CLIAMS:1. An explosion proof enclosure (A) with capacitive touch interfacing system for protectively enclosing and readily utilizing of electrical devices in hazardous area comprising:

a main housing (1) including an open housing space and an opening; a lid (2) removably attached with the main housing (1) for closing the opening of main housing (1) and an electronic circuit disposed within the open housing space of said main housing (1);

wherein said lid (2) comprises a toughened window glass (9), a display circuit board (10) disposed inwardly on the window glass (9) comprises LEDs based seven segment (L) for displaying set value and process value from the window glass (9) and a capacitive touch sense keyboard (11) disposed beneath the display circuit board (10) inwardly on the window glass (9) comprises a plurality of capacitive touch sensing buttons (C) that are designed on said window glass (9);

wherein said electronic circuit comprises a SMPS unit (4) (switch mode power supply unit) for generating regulated small DC voltage, a CPU card (5) (printed circuit board) operated using small DC voltage includes a microcontroller and a capacitive touch sense controller interfaced with said microcontroller;

wherein said capacitive touch sense controller is controlled by the microcontroller;

wherein the SMPS unit (4) is mounted on said CPU card (5) at desired height using spacer (6).

2. The explosion proof enclosure (A) with capacitive touch interfacing system as claimed in claim 1, wherein said main housing (1) and the lid (2) are removably fastened through a LN key operated screw (3).

3. The explosion proof enclosure (A) with capacitive touch interfacing system as claimed in claim 1, wherein said main housing (1) and the lid (2) are covered with explosion proof material for being used in Gas group I, II and III.

4. The explosion proof enclosure (A) with capacitive touch interfacing system as claimed in claim 1, wherein the display circuit board (10) and the capacitive touch sense keyboard (11) are controlled using said microcontroller and the capacitive touch sense controller respectively.

5. The explosion proof enclosure (A) with capacitive touch interfacing system as claimed in claim 1, wherein plurality of glands (5) are mounted on the outer body of main housing (1) to connect the external cables including main power cable and communication cable with said electronics circuit.

6. The explosion proof enclosure (A) with capacitive touch interfacing system as claimed in claim (1), wherein the main housing (2) comprises a backplate (8) disposed in the bottom side of said main housing (1) for supplying main power to the electronics circuit.
,TagSPECI:FORM 2
THE PATENT ACT 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION: AN EXPLOSION PROOF ENCLOSURE WITH CAPACITIVE TOUCH INTERFACING SYSTEM

2. APPLICANT:
(a) NAME : Masibus Automation and
Instrumentation Pvt. Ltd.
(b) NATIONALITY : Indian
(c) ADDRESS : B-30, GIDC Electronics Estate,
Sector 25, Gandhinagar - 382044,
Gujarat, India

3. PREMABLE TO THE DESCRIPTION
PROVISIONAL

The following specification describes the invention. þ COMPLETE

The following specification particularly describes the invention and the manner in which it is to be performed.

Field of the invention

The present invention relates to an explosion proof enclosure for enclosing electronic devices intended to be used in hazardous industrial location. More particularly, it relates to an explosion proof enclosure having capacitive touch technology for easy and safe operation of itself in the hazardous areas of industries.

Back ground and prior art of the invention

At locations where oil or gas are processed, a number of flammable gases may be present, including mixtures of oxygen, methane, ethane, propane, hydrogen sulphide and others. Similar potentially dangerous conditions exist in locations in which petroleum products are being transported, recovered, refined, or processed. Likewise, dangerous conditions exist in other industrial areas where large quantities of dust are present, such as in grain handling facilities or pulp and paper mills. Standard classifications have been adopted by regulatory agencies based on the nature of the hazardous material that is generally present or may be present. Areas that defined as hazardous because of an explosion hazard are called “classified areas.”

Often, electrical equipment must be used in classified areas. But electrical components may generate heat and sparks sufficient to ignite a flammable gas or other flammable mixture, even under normal operating conditions. Because of this danger, electrical components in a classified area must either be enclosed in an “explosion proof” container, or the electrical components themselves must be “intrinsically safe.”

