Mechanical latching system kit for a medium voltage contactor

Abstract

A mechanical latching accessory kit for a Medium Voltage contactor including one or more movable contacts connected through a mechanical link to a contact actuator moving the one or more movable contacts between a contact open position and a contact closed position. The mechanical latching accessory kit includes: a supporting interface adapted to be fixed to and removed from the Medium Voltage contactor; a latching element movable between a first operating position and a second resting position; a latching actuating system moving the latching element between the first, operating, position and the second, resting, position; the latching element being adapted, when it is in the first operating position, to cooperate with the mechanical link of the Medium Voltage contactor to latch the one or more movable contacts, and, when it is in the second resting position, to release the one or more movable contacts.

Claims

1. A mechanical latching accessory kit for a Medium Voltage contactor comprising one or more movable contacts connected through a mechanical link to a contact actuator moving said one or more movable contacts between a contact open position and a contact closed position, the mechanical latching accessory kit comprises: a supporting interface adapted to be fixed to and removed from said Medium Voltage contactor; a latching element movable between a first operating position and a second resting position; and a latching actuating system moving said latching element between said first operating position and said second resting position; wherein said latching element being adapted, when said latching element is in said first operating position, to cooperate with the mechanical link of said Medium Voltage contactor to latch said one or more movable contacts, and, when said latching element is in said second resting position, to release said one or more movable contacts.

2. The mechanical latching accessory kit according to claim 1, wherein said latching actuating system comprises: a first mechanical latching actuator moving said latching element from said second resting position to said first operating position, and a second electromagnetic unlatching actuator moving said latching element from said first operating position to said second resting position.

3. The mechanical latching accessory kit according to claim 2, further comprising switching means to switch on and off a feeding current of said second electromagnetic unlatching actuator.

4. The mechanical latching accessory kit according to claim 3, further comprising a rectifier for handling both DC and AC supply of feeding current of said second electromagnetic unlatching actuator.

5. The mechanical latching accessory kit according to claim 2, wherein said latching actuating system comprises a first mechanical latching elastic actuator snap-moving said latching element from said second resting position to said first operating position and said second electromagnetic unlatching actuator which, when energized, moves said latching element from said first operating position to said second resting position contrasting actuation of said first mechanical latching elastic actuator.

6. The mechanical latching accessory kit according to claim 1, wherein said latching actuating system comprises: a first mechanical latching elastic actuator snap-moving said latching element from said second resting position to said first operating position, and a second electromagnetic unlatching actuator which, when energized, moves said latching element from said first operating position to said second resting position contrasting actuation of said first mechanical latching elastic actuator.

7. The mechanical latching accessory kit according to claim 6, wherein said first mechanical latching elastic actuator is a compression spring which is compressed when said latching element is in said second resting position and is released when said latching element is in said first operating position.

8. The mechanical latching accessory kit according to claim 7, wherein said second electromagnetic unlatching actuator comprises a fixed magnetic yoke, a coil, and a movable magnetic plunger positioned inside said coil and operatively connected to said latching element, wherein said movable magnetic plunger moving said latching element between said first, operating, position and said second resting position.

9. The mechanical latching accessory kit according to claim 8, wherein said compression spring has one end rigidly connected to said fixed magnetic yoke and an other end rigidly connected to said movable magnetic plunger.

10. The mechanical latching accessory kit according to claim 9, wherein said compression spring has one end rigidly connected to said fixed magnetic yoke and the other end rigidly connected to said movable magnetic plunger.

11. The mechanical latching accessory kit according to claim 6, wherein said second electromagnetic unlatching actuator comprises a fixed magnetic yoke, a coil, and a movable magnetic plunger positioned inside said coil and operatively connected to said latching element, said movable magnetic plunger moving said latching element between said first operating position and said second resting position.

12. The mechanical latching accessory kit according to claim 6, further comprising switching means to switch on and off a feeding current of said second, electromagnetic, unlatching actuator.

13. The mechanical latching accessory kit according to claim 1, wherein said latching element is provided with means for reducing a friction with the mechanical link and/or other parts of said Medium Voltage contactor.

