| Title of Invention | FLEXIBLE CURRENT CARRYING LAMINATIONS FOR USE IN A VACUUM CIRCUIT BREAKER |
|---|---|
| Abstract | The invention discloses a flexible lamination for use in a vacuum interrupter assembly of a circuit breaker. The flexible lamination is disposed in the current carrying path of the vacuum interrupter and comprises a plurality of conductor metal foils stacked one above another and fixed together. The flexible lamination has an L-shaped geometry and further comprises a flexible portion and hardened ends, one hardened end comprises split halves, each half has a recess corresponding to the outer circumference of the movable electrode of the vacuum interrupter. The recesses are directly opposite to each other and the halves are adapted to be clamped together to the movable electrode positioned in the recesses in the halves, the other hardened end is adapted to be vertically removably fitted onto an outgoing conductor connecting the circuit breaker to a load. |
| Full Text | FORM 2 THE PATENTS ACT, 1970 (39 OF 1970) As amended by the Patents (Amendment) Act, 2005 & The Patents Rules, 2003 As amended by the Patents (Amendment) Rules, 2006 COMPLETE SPECIFICATION (See section 10 and rule 13) TITLE OF THE INVENTION FLEXIBLE LAMINATIONS FOR USE IN A VACUUM CIRCUIT BREAKER. APPLICANTS Name : Crompton Greaves Limited Address : CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, INDIA Nationality : an Indian Company INVENTOR Name : Kahane Ajay Janardan Address : Crompton Greaves Ltd, Switch Gear S2 Division, A3 MIDC, Ambad, Nashik 422010 Maharashtra, India Nationality : Indian Name : Gadekar Sunil Rangnath Address : Crompton Greaves Ltd, Switch Gear S2 Division, A3 MIDC, Ambad, Nashik 422010 Maharashtra, India Nationality : Indian PREAMBLE TO THE DESCRIPTION The following specification particularly describes the nature of this invention and the manner in which it is to be performed : 1 Field of invention: This invention relates to flexible laminations used in vacuum circuit breakers. Background of the invention: Vacuum circuit breakers are devices, which open and close high voltage and large electric current by opening and closing the electric path between a movable electrode and a fixed electrode, which are placed in a vacuum container called as 'Vacuum Interrupter'. A vacuum circuit breaker utilizes vacuum to extinguish arcing when the circuit breaker is opened and to act as a dielectric to insulate the contacts after the arc is interrupted. A vacuum circuit breaker connects or interrupts current between a power source and a load of high voltage and current. Vacuum interrupters are usually placed between the incoming & outgoing conductor of a vacuum circuit breaker. The fixed electrode of the vacuum interrupter is fitted to the incoming conductor and the moving electrode is connected to the outgoing conductor of the vacuum circuit breaker by a flexible current carriers consisting of thin conductor metal sheets/foils (usually copper) stacked one over another and transfers current from the movable electrode to the outgoing conductor with minimum electrical and mechanical losses. The outgoing conductor supplies the current to a load. The lamination is kept flexible so that it can offer minimum mechanical resistance during the operation of the circuit breaker. The current flowing through the flexible lamination follows the path, which provides the least resistance. Prior Art: Conventionally, various types of configurations are used while connecting the flexible lamination to the moving stem and the outgoing conductor. In accordance with one configuration known in the prior art, copper foils are stacked one over the other to form a flexible lamination. The flexible lamination is then soldered or welded to a separate component such as a contact block at each of the ends and the contact block along with the flexible lamination is bolted to the moving stem and the outgoing conductor of the circuit breaker. 2 In accordance with another configuration known in the prior art, a single thick copper sheet is wrapped to form the flexible lamination. The flexible lamination is then soldered or welded to a contact block and the contact block is then bolted to the moving electrode of the vacuum interrupter and the outgoing conductor to which a load is attached. In accordance with yet another configuration known in the prior art, copper foils are stacked one over the other and then hot pressed at the ends to form a flexible lamination with two hardened ends. The two hardened ends are further clamped one each to the moving electrode of the vacuum interrupter and the outgoing conductor. The disadvantages of the configurations known in the prior are that joints are formed at the locations where the flexible lamination is fitted to the moving electrode and the outgoing conductor of the circuit breaker. The presence of the joint results in formation of hot spots at the joint, which is not permissible according to industry standards relating to such laminations used in circuit breakers. Further the presence of such hot spots offers an increased resistance to the flow of current thus reducing the reliability of the circuit breaker to function as required. Further the laminations known in the prior art are soldered or welded to the contact block such that the ends of the lamination are along the horizontal axis of the contact block. In this case the flexible lamination have an 'S' shaped geometry. The 'S' shaped geometry of the flexible lamination reduces its flexibility, which in turn reduces the reliability of the