Contact element

Abstract: A contact element intended to be removably mounted on a wiring duct with continuous bare conductors on its inner walls, contact pins of said contact element being adapted to be contacted with respective conductors after mounting said element on said duct, said contact element being provided with locking claws which are adapted to grip behind undercut edges defining the opening of said duct in order to lock said element in said duct. This contact element comprises a bottom plate with an integrally moulded claw body having claws which, after insertion into the duct and rotation of said bottom plate, will engage the duct edges, which claw body is provided with contact pins which are adapted to con­ tact the current conductors, said body, moreover, having a through bore into which a grounding pin is inserted so as to be contacted with an earth conductor, on the bottom of said duct; furthermore said bottom plate is provided with female contacts or contact springs connected with respective contact pins; finally said contact element comprises a detachable cap which, can be fixed on said bottom plate, the edge portions of said cap then securing the assembly against rotation, and contact or switching means provided in said cap or cooperating therewith being adapted to be contacted with the female contacts or contact springs or said bottom plate.

Description: The invention relates to a contact element as defined in the preamble of Claim 1. Such a contact element is known from CH-A-483 132. A wiring duct of the kind as referred to above is, for instance, known from NL-C 170 787. Such wiring ducts find a still increasing application, in particular in office and factory spaces, said ducts allowing to make connections for lighting appliances in arbitrary points. Auxiliary elements for making a branch connection comprise a housing to be arranged on a duct and bearing on the open side of said duct, and being provided with lateral portions adapted to being applied against the lateral walls of said duct, a rotatable body provided with claws then being inserted into the inner space of said duct, said body being provided with a projecting operating handle by means of which said body can be rotated so as to engage said claws with the duct edges. Thereby the current bearing contact pins are rotated in such a manner that they are contacted with the conductors arranged in the lateral wall of the duct. Such an auxiliary element might, as such, be provided with a single or multiple socket allowing to make a branch connection by means of a cord with a contact plug. However the whole assembly will become rather high which, in the case of visible ducts, will be unsightly, and, moreover, its manufacture is complex and, therefore, relatively expensive, since wire connections between the auxiliary element and the female contacts of the socket are to be made. It is an object of the invention to provide a contact element for being used with such a duct, which element has a simple structure, fits smoothly on said duct, is adaptable by means of unitary parts to various circumstances, and is secured against rotation. According to the invention a contact element is provided as defined in Claim 1. Claims 2 to 7 set out particular embodiments of the invention. The bottom plate of this contact element which has a very small height is used for all the applications, and only this cap is then to be adapted to the different possibilities of use, such as for sockets with or without an earth connection, a switch element or the like. Mounting said bottom plate on a duct takes place in a very simple manner, no operating handle being needed thereto, and the eventual securing against rotation is provided by said cap. This contact element is not exclusively intended for the ducts as described in NL-C 170 787, but can also be used with ducts of a different type, provided that its contact pins are adapted to the position of the conductors of such a duct. The invention will be elucidated below in more detail by reference to a drawing, showing in: Fig. 1 a cross-section of a known wiring duct with a contact element according to the invention arranged therein and with a separately shown cap; Fig. 2 a cross-section according to the line II - II of Fig. 1; and Fig. 3 a top view, partly in section, of the bottom plate of Fig. 1. The contact element shown in the drawing comprises a bottom plate 1 and a cap 2. The bottom plate is adapted for being mounted on a wiring duct 3. The duct 3 as shown is the wiring duct according to NL-C 170 787, but the invention is not restricted to the application thereof to such a duct. The bottom plate 1 is provided in its central portion with a projecting and integrally formed claw body 4, said body having a core 5, a claw edge 6 and a projection 7. The claw edge 6 is, in the tranversal direction, wider than in the longitudinal direction, as shown in fig. 2. The core 5 is substantially circular, but the projection 7 has, in the transversal direction of Fig. 1, a smaller thickness than in the longitudinal direction of Fig. 2. At the upper side the bottom plate is provided with circumferential upstanding walls 8 defining