Field of Invention:
The present invention relates to a novel adjustable jib extension attachment on boom for pick
and carry type crane and more particularly a novel adjustable Jib Extension attachment on
telescopic extension booms for use on Pick and Carry type hydraulic mobile cranes wherein
there is provided machine boom having one or multiple boom extensions disposed within the
outer boom which is fixed to the crane. 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.
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 outer boom which is fixed to the crane.
For the better understanding of the invention we shall describe the known art and the novel
adjustable Jib Extension Attachment on Boom of the present invention with reference to
accompanying drawings which are given by way of illustration but does not restrict the scope
of present invention.
Figure 1 (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 Boom extension is marked as 101, first Boom Extension is marked
as 102 and Outer Boom is marked as 103.
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. In the boom assembly
the outer boom has fixed length and other extensions booms disposed in the outer boom also
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have fixed length. 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 telescopically, 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 as shown in Figure 1 (a), (b) and (c) of the accompanying drawings.
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 fixed to the crane.
In some work instances there is a need to handle and approach still more far placed and
higher placed loads with crane boom. In these work instances even when crane boom is
extended fully with all extension booms, still crane boom cannot reach near to these far
placed and higher placed loads. To enable crane work and access the farther placed and
higher placed loads, a fixed type of another boom member is attached to the last extension
boom. This fixed type of boom member is called the Jib extension. The last extension boom
member has provision to attach the fixed jib extension. Figure 4 thus illustrates the Last
Extension Boom with provision for Jib extension attachment on front side wherein Upper
Pivot positions for mounting Jib Extension is marked as (401) and Bottom Pivot positions for
mounting Jib Extension is marked as (402).
This fixed jib extension when attached to last boom extension member move with the
movement of last boom extension member only. With the Jib extension member the total
length of boom assembly when extended fully further increases than the length of boom
assembly when extended without having the Jib extension fixed to the last extension boom.
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) and Figure 5 shows a Jib
extension attachment which is mounted on front bottom pivot position and upper near pivot
position so that jib attachment is inline with the boom extension member marked as (b). The
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extension boom therein is marked as (501) and the jip boom as (502). The rope guide therein
is marked as (503) and the pulley on the jip extension is referred as (504).
Such a boom assembly with fixed jib extension attached can approach far placed and higher
placed loads as in Figure 3 which shows a Crane with Boom assembly with multiple boom
extensions extended vertically and fixed jib extension attached to last extension boom able to
reach far placed and higher placed loads (301).
This kind of arrangement has got a disadvantage that fixed type of Jib extension attachment
extends and retracts in line with single or multiple boom extensions. When work involves
placement of loads on higher levels like roof tops of multi story buildings, the extra height
achieved with jib extensions only helps placing loads till edge of higher roof as shown in
Figure 3.·
Yet another disadvantage of fixed type of jib extension attachment while placing loads on
higher roof is that boom assembly with single or multiple extensions while extended
vertically upwards can hit with edge of roof while trying to place loads further inside of
higher roof tops.
Yet another disadvantage of fixed type of jib extension attachment is that while lifting loads
like empty containers vertically higher, the container body hits with boom extensions.
The above disadvantages of the known prior art are overcome by the proposed novel
adjustable Jib Extension attachment on telescopic extension booms for use on Pick and Carry
type hydraulic mobile cranes wherein there is provided machine boom having one or multiple
boom extensions disposed within the outer boom which is fixed to the crane.
Object of the Invention:
Therefore in view of the various disadvantages cited above; a unique adjustable jib extension
attachment which overcomes the same is described in this disclosure. In this adjustable
arrangement, the angle of jib extension attachment can be changed with respect to the last
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extension boom members with which jib extension is attached. This angle placement
adjustment of jib extension attachment provides necessary reach to place loads inside the
higher roofs and avoid hitting of big loads like empty containers
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 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 extension boom with at least three pivot axis
Fig. 5 shows extension boom with at least three pivot axis and jib mounted at in line position.
Fig. 6 shows extension boom with at least three pivot axis and jib mounted at angle position.
Fig. 7 shows a Crane with Boom assembly fitted with adjustable position Jib attachment
working at a high erection work with horizontal reach.
