FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION
Auxiliary switch case - wire routing and the assembly thereof in respective compartments in Circuit breakers.
2. APPLICANT(S)
(a) NAME : Larsen and Toubro Ltd.
(b) NATIONALITY: Indian
(c)ADDRESS : L&T House, Ballard Estate, Mumbai-400 001, India.
3. PREAMBLE TO THE DESCRITION
COMPLETE
The following specification particularly describes the invention and the manner in which it is to be performed
4. DESCRIPTION (Description shall start from next page)
5. CLAIMS (not applicable for provisional specification. Claims should start with the preamble -"I/We claim" on separate page)
6. DATE AND SIGNATURE (to be given on the last page of specification)
7. ABSTRACT OF THE INVENTION (to be given along with complete specification on the separate page)
Note:
*Repeat boxes in case of more than one entry
*To be signed by the applicant(s)or the authorized registered patent agent
*Name of the applicant should be given in full, family name in the beginning
*Complete address of the applicant should be given stating with postal index no. / code, state and
country
*Strike out the column which is/are not applicable

Auxiliary switch case - wire routing and the assembly thereof in circuit breakers
Field of the invention
Invention relates to auxiliary switch case, wire routing in circuit breakers. In particular invention is related to the mounting of auxiliary switches in a molded case circuit breaker and the likes, to customize a low voltage circuit breaker.
Background of the invention
The present invention is related to low voltage current limiting circuit breaker and the likes, which are commonly used to receive, supply, protect and isolate the current supply in an electrical circuit.
Circuit breaker typically serves two basic purposes:
1. as a switching device: Switching On/Off during normal operating conditions for the purpose of operation and maintenance.
2. as a protecting device: Tripping or Isolating by breaking the contacts interrupting the fault current during abnormal conditions such as short-circuit, overload and under voltage.
Circuit breaker consists of one or more electric poles, whose number determined by the application as single pole circuit breaker, two pole circuit breaker, three pole circuit breaker, four pole circuit breaker, five pole circuit breaker and so on.
Each pole is made of a contact system and each contact system consists of a moving contact, a pair of fixed contacts, a pair of arc chutes and Insulated drive shaft to rotate the moving contact to make connection and disconnection of current during ON-OFF operation. In-tum the fixed contacts are connected electrically to the phase or natural conductor associated with said pole.
Breaker consists of a molded case in which all these poles are housed. An operating mechanism with manual operating handle protruding out of the cover and a trip device bringing the mechanism to default condition when fault occurs. Tripping of the mechanism can happen through systems such as trip unit or release unit, through UV/Shunt release, or through external push to trip button. The state of the contacts when breaker is tripped has to be sensed and

communicated outside the panel through auxiliary means. Auxiliary units perform indication and/or control these functions. The means of mounting are flexible and provide varied combinations of auxiliary switches in a Chassis compartment of the breaker unit.
The space available for mounting these units inside the breaker unit are at less level, where optimized utilization has to take place. Isolation and Indication of the breaker unit is essential for field installation and to maintain uniqueness of the circuit breaker. Due to minimum space availability and to have optimized utilization of arrangement, one compartment needed to be utilized for multi auxiliary switches mounting.
It is necessary and desirable to provide an easy and reliable means of mounting arrangement for auxiliary switches in the low voltage circuit breaker, to customize the unit according to individual applications.
In prior art, the method used for auxiliary switch mounting configuration are described.
Currently the auxiliary switches are snap fitted inside the breaker unit where the contact between the sensing elements and switch unit are meager. During operation vibrations and the meager contact may lead to unreliable operation and or false sensing.
In particular, for the correct operation of the auxiliary units in a low voltage circuit breaker is fundamentally important that the sensing of the various poles contacts be actuated synchronously with each other, and furthermore because of the significant force levels involved, the auxiliary unit in the circuit breaker must be able to withstand adequately the forces involved during its working life and function to its fullest.
In one of the first type of solution available, (US5440088A), where the auxiliary unit is mounted in the breaker compartments with the help of limbs projecting from the auxiliary switch cover and snap type of arrangement which gets held in the compartment of the mid cover assembly.
In the second type of solution available, (US6232859B1), where the auxiliary switch mounting configuration for a molded case circuit breaker is described where the compartment in the mid cover assembly can accommodate one or more, multiple auxiliary switches with the help of serrated arrangement provided on the switch cover and the respective latching component on the

