FORM 2
The Patents Act 1970
(39 of 1970)
&
The Patent Rules 2003
COMPLETE SPECIFICATION
(See Section 10 and rule 13)
TITLE OF THE INVENTION:
MODULE STATE INTERLOCK SYSTEM FOR MOTOR
CONTROLLERS
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 motor controllers in an electrical power distribution system and particularly to plug-in draw out module assembly for motor controllers. More particularly it relates to provide an inbuilt interlocking mechanism for motor controller feeder modules to ensure user safety during maintenance.
B) BACKGROUND OF THE INVENTION
[0002] In a typical electrical power distribution system, to effectively deliver the power to the home or business the power from the transmission grid is stepped-down to the distribution grid. Usually the conversion form the transmission to the distribution occurs in power substation. The transformers steps the transmission voltages down 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, incoming power is routed through various electrical monitoring and controlling devices hence forth called as switching devices. The use of electrical devices is well known for making, breaking and to provide safety in a typical electrical distribution system.
[0003] The switching devices are mounted inside an enclosure with all electrical connections made within the enclosure for the necessary power distribution and finally the required power is delivered to the end application devices. Thus the enclosure provides added safety to the operator since all electrical connections are housed in and the operator needs to operate the switching devices, from outside.
[0004] The installation of electrical devices is generally of two types. In one type of installation, electrical devices are stationary mounted to structural members or frame of the board. In such stationary installations, inspection and maintenance of the circuit breaker is difficult and quite hazardous if attempted while the board is live. To reduce the hazards of working with live boards, devices are provided with plug-in type contacts and interlocks, to primarily disconnect the power when the unit is drawn out of the board for any sort of maintenance. Considering safety, interlock mechanism plays major role.


[0005] The interlocks restrict undue operations when the circuit is closed. The installation of the modules within the switchboard is stationary in those areas where either no or very little maintenance is required. In such stationary installations, inspection and maintenance of the switching devices is difficult and quite hazardous if attempted while the board is live. Also if maintenance is required in these kind of setup, the devices upstream has to be switched off and hence a whole array of other applications gets disturbed.
[0006] The interlock mechanisms in the prior art require the user to manually engage the interlock mechanism when the control unit is fully engaged. This can damage electrical distribution system, the control unit or the equipment which the control unit is controlling. Therefore there is a need to provide an interlock mechanism which automatically engages when the control unit is fully inserted into the control unit compartment. There is, therefore, room for improvement in draw-out modules and panel locking mechanisms.
[0007] Operation of each of the foregoing mechanisms relies upon the position of the draw-out circuit breaker with respect to the enclosure. There is a need, therefore, for a panel interlock assembly capable of functioning independently from the position of the draw-out circuit breaker with respect to the enclosure in which it is housed.
C) OBJECTS OF THE INVENTION
[0008] The primary object of the present invention is to develop a stored energy type plug-in draw out module assembly with an inbuilt interlock mechanism for motor controllers in an electrical power distribution system.
[0009] Yet another object of the present invention is to develop a stored energy type plug-in draw out module assembly with a mechanism to interlock the module assembly with the panel, to prevent the draw-out of the module in service and test state.


[0010] Yet another object of the present invention is to develop a stored energy type plug-in draw out module assembly with a mechanism to interlock the switching devices mounted inside the module assembly with respect to the module state.
[0011] Yet another object of the present invention is to develop a stored energy type plug-in draw out module assembly with a mechanism to padlock the module in service, test and isolated state.
[0012] Yet anther object of the present invention is to develop a stored energy type plug-in draw-out module assembly with panel interlock assembly which is capable of functioning independently from the position of the draw-out circuit breaker with respect to the enclosure in which it is housed.
[0013] Yet anther object of the present invention is to provide an interlock mechanism which automatically engages when the control unit is fully inserted into the control unit compartment.
[0014] 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
[0015] The various embodiments of the present invention provide a stored energy type plug-in draw-out module assembly with inbuilt interlock mechanisms which functions independently from the position of the draw-out circuit breaker. It provides module interlock with panel, switching device interlock with module state and padlocking in three states of the module.
[0016] According to one embodiment of the present invention, a stored energy type retractable plug-in module assembly for switching devices is provided with with module state interlock system for motor controller for an end load device. The system has a module housing a switching device. A front face plate is arranged in the module. A back


