FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
AND
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2005
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
Modular enclosure for holding Printed Circuit Boards
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR
Sathe Mahesh of Crompton Greaves Ltd, Industrial Design Centre, Global R&D, Crompton Greaves, Kanjurmarg (East), Mumbai- 400042, Maharashtra, India; all Indian Nationals
PREAMBLE TO THE DESCRIPTION :
The following specification particularly describes the nature of this invention and the manner in which it is to be performed:

Field of the Invention:
This invention relates to the field of mechanics.
Particularly, this invention relates to the field of extruded mechanical assemblies.
Still particularly, this invention related to a modular enclosure for holding Printed Circuit Boards.
Background of the Invention:
Printed Circuit Boards (PCB) revolutionalised the world of electronics by providing a single flat board with electronic components soldered on to them, and tracks embedded onto said PCBs to interconnect said soldered electronic components. Typically, a PCB is a quadrangular board with a length side and breadth side. The height of the electronic components soldered on to the PCB defines the height of the PCB, in general.
Advancements in the field of electronics necessitated use of multiple PCBs for one single assembly, and required the need to house said multiple PCBs together. The limitations of installing multiple PCBs together lies in overcoming electromagnetic interference problems with respect to two adjacently located PCBs. A housing was designed to hold such PCBs together. A general limitation of the housing was to handle thermal loads of every PCB.
Typical enclosures include the design of a rectangular box (cuboid) with an open entry side. There were provided slots to receive the PCB, said

slots being defined in their gap in relation to thickness of said PCB. Also, in order to eliminate thermal overload and electromagnetic interference as discussed above, the PCBs were spaced apart at a pre-defined (particularly, greater) distance. This arrangement limited the number of PCBs in the housing.
The PCBs are generally slid in and out of the slots. Further, it was observed that the edges of the PCB may be uneven in their thickness. Thus, the sliding arrangement in the current enclosure may be redundant for an unevenly thick PCB. The power conducting tracks of the PCB are relayed on the edges throughout the perimeter of the PCB. These power conducting tracks cause a great deal of heating, and in the current enclosure, the heat from one PCB only translates to an adjacent PCB, thus harming the electronic components or the PCB itself.
PCB getting jammed into these slots / grooves which are integral with enclosure body makes the prior art design breakage prone while handling PCBs inside the enclosures. Apart from this absence of slots for accommodating enclosure mounting accessories like such enclosure draw out mechanism, clamping mechanism etc. have been restricting the use of such enclosures for relay and other similar products.
There is a need for a better enclosure for PCBs.
Objects of the Invention:
An object of the invention is to provide a modular enclosure for holding Printed Circuit Boards (PCB) with electronic components on them, which enclosure being adapted to accommodate PCBs with varying thickness.

Another object of this invention is to provide a thermally efficient modular enclosure for holding PCBs.
Summary of the Invention:
According to this invention, there is provided a modular enclosure for holding Printed Circuit Boards (PCB) in its operative configuration, said modular enclosure comprising:
a. housing means adapted to house at least one PCB, said housing
means including circular inner edges on at least two operatively
vertically opposite edges; and
b. at least two pairs of angularly displaced slats running parallel along
the depth of said housing with one pair extending out of one of said
circular inner edge and said other pair extending our of said other
operatively vertically opposite circular inner edge in order to define
a gap said two adjacent slats on each side for receiving a PCB.
Typically, said housing includes two pairs of operatively vertically opposite circular inner edges on the inner sides of the quadrangular housing.
Typically, said slats are unequally spaced from their adjacent slats on one edge, with corresponding unequal spaced apart adjacently located slats on the operative vertically opposite edge.
Typically, at least one pair of vertically opposite slats have different heights from an adjacently placed corresponding pair of slats.

Typically, at least a pair of non-angularly displaced slats are provided on a flat portion across a medial axis of said enclosure with corresponding non-angularly displaced slats on the flat portion of operatively vertically opposite flat portion.
Typically, said enclosure includes external slots for fitting said enclosure in an assembly of choice.
Brief Description of the Accompanying Drawings:
Figure 1 illustrates a prior art enclosure for PCBs.
The invention will now be described in relation to the accompanying drawings, in which:
Figure 2 illustrates a schematic of a front view of the modular enclosure for PCBs; and
Figure 3 illustrates a schematic of an auxiliary view of the modular enclosure for PCBs.
Detailed Description of the Accompanying Drawings:
Figure 1 illustrates a prior art enclosure for PCBs. A typically cuboidal housing (02) includes slots / grooves (04) for receiving PCBs (06). The PCBs with irregular thicknesses may not fit into or get jammed in to such slots / groove. Additionally, since the power conducting tracks are embedded on to the edges of the PCB, the heat from these tracks is emitted as shown, thus increasing the chance of damaging nearby

