Technical Field
This application is patent of addition to application for patent No. 369/KOL/2004
dated 29.06.2004.
This invention relates to an apparatus and method for loading of cement lined
ductile iron pipes for transportation by lorries or containers and to methods and
apparatus for unloading of pipes from the containers to warehouse.
This invention also relates to several accessories useful for the purpose of
handling cement lined ductile iron pipes.
Background
In pipe industry, cement lined ductile iron pipes are manufactured under extreme
care. The ductile iron pipes are made by spinning process in sizes varying from
nominal diameter (DN) 80mm to DN 1100 mm and length 5000 to 6000 mm in
India at present. The pipes are covered as per Indian Standard IS-8329 and
various other overseas standards. These pipes are generally cement lined from
inside and bitumen painted outside unless there is specific requirement by the
customers. These are used for conveying various fluids such as water, sewage,
oil and other. Utmost care is taken in handling these pipes and the pipes are
available in various diameters, lengths and are not subjected to excessive stress
and strain. Since the pipes are very costly the incurred losses due to damages in
handling, transportation are very high. Safe, quick economical transportation and
easy handling has always been a problem due to large size of pipes and brittle
nature of the cement lining.
The ductile iron pipes are normally transported through containers, trucks and
wagons.
Pipes for distribution are often stored in a warehouse and retrieved from there for
loading onto a vehicle for transport to customers. In an effort to increase the
speed and efficiency of the storage and delivery system, apparatus for quick and
safe retrieval of pipes from the storage space have been developed. This has
resulted into a large advance in the efficiency of order picking systems, which
traditionally heavily relied on manual handling. Further advantages of the present
system include reduced overall cost, increased accuracy and decreased risk of
personal injury.
At the time of loading / unloading, it is extremely important to note that no
damage is done not only to the cement lining but also the pipes are loaded and
unloaded carefully. It is also important to realize maximum utility of the transport
arrangement, pipes of smaller dimensions be nested within pipes of larger
dimensions, which is the central point of the invention.
An ongoing problem faced by warehouse managers is the efficient use of space
within a warehouse. Each square metre of space within the warehouse has an
associated cost and the warehouse management system must seek to obtain the
maximum use of the space in the warehouse to be efficient and competitive.
Thus, the invention is primarily concerned with the accessories to handle cement
lined ductile iron pipes so that these can be easily loaded, transported and
unloaded including the pipes of smaller dimensions nested within pipes of larger
dimensions.
The prior practice was by using forklift trucks. Two brackets were mounted in
tandem on a frame and one long boom inserted in the brackets. The frame was
provided with slots for insertion of the forklift arms. This boom was lagged by jute
or straw etc to avoid the damage to the inside cement lining of the pipe to be
handled. This boom was carefully inserted in the pipe by the forklift and the latter
then placed one by one inside the container till the container was full.
This method had limitations such as:
1. Breakage of expensive forklift arms.
2. Damage of the bearings of the cradle plate of forklift due to large
overhanging load of the pipe.
3. The large deflection of the forklift boom and whipping during the
movement of the forklift with the pipe made it very difficult to place
pipes inside the container and stuffing it fully since nesting was
impossible.
4. Due to the large size of the pipes the container could not be loaded to
its full capacity in terms of tonnage. Thus the cost of transportation per
tonne of pipes was high.
5. In case of the large pipes the forklift rear wheels got lifted off the
ground making it unsafe. Therefore it was necessary to find out
beforehand the largest size of the pipe, which could be lifted by the
forklift not merely considering the forklift capacity in terms of tonnage
but the permissible turning moment of the total overhanging load.
6. the process was very slow thus loading a container full took too much
time and hardly one or two containers could be loaded in a shift.
7. Generally pipes smaller than DN 300could not be loaded by available
5 or 6 tonne capacity forklifts by this method due to large boom
deflection and whipping of pipe during movement of the forklift. The
pipes larger than DN 500 also could not be handled safely by available
forklifts as explained above in para 5.
8. For economy in transport placing one pipe inside a larger pipe
(usually called nesting) before despatch was not possible due to large
deflection of boom and luffing of the pipes during the forklift
movements during pipes alignment.
It is an object of the present invention, to provide means of transport, storing
and/or retrieving pipes from containers and quickly restore and retrieve product,
overcoming or alleviating problems with storage and retrieval systems at present,
or at least to provide the public with a useful alternative.
Further objectives of the invention may become apparent from the following
description, given by way of example only.
