Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
1 FIELD OF INVENTIaN
This invention relates to an improved jib assembly for use with
an articulated boom.
BACKGROUND OF THE INVENTION
Articulated booms are well known in the art. They are usually
mounted on a truck and in operation, move a workperson carried for example in
a bucket c~rrier secured to one end of the boom to an elevated work position.
As the boom is extended,the bucket and the person carried in the bucket
maintains a vertical attitude. This is accomplished by the bucket carrier
lG being suspended on a shaft freely rotatable in a sleeve carried in the end of
the boom and to which the bucket carrier is secured so that irrespective of
the angle of the boom the bucket is oriented vertically.
To assist the workperson in for example the bucket carrier, a
work jib is carried in a sleeve proximate the end of the boom to pivot from
a horizontal, to a vertical position and to slide in the sleeve to assist the
workperson completing the job. The jib is slidable in the sleeve from
position to position where it is locked by a pin passing through aligned
apertures in both the jib and the sleeve. A metal quadrent carried by the
boom pivotally secures the sleeve thereto for locking by a pin carried by
the sleeve in one of a plurality of apertures in ihe quadrent. While the
addition of the jib was intended to reduce the work load of the operator, hand
adjustment and rotation of the jib to carry out various work functions was
difficult to say the least. In fact, in most instances manipulation of the
ji~ to move the heavy wires on a hydro line was impractical.
Z5 In my co-pendin~Canadian Patent Application 373,~58 and in co-pending
United States Application entitled Articulated ~oom and Assembly Therefor,
I disclosed an articulated boom and assembly comprising
(a) a lower boom arm;
(b) an upper boom arm foldable over the lower arm, pivotal with
respect to the lower boom arm;
~`
1 (c) hydraulic cylinders positioned between the boom arms and
having piston rods extending therefrom, the hydraulic cylinders
with the piston rods pivotally secured at one end to each boom arm
intermediate the boom arm's ends, one hydraulic cylinder being
pivotally secured to the underside of the upper arm and the other
cylinder pivotally secured to the upperside of the lower arm facing
the upperside when the upper arm is folded over the lower arm;
-and-
(d) a linkage for pivotally connecting the upper arm, lower arm
and hydraulic cylinders, the linkage comprising three points of
connection, the points when linearly connected forming a triangle
(preferably isoceles and equilateral triangles) and the points of
connection are the apexes of the triangle with:
(i) one apex of the triangle (for example, in the case of the points
of connection forming an isoceles triangle, the apex created by
the meeting of the two equal sides), directed towards the hydraulic
cylinders and piston rods between the upper and lower boom arms,
and the linkage being pivotally connected at this point of
connection to the free ends of the cylinders or piston rods not
connected to the arms;
(ii) another apex of the triangle proximate the upper arm being
pivotally secured to the end of the upper arm at this point of
connection;
-and-
Z5 (iii) another apex of the triangle proximate the lower arm being
pivotally secured to the end of the lower arm at this point of
connection.
While my development is a clear improvement over the structure of prior art
art7culate booms, still the workperson in the bucke~ carrier requires the
3a assistance of some easily manipulatable device for the movement of for example
--2--
1 the hydro electric wires, which cannot be easily displaced or moved.
It is therefore an object of this invention, to provide a jib
assembly for use with a boom of a work truck which overcomes the above
deficiencies.
Further and other objects of this invention will be realized by
those skilled in the art from the following summary of the invention and
detailed description of an embodiment thereof.
SUMMARY OF THE INVENTION
According to one aspect of the invention, an improved jib assembly
is provided for use with an articulated boom carried by a work truck and
which boom carries at least one workperson carrier on a freely rotatable
shaft extending through the boom, the jib assembly comprising a jib, a
speed reducer comprising a worm gear and a worm for rotating the worm gear,
the worm gear concentric with the shaft carrying the at least one workperson
carrier, the worm gear freely rotatable relative to the shaft, a motor,
preferably a hydraulic motor, for driving the worm gear, a connector for
connecting the jib to the worm gear to rotate the jib with the worm gear as
the worm gear is rotated by the worm to provide continuous 360 degree rotation
to the jib.
Where the jib is carried in a sleeve (as is preferable), the jib
is slideable in the sleeve and lockable therein and the sleeve is connected
by the connector to the worm gear. In one embodiment, the connector comprises
a plate rotatable with the worm gear. A locking pin assembly, preferably
spring loaded, secured to the sleeve or jib, as the case may be, may be used to
releaseably lock the jib or sleeve to the plate through an aperture in the plate.
