FORM 2
The Patents Act 1970
(39 of 1970)
&
COMPLETE SPECIFICATION
(See Section 10 and rule 13)
TITLE OF THE INVENTION:
STORED ENERGY TYPE PLUG-IN RETRACTABLE MODULE ASSEMBLY


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 electrical power distribution systems and particularly to motor controllers in electrical power distribution system. The present invention more particularly relates to a plug-in/out or draw-in/out type module assembly for motor controllers in power distribution system.
B) BACKGROUND OF THE INVENTION
[0002] In an electrical power distribution system provided in an industry, shopping malls, residential complexes etc, there is a requirement for the distribution of incoming electrical power to various end application devices such as motors, lighting loads, air conditioning loads etc. In a typical electrical power distribution system, the power from the transmission grid is stepped-down to the distribution grid to effectively deliver the power to the home or business. The transformers steps down the transmission voltages to distribution voltages. The bus splits the distribution power in multiple directions. In order to cater to the requirements of distribution and protection of the end application devices, the incoming power is routed through various electrical monitoring and controlling devices called as switching devices. The use of electrical switching devices is well known for making/ breaking electrical contacts and for providing safety in a typical electrical distribution system.
[0003] The switching devices are mounted inside an enclosure provided with all electrical connections for the distribution and the delivery of the necessary power to the end application devices. Thus the enclosure provides additional safety to an operator since all the electrical connections are housed inside the enclosure and the switching devices are operated from outside by the operator.


[0004] The installation of electrical devices is generally of two types. In one type of installation, the electrical devices are mounted to stationary structural members or frame of the board. In such stationary installations, the inspection and the maintenance of the circuit breaker is difficult and quite hazardous when the maintenance operation is performed during the live condition of the board. To reduce the hazards of working with live boards, the devices are provided with plug-in type contacts which primarily disconnect power and the unit is drawn out of the board for any sort of maintenance. Thus the electrical device can be plugged in and plugged out from a live board in a relatively safe manner.
[0005] The switching devices are mounted inside the enclosures called as modules. The enclosures broadly consist of power terminals and auxiliary terminals which are plugged onto an assembly of mating power and auxiliary terminals that are fixed inside the panel board. These modules are equipped with mechanism to aid the plug in and withdrawal of the modules from an interface assembly. The power terminals are used to receive and distribute the electrical power. The set of auxiliary contacts are used to provide preset signals or/and annunciation signal for the end application devices installed in the downstream.
[0006] Technically by the standard requirements, these modules are to be kept in three states such as service, test and isolated conditions. In the service state, both the power and the auxiliary circuits are kept closed. The power and the control signals are supplied to the end application devices in the service state. In the test state, the auxiliary circuit is only closed and the power circuit is kept open. The power is not distributed to the end application devices in the test state. However the auxiliary circuit is closed and the annunciation signal is fed to actuate a few end application devices. Also the devices connected in auxiliary circuit are not protected against the electrical faults. It is a common practice to provide a test position for the motor control unit to intermediate its engaged and disengaged positions so that the power connectors are separated but the auxiliary connectors are still engaged to the control unit. In the test position, the accessory functions can be tested thoroughly and safely while the Motor control unit is


dead. In the isolated state, both the power and auxiliary circuits are kept open so that all the electrical connections in the power and auxiliary circuits are disconnected.
[0007] The opening and the closing of the power and auxiliary circuits are achieved in all the three states mentioned above by physically engaging and disengaging the power connectors and auxiliary connectors in both the power and the auxiliary circuits. The module is provided with a set of power and auxiliary contacts that are mounted on the module or the contacts are mounted on a movable rigid linkage arrangement which is accessible from the front side. Hence the module of the adaptable link needs to be physically pushed in or to be racked in with the help of a screw and nut mechanism to engage the contacts in the power and auxiliary circuits.
[0008] Moreover the currently available such arrangements do not disconnect the power and the auxiliary circuits instantaneously. In case of an emergency, it is always preferred to have the electrical power disconnected with the mere press of a button.
[0009] Thus the currently available arrangements do not have a mechanism to disconnect the circuit instantaneously thereby resulting in the geiieration of arcing between the contacts.
[0010] Hence there is a need for an improved, compact plug-in or draw-out type module assembly for motor controllers in power distribution system to disconnect the power and the auxiliary circuits instantaneously with a single operation of a device or mechanism to provide protection to electrical loads and associated auxiliary circuits. Also there is a need to develop a mechanism to disconnect the power circuit rapidly to prevent the electrical arching between the contacts.
C) OBJECTS OF THE INVENTION
[0011] The primary object of the present invention is to develop a stored energy type retractable plug-in module assembly for motor controllers in an electrical power


