FORM 2
THE PATENTS ACT, 1970
COMPLETE SPECIFICATION
(See Section 10)
MODULAR SYSTEM FOR OPTIONAL MODULES IN PROTECTION AND CONTROL UNIT OF AIR CIRCUIT
BREAKER
APPLICANT:
LARSEN & TOUBRO LIMITED
L&T House, Ballard Estate, P.O. Box No. 278, Mumbai, 400 001, Maharashtra .
INDIA.
PREAMBLE OF THE DESCRIPTION:
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

A) TECHNICAL FIELD
[0001] The present invention generally relates to switching devices like circuit breakers and particularly relates to the protection and control units or main protection release in air circuit breakers. The present invention more particularly relates to optional modules for main protection release or protection and control units in air circuit breakers.
B) BACKGROUND OF THE INVENTION
[0002] A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit conditions. It is an electrical device used to protect the electrical load from an over current condition, when exposed to more electrical current than it is designed to handle. A circuit breaker is designed to break the circuit and stop the current flow, when the current exceeds a predetermined value.
[0003] Several types of circuit breakers are commonly used in electronic protection and control units. Two of the most common types of circuit breakers are molded case circuit breakers and air circuit breakers. In the molded case circuit breaker, the entire assembly is enclosed in a molded and non metallic case, lu the air circuit breaker, the operating mechanism is enclosed in a container, but it is accessible for inspection and maintenance.
[0004] The air circuit breakers (ACB) are commonly available in continuous current ratings of from 400 amperes to 6300 amperes, and at voltages up to 1000 volts. These air circuit breakers are suitable for lighting and power circuits as well as motor starting and
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running service. They are equipped with heavy-duty contacts, arc quenchers, and operating mechanism, which may be either manual or automatic.
[0005] The ACB has the advantages of being easy to inspect, test and maintain. The circuit protection is the main function of the air circuit breaker. But the most important function of the ACB is the protection release. The protection release issues a trip command to the air circuit breaker. The protection release offers a very simple, cost effective and reliable protection. Since the protection release operates directly on the trip mechanism of ACB, the protection release trips the breaker irrespective of the availability of the control supply or healthiness of the trip circuit. Though the circuit breaker configurations are normally ordered as per the system requirements, there are several instances where users have to add/delete accessories and where the modularity plays a vital role.
[0006] The optional modules are used in conjunction with the main protection release of the circuit breakers which includes communication module, configuration module and profibus module. Normally, the mounting of these modules is external to the circuit breaker i.e. on the Designed for Installation (DIN) rail provided on the side plates of the circuit breaker. Additional wire harness such as cable assemblies, connectors, and crimps and hardware such as washer, nut and screw are required for mounting and establishing the connectivity between the add-on modules and main protection and control unit. The modules contain maximum bulkier components.


[0007] The currently available protection and control units provide a system and method for mounting modules in circuit breakers. Earlier the mounting of these modules was external to the circuit breaker. The external mounting tends to the probe into Electro Magnetic Interference/Electro Magnetic Compatibility (EMI/EMC) problems. The modules contain maximum bulkier components thereby occupying more space.
[0008] The US Patent 6 734 380 discloses an add-on unit for coupling to a main electrical appliance with separable power contacts, including a housing having a front face and a rear face, and for mounting frontally against or into such main appliance. The add-on signaling units associated with the circuit breakers comprise at least one switch component and/or electronic processing circuit to communicate with the main appliance via mechanical dialogue components and/or electrical connection components.
[0009] The US Patent 6,696,654 discloses a novel design of secondary isolating contacts in the circuit breakers. It is aimed at achieving higher modularity so that various accessories provided in the circuit breaker can be easily added and/or replaced.
[0010] The US Patent 6,064,018 discloses a molded case circuit breaker with molded pole assembly. A molded case circuit breaker base is configured to receive the pole modules that include the circuit breaker components for multi pole operation. The base is configured to receive the bottom edges of the module enclosure in a press-fit relation. A complementary molded case circuit breaker cover is attached to the top of the modules to complete the multi pole circuit breaker enclosure.
