane of
the cab terminates approximately vertically above the front of the gear
box 13.
Tubular carriers 29 are secured to the sides of the housing of the gear box
13 at a position a short distance behind the front of this housing. These
carriers 29 are disposed symmetrically about the plane 9. At their ends
away from the housing of the gear box 13 the carriers 29 each terminate at
the level of the front ends of the tubes 7 of the horizontal H-shaped
frame part 5. Near these ends, the carriers 29 are fastened to housings 30
of gear wheel transmissions which will be described in detail later.
Tubular supports 31 are connected to the underside of the housings 30 and
extend from the housings 30 downwardly and slightly to the front, their
centerline being inclined at an angle of about 80.degree. to the
horizontal. The tubular supports 31 are pivotable about their longitudinal
center lines with respect to the housings 30 in a manner to be described
more fully later. At their lower ends the supports 31 are provided with
wheel carriers 32, which are rigidly connected to their supports 31. The
wheel carriers 32 are also tubular and extend horizontally and
transversely of the direction A when in the position shown in FIG. 3,
which corresponds to straight-ahead travel. Each wheel carrier 32, as can
be seen in FIG. 3, is symmetrical about a vertical plane parallel to the
plane 9. At least one front wheel 33 is mounted on each end of each wheel
carrier 32 so that the tractor has, in all, at least four front wheels
arranged in a row transverse to the direction A. The diameter of each
front wheel is about 1.3 meters or less, although not less than about
ninety centimeters, and the width of the pneumatic tire on each front
wheel is about forty centimeters. The tops of the wheels 33 are
approximately level with the top of the engine 10. The contact surface of
all front wheels 33, as shown in the front view of FIG. 3, thus covers a
width of at least 1.60 meters or, if more than four front wheels are
provided, more than 1.60 meters.
The differential gear in the housing 13 has two output shafts which extend
into the carriers 32 and drive bevel gear wheel transmissions in the
housings 30 in a manner such that shafts located in the supports 31 drive
bevel gear wheel transmissions arranged in the wheel carriers 32, the
output shafts of which are coupled with the front wheels on each wheel
carrier 32. The rotary axes of the front wheels 33 thus driven coincide
with the centerlines of the wheel carriers 32. The supports 31 are
journalled in the housings 30 so that the supports 31, with the associated
wheel carriers 32 and the associated front wheels 33, are pivotable about
the centerlines of the supports 31, these centerlines also coinciding with
the centerlines of the drive shafts accommodated within the supports 31
for transmitting the drive to the front wheels 33. At their top ends the
supports 31 are provided with levers 34, which are forwardly and inwardly
inclined and are pivotally coupled at their ends away from the supports 31
with track rods 35, which extend inwardly from the levers 34 and are
inclined to the rear. At their inner ends the track rods 35 are pivotally
coupled with the rear corners of a triangular steering plate 36 (FIG. 2)
which is pivotable about an upwardly directed pivotal shaft 37 with
respect to the housing of the gear box 13, shaft 37 thus being rigidly
secured relative to the frame 1. The pivotable shafts at both ends of the
track rods 35 and the pivotable shaft 37 are preferably parallel to the
centerlines of the supports 31. The rear end of the steering plate 36 is
also pivotally connected to the end of the piston rod of a hydraulic ram
38, the cylinder of which is pivotable about an upwardly directed pivotal
shaft with respect to the frame part 5 and one of the housings 39. The
hydraulic ram 38 is situated a short distance behind one of the housings
30 and can be actuated from the cab 6. Viewed on plan (FIG. 2) the track
rods 35 intersect a line perpendicular to the plane 9 and connecting the
housings 30, the pivotable connections between the track rods and the
steering plate 36 being located to the rear side of this connecting line.
Apart from being steerable, the front wheels 33 are arranged on a carrying
construction comprising the parts 29, 30, 31, 32, which is fixed with
respect to the tractor frame 1. The distance between the nearest of
steering axes 30a which is nearest the engine 10, and the engine 10 is
substantially equal to the diameter of each front wheel.
