FORM2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
1. Title of the invention: AN IMPROVED PADLOCK AND
INTERLOCK MECHANISM FOR EOM
2. Applicant(s):
(a) NAME : LARSEN & TOUBRO LIMITED
(b) NATIONALITY : An Indian Company
(c) ADDRES S : L & T House, Ballard Estate, Mumbai 400 001,
State of Maharashtra, India
3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed:

FIELD OF THE INVENTION
The present invention relates to an improved Padlocking and Interlocking mechanism of Electrically Operating mechanism (EOM) for Changeover Switch. More particularly the present invention relates to an improved Padlocking and Interlocking mechanism of Electrically Operating mechanism (EOM) for Changeover Switch having modular mechanism for padlock, multiple mechanisms with minimum components and two micro switches utilized in all functionalities
BACKGROUND AND PRIOR ART OF THE INVENTION
Changeover switches are widely used to switch between primary and backup power source. Electrically operating mechanism is used to operate the Changeover switches using electrical power providing easiness to the user. Changeover switches have three stable positions-ONl, OFF, ON2. EOM drives the shaft of the Changeover switch through a gear train powered by a motor as the input. EOM also has provision of Manual operation during which the supply to the motor is to be cut for the safety of the operator. Padlocking provision is also given to disable both manual operation and motor operation in OFF position. To establish the features like Selector switch, Padlocking and Interlock to ensure safety of the operator, a compact arrangement is developed.
Existing arrangements have interdependency and less flexibility. This arrangement provides greater flexibility with multiple interlocks to avoid any accidents.
Padlocking:
Provision to lock the device using portable locks (Padlocks) so that only authorized personnel can decide its operation and restrict the operation of device by others.
Interlock:

Provision to ensure that one action cannot be done without performing the other. One action is constrained by another,
Microswitch:
Small sized switches with contacts that can be closed/opened through an actuating
lever/projection.
NO contacts:
Normally Open contacts-The contacts will be open when the Microswitch is not actuated and will close when actuated.
NC contacts:
Normally Closed contacts-The contacts will be closed when the Microswitch is not actuated and will open when actuated.
EOM:
Electrically operated mechanism - Electrical power is used to operate the device.
In existing system, all the features like Padlock, Selector switch, Interlock system are provided as an integral part of the device. The features are provided at different areas of the device. In the event of failure of any of these functions, the EOM assembly should be dismantled and checked for the cause of the problem. Also, some interlock arrangements may not be present which may cause injury to the operator.
All the functions like Padlocking (both in Manual and Motor mode), Selector switch, Handle lock are provided as an single compact integral unit.
The invention discussed here is modular and hence without dismantling the EOM, it can be removed to check its functionality.

There are multiple interlocks providing double-point protection to ensure the safety of the operator. The arrangement is made such that there is always a secondary protection in series to ensure the operator's safety.
The invention provides the customer interactive features like Padlock, Motor-Manual mode selection switch with interlocks to prevent abuse and ensure that the operator is safe during operation of the switch through the EOM.
OBJECTS OF THE INVENTION
One object of the present invention is to overcome the disadvantages / drawbacks of
the prior art.
A basic object of the present invention is to provide an improved Padlocking and Interlocking mechanism of Electrically Operating mechanism (EOM) for Changeover Switch which is compact, modular and is easy to use.
Another object of the present invention is to provide an improved Padlocking and Interlocking mechanism of Electrically Operating mechanism (EOM) for Changeover Switch where Safety is ensured at two points for all functions performed so that even if there is a failure at one point, the other point in series takes care ensuring that the supply is cut when it is not necessary.
Yet another object of the present invention is to provide an improved Padlocking and Interlocking mechanism of Electrically Operating mechanism (EOM) for Changeover Switch in which the Operator safety is ensured and misuse of the device is prevented.
These and other advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying
drawings.

SUMMARY OF THE INVENTION
According to one of the aspect of the present invention relates to a Padlocking and an
Interlocking mechanism of Electrically Operating mechanism (EOM) for Changeover
Switch, said mechanism comprising :
a locking means comprises :
a padlock pin;
plurality of padlock means ;
padlock spring;
a selector switch to switch between manual and motor mode , said selector switch
comprises selector switch spring;
a driving shaft;
a handle means;
a over ride pin operatively connected with said handle means comprises an override
spring; such that when said handle is inserted within said driving shaft adapted to cut
the supply to the motor and said handle is locked when inserted in said shaft;
a shutter preventing entry of handle in motor mode;
a pair of micro switch comprises micro switch 1 and micro switch 2;
a slider with a slider spring to retain position;
such that said locking means is pushed in and flipped to insert the Padlock means
the said padlock pin enters the hole in the said shaft and arrests said shafts rotation to
have the padlock condition;
such that said locking means in padlock condition blocks the entry of said handle
means to couple with said shaft;
wherein said padlocking is done at OFF position where the hole in the shaft matches
with the axis of said padlock pin .

DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to an improved Padlocking and Interlocking mechanism of Electrically Operating mechanism (EOM) for Changeover Switch.
To lock the EOM and also the Changeover switch connected to restrict unauthorized operation. When Padlocked, the EOM should not run when the control signal is given. This is done by opening the circuit through the Micro switch so that the motor does not get the electrical supply to operate. Manual operation is also restricted in this
condition.
To switch between Manual and Motor operation. EOM should operate only when the Selector switch is put into Motor mode. When the Selector switch is in Manual mode, EOM should not operate since the rotation of shaft may cause injury to the operator who is trying to operate the Changeover switch manually. So, the electrical supply to the motor should be cut to ensure that EOM does not operate in Manual mode. This is done through the same Micro switches used for Padlocking operation.
According to one of the embodiment of the present invention there is provided a Padlocking and an Interlocking mechanism of Electrically Operating mechanism (EOM) for Changeover Switch. The mechanism comprising a locking means, a selector switch to switch between manual and motor mode ,a driving shaft, a handle means, a over ride pin operatively connected with the handle means such that when the handle is inserted within the driving shaft adapted to cut the supply to the motor and the handle is locked when inserted in the shaft, a shutter preventing entry of handle in motor mode, a pair of micro switch comprises micro switch 1 and micro switch 2, a slider with a slider spring to retain position.

The locking means comprises a padlock pin, plurality of padlock means, padlock spring. The selector switch comprises selector switch spring, a over ride pin comprises a pah^e£override spring.
The locking means is pushed in and flipped to insert the Padlock means the padlock
pin enters the hole in the shaft and arrests the shafts rotation to have the padlock
condition. The locking means in padlock condition blocks the entry of the handle
means to couple with the shaft. The padlocking is done at OFF position where the
hole in the shaft matches with the axis of the padlock pin.
The locking means is having provision of insertion of max. of three padlock means.
The padlock means is of 05 to 07.
The padlock means is padlocked, the locking means cannot flip back to its original
position ensuring that the supply is cut to the motor and blocks Manual operation.
The padlock pin comprises a support means.
The support means pushes the Slider to release the actuation of Microswitch 1 to cut
the supply to Motor.
The support means also actuates Microswitch 2 to cut the supply to the Motor.
The selector mode when selected in manual mode pushes the slider further to keep Microswitch 1 released and the Padlockpin arrests the shaft while the lockpin support actuates Microswitch 2 to cut the supply as a secondary protection The handle means is provided with a hole so that Padlocking can be done even when the handle is inserted.
Advantages
1. Modular mechanism for Padlock.
2. Multiple mechanisms with minimum components.
3. Two Micro switches utilized in all functionalities.

4. Various interlocks and double point protection to ensure safety of operator.
FEATURES:
a) Compact mechanism with minimum components.
b) Modular.
c) Multiple functions in all components.
d) Two Micro-switches are utilized for all functions thereby reducing number of
micro-switches.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
Other features as well as the advantages of the invention will be clear from the following description. In the appended drawing:
Figure 1 illustrates the outer view of the assembly with the accessible parts.
Figure 2 illustrates the inner view of the assembly with the arrangement of various components and springs.
Figure 3 illustrates the assembly padlocked in MOTOR mode.

Figure 7 illustrates the assembly with the handle inserted completely to engage with the operating shaft.
Figure 8 illustrates the assembly in Padlocked condition with the handle inserted.
Figure 9 illustrates the Override pin actuating Microswitch 2 when the handle is inserted.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWING
In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and illustrate the best mode presently contemplated for carrying out the invention. Further functioning of the system and method has been discussed below to describe the way it operates. However, such description should not be considered as any limitation of scope of the present system. The structure thus conceived is susceptible of numerous modifications and variations, all the details may furthermore be replaced with elements having technical equivalence. In practice the materials and dimensions may be any according to the requirements, which will still be comprised within its true spirit.
Construction:
The main embodiment of this patent consists of Padlock and Interlock mechanism which is used in EOM for Changeover switch.
Figure 1 shows the outer view of the assembly with the accessible parts.
Lock (5) is used to padlock the device. Padlock is done by pushing the Lock (5)and flipping it to put Padlocks ( 13)(max. 3 nos.). When padlocking is done, the EOM will not function and the Changeover switch cannot be operated manually since it blocks the insertion of handle (14) to couple the operating shaft.

Selector switch (4) is used to switch between MANUAL and MOTOR mode. Only when the Selector switch (4) is in MOTOR mode, the EOM gets the supply (When Padlocking is not done) and operates as per the control signal given to it. EOM drives the Changeover switch to its respective position (1,0,11) through the driving shaft.
Override pin/Handle lock (1) cuts the supply to motor when handle is inserted and also locks the handle in position when it is fully engaged with the shaft. The Override pin/Handle lock (1) must be pulled outwards to release the handle.
Shutter (2) prevents unnecessary access to the shaft (3) when the EOM is in MOTOR mode. The shutter (2) cannot be opened when the EOM is in MOTOR mode since the slider(6) (shown in figure 2) blocks its opening. When the Selector switch(4) is in MANUAL mode, the Shutter (2) can be opened to insert the Handle and operate the Changeover switch manually.
Figure 2 shows the inner view of the assembly with the arrangement of various components and springs i.e. the slider spring (5) , selector switch spring (7) , override spring (9) , padlock spring (11) which are used to retain the respective
position.
Figure 3 shows the assembly padlocked in MOTOR mode. Provision is made to insert upto 3 padlocks (13) of 05 to 07. The Lock (5) is pushed in and flipped to insert the Padlocks(13). Once padlocked, the lock (5) cannot flip back to its original position ensuring that the supply is cut to the motor and blocks Manual operation.
Figure 4 shows the inner view in padlocked condition. When the Lock (5) is pushed and flipped, the padlock pin (12)enters the hole (15) in the shaft and arrests its rotation. It also blocks the entry of handle (14) (Even if shutter is broken) to couple with the shaft. Also, the support of the Padlock pin (12) pushes the Slider (6) to release the actuation of Micro switch 1 (8) to cut the supply to Motor. As a secondary

