FORM 2
THE PATENT ACT 1970
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION:
"Compact Electrical Direct Drive Motor Operator for Circuit breaker"
2. APPLICANT:
(a) NAME: Larsen & Toubro Limited
(b) NATIONALITY: Indian Company registered under the
provisions of the Companies Act-1956.
(c) ADDRESS: LARSEN & TOUBRO LIMITED,
L&T House, Ballard Estate, P. 0. Box: 278, Mumbai 400 001, India
3. PREAMBLE TO THE DESCRIPTION:
COMPLETE
The following specification particularly describes the invention and the manner in which it is to be performed.

Compact Electrical Direct Drive Motor Operator for Circuit breaker
Field of the invention
The present invention relates to circuit breakers, and more particularly to a direct drive compact size motor operating mechanism for remote operations of the circuit breakers used for transmission and distribution of electrical power within industrial/domestic segment.
Background of the invention
Use of electrical devices, for example, circuit breakers is well known for making, breaking and to provide safety in a typical electrical distribution system. The circuit breakers get mounted inside a board or panel board for added safety to operator. Most often the circuit breakers are required to be operated either from outside or by opening an enclosure/panel.
In view of operator's safety, remote operation is an alternative way to operate the circuit breakers. Usually to achieve the remote operation of the circuit breakers, an add-on accessory is mounted over the circuit breakers, which may operate the circuit breakers when called for.
Further, in today's scenario response time for the circuit breaker to switchover from one desired source to the other is gaining importance. Thus, with a view of lesser operational time and remote operation and space of a circuit breaker, a direct driven type or stored energy type motor mechanism are used.
One such method of operating the circuit breaker remotely, uses portion of stored energy to close the circuit breaker. While the method is used to get the operations very fast, energy is wasted in overcoming resistance introduced by components used in charging systems. Further, if the charging system is manually operated, it requires several operations to change the system and has a limitation of instantaneous operation.

Yet another method of operating the circuit breakers remotely, uses two springs of different stiffness for charging and discharging mechanism in a motor operating system for the circuit breaker switching operation. But with use of stored energy principle, a latching system and other essentials elements creep in, thus increasing volume and overall size of the circuit breaker making it an overall bulk product.
Specifically, US Patent No. 6130392 discloses means for closing a circuit breaker assembly in shorter time period either through manual operation or electrical motor operation, The patent also includes a control module for such a motor driven circuit breaker operator.
Another US Patent No. 4042896 discloses a different arrangement for controlling a circuit breaker having both manual and motor driven operations.
Accordingly, there exists a need to provide a mechanism for operating a circuit breaker which overcomes drawbacks of the prior art.
Objects of the invention
An object of the present invention is to minimize effort for opening, closing and resetting of a circuit breaker mechanism.
Another object of the present invention is to provide a motor operating system with less number of components for circuit breaker operation.
Yet another object of the present invention is to provide an auto and manual mode of operation of the circuit breaker.

Summary of the invention
Accordingly, the present invention provides a mechanism for remotely operating a circuit breaker. The mechanism includes a base assembly comprising a couple-decouple mechanism supported between a primary support plate and a secondary support plate. The couple-decouple mechanism includes a gearbox with internally splined gears mounted on a base, a coupler shaft supported by the primary support plate and the secondary support plate at two positions, a knob-coupler capable of being seated in a cavity on the base, wherein the knob-coupler is capable of being accommodating a knob protrusion of the circuit breaker, a shaft coupled to the knob-coupler, wherein the shaft capable of being ingressing into the coupler shaft through the gearbox, a spring held between the coupler shaft and the primary support plate, wherein the spring maintains an engaged condition of the coupler shaft with the internally splined gears, and a bush held in the secondary support plate to allow free translational and rotational motion of the coupler-shaft. The mechanism further includes a motor operator connected to a prime mover. The mechanism furthermore includes a logic based electronic module housed in the base assembly for auto-mode operation and a cover supported on the base assembly. The cover includes a top-cover, a side cover, a rotary knob, a padlock arrangement, and a trip lever, wherein the rotary knob is directly to coupler shaft provides a positive indication of the circuit breaker state and assist to directly operate the circuit breaker manually. The logic based electronic module provides a required pulse supply to the prime mover which further transmits the power to the internally splined gears, and from the internally splined gear to the coupler shaft through which the power is transferred to the shaft and the knob coupler to operate the circuit breaker automatically
Brief description of the drawings
Figure 1 show a circuit breaker with a compact motor operator mounted thereon, in accordance with the present invention;

