Patent Publication Number: US-6342995-B1

Title: Lighted escutcheon plate for power distribution equipment

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention. 
     The invention relates to a lighted switch or remote panel plate with multiple replaceable light emitting diodes in banks that remain lighted when one or more fail, for use in power distribution systems. 
     2. Description of Related Art. 
     The use of LED lights in power distribution control circuits are known in the art. However, they are generally on the circuit breaker itself or should an LED bulb fail, you lose indication of operating status. 
     Known related art includes the use of LED bulbs incorporated into a circuit breaker as depicted in U.S. Pat. No. 5,353,014 to Carroll et al., U.S. Pat. No. 5,847,913 to Turner et al., U.S. Pat. No. 3,662,369 to Vinsani et al., U.S. Pat. Nos. 4,056,816, 5,051,731 and 4,633,240 to Guim, and an LED bulb incorporated into an electrical power load center panel as depicted in U. S, Pat. No. 5,909,180 to Bailey et al. 
     Other known related indicator apparatus for power distribution circuits incorporate lamps for a circuit breaker such as depicted in U.S. Pat. No. 3,742,403 to Nicol and U.S. Pat. No. 3,999,176 to Kellogg et al. 
     None of the devices in the above references solve the problem of providing reliable and low cost indicating equipment in power handling distribution equipment. Most indicator bulbs as noted above which are incorporated into the breakers themselves, are not readily visible to operators so operators can immediately note the operating circuit status. Therefore, in power distribution equipment, pilot lights are often used for status indication. Traditionally, these have been incandescent bulbs, but these fail regularly, due to filament burn out and vibration damage. Recently, clusters of LED&#39;s have also been used. Additionally, these traditional pilot indicators are stand alone units. This meant that the unit must be mounted and wired. The adaptation of an escutcheon plate, particularly with a control switch escutcheon plate, solves the above described problems. By incorporating LED bulbs in a switch escutcheon plate, the cost of individual lamps and sockets is saved and the cost of mounting them is also avoided. 
     Others have addressed these problems in different ways. For example, others have incorporated transformers and resistors into light sockets to reduce the voltage across the incandescent filament. This is very costly. Another way is to incorporate LED clusters that plug or screw into light sockets. However, when an LED bulb fails, indication is lost while they are being replaced and the use of a separately mounted lamp holder is not eliminated. Otherwise, LED bulbs have been incorporated directly into the escutcheon plate as commercially sold by Electroswitch&#39;s light duty control switch Model No. 644-6C. However, should any of the LED bulbs fail, status indication is lost and ease of service is not present. Loss of status indication could cause an operator working on the equipment not to realize that power is present or that power is not available to operate the circuit breaker. 
     The results obtained by the present invention is to offer uninterrupted status indication to the user at reduced installed costs and maintenance costs. This long felt need has not been satisfied because power engineers in the power distribution equipment manufacturing industry were simply not motivated to incorporate electronics into the equipment or components to increase operating safety since the trend in the industry is to simply “buy-out” commercially available off-the-shelf components. 
     SUMMARY OF THE INVENTION 
     The present invention is an escutcheon plate, with or without a switch handle for manually opening and closing a circuit, incorporating LED bulbs externally to the escutcheon plate with pairs of LED bulbs being bridges with a zener diode bridge so should an LED bulb fail, status indication will not be lost. In addition, the failed LED bulb is easily replaceable without interrupting the circuitry. 
     The invention is further adapted such that when a trip condition occurs, the amber or yellow colored LED bulbs flash or blink “on” and “off” repetitively, thereby giving an operator an immediate warning of a tripped circuit condition. 
     The present invention is a lighted escutcheon plate for power distribution equipment. It includes an escutcheon plate with terminals on a back side for electrical communication with a control power circuit. A first plurality of LED bulbs of a predetermined color is mounted in a predetermined arrangement on the escutcheon plate. The first plurality of LED bulbs is visible from the front side of the escutcheon plate, so as to provide a visual indication of an open circuit status by lighting when the power distribution circuit is opened. 
     A second plurality of LED bulbs of a predetermined color is also mounted in a predetermined arrangement on the escutcheon plate. The second plurality of LED bulbs is again visible from a front side of the escutcheon plate, so as to provide a visual indication of a close circuit status by lighting when the power distribution circuit is closed. 
     The first and second plurality of LED bulbs are electrically connected and mounted such that should any of the LED bulbs fail, the remaining LED bulbs are capable of lighting to provide the visual indication of the open or close circuit status and the failed LED bulbs are capable of being replaced from the front side of the escutcheon plate without interrupting the control power circuit. 
