Abstract:
An explosion-proof industrial signaling device. The explosion-proof industrial signaling device having an explosion-proof housing and a single module with the capability of emitting different colored lights to indicate the operating condition of a machine. The emitted light can be steady or flashing, and controlled by an external PLC or an onboard microprocessor. The PLC or microprocessor interprets incoming information and causes the color of the light or its flashing pattern to change accordingly. The light source maybe an LED.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to signaling devices used in Class I, Division I explosion-proof hazardous locations, and more particularly, to visual signaling devices that emit attention attracting light signals, and yet retain their various color identification.  
       BACKGROUND OF THE INVENTION  
       [0002]     Studies of light signaling devices used in industrial and commercial areas as well as on industrial equipment show that effective warning is best accomplished by signaling devices, which combine a bright visual light signal with high color identification. Color identification is highly desirable in light signaling devices because red, blue, green, and amber colored light signals have long become associated with stop, start, warning, and waiting indication in industrial and commercial application.  
         [0003]     Elevated industrial signaling devices are well known in factory-type environments where numerous industrial machines are present. Generally, such industrial signaling devices are mounted on a pole so they are high above each machine and clearly visible from a distance. Each device typically has a plurality of modules that emit differently colored light for visually signaling the operating status of each machine.  
         [0004]     In a typical signaling device, each of the lights is responsive to an operating status of the machine to which the device is connected. For example, a typical device has lights of various colors such as, blue, red, amber and green. Each of the these differing colors is contained in a discrete module. The differing colors of the lights correspond to various operating stages of the machine. For example, a blue light may indicate the machine is running correctly, an amber light may indicate that the machine is in need of service and a red light may indicate that the machine has ceased operating. The colors of the lights are very important because even at a distance an illuminated light of one color is immediately distinguishable from the other lights of different colors.  
         [0005]     FEDERAL SIGNAL of University Park, Illinois has Model 121X which is a rotating light which flashes 90 times per minute and produces a 360° visual signal. This explosion-proof light has an incandescent lamp and is available in five separate lens colors—amber, blue, clear, green and red. This device is ideal for use in indoor and outdoor areas such as oil rigs, mines refineries, and chemical plants.  
         [0006]     FEDERAL SIGNAL also has a Model FB2PSTX explosion-proof strobe light which is a compact unit that produces a “lightening bolt” flash of light. This device has an outer dome made of tempered glass. Polycarbonate inner lenses are available in amber, blue, clear, green and red.  
         [0007]     FEDERAL SIGNAL has a Model 27XST which is an explosion-proof strobe light which produces 80 high-intensity flashes per minute. This device is also ideal for use in areas such as oil rigs, mines, refineries, and chemical plants. The interior lens of this device is available in amber, blue, clear, green, red and magenta.  
         [0008]     It should be noted however, that none of the above-noted FEDERAL SIGNAL devices is capable of multiple color displays without the need for a colored interior lens.  
         [0009]     Another examples of these devices is U.S. Pat. No. 5,103,215 to James et. al which discloses a signaling light made from a plurality of differently colored vertically stacked modules with incandescent lights. The cover lens of each module may be removed separately and the bulbs in each module may be replaced without having to disassemble the entire piece.  
         [0010]     In addition, U.S. Pat. No. 5,769,532 to Sasaki discloses a LED signaling light made from a plurality of differently colored vertically stacked modules. Each module contains a portion bulged outwardly, which is coated with a reflective material. The LEDs are arranged in rows so that their emitted light is reflected off the reflecting surface and projected into the environment surrounding the module.  
         [0011]     Moreover, U.S. Pat. No. 5,929,788 to Vukosic discloses a LED signaling device where clusters of LEDs arranged in rings are mounted on a circuit board and emit light on to a conical reflective surface. The conical reflective surface is outwardly flaring. In order to change to color of the emitted light different colored covers must be manually changed.  
         [0012]     Elevated signaling devices are particularly effective in environments where the level of background noise is very high and there is a danger that an audible alarm will not be heard. Furthermore, the elevated signaling devices can distinguish between various malfunctioning conditions by relating different conditions to different colors of lights or to different frequencies of flashing lights. In a crowded factory, a system of elevated signaling devices enables maintenance people to quickly locate and identify specific problems in a large number of operating machines. Such a system is extremely effective and efficient because it enables a single individual to monitor a large number of machines from a distance where the operating status of all the machines can be simultaneously observed.  
