GB2212138A - Fluidtight housings - Google Patents

Abstract

A reinforced rigid housing e.g. for a camera comprises an outer plastics shell 15 and an inner metal jacket 1J. The shell 15 is of clear, rigid plastics, optionally with a bonded-on porthole cover of superior optical quality. <IMAGE>

Description

BUILDING OF REINFORCED ULTRA-COMPACT FLUIDTIGHT HOUSINGS This invention relates to a method for building of rigid fiuidtight housings with application of internal reinforcement which provides increased resistance against ambient hydraulic pressure.

Such a housing permits an apparatus built for use in the air to be operated submerged in a fluid (usually sea or fresh water) down to a depth limited by the design and used materials. Equipment encased within the housing normally should feature presence of optical functions andior requirement for visibility of operational controls (settings) and indications' reading.

As examples could serve: lighting appliances, scientific instruments, photo-, cine-, video-equipment, etc. Alternatively such a housing may protect only interior parts of an apparatus and partly or wholly replace its normal protective cover, in which case the housing becomes an integral part of the apparatus' marine version. The claimed method for building results in minimal overall size and dry weight of the housing which might prove indispensable for applications related to science, defence, intelligence, etc. and also could successfully fill a gap in the expanding market for equipment used in sub-aqua activities due to the low cost of materials and simplified manufacture.

A rigid hermetic housing when submerged in fluid is subjected to an ambient hydraulic pressure; further increase of this pressure deforms and finally breaks the housing's weakest wall (implosion). During the initial stages, before pressure becomes critical,deformation (although minimal in case of a rigid housing) may already cause malfunction of the encapsulated apparatus eg. jamming the film advance of a photo-camera. To withstand these effects rigid housings are made of highly tensile materials eg. metal alloys or have rounded forms and/or thick flat walls.

A housing cast in metal can be very compact and light-weight but it has its disadvantages viz. it is relatively expensive and does not permit visual inspection of seals and of equipment inside unless provided with appropriate portholes.

Housings built using clear or opaque plastic materials are seldom really compact; they normally have stress equalizing rounded forms and/or thick flat walls which are eventually reinforced by ribs or bulge of the same material and casually by single elements made of metal as plates, strips, struts, etc.

As a result plastic housings for higher ambient pressures or for larger items of equipment are bulky, cumbersome, and heavy (when not submerged) in relation to the protected apparatus' size and weight.

The claimed method for building of ultra-compact rigid fluidtight housings uses one relatively thin layer of clear plastic resin partially reinforced by a metal structure on its inner side. Basically such a housing comprises: - an internal non-hermetic partial metal structure, further referred to as jacket, cut out to allow reading and manipulation of the apparatus which is concentrically encased within with minimal clearance enabling easy removal and, - an external fully hermetic clear plastic casing, further referred to as shell, consisting of at least two separable co-operable portions (whose sealing rims may be externally reinforced by metal), which shell concentrically tightly encapsulates the jacket while maintaining minimal internal clearance to parts of the apparatus not covered by the jacket.

Reinforcement by a highly tensile metal jacket (with negligible thickness and weight) permits use of a thinner clear plastic resin for the shell walls without loss of rigidity. Hence thus reinforced housing, if properly designed and built,can be extremely compact (only slightly larger than the protected apparatus' size), strong, robust, and light-weight compared to conventional plastic housings designed to withstand the same ambient pressure; depending on used plastic resin the housing can be made also impact-resistant.

Four specific embodiments related to under-water photography describe the claimed method of building and reinforcement by way of example and illustrate it in the accompanying drawing. In order to enhance the claimed inventive features, all conventional parts and secondary details as manipulation gear, catchment design, etc. are not shown or if relevant are indicated schematically; later on, if appropriate, Utility Model resp.

Registered Design protection might be sought for individual versions of the housing built according to the claimed method.

