Patent Abstract:
An electrical connector assembly ( 10 ) incorporates a connector ( 12 ) with a switch and is designed to electrically and mechanically connect and disconnect to a mating electrical device ( 14 ) while maintaining a closed circuit continuously through the connector. The mating electrical device includes a plurality of conductive contacts ( 20 ). The electrical connector includes an insulating housing ( 30 ) with at least a pair of input and output terminals ( 32 ) mounted on the housing. The terminals include contact portions ( 32   b ) for engaging the contacts of the mating electrical device. A switch mechanism ( 40; 60 ) is movably mounted on the housing for movement between a connecting position and a disconnecting position. The switch mechanism includes a latch member ( 48; 17 ) and at least one switch terminal ( 44 ). In the connecting position, the latch member is interengaged with a latch ( 26; 62 ) on the mating electrical device with the switch terminal out of engagement with the input and output terminal. In the disconnecting position, the latch member ( 48, 17 ) is disengageable from the latch ( 26, 62 ) on the mating electrical device so that the device can be removed from the assembly with the switch terminal ( 44 ) in engagement with the input and output terminals ( 32 ) to maintain a closed circuit through the connector ( 12 ) when the mating electrical device ( 14 ) is removed.

Full Description:
FIELD OF THE INVENTION 
       [0001]    This invention generally relates to the art of electrical connectors and, particularly, to an electrical switch connector assembly incorporating a switch to electrically and mechanically connect and disconnect a mating electrical device while maintaining a closed electrical circuit continuously through the connector assembly. 
       BACKGROUND OF THE INVENTION 
       [0002]    Electrical power is supplied to an individual site by external electrical power line conductors located above or below ground. In a conventional arrangement, electrical power line conductors and electrical load conductors are connected directly to contacts in a watt-hour meter mounted on a building wall. The watt-hour meter is used to measure the electric power drawn through the circuit. 
         [0003]    These meters must be removed periodically for servicing, calibration or replacement. Since the meter is connected to the circuit in series, the removal of the meter will open the circuit. In order to avoid such an open circuit condition after the meter is removed, the input and output electrical conductors to and from the meter must be shorted. 
         [0004]    A number of methods exist to create this short circuit. Two such methods require the skill of an electrical technician. In one instance, the technician is required to place jumper wires between the input and output conductors. In another instance, the technician uses a separate device that connects to all of the input and output conductors at the same time. 
         [0005]    Still another method includes the use of a non-conductive blade inserted between input and output and shorting terminals. When the blade is inserted, the shorting arms are moved out of engagement with the input and output terminals allowing current to flow through the meter. When the blade is removed from between the terminals, the shorting terminals engage respective input and output terminals creating the short that will allow the meter to be removed without opening the circuit. This method works well but there is no provision for wiping the terminals to remove any non-conductive material on the contact surfaces. Also to allow for relatively easy insertion and removal of the non-conductive blade, the spring force in the shorting terminals cannot be too great. If there is any non-conductive material build-up on the contact surfaces, the spring force may not be great enough to force the shorting terminal through the build up resulting in an incomplete or even non-existent electrical connection. Also with a blade there is an extra part that can be lost and there still must be a separate feature that locks the meter with the connector. 
         [0006]    A final method includes a projection on the meter that acts like the blade method described above. Although the projection is part of the meter and does not require a separate part that can get lost, there still must be a separate feature that locks the meter with the connector. 
         [0007]    These prior art methods are expensive since in some cases an expensive technician must be employed or in other instances the meter is more complicated requiring extra parts. Also a consistent electrical contact is not always ensured since the contacting surfaces of the mating switch terminals don&#39;t provide any wiping that can remove any non-conductive build up on the mating surfaces of the terminals. Also some of these methods allow the terminals to be exposed to the weather and are also capable of accidental or unintentional contact by testing personnel or other personnel unaware of the exposed electrical potential. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention is directed to solving the problems of the prior art by providing an electrical connector assembly that uses a connector with a switch, the connector being readily connected and disconnected both electrically and mechanically to a mating electrical device, such as an electrical meter, while maintaining a continuous closed circuit current flow through the connector. Also, the connector provides a wiping action to improve the electrical connection and will be safer with fewer exposed terminals. 