plate is movably connected to the front plate through a slider mechanism. Pluralities of main contacts and auxiliary contacts are mounted on the back plate. A handle is mounted on the .front face plate. An indicator is mounted on the front face plate. A state changer knob is mounted on the front face plate. A module lock is fixed to the state changer knob. A spring is connected between the slider mechanism and the front plate. A rack is fixed with state changer knob. A coupler rigidly fixed with the handle. A padlock is hinged with front face plate.
[0017] A module interlock with panel is performed using the rack and the slider to prevents the withdrawal of the module until the main and the auxiliary contacts are brought to an isolated state. A switching device interlock with module state is performed using the handle, the rack and the coupler to prevent the change of state in the module and switching device, when the module is in service state. A padlocking for the module in service, isolated and test states are achieved using handle, rack, padlock and slider to ensure that the intended movement of the auxiliary and the main contacts in the intended state only. 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. A guide rail is connected between the front plate and the back plate to enable the movement of the slider mechanism between the front plate and the back plate. The spring assists the movement of the slider mechanism between the front plate and the back plate. The module lock is fixed to the state changer knob to lock the module in any one of the "SERVICE", "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 rack is provided with three step like structures that actually lead to move the slider mechanism. The rack has three slots for locking arrangement. The coupler is sandwiched between the handle and the switching device. The handle is provided with three slots for locking arrangement.
[0018] According to present invention the module interlock with panel ensures that the module cannot be drawn out unless and until the contacts are brought to an isolated state. It also ensures a cross interlock check with the switching device also being in OFF state.


If the switching device is in ON state, this interlock ensures that the contacts movement is not possible and hence the module too remains interlocked with the panel.
[0019] The switching device interlock with module state ensures that when a switching device is ON state then module should be in SERVICE state only and module state should not be changed to any other state. Precisely if module is in SERVICE state and if necessary to change into TEST or ISOLATED state then there should be interlocking mechanism is first switched OFF and then only it will allow to change the state otherwise not. The padlocking for three states of the module ensures that the intended movement of the contacts is all restricted so that the module can be in its intended state.
E) BRIEF DESCRIPTION OF THE DRAWINGS
[0020] 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:
[0021] FIG. I shows a typical flow diagram of the power distribution system in industrial scenario according to present invention.
[0022] FIG. 2 shows a typical schematic arrangement of distribution board or panel according to present invention.
[0023] FIG.3 shows a perspective view of the stored energy module assembly with padlock and status indicator on the front facia according to the present invention.
[0024] FIG.4 shows a perspective view of the stored energy panel with module interlock in service state according to the present invention.
[0025] FIG. 5 shows a perspective view of the various locking arrangement in the back facia of the stored energy panel according to one embodiment of the present invention.


[0026] FIG.6 illustrates a perspective view of the back facia when the module interlocks with the panel according to one embodiment of the present invention.
[0027] FIG.7 illustrates a perspective view of the back facia when the switching device interlocks with the module state.
[0028] FIG. 8 illustrates a perspective view of the back facia of stored energy panel showing padlocking in three states of the module.
[0029] FIG. 9 shows the side perspective view of the stored energy panel with the rack and the pinion arrangement according to present invention.
[0030] 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
[0031] 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.
[0032] The various embodiments of the present invention provide a stored energy type plug-in draw-out module assembly with inbuilt interlock mechanisms which functions independently from the position of the draw-out circuit breaker. It provides module interlock with panel, switching device interlock with module state and padlocking in three states of the module.