Figure 2 shows perspective view of a motor operator, in accordance with the present invention;
Figure 3 shows a base assembly housing a prime mover and a gearbox arrangement along with a couple-decouple mechanism, in accordance with the present invention;
Figure 4 shows an electronic module and a knob-coupler housed on a base assembly, in accordance with the present invention;
Figure 5 shows gearbox arrangement with internally spiined gear of the mechanism in accordance with the preset invention; and
Figure 6 shows exploded view of a couple-decouple mechanism of the mechanism in accordance with the preset invention.
Detailed description of the invention
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 present invention provides to a direct drive compact size motor operating mechanism for remote operations of the circuit breakers. The mechanism provides a have high speed compact motor which is capable of operating operation of the circuit breaker in less time and matches spring energy discharge time. Further, the mechanism provides a compact motor operator having manual and auto modes with minimum component assembly and unique internally splined gear couple-decouple arrangement for effective toggling between auto and manual mode. The mechanism consists of a prime mover, wherein the energy generated by the prime mover is then transmitted to a drive shaft through a gear mechanism which basically reduces RPM and increases torque. The prime mover and the circuit breaker are engaged through a coupler which causes the switching on and off operations of the device.

Referring now to figure 1 to 6, there are shown various embodiments of a direct drive compact size motor operating mechanism (200) for remote operations of the circuit breaker (300) (hereinafter the 'mechanism (200)'). The mechanism (200) comprises a base assembly (150), a couple-decouple mechanism (100), a motor operator (50), a logic based electronic module (30), and a cover (20).
The base assembly (150) houses the couple-decouple mechanism (100), the motor operator (50) and the logic based electronic circuit (30) for auto-mode operation for the circuit breaker (300).
The couple-decouple mechanism (100) is supported between a primary support plate (12) and a secondary support plate (14). In an embodiment, the primary support plate (12) and the secondary support plate (14) are held to a base (16) with screws. The couple-decouple mechanism (100) includes a gearbox (20) mounted on the base (16). The gearbox (20) includes internally splined gears (18). In an embodiment, the gearbox (20) includes a spur gear arrangement for achieving required torque and optimum speed.
The couple-decouple mechanism (100) further includes a coupler shaft (22), a knob-coupler (24), shaft (26), a spring (28) and a bush (28a). The coupler shaft (22) is supported by the primary support plate (12) and the secondary support plate (14) at two positions. The knob-coupler (24) is capable of being seated in a cavity on the base (16). Further, the knob-coupler (24) is capable of being accommodating a knob protrusion (32) of the circuit breaker (300). The shaft (26) is coupled to the knob-coupler (24). Further, the shaft (26) is capable of being ingressing into the coupler shaft (22) through the gearbox (20). The spring (28) is held between the coupler shaft (22) and the primary support plate (12). Specifically, the spring (28) maintains an engaged condition of the coupler shaft (22) with the internally splined gears (18). The bush (28a) is held in the secondary support plate (14) to allow free translational and rotational motion of the coupler-shaft (22).

