FIELD OF INVENTION
This invention relates to a hydraulic cylinder and pulley operated unloader for lifting
load. It: can be used. particularly for unloading, stacking and feeding of sugar cane
without restricting scope of the invention to the same.
;mil~:KGROUND/PRIOR ART OF INVENTION
Sugar cane transported from harvesting fields to ~ugar factories by truck and trailers,
which was unloaded by manual labours in earlier years i.e. before 1970 in India. This
process was. mechanized by an equipment called Mechanical Cane un..:loader with
fingered Grab. Cane un-loader is now an essential part of a sugar _mill for unloading~
stacking and feeding of sugar cane.
MZ>.c:hanical cane un-loader is known to have b~en provided, which comprises a three
motions (EOT) "Electrical Overhead Travelling Gantry crane with mechanical. Grab
·operating on a ·height of about ten meters over cane un-.loading area and feeding
conveyors for unloading sugar cane from trucks, stacking and feeding to milling plant.
The un-:-loader consisting of· two sets of rope drums reverse arid forward rotateq by
electrical motors through speed reduction gears boxes. A fingered mechanical grab
hanged with rope drums for hoisting/lowering and grabbing/ opening operations, of the
grab to un-load the sugar cane from trucks, trailers and for feeding to conveyors. One
. rope drum is rotated for opening/ grabbing of grab and both drums are to be rotated
reverse and forward simultaneously for hoisting/lowering of open or closed grab ..
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.iCkctro-·hydraulics thrusters operated brakes are provided to stop the motion when
motors an:: not working. Special rating (SS) hoisting motors being used for frequent
start/ stop, plugging and reversing operations. However, the above is associated with
Lhc disadvantage is that, huge maintenance and frequent replacement of Electrical/
Mechanical parts are required due to high rate of operations.
A Cane Un-loader with Hydraulic Grab is known to be available, wherein only one sets
of rope drums rotating reverse or forward for hoisting/lowering of grab is required.
None of the above fulfils requirements of the present invention, hence the present
invention has been introduced directing towards a Hydraulic Cylinder and Pulley
·operated U nloader.
OBJECTS OF THE INVENTION
An object of this invention is to propose a Hydraulic Cylinder and Pulley operated
Unloader which obviates the disadvantages associated with the prior arts.
1\nother obje<;:t of this invention is to propose a hydraulic cylinder and pulley operated
unloader which is not complicated in construction.
Stiil another object of this invention 1s to propose a hydraulic cylinder and pulley
operated unloader which is reliable.·
Yet another object of this invention IS to propose a hydraulic cylinder and pulley
operated unloader which is Energy efficient and cost effective.·
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SUMMARY OF INVENTION
According to this· invention there is provided a hydraulic cylinder and pulley operated
unloader for lifting load comprising a plurality of pairs of pulleys ·with multitude of
loops of a rope therearound for lifting a load up/down by m~ans of linear displacement
of hydraulic cylinder for pulley.
~RIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Further objects and advantages of this. invention will be more· apparent from the ensumg
description when read in conjunction with . the accompanying drawings of exemplary
embodiments of invention and wherein:·
Fig. 1 shows: one embodiment of present invention.
Fig. 2 shows: another embodiment of present invention.
Fi.g. 2A shows: still another embodiment of present invention.
U~~TAIL DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING
DRAWINGS
'l'he instant invention makes a disclosure regarding a hydraulic cylinder and pulley
operated unloader which is based on a principle that, number of loops travelling over a
plurality of pairs of pulleys multiplied by linear displacement of hydraulic· cylinder for
pulleys constitutes total lift of load suspended by means of said unloader. This can be
further simplified for understanding as follows:
Number of loops of rope around the pulleys- 4.
~_LC, --·· --·i.r_.il:_R• . ~~·- -- ~- )~• lL 11-li- l!.li-,.... ~ !;. sv- JL!I.b -· :_ ~ _!; 5, 1 7 ~; 1 Q
..... ,
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Lir1car displacement of cylinder -X.
Total linear lifting of load- 4X
For example Nine meters lift by said unloader can be achieved from a 1.5 meter
displacement of hydraulic r.yli.n.der with six loops on the pulleys.
Now reference may be made to fig.1 depicting one embodiment of Present invention,
according to which two pair of pulleys (1,2,3,4) are provided with four loops (5,6,7,8) of
a rope therearound. All the upper pulleys (1,2) are disposed at one level and similarly
the lower pulleys ( 3, 4) are also located at the same another. level.
... This system of pulley and hydraulic cylinder (H) has been shown in two positions.
l'low reference may be made to fig. 2. The upper pulleys are fixed to cross travel
crao' ,r C"1' ). moun t e d on long .travel bridge(LT). Further the hydraulic cylinder for
pulleys/ grab (H1, H2) is mounted on said crab. The lower pulleys are movable which
together with piston (P1,. P2) of each hydraulic cylinder are supported by a supporting
structure (S).
