U.S. patent number 3,601,342 [Application Number 04/835,049] was granted by the patent office on 1971-08-24 for cargo hoist system for helicopters.
This patent grant is currently assigned to Piasecki Aircraft Corporation. Invention is credited to Frank N. PIASECKI.
United States Patent |
3,601,342 |
PIASECKI |
August 24, 1971 |
CARGO HOIST SYSTEM FOR HELICOPTERS
Abstract
A cargo hoist system for a helicopter including a boom
extensible along its length, operatively connected at one end
thereof to the helicopter, carrier means detachably connectable to
a cargo unit to be hoisted, means disposed on the free end of the
boom detachably connectable to the carrier means, and means for
retracting the extensible boom.
Inventors: |
PIASECKI; Frank N. (N/A,
PA) |
Assignee: |
Corporation; Piasecki Aircraft
(PA)
|
Family
ID: |
25268444 |
Appl.
No.: |
04/835,049 |
Filed: |
June 20, 1969 |
Current U.S.
Class: |
244/137.4;
52/118; 52/121; 74/89.22; 212/230 |
Current CPC
Class: |
B64D
1/22 (20130101); Y10T 74/18848 (20150115) |
Current International
Class: |
B64D
1/22 (20060101); B64D 1/00 (20060101); B64D
009/00 () |
Field of
Search: |
;244/137 ;212/55
;254/143 ;52/118,121 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Buchler; Milton
Assistant Examiner: Weinrieb; Steven W.
Claims
I claim:
1. A cargo hoist system for a helicopter comprising a single boom
extensible along its length, operatively connected at one end
thereof to said helicopter, carrier means detachably connectable to
cargo to be hoisted, means disposed on the free end of said boom
detachably connectable to said carrier means, and means disposed on
said helicopter and extending entirely within said boom for
retracting said extensible boom along its length.
2. A cargo hoist system for a helicopter according to claim 1,
wherein said extensible boom comprises a plurality of telescopic
sections.
3. A cargo hoist system for a helicopter according to claim 1,
wherein said extensible boom comprises a plurality of telescopic
sections and wherein successive sections are provided with
engageable surfaces for preventing rotary displacement of
successive sections about the longitudinal axis of said extensible
boom.
4. A cargo hoist system for a helicopter according to claim 1,
wherein said extensible boom comprises a plurality of telescopic
sections each having a noncircular cross-sectional configuration
and means disposed at the opposite ends thereof for limiting the
longitudinal displacement thereof relative to a successive
telescopic section.
5. A cargo hoist system for a helicopter according to claim 1,
wherein the connection of said extensible boom to said helicopter
is operative to permit pitch and roll motions of said extensible
boom.
6. A cargo hoist system for a helicopter according to claim 1,
wherein said carrier means includes a collapsible hoop and said
means disposed on the free end of said extensible boom comprises a
hook device operatively engageable with said hoop for engaging and
suspending said carrier means on the free end of said extensible
boom.
7. A cargo hoist system for a helicopter according to claim 1,
wherein said means for retracting said extensible boom comprises a
winch including a cable having the free end thereof secured to the
free end of said extensible boom.
8. A cargo hoist system for a helicopter according to claim 1,
including means for pivoting said boom in the extended condition
about a pitch axis.
9. A cargo hoist system for a helicopter according to claim 1,
wherein said means for retracting said extensible boom comprises a
winch including a strap having the free end thereof secured to said
means detachably connectable to said carrier means.
10. A cargo hoist system for a helicopter according to claim 1,
wherein said extensible boom comprises a plurality of telescopic
sections each having a noncircular cross-sectional configuration
and means disposed at the opposite ends thereof for limiting the
longitudinal displacement thereof relative to a successive
telescopic section and wherein said means for retracting said
extensible boom comprises a winch disposed adjacent said helicopter
including a multiple-ply lifting strap having the free end thereof
secured to said means detachably connectable to said carrier
means.
11. A cargo hoist system for a helicopter according to claim 1,
wherein said extensible boom comprises a plurality of telescopic
sections each having a noncircular cross-sectional configuration
and means disposed at the opposite ends thereof for limiting the
longitudinal displacement thereof relative to a successive
telescopic section, said connection of said extensible boom to said
helicopter is operative to permit pitch and roll motions of said
extensible boom, said carrier means includes a hoop, said means
disposed on the free end of said extensible boom comprises a hook
device mounted on a telescopic boom section, operatively engageable
with said hoop for engaging and suspending said carrier means on
the free end of said extensible boom, and said means for retracting
said extensible boom comprises a winch disposed adjacent said
helicopter including a multiple-ply lifting strap having the free
end thereof secured to the telescopic boom section at the free end
of said extensible boom, and including means for pivoting said
extensible boom in the extended condition about its pitch axis.
