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| United States Patent | 4924961 |
| Link to this page | http://www.wikipatents.com/4924961.html |
| Inventor(s) | Bernardi; Guido (Milan, IT) |
| Abstract | The invention relates to a vehicle for gardening and agricultural work
provided with four wheels, of which at least two are drive wheels, and an
engine, comprising a frame consisting essentially of a longitudinally
extending beam preferably of hollow box section and internally housing the
drive shaft or shafts. It is provided with a least one power take-off, and
preferably two, of which one is at the front and one is at the rear. The
vehicle is preferably provided with a steering handlebar and a seat for
the operator. Preferably, the engine is positioned at the rear and at
least the front wheels are drive wheels. The vehicle is provided with a
gearbox and preferably a separate quick-reversing mechanism. This
mechanism and the gearbox are housed in casings preferably disposed on the
axis of the beam-frame to form a structural part thereof.
The vehicle is suitable for fast travel on and off the road and for use as
a vehicle without the addition of implements. |
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Title Information  |
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| Publication Date |
May 15, 1990 |
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| Filing Date |
June 27, 1988 |
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| Priority Data |
Jul 10, 1987[IT]21248 A/87 |
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Title Information  |
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Description  |
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This invention relates to a vehicle usable for gardening and agricultural
work and capable of fast travel both on and off the road.
Agricultural engineering has seen the development of a large number of
machines for specific agricultural operations. Many of these machines are
large and costly, slow-moving and mostly specialised for just one or a few
specific operations. Others are smaller and inexpensive, but again are
incapable of fast travel and are mostly operated by an operator who
follows then on foot. Agricultural implements can be operated from tractor
power takeoffs, but again there are serious cost, speed and operability
limitations.
An object of the present invention is to provide a light, economical
vehicle of simple structure which is simple to operate and fast-moving
both on and off the road, and by which, when connected to suitable known
implements which do not require further description, can perform a large
variety of gardening and agricultural operations.
A further object of the invention is to provide a vehicle of this type
which is of particularly simple and efficient design and consequently
light and economical while being of overall robustness and reliability.
A further object of the invention is to provide a vehicle of the kind
referred to above, which can be equipped with two power take-offs, front
and rear, so as to make possible a wide variety of gardening and
agricultural operations.
A further object, in a preferred embodiment of the invention, is to provide
a vehicle which can be reversed in particularly simple and fast manner.
A further object of the invention is to provide a vehicle which can be used
conveniently as such when not used for gardening or agricultural
operations.
Further objects and advantages of the invention will be more apparent from
the following description.
In its general form the vehicle according to the invention, provided with
four wheels, of which at least two are drive wheels, and an engine, is
characterised by comprising a frame consisting essentially of a
longitudinally extending beam preferably of hollow box section and
internally housing the drive shaft or shafts. It is provided with at least
one power take-off, and preferably two, namely one at the front and one at
the rear. The vehicle is preferably provided with handlebar steering and a
seat for the operator.
Preferably, the engine is positioned at the rear and at least the front
wheels are drive wheels.
The vehicle according to the invention is provided with a gearbox and
preferably a separate quick-reversing mechanism. This mechanism and the
gearbox are housed in casings preferably disposed on the axis of the
beam-frame to form a structural part thereof.
The quick-reversing mechanism, the structure and operation of which will be
more apparent from the description of a preferred embodiment, comprises a
drive shaft disposed axially to the mechanism and carrying a sun gear,
planet gears meshing with the sun gear and idle on planet carrier shafts
mounted to undergo revolution about the axis of the mechanism, an external
ring gear carrying a driven gear which transmits motion to the drive
wheels, and a friction clutch device which during forward travel is
arranged to lock the planet carrier shafts relative to the ring gear,
means for releasing these relative to the ring gear and thus interrupt the
linkage between the ring gear and drive shaft to produce the idle
position, and means for blocking the revolution of the planet carrier
shafts about the mechanism axis to cause the planet gears to rotate on
their shafts and consequently the ring gear and driven gear to rotate in
the reverse direction to the rotation of the drive shaft. Passage from the
forward running to the idle position and from the idle position to the
reverse running position is preferably done by an operator operating a
lever by means of a pedal or a hand lever.
Further preferred characteristics of the invention will be apparent from
the following description of a preferred embodiment thereof.
A preferred embodiment of the invention is illustrated on the accompanying
drawings, in which:
FIG. 1 is a diagrammatic perspective view of a vehicle according to the
invention provided with two front drive wheels;
FIG. 2 is a diagrammatic axial section through a preferred form of a
mechanism which acts as a friction clutch and travel reverser according to
the invention;
FIG. 3 is a diagrammatic axial section through a control device for the
mechanism of FIG. 2;
FIG. 4 is a diagrammatic axial section taken on the line 4--4 of FIG. 1 but
interrupted for ease of illustration, showing the beam forming the machine
frame, the transmission members, the gearbox and the front power take-off;
and
FIG. 5 is a perspective view similar to FIG. 1 but showing a modified
embodiment of the vehicle according to the invention, provided with four
drive wheels.
With reference firstly to FIG. 1, the vehicle comprises a frame consisting
essentially of a central beam 10 preferably of hollow box section and
internally housing the shafts and transmission members. In the figure a
part of the wall of the beam 10 is removed to show the shaft 26 which
extends from the engine. The engine 12, of any convenient type but
preferably a single or two-cylinder petrol or diesel engine, is positioned
at the rear and connected to the shaft 26.
