Object of Invention
The present invention relates to 4 stage telescopic boom crane assembly with semi automatic
quick open extension and modular assembly of 3 & 4 stage variant of crane boom.
Field of Invention:
The present invention relates to a novel Construction of a multistage telescopic boom
aggregates and method of extension of the last boom and for use on Pick and Carry type
hydraulic mobile cranes. Such a boom with single or multiple extensions can be extended or
retracted during working of the crane. The single or multiple boom extensions enable the
crane boom to handle and approach the far placed loads from the crane boom near end which
is fixed to the crane. Such pick and carry cranes are available with variety of boom options
like 2 stage boom, 3 stage boom and the 4 stage boom. With novel construction of multistage
telescopic boom aggregates the same extension booms can be used to construct a 3 stage
boom or a 4 stage boom.
Background of the Invention:
In known that in pick & carry and other types of cranes, a boom assembly is provided on
cranes for lifting and handling of load. This boom assembly has single or multiple boom
extensions disposed within the fixed outer boom, which is mounted on the crane. All the
boom extensions are of different but fixed length and cross section width with respect to each
other. These boom extensions are made by welding of steel plates. The manufacturing of
these crane booms involves use of tools as fixtures, which enable boom plates to be located
with respect to its length and cross section dimensions. Thus every boom member needs a
different set of tooling or fixture in order to manufactures these at required dimensions.
Such a boom assembly in known pick & carry and other types of cranes with single or
multiple extensions can be extended or retracted during working of the crane. During
extension of boom assembly the single or multiple extension booms telescopically extend so
as to increase the total length of boom assembly. When single or multiple boom extensions

are retracted teiescopically, the boom assembly reduces in length. The boom assembly can be
also turned vertically upwards so when single or multiple boom extensions are extended the
boom assembly length increases in terms of height of tip of last extension boom.
For the better understanding of the invention we shall describe the known art with reference
to accompanying drawings, which are given by way of illustration but does not restrict the
scope of present invention.
Figure I (a) shows Crane with Boom assembly with multiple boom extensions, Figure 1 (b)
shows a Crane with Boom assembly with multiple boom extensions extended horizontally
and Figure 1 (c) shows Crane with Boom assembly with multiple boom extensions extended
vertically wherein second extension Boom is marked as 101, first Extension Boom is marked
as 102 and Fixed outer Boom is marked as 103.
In working of crane this single or multiple boom extensions enable crane boom assembly to
handle and approach the far placed and higher placed loads from the crane boom end which is
always mounted on the crane. In market such pick and carry cranes are available with boom
heights of 8m to 9m for 2 stages of boom and 10m to 13m for 3 stages of boom. In some
work instances there is a need to handle and approach still more far placed and higher placed
loads with crane boom. To enable crane work and access the farther placed and higher placed
loads like 13m to 16m lift height, a type of another boom extension is placed inside the last
extension boom and is generally a manual extendable boom or semi powered or semi
automatic.
Also these boom assembly can be fitted with a jib extension which will add another 2m to 3m
working height of the boom. But jib extensions are fitted with bolts outside the last extension
boom manually. Jib is fitted on the last extension boom till the work is being done by the
crane and is removed after the completion of the work because since jib is fitted out side the
last extension boom and can not be teiescopically retracted. Hence this has to be removed
after completion of the work other wise the moving of crane becomes very unsafe. Figure 2
illustrates Crane with Boom assembly with multiple boom extensions [outer boom (203), first

boom extension (202) and second boom extension (201)] extended vertically and fixed jib
extension (204) attached to last extension boom (201).
While other extensions of boom can be extended by hydraulic power and rope or chain means
b\ operator sitting inside the cab. Such as these boom assembly extensions are known as full
power boom. While the manual extendable boom needs operator intervention to do manual
steps of locking/unlocking; connecting and removing rope to extended and retract this boom
but still with the movement of full power boom members. This is reason such a boom
member is known as manual extension boom or semi-powered boom. Also this manual or
semi powered boom is always a last extension boom in boom assembly. Also the last
extension boom has a provision to support a set of pulley so as to a wire rope is routed
through these pulleys to a load lifting block. The shape of last boom extension that rests out
of the boom assembly is generally of horse face type. The last extension boom is made
manual or semiautomatic to keep cost of the boom assembly less.
During manual opening of the last boom extension, which is manual or semi powered, the
operator needs to attach a rope, which is connected at rear inside end of the last boom
extension to the 1st fixed outer boom over a smaller puller fitted on extension boom in which
the last extension boom is placed. With this when full powered operation of boom moves the
extension boom in which the manual boom is placed, the manual boom gets pulled out by his
rope. The manual boom then is locked with a pin to the extension boom in which this is
placed thus keeping it fixed with respect to the extension boom in which it is placed. During
locking some adjustment of position of the manual boom is required because the pin pivots
do not align on manual boom and the extension boom in which manual boom is placed.
In known art pick and carry cranes are manufactured with varieties of Boom configuration
like full powered 2 stage, 3 stage boom and a 4 stage boom. The method of telescopic
extension can be full Power for a 2 and 3 stage boom. While for the 4 stage boom, the last
extension boom is manual or semi powered extension method type. And all these boom
configurations can be fitted with or without provision to attach Jib extension.