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[0011] All the above mentioned prior arts are related to the main housing of the breaker. The present invention provides modularity in the protection and control release of ACB. From the conventional methods, it is seen that an additional wire harness (cable assemblies, connectors, and crimps) and hardware (washer, nut, and screw) are required for mounting and establishing the connectivity between the add-on modules and main protection and control unit. The additional wire harness results in chances of bad connectivity due to loose contact, rupturing of the insulation thereby making the maintenance and replacements very much tedious. The additional wire harness requires shielding of wires which inturns increases the cost. Since additional hardware is required for mounting the circuit breaker modules, the cost of mounting of the modules also increases.
[0012] Hence there is a need to provide modularity in mounting or racking the optional modules used in protection and control releaseof circuit breaker for flexible insertion and extraction of modules. Hence there is a need to eliminate the additional internal wiring required for ease of maintenance/replacement operations. The conventional mounting techniques use maximum bulkier components thereby occupying more space. Hence there is a need to eliminate the cost of the mounting the modules in the main release of the circuit breaker.
[0013] The abovementioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.
C) OBJECT OF THE INVENTION

[0014] The primary object of the present invention is to provide a modular system for the optional modules in the protection and control release of a circuit breaker for the flexible insertion and extraction of the modules in the circuit breakers such as air circuit breakers.
[0015] Another object of the present invention is to provide a modular system for the optional modules in the main protection release of the air circuit breakers with a cassette pulling mechanism to insert and/or detach the modules from the main unit.
[0016] Yet another object of the present invention is to enclose the modules in a compact casing made of insulative material to avoid the electromagnetic interference and the direct exposure of the power circuit breaker to the environment.
[0017] Yet another object of the present invention is to provide a modular system for the optional modules in the main protection release of the air circuit breakers with connectors to plug in the optional modules into the main unit thereby reducing the need for wire harness and its inference on the connectivity.
[0018] Yet another object of the present invention is to provide a modular system for the optional modules in the main protection release of the air circuit breakers with a blind mating mechanism for the blind insertion of the optional modules in the main release to avoid any misalignment or loose connection of the mating connectors.

[0019] Yet another object of the present invention is to provide a modular system for the optional modules in the main protection release of the air circuit breakers with a click fit mechanism to engage the cover and the bottom casing of the add-on modules and to mount the add-on modules of the circuit breaker without using screws and tools.
[0020] Yet another object of the present invention is to provide a modular system for the optional modules in the main protection release of the air circuit breakers with a screwless mounting system for the optional modules so that the additional hardware required for mounting the modules is eliminated thereby reducing the maintenance cost.
[0021] These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.
D) SUMMARY OF THE INVENTION
[0022] The various embodiments of the present invention provide a modular system for the optional modules in the main protection and control release of the circuit breakers. According to one embodiment of the present invention, a modular system is provided for the easy insertion and withdrawal of the optional modules in a protection and control unit of an air circuit breaker. The system is provided with a main body to house a protection and control unit. Pluralities of recesses are arranged in the main body housing the protection and control unit to receive plurality of the optional modules. A guide rib is
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provided at the side wall in each of the plurality of the recesses. A stopper is provided in each of the plurality of the recesses.
[0023] A casing is provided to store each optional module. The casing has a bottom case and a top cover. A cassette pulling mechanism is provided in the casing to enable the insertion and the withdrawal of the modules from the protection and control unit of the air circuit breakers. A mating rib is provided on the side wall of casing to engage with the guide ribs provided in the recesses at the mainbody housing the protection and control unit during the insertion of the optional modules into the main body housing the protection and control unit. An optional module is received in one of the recesses and the cassette pulling mechanism is used to establish a connection between the protection and control unit and the inserted optional module.
