FORM2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003

COMPLETE SPECIFICATION
(See section 10; rule 13)
l. Title of the invention. - AN IMPROVED ARRANGEMENT FOR TRIPPING OF
SINGLE MODULAR ELECTRONIC RCBO IN CASE OF LEAKAGE AND SHORT CIRCUIT

2. Applicant(s)
(a) NAME :
(b) NATIONALITY :
(c) ADDRESS :

LARSEN & TOUBRO LIMITED
An Indian Company.
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 arrangement for tripping of single Modular Electronic RCBO. More particularly, the invention is concerned about tripping of single Modular Electronic RCBO by using a single trip pin means.
BACKGROUND OF THE INVENTION
A Residual current device is a generic term for all types of residual current operated device which is a mechanical switching device or association of devices intended to cause the opening of the contacts when the residual current attains a given value under specified conditions. One of the types of residual current device is Residual current circuit breaker with overcurrent protection (RCBO). A residual current operated circuit breaker designed to perform the functions of protection against earth fault currents, overloads and short-circuits.
There are two types of technology available in residual current devices, electromagnetic & electronic. Electromagnetic devices use a very sensitive torroid, which operates the trip relay when it detects very small residual currents. Electronic devices do not need such a sensitive torroid as electronic circuits within the device amplify the signal to operate the trip relay. The two module RCBO range are electromagnetic devices, while the single module RCBO range and Earth Fault Relays use electronic technology. The single module RCBO is an electronic unit designed for protection against earth fault currents, overloads and short-circuits.
US 5,089,796 discloses that circuit breakers of the type having both over-current and earth leakage protection, commonly referred to as residual current circuit breakers (RCBO's). RCBO generally has a partition wall which separates an over-current protection device from a residual current detection circuit. A plunger rod extends through a bore in the armature of a coil and is moved independently

through the coil to trip the breaker if a residual current is detected by the circuit. The plunger rod is moved by a drive rod, the operation of which is controlled by a permanent magnet which retains the drive rod retracted and an electromagnet which allows the drive rod to drive forwardly under the action of a spring in the event of a residual current being detected. The plunger rod is reset by a reset lever which is moved when an operating handle of the breaker moves from a non-tripped to a tripped position upon tripping of the breaker.
CN 201298515 discloses that an overload protection electronic miniature current leakage breaker comprises a handle, an insulating outer shell, an input wire connecting terminal and an output wire connecting terminal, an opening and closing mechanism , a locking mechanism, a trip mechanism and a circuit board . The trip mechanism comprises a trip coil and a dynamic iron core connecting rod; the trip coil drives the axial movement of the dynamic iron core connecting rod; the extension end of the dynamic iron core connecting rod is propped against the tail end of a lock catch. In the overload protection electronic miniature current leakage breaker, the extension end of the dynamic iron core connecting rod is propped against the tail end of the lock catch, so when the rated residual trip current reaches the specified value, maximum moment is produced by that the dynamic iron core connecting rod is directly vertical to the tail end of the lock catch, so as to reliably unlock the lock catch; and consequently, the dynamic contact and the static contact are separated to cut off the power.
CN 201069745 discloses that an operating mechanism for small-sized residual current operated breakers which comprises a static contact, a moving contact and a driving mechanism. The driving mechanism has a four-connecting-rod mechanism which consists of an operating handle, a first driving rod, a rocker, a second driving rod and a support member; a tripping device which consists of a lock catch, a trip buckle, a lever, a return spring for the trip buckle, a return spring for the lock catch, and a return spring for the lever; and a push rod controlled by the firing pin of a fault tripping relay.

