Note: Descriptions are shown in the official language in which they were submitted.
~X5~7
~XCAVA ~ LOAD~R
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~he present inven-tion is a novel vehicle which
combines the functions of excavator and loader and
displays important ad~antages over prior vehicles of
this general t~pe
A mlmber of vehicles areavailab].e which are described
~ariously as excavator/loaders, digger/loaders or bacl~oe/
loaders and which are designed to perform two main
functions. First].y, an articulated arm at one end of the
vehicle, usually the rear, carries a bucket designed to
lo dig below ground level and -thereby excavate a trench
or hole. ~his excavator.bucket is normally narrower -than
the overall width of the vehicle and digs back towards
the vehicle. Secondly, the vehicle carries, usually at
its front end, a loading bucket for lifting excavated
material from ground level upwards in-to lorries for transport
awa~ from the excavation site. ~he loader bucket is usually
at least as wide as the vehicleO Vehicles are also available
which perform onl~ one of these func-tions, or which perform
a second function b~ the provision of special secondary
attachments.
A major di~iculty in designing vehicles of this general
t~pe is that of providi-ng ade~uate counter-balancing to
balance -the effect of the respective operating bucket under
load. ~hus the unbalancin~ moment of a full loader bucket
at the end of the loader arm has to be off-set by a consider-
able weight rearward of the adjacent vehicle wheels, especially
when the loader is operating on a sloping site and/or at the
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;3827
limits of its reach. This weight must either take the ~orm
o~ heavy b~last built into the vehicle or be provided by the
weight of a di~ger arm and bucket fitted to the other end
of the vehicle~ This normally means that eithe~ the vehicle
carries undesirable excess weight in its design or the
two functions must be performed at opposite ends of the
vehicle.
A significant disadvantage of such prior excavator/
loaders is that, since the two functions are per~ormed
separately at opposite ends of the vehicle, seating and
controls have to be provided for the operator facing each
end of the vehicle as desired. Such duplication adds to
both the cost and dimensions of the vehicle,
In German Published Patent ~pplication (D0~) No.
3331516, an excavator/loader is illustrated in which both
functions are carried out at the same end of the machine.
In order to achieve this result, the operating ~ib is ~ormed
in three sections, described respectively as a pre-jib,a
main jib and an arm. When the machine is to function as
a loader~thelmain jib and the arm are set essentially at right
angles to each other and remain in that position throughout
the loading operation. When the machine is to function as
an e~cavator, the pre-jib and the main jib are set in approx-
imate relative alignment and remain in that position through-
out -the excavating operation. Controls are provided to
achieve the relative movements o~ the three jib sections,
as well as the movement o~ the aib overall relative to the
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turntable upon which it is mounted and the movement
of -the operating bucket relative to the jib.
It is an object of the present invention to provide
an improved excavator/loader in which both f11nctions are
performed at the same end of the vehicle, which none-
theless is stable in both modes of operation and which
is of a more simple design, and is therefore easier to
operate and maintain, than p~or forms of excavator/loader.
The excavator/loader according to the present invention
comprises a chassis carrying an articulated operating arm
having only two sections, a first arm section supported
at one end thereof upon said chassis for pivotal movement
relative thereto about a horizontal axis, and a second
arm section pivoted to the other end of said first arm
section for pivotal movement relative to said first arm
section about a horizontal axis, said first arm section
being pivotable into a position (the "stowed"posi~on)
in which the point of pivoting ~gether of the two arm
sections lies above or rearwa~d of the point of pivoting
of the first arm section upon the chassis.
~ virtue of the above-defined features, the
excavator/loader of the present invention is ableto
function, in a stable manner, both as an excavator when
the first arm section is in use and also as a loader when
said first arm sectDn is in its stowed position~ No third
arm section is necessar~. ~he duplication of controls
associated with a vehicle having the two functions at
opposite ends is rendered unnecessary. Thelocating of
L ~2S~8~
the fi.rst arm section as speci.fied during theloading
operation reduces or removes the need for counter-balance
weighting in the vehicle~ In spite of its diversity, the
excavator/loader is a relatively simple vehiclé~
~he point at which the first axm section is pivoted
to the vehicle (hereinafter referred to as the first pivot
point) depends upon other features of -the overall design
o~ the vehicle but in general it will normally lie towards
the forward end of the vehicle. It is about this pivot
point that the arm operates when in its excavating mode~
Preferably it is located in the general region of the
front end of the wheel-base or other ground-contacting
area (as for example when the vehi.cle is mounted on tracks)~
~hus~ for example, when -the vehicle is wheel-mounted, the
first pivot point preferably lies in the region of the axis
of the front wheels or slightly forward or rearward thereof.
The first pivot point i.s preferably set low on the
v~hicle. ~hus, for example, in the case of a wheel~mounted
vehicle, the first pivot point preferably lies below the
2 height of the upper circumference of the front wheels of
the vehicle~ When the overall vehicle geometry does not
allow the pivot point to be set between the front wheels
or in the corresponding position in the case of a track-
la~ing vehicle, as for example when the operating ar~ is
2~ ~ounted upon a turn-table, then the pi.vot point may be set
forward of that position, for example low on an overhanging
forward extension of the chassis.
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~ he rnountin~ of the first pivot point i9 such as -to
allow pivoting about a hori~ontal axis, to permit the
excavating function to be carried out and also to enable
the first arm section to be stowed. In addition, it is
advantageous to provide for pivoting of the arm about a
vertical axis 7 to allow -the vehicle to excavate to at least
a limited extent generally sideways of the vehicle~ ~he
mounting at -the first pivot point may therefore comprise
two separate pivots, of which it is preferred that the
vertical-axis pivot is towards the rear.
