Pool Section 29 Regulation 3.2(2) AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: Electrical apparatus comprising a pivoting control key The following statement is a full description of this invention, including the best method of performing it known to us: P111ABAU/0610 1 FIELD OF THE INVENTION The invention relates in general to electrical apparatuses having a pivoting control key. TECHNOLOGICAL BACKGROUND 5 It is known that there are electrical apparatuses, particularly electrical switches or, in some countries electrical outlets, that integrate a switch, said apparatuses comprising a body having an opening that is blocked by the key, said key cooperating with the body by means of mutually pivoting assembly elements. Also known, particularly by French patent application 2 872 339 and by 10 French patent application 2 935 192, are such electrical apparatuses the key of which has two opposite trunnions centered on the pivoting axis provided for the key and, on the body, two orifices forming a bearing in which the trunnions of the key are received, the trunnions being installed in the bearings by snapping them into place, and more specifically by elastic deformation of the body and/or the key. 15 OBJECT OF THE INVENTION The invention relates to such an apparatus wherein the installation of the key in the body is accomplished without deformation, or in any case with a minimum of deformation, while remaining simple, convenient and economical. 20 To that end, the invention proposes an electrical apparatus comprising a body and a pivoting control key blocking an opening of said body, said key and said body comprising mutually pivoting assembly elements comprising at least one pair formed by a trunnion and a bearing, with the trunnion pertaining to a first element between the body and the key while the bearing pertains to the second element between the body and the 25 key; characterized in that: - said trunnion comprises a lateral surface having a stop face and a pivot guide face, - said bearing comprises a lateral surface having a counter-stop face and 30 a pivot counter-guide face, - a groove extends between said bearing and one face of the second element situated on a first side, with the groove which leads to the bearing between the counter-stop face and the counter-guide face, - said apparatus is configured so that the key is movable between two 35 stable angular end-of-travel positions, with the stop face which is on the first side, the 2 pivot guide face which is on a second side opposite the first side, the counter-stop face which is on the first side, the pivot counter-guide face which is on the second side, the stop face which faces the counter-stop face, the guide face which faces the counter guide face, while an elastic component acts on the key to press the guide face and the 5 counter-guide face against each other, and if an effort is exerted on the key with a greater intensity than the effort exerted by the elastic component, the stop face comes against the counter-stop face; and - said body and said key are configured so that, when they are separated from the rest of the apparatus, the key allows an angular orientation, with respect to the 10 body, beyond one of said two end-of-travel positions, in which the trunnion can slide in the groove from the face of the second element situated on the first side to a position where the lateral surface of the trunnion is in contact with the counter-guide face, and so that the key can then pivot to take the angular positions situated between said two end of-travel positions. 15 It can be seen that the installation of the key in the body is accomplished simply by sliding and pivoting the key, which is particularly simple and easy to do, while the configuration of the trunnion and bearing makes manufacturing simple, convenient and economical. By avoiding deforming the body and/or key, the mechanical qualities of 20 these elements are preserved while avoiding the risks of breakage or the risks of flawed appearance. According to preferred characteristics that are particularly useful for preventing the key from being disassembled from the body before the unit formed by the body in the key is assembled to the rest of the apparatus, a lug protrudes in said groove 25 to form a hard spot when the trunnion slides in the groove from the face of the second element situated on the first side to said position where the lateral face of the trunnion is in contact with the counter-guide face. According to preferred characteristics that are particularly simple, convenient and economical to implement: 30 - said stop face and said counter-stop face are flat; - said guide face and said counter-guide face are curved; - said stop face and said counter-stop face are oriented to be parallel to each other when the key is in a median angular position between the two stable end-of travel positions; 35 - said stop face is a flat surface, said guide face is a curved surface with a semicircular cross-section each end of