BACKGROUND OF THE INVENTION
Currently there are two general types of underwater observation vessels in operation; firstly there are surface vessels with underwater viewing ports, some of the vessels of this type have additional ballast to further lower the viewing ports, and secondly there are tourist submarines capable of fully submerged underwater operation. The surface vessel has the advantage of being able to get to and from the observation sight at a reasonable speed under its own power, the submarine lacks this mobility due to the need for permanent ballast and a limited power supply. The surface vessel is also considerably less expensive to construct, operate and maintain. The surface vessel however can not afford the same viewing experience as the submarine since the passengers are positioned only a small distance below the water surface. In addition to the two types of vessels mentioned above there have been patents issued for vessels that rotate a passenger compartment below the surface of the water such as U.S. Pat. No. 5,117,774 and U.S. Pat. No. 3,129,681. These vessels share the disadvantage of separating the center of gravity from the center of buoyancy, in the horizontal plane, during their operation thus limiting their stability. U.S. Pat. No. 4,718,368 shows an articulated vessel requiring many moving parts and being incapable of lowering its passenger compartment beyond a certain point, this point being directly related to the beam of the vessel. This configuration would also constantly reduce the beam of the vessel and therefore the stability of the vessel as the passenger compartment is lowered beyond the point where the articulated connecting arms are in a horizontal position. U.S. Pat. No. 4,276,851 shows a diving bell type compartment rigidly connected to a surface vessel. The present invention combines the advantages of a surface vessel with the ability of the submarine to position its passengers at a greater depth than can be achieved by the above mentioned surface vessels.
SUMMARY OF THE INVENTION
This invention relates to a partially submersible vessel, said vessel comprising a passenger hull and a pair of outer hulls mounted one to each side of the passenger hull. A rigid framework connects the outer hulls into a catamaran type configuration. A pair of hydraulic cylinders vertically mounted at each end and on the centerline of the framework connect the passenger hull to the framework. The passenger hull is movable between a first position somewhat above being coplanar with the outer hulls and a second lower position determined by the stroke of the hydraulic cylinders.
According to a further feature the passenger hull has an air intake and an air exhaust which are connected to the atmosphere.
According to a further feature the outer hulls are divided horizontally between sealed air tanks occupying the upper section of each hull, and water ballast tanks occupying the lower section of each hull.
According to a further feature each water ballast tank is equipped with a water valve located in the bottom of each tank and an opening connecting the top of each tank to the atmosphere.
According to a further feature the combined buoyancy of the sealed air tanks exceeds the vessels displacement.
According to a further feature the passenger hull has positive buoyancy which is somewhat greater than the total displacement of the vessel when the passenger hull is fully submerged and the water ballast tank valves are in their open position.
BRIEF DESCRIPTION OF THE INVENTION
The invention will be more fully understood in the light of the following description of one specific embodiment. The description is made with reference to the accompanying drawings, not necessarily to scale, of which:
FIG. 1 is a front view of the vessel.
FIG. 2 is a side view of the vessel.
FIG. 3 is a top view of the vessel.
FIG. 4 is a front view of the vessel with the passenger hull fully submerged.
FIG. 5 is a cross-sectional view of one of the outer hulls with the water valve in the closed position.
FIG. 6 is a cross-sectional view of one of the outer hulls with the water valve in the open position.
FIG. 7 is a front view of an alternate embodiment of the vessel.
FIG. 8 is a top view of an alternate embodiment of the vessel.
FIG. 9 is an enlarged top view of the compensating means described in an alternate embodiment of the vessel.
FIG. 10 is a front view of the vessel with one outer hull raised out of the water.
