U.S. patent number 3,755,836 [Application Number 05/075,964] was granted by the patent office on 1973-09-04 for stabilization arrangement for communication buoys.
Invention is credited to Frank M. Milazzo.
United States Patent |
3,755,836 |
Milazzo |
September 4, 1973 |
STABILIZATION ARRANGEMENT FOR COMMUNICATION BUOYS
Abstract
In association with a communications buoy of the type launched
from a submerged vessel, an automatically deployable surface
stabilization arrangement for preventing inundation of the buoy
even under severe environmental conditions. A collar of continuous
and flexible material such as mylar film is arranged around the
buoy proximate to the water line, and is attached to the buoy via
the top portion thereof in a substantially leak-proof manner with
the bottom portion open in a conical or umbrella-like fashion. The
collar is rapidly deployed by a series of spring-loaded or bowed
arms fabricated of a resilient material and spaced from one another
around the buoy. Release of the force constraining the arms against
the buoy, such as occurs upon launch of the buoy from the submerged
vessel, permits the collar to automatically deploy, thus forming
around the buoy at the water line a pocket to trap air. The collar
may be compartmentalized to better maintain the air pocket and
insure stability. A plurality of spring-loaded fins may also be
provided on a submerged portion of the buoy remote from the collar
to provide broad surfaces for further damping of the forces acting
on the buoy.
Inventors: |
Milazzo; Frank M. (Wayne,
NJ) |
Family
ID: |
22129047 |
Appl.
No.: |
05/075,964 |
Filed: |
September 28, 1970 |
Current U.S.
Class: |
441/22; 367/4;
114/311 |
Current CPC
Class: |
B63B
22/20 (20130101) |
Current International
Class: |
B63B
22/00 (20060101); B63B 22/20 (20060101); B63b
021/48 (); B63b 021/52 () |
Field of
Search: |
;9/8R ;114/209 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Borchelt; Benjamin A.
Assistant Examiner: Hanley; James M.
Claims
What is claimed is:
1. A stabilization arrangement for a floatable body comprising a
collar composed of a continuous and flexible material arranged via
the top portion thereof around the body in a substantially
leak-proof manner, with the bottom portion open to the atmosphere
substantially at the water line to permit deployment in an
umbrella-like fashion to form in cooperation with the body a pocket
for trapping air.
2. The arrangement according to claim 1 further including a
plurality of arms coupled to said collar and the body for aiding in
deployment of said collar.
3. The arrangement according to claim 2 wherein said arms are
spaced from one another around the body and coupled thereto
proximate said top portion of said collar.
4. The arrangement according to claim 2 wherein said arms are
spaced from one another around the body and coupled thereto remote
from said top portion of said collar.
5. The arrangement according to claim 2 wherein said arms are
arranged on the underside of said collar.
6. The arrangement according to claim 2 wherein said arms are
arranged on the outer surface of said collar.
7. The arrangement according to claim 2 wherein said arms are
fabricated of a resilient material having a curved
cross-section.
8. The arrangement according to claim 2 wherein said arms are in a
spring-loaded position when said collar is undeployed.
9. The arrangement according to claim 8 wherein said arms in said
spring-loaded position are arranged substantially adjacent to the
surface of the body.
10. The arrangement according to claim 1 further including
plurality of dividers composed of a flexible and continuous
material coupled to said collar and to the body to compartmentalize
the pocket formed by said collar.
11. The arrangement according to claim 10 wherein said dividers are
homogeneous with said collar.
12. A stabilization arrangement for a communications buoy such as
is launched from a submerged vessel comprising a body portion of
said buoy which is located proximate to the water line and a collar
composed of a continuous and flexible material arranged around said
body portion and attached by way of the top portion thereof to said
body portion in a substantially leak-proof manner, with the bottom
portion of said collar opening to the atmosphere to be deployable
in an umbrella-like fashion and form in cooperation with said body
portion a pocket for trapping air, whereby the buoy is protected
from inundation.
13. The arrangement according to claim 12 further including a
plurality of dividers composed of a flexible and continuous
material coupled to said collar and to said body portion in a
substantially leakproof manner to compartmentalize said pocket
formed by said collar and said body portions.
14. The arrangement according to claim 12 further including a
plurality of arms coupled to said collar and to the buoy for
assisting in deployment of said collar.
15. The arrangement according to claim 12 further including a
plurality of fins arranged on a submerged portion of the buoy
remote from said collar, said fins being spaced from one another
around the buoy and providing broad surfaces for additional buoy
stability.
