FORM 2
THE PATENTS ACT, 1970 (39 of 1970)
COMPLETE SPECIFICATION (See section 10 and rule 13)
1. TITLE OF THE INVENTION
"A Rotary Stored-Energy Motor-Operating Mechanism for Electrical Switching
Devices"
2. APPLICANT(S)
(a) NAME: Larsen and Toubro Ltd.
(b) NATIONALITY: Indian
(c) ADDRESS: L&T House, Ballard Estate, Mumbai-400 001, India
3. PREAMBLE TO THE DESCRITION
COMPLETE
The following specification particularly describes the invention and the manner in which it is to be performed.

Title
A Rotary Stored-Energy Motor-Operating Mechanism for Electrical Switching Devices
Field of the invention
The present invention relates to a stored energy motor-operating mechanism for electrical switching devices. More particularly, the invention relates to a rotary setup for operating moulded case circuit breakers (MCCBs) incorporated with a rotary mechanism inbuilt in frame and also at the same time for catering to linear MCCBs by addition of a mechanism which converts the toggle type to a rotary type. The mechanism of the invention is provided with an arrangement operatively engaged and interconnected with a Cam-Latch arrangement which uses the length projected by a rotating disk to compress a spring to store energy and release it at requirement to switch on the MCCB.
Background of the invention
Use of electrical devices is well known for making, breaking and providing safety in a typical electrical distribution system. These devices get mounted inside a board or panel board for added safety to the operator. Most often these devices are required to be operated either from outside or by opening the enclosure/panel.
In view of operator's safety, remote operation is an alternative way to operate the switching devices. Usually to achieve this an add-on accessory is mounted over the switching device, which may operate the device when called for. An MCCB is a device used to make, break and carry the current. For high end operations wherein the electric supply needs to be reinstated in a very short span of time ranging in micro seconds, or while swapping ends between two supplies, a stored energy operating mechanism is mounted on the MCCB and used to release energy required to close the contacts of the circuit breaker and reinstate the supply
Also response time for an electrical switching system to switchover from one desired source to the other is critical. Thus with a view of lesser operational time and remote operation of a switching device, stored energy type of motor mechanism are used.
In current scenario, one of the inventions uses portion of stored energy to close the circuit breaker. Thus, energy is wasted in overcoming resistance introduced by components used in charging systems. Further, if the charging system is manually operated, it can be interrupted or overrun when the charging system is engaged during manual operation of manual charging system.

In another scenario two springs of different stiffness are used for charging and discharging mechanism in motor operating system for circuit breaker switching operation.
US patent specification 6130392 discloses a stored energy circuit breaker operator for association with an operating handle of a circuit breaker which contains springs that store energy when charged and that release energy when discharged. Energy is stored when a movement translation assembly is moved in a charging direction by an operator gear, and stored energy is released when a release apparatus releases the operator gear, causing the movement translation assembly to move in a discharging direction. The circuit breaker operating handle is moved to ON position by the charging movement of the movement translation assembly, and as stored energy is released, the discharging movement of the translation assembly moves the operating handle to OFF position. The operator gear is operated via an operator handle, operator shaft, and pinion gear assembly. The pinion gear assembly has a carrier pivotally associated with the operator shaft and a pinion gear that rotates the operator gear. The operator gear may also be turned by an electric motor and series of gears to accomplish electric operation of the circuit breaker.
US patent specification 6,166,343 discloses a unidirectional clutch assembly for use with an operator handle, pinion shaft assembly, a worm gear assembly and a pinion gear assembly of a stored energy assembly for use with a circuit breaker assembly, the operator handle and pinion shaft assembly including an operator handle having an outer handle hub having a first recess for receiving a first end of the pinion shaft assembly, the worm gear assembly fitting over the pinion shaft assembly and the pinion shaft assembly having a second end for receiving a pinion gear assembly, the unidirectional clutch assembly comprising a first unidirectional clutch structure, wherein the first unidirectional clutch structure fits over the first end of the pinion shaft and the unidirectional clutch structure is fitted into the first recess of the outer handle hub; and a second unidirectional clutch structure, wherein the second unidirectional clutch structure fits within the worm gear assembly and over the pinion shaft assembly between the first and second ends of the pinion shaft assembly, wherein the first unidirectional clutch structure and said second unidirectional clutch structure are oriented in the same direction so that they slip unidirectionally in the same direction.
US patent specification 6,192,718 discloses a key lock and locking hasp assembly for a stored energy circuit breaker operator assembly. It is provided with an electrical control module for use with a stored energy circuit breaker assembly having a motor for use with a circuit breaker assembly, the circuit breaker assembly providing an electrical signal through electrical contacts for actuating the circuit breaker assembly, the electrical control module comprising: a rectifying circuit, which receives and