FIG. 11 is a front view of the vessel with one outer hull resting on a dock structure.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the embodiment shown, and with reference to FIG. 1 through FIG. 6, this semi-submersible vessel consists of two outer hulls 1 connected to a framework 5 thereby forming a catamaran type structure. Hydraulic cylinders 6 are integrated vertically into the framework 5. The piston rods 13, of said main hydraulic cylinders 6, protrude below the framework 5 and connect rigidly to the passenger hull 2. The outer hulls are vertically divided into separate compartments; each compartment is horizontally divided by plates 23 into two separate sections. The upper section, of each compartment, forms a sealed air tank 25. The lower section, of each compartment, forms a water ballast tank 26. Each water ballast tank 26 is equipped with a vent pipe 24 connecting the top of the tank to the outside atmosphere. The bottom of the water ballast tank 26 is equipped with a water valve 21 said valve being formed and positioned in such a way that it is flush with the outer surface of the hull 1. The water valve 21 is connected to a hydraulic actuator 22, which in turn is rigidly connected to a support frame 27. An air supply to the passenger hull 2 is provided through an air supply tower 9. The tower 9 is internally divided between an air intake duct and an air exhaust duct. The lower end of the tower 9 attaches to the passenger hull 2. The upper end of the tower 9 is connected to a sliding block 11 which rides on a guide 12 mounted on the back of the aft-located hydraulic cylinder 6. Flexible pipes, not shown in the drawings, connect the air supply from the top of air supply pipes 10 to one-way valves located at the top of the tower 9. The air supply pipes 10 are in turn supplied with air from blowers located in the engine rooms 3 this air supply being routed through framework 5 to the base of said air supply pipes 10. Further features include engine rooms 3 and thrusters 4 Located on the outer hulls 1, conning tower 8 connected to the passenger hull 2, pilothouse 7 connected to framework 5. In operation the vessel would proceed out to the observation site with the water ballast tanks 26 empty and the water valves 21 in their closed positions and with the passenger hull 2 in its first position. At the observation site the water valves 21 are opened and the ballast tanks 26 begin to fill, the design of the vessel being such that the waterline of the vessel with the water ballast tanks 26 filled will be somewhat above the top of the water ballast tanks 26 themselves. With the water ballast tanks 26 filled the water valves 21 are closed and the hydraulic cylinders 6 move the passenger hull 2 to its second position. The observation tour commences, the vessel being controlled from the pilothouse 7. At the end of the observation tour the hydraulic cylinders 6 move the passenger hull 2 to a third position somewhat below but close to the surface of the water. The water valves 21 are opened and due to the buoyancy of the passenger hull 2 the water ballast tanks 26 start to drain, the position of the passenger hull 2 is adjusted so that the vessel remains level as the tanks empty. With the water ballast tanks 26 empty the water valves 26 are closed and the passenger hull 2 is returned to its first position at which point the vessel can return to port.
The preferred embodiment uses a combination of inertia, flex in the connecting piston rods 13 and water drag resistance on the passenger hull itself to dampen the effects of wave motion being transferred to the passenger hull 2. Therefore an alternate embodiment, to compensate for the effects of surface waves, is herein described with reference to FIG. 7 through FIG. 9. In this embodiment the main hydraulic cylinders 6 are able to maintain a vertical alignment, with respect to the force of gravity, regardless of the roll and pitch of the vessel itself. This vertical alignment is maintained through the use of a pivoting type mount at the base of each main hydraulic cylinder 6 and compensating hydraulic cylinders 30 connecting the main hydraulic cylinders 6 to the framework 5, somewhat above the pivoting type mount. This pivoting assembly comprising of: gimbal ring 33 connected to a pair of opposing pins, not shown, rigidly attached to the base of each main hydraulic cylinder 6. A second pair of opposing pins, arranged perpendicularly to the first pair, connects the gimbal ring 33 to the support ring 32. The support ring 32 being rigidly attached to the framework 5 via a set of support brackets 31. The gimbal ring 33 being able to freely rotate on said pins. The said compensating cylinders consist of: four compensating hydraulic cylinders 30 arranged around each main hydraulic cylinder 6 connected at their top ends to ball joint type mounts rigidly attached to each main hydraulic cylinder 6 and connected at their lower ends to ball joint type mounts rigidly attached to the framework 5. A gravity sensor connected to a control means operates automatic hydraulic valves connected to the compensating hydraulic cylinders 30 said compensating cylinders being able to exert a side force on the main hydraulic cylinders 6 thus maintaining the vertical alignment of the main hydraulic cylinders 6. A further compensating means is provided to maintain the passenger hull 2 in a horizontal plane while the attitude of the surface elements of the vessel vary as the vessel transverses the water surface. This compensating means consisting of a reversible hydraulic pump inline with suitable pipes and flexible hydraulic hoses such that the two main hydraulic cylinders 6 are hydraulically connected together. A gravity sensor connected to a control means determines the direction of fluid flow between the two main hydraulic cylinders 6, in order to maintain the passenger hull 2 in a horizontal plane. In this embodiment the main hydraulic cylinders 6 are not fully extended when the passenger hull 2 is in its lowered position but rather to a mean position which allows the pistons 13 to move up and down from this mean position.
The vessel in all embodiments has the further feature of being able to raise any of its hulls above the water surface by the following means. With reference to FIG. 10 and the waterline 42 as shown, this final position is obtained from a starting position as shown in FIG. 1 by firstly allowing ballast water into the outer hull 1 which will remain in the water and secondly lowering the passenger hull 2 to a point where its buoyancy raises the opposite outer hull 1 to the desired position above the waterline 42. In FIG. 11 the vessel is shown with the raised outer hull 1 resting on a dock structure 40 the raised outer hull 1 being supported on blocks 41 and with the passenger hull 2 in its fully raised position. The position of the passenger hull 2 as shown in FIG. 11 requires that the main hydraulic cylinders 6 be double acting or that a means such as a winch and cable system, between the framework 5 and the passenger hull 2, be utilized to raise the passenger hull 2 against the force of gravity. A deck structure, not shown in the drawing, is also provided in all embodiments. This deck structure being of sufficient size to accommodate all the passengers while moving to and from the observation site.
Patent Application
20050039660