Description
BACKGROUND OF THE INVENTION
This invention relates to stabilization of surface communications
buoys launched from submerged vessels and in particular to an
automatically deployable stabilization arrangement on a
communications buoy for damping the surface forces acting on the
buoy and preventing inundation of the buoy and its communications
antenna.
Existing submarine operating procedures call for the vessel to
remain submerged and moving at most if not all times especially
during a communication with the outside world. In most applications
this requires that an expendable communications buoy be launched
from the submerged vessel which is intended to surface while
remaining connected to the submarine by way of an umbilical cord
designed for example to transfer command signals and communications
information to and from the buoy. The mode envisioned for
establishing outside communication while remaining submerged and
moving necessarily involves the launching of this communications
buoy from the signal gun of the submarine and paying-out the
umbilical cord in sufficient length to permit the buoy to rise to
the surface and complete the communication assignment before the
cord becomes taut and snaps. This requires that the buoy be
designed for fast rise time to the surface to preserve for
communications as much of the total time available as possible. A
necessity arises therefore to eliminate for instance as much weight
from the buoy as design and other factors will allow as well as
provide the buoy with an exterior which effectively reduces to a
minimum the external drag forces, while ensuring at the same time
that the buoy will remain stabilized and free from inundation on
the surface. Thus, any surface stabilization arrangement
accompanying the buoy must not be allowed to adversely effect the
rise time due to added weight, such as is the case with existing
internally carried stabilization provisions, or by increasing the
drag forces through externally arranged stabilizers. Such
inadequacies are inherent in systems employing for example gas
supplies and gas release control mechanisms which are associated
with inflatable floatation collar stabilization arrangements. A
most important consideration to be made with regard to externally
arranged stabilization provisions is that deployment thereof must
occur after launch to prevent considerable damage to the buoy
itself as well as the launcher or signal gun.
A further requirement in the establishment of communications in the
manner described above is that the buoy's antenna, which may be
deployed upon command from the submarine at any time following
launch, remain completely out of contact with the water once the
buoy has surfaced and communications begun in order to prevent a
"shorting" condition which results in the loss of precious
communications time. The criticality of time dictates therefore
that the surfaced buoy become stabilized and the antenna protected
as soon as possible to permit transmission and reception with the
minimum of delay following launch.
DESCRIPTION OF THE PRIOR ART
Existing stabilization arrangements used in circumstances as
described above comprise various types of inflatable floatation
collars which are deployed after launch via command from the
submarine either before or after the buoy surfaces. These
arrangements, however, require some sort of compressed gas source
which, for safety, should be carried inside the buoy during launch.
This of course affects weight distribution and takes up badly
needed space, and necessitates a recalculation of the buoyancy
requirements to enable the buoy to stabilize at all times.
This is compounded by fact that additional means must be employed
and stored within the buoy to initiate and control the inflation of
the floatation collar; and of course some safety means must be
considered to ensure that the command signal to commence the
collar's inflation will not occur until after launch. The danger is
always present in these prior art arrangements for a premature
command signal to be given or the occurrence of a malfunction
wherein the collar begins to inflate while the buoy remains in the
launcher, which necessarily leads to extensive damage to both the
buoy and the launcher. Moreover, with the inflatable arrangements
there is required at least one penetration of the buoy or capsule
to permit the internally stored gas to reach the externally
arranged floatation collar.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a
stabilization arrangement for surface communications buoys launched
from a submerged vessel which obviates the need for inflatable type
stabilizers and associated support and control equipments.
It is another object of this invention to provide a buoy
stabilization arrangement which is automatically deployable upon
launch from the submarine without the need for command signals or
control mechanisms and which cannot be prematurely deployed.
It is a further object of this invention to provide a light-weight
buoy stabilization arrangement for minimizing adverse surface
forces acting on the buoy via utilization of the existing
atmosphere as an air cushion.
It is yet another object of this invention to provide a buoy
stabilization arrangement which aids in reducing the buoy's rise
time to the surface after launch from a submerged vessel.
According to the broader aspects of the invention, an automatically
deployable buoy stabilization arrangement is provided comprising a
collar of continuous and flexible material arranged around the
floating buoy or capsule in conical or umbrella-like fashion
proximate the buoy's natural water line, with the collar secured
via the top portion thereof to the capsule body in a substantially
leak-proof manner and opening at the bottom to form in conjunction
with the capsule body a pocket, which may be compartmentalized, for
trapping air. The collar is aided in deployment by a plurality of
resilient arms coupled to the collar and the capsule body wherein
the arms are in a spring-loaded or unstable position when the
collar is undeployed.
