US3870006A - Stabilizing device for buoyant body - Google Patents

Stabilizing device for buoyant body Download PDF

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Publication number
US3870006A
US3870006A US362111A US36211173A US3870006A US 3870006 A US3870006 A US 3870006A US 362111 A US362111 A US 362111A US 36211173 A US36211173 A US 36211173A US 3870006 A US3870006 A US 3870006A
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United States
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section
raft
water
container
liquid
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Expired - Lifetime
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US362111A
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English (en)
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Masami Hashimoto
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Individual
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B39/00—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude
    • B63B39/06—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude to decrease vessel movements by using foils acting on ambient water
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B39/00—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude
    • B63B39/06—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude to decrease vessel movements by using foils acting on ambient water
    • B63B2039/067—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude to decrease vessel movements by using foils acting on ambient water effecting motion dampening by means of fixed or movable resistance bodies, e.g. by bilge keels

Definitions

  • ABSTRACT A stabilizing device for a buoyant body made from a section of material secured to the buoyant body and contacting the liquid, for example, water, upon which the buoyant body floats. This section of material increases the attractive force between the buoyanat body, such as a life raft, and the water.
  • the stabilizing device hinders or precludes external air from entering the space between the buoyant body and the liquid surface.
  • the section of material takes the shape of a flat sheet, as is shown in one preferred embodiment, providing the material with one or more gascontaining ducts serves to spread the sheet upon the liquid.
  • the total weight of the life raft, its container, and all other included equipment must not exceed 400 lbs.
  • Prior efforts to stabilize buoyant bodies included devices to lower the center of gravity of the bodies and the shaping of the bodies to lessen their rolling within the water.
  • One devicefor the life raft in particular included a water bag, which permitted water to flow easily into and out of it, installed on the bottom of the life raft. However, since the bag obviously cannot retain its water, it has little effectiveness as a stabilizing device.
  • Efforts to ameliorate the minimal effectiveness of the stabilizing water bag include making the bag itself larger or increasing the number of bags attached to the raft. However, either approach leads to the loss of some of the buoyancy which represents the most appealing facet of the raft. Moreover, both techniques also increased the amount of waves surging into the raft since the raft and the water bags moved together as a unit.
  • Providing gas-tight ducts on the surface of the material or embedded within the material assists in the materials original extension upon first contacting the liquid and also helps to retain the effective surface area of the section of material over a period of time. The latter serves to enhance the efficiency of the suction and thus its stabilizing action.
  • FIG. 1 gives a perspective view of a life raft having a stabilizing sheet of material extending beyond the entire periphery of the raft.
  • FIG. 2 shows a plan view of the raft of FIG. 1.
  • FIG. 3 shows a cross-sectional view taken along the line 33 in FIG. 2.
  • the common inflatable rubberized life raft represents a particular example of a buoyant body to which a stabilizing device provides particular advantages. These life rafts, while carrying persons at sea, have on occasion overturned with unfortunate consequences.
  • Rafts are also sometimes made with a foam material for flotation and thus represent another buoyant body which can be combined with the stabilizing device described herein to realize the benefits of this invention.
  • the illustrated life raft includes a conventional raft body 10 formed from a main pair of inflatable buoyancy tubes 12 and 14 stacked upon each other and bonded together at their contact line by an adhesive, for example.
  • Rubberized cloth represents a common airtight material used in the construction of the tubes 12 and 14.
  • the seam lines 16 result from the joinder of the various pieces of rubberized cloth during the manufacture of the tubes 12 and 14.
  • the raft body 10 also includes a pressurized gas container 18 provided with a rupture valve 20.
  • the valve 20 either automatically or manually ruptures and permits the automatic introduction of the gas through passages into the main tubes.
  • the raft body 10 inflates after it is removed from its storage location and prior to or after it drops onto the water surface.
  • the bottom sheet 22 secured, for example, by an adhesive or a seam to the bottom of the lower tube 14, forms an open-ended chamber with the cylinders 12 and 14.
  • a flat inflatable gas container may replace the sheet 22 and form the bottom of the open-ended chamber.
  • the life raft in use, serves to prevent the sea water or the wind from entering the open-ended chamber.
  • the life raft also generally includes a'life rope 26 secured at various locations to the cylinders 12 and 14.
  • the lifev raft in the figures also includes the strip of material28 attached to the raft body 10.
  • This strip of material in the form of a sheet, extends beyond the periphery of the raft body Y and represents a stabilizing device for the raft.
  • FIG. 3 gives an alternative and more facile method for bonding the strip 28 to the raft body 10. That figure portrays the stabilizing device 28 as an integral extension of the sheet of material 22 forming the bottom of the raft 10.
