A current supply device for a cable duct

Abstract: Current supply device for a cable duct comprising a case-like channel track (3) forming a cable space (4) for cables and cords (12) and having a front plate provided with an installation slot (6) for outlet boxes (2). To simplify the electrical connection and attachment of the outlet box, its connecting means form a contact pin (14) with fingers (15) arranged to make contact with a conductor rail (9) positioned in the cable duct, and a frame (13) forms a socket outlet, whereby the contact pin projects from the frame in such a manner that when the frame is inserted to the installation slot of the channel track into the cable space, the contact pin extends into the conductor rail (9) into contact with electrical conductors (11) provided in the conductor rail.

Description: This invention relates to a current supply device for a cable duct comprising a case-like channel track forming at least one cable space for cables and cords and having a front plate provided with an installation slot opening into the cable space for current supply devices and other similar outlet boxes, whereby the current supply device comprises a frame provided with electrical equipment and arranged to be installed in the installation slot of the channel track, and means for connecting the equipment to electrical conductors in the cable duct. It is known from the prior art to use a cable duct arrangement in apartments, offices, staircases and the like, the required cables and cords for electricity, telephone, antenna, etc., being encased in a cable duct extending along a desired wall/desired walls. Only socket outlets and other outlets and connections mounted in the front plate of the cable duct for use at various points are outwardly visible. All cords, outlet boxes and installation equipment are invisible within the case-like channel track. The outlet boxes are attached to the channel track in such a way that their cover plates are positioned substantially flush with the cover of the installation slot. The outlet boxes may be installed side by side in contact with or spaced apart from each other. Openings possibly remaining between the boxes are covered with cover plates of suitable size. Today all cables and cords in a cable duct are positioned loosely in the cable space of the channel track either on the bottom of the cable space, in its different compartments or on separate shelves. For connecting socket outlets, junction boxes and other required outlet boxes, the respective electrically insulated cable or cord has to be drawn out from the cable space and connected electrically to the socket outlet, box, etc., at each desired point of the cable duct. This makes the installation and connection of outlet boxes difficult and time-consuming, and a great number of different tools are frequently needed. In addition, only an electrician can carry out the installation. It has been suggested previously to replace a round power cable with a band-like cable and to provide the outlet boxes with special connectors which cut through or penetrate into the insulation of each conductor to be connected in such a way that the conductor need not be separately revealed at the connection point. In such an arrangement, the frame of the outlet box is provided with connecting means which clamp the band-like cable in a jaw-like manner at a desired point in the channel track. This does make the connection of outlet boxes somewhat easier; however, an electrician is still needed for the installation and connection of the boxes. This invention relates to an outlet box including electrical equipment, which is called a current supply device below because it is primarily intended to be connected to a power cable of the cable duct to supply current e.g. to a socket outlet, to the connector of an outlet box or the like. Even though the invention will be described in the following mainly in connection with a power cable application, the invention may also be applied when connecting other cables and cords in the cable duct. WO87/01524 discloses an electrical supply rail system for a room comprising elongate sections of plastics material having a rear wall to be placed against the room wall, and a front wall with one or more longitudinal installation slots communicating with longitudinal grooves, within the plastic section which have side walls parallel with the front and rear walls of the section and which open downwardly towards the installation slot. Longitudinally extending electrical conductors are carried within these grooves on the side wall of each groove nearer the front wall of the plastics section. A connector device for use with the supply rail has a pin adapted to be extended through an installation slot, and contact fingers extending radially from the pin so that the pin can be inserted in the installation slot with the contact fingers extending in the longitudinal direction of the installation slot and the connector device turned through 90° about the pin axis to bring the contact fingers into the grooves opposite the conductors. A spring-biased button at the end of the pin urges the pin, and thus the contact fingers, in the direction away from the rear wall to push the contact fingers into contact with their respective conductors. The object of the invention is to provide a current supply device, which avoids the above-mentioned disadvantages and can be connected as such to the conductors of the cable in the supply rail with a few simple movements of the hand and is ready for use as an outlet