The motor operator (50) includes a prime mover (52) mounted on the base (16). In an embodiment, the prime mover (52) is a motor. The motor operator (50) has three operational modes for example an automatic, manual and locks. In automatic mode, ON and OFF operations of the circuit breaker (300) are done by giving electrical pulse to the prime mover (52) for example, the motor.
Specifically, the logic based electronic module (30) is housed in the base assembly (150) for auto-mode operation. The logic based electronic module (30) decides for the polarity reversal for the motor operator (50) to subsequently turn it ON or OFF. The logic based electronic module (30) provides a required pulse supply to the motor operator (50) which further transmits the power to the internally splined gears (18) and from the internally splined gear (18) to the coupler shaft (22) through which the power is transferred to the shaft (26) and the knob coupler (24) to operate the circuit breaker (300) automatically.
The cover (20) is supported on the base assembly (150). Specifically, primary support pins (2a) and secondary support pins (2b) are provided on the base assembly (150) which forms support architecture for the cover (20). The cover (20) includes a top-cover (10), a side cover (not shown), a rotary knob (06), a padlock arrangement (04), and a trip lever (02). The trip lever (02) is mounted on the cover (20) such that the trip lever (02) is accessible directly. The rotary knob (06) is coupled directly to the coupler shaft (22) which provides a positive indication of the circuit breaker (300) state and assists to directly operate the circuit breaker (300) manually. In an embodiment, the rotary knob (06) is coupled directly to coupler shaft (22) through a screw.
Once the circuit breaker (300) is turned ON, the logic based electronic module (30) senses the circuit breaker (300) condition and creates a polarity reversal for the next simultaneous operation of the motor operator (50) and vice-versa. When the motor operator (50) is supposed to be operated manually, the rotary knob (06) is pulled out which disengages the coupler shaft (22) from the internally splined gear (18) while maintaining the engagement with the shaft (26) and the knob-coupler (24) which are directly coupled with the circuit breaker (300), thus directly operating the circuit

breaker (300). The deliberate action of pulling the rotary knob (06) before operating, caters for the requirement stated by NFPA 79 standards which clearly asks for provision of handle directly coupled with the circuit breaker (300) for operating it when the door is open and in case of emergency but with a deliberate action induced.
Advantages of the invention
1. The mechanism (100) is a direct drive principle with improvised motor technology.
2. The mechanism (100) requires minimal component assembly for improved reliability and safety thereof.
3. The mechanism (100) is compact size with reduced weight
4. The mechanism (100) provides direct contact between manual operating knob and circuit breaker (300) knob to render simplified switching operations in manual mode but through a deliberate action for improved safety.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The. embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the present invention.

We claim
1. A mechanism for remotely operating a circuit breaker, the mechanism
comprising:
a base assembly;
a couple-decouple mechanism supported between a primary support plate and a
secondary support plate, the couple-decouple mechanism having,
a gearbox mounted on a base, the gearbox having internally splined gears, a coupler shaft supported by the primary support plate and the secondary support plate at two positions,
a knob-coupler capable of being seated in a cavity on the base, the knob-coupler capable of being accommodating a knob protrusion of the circuit breaker,
a shaft coupled to the knob-coupler, the shaft capable of being ingressing into the coupler shaft through the gearbox,
a spring held between the coupler shaft and the primary support plate, wherein the spring maintains an engaged condition of the coupler shaft with the internally splined gears, and
a bush held in the secondary support plate to allow free translational and rotational motion of the coupler-shaft;
a motor operator having a prime mover housed in the base assembly; a logic based electronic module housed in the base assembly for auto-mode operation; and
a cover supported on the base assembly, the cover comprising a top-cover, a side cover, a rotary knob, a padlock arrangement, and a trip lever, wherein the rotary knob being coupled directly to coupler shaft provides a positive indication of the circuit breaker state and assist to directly operate the circuit breaker manually,
wherein, the logic based electronic module provides a required pulse supply to the prime mover which further transmits the power to the internally splined gears, and from the internally splined gear to the coupler shaft through which the power is

transferred to the shaft and the knob coupler to operate the circuit breaker (300) automatically.
2. The mechanism as claimed in claim 1, wherein the gear box consists of spur gear arrangement for achieving required torque and optimum speed.
3. The mechanism as claimed in claim 1, wherein the base assembly includes a primary support pins and a secondary support pins fixed thereto which provides architecture for the cover.