Patent Application
20120140488
The present application relates generally to a notification device for use in life safety wall strobe applications.
Life safety systems include notification devices positioned on walls and ceilings, as required by law. These notification devices can include a horn for an audible alert and/or a strobe for a visual alert. Notification devices draw energy to illuminate a strobe in a life safety application, such as a fire alarm or other signaling device. A notification device can be mounted on a surface, e.g., a wall or a ceiling, and aimed at the floor. The notification device has a reflector with internal reflecting surfaces to reflect light toward the specified space. The reflector can also have some external secondary reflector elements mounted on the reflector body.
Notification devices for the hearing impaired are governed by standards that require a polar light distribution off-axis at any given rated candela. In order to achieve the standard, the notification device must produce a minimum output at specified angles off-axis. For example, for a notification device to be rated at 185 candela, UL 1971 requires that the strobe has specific light intensities at viewing angles ranging from zero to 90 degrees off axis. UL 1971 requires a polar light distribution pattern to enhance the likelihood of alerting hearing impaired individuals throughout an area. The light intensity is measured in a horizontal and vertical direction and at viewing angles ranging from zero to +90 degrees and zero to −90 degrees. In one example, the UL polar distribution requires a percentage of the candela output at specific angles off-axis, e.g., five degrees off-axis requires an output of 90% of the rated on-axis value. So a 15 candela strobe is required to output 13.5 candela at five degrees off-axis.
It is desirable to use less energy, but the light output of the strobe must meet the requisite standards to achieve underwriting. As a result, the amount of energy is limited by the minimum required light output. The amount of current drawn by the notification device can be affected by various aspects of its configuration, including reflector design, electrical efficiency, lamp efficiency, efficiency of a metalized coating used for high reflectance, and the efficiency of the lens. It is desirable to adjust the properties of the notification device so that less current is needed to power the notification device while maintaining a required amount of light output.
A notification device described herein can draw a lower current by providing a more efficient reflector configuration. The optically efficient reflector is generally a rectangular reflector being symmetrical about a central axis. The reflector is designed to be positioned on a wall and provide sufficient light output in each of the requisite directions, as required by the UL 1971 standard. For example, a notification device described herein can provide a 185 candela output using a 2.5 J flashtube lamp.
In one embodiment, a notification device comprises a housing configured to be installed on a wall; a reflector unit mounted to the housing and symmetrical about a vertical axis, the reflector unit comprising a base having a curved portion centered on the vertical axis and a flat portion extending from the curved portion on a first side of the vertical axis and a second side of the vertical axis; a reflective flange extending from a location near a top side of the base and along a plane perpendicular to the wall, the reflective flange having a lower surface that tapers from the vertical axis toward the top side of the base; a first specular protrusion and a second specular protrusion extending from the curved portion of the base, wherein the first specular protrusion is positioned on the first side of the vertical axis and the second specular protrusion is positioned on the second side of the vertical axis, the first specular protrusion and the second specular protrusion each comprising a surface substantially directed toward a lower edge of the base near the vertical axis; a third specular protrusion and a fourth specular protrusion extending from the base, wherein the third specular protrusion is positioned on the first side of the vertical axis and the fourth specular protrusion is positioned on the second side of the vertical axis, the third specular protrusion and the fourth specular protrusion each extending from a lower edge of the base and tapering in a direction parallel to the vertical axis; a fifth specular protrusion and a sixth specular protrusion extending from the curved portion of the base, wherein the fifth specular protrusion is positioned on the first side of the vertical axis and the sixth specular protrusion is positioned on the second side of the vertical axis, and wherein the fifth specular protrusion is proximate to the third specular protrusion on a side of the third specular protrusion nearest the vertical axis and the sixth specular protrusion is proximate to the fourth specular protrusion on a side of the fourth specular protrusion nearest the vertical axis, the fifth specular protrusion and the sixth specular protrusion each having a curved surface substantially directed toward a central point of the curved portion of the base; and a sixth specular protrusion and a seventh specular protrusion extending form the flat portion of the base, wherein the sixth specular protrusion is positioned on the first side of the vertical axis and the seventh specular protrusion is positioned on the second side of the vertical axis, and wherein the sixth specular protrusion and the seventh specular protrusion each taper toward the vertical axis; a lens coupled to the housing and positioned over the reflector unit; and a lamp positioned in the center of the curved portion of the base.