Summary of the Invention
This invention relates to an apparatus and method for loading/ unloading pipes
from the containers or warehouse. This invention also relates to several
accessories useful for the purpose of handling cement lined ductile iron pipes.
According to an aspect of the present invention, there is provided an apparatus
for loading and unloading of ductile iron pipes in a container
comprising of: a conventional forklift; a boom for handling / lifting / nesting / de-
nesting / retrieval of the cement lined ductile iron pipes; an assembly for handling
of the boom without the forklift arms.
According to another aspect of the present invention, there is provided an
apparatus for loading and unloading of ductile iron pipes in a container
comprising of: a conventional forklift; a boomless device for handling / lifting /
nesting / de-nesting / retrieval of the cement lined ductile iron pipes of smaller
diameter of DN 80 and DN 100 sizes; an assembly of handling boom with the
forklift without the arms.
According to another aspect of the present invention, there is provided an
apparatus for loading and unloading of ductile iron pipes in a container
comprising of: a conventional forklift; more than one boom device for handling /
lifting / nesting / de-nesting / retrieval of the cement lined ductile iron pipes; an
assembly of handling boom with the forklift without the arms.
According to yet another aspect of the present invention, there is provided a
method for loading and unloading of ductile iron pipes in a container comprising
the steps of: providing a conventional forklift; providing a boom for
handling / lifting / nesting / de-nesting / retrieval of the cement lined ductile iron
pipes; providing an assembly of handling boom with the forklift without the arms.
It is therefore the prime objective of the invention is to propose such method and
devices to enable to load the pipes in the container safely, quickly, economically
using the available forklifts, manpower without causing any damage to the
cement lining or painting of the pipes and the various parts of the forklift as well
as carry out nesting / denesting of the pipes.
The second objective of the present invention is to avoid any modification or
permanent changes to the forklift thus avoiding any tampering of original design
of forklift, to enable its use for other normal duties within a short time.
The third objective of the present invention to provide a device, which is
economical to manufacture, maintain and use, using the indigenously available
materials and skills.
The fourth objective of the present invention is to provide a simple reliable and
low cost solution to the aforesaid problems and pipes of several sizes be handled
by one device.
The fifth objective of the present invention is to provide apparatus for storage and
retrieval system even for pipes of smaller diameter i.e. including DN 80 pipes.
The sixth objective of the present invention is to provide apparatus, which can
also be used for nesting the pipes in a container and similarly can be used for the
retrieval of the same whenever needed.
The seventh objective of the present invention is to provide apparatus, by which
the full freight capacity of the container can be utilized by proper combination of
the nesting of pipes thereby reducing the transportation cost per tonne of pipes.
The eighth objective of the present invention is to provide apparatus for inserting
two tonne pipe bundles in a container upto full freight capacity.
Further aspects and embodiments of the present invention, which should be
considered in all its novel aspects, may become apparent from the following
description, given by way of example only and with reference to the
accompanying drawings.
Brief Description of the Accompanying Drawings
1. Fig 1 shows a boom for nesting DN 150 and DN 200 pipes.
2. Fig 2 shows an arrangement for loading pipes in a container by the special
device of the invention.
3. Fig 3 shows a boom for nesting DN 100 pipe.
4. Fig 4 shows a boom less device for nesting DN 80 and DN 100 pipes
according to another aspect of the present invention.
5. Fig 5 shows the pipe bundle in a container loaded by the special device of
the invention.
6. Fig 6 shows the device with twin booms to handle two numbers of
specified pipes simultaneously.
7. Fig 7 shows the device with triple booms to handle three numbers of
specified pipes simultaneously having the flexibility to change the centre
distances for different pipe sizes.
Detailed Description of the Invention
This invention relates to a method and apparatus for loading and unloading of
cement lined ductile iron pipes for storage in a warehouse environment of pipes
or other containers and to methods and apparatus for retrieval of pipes from the
warehouse or containers. The loading and unloading system includes one or
more storage areas for storing cement lined ductile iron pipes and the apparatus
and methods of the present invention are particularly directed to the transfer of
cement lined ductile iron pipes to and fro the storage areas / containers.
The safest and most convenient mode of transportation is by containers. Most of
the containers are open only from one end and inserting the pipes in the
container is very difficult since normal cranes cannot be used. Special purpose
cranes can be installed at the factory for loading but at the unloading point it is
always a problem. Invariably damage is caused to the outside paint and/ or the
cement lining during loading and unloading. No standard machines are available
in the market for this duty.
