Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This invention relates to a dolly and in particular
to a dolly for a helicopter or similar load.
While the device of the present invention was
designed specifically for moving small helicopters, it will be
appreciated that the dolly can be used to move similar loads
of the type including a body spaced apart from the ground so
that the dolly can be moved beneath the load and then lifted.
A helicopter constitutes an awkward load to move.
In order to move such a load, a dolly or lifting device
should be inserted beneath the load and then elevated to
raise the load. Ideally, the dolly should be lightweight, and
easy to operate and manipulate. Presently available
helicopter dollies require pushing of the helicopter which
cau5e5 undue stress on the airframe.
A search of the patent literature discloses dollies
of generally the type proposed by applicant. Such devices
are described in Canadian Patent No. 149,716, issued to E. M.
Chapman et al on August 5, 1913, and United States Patents
Nos. 2,327,583, issued to H. J. Framhein on August 24, 1943,
and 2,388,864, issued to H. E. Page on November 13, 1945. In
general, the patented devices are somewhat complicated and
consequently expensive to produce. Moreover, the patented
dollies are ill-suited to the lifting or transporting of a
helicopter or similar load.
25 ~ ~n object of the present invention is to solve the
~ problem of helicopter lifting by providing a relatively
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simple dolly for lifting a helicopter or similar load which,
because of its skeletal structure, is lightweight and easy to
produce.
Another object of the present invention is to
provide a dolly which includes a steering mechanism
facilitating manually maneuvering of the device.
Yet another object of the invention is to provide a
dolly which permits lifting of a helicopter at proper lift
points on the skid gear, without placing undue stress on any
part of the helicopter.
Accordingly, the present invention relates to a
dolly for a helicopter or other load comprising skeletal frame
means; front wheel means and rear wheel means supporting said
frame means for movement along the ground; drive means on said
frame means for driving said rear wheel means; skeletal
platform means; arms means pivotally connecting said platform
means to said frame means for movement between a lower, rest
position on the frame means and an elevated, load supporting
position; fluid actuated cylinder means on said frame means
for moving said platform means relative to said frame means;
post means for removable mounting on said platform means for
supporting a load above the platform means; handle means for
manually controlling movement of the dolly; and steering means
connecting said handle means to said front wheel means for
~urning said front wheel means when the handle is turned.
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The invention will be described in greater detail
with reference to the accompanying drawings, which illustrate
a preferred embodiment of the invention, and wherein:
Figure l is a side view of a dolly in accordance
with the present invention in the lower or rest position;
Figure 2 is an isometric view from one side and
above of all but the front end of the dolly of Fig. l in the
partially elevated position;
Figure 3 is an isometric view from above and in the
front of a frame used in the dolly of Figs. 1 and 2;
Figure 4 is an exploded, isometric view from above
and in the front of a platform and posts used in the dolly of
Figs. 1 and 2;
Figure 5 is an isometric view from the rear and one
side of the dolly of Figs. l and 2 in the lower position
beneath a helicopter; and
Figure 6, is an isometric view from the front and
the other side of the dolly of Figs. 1 and 2 in the elevated
or use position beneath a helicopter.
2~ Parts have purposely been omitted from some figures
of the drawings to facilitate clear illustration of the dolly.
With reference to the drawings, the principle
elements of the dolly of the present invention include a frame
generally indicated at l, and a lifting platform generally
indicated at 2. As best shown in Fig. 3 the frame l is
defined by rectangular cross section tubing, and includes
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sides 3, a front crossbar 4 and a rear end 5. Diagonal braces
6, extend between the sides 3 and the rear end 5 of the frame
for reinforcing the latter. A crossbar 8 extends between the
sides 3 of the frame closer to the front crossbar 4 than the
rear end 5. A pair of longitudinally extending bars 9 extend
forwardly from the crossbar 8 beyond crossbar 4 to define the
sides 10 of the end of the frame. The outer ends of the bars
10 are joined by a front bar 11. The front end carries a
hydraulic control valve 12 a gasoline engine 13 a hydraulic
pump 15 and a hydraulic reservoir 16. These elements are
supported on the front end 10 of the frame 1 by plates 16 and
17 (Fig. 3). A clevis 18 is pivotally mounted on a pin 19,
extending through the front bar 11 for carrying an elongated
inclined T-shape tow bar 20. The top transversely extending
end 22 of the tow b~r 20 defines a handle for controlling
movement o the dolly. The tow bar 20 carries a hydraulic
control valve 23 which is opened or closed using a lever or
handl~ 24 to control movement of the dolly.
The front end of the frame is supported by a pair of
wheels 26 mounted on stub axles 27. The axles 27 extend
outwardly from clevises 28, which are pivotally connected to
the outer ends of a transversely extending crossbar 29 mounted
on crossbar 30 at the front end of the frame.
Pins 31 extend through the clevises 28 and the
crossbar 29, so that the axles 27 can be rotated around the
vertical axes of the pins. Rotation of the clevises 28 and
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consequently steering of the dolly is effected using a pair of
levers 32 connected to the top ends of the clevises 28. The
levers 32 and a rod 33 pivotally connected thereto define part
of a linkage, which is connected to the front pin 19 by a bar
35, a pin 36, a pair of sprockets 38 and 39 and a chain 40.