The disadvantages of the conventional switches are requiring different pins in case of leakage and short circuit fault. So there is a need to provide a provision (either provide a engagement of both the pins or provide the provision in housing to carry both the pins) to trip the mechanism through any of the pin which sometimes creates problem in tripping. To overcome the tripping problem by having plural pins which also adds to the overall cost and complexity of the assembly, there is a need to provide only one trip pin means arrangement for tripping in the present invention.
OBJECTS OF THE INVENTION
An object of the present invention is to overcome the problems/disadvantages of the prior art.
Another object of the present invention is to provide a single trip pin means for tripping of single Modular Electronic RCBO.
Another object of the present invention is to provide a trip pin means movement free from spring.
Yet, another object of the present invention is to provide a compact ease assembly and ease of operation.
SUMMARY OF THE INVENTION
According to one aspect of the present invention there is provided an improved arrangement for tripping of single Modular Electronic RCBO during leakage fault and/or short circuit condition, said arrangement comprising:
a solenoid assembly adapted to receive leakage fault signals from conventional electronic system in the assembly, said solenoid assembly comprising plunger

means being located in the said assembly such that on receipt of leakage current signal by the solenoid assembly, the plunger means gets attracted towards the solenoid; pin member of solenoid being operatively located such that it is hit by said plunger means; and
an electromagnetic release assembly comprising trip member assembly including single trip pin means having unique profile and trip lever means wherein said trip pin means traverses all through the electromagnetic assembly, an electromagnetic coil wound on a magnetic core, hammer means; spring means located in between said magnetic core and said hammer such that said spring means is in operative engagement with the magnetic core and said hammer means; and fastener means ;
wherein said electromagnetic release assembly being in predetermined proximity to said solenoid assembly such that said trip pin means is in co-operation with said pin member of the solenoid assembly whereby said trip pin means being actuated by said pin member in succession hits said fastener means thereby further actuating said trip lever means so as to trip the switch during leakage fault condition;
wherein in case of short circuit condition said electromagnetic coil being energized by electromagnetic force causes said hammer means to get attracted towards said assembly, said hammer being restricted to move by means of said spring means upto a predetermined value of spring force after which said electromagnetic force exceeds said spring force causing said hammer means to move a specified distance so as to engage with unique profile of said trip pin means in a manner that thereafter said trip pin and said hammer means move in conjunction to actuate a pivot tripping the assembly.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig.l illustrates a single Modular Electronic RCBO having single trip pin means Fig.2 illustrates a leakage solenoid assembly

Fig.3 illustrates an Electromagnetic release assembly
Fig.4 illustrates a cross sectional view of the trip pin means.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
According to this invention the tripping on single modular electronic RCBO can be done by a single trip pin means in case of leakage as well as short circuit condition i.e. the present invention uses a single trip pin means for the tripping purpose in case of leakage and short circuit fault condition.
The present invention uses new constructional elements in addition to the known elements of single modular electronic RCBO for the tripping arrangement. The improved arrangement for tripping of single Modular Electronic RCBO comprising leakage solenoid assembly (1), Electromagnetic release assembly (2), trip pin means (2a), fastener means is a lock nut (3) and actuating pin member of solenoid (la) in addition to the existing elements used in the single Modular Electronic RCBO which is shown in Fig.l.
Figure 2 shows a leakage solenoid (1) assembly comprising an actuating pin member of solenoid (la), spooling means is a bobbin for coil (lb) and a plunger means (lc) of solenoid which hits the actuating pin member of solenoid (la).
Figure 3 shows an Electromagnetic release assembly (2) comprising a trip member assembly including single trip pin means (2a) having unique profile and trip lever means, an electromagnetic coil (2b), a hammer means (2c), a magnetic core (2d), spooling means is a bobbin (2e) and Spring means(4)located in between said magnetic core and said hammer means such that said spring means is in operative engagement with the magnetic core and said hammer means.

