DESC:TECHNICAL FIELD

The present subject matter described herein, in general relates to a circuit breaker or switchgears, and more particularly, to an improved operating mechanism of circuit breaker which enables it to make, carry and break current under normal circuit condition and also break during abnormal conditions.

BACKGROUND

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.
Circuit Breakers are employed for current interruption. More particularly Circuit Breakers are utilized to protect instruments from damage during adverse conditions prevailing during the operation of the circuit in which circuit breaker is employed. During adverse conditions like short circuit, over current or the current rises to an alarmingly high level. This high current may cause damage to the parts in the electrical system. Hence during these conditions the circuit has to be opened to protect the parts after the breaker.
A 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.
The 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 circuit breakers mechanism. They are
1. ON
2. OFF
3. TRIP
4. TRIP FREE
5. RESET
The first two operations 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.
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. Conventional type Circuit Breakers will feature three positions in the top cover near the knob to show ON, OFF and TRIP.
When the knob indicates ON it means the breaker is in ON condition i.e., the current path is closed. Similarly the position of the knob indicates the state of the circuit breaker.
According to standards, the top position of the knob (if the breaker is placed vertically) or the longest distant position of the knob away from the operator (if the breaker is mounted horizontally) should be marked as ON POSITION. The other extreme end in both cases is marked as the OFF POSITION. The knob will be near the center (based on the design of the mechanism) to indicate the TRIP POSITION.
As said above, TRIP command is given automatically to the contacts by the release if it senses an abnormal condition like overload and short circuit. If the trip signal is given, the breaker opens the circuit and the knob goes to the trip position to show the operator that a fault has occurred in the system.
If the operator wants to switch ON the breaker after the breaker is tripped, user cannot do it without resetting the breaker. This is to make sure that the operator shouldn't switch ON the breaker before clearing the fault.
Resetting of the breaker is done by moving the knob (Driver link) towards the OFF position from the TRIP position. This movement loads the mechanism spring and now it is possible for the operator to ON the breaker. All these mechanisms are called semi-automatic mechanisms since for ON and OFF operation, the knob of the breaker has to be taken from their respective ON or OFF positions to a position called dead center beyond which he mechanism becomes independent of the operator and completes the respective action by its own automatically.
The prior-art document US 4528531 discloses a molded case circuit breaker includes a highly integrated operating mechanism having an over-center toggle mechanism for opening and closing a pair of electrical contacts and a trip mechanism for responding to overload and short circuit or fault current conditions to separate the pair of electrical contacts. A generally flat, intermediate latch plate includes an upper latch surface for latching with a movable cradle of the over-center toggle mechanism and a lower latch surface for latching with a trip bar of the trip mechanism and a pair of outwardly projecting pivot arms disposed between the upper and lower latch surfaces. The over-center toggle mechanism includes a pair of upper toggle links and a pair of lower toggle links interconnected by a toggle spring pin. To increase the speed of separation of the first and second electrical contacts during a trip operation, the cradle is physically configured to engage and upwardly propel the toggle spring pin and, also, the upper toggle links have projections for physically contacting a rigid stop.
The prior-art document US 4864263 discloses an industrial rated molded case circuit breaker having an electronic trip circuit contained within the circuit breaker enclosure includes a reset spring in cooperation with the circuit breaker latch spring to insure manual reset of circuit breaker after an automatic trip function. The reset spring allows the circuit breaker latch assembly to be manually reset upon minimum travel of the circuit breaker operating handle due to internal circuit breaker component space restrictions. The circuit breaker latch assembly is robotically loaded to the operating mechanism which is then attached to the circuit breaker case by an automated fastening process.
The prior-art document US 6479774 discloses a circuit breaker operating mechanism comprises a movable handle yoke, a mechanism spring extending in tension from the handle yoke to a pin, and a lower link extending from the pin to a crank operable connected to a contact arm bearing a movable contact. The crank is positionable in open and closed positions, being in an open position when the movable contact is separated from an associated fixed contact and being in a closed position when the movable contact is mated to the associated fixed contact. The circuit breaker further comprises an interface formed on said crank and a blocking prop having a first surface that engages said interface, the first surface preventing the crank from rotating towards the closed position.
The prior-art document US 6590172 discloses a circuit breaker is provided wherein the circuit breaker comprises a contact arm movable between a closed position, an open position and a blown open position wherein the contact arm is disposed in the circuit breaker. A bumper disposed to contact the contact arm when the contact arm is in the blown open position. In addition, a stop member disposed to be in contact with a linkage assembly so as to create a gap between the bumper and the contact arm when the contact arm is disposed in the open position.