immediately after connection. Another object of the invention is to provide such a current supply device in combination with a channel track incorporating a conductor rail. According to one aspect of the invention, there is provided the combination of a current supply device with an elongate member having an installation slot extending longitudinally along the member, a longitudinally extending channel within said member opening toward said installation slot, the side walls of said channel carrying longitudinally extending exposed conductors, the current supply device comprising a frame, a pin extending from the frame along a pin axis and contact elements extending from the pin perpendicular to the pin axis, characterised in that said elongate member is in the form of a channel track having a back plate, a front plate spaced from said back plate to define a space between said front plate and back plate, and connecting walls connecting said front and back plates, the front plate being provided with said installation slot extending longitudinally along the track, said channel being provided by a conductor rail positioned in said space, and characterised in that the frame is a case-like frame which is elongate along a case axis, and which has said pin extending from one end of the frame, said pin axis being perpendicular to said case axis, said contact elements extending from said pin perpendicular to said case axis, said frame being of substantially uniform depth along its length, measured parallel with said pin axis, which depth is no greater than the width of said installation slot, and being of a width perpendicular to said case axis and to said pin axis, which is no greater than said depth, and the maximum dimension of the cross-section of the frame in at least a part of the frame not being greater than the depth of the frame, and the end surface of the frame nearer the pin not being further distant from the axis of the pin than the distance from the centre line of said channel to said back plate. According to another aspect of the invention, there is provided a current supply device for a channel track incorporating a conductor rail, the device comprising a frame, a pin extending from the frame along a pin axis and contact elements extending from the pin perpendicular to the pin axis, characterised in that the frame is a case-like frame which is elongate along a case axis, and which has said pin extending from one end of the frame, said pin axis being perpendicular to said case axis, said contact elements extending from said pin perpendicular to said case axis, said frame being of substantially uniform depth along its length, measured parallel with said pin axis, and being of a width perpendicular to said case axis and to said pin axis, which is no greater than said depth, the maximum dimension of the cross-section of the frame in at least a part of the frame not being greater than the depth of the frame, and the end face of the frame near the pin not being further distant from the axis of the pin than half of the width of the frame. The invention is based on the idea that the means for connecting the frame of the current supply device to the conductors in the conductor rail are formed in such a way that they come into contact with the conductors at the same time as the frame is otherwise installed in position in the installation slot of the channel track. In this way, the installation of the current supply device does not require any special connecting measures. With the preferred form of current supply device, the connecting means of the current supply device are automatically positioned in contact with the conductors of the conductor rail when the frame of the current supply device is positioned in its operating position in the installation slot of the channel track. Current supply devices developed for conductor rails are disclosed e.g. in Finnish Patent Specifications 44019 and 47236 (push/pull contacts), GB Patent Specification 1 329 663 (turnable contacts) and GB Patent Specification 1 000 925 (pivotable contacts). The conductors to be connected to the current supply device are arranged to extend in the said space of the channel track of the cable duct similarly as a conductor rail known per se, whereby it is possible to use bare conductors which are ready to be connected at any point in the channel track. A conductor rail of this type is disclosed e.g. in Finnish Patent Specification 44019. The current supply device of the invention can be connected to the conductors in the channel track of the cable duct without any installation or connecting measures which would require an electrician. If required, the user may himself carry out the connection and fastening to the channel track of the cable duct by a simple movement of the hand. An embodiment of the invention will be described in greater detail in the following with reference to the attached drawings, in which: Figure 1 is a perspective view of a cable duct arrangement in which current supply devices according to the invention are used; Figure 2 is an enlarged cross-sectional view of the channel track of the cable duct; Figure 3 is a perspective view of one embodiment of the current supply device to be used in the cable duct; and Figure 4 is a perspective view of the different steps for connecting the current supply device of Figure 3 to the cable duct. The cable duct arrangement shown in Figure 1 of the drawings mainly comprises a cable duct 1 and a number of outlet boxes 2 provided with electrical equipment and cover plates, some