rectifies said electrical signal so as to provide a rectified electrical signal; a motor switch circuit connected to the motor; and an electrical signal flow maintenance circuit, which is operatively connected to said rectifying circuit, said motor switch circuit and the motor, wherein said electrical signal flow circuit maintenance maintains at least a threshold rectified electrical when the electrical contacts are closed so that said motor switch circuit is on and the motor operates.
US patent specification 4042896 discloses a manual and motor operated circuit breaker. It is provided with a circuit function which is adapted for either manual or motor driven operation, as desired. Motor driven operation is achieved by the incorporation of a power unit comprising a motor selectively drivingly coupled to the circuit breaker operating mechanism and operating to charge the mechanism spring incident to closing the breaker contacts. Upon completion of a charging function, a closing solenoid is energized to effect release of the stored energy, which powers the breaker contacts to their closed position. Control elements sensitive to the condition of the operating mechanism and the position of the breaker movable contacts function to appropriately condition switching logic in the motor and closing solenoid circuit for sequencing the charging and closing functions in a reliable manner. The control elements further function to selectively position indicator means effective to visually identify the various breaker conditions.
US patent specification 6130392 discloses a stored energy circuit breaker operator, which is based on scotch yoke mechanism to convert the rotary motion to a linear motion.
Prior art is established around the concept of a cam pushing a hinged plate in-turn driving the knob of the switching device. In such a case the motion gets transmitted through the physical displacement by virtue of friction. Also the motion is purely unidirectional. In all the mechanism concepts of prior art the basic rotary motion that gets translated to rotary motion is unidirectional. So while the toggle movement is linear to and fro, the mechanism arrangement translates the unidirectional movement into a linear to and fro arrangement.
However, in the prior art systems there are significant energy losses due to friction between number of parts.
Thus, there is a need to overcome the disadvantages of the prior art.
Further, there is a need for mounting the stored energy motor operating mechanism on the circuit breaker such that the knob holder of the motor operating mechanism engages positively with the operating knob of the circuit breaker.

Objects of the invention
Accordingly, an object of the present invention is to overcome limitations of the prior art.
Another object of the present invention is to provide a rotary stored energy-operated motor operating mechanism which would be able to operate electrical switching devices with minimum amount of energy stored therein, by means of a Cam-Latch arrangement.
A further object of the present invention is to provide a rotary stored energy-operated motor operating mechanism for electrical switchgears wherein conversion of rotary to linear motion takes place by making a slider trace out linear path projected by a rotating disk, because of which the energy losses are minimal.
Another object of the present invention is to provide a unique adaptation arrangement for facilitating driving of knob of a rotary moulded case circuit breaker (MCCB).
Yet another object of the present invention is to provide a vertical latching arrangement for facilitating unidirectional motion and to avoid slippage between latching surfaces.
Yet another object of the present invention is to provide a pawl and ratchet arrangement along with vertical latch arrangement for facilitating driving of knob of switching device.
A further object of the present invention is to provide a double de-latching arrangement for facilitating safety of switching device.
Summary of the invention
In accordance with the above objects, there is provided a rotary stored-energy motor-operating mechanism for driving electrical circuit breakers/switching device(s) to one of ON, OFF or RESET states externally or remotely, the mechanism comprising:
a main shaft driven by a motor through a gear mechanism mounted on a ratchet sandwiched between a sun gear and an internal gear of the gear mechanism, the main shaft having a pawl carrier at its rear end;