An “explosion proof” container is a container that is designed to enclose electrical devices that are capable of igniting an explosive material. The container must be capable of withstanding, without damage, an internal explosion of the hazardous material. By containing the internal explosion, an explosion proof container prevents the ignition of any explosive material surrounding the container. As a result, equipment and personnel outside the explosion proof container will remain safe. Such flame proof and explosion proof containers are used in hazardous areas in industries since long time. However, still many problems occur during operation of electrical devices enclosed in such explosion proof container when they are used in several industries. Such equipments are operated by various interfacing system including push-button interface, keyboard man-machine interface, infrared remote man-machine interface. Among them, the button man-machine interface is more clumsy way of input data, resulting in poor data entry efficiency. Keyboard man-machine interface or infrared remote control man-machine interface leads to lower efficiency. Compared to these various man-machine interface, touch-screen human-machine interface has the advantages of efficient data input. However, the existing touch-screen human-machine interface due to its structural limitations, does not apply in the hazardous areas.

Moreover, during operation in hazardous locations, the electrical devices are often extracted from explosion proof enclosure which is quit cumbersome and time consuming process. Further, in typical applications conducted in classified areas, explosion proof electrical equipments like temperature controllers are operated using electro-mechanical keyboard to alter process variable and set variable which can also be damaged due to high temperature and other hazardous parameters as discussed above. Hence, such components also require protection in hazardous location that leads to increases in overall size, cost and limited numbers of keys operation. As overall size increases, installation of product at production and field become tedious and intricate. Moreover, due to industrial experience, it is observed that explosion proof compatible keys are difficult to operate and required more force from operator’s finger. These electro-mechanical keys need regular maintenance which increases the cost of manufacturing also. Hence to overcome mechanical key issue and obtain better industrial control system, resistive type touch and capacitive touch technologies are available heretofore. However, electro-mechanical components and resistive touch systems pressure for operation which becomes assembly issue and life expectancy of operation.

Hence, there is an instant need of such type of invention that overcomes the difficulties associated with conventional explosion proof containers.

Object of the invention

The main object of present invention is to provide an explosion proof enclosure with capacitive touch technology that protect the electronics equipments from flammable and explosive materials in industries so as to improve safe use of equipments.

Another object of present invention is to provide an explosion proof enclosure with capacitive touch technology that is comparatively and substantially compact with respect to conventionally utilized explosion proof enclosure.

Yet another object of present invention is to provide an explosion proof enclosure with capacitive touch technology which is certified to use in severe hazardous area of the industries.

Further object of present invention is to provide an explosion proof enclosure with capacitive touch technology that eliminates the use of electro-mechanical components like switches push buttons etc.

Summary of the Invention

The present invention relates to an explosion proof enclosure in which electronic equipments are safely operated using capacitive touch interfacing system in coal mine and other industries where hazardous locations are existed. The invention provides an explosion proof container which includes a main housing and a lid. The main housing has an accommodation place therein. The lid is pivotally connected to the main housing with LN key operated screw. Both the main body and lid are made of explosion proof material. The lid comprises a display circuit board and a capacitive touch sense keyboard. An electronic circuit disposed within the explosion proof main housing contains a SMPS unit and a CPU card unit. Said CPU card unit contains microcontroller that controls the function of the display circuit board and capacitive touch sense keyboard. Moreover, the CPU card is also connected to an external computer through an industry standard communication protocol RS485 so that parameters displayed on the display circuit board can be seen from external screen.

To provide a further understanding of the present invention, the following detailed description illustrates embodiments and examples of the invention, this detailed description being provided herewith only for example of present invention.

Detailed description of the drawings

The invention will be better understood by reference to the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 shows a cross-sectional view of an explosion proof enclosure with capacitive touch technology according to the present invention.

Fig. 2 shows an exemplary view of an explosion proof enclosure with capacitive touch technology according to the present invention.