     The invention further includes a third plurality of LED bulbs of a predetermined color mounted in a predetermined arrangement on the escutcheon plate. The third plurality of LED bulbs is also visible from the front side of the escutcheon plate, so as to provide a visual indication of a trip circuit status by lighting when the power distribution circuit is tripped. The third plurality of LED bulbs is further electrically connected and mounted such that should any of the LED bulbs fail, the remaining LED bulbs are capable of lighting to maintain the visual indication of the trip circuit status. In addition, the failed LED bulbs are capable of being replaced from the front side of the escutcheon plate without interrupting the control power circuit. The third plurality of LED bulbs are also electrically connected to flash “on” and “off” repetitively when lighted due to the trip circuit status. 
     Generally, the first plurality of LED bulbs is arranged in one of a single row and a single column, that is, in columnar form if mounted to the respective left and right sides of the front surface of the escutcheon plate or in a row arrangement if mounted to the respective top and bottom sides of the front surface of the escutcheon plate. No matter where located, the escutcheon plate would typically be labeled by engraving or other methods known in the art, near the row or column of LED bulbs to indicate that the LED bulbs represent open circuit status. 
     Similarly the second plurality of LED bulbs is arranged in one of a single row and a single column as the first plurality of LED bulbs, except that the labeling on the escutcheon plate would indicate close circuit status. In addition, the third plurality of LED bulbs is similarly arranged in one of a single row and a single column, except that the labeling on the escutcheon plate would note trip circuit status. In a typical application of the invention, the third plurality of LED bulbs may be arranged in one of two separate single rows and two separate single columns, that is, there may be one row on the top side of the front surface of the escutcheon plate and a second row on the bottom side of the front surface of the escutcheon plate. This dual set of LED bulb arrangement will enhance the visibility of the flashing LED bulbs warning of a trip circuit status for the operators. 
     The lighted escutcheon plate, for power distribution equipment according to the invention may have two different styles or embodiments regarding the color of the first and second plurality of LED bulbs. The first plurality of LED bulbs could typically be one of green colored LED bulbs and red colored LED bulbs, and the second plurality of LED bulbs typically include the corresponding opposite color, that is, red colored LED bulbs and green colored LED bulbs. 
     The third plurality of LED bulbs is anticipated to be the industry standard yellowish tinted color bulbs, in particular, yellow and amber. 
     In order to provide reliability by having no loss of status indication despite an LED bulb failure, each of the first plurality of LED bulbs, the second plurality of LED bulbs and the third plurality of LED bulbs include a zener diode bridge circuit across each pair of LED bulbs in series succession so that should one of the LED bulbs fail, a voltage will increase across the pair of LED bulbs having the failed LED bulb to cause the remaining LED bulbs in the corresponding first, second and third plurality of LED bulbs to remain lighted, thereby not losing corresponding open, close and trip circuit status indication. For example, if there are six LED bulbs in a bank of bulbs, then each two or pair of LED bulbs is bridged with a zener diode bridge. In this case, although both bulbs would not light with the actual failure of one bulb, the remaining four LED bulbs in the bank of bulbs will remain lighted. 
     In most applications, it is anticipated that the escutcheon plate is a control switch plate having handle means extending from the front side of the escutcheon plate for manually opening and closing of the power distribution circuit. However, in many applications where the operator may be some distance from the control switch, a remote panel or escutcheon plate may be required to provide real time status indication to the operator. In this case, the remotely located escutcheon plate will be in electrical communication with the power distribution circuit and more than likely, directly wired into the control switch escutcheon plate terminals. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which: 
     FIG. 1 a  is a frontal view diagram of one embodiment of the invention depicting a control switch escutcheon plate; 
     FIG. 1 b  is a frontal view diagram of the embodiment of FIG. 1 a  with the light arrangement for open and close circuit status reversed from that shown in FIG. 1 a;    
     FIG. 2 is a conceptual wiring schematic for the embodiments of FIGS. 1 a  and  1   b;    
     FIG. 3 is a table listing various LED voltage ratings and corresponding light arrangements for the embodiment of FIG. 1 a;    
     FIG. 4 is a table listing various LED voltage ratings and corresponding light arrangements for the embodiment of FIG. 1 b;    
     FIG. 5 a  is a conceptual wiring schematic for green lights indicating a closed circuit; 
     FIG. 5 b  is a conceptual wiring schematic for red lights indicating an open circuit; 
     FIG. 5 c  is a conceptual wiring schematic for blinking yellow lights indicating a tripped circuit; 
     FIG. 6 is a schematic of a typical control switch; 
     FIG. 7 a  is a frontal view diagram of an embodiment of the invention depicting an escutcheon plate without the switch mechanism; 
     FIG. 7 b  is a frontal view diagram of an embodiment of the invention depicting an escutcheon plate without the switch mechanism and with the open and close circuit status light indicators being reversed from the embodiment of FIG. 7 a;    
     FIG. 8 a  is a practical application of a schematic wiring diagram of a part of the circuitry for the LED bulbs; and 
     FIG. 8 b  is a continuation of the schematic wiring diagram of FIG. 8 a.   