which connects to a respective end of said stop 3 face, said counter-stop face is a flat surface and said counter-guide face is a curved surface with a semicircular cross-section, said groove being oriented transversely to the counter-stop face and having a width corresponding to the radius of the guide face; - said pivot counter-guide face has a larger diameter than said pivot 5 guide face; - said first element is said key, said second element is said body with said first side which is the side of an opening of said body opposite said opening that said key blocks and the second side which is the side of said opening that the key blocks; - said key has two lateral faces from each of which a trunnion protrudes, 10 while said body has a cavity defined by two opposite flat faces in each of which a bearing and a groove is made; and/or - said first element is said body, said second element is said key with the first side which is the side of said opening that the key blocks and the second side which is the side of an opening of said body opposite said opening that the key blocks. 15 BRIEF DESCRIPTION OF THE DRAWINGS An explanation of the invention will now be provided by a description of one embodiment, provided by way of nonlimiting illustrative example, with reference to the appended drawings in which: 20 - figure 1 is an elevation view of an electrical apparatus according to the invention, and more specifically of a front portion of such an apparatus comprising a pivoting control key and a front body in which the control key is mounted, with the pivoting control key which is shown in side view and the body of the front element which is shown in cross-section, the portion of the front body situated in front of the cutting 25 plane around the articulation trunnion of the control key also being shown in cross section; - figure 2 is a view in perspective of the control key; - figure 3 is a view in perspective, taken from a different angle, of the front body of the electrical apparatus according to the invention; 30 - figure 4 is a view in partial cross-section, taken at one of the grooves of the front body, showing the protruding lug provided to form a hard spot; - figures 5 and 6 are views similar to figure 1 showing both of the stable angular end-of-travel positions between which the key is movable when the apparatus is fully assembled; 35 - figures 7 and 8 are views similar to figure 1 showing the steps for installing the control key in the front body; 4 and - figure 9 is a view similar to figure 6, but showing a variation of formation of the slot formed by the bearing and by the access groove to the bearing. 5 DETAILED DESCRIPTION OF ONE EMBODIMENT The electrical apparatus 10 illustrated in the drawings includes a base, not shown, on which a front portion 11 is installed comprising a front body 12 and a pivoting control key 13 blocking an opening 14 of the front body 12. The pivotal mounting of the key 13 on the body 12 is accomplished, on 10 each of two opposite sides of the key 13, by a trunnion 15 pertaining to the key 13 and by a bearing 16 pertaining to the body 12. The pairs formed on each side by a trunnion 15 and by a bearing 16 are identical, except one is the mirror image of the other. In the following description, whatever is said about one trunnion 15 and 15 one bearing 16 is valid for both trunnions 15 and both bearings 16. The trunnion 15 has a lateral face having a flat surface 17 and a curved face 18 each end of which is connected to one respective end of the flat surface 17. Here, the curved face 18 has a semicircular cross-section and the flat surface 17 has a width (distance between its ends that are connected to the ends of the 20 face 18) corresponding to the diameter of the curved face 18. The trunnion 15 protrudes from a flat lateral face 20 of the key 13. The two opposite flat lateral faces 20 of the key 13 are connected by two curved opposite lateral faces 21 and by a front face 22, also curved. The lateral faces 21 are convex on the outer side, having a curvature 25 around the direction of the trunnions 15 (see more particularly figure 1) as well as a curvature around the axial direction. The front face 22 is slightly concave facing outward (see more particularly figure 1). From the center of the front key 13 a shaft 23 extends, projecting beyond 30 the lateral faces 20 and 21. The body 12 has a cavity 25 that extends between the opening 14 and the opposite opening 26. Between the openings 14 and 26, the cavity 25 is defined by two opposite flat faces 27 and by two opposite curved faces 28. 