  • the raft In use, the raft inflates and floats upon the water surface. There it becomes subject to forces generated by the wind, the weight carried by the raft and the waves.
  • the stabilizing sheet of material 28 retains its outer portion within the water and encloses this space between the water and the raft. Forming this stabilizing strip 28 from a flexible material, such as the rubberized cloth of the raft itself, helps maintain the outer edge of the] strip within the water. Moreover, providing the edge of the strip with a downward curve, as shown in FIG. 3, counteracts the wind which tends to raise the edge from the water.
  • the stabilizing device strip 28 hinders or even precludes the external air from entering the space between the bottom of the raft and the water, especially if airtight, the air pressure in this space becomes less than in the external air. This reduced pressure generates a partial vacuum which results in a positive at mospheric pressure applied to the upper surfaces of the raft. urging the raft bottom into contact with the water surface.
  • the stabilizing strip 28 Increasing the tilt of the raft body 10 enlarges the space enclosed by the raft body, the stabilizing strip 28,
  • An essential design criteria for the stabilized raft is that the center of the pneumatic forces generated by the strip 28 is related to the center of gravity and the hydraulic forces on the raft to urge the raft into conformance-with the water surface.
  • the portion of the stabilizing strip 28 on the lower side of the raft acts somewhat as a bilge keel. This behavior of the strip helps to retard and prevent further slanting of the raft.
  • the strip 28 may include one or more flotation means 30, preferably gas ducts, attached to the surface of the strip 28 or embedded within it. These gas ducts may communicate with the lower main tubes 14 of the raft or directly with the gas container 18 through appropriate conduits which, for convenience, are not shown. When inflated, these ducts 30 serve to automatically spread the stabilizing strip 28 when the raft becomes pressed into actual service. It is also possible to provide flotation means in the strip which does not require inflation- Moreover, for a flexible stabilizing strip 28, the gas ducts 30 also serve to maintain the stabilizing strip 28 in a stretched condition which thus presents a maximum area for contact with the water and enhances its effectiveness. The gas ducts also increase the buoyancy of the stabilizing strip 28 50 that the strip will not lower the overall buoyancy of the raft itself.
  • gas ducts provide a stabilizing strip 28 that has some stiffness during actual use while not detracting from the ease of handling a flexible material.
  • a permanently stiff strip would also maintain the effective area of the stabilizing device.
  • a stabilizing device would not represent an appreciable loss in its ease of handling.
  • EXAMPLE 1 Around the periphery of the bottom of a rubberized raft having an outer diameter of 54 cm., a height of 20 cm., and a weight of 1,280 gm. was attached a strip of rubberized cloth having a width of 25 cm., a thickness of 0.5 mm., and a weight of 720 gm. To a second and unstabilized raft was added a weight of 720 gm. in order to bring the weight on both rafts up to a total of 2,000 gm. After the placement of both of these rafts upon the surface of water, a torsion spring scale pulled upwardly upon each in turn.
  • the stabilized raft separated from the water surface only under the application of a force of 12,000 gm., while the unstabilized raft separated with a force of only 2,100 gm. Discounting the actual weight of the rafts themselves, the stabilized raft exhibited an attractive force to the water of 10,000 gm., which represents 100 times the 100 gm. of attractive force between the unstabilized body and the water.
  • EXAMPLE 2 A cylindrical raft of 290 cm. in diameter and cm. in height had attached to its bottom a stabilizing strip of 107 crri. in width and a thickness of 0.5 mm. This type of raft, which holds approximately 13 persons, represents a legally required fitting on vessels. The stabilized raft and a similar but unstabilized raft, while water beneath the bottom of the raft and moved in the downstream direction along with the raft itself.
  • a stabilizing device comprising a substantially fluid-impermeable flaccid section of material attached adjacent to the bottom-most portion of said body having a substantially airtight surface area which cooperates with said flexible section so that when said body floats upon the surface of a liquid, said section of material substantially surrounds the periphery of said body and contacts said liquid, said flexible section producing a partial vacuum effect between the bottom of said buoyant body and such liquid as said buoyant body floats upon the surface of such liquid whereby said buoyant body resists overturning in said liquid.
  • said stabilizing device is an integral extension of the material form ing the bottom of said body.
  • a raft comprising a gas-tight inflatable container made of rubberized cloth; a section of airtight flaccid material attached to the bottom portion of said container and constructed so that when said raft is inflated and floats upon the surface ofa body of water, said section of material extends beyond substantially all of the periphery of said container and contacts the water. said section effecting a partial vacuum between the bottom of said container and said body of water as said container floats upon the surface of said body of water whereby said container resists overturning in said body of water.
  • the life raft of claim 8 including a gas-tight duct attached to the surface of or embedded within said section of material.
  • the life raft of claim 10 including a gas-tight duct attached to the surface ofor embedded within said flexible material.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • Ocean & Marine Engineering (AREA)
  • Cleaning Or Clearing Of The Surface Of Open Water (AREA)
US362111A 1972-05-31 1973-05-21 Stabilizing device for buoyant body Expired - Lifetime US3870006A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5405172A JPS5620237B2 (sh) 1972-05-31 1972-05-31