a box-like space on which a cover 9 is fixed. As appears from Fig. 1, the bottom plate is to be fastened on the duct 3. To that end the bottom plate is placed with its longitudinal direction transversely to the longitudinal direction of the duct 3, and its claw body 4 is inserted into the duct 3. This duct has inwardly directed longitudinal edges 10 defining its opening, the free space between these edges 10 being smaller than the largest width of the claw edge 6. If, then, the bottom plate 1 is rotated, the wider part of the claw edge 6 will grip behind these edges 10, so that the bottom plate 1 is fixed on the duct 3. The duct 3 also possesses two lateral cavities 11 and a bottom cavity 11′, in which hollow resilient conductors 12 and 12′ resp. are arranged, which cavities each are provided with an entrance slot 13 and 13′ resp. For further particulars of such a duct, reference is made to the above-mentioned NL-C. Through the portions 5 and 6 of the claw body 4, two strip-like conductors 14 extend which, on the one hand, are situated laterally of the projection 7, and have, there, an extremity 14′ bent outwards, said extremities, when the bottom plate 1 has been rotated in the operative position as shown in Fig. 1, projecting into the corresponding slot 13, and will contact, there, the respective conductor 11. On the other hand said strips are bent outwards in the box-like portion within the walls 8 at 14″, and, there, each strip is connected with a corresponding contact spring pair 15, e.g. by means of a rivet connection 16. Each pair of contact spring strips 15 forms a contact spring, and the extremities thereof are bent at 17, and this in such a manner that both strips are adapted to engage opposite sides of a contact pin inserted through a hole 18 in the cover 9. In front of said holes 18, annular projections 19 are formed on the bottom plate 1 acting as a seat for such a contact pin. The cap 2 shown mainly corresponds with the cap of a double wall socket, in the case shown a wall socket with earth contacts. This cap 2 has a recessed portion 20 for accommodating a contact plug, the botton 21 of said recess being provided with holes 22 corresponding with the holes 18 in the cover 9. At the inner side of the bottom 21 a conducting strip 23 is arranged, which is provided with two pairs of earth contact springs 24 projecting inwards through slots 25 into the recesses 20 in question. In the central part a long flat pin 26 is connected with said strip 23. Said pin extends, in the mounted condition of the cap, through a hole 27 in the cover 9, and into a corresponding slot 28 in the body 4, said pin being so long that it projects through the slot 13′ of the bottom cavity 11′ of the duct 3 for making contact with the grounded conductor 12′. Moreover said strip 23 serves to support mounting screws 29 to be screwed into screw holes 30 of the bottom plate 1 in order to fix the cap. Both terminal walls 31 of the cap 2 are provided with a recess 32, having a width which is equal to that of the duct 3. In the mounted condition, the edges of said recesses grip around the duct 3, thus securing the bottom plate against rotation. If a normal socket without earth connection is desired, only an adapted cap 2 without the contact springs 24 and without the pin 26 is to be used, which can be mounted on the same bottom plate 1. Therefore only one bottom plate is to be used for both kinds of sockets. It is, of course, also possible to use, instead of the earth contact springs 24, one earth contact pin as is usual in some countries. Providing the earth contact springs 24 and the earth contact pin 26 on the cap is necessary, since the bottom plate 1 is to be rotated when being inserted, and a flat pin inserted through a slot 13′ would not allow a rotation. Moreover it will be clear that, in addition to sockets, other contact or switching means can be mounted on such a bottom plate, if they are provided with contact pins which can be contacted with the contact spring extremities 17. It will also be clear that such a bottom plate can be made suitable for triple or multiple sockets. For wiring ducts with conductors shaped in an other manner, the extremities 14′ of the strips 14 should be adapted accordingly. In the case of wiring ducts in which all the conductors are arranged on the bottom, the extremities 14′ should be directed downwards. In that case the portion of the body 4 carrying these contact strips 14 should not hinder the rotation of the plate 1. This can be obtained by accommodating said strips 14, and, as the case may be, also the grounding pin 26, in a core of the body 4, which is rotatable in the interior of said body, and is, for instance, maintained by means of a spring in such a position that, when inserting the body 4 in a duct 3, the various contact pins will be situated in the correct position in front of the bottom conductors. When rotating the plate 1, the core of the body 4 will then remain immobile. The connection with the contact spring strips 15 can be formed, for instance, by contact points at the upper end of the rotatable core, which will contact said strips 15 only in the rotated position of the plate 1.