14. The mechanical latching accessory kit according to claim 1, wherein said latching actuating system comprises a manual unlatching actuator moving said latching element from said first operating position said second resting position.

15. A Medium Voltage contactor comprising the mechanical latching accessory kit according to claim 1.

16. The Medium Voltage contactor according to claim 15, wherein said contact actuator comprises an electromagnetic actuator configured to move said one or more movable contacts from said contact open position to said contact closed position when energized, and a spring means for moving said one or more contacts from said contact closed position to said contact open position, said latching element of said mechanical latching accessory kit cooperating with the mechanical link of said Medium Voltage contactor for latching said one or more contacts in said closed position.

17. The Medium Voltage contactor according to claim 16, wherein when said one or more contacts are in the contact closed position, the electromagnetic actuator of said contact actuator are de-energized.

18. The Medium Voltage contactor according to claim 16, wherein the mechanical link of said Medium Voltage contactor comprises a rod operatively connected to said one or more movable contacts and linearly moving between said contact open position and said contact closed position, said rod being placed with a longitudinal axis perpendicular with respect to a direction of linear movement of said rod, the latching element of said mechanical latching accessory being inserted in a space between said rod and a fixed element of said Medium Voltage contactor when said one or more movable contacts are in the closed position and being extracted from said space when said one or more movable contacts are in the open position.

19. The Medium Voltage contactor according to claim 15, wherein the mechanical link of said Medium Voltage contactor comprises a rod operatively connected to said one or more movable contacts and linearly moving between said contact open position and said contact closed position, said rod being placed with a longitudinal axis perpendicular with respect to a direction of linear movement of said rod, the latching element of said mechanical latching accessory being inserted in a space between said rod and a fixed element of said Medium Voltage contactor when said one or more movable contacts are in the closed position and being extracted from said space when said one or more movable contacts are in the open position.

20. The Medium Voltage contactor according to claim 19, wherein said contact actuator comprises an electromagnetic actuator configured to move said rod from said contact open position to said contact closed position when energized, and spring means for moving said rod from said contact closed position to said contact open position, said electromagnetic actuator of said contact actuator being de-energized when said one or more contacts are in the contact closed position, said latching actuating system of said mechanical latching accessory kit being energized to move the latching element of said mechanical latching accessory kit from an inserted position in the space between said rod and a fixed element of said Medium Voltage contactor and an extracted position from said space.

Description

(1) Further features and advantages of the invention will emerge from the description of preferred, but not exclusive embodiments of the mechanical latching accessory kit for a Medium Voltage contactor, according to the invention, non-limiting examples of which are provided in the attached drawings, wherein:

(2) FIG. 1 is a schematic view of a first embodiment of a mechanical latching accessory kit and a Medium Voltage contactor according to the invention, in a first position (contact open—latching element in the resting position);

(3) FIG. 2 is a schematic view of a first embodiment of a mechanical latching accessory kit and a Medium Voltage contactor according to the invention, in a second position (contact closed—latching element in the operating position—contact latched);

(4) FIG. 3 is a schematic view of a second embodiment of a mechanical latching accessory kit and part of the mechanical link of a Medium Voltage contactor according to the invention, in a contact closed position (contact closed—latching element in the operating position—contact latched);

(5) FIG. 4 is a front view of a Medium Voltage contactor equipped with a mechanical latching accessory kit, according to the invention;

(6) FIG. 5 is a first perspective view of a third embodiment of a mechanical latching accessory kit, according to the invention;

(7) FIG. 6 is a second perspective view of a third embodiment of a mechanical latching accessory kit, according to the invention;

(8) FIG. 7 is a section view of a third embodiment of a mechanical latching accessory kit, according to the invention;

(9) FIG. 8 is a perspective view of a Medium Voltage contactor equipped with a mechanical latching accessory kit, according to the invention;

(10) FIG. 9 is a front view of a Medium Voltage contactor equipped with a mechanical latching accessory kit, according to the invention.

