Title of Invention

"A NOVEL STACKABLE IN WATER PRESSURE RESISTANT OCEANOGRAPHIC HOUSING"

Abstract

A novel stackable in-water pressure resistant oceanographic housing comprising of the basic configuration of sensor(s), electronics, and built-in power source by providing separate modules in stackable housings (8,9,10) one for each sub-system, the said housing being interconnected with each other through O rings (11) so as to admit the free passage of air between them an air valve [14] having cap [15] providing on a removable end-cap [13], the said end-cap (13) being accomodating sensor front end module (12), for self locking together of the separate housing [8,9, 10] into a mechanically stable segmented cylinder to get sealed to external pressure.

Full Text

The present invention relates to a novel stackable in-water pressure-resistant oceanographic housing*1. Oceanographic pressure-resistant housings are widely used in the marine technology world to contain or enclose electronic circuit boards, delicate optical components, motors and batteries. Sensors of temperature, pressure, salinity, oxygen, and flow, of such in-water instruments are often, externally mounted on the end-caps of their housings. The present invention relates particularly to a novel approach of building up an oceanographic instrument system composed of different modules, and of integrating such modules into one total system that is pressure-resistant and is sealed from the entry of water at all depths. The main usage of stackable housings will find application in remote recording instruments on mooring lines, pop-up buoys, drifters, and in all areas where expandability of a growing system is necessary. Hitherto known devices on instrument systems, in most cases, are constructed from a single cylindrical housing having at least a removable end-cap, and a fixed end-cap at either end of the housing. The principal drawback with such a widely used design is that, in general, the electronics cards, other optical or mechanical hardware, and batteries all compete for space within the fixed volume of the housing. This makes the design specific, often cumbersome to fabricate, and leads to a lack of modularity and reproducibility of the total system. Other major drawbacks of known oceanographic instrument systems include - • Possibility of a battery leak caused by a short or explosion during charging • Necessity to open up the entire housing to service a faulty component, or make a sensor change due to electronic circuits) drift or other faults, an adjustment to the optics, a battery change or to recharge the batteries. In order to highlight the novelty of this invention we consider a typical design example used widely in nearly all-commercial products. Fig 1 is a self-recording tide gauge comprising a single cylindrical PVC housing containing within it batteries, circuit boards, pressure sensor with hydraulic coupler. The entire contents of the gauge are built and supported upon single removable endcap of the housing. Any defect in a system part requires the removal of others connected to it. This very often, results in disturbing the O-ring seal on the end-cap, removing connectors, screws, spacers and other fixtures. The chances of maintaining integrity of the housing on reassembly are low, if due care and attention is not paid to the O-rings, removal of dirt on the grooves, and application of grease. A failure usually results in the destruction of the entire contents within the housing. Our new design of stackable housings is shown in Fig. 2. This consists of three (3) cylindrical housings cut from the same tube, and having the same diameter- namely a self-contained battery module [10] , an electronics module [9] with circuits boards ( not shown for the sake of clarity), together with a sensor module [8] and a front-end [12] to the sensor comprising of the hydraulic oil coupler built on the end-cap. All three housings are stacked vertically in a defined order-beginning with the battery module, the electronics, and the sensor module, and its front-end. The main object of the present invention is a device that implements stackable in-water pressure-resistant oceanographic housings that avoids the drawbacks of single mono-volume oceanographic housings, thus resulting in a high level of modularity, reproducibility, and high integrity of large numbers of the same. Another object of the present invention is to show that the same device used for implementing stackable housings works on securing end-caps on all single housings without the need of additional securing arrangements. In the drawings accompanying this specification: -Fig. 1 represents the conventional design of a self recording tide gauge used by us on a mooring line. The gauge comprises of a single housing of some marine grade material [1] having a fixed endcap [2], and a removable endcap [3] which is secured on the wall of the housing with screws. The sensor [4] is fitted to the endcap, and the hydraulic coupler [5] is locked onto the endcap. The circuit boards are mechanically fixed within the housing .A set of vertical supporting pillars are used to support the circuit boards [6], and the batteries [7]. The entire assembly is built on the endcap, and removed by pulling on the endcap. Fig. 2 represents the new device based on the design example of Fig.1, which comprises of three stackable housings [8], [9], and [10] with connecting air passages between two or more modules such that the modules can be interconnected. The battery housing [10] contains the batteries, but engages with the open