12. A cargo hoist system for a helicopter according to claim 1,
wherein said means for retracting said extensible boom comprises a
winch including a winding drum disposed adjacent the helicopter and
a cable reeved about a first set of sheaves mounted on the free end
of said extensible boom and a second set of sheaves mounted
adjacent said drum, and the free end thereof secured to the free
end of said extensible boom.
13. A cargo hoist system according to claim 1, wherein said carrier
means detachably connectable to cargo to be hoisted, comprises an
elongated frame adapted to be positioned on the cargo to be
hoisted, a hoop adapted to be engaged and connected by said
detachably connectable means disposed on the free end of said boom,
and means for detachably securing said cargo to the underside of
said frame.
14. A cargo hoist system for a helicopter according to claim 13,
wherein said means for securing said cargo to the underside of said
elongated frame comprises a plurality of straps adapted to be
passed under the cargo and drawn taut to positively secure the
cargo to the underside of said elongated frame.
15. A cargo hoist system for a helicopter according to claim 1,
wherein said extensible boom comprises a plurality of telescopic
sections each having a noncircular cross-sectional configuration
and means disposed at the opposite ends thereof for limiting the
longitudinal displacement thereof relative to a successive
telescopic section, and wherein said connection of said extensible
boom to said helicopter includes a mounting bracket mounted on said
helicopter, a mounting frame pivotally connected to said mounting
bracket and a base end telescopic section pivotally connected to
said mounting frame.
16. A cargo hoist system for a helicopter according to claim 13,
wherein said pivotal connection between said mounting frame and
said mounting bracket permits pivotal movement of said boom about a
roll axis and said pivotal connection between the base and
telescopic section of said boom and said mounting frame permits
pivotal movement of said boom about a pitch axis.
17. A cargo hoist system according to claim 16, including means for
dampening any oscillating motion of said extensible boom about at
least one of said axes.
18. A cargo hoist system for a helicopter according to claim 15,
wherein said means for retracting said extensible boom comprises a
winch including a winding drum operatively mounted on said mounting
frame and a cable extending through said telescopic boom sections
and connected at its free end to the telescopic boom section at the
free end of said boom, and means mounted on said mounting frame for
operating said winch.
19. A cargo hoist system according to claim 18, including a first
set of sheaves mounted on said mounting frame and a second set of
sheaves mounted on said telescopic boom section at the free end of
said boom, and wherein said cable is reeved about said sheaves.
20. A cargo hoist system according to claim 15, including a
hydraulic cylinder assembly operatively interconnecting said
helicopter and a base end telescopic section for pivoting said boom
fore and aft about a pitch axis, and remote control means for
operating said hydraulic cylinder assembly.
21. A cargo hoist system for a helicopter according to claim 15,
wherein said connection of said extensible boom to said helicopter
permits pivotal movements of said boom about roll and pitch axes,
and wherein said means for retracting said extensible boom
comprises a winch including a winding drum rotatably mounted on
said mounting frame, having an axis of rotation disposed parallel
to said pitch axis, and a multiple ply lifting strap extending
through said telescopic boom sections and connected at its free end
to the telescopic boom sections at the free end of said boom, and
means mounted on said mounting frame for operating said winch
including remote control means.
22. A cargo hoist system according to claim 17, including a first
set of sheaves rotatably mounted on said mounting frame, having
axes disposed parallel to the axis of rotation of said winding
drum, and a second set of sheaves rotatably mounted on said
telescopic boom section at the free end of said boom, and wherein
said strap is reeved about said sheaves.
23. A cargo hoist system according to claim 15, wherein said
extensible boom comprises a plurality of telescopic sections each
having a noncircular cross-sectional configuration and means
disposed at the opposite ends thereof for limiting the longitudinal
displacement thereof relative to a successive telescopic section,
and wherein said connection of said extensible boom to said
helicopter includes a bracket mounted on said helicopter, a
mounting frame pivotally connected to said mounting bracket to
permit movement of said extensible boom about a roll axis, said
mounting frame having a pair of downwardly extending arm sections,
a base end telescopic section pivotally connected to the arm
sections of said mounting frame to permit pivotal movement of said
extensible boom about a pitch axis, and wherein said means for
retracting said extensible boom comprises a winch including a
winding drum rotatably connected to said frame member between said
arm sections, having an axis of rotation disposed parallel with
said pitch axis, and a multiple-ply lifting strap extending through
said telescopic boom sections and connected at its free end to the
telescopic boom section at the free end of said boom, and means
mounted on said mounting frame for operating said winch having
remote control means.
24. A cargo hoist system according to claim 18, including a
hydraulic cylinder assembly operatively interconnecting said
helicopter and said base end telescopic section for pivoting said
boom fore and aft about said pitch axis, and remote control means
for operating said hydraulic cylinder assembly.
25. A cargo hoist system according to claim 23, including a first
set of sheaves rotatably mounted on said mounting frame between
said arm sections, having the axes thereof disposed parallel to the
axis of rotation of said winding drum, and a second set of sheaves
mounted on said telescopic boom section at the free end of said
boom, having the axes thereof disposed parallel to the axis of
rotation of said winding drum, and wherein said strap is reeved
about said sheaves.