When the tow bar 20 is rotated the pin 19 also rotates to
rotate the sprockets 38 and 39. Thus, the bar 35 is caused to
rotate with the pin 36 to rotate the clevises 28, and
consequently the stub axles 27.
A pair of wheel supporting bars 42 extend
rearwardly from the rear end 5 of the frame 1 for supporting
wheels 44. Diagonal braces 45 extend ~etween the rear end 5
of the frame 1 and the bars 42. Plates 46 on the outer free
ends of the bars 42 support pillow block bearings 47 (one
shown-Fig.l) which carry a rear wheel shaft 48. The shaft 48
iB driven by a hydraulic motor 4g (Fig.2) mounted in a
protective enclosure 50 on the rear end 5 of the frame 1. A
sprocket 52 is mounted on the shaft (not shown) of the motor
49 for rotating a chain 53, which connects the motor 49 to a
transmission 55. The transmission 55 is mounted on a plate 56
extending rearwardly from the frame 50, and incorporates a
gear (not shown) mounted on the shaft 48 for driving the
latter, and consequently the wheels 44.
The lifting platform 2 includes a pair of sides 60,
and front and rear ends 61 and 62, respectively. An expanded
~ met~l panel 64 extends downwardly and rearwardly from a ~ar 65
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near the rear end 6~ of the frame for carrying helicopter
mounting posts, generally indicated at 68 and 69, when the
latter are not in use. It will be noted that the posts 68 and
69 are shown in Fig. 4 on a larger scale than the platform 2.
A crossbar 70 extends between the sides 60 of the platform
2. Diagonal braces 72 extend between the crossbar 7G and the
sides 60 for reinforcing the frame. A clevis defined by a
pair of plates 7~ extends forwardly from the crossbar 70 for
pivotally connecting a piston rod 75 to the platform. The
piston rod 75 extends out of one end of a hydraulic cylinder
76. The other end of the cylinder 76 is pivotally connected
to the front end 4 of the frame 1 by a clevis defined by a
pair of plates 78. The cylinder 76 is used to raise the
platform 2 relative to the frame 1. A pair of arms 80 are
provided near the ~ront and rear of each side of the dolly for
pivotally connecting the platform 2 to the frame sides 3. The
arms 80 are pivotally connected to the frame 1 and the
platform 2 by pins 81 and 82, respectively (Figs. 1 and 2)
which extend through bushings 84 tone shown-Fig. 3) which are
mounted in the sides 3 and 60 of the frame 1 and the platform
2, respectively.
The posts 68 and 69 for supporting a helicopter 85
tFigs. 5 and 6) are mounted in square brackets 86 and 87,
respectively on the sides 60 of the platform 2. The post 68
includes an inverted generally L-shaped body 90. An arcuate
~radle 91 is pivotally connected to the top arm 92 of the body
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90 by a clevis 93 and a pin 95. A hole 96 is provided near
the bottom end of the post 90 for receiving a pin, which
connects the post to the bracket 86. The post 69 includes an
elongated body 98 with a stop 99 near the bottom end thereof
for limiting movement of the post into the bracket 87. A
cradle 100 is pivotally connected to the top end of the body
98 by a clevis 101 and pin 102.
In use, with the posts 68 and 69 absent from the
brackets 86 and 87, respectively and with the platform 2
resting on the frame 1 (Figs. 1 and 5), the frame 1 and the
platform are moved beneath the helicopter 85. Such movement
is effected by starting the engine 13, and the appropriate
movement of the control lever 24 on the valve 23 to operate
the reversible hydraulic motor 49. By starting the engine 13,
oil is caused to flow from the tank 15 to the forward and
reverse control valve 23, and to the lift and lower control
valve 12. When the dolly drive is in use, oil will by-pass
the valve 12 returning to the tank 15. By the same token,
when the control valve 12 is open to control lifting on
lowering of the platform 2, the drive control valve 23 will be
by-passed.
As described hereinbefore, steering of the dolly is
easily effected by rotating the handle 22 and tow bar 20
combination around the axis of the pin 19. Such movement
~ 25 .causes corresponding rotation of the pin 19, the sprocket 39,
~ the sprocket 38, the pin 36, the bar 35, the rod 33, the
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levers 32, and the cl~vises 28 carrying the axles 27 and the
wheels 26. Thus, lateral movement of the handle 20 is
accompanied by corresponding turning movement of the wheels
26.
Once the dolly has been driven beneath the
helicopter, with the bracket 86 and 87 vertically aligned with
the skid gear, the posts 68 and 69 are inserted into the
brackets to support the helicopter. With the movement control
handle in the closed or neutral position, a lever or handle
(not shown) controlling the valve 12 is operated to actuate
the cylinder 76. Thus, the platform 2 and the helicopter 85
are raised to the transport position (Pig. 6) in which the
helicopter landing gear is clear of the ground. The above
described procedure is repeated to move the dolly and
helicopter to another destination.
The preferred embodiment of the invention was
designed for an Aerospeciale-A-Star helicopter. This
particular helicopter has a low skid gear, and accordingly the
height of the dolly is less than 12" when the dolly is in the
lower position. With minor design changes, it would be
possible to adapt the structure to other helicopter.
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