Low voltage switch pole

Abstract

A low voltage switch pole including an insulating casing defining an internal space with a contact area and an arc extinguishing area, a fixed contact assembly and a movable contact assembly being position in the contact area, the movable contact assembly being movable between a closed position in which it is into contact with the fixed contact assembly and an open position in which it is spaced apart from the fixed contact assembly, an arc chamber including a plurality of substantially parallel metallic plates being position in the arc extinguishing area, wherein fixed contact assembly is provided with a contact support, a contact surface contacting the movable contact assembly in the closed position and positioned on the contact support, and a conductive expansion plate positioned on the contact support and extending toward the arc chamber, and wherein the fixed contact assembly is provided with a gasifying plate which is directly mounted on the conductive expansion plate.

Claims

1. A low voltage switch pole, comprising: an insulating casing defining an internal space with a contact area and an arc extinguishing area, a fixed contact assembly and a movable contact assembly being positioned in said contact area, said movable contact assembly being movable between a closed position in which said movable contact assembly is in contact with said fixed contact assembly and an open position in which said movable contact assembly is spaced apart from said fixed contact assembly, an arc chamber comprising a plurality of substantially parallel metallic plates being positioned in said arc extinguishing area, wherein said fixed contact assembly is provided with a contact support, a contact surface contacting said movable contact assembly in the closed position and positioned on said contact support, a conductive expansion plate positioned on said contact support and extending toward said arc chamber, and wherein said fixed contact assembly is provided with a gasifying plate which is directly mounted on said conductive expansion plate, wherein said gasifying plate is substantially T-shaped and has a first part positioned on said conductive expansion plate and protruding beyond an outer perimeter of said conductive expansion plate, and a second part perpendicularly extending from a first portion in a direction of said contact surface.

2. The low voltage switch pole according to claim 1, wherein said conductive expansion plate and said gasifying plate extend beyond said contact area and below said arc chamber.

3. The low voltage switch pole according to claim 2, wherein said gasifying plate having a first cutout portion at a center of said first part leaving uncovered a central portion of said conductive expansion plate.

4. The low voltage switch pole according to claim 3, wherein said gasifying plate has said first cutout portion at the center of said first part leaving uncovered said central portion of said conductive expansion plate and a second cutout portion at the center of said second part, said contact surface being at least partially positioned within said second cutout portion.

5. The low voltage switch pole according to claim 4, wherein said second cutout portion of said second part of said gasifying plate is wider than said first cutout portion of said first part of said gasifying plate.

6. The low voltage switch pole according to claim 5, wherein said first part of said gasifying plate is wider than said second part of said gasifying plate.

7. The low voltage switch pole according to claim 4, wherein said first part of said gasifying plate is wider than said second part of said gasifying plate.

8. The low voltage switch pole according to claim 4, wherein said conductive expansion plate and said gasifying plate are provided with engagement pins providing a retaining function for fixing said gasifying plate onto said conductive expansion plate.

9. The low voltage switch pole according to claim 1, wherein said conductive expansion plate and said gasifying plate are provided with engagement pins providing a retaining function for fixing said gasifying plate onto said conductive expansion plate.

10. The low voltage switch pole, according to claim 9 wherein said engagement pins providing a retaining function comprise one or more engagement pins positioned on one of said conductive expansion plate or gasifying plate and corresponding one or more engagement seats for said engagement pins positioned on an other of said conductive expansion plate or gasifying plate.

11. A low voltage switch comprising the low voltage switch pole according to claim 1.

12. The low voltage switch pole according to claim 1, wherein said gasifying plate protrudes beyond an outer perimeter of said conductive expansion plate.

13. The low voltage switch pole according to claim 12, wherein said gasifying plate has a first part positioned on said conductive expansion plate and protruding beyond the outer perimeter of said conductive expansion plate, said gasifying plate having a first cutout portion at a center of said first part leaving uncovered a central portion of said conductive expansion plate.

14. The low voltage switch pole according to claim 13, wherein said gasifying plate has a first part positioned on said conductive expansion plate and protruding beyond the outer perimeter of said conductive expansion plate, and a second part surrounding said contact surface.