The prior-art document US 5369384 discloses a breaker mechanism for power circuit breakers is the energy storage link between the handle and the contact systems. Known breaker mechanisms are generally too expensive to manufacture. When contact welding occurs, there is also the risk that, in spite of the tripping of the breaker mechanism, the contact system will not open. The new breaker mechanism reliably opens the contact system and consists of fewer and technologically simpler individual parts. It is inserted between two symmetrical breaker plates held in die cast housing, and in which a connecting piece is mounted. Two toggle levers are connected at a distance from one another by means of a connecting shaft engaged in crossbar cam slots. A toggle lever spring is engaged between the connecting piece and the connecting shaft. A bracing lever which can be driven by the connecting piece is friction locked in the breaker plates, and the toggle levers in the bracing lever. A latch lever and a latch holding the latter in the locked position are friction locked by means of a latch spring in recesses of the breaker plates.
The prior-art document DE 102006038191 which came up on the International Search Report discloses an invention regarding the fixing of a switching mechanism device onto a carrier whereas present invention is regarding the operating mechanism for a switching device itself.
The prior-art document US 20020100674 which came up on the International Search Report discloses an invention regarding a motor operator which is a driving means for the operating mechanism of a switching device whereas present invention is regarding the operating mechanism for a switching device itself.
The prior-art document EP 0798755 which came up on the International Search Report discloses an invention regarding only the latching system and release mechanism for electrical switching devices whereas present invention is regarding the operating mechanism of a switching device.
The prior-art document DE 102006059307 discloses an invention where the object is of converting a double breaker switching device to a single breaker switching device, with higher commonalities. The specified single breaker switching device requires a higher rotation with respect to the double breaker switching device within the same boundary conditions. The invention increases the trip rotation by increasing the distance between the supporting lever axis and the upper lever, lower lever pivot by pivoting the lower lever on a different additional axis.
Apart from above mentioned drawbacks, there are many other drawbacks in the existing circuit breakers, few of the drawbacks are mentioned below:
1. When the breaker experiences over current it should give trip signal to the operating mechanism, the latch link breaks and rotates by a certain degree to break the contact between moving and fixed contact by rotation of rotor. Due to confine space, rotation of latch link is low. Lesser is the degree of rotation between contacts lesser is the recovering voltage and hence results in delay in arc quenching. Thus improvement is needed
2. The Tripping link or Trip Plate used in previous inventions is purely metallic or plastic. They consist of bulk mass away from its pivot point hence the center of gravity of the tripping link is shifted downwards in the bulk area. Hence there is an inbuilt torque generated by the force components acting on the center of gravity (C.G.) while it is accelerated during shock and vibration, hence the tendency of Nuisance tripping is increased.
3. The Trip plate may be plastic or metallic which undergoes bearing motion in mechanism side plate. In case of plastic, there is plastic to metal contact between trip plate and latch bracket, being a plastic member the trip plate wears at its pivot end and latching contact, hence wear resistance is very small, which reduce the surface material at its pivot diameter and at latching surface, which indirectly result in reducing the intended overlap with latch bracket link due to low wear resistance, hence the tendency of Nuisance tripping is increased.
4. Multiple tripping input signals are given to Trip plate through various accessories, thus due to confine space the trip plate size is large and houses extra space in breaker to perform efficiently.
5. During ON-TRIP operation, the operation main spring and linkage arrangements are done such that the fork must take the central position of breaker for indicating the breaker trip position .after certain number of operations, frictional resistance is increased between number of linkages, hence this movement is not satisfactory. So improvement is required in this area.
6. In short circuit condition, the moving contacts experiences very high repulsive force due to which it gets flipped by crossing the dead center. When the operating mechanism experiences trip command the mechanical linkages should provide sufficient torque to rotor to reset the contacts to its initial position. Due to confine space and friction the energy generated is low. Hence additional torque is needed.
7. In Modular assembly, mechanism dose not allows the access for joining of modular circuit breaker. Hence compactness is required.
In the view of above mentioned drawbacks, there exists a need of new assembly, an improved and efficient operating mechanism of circuit breaker which enables it to make, carry and break current under normal circuit condition and also break during abnormal conditions.

SUMMARY

This summary is provided to introduce concepts related an improved operating mechanism for circuit breakers. This summary is not intended to identify essential features of the subject matter nor is it intended for use in determining or limiting the scope of the subject matter.
In one implementation, a way to create an assembly of linkages which avoids the use of high load springs is disclosed.
In one implementation, the invention proposes an improvement which is primarily delivered by the use of torsion springs in mechanical linkages to deliver an optimum torque to rotating member to reset flipped contacts in short circuit fault and delivering high design of fork biasing spring to retain Knob position, design of trip plate to perform multiple function and optimum navigating movement between side plates and navigation pin. The assembly procedure of mechanism is designed in such a way that, it cannot be assembled in wrong way.
In one implementation, an improved and efficient operating mechanism of circuit breaker which enables it to make, carry and break current under normal circuit condition and also break during abnormal conditions is disclosed.
