Title of Invention

A BREAKING POLE HOUSED IN A BREAKING CHAMBER OF AN ELECTRICAL SWITCHING DEVICE

Abstract

Breaking pole housed in a breaking chamber of an electrical switching device comprising a mobile contact and a fixed contact (2), and a generally U- shaped arc deflector (1) comprising an upper area (10) with a V- or Y-shaped cut-out (11) separating the upper area at one of its ends (12) into two side portions (14, 15), characterized in that the deflector (1) comprises side plates (30, 31) that are practically .perpendicular to the upper area (10) and parallel to the longitudinal axis of symmetry (XX') of the deflector and which are connected to tl!e side portions (14, 15) of the upper area respectively along corresponding folds (32, 33) parallel to the axis (XXI), each side plate (3D, 31) having a longitudinal recess (34) forming the U shape of the end of the deflector.

Full Text

This invention relates to a breaking pole housed in a breaking chamber of an electrical switching device comprising a mobile contact and a fixed contact placed on a contact support; and an arc deflector with a generally U-shaped end and with an upper area that has a V- or Y-shaped cut-out surrounding the fixed contact and separating the area at one of its ends into two side portions. An arc deflector is already known according to patent application EP 0 657 907. Its general U-shape improves the breaking capacity between the fixed and mobile contacts, in other words the maximum current that the pole can break at a given voltage. Specifically, this deflector comprises a solid lower supporting sole plate and an upper area approximately parallel to the sole plate, that are joined together at the front by bridges bent into arcs of a circle and forming the hollow part of the U in the deflector. However, the bridges forming this front link cannot make the part very stiff. Therefore the purpose of the invention is to improve the mechanical strength of a deflector, while maintaining the general U shape at its end. The breaking pole according to the invention is characterized in that the deflector comprises side plates that are approximately perpendicular to the upper area and are parallel to the longitudinal axis of symmetry of the deflector, and which are connected to the each of the side portions of the upper area respectively along corresponding folds parallel to the axis of symmetry, each side plate having a longitudinal recess forming the U-shape at the end of the deflector. Thus, the side folds have a larger connecting area with the deflector side plates than the front bridges with the lower sole plate in prior art, so that the deflector is stiffer. Accordingly, the present invention provides a breaking pole housed in a breaking chamber of an electrical switching device comprising a mobile contact and a fixed contact placed on a contact support, and a generally U-shaped arc deflector comprising an upper area with a V- or Y-shaped cut-out surrounding the fixed contact and separating the upper area at one of its ends into two side portions, characterized in that the deflector comprises side plates that are practically perpendicular to the upper area and parallel to the longitudinal axis of symmetry (XX') of the deflector and which are connected to the side portions of the upper area respectively along corresponding folds parallel to the axis (XX' ) , each side plate having a longitudinal recess forming the U shape of the end of the deflector. The invention will now be described with reference to the drawings in the appendix. Other characteristics and advantages of the invention will become evident in the description. In the drawings in the appendix: - .figure 1 is a perspective view of the top of the deflector according to the invention; - figure 2 illustrates the deflector in figure 1 associated with a contact support, ~ figure 3 is a bottom view of figure 2. The arc deflector 1 shown in the figures is designed to be housed in a breaking chamber of an electrical switching device to displace and extinguish an electrical arc that appears between a mobile contact (not shown) and a fixed contact 2 when they open. The fixed contact 2 is fixed at the end 21 of a contact support 20. The contact support 20 is a solid part, approximately flat, that has a lower face 22 and an upper face 23. The deflector 1 is made of a single piece basically in the shape of a J. It comprises an upper deflection area 10 extending along a longitudinal axis XXr and the side plates 30 and 31 approximately perpendicular to the area 10 and symmetrical about the XX' axis. The deflection area 10 comprises a V- or Y-shaped cut-out 11 at one of its ends 12, extending along the axis of symmetry XX'. The width of the cutout 11 increases at end 12 and gets narrower towards the opposite end 13 of the deflection area. The cutout 11 separates the area 10 at its end 12 into two side and longitudinal portions 14 and 15 that come together at the end 13 into an end portion 16. Side plates 30 and 31 lie in planes parallel to the longitudinal median plane P of the deflector containing the XX' axis. They are connected to side portions 14 and 15 of area 10 respectively, through corresponding folds 32 and 33 parallel to the XX' axis. The deflector is made by cutting and folding a single ferromagnetic plate such that magnetic and electrical continuity are both guaranteed, and manufacturing is also very easy. Side plates 30 and 31 are made by folding the plate at a right angle towards the folding planes parallel to the longitudinal median plane P. The connecting areas of folds 32 and 33 between the upper area and the side plates are thus sufficient for the