The front end of the drive shaft 22 is positioned, as shown in FIG. 1,
approximately in a plane containing the centerlines of the supports 31 and
at the level of the tops of the front wheels 33. As seen from the front,
the front end of the drive shaft 22 lies within the carrying construction
comprising the parts 29, 30, 31, of the front wheels 33, this construction
being generally in the form of an inverted U. Viewed from the side, the
cab 6 extends forwardly beyond the rotary axes of the front wheels 33.
The rear end 39 of the main frame tube 2 is situated, as viewed from the
side, approximately directly below the rear boundary of the cab 6. A
length of cylindrical tube 40 is joined to the rear end 39 of the main
tube 2. The front end of the length of tube 40, i.e. near the rear end 39,
is closed by a strong partition which is locally welded to the inner
periphery of the tube 40. To the front side of the partition is welded a
cylindrical tube 41 which extends through the tube 2 up to its front end.
The outer periphery of the tube 41 is a close fit in the inner periphery
of the tube 2 so that the length of tube 40 and the tube 41, which are
integral with one another, are rotatably journalled in the tube 2. The
centerlines of the length of tube 40, the tube 41 and the tube 2 coincide
with each other. A partition 42 is welded to the front of the tube 2 and
has a central hole through which a bolt 43 extends. The part of the bolt
43 located inside the tube 2 is screwed into a tapped hole in a partition
44A which is located in the front end of the tube 41 and is welded at its
periphery to the inner wall of the tube 41. The bolt 43 prevents the
length of tube 40 from sliding rearwards in the pipe 2 and also permits
adjustment of the contact pressure between the front end of the length of
tube 40 and the rear end 39 of the tube 2. The rear end of the length of
tube 40 is substantially directly below the rear end of the tube 7
supporting the cab 6 (FIG. 1). In the construction described above, the
length of tube 40, together with the tube 41, is pivotable with respect to
the main frame tube 2.
To the rear end of the length of tube 40 is welded a beam 44, which may be
tubular, which extends transversely of the direction A and, when the
tractor is standing on a horizontal surface, is symmetrical about the
plane 9. Each end of the beam 44 lies in a plane which is parallel to the
plane 9 and approximately coincides with, or lies outside, the vertical
plane of symmetry of the outermost front wheel on the same side of the
plane 9. At these outer ends, the rear of the beam 44 is provided with
carriers 45 which extend rearwardly and slope slightly downwards. Near the
rear end of each carrier 45 is fastened a rotary shaft 46 which is
parallel to the length of the beam 44 and projects to both sides of the
respective carrier 45. At least one rear wheel 47 is rotatably mounted on
each end of each of the rotary shafts 46, so that each carrier 45 has two
rear wheels 47, disposed one on each side. The wheels 47 of each pair are
mounted so that they are freely rotatable independently of the other.
The four front wheels 33, like the four wheels 47, are arranged in a row
transverse of the direction A, the disposition of the two rows being such
that, as viewed parallel to the direction A, each of the outer front
wheels 33 is located between the rear wheels 47 located on one side of the
plane 9 so that, as seen in FIG. 2, the vertical plane of symmetry of each
carrier 45 substantially coincides with the vertical plane of symmetry of
an outermost front wheel 33. Each of the inner front wheels 33 is arranged
so that, again viewed in the direction A, it is disposed substantially
between the plane 9 and the inner rear wheel 47 on the same side of the
plane 9. This is apparent from the front view of the tractor (FIG. 3),
which shows that the wheels are in contact with the ground substantially
over the entire width of the tractor so that the weight of the tractor is
distributed over the entire width of the tracks. Measured transversely of
the direction A, the overall dimension of the row of rear wheels 47 is
about three meters. The diameter of all wheels is substantially the same
and amounts to about 1.3 meters of less (but not less than about ninety
centimeters), the width of each wheel being about 40 cms.
The rear wheels 47 together with the carriers 45, the beam 44 and the
length of tube 40 with the tube 41 are pivotable about the centerlines of
the tube 2 with respect to the tractor frame and also with respect to the
front wheels 33.