         [0009]    In an exemplary embodiment of the invention, an electrical connector assembly incorporates a connector with a switch mechanism and is designed to electrically and mechanically connect and disconnect a mating electrical device while maintaining a closed circuit current flow through the connector. The mating electrical device includes a plurality of conductive contacts. The electrical connector includes an insulating housing with at least a pair of input and output terminals from one circuit mounted on the housing. The terminals include contact portions for engaging the contacts of the mating electrical device. 
         [0010]    The switch mechanism is movably mounted on the housing for movement between a connecting position and a disconnecting position. The switch mechanism includes a latch member and at least one switch terminal. In the connecting position, the latch member is inter-engaged with a latch on the mating electrical device with the switch terminal out of engagement with the input and output terminal. In the disconnecting position, the latch member is disengageable from the latch on the mating electrical device so that the device can be removed from the assembly with the switch terminal in engagement with the input and output terminals to maintain a circuit through the connector when the mating electrical device is removed. 
         [0011]    According to one aspect of the invention, the switch mechanism comprises a rotating shaft mounted on the housing. The switch terminal is disposed at an outer periphery of the shaft. The shaft is elongated and is rotatable about its longitudinal axis. The input and output terminals are spaced longitudinally along the shaft. The switch terminal extends longitudinally for shorting the input and output terminals in the disconnecting position of the shaft. 
         [0012]    According to another aspect of the invention, the mating electrical device includes an actuator for moving the switch mechanism between its connecting and disconnecting positions. The actuator includes the latch for inter-engagement with the latch member on the movable switch mechanism. In the exemplary embodiment, the actuator comprises a lever pivotally mounted on the mating electrical device on an axis coincident with the axis of rotation of the shaft that forms the switch mechanism. 
         [0013]    According to a further aspect of the invention, the connector housing and the mating electrical device have mounting faces mountable on a support structure in a coplanar relationship. The mating electrical device is mated onto the housing in a mating direction generally perpendicular to their mounting faces. A plurality of guide projections on the connector housing extend in the mating direction for positioning in a corresponding plurality of guide apertures in the mating electrical device. 
         [0014]    Other features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The features of this invention that are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which: 
           [0016]      FIG. 1  is a perspective view of an electrical connector assembly including a connector and a mating electrical device, with the connector and the device in a disconnecting position; 
           [0017]      FIG. 2  is a side elevation view of the assembly of  FIG. 1 ; 
           [0018]      FIG. 3  is a view similar to that of  FIG. 2 , but with the device connected to the connector and with the actuating lever on the device in its disconnecting position; 
           [0019]      FIG. 4  is a perspective view of the assembly with the actuating lever on the device pivoted to its connecting position; 
           [0020]      FIG. 5  is a view similar to that of  FIG. 3 , with the actuating lever on the device pivoted to its connecting position; 
           [0021]      FIG. 6  is a fragmented, partially cut-away perspective view of the assembly, with the connector housing removed to show the switch shaft, and with the housing of the electrical device removed to show the interconnection of the contacts and the terminals of the assembly in the disconnecting position; 
           [0022]      FIG. 7  is a perspective view of the switch shaft, with one of the switch terminals removed from the shaft; 
           [0023]      FIG. 8  shows an end elevation view of the switch shaft in conjunction with one of the connector terminals, and with the shaft in its disconnecting position from the electrical device; 
           [0024]      FIG. 9  is a view similar to that of  FIG. 8 , with the switch shaft in its connecting position when the connector is connected to the electrical device; 
           [0025]      FIG. 10  is a perspective view of an alternate embodiment with a sliding switch actuator in its disconnecting position from the electrical device; 
           [0026]      FIG. 11  shows an end elevation view of the switch shaft of the alternative embodiment in conjunction with one of the connector terminals, and with the shaft in its disconnecting position from the electrical device; 
           [0027]      FIG. 12  shows an end elevation view of the switch shaft in the alternative embodiment in conjunction with one of the connector terminals, and with the shaft in its connecting position from the electrical device; 
           [0028]      FIG. 13  shows a perspective view of the sliding actuator of the alternate embodiment; 
           [0029]      FIG. 14  shows a perspective view of the sliding switch shaft of the alternate embodiment; 
           [0030]      FIG. 15  is a perspective cross sectional view of the alternate embodiment similar to  FIG. 10  with a sliding switch actuator in its disconnecting position from the electrical device; and 
           [0031]      FIG. 16  is a perspective cross sectional view of the alternative embodiment view with the sliding switch actuator in its connecting position when the connector is connected to the electrical device. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0032]    Referring to the drawings in greater detail, and first to  FIGS. 1 and 2 , the invention is incorporated in an electrical connector assembly, generally designated  10 , which includes an electrical connector, generally designated  12 , and a mating electrical device, generally designated  14 . Although the invention has a variety of applications, the mating electrical device  14  is an electrical meter in the exemplary embodiment. An electrical current is supplied from a source into and out of the meter  14  through the connector  12  and through a current transformer. If the transformer secondary circuit is open while a load is connected to the transformer primary circuit, very high voltage spikes (kilovolts) induced over the open secondary circuit are likely to impair human safety and/or transformer isolation. To prevent this risk it is essential that a continuous closed electrical circuit be maintained even when the meter is removed. 