         [0013]     While these elevated signaling devices have proven to be very effective, they also have various disadvantages. Typical devices are made with a plurality of modules, where each module illuminates a different colored light. A design of one color per single module has numerous disadvantages.  
         [0014]     One such disadvantage is when the manufacturing operation takes place in a clean room, such as in the manufacture of semiconductor devices. In order to have better environmental control, it is desirable to reduce the volume of the clean room as much as possible. Industrial signaling devices that employ multiple modules are often too large to be used in clean rooms that have reduced height. Also, multiple module lights have numerous interfaces between the lens of the light and the housing of the electrical components. Each connection interface is a weak spot where water, liquid, dust, corrosive materials, etc. can enter the light and ruin electronic components. Moreover, the manufacture of such multiple module lights is wasteful, and sometimes assembly of the multiple modules is required by the end user. Multiple modules require greater storage space and can be more expensive to handle and ship. They are also more cumbersome to install or service and this can be difficult when the multiple modules are at the end of a pole ten feet or more above a factory floor. Usually, a maintenance person climbs a ladder in order to reach the signaling device.  
         [0015]     Accordingly, it is desirable to provide a method and apparatus that has the capability to provide the needed visual signals in a single multi-color changeable device resulting in greater versatility and functionality while maintaining its integrity in a hazardous environment.  
       SUMMARY OF THE INVENTION  
       [0016]     The foregoing needs are met, to a great extent, by the present invention, wherein in one aspect an apparatus is provided that in some embodiments a single multi-color changeable signal device for use in hazardous or explosive environments is provided.  
         [0017]     In accordance with one aspect of the present invention, an explosion-proof industrial signaling device is provided comprising a single lens module; at least one light source contained within the module, wherein the light source includes a plurality of clusters the clusters which are disposed spaced apart from one another, each of the clusters containing lights of different colors which are independently activated such that a signal is seen to be emitting from a signal housing as an individual color.  
         [0018]     In accordance with another aspect of the present invention, an explosion-proof industrial signaling device is provided comprising a single module means for protecting a light source, whereby the light source includes a plurality of light clusters, the clusters which are disposed spaced apart from one another, each of the clusters containing lights of different colors which are independently activated such that a signal is seen to be emitting from a signal housing an individual color, and a plurality of light sources disposed in a spaced apart arrangement and located at a focal point of the single module means of the signal housing.  
         [0019]     In accordance with still another aspect of the present invention, a method for processing visual indicator signals of an explosion-proof industrial signaling device is provided comprising the steps of utilizing incoming analog information to enable an LED cluster assembly to light, decoding one PLC input to light one LED cluster, and decoding at least two PLC inputs to light at least two LED clusters of differing colors.  
         [0020]     There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto.  
         [0021]     In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.  
         [0022]     As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]      FIG. 1  is an exploded view illustrating an explosion-proof visual signal device of a preferred embodiment of the invention.  
         [0024]      FIG. 2  is an exploded view of a subassembly of the explosion-proof visual signal device.  
         [0025]      FIG. 3  is a diagrammatic view illustrating a wall mounted explosion-proof visual signal device.  
         [0026]      FIG. 4  is a diagrammatic view illustrating a ceiling mounted explosion-proof visual signal device.  
         [0027]      FIG. 5  is a diagrammatic view illustrating a pendant mounted explosion-proof visual signal device.  
         [0028]      FIG. 6  is a schematic of the PLC circuit for the explosion-proof visual signal device.  
         [0029]      FIG. 7  is a diagrammatic view illustrating a jumper pin assembly for the explosion-proof visual signal device.  
         [0030]      FIG. 8  is a diagrammatic view illustrating the jumper pin assembly of  FIG. 6A  of the explosion-proof visual signal device.  
         [0031]      FIG. 9  is a top view of the LED configuration mounted within the explosion-proof visual signal device.  
         [0032]      FIG. 10  is a side view of  FIG. 9  along line A-A showing the LED configuration of the explosion-proof visual signal device.  
         [0033]      FIG. 11  is a cross-sectional top view of  FIG. 2  of the assembled explosion-proof visual signal device. 
