FORM2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
1. Title of the invention. - DOUBLE CATCH DOOR LOCKING
ARRANGEMENT IN A PANEL
2. Applicant(s)
(a) NAME : LARSEN & TOUBRO LIMITED
(b) NATIONALITY: An Indian Company.
(c) ADDRESS: L & T House, Ballard Estate, Mumbai 400 001, State of
Maharashtra, India
(a) NAME : TAMCO SWITCHGEAR SDN BHD
(b) NATIONALITY : A Malaysian Company
(c) ADDRESS: Sub Lot 24, Lot 16505, Jalan Keluli 1,
P.O. Box 2100, Kawasan Perindustrian Bukit Raja, Seksyen 7,
40000 Shah Alam, Selangor Darul Ehsan,
MALAYSIA
3. PREAMBLE TO THE DESCRIPTION
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 improved switchboards/panel structure which is capable to withstand higher dynamic force occurred during the transient conditions such as arc failures. More particularly, the invention is concerned about improved version of door locking of switchgear cubicles, which provides a higher withstand and pressure holding capacity with easier latching arrangement, thereby enhancing safety for the operating personnel
BACKGROUND OF THE INVENTION AND PRIOR ART
In the prior arrangements of switchboards/panel sheet metal type construction is done.
In prior art arrangement the operator safety from arc failures is ensured by fastening the door to the structure with multiple screws. This hinders the speedy operation and also endangers the operators safety if the all the screws are not properly fastened.
US 5,905,244 discloses upper and lower compartments are provided in metal-clad switchgear that are mirror images of each other. The compartments have doors that move toward one another to lock. The upper compartment has rails at the bottom for receiving a fuse truck, and the lower compartment has a division sheet between the compartment that has openings in it for receiving mating projections on the doors.
US 6,746,092 discloses a switchgear cabinet includes a plurality of securing apparatuses that are mounted on a vertical flange of the switchgear cabinet, with the securing apparatuses each being formed with a locking hole that is engageable by a pin of a locking mechanism on a door member. Each securing apparatus

includes an anchor plate connected with a first bracket and a second bracket, with the first and second brackets being mounted on the flange of the switchgear cabinet. The locking hole is formed in the anchor plate, and the anchor plate is substantially planar and free of bends. The anchor plate further is generally U-shaped and is configured to extend generally around at least a portion of the flange.
US 20080148642 discloses an arc-resistant door and casing design having a frame structure covered by a skin enhancing protection from damage and injury resulting from explosion and internal electrical fault. Thru-the-door breaker operation is provided by a racking mechanism having a threaded shaft operated by a user outside the door. An air cooling system for an arc-resistant switchgear cubicle having at least one insulated ventilation shaft longitudinally at a side of the cubicle whereby cooling air is drawn into the shaft from an inlet at a top end of the shaft and enters into the cubicle through an outlet of the shaft provided at a bottom area of the cubicle by convection. The cooling air mixes with warm air inside the cubicle and hot exhaust air flows upward to exit through at least one blow vent at a top area of the cubicle.
The drawbacks of the above mentioned prior art is that more number of hinge points is used resulting in more number of hinge component assemblies and related hardware. The panel assembly is cumbersome to assemble leading to higher material/manufacturing cost and assembly time which in totality results in the higher product cost leading ineffective optimized product in terms of cost. Further plenty of screws are used to fasten the door with the structure. This makes the door latching cumbersome, time consuming and gives a poor aesthetics. Also if all the screws are not fastened it may result in poor safety to the operating personnel. Hence the safety of the operator becomes manual dependent.
Thus there is a need to provide a unique double catch door locking arrangement which provides higher dynamic force withstanding capability, ease of operation,

better aesthetics & makes it independent of operators. In this arrangement more than double the locking points are offered as compared to the conventional method of door locking keeping the construction more rigid and light weighted at the same time
OBJECTS OF THE INVENTION
The basic object of the present invention is to overcome the disadvantages of the prior art.
Another object of the present invention is to provide an improved switchgear adapted to Withstand higher dynamic forces during transient state such as arc failure.
Yet another object of the present invention is to provide an improved switchgear panel structure adapted to make the operation safety and independent of manual efforts.
SUMMARY OF THE INVENTION
According to one aspect of the present invention there is provided An improved switchgear panel structure adapted to withstand high forces to enhance the rigidity of the panel structure, said structure comprising:
(i) plurality of door means comprising
atleast one metallic door catch means ;
atleast one elongated door slot means having a substantially L
shaped profile located on the outer casing of said door catch means
and

atleast one door catch pin means and
(ii) plurality of frame structure operatively connected with said door means comprising
atleast one metallic frame catch means
atleast one elongated frame catch slot means having a substantially L shaped profile located on the outer casing of said frame catch means
wherein said L shaped profile of the frame being provided symmetrically opposite in direction to said L shaped profile of the door and atleast one frame catch pin
such that said door catch slot accommodates into the pin of the frame catch and slot of the frame catch accommodates into the pin of the door catch to form a double catch locking arrangement of the frame structure and the door means.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to the improved version of door locking of switchgear cubicles, which provides a higher withstand and pressure holding capacity with easier latching arrangement, thereby enhancing safety for the operating personnel.
According to one of the embodiment of the present invention there is provided an improved switchgear panel structure adapted to withstand high forces to enhance the rigidity of the panel structure.
One embodiment of the present invention describes plurality of door means and plurality of frame structure operatively connected to the door means.

