US3893005A

US3893005A - Helicopter hook-up and static electricity grounding device

Info

Publication number: US3893005A
Application number: US483498A
Authority: US
Inventors: Joseph G Corbin
Original assignee: Individual
Current assignee: SKY-HOOK Inc
Priority date: 1974-06-27
Filing date: 1974-06-27
Publication date: 1975-07-01
Anticipated expiration: 1992-07-01

Abstract

A grounded pole for attaching a load-carrying sling to a helicopter comprising: a hollow extension pole made from a nonconducting material; a hook-up head attached to one end of the pole and made from a conducting material, the head including a frame, two U-shaped members mounted on the frame and spaced from each other along a line perpendicular to the pole axis; an arcuate member mounted on the frame midway between and below the U-shaped members and extending upwardly and outwardly from the pole; a grounding cable connectable at one end to a grounding rod and connected at the other end through the lower end of the pole to a metallic plug; and a wire braid extending through the bore of the pole to connect the plug to the hook-up head so as to conduct to ground any static electricity which may be transferred from the helicopter to the hook-up head.

Description

United States Patent Corbin 1 HELICOPTER HOOK-UP AND STATIC ELECTRICITY GROUNDING DEVICE [76] Inventor: Joseph G. Corbin, 5251 Alabama Ave., Camp LeJeune, NC. 28542 [22] Filed: June 27, 1974 [21] Appl. No.: 483,498

July 1, 1975 [57] ABSTRACT A grounded pole for attaching a load-carrying sling to a helicopter comprising: a hollow extension pole made from a nonconducting material; a hook-up head attached to one end of the pole and made from a conducting material, the head including a frame, two U- shaped members mounted on the frame and spaced from each other along a line perpendicular to the pole axis; an arcuate member mounted on the frame midway between and below the U-shaped members and extending upwardly and outwardly from the pole; a grounding cable connectable at one end to a grounding rod and connected at the other end through the lower end of the pole to a metallic plug; and a wire braid extending through the bore of the pole to connect the plug to the hook-up head so as to conduct to ground any static electricity which may be transferred from the helicopter to the hook-up head.

10 Claims, 14 Drawing Figures 1 HELICOPTER HOOK-UP AND STATIC ELECTRICITY GROUNDING DEVICE STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalities thereon or therefor.

BACKGROUND OF THE INVENTION This invention relates to the reduction or elimination of static electric shock in the external loading of helleopters and especially to a hand-held grounded pole device for externally loading a hovering helicopter.

In flight, a helicopter generates and stores a charge of static electricity. Since the advent of helicopter ex' ternal loading operations, helicopter support team personnel have been subjected to severe shock from this static electricity and the danger of being crushed between the aircraft and the external load during the hook-up phase of the cargo handling operation. Various wands. shepherd crooks and other devices have been utilized in an attempt to eliminate these hazards but none have been completely satisfactory.

The method currently in use by the Armed Forces for external helicopter loading requires the ground personnel to make the hook-up to the helicopter by hand. in this maneuver, the becket end of the sling is hooked to the aircraft lifting hook by a man who stands astride the proposed load under the hovering helicopter. This subjects the man to a severe. static electric shock and the danger of being crushed between the aircraft and the external load.

Shipboard loading is even more dangerous since the loader must contend not only with the aircrafts vertical and horizontal movements but also with the movement of the ship. This, coupled with the static electric shock, makes the hand hookup method of loading even more hazardous. Thus, a definite need exists for a device which eliminates or reduces the danger of electric shock.

SUMMARY OF THE INVENTION The invention comprises a pole-like device having means for holding a donut to which the becket ends of a load-carrying sling are attached. The donut can be raised by the pole-like device and placed over a hook carried on the bottom of a hovering helicopter. The device includes means for grounding the static electricity charge of the helicopter without allowing the man holding the device to be shocked.