Claims: A contact element suitable for being removably mounted on a wiring duct, said duct (3) having a substantially U-shaped cross-section and defining a longitudinal duct axis, said duct, on its inner walls, being provided with continuous, bare earth and current conductors (12',12), each having an insulating shield with a longitudinal slot, at least the earth conductor being arranged on the bottom of said duct (3), and said duct having undercut edges (10) defining the opening of said duct, said contact element comprising: current contact pins (14') for contacting under spring tension said current conductors (12), after being inserted through the respective longitudinal slots (13) of said shields, when mounting said element on said duct; a bottom plate (1) for being mounted on and against said duct, said bottom plate defining a longitudinal axis and being provided with a body portion (7) perpendicularly extending therefrom and, at its lower side, with an integrally moulded claw body (4) having locking claws (6) for locking said contact element to said duct, said locking claws extending transversely to the longitudinal axis of said bottom plate, such that, when mounting said element on said duct, after insertion into said duct and rotation of said bottom plate until its longitudinal axis has become substantially parallel to said longitudinal duct axis, said claws (6) will grip behind said duct edges (10); said claw body (4) being provided with said current contact pins (14') and having a through bore (28) into which a grounding pin (26) is or can be inserted for contacting said earth conductor (12') of said duct (3), and wherein said bottom plate is provided with contacts (15) connected with at least said current contact pins (14'); and a detachable, hollow open-ended cap (2) which is fixed on said bottom plate (1), characterized in that, said contacts (15) connected with at least said contact pins (14') consist of female contacts or contact springs; in that the cap (2) has edge portions (32) for engaging the duct edges (10) so as to secure the bottom plate (1) against rotation after having locked said bottom plate on said duct, thus completing the locking; and in that the cap (2) has contact or switching means (22) adapted for making contact with said female contacts or contact springs of said bottom plate. The contact element of claim 1, characterised in that said female contacts on contact springs (15) are shielded by a cover (9) fixed on the bottom plate (1) and provided with openings (18) giving access to these female contacts on contact springs (15). The contact element of claim 1, characterised in that said cap (2) has the shape of a wall socket, and is provided with holes (22) for inserting contact pins of a contact plug to be inserted into said cap. The contact element of claims 2 or 3, characterised in that said cap (2) is provided with earth contact means (24) which are connected with a contact pin (26), said pin being adapted to be inserted through said central bore (28) of the body portion (7) when mounting said cap, in order to be contacted with the earth conductor (12') of said duct (3). The contact element of any one of claims 1..4, characterised in that the current contact pins (14') laterally project from the body portion (7), and are adapted for being contacted with the respective current conductors (12) when rotating the bottom plate (1). The contact element according to any one of claims 1 to 5, characterised in that the claw body (4) is provided with a rotatable core from which the current contact pins (14') project outwards in such a manner that said springs are adapted to be contacted with a respective conductor provided on the bottom of said duct (3). The contact element of claim 6, characterised in that the rotatable core is provided with a return spring which, in the relaxed condition, will direct said core in such a manner that, when inserting said claw body (4) into said wiring duct (3), the current contact pins will be situated in front of the respective current conductors, said spring being tensioned when rotating the bottom plate (1) for locking the same.

Inventors: ATTEMA GIJSBERTUS, ATTEMA, GIJSBERTUS
Applicants: LUCOM ELECTRIC B V, LUCOM ELECTRIC B.V.
Application year: 1989
Main classification: H01R25
IPC codes: H01R25