of the outlet boxes being formed as current supply devices of the invention. The cable duct comprises a metallic, case-like channel track 3 having a rectangular cross-section. The channel track comprises an internal cable space 4 and an installation slot 6 in a front plate 5, the installation slot being covered with an openable cover plate 7. Both longitudinal edges of the installation slot are formed as fastening edges 8 for the outlet boxes and current supply devices. A conductor rail 9 is provided in the top portion of the cable space of the channel track; in this specific case, the conductor rail replaces the power cable of the cable duct. The conductor rail comprises an insulation strip 10 and a number of current conductors 11 embedded in it. The current conductors are grouped so as to be positioned on the inner surfaces of the front and back plates of the channel track. Other cables and cords 12 in the cable duct are positioned in the bottom portion of the cable space of the channel track and connected to the connectors of the corresponding outlet boxes 2', such as telephone and antenna outlets. Figure 3 of the drawings shows an outlet box 2 suitable for the conductor rail of the cable duct. In this specific case, the outlet box is a current supply device forming a base for a socket outlet. The current supply device comprises a case-like frame 13 and a contact pin 14 projecting from one narrow side of the frame. Two contact fingers 15 project in opposite directions from the contact pin. The contact finger intended for a phase conductor of the conductor rail is axially adjustable in the contact pin. The frame is provided on both sides with pairs of openings 16 for contact plugs, and required phase and neutral conductors and connections to the contact fingers are provided within the frame. The frame and the contact pin of the current supply device are dimensioned and shaped according to the height of the installation slot of the channel track and the position and dimensions of the conductor rail in such a way that the current supply device can be connected electrically to the conductor rail and fastened to the channel track as shown in Figure 4. The current supply device is first inserted in a horizontal position in the installation slot of the channel track with the pin end ahead so as to be pressed against the back wall of the cable space, step A in Figure 4. Thereafter the frame is turned through 90° into a vertical position in such a manner that the frame is still positioned perpendicularly to the channel track and the contact pin points upwards. The contact pin thereby extends into the conductor rail between the two current conductor groups. A retaining shoulder 17 on the bottom of the frame is positioned behind the lower edge of the installation slot, keeping the frame in position in the installation slot of the channel track, step B. The frame is then turned through 90° in a sideward direction, so that the whole frame is displaced within the channel track and the front surface of the frame is positioned substantially flush with the front plate of the channel track. In this position the contact fingers are turned towards the current conductors into contact with the corresponding conductors. A latch 18 at the other end of the frame is now displaced into a locking position, in which it is positioned behind the upper edge of the installation slot, step C. Finally, a cover plate 19 is fastened to the frame, step D. Grounding bows in the cover plate are provided with a prod which makes contact with a grounding strip 20 in the frame, and the grounding strip 20 in turn makes contact with a grounding strip 21 in the back wall of the channel track. To enable the frame to be turned within the installation slot, the frame is provided with notches 22. The drawings and the description related to them are only intended to illustrate the idea of the invention. In its details, the cable duct of the invention may vary within the scope of the claims. In the embodiment shown in the drawings, the current supply device is provided with a cylindrical contact pin attached rigidly to the frame. The contact member of the current supply device may also be arranged to be pivotable or turnable with respect to the frame, as is known per se from British Patent Specifications 1 000 925 and 1 396 058. The contact member of the current supply device may also be plate-like, in which case the contact fingers are turnable or displaceable into different positions, as described e.g. in Finnish Patent Specifications 44019 and 47236 and British Patent Specification 1 329 663. In the embodiment shown in the drawings, the conductor rail is of the type disclosed in Finnish Patent Specification 44019. If required, the current conductors may be grouped in some other way, whereby the corresponding ing grouping is taken into account in the structure of the current supply device. Even though it seems to be advantageous to position the conductor rail in the top portion of the cable space, whereby there is no danger of cables and cords or other foreign objects falling on the conductor rail, the conductor rail may be positioned in some other portion of the cable space, if required. Accordingly, the current supply device may deviate in type and structure from that shown in the figures, depending on the structure, shape and dimensions of the cable duct in each particular case. In place of the disclosed socket outlet structure, the frame of the current supply device may be formed e.g. as a connector for connecting an extension cable.