OBJECTS OF THE INVENTION An object of this invention is to eliminate the danger of static electric shock to a man who is externally loading a hovering helicopter.

Another object is to provide a safe, rapid method of hooking-up external loads to a hovering helicopter.

Another object is to provide a man who is externally loading a hovering helicopter with a safe distance between the aircraft and the load.

A further object is to permit a man who is loading a hovering helicopter to do so from the ground plane rather than from the top of the load itself.

Other objects, advantages. and novel features of the present invention will become apparent from the following detailed description of the invention when con- 2 sidered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES FIG. I is a front view, partially broken away, of an embodiment of the invention.

FIG. 2 is a side view, partially broken away, of the same embodiment.

FIGS. 3A. 3B, and 3C are a front. side and rear view. respectively. of the hook-up head.

FIG. 4A is a front view of a grip.

FIG. 4B is a side view of the outer side of a grip.

FIG. 4C is a front view of the back of a grip.

FIG. 4D is a side view of the inner side of a grip.

FIG. 5 is a view of the bottom ofthe pole showing the slot cut through the pole to expose the side hold in the bottom plug.

FIG. 6 is a view of the bottom plug.

FIG. 7 is a cut-away view through the pole.

FIG. 8 is a view of the bottom ofthe pole showing the sleeve, shields and clamps.

FIG. 9 is a perspective view of a man using the invention.

DETAILED DESCRIPTION OF THE INVENTION A grounding/sling attacher device made according to the present invention is shown in FIG. I. In this front view, a hook-up head 10 is attached at the upper end of a pole 12. An electrical cable 14 is attached at one end to a clamp 16 which is attached to a metallic grounding rod 18, for example, a brass rod. which is inserted in the ground 20. At its other end. the cables center conductor is attached to a plug in the pole I2. as will be described later.

The pole 20 is typically about 5 feet 3 inches long. with a l-inch ID. and is a hollow tube, preferably of fiberglass, although any structurally strong, rigid, nonconductive material could be used.

The hook-up head I0 is shown in front view in FIG. I and in side view in FIG. 2. However, the details of its construction are best seen in FIGS. 3A, B and C. In the front view, FIG. 3A. it can be seen that the head 10 comprises an inverted triangular frame 22 having U-

shaped grips

24 and 24 attached at the ends of the base 26 of the triangular frame. The sides of the triangular frame 22 are attached at the apex of the triangle to a metallic plug 28 of cylindrical shape. The upper end of the plug 28 is narrowed to receive the ends of the sides of the frame 22 and is slotted to receive one end of an arcuate member 30. The plug 28 may be formed from a l-inch diameter piece of aluminum round stock knurled along its entire length which is about 6 inches. It has a threaded hole 32 at its lower end which is drilled and tapped for a V4 X 1 inch machine screw.

The frame 22 also includes a pair of upstanding members 34 and 34' which are substantially rectangular when viewed from the side (FIG. 3C). These members are placed in the middle of and support the U-shaped grips 34 and 34'.

The dimensions of the hook-up head are typically as follows:

plug height, 6 inches;

distance from bottom of plug to uppermost tip of arcuate member. 8-V2 inches;

distance from bottom of plug to top of grips, 14-5/16 inches;

distance from bottom of plug to bottom of grips. 10-5/16 inches.

distance between inner sides of grips. 4%: inches;

distance between inner sides of upstanding frame members. 5- /8 inches.

The hookup grips and the frame are constructed from i i-inch aluminum plate. The triangular frame members are 1-inch wide. The edges of the side mem bers are leveled and smoothed.

All parts of the hook-up head It) are securely attached in the configuration shown. preferably by welding. The plug 28 is then inserted in the upper end of the pole l2 and securely attached thereto. as by cementing with epoxy. for instance.

Another 6 inch metallic plug 42 (FIG. 6) is inserted at the bottom end of the pole [2. This plug is a straight cylinder without any narrowed segment. It has a threaded hole 44 at the top and a threaded hole 46 in its side about Vs of the way down from the top. It. also. is knurled on the outer surface.