In one implementation, an operating mechanism used in switchgear applications using multiple or single poles is disclosed. The said operating mechanism comprises of a plurality of linkages connected to each other in a revolute manner, at least one of these is connected to a rotating member. The linkages being housed in structural bearing members called as side plates which can be an extension of the said structural members. The said linkages are retained in place by the use of single or multiple springs, the attachment of either end of these is made with an operating member which makes a revolute joint with the said structural members. The ultimate link in the said linkage connects rotatably with a rotating member which is rotatably connected within the structural members. The revolute joints mention in the said linkages make revolute axes which are parallel to each other.
Accordingly, in one implementation, a circuit breaker operating mechanism (3) having multiple or single pole is disclosed. The circuit breaker operating mechanism (3) comprises of a plurality of linkages coupled using revolute joints in a revolute manner, wherein at least one of said plurality of linkages is coupled to a rotating member; said plurality of linkages are housed in a structural bearing members, wherein said structural bearing members are side plates; said plurality of linkages are retained in place by a use of at least one spring; an attachment of either end of said plurality of linkages is coupled with an operating member which makes a revolute joint with the said structural members; an ultimate link in said plurality of linkages connects rotatably with said rotating member which is rotatably coupled within said structural members; and said revolute joints makes revolute axes parallel to each other.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer like features and components.
Figure 1 illustrates a perspective view of mechanism with cassette. is shown, in accordance with an embodiment of the present subject matter.
Figure 2 illustrates a mechanism assembly with structural members is shown, in accordance with an embodiment of the present subject matter.
Figure 3 illustrates the mechanism assembly is shown, in accordance with an embodiment of the present subject matter.
Figure 4 illustrates an exploded view of the mechanism is shown, in accordance with an embodiment of the present subject matter.
Figure 5 illustrates a mechanism assembly in the ON condition is shown, in accordance with an embodiment of the present subject matter.
Figure 6 illustrates a Mechanism assembly in the OFF condition is shown, in accordance with an embodiment of the present subject matter.
Figure 7 illustrates a cross section of the mechanism showing TRIP condition is shown, in accordance with an embodiment of the present subject matter.
Figure 8 illustrates a right side plate is shown, in accordance with an embodiment of the present subject matter.
Figure 9 illustrates a Latch link pivot pin is shown, in accordance with an embodiment of the present subject matter.
Figure 10 illustrates a latch bracket pivot pin is shown, in accordance with an embodiment of the present subject matter.
Figure 11 illustrates a latch link stopper pin is shown, in accordance with an embodiment of the present subject matter.
Figure 12 illustrates a left side plate is shown, in accordance with an embodiment of the present subject matter.
Figure 13 illustrates a sub-assembly of right side plate is shown, in accordance with an embodiment of the present subject matter.
Figure 14 illustrates a sub-assembly of Latch Link is shown, in accordance with an embodiment of the present subject matter.
Figure 15 illustrates a resetting pin is shown, in accordance with an embodiment of the present subject matter.
Figure 16 illustrates torsion springs left and right is shown, in accordance with an embodiment of the present subject matter.
Figure 17 illustrates a latch bracket is shown, in accordance with an embodiment of the present subject matter.
Figure 18 (a) illustrates a trip plate metallic insert is shown, in accordance with an embodiment of the present subject matter.
Figure 18 (b) and figure 18 (c) illustrates the trip plate is shown, in accordance with an embodiment of the present subject matter.
Figure 19 illustrates a latch link is shown, in accordance with an embodiment of the present subject matter.
Figure 20 illustrates a upper link is shown, in accordance with an embodiment of the present subject matter.
Figure 21 illustrates an upper link stopper pin is shown, in accordance with an embodiment of the present subject matter.
Figure 22 illustrates a floating pin is shown, in accordance with an embodiment of the present subject matter.
Figure 23 illustrates a Fork is shown, in accordance with an embodiment of the present subject matter.

DETAILED DESCRIPTION

Preferred embodiments of the present disclosure will be described herein below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail.
The terms and words used in the following description are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention.
In one implementation, a compact design and arrangement of terminals for multi-functional modular devices is disclosed.
In one implementation, the present invention describes the proposed invention as the design of terminals for any multi-functional modular device which may require more than two input or output signals, for example , an accessory which combines most of the existing accessories of today such as Overvoltage, Under voltage, Shunt trip, Aux. Contact, trip alarm, and the like.
In one implementation, the invention proposes an operating mechanism for circuit breakers.