The hydraulic cylinder for pulley . is employed for up and down movement of the
. suspended pulleys. The hydraulic cylinder· for grab is implemented for controlling
~>pcning and closing thereof.
The grab is optionally provided, which depends upon type of load. For example for
lifting sugarcane it can be used. In case it is a big machine, grab is not required.
!.PO 17 :.10.
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Thus grab for load/load is connected to set of pulleys with. the help of rope for lifting
up/down.
Now according to another embodiment as shown in fig.2A a plurality of pairs of pulleys
(fixed and suspended) on both sides of the hydraulic cylinder (H) can be provided,
which are equal in number.
··rhc above provision may be required for a longer load.
In accordance with still another embodiment as illustrated in fig.2, multitude of and
equal number of pairs of pulleys are placed on both sides of the central axis of the
unloader. Here two rows of pulleys are provided on each side of said central axis.
The number of rows can vary as per requirement. Further instead of two pairs of
pulleys in each row, more number of pairs can be introduced to increase number of
loops, which again depends upon requirement. The height of lifting is directly.
proportional to number of loops as indicated hereinbelow:
Lifting height of load/ grab =Number of loops * displacement of hydraulic cylinder; for
pulleys.
To maintain balance pulley arrangement on both sides of centrc~.l axis are symmetrical
as in fig.2.
llere the hydraulic cylinder for pulleys can be provided on both sides. However said
two cylinders can be replaced with one cylinder (H1) preferably at the middle.
n_\l: =.t H-1'.' ........ - ... ·- 30--0S- 2015- 17 :.10
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_ In case of provision of grab(G), the hydraulic cylinder for grab (H2) can be positioned in
r
parallel with the hydraulic cylinder for pulleys as in fig. 2.
Hydraulic cylinder and pulley operated unloader of present invention is powered by an
·Electro--Hydraulics power pack driven by a single direction running standard motor,
·which controls all functions including Hoisting, Lowering, Grabbing and Opening of
Grab. There is provision of directional solenoid valve to control hydraulic cylinder(s) to
push or pull sets of pulleys.
The above system can be also useful for other lifting and grabbing applications like
wood, bamboo, pipes, paper, steel, coal and minerals etc ..
Advantageous Features
Low power consumption
·No jerks on power generation system
Save in energy
Requirement of minimum parts, which makes it cost effective
Easy and less maintenance
. Improved safety.
It is to be noted that the present invention is susceptible to modifications, adaptations and
changes by those skilled in the art. Such variant embodiments employing the concepts and
features of this invention are intended to be within the scope of the present invention, which
is further set forth under the following claims:-

CLAIMS:
1. A hydraulic cylinder and pulley operated unloader for lifting load comprising a
plurality of pairs of pulleys with multitude of loops of a rope therearound for
lifting a load upjdown by means of linear displacement of hydraulic cylinder for
pulley.
2. A hydraulic cylinder and pulley operated unloa.der as claimed in claim 1 wherein
said plurality of pairs of pulleys comprises atleast two pairs of pulleys.
3. A hydraulic cylinder and pulley operated unloader as claimed in claim 1 or 2
wherein said pair of p-qlleys includes fixed upper pulleys and suspended lower
•
pulleys.
4. A hydraulic cylinder and pulley operated unloader as claimed in any of the
preceding claims wherein a grab may be provided with a hydraulic cylinder
therefor, which is employed for grabbing of load.
5. A hydraulic cylinder and pulley operated unloader as claimed in any of the
preceding claims wherein said upper pulleys and hydraulic cylinder for
pulleys/grab are secured with cross travel crab mounted on long travel bridge .
. 6. A hydraulic cylinder and pulley operated unloader as claimed in any of the
preceding claims wherein the lower suspended pulleys are movable which
together with piston of each said hydraulic cylinder are supported by a
supporting structure.
!PO 30- OS.-. 2 01 5- 17:1f.).
.·
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7. A hydraulic cylinder and pulley operated unloader as claimed in any of the
preceding claims wherein the upper pulleys are disposed at one level and said
lower pulleys are also positioned at the same another level.
8. A hydraulic cylinder and pulley operated unloader as claimed m. any of the
preceding· claims wherein the hydraulic cylinder for pulley is employed for up
and down movement of the suspended pulleys and the hydraulic cylinder for
grab is implemented for controlling opening and closing thereof.
9. A hydraulic cylinder and pulley operated unloader as claimed m any of the
preceding claims which is based on a principle that, number of loops travelling
over a plurality of pairs of pulleys multiplied by linear displacement of hydraulic
cylinder constitutes total lift of load suspended by means of said unloader.
10. A hydraulic cylinder and pulley operated unloader as claimed in any of the
preceding claims wherein a symmetrical arrangement of multitude of pairs of
pulleys may be provided on both sides of central axis of the unloader such as
herein described.
11.. . A hydraulic cylinder and pulley operated unloader as claimed in claim 10
wherein a hydraulic cylinder may be provided f