an arrangement comprising a pinion fixed on the motor and a follower having a profile cut which fixes itself in a pin coming out of one of the gears of the gear mechanism, the arrangement converting rotary motion of the main shaft into linear motion and driving a controlling knob of the breaker/device to one of ON, TRIP or OFF states;
one or more compression springs connected to and compressed by the follower and thereby storing energy;
an adaptive mechanism operatively connected to the controlling knob and comprising a base plate, a charging mechanism receiving power from the main shaft, a core mechanism, and a motor mechanism, the motor mechanism catering to a user manual interface;
a cover base guiding motion of the follower;
one of more guides for the springs housed in the cover base;
a latch opening linkage housed in the cover base;
a motor plate housing the motor and also housing the main shaft together with the cover base;
a handle assembly for manual charging driven by a detachable lever and housed in the motor plate, the handle assembly driving a manual charging shaft that carries a pawl carrier at its rear end which pushes the internal gear when the lever is rotated anticlockwise, the lever getting disengaged from the internal gear at resting position;
a switching ON linkage housed in the motor plate;
a Trip linkage housed in the motor plate;
a pawl always holding teeth of the ratchet in its stable position and allowing transfer of torque axially thereby avoiding freewheeling of the mechanism and transferring motion to the internal gear;
a vertical latch which restricts the follower by meshing with teeth thereof and thereby does not allow the springs to discharge, and also allows the main shaft to rotate only in one direction;
a knob adaptive mechanism receiving motion from the pinion, comprising plurality of sliding plates fixed to an outer cover of the mechanism with compression springs, the

sliding plates being capable of flexibly accommodating the knob of the breaker/device; and
an L-linkage having one end hinged to the cover base and another end pushing the vertical latch in upward direction when hit by a solenoid and de-meshing the vertical latch from the follower, thereby discharging the mechanism.
Brief Description of Drawings
Figure 1 shows isometric view of a rotary stored energy-operated motor-operating mechanism for electrical switching device in accordance with the invention, along with the electrical switching device.
Figure 2 shows the spring charging mechanism forming part of the rotary stored energy-operated motor-operating mechanism, along with the core mechanism sandwiched between the motor plate (2) and the base plate (4).
Figure 3 shows the spring charging mechanism in the charged mode, wherein the springs are compressed and the vertical latching arrangement meshes with the teeth of the follower, in order to store energy.
Figure 4 shows the charging mechanism in discharged mode, wherein the switching device is switched on by the release of energy from the springs (9) and the vertical latching system (10) is forced to de-mesh by the hit of the solenoid (13).
Figure 5 shows a knob adaptive mechanism forming part of the rotary stored energy-operated motor-operating mechanism, for accommodating misalignments and keeping variations of the operating forces in check.
Figure 6 shows a pawl and ratchet arrangement in open condition and a wedge mechanism used to de-mesh the pawl from the rotary stored energy-operated motor-operating mechanism.
List of Components

Component No. Name of the Component
1. motor
2. motor plate
3. gear train
4. base plate

5.
handle assembly for manual charging
6. pinion (knob driver)
7. pinion knob holder
8. follower
9. springs
10. vertical latch
11. sliding screws for vertical latch
12. L-linkage (latch opening linkage)
13. solenoid
14. main shaft
16. knob adaptive mechanism
18. controlling knob of switching device
19. charging mechanism
20 user manual interface
21 pawl
22 cover base
23 switching ON linkage
24. Trip linkage
25. solenoid for disengaging the pawl from the ratchet when vertical latch is de-meshed from the follower
26. ratchet
27. lever for the handle assembly for manual charging
28. pawl carrier
29. sliding plates fixed to outer cover

30. slider
Detailed Description
The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
The terms and words used in the following description and the claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention is provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
It is to be understood that the singular forms "a", "an" and "the" include plural referents unless the context clearly indicates otherwise.
By the term "substantially" it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.
According to the present invention there is provided a rotary stored energy-operated motor-operating mechanism for operating mechanism for circuit breaker, to drive the circuit breaker to one of ON, OFF or RESET state externally or remotely.
According to one embodiment of the present invention, the mechanism comprises a motor (1) which is a primary mover. This rotary motion is bidirectional, so it aids to higher mechanical efficiency. Rotational energy generated by motor is transmitted to a drive shaft through a gear mechanism which reduces RPM and increases torque. The rotary motion is converted to a linear motion by a pinion and follower arrangement. A

