Note: Descriptions are shown in the official language in which they were submitted.
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c, p E C I F I C A T I O N
l TITLE OF THE INVENTION
Counterweight Removal Device
2. BACKGROUND OF THE INVENTION
The present invention relates to a counterweight removal
device for construction equipments such as crane and hydraulic
excavators. Regarding a counterweight for this type of
conventional construction machines, it is common that the swing
frame is provided with horizontal weight bearing extension on
its rear end, on which the counterweight is placed so as to be
screwed on said frame. However, said counterweight has to be
lifted so as to clear the weight b,earing extensions and moved
forward so as to lean against the mountinq frame and fixed with
set screws, because the weight bearing extensions themselves
stand on the uplifting route of the counterweight.
Then it is necessary to have some means for lifting or
lowering the counterweight vertically and for moving it forward
or backward, that is to say that the crane or the like itself
requires other auxiliary heavy equipment for handling proper
counterweight in the field or some proper heavy device of com-
plicated structure only for mounting and dismo~unting the coun-
terweight. - '
As shown in the Figure 8, a counterweight handling system
has been disclosded by the Japanese Patent Application Laid-open
No. 59-1625, wherein a l,ift cylinder for operating arm pivoted
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l the rear end of swing frame of said equipment is mounted for
replacing said counterweight bearing extension, by which the
counterweight is lifted so as to be fixed on the swing frame with
shear pins and set screws.
However, it is necessary to provide an arm pivoted on the
frame and a lift cylinder on the counterweight lifting system as
aforementioned. The counterweight mounting operation is not easy
because of hard positioning of shear pins for bearing
counterweight. Further, this type of counterweight lifting system
is rather expensive.
The present invention was developed considering the above
situation and is to provide a counterweight removal device, whereby
it is enough to only lift and lower the counterweight vertically
for removing.
3. SUMMARY OF THE DISCLOSURE
In order to carry out above purpose according to the present
invention, there is provided a counterweight removal device
comprising: a counterweight frame; a counterweight supporting
means mounted on the counterweight mounting frame for supporting
the counterweight in position on the frame; counterweight lifting
means mounted on the rear end of said counterweight mounting frame
for lifting the counterweight into position on the counterweight
mounting frame; a counterweight for fixing on said counterweight
mounting frame, having a plurality of substantially vertical
grooves for receiving said counterweight lifting means, and a
plurality of support points for engaging with said counterweight
supporting means, wherein the supporting means includes
counterweight supporting members and the support points are hollows
in the counterweight to receive the supporting members, wherein the
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~unterweight supporting members include rectangular rotating
blocks, wherein said hollows are formed horizontally at the lower
end of the grooves formed on the back of the counterweight for
receiving the rotating blocks, wherein said hollows are rectangular
and the rotating blocks are rotatably mounted on the counterweight
mounting frame so as to slide vertically in the grooves when said
blocks are oriented in a substantially vertical position and engage
in said rectangular hollows when said blocks are oriented in a
substantially horizontal position.
4. BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 (a) shows a front view showing an embodiment
according to the present invention. Figure 1 (b) shows a front
view of other embodiment. Figure 2 (a) shows a plan view. Figure
2 (b) shows a front view of other embodiment. Figure 3 illustrates
a lateral section of counterweight. Figure 4 shows an amplified
rear view of weight rotating bed. Figure 5 shows an amplified
lateral view of rotating bed. Figure 6 shows an amplified lateral
view of stuck out supporting pin. Figure 7 shows an amplified
lateral view of retreated supporting pin. Figure 8 shows a lateral
view of prior art.
5. EMBODIMENT
Hereinafter, an embodiment according to the present invention
will be explained referring to the drawings.
According to the Figure 1 (a), 2 (a), 3, 4 and 5, numeral 1
indicates a counterweight mounting frame provided on the rear end
of swing frame. A pair of rectangular rotating bed 2 incorporated
with pin 3 are rotatably mounted on the lower part of
2 0 ~ 2 4
weight mounting frame. On the upper portions of each rotating
bed 2, through holes 5 are perforated for inserting set screws
30 to be explained later. On the back of counterweight, back
plates with threaded holes 4 are mounted. A pair of weight
lifting system 10 are mounted in the inner grooves in relation
to the rotating beds with bracket 8 and 9, and on the upper ends
of piston rod to be lifted or lowered by oil pressure in the
cylinder 11, sprockets 13 are mounted, with which chains 14 are
engaged. The front ends of the chain 14 are fixed on the coun-
terweight mounting frame 1 as showrl in the Figure 3 and other
ends are mounted detachably on the fixing plates 21 provided in
the vertical grooves 26.
