Abstract:
A pair of mating electrical connectors are disclosed that include at least one heat generating element to prevent the electrical connectors from becoming covered with ice or snow in cold climates and to also make the electrical connectors easier to separate or plug together in cold environments. When the mating electrical connectors are connected and energized, electricity will flow through the at least one electrical heat generating element generating heat within the electrical connectors. The amount of heat that is generated within the electrical connectors is sufficient to prevent snow and ice from forming on the exterior of the mating electrical connectors, even in very cold ambient weather conditions, and to ease the disconnection of the mated electrical connectors in such cold ambient weather conditions.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates generally to electrical connectors, and more specifically to mating electrical connectors that include at least one heat generating element to prevent the electrical connectors from becoming covered with ice or snow in cold climates and to also make the electrical connectors easier to separate or plug together in cold environments. 
     Snow plows, spreaders, and other cold weather vehicle accessories have been mounted on vehicles such as pickup trucks or sport utility vehicles (SUV&#39;s) for some time. Such snow plows, spreaders, and other cold weather vehicle accessories are removable from the vehicle so that they need be attached to the vehicle only when needed. Typically, the installation and removal of such cold weather vehicle accessories has two aspects, namely a mechanical attachment aspect and an electrical connection aspect. The mechanical attachment aspect involves the mechanical apparatus used to conveniently and removably mount such cold weather vehicle accessories onto a vehicle. 
     The electrical connection aspect involves supplying electrical power as well as electrical control signals from the vehicle to the cold weather vehicle accessory. For example, for snow plows, electrical connections between the vehicle and the snow plow include a power connection, multiple electrical connections to operate the plow mechanism to raise, lower, and angle a snow plow blade, and multiple connections to operate headlights, running lights, and turn signals mounted on the snow plow. For spreaders, electrical connections between the vehicle and the spreader include a power connection multiple electrical connections to operate the spreader. 
     Since such cold weather vehicle accessories must be easy and convenient to install onto and remove from a vehicle, those skilled in the art will understand that the electrical connections between a vehicle and the cold weather vehicle accessory must necessarily be made using one or more mating pair of electrical connectors that may be conveniently engaged and disengaged to respectively connect and disconnect a cold weather vehicle accessory onto a vehicle. Such mating pairs of electrical connectors typically have engageable male and female connectors each having a multiplicity of electrical connections. Due to the application for use in which the connectors are exposed to harsh winter weather, such electrical connectors must be sealingly engageable and must also contain an locking mechanism maintaining the male and female connectors securely together until they are to be disengaged. 
     Such connectors typically have engageable housings with mating shrouds to seal the mating electrical contacts contained in the connectors from the harsh winter weather. While it is generally quite simple to connect the male and female electrical connectors together, it is often substantially more difficult to disconnect them while the vehicle is located in a cold outside environment. Often, snow and ice will build up on the mated connectors, which may need to be chipped off in order to access the locking mechanism on the connectors. Additionally, since the mated connectors are located in a very cold ambient environment, they often prove to be quite difficult to disconnect, since the extreme cold tends to make them difficult to pull apart even when they are no longer locked together. 
     Thus, it is apparent that it would be desirable to improve the characteristics such electrical connectors exhibit in cold ambient weather conditions by heating the electrical connectors. In this regard, it would be desirable that such heated electrical connectors exhibit the capability of inhibiting the buildup of snow and ice on the exterior surface of the electrical connectors. Further, it would be desirable that such heated electrical connectors are substantially easier to disconnect from each other even in very cold ambient weather conditions. 
     The heated electrical connector of the present invention should also be of a construction which is both durable and long lasting, and it should also require little or no maintenance to be provided by the user throughout its operating lifetime. In order to enhance the market appeal of the heated electrical connector of the present invention, it should also be of inexpensive construction to thereby afford it the broadest possible market. Finally, it is also desirable that all of the aforesaid advantages and objectives of the heated electrical connector of the present invention be achieved without incurring any substantial relative disadvantage. 
     SUMMARY OF THE INVENTION 
     The disadvantages and limitations of the background art discussed above are overcome by the present invention. With this invention, a pair of mating electrical connectors are provided with an electrical heat generating element that is contained within one or both of the electrical connectors. When the mating electrical connectors are connected and the vehicle to which one of the electrical connectors is connected is being operated, electricity will flow through the electrical heat generating element(s) generating heat within the electrical connector(s). 