distribution system to connect and disconnect the power and the auxiliary contacts instantaneously thereby preventing the generation of arcing between the contacts.
[0012] Another object of the present invention is to develop a stored energy type compact, retractable, plug-in enclosure housing electrical devices to carry specific current and to provide requisite overload and short circuit protection to a motor unit or a power distribution network or to an end application device/ devices.
[0013] Yet another object of the present invention is to develop a stored energy type retractable plug-in module assembly provided with a spring assisted mechanism to change the switching device among service, test and isolated positions quickly, easily and efficiently.
[0014] Yet another object of the present invention is to develop a stored energy type retractable plug-in module assembly for interrupting or providing current supply through the power and auxiliary circuits in a motor controller unit to the end application devices as and when required.
[0015] Yet another object of the present invention is to develop a stored energy type retractable plug-in module assembly with a spring assisted mechanism to make and break the contacts so that the energy stored during the making of the pluralities of power and auxiliary contacts is used to disconnect the contacts rapidly during the emergency conditions.
[0016] Yet another object of the present invention is to develop a stored energy type retractable plug-in module assembly provided with two different mechanisms to move the controller from the service to test/isolated conditions and vice versa. .
[0017] Yet another object of the present invention is to develop a stored energy type retractable plug-in module assembly provided with a mechanical position indicator to show the actual contact position of the module positively.
- 1 APR 2009

[0018] 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
[0019] The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.
[0020] The various embodiments of the present invention provide a stored energy type retractable plug-in module assembly for control units or switching devices in an electrical power distribution system to connect and disconnect the power and the auxiliary contacts instantaneously thereby preventing the generation of arcing between the contacts.
[0021] According to one embodiment of the present invention, a stored energy type retractable plug-in module has an enclosure to house a switching device provided with an operating shaft. The enclosure has a front face plate mounted with a handle, an operating knob and a state changer knob. A back plate is movably connected to the front face plate through a slider mechanism. The back plate is mounted with the main and auxiliary contacts for mating with the main and the auxiliary contacts that are mounted on an interface provided with an end load device to close the main and the auxiliary circuits.
[0022] The handle mounted on the front face plate is pushed in to move the back plate to make the main and the auxiliary contacts to mate successively with the main and the auxiliary contacts mounted on the interface during the movement of the module from the "ISOLATED" to "TEST" and "SERVICE" conditions respectively. The state changer knob mounted on the front face plate is pulled upwards to move the back plate away from the interface to release the main and the auxiliary contacts mounted on the back plate
- 1 APR 2009

successively from the main and the auxiliary contacts mounted on the interface during the movement of the module from "SERVICE" to "TEST" and "ISOLATED" conditions.
[0023] The slider mechanism is mounted and moved on a guide rail arranged between the front plate and the back plate. A spring is provided in the slider mechanism and is rigidly fixed to the front plate to assist the movement of the slider mechanism between the front plate and the back plate. The spring is charged, when the handle is pushed in to move the back plate to make the auxiliary and the main contacts mounted on the back plate to successively mate with the auxiliary and the main contacts mounted on the interface connected to the end load device during the movement of the module from the "ISOLATED" to "TEST" and "SERVICE" conditions. The spring is used to release the main and the auxiliary contacts mounted on the back plate successively from the main and the auxiliary contacts mounted on the front plate using the stored energy in the spring, when the state changer knob is pulled upwardly to make the back plate to move backwards to move the module from the "SERVICE" to "TEST" and "ISOLATED" conditions respectively.
[0024] A module lock is fixed to the state changer knob to lock the module in any one of the "SERVICE", "TEST" and "ISOLATED" conditions. The state changer knob is pulled upwards to move the module lock upwardly to enable the spring to release stored energy to make the back plate to move away from the interface to release the main and the auxiliary contacts mounted on the back plate from the main and the auxiliary contacts mounted on the interface to move the module from the "SERVICE" to "TEST" and "ISOLATED" conditions. The operating knob or an indicator is mounted on the front face plate to show the operating condition of the switching device.
[0025]The module assembly is stacked inside the panel board. Pluralities of the modules are horizontally stacked within the width of the board. The modules with half the size of the panel board are known as half modules. The modules with one fourth the size of the panel board are called quarter modules. The sizes of the modules depend on the sizes of the safety devices installed and also the electrical clearances required for the functioning.