26. A cargo hoist system for a helicopter comprising a boom
extensible along its length, operatively connected at one end
thereof to said helicopter, carrier means detachably connectable to
cargo to be hoisted, means disposed on the free end of said boom
detachably connectable to said carrier means, and means for
retracting said extensible boom, said extensible boom comprising a
plurality of telescopic sections each having a noncircular
cross-sectional configuration and means disposed at the opposite
ends thereof for limiting the longitudinal displacement thereof
relative to a successive telescopic section and said means for
retracting said extensible boom comprising a winch disposed
adjacent said helicopter including a multiple-ply lifting strap
having free end thereof secured to said means detachably
connectable to said carrier means.
27. A cargo hoist system for a helicopter comprising a boom
extensible along its length, operatively connected at one end
thereof to said helicopter, carrier means detachably connectable to
cargo to be hoisted, means disposed on the free end of said boom
detachably connectable to said carrier means, means for retracting
said extensible boom, aid extensible boom comprising a plurality of
telescopic sections each having a noncircular cross-sectional
configuration and means disposed at the opposite ends thereof for
limiting the longitudinal displacement thereof relative to a
successive telescopic section, said connection of said extensible
boom to said helicopter being operative to permit pitch and roll
motions of said extensible boom, said carrier means including a
hoop, said means disposed on the free end of said extensible boom
comprising a hook device mounted on a telescopic boom section,
operatively engageable with said hoop for engaging and suspending
said carrier means on the free end of said extensible boom, and
said means for retracting said extensible boom comprising a winch
disposed adjacent said helicopter including a multiple-ply lifting
strap having the free end thereof secured to the telescopic boom
section at the free end of said extensible boom, and means for
pivoting said extensible boom in the extended condition about its
pitch axis.
28. A cargo hoist system for a helicopter comprising a boom
extensible along its length, operatively connected at one end
thereof to said helicopter, carrier means detachably connectable to
cargo to be hoisted, means disposed on the free end of said boom
detachably connectable to said carrier means, and means for
retracting said extensible boom, said means for retracting said
extensible boom comprising a winch including a winding drum
disposed adjacent the helicopter and a cable reeved about a first
set of sheaves mounted on the free end of said extensible boom and
a second set of sheaves mounted adjacent said drum, and the free
end thereof secured to the free end of said extensible boom.
29. A cargo hoist system for a helicopter comprising a boom
extensible along its length, operatively connected at one end
thereof to said helicopter, carrier means detachably connectable to
cargo to be hoisted, means disposed on the free end of said boom
detachably connectable to said carrier means, and means for
retracting said extensible boom, said extensible boom comprising a
plurality of telescopic sections each having a noncircular
cross-sectional configuration and means disposed at the opposite
ends thereof for limiting the longitudinal displacement thereof
relative to a successive telescopic section, said connection of
said extensible boom to said helicopter boom sections and connected
at its free end to the telescopic boom section at the free end of
said boom, and means mounted on said mounting frame for operating
said winch including remote control means.
30. A cargo hoist system according to claim 29, including a first
set of sheaves mounted on said mounting frame and a second set of
sheaves mounted on said telescopic boom section at the free end of
said boom, and wherein said cable is reeved about said sheaves.
31. A cargo hoist system for a helicopter comprising a boom
extensible along its length, operatively connected at one end
thereof to said helicopter, carrier means detachably connectable to
cargo to be hoisted, means disposed on the free end of said boom
detachably connectable to said carrier means, and means for
retracting said extensible boom, said extensible boom comprising a
plurality of telescopic sections each having a noncircular
cross-sectional configuration and means disposed at the opposite
ends thereof for limiting the longitudinal displacement thereof
relative to a successive telescopic section, said connection of
said extensible boom to said helicopter including a mounting
bracket mounted on said helicopter, a mounting frame pivotally
connected to said mounting bracket and a base end telescopic
section pivotally connected to said mounting frame, said connection
of said extensible boom to said helicopter permits pivotal
movements of said boom about roll and pitch axes, and said means
for retracting said extensible boom comprising a winch including a
winding drum rotatably mounted on said mounting frame, having a
axis of rotation disposed parallel to said pitch axis, and a
multiple ply lifting strap extending through said telescopic boom
sections and connected at its free end to the telescopic boom
section at the free end of said boom, and means mounted on said
mounting frame for operating said winch including remote control
means.
32. A cargo hoist system according to claim 31, including a first
set of sheaves rotatably mounted on said mounting frame, have axes
disposed parallel to the axis of rotation of said winding drum, and
a second set of sheaves rotatably mounted on said telescopic boom
section at the free end of said boom, and wherein said strap is
reeved about said sheaves.