laminations The thickness of flexible lamination increases with respect to the current rating of the circuit breaker. As the thickness of the flexible lamination increases the flexibility of the lamination reduces. Conventionally the lamination known in the prior art have an 'S' shaped geometry, thus for a lamination of a higher thickness the flexibility of the lamination is reduced considerably and also the reliability of the circuit breaker. Also due to the 'S' shape of the lamination the size of the lamination that can be provided in the 3 space between the moving electrode of the vacuum interrupter and the outgoing conductor is limited. Due to reduced flexibility the mechanical resistance during the breaker operation increases. These will result in slower operating velocities of a circuit breaker. Because of slower operating velocities the vacuum interrupter will fail to interrupt the current. This phenomenon shall lead to failure and damage the load to which the current/voltage is supplied. This invention seeks to overcome the limitations of the prior art. Another object of this invention is to provide a joint less flexible lamination which eliminates the possibility of hot spots thus reducing the resistance to the flow of current through the lamination. Another object of this invention is to provide a lamination which is directly mounted on the moving electrode of the vacuum interrupter and the outgoing conductor thus eliminating the use of any contact block. Another object of this invention is to provide a lamination which is fitted vertically onto an outgoing conductor thus providing better flexibility and movement of the lamination. Another object of this invention is to provide a lamination which allows laminations used for high ratings to be mounted in the space between the moving electrode of the vacuum interrupter and the outgoing conductor. Summary of the invention: In accordance with this invention there is provided a flexible lamination for use in a vacuum interrupter assembly of a circuit breaker, the flexible lamination being disposed in the current carrying path of the vacuum interrupter and comprises a plurality of conductor metal foils stacked one above another and fixed together, the flexible lamination having an L-shaped geometry and further comprises a flexible portion and hardened ends, one hardened end comprises split halves, each half has a recess 4 corresponding to the outer circumference of the movable electrode of the vacuum interrupter, the recesses are directly opposite to each other and the halves being are adapted to be clamped together to the movable electrode positioned in the recesses in the halves, the other hardened end is adapted to be vertically removably fitted onto an outgoing conductor connecting the circuit breaker to a load. Typically, one hardened end has at least two lateral holes for clamping the split halves onto the movable electrode with screws tightened in said lateral holes. Typically, the other hardened end has at least two vertical holes for fitting said other hardened end vertically onto said outgoing conductor by tightening screws in said holes against a helical coil inserted in each of said vertical holes. Brief description of the accompanying drawings: An embodiment of this invention is represented in the accompanying drawings. However the represented embodiment is only illustrative and does not limit the scope of the invention. In the drawings: Figure la illustrates a plan view of the flexible lamination; Figure lb illustrates an elevational view of the flexible lamination; Figure 2a illustrates an isometric view of the flexible lamination; Figure 2b illustrates a sectional view of a portion of the flexible lamination as seen along BB; Figure 3 illustrates a disassembled view of a vacuum interrupter, using a flexible lamination of this invention and outgoing conductor. 5 Figure 4 illustrates an assembled view of a vacuum interrupter, with a flexible lamination of this invention and outgoing conductor. Detailed Description of the accompanying drawings: The invention will now be described in detail with reference of the figure la to 4 of the accompanying drawings. The flexible lamination (10) as seen in figure la, lb, 2a and 2b has an arcuate geometry and is made of stacked conductor metal foils. The flexible lamination (10) defines a flexible portion (12) and hardened ends (14) and (16) respectively. The hardened end (14) comprises split halves which can be clamped together. Each half has a recess (18) matching with each other and directly opposite to each other. The hardened end (14) has at least two lateral holes (20) and the hardened end (16) has at least two vertical holes (22). The flexible lamination (10) is fitted in the current carrying path of the vacuum interrupter (22) between the moving electrode (24) and the outgoing conductor (26) as particularly seen in figure 3 and 4 of the accompanying drawings. The profile of the recess (18) provided in each half of the hardened end (14) is corresponding to the outer circumference of a movable electrode (24) of the vacuum interrupter (22). The recesses are directly opposite to each other so as to clamp the halves together by positioning the movable electrode (24) in the recesses (18) in the halves of the hardened end (14). The hardened end is clamped onto the movable electrode (24) by tightening the screws (28) in the lateral holes (20) provided in the hardened end (14). The hardened end (16) is fitted vertically onto the outgoing conductor (26) by tightening screws (28) in the vertical holes