     The electrical heat generating element(s) is (are) selected so as to generate an amount of heat that is sufficient to prevent snow and ice from forming on the exterior of the mating electrical connectors, even in very cold ambient weather conditions. Additionally, the amount of heat that is generated within the electrical connector(s) is sufficient to ease the disconnection of the mated electrical connectors, even in such cold ambient weather conditions. The electrical heat generating element(s) is (are) also selected so than it (they) do not draw an excessive amount of electrical current or electrical power when they are being operated. 
     Optionally, more than one electrical heat generating element may be used in an electrical connector. If multiple electrical heat generating elements are used in an electrical connector, they may be optionally be connected in parallel so that only a single one of the electrical connections to the electrical connector is required. In a preferred embodiment, the electrical heat generating element may be a resistor installed within the electrical connector. Optionally, more than one resistor may be installed within the electrical connector. 
     The electrical heat generating element(s) in the electrical connector(s) is (are) electrically connected so that whenever the mating electrical connectors are connected together, and the vehicle to which one of the electrical connectors is connected is operating, the electrical heat generating element(s) is (are) being electrically energized. Thus, the mated electrical connectors will not be heated when the vehicle to which one of the electrical connectors is connected is not being operated, thereby preventing the battery in the vehicle from becoming discharged by the heated electrical connector. Additionally, if the electrical connectors are not connected together, neither the electrical connector that is connected to the vehicle nor its mater is either drawing electrical power or being heated. 
     It may therefore be seen that the present invention improves the characteristics electrical connectors exhibit in cold ambient weather conditions by heating the electrical connectors. Such heated electrical connectors exhibit the capability of inhibiting the buildup of snow and ice on the exterior surface of the electrical connectors. Further, such heated electrical connectors are substantially easier to disconnect from each other even in very cold ambient weather conditions. 
     The heated electrical connector of the present invention is of a construction which is both durable and long lasting, and which will require little or no maintenance to be provided by the user throughout its operating lifetime. The heated electrical connector of the present invention is also of inexpensive construction to enhance its market appeal and to thereby afford it the broadest possible market. Finally, all of the aforesaid advantages and objectives of the heated electrical connector of the present invention are achieved without incurring any substantial relative disadvantage. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       These and other advantages of the present invention are best understood with reference to the drawings, in which: 
         FIG. 1  is a schematic depiction of a pair of mating connectors one of which includes a heating resistor therein which resistors, when the mating connectors are mechanically mated together and the device is electrically connected to a power source, will heat the mating connectors; 
         FIG. 2  is a schematic depiction of a pair of mating connectors each of which includes a heating resistor therein which, when the mating connectors are mechanically mated together and the device is electrically connected to a power source, will heat the mating connectors; 
         FIG. 3  is a schematic depiction of a pair of mating connectors each of which includes a plurality of heating resistors therein each of which is connected to a different pin which resistors, when the mating connectors are mechanically mated together and the device is electrically connected to a power source, will heat the mating connectors; 
         FIG. 4  is a schematic depiction of a pair of mating connectors each of which includes a plurality of parallel connected heating resistors therein which, when the mating connectors are mechanically mated together and the device is electrically connected to a power source, will heat the mating connectors; 
         FIG. 5  is a schematic depiction of a pair of mating connectors each of which includes a heating resistor therein which, when the mating connectors are mechanically mated together and the device is electrically connected to a power source in a circuit including an externally located resistor, will heat the mating connectors; 
         FIG. 6  is a schematic depiction of a pair of mating connectors each of which includes a heating resistor therein which, when the mating connectors are mechanically mated together and the device is electrically connected to a power source in a circuit including an externally located PTC thermistor, will heat the mating connectors; 
         FIG. 7  is an isometric drawing showing an exemplary pair of mating connectors; and 
         FIG. 8  is a cutaway isometric drawing showing the resistors located inside each of the mating connectors shown in  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The preferred embodiment of the present invention involves the placement of one or more resistors into one or both of a mating pair of connectors that will be used in a cold ambient environment. When the mating pair of connectors are installed into an energized electrical circuit (which, in a vehicle, will typically require that the ignition switch is turned on) and when the pair of connectors are mated together, electricity will flow through the resistor(s) in the connector(s). The resistor(s) are appropriately sized so that the electrical power that is dissipated in it (them) will generate sufficient heat to prevent the formation of ice or the accumulation of snow on the exterior surfaces of the mated pair of connectors. 
     There are several different embodiments of the heated electrical connector of the present invention that are presently contemplated. A number of these embodiments are shown in exemplary form  FIGS. 1 through 6 , with various embodiments and features being shown in these figures. It will be appreciated by those skilled in the art that the features shown in these examples could be combined together in various combinations even though not all such combinations are shown herein for purposes of relative brevity of this specification. 