The panel board incudes an adapter assembly with mating power and auxiliary terminals. The adapter assembly acts as an interface.
[0026] Thus the various embodiments of the present invention provide a stored energy-type retractable plug-in module assembly for control units or switching devices in an electrical power distribution system to connect and disconnect the power and the auxiliary contacts instantaneously thereby preventing the generation of arcing between the contacts. It is designed to carry specific current and also to provide requisite overload and short circuit protection to a motor unit or a power distribution network or to an end application device/ devices. The stored energy type retractable module assembly in the present invention disconnects the power circuit rapidly in emergency conditions to avoid electrical arcing between the contacts. The entire design is made simple for the user by having only two Interface nodes. It provides a spring mechanism to have the energy stored while the plurality of power and Auxiliary contacts make and the stored energy in the spring is discharged to disengage the contacts almost instantaneously to provide a boom in situations of emergency. The front plate is provided with a mechanical position indicator to indicate the actual contact position (positive status) of the module.
E) BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The other objects, features and advantages will occur to those skilled in the art drawings in which:
[0028] FIG. 1 shows a block diagram of a power distribution system provided with a motor control system equipped with a stored energy type plug-in retractable module assembly according to one embodiment of the present invention.


[0029] FIG. 2 shows a perspective view of a quarter module and a half module of a stored energy type plug-in retractable module assembly mounted in distribution or panel board according to one embodiment of the present invention.
[0030] FIG. 3 shows a top perspective view of a stored energy type plug-in retractable module assembly according to one embodiment of the present invention.
[0031] FIG. 4 shows a side perspective view of the stored energy type plug-in retractable module assembly in isolated state according to one embodiment of the present invention.
[0032] FIG. 5 shows a front perspective view of the stored energy type plug-in retractable module assembly in isolated state according to one embodiment of the present invention.
[0033] FIG. 6 shows a side perspective view of the stored energy type plug-in retractable module assembly in test state according to one embodiment of the present invention.
[0034] FIG.7 shows a front perspective view of the stored energy type plug-in retractable module assembly in test state according to one embodiment of the present invention.
[0035] FIG. 8 shows a side perspective view of the stored energy type plug-in retractable module assembly in service state according to the one embodiment of present invention.
[0036] FIG. 9 shows a front perspective view of the stored energy type plug-in retractable module assembly in service state when the switching device is in ON state, according to one embodiment of the present invention.
[0037] FIG. 10 shows a front perspective view of the stored energy type plug-in retractable module assembly in service state when the switching device is in OFF state according to one embodiment of the present invention.


[0038] Although 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 INVENTION
[0039] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be 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.
[0040] The various embodiments of the present invention provide a stored energy type retractable plug-in module assembly for control units or switching devices in an electrical power distribution system to connect and disconnect the power and the auxiliary contacts instantaneously thereby preventing the generation of arcing between the contacts.
[0041] According to one embodiment of the present invention, a stored energy type retractable plug-in module has an enclosure to house a switching device provided with an operating shaft. The enclosure has a front face plate mounted with a handle, an operating knob and a state changer knob. A back plate is movably connected to the front face plate through a slider mechanism. The back plate is mounted with main and auxiliary contacts for mating with the main and the auxiliary contacts that are mounted on an interface provided with an end load device to close the main and the auxiliary circuits.
[0042] The handle mounted on the front face plate is pushed in to move the back plate to make the main and the auxiliary contacts to mate successively with the main and the auxiliary contacts mounted on the interface during the movement of the module from the


