The present invention relates to luminaires for roadway lighting, and more particularly to a roadway luminaire having improved mounting adjustability and photometrics, and is easier to manufacture and assemble, as compared to conventional prior art roadway luminaires.
Luminaires with horizontally mounted lamps are generally used to illuminate roadways from a location on the side of the road or from the center if a median is present. These types of luminaires are sometimes called cobraheads since their shape resembles that of the head of a cobra.
Typically, roadway luminaires consist of a cast aluminum housing, a cast aluminum door, control gear to operate a lamp, usually a high intensity discharge lamp, an optical or reflector system to project the light in a desired distribution and direction, and a mounting means to attach it to an arm that is attached to a pole or the side of a structure.
Within the American National Standards Institute (ANSI) there is a committee, C136, which publishes standards defining some of the mechanical and electrical requirements for this type of lighting equipment. The relevant standards to this invention are: C136.2 (American National Standard for Roadway and Area Lighting Equipment—Luminaire Voltage Classification), C136.3 (American National Standard for Roadway and Area Lighting Equipment—Luminaire Attachments), C136.10 (American National Standard for Roadway and Area Lighting Equipment—Locking-type Photocontrol and Mating Devices—Physical and Electrical Interchangeability and Testing), C136.14 (American National Standard for Roadway and Area Lighting Equipment—for Elliptically Shaped, Enclosed Side-mounted Luminaires for Horizontal-burning High-intensity Discharge Lamps), and C136.17 (American National Standard for Roadway and Area Lighting Equipment—Enclosed Side-mounted Luminaires for Horizontal-burning High-intensity Discharge Lamps—Mechanical Interchangeability of Refractors).
Also, the Illumination Engineering Society of North America (IESNA) also publishes a standard defining the classifications of light patterns for a roadway luminaire which are useful to lighting practitioners in properly applying this equipment. The relevant standard is ANSI/IESNA RP-8-2005, American National Standard Practice for Roadway Lighting.
The present invention is a roadway luminaire generally including a housing and a door pivotably connected to the housing. The housing includes a rear wall having an opening sized and shaped to receive a mounting arm for mounting the luminaire thereto, a top wall extending from the rear wall and an arm receiving channel formed in the top wall adjacent the rear wall for receiving an end of the mounting arm. The channel is formed with a step arrangement having a plurality of steps ascending in order along a length of the channel. The steps permit angular mounting adjustment of the housing with respect to the mounting arm depending on which step the end of the mounting arm rests.
In a preferred embodiment, the steps have a height to permit 1.5° increments of angular mounting adjustment. The step arrangement also preferably includes eight steps including a center step. The opening in the rear wall is preferably defined by an orthogonal centerline axis and a top-most edge adjacent the top wall, wherein a plane defined between the center step of the step arrangement and the top-most edge of the rear wall opening is parallel with the centerline axis of the rear wall opening. Thus, the step arrangement preferably includes four steps on a distal side of the center step proximal the rear wall opening. The channel further preferably includes a floor extending between the rear wall opening and a first of the three steps on the proximal side of the center step.
The channel further preferably includes a stop arrangement disposed at a distal end of the channel adjacent a last step of the step arrangement opposite the rear wall opening. The stop arrangement preferably includes at least one banking pin extending above the last step of the step arrangement for engaging the end of the mounting arm to prevent further insertion of the mounting arm in the housing.
In another embodiment, the housing of the luminaire includes a unique reflector adapted to optically perform with both a flat lens and a prismatic drop lens. The reflector includes a generally spherical side wall defining an opening and terminating at a top edge opposite the opening, a concave ring portion extending from the top edge of the sidewall in a direction radially inward and in a direction back toward the reflector opening and terminating at an inner edge and a generally spherical top portion connected to the inner edge of the ring portion, wherein at least a portion of the top portion is axially sunken within the sidewall.