protection, the Padlock pin (12) support also actuates Micro switch 2 (10) to cut the supply to the Motor.
Note that Padlocking can be done only at OFF position of the Switch where the hole (15) in the shaft matches with the axis of Padlock pin (12) . When the Switch is in ON condition, the hole will not match and Padlocking cannot be done.
Figure 5 shows the inner parts in when the selector switch (4) is in MANUAL mode. The Selector switch (4) pushes the slider (6) and releases the actuation of Micro switch 1 (8) thereby cutting supply to the motor. When the Shutter (2) is opened and handle (14) is inserted, the override pin (1) actuates the Micro switch 2 (10) and cuts the supply to the motor acting as the second point of protection.
Figure 6 shows the Padlocked condition in MANUAL mode without insertion of handle (14). In this case, Micro switch 1 (8) is already blocking supply to motor due to the movement of slider (6). When Lock(5) is pushed, it pushes the slider (6) further to keep Micro switch 1 (8) released .The Padlock pin (12) arrests the shaft while the lock pin (1) support actuates Micro switch 2 (10) to cut the supply as a secondary protection.
Figure 7 shows the assembly with the handle (14) inserted completely to engage with the operating shaft. Now the slider de-actuates Micro switch 1 (8) and override pin (1) actuates Micro switch 2 (10) to cut the supply at two points in series. A hole (15) is provided in Handle (14) coupler so that Padlocking can be done even when the handle (14) is inserted.
Figure 8 shows the assembly in Padlocked condition with the handle (14) inserted. The handle (14) and shaft gets arrested by the padlock pin ( 12) to block Manual operation by the operator and Supply to the motor is cut to prevent EOM operation as seen earlier. Once Padlocked, the Handle (14) cannot be removed without releasing the Padlock.

Figure 9 shows the Override pin actuating Micro switch 2 (10) when the handle (14) is inserted and also locks the vertical movement of Handle (14) to ensure the engagement of shaft and handle via the coupler. To take out the handle, the override pin/Handle lock (1) should be pulled outwards to release the handle (14).

WE CLAIM:
1. A Padlocking and an Interlocking mechanism of Electrically Operating mechanism (EOM) for Changeover Switch, said mechanism comprising : a locking means comprises :
a padlock pin;
plurality of padlock means ;
padlock spring; a selector switch to switch between manual and motor mode , said selector switch comprises selector switch spring; a driving shaft; a handle means;
a over ride pin operatively connected with said handle means comprises an override spring; such that when said handle is inserted within said driving shaft adapted to cut the supply to the motor and said handle is locked when inserted in said shaft; a shutter preventing entry of handle in motor mode; a pair of micro switch comprises micro switch 1 and micro switch 2; a slider with a slider spring to retain position;
such that said locking means is pushed in and flipped to insert the Padlock means the said padlock pin enters the hole in the said shaft and arrests said shafts rotation to have the padlock condition; such that said locking means in padlock condition blocks the entry of said handle means to couple with said shaft;
wherein said padlocking is done at OFF position where the hole in the shaft matches with the axis of said padlock pin .

2. Mechanism as claimed in claim 1 wherein said locking means having provision of insertion of max of three padlock means.
3. Mechanism as claimed in claim 2 wherein said padlock means is of 05 to 07.
4. Mechanism as claimed in claim 3 wherein said padlock means is padlocked, the locking means cannot flip back to its original position ensuring that the supply is cut to the motor and blocks Manual operation.
5. Mechanism as claimed in claim 1 wherein said padlock pin comprises a
support means.
6. Mechanism as claimed in claim 5 wherein said support means pushes the Slider to release the actuation of micro switch 1 to cut the supply to Motor.
7. Mechanism as claimed in claim 5 wherein said support means also actuates micro switch 2 to cut the supply to the Motor.
8. Mechanism as claimed in claim 1 wherein said selector mode when selected in manual mode pushes said slider further to keep micro switch 1 released and said padlock pin arrests the shaft while the lock pin support actuates micro switch 2 to cut the supply as a secondary protection,
9. Mechanism as claimed in claim 1 wherein said handle means is provided with a hole so that Padlocking can be done even when the handle is inserted.

10. A Padlocking and an Interlocking mechanism of Electrically Operating mechanism (EOM) for Changeover Switch as herein substantially described and illustrated with the accompanying drawings.