15. The low voltage switch pole according to claim 1, wherein said gasifying plate has a first part positioned on said conductive expansion plate and protruding beyond an outer perimeter of said conductive expansion plate, said gasifying plate having a first cutout portion at a center of said first part leaving uncovered a central portion of said conductive expansion plate.

16. The low voltage switch pole according to claim 1, wherein said gasifying plate has a first part positioned on said conductive expansion plate and protruding beyond an outer perimeter of said conductive expansion plate, and a second part surrounding said contact surface.

Description

(1) Further features and advantages of the invention will emerge from the description of preferred, but not exclusive embodiments of the low voltage switch pole, according to the invention, non-limiting examples of which are provided in the attached drawings, wherein:

(2) FIG. 1 is a perspective view of an embodiment of a low voltage switch pole, according to the invention;

(3) FIG. 2 is a perspective view of an embodiment of the fixed contact assembly in a low voltage switch pole, according to the invention;

(4) FIG. 3 is an exploded view of an embodiment of the fixed contact assembly in a low voltage switch pole, according to the invention;

(5) With reference to the attached Figures, the low voltage switch pole according to the invention, designated with the reference numeral 1, comprises in its more general definition, an insulating casing 2 defining an internal space. In the embodiment shown in FIG. 1, a double interruption switch pole is represented. The present invention is not intended to be limited to such double-interruption switching technology, but it is of more general applicability.

(6) With particular reference to FIG. 1, in the internal space of the casing 2 of the low voltage switch 1 there are provided one or more contact areas 3, 30 and a corresponding one or more arc extinguishing areas 4, 40.

(7) A fixed contact assembly 5, 50 and a movable contact assembly 6, 60 are positioned in corresponding contact areas 3, 30. According to known technical solutions, the movable contact assembly 6, 60 is movable between a closed position, in which it is into contact with said fixed contact assembly 5, 50, and an open position, in which it is spaced apart from the corresponding fixed contact assembly 5, 50.

(8) An arc chamber 41, 410 comprising a plurality of substantially parallel metallic plates, generally inserted in a corresponding enclosure, is conventionally positioned in said arc extinguishing area 4, 40.

(9) In general, the operating principles and functioning, as well as the related components and mechanisms, of the a low voltage switch used in the present invention can be of the conventional type and will not be described in further details.

(10) With reference also to FIGS. 2 and 3, one of the distinguishing features of the low voltage switch 1 of the present invention is given by the fact that said fixed contact assembly 5, 50 is provided with a contact support 51, 510 onto which a contact surface 52, 520 is positioned. The contact surface 52, 520 comes into contact with the movable contact assembly 6, 60 in the closed position and is spaced apart therefrom in the open position of the switch 1.

(11) The fixed contact assembly 5, 50 further comprises a conductive expansion plate 53, 530—which is also positioned on said contact support 51, 510—and which extends toward said arc chamber 41, 410.

(12) A further distinguishing features of the low voltage switch 1 of the present invention is given by the fact that said fixed contact assembly 5, 50 is also provided with a gasifying plate 54, 540 which is directly mounted on said conductive expansion plate 53, 530.

(13) As shown in the attached figures, the conductive expansion plate 53, 530 and the gasifying plate 54, 540 positioned thereon extend beyond said contact area 3, 30 and below said arc chamber 41, 410, so that the arc can be effectively urged from the contact areas 3, 30 to the arc extinguishing areas 4, 40.

(14) In the embodiment shown in the attached figures, the area subtended by the gasifying plate 54, 540 is greater than the area subtended by the conductive expansion plate 53, 530. In practice, in this embodiment when the gasifying plate 54, 540 is mounted on the conductive expansion plate 53, 530, said gasifying plate 54, 540 protrudes beyond the outer perimeter of said conductive expansion plate 53, 530.

