Claims:
1. A contact isolation promising system, to provide an indication against true position of welded contacts, for a switching device, said contact isolation promising system comprising:
an isolation promiser component 20, having a first end and a second end, mechanically coupled with a fork link 6 at first end and coupled with a drive shaft pin 22 associated with a drive shaft 21 at second end, wherein:
said second end of said isolation promiser component 20 comprises an elongated slot/profile 27 adapted receive said drive shaft pin 22 and restrict movement of said drive shaft 21 between said elongated slot/profile 27 to provide an accurate contact position indication thereby achieving a positive isolation to a user during occurrence of a fault associated with contact welding.

2. The contact isolation promising system as claimed in claim 1, wherein said isolation promiser component 20 is mechanically coupled with the fork link 6 at a first end using an isolation promiser rivet 23.

3. The contact isolation promising system as claimed in claim 1, wherein said isolation promiser component 20 comprises an elongated slot/profile 27 at the second end which receives a drive shaft pin 22 for coupling, wherein said drive shaft pin 22 have a restricted movement between said elongated slot/profile 27.

4. The contact isolation promising system as claimed in claim 1, wherein said isolation promiser component 20 is assembled while assembling the operating mechanism to at least one pole of the switching device through the drive shaft pin 22 which passes through at least lower link 5, drive shaft 21, and through an elongated slot/profile 27 provided at the second end of the isolation promiser component 20.

5. The contact isolation promising system as claimed in claim 1, wherein said switching device is selected from any or combination of a molded case circuit breakers, miniature circuit breaker, residual current circuit breaker, and isolator.

6. The contact isolation promising system as claimed in claim 1, wherein said isolation promiser component 20 provides a positive isolation in case of welded contacts by providing a visual warning to a user through the Knob 19 mounted on the Fork 6.

7. The contact isolation promising system as claimed in claim 1, wherein said isolation promiser component 20 provides a positive isolation (true indication) when circuit is still closed.

8. The contact isolation promising system as claimed in claim 1, wherein when the contacts are welded and if a TRIP command is provided to a trip plate 14, a rotational movement of the drive shaft 21 is restricted by said isolation promiser component 20 to thereby maintain ON condition to provide accurate contact position indication to a user.

9. The contact isolation promising system as claimed in claim 1, wherein when the contacts are welded and if a user tries to switch the switching device to OFF condition, a rotational movement of the drive shaft 21 is restricted by said isolation promiser component 20 to thereby maintain ON condition to provide accurate contact position indication to a user.

10. A contact isolation promising system to provide an indication against true position of welded contacts, for a switching device, said contact isolation promising system comprising:
a moving contact assembly having a drive shaft 21, with a drive shaft pin 22, to transmit power to the switching device;
a knob 19 projecting outward from a housing of the switching device, and placed over a fork link 6 of an operating mechanism, to indicate at least a contact position specifying an operation of the switching device; and wherein the contact isolation promising system is characterized in that comprising:
an isolation promiser component 20 mechanically coupled with the fork link 6 at first end and coupled with the drive shaft 21 at second end, wherein said second end of said isolation promiser component 20 is adapted to restrict movement of said drive shaft 21 to provide an accurate contact position indication thereby achieving a positive isolation to a user during occurrence of a fault associated with contact welding.

, Description:
TECHNICAL FIELD
[0001] The present disclosure generally relates to switching devices and more particularly it relates to contact indication for switching devices such as, but not limited to molded case circuit breaker, miniature circuit breaker, residual current circuit breaker, and isolator to provide safety indications to the technicians or end users.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Switching devices such as molded case circuit breaker, miniature circuit breakers, residual circuit breakers and isolators etc are used in domestic and industrial applications for protection against over currents. It is generally required to control electrical power networks by switching circuit “ON”, by carrying load and by switching circuit “OFF” under manual or automatic suspension. Whenever there is an over current resulting in an electrical short circuit, the contacts in the switching devices open or trips to block the current flow which is greater than the rating of the current device.