pinion (knob driver/knob holder 6, 7) and follower (8) mechanism is provided in order to drive the knob between states ON, TRIP, OFF and at the same time to compress the springs. The stored energy operator and the switching device are engaged through a pinion (6) thus the movement of pinion (6) causes the switching on and off operations of the device and the linear movement of the follower causes compression of the springs, storing the energy.
With reference to Figure 1, the apparatus is fixed with the switching device by means of screws. The knob of switching device (18) is controlled by a knob adaptive mechanism (16). The rotary stored energy-operated motor-operating mechanism comprises three sub-assemblies, namely Base and charging mechanism (19), Core mechanism (3) and motor mechanism which caters to the user manual interface (20) as well.
The cover base (22) channelizes incoming power supply through logic circuit to various electrical components which includes safety devices as well. Recesses are provided on the cover base to facilitate wire routing as it keeps away from the moving components of the mechanism. It further acts as guide for the motion of the follower (8) and also houses the guides of springs (9) and also houses the latch opening linkage (12).
As shown in Figure 2, the core mechanism is built between the two plates of the mechanism i.e. the base plate (4) and the motor plate (2). The motor plate (2) houses the motor (1) and other linkages which lead to manual operations like the handle charging system (5) and the switching ON linkage (23) and the TRIP linkage (24). The main shaft (14) is housed between the motor plate and the cover base and is responsible for the transmission of power to the charging mechanism (19). The motor (1) transfers power though a gear train (3) which serves the purpose of increasing the torque by reducing the speed. The ratchet and pawl system (21) latch together to allow transfer of torque axially which if not done would lead to free-wheeling of the system without any transmission of energy.
As displayed in Figure 2, the gearing system starts from the small pinion fixed on the motor. Pinion transmits this energy to epicyclic gears through a series of two gears. The epicyclic gears are mounted on ratchet (26) which is sandwiched between sun gear and internal gear. For positive transmission of motion and to avoid freewheeling it is necessary to hold a ratchet. This is done by means of a pawl (21) which holds the ratchet teeth. While the pawl is not holding the ratchet it allows a free movement of the gear train with respect to main shaft (14), thereby not effecting power transmission.
For manual charging a handle assembly (5) is provided. This assembly has a lever (27) which is detachable and helps to rotate the manual charging shaft. The shaft carries a pawl carrier (28) at its rear end which pushes the internal gear when lever (27) is

rotated anti clockwise. At resting position of handle lever gets disengaged from the internal gear and does not interfere with internal gear.
At the time of charging, power is supplied to the motor and then motion is transmitted through gear train to the main shaft. Pawl, in its stable condition, is always engaged with the ratchet and provides positive transition of motion through epicyclic gear to internal gear. On the other side, the follower (8) is restricted by the vertical latch (10). This arrangement holds the shaft and allows it to rotate only in one direction. Pinion (6), which is fixed on main shaft also rotates with it and transfers its rotational motion to the knob adaptive mechanism (16). The pinion (6) meshes with gear (7) which also rotates along with the pinion. The follower (8) is mounted such that it has a profile cut which fixes itself in a pin coming out of the gear (7). This arrangement ensures that the follower traces the linear path projected by the rotating gear. The follower is constrained in such a way by the cover base (22) that it only has one degree of freedom for its motion and the distance linearly covered by the follower is used to compress the springs (9).
Figures 3 and 4 show how the charging mechanism and the latching function. Figure 3 shows the mechanism in charged condition wherein the springs are compressed and the follower is in its final position. The vertical latch (10) meshes with the teeth of the follower and does not allow the spring to discharge. The vertical latching ensures that the plane of application of force and slippage are orthogonal and hence ensures that there is no slippage or roll back at the time of motor charging and ensures that the switching device is switched off smoothly.
Figure 4 shows the charging mechanism in discharged position. The discharging of the mechanism takes place by opening the vertical latch. The electronic system provides a pulse to the solenoid (13) which in turn hits the latch opening linkage (L- linkage) (12). The L-linkage is hinged on a feature of the cover base in such a way that the other end of the L-linkage pushes the vertical latch in the upward direction. The vertical latch slides on sliding screws (11) till there is no meshing between the latch and the teeth of the follower. This ensures that the follower is free to move and so the springs push it back. The follower pushes the gear pin and makes the gear (7) rotate which further makes the gear (6) rotate. The gear (6) has the knob adaptive assembly coupled with it which ensures that the knob is turned and the switching device is put in ON condition.
Another thing to be ensured is that every time the vertical latch is de-meshed from the follower, the pawl (21) needs to be disengaged from the ratchet (21) by the solenoid (25) so as to ensure that the mechanism does not get jammed at the pawl end. So both the solenoids (13, 25) are provided a simultaneous electronic pulse to ensure smooth switching. The pawl (21) opens in a wedge action since the opening of pawl and the stoke of the solenoid are in mutual orthogonal directions wherein the solenoid

