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:
SAFETY SHUTTER MECHANISM 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 draw in type feeder modules. The present invention more particularly relates to a safety shutter mechanism.
B) BACKGROUND OF THE INVENTION
[0002] Control devices are used to control the electrical current distribution to multiple motors or loads. Plurality of motor control centre (MCC) modules in a central location, arc generally housed in compartmented panels called Motor Control Centres (MCC). The MCC are part of switchboard. MCC modules get mounted inside a board or panel board for operator safety. The installations of electrical devices are generally of two types. In one type of installation, electrical devices are stationary mounted to structural members or frames of the board. In such stationary installations, inspection and maintenance of the circuit breaker is difficult and quite hazardous to personnel. In these cases the switchboard has to be necessarily shut down to carry on the maintainance as the electrical devices are stationary mounted to the structural members or frames. While in other type of installation, the switching devices are mounted on a frame that are drawn in / out for operation without out shutting down the power. In this type of installation, the frame is drawn out for maintenance. While the frame is drawn out, the main power distribution channel, commonly called as bus bars are still live. To reduce the hazards of working with live boards shutter mechanism is proposed. The shutter mechanism automatically closes off access to bus bars used in switchboard enclosures to reduce the risk of inadvertent electrical contact by a technician installing or removing equipment from the enclosure.
[00031 MCC are equipped with draw-out type protective control devices called MCC modules. These control devices are inserted into individual compartments within the panel to establish mechanical and electrical contact with droppers through bus bars and loads. Plurality of control devices are stacked together, the terminals at stationary


electrical connector usually remain energized all the time even when any one of the individual MCC module is removed.
[0004] The stationary exposed terminals create a safety hazard and are very dangerous causing serious injuries to the personnel. Therefore, when a control device is removed, it is desirable to close off access to the exposed terminals to prevent direct contact with the energized terminals.
[0005] As a safety device, safety shutter restricts direct user access to exposed stationary terminals and provides access only when MCC module is been inserted into the panel.
[0006] In current scenario, shutter arrangements are mounted on rear portion of the individual compartments in a panel. When the MCC module is inserted into the compartment, shutters slide to different areas to expose the terminals for connection with the control device. Moreover, these safety shutter mechanisms are slow. The sliding mechanisms supporting the shutters are complex and bulky, requiring a complex interaction with the control device during the insertion procedure for the shutters to open properly. The sliding shutters and accompanying support mechanism occupy a substantial amount of space in the rear portion of the compartment.
[0007] In light of foregoing discussion, there exists a need for an efficient, instant, inexpensive and space saving shutter using a simple assembly which does not interfere with the other components or operation of the MCC module. There also exists a need for a field-installed protective shutter assembly that fits the MCC module designs of various manufactures.
[0008] The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.
C) OBJECT OF THE INVENTION


[0009] The primary objective of the present invention is to provide a safety shutter mechanism for motor controllers for electrical distribution system to restrict physical interaction between human and live stationary contacts and to avoid entry of unwanted foreign materials into the electrical distribution system.
[0010] Another object of the present invention is to provide an emergency defeat
feature in the safety shutter mechanism to get access to live terminals for Non-touch
optical temperature sensing instruments for temperature measurement and visual
inspection.
[0011] Yet another objective of the invention is to provide a shutter assembly with a
rotary hinged door cover and a latch lever adapted to restrict user access to live
electrical connectors when the MCC module is removed from the enclosure.
[0012] Yet another object of the invention is to provide an efficient, instant, inexpensive and space-saving shutter using a simple assembly which does not interfere with the other components or operation of the MCC module.
[0013] Yet another object of the invention is to provide a safety shutter mechanism having a field-installed protective shutter assembly that fits the MCC module designs of various manufactures.
[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 safety shutter mechanism for motor controllers for electrical distribution system to restrict physical interaction between human and live stationary contacts and to avoid entry of unwanted foreign materials into the electrical distribution system. The safety shutter mechanism emergency defeat feature in the safety shutter mechanism is to get access to live terminals for non-touch optical temperature sensing instruments for temperature measurement and visual inspection.