(11) With reference to the attached Figures, a mechanical latching accessory kit according to the invention—designated by the reference numeral 1—is adapted to be used with a Medium Voltage contactor—designated by the reference numeral 100.

(12) The Medium Voltage contactor 100 generally comprises one or more movable contacts 100 connected through a mechanical link 110 to a contact actuator 102. According to the needs, the contact actuator 102 can be of different kinds and have different features and it is used to move said one or more movable contacts 101 between a contact open position (e.g. FIG. 1) and a contact closed position (e.g. FIG. 2).

(13) The mechanical latching accessory kit 1 of the present invention, in its more general definition, comprises a supporting interface 2 which is used for fixing the mechanical latching accessory kit 1 on a Medium Voltage contactor 100, normally on the front side of said Medium Voltage contactor 100.

(14) Then, mechanical latching accessory kit 1 comprises a latching element 3 which is movable between a first operating position and a second resting position and a latching actuating system 4 moving said latching element 3 between said first, operating, position and said second, resting, position, according to operating principles better described hereinafter.

(15) The latching element 3 of the mechanical latching accessory kit 1 is adapted—when it is in said first operating position—to cooperate with the mechanical link 110 of said Medium Voltage contactor 100 to latch said one or more movable contacts 101 (as schematically represented in FIG. 2), and—when it is in said second resting position—to release said one or more movable contacts 101 (as schematically represented in FIG. 1).

(16) In a preferred embodiment of the mechanical latching accessory kit 1 of the present invention, the latching actuating system 4 comprises a first, mechanical, latching actuator 41 which moves the latching element 3 from the second resting position to said first operating position.

(17) Furthermore, the latching actuating system 4 comprises a second, electromagnetic, unlatching actuator 42 which moves the latching element 3 from said first operating position to said second resting position.

(18) With particular reference to FIGS. 1-3 and 7, the latching actuating system 4 comprises preferably a first, mechanical, latching actuator 41 which is provided with an elastic element 410 snap-moving the latching element 3 from said second resting position to said first operating position.

(19) In particular, the elastic element 410 of the first, mechanical, latching actuator 41 can be a compression spring which is compressed when said latching element 3 is in said second resting position and is released when said latching element 3 is in said first operating position. Thus, as shown in the attached figures, when the contact(s) of the Medium Voltage contactor 100 are in the closed and latched position (e.g. FIGS. 2 and 3), the compression spring is extended in a stable position, whereas when the contact(s) of the Medium Voltage contactor 100 are in the open position (e.g. FIG. 1), the compression spring is compressed in a loaded position and is ready to carry out a latching operation of the Medium Voltage contactor 100 by moving the latching element 3 in its first operating position.

(20) Then, the latching actuating system 4 preferably comprises also a second, electromagnetic, unlatching actuator 42 which, when energized, moves said latching element 3 from said first operating position to said second resting position contrasting the action of said first, mechanical, latching elastic actuator 410. Thus, when the latching element 3 is in its first operating position latching the contact(s) of the Medium Voltage contactor 100, the first, mechanical, latching actuator 41 (i.e., in the embodiment shown, the compression spring 410) are in a stable condition and the second, electromagnetic, unlatching actuator 42 are not energized.

(21) In a detailed preferred embodiment of the mechanical latching accessory kit 1 of the present invention said second, electromagnetic, unlatching actuator can preferably comprise a fixed magnetic yoke 421, a coil 422, and a movable magnetic plunger 423 which is positioned inside said coil 422. By energizing/de-energizing the coil 422, the magnetic plunger 423 is linearly moved in and out according to well-known operating and design principles.

(22) Accordingly, the magnetic plunger 423, which is operatively connected to the latching element 3, moves said latching element 3 between said first, operating, position and said second resting position under the action of the first, mechanical, latching actuator 41 (i.e., in the embodiment shown, the compression spring 410); then, when the coil 422 is energized, the magnetic plunger 423 is withdrawn inside the magnetic yoke 421 and moves said latching element 3 between the second resting position and said first, operating, position. At the same time, during such movement, the elastic means of the first, mechanical, latching actuator 41 (i.e., in the embodiment shown, the compression spring 410) are loaded and brought in condition to carry out latching operation again.