against a helicoil (30) is inserted in the vertical holes. The use of the flexible lamination (10) known in accordance with this invention offers a least resistant path for the flow of current. The flexible lamination (10) has a joint less construction which eliminates the possibility of hot spots thus reducing the resistance to 6 the flow of current through the flexible lamination (10). Since the flexible lamination (10) is directly clamped to the moving electrode (24) of the vacuum interrupter (22) and fitted to the outgoing conductor (26) the use of a contact block for fitting the flexible lamination (10) to the moving electrode (24) and outgoing conductor (26) is eliminated. When the vacuum interrupter (22) is used in the circuit breaker the moving electrode (24) moves vertically up and down making and breaking the current flow path. Since the flexible lamination (10) is fitted vertically onto an outgoing conductor (26) it provides better flexibility and movement of the flexible lamination thus helping in efficient working of the vacuum interrupter (22). The arcuate geometry of the flexible lamination (10) allows the use of thicker flexible lamination (10) used for high ratings to be mounted in the space between the moving electrode (24) of the vacuum interrupter (22) and the outgoing conductor (26). Even though emphasis is laid herein on the components and component parts of the preferred embodiment, it should be understood that the disclosure herein is only illustrative and does not limit the scope of this invention. Further many modifications and alterations can be made in the preferred embodiment without departing from the scope of this invention. 7 We Claim: 1. A flexible lamination for use in a vacuum interrupter assembly of a circuit breaker, said flexible lamination being disposed in the current carrying path of the vacuum interrupter and comprising a plurality of conductor metal foils stacked one above another and fixed together, said flexible lamination having an L-shaped geometry and further comprising a flexible portion and hardened ends, one hardened end comprising split halves, each half having a recess corresponding to the outer circumference of the movable electrode of said vacuum interrupter, said recesses being directly opposite to each other and said halves being adapted to be clamped together to the movable electrode positioned in the recesses in the halves, the other hardened end being adapted to be vertically removably fitted onto an outgoing conductor connecting the circuit breaker to a load. 2. A flexible lamination as claimed in claim 1, wherein said one hardened end has at least two lateral holes for clamping the split halves onto the movable electrode with screws tightened in said lateral holes. 3. A flexible lamination as claimed in claim 1 or 2, wherein the other hardened end has at least two vertical holes for fitting said other hardened end vertically onto said outgoing conductor by tightening screws in said holes against a helical coil inserted in each of said vertical holes. Dated this 22nd day of May 2007 8 Abstract: The invention discloses a flexible lamination for use in a vacuum interrupter assembly of a circuit breaker. The flexible lamination is disposed in the current carrying path of the vacuum interrupter and comprises a plurality of conductor metal foils stacked one above another and fixed together. The flexible lamination has an L-shaped geometry and further comprises a flexible portion and hardened ends, one hardened end comprises split halves, each half has a recess corresponding to the outer circumference of the movable electrode of the vacuum interrupter. The recesses are directly opposite to each other and the halves are adapted to be clamped together to the movable electrode positioned in the recesses in the halves, the other hardened end is adapted to be vertically removably fitted onto an outgoing conductor connecting the circuit breaker to a load. |
|---|
961-MUM-2007-ABSTRACT(7-4-2010).pdf
961-mum-2007-abstract(granted)-(17-5-2010).pdf
961-MUM-2007-CANCELLED PAGES(7-4-2010).pdf
961-MUM-2007-CLAIMS(AMENDED)-(7-4-2010).pdf
961-mum-2007-claims(granted)-(17-5-2010).pdf
961-MUM-2007-CORRESPONDENCE(21-10-2009).pdf
961-MUM-2007-CORRESPONDENCE(22-1-2010).pdf
961-mum-2007-correspondence(3-7-2007).pdf
961-mum-2007-correspondence(ipo)-(18-5-2010).pdf
961-mum-2007-correspondence-received.pdf
961-mum-2007-description (complete).pdf
961-mum-2007-description(granted)-(17-5-2010).pdf
961-mum-2007-drawing(granted)-(17-5-2010).pdf
961-mum-2007-form 1(3-7-2007).pdf
961-MUM-2007-FORM 1(7-4-2010).pdf
961-mum-2007-form 18(29-6-2007).pdf
961-mum-2007-form 2(granted)-(17-5-2010).pdf
961-MUM-2007-FORM 2(TITLE PAGE)-(7-4-2010).pdf
961-mum-2007-form 2(title page)-(granted)-(17-5-2010).pdf
961-mum-2007-mark copy(7-4-2010).pdf
961-MUM-2007-REPLY TO EXAMINATION REPORT(7-4-2010).pdf
961-MUM-2007-SPECIFICATION(AMENDED)-(7-4-2010).pdf
| Patent Number | 240547 | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Indian Patent Application Number | 961/MUM/2007 | |||||||||
| PG Journal Number | 22/2010 | |||||||||
| Publication Date | 28-May-2010 | |||||||||
| Grant Date | 17-May-2010 | |||||||||
| Date of Filing | 23-May-2007 | |||||||||
| Name of Patentee | CROMPTON GREAVES LTD | |||||||||
| Applicant Address | DR ANNIE BESANT ROAD, WORLI, MUMBAI | |||||||||
Inventors:
|
||||||||||
| PCT International Classification Number | H05B3/00 | |||||||||
| PCT International Application Number | N/A | |||||||||
| PCT International Filing date | ||||||||||
PCT Conventions:
|
||||||||||