FIELD OF THE INVENTION
[0001] This invention is a mobile carrier with a vertical and horizontally controllable
crane for a work station or bucket, often referred to as a "cherry picker", which
apparatus is particularly adapted for the clearing of power line right-of-ways of
tree limbs and brush. More particularly this invention is concerned with an improvement
of such known bucket platforms of this type, the improvement residing in a means to
horizontally move the crane laterally from the side of the carrier, usually a truck,
underneath a power line so that the work station can be raised upwardly on the other side and
moved side-to-side to permit limbing. By moving the crane in
under the power line the effective reach of the crane can be increased 30 to 50% or more.
This apparatus can also be used for placing and repair of power and telephone lines
in a known manner.
BACKGROUND OF THIS INVENTION
[0002] For many years power line right-of-ways have been cleared of tree limbs that might
come in contact with the power lines by the use of a bucket or "cherry picker" carried
by a crane on the bed of the truck. The truck is parked along side the power line
at the edge of the road, the stabilizers for the truck are extended and the bucket
and its supporting boom from the crane are raised up and over the power line and down
again to permit the worker in the bucket to reach the tree limbs that must be removed.
This has some inherent dangers and disadvantages. It is often difficult to lower and
control the bucket in a manner that permits the offending limbs to be reached and
there is of course the danger of contact with the power lines.
[0003] While this manner of clearing power lines and the problems associated with this approach
have been practiced for years, apparently no one has conceived that it might be better
practice to provide means for permitting the crane mechanism to be extended
under the power line before raising the bucket.
THIS INVENTION
[0004] The present invention is the carrier for a work station or bucket and its supporting
crane which comprises a vehicle and mounted to the chassis of the vehicle a laterally
extensible platform carrying the bucket crane which platform can be extended telescopically
out from the side of the vehicle 10 to 15 feet or so. Thus when the vehicle is parked
along side the road adjacent a power line the crane and work station can be extended
from the vehicle under the power line with the crane and work station thereafter being
raised to trim the trees along the right-of-way.
[0005] It is somewhat impressive that over the years this method of placement of the crane
and work station has not been thought of. Once this concept is appreciated the mechanical
arrangement necessary to implement it is relatively uncomplicated and straight forward.
[0006] In brief compass, this invention is a mobile horizontally and vertically adjustable
carrier and work station comprising a transport means such as a truck having a chassis.
An extensible platform is carried by the chassis and is adapted to telescope in and
out from the truck laterally to the line of travel of the truck. The extensible platform
has extensible stabilizers or outriggers on either side, approximately midway when
it is extended, that are adapted to be dropped down to contact the ground and support
the platform when it is extended. An articulated crane of conventional construction
is rotatably supported by the extensible platform at its outboard end. As is customary
the crane has at least two joints. The upper end of the crane, or boom, carries a
work station or bucket that can hold a worker.
[0007] While the extensible platform can be moved in and out by means of electrically powered
screws it is preferred to operate by hydraulic power. In one design the extensible
platform consists of three telescoping sections operated hydraulically for extension
and retraction.
[0008] The rotating base and crane can be of conventional construction. For example, it
can be a Versilift VO-50 manufactured by Time Manufacturing. The crane and rotation
mechanism are operated hydraulically. The hydraulic power for both the extensible
platform and the crane can be supplied from the truck in a known manner.
[0009] The stabilizers attached to the extensible platform preferably are capably of being
extended laterally from each side of the platform before the feet are dropped down
to contact the ground. The stabilizers can also be operated hydraulically although
mechanical screws could also be used to accomplish the outward extension of them and
the downward placement of the feet. If the platform is 4 feet or so wide and the stabilizers
each can be extended at least another 2 feet this gives a good 8 foot wide very stable
base for supporting the crane and bucket in addition to the stability imparted by
having the platform mounted to the chassis of the truck.