Fig. 1 of the drawing represents exploded view of a housing for the compact 35mm photo-camera "Zenith",Model LOMO LC-A with vertical separation of the jacket; Fig.2 shows the central elevation of an assembled housing illustrated in Fig.1; Fig.3 shows exploded view of a housing for the 35mm SLR photo-camera "Cosina", Model CS - 1 with a Zoom-Lens and with horizontal separation of the jacket; Fig.4 shows the central elevation of an assembled housing illustrated in Fig.3 with a jacket made of metal sheeting; Fig.5 illustrates an alternative jacket example incorporating two fixed length round struts; Fig. refers to encircled detail in Fig.5 and shows an example of adjustable-length struts;; Fig.7 shows a cross-section through a miniature housing for the flash "Sunpack", Model Fotomatic 140 (open jacket version); Fig.8 represents the exploded view of a housing for the 35mm compact photo camera "Halina 1600" (closed jacket version); Fig.9 shows central elevation of the assembled housing illustrated in Fig.8.

Photo-equipment inside the assembled housings is shown with a dotted line and the basic parts of the housings are denoted as follows.

The main (body) portion accommodating the camera is 1 and the cover (lid) portion is 2; J stands for jacket and S - for shell; thus wherever applicable 1J is the body portion of the jacket and 1S is the body portion of the shell; the same is valid for the cover components 2J and 2S. Parts 1J and 1S resp. 2J and 25 are usually firmly fixed together thus forming the mentioned housing's portions 1 and 2. On assembly shell portions 1S and 2S surrounding the jacket are made hermetic by the O-ring 3; they also carry manipulation devices and catchments for holding the housing portions together (not shown or indicated schematically).

The plastic resin used for the shell should be sufficiently clear to allow optical functions as well as visual inspection of the equipment inside (through cut-outs on the jacket) including the visual check of seals' condition. If superior optical quality is indispensable for certain parts of the shell, then these can be made of another transparent resin or silicat glass and bonded on resp. attached to the main housing by means of a fluidtight seal; item 11 on Fig.8 and 9 serves as an example.

The other remaining items not mentioned specifically further on are: 4-camera fixing screw; 5-lens barrel extension with the porthole; 8-lens barrel O-ring. .

Assembly and disassembly, alignment and centring of housings' portions 1 and 2 can be deducted from Fig.1, 3, and 8 elucidated on the drawing by location of the co-operable jacket resp. shell portions. Three basic versions of the jacket are illustrated, each with a shell of appropriate design: 1. The CLOSED jacket (Fig.8 and 9) conveniently applicable to comparatively flat items of equipment lacking excessive frontal an/or hind protrusions as eg. some popular compact photo-cameras with motorized film advance. The closed jacket consists of an appropriately wide metal strip 1J bent to form a contiguous four-(or more)-edged casing around the middle of the camera; on assembly the latter is "threaded" through the jacket sidewise.

2. The OPE jacket (Fig.7) applicable to smaller housings comprising one U-shaped metal strip 1J of sufficient width which encases three sides of the apparatus; the gap on the fourth side is filled by the co-operable butt 2SB belonging to the complementary shell portion 2; in this particular example housing's (bottom) cover portion 2 is identical with both 2J and 28.

3. The universally applicable, vertically or horizontally SEPARABLE jacket consists of at least two co-operable portions 1J and 2J as illustrated on Fig. 1, 2, 3, 4, and 5. The co-operable jacket portions 1J and 25, with configuration dictated by the piece of equipment inside, fulfil the same dual function viz.: 1. Reinforcement of the shell effected by the exactly fitting surfaces (Fig.1,2,5,6) or edges (Fig.3,4) marked 1JF and 2JF (front) resp. 1JR and 2JR (rear), whose contact turns the assembled jacket into a strong protective casing which encases the apparatus within and strengthens the flat walls of the surrounding shell outwards.