stiffness of the deflector. Side plates 30 and 31 each have a U-shaped longitudinal recess 34 parallel to the XX' axis. The recess 3 separates each side plate into an upper arm 3 and a lower arm 3 6 that join together at an end part 37 to form the hollow of the U. The hollow of the U in the side plates corresponds to the hollow in the deflector J. The deflector 1 is associated with the contact support 2 0 such that the end 21 of the support is level with the end 12 of the deflection area 10, the cut-out 11 of the area surrounding the fixed contact 2. The deflection area 10 is not in contact with the upper surface 23, so as to create an insulating space e along its entire length. The edges 24 of support 2 0 are rigidly connected to the lower arms 36 of the deflector side plates 3 0 and 31 by any attachment method, preferably by welding. All that is necessary is spot welds at the free ends 38 of the arms. The contact support 20 and the deflector 1 thus form an individual assembly 4 that facilitates a standard exchange of the contact 2 and the deflector when they are worn, when assembly 4 is installed removably in an arc breaking chamber. The individual assembly 4 is installed in the device by an attachment screw 5. Screw 5 is preferably built into assembly 4 so that it cannot be lost. It comprises a head 50 and a body 51. The end 13 of the deflector area 10 and the contact support 20 comprise orifices 17 and 25 facing each other, the dimensions of orifice 17 being suitable for access to turn the screw head 50, and the dimensions of orifice 25 being sufficient to enable passage of the body 51 of the screw to be screwed to a power outlet connection area in the breaking chamber. To make screw 5 captive, a washer is provided associated with its body 51 and larger than the deflector orifice 17. The washer 6 traps the head 5 0 of the screw between the lower surface 18 of the deflector area 10 and the upper surface 2 3 of the contact support. The individual assembly 4 including screw 5 is assembled as follows. The screw body 51, which is fitted with washer 6, is inserted in orifice 25 of the contact support. Holding the screw through orifice 25, the edges 24 of the contact support are welded to the free ends 3 8 of the deflector side plates. Before assembly 4 is installed in the fitting, the screw slides freely through orifice 25 in the contact, support, washer 6 is free to come into contact with the lower surface 18 of the deflection area 10, or with the upper surface 23 of the contact support, to stop the screw from sliding outside the deflector through orifice 1 , or outside the contact support through orifice 25. WE CLAIM: 1. A breaking pole housed in a breaking chamber of an electrical switching device comprising a mobile contact and a fixed contact (2) placed on a contact support (20), and a generally U-shaped arc deflector (1) comprising an upper area (10) with a V- or Y-shaped cut-out (11) surrounding the fixed contact (2) and separating the upper area at one of its ends (12) into two side portions (14, 15), characterized in that the deflector (1) comprises side plates (30, 31) that are practically perpendicular to the upper area (10) and parallel to the longitudinal axis of symmetry (XX') of the deflector and which are connected to the side portions (14, 15) of the upper area respectively along corresponding folds (32, 33) parallel to the axis (XX'), each side plate (30, 31) having a longitudinal recess (34) forming the U shape of the end of the deflector. 2. The breaking pole as claimed in claim 1, wherein the contact support (20) is rigidly fixed to the deflector (1) by assembling the edges (24) of the contact support to the deflector side plates (30, 31), the contact (2) being housed in the deflector cut-out (11). 3. The breaking pole as claimed in claim 2, wherein each side plate (30, 31) is separated by the recess (34) into a lower arm (36) and an upper arm (35), the lower arm (36) having a free end (38) that is welded to one of the edges (24) of the contact support (20). 4. The breaking pole as claimed in any one of the preceding claims, wherein the deflector (1) and the contact support (20) form an individual assembly (4) that is designed to be installed removably in the switching device box by means of an attachment screw (5), the screw (5) being added in the assembly (4) so that it cannot be lost. 5. The breaking pole as claimed in claim 4, wherein the screw (5) comprises a head (50) and the body (51) , the body (51) being fitted with a washer (6), and the contact support (20) comprises an orifice (25), through which the screw body (51) can pass and the deflector (1) comprises an orifice (17) facing passage orifice (25) providing access to the screw head (50) for turning it, the screw (5) being trapped between the deflector and the contact support by means of washer (6) that can come into contact with the upper surface (23) of the contact support or the lower surface (18) of the deflector area (10). 6. The breaking pole as claimed in any one of the preceding claims wherein the deflector is in the general shape of a J. 7. A breaking pole housed in a breaking chamber of an electrical switching device, substantially as herein described with reference to the accompanying drawings.

Documents:

571-mas-1998-abstract.pdf

571-mas-1998-claims duplicate.pdf

571-mas-1998-claims original.pdf

571-mas-1998-correspondence others.pdf

571-mas-1998-correspondence po.pdf

571-mas-1998-description complete duplicate.pdf

571-mas-1998-description complete original.pdf

571-mas-1998-drawings.pdf

571-mas-1998-form 1.pdf

571-mas-1998-form 26.pdf

571-mas-1998-form 3.pdf

571-mas-1998-form 4.pdf