Lighting system, as well as current conductor rail and cur¬ rent collectors to be used with it
The invention relates to a lighting system, comprising a current conductor rail for supply of electric current and one or more lighting units, each having an armature consis¬ ting of a hollow, rigid, conductive armature tube with an insulated inner conductor led through it, and with the outer end of each fitting tube being provided with a current collector mountable to the current conductor rail, said current collector having a conductive outer rail being U-shaped in cross-section and having hook-shaped end ridges turned inwardly, and a conductive inner rail exten¬ ding across the bottom of the outer rail and being insulated in relation to it, and said current collector having a conductive contacting body being provided with a central bore and being slidable with tolerance and rotatable over the armature tube; a metal coil spring slid over the armature tube and on contact being supported in the contacting body at one side and against a widened end flange rim of the armature tube at the other side; and a rounded contact head contacting the end flange rim with intermediate insulation and being connected to the inner conductor of the armature, the contacting body having an insert portion narrower than the longitudinal opening between the turned-back end ridges of the outer rail of the current conductor rail, said insert portion having its end in one direction double-sided- ly widened by opposing contact wings, to a length larger than the width of the longitudinal opening and slightly narrower than the distance between the U-legs of the outer rail.
Such a system is known from the European Patent Appli¬ cation No. 640 309, in particular Fig. 10 thereof, which illustrates a current collector being connected to the current conductor rail. With this known system, contacting and mounting the current collector can take place in a simple way by sliding the current collector by the contact wings in longitudinal direction of the contact gap between the turned-back end ridges of the outer conductor and pus-
hing them against the force of the spring until the contact head (133) presses against the inner rail (113), and both contact wings (132) are situated beneath the end ridges (122) of the outer rail. By subsequently performing a quar- ter of a turn and releasing, the contact wings will contact the end ridges of the outer rail, and the contact will have been established. Since such a contact does not guarantee a proper fastening, particularly not with the intended appli¬ cation in which the current conductor rail has its contact opening to the side, additional provisions have been made, namely the inner rail has been designed U-shaped in cross- section in order to more or less enclose the contact head, and the rounded extremities of the hook-shaped end ridge of the outer rail engage in corresponding grooves made in the respective contact wings, in order to obtain both the con¬ tact at that point and a locking with a view to mounting the armature to the rail.
However, such a system has a number of important disad¬ vantages. Since the neck of the insert portion of the moun- ting body is of relatively narrow design with very wide tolerance in the plug-in opening, particularly with the lateral application shown, a torque is exerted that will result in the fact that the lower contact wing will be pushed out of its contact with the end ridge of the outer rail, which will make the fastening relatively wobbly, and furthermore can lead to contact interruption. In order to counteract this, the inner rail has been designed in U- shape, yet since the contact head lies pressed in said U- rail with a certain tolerance, sliding can occur here too, which could lead to contact reduction or contact interrupt¬ ion.
Since such an "open rail" system is a low voltage system, such contact malfunctions are a very critical factor. Fur¬ ther, the necessity of a U-shaped inner rail renders the device unnecessarily more complicated and expensive, and the choice of the narrow socket neck limits the size of the coil spring, so that in fact one has to work with springs that are too weak. Another point is, that the contact between the rounded end ridges and the grooves in the contact wings will not lead to an optimal contact, particularly not because of
the fact that during mounting, the rounded hook ridges of the end ridge of the outer rail will be slightly bevelled by scraping, so that contact with the slots in de contact wings will be deteriorate (flat against round). The object of the invention is to eliminate these disadvantages and design the system in such a way, that a good contact and good fastening between current collectors and current conductor rail will remain guaranteed at all times. To that end, the invention provides for a lighting system as defined in the preamble, characterized in that the insert portion fits closely into the longitudinal opening between the turned-back end ridges of the outer rail, and that in the U-shaped outer rail of the current conductor rail, opposite inner ridges are formed beneath the end ridges at such a distance, that the contact wings of the insert portion of the contact body fit closely into the intermediate space between the end ridges and the inner ridges. With the invention, on contacting, the contact wings are so to speak enclosed in sections, defined by the end ridges and inner ridges, which in itself already guarantees a reliable grip. Further, it is an advantage that contacting the wings through grooves can be completely left out, since these are superfluous with the invention. The roundings of the hooks of the end ridges of the outer rail can further be efficiently polished, so that a good, wide contact surface will be obtained between the contact wings and the end ridge. A further advantage lies in the fact that with such a construction, the U-shape of the inner rail can be left out and said inner rail can be manufactured simply and cheap as a strip, since the fastening of the wings between the inner ridges and the end ridges, in combination with the contact- ing body insert portion fitting closely in the socket ope¬ ning, guarantees an almost immobile grip.