A disadvantage of such varieties of boom configurations is that due to unique length size of
each boom extension, multiple tooling and fixtures are required to make variety of these
booms. For example in a known art of a pick and carry crane, the 4 stage boom assembly
consists of four different booms the 1st fixed outer fixed boom, 2nd extension boom, 3rd
extension boom and 4th extension last boom which will have provision to fit pulleys in front
for lifting load can be full powered, semi powered or manual extension type. So four type of
tooling and fixtures are required in 4 stage boom assembly. Now the same pick and carry
crane manufactured with 3 stage boom assembly consists of three different booms the Is
fixed outer fixed boom, 2nd extension boom, 3rd extension last boom will have provision to
fit pulleys in front for lifting load. So three type of tooling and fixtures are required in 3 stage
boom assembly. By virtue of common elements in three stage boom assembly and four stage
boom assembly the Ist fixed outer boom and 2nd extension boom can be used as common
parts while the 3rd extension boom and 4th extension boom will be different. So the total
number of tooling and fixtures required to manufacture a combination of 3 and 4 stage boom
assembly is two fixtures of making common 1st and 2nd booms, further one fixture for making
3"1 boom for 3 stage boom configuration and further two fixtures for making 3rd and 4th stage
booms for 4 stage boom configuration thus need of total five different tooling fixtures for
manufacturing of boom.
Another disadvantage of a such configuration of boom assembly is that the 4th stage boom
which is manual or semi powered used a rope which is attached and detached manually to
enable 4th stage boom to pull open with help of full power boom extensions. This manual use
or rope to pull 4lh stage boom results in frequent breakage of this rope due to rope getting
stuck in working and error in operator while using this rope to pull the 4th stage boom.
Yet another disadvantage is that the 4th stage manual or semi powered boom when is pulled
open with rope the pin lock position of the manual boom and the extension boom in which
this is placed do no align and manual efforts are required to push manual boom in or out of
the extension boom in which it is placed. The booms are very heavy and the push pull effort
to adjust position of manual boom takes lot of physical effort of the operator and also time is
wasted in this operation.

Yet another disadvantage is that the 3 stage boom can not be converted into 4 stage boom
without having one full boom scraped and buying two more booms along with additional
assembly parts.
The above disadvantages of the known prior art are overcome by the proposed novel
construction of the boom assembly having a 1st outer fixed boom and at least one or more full
power extension boom and another boom placed inside the last full power extension boom
which can be telescopically extended and retracted by combination of manual and semi
power method. Further the operation of the last manual extension is such that a precise beam
is used to pull out manual extension so that the pin location of manual extension and the
extension boom in which manual extension is placed aligns so that these booms can be
locked in position with very less effort and time.
further advantage of the proposed novel construction of the boom assembly is that the
configuration of the boom assembly in 3 stage or 4 stage types uses common boom elements
so that the total no. of tooling fixtures is four only instead of present five tooling fixtures
required to manufacture the boom assembly in 3 stage or 4 stage configurations.
Objective of the Present Invention:
Therefore in view of the various disadvantages and proposed efficient construction of boom
cited above the unique design of efficient boom is achieved by having two boltable adapter
assembly in boom which can be used with four sets of booms viz Fixed outer boom, 1st
extension boom, 2nd extension boom and 3rd manual of semi powered boom. With the
boltable adapter assembly the these 4 sets of boom can be arranged to have 3 stage boom
configuration and 4 stage boom configuration and with four set of tooling fixtures only.
Further a fixed length beam is also used instead of rope to pull out or telescopically extend
the 3rd extension boom from the 2nd extension boom precisely and pin can locked without
need of any adjustment. Further the bolt able adapter fitted on the last extension boom which
can be full powered in case of 3 stage boom and manual or semi automatic in case of 4 stage
boom to be removed and other working accessory to be fitted on last boom such as man