|00I6] According to one embodiment of the present invention, a safety shutter assembly has a safety shutter door, A safety lever is latched to safety shutter. The safety lever is rotated to delatch the safety shutter door lo move the safety shutter door when a feeder module is inserted in to the enclosure in the power distribution panel.
[00I7] The safely shutter door has a base support structure and two limbs provided at top portion of the base support structure. The two limbs of the safety shutter are inserted into the holes provided in the tray at the enclosure to keep the shutter in suspended condition. The shutter door is connected to the top wall of the enclosure through a first spring.
[0018] The safety lever has an elongated member. A hook is formed integrally at one end of the elongated member. A hole is formed at tone end of the elongated member. There is a protrusion with inclined surface at the middle portion of the elongated member. The hook at the safety lever is latched to the bottom end of the shutter door to keep the door in latched condition. The safety lever is pivotally connected to the tray in the enclosure. The protrusion is pressed down to rotate the safety lever to delatch the shutter door to move the shutter door to permit the entry of the feeder module, when the feeder module is inserted into the enclosure. The safety lever is connected to the enclosure through a second spring. The safety lever is moved by the second spring to latch with the shutter door with the hook, when the feeder module is withdrawn from the enclosure.
[0019] The assembly has an emergency defeat feature. For emergency defeat the safety lever is rotated by pushing the protrusion by one hand and rotating the safety shutter by other hand. During the emergency situation, the control operator first releases the safety shutter and then defeats the feature of safety lever so as to maintain latching between the two.


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 block diagram of the power distribution system in industrial scenario according to present invention.
[0022] FIG. 2 shows a perspective view of distribution board according to one embodiment of the present invention.
[0023] FIG. 3 illustrates a side perspective view of a single row of distribution board according to one embodiment of the present invention.
[0024] FIG. 4 illustrates a side view or a MCC module sliding into one of the compartments of the distribution board provided with a safety shutter assembly according to one embodiment of the present invention.
[0025] FIG. 5 illustrates a sectional view a MCC module just sliding into one of the compartments of the distribution board provided with a safety shutter assembly according to one embodiment of the present invention.
[00261 FIG. 6 shows a perspective view of safety shutter in a safety shutter assembly according to one embodiment of the present invention.
[0027] FIG. 7 shows a perspective view of safety lever in a safety shutter assembly according to one embodiment of the present invention.
[0028] FIG. 8 shows a perspective view of a tray in a distribution enclosure provided with a safety shutter assembly according to one embodiment of the present invention.


[0029] FIG. 9 illustrates a sectional view of MCC module sliding into one of the compartments of the distribution board provided with a safety shutter assembly according to one embodiment of the present invention, with the safety shutter and safety lever in latched condition.
|0030] FIG. 10 illustrates a sectional view of MCC module sliding towards one of the compartments of the distribution board provided with a safety shutter assembly according to one embodiment of the present invention, with the safety shutter and safety lever in partially de-latched condition.
[0031] FIG. 11 illustrates a sectional view of MCC module completely slides into one of the compartments of the distribution board board provided with a safety shutter assembly according to one embodiment of the present invention, with the safety shutter and safety lever in completely de-latched condition.
[0032] 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
[0033J 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.
[0034] The various embodiments of the present invention provide a safety shutter mechanism for motor controllers to restrict physical interaction between human and

live stationary contacts, and to avoid entry of unwanted foreign materials into the electrical distribution system. The safety shutter also provides an emergency defeat feature in the safety shutter mechanism to get access to live terminals for Non-touch optical temperature sensing instruments for temperature measurement and visual inspection.
[0035] According to one embodiment of the present invention, a safely shutter assembly has a safety shutter door. A safety lever is latched to safety shutter. The safety lever is rotated to delatch the safety shutter door to move the safety shutter door when a feeder module is inserted in to the enclosure in the power distribution panel.
[0036] The safety shutter door has a base support structure and two limbs provided at top portion of the base support structure. The two limbs of the safety shutter are inserted into the holes provided in the tray at the enclosure to keep the shutter in suspended condition. The shutter door is connected to the top wall of the enclosure through a first spring.
[0037] The safely lever has an elongated member. A hook is formed integrally at one end of the elongated member. A hole is formed at tone end of the elongated member. A protrusion with inclined surface at the middle portion of the elongated member. The hook at the safety lever is latched to the bottom end of the shutter door to keep the door in latched condition. The safety lever is pivotally connected to the tray in the enclosure. The protrusion is pressed down to rotate the safety lever to delatch the shutter door to move the shutter door to permit the entry of the feeder module, when the feeder module is inserted into the enclosure. The safety lever is connected to the enclosure through a second spring. The safety lever is moved by the second spring to latch with the shutter door with the hook, when the feeder module is withdrawn from the enclosure.
[0038] The assembly has an emergency defeat feature. For emergency defeat the safety lever is rotated by pushing the protrusion by one hand and rotating the safety


