Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF THE INVENTION
This invention relates to a loader for use in a tunnel or
mine haulage in which there is liktle room for
manoeuverability.
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In the specification of U.S.A. Patent No. 4188165 there is
described a loader which includes a bucket mounted on the
end of a dipper arm swinging from a cross member on an
upstanding yoke. The dipper arm swings between the
upright of the yoke for the bucket to pick up material on
one side and deposit it on the other side~ In some
respects this loader is satisfactory but it suffers from
the serious disadvantage that the bucket extends between
spaced supports and consequently when it is necessary to
move large material which possibly extends beyond at least
one side of the bucket the material can be wedged between
the bucket and the upright supports or, alternatively, is
simply pushed off the bucket. This drawback substantially
minimizes the efficiency of the loader.
SUMMARY OF THE INVENTION
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It is an ob~ect of the present invention to provide a
loader wherein the aforementioned disadvantage is
minimized.
It is a further object of the invention to provide a
loader which can under certain conditions handle material
o larger dimensions than the bucket.
Another object of the invention is to provide a loader the
construction of which requires less material and fewer
components than does the loader referred to.
These and other objects of the invention are achieved by a
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loader which includes a base member, a single upright arm
connected to the base member, a single dipper arm which is
pivotally connected to the upright arm, a cantilevered
shaft which extends from the dipper arm, a bucket which is
mounted on the shaft and which extends on one side of the
dipper arm, the bucket being pivotal relatively to the
dipper arm, and means for moving the dipper arm between a
first position at which the bucket is orientated for
digging and a second position at which the bucket is
orientated for discharge.
; The means for moving the dipper arm may include a first
link which is pivotally connected at one end to the
upright arm, a second link which is pivotally connected at
one end to the dipper arm, the free ends of the two links
~eing pivotally interconnected, and a ram which is
connected between the upright arm and the two links.
The work "ram'l as used in this specification denotes in a
first instance an hydraulic ram or similar device but it
is also intended to include any other device which is
capable of force transmitting movement in each of two
opposing directions.
The length of the second link may be adjustable.
The loader may include means for orientating the bucket
which includes a first drum which is mounted on the upper
end of the upright arm, a second drum which is
eccentrically mounted on the cantilevered shaft, a first
flexible member the ends of which are fixed to the first
and second drums respectively, a third drum which is
mounted concentrically with the first drum, a second
flexible member one end of which is fixed to the third
; 35 drum, and a ram which is engaged with the other end of the
second flexible member.
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~The two flexible members may be cables, ropes or the like
and preferably are constituted by chains.
The bucket may be releasably connected to the shaft by
means o~ releasable clamps which are located on the rear
face vf the bucket.
The loader may include means for supporting the upright
arm on the base member at a desired angle of inclination
relatively to the base member.
The base member is preferably a turntable or the like so
that the orientation of the loader can be adjusted.
The loader may be located on a rail or other vehicle.
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~ BRIEF DESCRIPTION OF THE DRAWINGS
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20 The invention is further described by way of axample with
reference to the accompanying drawings in which :
Figure 1 is a view from the side of a loader according to
the invention, and
Figure 2 is an end view of poxtion of the loader shown in
Fi~ure 1.
DESCRIPTION OF PREFERRED EMBODIMENT
; 30
The drawings illustrate a loader 8 according to the
invention mounted on a rail vehicle 10 which may form a
kerminal portion of a tunnel cleanin~ train. The vehicle
10 includes a base member which is conskituted by a
turntable 12 which is rotatable about a vertical axis 14.
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The loader 8 includes a single upright arm 16 which i5
`pivotally connected to the turntable 12, a single dipper
arm 18 which is pivotally connected, as may more clearly
be seen in Figure 2, to the upper end of the arm 16, a
; 5 cantilevered shaft 20 which is mounted on the dipper arm
at its free end and which extends to the side of the
dipper arm remote from the upright arm 16, the shaft ~eing
~ournalled for rotation in bearings, and a bucket 22 which
is releasably clamped to the shaft 20 by means of clamps
24 on the rear face of the bucket. The clamps 24 may be
- constituted by any suitable devices. The advantage of
locating the clamps on the rear face of the bucket is that
a sompact structure is provided wherein the side of the
bucket which is closer to the dipper arm may freely move
without the respective clamp fouling the dipper arm and
wherein the clamp on ~he other side of the bucket is not
in any way exposed. This enables the bucket to be used
for loading material which may be located adjacent a wall
or the like.
The rail vehicle 10 includes two hydraulic rams, not
~shown, for rotating the turntable 12 to slew the loader.
The rams are used for centralizing the loader 8 to the
position shown in Figure 1.
The upright arm 16 is supported on a hydraulic jack 26
which extends between the vehicle and the arm. This jack
; is used to vary the inclination of the arm 16 and to
retract it to a low level travelling position when the
loader is being moved for example in a tunnel.