[0004] Circuit breakers are mechanical switching devices capable of making, carrying and breaking currents under normal circuit conditions and also making, carrying for a specified time and breaking currents under specified abnormal conditions. A circuit breaker basically consists of a pair of separable contacts (also alternatively referred to as “electrical contacts”) and an interrupting medium. The function of the contacts is to conduct the electrical current when the breaker is closed and to withstand the arcs while interrupting. Generally the electrical contacts have a stationary part and a moving part. By bringing the moving contact to touch the stationary contact, an electric current flows and the breaker is closed. By driving the moving contact away from the stationary contact, an electric arc is developed and by quenching the electrical arc, the flow of electrical current is stopped and the breaker is opened.
[0005] There are several provisions available to control the electrical contacts. In some cases it includes manual operation, where the moving contact is moved in conjunction with the fixed contact to open or close the electrical connection. In other cases, whenever the over current occurs in the power circuits, the circuit breakers trips automatically to break the contacts. The function of the circuit breakers is to maintain two stable conditions close and open and three stable conditions Open(OFF), Closed(ON) and Isolated(TRIP) in case of molded case circuit breakers.
[0006] However in certain cases the switching devices like molded case circuit breaker, miniature circuit breaker, residual current circuit breaker, and isolator, etc., there are chances that due to high current, contacts get welded and mechanism force is not enough to break the joint as a result current still flows through circuit even after the breaker is switched to OFF mechanically and knob of device showing “OFF” state. During the maintenance, if someone encounters this situation and comes in direct contact with circuit, thinking breaker is in “OFF” state, it may result in serious shock and can be fatal. In such exceptional circumstances, it is necessary that the switch control indicates the closed position of the switch.
[0007] Generally operating knob of switching device is hinged about an axis rotating between certain angles. The operating knob has two stable states, “OFF” and “ON” for all Circuit Breakers except for molded case circuit breakers which has three stable states “OFF”, “ON” and “TRIP” between which it gets toggled. However in certain cases, when switching devices are operated during fault i.e. Breaker knob is brought to either “OFF” or “TRIP” from “ON” , sometimes the contacts gets welded and current still flows through device. Due to the wrong indication of the state of contacts, accident can occur with operator. In order to prevent such a condition there should be some means to clearly indicate the TRUE status of the circuit breaker i.e. either “ON”, “OFF” or “TRIP”. In industrial and domestic application, it is very important for the technicians and the end users to have basic knowledge of the working of an electrical load or appliance connected to the power circuit before working on it. When several technicians are engaged in serving the electrical equipment, there is a need to identify if switching devices are turned “OFF” or isolated. There is a need of provision for proper identification / preventive tool in device itself.
[0008] Prior art provide the method for promising isolation / true contact position identification of switching devices at the same platform. In conventional indication system, if seen from a distance, many times it is difficult to differentiate red and green colour in indication window as both look as black due to small size which creates confusion. Many switching devices are having either contact indication or label holder for identification, which are much complex in assemblies and are time consuming.
[0009] It is very essential that switching device should indicate its true or actual contact positions i.e. either “ON” or “OFF” or “TRIP”. In domestic or industrial applications there are chances that due to lack of proper identification on switching devices operator switches “ON” or “OFF” wrong device which can be problematic sometimes. So there should be a provision for proper identification in device itself. Technicians find difficult to identify the true contact of the switching devices and also in identifying the switching devices which is time consuming. Each time technicians are required to inspect the switching devices for proper identification. Further, if the switching device fails to indicate the true position in case of any failure in Mechanism, then the mechanism may indicate some state other than ON. It will become too risky and can lead to mishapenning such as risk of electric shock, accidental death, etc. Furthermore, if the mechanism does not have an inherent capacity to provide isolation i.e., the true indication of the state of the contacts, for sure the lives of the user / operator / service person is at risk.
[0010] Hence there is a need to develop an improved means for contact indication and identification of switching devices for user reliability which consumes less time. There is a further need to provide features of contact indication for identification using same component to reduce cost and improve efficiency of assembly.