compartment. The entire set up formed with a single case. And the Switches are multiplied and placed adjacent to each other to form multiple options.
In the next type of solution available, (US20080237192A1), where electrical switching apparatus and accessory tray are described. The accessory tray provided may be a single piece molded member having a plurality of mounting portions for removable securing a plurality of circuit breakers along the guide mechanism provided on the mid cover.
In another type of solution (US20020112946A1), Ganged auxiliary switch consisting of at least two auxiliary switches attached to each other in a side-by-side relationship so that they may be inserted into the breaker unit together.
In all the above cases, a critical aspect arises from the use of the outer containment covers, for covering the auxiliary micro switch, which generally have a complicated, bulky shape and critical features to house the snap fit arrangement. Moreover, because of the stresses and vibrations that the outer cases have to withstand, these containment elements are subjected to deterioration and deformation in the mounting arrangement leading to unreliable signal output or sensing during fault operation.
Accordingly, it is often necessary to replace the auxiliary unit in the circuit breaker completely or possibly perform difficult and expensive maintenance operations in order to ensure adequate reliability. Clearly this has negative repercussions on the overall operating costs, and maintenance at site, of the circuit breaker intelligence performance as per customer requirements.
Object of the invention:
One object of the present invention is to provide a single case or multi case molded member shaped to accommodate standard micro-switch and extension thereof on to the breaker and shaped to accommodate wire-routing.
Another object of the present invention is to provide for multi-case construction, where combination of auxiliary units fitment is possible, which enables reliable performance and easy assembly and disassembly.

Yet another object of the present invention is to provide plurality of the slots on the chassis member to allow the auxiliary switch connection to the contacts sensing or trip bar sensing and communicate outside the mounting panel.
Further object of the present invention is to ensure correct operation of the auxiliary units in a low voltage circuit breaker where it is fundamentally important to sense various pole contacts be actuated synchronously with each other, and furthermore because of the significant force levels involved, the auxiliary unit in the circuit breaker must be able to withstand adequately the forces involved during its working life and function to its fullest.
Summary of the invention:
Single case or housing for auxiliary switch (13) consists of micro-switch actuator (17) projecting from the bottom side of the case. Holes (18) provided for assembling standard micro-switch with the switch-case (13) by passing two pins. Snap fits (19) are provided to accommodate the closing of live hinged cover (22), Cavity(20) formed between the bottom of the switch-case (13) and the hinge cover (22) is used to route wires in the sides. Extension (21) is provided from the switch-case (13). Extension (21) on the top side and captive locking (24) on the bottom side is used to mount the Auxiliary switch case assembly on to the breaker with captive locking and the likes on top sides and latching with the chassis compartment (4) on the bottom sides. Captive locking (24) also acts a guide. Cavity (23) at the back side is used to route wires on the top or bottom side. Number of micro-switches can be assembled together using holes (18) provided for assembling standard micro-switch with the switch-case (13) by passing two pins.
Description of the Drawings:
Figure 1: shows full view of all the elements involved with Low voltage breaker
Figure 2: assembly (12), shows the front view of the single case auxiliary switch assembly
Figure 3: shows a single case with standard auxiliary micro-switch (13) assembling with the
breaker unit
Figure 4: shows a multi-case with 2 or more standard micro-switch (15) assembling with the
breaker unit
Figure 5: shows Single case for standard auxiliary switch (13)
Figure 6: shows Multi case for standard auxiliary switch (15)

Figure 7: shows a sample, Top or bottom wires (10) routing in the cavity (23) Figure 8: shows a sample, side wire routing in opened and closed condition.
Figure 9: shows Multi-case auxiliary switch (15) assembled in the chassis compartment (4), with wires (10) routed on the sides
Detailed Description:
The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.
In the present invention the construction of auxiliary switch case or housing, the required performance of the unit is achieved by using a unique structural insulated member which is used as a single case member or multi-cavity member in case of multi-pole construction assembled in the chassis chamber. This member is a single piece molded structure which bears all the details shaped up on internal and External sides, to place / accommodate the micro-switch elements and the mounting elements and also provided with Closing live-hinge cover which provides Ingress protection and Also there is a through and through passages provided to accommodate proper wire routing in different configurations, where these routed wires are held between the cavities formed in the lower half and Hinge cover.
The proper holding of the wires provides the advantage pulling force not being transferred to the soldered wires, resulting in soldering reliability of the wires and termination feasibility by the customer with ease. As the construction of the component is a single piece mold, the structural strength is inherited and due to the type of mounting arrangement, gives positive locking and ensures the positional accuracy and rigidity. This in turn withstands the forces generated during the operation. In a multi-case construction, where combination auxiliary units fitment are possible, guiding and fitted together, enables reliable performance and easy assembly and disassembly.
In this kind of arrangement the Pluralities of the slots are provided on the chassis member to allow the auxiliary switch means connection to the contacts sensing or trip bar sensing and communicate outside the mounting panel.