In another embodiment, a reflector unit configured for a notification device on a wall comprises a base having a curved portion centered on the vertical axis and a flat portion extending from the curved portion on a first side of the vertical axis and a second side of the vertical axis; a reflective flange extending from a location near a top side of the base and along a plane perpendicular to the wall, the reflective flange having a lower surface that tapers from the vertical axis toward the top side of the base; a first specular protrusion and a second specular protrusion extending from the curved portion of the base, wherein the first specular protrusion is positioned on the first side of the vertical axis and the second specular protrusion is positioned on the second side of the vertical axis, the first specular protrusion and the second specular protrusion each comprising a surface substantially directed toward a lower edge of the base near the vertical axis; a third specular protrusion and a fourth specular protrusion extending from the base, wherein the third specular protrusion is positioned on the first side of the vertical axis and the fourth specular protrusion is positioned on the second side of the vertical axis, the third specular protrusion and the fourth specular protrusion each extending from a lower edge of the base and tapering in a direction parallel to the vertical axis; a fifth specular protrusion and a sixth specular protrusion extending from the curved portion of the base, wherein the fifth specular protrusion is positioned on the first side of the vertical axis and the sixth specular protrusion is positioned on the second side of the vertical axis, and wherein the fifth specular protrusion is proximate to the third specular protrusion on a side of the third specular protrusion nearest the vertical axis and the sixth specular protrusion is proximate to the fourth specular protrusion on a side of the fourth specular protrusion nearest the vertical axis, the fifth specular protrusion and the sixth specular protrusion each having a curved surface substantially directed toward a central point of the curved portion of the base; and a sixth specular protrusion and a seventh specular protrusion extending form the flat portion of the base, wherein the sixth specular protrusion is positioned on the first side of the vertical axis and the seventh specular protrusion is positioned on the second side of the vertical axis, and wherein the sixth specular protrusion and the seventh specular protrusion each taper toward the vertical axis.
These and other aspects, objects, and features of the invention will become apparent to those having ordinary skill in the art upon consideration of the following detailed description of exemplary embodiments exemplifying the best mode for carrying out the invention as presently perceived.
The objects and advantages of the invention will become apparent from the following detailed description of preferred embodiments thereof in connection with the accompanying drawings in which like numerals designate like elements and in which:
a is a frontal view of a notification device according to an exemplary embodiment.
b is a side view of a notification device according to an exemplary embodiment.
c is a bottom view of a notification device according to an exemplary embodiment.
d is a rear perspective view of a notification device according to an exemplary embodiment.
a is a perspective view of a reflector unit according to an exemplary embodiment.
b is a frontal view of a reflector unit according to an exemplary embodiment.
c is a top view of a reflector unit according to an exemplary embodiment.
d is a rear view of a reflector unit according to an exemplary embodiment.
a shows a frontal view of a notification device according to an exemplary embodiment.
b shows a perspective view of a notification device according to an exemplary embodiment.
c shows a side view of a notification device according to an exemplary embodiment.
a shows a frontal view of a notification device according to an exemplary embodiment.
b shows a side view of a notification device according to an exemplary embodiment.
c shows a perspective view of a notification device according to an alternative exemplary embodiment.
The present invention may be better understood by reading the following description of non-limitative embodiments with reference to the attached drawings wherein like parts of each of the several figures are identified by the same reference characters.
The notification device described herein can be adapted for operation under any one or combination of standards, such as UL 1971, and can be installed in different locations, such as a corridor, a sleeping room, or a non-sleeping room. Although the exemplary embodiments describe a notification device configured for a wall, it is intended that the notification device can be used on a ceiling when UL 1971 light distribution is not required.