According to one aspect of the present invention, the apparatus is suitable for
storage and retrieval of ductile iron pipes held in containers / warehouse. The
said apparatus includes a boom for handling / lifting / nesting / de-nesting /
retrieval of the cement lined ductile iron pipes. Various booms have been
designed to satisfy the above objectives to suit the available conventional
forklifts.
Referring to Figure 1, the boom (1A) cross section should be circular so that it
can be manufactured by pipes to reduce its weight and its circular surface will not
damage the cement lining inside the pipe to be lifted. For further precaution the
boom outer surface should be lagged by environmental friendly straw or jute
wrappings for giving a cushioning effect to the cement lining at minimum cost.
The length of the boom is such that it gets inserted in the pipe beyond the centre
of gravity of the pipe. It is not necessary to support the entire length of the pipe
on the boom. Preferably the length of the boom should be slightly more than half
of the ductile iron pipe, which is to be lifted. This minimizes the weight, cost and
turning moment on the boom. The tip of the boom should be covered by a
rounded cover to avoid damage to the cement lining by the front edge of the
boom.
The boom is welded perpendicularly to a back plate (2A) of adequate thickness
and size. The assembly is suspended from the top of the cradle plate of the
forklift by means of welded lugs (4A), which snugly fit with the cradle plate and
transfer total load to the cradle plate instead of the forklift arms, which are
removed and stored separately. This reduces the load moment considerably and
there is no chance or damage to the forklift arms. The boom remains horizontal
in suspended condition. Though the vertical back plate of the boom rests against
the forklift cradle plate due to the overhang load on the boom it is safer to fix it
with the cradle plate by hooks bolts (5A) at the bottom also to avoid jumping off
accidentally (see fig 1 and 2). The ground of movement of the forklift while
loading / nesting of the pipes should be hard and leveled and preferably
concreted.
The cross section of the steel tube used to manufacture the boom should be
selected considering the boom as a cantilever and turning moment about the
centre line of the forklift cradle plate due to: -
i) its own weight plus;
ii) the weight of the largest pipe to be handled plus;
iii) the weight of the back plate on which the boom is welded,
iv) the boom outer diameter should be selected smaller than the
smallest pipe to be handled such that the lagged boom can be
inserted by the forklift driver inside the pipe without abrading its
cement lining.
For the loading apparatus it is necessary that there are no parts projecting
outside the limits set by the opening of the container and that there are no parts
projecting forwardly beyond the pipe length, against which the articles are loaded
in and piled, irrespective of that wall being a container end wall or any other
wall/end.
It will thus be seen from fig 1 that the boom is useful for loading and unloading
pipes of standard DN 150 and DN 200 size. It is also possible to nest DN 160
pipes inside DN 250 pipe and so on.
Similarly Fig 2 shows schematically loading of the pipes inside a container using
the boom.
The smaller pipes (smaller diameter) of DN 100 size can be loaded, nested and
unloaded by the boomless device illustrated therein Fig. 4.
The pipes with smaller diameter are nested within the pipes of approx. 100mm
higher diameter carefully with the help of the newly developed booms.
For much smaller pipes e.g. DN 80 and DN 100 size, booms are not necessary
and the specially developed accessory is a boomless device where the pipe is
carried by a special arrangement and can be loaded and unloaded. The said
device uses the grooves in the socket of the pipe and locks / engages the said
grooves with the specially designed boomless device.
The deflection of the boom at its free end may be calculated as cantilever under
loads as mentioned and be lesser than its length /100.
Moreover, the total weight of pipe, boom assembly including the weight of the
back plate should be lesser than the forklifts specified load capacity. The total
turning moment should be lesser than the forklift capacity multiplied by the
permissible load centre as given in the catalogue of the forklift.
At the fixed end of the boom (1A) with the back plate (2A) a rib plate (3A) is
welded at the top of the bottom pipe to make it stiff. The rib design minimizes the
stress concentration in the boom at the beginning of the rib, such that the change
of the cross-section is gradual. The particular feature is clearly visible in Fig 1. It
is also found that for upto DN250 pipes the boom can be made out of pipe of
uniform cross-section. To handle DN200 and smaller pipes the boom, should be
made out of three pieces of tubes welded in reducing order of thickness towards
the free end keeping the outer diameter of all the pieces same. The fixed end of
the boom welded to back plate should be out of solid round reduced gradually to
the same diameter as the rest of the boom. The boom back plate (1 A) should be
made to suit to the specific forklift.