[0033] According to one embodiment of the present invention, a stored energy type retractable plug-in module assembly for switching devices is provided with with module state interlock system for motor controller for an end load device. The system has a module housing a switching device. A front face plate is arranged in the module. A back plate is movably connected to the front plate through a slider mechanism. Pluralities of main contacts and auxiliary contacts are mounted on the back plate. A handle is mounted on the front face plate. An indicator is mounted on the front face plate. A state changer knob is mounted on the front face plate. A module lock is fixed to the state changer knob. A spring is connected between the slider mechanism and the front plate. A rack is fixed with state changer knob. A coupler rigidly fixed with the handle. A padlock is hinged with front face plate.
[0034] A module interlock with panel is performed using the rack and the slider to prevents the withdrawal of the module until the main and the auxiliary contacts are brought to an isolated state. A switching device interlock with module state is performed using the handle, the rack and the coupler to prevent the change of state in the module and switching device, when the module is in service state. A padlocking for the module in service, isolated and test states are achieved using handle, rack, padlock and slider to ensure that the intended movement of the auxiliary and the main contacts in the intended state only. 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. A guide rail is connected between the front plate and the back plate to enable the movement of the slider mechanism between the front plate and the back plate. The spring assists the movement of the slider mechanism between the front plate and the back plate. The module lock is fixed to the state changer knob to lock the module in any one of the "SERVICE", "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 rack is provided with three step like structures that actually lead to move the slider mechanism. The rack has


three slots for locking arrangement. The coupler is sandwiched between the handle and the switching device. The handle is provided with three slots for locking arrangement.
[0035] According to present invention the module interlock with panel ensures that the module cannot be drawn out unless and until the contacts are brought to an isolated state. It also ensures a cross interlock check with the switching device also being in OFF state. If the switching device is in ON state, this interlock ensures that the contacts movement is not possible and hence the module too remains interlocked with the panel.
[0036] The switching device interlock with module state ensures that when a switching device is ON state then module should be in SERVICE state only and module state should not be changed to any other state. Precisely if module is in SERVICE state and if necessary to change into TEST or ISOLATED state then there should be interlocking mechanism is first switched OFF and then only it will allow to change the state otherwise not. The padlocking for three states of the module ensures that the intended movement of the contacts is all restricted so that the module can be in its intended state.
[0037] FIG. 1 shows a typical flow diagram of a power distribution system in an industrial scenario. 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 power distribution, monitoring and control equipments called switching devices. It is schematically shown in figure. 1 as power control centre (PCC) and motor control centre (MCC). The motor controllers are mounted inside a compact enclosure called module assembly. All electrical connections are made within the enclosure for the necessary power distribution and finally the required power is delivered to the end application devices. The present invention provides an interlock mechanism for motor controller feeder modules, wherein the module ca be plugged in and plugged out from live board in a safe manner.
[0038] FIG. 2 shows a typical schematic arrangement of distribution board or panel according to present invention. The controller modules are mounted on tray 20 inside the


panel board. The tray 20 includes slots 20A for interlocking with the module. The module assemblies are stacked inside the panel board. The motor controller module is locked with the panel in service and test state due to which even if somebody tries to pullout the motor controller module from the panel it will not get removed. The modules are of half the size of the panel board referred to as half module 4 and further could be one fourth the size of the panel board called quarter module 3. The plug-in withdrawal enclosure houses various switching devices commonly called as a feeder module. The sizes of these modules depend on the sizes of the safety devices installed and also the electrical clearances required for the functioning. The panel board consists of 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.
[0039] FIG.3 shows a perspective view of the stored energy module assembly with padlock and status indicator on the front facia according to the present invention. As shown in figure 3, it consists of horizontally stacked modules, called fractional modules within the width of the panel board. The modules include a spring assisted mechanism to support the plug-in and withdraw against the interface assembly 5. The compact enclosure 9 consist of power terminals 4a and auxiliary terminals 4b which are plugged on to an adaptor assembly 5 of mating power 5a and auxiliary terminals 5b fixed inside the panel board. The housing 9 comprises of a slider component 6 and a module back plate component 7. The slider component 6 and the back plate component 7 acts a mechanical link between the operating handle 8 and the movable connectors 4a and 4b.
[0040] The front facia 10 of the housing holds the module state changer knob 11 and module padlock 21 (Figure 4). The module state changer knob reciprocates in the slots 10A provided in facia. The padlock 21 is assisted by spring which is rigidly fixed with facia 10. User can pull out or rotate the padlock 21 by pulling portion 21C due to which extruded portion of padlock 21 gets engaged in slots of rack 15 and handle 8 respectively. It prevents the horizontal movement of handle 8 and vertical movement of rack 15. User can put the locking devices into the slot 21D of padlock 21.


