WO2006076770A1

WO2006076770A1 - Camera enclosure for explosive environments

Info

Publication number: WO2006076770A1
Application number: PCT/AU2006/000064
Authority: WO
Inventors: Fritz Enderweit
Original assignee: Thermtech Pty Ltd
Priority date: 2005-01-21
Filing date: 2006-01-19
Publication date: 2006-07-27

Abstract

An enclosure (111) adapted to receive a camera (150) to render the camera safe in an explosive environment, the enclosure comprising a wall defining an interior which is isolated from the environment exterior to the enclosure and which is adapted to engage and support the camera such that the camera is held stationary relative to the enclosure, the enclosure being adapted to be able to be opened to enable insertion and removal of the camera from the enclosure, a window (117) in the wall of the enclosure and positioned to be aligned with the lens (152) of the camera when located in the interior, the window being transparent to the electromagnetic radiation to which the camera is sensitive, a display face (145) on the exterior of the enclosure adapted to provide visual access to the display of the camera, a set of control members manipulable from the exterior of the enclosure and adapted to facilitate manipulation of the camera control elements, the interior of the enclosure being sealingly isolated from the exterior when closed, an isolation means adapted to isolate the interior of the enclosure from the exterior environment.

Description

Camera enclosure for explosive environments

Field of the Invention

This invention relates to the enclosure which is intended to accommodate a camera in order that the camera can safely be used in a potentially explosive environment.

Background

In installations such as oil rigs, coal mines and similar sorts of environments in which combustible gases or readily flammable materials can be present it is not possible to safely use many forms of electronic devices including cameras because of the dangers of explosion. Any cameras including video cameras and particular video cameras which incorporate electronic circulatory can present a potential explosion risk if used in an explosive environment. However many instruments and appliances such as cameras can provide a very important monitoring tool in recording events and situations and are used in a wide variety of situations for that purpose but despite such advantages and because of safety considerations and regulations such instruments and appliances are restricted in their use in environments which can be potentially explosive. Generally such devices can only be used in such an installation which can be potentially explosive when such it is potentially explosive. Therefore in installations such as drill rigs which may be the subject of a gas leak it is usually only possible to use devices, such as cameras, which can be used to monitor and detect leaks in circumstances when there can be no leak which defeats the purpose for using the device. This restriction creates difficulties where it is necessary to monitor equipment whist it is active or to provide a monitoring service for such equipment for safety or security purposes. Disclosύre of the Invention

Throughout this specification the term camera shall be taken as comprising any form of camera or like device having a lens adapted to receive an image derived from the emission and /or reflection of an electromagnetic radiation and convey that image to a processing means which is able to produce at least an instantaneous display of the incoming image at a display, the camera having control elements which enable the operation of the camera to be controlled.

Accordingly the invention resides in an enclosure adapted to receive a camera to render the camera safe in an explosive environment, said enclosure comprising a wall defining an interior which is isolated from the environment exterior to the enclosure and which is adapted to engage and support the camera such that the camera is held stationary relative to the enclosure, the enclosure being adapted to be able to be opened to enable insertion and removal of the camera from the enclosure, a window in the wall of the enclosure and positioned to be aligned with the lens of the camera when located in the interior, the window being transparent to the electromagnetic radiation to which the camera is sensitive, a display face on the enclosure adapted to provide visual access to the display of the camera, a set of control members manipulable from the exterior of the enclosure and adapted to facilitate operation of the camera control elements from the exterior of the enclosure, the interior of the. enclosure being sealingly isolated from the exterior when closed, an isolation means adapted to isolate the interior of the enclosure from the exterior environment.

According to a preferred feature of the invention the isolation means comprises a controller to prevent the operation of the camera.

According to a preferred feature of the invention in use the enclosure is to be associated with a pressurised source of a non-flammable gas, the isolation means comprising:

an inlet adapted to be connected to the pressurised source of a non-flammable gas; a pressure sensor adapted to sense the pressure within the enclosure; and

an exhaust valve in the enclosure adapted to allow a controlled flow of gas from within the interior at a rate enabling the interior of the enclosure to attain a desired positive pressure differential relative to ambient pressure; and

the controller adapted to enable the operation of the camera after the interior has been pressurised from the source to the desired pressure differential.

According to a preferred feature of the invention a the controller is associated with a timer; the controller adapted to enable the operation of the camera after predetermined period has elapsed subsequent to the interior having been pressurised from the source to the desired pressure differential. According to a preferred feature of the invention the non-flammable gas medium comprises a gas sourced from an environment other than the surroundings of the enclosure. According to a preferred feature of the invention the source comprises a reservoir of compressed air.

