FORM 2
THE PATENTS ACT, 1970 (39 of l970)
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION
ROTO-SHIFT DOUBLE LATCHING MECHANISM OF A REMOTE MOTOR OPERATOR FOR A SWITCHING DEVICE
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
4. DESCRIPTION (Description shall start from next page)
5. CLAIMS (not applicable for provisional specification. Claims should start with the preamble -"I/We claim" on separate page)
6. DATE AND SIGNATURE (to be given on the last page of specification)
7. ABSTRACT OF THE INVENTION (to be given along with complete specification on the separate page)
Note:
*Repeat boxes in case of more than one entry
*To be signed by the applicant(s)or the authorized registered patent agent
*Name of the applicant should be given in full, family name in the beginning
*Complete address of the applicant should be given stating with postal index no! / code, state and
country
*Strike out the column which is/are not applicable

FIELD OF INVENTION:
The invention pertains to a stored energy type motor operating mechanism for a switching device used for transmission and distribution of electrical power within industrial / domestic segment.
BACKGROUND OF THE INVENTION
Use of electrical devices is well known for making, breaking and to provide safety against fault conditions like short circuit, over loads, earth fault conditions etc. 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 the panel with means of an operating handle that's coupled to the switching device from inside or by opening the enclosure/ panel.
In view of operator's safety, remote operation is an alternative and upcoming 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. These add-on's generally have a electrical motor with relevant gearing arrangement that couples with the switching devices and operates the unit by means of electrical energy.
In addition to remote operation response time for an electrical switching system to switchover from one desired source to the other is gaining importance. Thus with a view of lesser operational time and remote operation of a switching device, stored energy type of motor mechanism are used. Here energy for switching ON is preserved while switching OFF in form of potential energy in a spring which gets discharged while switching ON the device, whenever it is called for.

This mechanism consists of a motor which is a primary mover. The rotational energy generated by motor then transmitted to a drive shaft through a gear mechanism which basically reduces RPM and increases torque. The required torque is then transferred to switch OFF / ON the switching device by suitable mechanical linkages / mechanisms which generally vary from one to one.
There are basically two operations: Charging and Discharging. In a charging mode, Motor is powered up and spring gets charged which finally disconnects the electrical connections of switching device. In the Discharging operation the energy stored in the spring is used for reverse movement of mechanical linkages making the switching device ON. When the spring is fully charged, it has to be held at that position. Mechanism comprising of cam, latch & a profiled shaft does this work and at the time of releasing electrical pulses are given to closing coils which disengages the latch from profiled shaft. One of the design challenges of this latching linkage is to reduce the effort required to release the huge stored energy of the spring.
A stored energy operator generally has three operational modes: Automatic, Manual and Lock. In Automatic operations charging is done by giving electrical pulse to motor which finally charges the main spring. For discharging electrical pulse is given to solenoids which will then release the charged spring. In manual mode of operation the charging is done manually by a handle and discharging by a press of a button provided on front facia of the operator.
Patent No. 6130392, This invention relates to an apparatus, means, system and method for closing a circuit breaker assembly in shorter time period either through manual operation or electrical motor operation, and further relates to a control module for such a motor driven circuit breaker operator.

Patent No. 4042896, This invention shows a different arrangement for controlling a
circuit breaker having both manual and motor driven operations. However it is
desirable to have an arrangement which can accommodate in smaller space, which
can operate at higher speed.
The double de-latching could be achieved through two closing coils - one closing coil
disengages the main latch from the catch and the other closing coil disengages the
fixed arm of the epicyclic gear train from the Pawl latch. However the addition of
extra closing coil increases the cost of the stored energy operator and the space
required for the assembly of extra closing coil in the stored energy operator.
What is needed is a unique double de-latching mechanism with only a single closing
electrical means and an arrangement providing a unique roto-shift latching
mechanism.
Object of the invention:
The object of the present invention is using stored energy type motor mechanism in
switching devices for operator safety and ease of operation.
Another object of the invention is to provide both manual and motor driven
operations for double de-latching, with only a single closing electrical means. In this
invention the same double de-latching is achieved through one closing coil only.
Yet another object of the invention is to provide a roto-shift latching mechanism in
order to balance the repercussions of using a single closing coil for employing a
double de-latching mechanism.
Thus the invention at hand solves the problems related to extra costs and spatial
constraints for introducing a second closing coil for double de-latching.
Summary:
To achieve above objects a roto-shift double latching mechanism for actuating electrical devices is provided. A rack and pinion arrangement mounted on the