In another embodiment, the housing has a strike plate disposed at a forward end thereof and the door has a pocket member disposed at a forward end thereof. The pocket member includes a wall forming a passage and having two torsion spring apertures extending through the wall and communicating with the passage. A latch assembly is provided, which is insertable in the door pocket member passage. The latch assembly includes a latch member, a pivot pin removably attached to the latch member and a torsion spring engaged between the latch member and the pivot pin. The latch member has a hook end engageable with the housing strike plate and a transverse through-hole formed therethrough for removable insertion of the pivot pin. The torsion spring has two engagement ends received within the torsion spring apertures of the door pocket member when the latch assembly is inserted in the pocket member passage. In this manner, the latch member, the pivot pin and the torsion spring can be pre-assembled together prior to the latch assembly being inserted in the door pocket member.
In another embodiment, the door has a floor and a perimeter wall extending generally perpendicularly from the floor. The perimeter wall has a bottom wall portion disposed at the rearward end of the door, a top wall portion opposite the bottom wall portion and sidewall portions connecting the top wall portion and the bottom wall portion. A ballast is mounted to the floor adjacent the bottom wall portion, wherein the ballast is substantially equidistant to the side wall portions. A first electrical component is mounted to the door on a first side of the ballast and a second electrical component is mounted to the door on a second side of the ballast opposite the first side.
In a preferred form of this embodiment, the ballast is also mounted to the bottom wall portion of the door, and the ballast is preferably in thermal contact with the floor and the bottom wall portion of the door for dissipating heat from the ballast to the door. In this regard, the floor and/or the bottom wall portion of the door preferably include at least one raised landing integrally formed thereon, wherein the ballast is mounted to the landing. At least one mounting fastener connects the ballast to the landing, wherein the fastener is in thermal contact with the ballast and the landing for conducting heat therebetween.
A preferred form of the roadway luminaire, as well as other embodiments, objects, features and advantages of this invention, will be apparent from the following detailed description of illustrative embodiments thereof, which is to be read in conjunction with the accompanying drawings.
a is a cross-sectional view of the latch receiving aperture of the latch pocket formed on the housing.
Referring first to
In
The housing 12 further includes a rear wall 24 formed with several stepped offsets 26. The offsets 26 are stepped in the lateral direction to stiffen the rear wall 24 and also provide a unique appearance. Referring to
The rear wall 24 further includes an opening 28 through which a mounting arm 29 is inserted for mounting the luminaire to a pole. The common means of roadway luminaire attachment to an arm 29 is by clamping onto the outside of the arm using a clamp bracket 30, known as a fitter clamp, and using two bolts 32 to secure the arm within an arm receiving channel 36 cast within a top wall 37 of the housing 12.
In the present invention, however, the arm receiving channel 36 of the housing is formed with a step arrangement 34 cast within the arm receiving channel 36 of the housing 12. As shown most clearly in
The height of the steps 35 are chosen to allow 1.5° increments of adjustment depending on which step the pole rests. Thus, the eight steps 35 of the stepped arrangement 34 of the receiving channel 36 of the present invention allows for ±6° of leveling adjustment. For example, the housing 12 can be adjusted to a +3° angle by positioning the mounting pole 29 on the sixth step 35 (i.e., the second step beyond the fourth step 35a). Alternatively, the housing can be mounted at a −6° angle by positioning the mounting pole on the floor 33 of the mounting channel 36. In any event, the pole 29 is secured within the channel by tightening the bolts 32 of the clamp 30, once the desired angle is selected.
The housing 12 further includes a stop arrangement 38, which prevents the arm 29 from being inserted too far within the housing. The stop arrangement 38 preferably takes the form of one or more banking pins 39 integrally cast with the housing at the end of the arm receiving channel 36 opposite the arm opening 28. The pins 39 contact the end of the arm 29 when the arm has reached the far end of the arm receiving channel 36 and serve to stop further insertion of the arm. Again, this can be seen most clearly in
The arm receiving opening 28 in the rear wall 24 is sized for clearance around a 1¼ inch NPS pipe arm 29. This is equal to a diameter of 1.660 inches. The close tolerance opening reduces entry of contaminants. With the aid of a gasket 20 the luminaire can be rated IP66.