According to a preferred feature of the invention the opening of the enclosure is facilitated by a closure associated with an opening in the wall to define a portion of the wall of the enclosure when closed and which is movable from engagement with the opening to enable said insertion and removal of the camera. According to a preferred feature of the invention the controller is adapted to prevent the operation of the camera when the closure is not closed.

According to a preferred feature of the invention the wall of the enclosure comprises at least two portions which are separable from each other to enable said insertion and removal of the camera. According to a preferred feature of the invention the controller is adapted to prevent the operation of the camera when the two portions are separated. - A -

According to a preferred feature of the invention the display face comprises a transparent panel which is to be aligned with the camera display to enable the camera display to be visible from the exterior of the enclosure.

According to a preferred feature of the invention the display face comprises a display means provided on the exterior of the camera and separate from the camera said display means being connected to the camera through circuitry to replicate the visual display of the camera at the display means.

According to a preferred feature of the invention the control members are mechanically connected to the camera to facilitate the operation of the control elements of the camera by the control members. According to an alternative preferred feature of the invention the control members are remotely connected through signal conductors to the camera to facilitate the operation of the control elements of the camera by the control members. According to a further alternative preferred feature of the invention the control members are associated with a transmitter which is able to communicate with a receiver associated with the camera to facilitate the operation of the control elements of the camera by the control members.

According to a preferred feature of the invention the display means comprises an electronically operated display means and said control members comprise touch elements provided on the display means.

According to a preferred feature of the invention the enclosure further comprises a support means provided to enable the support of the enclosure during use of the camera. According to a preferred feature of the invention the support comprises at least one handle. According to a preferred feature of the invention the support comprises a means receivable over a portion of the body of the operator. According to a preferred feature of the invention the support comprises a strap mounted to the enclosure and receivable around a portion of the operator. According to a preferred feature of the invention the support comprises a base adapted to be able to be fixedly supported from a support element. According to a preferred feature of the invention the support element comprises a tripod. According to a preferred feature of the invention the support element comprises a fixed structure.

The invention will be more fully understood in the light of the following description of several specific embodiments.

Brief Description of the Drawings

The description is made with reference to the accompanying drawings of which:

Figure 1 is a schematic isometric view of the enclosure according to the first embodiment;

Figure 2 comprises a plan view of the enclosure according to the first embodiment;

Figure 3 comprises a front elevation of the first embodiment;

Figure 4 comprises an inverted plan view of the first embodiment;

Figure 5 comprises a side elevation of the first embodiment;

Figure 6 comprises the other side elevation of the first embodiment;

Figure 7 comprises a rear isometric view of an enclosure according to the second embodiment;

Figure 8 comprises a front isometric view of an enclosure according to the second embodiment;

Figure 9 is a sectional view of an enclosure according to the second embodiment showing schematically a camera in position within the enclosure; and.

Figure 10 comprises a block circuit arrangement which is applicable to both embodiments. Detailed Description of Specific Embodiments

Each of the embodiments comprises an enclosure which is intended to receive an infrared camera which can provide infrared imaging and which can be utilised for the monitoring for the presence of adverse conditions such as overheating, leakages and the like in explosive environments. A particular application of the embodiments relates to an enclosure which can enable the camera to be used on an oil rig, in a coal mine or like hazardous environments. In the past a difficulty which has prevented the usage of such cameras in such environments is that they are electronically operated and there can be a likelihood of the generation of a spark. Therefore such cameras are very restricted in regard to their use in potentially explosive environments such as coal mines, oil rigs and like hazardous environments. This deprives such environments from the benefit of the use of such cameras for monitoring and/or diagnostic purposes when the environment is potentially explosive.

Each of the embodiments provides an enclosure for such cameras whereby the camera can be positively and securely stored within the enclosure and is able to be safely used in a potentially explosive environment without the likelihood of generating an explosion.

The first embodiment as shown Figures 1 to 6 comprises an enclosure 11 which is provided on its exterior with a handle 13 to facilitate manipulation of camera by an operator. In addition the enclosure 11 can be provided with a suitable strap

(not shown) which is receivable around the neck and/or body of the operator to provide support for the camera and enclosure in use. The underneath of the enclosure is provided with sockets or like location means 15 which can be engaged by a tripod or a fixed structure where the camera is to be held in a fixed location.