35 Near the opening 14, the curved faces 28 have a configuration similar to that of the curved lateral faces 21 of the key 13, i.e. with a curvature that is both centered 5 around an axial direction and around a direction transverse to the axial direction (see more particularly figures 1 and 3). The remainder of the faces 28 are curved around the axial direction. The separation between the flat faces 27 corresponds substantially to the 5 separation between the flat lateral faces 20 of the key 13. A slot 30 is made in each flat face 27, one portion of said slot, disposed centrally in the face 27, forming the bearing 16 and the remainder forming a groove 31 extending from the bearing 16 to the face of the body 12 surrounding the opening 26. The bearing 16 has a contour similar to that of the trunnion 15 with a flat 10 surface 32 and a curved surface 33 of the same configuration as the curved surface 18 of the trunnion 15 (semicircular cross section) except the diameter of the curved surface 33 is slightly larger than the diameter of the curved surface 18. The groove 31 extends along the axial direction with a width corresponding to one half that of the flat surface 17 or, in other words, corresponding to 15 the radius of the curved surface 18. The depth of the slot 30 is greater than the thickness of the trunnion 15, i.e. the dimension of the trunnion 15 in the direction in which it protrudes from the face 20. Between the face of the body 12 surrounding the opening 26 and the 20 bearings 16, the groove 31 has a lug 34 that is visible in figure 3 and shown in cross section in figure 4. The face 35 of the lug 34 turned toward the opening 26 is curved or sloped. The face 36 of the lug turned toward the bearing 16 is straight, i.e. oriented transversely to the groove 31. 25 The flat surface 32 has substantially the same width as the groove 31. One of the ends of the curved surface 33 is connected to the flat surface 32 while the other end is connected to the surface defining the groove 31 opposite the flat surface 32. When the key 13 and the body 12 (figures 1, 5 and 6) are assembled, the 30 front portion 11 is in place on the rest of the apparatus 10, the shaft 23 of the key 13 which cooperates with the elements permitting two stable positions at each of which corresponds one of the stable positions of the key 13 illustrated in figures 5 and 6. In a first stable position, the key 13 is in a predetermined angular position where, with respect to the angular position illustrated in figure 1, it has turned by a certain 35 angle in one direction. In the second stable position, the key 13 is in a predetermined 6 angular position where, with respect to the position illustrated in figure 1, it has turned by a certain angle in the reverse direction. The position illustrated in figure 1 is an unstable intermediate position that the key 13 takes when it passes from one of the stable positions to the other stable 5 position. The two stable positions are end-of-travel positions. Here, in one of the stable positions, a movable contact of the apparatus 10 is separated from a fixed contact while in the other position, the movable contact is pressed against the fixed contact. The elements with which the shaft 23 of the key 13 cooperates comprise 10 an elastic component that pushes the key 13 outwards, i.e. in the direction where the key 13 tends to emerge outside of the body 12 through the opening 14. Said elastic component is indicated in figure 1 by the arrow 37. The elastic effort due to the action of the elastic component 37 on the key 13 presses the curved surface 18 of the trunnion 15 against the curved surface 33 of the 15 bearing 16. The contact between these two curved surfaces guides the pivoting movement of the key 13 with respect to the body 12. Because the curved surface 33 of the bearing 16 has a diameter slightly larger than the curved surface 18 of the trunnion 15, when the surfaces 18 and 33 are in contact with each other while the flat surface 17 of the trunnion 15 is oriented parallel to 20 the flat surface 32 of the bearing 16, the flat surfaces 17 and 32 are separated from each other. Said separation allows the key 13 to change from the position illustrated in figure 1 to the stable position illustrated in figure 6 where, with respect to the position of figure 1, the key 13 has turned in the clockwise direction, i.e. in the direction where the flat surface 17 approaches the flat surface 32. 25 If an axially oriented effort is exerted on the key 13 with an intensity that is greater than the effort exerted by the elastic component 37, the coming into contact of the flat surface 17 of the trunnion 15 with the flat surface 32 of the bearing 16 stops the penetration of the key 13 into the body 12. In order for the key 13 to be able to leave the body 12, it would be 30 necessary for the key 13 to turn one quarter turn with respect to the median position illustrated in figure 1 in the counterclockwise direction in figure 1. In practice, when the device 10 is assembled, such angular pivoting of the key 13 is not possible due to its cooperation with the other components of the electrical apparatus 10. 35 Figures 7 and 8 show the process of assembling the key 13 with the body 12.
