Abstract:
This invention is directed to a receptacle having an indictor which identifies the receptacle as being a hospital grade receptacle. The indicator can be a green colored window in the face of the receptacle that is always visible. A light emitting means such as a light emitting diode located behind the window and coupled across the phase and neutral contacts of the receptacle provides a positive indication that the receptacle is connected to a live circuit.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This invention relates generally to hospital grade receptacles and, more specifically to a hospital grade receptacle having a new improved identifier.  
           [0003]    2. Background of the Invention  
           [0004]    The National Electric Code published by the National Fire Protection Association, and as revised from time to time specifies that receptacles that are used in hospitals and may be wired to an emergency power supply branch circuit be designated with a distinguishing feature. This requirement is commonly met by marking hospital grade receptacles with a distinctive color such as, for example, a green dot. In contrast, general purpose receptacles located within a hospital are normally of a non-conspicuous color such as ivory or white without a distinguishing mark. It is to be noted that electrical receptacle manufactures may manufacture as many as four different grades of receptacles which are classified as residential grade receptacles, commercial grade receptacles, industrial grade receptacles and hospital grade receptacles. Of the four grades, the hospital grade receptacle is made to the highest and most rigid mechanical and electrical standards. The distinctive color, such as the green dot permits health care personnel to immediately identify the receptacle as being both a hospital grade receptacle and that it may be connected to an emergency power supply branch circuit of the hospital. Unfortunately, the green dot can not indicate to a health care person that the hospital grade receptacle is connected to a “live” emergency power supply branch circuit and is ready to power equipment connected to it. Thus, in those instances where there is an immediate need to connect a medical device to a source of power, the health care person may unknowingly plug the needed device into a hospital grade receptacle that is not connected to a “live” circuit. As the device that is plugged in will not operate because the receptacle in not currently energized, the health care person may reasonably assume that the non-operating device is defective, not that the device is connected to a receptacle with no power, and will lose valuable time searching for another device to use. Clearly, what is needed is a receptacle that can be easily and readily identified by a health care person that the receptacle is not only a hospital grade receptacle but, in addition, that the receptacle is connected to a live electrical circuit.  
         SUMMARY OF THE INVENTION  
         [0005]    This invention is directed to a receptacle having an indicator which identifies the receptacle as being a hospital grade receptacle. The indicator can be a green colored window in the receptacle face that is always visible. A light emitting means such as a light emitting diode located behind the window and coupled across the phase and neutral contacts of the receptacle provides a positive indication that the receptacle is connected to a live circuit.  
           [0006]    The above and other aspects, features and advantages of the invention will be more readily apparent from the description of the preferred embodiments taken in conjunction with the accompanying drawings and appended claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    The invention is illustrated by way of example, and not limitation, in the figures of the accompanying drawings in which like reference characters denote like and corresponding parts and in which:  
         [0008]    [0008]FIG. 1 is a side perspective view of a 15 amp. or 20 amp. 125 volt duplex electrical receptacle having an indicator in accordance with the principles of the invention;  
         [0009]    [0009]FIG. 2 is a partial exploded, side perspective view of the duplex electrical receptacle of FIG. 1;  
         [0010]    [0010]FIG. 3 is a perspective view of the phase contacts prior to being placed within the base member of the duplex receptacle;  
         [0011]    [0011]FIG. 4 is a perspective view of mounting strap and ground contacts prior to being assembled to the base member of the duplex receptacle;  
         [0012]    [0012]FIG. 5 is a perspective view of the underside of the face of a 15 amp. 125 volt and 20 amp. 125 Volt duplex electrical receptacle showing an insulating member covering the bottom of a printed circuit board located in the receptacle face;  