The counterweight 20 has hollows 22 wherein through holes
23 are formed as shown in the Figu~e 1 (a) and 2 (a). On the
back of counterweight 20, a pair of guide groove are formed
vertically. On the lower ends of said guide grooves 24, said
supporting hollow 25 which are wider than said guide grooves are
formed.
Further, a pair of groove 26 for mounting said weight
lifting systems 10 are formed vertically between the guide
grooves 24 on the back of counterweight 20.
In the Figure (b), 2 (b), 3, 6 and 7, the lifting systems
are same with the aforementioned. There are a pair of supporting
pins 3a in the place of rectangular rotating beds. The counter-
weight has a pair of notch in inverted letter form V 25a at the
identical positions in the place of guide grooves.
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In the next place, the function of the present system will
be explained. In order to mount -the counterweight 20 on the
swing frame, the rotating beds 2 have to be turned first so as
to be put in vertical position as illustrated with double chain h
lines in the Figure 4. Then rear ends of chain 14 have to be
fixed on the fixing plates Z1 of counterweight on the ground
using bolts or equivalents and the piston rods 12 are extended
by driving the lift cylinders 11. Then the counterweight 20 is
lifted up being driven by the sprockets 13 and the chains 14,
but the rotating beds 2 do not block the guide grooves 24 on the
back of counterweight 20, because they slide freely through the
guide grooves 24. When the counterweight 20 is elevated to the
height where the rotating beds 2 may turn in the supporting
hollows 25 formed on the lower end of yuide grooves 24. Then,
after finishing the lifting operation of counterweight, the
rotating beds can be turned 90 so as to be positioned horizon-
tally as shown with a line in the Figure 4. Then the counter-
weight can be lowered a little so as to be placed on the rotat-
ing beds 2. ~ccordingly the counterweight can be fixed on the
counterweight mounting frame with set screws 30 inserted in the
through holes 23 and the fixing plates 4.
However, the frequency of replacement of counterweight is
not so high-generally, therefore the chains 14~can be taken off
and the piston rods 12 can be kept in the lowest position of
cylinders 11 after having mounted the counterweight. Further,
the cylinders can be covered with some protectors or taken off
for storing.
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Also in order to take off the counterweight 20 after taking
off the set screws 30 first, the counterweight 20 has to be
lifted until the rotating beds 2 may be put in vertical position
turning 90. Then the counterweight Z0 has to be lowered down
to the ground letting the rotating beds 2 slide in the guide
grooves 24, then the chains can be taken off
At the time of lifting the counterweight, the rotating beds
are vertically positioned so as to slide freely through the
guide grooves and then positioned horlzontally in the supporting
hollow so as to receive the counterwelght on themselves when the
counterweight is lowered. Then the counterweight can be fixed
on the counterweight mounting frame with set screws.
As shown in the Figure 1 (b), 2 (b), 6 and 7, in a coun-
terweight removal device comprising supporting pins 3a and
notched hollows 25a, when the counterweight is lifted, the
supporting pins 3a are retreated back i.nto the mounting frame 1
as shown in the Figure 7 not staying in uplifting rout of coun-
terweight. When the counterweight is lifted up clearing the
height of pins 3a, the slidable pins can stick out under the
counterweight. Then the counterweight 20 can be positioned on
the pins 3a by means of notched portions 25a so as to be fixed
on the counterweight mounting frame with set screws 30.
In order to take off the counterweight 20, the same process
has to be done reversely and the supporting pins 3a can be
retreated back into the counterweight mounting frame 1.
According to the present invention aforementioned, it is
sufficient to mount two weight lifting systems of simple con-
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struction which may work verticallly, therefore the counter--
weight mounting systems themselves can be simpLified and the
weight lifting systems will not disturb other operations, be-
cause they are mounted in the grooves on the back of the coun-
terweight. In addition, the positioning of counterweight can be
done easily and exactly, because the counterweight can be fixed
on the swing frame after being placed on the rotating beds or on
the supporting pins. Accordingly the counterweight mounting
operation in the field can be largely simplified.
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