7 In order to allow the trunnion 15 to reach the bearing 16, the key 13 is presented at the side of the opening 26 of the cavity 25 with an orientation such that the flat surface 17 of the trunnion 15 is oriented axially, i.e. parallel to the general direction of the groove 31. 5 The trunnion 15 can thus be inserted in the groove 31 (see figure 7) until the trunnion 15 meets the curved surface 33 (see figure 8). As it moves toward the bearing 16, the trunnion 15 encounters the lug 34 and slides along the curved or sloped face 35, allowing the trunnion 15 to clear the lug 34. Once the trunnion 15 has cleared the lug 34, it is difficult for the trunnion to clear the 10 lug again in the reverse direction, because the face 36 of the lug 34 is straight. The separation between the sections of the trunnions 15 and the sections of the lugs 34 is such that the trunnions 15 clear the lugs 34, while forcing them very slightly, without the key 13 being deformed or with a minimum deformation (it involves a single hard spot). 15 To complete the assembly, the key 13 is simply pivoted in the direction that approaches the flat surface 17 of the trunnion 15 of the flat surface 32 of the bearing 16, i.e. in the direction seen in figure 8 as the clockwise direction. It will be noted that the walls of the key 13 forming the flat faces 20 comprise, on the side of the flat surface 17, a protruding lobe 40 (figure 2), here with a 20 semicircular cross-section. The lobe 40 is useful during assembly of the key 13 in the body 12 to guide the trunnion 15 toward the groove 31. In the variation illustrated in figure 9, the slot 30 is configured differently: the surfaces that laterally define the groove 31, rather than being parallel to each other, are inclined towards each other and towards the bearing 16. Thus, the width of the 25 groove 31 decreases as it approaches the bearing 16. The flat surface 32, rather than being straight, his inclined towards the groove 31 and towards the opening 14. It will be observed that the flat surface 17 and the curved surface 18 form for the trunnion 15 respectively a stop surface and the pivot guide surface; and that the 30 flat surface 32 and the curved surface 33 of the bearing 16 form respectively a counter stop surface and a pivot counter-guide surface. In variations that are not illustrated: - the trunnion 15 and the bearing 16 comprise stop, pivot guide, counter stop and pivot counter-guide surfaces that are configured differently, with for example the 35 pivot guide surface and the pivot counter-guide surface that are curved with a cross section other than a semicircle, for example two fifths of a section of circle for the guide 8 surface and a semicircle section for the counter-guide surface, a section other than a portion of circle, for example a portion of an ellipse or the pivot guide surface and the pivot counter-guide service have a V-shaped section with an angle at the top that is smaller for the guide surface; and the stop and counter-stop surfaces that are other than 5 a flat surface, for example curved; - the stop surface does not connect to each end of the pivot guide surface, with for example an additional surface between the stop surface and the pivot guide surface; and/or - the groove has a shape other than a groove with parallel sidewalls or 10 walls inclined toward each other converging toward the bearing, with for example only one inclined sidewall. It will be observed that in the illustrated example where the trunnion pertains to the key 13 and the bearing 16 pertains to the body 12, if the side of the opening 26 is called "first side" and the side of the opening 14 is "second side," then the 15 groove 31 extends between the bearing 16 and the face of the body 12 situated on the first side, the stop surface 17 is on the first side, the pivot guide surface 18 is on the second side, the counter-stop surface 32 is on the first side and the pivot counter-guide surface 33 is on the second side. In a variation not illustrated, the trunnion such as 15 pertains to the body 20 such as 12 and the slot such as 30 pertains to the keys such as 13 with the key such as 13 which is installed in the body such as 12, as in the illustrated example, on the side of the opening 26, with an elastic component such as 37 which acts on the keys such as 13 in the direction going from the opening 26 toward the opening 14, the slot such as 31 leads to the side of the opening 14. In this variation, if the side of the opening 14 is called 25 "first side" and the side of the opening 26 "second side," there is also the groove such as 31 which extends between the bearings such as 16 and the face of the key such as 13 situated on the first side, the stop surface such as 17 which is on the first side, the pivot guide surface such as 18 which is on the second side, the counter-stop surface such as 32 which is on the first side and the pivot counter-guide surface such as 33 which is on 30 the second side. In another variation not represented, there is a single pair formed by one trunnion and one bearing. Numerous variations are possible depending on the circumstances, and in this regard the invention is not limited to the examples described and represented. 35