In one of the embodiment of the present invention, each boom designed as
above can handle more than one size of pipes to reduce frequent changing and
inventory.
For DN 100 pipe the boom tip is made like a tapered cone for ease of insertion.
The body of the boom is made out of three pieces having different thickness but
same outer diameter. The pieces should be welded towards the fixed end of the
boom in ascending order of thickness. The boom end piece welded to the back
plate should be out of solid round. Pipe socket to be located at the solid round
portion of the boom, which smoothly reduces to the outer diameter of the
remaining boom by machining giving large double radii fillets to minimize the
stress concentration effect. The particular feature is clearly visible in fig 3.
For the DN 80 pipe the boom as mentioned above is not possible so a boomless
device has been invented. The boomless device locates the pipe from the inside
of the socket by a hook (6B) engaged in the grooves of the socket while the
lower end of the socket rests against the vertical part of the hook mounting
bracket (7B) as shown in Fig 4.
These booms can also be used to nest one pipe inside the other. With practice it
is possible to insert smaller pipe having outer diameter - 100mm smaller than
inner diameter of the larger pipe. It is necessarily to lag the outer diameter of the
smaller pipe properly (just like the boom) to avoid any damage to the cement ling
of the bigger pipe. After insertion the pipes should be prevented from any rolling
or sliding one inside the other by proper rubber seals. Thus the full freight
capacity of the container can be utilized by proper combination of the nested
pipes. Thus reducing the transportation cost per tonne of pipes to less than half.
The boom as explained above could also lift larger than DN 700 pipes by a 5
tonne capacity forklift by using a counter weight arrangement, which has been
covered by a separate patent application no. 369/KOL/2004 (main invention) by
the same applicant.
Special boom for inserting two tonne pipe bundles in a container upto full freight
capacity is also possible using the device as per fig 5. Here the boom is made
out of flat laminated plate construction (like a leaf spring). The leaves of the
boom were selected to make the boom gradually thicker towards the fixed end.
Two loose steel straps were tied to each bundle and the boom inserted in the
upper loose part of the straps to lift the bundle and place the same in the
container. The straps in raised condition were left inside the container along with
the bundle so that at the unloading station the same straps can be used to take
out the bundle using similar arrangement. Depending upon the capacity of the
forklift and weight of the bundle the need of the counter weight can be
determined as covered in separate application as referred above.
The booms should not be bent and kept safely after the use and correct boom
should be used for the specified pipe.
Fig 6 shows another embodiment of the present invention there is provided a
mechanism to mount twin booms each of DN 250 and DN 300 pipes for using
with standard forklift of 5 tonne capacity, for lifting two pipes at a time for loading
in a container. This requires that the booms should maintain same centre-to-
centre distance and parallelity to each other throughout the length. The base
plate (2C) is made common to each pair of twin booms (1C1, 1C2 ). The booms
should be fitted in the machined bores (8C) in the base plate before welding.
These booms can increase the loading / unloading capacity to almost double.
Fig 7 shows another possibility of handling three pipes at a time of sizes DN 150
and DN 200, by using standard 5 tonne capacity forklift. Here the center to center
distance of the booms can be adjusted to suit DN 150 or DN 200 pipes. This will
reduce the loading/ unloading time to almost 1/3rd of the single pipe boom.
The above-described embodiments of the invention are intended to be examples
of the present invention. Numerous modifications changes and improvements
within the scope of the invention will occur to the reader. Those of skill in the art
may effect alterations and modifications thereto without departing from the scope
of the invention which is defined solely by the claims appended hereto.
WE CLAIM: -
1. An apparatus for loading and unloading of ductile iron pipes in a container
comprising of: -
a conventional forklift;
a boom (1A) for handling / lifting / nesting / de-nesting / retrieval of the
cement lined ductile iron pipes; and
an assembly (2A, 3A, 4A, 5A) for handling of the boom without the forklift
arms.
2. The apparatus as claimed in claim 1, wherein the boom cross section is
circular and the boom outer surface is lagged by environmental friendly straw or
jute wrappings for giving a cushioning effect to the cement lining.
3. The apparatus as claimed in claim 1, wherein the boom length is slightly
more than half of the ductile iron pipe, which is to be lifted and the tip of the boom
is covered by a rounded cover to avoid damage to the cement lining by the front
edge of the boom.
4. The apparatus as claimed in claim 1, wherein the assembly for handling
the boom comprises of a back plate (2A) wherein the boom is welded
perpendicularly.