bottom housing. The rack and pinion arrangement has a slot corresponding to a slot on the housing for mounting over the knob of the electrical device. A charging spring is connected between rack and shaft between side plates. Gearing arrangement is provided on the second side plate to transmit drive from prime mover to rack and pinion arrangement which charges the charging spring. The gearing mechanism contains ratchet wheel. A pawl is engaged with ratchet wheel to provide unidirectional motion while charging. A triangular latch is provided on the second side plate which engages with D-shaft. Ratchet -pawl arrangement and the triangular latch-D-shaft arrangement restricts the movement of the rack. A solenoid is mounted between two plates and actuating link connects the solenoid with ratchet and pawl arrangement and triangular latch. When solenoid actuates the connecting link, link simultaneously de-latches the pawl from the ratchet and triangular latch from the D-shaft thus allowing release of charged spring and linear motion of the rack resets the electrical device.
Detail description:
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.

Components:
1. Prime mover(motor)
2. Base assembly
3. Slider
4. Slider rest 5.Fist side palte

6. Latch
7. Cam cover
8. Second side plate
9. D-Shaft extension spring

10. Latch spring
11. Knob holder
12. Microswitch assembly
13. Knob
14. Cover
15. Housing
16. Fuse assembly
17. Toggle switch
18. Ratchet pin
19. Trip lever
20. On-Off indication lever
21. Charging spring
22. Motor pinion
23. Intermediate gear
24. Sun gear
25. Handle assembly
26. Planet gear
27. Ratchet

28. Support plate
29. Internal gear
30. Trip knob
31. On knob
32. Indication lever
33. Micro-switch assembly
34. Indication flags
35. Mechanism pinion
36. Pawl latch
37. Pawl-latch connector plate
38. D-SHAFT
39. Cam assembly
40. D-Shaft connector plate
41. Retention spring
42. Main shaft
43. Pawl latch torsion spring
44. D-Shaft torsion spring
45. Closing coil (Solenoid]
The operating mechanism majorly comprises three sub assemblies:
1. Base assembly (2]
2. Core mechanism
3. Cover (not shown in figure)
The function of base assembly (2] is to support the Core mechanism and channelizes incoming power supply through logic circuit to various electrical components. Various recesses in the base are given to secure the wires against moving mechanism components.
The Core mechanism of the operator is supported on: SECOND SIDE plate (8) and

First side plate [5]
Gearing mechanism for driving the operator and handle mechanism for manual charging are mounted on second side plate. Pawl and ratchet arrangement which act as fixed arm to transfer motion, Trip lever [19] for manual tripping the switching device & ON-OFF indication lever are supported on second side plate.
Latch(6], Cam assembly(39), D-shaft (38] are mounted on FIRST SIDE plate on the outer side and a closing coil for transmitting the switching ON command from ON knob to the operator mechanism on the inner side of the FIRST SIDE plate. Between these plates there is a main driving mechanism and a charging spring (21]. Main shaft (42] is rested on these plates through rollers. Both these plates are held together by the screws.
Core mechanism has a motor fixed on the SECOND SIDE plate in the operator and a gearing system is connected to the motor. A knob driving mechanism is mounted between side plates in the operator. A knob holder (11] is attached to the knob driving mechanism. A charging spring (21] is connected to the knob driving mechanism. To accommodate the variations of knob travel, a pin & compression spring assembly is used in conjunction with knob driver.
For positive transmission of motion from motor to the knob driving mechanism it is necessary to hold the ratchet which serves the purpose of fixed arm in epicyclical gear train of the motor. This is done by means of a pawl latch (36] which holds the ratchet teeth. While the pawl is not holding the ratchet it actually allows a free movement of gear train with respect to main shaft (42], thereby not effecting power transmission. At resting position of handle lever gets disengaged from the internal gear (29] and does not interfere with the auto operation of the operator.