A hydraulic jack or ram 28 has one end fixed to the
upright arm 16 and its other end is pivotally connected to
a toggle linkage consisting of links 30 and 32. The link
30 extends between the upright arm 18 and the outer end of
the ~ack 28 while the link 32 extends between the outer
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end of the jack 28 and a pivot point on the dipper arm 18.
The link 32 is telescopic and during normal operation of
the loader is locked in an extended position illustrated
in Figure 1. The link 32 is telescoped to enable the
5 loader to be dropped into its low level travelling
configuration.
The loader includes a bucket orientation control
arrangement to hold the bucket in a load retaining
position as it is moved from its digging position to its
discharge position. The control arrangement consists of a
first drum 34 which is rotatably mounted on an axis
between the upper ends of the two arms 16 and 18~ a second
drum 36 which is fixed eccentrically to the shaft 20 t and
a chain 38 the ends of which are fixed to the drums 34 and
36 respectively. The arrangement further includes a drum
40 which is fixed concentrically to the drum 34, a jack or
ram 42 which is mounted on the upright arm 16, and a chain
44 the ends of which are fixed to the drum 40 and to the
jack 42 respectively.
When the jack 42 i5 extended the drums 40 and 34,
referring to Figure 1, are moved in a clockwise direction
and, under the action of gravity, the drum 36 is also
moved in a clockwise direction. The bucket 22 is
therefore lowered to its digging position. Digging i.e.
filling of the bucket, is effected by movement of the
~acks 28 and 42. As the jack 28 is extended and retracted
reciprocating movement is imparted to the dipper arm 18
3Q via the link 32, the jack 42 on the other hand is operated
to get the bucket filled as it causes the orientation of
the bucket to be changed.
When the bucket is fully loaded the jack 42 is fully
retracted and the drums 40 and 34 are rotated in an
anticlockwise direction by means of the chain 44. The
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chain 38 moves upwardly and the drum 36 is rotated in an
; anticlockwise direction thereby tilting the bucket
upwardly to a load retaining position.
Figure 1 illustrates in dotted outline the position of the
bucket 22 and the dipper arm 18 when the bucket has been
moved to a discharge position. Movement to this position
is achieved by extending the jack 28~ Since the link 30
is fixed to the upright arm 16 the extension of the jack
28 causes the dipper arm 18 to move in a clockwise
direction around ~he axle on the upright arm on which the
dipper arm is mounted. It should be noted that a cam
action is achieved by the fact that this axle is offset
with respect to the axis on which the dipper arm is fixed
to the upright arm. In the course of this movement the
length of the chain 38 between the drums 34 and 36 is
effectively varied, because of the eccentric mounting of
the drum 35, and because of the cam action referred to,
and in so doing the orient&tion of the bucket is
maintained in a load retaining attitude. As the dipper arm
i5 swung passed the upright arm to the discharge position
the chain 38 causes rotation of the drum 36 and thereby
the bucket 22 so that although the bucket is maintained in
a load carrying attitude it is gradually tipped until a
stage is reached at which gravity takes over, rotating the
bucket into the load discharge position shown in dotted
outline in Figure 1. A suitable container, also shown in
dotted outline, receives the discharged material.
When the bucket is swung to its digging position the
effective length of the chain 38 again varies so that the
bucket is again orientated into a load carrying attitude.
When the dipper ~rm reaches the position shown in Figure 1
the jack 42 is again extended to drop the bucket into a
digging position.
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The loader can be moved to a low level travelling
configuration by partially retracting the ~ack 42 so that
the bucket is rotated towards the upper arm, and
retracting the ram 26 to lower both the upright arm 16 and
the dipper arm 18, unlocking the arm 32 and retracting the
jack 28.
A principal advantage of the invention is achieved by the
fact that the bucket 22 extends to one side of the dipper
arm 18, as shown in Figure 2, with no support being
provided on the side of the bucket remote from the dipper
arm. This means in the first instance that the bucket can
be used for clearing material located adjacent a wall and
in the second instance that material which is nominally of
greater dimensions than the bucket width can be loaded by
the bucketO 5uch material should of course not extend
over the side of the bucket which is adjacent the dipper
arm but on the other hand it can extend over the side of
the bucket which is remote from the dipper arm. Another
advantage of the invention is that use is made of a single
support arm 16 and a single dipper arm 18 and as opposed
to the prior art device disclosed in the specification of
U.S.A. patent No. 4188165, a considerable savings in
material and components is thereby achieved. Ansther
point is that the width of the bucket can be increased as
this dimension is no longer constrain~d by the spacing of
two uprights.
The invention is not limited to the precise constructional
details as herein described and for example the drums 34
and 36 could be moved-to the right, referring to Figure 2,
so that the drum 36 is substantially adjacent the
respective ~ide of the bucket. This configuration under
certain conditions can increase the stability of the
loader. The drums 34 and 40, although referred to as
separate units, can be, and preferably are, constituted by
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different portions of an integral unit and references to
`these drums are to be construed in this sense.
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