A feature of this invention is that a low-cost arrangement is
provided which insures surface stability and helps to reduce the
buoy rise time while requiring no penetration of the capsule
body.
A further feature is that the stabilization arrangement according
to the invention does not hinder in any way the launch of the buoy
even though it is externally arranged thereon.
Yet another feature of the invention is that while the
stabilization arrangement has a primary responsibility to control
heaving forces and prevent inundation of the communications
antenna, there is additionally provided a substantial tempering of
the roll, surge and other rotational and rectilinear forces acting
on a buoy.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned and other objects and features of the invention
will become more apparent and the invention itself will be best
understood by referring to the following description when taken in
conjunction with the accompanying drawings in which:
FIGS. 1A-1E illustrate in a pictorial time sequence a method of
launching a surface communications buoy from a submerged
vessel;
FIGS. 2A and 2B illustrate a buoy arrangement according to the
prior art; and
FIGS. 3A and 3b illustrate the buoy stabilization arrangement
according to the invention in respectively a side elevation with a
partial sectional water-line stabilizer and a top view.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Reliable communications involving a buoy depend on several factors,
not the least of which is the stability of the buoy at the surface
of the water. Reliability is of course impossible if the buoy's
antenna may possibly become inundated or located in a trough
between two waves which block the path of radio signals. It is
known that a cylindrical configuration is perhaps the most
appropriate shape available to submarine communications buoys, both
from a launching point of view, and from rise time and surface
stability considerations; and it can generally be stated that
success in optimizing buoy performance may be accomplished by
making the natural period along the vertical axis of a cylindrical
configuration short (i.e., maintaining a high buoy natural
frequency) and the natural period along the roll axis long, in
order for instance to maintain a high heave stability, ie.,
maintaining a near constant water mark, in spite of the wave forces
acting on the buoy. It is required therefore that the buoy natural
frequency be considerably above the forcing wave frequencies, which
of course enables the buoy to react quickly to the changes in water
level.
The natural frequency of the buoy is given approximately by
f.sub.M = 1/2.pi. .sqroot.K/M,
where K is the spring constant of the buoy on the water and M is
the buoy's mass. Since stability, and in particular buoy heave
stability, is in a direct relationship with the natural frequency
of the buoy, a high natural frequency according to the above
formula requires that the buoy mass be minimized and/or the
spring-constant thereof be maximized. Due to limitations upon the
buoy or capsule system and the design thereof, and in further view
of the fact that some added mass is desirable for high roll
stability, it is therefore desirable to achieve high heave
stability through an increase in the buoy spring constant. Since
the spring constant is determined largely by the cross-sectional
area of the buoy at the water line, this fact must be considered in
the design of any worthwhile stabilization arrangement. Thus, it is
most advantageous and necessary to increase the buoy size at this
point; in fact, the buoy dispacement cross-section should be
largest at the water line for optimum results. However, due to the
limitations imposed by the diameter of the launcher (signal gun of
the submarine) it becomes necessary to provide stabilization means
which increase in size only after the buoy is launched.
FIGS. 1A - 1E in a pictorial sequence illustrate an existing method
of launching a communications buoy from below the surface of the
water and establishing communications with the outside world while
the submarine remains submerged and moving at a more or less
constant speed. FIG. 1A illustrates that point in time of the buoy
deployment sequence which occurs just after launch of the buoy
vehicle from the submarine. The vehicle is shown having two parts
coupled together, a main portion constituting the communications
buoy 1 and a positive-buoyancy secondary buoy 1a. Attached between
the secondary buoy 1a and the submarine is an umbilical cord 12,
which is shown paying-out from the submarine. The purpose of the
secondary part 1a of the vehicle is to create enough positive
buoyancy in the system to keep the umbilical cord 12 and the buoy
vehicle away from the submarine's propeller, and also to assist in
lowering the rise time of the communication capsule 1 to the
surface. FIG. 1B, illustrates the next important step in the launch
sequence in which the two portions 1 and 1a of the buoy vehicle
separate upon exhausting cord 12 while remaining coupled together
via a secondary umbilical cord 12a. The separation will occur after
all of cord 12 is expended which ensures that the buoy vehicle
and/or the umbilical cord is sufficiently elevated from the
submarine that it will not become engaged with or approach the
submarine propeller. The positive buoyancy requirements of the
secondary buoy 1a become even more important following the
separation of the two vehicle parts, inasmuch as there are now two
separate sections of umbilical cord (12 and 12a) as well as two
buoy portions (1 and 1a) which must remain away from the
submarine's propeller. The secondary umbilical cord 12a is
payed-out from the secondary buoy 1a rather than the main capsule 1
in order to conserve space in and to better control stabilization
of the capsule 1 and improve its rise time.