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Summary of Invention
According to the present invention there is provided a novel adjustable jib extension
attachment on boom for pick and carry type crane boom assembly comprising of a fixed
outer boom and with at least one or more extension booms, the first extension
boom being extended telescopically with a hydraulic cylinder" the second and
subsequent extension booms being extended by means of ropes or yet another
hydraulic cylinder wherein the last extension boom member being provided with
arrangement of at least three pivot axis such that one of the pivot axis being placed
at the bottom side and, the other two pivot axis being placed on the upper side for
mounting arrangement of a Jib member, the said jib member having upper and
bottom pivot axis which can be fitted on to two of the three pivot axis on the last
extension boom such that when the bottom axis on both the boom and the jib being
fitted together with the help of a bolt or pin joint, wherein the upper pivot axis of jib
being fitted on to any of the two upper pivot axes of the last extension boom,
the said jib member being fitted with such a pivot axis arrangement which can
be rotated around the bottom pivot axis and can change its own position
depending on its matching of the upper pivot axis with any of the two
matching pivot axis available on the last extension boom.
Its both the upper pivot axis being placed at a suitable distance with respect to the
bottom pivot axis such that when the jib is mounted at the bottom pivot axis and
inner upper pivot axis, the jib will be collinear with the fixed outer boom and the
extension booms, whereas when the jib is mounted at the bottom pivot axis and
outer upper pivot axis, the jib will point down at an angle equal to or less than the
luffing angle or lifting angle of the boom assembly.
Additional to the three pivot axis position for mounting, the said jib member being
provided alternatively for mounting roller or guide pulley to enable routing of the
rope from fixed outer boom to the extension members and to the rear side of jib near
pivot axis mountings and finally to the front side of the jib member.
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The mounting arrangement being suitable to cranes such as of pick and carry type of
crane but however being not limited to this application only.
In Figure 4, is shown the last boom extension member having at least three or more pivot axis
positions (401) and (402) for attachment of Jib extension. One of these three or more pivot
axis positions at front bottom mounts the Jib extension attachment. The jib extension
attachment can be turned about this bottom pivot axis (402) and then can be locked at either
of the upper pivot axis positions (401).
In Figure 5 is shown the Jib extension attachment which is mounted on front bottom pivot
axis position and upper inner pivot axis position (b) so that the jib attachment (502) is inline
with the boom extension member (501).
While Figure 6 shows the jib attachment which is mounted on bottom pivot axis position and
upper outer pivot axis position (c) so that Jib attachment (602) is at an angle to the boom
extension member (601). This angle placement adjustment of jib extension attachment
provides necessary horizontal reach to place loads as shown in Figure 7 which shows Angle
placement adjustment of jib extension attachment provide necessary reach to place loads
inside the higher roofs and avoid hitting the sides at higher places marked as (d).
In Figure 5 is shown details of placement of rope guide (503) relevant to pivot axis positions
for mounting Jib attachment so that the rope from boom can be routed to front pulley (504)
fitted to jib extension in inline position as well as angle position of jib attachment relevant to
last boom extension member.

WE CLAIM:
1. A novel adjustable jib extension attachment on boom for pick and carry type crane
comprising of a fixed outer boom and with at least one or more extension
booms, the first extension boom being extended telescopically with a
hydraulic cylinder, the second and subsequent extension booms being
extended by means of ropes or yet another hydraulic cylinder wherein the last
extension boom member being provided with arrangement of at least three
pivot axis such that one of the pivot axis being placed at the bottom side and,
the other two pivot axis being placed on the upper side for mounting
arrangement of a Jib member, the said jib member having upper and bottom
pivot axis which can be fitted on to two of the three pivot axis on the last
extension boom such that when the bottom axis on both the boom and the
jib being fitted together with the help of a bolt or pin joint, wherein the upper
pivot axis of jib being fitted on to any of the two upper pivot axes of the last
extension boom, he said jib member being fitted with such a pivot axis
arrangement which can be rotated around the bottom pivot axis and can
change its own position depending on its matching of the upper pivot axis with
any of the two matching pivot axis available on the last extension boom.
2. A novel adjustable jib extension attachment on boom for pick and carry type crane
as claimed in claim 1, wherein its both the upper pivot axis being placed at a
suitable distance with respect to the bottom pivot axis such that when the jib is
mounted at the bottom pivot axis and inner upper pivot axis, the jib will be
collinear with the fixed outer boom and the extension booms, whereas when
the jib is mounted at the bottom pivot axis and outer upper pivot axis, the jib
will point down at an angle equal to or less than the luffing angle or lifting
angle of the boom assembly.
3. A novel adjustable jib extension attachment on boom for pick and carry type crane
as claimed in claim 1, wherein in additional to the three pivot axis position for
mounting, the said jib member being provided alternatively for mounting roller
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or, guide pulley to enable routing of the rope from fixed outer boom to the
extension members and to the rear side of jib near pivot axis mountings and
finally to the front side of the jib member.
4. A novel adjustable jib extension attachment on boom for pick and carry type crane
as claimed in claim 1, wherein the mounting arrangement being suitable to
cranes such as of pick and carry type of crane but however being not limited
to this application only.