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, in particular FIGS. 1 a ,  1   b ,  7   a  and  7   b , the invention which is a lighted escutcheon plate for power distribution equipment and is depicted generally as  10  in FIGS. 1 a - 1   b  and  20  in FIGS. 7 a - 7   b , comprises an escutcheon plate  12 , the escutcheon plate  12  having terminals  14 A- 14 F on a back side  16  for electrical communication using control power circuit  18 ; a first plurality of LED bulbs  22  of a predetermined color mounted in a predetermined arrangement on the escutcheon plate  12 , the first plurality of LED bulbs  22  being visible from a front side  28  of the escutcheon plate  12 , so as to provide a visual indication of an open circuit status by lighting when the power distribution circuit is opened; a second plurality of LED bulbs  24  of a predetermined color mounted in a predetermined arrangement on the escutcheon plate  12 , the second plurality of LED bulbs  24  being visible from a front side  28  of the escutcheon plate  12 , so as to provide a visual indication of a close circuit status by lighting when the power distribution circuit is closed; the first plurality of LED bulbs  22  being electrically connected and mounted such that should any of the first plurality of LED bulbs  22  fail, the remaining LED bulbs are capable of lighting to provide the visual indication of the open circuit status and the failed LED bulbs are capable of being replaced from the front side  28  of the escutcheon plate  12  without interrupting the control circuit  18 ; and the second plurality of LED bulbs  24  being electrically connected and mounted such that should any of the second plurality of LED bulbs  24  fail, the remaining LED bulbs are capable of lighting to provide the visual indication of the close circuit status and the failed LED bulbs are capable of being replaced from the front side  28  of the escutcheon plate  12  without interrupting the control power circuit  18 . 
     The present invention may also include a third plurality of LED bulbs  26  of a predetermined color mounted in a predetermined arrangement on the escutcheon plate  12 , the third plurality of LED bulbs  26  being visible from a front side  28  of the escutcheon plate  12 , so as to provide a visual indication of a trip circuit status by lighting when the power distribution circuit is tripped; and the third plurality of LED bulbs  26  being electrically connected and mounted such that should any of the third plurality of LED bulbs  26  fail, the remaining LED bulbs are capable of lighting to provide the visual indication of the trip circuit status and the failed LED bulbs are capable of being replaced from the front side  28  of the escutcheon plate  12  without interrupting the control power circuit  18 . 
     As shown in FIG. 6, the escutcheon plate  12  for incorporation into the present invention would typically have terminals  14 A- 14 F accessible on the back side  16  of the escutcheon plate  12 . FIG. 2 depicts two different anticipated styles wherein style  1  shows the application of green (G) colored LED bulbs  30  for open status indication, red (R) colored LED bulbs  32  for close status indication, and yellow (Y) colored LED bulbs  34  for trip status indication. This light configuration is anticipated to be a standard application of the invention as shown in FIGS. 1 a  and  7   a . FIG. 2 also shows a conceptual depiction of a reversed light configuration, that is, style  2  which incorporates the green (G) colored LED bulbs  30  for close circuit status indication and red(R) colored LED bulbs  32  for open circuit status indication. The reversed light configuration is also shown in FIGS. 1 b  and  7   b.    
     FIG. 3 is a representative tabulation depicting typical LED voltage ratings, anticipated number of rows of LED bulbs, and a practical application of the color designation or determination and display result for the style  1  arrangement of FIGS. 1 a  and  7   a . Similarly, FIG. 4 is an equivalent tabulation for the style  2  arrangement of FIGS. 1 b  and  7   b . In a typical application, the LED bulbs corresponding to open, close or tripped status indication may provide a steady light when activated; however, it is preferred that the tripped status indication yellow LED bulbs  34  flash or blink “on” and “off” repetitively to enhance the warning effect of a tripped circuit. A typical conceptual wiring diagram for a Style  1  escutcheon plate is shown in FIGS. 5 a - 5   c  which depicts a typical functional relationship of the lights to the circuit breaker operating contacts. For example, in the flashing circuit shown in FIG. 5 c , if there is a fault in the power distribution circuit and the circuit breaker trips, an auxiliary switch contact (bell circuit) in the circuit breaker will close and the yellow LED bulbs  34  will begin to flash “on and off”. Also see FIG. 8 a.    