[0011] The aforementioned limitations of the existing switching devices are recognized by the inventors hereof and some or all of these limitations have been addressed by various embodiments of the current invention.
[0012] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[0013] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[0014] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0015] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0016] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

SUMMARY
[0017] It may be appreciated from the background that, a major limitation of the existing switching devices is that if the mechanism fails to indicate the true position especially when the contacts are live, in case of any failure in mechanism, then the mechanism may indicate some state other than ON state. Thus it becomes too risky and can lead to mis-happenings such as risk of electric shock, accidental death, etc. Another major limitation of the existing switching devices is that if the mechanism does not have an inherent capacity to provide isolation i.e., the true indication of the state of the contacts, for sure the lives of the user / operator / service person is at risk.
[0018] Yet another major limitation of the existing switching devices is that when the contacts of one or more poles of a breaker get welded due to any faults which occur in the circuit where the breaker is connected, it becomes difficult for the mechanism to break the weld by itself when the mechanism is given a TRIP command or manually tried to open the contacts by OFF command, through mechanism by user / operator / service person. In cases it can happen like the contacts are still welded and the mechanism indicate TRIP/OFF based on the mechanism operation just happened. In that case if the user / operator / service person come in contact to the circuit without knowing that it is live, it can cause accidental death. In case a load is connected in the circuit downstream, it can cause severe damage to the load/equipment
[0019] The aforementioned limitations of the existing switching devices are recognized by the inventors hereof and some or all of these limitations have been addressed by the current invention by providing a new apparatus/Contact isolation promising system that is used to provide isolation and is connected directly to a drive shaft and a fork of an operating mechanism of the switching device. Thus ensuring that it provides positive isolation i.e., the true indication to the user / operator / service person.
[0020] An object of the present disclosure is to provide a switching device that provides a positive isolation in case of welded contacts preventing mis-happenings such as risk of electric shock, accidental death, etc. by providing a warning to the user / operator / service person.
[0021] Another object of the present disclosure is to provide an Contact isolation promising system that is connected directly to a drive shaft and a fork of an operating mechanism of the switching device provides positive isolation i.e., the true indication in case the circuit is still closed.
[0022] Accordingly, an aspect of the present disclosure relates to a contact isolation promising system, to provide an undefeatable indication against true position of welded contacts, for a switching device. The contact isolation promising system includes an isolation promiser component, having a first end and a second end, mechanically coupled with a fork link at first end and coupled with a drive shaft pin associated with a drive shaft at second end. The second end of said isolation promiser component includes an elongated slot/profile which is adapted receive said drive shaft pin and restrict movement of said drive shaft between said elongated slot/profile to provide an accurate contact position indication thereby achieving a positive isolation to a user during occurrence of a fault associated with contact welding.
[0023] Another aspect of the present disclosure relates to a contact isolation promising system, to provide an undefeatable indication against true position of welded contacts, for a switching device. The contact indication system includes a moving contact assembly having a drive shaft, with a drive shaft pin, to transmit power to the switching device; and a knob projecting outward from a housing of the switching device. The knob is placed over a fork link of an operating mechanism, to indicate at least a contact position specifying an operation of the switching device. The contact indication system includes an isolation promiser component mechanically coupled with the fork link at first end and coupled with the drive shaft at second end. The said second end of said isolation promiser component is adapted to restrict movement of said drive shaft to provide an accurate contact position indication thereby achieving a positive isolation to a user during occurrence of a fault associated with contact welding.
[0024] In an aspect, said isolation promiser component is mechanically coupled with the fork link at a first end using an isolation promiser rivet.
[0025] In an aspect, said isolation promiser component includes an elongated slot/profile at the second end which receives a drive shaft pin for coupling, wherein said drive shaft pin have a restricted movement between said elongated slot/profile.
[0026] In an aspect, said isolation promiser component is assembled while assembling the operating mechanism to at least one pole of the switching device through the drive shaft pin which passes through at least lower link, drive shaft, and through an elongated slot/profile provided at the second end of the isolation promiser component.