The interior of the enclosure (not shown) is adapted to accommodate a camera

(not shown) such that the camera is fixed relative to the enclosure and to this end the wall of enclosure is provided with a panel (not shown) which is removable to enable the camera to be installed into or removed from the enclosure. The front wall of the enclosure is provided with a window 17 which in use is to be aligned with the lens of the camera and which is formed of a material which will not interfere with the form of electromagnetic radiation to which the camera is to be sensitive. One particular application of the first embodiment relates to use with an infra-red camera to monitor a site for hot and/or cool spots and the like. Therefore in such an instance the lens will need to be transparent to the relevant range of infra-red radiation.

In addition the upper face of the enclosure is provided with a display element 19 comprising a liquid crystal display. The liquid crystal display is connected through suitable circuitry to the circuitry of the camera in order that the visual display of the camera is replicated from the display element 19. In addition the liquid crystal display is provided with touch elements which are operatively connected to the camera in order that by touching the touch elements, the actions of the control elements of the camera can be replicated and the operation of the camera can be controlled by appropriate touching of the touch elements. The circuitry of the display element is isolated from the exterior of the enclosure.

In addition the enclosure is provided with an air inlet 21 which is adapted to be connected to a source of pressurised air which can be supplied from a compressed air cylinder or alternatively a compressor where the inlet for the compressor is located remote from the location in which the camera is to be used. The enclosure is further provided with a release valve 23 which is adapted to enable the interior of the enclosure to be vented however the venting of the interior of the enclosure will only occur at a pressure greater than the ambient pressure of the environment in which the enclosure is to be located in order that a positive pressure differential will exist between the interior and exterior of the enclosure.

The operation of the camera is effected through a controller 30 which overrides the delivery of power to the camera. The circuitry associated with the controller

30 to control the camera accommodated by the enclosure is shown at Figure 10 and comprises a flow switch 31 which senses the flow of gas from the enclosure through the release valve. The circuitry further comprises a pressure switch 33 which is sensitive to the differential pressure between the interior of the enclosure and the surrounding environment whereby it is closed on the pressure differential being at the desired magnitude. The flow switch 31 , and the pressure switch 33 35 are all connected to the controller 30 through a primary interlock circuit 37. The controller is further associated with a timer circuit (not shown) which is activated on the desired flow as sensed by the flow switch being delivered from the enclosure through the release valve and on the pressure differential within the enclosure reaching the desired magnitude (i.e. the flow switch 31 and the pressure switch 33 are both closed). In use the camera is installed in the enclosure which is closed. The connection to the pressurised source is then opened to provide a flow of gas to the enclosure. After a satisfactory gas flow to the enclosure has been generated (as sensed by the flow switch) and pressure differential having been created (as sensed by the pressure switch) the timer is activated and on a predetermined period of time elapsing the controller enables power to be delivered to the camera and consequently the camera controls are able to be activated through the control members. The operating status of the camera is observable though a set of illuminated indicators which will illuminate according to the operational status of the controller. The indicators comprise;

• a first indicator which indicates that power is connected to the controller (i.e. whether it is in an ON or OFF status);

• a second indicator indicating the enclosure is closed, gas is being delivered out of the enclosure and that the desired pressure has been attained within the enclosure (i.e. the closure switch 31 , the pressure switch 33, temperature switch 37 and the flow switch 39 are all closed); and

• a third indicator indicating that the camera is active. In the event that the flow switch 39 is opened as a result of a reduced or nil flow of gas from the enclosure the controller will deactivate the camera by switching off the power supply to the camera. Similarly in the event that the pressure switch 33 is opened the controller will deactivate the camera by switching off the power supply to the camera.

In an example of the embodiment the enclosure is associated with a module such as a back pack or a like separate facility (not shown) which accommodates a gas cylinder and a power source (e.g. battery pack) and which is connected to the enclosure through an umbilical or the like which accommodates the gas delivery line which is to be connected to the inlet 21 and the power supply.

In an alternative example of the first embodiment the enclosure is associated with a module such as a back pack or a like separate facility (not shown) which accommodates a gas cylinder and the controller and which is connected to the enclosure through an umbilical or the like which accommodates the gas delivery line which is to be connected to the inlet 21 and the power supply (not shown) as well as the control lines (not shown) to the enclosure which control the activation of the camera upon all of the required parameters having been met to ensure the safe operation of the camera. The controller controls the deliver of power to the camera.