"ISOLATED" to "TEST" and "SERVICE" conditions respectively. The handle is pushed in to move the back plate to make the auxiliary contacts mounted on the back plate to mate with the auxiliary contacts mounted on the interface to close an auxiliary circuit, when the module is moved from the "ISOLATED" to "TEST" conditions. The handle is pushed in further to move the back plate to make the main contacts mounted on the back plate to mate with the main contacts mounted on the interface to close a main circuit, when the module is moved from the "TEST" to "SERVICE" conditions.
[0043] The state changer knob mounted on the front face plate is pulled upwards to move the back plate away from the interface to release the main and the auxiliary contacts mounted on the back plate successively from the main and the auxiliary contacts mounted on the interface during the movement of the module from "SERVICE" to "TEST" and "ISOLATED" conditions. The state changer knob is pulled upwards to make the back plate to move backwards to release the main contacts mounted on the back plate from the main contacts on the interface, when the module is moved from the "SERVICE" to "TEST" conditions. The state changer knob is pulled further upwards to make the back plate to move further backwardly to release the auxiliary contacts mounted on the back plate from the auxiliary contacts mounted on the interface, when the module is moved from the "TEST" to "ISOLATED" conditions.
[0044] The slider mechanism is mounted and moved on a guide rail arranged between the front plate and the back plate. The guide rail is provided between the front plate and the back plate to enable the movement of the slider mechanism between the front plate and the back plate. A spring is provided in the slider mechanism and is rigidly fixed to the front plate to assist the movement of the slider mechanism between the front plate and the back plate. The spring is charged, when the handle is pushed in to move the back plate to make the auxiliary and the main contacts mounted on the back plate to successively mate with the auxiliary and the main contacts mounted on the interface connected to the end load device during the movement of the module from the "ISOLATED" to "TEST" and "SERVICE" conditions. The spring is used to release the main and the auxiliary contacts mounted on the back plate successively from the main and the auxiliary contacts mounted
1 APR 2009

on the front plate using the stored energy in the spring, when the state changer knob is pulled upwardly to make the back plate to move backwards to move the module from the "SERVICE" to "TEST" and "ISOLATED" conditions respectively.
[0045] A module lock is fixed to the state changer knob to lock the module in any one of the "SERVICE", "TEST" and "ISOLATED" conditions. The state changer knob is pulled upwards to move the module lock upwardly to enable the spring to release stored energy to make the back plate to move away from the interface to release the main and the auxiliary contacts mounted on the back plate from the main and the auxiliary contacts mounted on the interface to move the module from the "SERVICE" to "TEST" and "ISOLATED" conditions. The front plate is provided with self locking slots in which the state changer knob is moved reciprocatably to move the bake plate away from the interface and towards the front plate. The self locking slots in the front plate lock the module lock at two different positions. The self locking slot in the front plate locks the module lock at "TEST" condition or at "SERVICE" condition. The operating knob or an indicator is mounted on the front face plate to show the operating condition of the switching device.
[0046]The module assembly is stacked inside the panel board. Pluralities of the modules are horizontally stacked within the width of the board. The modules with half the size of the panel board are known as half modules. The modules with one fourth the size of the panel board are called quarter modules. The sizes of the modules depend on the sizes of the safety devices installed and also the electrical clearances required for the functioning. The panel board includes an adapter assembly with mating power and auxiliary terminals. The adapter assembly acts as an interface.
[0047] Initially the half module and quarter module assemblies are inserted into the cavity block of the switchboard or panel board. The handle is used to engage and disengage the power and auxiliary contacts with the contacts in the adapter assembly. In test state the handle is pushed back to have the auxiliary contact first mate with the
1 APR 2009

corresponding auxiliary contacts in the adapter interface. This push is against the tension spring. The handle is to be pushed till the profiled module lock pops down due to the spring action. Further a little push from this position would let the power contacts also get engaged with the power contacts of the adapter interface. These further charges the spring and the assembly of back plate with slider and handle get locked by another profile of the module lock. This lets the module to achieve the service state. At this point both the power and auxiliary contacts are engaged and hence all the connections are complete. In service position energy is stored in the spring, which is useful to disconnect the contacts.
[0048] The module state changer knob is to be pushed up to disconnect the power contacts or auxiliary contacts or both. By pushing the module state changer knob the module lock also gets pulled up. The Module lock thus releases the slider. The slider with the tension spring brings the entire assembly of back plate slider and the handle to the test state. By further pushing it up, further releases the energy and this brings the entire assembly of back plate slider and the handle to its isolation state.
[0049] The module assembly consists of two user interface nodes handle and module state changer knob to change the state of the module. Either handle or the state changer knob can be used to operate the switching device in test, service and isolated state. When module state is to be changed from service to isolated state module state changer knob is to be operated and to change the state from isolated to service handle is to be operated.
[0050] Thus the various embodiments of the present invention provide a stored energy type retractable plug-in module assembly for control units or switching devices in an electrical power distribution system to connect and disconnect the power and the auxiliary contacts instantaneously thereby preventing the generation of arcing between the contacts. It is designed to carry specific current and also to provide requisite overload and short circuit protection to a motor unit or a power distribution network or to an end application device/ devices. The stored energy type retractable module assembly in the