33. A cargo hoist system for a helicopter comprising a boom
extensible along its length, operatively connected at one end
thereof to said helicopter, carrier means detachably connectable to
cargo to be hoisted, means disposed on the free end of said boom
detachably connectable to said carrier means, and means for
retracting said extensible boom, said extensible boom comprising a
plurality of telescopic sections each having a noncircular
cross-sectional configuration and means disposed at the opposite
ends thereof for limiting the longitudinal displacement thereof
relative to a successive telescopic section, said connection of
said extensible boom to said helicopter includes a mounting bracket
mounted on said helicopter and a mounting frame pivotally connected
to said mounting bracket, said mounting frame having a pair of
downwardly extending arm sections, a base end telescopic section
pivotally connected to the arm sections of said mounting frame to
permit pivotal movement of said extensible boom about a pitch axis,
and said means for retracting said extensible boom comprising a
winch including a winding drum rotatably connected to said frame
member between said arm sections, having an axis of rotation
disposed parallel with said pitch axis, and a multiple-ply lifting
strap extending through said telescopic boom sections and connected
at its free end to the telescopic boom section at the free end of
said boom, and means mounted on said mounting frame for operating
said winch having remote control means.
34. A cargo hoist system according to claim 33, including a
hydraulic cylinder assembly operatively interconnecting said
helicopter and said base end telescopic section for pivoting said
boom fore and aft said pitch axis, and remote control means for
operating said hydraulic cylinder assembly.
35. A cargo hoist system according to claim 33, including a first
set of sheaves rotatably mounted on said mounting frame between
said arm sections, having the axes thereof disposed parallel to the
axis of rotation of said winding drum, and a second set of sheaves
mounted on said telescopic boom section at the free end of said
boom, having the axes thereof disposed parallel to the axis of
rotation of said winding drum, and wherein said strap is reeved
about said sheaves.
Description
This invention relates to a hoist system and more particularly to a
cargo hoist system for helicopters.
The advent of heavy lift helicopters for transporting cargo in
military and commercial applications has necessitated the
development of a cargo hoist system having the capability of
lifting and lowering various types of bulky loads. It particularly
has become desirable to provide a cargo hoist system which is
effective in rapidly and reliably attaching, lifting and lowering,
and detaching the cargo, while being compatible with the helicopter
in flight.
Various types of hoist system for helicopters have been developed
in the prior art. However, it has been found that such systems are
not entirely satisfactory in performance. Many conventional-type
systems have been found to be undesirable in that they often have
excessive component weights, incompatible configurations, poor
reliability and maintainability, inadequate in flight safety
capabilities and complex controls.
Accordingly, it is the principal object of the present invention to
provide a novel cargo hoist system.
Another object of the present invention is to provide a novel cargo
hoist system adapted for use with helicopters.
A further object of the present invention is to provide a novel
cargo hoist system adapted for use with helicopters either while
landed or hovering.
A still further object of the present invention is to provide a
novel cargo hoist system adapted for use with helicopters and which
is adapted to lift and lower bulky loads.
Another object of the present invention is to provide a novel cargo
hoist system for a helicopter having a minimum weight.
A further object of the invention is to provide an improved cargo
hoist system for a helicopter which is reliable in performance, and
which requires minimum maintenance.
A still further object of the present invention is to provide an
improved cargo hoist system for a helicopter which provides maximum
in-flight safety.
A more specific object of the present invention is to provide a
novel cargo hoist system for a helicopter which permits acceptable
freedom of movement of the cargo in pitch and roll, and which
further provides yaw stabilization.
Another object of the present invention is to provide a novel cargo
hoist system for a helicopter which is effective in minimizing
unsafe oscillations of a suspended load.
A further object of the invention is to provide a novel cargo
hoisting system for a helicopter which is capable of rapid load
acquisition and removal with manual ground assistance while the
helicopter is hovering or landed.
A still further object of the present invention is to provide a
novel cargo-handling system for a helicopter wherein the major
components thereof may be quickly detached and removed from the
helicopter so that the helicopter can function in other modes of
operation.
Another object of the present invention is to provide a novel hoist
assembly for a cargo-hoisting system.
A further object of the present invention is to provide a novel
pallet adapted for use in a cargo hoist system.
A still further object of the present invention is to provide a
novel cargo hoist system for a helicopter which is comparatively
simple in construction, relatively inexpensive to manufacture, and
simple to operate .