[0024] The cassette pulling mechanism has a cam which is rotated during the insertion of the optional module into the recesses provided in the main body housing the protection and control unit to establish an electrical contact between the connectors that are provided respectively in the protection and control unit and the optional module. The cam is positioned vertically in the optional module, when the optional module is not inserted into the main body of the protection and control unit. The cam is further provided with a hook for locking. The cam is rotated after the insertion of the optional module into the recess provided in the main body housing the protection and control unit to engage the hook with the stopper provided in the recess to lock the optional module with the protection and control unit. The cam is rotated against the stopper to release the
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locking of the hook from the stopper provided in the recess at the main body of the protection and control unit, when the optional module is removed from main body of the protection and control unit. The cam is rotated from the vertical position to horizontal position to separate the contact between the connectors of the protection and control unit and the optional module, when the optional module is removed from main body of the protection and control unit.
[0025] The guide rib is provided at the side wall of the recess provided in the main body of the protection and control unit to receive the mating guide rib provided in the side wall of the casing housing the optional module to establish a blind mating connection, when the optional module is inserted into the recess at the main body of the protection and control unit. The stopper is provided at the side wall of the recess to engage with the hook provided in the cam arranged at the side wall of the casing of the optional module to prevent the removal of the optional module from the main body of the protection and control unit after the insertion of the optional module into the main body of the protection and control unit.
[0026] The casing housing the optional module has a bottom case and a cover. The cover and the bottom case of the optional module are provided with click fit mechanism to fasten the cover with the bottom case in the optional module. The casing is made up of insulative material to provide protection for the printed circuit board stored inside the casing of the optional module against electromagnetic interference and electromagnetic compatibility problems.
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[0027] According to one embodiment of the present invention, the modular optional and/or add-on modules are made as part of the main protection release. All optional modules reside in the main release itself. The electronics circuit of the module is enclosed in a small thermoplastic casing made up of material such like polycarbonate. The casing has bottom housing and a cover. The bottom housing and the cover are engaged with one or more click-fit arrangements. The casings are more compact to fit into the main unit. The casings are designed in such a way that module gets locked inside and is designed to avoid direct exposure of the power circuit breakers to outside environment and to avoid electromagnetic interference. The connectors are used to plug in the main unit. This lessens the need of wire harness and its implications on the connectivity. The whole assembly of optional modules is screw less or tool free.
[0028] According to the embodiment of the present invention a cassette pulling mechanism is provided to insert and/or detach the modules from the main unit. The pulling mechanism includes a rotating cam with a hook profile, rotatably engaged in the support protruded from the casing on both sides. While inserting the module, the rotating cam position should be perpendicular to the main release. At the end of the insertion, when connectors are aligned properly and connections are made between the connectors, the module is needed to be locked inside the main release. For this, the rotating cam position is changed from the horizontal position to the vertical position and the hook profile on the rotating cam gets locked with a vertical stopper placed in the main release.
[0029] Once connection is established between the connectors, the disengagement force of connector is tremendous. To remove the module from the main release, there is a
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special rotating cam mechanism. To remove the module from the main release, user rotates the rotating cam against the vertical stopper in the main housing. After rotating the rotating cam about 90 degree, the connectors are disengaged from each other.
[0030] A sliding guide is given in the main unit for proper insertion and extraction of cassette module. The insertion of module in main release is a blind insertion. To avoid any misalignment or loose connection of mating connectors, guide ribs are provided in the main release housing. Corresponding mating ribs are also provided on each module at both sides. While inserting the module in the main release, the guide ribs in main release housing guide the module in such a way that, the module does not get any horizontal or vertical movement area, so that the mating connectors get properly aligned.
[0031] Hence insertion of module while making connection and removal of module while performing maintenance are achieved simply and quickly without requiring any tool. Hence the present invention provides modularity in mounting the optional modules used in protection and control release of circuit breaker for flexible insertion and extraction of modules. Moreover the system eliminates the additional internal wiring required for ease of maintenance/replacement. The entire system is unique, compact, light weight and advanced.
E) BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:
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[0033] FIG. 1 illustrates a perspective view of a modular system for optional modules in the main protection and control release of the circuit breaker according to one embodiment of the present invention,
[0034] FIG. 2 illustrates a perspective view of a modular system for optional modules in the main protection and control release of the circuit breaker with optional modules inserted, according to one embodiment of the present invention.
[0035] FIG. 3 illustrates a perspective view of a modular system for optional modules in the main protection and controlrelease/ with the optional modules in assembled and pulled-out condition, according to one embodiment of the present invention.
[0036] FIG. 4 illustrates a perspective view of an optional module in the modular system for optional modules in the main protection and control release according to one embodiment of the present invention.
[0037] Although the specific features of the present invention are shown in some drawings and not in others, this is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.
F) DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0038] In the following detailed description, a reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be
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practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.
[0039] The various embodiments of the present invention provide a modular system for the optional modules in the main protection release/main release of the circuit breakers. According to one embodiment of the present invention, a modular system is provided for the easy insertion and withdrawal of the optional modules in a protection and control unit of an air circuit breaker. The system is provided with a main body to house a protection and control unit. Pluralities of recesses are arranged in the main body housing the protection and control unit to receive plurality of the optional modules. A guide rib is provided at the side wall in each of the plurality of the recesses. A stopper is provided in each of the plurality of the recesses.
[0040] A casing is provided to store each optional module. The casing has a bottom case and a top cover. A cassette pulling mechanism is provided in the casing to enable the insertion and the withdrawal of the modules from the protection and control unit of the air circuit breakers. A mating rib is provided on the side wall of casing to engage with the guide ribs provided in the recesses at the mainbody housing the protection and control unit during the insertion of the optional modules into the main body housing the protection and control unit. An optional module is received in one of the recesses and the
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cassette pulling mechanism is used to establish a connection between the protection and control unit and the inserted optional module.
[0041] The cassette pulling mechanism has a cam which is rotated during the insertion of the optional module into the recesses provided in the main body housing the protection and control unit to establish an electrical contact between the connectors that are provided respectively in the protection and control unit and the optional module. The cam is positioned vertically in the optional module, when the optional module is not inserted into the main body of the protection and control unit. The cam is further provided with a hook for locking. The cam is rotated after the insertion of the optional module into the recess provided in the main body housing the protection and control unit to engage the hook with the stopper provided in the recess to lock the optional module with the protection and control unit. The cam is rotated against the stopper to release the locking of the hook from the stopper provided in the recess at the main body of the protection and control unit, when the optional module is removed from main body of the protection and control unit. The cam is rotated from the vertical position to horizontal position to separate the contact between the connectors of the protection and control unit and the optional module, when the optional module is removed from main body of the protection and control unit.
[0042] The guide rib is provided at the side wall of the recess provided in the main body of the protection and control unit to receive the mating guide rib provided in the side wall of the casing housing the optional module to establish a blind mating
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connection, when the optional module is inserted into the recess at the main body of the protection and control unit. The stopper is provided at the side wall of the recess to engage with the hook provided in the cam arranged at the side wall of the casing of the optional module to prevent the removal of the optional module from the main body of the protection and control unit after the insertion of the optional module into the main body of the protection and control unit.
[0043] The casing housing the optional module has a bottom case and a cover. The cover and the bottom case of the optional module are provided with click fit mechanism to fasten the cover with the bottom case in the optional module. The casing is made up of insulative material to provide protection for the printed circuit board stored inside the casing of the optional module against electromagnetic interference and electromagnetic compatibility problems.
[0044] According to one embodiment of the present invention, the modular optional and/or add-on modules are made as part of the main protection release. All optional modules reside in the protection and control release itself and to avoid external mounting of modules which tends to the probe into Electro Magnetic Interference/Electro Magnetic Compatibility (EMI/EMC) problems.