present invention disconnects the power circuit rapidly in emergency conditions to avoid electrical arcing between the contacts. The entire design is made simple for the user by having only two Interface nodes.
It provides a spring mechanism to have the energy stored while the plurality of power and Auxiliary contacts make and the stored energy in the spring is discharged to disengage the contacts almost instantaneously to provide a boom in situations of emergency. The front plate is provided with a mechanical position indicator to indicate the actual contact position (positive status) of the module.
[0051] FIG.l shows a typical block diagram of a power distribution system provided with a motor control system equipped with a stored energy type plug-in retractable module assembly according to one embodiment of the present invention. With respect to FIG.l, the power from the transmission grid is stepped-down to the distribution grid to effectively deliver the power to the home or business in a typical electrical power distribution system,. Usually the conversion form the transmission to the distribution occurs in power substation. The transformers steps the transmission voltages down to distribution voltages. The power from the grids is transferred to the end application devices such as motors, lighting loads and air conditioning loads etc. In order to cater to the requirements of distribution and protection of the end application devices, the input power is routed through various electrical monitoring and controlling devices known as switching devices installed inside enclosures schematically mentioned as power control centre (PCC) and motor control centre (MCC). In real applications, both PCC and MCC are placed within an enclosure. The motor controllers are mounted inside a compact enclosure with all electrical connections made within the enclosure for the necessary distribution and finally the required power is delivered to the end application devices. The switching devices used in the above mentioned layout for distribution, monitoring and control equipments gets installed in an enclosure/ panel. These are then connected as per the distribution plan. The enclosure /panel thus houses these switching devices with all electrical wiring within and also provides human/ operator safety since they are controlled, monitored from outside the enclosure. A stored energy type plug-in retractable module assembly is provided for the motor controller. It is designed to carry
1 APR 2009

specific current and also to provide requisite overload and short circuit protection to a motor unit or a power distribution network or to the end application device/devices.
[0052] FIG. 2 shows a typical schematic arrangement of distribution board or panel mounted with stored energy type plug-in retractable module assembly according to one embodiment of the present invention, with respect to FIG.2, pluralities of the module assemblies are horizontally stacked within the width of the panel board. The plug-in withdrawal enclosure housing the various switching devices are commonly called as a feeder module. The sizes of the modules depend on the sizes of the safety devices installed and also the electrical clearances required for the functioning. The module assembly is stacked inside the panel board. The modules with half the size of the panel board are known as half modules 3. The modules with one fourth the size of the panel board are called quarter modules 4. The half module 3 and quarter module 4 are inserted into the cavity block of the switchboard or panel board. The panel board includes an adapter assembly with mating power and auxiliary terminals which acts as an interface to the power and the auxiliary terminals of the switching device. The number of auxiliary power and auxiliary contacts depends on the layout scheme and it can vary between 2 to 30.
[0053] FIG. 3 shows a perspective view of the stored energy type plug-in retractable module assembly according to one embodiment of the present invention. With respect to FIG. 3, a stored energy type retractable plug-in module has an enclosure 9 to house a switching device provided with an operating shaft. The enclosure 9 has a front face plate 10 mounted with a handle 8, an operating knob and a state changer knob 11. A back plate 7 is movably connected to the front face plate 10 through a slider mechanism 6. The back plate 7 is mounted with main contacts 4A and auxiliary contacts 4B for mating with the main contacts 5A and the auxiliary contacts 5B that are mounted on an interface 5 provided with an end load device to close the main and the auxiliary circuits.
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[0054] The handle 8 mounted on the front face plate 10 is pushed in to move the back plate 7 to make the main and the auxiliary contacts 4A.4B to mate successively with the main and the auxiliary contacts 5A,5B mounted on the interface 5 during the movement of the module from the "ISOLATED" to "TEST" and "SERVICE" conditions respectively. The state changer knob 11 mounted on the front face plate 10 is pulled upwards to move the back plate 7 away from the interface 5 to release the main contacts 4A and the auxiliary contacts 4B mounted on the back plate 7 successively from the main contacts 5A and the auxiliary contacts 5B mounted on the interface 5 during the movement of the module from "SERVICE" to "TEST" and "ISOLATED" conditions.
[0055] The slider mechanism 6 is mounted and moved on a guide rail 9A arranged between the front plate 10 and the back plate 7. A spring 13 is provided in the slider mechanism 6 and is rigidly fixed to the front plate 10 to assist the movement of the slider mechanism 6 between the front plate 10 and the back plate 7. The spring 13 is charged; when the handle 8 is pushed in to move the back plate 7 to make the auxiliary contacts 4B and the main contacts 4A mounted on the back plate 7 to successively mate with the auxiliary contacts 5B and the main contacts 5a mounted on the interface 5vconnected to the end load device during the movement of the module from the "ISOLATED" to "TEST" and "SERVICE" conditions. The spring 13 is used to release the main contacts 4A and the auxiliary contacts 4B mounted on the back plate 7 successively from the main contacts 5A and the auxiliary contacts 5B mounted on the front plate 10 using the stored energy in the spring 13. when the state changer knob 11 is pulled upwardly to make the back plate 7 to move backwardly to move the module from the "SERVICE" to "TEST" and "ISOLATED" conditions respectively.
[0056] A module lock is fixed to the state changer knob 11 to lock the module in any one of the "SERVICE", "TEST" and "ISOLATED" conditions. The state changer knob 11 is pulled upwards to move the module lock upwardly to enable the spring 13 to release stored energy to make the back plate 7 to move away from the interface 5 to release the main contacts 4A and the auxiliary contacts 4B mounted on the back plate 7 from the