Other objects and advantages of the present invention will become
more apparent to those persons having ordinary skill in the art to
which the invention pertains, from the following description taken
in conjunction with the accompanying drawings, wherein:
FIG. 1 illustrates an embodiment of the invention shown in
different sequences of operation;
FIG. 2 is a perspective view of a pallet which constitutes a part
of the embodiment illustrated in FIG. 1;
FIG. 3 is an enlarged end view of the pallet illustrated in FIG. 2,
having portions thereof broken away;
FIG. 4 is an enlarged cross-sectional view taken along line 4--4 in
FIG. 3;
FIG. 5 is a front view of a modified pickup bail or hoop assembly
adapted for use in the pallet illustrated in FIG. 2;
FIG. 6 is an enlarged cross-sectional view taken along line 6--6 in
FIG. 5;
FIG. 7 is an enlarged front view of the upper end of the assembly
illustrated in FIG. 5;
FIG. 8 is an enlarged perspective view of the hoist assembly of the
embodiment illustrated in FIG. 1, having a portion thereof broken
away;
FIG. 9 is an enlarged cross-sectional view taken along line 9--9 in
FIG. 8;
FIG. 10 is a perspective view of a part of the lifting strap
illustrated in FIG. 8, and
FIG. 11 is a perspective view of a modification of the hoist
assembly illustrated in FIG. 8, having a portion thereof broken
away.
Briefly described, the present invention relates to a cargo hoist
system for a helicopter generally including a boom extensible along
its length, operatively connected at one end thereof to the
helicopter, carrier means detachably connected to the cargo to be
hoisted, means disposed on the free end of the boom detachably
connectable to the carrier means, and means for retracting the
extension boom.
Preferably, the extensible boom comprises a plurality of telescopic
sections each having a noncircular cross-sectional configuration
and means disposed at the opposite ends thereof for limiting the
longitudinal displacement thereof relative to successive telescopic
sections. The connection of the extensible boom to the helicopter
is operative to permit pitch and roll motions of the extensible
boom, and the carrier means includes a rigid ball or hoop. In
addition, it is preferred that the means disposed on the free end
of the extensible boom comprises a hook device mounted on a
telescopic boom section, operatively engageable with the hoop of
the carrier means for engaging and suspending the carrier means on
the free end of the extensible boom, and the means for retracting
the extensible boom comprises a winch disposed adjacent the
helicopter, including a multiple-ply strap having the free end
thereof secured to the telescopic boom section at the free end of
the extensible boom.
Referring to FIGS. 1 through 4, and 8 through 9 of the drawings,
there is illustrated an embodiment of the invention. The embodiment
consists of a cargo hoist system for a helicopter, including a
hoist assembly 10 connected to the fuselage of a helicopter 11, and
a pallet 12 on which a cargo unit 13 may be secured, and which is
adapted to be detachably connected to the hoist assembly. As best
illustrated in FIG. 8, the boom assembly 10 includes an extensible
boom 14, a connecting assembly 15 for connecting the upper end of
the extensible boom to the helicopter 11, a hook device 16 disposed
on the free end of the extensible boom, a winch assembly 17 for
retracting the extensible boom, and an actuating unit 18 for
pivoting the extensible boom in its extended position,
substantially fore and aft about the pitch axis of the boom.
The extensible boom 14 consists of a plurality of telescopic
sections 19, each having a rectangular cross-sectional
configuration. As best illustrated in FIG. 9, each section 19 is
provided with an outwardly projecting peripheral flange 20 and an
inwardly projecting peripheral flange 21 at the upper end thereof,
and an inwardly projecting peripheral flange 22 at the lower end
thereof. The outwardly projecting flange 20 of each section 19 is
engageable with the inwardly projecting flanges 21 and 22 of a
successive section 19 to limit the displacement of each section 19
relative to a successive similar section. It will be appreciated
that when the extensible boom is in its maximum extended position,
each section will be supported upon an upper successive section by
means of the flange 20 thereof engaging and resting on the flange
22 of the upper successive section. Also, when the extensible boom
is in its maximum retracted position, the outwardly projecting
flange 20 of a section 19 will engage the inwardly projecting
flange 21 of an upper successive section to limit the upward travel
of each section 19 and position the plurality of sections in nested
relation.
The lowermost telescopic section 19a is formed integral with a
shank portion 16a of the hook device 16. The device 16 may be of
any suitable construction which is cooperable with the pallet 12 to
rapidly attach or detach the pallet 12 on or off the free end of
the extensible boom 14. Preferably, the hook device is of the type
as disclosed in U.S. Pat. No. 3,039,746, issued June 19, 1962. The
uppermost telescopic section 19b is provided with a pair of
upstanding brackets 23 and 24 for pivotally connecting the upper
end of the extensible boom to the connecting assembly 15.
The connecting assembly 15 includes a base member 25 rigidly
mounted to the fuselage of the helicopter 11, and a mounting frame
26 interconnecting the base member 25 and the upper end of the
extensible boom 14 and supporting the winch assembly 17. The base
member 25 is provided with a pair of depending brackets 27 and 28
having a longitudinally disposed pivot pin 29 on which the upper
end of the mounting frame 26 is pivotally connected. The mounting
frame 26 includes a base section 30 pivotally mounted on pivot pin
29, and a pair of transversely spaced depending arms 31 and 32. The
lower ends of the arm members 31 and 32 are provided with aligned,
transversely disposed pivot pins 33 and 34 which pivotally
interconnect the lower ends of depending arms 31 and 32 on the
mounting frame and the upper ends of brackets 23 and 24 of
telescopic section 19b. It will be appreciated that the pivotal
connection between the mounting frame 26 and the base member 25,
and the pivotal connection between the telescopic section 19b and
the mounting frame 26 permits the extensible boom to freely roll
and pitch. The connecting assembly 15 may be provided with suitable
devices for damping any oscillating motion of the extensible boom
about its roll and pitch axes.