The enclosure according to the first embodiment provides a facility whereby a conventional video camera or the like can be utilised in an otherwise dangerous environment without the likelihood of generating an explosion or fire. This is effected by isolating the display of the camera and the control elements of the camera from the ambient conditions and maintaining the camera in a non- explosive environment.

The second embodiment as shown at Figures 7, 8 and 9 incorporates a controller which is of a similar form to that described in relation to the first embodiment and as shown at Figure 10 and which controls the deliver of power to the camera.. The significant difference between the embodiments comprises the configuration of the enclosure. As in the first embodiment the second embodiment comprises an enclosure 111 which is provided on its exterior with a handle (not shown). In addition the enclosure 111 can be provided with a suitable strap (not shown) which is receivable around the neck and/or body of the operator to provide support for the camera and enclosure in use. The underneath of the enclosure is provided with sockets or like location means (not shown) which can be engaged by a tripod or a fixed structure where the camera is to be held in a fixed location.

The second embodiment is intended for use with an infra-red camera 150 to monitor a site for hot and/or cool spots and the like and the interior of the enclosure is configured to accommodate the infrared camera 150 such that it is fixed relative to the enclosure. The camera with which the enclosure is to be used comprises a camera 150 having a body which is of a generally cubic form having a lens 152 at its forward face and a display panel 154 incorporating a liquid crystal display which is supported from the upper face of the body and extends from the body in a forwardly inclined manner. An example of a camera which can be used within the enclosure comprises on marketed under the trade mark FLIR ThermaCam P65.

The rear wall 123 of the enclosure is provided with a panel 125 which is removable to provide access to the data storage card of the camera and which is associated with an appropriate locking means and seal to ensure that when the panel is in the closed position it is sealingly retained in place . The front wall 127 of the enclosure is provided with a window 117 which in use is to be aligned with the lens 152 of the camera and which is formed of a material which will not interfere with the infrared image to be processed by the camera through the lens. The outer face of the window is associated with a grille 129 which overlies the window in order to protect it from damage.

In addition the upper face 141 of the enclosure is provided at its forward edge with a forward extension 119 which is configured to receive and enclose the display panel 154 of the camera. The upper face 143 of the forward extension is formed with a transparent panel 145 through which the display of the camera can be observed. The transparent panel 145 is formed of a suitably toughened transparent material which will not interfere with the image to be observed and will resist the anticipated forces to which the enclosure is expected to be subjected.

The upper face 141 of the enclosure is provided with a control members 147 in the form of knobs and the like which are associated with switches and like control elements within the enclosure and which are in use to be connected to the camera and which can activate the camera in order that by touching the switches and like control elements, the actions of the control elements of the camera can be replicated and the operation of the camera can be controlled.

In addition and as in the case of the first embodiment the enclosure of the second embodiment is provided with an air inlet 149 which is adapted to be connected to a source of pressurised air which can be supplied from a compressed air cylinder or alternatively a compressor where the inlet for the compressor is located remote from the location in which the camera is to be used. The enclosure is further provided with a release valve (not shown) which is adapted to enable the interior of the enclosure to be vented however the venting of the interior of the enclosure will only occur at a pressure greater than the ambient pressure of the environment in which the enclosure is located in order that a positive pressure differential will exist between the interior and exterior of the enclosure.

In an example of the embodiment the enclosure is associated with a module such as back pack or a like separate facility (not shown) which accommodates a gas cylinder and the controller and which is connected to the enclosure through an umbilical or the like which accommodates the gas delivery line which is to be connected to the inlet 149 and the power supply (not shown) which is connected to the enclosure though a cable 151 as well as the control lines 153 to the enclosure which control the activation of the camera upon all of the required parameters having been met to ensure the safe operation of the camera. According to an alternative form of the previous embodiment the invention the control members 147 of the previous embodiment may communicate with the camera control elements through a remote control transmitter accommodated within the enclosure in order that by touching the switches and like control elements, the actions of the control elements of the camera can be replicated and the operation of the camera can be controlled.

Throughout the specification and claims, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

It should be appreciated that the scope of the present invention need not be limited to the particular scope of the embodiments described above.