[0041] By design facia slots are self locking such that it will lock the module lock at two different positions. As shown in figure 3, the set of power and auxiliary terminals are mounted on the component Back plate 7, which is rigidly fixed with the component slider 6. The slider is intern rigidly fixed with handle 8. The entire mechanism including contacts, back plate, slider and handle is housed by module housing 9. The slider assembly is tension spring 13 assisted. One end of spring is hooked in slider component and other is hooked in housing. The slider assembly is free to slide in housing with proper guiding provided in housing 9A. The module state changer knob 11 is the component which is operated by operator to vertically move the Module lock or rack (Figure 4).
[0042] The power input to the entire module assembly is through the interface assembly 5. The power input is distributed to the fixed contacts on to this interface. Each set of power contacts adaptable to one module has got a set of 4 power contacts each for incoming and outgoing. The interface 5 houses plurality of the auxiliary contacts 5B. The number of such contacts depends on the layout scheme and can vary between 2 to 30. The module assembly includes adaptable counter members for these contacts, both power 4A and 4B.
[0043] For the operation, the modules are inserted into the cavity block of the switchboard. The handle is operated with the slider mechanism to operate the switching device in service, test and isolated positions. In service state, both powers as well auxiliary circuits are remain closed. In test state only auxiliary circuit is closed and power circuit remains open. In isolated state both power and auxiliary contacts are remains open. The handle 8 is pushed to have the auxiliary contact 4B first mate with the corresponding auxiliary contacts 5B in the interface. This push is against the tension spring 13, and needs to be pushed till the profiled module lock pops down due to another spring action. This lets the state of test get achieved. Further push from test position, would let the power contacts 4A, also get engaged with the power contacts of the interface 5A. This further charges the spring and the assembly of back plate 7 with slider


6 and handle 8 get locked by a profile in the module lock 12. This lets the module to achieve the isolated state. At this state both the power and auxiliary contacts engaged and all the connections are complete.
[0044] In order to disconnect the power or auxiliary or both, the module state changer knob 11 should be pushed up. By pushing the module state changer in vertical directions, it further results in pulling the module lock. The Module lock thus releases the slider and the tension spring brings the entire assembly of back plate slider and the handle to its test state. Further, by pushing the module state changer up a spring mechanism releases the energy and this brings the entire assembly of back plate slider and the handle to its isolation state.
[0045] The two user interface nodes, handle and module state changer knob is provided to change the state of the module. Any one of them is used to operate the mechanism in either direction. When module state is to change from service to isolated state, the module state changer knob is to be operated and to change the state from isolated to service, handle is to be operated.
[0046] To change the state of the module from service to test and further to isolated operator has to lift the module state changer knob which correspondingly will lift the module lock. The slider assembly will be released from the first step of the module lock and travel to the second step where test state will be achieved. Further lifting of the module state changer knob will cause to release slider assembly from the second step and to reach the third step by which isolated state will be achieved. To change the state of module from isolated to test, operator has to push the handle till the second step of module will come down and stop. Slider in test position. Further pushing of the handle will cause first step to come down and stop the slider assembly where service state will be achieved.
[0047] In electrical application, this arrangement serves various advantages which are new and unique. It disconnects the power circuit very fast that helps to avoid electrical arching between the contacts. It consumes very less time to immediately disconnect the