The movement of the extensible boom in substantially a fore-and-aft
direction is controlled by the actuating unit 18 consisting of a
fluid cylinder assembly operatively interconnecting the fuselage of
the helicopter and the upper end of the extensible boom. As
illustrated in FIG. 8, the fluid cylinder assembly is provided with
a cylinder 35 having the forward end thereof pivotally connected to
a bracket 36 rigidly mounted on the fuselage of the helicopter, and
a piston 37 having the rear end thereof pivotally connected to a
bracket 38 rigidly mounted on the uppermost telescopic section 19b.
The actuating unit 18 is positioned to move the boom to the right
as well as forward, for a purpose hereinafter explained.
The winch assembly 17 consists of a winding drum 39, a lifting
strap 40, a gear reduction unit 41, and a fluid motor 42. The
winding drum 39 is disposed within the mounting frame 26 and is
rotatably supported on a shaft 43 mounted in the depending arms 31
and 32. The lifting strap 40 extends through the interior of the
extensible boom 19, having the lower end thereof secured to the
lowermost telescopic section 19a and the upper end thereof
operatively connected to the winding drum 39 to permit the strap to
be wound on the winding drum as the drum is rotated. The drum is
driven by means of the fluid motor 42 mounted on the mounting frame
26. Drive is transmitted from the fluid motor 42, through the gear
reduction unit 41, to a pair of gears 43 and 44 mounted on the ends
of the drum. The fluid motor 42 also is provided with suitable
fluid supply lines 45 and 46 connected to a source of fluid under
pressure on the helicopter, and is controlled by a suitable control
system aboard the helicopter.
Although the cross-sectional configuration of each of the
telescopic sections 19 is illustrated as rectangular in the
drawings, it is to be understood that any configuration which will
prevent rotary displacement between successive telescopic sections
may be employed. Practically any noncircular cross-sectional
configuration can be employed, although it is preferred that the
configuration be streamlined so as not to appreciably affect the
operation of the helicopter in flight. The telescopic sections 19
can also be constructed of any lightweight material having
sufficient strength characteristics, and being capable of assuming
the torsional load applied on the boom by the cargo carried by the
boom. It further is contemplated that the telescopic boom sections
may be constructed of a low-density fiber glass material.
As illustrated in FIG. 10, the lifting strap 40 consists of a
plurality of plies 40a, preferably secured together by a resilient
bonding material 40b. This construction of the lifting strap
provides sufficient strength to permit lifting of heavy loads and
facilitates the winding and unwinding of the strap on the drum 39.
The multiple-ply construction provides a small bending radius and
will wrap upon itself while under load without any wear results or
fatigue. Normal wear of the lifting strap in a torsional direction
is eliminated as a result of the torsional load on the system being
taken by the telescopic sections of the boom.
An appropriate control system is provided in the helicopter for the
winch assembly 17 and the actuating unit 18 to lift and lower the
extensible boom, and to pitch it forward and aft. In addition, the
control system is adapted to control the hook device 16 to pick up
and release the pallet 12.
Referring to FIG. 2, the pallet 12 includes an elongated frame
assembly 47 and a bail or hoop assembly 48. The frame assembly
consists of a pair of triangularly arranged end members 49 and 50
having the upper apices thereof interconnected by extruded beam 51
and corresponding lower apices interconnected by extruded beams 52
and 53. The frame further is provided with a plurality of cross
braces 54. The beam 51 is provided on its upper end with a T-shaped
groove 55 which extends the entire length of the beam. The lower
beam 52 is provided with T-shaped slots 56 and 57 along the side
and bottom portions thereof, which are similar in cross-sectional
configuration to the slot 55. Similarly, the beam 53 is provided
with T-shaped slots 58 and 59 on the side and bottom portions
thereof. The bail unit 48 is provided with a transverse beam 60
having a pair of upstanding brackets 61 and 62 mounted on the ends
thereof. The lower ends of an inverted V-shaped hoop 63 are
pivotally connected on the upper ends of the brackets 61 and 62, by
means of a pair of pivot bolts 64 and 65, so that the hoop can be
positioned in the vertical position as illustrated by the solid
lines in FIG. 2, or pivoted downwardly to a stowage position, as
illustrated by the phantom lines.