On the top of the hollow beam 44, which is square in this embodiment, there
is a support 48A, which is the same distance from the plane 9 as is the
output shaft 26 of the drive casing 25. A shaft 48 is received in the
support 48A and projects from the front and rear of the support 48A. The
shaft 48 is substantially horizontal and parallel to the plane 9. The
forwardly projecting part of the shaft 48 is coupled by a drive shaft 49
including two universal joints with the output shaft 26 of the drive
casing 25 so that the shaft 48 can be driven at a rotary speed
proportional to the rotary speed of the driven front wheels 33 and hence
also to that of the non-driven rear wheels 47. Two support plates 50 are
secured to the top of the beam 44 near the plane 9. These support plates
50 are close to each other and extend upwardly and to the rear away from
the beam 44. Near their free ends, the support plates 50 have fastening
holes 51, for attaching an upper lifting arm. Viewed from the side, the
holes 51 are located close to a vertical plane touching the front points
of the wheels 47. Fastening lugs 52 are rigidly secured to the rear of the
beam 44 on both sides of the plane 9. Lower lifting arms 53 are pivotally
fastened to the lugs 52 and extend rearwardly from the lugs 52. The
lifting arms 53 are slightly inclined outwardly and are symmetrical about
the plane 9. The lifting arms 53 are pivotable relatively to the lugs 52
about pivotal shafts 54 which extend parallel to the beam 44. Viewed from
the side, the pivotal shafts 54 are situated near the front points of the
rear wheels 47.
A shaft 55, extending parallel to the beam 44, is journalled in the support
plates 50, at a position above the pivotal shafts 54 and above the beam
44. The shaft 55 projects from the support plates 50 at both sides and is
rigidly secured near its ends to levers 56 which extend to the rear, in
the position shown in FIG. 1, from the respective end of the shaft 55 to a
position approximately above the rotary axes of the rear wheels 47. The
rear end of each lever 56 is pivotally connected by a downwardly extending
lifting arm 57 to the adjacent neighboring lower lifting arm 53. The
levers 56 and the lifting arms 57 are symmetrical about the plane 9. Near
its center located in the plane of symmetry 9 the shaft 55 is rigidly
secured to a lever 58, which extends downwards from the shaft 55 near to
the beam 44, where it is pivotally connected to the end of the piston rod
of a hydraulic ram 59 accommodated in the length of the tube 40. The ram
59, which can be actuated from the driver's cab 6, is pivotally connected
near its front end to the length of tube 40 by a horizontal pivotal shaft
60 which is transverse of the direction A. Suitable openings are provided
in the front and rear walls of the beam 44 to receive the ram 59 with its
piston rod. By actuating the hydraulic ram 59 the lower lifting arms 53
can be moved upwards and downwards by the lever 58, the two levers 56 and
the two lifting arms 57. The lifting arms 53 and a top rod pivotally
connectable in the fastening holes 51 of the support plates 50 constitute
a three-point lifting device 61.
At the front of the tractor the change-speed and differential gear housing
13 has fastened to it two support plates 62, which are disposed at a short
distance from the plane 9 and extend forwardly. A holder 64 is pivotable
about a pivotal shaft 63 located near the front and top edges of the
support plates 62 at the level of the top of the gear box 13. The holder
64 is welded at the front to the rear of an upwardly directed, hollow tube
65, which slopes to the rear from bottom to top in the position shown.
Near its lower end the holder 64 is provided with a pivotal shaft 66,
about which one end of a hydraulic ram 67 is pivotable. The other end of
the ram 67 is pivotable about a pivotal shaft 68 which is disposed between
the plates 62 near the front of the housing of the gear box 13. The
hydraulic ram 67 is substantially horizontal and extends forwardly away
from the pivotal shaft 68. One end of a hydraulic ram 69 is also pivotable
about the pivotal shaft 66, the ram 69 being mounted between two limbs of
the holder 64 extending upwardly from the pivotal shaft 66. The top end of
the piston rod of the hydraulic ram 69 is pivotally connected by a pivotal
shaft 70 to a support 71, the front of which is rigidly welded to a tube
72 which is accommodated at least partly inside the tube 65 and is
telescopically slidable up and down in the tube 65. For this purpose the
rear side of the tube 65 has a slot extending parallel to its centerline,
through which slot the support 70 projects to the rear. The tube 72,
which, like the tube 65, preferably has a rectangular cross-section,
projects from the bottom end of the tube 65 and is rigidly connected by a
fastening lug 73 with an arcuate tube 74, the centerline of which is
located in a plane at right angles to the plane 9. As can be seen in FIG.