circuit, which is required in emergency. The entire design is made simple for the user by having only two Interface nodes.
[0048] FIG.4 shows a perspective view of the stored energy panel with module interlock in service state according to the present invention. As shown in the figure 4, the compact enclosure 9 with electrical devices 12 is mounted on the component tray 20. The tray 20 includes slots 20A for interlocking the module with panel. The back facia of the module assembly includes a mechanism to interlock the module with panel. In service state the operating handle 8 is completely pushed inside to engage the power and auxiliary contacts. When module is in service and test condition, the legs of the rack are engaged in the slot 20A of tray 20 and motor controller module will get locked with the panel, due to which even somebody tries to pullout the motor controller module from the panel it will not get removed. In draw-out state, the component rack 15 is lifted at sufficient height so that leg 15E and Leg 15F (refer figure 8) are disengaged from the slots 20A of tray 20 and then motor controller module is free to remove from the panel.
[0049] The padlock 21 is hinged with facia 10 and can rotate only in clockwise direction. The padlock 21 is assisted by spring 18 which is rigidly fixed with facia 10. User can pull out or rotate the padlock 21 by pulling portion 21C (Fig 3) due to which extruded portion 21A and 21B of padlock 21 gets engaged in slots of rack 15 and handle 8 respectively which prevents horizontal movement of handle 8 and vertical movement of the rack 15. User can put the locking devices into the slot 21D of padlock 21.
[0050] In this state the switching device is in ON position. The state changer knob 11 is in bottom most position indicating that the assembly is in service state. Either the state changer knob 11 of the handle 8 is used to bring back the module to test and isolated state. The switching device 12 includes an operating shaft 12A protruding out that is connected with the handle 16. The switching device can be switched OFF and ON by shaft 12A which is connected to handle 16 coupled by coupler 19. [0051] FIG. 5 shows a perspective view of the various locking arrangement in the back facia of the stored energy panel according to the embodiment of the present invention. The rack 15 is placed on back surface of facia such that gear tooth profile of rack 15 is


matched with gear tooth profile of pinion 14. The rack 15 reciprocates in the guides provided in facia 10B, due to the rotation of the pinion 14 by the knob 11. The rack movement is assisted by tension spring 17. One end of the tension spring is hooked to the rack 15A and other is hooked to the facia. The tension spring tries to pull down the rack 15. So to lift the rack 15 force is to be applied against the spring.
[0052] The rack 15 is provided with three steps 15B, 15C and 15D (refer figure 9), which moves the slider mechanism 6 by two differential distances. Three slots 15H, 151 and 15J (refer figure 7) are provided in rack 15 for locking arrangement. Two legs 15E and 15F are protruding out which is contributing in panel interlocking. The handle 8 is rigidly assembled with slider 6 such that facia 10 gets sandwiched between the two. Three slots 8A, 8B and 8C are provided in handle 8 for locking purpose.
[0053] The padlock 21 is hinged with facia 10 and can rotate only in clockwise direction. The padlock 21 is assisted by spring 18 which is rigidly fixed with facia 10. User can pull out (rotate) the padlock 21 by pulling portion 21C (Fig 3) due to which extruded portion 21A and 21B of padlock 21 gets engaged in slots of rack 15 and handle 8 respectively which prevents horizontal movement of handle 8 and vertical movement of the rack 15. User can put the locking devices into the slot 21D of padlock 21.
[0054] The switching device/devices 12 and coupler 19 is assembled such that facia 10 is sandwiched between the handle 17 and the switching devices 12. The handle 16 and coupler 19 is fixed rigidly with each other. It is free to rotate in the facia. The extended shaft 12A is inserted into the coupler 19 and rotates along with coupler to operate switching device. When the handle 16 is showing ON position surface 19A of coupler 19 remain facing downwards and when the handle 16 in OFF state, the surface 19A of coupler 19 rotates clockwise by 90 degree with respective to its position in ON. In service state the handle 16 is at ON position and the rack 15 remain at its bottom most position. The surface 6A (refer figure 9) of slider 6 is supported at step 15B of rack 15 and surface 19A of coupler 19 is remain parallel to surface 15G of 'Rack'15. In this condition the coupler 19 is free to rotate at an angle of 90 degree only in clockwise direction. Surface 10C of facia 10 restricts anticlockwise rotation of coupler 19. Also in this condition