     The escutcheon plate  12 , as a minimum, will have a first plurality of LED bulbs  22  and a second plurality of LED bulbs  24 . However, it is preferred to incorporate at least one row or column of a third plurality of LED bulbs  26  to indicate trip circuit status. 
     Practically, it is desirable to have the first plurality of LED bulbs  22  arranged in a single row or a single column as shown in FIGS. 1 a ,  1   b    7   a  and  7   b ; however, a bank of two rows or columns would be acceptable. For example, a row or column may consist of six LED bulbs or two rows or columns of 3—4 LED bulbs in each row or column, the rows or column being grouped together. The second plurality of LED bulbs  24  may be similarly arranged. 
     Although the third plurality of LED bulbs  26  may be similarly arranged in a single row, a single column or a bank of two rows or columns of LED bulbs grouped together, it is preferable that the third plurality of LED bulbs  26  be arranged in two separate single rows or two separate single columns, generally at opposite sides of the front side  28  of the escutcheon plate  12  as depicted in FIGS. 1 a ,  1   b ,  7   a  and  7   b.    
     As discussed above for the anticipated style  1  and style  2  configuration of lights, a practical application of the invention would incorporate green colored LED bulbs  30  for the first plurality of LED bulbs  22  and red colored LED bulbs  32  for the second plurality of LED bulbs  24  or the reversed configuration would have red colored LED bulbs  32  for the first plurality of LED bulbs  22  and green colored LED bulbs  30  for the second plurality of LED bulbs  24 . 
     The third plurality of LED bulbs  26  are generally yellowish color. An amber color, for example, is acceptable in the industry. 
     A novel feature of the present invention heretofore not incorporated in such escutcheon plates for power distribution circuits is that should an LED short circuit, all others will remain lighted. If an LED open circuits, only two LED bulbs will not light. Further, failed LED bulbs can be removed by pulling the LED bulb straight out and the failed LED bulb can be replaced without deenergizing the circuit. 
     This is accomplished by including in the circuitry for the LED bulbs, zener diode bridge circuits  36  as shown in FIGS. 8 a  and  8   b . For the first plurality of LED bulbs  22  and the second plurality of LED bulbs  24 , a zener diode bridge circuit  36  is placed across each pair of LED bulbs in series succession so that should one of the LED bulbs fail, a voltage will increase across the pair of LED bulbs having the failed LED bulb to cause the remaining LED bulbs in the corresponding first and second plurality of LED bulbs  22 , 24  to remain lighted, thereby not losing corresponding open and close circuit status indication. 
     Similarly, the third plurality of LED bulbs  26  includes a zener diode bridge circuit  36  across each pair of LED bulbs in series succession so that should one of the LED bulbs fail, a voltage will increase across the pair of LED bulbs having the failed LED bulb to cause the remaining LED bulbs in the third plurality of LED bulbs  26  to remain lighted, thereby not losing trip circuit status indication. 
     As shown in FIG. 6, the escutcheon plate  12  in the present invention may be a control switch plate having handle means  38  extending from the front side  28  of the escutcheon plate  12  for manually opening and closing of the power distribution circuit. In another practical application of the present invention, the invention takes the form of a remotely located device wherein the escutcheon plate  12  is remotely located and in electrical communication with a control switch plate having handle means  38  extending from the front side  28  of the escutcheon plate  12  for manually opening and closing of the power distribution circuit. The advantage to this alternative embodiment is that in circumstances where an operator may have an obstructed view of the control switch plate, the operator can have a remotely located escutcheon plate  12  incorporating the open, close and trip status indication LED bulbs which is located near the operator&#39;s workstation and is viewed without any obstruction. 
     As seen from the foregoing description, the present invention satisfies a long felt need to provide a device which improves reliability and safety, while reducing costs, in the operation of power distribution equipment. 
     The invention is clearly new and useful. Moreover, it was not obvious to those of ordinary skill in this art at the time it was made, in view of the prior art considered as a whole as required by law. 
     It will thus be seen that the objects set forth above, and those made apparent from the foregoing description, are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing construction or shown in the accompanying drawings shall be interpreted as illustrative and not in the limiting sense. 
     It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. 
     Now that the invention has been described,