     
    
     DETAILED DESCRIPTION  
       [0034]     The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. An embodiment of the present inventive apparatus and method is illustrated in  FIG. 1 . This embodiment in accordance with the present invention provides an explosion-proof multi-color, multi-status signaling device  100  having an effective balance between signal brightness and color identification provided by placing a light emitting diode (LED) light source or cluster  140  in red, blue, and amber or in red, green, and amber in front of a highly reflective material  905  that amplifies and distributes the light output. The LED light source or cluster  140 , the reflector  905 , and all associated electronics are housed in the top end of a heavy-duty explosion-proof housing  110 , preferably made of cast aluminum. This housing  110  is connected to a glass dome or lens  130  via a ring mount  135 . The glass dome is preferably made of a polycarbonate material. An exterior guard  120  encased the glass dome  130  to add additional protection.  
         [0035]     Referring to  FIG. 2 , the explosion-proof multi-color, multi-status signaling device  100  may be mounted to various types of mounts with mounting screws  220  and gasket  210 . A programmable logic control (PLC) unit  200  may be internal to the signaling device  100  in order to operate the LED light cluster  140 .  
         [0036]     Referring to  FIGS. 3-5 , it is anticipated that the multi-color, multi-status signaling device  100  including housing  110  may be mounted in at least three arrangements. A wall mount  300  shown in  FIG. 3 , a ceiling mount  400  shown in  FIG. 4 , or a pendant mount  500  shown in  FIG. 5 . These various mounting options may be incumbent upon the required use and location of the multi-color, multi-status signaling device  100 .  
         [0037]     Referring to  FIG. 6 , the multi-color, multi-status signaling device  100  may be configured with an internal microprocessor PLC sinking output circuit  600  or without an internal microprocessor PLC circuit utilizing instead an external PLC (not shown). The embodiment of the multi-color, multi-status signaling device  100  having the internal microprocessor PLC sinking output circuit  600  interprets incoming analog information to enable the LED light cluster  140  to light according to the input or information provided.  
         [0038]     Referring to  FIGS. 7 and 8 , the multi-color, multi-status signaling device  100  may also have an internal jumper  700  with associated jumper pins  710  connected to a circuit board  810  having a circuit board power connector interface  800 . This jumper  700  may allow the first selected light to illuminate as either a steady or flashing light. For example, if jumper pins  710  has jumper  700  on pins  1  and  2  a flashing light may be enabled while having jumper  700  on pins  2  and  3  enables a steady light configuration.  
         [0039]     Referring to  FIGS. 9-11 , the LED light source or cluster  140  may include a printed circuit board  900  connected to circuit board  810  and configured as a three-sided vertical structure to illuminate the LED light cluster  140  in a 360° hemi-spherical range. A reflective material  905  is disposed adjacent to LED light cluster  140  to increase the illumination upon activation of LED light cluster  140 . The printed circuit board contains an array of red LEDs  910 , an array of blue or green LEDs  920  and an array of amber LEDs  930 .  
         [0040]     The explosion-proof visual signal device  100  provides a rugged case enclosing the necessary elements of proper operation of the signal lights and isolating these elements from any explosive external atmosphere which may exist via glass dome  130 .  
         [0041]     In operation, the internal microprocessor embodiment utilizes incoming analog information to cause the LED light cluster  140  to illuminate. For example, if the microprocessor PLC unit  200  detects one contact closure for PLC input, then one selected LED cluster  910 ,  920 , or  930  will illuminate. If two or more PLC inputs or contact closures are received, then microprocessor PLC unit  200  decodes this information and causes the light to cycle between two or more selected LED clusters  910 ,  920 , or  930 .  
         [0042]     In an alternative use for the present invention, it should be noted that the housing  110  may be moisture-proof allowing the signal lights or cluster  140  to be used in damp environments or outdoors where various weather conditions may occur.  
         [0043]     In another embodiment, the multi-color, multi-status signaling device  100  without the internal microprocessor PLC unit  200  functions in the same manner as the signaling device  100  with the microprocessor PLC unit  200  with the exception that all functionality is controlled by inputs from an external PLC (not shown). Therefore, each color of the LED light source or cluster  140  can be separately activated through an external contact closure or input from an external industrial programmable logic controller.  
         [0044]     The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.