US3428977A

US3428977A - Safety latch for a messenger buoy

Info

Publication number: US3428977A
Application number: US664217A
Authority: US
Inventors: Robert Allen Jones
Original assignee: US Department of Navy
Current assignee: US Department of Navy
Priority date: 1967-08-29
Filing date: 1967-08-29
Publication date: 1969-02-25
Anticipated expiration: 1986-02-25

Description

Feb. 25, 1969 R. A. JONES 3,428,977

SAFETY LATCH FOR A MESSENGER BUOY Filed Aug. 29, 1967 mi I INVENTOR ROBERT A. JONES BY 1 H64 United States Patent 4 Claims ABSTRACT OF THE DISCLOSURE A variable buoyancy messenger type buoy for recovering sunken objects. The buoy, being neutrally buoyant, is taken down to the working depth by a diver. A lifting pad is attached to the sunken object. The buoy is then separated from the connector-plug, allowing the buoy to ascend to the surface while paying out a messenger line.

Background of the invention The present invention relates generally to a safety latch for a buoy and more particularly to variable buoyancy messenger type buoys which may be variably ballasted to obtain neutral buoyancy to provide for easy handling by a diver at depth, and to obtain positive buoyancy for ascension to the surface, Variable ballasting may be accomplished by providing the buoy with a container for lead shot and a plug therefor.

Many varieties of such buoys have been suggested, among them being types utilizing a deformable bladder which is normally carried by a diver in a deflated condition and which may be filled with a gas, as from a high pressure cartridge, and released on a messenger line when desired by the diver. These have the obvious disadvantage in that the messenger line must be carried separately from the buoy and the buoy will not support much weight when submerged.

A still further disadvantage of the bladder type of messenger buoy is that the amount of positive buoyancy or lifting capability is inversely proportional to the releasing depth. That is, the greater the depth, the greater the static liquid pressure and the smaller the volume of liquid displaced by the inflated bladder, for a given pressure cartridge. Other varieties of messenger buoys are known which contain a coiled line within the buoy but these generally are not capable of variable buoyancy.

Salvaging of shipwrecks is attended with many problerns, one of which is the attachment of lifting-pads which may be done by either hard-hat or scuba divers. Because fatigue to the diver occurs rapidly at the depths involved, it is imperative to keep the mans work-load as light as possible to prevent undue strain and permit longer work-periods. It is therefore, desirable that tools and other items that he is required to handle be neutrally buoyant. It is necessary, in particular with reference to messenger buoys, to have them neutrally buoyant while being handled around the submerged wreck, etc. by the diver but also to be positively buoyant to permit it to rise to the surface and pay out a messenger line while rising. However, it is imperative that the diver not ascend with the messenger buoy, especially by being accidentally entangled with the buoy. Also, it is important that the buoy be constructed to prevent accidental releasement of the buoy from the lifting pad, to prevent the diver from accidently ascending with the buoy. Such rapid ascension could cause aeroembolism or the bends within the diver, with fatal results. The prior art has not suggested a solution to the above problems.

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Summary The general purpose of this invention is to provide a messenger buoy which overcomes the aforesaid disadvantages of the prior art. To attain this, the present invention contemplates a buoy, which is initially neutrally buoyant in sea water, which may be made positively buoyant by varying the ballast when released at depth, which contains its own messenger line and means for paying out the line during its ascend to the surface of the sea, and which provides a safety latch means attached to the portion of the salvage system that remains upon the bottom of the sea.

Accordingly, an object of the present invention is to provide a messenger buoy capable of being variably ballasted.

Still another object is to provide a messenger buoy that may be variably ba'llasted to provide neutral buoyancy when attached to various loads.

A further object is to provide a messenger buoy that may be rendered either neutrally or positively buoyant.

Yet another object is to provide a messenger buoy that is easily handled by a diver.

Still another object is to provide a safety latch that remain upon the bottom of the sea while the buoy ascends.

Still a further object is to prevent accidental releasement of the buoy.

Other objects and features of the invention will become apparent to those skilled in the art as the disclosure is made in the following detailed description of a preferred embodiment of the invention as illustrated in the accompanying sheet of drawing in which:

FIG. 1 is a perspective view of the messenger buoy and a scuba diver;

FIG. 2 is a perspective View, partly in section, of the messenger buoy;

FIG. 3 is a side elevation view, partly in section, of the safety latch means of FIG. 2; and

FIG. 4 is a side elevation of the buoy core of FIG. 2..