Referring to
Lettering or a graphic, such as “FIRE” 160 can be printed on the device 100. The lens 130 can cover the FIRE 160 to protect it from tampering. When using a lens that is colored or translucent, however, it may be desirable to locate the FIRE 160 outside of the lens 130. The housing 110 can also include a light intensity selector, which can be adjusted from the rear of the device 100, that has a window for viewing the selected intensity of the lamp in candela units. In order to prevent tampering, the candela intensity window (shown as window 290 in
Alternatively, the lens can cover only the optical elements. Referring to
In another alternative embodiment, as shown in
In an exemplary embodiment, the lens can be made from a polycarbonate material for improved mechanical protection and flame retardant characteristics. The lens can be made of a transparent or opaque material. The lens can also have a color or hue, such as red, green blue, amber, or clear. In another embodiment, the lens can be transparent in only the area positioned over the optical elements, whereby the lens would still allow a complete light distribution pattern.
A reflector unit is installed in the housing and protected by the lens. In the exemplary embodiment described herein, the reflector is symmetrical about a central axis that extends from the bottom of the reflect unit to the top of the reflector unit, though it is intended that the configuration can be adapted to other configurations, such as where the reflector unit is not symmetrical. The reflector unit can be manufactured using a vacuum metalized injection-molded polycarbonate with UV resistant and scratch resistant lacquer. In one exemplary embodiment, the reflector unit can be approximately 85% reflective.
Referring to
The reflector unit 200 has a base 220. The base 220 has a continuously smooth, specular surface that is designed to reflect a significant portion of direct light from a lamp to illuminate both the vertical and horizontal planes. The base 220 has a curved base portion 220a and a flat base portion 220b. The curved base portion 220a is a substantially parabolic or freeform curvature shape that is symmetric about a central axis extending through the reflector unit, wherein the central axis is perpendicular to the plane of the wall. The curved base portion 220a can have two different contoured portions, shown as an upper portion 221a and a lower portion 221b, each having a different curvature. The lower portion 221b forms a cavity that directs light from the lamp to its nadir in the center of the reflector unit. The cavity can also double the intensity of the illumination effect on both horizontal and vertical planes. The flat base portion 220b extends from the left and right sides of the curved base portion 220a. The base 220 can be installed in a housing whereby the edge 220c aligns with an exposed surface of the housing.
A lamp 230 is positioned in the center of the base 220 through a keyhole 220d and extends in a direction along a central axis perpendicular to the plane of the wall. As shown in this exemplary embodiment, lamp 230 is a vertical flash tube that can be rated at 2.5 J. The lamp 230 can be a Xenon flashtube or any other suitable light source.
An upper reflective flange 240 extends from the base 220 in a direction away from the wall having a length substantially the same as the lamp 230. The width of upper reflective flange 240 is approximately the width of an outer edge of the curved base portion 220a substantially near the top of the reflector unit 200. The upper reflective flange 240 has sides 240a that taper toward the lamp 230. In the proximity of the lower portion 221b, the upper reflective flange 240 has a side 240b that is substantially parallel to the plane of the ceiling and floor. Between a first side 240b and a second side 240b, the upper reflective flange 240 has a recess 240c that has a width approximately the same as the widest diameter of the keyhole 220d. The surfaces of upper reflective flange 240 are continuously smooth and can reflect a significant portion of direct light from the lamp 230 to illuminate the horizontal and vertical planes. More specifically, side 240a can reflect light in a horizontal plane, whereas sides 240c can reflect light in a vertical plane, and sides 240b can reflect light in between horizontal and vertical planes at about 45 degrees.
A first and second specular protrusion 250 extend from the upper portion 221a. The specular protrusion 250 has a surface 250a substantially facing the a lower edge of the base 220 near the lowest point of the lower portion 221b of the curved base portion 220a. The specular protrusion 250 can reflect direct light from the lamp 230 to illuminate the vertical plane.
A first and second specular wedge 260 extend from an upper portion of the flat base portion 220b. The specular wedge 260 has a surface 260a that tapers to an edge 260b closest to the lamp 230. Light can travel from the lamp 230 to side 240a, which is then reflected to the specular wedge 260, which can reflect the light to the horizontal plane to compensate illumination in the specified area.