A metallic braid 42 with lugs on each end is fastened to the top and bottom plugs 28 and 42, respectively. by putting screws through the end lugs and screwing the screws into the holes in the plugs. The plugs are then cemented into place in the tube. preferably with epoxy resin (see FIG. 7).

A slot 52 is cut through the pole 12 in such a way as to expose the hole 46 in the side of the bottom plug 42 (see FIG. 5). The other end of the cable I4 is placed in the slot 52 and fastened down so that the cable con ductor makes electrical contact with the side of the plug 42. This can be done for example. by soldering a lug to the end of the cables inner conductor and screwing the lug down over the hole 46.

A rubber sleeve 50 is now placed over the pole about two or three inches up from the bottom. The sleeve 50 cover the cable. the cable connection to the plug and the slot 52 in the pole 12 (see FIG. 8).

A pair of substantially

semicircular shield members

54 and 54'. cut from a piece of the fiberglass pole. are placed around the rubber sleeve 50 so that one covers the slot 46 and cable emerging from the slot. The shield members are then kept in place by any suitable means. such as water hose clamps 56 and 56' of the type used to hold radiator hoses in automobiles.

The pair of

shield members

54 and 54 may be a single shield member if a piece of tubular fiberglass with a slightly larger diameter than that used for the pole I2 is available.

A protecting cap 58. preferably of rubber. is placed over the bottom end of the pole [2.

It is obvious. of course. that there are other ways to construct the grounding and attachment device within the spirit of the invention. For example. the cable could enter the bottom of the pole and the center cable could be attached to the bottom plug by a machine screw. the plug having a threaded hole in extending upward from its bottom surface.

Coming now to the way in which the grounding sling attacher is used. the Marine Corps. for example. in attaching loads. such as a crate 60, to the carrying hook 62 beneath a helicopter 64, usually utilizes a netlike sling 66. The load is placed in the sling 66 and the sling straps are formed into four clusters. for example. which are looped around what is known as a donut 68. (The donut 68 is simply a lifting ring formed from a circle of loops of a single strap held together by one or more fasteners.)

When the sling straps are coupled to the donut 68. the donut is placed in the grips 24 and 24', one side of 5 the donut in each grip. The bottom of the donut is placed between the frame of the hookup head and the arcuate member 30 so that it is held in by the latter.

The man 70 who is doing the loading now lifts the hook-up head by means of the pole with the rear of the hook-up head towards him and. as the helicopter. hov' crs above him. slips the donut over the helicopters car rying hook 62. He then pulls the head backwards. releasing the donut from the head. The donut stays on the hook 62 and the copter is ready to rise with the load as soon as the man steps back out of the way.

If the copter is carrying a charge of static electricity. a discharge will take place from the copter to the hookup head. The electricity will then be grounded through the following path: hook-up; top plug; wire braid inside the pole; bottom plug; cable; clamp; grounding rod. The man 70 is protected from the static-electricity discharge since he is holding the non-conducting pole and has no contact with any of the metallic parts.

The dimensions given herein are typical. but approximate.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that. within the scope of the appended claims. the invention may be practiced otherwise than as specifically described.

What is claimed is: l. Grounded pole means for attaching a donut to an elevated hook. said donut having straps from a loadcarrying sling coupled to it. comprising, in combination:

a hollow pole made from electrically non-conductive material and having top and bottom ends;

hook-up means attached to the pole at its top end for holding said donut and placing it on said helicopter hook. said hook-up means being made from electrically conductive material; grounding means. attached to the pole at its bottom end, for grounding electrical discharges. and

electrical connection means forming a conductive path between said hook-up means and said grounding means. r

2. Grounded pole means as in claim I, wherein said hook-up means is made from aluminum and said pole is made from fiberglass.