mechanism cannot change its position from service to any other state as surface 19A of coupler 19 is just touched with surface 15A of rack 15 and restricting upward movement of rack 15. When the mechanism is in any state other than service state and if the handle 16 is in OFF position, surface 19A of coupler 19 is at 90 degree with respect to its position in ON state. This time if somebody tries to rotate the handle towards ON surface 15A of rack 15 will restrict the rotational movement of coupler 19. Hence the coupler 19 can freely move only if module mechanism is in 'Service' state and module mechanism can change its state from 'Service' from any other state only if handle' 16 is in 'OFF' state.
[0055] FIG.6 illustrates a perspective view of the back facia when the module interlocks with the panel in different states according to present invention. The module interlock with the panel is achieved by components rack 15, tray 20 and slider 6. In service state, the surface 6A of slider 6 is supported at step 15B of rack 15. The Rack 15B is the bottom most position of the rack 15. When the mechanism moves to test state from service state, rack 15 gets lifted and slider 6 travels toward and gets supported at step 15C of rack 15. When the mechanism moves to isolated state from test state, rack 15 gets lifted again and slider 6 travels toward and get supported at step 15D of Rack 15. When the mechanism moves to draw-out state from service, only rack 15 moves upward.
[0056] When module is in service, test and isolated condition, the legs 15E and 15F (refer figure 8) of rack 15 are engaged in the slot 20A of tray 20 and motor controller module will get locked with the panel, due to which even somebody tries to pullout the motor controller module from the panel it will not get removed. At the same time in service or test condition if somebody tries to insert the motor controller module into the panel it will not get inserted because of interference between Iegl5E of rack 15 and tray 20. While in draw-out state, component rack 15 is lifted at sufficient height so that leg 15E and Leg 15F are disengaged from the slots 20A of tray 20 and then motor controller module is free to remove from the panel. Same concept is applicable while insertion of motor controller module into the panel, motor controller module will easily get inserted into the panel in draw-out state as there is no interference between rack 15 and tray 20.


[0057] FIG.7 illustrates a perspective view of the back facia when the switching device interlocks with the module state. The interlock between the switching device and the module state is achieved by the component handle 16, rack 15, coupler 19, spring 17, shaft 12A and slider 6. The switching device 12 includes an operating shaft 12A protruding out that gets connected with the handle 16. The switching device can be switched OFF and ON by shaft I2A which is connected to handle 16 coupled by coupler 19. When handle 16 is showing ON position surface 19A of coupler 19 remain facing downwards and when the handle 16 is showing OFF surface 19A of coupler 19 rotates clockwise by 90 degree with respective to its position in ON.
[0058] In service state, the handle 16 is at ON position, and rack 15 remains at its bottom most position. In this state the surface 6A of slider 6 is supported at step 15B of rack 15 and the surface 19A of the coupler 19 remains parallel to the surface 15G of the rack 15. In this condition, the coupler 19 is free to rotate at an angle of 90 degree only in clockwise direction. Surface 10C of facia 10 restricts anticlockwise rotation of the coupler 19. In this condition, the mechanism cannot change its position from service to any other state as surface 19A of the coupler 19 is just touched with surface 15A of rack 15, restricting upward movement of'Rack'15.
When mechanism is in any state other than service state and if the handle 16 is showing OFF, surface 19A of Coupler' 19 is at 90 degree angle with respect to its position in ON state. At this position if somebody tries to rotate the handle towards ON position, surface 15A of rack 15 will restrict the rotational movement of the coupler 19. In this way the coupler 19 can move freely only if the module mechanism is in service state. The module mechanism can change its state to service from any other state only when the handle 16 is in OFF state.
[0059] FIG. 8 illustrates a perspective view of the back facia of stored energy panel showing padlocking in three states of the module. The interlocking is achieved by component handle 8, rack 15, padlock 21, facia 10 and slider 6. The padlock in the present invention is nothing but locking the horizontal movement of handle 8 vertical