shutter by other hand. During the emergency situation, the control operator first releases the safety shutter and then defeats the feature of safety levee so as to maintain latching between the two.
[0039] The safety shutter mechanism operates as described herein .When MCC module is inserted into the panel the safety shutter gets away from the MCC module, without interrupting the MCC module path towards stationary electrical connector, further, the safety shutter comes to its position instantly when MCC module is getting removed from the panel.
[0040] FIG. I shows a typical flow diagram of a power distribution system in an industrial scenario. The powers from grids are transferred to the end application devices such as motors, lighting loads and air conditioning loads etc. In order to cater 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. 1 he motor controllers are mounted inside a compact enclosure with all electrical connections made within the enclosure for the necessary distribution. Finally the required power is delivered to the end application devices.
[0041] FIG. 2 shows a typical schematic arrangement of distribution board according to present invention. A (ray 2 is fixed to four columns and mounted one above the other forming compartments. The MCC module 1 with quarter size and half size of the compartment width are drawable modules carrying moving dead contact. An Interface 5 is fixed to the rear end and housing fixed live contacts. The MCC module I and Interface 5 are mounted in the compartments formed between stacked trays 2.
[0042] FIG. 3 illustrates a side perspective view of a single row of distribution board according to the present invention. The MCC modules 1 and interface 5 are mounted into the compartments formed between stacked trays 2.


[0043] FIG. 4 illustrates a side view of a MCC module sliding into one of the compartments of the distribution board according to the present invention. The Interface 5 is fixed on the tray 2. A module guide 7 is fixed to the tray 2 which guides the MCC module I to get aligned with interface 5. A partition 6 is used for parting the compartment among different MCC modules 1. A safety shutter 3 is hinged to the tray 2 hanging perpendicular to the direction of movement of the MCC module 1. A safety lever 4 is in latched position with the safety shulter 3.
[0044] FIG. 5 illustrates a sectional view a MCC module just sliding into one of the compartments of the distribution board according to one embodiment of the present invention. With respect to FIG. 5, the safety shutter 3 is assisted by torsion spring 8 and Safety levur 4 is assisted by torsion spring 9. The Interface 5 is fixed on the tray 2. A module guide 7 is fixed to the tray 2 which guides the MCC module 1 to get aligned with interface 5. A partition 6 is used for parting the compartment among different MCC modules I. A safety shutter 3 is hinged to the tray 2 hanging perpendicular to the direction of movement of the MCC module I with spring 8 in normal radially uncompressed condition. The safety shutter 3 is in hanging position and covers the compartment region equal to size of the MCC module 1 to avoid entry of any foreign particle.
[0045] FIG. 6 shows constructional details of safety shutter according to the present invention. The safety shutter 3 includes two limbs limb 3A and limb 3B.
|0046] FIG. 7 shows constructional details of safety lever according to the present invention. The safety lever 4 has surfaces 4A, 4B, 4D and 4E. The safety lever 4 also includes a hole 4C
[0047] FIG. 8 shows constructional details of tray according to the present invention. The tray includes holes 2A and 2B. The tray also includes slots 2C and 2D. The safety shutter 3 has two limhs 3A which get hinged in to the hole 2A of tray 2. Surface 3B of the safety shutter 3 gets latched with the surface 4A of safety lever 4. The safety lever 4 is hinged with hole 4C at hole 2B of tray 2, Due to rotation of the safety lever 4
31 MAR 2009

region 4D and 4h of the safety lever 4 pops up or down in slots 2C and 2D of tray 2 respectively. While inserting MCC module l. surface lA-of MCC module I hits with surface 4B of safety lever 4 and rotates the safety lever 4-
[004S] PIG. 9 illustrates sectional view of MCC module sliding into one of the compartments of the distribution board according to one embodiment of the present invention. Where the safety shutter and safety lever are latched together. The safety shutter 3 is assisted by torsion spring 8 and Safety lever 4 is assisted by torsion spring 9. The Interface 5 is fixed on the tray 2. A module guide 7 is fixed to the tray 2 which guides the MCC module 1 To gel aligned with interface 5. A partition 6 is used for parting the compartment among different MCC modules 1- A safety shutter 3 is hinged to the tray 2 hanging perpendicular to the direction of movement of the MCC module 1 with spring 8 in normal radially uncompressed condition.
[0049] The safety shutter 3 is in hanging position and covers the compartment region equal to size of the MCC module I to avoid entry of any foreign particle. Further, simultaneously region 4D and 4E of safety lever 4 are popped up through the slots 2C and 2D of tray 2 with spring 9 in normal radially uncompressed condition. Surface 3B of safety shutter 3 and surface 4A of safety lever 4 are latched together so to avoid forceful insertion of foreign material or human intervention
[0050] PIG. 10 illustrates sectional view of MCC module sliding towards one of the compartments of the distribution board according to one embodiment of the present invention. Where the safety shutter and safety lever are partially de-latched. The safety shutter 3 is assisted by torsion spring 8 and Safety 'ever 4 is assisted by torsion spring 9. The Interface 5 is fixed on the tray 2. A module guide 7 is fixed to the tray 2 which guides the MCC module 1 to get aligned with interface 5. A partition 6 is used for parting the compartment among different MCC modules 1. A safety shutter 3 is hinged to the tray 2 hanging perpendicular to the direction of movement of the MCC module 1 with spring 8 in normal radially uncompressed condition.


