LIFTING FRAME

CADRE DE LEVAGE

English Abstract

A pivoting rigid frame (constructed of two legs and a cross
member) is used to transfer material from one platform to
another. The frame, legs being pinned to the base allow the
frame to rotate or pivot about the pins. The resulting motion
allows the pivoting frame to move or transfer material from one
location to another. (The maximum distance being twice the
length of the frame leg). Rotation of this frame can be
accomplished through a variety of methods. One such method
involves the utilization of two hydraulic cylinders. The rod end
of each cylinder is connected to the frame leg pins. The head of
each hydraulic cylinder is connected to the frame and to the
base through a double linkage set-up. The length and location of
the links can vary to optimise the performance of the lifting
frame. A winch can be added to the cross member of the frame to
aid in the flexibility of the device and allow positioning of
the load to become easier.

Claims

THE EBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVELEDGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A lifting frame composed of two legs connected together
with a cross-member.
2. A frame claimed in claim 1 wherein the legs are pinned to
a base.
3. A frame claimed in claim 1 the frame can rotate or pivot

Description

CA 02354112 2001-07-10
LIFTING FRAME
The present invention relates to a device for lifting and
transferring material from one position to another. In this
particular embodiment the device is used to handle small cargo
(under 3 Ton) and is mounted on a mobile platform such as a
truck and is utilised to lift and transfer material onto the
truck platform.
Various types of equipment are available that are mounted to a
mobile platform and are capable of transferring material to that
platform. One such device is a simple boom type device that can
be mounted on a truck frame. These devices can be very bulky and
expensive requiring a large truck as the platform. The smaller
booms that can be mounted on smaller truck are cumbersome and
can detract from the cargo capacity of the truck.
Another type of device is mounted on the rear of the truck and
replaces the tail gate. This device which is essentially a
platform can be lowered to the ground where the material is
positioned on the platform. The platform and cargo can then be
raised to the level of the truck bed. This type of device
requires that the material being lifted has wheels to allow the
it to be transferred to the truck bed.
Yet another type of device incorporates a winch mounted at the
front of a tiltable bed. As the bed tilts itself into position
the winch pulls the load onto the bed. Again this type of device
requires that the material has wheels to allow it to be pulled
onto the truck bed.
It is desirable to have a relatively inexpensive material
transfer device that can be mounted on the back of a small truck
that can provide a reasonable lifting capacity while maintaing
the original cargo space. The material transfer device is to be
simple in operation and is inconspicuous when not being used.
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CA 02354112 2001-07-10
The present invention consists of a rigid hinged frame with each
leg being pinned (hinged) to a base. The frame is free to rotate
or pivot 180 degrees. Parallel and concurrent to each leg of the
frame is a hydraulic cylinder whose rod shares (and rotates
about) the same pin as the corresponding leg. The hydraulic
cylinder is free to rotate about the same axis as the frame. The
hydraulic cylinder rotates independent of the frame. one end of
a lower link is pinned to the head of the hydraulic cylinder and
while the other end is pinned to the base. The orientation of
the lower link, in this embodiment, is substantially vertical
when the hydraulic cylinder is at 45 degrees. An upper link
,Identical in shape to the lower link, has one end pinned to the
head of the hydraulic cylinder while the other end is pinned to
the arm. The orientation of the upper link in this embodiment is
horizontal when the hydraulic cylinder is at 45 degrees. The
resulting position of the frame is vertical when the hydraulic
cylinder is at 45 degrees . The location of the pins and length
of the linkages determine the capacity and range of motion of
the device. A winch mounted on the horizontal member of the
rigid frame allows further flexibility for load positioning as
the load can be raised and lowered as required by the operator.
In another aspect of the invention a threaded rod of sufficient
size and strength replaces the hydraulic cylinder. The links are
pinned to a trunnion block instead of the head of the hydraulic
cylinder. The block moves up and down the threaded rod as the
rod is rotated by a hydraulic motor.
In another aspect of the invention a combination hydraulic motor
and worm gear rotate the arm directly thus eliminating the need
for the linkage.
The invention as exemplified by a preferred embodiment, is
described with reference to the drawings in which.
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CA 02354112 2001-07-10
Figure 1 is a side view of an embodiment.
Figure 2 is a perspective view of the lifting device
Referring to the drawings, the embodiment of the invention
shown, a lifting device comprises a lifting arm 1 a hydraulic
cylinder 2, An upper link 3 and a lower link 4 and a mounting
frame or base 5. The arm is connected to the mounting frame
using a pin 6 allowing the arm free rotation. The hydraulic
cylinder is concurrent with the arm and is also connected
through pin 6 and is also allowed to rotate however independent
of the arm. One end of the lower link is attached to the
mounting frame using pin 7 while the other end is pinned to the
head of the hydraulic cylinder using pin 8 the upper link is
connected to the hydraulic cylinder through pin 9 while the
other end is pinned to the arm using pin 10. Two of these
structures mounted side by side and connected through a
horizontal member 11 at the ends of the arms, provides a means
to lift materials ( when suspended from the horizontal member)
from one position to another. To further enhance the capability
of this device a winch 12 is mounted on the horizontal member of
the ridged frame. The winch allows the load to be raised and
lowered to allow precise positioning of the load as it is placed
in the back of the mobile platform. A feature of this set-up and
due to the linkage arrangement is it's ability to potentially
rotate 180 degrees. When mounted on the back of a mobile
platform i.e. truck bed. The device has the ability to lift and
transfer material from behind the truck up and onto the truck
bed. And vice versa.
Although only a single embodiment of the present invention has
been described and illustrated, the present invention is not
limited to the features of this embodiment, but includes all
variations and modifications with
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Representative Drawing