         [0033]    The meter, according to this invention, can be very easily and safely mated and unmated with the connector in the direction of double-headed arrow “A.” As will be seen hereinafter, when the meter is mated with the connector, an electrical circuit flows through the connector into and out of the meter. When the meter is unmated from the connector, the current continues to flow through the connector with the help from a shorting circuit created by a shorting terminal. The connector housing  30  and the mating electrical device  14  have mounting faces  30   a ,  16   a  that are mountable on a support structure in a coplanar relationship. The mating electrical device is mateable onto the housing in a direction generally perpendicular to their mounting faces. 
         [0034]    Still referring to  FIGS. 1 and 2 , the electrical device  14  includes a non-conductive housing  16  having a generally planar rear mounting face  16   a  and a bottom face  16   b . A pair of guide bosses  18  project from the bottom face  16   b . The guide bosses  18  have through-holes  18   a  that extend in the mating direction “A.” As best seen in  FIG. 1 , a row of blade contacts  20  made from a conductive material are exposed across the bottom of the housing  16 . An actuator in the form of an actuating lever, generally designated  22 , is pivotally mounted at the bottom of the housing  16 . The lever has a pair of pivot arms  22   a  that is pivotally mounted by means of a pair of pivot bosses  22   b  inside a pair of pivot flanges  24  that project forwardly of the housing  16  at opposite ends of the row of blade contacts  20 . A somewhat elongated latch projection or boss  26  projects inwardly at the distal end of each pivot arm  22   a . Pivot bosses  22   b  project outwardly at the distal end of each pivot arm  22   a . A pair of locks or latch projections  26  is located generally on the pivot axis. The pivot axis of the actuator lever  22 , as defined by the pivot bosses  22   b , is coincidental with the axis  42  of rotation of the switch shaft  40  described below. 
         [0035]      FIG. 3  shows the electrical device  14  moved into full mating condition with the connector  12 . Once the device is mated with the connector, the actuating lever  22  on the meter can be pivoted in the direction of arrow “B” until the lever reaches a connecting position as shown in  FIGS. 4 and 5 . 
         [0036]    Referring to  FIG. 6  in conjunction with  FIGS. 1 and 5 , the connector  12  includes a non-conductive housing  30  ( FIGS. 1 and 5 ) that mounts a plurality of input and output terminals  32  ( FIG. 6 ). The housing  30  has a pair of guide projections  34  as best seen in  FIGS. 1 and 5 . The guide projections  34  are received within the guide holes  18   a  ( FIG. 1 ) of the guide bosses  18  at the bottom of the housing  16  of the meter  14  as can be seen clearly in  FIG. 4 . The terminals  32  are elongated and include terminating portions  32   a  ( FIG. 6 ) at one end for termination to a plurality of electrical wires  36 . The terminals have contact portions  32   b  at the opposite ends thereof for receiving the blade contacts  20  from the device  14 . The contact portions  32   b  are spring-loaded and are bifurcated for receiving the blade contacts and clamping the blade contacts under good contacting forces. 
