Luminaire pendant system

[00002] This application claims the benefit of U.S. Provisional Application No. 60/350,657, filed Jan. 22, 2002.

[00003] Not applicable.

[00004] 1. Field of the Invention

[00005] This invention relates to pendant suspension systems for luminaires, and more particularly to a continuously adjustable cable suspension system for a suspended linear style track lighting luminaire having two suspension points at either end of the luminaire.

[00006] 2. Description of Prior Art

[00007] Suspended linear style track lighting luminaires are typically provided with fixed length rigid stems for attaching the luminaries to lighting track. For example, ½ inch diameter pipe is often used for the stems for such pendant mounting type luminaires. However, vertical height adjustment of such rigid pendant systems is limited by the available lengths of the fixed length stems, or requires cutting and rethreading the stems to the desired length. Further, once installed, additional vertical height adjustment of the luminaire requires replacement of the stems with stems of the desired length.

[00008] Additionally, since track lighting luminaires are typically aimable, the pendant mounting system requires balance and stability to counteract the moment arms created when pivoting the luminaire for aiming.

[00009] Thus, it is an object of the present invention to provide a suspended linear style track lighting luminaire with a continuously adjustable pendant system for attaching the luminaire to the lighting track.

[00010] It is a further object of the invention to provide a pendant system which allows vertical height adjustment of the luminaire after installation without addition or replacement of any of the pendant system components.

[00011] It is yet a further object of the invention to provide a pendant system which provides balance and stability to the luminaire to counteract the moment arms created when pivoting the luminaire for aiming.

[00012] These and other objects are met through a pendant system having twin suspension assemblies, with each assembly having a track adapter body for engaging a lighting track, a flexible support element gripper attached to the track adapter body, and an elongated flexible support element having two ends, where a first end is held by the track adapter body and the second end is adjustably held by the flexible support element gripper, where each of the flexible support elements forms an adjustable length loop from which each end of the luminaire may be suspended.

[00013] The objects are further met by a pendant system having rotation housings rotatably connected each end of a luminaire, defining an axis about which the luminaire may rotate, where each rotation housing has a channel through which a flexible support element loop suspends the luminaire. Each flexible support element loop is formed from a flexible support element having two ends, with both ends being held by a suspension assembly for attaching to a lighting track.

[00023] FIGS. 1 and 7-9 show a suspended linear style track lighting luminaire 10 attached to a lighting track 12 by a pendant system 14 of the present invention. The pendant system 14 is comprised of twin suspension assemblies 16 which engage the lighting track 12 and provide support to each end of the luminaire 10. Each suspension assembly 16 has a track adapter 18 and a cable 20. Each cable 20 is held at both ends by the respective track adapter 18, thus forming a loop. Each loop then supports an end of the luminaire 10.

[00024] The cable of the preferred embodiment of the invention is a {fraction (1/32)} inch stainless steel aircraft type cable having 7×7 construction (7 twisted strands of 7 twisted strands), which provides the strength, resistance to the elements and appearance desired for the pendant system application. However, those of skill in the art will recognize that other equivalent flexible support elements may be substituted without altering the spirit or the scope of the invention described herein.

[00025] As also shown in FIGS. 1 and 7-9, a rotation housing 22 extends outward from each end of the luminaire 10. The luminaire 10 hangs by the rotation housings 22 from the loops of each cable 20.

[00026] As shown in FIG. 9, a channel 24 is formed through each rotation housing 22. In the embodiment shown, the channels 24 are U-shaped and have entry points located along opposite sides of each rotation housing 22. Each cable 20 runs through the respective channel 24 and a cover 26 closes a side of the channel 24 in order to hold the cable 20 in the channel 24. Further, each channel 24 is large enough to allow the corresponding cable 20 to slide freely within the channel 24 so that the luminaire 10 will slide along the cables 20 to the bottom of the loops. Thus, both ends of each cable 20 support each end of the luminaire 10 in a balanced manner. Further, since the luminaire will always slide to the bottom of the loops, the pendant system is suitable for use with sloped and other ceiling configurations.

[00027] The rotation housing 22 separates the entry points into each channel 24 approximately the same distance that the ends of the cable are separated by the track adapter 18 creating a two point suspension at each end of the luminaire 10. This two point suspension provides balance and stability to the suspension of the luminaire 10 by creating multiple axes of rotation which serve to resist any rotational moments that may be created about any one of the axes alone.