FIG. 1C illustrates an advanced point in time of the deployment
sequence in which the umbilical cord portion 12 is fully payed-out
and the communications buoy 1 is approaching the surface of the
water. The secondary umbilical cord 12a is indicated as only
partially expended with a substantial amount stored within buoy 1a
which of course will be taken-up during the course of the impending
communication.
FIG. 1D shows the communications buoy 1 having arrived at the
surface of the water while considerable cord 12a remains in the
buoy 1a. Communication with the outside world begins at this point
and continues for as long as the cord 12a remains in buoy 1a. Thus
is seen the desirability of a fast rise time for the communications
buoy and the establishment of buoy stability as soon as possible
after it breaks water.
FIG. 1E illustrates that point in the time sequence by which the
communication must be completed, in that all of the umbilical cord
(12a) is paid out and it is about to be snapped or purposely
separated from the submarine. It is not intended that the umbilical
cord (12, 12a) be sufficiently strong to allow the communications
buoy 1 to be towed along by the submarine inasmuch as this would
require a much greater weight cable as well as giving rise to an
undesirable transmitting and receiving mode.
Referring to FIGS. 2A and 2B, there is shown a prior art approach
to buoy stabilization employing the use of an inflatable collar 3.
As stated hereinbefore, this approach requires that a gas cartridge
or other source of gas be contained within the buoy 1. Moreover,
consideration must be given as to a timing and firing mechanism to
prevent premature firing while the buoy is in the launcher or in
the submarine. As shown in FIGS. 2A and 2B, the communications buoy
1 has positioned therearound the inflatable floatation collar 3
just above the water line 4, leaving a protected top portion 1b of
the buoy out of the water from which extends the communications
antenna 2.
Turning to FIGS. 3A and 3B, there is illustrated the buoy
stabilization arrangement according to the invention, in which the
intended increase in cross-sectional area of the buoy at the water
line 4 is developed by means of a conical or umbrella-like collar 5
which has the lower face 6 thereof open. The collar is secured to
the buoy 1 in a substantially leak-proof manner via the top portion
9, and, in cooperation with the body of the buoy, forms an air
pocket. The collar provides a protected portion 1b of the buoy
which is maintained free from inundation, from which extends the
communications antenna 2. The collar 5 is fabricated of a
continuous and flexible material such as a mylar film, and is
deployed around the capsule 1 from a recessed area 10 in the body
thereof, which may be provided for storage of the undeployed collar
5 to prevent interferences with the signal gun during launch. The
collar automatically deploys immediately after launch as is
illustrated in FIG. 1A. It is to be understood that any continuous,
flexible, lightweight and substantially leak-proof material may be
utilized for the conical collar 5, and that the collar 5 may be
secured to the buoy 1 by any acceptable means such as clamps, glue
etc.
To aid in deployment of the collar 5 there is provided a series of
arms or spokes 7 coupled to the collar 5. One arrangement
envisioned provides for the arms to be constructed of a bowed
resilient material, or alternatively a light metal with curved
cross-section (not unlike the metallic roll-up tape measures),
wherein the arms 7 form ribs within or on the surface of the collar
5 substantially equally spaced around the buoy 1 and run from the
open face 6 of the collar 5 to the top portion 9 thereof, at which
point the rib-like arms 7 are attached to the capsule body 1. The
manner of attachment to the capsule body 1 is such as to place the
arms 7 in a spring-loaded or unstable position substantially
adjacent to the buoy 1 when the collar 5 is undeployed. The arms
may be in continual contact and attachment with the collar 5
substantially along their entire lengths or may be coupled at
discrete points, such as at or near the top and bottom portions (9
and 6 respectively) of the collar 5. Also, the arms may be arranged
on either or both the underside of the collar 5 and on the outer
surface thereof. Another possible arrangement is to have the arms 7
coupled to the collar near the open face 6 and to the capsule body
1 at points remote from the upper portion 9 of the collar 5 such
that when the collar 5 is undeployed the arms 7 are elastically
buckled in a U-shaped manner. It is to be understood, however, that
any manner of connection or any arrangement of the arms 7, in
association with the collar 5 and the capsule body 1, falls within
the spirit of this invention as long as the arms 7 assist in the
deployment of the collar 5 through achieving a stable position when
the collar 5 is deployed, as arrived at from an unstable position
when the collar 5 is constrained in the undeployed state, such as
occurs when the buoy is in the signal gun prior to launch. It is to
be noted also that the choice of material and the arrangement of
the collar 5 may be such as to permit self-deployment without
requiring the assistance of arms 7.