3. Grounded pole means as in claim I, wherein said hook-up means comprises:

frame means;

a pair of spaced U-shaped grips attached at the top of the frame means; and

an arcuate member attached to the frame means near the pole. said arcuate member extending outwardly from the axis of the pole and upwardly toward the grips in the shape of a hook.

4. Grounded pole means as in claim 1, wherein said hook-up means comprises:

frame means substantially triangular in shape. the

base of the triangle being above the top end of the pole and the sides of the triangle extending downwards for attachment at the pole end;

a pair of U-shaped grips. a different one attached at each end of the base of the frame means; and

an arcuate member attached to the frame means near the pole end, said arcuate member extending outwardly from the axis of the pole and upwardly toward the grips in the shape of a hook.

5. Grounded pole means as in claim 1, wherein said grounding means includes a conductive cable attached at one end to the bottom end of said grounded pole means, a clamp attached to the other end of said conductive cable, and a grounding rod for penetrating the earth. the clamp being attachable to the grounding rod.

6. Grounded pole means as in claim 4, wherein said frame means includes a first plug which fits into the top end of said pole, the apical ends of said triangular frame means and the lower end of said arcuate member being attached to the plug at the end of the plug nearest the top end of the pole.

7. Grounded pole means as in claim 6, wherein said 6 pole is tubular and said plug is cylindrical in shape 8. Grounded pole means as in claim 6, further including a second conductive plug and a length of conduc tive material. said second plug fitting into the bottom end of said pole, the conductive cable being attached to said plug and the length of conductive material is attached internally of said pole between said first and second plugs 9. Grounded pole means as in claim 6. wherein said frame means. said grips, said arcuate member and said plugs are fabricated from aluminum and said pole from fiberglass.

l0. Grounded pole means as in claim 9. wherein all attachments on said hook-up means are made by weld-

Claims

1. Grounded pole means for attaching a donut to an elevated hook, said donut having straps from a load-carrying sling coupled to it, comprising, in combination: a hollow pole made from electrically non-conductive material and having top and bottom ends; hook-up means attached to the pole at its top end for holding said donut and placing it on said helicopter hook, said hook-up means being made from electrically conductive material; grounding means, attached to the pole at its bottom end, for grounding electrical discharges; and electrical connection means forming a conductive path between said hook-up means and said grounding means.

2. Grounded pole means as in claim 1, wherein said hook-up means is made from aluminum and said pole is made from fiberglass.

3. Grounded pole means as in claim 1, wherein said hook-up means comprises: frame means; a pair of spaced U-shaped grips attached at the top of the frame means; and an arcuate member attached to the frame means near the pole, said arcuate member extending outwardly from the axis of the pole and upwardly toward the grips in the shape of a hook.

4. Grounded pole means as in claim 1, wherein said hook-up means comprises: frame means substantially triangular in shape, the base of the triangle being above the top end of the pole and the sides of the triangle extending downwards for attachment at the pole end; a pair of U-shaped grips, a different one attached at each end of the base of the frame means; and an arcuate member attached to the frame means near the pole end, said arcuate member extending outwardly from the axis of the pole and upwardly toward the grips in the shape of a hook.

5. Grounded pole means as in claim 1, wherein said grounding means includes a conductive cable attached at one end to the bottom end of said grounded pole means, a clamp attached to the other end of said conductive cable, and a grounding rod for penetrating the earth, the clamp being attachable to the grounding rod.

7. Grounded pole means as in claim 6, wherein said pole is tubular and said plug is cylindrical in shape.

8. Grounded pole means as in claim 6, further including a second conductive plug and a length of conductive material, said second plug fitting into the bottom end of said pole, the conductive cable being attached to said plug and the length of conductive material is attached internally of said pole between said first and second plugs.

9. Grounded pole means as in claim 6, wherein said frame means, said grips, said arcuate member and said plugs are fabricated from aluminum and said pole from fiberglass.

10. Grounded pole means as in claim 9, wherein all attachments on said hook-up means are made by welding.