[0027] In an aspect, said operation is switched from any one of ON, OFF, TRIP, TRIP FREE and RESET to remaining operations.
[0028] In an aspect, said switching device is selected from any or combination of a molded case circuit breaker, a miniature circuit breaker, residual current circuit breaker, and isolator.
[0029] In an aspect, said isolation promiser component provides a positive isolation in case of welded contacts by providing a visual warning to a user.
[0030] In an aspect, said isolation promiser component provides a positive isolation (true indication) when circuit is still closed.
[0031] In an aspect, when the contacts are welded and if a TRIP command is provided to a trip plate, a rotational movement of the drive shaft is restricted by said isolation promiser component to thereby maintain ON condition to provide accurate contact position indication to a user. In another aspect, when the contacts are welded and if a user tries to switch the switching device to OFF condition, a rotational movement of the drive shaft is restricted by said isolation promiser component to thereby maintain ON condition to provide accurate contact position indication to a user.
[0032] Unlike the existing/conventional products which may not have one or more components directly attached to the mechanism, the isolation promiser according to the present disclosure ensures that it provides positive isolation i.e., the true indication in case the circuit is still closed.
[0033] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components

BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0035] FIG. 1 illustrates a first isometric view of an operating mechanism of switching device, in accordance with an embodiment of the present disclosure.
[0036] FIG. 2 illustrates a second isometric view of an operating mechanism of switching device, in accordance with an embodiment of the present disclosure.
[0037] FIG. 3 illustrates an exploded isometric view of an operating mechanism of switching device, in accordance with an embodiment of the present disclosure.
[0038] FIG. 4 illustrates an isometric view of single pole assembly with isolation promiser, in accordance with an embodiment of the present disclosure.
[0039] FIG. 5 illustrates an exemplary isolation promiser, in accordance with an embodiment of the present disclosure.
[0040] FIG. 6 illustrates a front view of single pole assembly with mechanism at OFF position, in accordance with an embodiment of the present disclosure.
[0041] FIG. 7 illustrates a front view of single pole assembly with mechanism at ON position, in accordance with an embodiment of the present disclosure.
[0042] FIG. 8 illustrates a front view of single pole assembly with mechanism while trying to switch OFF after contacts welded, in accordance with an embodiment of the present disclosure.
[0043] FIG. 9 illustrates a front view of single pole assembly with mechanism after contacts welded and TRIP command provided, in accordance with an embodiment of the present disclosure.
[0044] FIG. 10 illustrates a front view of single pole assembly with mechanism while trying to reset after contacts welded and TRIP command provided, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0045] The following is a detailed description of embodiments of the disclosure illustrated in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0046] In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent to one skilled in the art that embodiments of the present invention may be practiced without some of these specific details.
[0047] If the specification states a component or feature “may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[0048] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0049] Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. These exemplary embodiments are provided only for illustrative purposes and so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those of ordinary skill in the art. The invention disclosed may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Various modifications will be readily apparent to persons skilled in the art. The general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Moreover, all statements herein reciting embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure). Also, the terminology and phraseology used is for the purpose of describing exemplary embodiments and should not be considered limiting.
[0050] Thus, the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed. For purpose of clarity, details relating to technical material that is known in the technical fields related to the invention have not been described in detail so as not to unnecessarily obscure the present invention.
[0051] Thus, for example, it will be appreciated by those of ordinary skill in the art that the diagrams, schematics, illustrations, and the like represent conceptual views or processes illustrating systems and methods embodying this invention. The functions of the various elements shown in the figures may be provided through the use of dedicated hardware as well as hardware capable of executing associated software. Similarly, any switches shown in the figures are conceptual only. Their function may be carried out through the operation of program logic, through dedicated logic, through the interaction of program control and dedicated logic, or even manually, the particular technique being selectable by the entity implementing this invention. Those of ordinary skill in the art further understand that the exemplary hardware, software, processes, methods, and/or operating systems described herein are for illustrative purposes and, thus, are not intended to be limited to any particular named element.