It is clear from the above that, in view of the open lower face 6
and the resultant air pocket formed by the collar 5 cooperating
with the capsule body 1, there is no longer required to be a
penetration of the capsule body 1 or timing and firing mechanisms
for deployment of a buoy stabilization arrangement. This open lower
face 6, moreover, continually drains off any water entering,
thereby periodically reforming the air pocket. In view of the fact
that the inventive collar arrangement also increases the damping
constant, there results a corresponding further reduction of the
effects of heaving vibrations on the capsule 1.
To further improve the effectiveness of the inventive principle,
the conical collar 5 may be compartmentalized in order to minimize
spillage of the air trapped by the pocket. The compartmentalization
may be achieved by coupling to the conical collar 5 and to the
capsule body 1 in a substantially leak-proof manner a plurality of
dividers 13 spaced apart from one another around the buoy to form a
series of individual compartments 8. In a preferred embodiment the
dividers 13 are fabricated of a continuous and flexible material
and may be coupled to the capsule body by clamps, glue or any other
acceptable and lightweight means. The dividers 13 may be similarly
coupled to the collar 5 or, in the alternative, may be homogeneous
therewith. One very practical arrangement envisioned combines the
functions of the dividers 13 and the deployable arms 7 into one,
wherein the combined arms/dividers are fabricated of such a
material and arranged in such manner as to automatically provide
compartmentalization and assist in deployment of the collar 5 by
being arranged in an unstable state when the collar is undeployed.
A preferred embodiment which satisfies the above criteria may have
the compartment dividers 13 constructed in concertina-like fashion
and perhaps made out of a resilient material. Of course, the
concertina-like arms/dividers in the undeployed or unstable state
could be stored in the recessed area 10 provided for a streamlining
of the exterior of the buoy 1 when the collar 5 remains undeployed.
One major advantage of compartmentalization is that whenever one or
two compartments become punctured, the air pocket would yet remain
via the other compartments and thus the effectiveness of the
stabilization arrangement would be largely maintained. This is of
course not true in general with the inflatable floatation collar
arrangements.
In view of the severe rotational and rectilinear forces experienced
from time to time which act on the buoy or capsule 1 at the
surface, it is perhaps desirable to incorporate further
stabilization means in the form of a plurality of vanes or fins 11
added to the buoy 1 on a submerged portion thereof remote from the
collar 5. These fins 11, with respect to the cylindrical capsule
illustrated in FIG. 3A, are arranged at the submerged end thereof,
and are triangularly shaped and substantially equally spaced from
one another around the capsule body. Application of the fins
according to the invention is particularly effective in maintaining
roll stabilization, which is most desirable for minimizing signal
fading. The fins or vanes 11 may be constructed of a continuous
film plastic or other suitable material and may be deployed in the
same manner as the conical collar 5, i.e, by securing thereto
deployable or hinged arms. Alternatively, a sliding ballast may be
used which will force out rigid vanes as the buoy initially rights
itself at the surface; or a separate cable could be used, one end
thereof being attached to the interior of the launcher and the
other end to the rigid vanes. When the buoy is enjected, the cable
will force out the fins prior to breaking. It is of course possible
and entirely within the scope of this invention to have fin shapes
and arrangements other than as illustrated in FIG. 3A or described
above, the important consideration being that the fins offer
substantially broad surfaces to increase the buoy damping constant.
Moreover, the stabilization arrangement according to the invention
has application to floating bodies other than communications buoys,
which bodies may have for instance rectangular, spherical or other
non-cylindrical shapes. Additionally, the invention has application
to non-geometrical shapes, particularly the human body.
While the principles of this invention have been described above in
connection with specific apparatus, it is to be understood that
this description is made only by way of example and not as a
limitation to the scope of the invention as set forth in the
objects and features thereof and in the accompanying claims.
* * * * *