[005I] Further the MCC module 1 moves towards the interface 5. Further down the MCC module 1 passes through lever surface 1A of MCC module 1, the MCC module I slides over surface 4B of safety lever 4 and forces the safety lever 4 to rotate until the safety shutter 3 de-latches from the safety lever 4.
[0052] FIG, 11 illustrates sectional view of MCC module completely slides into one of the compartments of the distribution board according to one embodiment of the present invention. Where the safety shutter and safety lever are completely de-latched. The safety shutter 3 is assisted by torsion spring 8 and safety lever 4 is assisted by torsion spring 9. The Interface 5 is fixed on the tray 2. A module guide 7 is fixed to the tray 2 which guides the MCC module 1 to get aligned with interface 5. A. safety shutter 3 is hinged to the tray 2 hanging perpendiculav to the direction of movement of the MCC module 1 with spring 8 in normal radially uncompressed condition,
[0053] When the MCC module I moves towards the interface 5. Further down the MCC module 1 passes through lever surface 1A of MCC module 1, the MCC module 1 slides over surface 4B of Safety lever 4 and forces the safety lever 4 to rotate until the safety shutter 3 de-latches from the safety lever 4.
[0054] Further movement of MCC module 1 forces to rotate safety shutter 3, Finally the MCC module 1 gets aligned with the Interface 5 through module guide 7 (as shown in Fig. 9),
[0055] Similarly when the MCC module 1 is drawn or moved away from the Interface 5, the safety shutter 3 rotates along with the top surface of the MCC module 1 due to discharging action of Spring 8. Further, the surface 1A of MCC module 1 gets away from surface 4B of Safety lever 4. Hence, the safety lever 4 rotates due to discharging action of the Spring 9 and latches with the safety shutter 3.


[0056] for emergency defeat the safety lever 4 is rotated by pushing surface 4B by one hand and rotating safety shutter 3 by other hand. When the emergency situation is in control, operator releases the safety shutter 3 and then defeat feature of safety lever 4 to maintain latching between the safety shutter 3 and safety lever 4.
G) ADVANTAGES OF THE INVENTION
[0057] Thus the various embodiments of the present invention provide a safety shutter mechanism for motor controllers to restrict physical interaction between human and live stationary contacts, and to avoid entry of unwanted foreign materials into the electrical distribution system. The safety shutter also provides an emergency defeat feature in the safety shutter mechanism to get access to live terminals for Non-touch optica] temperature sensing instruments for temperature measurement and visual inspection. The invention provides an efficient, instant, inexpensive and space-saving shutter using a simple assembly which does not interfere with the other components or operation of the MCC module. The invention provides a shutter assembly that lits the MCC module designs of various manufactures. Further, online assembling of the safety shutter is easy.
[0058| 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.

[0059] 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, 2009. Place: Bangalore.
RAKESH PRABHU
Patent Agent

CLAIMS
What is claimed is:
1. A safety shutter assembly for plug in draw out type module in electrical power
distribution panel including an enclosure provided with tray for receiving a
feeder module, the assembly comprising:
a base support structure
a safely shutter door: and
a safety lever latched to safety shutter,
wherein the safety lever is rotated to delatch the safety shutter door to move
the safety shutter door into open condition when a feeder module is inserted in
to the enclosure in the power distribution panel.
2. The assembly according to claim t, wherein the base support structure has two limbs provided at top portion of the base support structure-
3. The assembly according to claim 2, wherein the two limbs of the safety shutter door are inserted into the holes provided in the tray at the enclosure to keep the shutter in suspended condition by a first spring.
4. The assembly according to claim I, wherein the safety shutter door is suspended from the top wall of the enclosure through the first spring,
5. The assembly according to claim I, wherein the safety lever comprising: an elongated member;
a hook formed integrally at one end of the elongated member;


a hole formed at tone end of the elongated member; and
a protrusion with "inclined surface at the middle portion of the elongated
member.

6. The assembly according to claim 1, wherein the hook at the safety lever is latched to the bottom end of the shutter door to keep the door in latched condition.
7. The assembly according to claim 1, wherein the safety lever is pivotally connected to the tray in the enclosure.
8. The assembly according to claim 1, wherein the protrusion is pressed down to rotate the safety lever to delatch the shutter door to move the shutter door to permit the entry of the feeder module, when the feeder module is inserted into the enclosure,
9. The assembly according to claim 1, wherein the safety lever is connected to the enclosure through a second spring.
10. The assembly according to claim 1, wherein the safety lever is moved by the second spring to latch with the shutter door with the hook, when the feeder module is withdrawn from the enclosure.
Date: March 30, 2009. 'RAKESH PRABHU
Place: Bangalore. Patent Agent