The plurality of door means is having one or more metallic door catch means, atleast one elongated door slot means having a substantially L shaped profile located on the outer casing of said door catch means and atleast one door catch pin means.
The plurality of frame structure having atleast one metallic frame catch means, atleast one elongated frame catch slot means having a substantially L shaped profile located on the outer casing of said frame catch means where the L shaped profile of the frame being symmetrically opposite to said L shaped profile of the door and atleast one frame catch pin .
The door catch slot accommodates into the pin of the frame catch and slot of the frame catch accommodates into the pin of the door catch to form a double catch locking arrangement of the frame structure and the door means.
In the present invention the equivalent or higher strength for fastening the door is achieved by double hook ( L-shaped) method which ensures easy, quick and safe operation independent of the operating personnel. The uniqueness of the locking is that the structure holds the door and the door holds the structure thus doubling the locking between two of them.
In this arrangement the catch pin and catch slot are arranged in such a manner so as to give more than double the locking points as compared to the conventional method of door locking keeping the construction more rigid and light weighted at the same time.
Addition to this the arrangement gives a different dimension to the Aesthetics and ergonomics of the structure making much more competent with the modern day structure.

The main feature of the device of the invention in which protection is sought is as follows:
♦ Provides a higher withstand and pressure holding capacity with easier latching arrangement, thereby enhancing safety for the operating personnel.
♦ Easy, quick & safe operation independent of the operating personnel.
♦ Provide better aesthetics and ergonomics as compared to screws on the frontdoor of the structure.
Another embodiment describes anti slipping feature in the structure in the present invention. The structure comprises additional door slots and frame pins which provides additional locking sideways (Perpendicular to the locking direction provided by the double catching door locking arrangement). This feature provides a higher withstand and pressure holding capacity with easier latching arrangement, thereby enhancing safety for the operating personnel.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
Fig. 1 illustrates the Panel.
Fig. 2 illustrates the Panel with door in open position.
Fig. 3 illustrates the Panel with door in open position in different orientation.
Fig. 4 illustrates the door with door catch on both the side.
Fig. 5 illustrates the frame structure with frame catch.
Fig.6 illustrates the frame structure with frame catch in different orientation
Fig.7 illustrates the door catch and frame catch in front view with the direction for locking.

Fig. 8 illustrates the door catch and frame catch in isometric view with the direction for locking.
Fig.9 illustrates the door catch and frame catch in front view with the direction for locking.
Fig. 10 illustrates the door catch and frame catch in front view in locked position.
Fig. 11 illustrates an isometric view of door (02).
Fig. 12 illustrates an isometric view of the door and the frame pin (11).
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWING
Figure 1 illustrates the panel (01) which is the final assembly.
Figure 2 illustrates the panel (01) having the Door (02) for'assembly of Panel (01) components, interlocks, indication and connections.
Figure 3 and figure 4 illustrates the door catch (03) which is the Metallic component for locking with the frame structure (06) (not shown in figure 3). The door catch slot (04) is the slot in door catch (03) for housing frame catch pin (09) (not shown in figure 3) and door catch pin (05) which provides locking by housing itself with the frame catch slot (08) ( not shown in figure 3).
Figure 5 and 6 illustrates the Frame structure (06) having metallic bar structure to make the panel assembly (01) rigid. The frame structure having frame catch (07) having metallic component for locking with the door (02).
Figure 7 and 8 illustrates the Frame catch slot (08) where the Slot in the frame catch (07) for housing door catch pin (05). The Frame catch pin (09) provides locking by housing itself with the door catch slot (04).
Figs. 11 and 12 show door slot (10) and the frame pin (11) which cooperate with each other so as to provide locking by housing the frame pins inside the slots.

The invention has been described in a preferred form only and many variations may be made in the invention which will still be comprised within its spirit. The • invention is not limited to the details cited above. The structure thus conceived is susceptible of numerous modifications and variations, all the details may furthermore be replaced with elements having technical equivalence. In practice the materials and dimensions may be any according to the requirements, which will still be comprised within its true spirit.

WE CLAIM
1. An improved switchgear panel structure adapted to withstand high forces
to enhance the rigidity of the panel structure, said structure comprising :
(i) plurality of door means comprising
atleast one metallic door catch means ;
atleast one elongated door slot means having a substantially L
shaped profile located on the outer casing of said door catch means
and
atleast one door catch pin means and
(ii) plurality of frame structure operatively connected with said door means comprising
atleast one metallic frame catch means
atleast one elongated frame catch slot means having a substantially L shaped profile located on the outer casing of said frame catch means
wherein said L shaped profile of the frame being provided symmetrically opposite in direction to said L shaped profile of the door and
atleast one frame catch pin
such that said door catch slot accommodates into the pin of the frame catch and slot of the frame catch accommodates into the pin of the door catch to form a double catch locking arrangement of the frame structure and the door means.
2. Structure as claimed in claim 1 wherein said door slot means is located on
each of the opposite sides of the outer casing of said door catch means
along its x-axis.

3. Structure as claimed in claim 1 wherein said door catch pin is located substantially on the base of said door catch means such that said pin provides locking by securing itself into said frame slot means.
4. Structure as claimed in claim 1 wherein said frame catch means is located on each of the opposite sides of the outer casing of said door frame catch means along its x-axis.
5. Structure as claimed in claim 1 wherein said frame catch pin is located substantially on the base of said frame catch means such that said frame pin provides locking by securing itself into said door slot means.
6. Structure as claimed in any of the preceding clams further comprises door slots.
7. Structure as claimed in any of the preceding clams further comprises frame pins.
8. Structure as claimed in claims 6 and 7 wherein said frame pins cooperatively engages with said door slots so as to provide sideway locking.
9. An improved switchgear panel structure adapted to withstand high forces to enhance the rigidity of the panel structure as substantially described hereinbefore with reference to accompanying drawings.