Two Circuit Track Lighting System

Abstract

A device is provided for connecting an electrical fixture to a three-conductor, two-circuit power distribution track. The device includes a housing adapted to be secured to the track containing a fixed contact adapted to engage one conductor and a movable contact adapted to be shifted to a proper position to engage either of the other two conductors. Movement of the second contact is controlled by an indicator which extends outside the housing. The indicator assumes two positions corresponding to the positions of the contact with both positions being readily visible when the device is secured to a track so as to provide a clear indication of the circuit associated with the fixture.

Description

BACKGROUND OF THE INVENTION

The present invention relates to electrical fixtures adapted to receive power from distribution tracks and more particularly to means for connecting a fixture to either of the circuits of a three-conductor, two-circuit track.

In recent years track lighting systems have gained in popularity for both commercial and residential applications. The systems consist basically of a channel-type track, the internal sides of which support elongated conductors which may be tapped at any point along their length by suitable connectors to provide power for fixtures mounted to the track. The fixtures may then be used as spotlights, accent lights or to provide general illumination for an area.

The number of fixtures which can be supported by a track is limited to a large extent by the current which the conductors can carry which generally is not greater than 20 amps. In order to increase the track capacity electrical load, it has been suggested that a second circuit, in the form of a second power conductor be introduced into the track and various schemes have developed to enable a fixture to be connected to either of the two circuits (see for example, U.S. Pat. Nos. 3,496,518, 3,559,146 and 3,613,045). In these arrangements, the power conductors are positioned on one side of the channel vertically spaced apart from each other and a common neutral return conductor is provided on the other side of the channel.

Since the two power conductors are vertically separated from each other, the associated connector requires a vertically shiftable contact which can be positioned to make electrical connection with either power conductor as required. To this end, the prior art suggests various shim arrangements designed to maintain the shiftable contact in the desired raised or lowered position. Because all the electrical interconnections between the conductors and fixture connector are made within the track channel, a major problem with such prior art connectors is that once installed, there is no way to readily determine which circuit a particular fixture is connected to. This poses both maintenance and safety problems. This is especially so where one of the power leads carries a relatively low power audio signal for speaker fixtures which may be mounted to the track and the other carries power to light fixtures mounted to the same track.

In view of the above, the principal object of the present invention is to provide an improved three-conductor, two-circuit track connector which may readily be shifted between circuits and which, when in position, gives ready, visible indication of the circuit to which an associated fixture is connected.

SUMMARY OF THE INVENTION

The above and other beneficial objects and advantages are attained in accordance with the present invention by providing an improved connector adapted to connect an electrical fixture to a three-conductor track of the type having two opposed sides with a first conductor extending longitudinally along one side and the second and third conductors spaced vertically apart from each other extending along the opposite side. The connector comprises a housing having means thereon for securing the connector to the track in locking engagement. A first contact extends from the housing adapted to engage the first conductor when the housing is locked in position. A second, vertically shiftable contact also extends from the housing. The second contact is shiftable between a first position for engagement with the second conductor and a second position for engagement with the third conductor when the housing is in locked position. Means are provided for shifting the second contact between positions and indicator means in controlling relationship with the shifting means are provided. The indicator means assumes a first, clearly visible position when the second contact is in its first position and a second, clearly visible position when the contact is in its second position.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 is a fragmentary perspective environmental view of a track lighting system incorporating the improvement of the present invention;

FIG. 2 is a perspective view of the improved connector of the present invention;

FIG. 3 is a fragmentary sectional view taken along reference lines 3--3 of FIG. 2 in the direction indicated by the arrows shown with an associated track which is also in section;

FIG. 4 is a sectional view taken along reference lines 4--4 of FIG. 3 in the direction indicated by the arrows;

FIG. 5 is a fragmentary sectional view taken along reference lines 5--5 of FIG. 2 in the direction indicated by the arrows; and,

FIG. 6 is a sectional view taken along reference lines 6--6 of FIG. 3 in the direction indicated by the arrows.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference is now made to the drawings wherein similar components bear the same reference numeral throughout the several views. Accordingly, in FIG. 1 there is shown a track lighting system 10 installed on a wall or ceiling 12. The system comprises an elongated track 14 secured to the ceiling by suitable bolts 16 and capped at its ends by closures 18.