[0052] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0053] All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0054] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[0055] Circuit Breaker is a mechanical switching device capable of making, carrying and breaking currents. Under normal circuit conditions it will make the circuit closed, carry current for a specified time and breaks the circuit under specified abnormal circuit conditions.
[0056] Moulded Case Circuit Breakers (MCCB) is employed for current interruption. More particularly MCCBs are utilized to protect machine(s)/equipment(s) from damage during adverse conditions prevailing during the operation of the circuit in which moulded case circuit breaker is employed. During adverse conditions like short circuit, the current rises to an alarmingly high level. This high current may cause damage to the parts/equipments in the electrical system. Hence during these conditions, the circuit has to be opened to protect the parts/equipments connected after the breaker.
[0057] The circuit breaker can be manually opened and closed, as well as automatically opened to protect conductors or equipments from damage caused by excessive heating due to over current in abnormal conditions such as overload or short-circuit.
[0058] An operating mechanism (alternatively and hereinafter referred to as “mechanism”) of the circuit breaker plays a vital role in determining the credibility of the breaker. A good mechanism should ensure quick and manually independent opening and closing of contact system. Five operations are to be performed by the MCCB mechanism. They are ON, OFF, TRIP, TRIP FREE, and RESET.
[0059] The first two operations i.e., ON, OFF are initiated by operator whereas the trip signal is given by the release which senses the abnormal conditions and gives TRIP command to the mechanism, so that the latter opens the circuit.
[0060] The operator has access to the mechanism through the knob which will be projected outwards from the housing of the breaker. The knob is placed over the fork of the operating mechanism. In conventional type MCCBs, breaker will feature three positions in the top cover near the knob to show ON, OFF and TRIP.
[0061] The thermal magnetic release helps in protecting the parts/equipments connected after the breaker during adverse conditions thereby disconnecting the supply downstream. And for disconnecting the supply, the thermal magnetic release depends on the mechanism of the breaker, and in particular, it depends on the TRIP and TRIP FREE operations of the breaker. TRIP is the requirement of the tri-state breaker for isolating the breaker from the circuit, and the breaker may not become a part of the circuit unless it is RESET to regain OFF position. Also, TRIP FREE is a required feature particularly in case of motor operated / interlocked breakers as the knob will be held at ON condition and cannot come back to TRIP position on its own.
[0062] The operating mechanism of the MCCB is responsible for indicating the true position of the contacts (open or closed). For a MCCB to claim isolation, it should indicate the true position of the contacts to the user/operator. So, in case the contacts of a pole or more than one gets welded, the knob which is the only direct indicator of the present condition of the MCCB, and should be there only at ON position. Unlike the requirement of isolation when the contacts are open/repelled open, isolation should be promised in case the contacts are closed i.e., circuit is closed to prevent from any mis-happenings such as risk of electric shock, accidental death, etc.
[0063] Even, if there is a case of repelled contacts (circuit open) and the breaker is indicating ON, the mechanism will reset the breaker to its original position when actuated by the user / operator / service person i.e., resetting the contacts and bringing the breaker to OFF/TRIP condition as the user/service person desires. This case is non-hazardous as the circuit is still open.
[0064] In case of servicing, mostly the user / operator / service person will either switch the breaker OFF or triggers the TRIP condition and will lock the breaker in that condition to prevent mis-happenings due to any other person knowingly/un-knowingly. However, in case when the contacts are welded and the user / operator / service person is able to bring the mechanism to OFF/TRIP, then this case is very hazardous as the circuit is still closed and live but indicating that the circuit is open through the direct indicator, knob. Accordingly, when the user / operator / service person comes in contact with the live parts, it becomes a threat to his life.
[0065] Thus, a major limitation of the existing switching devices is that if the mechanism fails to indicate the true position in case of any failure in mechanism, then the mechanism may indicate some state other than ON state. Thus it becomes too risky and can lead to mis-happenings such as risk of electric shock, accidental death, etc. Another major limitation of the existing switching devices is that if the mechanism does not have an inherent capacity to provide isolation i.e., the true indication of the state of the contacts, for sure the lives of the user / operator / service person is at risk.