Efficiently, the embodiment can be such, that the inner ridges are turned back in hook-shape and the inner rail is fixed to an insulation U-shaped in cross-section and being held between the bottom of the outer rail and the turned-
back inner ridges.
In order to optimize the grip of the contact wings, c.q. the fastening of the current collector on the current conductor rail, the invention further provides for, that the insert portion of the contacting body opens into a widened part forming a bearing surface, with the distance between the contact wings and said bearing surface substantially corresponding to the ridge thickness of the end ridges of the outer rail. Owing to this, the end ridges of the outer rail are clasped almost completely, as a consequence of which any lateral deflection as a result of torque is exclu¬ ded. Very efficiently, the embodiment can be such, that said widened part has a round shape, so that the bearing surface acts as an indicating surface at the same time. Therefore, if one presses the current collector in the current conduc¬ tor rail, one alway achieves the proper position for rota¬ ting the contact wings, namely as soon as the bearing surfa¬ ce presses against the outer ridge of the rail.
According to the invention, the contact wings have their ends efficiently rounded-off, in order to facilitate the quarter turn within the U-shaped current conductor rail.
Further, the invention provides for a current conductor rail as described above, as well as for current collectors to be used with it. Here, a great advantage is the fact, that because of their relatively robust dimensions (an insert portion as wide as possible), the current collectors according to the invention can easily be manufactured inte¬ grally. At the same time, this robust embodiment implies that one can choose the coil spring to be used from a wide variety of coil springs.
The invention will be explained further by means of an exemplified embodiment. In the drawing:
Fig. 1 shows in cross-section a current collector according to a lighting system of the invention mounted in a current conductor rail;
Fig. 2 shows a plan view of the current conductor rail with current collector of Fig. 1; and
Fig. 3 shows a perspective view of the contacting body of the current collector of Fig. 1. Fig. 1 shows a rail profile of U-shaped cross-section,
that is attached to a wall. In said rail profile, a current conductor rail is placed, consisting of a conductive inner rail 2 being in the shape of a strip, and being bonded (2a) on an insulation 2b of U-shaped cross-section positioned in a conductive outer rail 3 having a U-shaped cross-section as well. Said outer rail has turned-back inner ridges 13 kee¬ ping the insulation 2b in place in downward direction. The outer rail further also has turned-back end ridges 14. Fig. 1 further shows a portion of an armature having a current collector connected therewith.
The armature has a hollow armature tube 11 of conducti¬ ve material provided with a widened end flange rim 7. An inner conductor 6 provided with an insulation 10 extends within said armature tube 11. The current collector substantially consists of three parts, namely a rounded-off contact head 4 of conductive material, lying on the widened end flange rim 7 of the armature tube 11 via an insulation 5, and connected to the inner conductor 6. The second element of the current collector is a con¬ tacting body 9 having a insert portion consisting of a neck 9a, having its diameter corresponding to the gap distance between the end ridges 14 of the outer rail 3, and contact wings 12 protruding in one direction two-sidedly. At the other side of the neck 9a there is a widened portion 9b. The contacting body 9 consists of conductive metal and is made hollow, in such a way that it can slide and rotate across the armature tube 11.
The third current collector element consists of a pressure spring 8 positioned around the armature tube, said spring being receivable in the hollow bore of the contacting body 9 rebounding against the end flange rim 7.
The contact wings 12 have a height dimension correspon¬ ding substantially with the distance between the inner ridges 13 and the end ridges 14 of the outer rail 3 of the current conductor rail, and further, the distance between the contact wings 12 and the widened portion 9 approximately corresponds to the thickness of the end ridges 14.
In fig. 1, the current collector is shown in mounted condition. This condition is achieved by pushing the current
collector - moved over a quarter turn - against the spring force of the pressure spring 8 down into the gap opening of the current conductor rail until the contact head 4 presses against the inner rail 2. By performing a quarter turn, the contact wings 12 will be subsequently rotated between the ridges 13 and 14, the rounded-off shape of the contact wings facilitating this action.
A thus fixed current collector has an excellent contact both through the current head with the inner rail 2 and through the contact wings 12 with the flat-polished lower edge of the end ridge 14. The advantageous filling of the contacting body between the inner ridges 13 and the end ridges 14 of the outer rail as well as the enclosure of said outer rail by the contacting body on the one hand causes the contact head 4 to be kept firmly pressed and centered on the strip-shaped inner rail, whereas on the other hand it is guaranteed that lateral forces or torque can not result in any deflection of the contacting body. Due to this, the current collector performs the function of both current contact member and that of fastening member in an efficient way.
According to a further embodiment, the widened portion 9b has a round shape, as consequence of which the bottom side is not only the upper supporting surface of the contac- ting body, but is also an index surface, so that on inser¬ ting the current collector into the current conductor rail, one need not look for the proper plug-in depth.
After having read the above, further variations and modifications will be apparent. - claims -