electrical components or adjacent PCB or power conducting tracks. The typical heat flow is depicted by the arrows (dotted).
Figure 2 illustrates a schematic of a front view of the modular enclosure for PCBs; in accordance with this invention. Figure 3 illustrates a schematic of an auxiliary view of the modular enclosure for PCBs in accordance with this invention.
In accordance with an embodiment of this invention, there is provided a housing means (10) or an enclosure adapted to house a plurality of PCBs (20A, 20B,...,20C) in their operative configuration. Typically, the PCBs are disposed in fashion parallel to one another and are spaced apart to accommodate electrical components that are mounted on them.
Typically, said housing means is circular (30) at the edges from the inside. Thus, the lateral cross-section of the housing is ellipsoidal in nature. A portion extending breadth-wise from the medial axis (40A — 40B), on either side, may be flat in nature.
In accordance with another embodiment of this invention, there are provided angularly displaced slats (50A, 50B, 50C,....,50N) through the depth of the housing. Typically the angularly displaced slates are of variable heights. These angularly displaced slates are mounted about the inner circular portion of the housing such that they extrude into the housing from the circular edge, running through the depth of the housing. Typically, a pair of adjacently placed slats forms a slot or a groove into where a PCB may be slid in or be slid out from. The angular displacement of the slats ensures that PCBs with variable thicknesses or irregularities may be slid in or out with ease. Further, the varying heights
t

of the slats also ensure that PCBs with variable breadths may be accommodated in the same housing, thus increasing its modularity. Still further, since the power conducting tracks are embedded on to the edges, the emission of heat is from an inner PCB shall steer away from the adjacently located PCB (as hot air has a tendency to rise). Thus, most of the heat dissipation will be through the top of the housing, with reduction in affecting the nearby PCB. The typical heat flow is depicted by the arrows (dotted).
In accordance with yet another embodiment of this invention, there are provided at least one pairs of slats (60) adjacently placed to form a groove or slot on said flat portion of the housing. These provide the maximum width / height possible for inlay of PCBs in to the housing.
In accordance with another embodiment of this invention there are provided external slots (70) for fitting said enclosure in an assembly of choice.
The electromagnetic interference noise problems are reduced. This particular enclosure apart from serving on aforesaid front, also offers features like slot of space for flush accommodation of relay draw out mechanism and slot for maintaining gap between outer enclosure and this enclosure for improvement of cooling efficiencies, thus making it superior in terms of thermal efficiency.
Typically, the gap between the slots defined by two adjacent slats is higher than IT VALUE, which eliminates use of card guides with use of PCB electrical insulation property carrying edge protection. PCB

insertion in card guides is sometimes problematic if the PCB depth is more i.e. above 100mm, as possible tilting of PCB during insertion and limited clearances width wise and height wise between card guides and PCB makes the process jamming prone. In the current invention, these problems are very difficult to occur.
In the prior art, the length and width of enclosure cross-section being big, the extrusion die design constraint did not allow slots of larger depth for single piece thin extrusion which ultimately did not allow use of any accessory which would have been flush mounted. Due to this, sometimes outer enclosure size increased, previously. But with the current invention, such limitation does not exist and flush mounting accessories can be accommodated with ease. Since no additional tooling is needed for building complete enclosure, tool cost is saved which is favorable for low off take products. Further, staggering PCBs inside enclosure also improves product internal aesthetics and provides flexibility to an electronics' designer to have thicker multilayer PCB designed in centre portion and normal thickness PCB'S designed for other reduced size PCB's of staggering construction.

We claim,
1. A modular enclosure for holding Printed Circuit Boards (PCB) in its
operative configuration, said modular enclosure comprising:
a. housing means adapted to house at least one PCB, said housing
means including circular inner edges on at least two operatively
vertically opposite edges; and
b. at least two pairs of angularly displaced slats running parallel along
the depth of said housing with one pair extending out of one of said
circular inner edge and said other pair extending our of said other
operatively vertically opposite circular inner edge in order to define
a gap said two adjacent slats on each side for receiving a PCB.
2. An enclosure as claimed in claim 1 wherein, said housing includes two pairs of operatively vertically opposite circular inner edges on the inner sides of the quadrangular housing.
3. An enclosure as claimed in claim 1 wherein, said slats are unequally spaced from their adjacent slats on one edge, with corresponding unequal spaced apart adjacently located slats on the operative vertically opposite edge.
4. An enclosure as claimed in claim 1 wherein, at least one pair of vertically opposite slats have different heights from an adjacently placed corresponding pair of slats.
5. An enclosure as claimed in claim 1 wherein, at least a pair of non-angularly displaced slats are provided on a flat portion across a medial axis of said enclosure with corresponding non-angularly displaced

slats on the flat portion of operatively vertically opposite flat portion.
6. An enclosure as claimed in claim 1 wherein, said enclosure includes external slots for fitting said enclosure in an assembly of choice.