Whenever there is any leakage fault in the system, sensing devices such as electronic system and CBCT (Core Balance Current Transformer) senses the leakage fault and gives the signal to solenoid assembly (1) to trip. The moment solenoid receive the signal, the plunger means (1c) gets attract in the solenoid (1) which hits the actuating pin member of solenoid (la). This actuating pin member of solenoid (la) further hits the lock nut (3). The lock nut (3) is fixed in trip pin means (2a) so that the lock nut (3) drives the trip pin means (2a) which hits trip lever of mechanism to trip the switch.
In case of short circuit fault, electromagnetic forces in the Electromagnetic release assembly (2) causes a force on hammer means (2c). So, the hammer means (2c) in the electromagnet gets attracted in the assembly. The said hammer movement is restricted by means of spring means (4) upto a predetermined value of spring force. When said electromagnetic force exceeds said spring force then said electromagnetic force causing said hammer means (2c) to move a specified distance. After some specified movement said hammer means (2c) gets engage with the trip pin means (2a) because of unique profile of said trip pin means (2a) which is having a slot profile to accommodate said hammer means (2c) for lateral movement. After this engagement both said trip pin means (2a) and hammer means (2c) moves together and actuate a pivot for tripping the assembly. While resetting, the hammer means (2c) movement in the reverse direction is restricted by the bobbin (2e). In this manner, the single trip pin means (2a) is used in both leakage and short circuit case to trip the switch.
The trip pin means (2a) is passing through solenoid (responsible for leakage tripping) and electromagnetic release (responsible for short circuit tripping) and hitting the pivot in case of any of the fault which further trip the mechanism. The trip pin means (2a) is made free from the spring (4) so that it can travel freely in any condition. In case of leakage fault force exerted by the solenoid on the pin is very low which is not sufficient to drive a spring loaded pin. So we have made the trip pin means (2a) movement free from the spring.

ADVANTAGES OF THE INVENTION
1. Tripping with the help of single trip pin means
2. Saving of one part
3. Ease of assembly
4. Ease of operation
5. Improvement in reliability.
The invention has been described in a preferred form only and many variations may be made in the invention which will still be comprised within its spirit. The invention is not limited to the details cited above. The solenoid, bobbin, plunger, electromagnetic coil, hammer and magnetic core as stated do not limit the scope of the present invention. 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.

WE CLAIM
1. An improved arrangement for tripping of single Modular Electronic RCBO during leakage fault and/or short circuit condition, said arrangement comprising:
a solenoid assembly adapted to receive leakage fault signals from conventional electronic system in the assembly, said solenoid assembly comprising:
plunger means being located in the said assembly such that on receipt of leakage current signal by the solenoid assembly, the plunger means gets attracted towards the solenoid; pin member of solenoid being operatively located such that it is hit by said plunger rneans; and an electromagnetic release assembly comprising:
trip member assembly including single trip pin means having unique profile and trip lever means wherein said trip pin means traverses all through the electromagnetic assembly, an electromagnetic coil wound on a magnetic core , hammer means;
spring means located in between said magnetic core and said hammer such that said spring means is in operative engagement with the magnetic core and said hammer means; and fastener means ;
wherein said electromagnetic release assembly being in predetermined proximity to said solenoid assembly such that said trip pin means is in co-operation with said pin member of the solenoid assembly whereby said trip pin means being actuated by said pin member in succession hits said fastener means thereby further actuating Said trip lever means so as to trip the switch during leakage fault condition;
wherein in case of short circuit condition said electromagnetic coil being energized by electromagnetic force causes said hammer means to get

attracted towards said assembly, said hammer means being restricted to move by means of said spring means upto a predetermined value of spring force after which said electromagnetic force exceeds said spring force causing said hammer means to move a specified distance so as to engage with unique profile of said trip pin means in a manner that thereafter said trip pin means and said hammer means move in conjunction to actuate a pivot tripping the assembly.
2. Arrangement as claimed in claim 1, wherein said fastener means is a lock nut.
3. Arrangement as claimed in claim 1, wherein said the trip pin comprising slot proftle adapted to provide lateral engagement with said hammer means such that trip pin means move in co-operation with said hammer means.
4. Arrangement as claimed in claim 1 further comprising spooling means.
5. Arrangement as claimed in claim 4 wherein said spooling means is a bobbin.
6. An improved arrangement for tripping of single Modular Electronic RCBO during leakage fault and/or short circuit condition as herein substantially described and illustrated with the accompanying drawings.