     For purposes of the examplary embodiments discussed herein with reference to  FIGS. 1 through 6 , the implementation will be assumed to be as electrical connectors used to connect the electrical system of a snow plow to the electrical system of a vehicle such as a truck on which the snow plow is mounted. It will, however, be appreciated by those skilled in the art that the heated electrical connector of the present invention could be used in any other application in a cold ambient environment. 
     Referring first to  FIG. 1 , a first embodiment of the present invention is illustrated which includes a first electrical connector  30  and a second electrical connector  32  are shown in schematic form. For purposes of discussion, it will be assumed herein that the first electrical connector  30  will be electrically connected to a vehicle (not shown herein) and that the second electrical connector  32  will be electrically connected to a snow plow (also not shown herein). Each of the first electrical connector  30  and the second electrical connector  32  is a ten-pin electrical connector, with the first electrical connector  30  being shown as a male connector and the second electrical connector  32  being shown as a female connector (although they could certainly be reversed if desired). 
     The first electrical connector  30  has ten male contacts  34 ,  36 ,  38 ,  40 ,  42 ,  44 ,  46 ,  48 ,  50 , and located therein. The second electrical connector  32  has ten female contacts  54 ,  56 ,  58 ,  60 ,  62 ,  64 ,  66 ,  68 ,  70 , and  72  that will respectively mater with the ten male contacts  34 ,  36 ,  38 ,  40 ,  42 ,  44 ,  46 ,  48 ,  50 , and  52  in the first electrical connector  30  when the first electrical connector  30  and the second electrical connector  32  are mated together. As shown in  FIG. 1 , the first electrical connector  30  and the second electrical connector  32  each have ten contacts, although it will be appreciated by those skilled in the art that they could each have more or fewer contacts, and that they may be any of a wide variety of different types of mating electrical connectors, with the specific application generally dictating the type of electrical connectors to be utilized. 
     It may be seen that there are ten wires  74 ,  76 ,  78 ,  80 ,  82 ,  84 ,  86 ,  88 ,  90 , and  92  extending from the first electrical connector  30 . The wires  74 ,  76 ,  78 ,  80 ,  84 ,  86 ,  88 ,  90 , and  92  are respectively electrically connected to male contacts  34 ,  36 ,  38 ,  40 ,  44 ,  46 ,  48 ,  50 , and  52 . The male contact  42  is electrically connected to one side of a resistor  94 , the other side of which is electrically connected to one end of the wire  82 . 
     The other end of the wire  82  is electrically connected to one side of a power source  96 , which may be, for example a battery (in a vehicular application, the battery of the vehicle), the other side of which power source  96  is electrically connected to ground (in a vehicular application, the battery of the vehicle). The wire  84  is also electrically connected to ground. (Alternatively, the side of the power source  96  shown as being electrically connected to ground could instead be electrically connected to the wire  84 .) 
     There are also ten wires  98 ,  100 ,  102 ,  104 ,  106 ,  108 ,  110 ,  112 ,  114 , and  116  extending from the second electrical connector  32 . The wires  98 ,  100 ,  102 ,  104 ,  106 ,  108 ,  110 ,  112 ,  114 , and  116  are respectively electrically connected to the female contacts  54 ,  56 ,  58 ,  60 ,  62 ,  64 ,  66 ,  68 ,  70 , and  72 . The wire  106  is electrically connected to the wire  108 , thereby electrically connecting the female terminals  62  and  64 . 
     When the first electrical connector  30  and the second electrical connector  32  shown in  FIG. 1  are matingly connected together, the ten male contacts  34 ,  36 ,  38 ,  40 ,  42 ,  44 ,  46 ,  48 ,  50 , and  52  in the first electrical connector  30  will be respectively electrically connected to the ten female contacts  54 ,  56 ,  58 ,  60 ,  62 ,  64 ,  66 ,  68 ,  70 , and  72  in the second electrical connector  32 . This will accordingly electrically connect the wires  74 ,  76 ,  78 ,  80 ,  84 ,  86 ,  88 ,  90 , and  92  extending from the first electrical connector  30  to wires  98 ,  100 ,  102 ,  104 ,  108 ,  110 ,  112 ,  114 , and  116  extending from the second electrical connector  32 . 
     It will also complete the circuit including the power source  96  and the resistor  94 , with that circuit beginning at one side of the power source  96  and including the wire  82 , the resistor  94 , the male contact  42 , the female contact  62 , the wire  106 , the wire  108 , the female contact  64 , the male contact  44 , and the wire  84 , and ending at the other side of the power source  96 . This will energize the resistor  94 , causing power to be dissipated in the resistor  94 , thereby heating it and the first electrical connector  30 , as well as heating the second electrical connector somewhat by virtue of its proximity to the first electrical connector  30 . 