(23) As shown in the attached figures, the compression spring has one end advantageously rigidly connected to said fixed magnetic yoke 421 and the other end rigidly connected to said movable magnetic plunger 423, thereby realizing a very simple but very effective system for moving the latching element 3 between the latching an unlatching positions of the contact(s) of the Medium Voltage contactor 100.

(24) According to a particular embodiment of the mechanical latching accessory kit 1 of the present invention, switching means 5 can be provided to switch on and off the feeding current of said second, electromagnetic, unlatching actuator 42. In practice, a micro-switch 5 can be appropriately positioned on the mechanical latching accessory kit 1 so as to switch on and off the excitation current of the coil 422 depending on the position of the magnetic plunger 423, and consequently on the latched/unlatched conditions of the contact(s) of the Medium Voltage contactor 100.

(25) Furthermore, the second, electromagnetic, unlatching actuator 42 is conveniently provided with a current supply system for handling, e.g., the excitation current of said coil 422. For instance, said current supply system can advantageously comprise a rectifier, preferably a diode rectifier, for handling both DC and AC supply for the excitation current of said coil 422.

(26) As shown in the attached figures, and as better explained in the following description of preferred embodiments of the present invention, the latching element 3 is intended to be inserted in a space between a movable part of the mechanical link 110 and a fixed part of the Medium Voltage contactor 100, so as to latch the mechanical link 110 and consequently the contact(s) part of the Medium Voltage contactor 100 in a desired position. During the insertion (and extraction) of the latching element 3 into (and from) said space, considerable friction may arise between the latching element 3 and the mechanical link 110 and/or other parts of the Medium Voltage contactor 100.

(27) In order to reduce such friction, in a preferred embodiment of the mechanical latching accessory kit 1 of the present invention, the latching element 3 is preferably provided with means 35 for reducing such friction, for example one or more roller bearings 31, 32 positioned on said latching element 3 so as to interact with the mechanical link 110 and/or other parts of the Medium Voltage contactor 100 during the insertion/extraction of the latching element 3 into/from said space.

(28) In a particular embodiment of the mechanical latching accessory kit 1 of the present invention, the latching actuating system 4 can conveniently comprises also a manual unlatching actuator 43, for instance an operating handle or knob, for moving said latching element 3 from said first operating position to said second resting position. In other words, the manual unlatching actuator 43 is intended to be used for carrying out a manual emergency tripping of the latching system. In practice, in an exemplary embodiment of the present invention, when the latching element 3 is in its said first operating position (latching condition of the Medium Voltage contactor 100), by manually pulling the operating handle or knob 43 against the action of the spring 410, the latching element 3 is brought into the second resting position (unlatching condition of the Medium Voltage contactor 100), thereby releasing the mechanical link 110 of said Medium Voltage contactor 100.

(29) In a further aspect, the present invention also relates to a Medium Voltage contactor 100 comprising a mechanical latching accessory kit 1 as described in the present disclosure.

(30) With reference to the attached figures, the Medium Voltage contactor 100 of the present disclosure, comprises one or more movable contacts 101, which are connected through a mechanical link 110 to a contact actuator 102 moving said one or more movable contacts 101 between a contact open position (e.g., as represented in FIG. 1) and a contact closed position (e.g., as represented in FIG. 2). Although a three pole 200 contactor 100 is represented in the attached figures, other configurations of the Medium Voltage contactor 100 are also possible.

(31) In the embodiment shown, the latching element 3 of the mechanical latching accessory kit 1 previously described cooperates with the mechanical link 110 of said Medium Voltage contactor 100 for latching said one or more contacts 101 in said closed position. In practice, the Medium Voltage contactor 100 can be a basic, electrically latched, Medium Voltage contactor which has been up-graded to a mechanically latched Medium Voltage contactor by using the mechanical latching accessory kit 1 previously described.