Referring now to the drawing, there is shown in FIG. 1 a messenger buoy and a scuba diver 101. The divers air hose 102 is shown in its natural, buoyant, outwardly extending, state. It is to be understood that while the air hose 102 presents a readily apparent portion of the divers equipment that may become entangled with the buoy 100, other portions of the divers equipment are likewise ensnaringly dangerous to the diver.

The variable buoyancy messenger buoy has been successfully tested at a depth of 200 feet. The buoy is ex pected to exceed a depth of 400 feet. At such depths it becomes readily apparent that the diver must not ascend with the rapidly ascending buoy.

This is shown in FIG. 2 the messenger buoy 100 having a hollow buoyant metal sphere 10 which may be filled with air or, in the case of deep depth or high pressure applications, it may be filled with gasoline or other low specific-gravity liquids.

Attached and sealed to the periphery of the sphere is a compartment portion 11 having a first hollow cone 14 truncated at both the top and the bottom. Attached subjacent the first truncated core is a second truncated hollow cone 16 having a greater taper angle than the first cone. The bottom is open forming a narrow spout 18, the inner surface of which is tapered upwardly and inwardly to form a seat for the tapered section 22 of plug 20.

At the intersection of the first and second truncated cones, there is attached therein a drum or messenger line tub 32 which when ready for use will contain the messenger line 34 attached at 33 to the tub and coiled in such 3 a manner as to readily pay off the line from the center of the coil. Attached subjacent the tub is a third hollow truncated cone or line guide 36. It is to be understood that the bottom of the line guide 36 and the bottom of the second cone 16 are not attached.

The space enclosed by the bottom of the tub 32, the line guide 36, and the-second truncated cone 16 is a chamber 38 which may be filled with steel or lead shot 40 or other particulate material heavier than water.

The connector-plug shown generally at 20 is multipurpose. First, it provides for attachment between the buoy and a lifting pad. The cable 34 is connected to the axial plug section 21, which is connected to the tapered section 22, which is connected to the shaft 23, which is connected to the safety latch support 50, which is connected to the shackle eye 26, which is connected to the lift pendant 28, and which is connected to a lifting pad (not shown). Secondly, the tapered section 22, of the plug 20, effectively seals the spout 18 precluding the release of shot 40 from the shot chamber 38.

The connector-plug 20 is secured to the second truncated cone 16 by a safety-latch 52. The latch 52, as shown in FIGS. 2 and 3, comprises locking pins 53, a spring 54 which is shown biased in FIGS. 2 and 3, and two identical handles 56. The spring 54 requires the diver to simultaneously extend outwardly both handles 56 to release the buoy 100 from connector-plug 20. Each handle 56 comprises a hand-hold 58, a first elongated flat ear 60, a shaft 61 and a second elongated flat ear 62. The ear 62 is attached, such as by welding, after the shaft 61 has passed through the opening 63, since the ear is longitudinally longer than the longitudinal opening 63. It is to be noted that the longitudinal axes, of each

flat ear

60 and 62, are 90 degrees offset relative to each other. This offset necessitates, as will be more fully explained, the diver to pull outwardly on each handle, rotate each handle 90 degrees, and additionally pull outwardly on each handle to release the buoy 100.

The second truncated cone 16 is provided with two directly opposed L-shaped openings 64. The horizontal opening 66, of opening 64, is slightly larger than the ear 62, as shown in FIG. 4, to permit the ear 62 to pass through the opening 66. It is to be understood that both vertical openings 68, of openings 64, are not diametrically opposed to each other but are located to the same side from the diametrical axis of the horizontal openings 66. Also the opening 68 is smaller than the diameter of shaft 61, to prevent the shaft 61 from passing through the opening 68. The spring 54 is biased about shaft 23 so that when the handles 56 are outwardly extended, as shown in FIG. 2, the spring 54 will be biased into the vertical openings 68 and release the cone 16 from the safety latch 52. Thus, in operation, the diver will remove the locking pins 53, pull outwardly on both handles 56, turn each handle 90 degrees and additionally pull outwardly on the handles 56 to move the ear 62 through the opening 66. The spring 54, biased to the openings 68, will then pass through the openings 68 and allow the cone 16 to ascend.