The present invention consists of single case or multi case molded member shaped to accommodate standard micro-switch and extension to accommodate to mounting means on to the breaker and shaped to accommodate wire-routing.
In the present Invention. The disadvantages faced in prior art are over-ridden and many advantages are being achieved. Another object of the invention is to provide an auxiliary switching unit case for a LV power circuit breaker in which the connection among the various elements associated are provided simply and reliably, avoiding complicated joining and assembly operations. Another object of the present invention is to provide an auxiliary switching unit case for a LV circuit breaker and the likes that is easy to manufacture and at modest costs. The construction and mounting philosophy is explained with reference to the figures attached.
In Fig. 1, The assembly (11), shows the particular range of a Low voltage circuit breaker, multi pole v-construction, which consists of Line terminals(l), Load terminals(2), Housing unit (3), Chassis compartment (4), trip release unit (5), Front covering or closing elements (6), Internal accessories assembly (7). Operating mechanism (8), Push to Trip button (9). and a Auxiliary switch termination wires (10).The assembly gives a full view of all the elements involved with Low voltage breaker and clarity of the terms used as chassis compartment, Auxiliary switch assembly.
In Fig. 2 The assembly (12), shows the front view of the single case auxiliary switch assembly (13), in the cavities provided in the chassis compartment(4), with the wires(lO) routed by the sides of the breaker.
Fig. 3 represents a single case with standard auxiliary micro-switch (13) assembling with the breaker unit.
Fig. 4 represents a multi-case with 2 or more standard micro-switch (15) assembling with the breaker unit.
In Fig. 5, Single case for standard auxiliary switch (13) is explained.
Single case for standard auxiliary switch (13) consists of micro-switch actuator (17) projecting from the bottom side of the case. Holes (18) provided for assembling standard micro-switch with the switch-case (13) by passing two pins. Snap fits (19) are provided to accommodate the closing

of live hinged cover (22), Cavity(20) formed between the bottom of the switch-case (13)and the hinge cover (22) is used to route wires in the sides. Element (21), formed as a extension from the switch-case (13). Element (21) on the top side and element (24) on the bottom side is used to mount the Auxiliary switch case assembly on to the breaker with captive locking and the likes on top sides and latching with the chassis compartment (4) on the bottom sides. Element (24) also acts a guide. Cavity (23) at the back side is used to route wires on the top or bottom side.
In Fig. 6, Multi case for standard auxiliary switch (15) is explained.
Multi case for standard auxiliary switch (15) consists of one or more micro-switch actuator (17) projecting from the bottom side of the case. Holes (18) provided for assembling standard micro-switch with the switch-case(13) by passing two pins. Snap fits (19) are provided to accommodate the closing of live hinged cover (22), Cavity(20) formed between the bottom of the switch-case (13)and the hinge cover (22) is used to route wires in the sides. Element (21), formed as a extension from the switch-case(13). Element (21) on the top side and element (24) on the bottom side is used to mount the Auxiliary switch case assembly on to the breaker with captive locking and the likes on top sides and latching with the chassis compartment (4) on the bottom sides. Element (24) also acts a guide.
Cavity (23) at the back side is used to route wires on the top or bottom side.
Fig represents a exemplary two switches assembly. The case can be used to make more switches also.
Fig 7 represents a sample, Top or bottom wires (10) routing in the cavity (23).
Fig 8 represents a sample, side wire routing in opened and closed condition.
Fig. 9, represents the Multi-case auxiliary switch (15) assembled in the chassis compartment (4), with wires(lO) routed on the sides.
Comparing Fig 9 and Fig 2, where a single multi-case auxiliary switch-case and two single auxiliary switch case is assembled respectively shows that customer has an option of customizing the breaker with any number of auxiliary combinations at any point of the breaker
life.

Representation is only for a particular range and the Case of combining varied auxiliary switches and the wire routing methodologies vary from frame to frame. Some of the advantages of the present invention are as follows:
1. Accommodating standard micro-switch.
2. Forming single-case and Multi-case.
3. Optimizing space utilization.
4. Using reliable mounting arrangement.
5. Reliable Wire-routing arrangement is achieved.
6. Forming live-hinge component.
7. Holding wires between lower part of the case and the hinge part.
8. Avoiding force from being transmitted to the soldered wire joints.
9. Material advancement.
10. Inherently increasing the structural strength.
11. Reducing number of varieties.
12. Elimination of duplication of walls in multi-case
13. Achieving flexibility of combining switches to accommodate customer requirements.
14. Achieving modularity, improving functionality and increasing the ease of assembly.
15. Reducing assembly time and increasing manufacturing ease.

We claim,
1) A single switch case molded member for mounting standard micro-switch and extension
thereof on the breaker, the case comprising,
a housing, the housing having substantially rectangular profile with one pair of the
parallel edges of the housing have plurality of female slots (20) and an extension (21 and
24) on top and bottom of the housing respectively to clamp fit the said housing with the
breaker,
a housing cover (22), the housing cover has plurality of male protrusions which snap fit
in some of the female slots (20) on the said parallel edges and the housing cover hinged
on the second parallel pair of edges,
wire routing mode, wires on top and bottom side are routed through the cavity (23)
formed at the hinge point between housing cover (22) and the edge of the housing, wires
on sides are routed through cavity (20) formed by the said female protrusions on the
parallel edges and
Plurality of holes (18) in the said housing for assembling the standard micro-switch with
the switch case by passing pins through the holes.
2) A single case or multi case molded member for mounting standard micro-switch and
extension thereof on the breaker of the claim 1, wherein, plurality of single case members
can be joined to form multi-case mounting for micro-switches.