basket, forks, box handler attachment. This increases the versatility and application of crane
in many work areas.
Further if any customer if have purchased the 3 stage boom machine can convert the boom
into 4 stage boom machine by just getting the 3rd extension boom and bolting on the
additional components. No boom is scraped in this change thus saving cost and efforts.
Brief Description of the Accompanying Drawing
We shall now describe the present invention with reference to accompanying drawings,
which are given by way of illustration but does not restrict the scope of present invention.
These accompanying drawings provide further objects and advantages of this invention
which will be more apparent from the ensuing description when read in conjunction with the
accompanying drawing and wherein:
Fig. 1 (a, b & c) shows a prior art Crane with Boom assembly with multiple positions of
boom and possible extensions
Fig. 2 shows a Crane with Boom assembly fitted with a prior art fixed position Jib
attachment.
Fig. 3 shows a Crane with Boom assembly fitted with a prior art fixed position Jib attachment
working at a high erection work.
Fig. 4 shows parts of efficient multi stage boom, the outer fixed boom, three extendable
booms and two adapters along with extension beam.
Fig. 4A shows three stage boom configurations by using the outer fixed boom, two
extendable booms and one adapter

Fig. 4B shows four stage boom configurations by using the outer fixed boom, three
extendable booms and two adapters.
Fig. 4C shows four stage boom configurations by using the outer fixed boom, three
extendable booms and two adapters and opening of fourth stage with beam.
Description of Invention
Given here is the efficient design of the fixed outer boom (401), 1st extension boom (402), 2nd
extension boom (403), 3rd Extension boom (404), Boom adapter (405) and a boom nose
adapter (406), which has set of pulley for handling rope. The fixed Outer boom (401) has a
set of pivot brackets (408) and (409) welded to its side to mount the extension beam (407).
Also boom nose adapter (406) has a pivot bracket (410) welded to its side as shown in figure
4.
The design of 2nd extension boom (403) is such that a plate (403A) is welded on its end,
which is outside, and the said plate is having holes for bolting provision. Similarly design of
the 3td extension boom (404) is such that a plate (404A) is welded on its end which is outside
and the said plate is having holes for bolting provision. Further the boom adapter (405) also
has a plate (405A) and the boom nose adapter (406) also has the plate (406A) having similar
holes for bolting provision.
Thus bolting provision holes on plates 403A, 404A, 405A and 406A match with each other
so that these parts can be bolted together and removed as required to make assembly for the 3
stage boom or the 4 stage boom.
The boom adapter (405) also has a through hole (405B) at a suitable position so that it can
align with the front hole on the 3rd extension boom (404) front hole (404B) and the rear hole
(404C) when assembled together with the help of the lock pin.

The fixed outer boom (401), the 1st extension boom (402), the 2nd extension boom (403) fitted
with boom nose adapter (406) can be assemble together to form a three stage boom as shown
in figure (4A).
Further the same outer fixed boom (401), 1st extension boom (402), 2nd extension boom
(403), and the boom nose adapter (406) which has set of pulley can be used along with two
other parts boom adapter (405) and 3rd extension boom (404) as shown in figure (4B) can be
assemble together to form a four stage boom as shown in figure (4B). In this four stage boom
configuration, boom adapter (405) is bolted on 2nd extension boom (403) and the boom nose
adapter (406) is bolted with 3rd extension boom (404). With this bolted configuration when
the 3rJ extension boom (404) is put inside the 2nd extension boom (403) the front hole on the
3'd extension boom matches with the hole (405B) on the boom adapter (405). This is the
retracted form of the boom assembly and a Pin can be placed to lock the 3rd extension boom
with the 2nd extension boom through boom adapter as shown in figure (4C).
Now the outer fixed boom (401) having two additional pivot brackets (408) and (409) welded
to mount the extension beam (407) can be used for the semi automatic extension of the 3r
extension boom (404). The extension beam (407) can be pivoted around the pivot bracket
(408) but rests on pivot bracket (409) if this is not in use. When there is need to extend the 3rd
extension boom (404), the extension beam is taken out from the rest position from pivot
bracket (409) and turned around bolt on pivot bracket (408) to engage with the pivot bracket
(410) welded on boom adapter (406) by opening the telescopic boom to equal to length of
extension beam as shown in figure (4D).
After the extension beam is engaged with the bolt on the pivot bracket (410) on the boom
nose adapter (406), the boom assembly is now retracted, with this action the extension beam
pushes out the 3rd extension boom (404) equal to its length of the extension beam (407) so
that the rear lock hole on the 4th extension matches with the lock hole (405B) on boom
adapter (405). The pin can be put in place to hold the 3rd extension in place with 2nd extension
boom as shown in figure (4D).