         [0013]    [0013]FIG. 6 is an exploded side perspective partial assembly of the underside of the face of a 15 amp. 125 volt and 20 amp. 125 volt duplex electrical receptacle and the printed circuit board assembly;  
         [0014]    [0014]FIG. 7 is another exploded side perspective partial assembly of the underside of the face of a 15 amp. 125 volt and 20 amp. 125 volt duplex electrical receptacle and printed circuit board assembly;  
         [0015]    [0015]FIG. 8 is a top perspective view of the printed circuit board assembly;  
         [0016]    [0016]FIG. 9 is a bottom perspective view of the printed circuit board assembly;  
         [0017]    [0017]FIG. 10 is a bottom perspective view of the printed circuit board assembly showing the location of room temperature vulcanizing silicon dabs for holding an insulating member;  
         [0018]    [0018]FIG. 11 is a view of the insulating member;  
         [0019]    [0019]FIG. 12 is a schematic diagram of the circuit on the printed circuit board;  
         [0020]    [0020]FIG. 13 is a perspective view of the top of the face of a 20 amp. 125 volt receptacle in accordance with the principles of the invention;  
         [0021]    [0021]FIG. 14 is a perspective view of a 15 amp. 125 volt, and in phantom, a 20 amp. 125 volt duplex electrical receptacle having a flat face and an indicator in accordance with the principles of the invention.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0022]    Referring to FIG. 1, there is shown a side perspective of a duplex 15 amp. 125 volt electrical receptacle  10  having a face  12  in accordance with the principles of the invention. Apertures  14 ,  16  and  18  in the face plate are arranged to receive the neutral, phase and ground blades of a first electrical plug, and apertures  20 ,  22  and  24  are arranged to receive the neutral, phase and ground blades of a second electrical plug. A mounting strap  26  having slots  28  permits the receptacle  10  to be mounted to threaded mounting holes of a standard outlet box (not shown). A threaded aperture  30  permits a wall plate (not shown) to be installed over the receptacle  10 .  
         [0023]    Referring to FIG. 2, there is illustrated a partial exploded side perspective view of the duplex receptacle of FIG. 1 wherein base member  32  has a top contact section  33  which contains a number of chambers defined by insulation barriers within which are placed electrical contacts for receiving the prongs of a plug and adapted, by means of screw terminals  6 , to be connected to conductors of an AC power source. As best seen in FIG. 2, insulation barriers are provide to form chambers to house the neutral and phase electrical contact  34 ,  36  and ground contact  38  for one plug. In a similar manner, insulation barriers are provided to form chambers to house neutral and phase electrical contacts  40 ,  42  and ground contact  44  for a second plug. FIG. 3 is an isometric view of one set of contacts such as phase contacts  36 ,  42  adapted to be connected to the phase blade of a plug and the phase conductor of a source of electricity. A similar set of contacts such as neutral contacts  34 ,  40  (see FIG. 2) are adapted to be connected to the phase blades of two plugs and the phase conductor of the source of electricity. Terminal screws  46  located on the side surface of the base member are provided for connecting contacts  36 ,  42  to the phase conductor of a source of power. In a similar manner, two terminal screws located on the other side surface of the base member are provided to couple the other set of contacts  34 ,  40  to the neutral conductor of a source of power. Referring to FIG. 4, mounting strap  26  supports ground contacts  38 ,  44  which, in the assembled receptacle, are located in separate chambers of the base member formed by insulating barriers. Mounting strap  26  is coupled to base member  32  by means of two projections  48  (see FIG. 2) located on the base member which engage openings  50  (see FIG. 4) in each side leg of the mounting strap. In one embodiment the chambers for housing the ground contacts have open bottoms to allow the ground contacts to enter their respective chamber from the bottom. A terminal screw  45  connected to the mounting strap is provided for connecting a ground conductor to the mounting strap to provide a ground connection for the ground contacts  38 ,  44 .  
         [0024]    Referring to FIG. 5, there shown a perspective view of the underside of the face  12  of the duplex electrical receptacle supporting a printed circuit board covered by an insulating member  66 . As shown in FIG. 5, the printed circuit board is located within the underside of the receptacle face and is supported by the edges of some of the insulating barriers. The printed circuit board assembly comprises a series circuit of a resistor  54 , a diode  56  and a light emitting diode  58  (LED). See FIG. 6.  