Publications (1)

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US3870006A true US3870006A (en) 1975-03-11

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ID=12959796

Family Applications (1)

Application Number Title Priority Date Filing Date
US362111A Expired - Lifetime US3870006A (en) 1972-05-31 1973-05-21 Stabilizing device for buoyant body

Country Status (4)

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US (1) US3870006A (sh)
JP (1) JPS5620237B2 (sh)
FR (1) FR2186379B1 (sh)
GB (1) GB1432585A (sh)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE32560E (en) * 1972-12-12 1987-12-15 Stabilized survival raft
US5397258A (en) * 1993-12-30 1995-03-14 Switlik Parachute Company, Inc. Polygonally shaped inflatable raft apparatus
US20040203315A1 (en) * 2003-04-09 2004-10-14 Fielding Jerry J. Submersible water toy and related method of use
US20050064781A1 (en) * 2003-04-09 2005-03-24 Jerry Fielding Submersible water toy and related methods of use
US20070256719A1 (en) * 2006-05-03 2007-11-08 Robert Thomas Hill Flexible waterproof flood protection container
US10239590B2 (en) 2010-10-13 2019-03-26 James Montgomery Suction stabilized floats
US20220106021A1 (en) * 2019-09-29 2022-04-07 Ichiro Sakamoto Aquatic play equipment

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2536900B (en) * 2015-03-30 2021-06-09 Salvare Ip Ltd Survival platform

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1102526A (en) * 1914-04-20 1914-07-07 Ladislas Luki Swimming device.
US1517007A (en) * 1924-01-22 1924-11-25 Hunt Charles Float for sport, pleasure, and rescue use
US2110596A (en) * 1935-05-28 1938-03-08 William S Goertzen Bob for a fishing line
US2211104A (en) * 1939-09-06 1940-08-13 Henry M Doiguchi Combined cushion and swimming belt
US2642590A (en) * 1948-10-01 1953-06-23 Klepper Werke Kg Boat
US2888690A (en) * 1955-07-01 1959-06-02 Shaw Eric Baden Inflatable life-saving raft
US3029606A (en) * 1957-10-25 1962-04-17 Horace W Olsen Means for protecting marine structures against the effect of waves

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1102526A (en) * 1914-04-20 1914-07-07 Ladislas Luki Swimming device.
US1517007A (en) * 1924-01-22 1924-11-25 Hunt Charles Float for sport, pleasure, and rescue use
US2110596A (en) * 1935-05-28 1938-03-08 William S Goertzen Bob for a fishing line
US2211104A (en) * 1939-09-06 1940-08-13 Henry M Doiguchi Combined cushion and swimming belt
US2642590A (en) * 1948-10-01 1953-06-23 Klepper Werke Kg Boat
US2888690A (en) * 1955-07-01 1959-06-02 Shaw Eric Baden Inflatable life-saving raft
US3029606A (en) * 1957-10-25 1962-04-17 Horace W Olsen Means for protecting marine structures against the effect of waves

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE32560E (en) * 1972-12-12 1987-12-15 Stabilized survival raft
US5397258A (en) * 1993-12-30 1995-03-14 Switlik Parachute Company, Inc. Polygonally shaped inflatable raft apparatus
US20130171907A1 (en) * 2003-04-09 2013-07-04 Jerry Fielding, Jr. Submersible water toy and related methods of use
WO2004091743A2 (en) * 2003-04-09 2004-10-28 Subskate, Inc. Submersible water toy and related method of use
WO2004091743A3 (en) * 2003-04-09 2005-03-10 Jerry J Fielding Submersible water toy and related method of use
US20050064781A1 (en) * 2003-04-09 2005-03-24 Jerry Fielding Submersible water toy and related methods of use
US20110263170A1 (en) * 2003-04-09 2011-10-27 Fielding Jerry Jr Submersible water toy and related method of use
US8388402B2 (en) * 2003-04-09 2013-03-05 Jerry Fielding, Jr. Submersible water toy and related method of use
US20040203315A1 (en) * 2003-04-09 2004-10-14 Fielding Jerry J. Submersible water toy and related method of use
US8845382B2 (en) * 2003-04-09 2014-09-30 Jerry Fielding, Jr. Submersible water toy and related methods of use
US20070256719A1 (en) * 2006-05-03 2007-11-08 Robert Thomas Hill Flexible waterproof flood protection container
US10239590B2 (en) 2010-10-13 2019-03-26 James Montgomery Suction stabilized floats
US20220106021A1 (en) * 2019-09-29 2022-04-07 Ichiro Sakamoto Aquatic play equipment

Also Published As

Publication number Publication date
JPS5620237B2 (sh) 1981-05-12
FR2186379B1 (sh) 1976-04-23
JPS4913894A (sh) 1974-02-06
FR2186379A1 (sh) 1974-01-11
GB1432585A (en) 1976-04-22

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