[0010] A particular advantage of this invention resides in the fact that the trend in the
industry has been to go to larger cranes - ones that will reach 90 to 100 feet. such
equipment is usually maintained in good mechanical order. These operators have been
loath to purchase the far more expensive, larger cranes. The present invention ameliorates
this problem in that the laterally extensible platform permits the smaller canes to
continue to be used and to just as effective as the larger ones when the latter are
used in the conventional manner to reach
over the power lines.
DRAWINGS
[0011] In the drawings:
Fig. 1 is a side elevational view of the apparatus of invention;
Fig. 2 is a front elevational view;
Fig 3 is a top plan view;
Fig 4 is a top plan view with the extensible platform extended and the crane and bucket
in operation;
Fig. 5 is a front elevational view of the apparatus shown in Fig. 4;
Fig. 6 is a perspective view of the apparatus of this invention in service.
Fig. 7 is a perspective view of the partially extended telescoping platform; and
Fig 8 is a cross sectional view of one of the telescoping arms of the platform, showing
the nestled arrangement of the beams when the platform is retracted.
[0012] The same reference numerals are used in Figures 1 - 5 to refer to the same parts,
and Figures 7 and 8 the same parts have the same number.
DESCRIPTION
[0013] Referring to Figs 1 - 5, a truck 10 has a chassis 11 to which is mounted the laterally
extensible platform 12 of this invention.
[0014] The truck at the rear end may have a carrier 13 of some sort, such as one to receive
wood chips.
[0015] As illustrated, the telescoping platform consists of three sections. The main one
14 slides in and out of mounting bracket 15 affixed to the truck chassis. Sections
16 and 17 extend therefrom. The outboard section 17 has mounted to it, for rotation,
the crane base 20 which in turn carries crane arm 21, boom 22 and work station or
bucket 23. The crane is operated by hydraulic cylinders 24 and 25. Items 20 - 25 are
commercially available and operated in a known manner with hydraulic power supplied
from truck 10. Usually the platform will be extendable at least 10 feet and can be
designed to extend 15 to 20 feet or more depending on the number sections utilized.
[0016] Stabilizers 31 and 32 are carried at the outboard end of the first platform section
14. When the apparatus is collapsed for travel the feet 33 and 36 of the stabilizers
are retracted and the stabilizers nestle against the side of the truck as shown in
Figs. 1, 2 and 3. In operation, after the platform 14 is extended the two stabilizers
31 and 32 are extended outwardly by arms 34 and 35 and feet 33 and 36 are lowered
to contact the ground and stabilize the platform. This may be done hydraulically or
more simply by manually pulling them out and pinning and allowing the legs to drop
and pinning.
[0017] Fig. 6 is a perspective view of the apparatus of this invention. A truck 50 is parked
along side the road next to a power line 60. Extensible platform 51 is extended laterally
from the side of the truck outwardly
under the power lines. It carries the crane bucket generally indicated at 52. The worker
or operator 53 rotates, elevates and positions the crane from controls within the
bucket in a known manner to position himself to cut the limbs of tree 54 which might
damage power line 60. When finished at this point the whole of the system can be retracted
to the truck bed and the truck moved to the next station between the power line poles.
[0018] Looking at Figs. 7 and 8, illustrated is the telescoping frame and hydraulics of
the extensible platform. Fig. 8 is a cross section of the beams on the left side when
the platform is collapsed. Channel beams 71 and 72 are braced by cross member 73 and
attach to the truck body. Nestled and sliding within these beans are channel beams
75 and 76 of the first stage. Nestled and sliding within beams 75 and 76 are channel
beams 77 and 78 of the second stage and, finally, nestled and sliding within beams
77 and 78 are box beams 79 and 80. The box beams end in cross box beams 81 and 82.
[0019] Inset within the box beams is a metal plate 83 having an opening 84 to receive the
crane. Underlying and attached to and supporting beams 75 and 76 is a double box member
85 that carries within it two hydraulically extendable and retractable box beams or
outriggers 87 and 88. These carry housings 89 and 99 respectively, that have hydraulic
cylinders to lower legs 90 and 100 to stabilize the platform.