main contacts 5A and the auxiliary contacts 5B mounted on the interface 5 to move the module from the "SERVICE" to "TEST" and "ISOLATED" conditions.
[0057] The front plate 10 is provided with self locking slots 10A in which the state changer knob 11 is moved reciprocatably to move the bake plate 7 away from the interface 5 and towards the front plate 10. The self locking slots 10A in the front plate 10 lock the module lock at two different positions. The self locking slot 10A in the front plate 10 locks the module lock at "TEST" condition or at "SERVICE" condition. The operating knob 16 or an indicator is mounted on the front face plate to show the operating condition such as switch ON or OFF condition of the switching device.
[0058] FIG. 4 shows a side perspective view of the stored energy type plug-in retractable module assembly in isolated state according to one embodiment of the present invention. With respect to FIG. 4, the switching device 14 is connected to the operating handle 16 through an operating shaft 15. In the isolated state, the power contacts 4A and the auxiliary contacts 4B of the module are not engaged with the power contacts 5A and the auxiliary contacts 5B in the adapter assembly 5. In the isolated state both the power contacts 4A, 5A and the auxiliary contacts 4B. 5B are kept open. Application wise all the electrical circuits including the power circuit and auxiliary circuit are kept open. At the isolated state, the operating handle is in completely pulled out condition and the state changer knob is completely pulled up.
[0059] The handle mounted on the front face plate is pushed in to move the back plate to make the main and the auxiliary contacts 4A. 4B to mate successively with the main and the auxiliary contacts 5A, 5B mounted on the interface 5 during the movement of the module from the "ISOLATED" to "TEST" and "SERVICE" conditions respectively. The handle is pushed in to move the back plate to make the auxiliary contacts 4B mounted on the back plate to mate with the auxiliary contacts 5B mounted on the interface 5 to close an auxiliary circuit, when the module is moved from the "ISOLATED" to "TEST" conditions. During the movement of the module from the "ISOLATED" to "TEST" conditions, the spring provided in the slider mechanism is charged.
- 1 APR 2009