5. The apparatus as claimed in claim 4, wherein the assembly is suspended
from the top of the cradle plate of the forklift by means of welded lugs (4A), which
snugly fit with the cradle plate and transfers total load to the cradle plate.
6. The apparatus as claimed in claim 4, wherein the vertical back plate of the
boom rests against the forklift cradle plate and fixed with the cradle plate by
hooks bolts (5A) at the bottom.
7. The apparatus as claimed in claim 1, wherein the total weight of the boom
assembly including the weight of the back plate is lesser than the forklifts
specified load capacity and the total turning moment is lesser than the forklift
load center multiplied by the permissible carrying load of the forklift.
8. The apparatus as claimed in claim 1, wherein the fixed end of the boom
with the back plate is welded with a rib plate (3A) at the top of the bottom pipe
such that the rib design minimizes the stress concentration in the boom at the
beginning of the rib.
9. The apparatus as claimed in claim 1, wherein the boom is made out of
steel tube of uniform cross-section for handling of pipes of diameter >=DN250.
10. The apparatus as claimed in claim 1, wherein the boom is made out of
three pieces of tubes arranged in reducing order of thickness towards the free
end keeping the outer diameter of all the pieces same to handle pipes of
diameter DN200 and smaller, the fixed end of the boom welded to back plate is
made out of solid round having diameter gradually reduced to the same as the
rest of the boom.
11. The apparatus as claimed in claim 1, wherein the boom is made out of flat
laminated plate construction (like a leaf spring) and the leaves of the boom are
gradually thicker towards the fixed end, for handling pipe bundles.
12. An apparatus for loading and unloading of ductile iron pipes in a container
comprising of. -
a conventional forklift;
a boomless device (6B, 7B) for handling / lifting / nesting / de-nesting /
retrieval of the cement lined ductile iron pipes of smaller diameter of DN
80, DN 100 and DN 125 sizes; and
an assembly (2B, 3B, 4B, 5B) for handling of the boom without the forklift
arms.
13. The apparatus as claimed in claim 12, wherein the boomless device
locates the pipe from the inside of the socket by a hook engaged in the grooves
of the socket while the lower end of the socket rests against the vertical part of
the hook mounting bracket.
14. The apparatus as claimed in any of the preceding claims, wherein the
nesting is done by inserting the pipes of lower diameter inside the pipes of higher
diameter and further the pipes are prevented from any rolling or sliding inside the
other by sealing, using rubber seals.
15. An apparatus for loading and unloading of ductile iron pipes in a container
comprising of: -
a conventional forklift;
a twin boom device (8C1, 8C2) for handling / lifting / nesting / de-nesting /
retrieval of the cement lined ductile iron pipes; and
an assembly (2C, 3C, 4C, 5C) for handling of the boom without the forklift
arms.
16. The apparatus as claimed in claim 15, wherein the twin booms have same
centre-to-centre distance and parallel to each other throughout the length and the
base plate is made common to each pair of twin booms.
17. An apparatus for loading and unloading of ductile iron pipes in a container
comprising of: -
a conventional forklift;
a triple boom device (9D, 10D, 11D) for handling / lifting / nesting / de-
nesting / retrieval of the three cement lined ductile iron pipes; and
an assembly (2D, 3D, 4D, 5D) for handling of the boom without the forklift
arms.
18. The apparatus as claimed in claim 17, wherein the triple booms have
adjustable centre-to-centre distance and parallel to each other throughout the
length and the base frame is made common to three booms.
19. A method for loading and unloading of ductile iron pipes in a container
comprising the steps of: -
providing a conventional forklift;
providing a boom for handling / lifting / nesting / de-nesting / retrieval of
the cement lined ductile iron pipes,
providing an assembly for handling of the boom without the forklift arms;
engaging / inserting the boom inside the ductile iron pipe;
lifting the pipe by lifting the forklift arm; and
storing / retrieval or nesting the pipe inside the container or another
pipe.
20. An apparatus for loading and unloading of ductile iron pipes in a container,
substantially as herein described with particular reference to accompanying
drawings.
21. A method for loading and unloading of ductile iron pipes in a container,
substantially as herein described with particular reference to accompanying drawings.

Present invention relates to an apparatus and method for loading of cement lined ductile iron pipes for transportation / movement by lorries or containers and to methods and apparatus for unloading of pipes from the containers to warehouse, said invention also relates to several accessories useful for the purpose of
handling cement lined ductile iron pipes.