At the time of charging, power is supplied to 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 cam is restricted by latch which in turn is restricted by D-shaft. This arrangement holds the main shaft and allows it to rotate only in one direction. Mechanism pinion (35), which is fixed on main shaft also rotates with it and transfers its rotational motion to knob driver as linear motion. Knob driver finally drives the knob of switching device and makes it OFF/RESET. After the spring is fully charged, switching device goes into OFF/RESET condition. At the same time power to the Motor is cut off by toggle switch [17] mounted in base.
At the time of discharging, electrical pulse is given to Closing coil. Closing coil pushes the D-shaft connector plate down, this rotates the pawl latch assembly and D-shaft. As the pawl latch assembly rotates, it frees the ratchet and all the load of main spring comes on main latch & D-shaft. As the D-shaft rotates and as soon as the cut portion of the D-shaft comes, the Latch becomes free & moves upwards and allows cam to become free on shaft. As soon as the shaft becomes free, because of stored energy into the spring, spring pulls the knob driver and it comes back to its initial position with changing the knob position to ON condition of switching device.
During next charging operation, Latch returns to its original position - locked position [under D-shaft) by pushing D-shaft backwards. D-shaft extension spring (9) pulls the D-shaft down in Y direction when it is in unlocked position and brings D-shaft in the direction of oblong slot in X direction. To come down of D-shaft, Latch pushes the D-shaft away in the X direction of oblong slot and reaches the original position (under D-shaft). As soon as the Latch comes down of D-shaft, the D-shaft

torsion spring (44) pushes the D-shaft back to its original position. Thus locking happens which is required for next charging operation.
Description of drawings:
Figure 1 shows side view of roto-shift double latching mechanism
Figure 2 shows another side view of roto-shift double latching mechanism
Figure 3 shows position of spring in roto-shift double latching mechanism
Figure 4 shows gearing arrangement and position of charging handle
Figure 5 shows exploded view of gearing arrangement and ratchet wheel
Figure 6 shows position of ratchet wheel and its connections
Figure 7 shows indicator flags
Figure 8 (a) shows Latch in Locked condition
Figure 8(b) shows Latch in Unlocked condition
Figure 8(c) shows Latch pushing D-SHAFT away to return its original location
Figure 8(d) shows Latch coming to its original position (under D-SHAFT)
Figure 9 shows oblong slot in X and Y direction

We claim,
1] Roto-shift double latching mechanism for actuating electrical device . comprising;
a bottom housing; the bottom housing having slot for operating the knob of the electrical device;
two side plates; the side plates mounted parallel on the said bottom housing and side plates having plurality of slots for mounting shafts across wherein the first side plate has oblong slot on it and second side plate has epicyclic gear train mounted on it;
plurality of shafts connecting two side plates, a fixed shaft connecting two side plates on rear side and a D-shaft passing through oblong slot on the first plate and connecting to second plate;
rack and pinion arrangement; the rack and pinion mounted between the said two side plates and having a slot for operating the knob of the electrical device corresponding to slot on the said bottom housing wherein, the rack has a shaft connecting opposite walls and rack capable of linear movement;
a driving shaft, the driving shaft passing through the said pinion and one end of the driving shaft is connected to epicyclic gear train and a cam is mounted on other end of the driving shaft;
a triangular latch, the latch pivoted on the said first side plate and the latch engaged with the said D shaft on one end and bottom of the latch engaged with the said cam;

epicyclic gear train; the gear train mounted on the said driving shaft and having a ratchet-pawl arrangement for unidirectional charging;
a prime mover, the said prime mover connected through epicyclic gear train to the said driving shaft;
stored energy charging and discharging mechanism consisting of a charging spring; charging spring mounted between said fixed shaft between two side plates and said shaft connecting side walls of the rack wherein, during charging the said pawl remains engaged with the said ratchet and the said triangular latch remains engaged with the said D shaft;
a manual charging handle, the charging handle connected to driving shaft through an internal gear for charging spring;
a solenoid, the solenoid mounted between two side plates and connected to first side plate;
an actuating link, the actuating link extending from said ratchet and pawl arrangement of the said epicyclic gear train to the said triangular latch, the actuating link mounted below the said solenoid wherein, the actuating link simultaneously de-latches the said pawl from the ratchet on one end and the triangular latch from D-shaft on other end when actuated by the said solenoid and allows linear movement of the rack to reset the electrical device.
2] Roto-shift double latching mechanism for actuating electrical device of the claim 1, where in, in auto mode, during charging of mechanism spring, pawl remains engaged with ratchet and rack moves to reset the switching device and switching ON is carried out by closing release.

3] Roto-shift double latching mechanism for actuating electrical device of the claim 1, where in, in manual mode, charging of mechanism spring is carried out with charging handle and rack moves to reset the switching device and switching ON is carried out by ON push button.
4] Roto-shift double latching mechanism for actuating electrical device of the claim 1, where in, in lock mode only manual charging of mechanism spring is possible to reset the electrical device.