Claims: The combination of a current supply device (2) with an elongate member (3) having an installation slot (6) extending longitudinally along the member, a longitudinally extending channel (9) within said member opening toward said installation slot, the side walls of said channel (9) carrying longitudinally extending exposed conductors, the current supply device comprising a frame (13), a pin (14) extending from the frame (13) along a pin axis and contact elements (15) extending from the pin (14) perpendicular to the pin axis, characterised in that said elongate member is in the form of a channel track (3) having a back plate, a front plate (7) spaced from said back plate to define a space (4) between said front plate and back plate, and connecting walls connecting said front and back plates, the front plate being provided with said installation slot (6) extending longitudinally along the track, said channel being provided by a conductor rail (9) positioned in said space (4), and characterised in that the frame (13) is a case-like frame which is elongate along a case axis, and which has said pin (14) extending from one end of the frame (13), said pin axis being perpendicular to said case axis, said contact elements (15) extending from said pin (14) perpendicular to said case axis, said frame (13) being of substantially uniform depth along its length, measured parallel with said pin axis, which depth is no greater than the width of said installation slot, and being of a width perpendicular to said case axis and to said pin axis, which is no greater than said depth, and the maximum dimension of the cross-section of the frame (13) in at least a part of the frame (13) not being greater than the depth of the frame (13), and the end surface of the frame nearer the pin not being further distant from the axis of the pin than the distance from the centre line of said channel to said back plate. The combination of claim 1 wherein the spacing of said front plate (7) of the channel track from the centre line of said channel (9) corresponds with the spacing of the plane of a front surface of the frame (13) from said pin axis, whereby said front surface of the frame (13) is positioned substantially flush with the front plate (7) of the channel track (3) when the frame (13) has been swung into said slot with said pin in said channel and said pin axis perpendicular to said slot. The combination of claim 1 or claim 2 wherein a grounding strip is provided within the channel track extending longitudinally along the channel track, and the frame (13) has a grounding strip (20) which contacts the grounding strip (21) in the channel track (3) when the case (13) is inserted in the installation slot (6) of the channel track. The combination of claim 1 wherein the frame (13) can be turned through 90° in either direction from the position in which the pin (14) is in said channel (9) with the pin axis perpendicular to said slot (6) and the casing axis perpendicular to said front and back plates. A current supply device (2) for a channel track (3) incorporating a conductor rail, the device (2) comprising a frame (13), a pin (14) extending from the frame (13) along a pin axis and contact elements (15) extending from the pin (14) perpendicular to the pin axis, characterised in that the frame (13) is a case-like frame which is elongate along a case axis, and which has said pin (14) extending from one end of the frame (13), said pin axis being perpendicular to said case axis, said contact elements (15) extending from said pin (14) perpendicular to said case axis, said frame (13) being of substantially uniform depth along its length, measured parallel with said pin axis, and being of a width perpendicular to said case axis and to said pin axis, which is no greater than said depth, the maximum dimension of the cross-section of the frame (13) in at least a part of the frame (13) not being greater than the depth of the frame (13), and the end face of the frame near the pin not being further distant from the axis of the pin than half of the width of the frame. A current supply device according to claim 5 including a grounding strip (20) extending around said one end of the frame (13). The combination of any of claims 1 to 4 or the current supply device of claim 5 wherein at least one contact finger (15) is adjustable in position along the pin axis. The combination of claim 4 or the current supply device of claim 5 wherein a socket outlet is provided on two opposite sides of said frame (13).

Inventors: VALTONEN RAINER, VALTONEN, RAINER
Applicants: NORDIC ALUMINIUM OYJ, NORDIC ALUMINIUM OY
Application year: 1991
Main classification: H01R25
IPC codes: H01R25