The transverse beam 60 is secured to the beam 51 of the frame
assembly by means of a bolt 66 extending through vertically aligned
openings in the transverse beam and threaded into a threaded
opening in a slide key 67 disposed in slot 55, as best illustrated
in FIG. 4. It will be seen that the transverse beam 60 may be
positioned anywhere along the beam 51 by loosening the bolt 66,
sliding the transverse beam to the desired location along the beam
51, and tightening the bolt 66. The transverse beam 60 further is
rigidly secured to the frame assembly by means of pairs of straps
68a and 69a. The pairs of straps are provided with fittings 70 and
71 and have the upper ends thereof secured to lugs depending from
the end portions of the transverse beam 60. The lower ends of the
straps are connected to slide keys 68b and 69b which are mounted in
slots 57 and 59. The strap fittings are used to draw the straps 68a
and 69a taut to firmly secure the transverse beam 60 in position on
the frame assembly. The hoop 63 further is provided with a pin 72
secured to a chain, which is adapted to be inserted through
registerable openings in the end portion 63a of the hoop and the
bracket 62 when the hoop is in the upright position to lock the
hoop in such position. The frame assembly further is provided with
a plurality of straps 73 which are adapted to pass under the cargo
unit and be connected together to firmly secure the cargo to the
underside of the frame assembly. The upper ends of the securing
straps are connected to slide keys 74 which are disposed in the
slots 56 and 58. The slide elements 74 may be positioned anywhere
along the slots 56 and 58 to accommodate cargo units of different
lengths. The frame assembly also is provided with a plurality of
cushion pads 68c which are slidably mounted in key slots 57 and 59,
and which are adapted to be positioned along the lengths thereof to
engage the cargo unit when the cargo unit is secured to the
pallet.
In the use of the cargo hoist system as described, the cargo unit
13 is secured to the pallet 12, as illustrated in FIG. 1. This may
be accomplished by first positioning the hoop assembly 48 on the
frame assembly 47, securing the hoop assembly in position by
tightening the bolt 66 and adjusting the fittings 70 and 71,
placing the hoop 63 in the upright position, and locking the hoop
in position by means of the locking pin 72. The pallet is then
placed on the cargo unit 13 so that the cushion pads engage and
rest on the cargo unit. The securing straps 73 are then passed
under the cargo unit and connected together to firmly secure the
cargo unit to the frame assembly 47. It will be noted that the hoop
assembly 48, the securing straps 73, and the cushion pads 74 may be
positioned along the length of the frame assembly in accordance
with the length of the cargo unit. The pallet and cargo unit then
are ready to be picked up by the hoist assembly 10 on the
helicopter.
To pick up the pallet and attached cargo unit, the pilot of the
helicopter operates the winch assembly to extend the boom to its
maximum extended position. The hook device 16 of the boom is then
positioned near ground level on the right side of the helicopter at
a lateral distance approximately equal to the main landing gear
width, and forwardly at approximately the front end of the
helicopter nose, as illustrated in the first sequence in FIG. 1.
The fluid pressure in cylinder 35 is sufficient to position the
boom in this manner only when it has no cargo attached. The pilot
maneuvers the helicopter so that the hook device is positioned at
the left rear end of the cargo unit and then maneuvers slowly
forwardly and laterally to place the hook through the loop of the
pallet. After the hook is through the loop, the helicopter's
collective pitch is raised slightly and the hook automatically
engages the loop and locks. The pilot then continues to raise the
helicopter with a slight forward motion, thus allowing the boom
holding the pallet to lower automatically below the center of
gravity of the helicopter. This motion is continued until the cargo
unit is off the ground and forward translation is accelerated.
When the cargo unit is positioned below the center of gravity of
the helicopter, as illustrated in the second sequence in FIG. 1,
the winch assembly is operated to lift the cargo unit adjacent the
fuselage of the helicopter, as illustrated in the third sequence in
FIG. 1. The helicopter and the cargo load are then in condition for
normal flight operations. When it is desired to unload the cargo
unit, the pilot may either land the helicopter and remove the cargo
unit, or maneuver the helicopter to a position approximately 150
feet off the ground and hover while operating the winch to extend
the boom. As soon as the cargo unit is positioned on the ground,
the pilot may disengage the hook device and resume his flight
operations. In doing so, the winch assembly is operated to retract
the boom. Ground personnel also may then quickly remove the cargo
unit from the pallet and stow the pallet for future use.
It thus will be appreciated that once the cargo unit is secured to
the pallet, the helicopter pilot may easily and rapidly pick up the
cargo unit, transport it to another location, and easily and
rapidly deposit it on the ground.
It is contemplated that the boom 14 have a length of approximately
150 feet when extended to its maximum extended length. It further
is contemplated that because of the telescopic construction of the
boom, it can be readily retracted to a length as little as 2 feet.
As previously mentioned, both the pitch and roll motions can be
dampened about the boom's pivotal connections with the helicopter
with hydraulic dampeners. Wear on the lifting strap by winding and
unwinding forces in a torsional direction are eliminated by the
torsional load being applied to the boom in lieu of the lifting
strap. In order to maintain a minimum slack in the lifting strap, a
constant tension clutch can be used on the winding drum of the
winch assembly.