3, the tube 74 is curved in the form of a semi-circle and from the region
where it is connected to the pipe 72 it extends downwardly, symmetrically
with respect to the plane 9. A fastening lug 75 is provided near each
lower end of the tube 74. The two fastening lugs 75 and the fastening lug
73 have at their ends fastening holes for attaching machines or implements
to the tractor so that the construction 72 to 75 constitutes a three-point
lifting device 76. The pivotal shafts 63, 66, 68 and 70 are parallel to
each other and at right angles to the plane 9. As seen in the front view
of FIG. 3, the fastening lugs 75 of the lifting device 76 are positioned
in front of the inner front wheels 33. As seen in FIG. 1 the lifting
device 76 is disposed near the front sides of the front wheels 33.
In the arrangement shown in FIGS. 4 and 5, machines or implements are
attached to both the front lifting device 76 and the rear lifting device
61. The whole assembly of FIGS. 4 and 5 constitutes agricultural machinery
in which the tractor constitutes the prime mover.
In the agricultural machinery shown in FIGS. 4 and 5 the front lifting
device 76 is connected to a soil cultivator 77 comprising a horizontal
shaft 78, extending transversely of the direction A, to which is fastened
throughout its length (which is about three meters in this embodiment)
cultivator bodies 79. This operative part of the soil cultivator 77 is
covered over its entire effective length by an arcuate cover plate 80
which, at the rear, is curved towards a horizontal position, this cover
plate 80 bearing on the worked soil surface during operation. The shaft 78
can be driven through a gear box 81 extending upwardly from one end of the
shaft 78 and disposed on one side of the cultivator 77. The input to the
gear box 81 comprises a drive shaft 82 disposed on top of the cultivator
and extending transversely of the direction A (FIG. 5). The shaft 82 is
drivable through a gear box 83 from an input shaft 84. The input shaft 84
is coupled by an auxiliary shaft 85 including universal joints with the
front end of the drive shaft 22 of the tractor. As mentioned above, the
drive shaft 22 can be driven at a rotary speed proportional to the rotary
speed of the output shaft of the engine 10 of the tractor.
The gear box 81 of the soil cultivator 77 is supported by a side plate 86,
and another side plate is provided at the other end of the cultivator. The
two side plates 86 are supported at the front and rear by beams 87A. The
two beams 87A are at right angles to the plane 9, and are interconnected
by two relatively spaced, curved tubes 87 which are disposed side by side
symmetrically with respect to the gear box 83 and to the plane 9. The two
tubes 87 are interconnected near their tops by tie beams 88 which are
parallel to the shaft 78. Near the plane 9 there are two parallel,
vertical supporting plates 89 which extend in the direction A and are
rigidly secured to the tie beams 88. As shown in FIG. 4, the tubes 87, the
tie beams 88 and the supporting plates 89 are symmetrical about a vertical
plane 90 which goes through the shaft 78 and is at right angles to the
plane 9. On the rear side of the rear beam 87A and also on the front side
of the front beam 87A there are supporting plates 91 which are rigidly
secured to the respective beam 87A. The supporting plates 91 have
fastening holes 92 for attaching the soil cultivator 77 to the lifting
device of a prime mover. Near the two ends of the supporting plates 89
there are fastening holes 93 for attaching the cultivator to the top point
of a three-point lifting device. The vertical distance between supporting
plates 91 and the supporting plates 89 corresponds to that between the
upper and lower fastening tags 73 and 75 of the lifting device 76. As
shown in FIG. 4, the three coupling points 92, 93 on one side of the
cultivator 77 and those on the other are disposed symmetrically about the
plane 90 so that the cultivator 77 can be attached to a three-point
lifting device either at its front or rear. Obviously it is possible in an
analogous manner to construct other types of agricultural machines or
implements with such dual coupling capability. In the embodiment shown in
FIG. 4, the fastening holes 93 are disposed, a | | |