[0045] The electronics circuit of the module is enclosed in a small thermoplastic casing made up of material such like polycarbonate. The casing has bottom housing and a cover. The bottom housing and the cover are engaged with one or more click-fit arrangements. The casings are more compact to fit into the main release/protection release. The casings
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are designed in such a way that module gets locked inside the main release after the insertion of module into the main release. The casings are designed to avoid direct exposure of the power circuit breakers to outside environment and to avoid electromagnetic interference. The sleek connectors are used to plug in the main unit. This arrangement reduces the need of wire harness and its implications on the connectivity. The whole assembly of optional modules is a screw less and a tool free.
[0046] According to the embodiment of the present invention, a cassette pulling mechanism is provided to insert and/or detach the modules from the main unit. The cassette pulling mechanism includes a rotating cam with a hook profile. The rotating cam with the hook profile is rotatably engaged in the support protruded from the casing on both sides. While inserting the module into the main release, the rotating cam position should be perpendicular to the main release. At the end of the insertion, when connector is aligned properly and connections are made between the connectors, the module is needed to be locked inside the main release. For this, the rotating cam position is changed from the horizontal position to the vertical position and the hook profile on the rotating cam gets locked with a vertical stopper placed in the main release.
[0047] Once connection is established between the connectors, the disengagement force of connector is tremendous. To remove the module from the main release, user rotates the rotating cam against the vertical stopper in the main housing. After rotating the rotating cam about 90 degree, the connectors are disengaged from each other.


[0048] A sliding guide is given in the main unit for proper insertion and extraction of cassette module. The insertion of module into the main release is a blind insertion. To avoid any misalignment or loose connection of mating connectors, guide ribs are provided in the main housing of the main release. Corresponding mating ribs are also provided on each module at both sides. While inserting the module in the main release, the guide ribs in main housing guide the module in such a way that the module does not get any horizontal or vertical movement area, so that the mating connectors get properly aligned.
[0049] Hence insertion of module while making connection and removal of module while performing maintenance are achieved simply and quickly without requiring any tool. Hence the present invention provides modularity in mounting the optional modules used in protection release/main release of circuit breaker for flexible insertion and extraction of modules.
[0050] FIG. 1 illustrates a perspective view of a modular system for the optional modules in the main protection release/main release of the circuit breaker according to one embodiment of the present invention. With respect to FIG. 1, the protection and control release/ of the circuit breaker 100 includes one or more slots/recesses 102 at the front side. These slots/recesses 102 are used to engage the optional modules and/or add¬on modules which are part of the protection and control release 108. The recesses 102 are provided with guide ribs 104 and a vertical stopper 106. The guide ribs 104 are horizontally mounted on both the inner walls of the recesses 102. The vertical stopper 106 is mounted at the front side of the recesses 102.
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[0051] The guide ribs 104 are used to guide the mating ribs provided in an optional module or an add-on module, when the optional module or the add-on module is inserted into the system 100 sothat the optional module or the add-on module is not provided with any horizontal or vertical movement area. The vertical stopper 106 is locked with a hook profile in the optional module or add-on module after the entire insertion of the optional module or add-on module into the system 100. Thus the guide ribs 104 and the vertical stopper 106 in the system 100 are used to align the mating connectors properly and to make strong connections between the mating connectors.
[0052] FIG. 2 illustrates a perspective view of a system for optional modules in the main protection and control release of the circuit breaker with optional modules being inserted, according to one embodiment of the present invention. With respect to FIG. 2, the system 100 includes optional modules 2001, 2002 and 2003 which are partially racked-in into the system 100. Each optional module 2001, 2002 and 2003 includes a cassette pulling mechanism comprising a rotating cam 202 with a hook profile. The cassette pulling mechanism is mounted on both the sides of each optional module 2001, 2002 and 2003. The cassette pulling mechanism is used to insert and detach the optional modules 2001, 2002 and 2003 in the system 100 with the help of the guide ribs and the vertical stopper.