(15) In a preferred embodiment of the voltage switch pole 1, according to the invention, the gasifying plate 54, 540 is provided with a first part 7 which is positioned on said conductive expansion plate 53, 530 and which protrudes beyond the outer perimeter of said conductive expansion plate 53, 530. Then, as shown FIGS. 2 and 3, said gasifying plate 54, 540 has a first cutout portion 71 at the center of said first part 7 which leaves uncovered a central portion of said conductive expansion plate 53, 530, providing a conductive path for the electrical arc toward the arc chamber.

(16) In another embodiment of the low voltage switch pole 1, according to the invention, the gasifying plate 54, 540 is provided with a first part 7 which is positioned on said conductive expansion plate 53, 530 and which protrudes beyond the outer perimeter of said conductive expansion plate 53, 530. Then, as shown FIGS. 2 and 3, said gasifying plate 54, 540 is also provided with a second part 8 surrounding said contact surface 52, 520.

(17) In a further embodiment of the low voltage switch pole 1, according to the invention, the gasifying plate 54, 540 is substantially T shaped and is provided with a first part 7 which is positioned on said conductive expansion plate 53, 530 and which protrudes beyond the outer perimeter of said conductive expansion plate 53, 530. Then, with reference to FIGS. 2 and 3, said gasifying plate 54, 540 is also conveniently provided with a second part 8 which extends perpendicularly from said first portion 7 in the direction of said contact surface 52, 520, i.e. opposite to the arc extinguishing area 4, 40.

(18) In this latter embodiment of a low voltage switch pole 1 of the present invention, said gasifying plate 54, 540 has conveniently a first cutout portion 71 at the center of said first part 7 which leaves uncovered a central portion of said conductive expansion plate 53, 530, thereby providing a conductive path for the electrical arc toward the arc chamber. Then, the gasifying plate 54, 540 has also a second cutout portion 81 at the center of said second part 8, thereby providing a seta for said contact surface 52, 520 which is at least partially positioned within said second cutout portion 81.

(19) In the embodiment of the low voltage switch pole 1 shown in the attached figures, said second cutout portion 81 of said second part 8 of said gasifying plate 54, 540 is wider than said first cutout portion 71 of said first part 7 of said gasifying plate 54, 540.

(20) Likewise, in such embodiment, said first part 7 of said gasifying plate 54, 540 is wider than said second part 8 of said gasifying plate 54, 540. A different choice of shape and dimensions of gasifying plate 54, 540, as well as of the conductive expansion plate 53, 530, can also be made depending on the operating needs and design of the low voltage switch.

(21) In atypical embodiment of a low voltage switch pole 1, according to the invention, said conductive expansion plate 53, 530 and/or said gasifying plate 54, 540 can be provided with suitable retaining means for fixing said gasifying plate 54, 540 onto said conductive expansion plate 53, 530.

(22) For instance, with reference to the attached figures, the low voltage switch pole 1 according to the invention, can be provided with retaining means which comprise one or more engagement pins 91 positioned, e.g., on said conductive expansion plate 53, 530 and with corresponding one or more engagement seats 92 for said pins 91 which are positioned, e.g., on the gasifying plate 54, 540.

(23) An alternative layout, i.e. with the pins 91 positioned on the gasifying plate 54, 540 and the corresponding one or more engagement seats 92 for said pins 91 which are positioned on said conductive expansion plate 53, 530, is also possible, as well as the use of alternative fixing means.

(24) It is clear from the above that the low voltage switch pole 1 of the present invention allows solving the above underlined problems. Indeed, thanks to the proper layout of the contact area and arc extinguishing area, and in particular thanks to the proper positioning of the gasifying plate, in the low voltage switch pole 1 of the present invention there an increased gasification effect and an increased arc quenching effect, compared with the more conventional solutions of the prior art switches.

(25) Moreover, the low voltage switch pole 1 is very simple from a mechanical standpoint and requires a limited number of components, thereby not affecting negatively the overall costs of the circuit breaker.

(26) Several variations can be made to the low voltage switch pole 1, as well as to the low voltage switch comprising such pole, thus conceived, all falling within the scope of the attached claims. In practice, the materials used and the contingent dimensions and shapes can be any, according to requirements and to the state of the art.