[0020] A cross plate 74 is attached to the inner ends of beams 75 and 76 to space them and
to receive the impetus from twin hydraulic pistons 91 and 92 the ends of which are
held by cross member 93, attached to the underside of beams 71 and 72.
[0021] A two stage hydraulic piston 94, the ram of which is attached to box member 82, serves
to extend and collapse the second and third stages of the platform.
[0022] Top surfaces for the spaces between beams 71 and 72, and 75 and 76 are indicated
at 101 and 102 respectively.
[0023] Plastic glides as illustrated at 95, 96 and 97 extend along the bearing surfaces
of beams 71, 72, 75, 76, 77 and 78. These tighten the assembly and help provide a
smooth action. The glides can be made of a polytetraflouroethylene, a polyester or
similar material.
[0024] When the platform is to be extended, hydraulic cylinders 91 and 92 are activated
and push out the first stage members 75 and 76. Outriggers 87 and 88 are then hydraulically
extended and legs 90 and 100 are hydraulically extended to the ground. Thereafter,
hydraulic piston 94 is activated pushing out the third stage which carries with it
the second stage. Stops (not shown) prevent one stage from sliding out of its supporting
stage. Retraction is accomplished by reversing the above steps.
1. A mobile horizontally and vertically adjustable worker carrier comprising:
A. a transport means having a chassis;
B. an extensible platform having at least two sections carried by said chassis and
adapted to telescope in and out from said transport means laterally to the line of
travel thereof;
C. extensible stabilizers or outriggers on either side of said extensible platform
on one of said sections and traveling therewith said extensible stabilizers including
vertical legs adapted to be dropped down to contact the ground and support said extensible
platform when extended;
D. an articulated crane rotatably supported by said extensible platform at the outboard
end thereof and adopted to reach well above the level of said extensible platform,
said articulated crane having rotation means to rotate said articulated crane on an
axis perpendicular to said platform; and
E. a work station carried by said articulated crane at the outer end thereof.
2. The worker carrier of Claim 1 wherein said transport means is a motor vehicle and
provides hydraulic power, said worker station is a bucket, said extensible platform
and stabilizer are operated hydraulically for extension and retraction, said articulated
crane having at least two joints and said two joints and rotation means operate hydraulically
from controls at said work station.
3. The worker carrier of Claim 2 wherein said extensible platform has three sections
telescoping one within another, the total extensibility thereof being at least 10
feet and the width of the outboard end being at least 3 feet.
4. The worker carrier of Claim 2 wherein said extensible stabilizers are extensible laterally
from the line of said extensible platform at least 2 feet on either side, and are
operated hydraulically both through the lateral motion and the downward motion.
5. A method of clearing power and communication line rights-of-way comprising placing
a mobile work station carrier adjacent a raised power or communication line with the
line of travel thereof generally parallel to the right-of-way; said mobile work station
comprising a transport means having a chassis, an extensible platform carried by said
chassis adapted to telescope in and out from said transport means laterally to the
line of travel thereof, extensible stabilizers (outriggers) on either side of said
extensible platform, said extensible stabilizers including vertical legs adopted to
be drop down to contact the ground and support said. extensible platform when extended,
an articulated crane rotatably supported by said extensible platform at the outboard
end thereof, said crane having at least two joints and a work station carried by said
articulated crane adapted to hold a worker; extending said extensible platform with
said articulated crane and work station laterally from the side of said carrier underneath
said raised power or communication lines, thence moving said work station by means
of said crane with a worker positioned therein upwardly to a position for said worker
to remove objects that may potentially interfere with said power or communication
line and removing said objects.
6. The method of Claim 5 wherein after said extensible platform is extended said extensible
stabilizers are extended and said vertical legs are dropped to the ground and support
said extensible platform prior to the use of said work station.
7. The method of Claim 6 wherein said transport means is a truck having hydraulic power
supply means and said extensible platform, extensible stabilizers, vertical legs and
articulated crane are all powered therefrom.