[0053] While inserting the optional modules 2001, 2002 and 2003 into the system 100, the position of the rotating cam 202 of the cassette pulling mechanism should be perpendicular to the main release. The mating ribs of the optional module 2001-2003 are
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guided by the guide ribs in the recesses provided in the main body housing the main release in such a way that the optional modules 2001, 2002 and 2003 are not provided with any horizontal or vertical movement area.
[0054] After the insertion the mating connectors are aligned properly and the connections are made between the mating connectors. Then the position of the rotating cam is changed from the horizontal position to the vertical position so that the hook profile on the rotating cam is locked with the vertical stopper in the recesses. Thus the optional modules 2001, 2002 and 2003 are locked inside the recesses provided in the main body. Thus any misalignment or loose connection of the mating connectors is avoided during the insertion of optional modules 2001, 2002 and 2003 inside the recesses in the system 100.
[0055] FIG. 3 illustrates a perspective view of a modular system for optional modules in the main protection and control release/main release with the optional modules in assembled and pulled-out condition, according to one embodiment of the present invention. With respect to FIG. 3, the optional module 2001 is in the pulled-out condition while the optional modules 2002 and 2003 are fully racked-in position in the system 100.
[0056] While removing the optional modules 2001, 2002 and 2003 from the system 100, the rotating cam 202 of the cassette pulling mechanism is rotated against the vertical stopper in the recesses provided in the system 100. After rotating the rotating cam 202 about 90 degrees, the hook profile of the rotating cam 202 is unlocked from the vertical

stopper. Thus the mating connectors are disengaged from each other and the optional modules 2001, 2002 and 2003 are disengaged from the main release.
[0057] FIG. 4 illustrates an isometric view of an optional module to be inserted into a protection and control release/main release according to one embodiment of the present invention. With respect to FIG. 4, the optional module 2001 includes a thermoplastic casing comprising a bottom housing 402 and a cover 404. The thermoplastic casing is used to engage the electronic power circuit board components in a secured manner. The bottom housing 402 and the cover 404 are locked together by using one or more click-fit mechanisms 406. The optional module 2001 further includes the cassette pulling mechanism to insert and/or detach the optional module 2001 from the main release 100. The cassette pulling mechanism comprises a rotating cam 204 with a hook profile 410 at both sides of the casing. The rotating cam 202 with a hook profile 410 is provided on both the sides of the casing. The mating ribs 412 are mounted horizontally on both the sides of the optional module 2001.
[0058] The optional module 2001 is inserted into the main body housing the main release using a blind insertion technique. While inserting the optional module 2001 into the main release, the position of the rotating cam 202 should be perpendicular to the main release. The mating ribs 412 of the optional module 2001 are guided by the guide ribs in the recess provided in the mainbody housing the main release in such a way that the optional module 2001 are not provided with any horizontal or vertical movements. At the end of the insertion, the mating connectors are aligned properly and the connections are made between the mating connectors. The position of the rotating cam 202 is changed
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from the horizontal position to the vertical position so that the hook, profile 410 on the rotating cam 202 gets locked with the vertical stopper 106 in the recess. Thus the optional module 2001 is locked inside the recess. Thus any misalignment or loose connection of mating connectors is avoided during the insertion of the optional module 2001 into the system housing the main release.
[0059] To remove the optional module 2001 from the main release, the rotating cam 202 is rotated against the vertical stopper in the recesses. After rotating the rotating cam 202 by 90 degrees, the hook profile 410 is unlocked from the vertical stopper. Thus the mating connectors are disengaged from each other.
G) ADVANTAGES OF THE INVENTION
[0060] The various embodiments of the present invention provide modularity in the optional modules used in protection release/main release of circuit breaker for flexible insertion and extraction of the modules in circuit breaker. The optional module is a compact thermoplastic casing that easily fit into the main release unit. The modular optional casing avoids electromagnetic interference and the direct exposure of the power circuit breaker to environment. The optional modules use sleek connectors to plug in the modules into the main release unit and hence reduce the need of wire harness and its implications on the connectivity.