[0066] Yet another major limitation of the existing switching devices is that when the contacts of one or more poles of a breaker get welded due to any faults which occur in the circuit where the breaker is connected, it becomes difficult for the mechanism to break the weld by itself when the mechanism is given a TRIP command or manually tried to open the contacts through mechanism by user / operator / service person. In cases it can happen like the contacts are still welded and the mechanism indicate TRIP/OFF based on the mechanism operation just happened. In that case if the user / operator / service person come in contact to the circuit without knowing that it is live, it can cause accidental death. In case a load is connected in the circuit downstream, it can cause severe damage to the load/equipment
[0067] The aforementioned limitations of the existing switching devices are recognized by the inventors hereof and some or all of these limitations have been addressed by the current invention by providing a new concept which is used to provide isolation and the component involved in the concept is connected directly to a drive pin connecting drive shafts of one or more poles and a fork of an operating mechanism of the switching device. Thus ensuring that it provides positive isolation i.e., the true indication to the user / operator / service person.
[0068] The purpose of the present disclosure is to provide a positive isolation in case of welded contacts preventing mis-happenings such as risk of electric shock, accidental death, etc. by providing a warning to the user / operator / service person.
[0069] For the sake of understanding and for better clarity, below parts/components/elements/feature of the present invention are marked with associated reference numerals. However, it may be appreciated that, such components are provided merely for the sake of understanding of the present disclosure and the actual implementation may have certain new components as well (apart from what are claimed essential components of the present disclosure). Thus, the below provided components shall not restrict the protection scope of the present disclosure whatsoever.
1 MOUNTING PLATES
2 LATCH LINK
3 UPPER LINK
4 UPPER LINK RIVET
5 LOWER LINK
6 FORK LINK / FORK
7 LATCH BRACKET
8 LATCH BRACKET PIN
9 FORK SPRING PIN
10 LATCH LINK PIN
11 FORK RIVET
12 TMR RESETTER RIVET
13 TRIP PLATE PIN
14 TRIP PLATE
15 TRIP BIASING SPRING
16 RESET PIN
17 SPRING PIN
18 MAIN SPRINGS
19 KNOB
20 ISOLATION PROMISER/ ISOLATION PROMISER COMPONENT
21 DRIVE SHAFT
22 DRIVE SHAFT PIN
23 ISOLATION PROMISER RIVET
24 TMR RESETTER
25 LATCH BRACKET PIVOT
26 RESET PIN RIVET
27 ELONGATED SLOT/PROFILE
[0070] Accordingly an aspect of the present disclosure is to a contact isolation promising system to provide true position of welded contacts for a switching device. The contact isolation promising system includes an isolation promiser component 20, having a first end and a second end, mechanically coupled with a fork link 6 at first end and coupled with a drive shaft pin 22 associated with a drive shaft 21 at second end. The second end of said isolation promiser 20 component includes an elongated slot/profile 27 which is adapted receive said drive shaft pin 22 and restrict movement of said drive shaft 21 between said elongated slot/profile to provide an accurate contact position indication thereby achieving a positive isolation to a user during occurrence of a fault associated with contact welding.
[0071] Another aspect of the present disclosure is to a contact indication system to provide switching condition indications for a switching device. The contact isolation promising system includes a moving contact assembly a drive shaft 21, with a drive shaft pin 22, the operating mechanism to transmit power to the switching device; and a knob 19 projecting outward from a housing of the switching device. The knob 19 is placed over a fork link 6 of an operating mechanism, to indicate at least a contact position specifying an operation of the switching device.
[0072] In an aspect, said isolation promiser component 20 is mechanically coupled with the fork link 6 at a first end using an isolation promiser rivet 23.
[0073] In an aspect, said isolation promiser component 20 comprises an elongated slot/profile 27 at the second end which receives a drive shaft pin 22 for coupling, wherein said drive shaft pin 22 have a restricted movement between said elongated slot/profile 27.