[00028] Each rotation housing 22 is rotatably connected to the luminaire 10 through an eyelet type rotation joint which allows free rotation of the luminaire about an axis defined by the rotation housings 22 located at each end of the luminaire 10. Thus, the luminaire 10 may be rotated about the rotational axis for aiming the light output of the luminaire 10 a full 360 degrees around the rotational axis. In practice, rotation stops are provided within the eyelet type rotation joint in order to prevent rotation through an arc greater than 360 degrees, and damage to the electrical wiring within the luminaire 10.

[00029] Also shown in FIG. 1 is a power adapter 28 and the power cord 30 which supply power from the lighting track 12 to the luminaire 10.

[00030] As shown in FIGS. 2 through 6, each track adapter 18 has a body 32 and a cover 34.

[00031] As best seen in FIGS. 2 and 6, each track adapter body 32 has a track adapter head section 36, an upper flange 38, a cable take-up section 40, and a base section 42 which retains the ends of the cable 20. Each track adapter head section 36 has track engaging ears 44. Each base section 42 has a channel 46 which accepts and holds a hex nut 48 in a stationary position. Aligned with and under the hex nut 48, each base section 42 further has a first hole 43. Spaced from each first hole 43, each base section 42 has a second hole 45. A flexible support element gripper, such as a cable lock device 50, having a threaded cylindrical body is threaded into each hex nut 48 through the corresponding first hole 43. A first end 51 of each cable 50 is fed through the corresponding second hole 45 and held from being pulled through the hole by a copper stop 52 crimped thereto. A second end 49 of each cable 20 is fed through and held by the corresponding cable lock device 50.

[00032] Turning now to FIGS. 2 and 3, the track adapter body 32 is attached to the track 12 by inserting the track adapter head 36 into the central channel 53 of the track cavity and rotating the track adapter body 90 degrees such that the track engaging ears 44 mechanically engage the rails 55 of the track 12. Thus, the track adapter body 32 is securely held by the track 12.

[00033] As shown in FIG. 3, following attachment of the track adapter body 32 to the track 12, the cable lock device 50 may be utilized to adjust the vertical height of the luminaire 10. The cable lock device 50 allows the cable 20 to be drawn through in one direction while preventing it from being pulled back through in the other direction unless a release mechanism is activated.

[00034] For instance, the cable lock device 50 of the embodiment shown herein is commercially available as Reutlinger Grip Lock Systems™ part number 12-M8, which utilizes a ball bearing mechanism inside of the device to wedge against the cable 20 when a force is applied to pull the cable out of the device, while easing when the cable is pulled into the device or the plunger 54, acting as a release mechanism, is depressed. One of skill in the art will recognize that other cable types and cable lock devices may be utilized without departing from the spirit or the scope of the invention described herein.

[00035] Thus, as shown in FIG. 3, the first end 49 of the cable 50 may be pulled through the cable lock device 50 to shorten the amount of cable in the loop and raise the vertical height of the luminaire 10. The luminaire 10 will balance itself at the bottom of the loop via the free movement of the cable in the rotation housing channel 24 (FIG. 9). Thusly, the vertical height of the luminaire is continuously adjustable for installation of the luminaire 10 as desired.

[00036] Further, as shown in FIG. 4, excess cable 10 may be wrapped around the take-up section 40 for future adjustment of the vertical height of the luminaire 10. V-shaped grooves 56 are supplied on either side of the track adapter body 32 for use as a cleat to lock the cable 10 in place. Thus, securing the cable 10 in the V-shaped grooves 56 will prevent an unintended release of the cable lock device 50 by an accidental depression of the spring loaded plunger 54.

[00037] The cover 34 slides up the cable 10 and over the track adapter body 32 and mates with the track adapter upper flange 38 to enclose the mechanical components of the track adapter body 32, thus giving the track adapter 18 a finished and aesthetically pleasing appearance.

[00038] This detailed description of the invention, including specific elements and configurations of elements, shall not be construed as a limitation of the invention, as it will be readily apparent to those skilled in the art that design choices may be made changing the configuration of the luminaire pendant system without departing from the spirit or scope of the invention. For instance, alternative ceiling interface arrangements, such as a fixed mount other than with a lighting track, or use of the pendant system with a luminaire other than a linear fluorescent track luminaire, would be equivalent embodiments to the embodiment of the invention disclosed herein.