end of the electronics module [9] and sensor module [8] through a set of wall mounted O-rings [11]; power connections may be routed by appropriate means to the electronics module. Similarly the sensor front-end module [12J contains only such components as would be required to be fitted to the sensor [4] as would allow it to perform its function - i.e. for use as a tide gauge, a pressure sensor would be fitted with a capillary hydraulic coupler to filter out high frequency fluctuations. The sensor front-end module [12] can be replaced and is accommodated within the removable end-cap [13], On the end-cap [13] sits an air valve [14] having a cover cap [15]. Fig.3 represents is identical to Fig.2 but with only inner-wall mounted O-ring arrangement [16] as the interconnection between housing modules; all other features being the same as in Fig.2.. This version of stackable housings would suffice for shallow water operation. Accordingly the present invention provides for A novel stackable in-water pressure resistant oceanographic housin comprise of the basic configuration of sensor(s), electronics, and built-in power source by providing separate modules in stackable housings (8,9,10) one for each sub-system, the said housings being interconnected with each other through 0 rings (11) so as to admit the free passage of air between them an air valve [14] having cap 15 provided on a removable end-cap [13],/the said end cap (13)bezy accomodating sensor front end module (12), for self locking together of the separate housings [8, 9, 10] into a mechanically stable segmented cylinder to get sealed to external pressures. In an embodiment of the present invention, a single cylindrical housing with an air valve may be mounted on the removable end-cap, and by evacuating the air from within the housing, the end-cap will be pulled tightly inwards to sit on the rim of the housing thus obviating the need of screwing the end-cap on the housing wall, or by other conventional means using extended flanges and connecting pillars on either end of the housing. The stackable housings of Fig.2 are each joined to each other by the use of wall mounted O-ring [11]. This sealing arrangement is necessary to prevent the entry of water when used in shallow and deep water environments. The air-valve [14] is seated on the removable end-cap [13], and by connecting a vacuum line to this valve, air from within all the stacked housings is removed creating a partial vacuum less than 1 atmosphere. Thus the segmented housing is mechanically rigid both in air, and when deployed to different depths in the ocean by virtue of the continuing pressure difference between the internal and external walls of the system. When retrieving the system from the ocean, it is necessary to open the air valve, resulting in an equalization of pressures across the walls, and thus dismantling with ease the separate modules of the system for servicing, replacement, or otherwise. This aspect of segmenting an oceanographic housing into separate modules is both novel and useful, as it does not constrain the designer to work within the limited volume of single pressure housing. The segmented approach of the present invention may also be applied to miniature housings of diameters less than 2 inches. The main advantages of the present invention are: - 1. Introduces a high degree of modularity in instrument systems for use in the oceanic environment. 2. Does not constrain the designer to work within a fixed volume of a single housing; expansion of space is built into the present invention. 3. Can be applied to current single housing system with end-caps without the need of introducing additional fixtures to secure the end-cap in place as is the case in all current designs of in-water instruments 4 The stacked system can work to any desired depth by suitable choice of wall thickness and diameter of individual housings. 5. The evacuation of air from within the system creates a moisture-free environment inside the system. 6. The use of re-chargeable batteries is safe in the present system as dismantling the battery module in open air can do charging. 7. Can provide a single cylindrical housing with an air valve may be mounted on the removable end-cap, thus obviating the need of screwing the end-cap on the housing wall, or by other conventional means using extended flanges and connecting pillars on either end of the housing. We claim: 1. A novel stackable in-water pressure resistant oceanographic housing Comprising of the basic configuration of sensor(s), electronics, and built-in power source by providing separate modules in stackable housings (8,9,10) one for each sub-system, -the said housings being interconnected with each other through O rings (11) so as to admit the free passage of air between them and air valve [14] having cap[15] ; provided on a removable end-cap [13],the said end cap(13)being accomodating sensor front end module (12), for together self locking of the separate housings [8, 9, 10] into a mechanically stable segmented cylinder to get sealed to external pressures. 2. A novel stackable in water pressure resistant oceanographic housing substantially herein described with reference to Fig. 2 of the drawings accompanying this specification.

Documents:

440-del-1999-abstract.pdf

440-del-1999-claims.pdf

440-del-1999-complete specification (granted).pdf

440-del-1999-correspondence-others.pdf

440-del-1999-correspondence-po.pdf

440-del-1999-description (complete).pdf

440-DEL-1999-Drawings.pdf

440-del-1999-form-1.pdf

440-del-1999-form-19.pdf

440-del-1999-form-2.pdf