The arrangement may consist of following components:
1 Rotor
2 Cassette
3 Mechanism
31Side plate (Left)
311Stopper at ON
312Stopper at OFF/TRIP
313Navigation profile
314TAC slot
314Trip plate stopper
315Latch link pivot pin hole
32 Side plate (Right)
321 Stopper at ON
322 Stopper at OFF/TRIP
323 Navigation profile
324 Spring mounting profile
325Latch link pivot pin hole
33 Latch link pivot
331 Step to maintain latch link dimension
34 Latch link stopper pin
341 Torsion spring stopper
342 Latch link stopper
35 Latch bracket pivot pin
351 Latch Bracket mounting surface
36 side plate spacer
4 Torsion spring left
41 Fixed arm on latch stopper pin
42 Moving arm in latch oval Slot
5 Torsion spring right
51 Fixed arm on latch stopper pin
52 Moving arm in latch oval Slot
6 Latch link
61 Latching surface
62 Hole for reset pin
63 Hole for upper link latch link pin
64 Dual slots for torsion spring
65 Stopper in trip condition
66 Slot of TAC relief
67 ON support
68 Mounting Holes
69 Oval slots for Torsion spring
7 Upper link latch link pin
8 Upper link
81 Upper link pivot area on latch link
82 ON stopper pin/navigator pin hole
83 Floating pin insertion slot
84 L and LL connecting pivot
9 Floating pin
91 Spring mounting curve,
92 Step inserted in Upper link slot
93 UL Mounting surface
10 Upper link stopper pin/Navigation pin
101 Stopper surface
102 Navigation surface
11 Upper link Lower link pin
12 Lower links
121 Drive shaft hole
122 UL-LL Pin Hole
13 Lower link-drive shaft pin
14 Latch bracket
141 Latch bracket resetting surface
142 Pivot hole
143 Roller pin hole
144 Stopper surface
145 Trip plate latching surface
146 Tripping cam
147 Slot surface with accommodation of insulator cover
15 Trip plate Assembly
151Trip Plate Insert
152 Over lapping surface with LB
153 TMR tripping surface
154 FSD tripping surface
155 UV tripping surface
156 Hardware assessable slot
157 Pivoting surface
158 Trip plate stopper
159 Biasing spring mounting surface
1510 Push To Trip Area
1511 Insert surface Sliding on Latch Bracket during triping
16Fork
161 Fork Pivot Hole
162 ON Stopper
163 Resetting Profile
164 Knob stopper
165 Fork baising slot
166 FSD hole
167 UV hole
168 Spring pin embose
169 TMR resetor surface
1610 Stopper limb
17 Resetting Pin
171 Resetting surface
172Crimped surface
173 spring curve
174 Area to be Crimp
18 Main Springs
19 Fork Biasing Spring
191 Hook End in Fork
192 Arm in Stationary Pin Grove
20 Trip plate biasing spring
21 Fork pivot pin left
22 Fork pivot pin right
23 Spring Pin
24 Knob
25 Roller Pin
26 Spacer pin
In one implementation, a circuit breaker operating mechanism (3) having multiple or single pole is disclosed. The circuit breaker operating mechanism (3) comprises of a plurality of linkages coupled using revolute joints in a revolute manner, wherein at least one of said plurality of linkages is coupled to a rotating member; said plurality of linkages are housed in a structural bearing members, wherein said structural bearing members are side plates; said plurality of linkages are retained in place by a use of at least one spring; an attachment of either end of said plurality of linkages is coupled with an operating member which makes a revolute joint with the said structural members; an ultimate link in said plurality of linkages connects rotatably with said rotating member which is rotatably coupled within said structural members; and said revolute joints makes revolute axes parallel to each other.
In one implementation, a said structural bearing member comprises of an optimized navigation profile on which a navigation pin navigates, wherein said navigation pin is a part of said linkages.
In one implementation, a latch link assembled in said structural bearing members is disclosed, wherein said latch link comprises a resetting pin and torsion spring.
In one implementation, said torsion springs are accommodated between said latch link and a stopper pin, and wherein said torsion springs, in short circuit fault due to high repulsive force, exerts an additional torque on said rotating member flipped to reset a moving contact.
In one implementation, said resetting pin is assembled in latching link by inserting in through coincident holes wherein said resetting pin undergoes crimping operation such that a pre crimped area flows under pressure without distorting the latch link, ensuring a free rolling motion and restricting axial movement of said plurality of linkages.
In one implementation, a plurality of tipping links called trip plates are disclosed and are insert moulded component.
In one implementation, a metallic insert in said trip plates is disclosed such that center of gravity of said trip plate is shifted towards a bulk mass which is concentrated near a pivot point.
In one implementation, said rotating member is a driving member called as fork having a grove in place for placing on said structural bearing members.
In one implementation, a floating pin is disclosed which is inserted in an upper link assembly.
In one implementation, the present invention is characterized in a use of said torsion springs in plurality of linkages to deliver an optimum torque to said rotating member to reset said flipped contacts during short circuit fault and delivering high design of fork biasing spring to retain a knob position, an optimum navigating movement between said side plates and said navigation pin.