         [0037]    It should be understood that electrical device  14  can take a variety of configurations or characteristics. In the exemplary embodiment, for instance, the electrical device  14  is a three-phase meter requiring four inputs and four outputs. One pair of input and output terminals is used for each phase with the remaining pair used for a neutral circuit. In other words, it can be seen that there are eight electrical wires  36  leading to eight terminals  32  in the connector  12 , with the eight terminals being engageable with eight blade contacts  20  of the meter  14 . 
         [0038]    When the meter  14  is mated with the connector  12  in the connecting position, alternating ones of the electrical wires/terminals/blade contacts would be inputs from a power source or load, while the other alternating electrical wires/terminals/blade contacts would be outputs of the system, resulting in four pairs of inputs and outputs. Each current circuit is then closed by a current measuring device (not shown) located inside the meter housing. When the meter  14  is to be unmated from the connector  12 , short circuits must first be provided between the inputs and the outputs of each pair in order to prevent each current circuit from being opened. Therefore, a switch mechanism in the form of a rotatable switch shaft, generally designated  40  ( FIG. 6 ), is rotatably mounted within the housing  30  of the connector  12 . 
         [0039]    In an alternative embodiment, the switch mechanism takes the form of a sliding actuator generally designated  62  ( FIGS. 10 ,  13 ,  15 , and  16 ) that is moved within the housing  30  of the connector  12 . In either embodiment the switch mechanism can include portions of the housing ( 30 ). 
         [0040]    More particularly, referring to  FIG. 7  in conjunction with  FIG. 6 , the switch shaft  40  is elongated and is rotatable about its longitudinal axis indicated at  42 . Four switch terminals, generally designated  44 , are mounted on the switch shaft at spaced intervals longitudinally therealong. As seen by the removed switch terminal  44  in  FIG. 7 , each switch terminal includes a blade-like body portion  44   a  that is press-fit into a respective slot  46  in the switch shaft  40  in the direction of arrow “C.” Each switch terminal includes a pair of contact portions  44   b  for engaging a pair of the input and output terminals  32  related to the same circuit. In other words, with each adjacent input and output electrical wire  36  and their respective input and output terminals  32 , one switch terminal  44  is provided with two contact portions  44   b  for shorting out that respective pair of input and output wires/terminals, as will be seen hereinafter. 
         [0041]    Still referring to  FIGS. 6 and 7 , the switch shaft  40  may be fabricated of a non-conductive material such as plastic or the like, and each opposite end of the shaft is provided with a locking member or latch slot  48  that is somewhat elongated for receiving one of the latch projections  26  ( FIG. 1 ) inside one of the pivot arms  22   a  of the actuating lever  22 . When the elongated latch projections  26  on the lever  22  are inserted into the elongated latch slots  48  of the switch shaft  40 , a driving connection is created between the lever and the switch shaft for rotating the shaft in response to pivoting the lever. As best seen in  FIG. 7 , a pair of locking bosses  50   a  and  50   b  project radially from the switch shaft at each opposite end thereof. Referring back to  FIG. 2 , it can be seen that the housing of the connector  12  is provided with a locking recess  52  for receiving either one of the locking bosses  50   a  or  50   b.    
         [0042]    In an alternate embodiment, the switch shaft  40  is replaced with a sliding shaft  70  that slides in either direction “E” or “F” in  FIG. 10 . The switch terminals  74  are mounted at spaced intervals longitudinally along the actuator  60 . The electrical device  14  includes a non-conductive housing  16  having a generally planar rear mounting face  16   a  and a bottom face  16   b . A pair of guide bosses  18  project from the bottom face. The guide bosses have through-holes  18   a  that extend in the mating direction “A”. An actuator in the form of an actuating lever, generally designated  62 , is slidably mounted at the bottom of the housing  16 . The lever has a pair of sliding arms  62   a  that are mounted by means of a pair of sliding bosses  62   b  inside an opening  64   b  in a pair of flanges  64  that project forwardly of housing  16  at opposite ends. As shown in  FIG. 13 , the elongated latch slot  66  is directed inwardly at the distal end of each sliding arm  62   a.    
         [0043]      FIG. 10  shows the electrical device  14  moved into full mating condition with the connector  12 . Once the device is mated with the connector, the actuating lever  62  on the meter can be slid in the direction of arrow “E” until the lever reaches a connecting position. 