A third and fourth specular protrusion 270 extend from a lower portion of the base 220 on each side of the lamp 230. The specular protrusion 270 has a surface 270a that tapers to an edge 270b proximate to the base 220. In this embodiment, the edge 270b is aligned with the plane of the flat base portion 220b and is not curved along with the curved base portion 220a, thereby forming surface 270c. As shown in the exemplary embodiment, the specular protrusion 270 extends from both the curved base portion 220a and the flat base portion 220b. The specular protrusion 270 acts as a secondary reflector to reflect light reflected by the specular protrusion 250 to compensate illumination in a specified area in the vertical plane.
A fifth and sixth specular protrusion 280 extend from a lower portion of the base 220 on each side of the lamp 230 and abut the specular protrusion 270. The specular protrusion 280 extends in a direction along a plane perpendicular to the wall and extends further than the specular protrusion 270, but has a height of approximately the height of the specular protrusion 270. The specular protrusion 280 has a curved surface 280a that substantially faces the lamp 230. The specular protrusion 280 can reflect light to illuminate the horizontal plane.
When the lamp 230 is illuminated, the light from the lamp 230 reflects off the reflective surface described above and into the vertical and horizontal planes. As a result, the notification device can achieve the polar light distribution pattern required by UL 1971.
The notification device incorporating this reflector has a greater optical efficiency than a conventional strobe having a 185 candela output. The efficiency allows for a reduction in power needed to operate the lamp. This reduction in lamp wattage translates into a lower current rating for the appliance. While a conventional 185 candela strobe may need to expend as much as 4.5 J of electrical energy for the strobe to meet the UL 1971 requirements for 135 candela and 185 candela settings, the notification device described herein can achieve the UL 1971 standard with only 2.5 J of energy expended by the flashtube at both 135 candela and 185 candela, which is almost a doubling in optical efficiency. Rather than using two separate models of notification devices for low candela (e.g., 15, 30, 75, and 110 candela) and high candela (e.g., 135 and 185 candela), a single notification device described herein can be used in all wall applications from about 15 to 185 candela output. For example, the notification device can be set via a switch to 15, 15/75, 30, 75, 95, 110, 135, and 185 candela. The 15/75 candela setting delivers 75 candela light output on axis and provides a 15 candela light distribution.
Because the notification device allows for a lower energy flash-tube, high and low intensity strobes can use the same lower energy flash tube and can therefore be combined into one unit. This reduces cost as the lower energy tube is not as expensive as the higher energy one and it also reduces the number of product models or variations, i.e., Stock Keeping Units (“SKU”) reduction. As a result, customers only need to purchase one type of notification device, eliminating any confusion or mistaken purchases of the wrong device. Also, managing one model is easier for distribution and stocking purposes.
Although the exemplary embodiment recites a 185 candela output, it is intended that the reflector unit can be configured for other candela outputs, such as 110 candela. The light output can be adjusted electrically by lowering or raising the energy to the lamp from about 0.6 J to about 2.5 J. The configuration of the reflector unit can be adjusted to affect the amount of reflected light from the lamp, such as reducing the size of the base for a lower light distribution, reconfiguring the base to accommodate a larger lamp, or increasing or decreasing the surface area of any component, such as by varying the size of the upper and/or lower portions of the base.
Therefore, the present invention is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present invention may be modified and practiced in different but equivalent manners apparent to those having ordinary skill in the art having the benefit of the teachings herein. While numerous changes may be made by those having ordinary skill in the art, such changes are encompassed within the spirit and scope of this invention as defined by the appended claims. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present invention as defined by the claims below. The terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee.
This application is a continuation of and claims priority under 35 U.S.C. §120 to U.S. patent application Ser. No. 12/558,886, titled “Optically Efficient Notification Device for Use in Life Safety Wall Strobe Applications,” filed on Sep. 14, 2009, the entire contents of which are hereby incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12558886 | Sep 2009 | US |
| Child | 13372730 | US |