Referring briefly to FIG. 3, it will be noted that track 14 is formed with a series of internal flanges. Accordingly, on one side 20 of track 14 the internal flanges support an insulator 22 which in turn carries a single conductor 24. On the opposite side 26 of track 14 the flanges support insulator 28 which in turn carries a pair of conductors 30 and 32 spaced vertically apart from each other. The two conductors 30 and 32 may be connected to separate power supply circuits or, one of the circuits may be used to carry power to light fixtures while the other circuit carries audio signals to appropriate speakers. The single conductor 24 provides a common neutral return for both active conductors 30 and 32. The present invention is particularly adapted to the latter arrangement since any inadvertent connection of a speaker to a power line could cause irreparable damage to the speaker. The three conductors 24, 30 and 32 extend along substantially the entire length of the track permitting contact to be made at any point along their length.

The track 14 further includes internal flanges 34 (a and b) and 36 (a and b) which cooperate with mating parts 38 and 40 of a connector 42 to secure the connector to the track in locking engagement. The distance between flanges 34a and 34b differs from that between 36a and 36b as do the corresponding dimensions of mating parts 38 and 40 so that the connector is polarized in the manner in which it may be mounted to the track. That is, mating part 40 only fits between flanges 36a and 36b and will not fit between flanges 34a and 34b.

Referring to FIGS. 1 and 2, the connector device 42 is shown comprising an elongated housing 44 having a bottom opening 46 to receive a suitable fastener to secure a fixture 48 and through which a power lead can pass and a side opening 47 for a toggle switch. A locking tongue 52 extends from the top surface 54 of the housing. The tongue 52 is dimensioned to fit between the bottom flanges 34b and 36b of the track and serves to prevent rotation of the housing once in position. As shown in FIG. 5, a tab 56, which extends outside the housing is connected to the tongue and permits the tongue to be retracted into the housing during installation whereafter a biasing spring 58 serves to urge the tongue outwardly to lock in position between the bottom track flanges and thereby lock connector 42 in position.

As also shown in FIG. 2, the mating parts 38 and 40 of the connector extend radially outwardly from opposite sides of a central shaft 60 which in turn extends upwardly through the top surface 54 of the housing. The center of shaft 60 is hollow thereby providing access to the interior of the housing. A pair of contacts 62 and 64 extend outwardly from the opening in the top of the shaft. Each of the contacts has a 90.degree. bend adjacent the top end thereof defining top portions extending parallel to mating parts 38 and 40 and away from each other. Accordingly, contact 62 top portion 66 extends radially outwardly parallel to part 38 and contact 64 top portion 68 extends radially outwardly parallel to part 40. Contact 62 is coupled through connector 57 to wire 59 which along with a similar wire (not shown) connected to contact 64 comprises the power lead 50 which feeds fixture 48 from conductors 24 and 30 or 32.

Still referring to FIG. 3, it can be seen that contact 62 is provided with a dimple 63 which fits in a recess 65 on the inside wall of shaft 60. This serves to fix the contact with respect to the shaft. It should also be noted that the top portion 66 of contact 62 is designed to make electrical contact with conductor 24 when the connector is in position. Contact 64 is fixed to an elongated rod 72 positioned for movement within the base of shaft 60. To this end, rod 72 is formed with a longitudinal slit extending downwardly from its top end and the body portion of contact 64 is positioned in the slit. A stake 70 is formed in the contact which engages a recess 71 in rod 72 and thus firmly secures contact 64 to the rod. The top end 68 of contact 64 is bent over the top of the rod extending away from contact 64 and designed to make contact with conductors 30 or 32 as will be described forthwith. Rod 72 is formed of a plastic insulating material and thus serves to provide insulation between the contacts over their entire lengths.

As stated, rod 72 is disposed for vertical movement within the housing with its top end adapted to extend through the opening in the top of the shaft. When the rod is in its raised position and the connector is secured to a track, contact 64 top portion 68 is in position to make electrical contact with the upper conductor 32 of the track as shown in solid line in FIG. 3. When the rod is in its lowered position, the top portion of the contact is in position to make electrical contact with the lower conductor 30 of the track as shown in phantom in FIG. 3. In both positions, rod 72 fully insulates the contacts 62 and 64 from each other.