2. Achievement of secure, exact, and quick centring of housing portions 1 and 2 on assembly by means of: in Fig.l and 2 (vertical assembly)-two side guides 1JG which forcibly align the frontal surface 2JF from both sides; in Fig.3 and 4 (horizontal assembly)-two side guides 23G for horizontal alignment and a lug 1JL for vertical alignment.

In Fig.5 and 6 reinforcement and alignment/centring are achieved by the cooperable round struts 9 and their receptacles 10.

A housing with widely spaced catchments as illustrated in Fig.3 and 4 is provided with an external frame 6 made of perforated metal sheeting; it is partially modified into four hooks 6H which co-operate with four catchment devices 7. The pressure frame 6 is an example of the external reinforcement which equalizes sealing pressure on O-ring 3; perforations permit visual inspection of the sealing line.

Claims (7)

1. A method for building of fluidtight housings withstanding ambient hydraulic pressure through application of internal reinforcement, wherein a highly tensile metal jacket, partially encasing the protected apparatus within, itself is concentrically encased inside of a separable, hermetic, rigid, clear plastic resin shell.

2. A fluidtight housing built as claimed in Claim 1, wherein the jacket consists of one metal piece which contiguously encases at least four adjacent sides of the protected apparatus (jacket's closed version).

3. A fluidtight housing built as claimed in Claim 1, wherein the jacket consists of one metal piece which surrounds at least three adjacent sides of the protected apparatus, while the fourth side is enclosed by a co-operable closely fitting plastic butt located on the complementary portion of the shell (jacket's open version).

4. A fluidtight housing built as claimed in Claim 1, wherein the metal jacket consists of at least two separable co-operable portions which, when assembled together, form a self-contained deformation-resistant casing surrounding at least four adjacent sides of the protected apparatus wherein rigidity, alignment, and centring of the said casing are achieved by fixed or adjustable guiding surfaces, edges, struts or their combinations.

5. A fluidtight housing built as claimed in Claim 1, wherein at least one sealing rim of a shell portion is provided with an external metal reinforcement frame which can be used as a part of the catchment device.

6. A housing built as claimed in Claim 1, wherein cover elements made of optically superior clear plastics or glass are bonded or otherwise hermetically affixed onto out-outs and portholes of the original plastic size

7. A fluidtight housing built as claimed in all preceeding Claims.

substantially as described herein. with reference to Fig. 1 to 9 of the accompanying drawing which illustrate four application examples of the elucidated building method.

6. A fluidtight housing built as claimed in all preceeding Claims, substantially as described herein with reference to Fig. 1 to 9 of the accompanying drawing which illustrate four application examples of the elucidated building method.

- 10 Amendaments to the claims have been filed as follows CLAIMS 1. Reinforcement technique for building of pressure resistant fluidtight housings, wherein the apparatus encased inside is double protected by two concentric layers of different material: firstly by an internal partial highly tensile metal jacket withstanding deformation and secondly by a hermetizing external rigid separable shell made of plastic resin.

2. A housing built as claimed in Claim 1, wherein the jacket consists of a single slit or seamless metal sleeve of any prdfile which contiguously encases at least four adjacent sides of the protected apparatus (jacket' s closed version).

3, A housing built as claimed in Claim 1, wherein the jacket consists of one metal piece which surrounds at least three adjacent sides of the protected apparatus, while the fourth side is enclosed by a co-operable closely fitting plastic butt located on the complementary portion of the shell (jacket's open version).

4. A housing built as claimed in Claim 1, wherein the metal jacket consists of at least two separable co-operable portions which, when assembled together, form a seif-contained deformation-resistant casing surrounding at least four adjacent sides of the protected apparatus wherein rigidity, alignment, and centring of the said casing are achieved by fixed or adjustable guiding surfaces, edges. struts or their combinations.

5. A housing built as claimed in Claim 1, wherein at least one sealing rim of a shell portion is provided with an external metal reinforcement frame which can be used as a part of the catchment device.