Claims

ClaimsThe claims defining the invention are as follows:

1. An enclosure adapted to receive a camera to render the camera safe in an explosive environment, said enclosure comprising a wall defining an interior which is isolated from the environment exterior to the enclosure and which is adapted to engage and support the camera such that the camera is held stationary relative to the enclosure, the enclosure being adapted to be able to be opened to enable insertion and removal of the camera from the enclosure, a window in the wall of the enclosure and positioned to be aligned with the lens of the camera when located in the interior, the window being transparent to the electromagnetic radiation to which the camera is sensitive, a display face on the exterior of the enclosure adapted to provide visual access to the display of the camera, a set of control members manipulable from the exterior of the enclosure and adapted to facilitate manipulation of the camera control elements, the interior of the enclosure being sealingly isolated from the exterior when closed, an isolation means adapted to isolate the interior of the enclosure from the exterior environment.

2. An enclosure as claimed at claim 1 wherein the isolation means comprises a controller to control the delivery of power to the camera when the interior is not at a desired pressure.

3. An enclosure as claimed at claim 2 wherein in use the enclosure is to be associated with a pressurised source of a non-flammable gas, the isolation means comprising:

an exhaust valve in the enclosure adapted to allow a controlled flow of gas from within the interior at a rate enabling the interior of the enclosure to attain a desired positive pressure differential relative to ambient pressure,

4. An enclosure as claimed at claim 3 wherein a the controller is associated with a timer; the controller adapted to enable the operation of the camera after predetermined period has elapsed subsequent to the interior having been pressurised from the source to the desired pressure differential.

5. An enclosure as claimed at claim 3 or 4 wherein the non-flammable gas medium comprises a gas sourced from an environment other than the surroundings of the enclosure.

6. An enclosure as claimed at claim 3 or 4 or 5 wherein the source comprises a reservoir of a compressed or liquefied gas.

7. An enclosure as claimed at claim 6 wherein the enclosure is associated with a module which accommodates isolation means, and the pressurised source, the module being separate from the enclosure is connected thereto by an umbilical accommodating the fluid line between the a pressurised source and the inlet and the delivery of electricity to the camera.

8. An enclosure as claimed at claim 7 wherein the module comprises a back pack.

9. An enclosure as claimed at any one of claims 1 to 8 wherein the opening of the enclosure is facilitated by a closure associated with an opening in the wall, the closure being movable from engagement with the opening to enable insertion and removal of the camera and access to a camera located within the interior.

10.An enclosure as claimed at claim 9 as dependant from any one of claims 2 to 6 wherein the controller is adapted to prevent the operation of the camera when the closure is not closed.

11.An enclosure as claimed at any one of claims 1 to 8 wherein the wall of the enclosure comprises at least two portions which are separable from each other to enable said insertion and removal of the camera.

12. An enclosure as claimed at claim 11 as dependant from any one of claims 2 to 9 wherein the controller is adapted to prevent the operation of the camera when the two portions are separated.

13.An enclosure as claimed at any one of claims 1 to 12 wherein the display face comprises a transparent panel which is to be aligned with the camera display to enable the camera display to be visible from the exterior of the enclosure.

14.An enclosure as claimed at any one of claims 1 to 12 wherein the display face comprises a display means provided on the exterior of the camera and separate from the camera said display means being connected to the camera through circuitry to replicate the visual display of the camera at the display means.

15.An enclosure as claimed at any one of the preceding claims wherein the control members are mechanically connected to the camera to facilitate the operation of the camera by the control members.

16.An enclosure as at any one of the claims 1 to 14 wherein the control members are connected to the camera through signal conductors to facilitate the operation of the control elements of the camera by the control members.

17.An enclosure as at any one of the claims 1 to 14 wherein the control members are associated with a transmitter which is able to communicate with a receiver associated with the camera to facilitate the operation of the control elements of the camera by the control members.

18.An enclosure as claimed at claim 16 or 17 wherein the display means comprises an electronically operated display means and said control members comprise touch elements provided on the display means.

19.An enclosure as claimed at any one of claims 1 to 18 further comprising a support means provided to enable the support of the enclosure during use of the camera.

20.An enclosure as claimed at claim 19 wherein the support comprises at least one handle.

21.An enclosure as claimed at claim 19 or 20 wherein the support comprises a means receivable over a portion of the body of the operator.

22.An enclosure as claimed at claim 21 wherein the support comprises a strap mounted to the enclosure and receivable around the a portion of he operator.

23.An enclosure as claimed at any one of claims 19 to 22 wherein the support comprises a base adapted to be able to be fixedly supported from a support element.

24.An enclosure as claimed at claim 23 wherein the support element comprises a tripod.

25.An enclosure as claimed at claim 23 wherein the support element comprises a fixed structure.

26.An enclosure substantially as herein described with reference to the accompanying drawings.