In one implementation, the improvement in the proposed invention is primarily delivered by the use of Torsion Springs in mechanical linkages to deliver an optimum torque to rotating member to reset flipped contacts in short circuit fault and delivering high design of fork biasing spring to retain knob position, design of trip plate to perform multiple function and optimum navigating movement between side plates and navigation pin. The assembly procedure of mechanism is designed in such a way that, it cannot be assembled in wrong way.
In one implementation, the disclosed invention comprises of right side plate (32), latch link pivot pin (33), latch link stopper (342), latch bracket pivot (35), fork pivot pin right (22) and side spacer (36) as shown in figure 4. The latch link (6) is assembled into the right side plate (32) by matching the axes of the pivot pin (33) and latch link (6).The assembly is designed in such a way that by providing unequal holes on latch link and steps on corresponding to pivot pin (33) as shown in figure (9) and figure 19, the latch link cannot be assembled from opposite side. As shown in figure 4 torsion springs left (4) and right (5) are assembled over latch link pivot pin (33) in such a way that they are accommodated between latch link (6) and latch link stopper (342). Due to Short circuit fault moving contacts (110) get flipped because of high repulsive force, a certain amount of energy is needed to reset this contacts. Hence during tripping operation this Spring exerts an additional torque to rotor through mechanical linkages, here linear momentum of linkages gets transfers to rotary movement of rotor which flip back the moving contact against the stationary structural member (2).The Trip plate (15) is assembled into the side plate left (31) assembly by matching the pivot hole in the side plate left (31) and the trip plate insert’s (151) through pivoting surface157. The above said assembly structure consists of trip plate biasing spring (20) which is a compression spring, In which the moving end is fixed in the biasing spring mounting surface of trip plate (159) and fixed end is mounted in spring mounting surface on side plate right (324) as shown in figure 18 (a), figure 18 (b), figure 18 (c) and figure 4. The latch bracket (14) too is assembled in a similar manner by matching the axis of the unequal holes and the steps in latch bracket pivot pin (351) in the right side plate (32). A roller pin (25) is inserted in latch bracket holes (143), main function this pin is that it latches with latch link during ON and OFF operation and rolls over the latching surface (61) in Tripping operation as shown in figure 7. The upper link (8) is assembled with the latch link (6) by inserting the grove on upper link (81) in upper link latch link pin (7) as shown in figure 4. This pin is flush riveted to the latch link by internal riveting. The upper link lower link assembly is a separate sub-assembly consisting of upper link (8), two lower links (12) which are pivoted at a hole (84).Lower links are riveted to upper link by UL-LL rivet (11) to achieve free rotation. To transfer dynamic load to rotor, the rivet length is designed in such a way that free rotation of lower link is obtain with respect to upper link. Floating pin (9) is inserted in the upper link slot (83) shown in figure 20, this pin carries one hook end of the Extension spring (18) while the other end is mounted in the spring pin (23) assembled to Fork (16) in slot (168) as shown in figure 23. Upper link stopper pin (10) is assembled in upper link (8) during the substantial stage of tooling operation in the hole (82). The hole position is designed in such a way that the pin (10) is touched to both side plates at their navigation profile (313) and (323).When TRIP signal is given latch link (6) gets rotated and navigated by the cam connection between side plate navigation profile and pin (7). Figure 7 shows the intermediate condition from ON to TRIP. This navigation enables the full rotation of moving contact (110) from ON to TRIP position corresponding to less rotation of latch link (6).Side plate Left (31) can be mounted on the assembly by dome riveting as shown in figure 4.
The distance between side plates are maintained by using a side plate spacer (36) on SP right (32) and a spacer pin (26) on Latch link pivot pin (33) as shown in figure 4.This plate (31) comprises of fork pivot pin left which is flush riveted in pivot pin hole (325). A Fork (16) which acts as driver link is placed on top of this mechanism by placing the grove in the fork on the pivot pins on respective side plates as shown in figure 4.The Fork (16) and pivot pins (21) and (22) are designed in such a way that it cannot be mounted in either way w.r.to each other. When Fork (16) rotated by user applied force, spring (18) connected between spring pin (23) and Floating pin (9) get deflected up to dead centre condition which leads in charging of spring with potential energy and after the dead centre the stored energy in the spring is converted in to kinetic energy which is used to rotate the moving contact (110) in rotor from ON to OFF, vice versa position through upper link (8) and lower link (12) as shown in figure 5 and figure 6.