[0074] In an aspect, said isolation promiser component 20 is assembled while assembling the operating mechanism to at least one pole of the switching device through the drive shaft pin 22 which passes through at least lower link 5, drive shaft 21, and through an elongated slot/profile 27 provided at the second end of the isolation promiser component 20.
[0075] In an aspect, said operation is switched from any or combination of ON, OFF, TRIP, TRIP FREE and RESET operations to remaining operations..
[0076] In an aspect, said switching device is selected from any or combination of a molded case circuit breaker, miniature circuit breaker, residual current circuit breaker, and isolator.
[0077] In an aspect, said isolation promiser component 20 provides a positive isolation in case of welded contacts by providing a visual warning to a user.
[0078] In an aspect, said isolation promiser component 20 provides a positive isolation (true indication) when circuit is still closed.
[0079] In an aspect, when the contacts are welded and if a TRIP command is provided to a trip plate 14, a rotational movement of the drive shaft 21 is restricted by said isolation promiser component 20 to thereby maintain ON condition to provide accurate contact position indication to a user. In another aspect, when the contacts are welded and if a user tries to switch the switching device to OFF condition, a rotational movement of the drive shaft 21 is restricted by said isolation promiser component 20 to thereby maintaining ON condition to provide accurate contact position indication to a user.
[0080] Unlike the existing/conventional products which may not have one or more components directly attached to the mechanism, the isolation promiser according to the present disclosure ensures that it provides positive isolation i.e., the true indication in case the circuit is still closed.
[0081] In an embodiment, the present disclosure includes a fork 6, which is mounted on the mounting plates 1. The fork 6 can be fitted with knob 19, which may be used to operate the fork 6 mobilizing the mechanism to the desired position.
[0082] The upper links 3and main springs 18 can be placed in their respective positions in the spring pin 17 and the assembly is riveted to each side of the latch link 2 with the help of upper link rivet 4 as shown in FIG. 3. FIG. 3 illustrates an exploded isometric view of an operating mechanism of switching device, in accordance with an embodiment of the present disclosure.
[0083] The latch link assembly is hinged to the mounting plates 1 with the help of latch link pin 10, and lower links 5 are attached to each side of the latch link assembly in the spring pin 17 which are used for transmitting the power to the circuit breaker through the drive shaft pins 22 to the drive shaft 21.
[0084] The rollable reset pin 16 is assembled with the latch link 2 with the help of the reset pin rivet 26 which is used to reset the mechanism back to the off position as indicated and to stop the fork 6 in the OFF and TRIP position.
[0085] Drive shaft 21, belongs to the contact system, holds the moving contact assembly, whereas lower links 5 are responsible for the operation of the breaker. Similarly, the latch bracket 7 is hinged to the mounting plates 1 with the help of the latch bracket pin 8 and the latch bracket pivot 25 which is riveted to TMR resetter rivet 12 which holds the TMR resetter 24. The trip plate 14 is hinged along with the trip biasing spring 15 to the mounting plates 1 with the help of the trip plate pin 13.
[0086] The main springs 18 provides the force required to operate the breaker and is mounted to the spring pin 17 and fork 6 with the help of the fork spring pin 9.
[0087] In an embodiment, the isolation promiser component 20 is mounted to the fork 6 of the mechanism assembly as shown in FIG. 1 with the help of the isolation promiser rivet 23. FIG. 1 illustrates a first isometric view of an operating mechanism of switching device, in accordance with an embodiment of the present disclosure. FIG. 2 illustrates a second isometric view of an operating mechanism of switching device, in accordance with an embodiment of the present disclosure.
[0088] The isolation promiser component will be assembled to the breaker as shown in FIG. 4 while assembling the mechanism to the Y pole of the breaker through the drive pin which passes through the lower links 5, drive shaft 21 and through the slot (as shown in FIG. 5) of the isolation promiser component 20. FIG. 4 illustrates an isometric view of single pole assembly with isolation promiser, in accordance with an embodiment of the present disclosure. FIG. 5 illustrates an exemplary isolation promiser, in accordance with an embodiment of the present disclosure.