[0061] The optional modules ensure blind insertion of modules in the main release and avoid any misalignment or loose connection of mating connectors. The optional modules are easily inserted and detached in the main release by using a cassette pulling
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mechanism. The entire optional module assembly is screw less and tool free, since the optional module uses one or more click-fit arrangements to engage the cover and casing to mount the modules of the circuit breaker.
[0062] The optional module reduces additional hardware required for mounting the modules and hence reduces the cost of maintenance. Moreover the system eliminates the additional internal wiring for ease of maintenance/replacement. With all these features, insertion for making connection and removal for maintenance purpose are achieved. The entire system is unique, compact, light weight, advanced and cost effective.
[0063] Although the invention is described with various specific embodiments, it will be obvious for a person skilled in the art to practice the invention with modifications. However, all such modifications are deemed to be within the scope of the claims.

[0064] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the present invention described herein and all the statements of the scope of the invention which as a matter of language might be said to fall there between.
Date: July 31, 2009 RAKESH PRABHU
Place: Bangalore. Patent Agent
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=5 AUG2009

CLAIMS
What is claimed is:
1. A modular system in protection and control unit of air circuit breaker comprising:
a main body housing a protection and control unit;
plurality of recesses arranged in the main body housing the protection and control
unit to receive plurality of optional modules;
a guide rib provided in each of the plurality of the recesses;
a stopper provided in each of the plurality of the recesses;
a casing to store an optional module;
a cassette pulling mechanism provided in the casing housing the optional module;
a mating rib provided on the casing housing the optional module and
Wherein an optional module is received in one of the recesses and the cassette
pulling mechanism is used to establish connection between the protection and the
control unit and the optional module which is inserted into one of the recesses.
2. The system according to claim 1, wherein the cassette pulling mechanism has a cam which is rotated during the insertion of the optional module into the recesses provided in the main body housing the protection and control unit to establish an electrical contact between the connectors that are provided respectively in the protection and control unit and the optional module.
3. The system according to claim 1, wherein the cam is positioned vertically in the optional module, when the optional module is not inserted into the main body of the protection and control unit.
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4. The system according to claim 1, wherein the cam has a hook for locking.
5. The system according to claim 1, wherein the cam is rotated after the insertion of the optional module into the recess provided in the main body housing the protection and control unit to engage the hook with the stopper provided in the recess to lock the optional module with the protection and control unit.
6. The system according to claim 1, wherein the cam is rotated against the stopper to release the locking of the hook from the stopper provided in the recess at the main body of the protection and control unit, when the optional module is removed from main body of the protection and control unit.
7. The system according to claim 1, wherein the cam is rotated from the vertical position to horizontal position to separate the contact between the connectors of the protection and control unit and the optional module, when the optional module is removed from main body of the protection and control unit.
8. The system according to claim 1, wherein the guide rib is provided at the side wall of the recess provided in the main body of the protection and control unit.
9. The system according to claim 1, wherein the mating guide rib is provided in the side wall of the casing housing the optional module.
10. The system according to claim 1, wherein the guide rib is provided at the side wall of the recess provided in the main body of the protection and control unit to receive the mating guide rib provided in the side wall of the casing housing the
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optional module to establish a blind mating connection, when the optional module is inserted into the recess at the main body of the protection and control unit.
11. The system according to claim 1, wherein the stopper is provided at the side wall
of the recess to engage with the hook provided in the cam arranged at the side
wall of the casing of the optional module to prevent the removal of the optional
module from the main body of the protection and control unit after the insertion of
the optional module into the main body of the protection and control unit.
12. The system according to claim 1, wherein the casing housing the optional module has a bottom case and a cover.
13. The system according to claim 1, wherein the cover and the bottom case of the optional module are provided with click fit mechanism to fasten the cover with the bottom case in the optional module.

14. The system according to claim 1, wherein the casing is made up of insulative
material to provide protection for the printed circuit board stored inside the casing
of the optional module against electromagnetic interference