[0060] The state changer knob mounted on the front face plate is pulled upwards to move the back plate away from the interface to release the auxiliary contacts 4B mounted on the back plate from the auxiliary contacts 5B mounted on the interface 5 during the movement of the module from "TEST" to "ISOLATED" conditions. When the state changer knob is pulled upwards, the module lock is popped up to make the spring to release the stored energy to pull the back plate away from the interface 5 thereby disconnecting the auxiliary contact 4B mounted on the back plate from the auxiliary contact 5B mounted on the interface 5.
[0061] FIG. 5 shows a front perspective view of the stored energy type plug-in retractable module assembly in isolated state according to one embodiment of the present invention. With respect to FIG.5, the front plate 10 is mounted with a handle, a status indicator 16 and a module state changer knob 11. The module state changer knob 11 reciprocates in the slot 10A. The status indicator 16 indicates ON, TRIP and OFF status of the switching device. In isolated state, the handle 8 is completely outside. In the isolated state, the power and the auxiliary contacts of the module are not engaged with the power and the auxiliary contacts in the interface. The module state changer knob 11 is pulled up completely in the isolated state. The status indicator 16 indicates OFF state of the switching device.
[0062] FIG. 6 shows a side perspective view of the stored energy type plug-in module assembly in test state according to one embodiment of the present invention. With respect to FIG.6, the handle 8 is pushed inside to have the auxiliary contact 4B to mate with the corresponding auxiliary Contacts 5B in the interface. During the movement of the handle the spring provided in the slider mechanism also gets charged. The handle 8 is to be pushed till the profiled module lock 12 pops down due to the spring action. Thus the state of test is achieved. In the test position, the switching device will be in OFF position. The handle is further pushed from the test position to make the power contacts 4A to get engaged with the power contacts 5A of the interface 5 to achieve a service state. The pushing in movement of the handle further charges the spring to make the module lock
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12 to pop down again to lock the assembly of back plate 7 with the slider mechanism. 12. The state changer knob is pulled up to make the back plate to move away from the interface assembly 5 to disconnect the power contacts 4A mounted on the back plate from the power contacts 5A mounted on the interface 5, when the module is moved from the service state to the test state.
[0063] FIG.7 shows a front perspective view of the stored energy type plug-in module assembly in test state according to one embodiment of the present invention. With respect to FIG.7, the handle 8 is pushed in to have the auxiliary contact 4B to mate with the corresponding auxiliary contacts 5B mounted in the interface to achieve test position from the isolated state,. When the handle 8 is pushed inside to achieve the test position, the state changer knob 11 is moved down simultaneously to settle in the middle position. Since the contacts are not completely engaged in test position, status indicator knob 16 indicates OFF position of the switching device.
[0064] FIG. 8 shows a side perspective view of the stored energy type plug-in retractable module assembly in service state according to one embodiment of the present invention. With respect to the FIG.8, the handle is further pushed in to move the back plate to make the power contacts 4A to get engaged with the power contacts 5A of the interface 5, when the module is moved from the test state to the service state. The spring provided in the slider mechanism is charged again when the handle is pushed to move the module from the test state to service state. In the service state, both the main and the auxiliary contacts 4A, 4B mounted in the module are engaged with the corresponding main and the auxiliary contacts 5A, 5B of the interface 5 to close the main and the auxiliary circuits. The spring is charged completely and the assembly of back plate 7 is locked by another profile of the module lock 12 in the service state.
[0065] FIG. 9 shows a front perspective view of the stored energy type plug-in retractable module assembly in service state when the switching device is in ON state according to one embodiment of the present invention. With respect to FIG.9, the handle 8 is pushed
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completely inside in the service state. As a result the power and the auxiliary contacts of the controller module are completely engaged with the power and the auxiliary contacts in the interface. The status indicator 16 shows that the switching device is in ON state. The state changer knob 11 is moved down to the bottom most position in the slot 10A.
[0066] FIG. 10 shows a front perspective view of the stored energy type plug-in retractable module assembly in service state when the switching device is in OFF state according to one embodiment of the present invention. With respect to FIG. 10, the handle 8 is completely pushed inside to engage the power and auxiliary contacts of the module to engage with the power and auxiliary contacts of the interface. In the service state, the state changer knob 11 is moved down to the bottom most position in the slot 10A. The operating knob 16 indicates the OFF condition of the switching device.
G) ADVANTAGES OF THE INVENTION
[0067] The present invention provides a stored energy type plug-in retractable module assembly for electrical power distribution system. It provides a plug-in type, compact enclosure for housing the electrical devices. The module is designed to carry specific current and also to provide requisite overload and short circuit protection to a motor unit or a power distribution network or to the end application device/ devices. The stored energy type retractable module assembly disconnects the power circuit very fast using the spring assisted slider mechanism to avoid electrical arcing between the contacts. It takes a very less time to disconnect the contacts in emergency conditions. The entire design is made simple for the user by having only two Interface nodes. The present invention finds its application in an electrical power distribution system, like in a industry , shopping malls, residential complexes etc, in which the incoming electrical power is distributed to various end application devices like motors, lighting loads , air conditioning loads etc. [0068] 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.
1 APR 2009

[0069] 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.
RAKESH PRABHU
Patent Agent
Date: March 30, 2009. Place: Bangalore.

