Pressure Resistant Underwater Casing

Abstract

A housing or casing having a pressure balancing mechanism such as a diaphragm or bellows is filled with a suitable fluid, such as oil, to both prevent erosion and to permit the casing structure to be immune to the effects of ambient pressure. The casing is designed specifically to protect such devices as cameras used underwater.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a casing structure used for enclosing underwater devices such as an underwater camera and the like.

2. Description of the Prior Art

Generally, the conventional casings for enclosing underwater mechanisms such as underwater cameras, submarine robots, oceanographical instruments, and the like, have, by necessity, been provided with both water-proof means so that the mechanism will not be damaged by sea water and a pressure resistant structure for protecting the mechanism in the casing from the relatively high pressure exerted by the water as a device is progressively used further beneath the surface of the sea. As a result of these requirements, the conventional casing structure has been both complicated construction and costly to manufacture.

SUMMARY OF THE INVENTION

The present invention solves the problems that existed in the prior art in a simple and efficient manner, by providing an underwater casing which does not require elaborate pressure resistance means or water-proofing means. This is accomplished by combining in a simple structure apparatus which jointly permits equalization of the pressure, while preventing the eroding effects of sea water. This is accomplished by filling the underwater casing with a fluid that will have the same pressure as the surrounding sea water and permitting the pressure within the casing structure to be controlled to be always equal to that of the water pressure outside the casing by providing pressure balancing means on the casing wall. This removes the necessity for having a sturdy and bulky structure as generally is required in the prior art. By filling the underwater casing with a fluid, such as oil, the mechanism contained within the underwater casing is prevented from being damaged by the water.

The pressure balancing means utilized in the present invention can be for instance, a flexible wall portion provided on the wall of the casing structure. This flexible wall portion will be fluid tight and prevent the leakage of the enclosed fluid while permitting the equalization of the pressure in the fluid to that of the water pressure outside the casing. By selecting the appropriate fluid to fill the underwater casing, such as oil, the mechanism will be preserved within the casing structure and thus, prevent it from being damaged.

Fluids for filling the underwater casing can be, for example, colloid of gel or sol, such a gelatin, as well as oil, and other similar materials possessing the same characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic sectional view of one embodiment of the underwater casing in accordance with the present invention, and,

FIG. 2 is a schematic sectional view of another embodiment of the underwater casing in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, a closed underwater container 1 is provided with a diaphragm 2 as a part of its top wall. The closed container 1 is filled with a fluid, such as liquid paraffin 3. The underwater casing structure can maintain its fluid tight relationship with the liquid paraffin 3 without resorting to excessive bulky structure due to the ability of the casing to balance the pressure on the inside of the casing with the pressure on the outside of the casing by virtue of the diaphragm 2.

In the particular embodiment disclosed in FIG. 1, an underwater camera 7 is connected through a driving shaft 6 with a motor 4. The motor 4 is driven by an electric cell 5. The electric cell 5, its electrical connections and the motor 4 along with a portion of the shaft 6, is enclosed within the underwater casing. The underwater camera 7 has its own fluid tight structure, but a possible modification would permit the underwater camera 7 to be positioned within the underwater casing 1. The liquid paraffin 3 protects those parts of the underwater camera system that are most susceptible to damage by the sea water. The clearance or bore between the underwater casing 1 and the shaft 6 is sealed to prevent the introduction of sea water into the interior of the underwater casing 1. As one of the advantages of the present invention, the seal employed can be of a relatively simple structure, since there will be no marked difference in pressure between the outside and the inside of the underwater casing 1.

In operation, the diaphragm 2 maintains the pressure within the underwater casing 1 equal to the water pressure outside the underwater casing 1. Thus, by an extremely simple construction, the pressure resistant means and the water-proofing means utilized in a conventional underwater casing is eliminated. It is clear that other accessories of a camera, or similar devices, could be enclosed within the underwater casing, such as a flashlight device or a strobe.

Actual experiments were conducted on the present invention and produced the following data, which disclosed that a motor and battery protected by the underwater casing of the present invention were not damaged over an extended period of time:

INFLUENCE ON ELECTRIC PARTS BY IMMERSION (LIGHT OIL)

MOTOR Maker Copal Japan Micromotor Type 12 D 22-76 CL-2A-1 Reduction Device None Equipped Number of rotation 7,600rpm 1.37rpm &Rated Voltage (motor shaft) (terminal output shaft) 9 V 7.5 V Brush Silver(90%) Metal(special) containing brush Metal brush Oil immersion driving test Repeated Starting Good Good Test(100 times) Continuous 40 hrs. Good Good Test

BATTERY(DRY CELL) Maker & Kind Mercury Cell Dry Cell of Cell Matsushita Matsushita Elec. Elec. Model No. Matsushita Matsushita (M-1U) (UM-3D) Rated Voltage 7.8V(1.3V.times.6) 9V(1.5V.times.6) No-load Voltage 8V 8.2V

variation in Voltage when the motor is driven (I=22mA)

After 1 hour 7.9V 7.7V 2 hours 7.9V 7.7V 3 hours 7.9V 7.7V 4 hours 7.9V 7.7V In the above experiments, the output shaft is subject to 1 Kgem load.

In the second embodiment disclosed in FIG. 2, the underwater casing 1 is provided with a bellows 20 instead of the diaphragm 2 employed in the first embodiment. The function of the bellows is the same as that of the diaphragm 2 utilized in the embodiment of FIG. 1. The reference numeral 40 of FIG. 2 is indicative of any underwater instrument that needs to be protected when submerged.

Various fluids can be employed to fill the underwater casing 1, such as, diphenyl chloride, kerosene, light oil, silicone oil, machine oil, heavy oil, and other similar fluids having the same or similar properties. In those cases where the camera body is located outside the underwater casing 1, the fluid utilized within the underwater casing 1 need not be transparent and accordingly, it is possible to use a gel like gelatin to fill the underwater casing 1.

Thus, the present invention as described above, provides a pressure balancing means on the wall of the underwater casing structure, which permits the pressure within the underwater casing to be maintained at a pressure equal to that of the water pressure outside of the underwater casing. Consequently, the pressure resistant means generally employed in a conventional underwater casing, and further, the water-proofing means required in an underwater instrument casing, can be eliminated. The present casing for underwater instruments, such as cameras, can be made extremely simple in construction and accordingly, in an economical manner.

Since various modifications could be made by skilled craftsman within the concepts of the present invention, the present invention should be measured in accordance with the following claims in which I claim;

Claims

What is claimed is:

1. The combination of an underwater camera and casing for its electrical power source and motor for use underwater comprising a housing member for enclosing the electrical power source and motor;

pressure balancing means regulating the interior pressure within the housing member in accordance with the ambient pressure;

a non-corrosive fluid filling the housing member and covering the electrical power source and motor;

electrical connectors connecting the electrical power source and motor, and,

a shaft extending from the motor through the housing in operative connection with the underwater camera whereby the electrical power source and motor are protected from the water.

2. The combination of claim 1, where the pressure balancing means is a flexible diaphragm.

3. The combination as claimed in claim 1, wherein said pressure balancing means comprises a bellows member.

4. The combination as claimed in claim 1, wherein said fluid is oil.

5. The combination as claimed in claim 1, wherein said fluid is gelatin.

6. The combination as claimed in claim 1, wherein said fluid is silicone.