In one embodiment the speed reduction provided by the speed reducer
is in the order of 1:60. Therefore, with the speed reducer concentric with the
shaft on which the carrier is mounted, a Full 360 degrees continuous rotatable
adjustment of the jib is provided while at all times giving the jib substantial
torque provided by the ~otor is inversely proportional to the speed of the
- 3 --
1 motor. Therefore,by reducing the output of the motor through the use of the
speed reducer, the torque from the motor is increased giving the jib greater
leverage for use to lift and/or move materials as for example, hydroelectric
wires carried by adjacent hydro poles, during repair opera~ions.
S Theinvention will now be illustrated with reference to the following
drawings of an embodiment thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of a truck carrying a boom supporting
a bucket carrier and jib assembly thereon according to one embodi~ent of
the invention.
Figure 2 is a close up perspective view of part of the structure
shown in Figure 1.
Figure 3 illus~rates the struc~ure shown in Figure 2 in another
position.
Figure 4 is a schematic side view of the 360 rotational ability of
the jib assembly according to the embodiment of the invention.
Figure 5 is a side view of a portion of the drive mechanism used
~or rotating the jib assembly according to the embodiment of the invention.
DETAILED DESCRIPTION OF THE DRAWINGS
With reference to figure 1, there is shown truck 10 comprising cab
12 and trailer 14 at the rear of truck 10. Articulated bocm 16 is supported
on trailer 14 and comprises lower boom arm 18 upper boom arm 20 folded over
lower arm 18 and pivotal at 22 with respect to lower boom arm 18.
With reference to Figures 1 to 4 a pair of bucket carriers only one
of which is shown at 26 are mounted at the ends of shaft 28 extending
through boom arm 20 proximate end 24. Assembly 30 is interposed between
the ends of shaft 28 and each bucket carrier 26 for the change of the
relative position of bucket carrier 26 with respect to the end of shaft 28
by thc rotation of annular ring 32. Plate 34 is secured to each end of
shaft 28 and carrier two arms 36 and 38 extending away from shaft 28
a
1 secured to bucket carrier 26. Arms 36 and 38 carry axis 40 to which is
secured gear 42. Ring 32 is secured to shaft 44 supported by arms 36 and 38,
shaft 44 carries on its lower end gear ~6 meshed with gear 42. Therefore, as
ring 32 is rotated, gear 46 is rotated about gear 42 rotating bucket carrier
26 relative to end 28.
Mounted concentrically with shaft 28 is speed reducer 50 (see Figures
3,4 and 5) manufactured by Amador Hydraulic Services Limited under model
AHJ-500, and comprises worm gear 52 driven by worm 54 driven by hydraulic
motor 56 for reducing the speed and thus the output of the motor by a ratio
of 1:60. Hydraulic motor 56 is a Char-lynn Motor no. 101-1029. Speed reducer
50 and hydraulic motor 56 are secured to boom 20 by bolts or cap screws (see
Figure 3). Cover plate 60 covers worm gear 52 and is adapted to rotate
therewith. Plate 60 includes apertures 62 and 64 for receiving to bolts or
cap screws 66 and 68 secured to arms 70 and 72 secured to metal sleeve 74 of
the jib assembly. Sleeve 74 carries an aperture 75 therethrough which locking
pin 76 extends. Sleeve 74 carries jib 78 having apertures 80 aligned with
aperture 75. When jib 78 is mounted in sleeve 74, jib 78 is slidable in the
sleeve 74 until locked by pin 76 passing through one of apertures 70 and
aperture 75. As is apparent from Figure 4, worm gear 52 of speed reducer 50
is concentric with shaft 28 of bucket carrier 26 a full 360 continuous rotation.
Thus jib 78 is rotatable about shaft 28 a full 360 for maximum adjustability.
Worm gear 52 is freely rotatable relative to shaft 28. Because the torque
provided by motor 56 is inversely proportional to the speed of motor 56, by
reducing the speed of the motor through the use of the speed reducer to rotate
the jib 78 and sleeve 74, jib 78 has a greater ability for lifting and moving,
for example, overhead wires on telephone poles.
As many changes can be made to the embodiment of the invention without
departing from the scope of the invention, it is intended that all matter con-
tained herein be interpreted as illustra~ive of the invention and not in a
limiting sense.