FIGS. 5 through 7 illustrate a modification of the pallet 12. The
modification includes a frame assembly 75 which is essentially
similar to the frame assembly 47, and a hoop assembly 76. The hoop
assembly includes a mounting bracket 77 having a pair of spaced
upright sections 78 and 79, secured to a longitudinal beam 80 of
the frame assembly, a connecting member 81 pivotally connected to
the bracket 77, a pair of lower rigid hoop sections 82 and 83, and
a pair of upper rigid hoop sections 84 and 85. The connecting
member 81 is provided with a pair of upright portions 86 and 87, in
which a pair of pivot bolts 88 and 89 are secured, and a depending
arm portion 90 which is pivotally mounted on a pivot pin 91 mounted
in the upright sections 78 and 79 of the bracket 77. The depending
arm portion 90 of the connecting member and the upright sections 78
and 79 are provided with openings which are registerable when the
hoop assembly is disposed vertically, for receiving a locking pin
91a therethrough, as best illustrated in FIG. 5.
The lower ends of the hoop sections 82 and 83 are pivotally mounted
on pivot pins 88 and 89 to permit pivotal movement thereof in a
vertical plane. The lower ends of the hoop sections 82 and 83 are
provided with stop elements 92 and 93 which are adapted to engage
the connecting member 81 to limit the lateral movement of the lower
hoop sections, thus preventing the hoop assembly from totally
collapsing. The lower ends of the upper hoop sections 84 and 85 are
pivotally connected to the upper ends of the hoop sections 82 and
83, and are pivotally connected together at their upper ends. As
best illustrated in FIGS. 5 and 7, the upper ends of the hoop
sections 84 and 85 are curved inwardly as at 84a and 85a, so that
when a hook 16a of the hook-on device engages the underside of
either hoop section 84 or hoop section 85, and moved upwardly to
cause the upper hoop members to move inwardly as illustrated by the
phantom lines in FIG. 5, the upper end of the hoop assembly will
provide a curved engaging portion for the hook, thus preventing any
binding action between the hook and the upper end of the hoop
assembly.
The pallet illustrated in FIGS. 5 through 7 is utilized essentially
in the same manner as the pallet illustrated in FIGS. 2 through 4.
However, when the pallet is being prepared for a pickup operation,
it is necessary for ground personnel to lock the hoop assembly in
the vertical position by means of the locking pin 91, and spread
the lower hoop sections 82 and 83 so that the stop elements 92 and
93 engage the connecting member 81, thus providing a sufficiently
large opening in the assembly to facilitate the insertion of the
hook therewith.
FIG. 11 illustrates another embodiment of the hoist assembly which
consists of an extensible boom 94, an assembly 95 for connecting
the upper end of the extensible boom to the fuselage of the
helicopter, a hook-on device 96 mounted on the free end of the
extensible boom, and a winch assembly 97. The extensible boom 94
comprises a plurality of telescopic sections 98 which are similar
to the telescopic boom sections 19 of the extensible boom 14
illustrated in FIG. 8, except that the telescopic sections 98 are
provided with a streamlined cross-sectional configuration. The
uppermost telescopic section 98a is mounted on an upper mounting
frame 99 which is connected by means of a linking member 100 to a
mounting bracket similar to bracket 25 of hoist assembly 14
illustrated in FIG. 8. The upper frame unit 99 includes a pair of
laterally spaced sidewalls 101 and 102 which are provided with a
pair of upright brackets 101a and 102a. The upper ends of brackets
101a and 102a are pivotally connected to the linking member 100 by
means of a transverse pivot pin 103, while the upper end of the
linking member 100 is provided with an opening for receiving a
longitudinal pivot pin similar to the pivot pin 29 of the hoist
assembly 14 illustrated in FIG. 8. Such pivotal connections permit
the extensible boom 94 to roll and pitch similar to the hoist
assembly 14.
The winch assembly 97 consists of a winding drum 104 journaled in
side members 101 and 102 of the upper mounting frame, a first set
of sheaves 105 and 106 also journaled in the side members 101 and
102 of the upper mounting frame, a second set of sheaves 107 and
108 journaled in a lower mounting frame 109 secured to the
lowermost telescopic section 98b, and a lifting strap 110 having
one end thereof operatively connected to the winding drum 104, the
intermediate portion thereof reeved under sheave 107, over sheave
105, under sheave 108 and over sheave 106, and the other end
thereof secured to the lower mounting frame 109. The winding drum
104 further is provided with a fluid motor 111 which is remotely
operated to drive the winding drum 104 through a gear reduction
train 112. It will be appreciated than upon operation of the fluid
motor 97 to drive the winding drum 104, the lifting strap 110 will
be taken in or played out to extend or retract the extensible boom.
In other respects, the extensible boom 94 is similar in
construction and operation to the extensible boom 14, as
illustrated in FIG. 8. The hook-on device 96 also may be similar to
the hook-on device 16 of the extensible boom 14.
* * * * *