[0089] In an exemplary embodiment, when the contacts of one or more pole gets welded when the breaker is in ON condition as shown in FIG. 7, it becomes difficult for the mechanism to break the weld by itself when the mechanism is given a TRIP command as shown in FIG. 9 or manually tried to open the contacts through Mechanism by user / operator / service person as shown in FIG. 8. FIG. 6 illustrates a front view of single pole assembly with mechanism at OFF position, in accordance with an embodiment of the present disclosure. FIG. 7 illustrates a front view of single pole assembly with mechanism at ON position, in accordance with an embodiment of the present disclosure. FIG. 8 illustrates a front view of single pole assembly with mechanism while trying to switch OFF after contacts welded, in accordance with an embodiment of the present disclosure.
[0090] Thus, the isolation promiser component 20 according to the present disclosure assists to overcome the above problems.
[0091] In the first case, when the contacts are welded and if a TRIP command is provided to trip plate 14 externally or internally by any fault detection of the release module of the MCCB, the trip plate 14 releases the latch bracket 7 releasing the latch link assembly of the mechanism. The latch bracket 7 then allows the latch link 2 to pull the lower links 5, trying to rotate the drive shaft 21 with the help of drive shaft pin 22. Since the drive shaft 21 is not able to rotate, due to the restriction/limitation provided by the isolation promiser component 20, after the position as indicated in FIG. 9, the trip operation will not get completed, and thus leaving the fork 6 at ON position itself. FIG. 9 illustrates a front view of single pole assembly with mechanism after contacts welded and TRIP command provided, in accordance with an embodiment of the present disclosure.
[0092] In this case, if the user / operator / service person try to bring the breaker to trip condition by triggering externally, nothing will happen and the knob 19 will remain in on position. Beyond this, if the user / operator / service person tries to bring the breaker to off position, the fork 6 connected to the isolation promiser component 20 is not able to move beyond the position as shown in FIG. 10, the fork 6 will return back to the position as shown in FIG. 9, again indicating that the breaker is in on condition, providing warning to the user / operator / service person. FIG. 10 illustrates a front view of single pole assembly with mechanism while trying to reset after contacts welded and TRIP command provided, in accordance with an embodiment of the present disclosure.
[0093] In the second case, if the contacts are welded and if a user / operator / service person tries to switch the breaker to OFF condition as shown in FIG. 8, the user / operator / service person will try to bring the knob 19 towards OFF. The knob 19 mounted to fork 6, will try to rotate the drive shaft 21 with the help of drive shaft pin 22. However, since the fork 6 with the help of the isolation promiser 20 was not able to rotate the drive shaft 21 after the position as indicated in FIG. 8, due to the restriction/limitation provided by the isolation promiser component 20, the mechanism will not come to OFF position. Thus, when the user / operator / service person leaves the fork 6, the fork 6 will return back to the position as shown in FIG. 7, again indicating that the breaker is in on condition, providing warning to the user / operator / service person.
[0094] Although the preferred embodiments have been described, it should be pointed out that changes are possible and attainable without departing from the scope of the present invention.
[0095] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[0096] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE INVENTION
[0097] Unlike convention/existing products which may not have one or more component attached to the mechanism, the isolation promiser component 20 ensures that it provides positive isolation and indication in case the circuit is still closed.
[0098] In case of welded contacts, it helps preventing mis-happenings such as risk of electric shock, accidental death, etc. by providing a warning to the user / operator / service person not to touch/come in to contact with the live parts.
[0099] It provides warning to the user / operator / service person that all the downstream load/equipments are still live. To disconnect the load/equipments, from the circuit, the user / operator / service person has to disconnect any of the breakers in the upstream to prevent from electrical hazards.
[00100] A positive isolation of the breaker with just two components i.e., the isolation promiser component 20 and isolation promiser rivet 23, thereby avoiding requirement of many components.
[00101] The isolation promiser component ensures that a true indication of the condition of one or more set of contacts is provided when there is a fault occurred causing the contacts to be welded.
[00102] The isolation promiser helps in providing warning to the user / operator / service person saving the life of many from electrical hazards.