hits a slider (30) which slides in the profile wedge cut of the pawl and thus creating a component of the applied force which moves the pawl and de-meshes it from the ratchet (21).
Figure 5 shows the knob adaptive assembly (16) which is made up of sliding plates (29) fixed to the outer cover by means of compression springs. The knob of the switching device sits in the space between the two plates which are capable of moving to accommodate the knob, thus, eliminating the misalignment between the operating axis and the axis of rotation of the switching device. The second purpose served by the knob adaptive assembly is that it looks after the variation of forces either from the motor mechanism or from the switching device. The compression springs are so designed as to incorporate any additional forces beyond a required limit. They get compressed after a limit to ensure that the knob of the switching device does not face heavy forces.

We claim:
1. A rotary stored-energy motor-operating mechanism for driving electrical circuit breakers/switching device(s) to one of ON, OFF or RESET states externally or remotely, the mechanism comprising:
a main shaft driven by a motor through a gear mechanism mounted on a ratchet sandwiched between a sun gear and an internal gear of the gear mechanism, the main shaft having a pawl carrier at its rear end;
an arrangement comprising a pinion fixed on the motor and a follower having a profile cut which fixes itself in a pin coming out of one of the gears of the gear mechanism, the arrangement converting rotary motion of the main shaft into linear motion and driving a controlling knob of the breaker/device to one of ON, TRIP or OFF states;
one or more compression springs connected to and compressed by the follower and thereby storing energy;
an adaptive mechanism operatively connected to the controlling knob and comprising a base plate, a charging mechanism receiving power from the main shaft, a core mechanism, and a motor mechanism, the motor mechanism catering to a user manual interface;
a cover base guiding motion of the follower;
one of more guides for the springs housed in the cover base;
a latch opening linkage housed in the cover base;
a motor plate housing the motor and also housing the main shaft together with the cover base;
a handle assembly for manual charging driven by a detachable lever and housed in the motor plate, the handle assembly driving a manual charging shaft that carries a pawl carrier at its rear end which pushes the internal gear when the lever is rotated anticlockwise, the lever getting disengaged from the internal gear at resting position;
a switching ON linkage housed in the motor plate;

a Trip linkage housed in the motor plate;
a pawl always holding teeth of the ratchet in its stable position and allowing transfer of torque axially thereby avoiding freewheeling of the mechanism and transferring motion to the internal gear;
a vertical latch which restricts the follower by meshing with teeth thereof and thereby does not allow the springs to discharge, and also allows the main shaft to rotate only in one direction;
a knob adaptive mechanism receiving motion from the pinion, comprising plurality of sliding plates fixed to an outer cover of the mechanism with compression springs, the sliding plates being capable of flexibly accommodating the knob of the breaker/device; and
an L-linkage having one end hinged to the cover base and another end pushing the vertical latch in upward direction when hit by a solenoid and de-meshing the vertical latch from the follower, thereby discharging the mechanism.
2. The mechanism of Claim 1 wherein the pawl is disengaged from the ratchet every time the vertical latch is de-meshed from the follower with the help of a solenoid and a wedge profile cut in the pawl.
3. The mechanism of Claim 1 wherein the vertical latch ensures that planes of application of force and slippage are orthogonal, thereby ensuring smooth switching of the breaker/device.
4. The mechanism of Claim 1 wherein the compression springs of the knob adaptive mechanism get compressed after a limit ensuring that the knob of the breaker/device goes not face heavy forces.
5. The mechanism of Claim 1 wherein the gear mechanism comprises plurality of epicyclic gears.
6. The mechanism of Claim 1 wherein rotary motion by the motor is bidirectional, enhancing mechanical efficiency.
7. The mechanism of Claim 1 wherein the force applied to compress the compression springs of the mechanism acts directly and is not any component of the acting force and hence the overall mechanical output from the mechanism increases.

8. The mechanism of Claim 1 wherein the cover base channelizes incoming power supply through logic circuit to the breaker/device, and also has recesses for wire routing.
9. The mechanism of Claim 1 wherein the mechanism is fixed to the device with one or more fasteners such as screws and nut-bolts and like.