movement of rack 15 in three states service, test and isolated. When the module is in service state the surface 6A of slider 6 is supported at step 15B of rack 15 and which is the bottom most position of the rack 15. Spring 18 assisted padlock 21 is just touching surface 10B of facia 10 (refer figure 5). If somebody rotates (Pull out) 'Padlock' 21 by holding surface 21C, extension spring 'Spring' 18 get pulled and energy get stored in spring 18 and put the locks in slots 21D of padlock 21 and extruded portion 21A of padlock 21 get engaged in the slot 15H of rack 15 simultaneously extruded potion 21B get engaged in the slot 8A of handle 8. Due to which neither handle 8 can move not rack 15.
[0060] Similarly in test state if padlock 21 is locked, extruded portion 21A of padlock 21 get engaged in the slotl 51 of rack 15 simultaneously extruded potion 21B get engaged in the slot 8B of handle 8. Similarly in service state if padlock 21 is locked, extruded portion 21A of padlock 21 get engaged in the slotl5J of rack 15 simultaneously extruded potion 21B get engaged in the slot 8C of handle 8. If lock is removed from the slot 21D of padlock 21 due to spring 18 librates stored energy instantly padlock 21 automatically rotates and extruded portion 21A of padlock 21 touches the surface 10B of facia 10.
[0061] FIG. 9 shows a side perspective view of the stored energy panel with rack and pinion arrangement according to present invention. In service state, the surface 6A of slider 6 is supported at step 15B of rack 15. The Rack 15B is the bottom most position of the rack 15. When the mechanism moves to test state from service state, rack 15 gets lifted and slider 6 travels toward and gets supported at step 15C of rack 15. When the mechanism moves to isolated state from test state, rack 15 gets lifted again and slider 6 travels toward and get supported at step 15D of Rack 15. When the mechanism moves to draw-out state from service, only rack 15 moves upward.
G) ADVANTAGES OF THE INVENTION
[0062] The various embodiments of the present invention provide a stored energy type plug-in draw-out module assembly with inbuilt interlock mechanisms which functions independently from the position of the draw-out circuit breaker. It provides an interlock


mechanism for motor control feeder modules, wherein the module can be plugged in and unplugged from a live board in a safe manner. It prevents the draw out of the module when the contacts are live. It ensures that the module assembly can only be drawn out in the safest state of the circuitry. It provides module interlock with panel, switching device interlock with module state and padlocking in three states of the module.
[0063] The module interlock with the panel ensures that the module cannot be drawn out unless and until the contacts are brought to an isolated state. If the switching device is in ON state, the interlock ensures that the contacts movement is not possible and hence the module too remains interlocked with the panel. Switching device interlock with module state ensures that when a switching device is ON then module should be in SERVICE state only and module state should not be change to any other state. Padlocking for three states of the module ensures that the intended movement of the contacts is restricted so that the module can be in its intended state.
[0064] 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.

[0065] 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: March 30, 2008. RAKESH PRABHU
Place: Bangalore. Patent Agent

CLAIMS
What is claimed is:
1. A stored energy type retractable plug-in module assembly for switching devices
with module state interlock system for 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;
a rack fixed with state changer knob;
a coupler rigidly fixed with the handle;
a padlock hinged with front face plate.
2. The assembly according to claim 1, wherein a module interlock with panel is performed using the rack and the slider to prevents the withdrawal of the module until the main and the auxiliary contacts are brought to an isolated state.
3. The assembly according to claim 1, wherein a switching device interlock with module state is performed using the handle, the rack and the coupler to prevent the change of state in the module and switching device, when the module is in service state.


4. The assembly according to claim I, wherein a padlocking for the module in service, isolated and test states are achieved using handle, rack, padlock and slider to ensure that the intended movement of the auxiliary and the main contacts in the intended state only.
5. 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.
6. 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.
7. The assembly according to claim 1, wherein the spring assists the movement of the slider mechanism between the front plate and the back plate.
8. 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;
9. 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.
10. The assembly according to claim 1, wherein the self locking slots in the front plate lock the module lock at two different positions.
11. The assembly according to claim 1, wherein the rack is provided with three step like structures that actually lead to move the slider mechanism.
12. The assembly according to claim 1, wherein the rack has three slots for locking arrangement.
13. The assembly according to claim 1, wherein the coupler is sandwiched between the handle and the switching device.
14. The assembly according to claim 1, wherein the handle is provided with three slots for locking arrangement.
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 Patents office, Mumbai