Now the extension beam can be disengaged from the pivot bracket (410) and can be turned
around the pivot bracket (408) to rest on the pivot bracket (409). To close the 3rd extension
boom, the lock pin is removed from the hole (405B) of boom adapter (405) the winch is
operated so that the 3rd extension is retracted with the force of winch rope winding. After the
3td extension is fully closed, its front hole of 3rd extension boom (404) will again match with
the hole on boom adapter (405). Now the pin can be put in place to hold the 3rd extension in
place with 2nd extension boom.

WE CLAIM:
1. An improved 4 stage telescopic boom crane assembly with semi automatic quick open
extension and modular assembly which comprises fixed outer boom (401), Is extension
boom (402). 2nd extension boom (403), 3rd Extension boom (404), Boom adapter (405) and a
boom nose adapter (406), which has set of pulley for handling rope, the fixed Outer boom
(401) has a set of pivot brackets (408) and (409) welded to its side to mount the extension
beam (407), also boom nose adapter (406) has a pivot bracket (410) welded to its side..
2. An improved 4 stage telescopic boom crane assembly with semi automatic quick open
extension and modular assembly of 3 & 4 stage variant of crane boom as claimed in claim 1,
wherein 2nd extension boom (403) is such that a plate (403A) is welded on its end, which is
outside, and the said plate is having holes for bolting provision, the 3rd extension boom (404)
is such that a plate (404A) is welded on its end which is outside and the said plate is having
holes for bolting provision, the boom adapter (405) also has a plate (405A) and the boom
nose adapter (406) also has the plate (406A) having similar holes for bolting provision.
3. An improved 4 stage telescopic boom crane assembly with semi automatic quick open
extension and modular assembly of 3 & 4 stage variant of crane boom as claimed in claim 1
or 2, bolting provision holes are provided on plates 403A, 404A, 405A and 406A match with
each other so that these parts can be bolted together and removed as required to make
assembly for the 3 stage boom or the 4 stage boom.
4. An improved 4 stage telescopic boom crane assembly with semi automatic quick open
extension and modular assembly of 3 & 4 stage variant of crane boom as claimed in any one
of claims 1 to 3, boom adapter (405) also has a through hole (405B) at a suitable position so
that it can align with the front hole on the 3rd extension boom (404) front hole (404B) and the
rear hole (404C) when assembled together with the help of the lock pin.
5. An improved 4 stage telescopic boom crane assembly with semi automatic quick open
extension and modular assembly of 3 & 4 stage variant of crane boom as claimed in any one

of claims 1 to 4, the fixed outer boom (401), has the 1st extension boom (402), the 2nd
extension boom (403) fitted with boom nose adapter (406) can be assemble together to form a
three stage boom as shown in figure (4A).
6. An improved 4 stage telescopic boom crane assembly with semi automatic quick open
extension and modular assembly of 3 & 4 stage variant of crane boom as claimed in any one
of claims 1 to 5, outer fixed boom (401), has 1st extension boom (402), 2nd extension boom
(403), and the boom nose adapter (406) which has set of pulley can be used along with two
other parts boom adapter (405) and 3rd extension boom (404), four stage boom has
configuration, boom adapter (405) is bolted on 2nd extension boom (403) and the boom nose
adapter (406) is bolted with 3rd extension boom (404), with this bolted configuration when
the 3rd extension boom (404) is put inside the 2nd extension boom (403) the front hole on the
3rd extension boom matches with the hole (405B) on the boom adapter (405), this is the
retracted form of the boom assembly and a Pin can be placed to lock the 3rd extension boom
with the 2nd extension boom through boom adapter.
7. An improved 4 stage telescopic boom crane assembly with semi automatic quick open
extension and modular assembly of 3 & 4 stage variant of crane boom as claimed in any one
of claims 1 to 6, wherein outer fixed boom (401) having two additional pivot brackets (408)
and (409) welded to mount the extension beam (407) can be used for the semi automatic
extension of the 3rd extension boom (404), the extension beam (407) can be pivoted around
the pivot bracket (408) but rests on pivot bracket (409) if this is not in use, when if required
the same can be extended 3rd extension boom (404), the extension beam is taken out from the
rest position from pivot bracket (409) and turned around bolt on pivot bracket (408) to
engage with the pivot bracket (410) welded on boom adapter (406) by opening the telescopic
boom to equal to length of extension beam.
8. An improved 4 stage telescopic boom crane assembly with semi automatic quick open
extension and modular assembly of 3 & 4 stage variant of crane boom as claimed in any one
of claims 1 to 7, wherein the extension beam is engaged with the bolt on the pivot bracket
(410) on the boom nose adapter (406), the boom assembly is now retracted, with this action
the extension beam pushes out the 3rd extension boom (404) equal to its length of the