CLAIMS
What is claimed is:
. A stored energy type retractable plug-in module assembly for switching devices in motor controller for an end load device provided with an interface having pluralities of main and auxiliary contacts, the assembly comprising:
A module housing a switching device;
a front face plate arranged in the module;
a back plate movably connected to the front plate through a slider mechanism;
pluralities of main contacts and auxiliary contacts mounted on the back plate;
a handle mounted on the front face plate;
an indicator mounted on the front face plate;
a state changer knob mounted on the front face plate;
a module lock fixed to the state changer knob; and
a spring connected between the slider mechanism and the front plate;
wherein the handle is pushed in to move the back plate during the movement of
the module from the " ISOLATED" to "TEST' and "SERVICE" conditions
while the state changer knob is pulled upwards to move the module from the
"SERVICE" to "TEST' and "ISOLATED" conditions
1 APR 2009

The assembly according to claim 1, wherein pluralities of main contacts and auxiliary contacts are mounted on the back plate for mating with the pluralities of main and auxiliary contacts mounted on the interface connected to the end load device.
The assembly according to claim 1, wherein the handle is mounted on the front face plate to move the back plate to make the main and the auxiliary contacts to mate successively with the main and the auxiliary contacts mounted on the interface during the movement of the module from the "ISOLATED" to "TEST" and "SERVICE" conditions respectively.
The assembly according to claim I, wherein the state changer knob mounted on the front face plate is pulled upwards to move the back plate away from the interface to release the main and the auxiliary contacts mounted on the back plate successively from the main and the auxiliary contacts mounted on the interface during the movement of the module from "SERVICE" to "TEST" and "ISOLATED" conditions.
The assembly according to claim I, wherein the handle is pushed in to move the back plate to make the auxiliary contacts mounted on the back plate to mate with the auxiliary contacts mounted on the interface to close an auxiliary circuit, when the module is moved from the "ISOLATED" to "TEST" conditions.
1 APR 2009

The assembly according to claim 1, wherein the handle is pushed in further to move the back plate to make the main contacts mounted on the back plate to mate with the main contacts mounted on the interface to close a main circuit, when the module is moved from the "TEST" to "SERVICE" conditions.
The assembly according to claim 1, wherein the state changer knob is pulled upwards to make the back plate to move backwards to release the main contacts mounted on the back plate from the main contacts on the interface, when the module is moved from the "SERVICE" to "TEST" conditions.
The assembly according to claim 1, wherein the state changer knob is pulled further upwardly to make the back plate to move further backwardly to release the auxiliary contacts mounted on the back plate from the auxiliary contacts mounted on the interface, when the module is moved from the "TEST" to "ISOLATED" conditions.
The assembly according to claim 1, wherein the slider mechanism is connected between the main and the auxiliary contacts mounted on the back plate and the handle mounted on the front plate.
i. The assembly according to claim 1, further comprising a guide rail connected between the front plate and the back plate to enable the the movement of the silder mechanism between the front plate and the back plate.


The assembly according to claim 1, wherein the spring assists the movement of the slider mechanism between the front plate and the back plate.
The assembly according to claim 1, wherein the spring is charged, when the handle is pushed in to move the back plate to make the auxiliary and the main contacts mounted on the back plate to successively mate with the auxiliary and the main contacts mounted on the interface connected to the end load device during the movement of the module from the "ISOLATED" to "TEST' and "SERVICE" conditions.
The assembly according to claim 1, wherein the spring is used to release the main and the auxiliary contacts mounted on the back plate successively from the main and the auxiliary contacts mounted on the front plate using the stored energy in the spring, when the state changer knob is pulled upwardly to make the back plate
to move backwards to move the module from the "SERVICE" to "TEST" and "ISOLATED" conditions respectively.
The assembly according to claim 1, wherein the module lock is fixed to the state changer knob to lock the module in any one of the "SERVICE", "TEST" and "ISOLATED" conditions;
1 APR 2009

. The assembly according to claim 1, wherein the front plate is provided with self locking slots in which the state changer knob is moved reciprocatably to move the bake plate away from the interface and towards the front plate.
. The assembly according to claim 15, wherein the self locking slots in the front plate lock the module lock at two different positions.
. The assembly according to claim 16 wherein the self locking slot in the front plate locks the module lock at "TEST" condition.
. The assembly according to claim 16 wherein the self locking slot in the front plate locks the module lock at "SERVICE" condition.
. The assembly according to claim 1, wherein the state changer knob is pulled upwards to move the module lock upwardly to enable the spring to release stored energy to make the back plate to move away from the interface to release the main and the auxiliary contacts mounted on the back plate from the main and the auxiliary contacts mounted on the interface to move the module from the "SERVICE" to 'TEST' and "ISOLATED" conditions.
1 APR 2009

20. The assembly according to claim 1, wherein the indicator mounted on the front face plate to show the operating condition of the switching device.
Dated this the 30th day of March 2009
RAKESH PRABHU
Patent Agent,
ALMT Legal,
#2, Lavelle Road, Bangalore-560 001
To,
The Controller of Patents, The Patent Office, Mumbai