Fork biasing spring (19) is assembled between fork (16) and Left pivot pin (21), the hooked end is accommodated in oval shaped slot on fork and other end is in the grove of fork pivot pin left as shown in figure 6. Knob (24) is mounted in fork by sliding it up to knob stopper feature (164). This feature avoids the slipping of knob on one side of mechanism while on other side due to Ingress protection cover and front cover knob slipping is protected. Knob should be able to indicate desired breaker condition, thus in TRIP condition the position of knob should be in center position. Mechanism Linkages are designed in such a way that the main spring (16) have to discharge its energy to rotate moving contact to trip condition as well as to position the knob in center position, thus an additional energy is provided by Fork Biasing spring (19) to bring knob at center position. The mechanism is mounted onto a structural member called as cassettes (2) that houses a rotating member (1) and is fastened. The axes of the rotating member and the instantaneous axis of rotation created by the Fork (16) are parallel. The side plates (31) and (32) thus do not experience any relative motion with respect to the structural member (2). The lower link (12) is assembled pivotally with the rotating member (1) with lower link drive shaft pin (25) as shown in figure 2. The motion of the driving link i.e. Fork (16) actuates the motion of the upper link (8), the motion of which in turn actuates the motion of the lower link (12).The motion of the lower link (12) thus actuates the motion of the rotating member (1). The rotating member (5) can traverse multiple discrete positions with respect to the structural member (2).
In one implementation, the current invention defines a way to create an assembly of linkages which avoids the use of high load springs. This is done by designing a navigation pin assembled to upper link such that its free rotation is maintained and having corresponding navigating profile on stationary side plate. This arrangement improves the disadvantage of previous inventions by providing an extra degree of rotation to rotor through mechanical linkages. This navigation pin position is designed in such a way that it acts as upper links ON stopper. Thus can also be called as Upper link stopper pin.
In one implementation, the trip plate used in current invention is an assembly of metallic insert and an insert moulded plastic part, by using Metallic insert the resistance to wear is increased significantly due to the direct metal to metal contact between trip plate and latch bracket (14) as well as at the bearing motion between side plate left and right.
In one implementation, tripping link used current invention is a combine assembly of metallic insert which is insert moulded with plastic material, so the C.G is shifted towards the bulk mass which is concentrated near the pivot point. Hence the inbuilt torque due to force component at C.G in minimized and the tendency of Nuisance tripping due to shock and vibration becomes negligible.
In one implementation, the trip plate insert is a machined component, is designed in such a way that the surface overlapping with latch bracket is radial with pivot pin. Thus said trip plate comprises a line contact between mating surface. During tripping operation the lower surface of insert does not consists of plastic material at its lower surface, thus during TRIP operation this surface slides over latch bracket.
In one implementation, multiple tripping input signals are given to Trip plate through various accessories, thus the plastic part of trip plate assembly is given intricate shape such that with minimum usage of space all the inputs are responded efficiently.
In one implementation, short circuit condition, the moving contacts experiences very high repulsive force due to which it gets flipped by crossing the dead center. In current invention additional torsion springs are used which exerts a significant torque on rotor to reset the contacts by flipping back to its initial condition.
In one implementation, the latch link is a U-shaped component; resetting pin is inserted in the pin and is crimped such that the resetting pin diameter flows under punching pressure without distorting the latch link. This crimping operation avoids axial motion and gives free rolling motion to resetting pin. The sidling motion between fork and pin is avoid due to improved free rolling and even during frequent impact in OFF condition the pin will rotate and the denting operation is reduced significantly. Hence, the breaker resetting load is reduced.
In one implementation, to improve the movement of fork in TRIP operation, an additional torque is given to fork by fork biasing spring .This spring is accommodated over a stationary member with respect to which fork rotates and comes at center to indicate desired TRIP condition of breaker. The spring is designed in such a way that its impact on breaker resetting force is infinitesimally small.
In one implementation, for resetting, the thermal magnetic release tripper an actuator is assembled to which rotational movement input is given by fork. When Breaker is in ON condition the actuator should not interrupt the motion of thermal magnetic release tripper movement to trip the mechanism. Hence an extended limb is provided on fork which maintains the actuator position. Thus using of an additional elastic component like spring is avoided.

In one implementation, in the present invention to retain the mechanical linkages so as to deliver desired breaker requirements large energy is generated by using concentric extension springs. The spring hooks are so designed that the tilting of spring is avoided without exceeding the spring stresses.
In one implementation, the floating pin (9) is a multifunctional pin. No special arrangements are made on upper link (8) for its insert. It is easily inserted in the curved slot (83) on the link. The surface (93) helps in maintaining the inner to inner distance on Upper link. The curve (91) provided at the centre of pin on which main spring (18) is mounted; this avoids the axial motion of spring.
In one implementation, The improvement in the present invention is primarily delivered by the use of torsion springs in mechanical linkages to deliver an optimum torque to rotating member to reset flipped contacts in short circuit fault and delivering high design of fork biasing spring to retain Knob position, design of trip plate to perform multiple function and optimum navigating movement between side plates and navigation pin. The assembly procedure of mechanism is designed in such a way that, It cannot be assembled in wrong way.
Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include those provided by the following features:
One features of the invention is that, the Torsion Springs (4) and (5) accommodated between latch link (6) and latch link stopper pin (34) which exerts additional torque to reset the flipped moving contacts (110) against the structural member during tripping operation. Also delivers high tripping velocity for electrical contacts.
One features of the invention is that, the Current invention to retain the mechanical linkages so as to deliver desired breaker requirements large energy is generated by using concentric extension springs. The spring hooks are so designed that the tilting of spring is avoided without exceeding the spring stresses.
One features of the invention is that, by using insert moulded Trip plate (15), the C.G of trip plate is shifted towards the bulk mass which is concentrated near the pivot point. Hence the inbuilt torque due to force component at C.G in minimized and the tendency of Nuisance tripping due to shock and vibration becomes negligible.
Another feature of the invention is that, the Trip plate insert (151) is a machined component, is designed in such a way that the surface (152) overlapping with latch bracket is radial with pivot point comprising a line contact between mating surface. During tripping operation the lower surface (1511) of insert dose not consists of plastic material at its lower surface, thus during TRIP operation this surface slides over latch bracket, providing smooth movement.
Another feature of the invention is that, the trip plate (15) used in current invention is an assembly of metallic insert (151) and an insert moulded plastic part, by using Metallic insert (151) the resistance to wear is increased significantly due to the direct metal to metal contact between trip plate and latch bracket (14) as well as at the bearing motion between side plate left (31) and right (32).
Another feature of the invention is that, the multiple tripping input signals are given to Trip plate through various accessories, thus the plastic part of trip plate assembly is given intricate shape such that with minimum usage of space all the inputs are responded efficiently.
Another feature of the invention is that, the U-Shaped latch link (6) is used without any special arrangement to accommodate reset pin (17). Reset pin is inserted in its intended holes (62) of latch link then crimping operation is done such that the pre Crimped area (174) flows under pressure without distorting the latch link, ensuring the free rolling motion and restricting axial movement..Hence the breaker resetting torque is reduced substantially.
Yet another feature of the invention is that, the improved design of navigation pin (10) and navigation profile (313) and (323). Navigation pin is assembled to upper link during tooling operation such that its free rotation is maintained and having corresponding navigating profile (313) and (323) on stationary side plates (32) and (31). This arrangement improves the disadvantage of previous inventions by providing an extra degree of rotation to rotor through mechanical linkages, with corresponding lesser rotation of latch link. Hence increasing the recovery voltage and arc quenching time is reduced. This navigation pin position is designed in such a way that it acts as upper links ON stopper. Thus because of its multi function can also be called as Upper link stopper pin.
Yet another feature of the invention is that, the floating pin (9) is a multifunctional pin. No special arrangements are made on upper link (8) for its insert. It is easily inserted in the curved slot (83) on the link. The surface (93) helps in maintaining the inner to inner distance on Upper link. The curve (91) provided at the centre of pin on which main spring 18 is mounted; this avoids the axial motion of spring.
Still another feature of the invention is that, the assembly of breaker with release module is done by fastening. For housing of tool for fastening the modules optimum slot (156) is designed on trip plate (150). Similar slot (147) is designed on latch bracket (14) for housing of tool as well as an insulator which insulates the mechanism from direct live contact.
Apart from above mentioned feature that are few other important features of the invention mentioned below:
1. An operating mechanism used in switchgear applications using multiple or single poles is disclosed. The said operating mechanism comprising of a plurality of linkages connected to each other in a revolute manner, at least one of these is connected to a rotating member. The linkages being housed in structural bearing members called as side plates which can be an extension of the said structural members. The said linkages are retained in place by the use of single or plural springs; the attachment of either end of these is made with an operating member which makes a revolute joint with the said structural members. The ultimate link in the said linkage connects rotatably with a rotating member which is rotatably connected within the structural members. The revolute joints mention in the said linkages make revolute axes which are parallel to each other.
2. The Stationary bearing member where in a optimized navigation profile is provided on this members, on which a navigation pin navigates. This pin is a part of said linkages in claim 1 which improves the degree of rotation of rotating member in ON-TRIP Condition corresponding to lesser rotation of Latch link. Hence increasing the recovery voltage and arc quenching time is reduced.
3. A Latch Link assembled in structural member comprises resetting pin and Torsion spring. The Link is designed in such a way that it consists of a continuous latching surface which mates with the corresponding surfaces in the latch bracket creating a unified turning moment from multiple, differential and distributed normal forces created between the said combinations of surfaces.
4. Torsion springs are accommodated between latch link and stopper pin where in the exerts an additional torque on the rotating member to reset the moving contact which were flipped in short circuit fault due to high repulsive force makes a lateral shoulder with the plane, the shoulder having an indentation .
5. A multi functional resetting pin is assembled in latching link by inserting in through coincident holes. The pin under goes crimping operation such that the pre Crimped area flows under pressure without distorting the latch link, ensuring the free rolling motion and restricting axial movement, this results in reduced coefficient of friction between linkages. Hence the breaker resetting load is reduced substantially.