         [0044]    Referring to  FIG. 10  in conjunction with  FIGS. 11 and 12 , the connector  12  includes a non-conductive housing  30  that mounts a plurality of input and output terminals, generally designated  32 . The housing has a pair of guide projections  34  that is received within the guide holes  18   a  of the guide bosses  18  at the bottom of the housing  16  of the meter  14 , as can be seen clearly in  FIG. 10 . The terminals  32  are elongated and include the terminating portions  32   a  at one end for termination to a plurality of electrical wires  36 . The terminals have contact portions  32   b  at the opposite ends thereof for receiving blade contacts from the device  14 . The contact portions  32   b  are spring-loaded and bifurcated for receiving the blade contacts and clamping the blade contacts under good contacting forces. 
         [0045]    Referring to  FIG. 14  in conjunction with  FIGS. 11 ,  12 , and  14 , the switch shaft  70  is elongated and is slidable within the housing  16 . Four switch terminals, generally designated  74  ( FIGS. 11 and 12 ), are mounted on the switch shaft at spaced intervals longitudinally therealong. Each switch terminal includes a blade-like body portion  74   a  that is press-fit into a respective slot  76  in the switch shaft  70 . Each switch terminal includes a pair of contact portions  74   b  for engaging a pair of the respective input and output terminals  32 . In other words, with each adjacent input and output electrical wire  36  and their respective input and output terminals  32 , one switch terminal  74  is provided with the two contact portions  74   b  for shorting out that respective pair of input and output terminals. 
         [0046]    Referring to  FIGS. 13 ,  14 ,  15 , and  16 , the switch shaft  70  may be fabricated of a non-conductive material such as plastic or the like, and each opposite end of the shaft is provided with a latch projection  78  that is somewhat elongated for being received in one of the latch slots  66  inside one of the sliding arms  62   a  of actuating lever  62 . When the elongated latch slots  66  on the lever  22  are inserted into the elongated latch projections  78  of the switch shaft  70 , a driving connection is created between the lever and the switch shaft for sliding the shaft in response to sliding of the lever. As seen in  FIGS. 15 and 16 , a pair of locks or locking bosses  68  project outwardly from the actuator lever  62  at each opposite end thereof  FIG. 15  shows the electrical device  14  and the connector  12  when they are first moved together but prior to their being locked together. This corresponds to  FIG. 11  where the switch terminals  74  are in the shorting position with the input output terminals  32 . In  FIG. 16  the actuator lever  62  has been moved in the direction “E” that is where the electrical device  14  and the connector  12  are locked together. In this position, the locking boss  68  slides under the locking member or the locking shoulder  16   d . This corresponds to  FIG. 12  where the switch terminals  74  are slid out of their shorting position with the input output terminals  32 . 
         [0047]    The operation of the electrical connector assembly  10  now will be described, particularly in relation to the function of the switch shaft  40  as seen in  FIGS. 8 and 9  and the sliding actuator  62  in  FIGS. 10-16 . In particular, after proper calibration, the meter  14  is mated with the connector  12  as described above in relation to the sequential depictions in  FIGS. 2 and 3 . It should be noted that the connector, in the disconnected position as seen in  FIGS. 1 and 2 , have fewer areas of exposed terminals that can be contacted by other conductive parts or by an operator&#39;s hands. This makes the connector safer than the prior art connectors. 
         [0048]    For mating to occur, the actuating lever  22 ,  62  must be in the position shown on  FIGS. 2 and 10  respectively with respect to the meter housing  16 . At the electrical connectors side, the switch shaft  40  is in a shorting position wherein the contact portions  40   b  of the switch terminals  44  are establishing short circuits between the input and output terminals  32  and their respective input and output electrical wires  36 , and wherein the latch slots  48  at opposite ends of the shaft open upwardly or the latch projections  78  open downwardly (see  FIGS. 15 ,  16 ). It can be seen that locking bosses  50   a  at opposite ends of the shaft are locked within the locking recesses  52  to hold the shaft in this position. 