Rod 72 is formed with an integral tab 74 which extends out horizontally. The tab 74 rides in a slot 76 provided in a horizontally shiftable indicator bar 78 the end sections 80 and 82 of which are adapted to pass through openings 81 and 83 in the ends 84 and 86 respectively of housing 44 as shown in FIGS. 1, 2 and 6. Referring to FIG. 4, it can be seen that the slot 76 of bar 78 includes an inclined portion 88 the height and depth of which are such as to be able to receive tab 74. Bar 78 is constrained to horizontal movement by the housing top surface 54 in combination with the surfaces of housing ends 84 and 86 surrounding openings 81 and 83. In addition, a ferule 90 secured in position by screw 92 helps maintain alignment of bar 78 and keeps tab 74 captive in slot 76 by limiting horizontal movement of the bar. Screw 92 further cooperates with screw 94 in securing the top surface 54 of the housing in position.

Since tab 74 is captive in slot 76, as bar 78 is shifted back and forth, the tab will ride up and down inclined portion 88 of the slot following the incline of the slot which serves as a cam. This movement of the tab causes a vertical movement of the connected plastic part 72 and the attached contact 64. The slot is suitably inclined so that the vertical movement of rod 72 corresponds to the vertical distance between conductors 30 and 32. Thus, the horizontal position of bar 78 determines the vertical position of rod 72 and hence determines which of the vertically spaced conductors 30 or 32 will be contacted by the top portion 68 of contact 64.

The bar is dimensioned and the inclined portion of slot 88 is positioned so that a portion of bar 78 extends out of one end of the housing only when the contact 64 is in its fully raised position and the bar extends out of the other end of the housing only when the contact is in its fully lowered position. Further, since the connector 42 is polarized in the manner described before to fit into the track in a particular orientation, the position of bar 78 and more specifically a determination of which end 80 or 82 extends from the housing is indicative of which of the conductors 30 or 32 is electrically connected to contact 64 and hence which circuit is feeding the associated fixture. If desired, the ends of bar 78 may be color coded and elongated to facilitate visual determination of the active circuit.

Thus, in accordance with the above, the aforementioned objectives are effectively attained.

Claims

Having thus described the invention, what is claimed is:

1. A device adapted to connect an electrical fixture to a three-conductor track of the type having two opposed sides with a first conductor extending longitudinally along one side and second and third conductors spaced vertically apart from each other extending along the opposite side, said device comprising: a housing; means on said housing for mechanically securing said device to said track; a first contact extending from said housing adapted to engage said first conductor when said housing is in said secured position; a second contact extending from said housing, said second contact being vertically shiftable between a first position for engagement with said second conductor and a second position for engagement with said third conductor; means for switching said second contact between positions; and indicator means extending from said housing in control relationship with said switching means, said indicator means assuming a first indicator position when said second contact is in its first position and a second indicator position when said second contact is in its second position, both of said indicator positions being readily visible when said housing is locked to said track.

2. The invention in accordance with claim 1 wherein said second contact is constrained to vertical movement within said housing, said indicator means comprises a bar disposed for horizontal movement through said housing, and said switching means comprises cooperating means coupled to said second contact and horizontal bar for translating horizontal movement of said bar to vertical movement of said contact.

3. The invention in accordance with claim 2 wherein said translating means comprises a cam mounted to one of said bar or second contact and a follower mounted to the other of said bar or second contact.

4. The invention in accordance with claim 3 further comprising a rod coupled to said second contact and adapted to move therewith, said rod being interposed between and insulating said first and second contacts from one another.

5. The invention in accordance with claim 4 wherein said cam comprises an inclined slot carried by said bar and said follower comprises a tab extending from said rod and constrained to ride in said slot.

6. The invention in accordance with claim 2 wherein said bar has a first end section adapted to extend through one end of said housing only when second contact is in its first position and an opposite end section adapted to extend through an opposite end of said housing only when said second contact is in its second position.

7. The invention in accordance with claim 6 wherein said bar end sections are color coded.