(32) In a typical embodiment of the Medium Voltage contactor 100 of the present invention, the contact actuator 102 conveniently comprises electromagnetic means 103 which are energized to move said one or more movable contacts 101 from said contact open position to said contact closed position, and spring means 105 for moving said one or more contacts 101 from said contact closed position to said contact open position

(33) As schematically shown in FIGS. 2 and 3, the latching element 3 of the mechanical latching accessory kit 1 cooperates with the mechanical link 110 of said Medium Voltage contactor 100 for latching the contact(s) 101 in said closed position.

(34) Accordingly, when said one or more contacts 101 are in the contact closed position, the electromagnetic means 103 of said contact actuator 102 can be de-energized, since the contact closure condition is maintained by the mechanical interference between the mechanical link 110 of the Medium Voltage contactor 100 and the latching element 3 of the mechanical latching accessory kit 1.

(35) In a typical example of a Medium Voltage contactor 100, according to the present invention, the mechanical link 110 of said Medium Voltage contactor 100 comprises a rod 111 which is operatively connected to a linearly movable member of said contact actuator 102 on to said one or more movable contacts 101, e.g. thorough a second actuating rod 115.

(36) The rod 111 linearly moves between said contact open position and said contact closed position, and is placed with its longitudinal axis perpendicular with respect to the direction of its linear movement; in the embodiment shown, the rod 111 is perpendicularly connected to the second actuating rod 115 so that the longitudinal axis of the second actuating rod 115 is perpendicular to the longitudinal axis of the rod 111 and substantially parallel to the direction of movement, so that the linear movement of the one or more movable contacts 101 and of the movable member of the contact actuator 102.

(37) In the embodiment shown, when said one or more movable contacts 101 are in the closed position, the latching element 3 of said mechanical latching accessory 1 is inserted in a space 112 between said rod 111 and a fixed element 113 of said Medium Voltage contactor 100, for instance the frame of said Medium Voltage contactor 100 or another fixed part thereof.

(38) The mechanical latching accessory 1 and is then extracted from said space 112 when said one or more movable contacts 100 are in the open position.

(39) Typically, the contact actuator 102 of the Medium Voltage contactor 100, can comprise electromagnetic means 103 which are energized to move said rod 111 from said contact open position to said contact closed position.

(40) In practice, the contact actuator 102 conveniently comprises a linear monostable electromagnetic actuator 103, having a coil, a fixed armature and a movable plunger which is connected to the one or more contact(s) 101, with a mechanical link 110 comprising, e.g., the rod 111 and/or the second actuating rod 115. Once said one or more contacts 101 are in the contact closed position, the latching element 3 of the mechanical latching accessory kit 1 is urged in the operating position in the space 112 between the rod 111 and a fixed element 113 of the Medium Voltage contactor 100.

(41) Under these conditions, the contact(s) 101 of the Medium Voltage contactor 100 are latched in the closed position, and the electromagnetic means 103 of said contact actuator 102 can be therefore de-energized.

(42) Furthermore, the contact actuator 102 conveniently comprises spring means 105 for moving said rod 111 (and/or said second actuating rod 115) from said contact closed position to said contact open position.

(43) So, in order to carry out the unlatching operation of the contact(s) 101 of the Medium Voltage contactor 100 (e.g. following a tripping command of the Medium Voltage contactor 100), the coil 422 of the second, electromagnetic, unlatching actuator 42 of the mechanical latching accessory kit 1 is excited, and the latching element 3 of said mechanical latching accessory kit 1 moves from the inserted position in the space 112 between the rod 111 and a fixed element 113 of said Medium Voltage contactor 100 into an extracted position outside said space 112 (unlatching operation).

(44) Under these conditions, the spring means 105 of the contact actuator 102 pull the rod 111 (and/or said second actuating rod 115) from the contact closed position to the contact open position, thereby carrying out the opening operation of the contact(s) 101 of the Medium Voltage contactor 100.

(45) Several variations can be made to the mechanical latching accessory kit for Medium Voltage contactors and to the Medium Voltage contactor 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.