The side walls 40 of the reflector 16, near the opening 42, are defined by a series of points of which the normal to the surface at that point is positioned to direct the light up and down the roadway at the desired levels. The top 44 of the reflector 16 is unique in that it directs light into the lower portions of the side walls 40 and out of the opening 42 at higher vertical angles providing a more uniform distribution of the light and eliminating a bright spot directly under the luminaire 10. Due to the way the light rays are directed out of the reflector 16, it performs optimally with either a flat lens or a prismatic drop lens.
As also shown in
The floor 52 of the door 14 is also preferably formed with additional horizontal ribs 65 to facilitate mounting of the smaller ballast 46, as shown in
Turning now to
However, unlike prior art designs, the trigger latch 68 of the present invention is easy to install and requires no additional hardware. In particular, conventional prior art luminaire latch assemblies typically include a trigger latch member having a latch pivot pin integrally cast into the latch member. The latch is then fixedly secured to the door with two screws and two flat washers making assembly difficult.
In contrast, the latch mechanism 66 according to the present invention includes a pivot pin 72 that slides through a hole 73 in the trigger latch member 68, which allows the torsion spring 72 to be assembled prior to inserting the pin. The latch-pin-spring assembly 66, as shown in its assembled form in
As shown in
Upon installation, the pre-assembled latching mechanism 66 easily snaps into place within the pocket 78 without the need for any additional hardware. This is accomplished by squeezing the ends of the torsion spring 70 together, while inserting the latch assembly 66 through the aperture 79 of the pocket 78. At a certain point during insertion of the latch mechanism 66, the ends of the torsion spring 70 will become resident within the torsion spring apertures 79 of the pocket, thereby locking the latch mechanism 66 in place. When the door 14 is latched, the assembly 66 is in tension further securing it. Thus, no screws or washers are required, thereby saving time and material, and making installation simple and easy.
As a result of the present invention, a roadway luminaire for general roadway lighting is provided. The luminaire of the present invention incorporates a high intensity discharge lamp system in a very small housing and meets industry requirements. The luminaire of the present invention is of the smallest possible size to house all of the necessary components in the proper configuration to meet industry requirements. In particular, for this series, the largest is a 250 watt high pressure sodium lamp with an E-18 envelope as defined by ANSI C78.42-2001 (American National Standard for Electric Lamps—Guidelines for High-pressure Sodium Lamps) along with its necessary ballast, capacitor, lampholder, reflector, terminal block, wiring and mounting means. The invention has the shortest length of any similar product on the market.
The invention further utilizes a unique means of mounting the ballast to operate it at lower temperatures than in other versions of this product currently on the market. The ballast is mounted at the bottom center of the luminaire to give it greater balance and a lower center of gravity with respect to its mounting means. Further, the ballast and serviceable components are mounted on the door for easier servicing or replacement.
The roadway luminaire of the present invention further includes a ballast mounted within the luminaire door so as to extract heat from two directions simultaneously so that the ballast can operate in a smaller space below maximum allowable temperatures. The ballast is preferably mounted in the bottom center of the door so as to balance the unit and lower the center of gravity. The ballast and related components are also preferably mounted to the door for easy servicing or replacement.
The luminaire of the present invention further preferably includes an upper housing and a lower door connected by a hinge mechanism with a keyed arrangement so that the door cannot accidentally disconnect from the upper housing in any position except at a particular angle.
The luminaire of the present invention further preferably utilizes a specially designed reflector to provide better than normal photometric performance with either a flat lens or a convex prismatic lens. In general, the luminaire system of the present invention has an optical system of such configuration so as to perform optimally with either a drop lens refractor or a flat lens.
The luminaire of the present invention further preferably includes a unique latching arrangement to provide closure between housing and door so that no fasteners are required to secure the latch itself to the door or housing.
The luminaire of the present invention also preferably has a means of leveling the luminaire ±6° from horizontal to compensate for pole and arm misalignment with respect to the roadway.
Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be effected by one skilled in the art without departing from the scope or spirit of the invention.
This application claims the benefit of U.S. Provisional Application No. 60/837,221, filed Sep. 21, 2007, which is incorporated herein by reference in its entirety for all purposes.