Detail description of the invention

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of the construction and arrangement of parts illustrated in the accompany drawings. The invention is capable of other embodiments, as depicted in different figures as described above and of being practiced or carried out in a variety of ways. It is to be understood that the phraseology and terminology employed herein is for the purpose of description and not of limitation.

In order to be operated in industrial installations with explosive and potentially explosive atmosphere, an electrical device should meet an accepted system of protection. The accepted system of protection should ensure that any explosive condition is contained within the device enclosure and does not ignite the surrounding environment. In this description, the term “explosion proof” and “flame proof” are used synonymously to avoid global variation in terminology. There are established standards for explosion proof or flame proof designs and device is certified to meet these standards.

The present invention discloses an explosion proof enclosure (A) with capacitive touch technology that is certified for use in gas group I, IIA, IIB and IIC to protect electronic devices. As shown in Fig. 1, the cross sectional view of the present invention, it mainly comprises a main housing (1) including an open housing space and an opening; a lid (2) configured to removably attached with the main housing structure (1) to cover the opening and provide enclosed explosion-proof housing structure (A); an electronic circuit disposed within said open housing space of the explosion-proof main housing structure (1). The main housing (1) and said lid (2) are removably fastened together by LN keys operated screw (3).

The electronic circuit comprises a SMPS unit (4) (switch mode power supply unit) for supplying regulated small DC voltage and a CPU card (5). The SMPS unit (4) is mounted on the CPU card (5) at desired height using a spacer (6). The DC voltage generated from said SMPS unit (4) is fed to the CPU card (5). The CPU card (5) comprises a microcontroller interfaced with a capacitive touch sense controller (not shown). The capacitive touch sense controller is controlled by said microcontroller.

The explosion proof housing structure (A) of the present invention is surrounded by aluminum alloy suitable for installation in hazardous location zone 0, zone-1 and zone 2 and also to provide ingress protection from dust and other liquids like water to the internal components.

The main housing (1) is further provided with multiple cable glands (7) for multi-core cable wiring to secure the cables coming from out side such as main power supply cable, data transmission cable etc.

A backplate (8) fixed by a screw on bottom of enclosure body (1) on which wiring connection is done to brought the main supply from the glands (7) to the SMPS unit (4).
Now as shown in Fig. 1 and Fig. 2, the lid (2) comprises a 100mm diameter toughened window glass (9), a display circuit board (10) disposed inwardly on the window glass (9) that is controlled by said micro controller comprises LEDs based seven segments (L) for displaying set value and process value from the window glass (9) and a capacitive touch sense key board (11) disposed beneath the display circuit board (10) inwardly on the window glass (9) that is controlled by said capacitive touch sense controller contains a plurality of capacitive touch sensing buttons (C) that are designed on said window glass (9) for changing parameters such as set value, auto/manual mode etc., as per requirement. The number of the capacitive buttons (C) is varied according to the parameter to be controlled. The window glass (9) provides excellent protection to the display circuit board (10) and the capacitive touch sense key board (11) so that user conveniently operates the capacitive sensing buttons (C) from the window glass (9) in hazardous locations of industries.
Furthermore, the CPU card (5) is connected to an external computer via the communication cable using RS485 interface protocol. Data within the CPU card (5) timely feedback via RS485 interface protocol to non-illustrated external computer when the capacitive touch sense controller receives commands from an Operator for projecting the parameters value displayed on said display circuit board (10) on the screen of the computer.
The present invention itself provides concept to safely operate all kinds of electronics devices being used in hazardous location. Said enclosed explosion-proof housing structure (A) according to present invention is not subjected to any limitation with respect to the shape and material to be used in the manufacturing of outer enclosed body of said explosion-proof housing structure (A). Moreover, arrangement of power supply and CPU card can be changed and also more components can be added in electronic circuit as per requirement.
It should be apparent to those skilled in the art that the above description is only illustrative of specific embodiments and examples of the invention. The invention should therefore cover various modifications and variations made to the herein-described structure and operations of the invention, provided they fall within the scope of the invention as defined in the following appended claims.