FIG. 1 also shows additional structure to facilitate convenient handling by a diver at depth. The messenger buoy is provided with at least two handles 72 attached to the buoy by any well known means as by welding or riveting. Attached at the top of the spherical float portion is an eye 12 which may be used by the surface salvage ship for engaging by a boat-hook and subsequent attachment of a lifting rig. Additionally, at the side of the second truncated cone there is a screw plut 74 that permits access to the shot chamber for filling when the connector-plug 20 is in place. The shot ballast may be varied to obtain neutral buoyancy depending on whether the buoy is to be handled by the diver by itself or attached to a lifting pad.

In operation, the messenger buoy is prepared for use on board a surface vessel moored on station over a submerged wreck. The sphere 10 normally contains air, but if deep depths are anticipated, the air may be replaced by a non-compressible, low specific-gravity fiuid such as gasoline through a port (not shown). A length of messenger line 34, depending on the depth anticipated, is coiled into the tub with the outer end secured to the tub and the connector end Wound until the connector-plug 20 may be placed in the spout 18 without any slack.

The safety-latch 52 is actuated to retain the connectorplug 26 in the cone 16 and thereby close the spout 18. Now the spout 18 is closed, the plug 74 is removed and lead or steel shot is poured into the chamber 38. Sufficient shot to render the messenger buoy neutrally buoyant is used, and the quantity depends on whether the buoy will be handled by itself or with a lifting pad attached to the pendant 28. The messenger buoy is now ready for deployment. It may be lowered down a previously placed calbe near the wreck or carried down with the diver. Because the messenger buoy is neutrally buoyant, no impediment save inertia and water friction will occur, and the diver may freely move it into place over the wreck to be salvaged using the handles 72 and make the attachment of the lift-pad. The diver may then pull, turn and pull the safety-latch handles 56 and thereby disengage the connector-plug from the cone 16. It is to be noted that the safety latch 52 necessitates that the diver use both hands to release the buoy 100. Also, since the safety latch 52 is located below the main portion of the buoy and since the safety latch remains upon the bottom of the sea, the danger of the ascending buoy ensnaring the diver is eliminated. The shot 40 will spill out the spout 18, thereby rendering the messenger buoy positively buoyant. The buoy will then ascend to the surface while paying out the messenger line 34.

The salvage ship can pick up the buoy by a boat-hook hooked into the eye 12 and hoist it aboard. A female con nector attached to a lifting cable according to the disclosure of US. patent application Ser. No. 483,908 may be slid down the messenger line 34 and automatically grip the connector-plug 20.

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.

What is claimed is:

1. A messenger buoy for carrying a messenger line from a position on a submerged wreck to the surface, comprising:

a buoyant portion;

a messenger line;

a first compartment portion for containing said messenger line attached to the buoyant portion;

a quantity of particulate material heavier than water;

a second compartment portion attached to the buoyant portion for containing said quantity of particulate material;

a connector-plug attached to the submerged wreck and to said messenger line and removably secured to said second compartment for plugging said second compartment to retain said particulate material within said second compartment;

a safety latch, attached to said connector plug, releasably securing said connector plug to said second compartment; and

said safety latch comprising two handles and a biased spring therebetween so that both handles must be simultaneously moved outwardly to release said connector-plug from said second compartment.

2. A messenger buoy for carrying a messenger line from a position on a submerged wreck to the surface, as defined in claim 1, wherein each of said handles comprises:

a hand hold;

a first ear attached to said hand hold;

a second ear; and

a shaft attached to said first and said second ear and extending therebetween. 3. A messenger buoy for carrying a messenger line from a position on a submerged wreck to the surface, as defined in claim 2, wherein said second compartment comprises:

two first openings diametrically opposed; said first openings being larger than said second ears to permit said second ears to pass therethrough; and

two second openings extending from said first openings to the lower edge of said second compartment, to permit said spring to pass through said second opening to release said buoyant portion from said conhector-plug.

defined in claim 3, wherein said connector-plug comprises:

a support; and two support openings located within said support, said support openings being smaller than said second ears to prevent said second ears from passing through said support openings.

References Cited UNITED STATES PATENTS 4. A messenger buoy for carrying a messenger line 15 TRYGVE M. BLIX, Primary Examiner.

from a position on a submerged wreck to the surface, as