         [0049]    The meter  14  is moved into mating position with the connector in the direction of arrow “A” whereby the blade contacts  20  of the meter  14  are pushed into the bifurcated contact portions  32   b  of terminals  32  as seen in  FIG. 6 . As seen in  FIG. 3 , the latch projections  26  ( FIG. 1 ) on the lever  22  will move into the latch slots  48  or, as seen in  FIGS. 15 and 16 , the latch projection  78  will move into the latch slots  66  in the sliding lever  62  to establish a driving connection between the actuation lever  22 ,  62  and the shaft  40 ,  70 . Also the guide projections  34  are received within the guide holes  18   a , which helps to prevent movement between the electrical device  14  and the connector  12  in either direction “E” or “F”. In this pre-existing position, the switch shaft  40 ,  70 , as seen in  FIGS. 8 and 11 , the contact portions  40   b ,  70   b  of the switch terminals  44 ,  74  are still establishing short circuits between the input and output terminals  32  and their respective input and output electrical wires  36 . However, additional current circuits provided by the meter in parallel to short circuits will now exist, making it possible to remove the short circuits with out any risk of an open circuit. 
         [0050]    The actuating lever  22  then is pivoted in the direction of arrow “B” ( FIG. 3 ) to the position shown in  FIGS. 4 and 5  or the actuator lever  62  is slid in the direction of arrow “E”. Pivoting of the lever  22  correspondingly rotates the switch shaft  40  in the direction of arrow “D” as seen in  FIG. 9 . Moving the sliding actuator  62  in the direction of arrow “E” slidably moves the switch shaft  70 , as seen in  FIG. 12 . This moves the contact portions  44   b ,  74   b  of the switch terminals  44 ,  74  out of shorting engagement with the input and output terminals  32 . The movement of the switch terminals  44 ,  74  over the input and output terminals  32  will remove some of any non-conductive material that may build up on either of the contact surfaces between the switch terminals  44 ,  74  and the input and output terminals ensuring a better electrical connection. 
         [0051]    With the blade contacts  20  of the meter  14  inserted into the contact portions  32   b  of the terminals  32 , circuits now are closed with electrical current flowing into and out of the meter  14 . In the shorting condition of the switch shaft  40 , the locking bosses  50   a  are snapped into the locking recesses  52  as seen in  FIG. 2  to hold the switch shaft in its shorting position. When the lever rotates the shaft to the position of  FIG. 9 , the locking bosses  50   a  snap out of the locking recesses  52  and the locking bosses  50   b  snap into the locking recesses to hold the shaft and the lever in the connecting position of the meter and the connector. 
         [0052]    Other features that should be noted include the fact that the meter  14  cannot be disconnected from the connector  12  when the rotating lever  22  is in the position of  FIGS. 4 and 5  or when the sliding actuator  62  is in the position as seen in  FIG. 16 . In other words, the interengagement of the latch projections  26  on the lever within latch the slots  48  on the shaft or of the locking boss  68  of the sliding actuator  62  under the locking shoulder  16   d  will provide latch means to help hold the meter and the connector in a mated condition.  FIG. 8  represents a disconnecting position of the switch shaft  40  whereby the latch projections  26  can be easily moved out of the latch slots  48  and further whereby the switch terminals  44  engage the input-output terminals  32 .  FIGS. 10 and 15  also represent a similar disconnecting position.  FIGS. 9 and 12  represent a connecting position of switch shaft  40 ,  70  with the meter and connector connected to each other. This locking occurs because the latch projections  26  can not be removed from the latch slots  48  or the locking boss  68  cannot be removed from under locking shoulder  16   d  along with the interaction between the guide projections  34  and the guide holes  18   a . In this connecting position the switch terminals  44 ,  74  are out of engagement with the input and output terminals  32 . 
         [0053]    As seen in  FIGS. 4 and 10 , the housing  30  of the connector  12  has a rear mounting face  30   a  that is coplanar with the rear mounting face  16   a  of the housing  16  of the meter  14 , whereby the connector assembly  10  can be mounted on a flat or generally planar support surface. To that end, as seen in  FIG. 5 , the housing of the connector has a mounting flange  30   b  projecting out of each opposite side thereof for receiving appropriate fasteners to mount the connector to the support surface. The meter  14  has a mounting flange  16   c  for receiving appropriate fasteners to mount the meter to the support structure. 
         [0054]    It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.

Technology Classification (CPC): 7