6. A plurality of Tripping link called as trip plate which is a insert moulded component i.e. combination of metallic insert and plastic member which is insert moulded to metallic member. Due to compact and intricate design of trip plate especially at the plastic region, accessories multiple tripping signals can be responded with minimum usage of space.
7. The Metallic insert in Trip plate as mentioned in where in the C.G of trip plate is shifted towards the bulk mass which is concentrated near the pivot point. Hence the inbuilt torque due to force component at C.G in minimized and the tendency of Nuisance tripping due to shock and vibration becomes negligible.
8. The Metallic insert in Trip plate is made up of a frequent metal to metal with latch bracket and side plate, this contact which experiences multiple and differential normal forces at mating surfaces. Thus due to metal to metal contact the wear resistance is very high.
9. The driving member called as fork as mentioned which has a grove in place for placing on the said bearing members. Fork should indicate Breakers TRIP position. Thus this indication is possible by accommodating a biasing spring between rotating fork and stationary pin .The driving member making a provision for oval holes to accommodate hooks of fork Biasing springs for retaining the linkage. Oval slot aids the spring hook to have linear movement with respect to forks rotational movement.
10. The Floating pin inserted in Upper link assembly. This Pin rotates corresponding to movement of upper link. It avoids axial movement of spring due to curved area at center and also maintains the inner to inner distance of upper link.
11. The mechanical linkages have to deliver desired breaker requirements in the given confine space hence large energy is generated by using concentric extension springs. The spring hooks are so designed that the tilting of spring is avoided without exceeding the spring stresses. Hooks are at certain angle to axis of wounding of spring .Thus the angled hooks of concentric spring helps to avoid the distribution of stress in transverse direction and resultant load of concentric spring is concentrated at center of concentric spring assembly.
Although an operating mechanism for an improved operating mechanism for circuit breakers has been described in language specific to structural features and/or methods, it is to be understood that the embodiments disclosed in the above section are not necessarily limited to the specific features or methods or devices described. Rather, the specific features are disclosed as examples of implementations of an improved operating mechanism for circuit breakers.
,CLAIMS:1. A circuit breaker operating mechanism (3) having multiple or single pole, said circuit breaker operating mechanism (3) comprising:
a plurality of linkages coupled using revolute joints in a revolute manner, wherein
at least one of said plurality of linkages is coupled to a rotating member;
said plurality of linkages are housed in a structural bearing members, wherein said structural bearing members are side plates;
said plurality of linkages are retained in place by a use of at least one spring;
an attachment of either end of said plurality of linkages is coupled with an operating member which makes a revolute joint with the said structural members;
an ultimate link in said plurality of linkages connects rotatably with said rotating member which is rotatably coupled within said structural members;
said revolute joints makes revolute axes parallel to each other.
2. A circuit breaker operating mechanism (3) as claimed in claim 1, wherein said structural bearing members comprises an optimized navigation profile on which a navigation pin navigates, wherein said navigation pin is a part of said linkages.
3. A circuit breaker operating mechanism (3) as claimed in claims 1 and 2 comprises a latch link assembled in said structural bearing members, wherein said latch link comprises a resetting pin and torsion spring.
4. A circuit breaker operating mechanism (3) as claimed in claims 1-3, wherein said torsion springs are accommodated between said latch link and a stopper pin, and wherein said torsion springs, in short circuit fault due to high repulsive force, exerts an additional torque on said rotating member flipped to reset a moving contact.
5. A circuit breaker operating mechanism (3) as claimed in claims 1-4, wherein said resetting pin is assembled in latching link by inserting in through coincident holes wherein said resetting pin undergoes crimping operation such that a pre crimped area flows under pressure without distorting the latch link, ensuring a free rolling motion and restricting axial movement of said plurality of linkages.
6. A circuit breaker operating mechanism (3) as claimed in claims 1-5 comprises a plurality of tipping links called trip plates and are insert moulded component.
7. A circuit breaker operating mechanism (3) as claimed in claims 1-6 comprises of a metallic insert in said trip plates such that center of gravity of said trip plate is shifted towards a bulk mass which is concentrated near a pivot point.
8. A circuit breaker operating mechanism (3) as claimed in claims 1-7, wherein said rotating member is a driving member called as fork having a grove in place for placing on said structural bearing members.
9. A circuit breaker operating mechanism (3) as claimed in claims 1-8 comprises a floating pin inserted in an upper link assembly.
10. A circuit breaker operating mechanism (3) as claimed in claims 1-9 is characterized in a use of said torsion springs in plurality of linkages to deliver an optimum torque to said rotating member to reset said flipped contacts during short circuit fault and delivering high design of fork biasing spring to retain a knob position, an optimum navigating movement between said side plates and said navigation pin.