If desired, the first pivot point may be so mounted
as to be displaceable laterall~ relative to the length
of the vehicle so that the latter may more effectively
operate close to an obstruction when in it~ excavating mode.
~his may be achieved by mounting the pivot point upon a
laterally displaceable carriage or bracket or, less conveniently,
upon a turntable~
In the stowed position of the first arm section, the
point at which the latter is pivoted to the second arm section
(hereinafter referred to as the second pivot point) lies
above or rearward of the first pivot point. In order not
undul~ to limit the outreach of the arm in its loading
function, the second pivot point preferably lies at most
onl~ a short distance, measured ina horizontal direction,
behind the first pivot point. ~or example, the horizontal
distance may be of the general order of about 25 per cent
o~ the len~th of the wheelbase or other ground-contacting
area of the vehicle, ~hus, in its stowed position, the
fir3t arm section may be vertical or more pre~erably may
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have a rearward orientation, inclined -to the vertical
by an angle of the order of 5 to 45 degrees, e.g. 20
to 40 de~rees, although the angle may be greater i~
desired.
~he first arm section may be lockable in its stowed
position, but need no-t be so. For example, an electrical,
hydraulic or mechanical locking device may be provided so
that, when the vehicle is being used in its loading mode,
the operating lever which controls the pivo-ting of the
first arm section, or a ram which brings about that pivoting,
is rendered inoperative.
To gain the maximum benefit of the vehicle of the
present invention, it is desirable that the bucket be of
a quick-release variety in order that, when the operator
changes from a~ excavating to a digging operatlon or vice
versa, a bucket appropriate to the relevant operation can
rapidly be fitted. Thus the attachment fitting may be of
a type which permits a quick interchange by conventional
manual methods, for example of the nut-and~bolt type.
Alternatively, an attachment mechanism of the claw type,
optionally operable by the operator without descending
from the vehicle, may be pre~erred.
~ he stability of the vehicle, especially in the
excavating mode, may be enhanced by the provision of out-
riggers or other ground-contacting stabilisers, which may
be used merely to brace the vehicle against the ground or
may, by jac~ing, lift two or all of the wheels clear of
the ground. Manoeuvrability of the vehicle may be enhanced
-- 7 --
b~ providing a skid-steer drive arrangemen-t.
~he inventian will now be further described with
re~erence -to the accompan~ing drawings, in which:-
~ ~ig. 1 is an elevation ~rom the side
of one form of excavator/loader according
to the present invention; and
~ig~ 2 is a plan view of the excavator/
loPder of ~ig. 1.
More specifically, in ~ig. 1 the excavator/loader
is illustrated with the vehicle in loading mode shown
in full line and with the excavating mode operation
shown in chain-dotted`line. In ~ig. 2, the excavator~
loader is shown in excavator mode and with outriggers
and stabiliser extended.
~he illustrated embodiment is a particularl~ compact
form of the invention. ~he vehicle has a wheelbase (that
is, the horizontal distance between ~ront and rear axles)
of about 1.3 metres and an overall maximum dimansion,
with the operating arm and bucket retracted, of less
than 3 metres~
The illustrated vehicle has front wheels 3, 3 and
rear wheels 4, 4 and carries a single, forward-~acing
seat 5 fo~ the operator.
The operating arm consists of a first arm SeCtiQn
~5 6, pivoted about a horizontal pivot 7 which in turn is
linked to the vehicle body about a vertical pivot 8~ and
a second arm section 9, pivo-~ed at 10 to the outer end
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-- 8 ~
of -the ~irst arm section 6. The ve~-tical pivot 8 lies
about 0.2 metres -to the rear of the axis o~ rotation of
the ~ront wheels 3, 3 and the horizontal pivot 7 lies
approximate]~ in line with that axis.
At the outer end of second arm section 9, a bucket
(11 or 12) appropriate to the operating mode is carried.
The bucket 11 is the loading bucke-t and the bucket 12,
mounted the opposite wa~ round from bucke-t 11, is the
excavating bucket. Each bucket is secured to the arm
at just two moun-ting points (as ~iewed from the side),
namely a pivot mounting 13 and a con-trol link mounting 14,
by means of which latter the tipping action is transmitted
to each bucket. Alternatively, the mounting points 13 and
14 may support an intermediate carrier plate on the end of
the operating arm, the alternative buckets then being
detachably secured on the carrier plate by a quick-release
mounting.
Operation o~ the arm and bucket is effected by means of
four double-acting hydraulic ram5, A first ram 15 controls
the pi~oting of the ~irst arm sec~on 6 about the firs-t pivot
point 7; a pair of rams 16, 16 effect relative pivoting of
the arm sections about the second pivot pOilit 10; a fourth
ram 17 controls the bucket tipping.
The excavator/loader is also provided with out-riggers 18,
18 and a rear stabiliser 19, which may be lowered into contact
with the ground to give increased stabilit~ o~ operation of
the vehicle in the excavating mode.
9 ~ ~5~32~
As i.s most clearly shown in Fig~ 1, the vehicle
may function as a convention.al excavator (the chain-
dotted feature) by operation of the four rams as desired.
However, the design is such that, by operatio~ of the ram 1~,
the first arm section 6 may be swung upwards and backwards
until the pivot point 10 is in the position illustrated
in full line, in which position the pivot point 10 lies
about 0.3 metres to the rear of pivot point ~ With the
first arm section 6 in this position, where it is incli.ned
backwards at an angle of the ord.er of 30 degrees to 40
degrees to the vertical, the vehicle ma~ be used as a
conventional . loader, by operation of -the rams 16 and 17
only.
~hus the vehicle of the present invention is a true
excavatorJloader, in which the two primary functions may
be carried out using a single set of controls b~ an operator
i.n a single forward-facing seat.