         [0025]    Referring to FIG. 6, there is shown the printed circuit board  60  about to be positioned into the underside of face  12 . The top surface of the printed circuit board  60  supports the resistor  54 , diode  56  and LED  58  which are electrically coupled via conductive traces to a first contact pad  62  and a second contact pad  64 . Contact pad  62  is located at one end of the series circuit of the resistor, diode and LED; and the second contact pad  64  is located at the other end of the series circuit.  
         [0026]    [0026]FIG. 7 is another exploded side perspective partial assembly view of the underside of the face of the duplex electrical receptacle just prior to receiving the assembled printed circuit board. The printed circuit board, when positioned within the face of the receptacle, is supported by ends of the insulating barriers, and the light emitting diode  58  is positioned directly behind the window  74  (see FIG. 2) in the receptacle face.  
         [0027]    Referring to FIGS. 8 and 9, the series resistor  54 , diode  56 , light emitting diode  58  circuit on the printed circuit board  60  is connected as follows: Initially, it is to be noted that each of the three components, the resistor  54 , the diode  56  and the LED  58  are located on the top side of the printed circuit board. Contact pad  62  is connected via a conductive trace on the underside of the board  60  to a first lead of the resistor  54 . The second lead of the resistor  54  is connected via a conductive trace on the underside of the board to a first lead of the LED  58 . The second lead of the LED  58  is connected to a first lead of the diode  56  via a conductive trace on the top side of the printed circuit board, and the second lead of the diode  56  is connected to the contact pad  64  via a conductive trace on the underside of the printed circuit board.  
         [0028]    As noted above, this invention is directed to providing an identifier for a receptacle to identify the receptacle as being a hospital grade receptacle and, in addition, to indicate if the circuit that is connected to the receptacle is a live circuit. This invention is not limited to any one specific type of hospital grade receptacle, but can be use in combination with any hospital grade receptacle. The receptacle itself, not including the identifier, shown in the Figs. is representative of any hospital grade receptacle.  
         [0029]    Referring to FIGS. 5, 6 and  7 , to assemble the printed circuit board into the face of the receptacle, the face may be positioned underside up to receive the printed circuit board. The printed circuit board, shown in FIG. 6 as being right side up, is turned over, see FIG. 7, and placed on top of the insulation barriers on the inside of the face  12 . The face  12  has a window opening  74  which extends through the top surface of the face and the LED  58  on the printed circuit board is aligned with the window to allow light from the LED to pass through the window to be visible from the outside of the receptacle. The window  74  in the face can have a round green lens which will not only help identify the receptacle as being a hospital grade receptacle, and, at the same time, help keep dirt from entering the receptacle. A sheet of fiber insulating material  66 , see FIG. 11 is attached to the bottom of the printed circuit board. The sheet of insulating material is held to the bottom of the printed circuit board with room temperature vulcanizing (RTV) silicon. FIG. 10 shows the location of three small dabs  68  of RTV on the bottom surface of the printed circuit board for holding the fiber insulating material to the printed circuit board. The fiber insulating material covers the bottom surface of the printed circuit board.  
         [0030]    After the printed circuit board and attached fiber insulating material is positioned within the face as shown in FIG. 5, the base member is assembled to the face  12  and held in place by means of locking tabs  70  (see FIG. 5) located on the face which engage holding members  72  (see FIG. 2) on the base member. As the base member is moved toward the face, the ends of the contact pads  62 ,  64  on the printed circuit board engage and make electrical contact with the neutral and phase contacts in the base member. More specifically, the end of conductive pad  64  makes electrical contact with the small vertical projection  74  (see FIG. 3) on the neutral contact and the end of conductive pad  62  makes electrical contact with a similar small vertical projection of the phase contact.  
         [0031]    Referring to FIG. 13, there is illustrated the face of a 20 amp. 125 volt receptacle with indicator in accordance with the principles of the invention.  
         [0032]    [0032]FIG. 14 shows a flat face of a 15 amp. 125 volt receptacle and, in phantom, a 20  
         [0033]    While there have been shown and described and pointed out the fundamental novel features of the invention as applied to the preferred embodiment, as is presently contemplated for carrying them out, it will be understood that various omissions and substitutions and changes of the form and details of the device illustrated and in its operation may be made by those skilled in the art, without departing from the spirit of the invention.