A rear power take-off is connected to the shaft of the engine 12, and a
front power take-off 14 is positioned at the front end. A handlebar 15 is
used for steering, and in the rear of the vehicle there is provided a seat
16 for the driver, whose feet rest on fixed pedals 17. The two front drive
wheels 18 are mounted on rocker arms 21 hinged to the sides of the gearbox
and are rotated by axles 19 provided with universal couplings 20, whereas
the rear wheels 50 are idle and mounted on fixed axles 22. The reference
numerals 23 and 23' indicate the elastic suspensions for the front and
rear wheels respectively. The front wheels are also steerable wheels, and
can be steered by a steering mechanism of any convenient structure which
transmits the rotation of the handlebar to the wheels by way of struts and
ties.
As can be seen in FIG. 4, the drive shaft 26 originating from the engine
passes through and operates a clutch and quick-reversing device indicated
overall by 55 and described in detail with reference to FIGS. 2 and 3. A
gear 31 which receives motion from said device 55 engages with a gear 60
fixed onto a countershaft 61. This latter drives the shaft 19 of the front
wheels by way of a gearbox indicated overall by 24 and of any known type,
and by way of a pinion 62-bevel gear 63 and a differential device of any
convenient structure indicated overall by 64. Said countershaft 61 also
operates the rear wheels if these are drive wheels. The shaft 26 extends
beyond the device 55 into the front part of the beam 10, not shown in the
sectioned part of FIG. 4, to operate the front power take-off 14 in any
convenient manner.
FIG. 2 is a similar sectional view but to a larger scale of the clutch and
quick-reversing device 55. The shaft 26 from the engine is rigid with a
sun gear 27 which engages a certain number of planet gears 28, for example
three, of which only one is shown in FIG. 2. These engage a cup-shaped
ring gear 29 which extends in the form of a sleeve 30 carrying the
aforesaid gear 31, which operates the gear 60 and the countershaft 61. The
planet gears 28 are mounted idle on planet-carrier shafts 32 which are
rigid with discs 33.
The ring gear 29 is rigid with discs 34 provided with a lining. A spring 35
resting against the plate 45 urges a plate 36 towards the right as shown
in FIG. 2, this latter being axially slidable on a cylindrical member 57
housing the shaft 26. The planet-carrier shafts 32 pass through the plate
36 and consequently while this latter rotates, and together therewith,
they undergo a revolutionary movement about the longitudinal axis of the
device. A control device shown in FIG. 3 enables the elastic force of the
spring to be overcome and the plate 36 to be pushed towards the left.
The control device comprises a lever 37 which can be rotated by a pedal
control 56 shown in FIG. 1.
Rotating the lever results in rotation of a pin 38 which is rigid with it
and housed in the bush 39 fixed by screws 46 to the gearbox 44, a fragment
of which is shown at 44'.
This rotation of the pin 38 results in leftward movement (with respect to
the figures) of the bearing 40 which is carried by the pin 38 and is in
contact with the portion 41 of the plate 36. The bush 39 has a projection
42 facing a part 43 of the plate 36. The operation of the described device
is as follows. When the vehicle is under forward travel the various parts
of the mechanism are in the positions shown in the figures. The plate 36,
urged by the spring 35, presses together the lined discs 34 rigid with the
ring gear 29 and the discs 33 rigid with the planet-carrier shafts. The
entire epicyclic mechanism then rotates as a single body together with the
sun gear 27, and thus the rotation of the shaft 26 is transmitted directly
to the gear 31, the speed of rotation being determined by the engine
r.p.m.
If the control lever 37 is rotated, the pin 38 rotates and the bearing 40
moves towards the left to urge the plate 36 in the same direction and
compress the spring 35. Pressure on the discs 33 and 34 ceases, and
consequently the linkage between the shaft 26 and ring gear 29 is
interrupted. The clutch is therefore disengaged, and the gear 31 which
drives the wheels stops although the shaft 26 continues to rotate.
As the lever 37 is turned further, the plate 36 moves further towards the
left until its part 43 comes into friction contact with the part 42 of the
bush 39, which is at rest. Consequently the plate 36 also stops and the
planet-carrier shafts 32 are halted. As these are now at rest, the planet
gears 28 rotate about their axes entrained by the sun gear 27, and compel
the ring gear to rotate in the opposite direction to the sun gear and
shaft 26. The gear 31 also rotates in the opposite direction to the shaft
26 to produce reverse travel without moving or shifting any gear. This
travel reversal can be done with the gearbox in any of its positions and
thus in any gear ratio. The device as described would be incorporated in a
preferred embodiment of the invention. It can however be replaced by
mechanical equivalents available to the expert of the art on the basis of
the present description, and in the most general form of the invention it
could be dispensed with and a conventional gearbox with a reverse gear be
used.
FIG. 5 shows the modified embodiment of the invention, in which the four
wheels are indicated by the same reference numerals as heretofore. Axles
51 for rotating the rear wheels 50 are present, each provided with a
universal coupling 52. In FIG. 5 the beam-frame 10 is interrupted to show
the two shafts 26 and 61. The vehicle according to the invention can be
used for a large variety of gardening and agricultural operations by
virtue of its power take-offs and its flexibility. It can be provided with
a servocontrol for raising implements.
A lever-controlled clutch is provided for the power take-offs. For garden
work, for example, the vehicle when fitted with a suitable implement can
operate as a frontal or central lawn mower or as a frontal snow remover.
For forage collection it can be fitted with a cutter bar at its front, a
side-delivery rake at its front and a tedder at its rear. For other
agricultural work it can be connected to a cutter at its rear, a plough at
its front, a trailer, pumps, seeders etc. All the devices and accessories
required for these operations are conventional and well known and can be
connected to any power take-off, and are therefore not described.
The vehicle itself is suitable for fast travel on and off the road and for
use as a vehicle as such without any additional implements being fitted.
Because of its specially designed simple and robust structure it is
efficient, safe, strong and economical. Its manoeuvrability is
exceptional, especially when provided with the quick-reversing device. It
therefore represents considerable progress in agricultural engineering.
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