     It will also be appreciated by those skilled in the art that instead of providing the return current path through the wire  108 , the female contact  64 , the male contact  44 , and the wire  84 , the wire  106  could instead be grounded and thereby connected to the other side of the power source  96 . 
     Turning next to  FIG. 2 , a second embodiment of the heated electrical connector of the present invention is illustrated. In  FIG. 2 , as well as in  FIGS. 3 through 6 , elements that are similar to components illustrated in  FIG. 1  shall be referred to using identical reference numerals. The embodiment of  FIG. 2  is identical to the embodiment of  FIG. 1 , with a single difference. Instead of the wire  106  being electrically connected directly to the female contact  62 , it is instead electrically connected to one side of a resistor  120 , the other side of which is electrically connected to the female contact  62 . 
     When the first electrical connector  30  and the second electrical connector  32  shown in  FIG. 2  are matingly connected together, the circuit including the power source  96 , the resistor  94 , and the resistor  120  will be connected together. This circuit begins at one side of the power source  96  and includes the wire  82 , the resistor  94 , the male contact  42 , the female contact  62 , the resistor  120 , the wire  106 , the wire  108 , the female contact  64 , the male contact  44 , and the wire  84 , and ending at the other side of the power source  96 . This will energize both the resistor  94  and the resistor  120 , causing power to be dissipated in both of the resistors  94  and  120 , thereby heating them and both the first electrical connector  30  and the second electrical connector  32 . 
     For the embodiments of  FIGS. 1 and 2 , the value of the resistor  94  ( FIG. 1 ) or the values of the resistors  94  and  120  ( FIG. 2 ) will determine the power that will be dissipated as heat inside the first and second electrical connector  30  and  32 . Since the power source  96  is approximately 14.7 Volts in a vehicle, various resistances can be calculated as a function of the power to be dissipated in the resistor  94  ( FIG. 1 ) or the combined resistance of the resistors  94  and  120  ( FIG. 2 ) using the formula P=V 2 M. For example, 0.25 Watt requires 864 Ohms, 0.5 Watt requires 432 Ohms, 1.0 Watt requires 216 Ohms, 1.5 Watts requires 144 Ohms, 2.0 Watts requires 108 Ohms, 2.5 Watts requires 86 Ohms, and 3.0 Watts requires 72 Ohms, and 3.6 Watts requires 60 Ohms. As those skilled in the art will realize, the resistors  94  and  120  will likely need to be power resistors in order to avoid degradation caused by heating. The exact power required will of course depend upon both the design of the first and second electrical connectors  30  and  32 , as well as the lowest ambient temperature that the first and second electrical connectors  30  and  32  are to be used in. 
     Turning now to  FIG. 3 , a third embodiment of the heated electrical connector of the present invention is illustrated. The embodiment of  FIG. 3  is identical to the embodiment of  FIG. 2 , with several differences. Instead of the wire  86  being electrically connected directly to the male contact  46 , it is instead electrically connected between one side of a resistor  130  and the wire  82 , with the other side of the resistor  130  being electrically connected to the male contact  46 . Instead of the wire  110  being electrically connected directly to the female contact  66 , it is instead electrically connected between one side of a resistor  132  and the wire  108 , with the other side of the resistor  132  being electrically connected to the female contact  66 . 
     When the first electrical connector  30  and the second electrical connector  32  shown in  FIG. 3  are matingly connected together, the resistor  94  and the resistor  120  are electrically connected in series, and the resistor  130  and the resistor  132  are also electrically connected in series. The series connected resistors  94  and  120  are electrically connected in parallel with the resistors  130  and  132 . The circuit including the power source  96 , the resistor  94 , the resistor  120 , the resistor  130 , and the resistor  132  will be connected together. 
     This circuit has two parallel paths: the first begins at one side of the power source  96  and includes the wire  82 , the resistor  94 , the male contact  42 , the female contact  62 , the resistor  120 , the wire  106 , the wire  108 , the female contact  64 , the male contact  44 , and the wire  84 , and ends at the other side of the power source  96 ; the second begins at one side of the power source  96  and includes the wire  82 , the wire  86 , the resistor  130 , the male contact  46 , the female contact  66 , the resistor  132 , the wire  110 , the wire  108 , the female contact  64 , the male contact  44 , and the wire  84 , and ends at the other side of the power source  96 . This energizes the resistor  94 , the resistor  120 , the resistor  130 , and the resistor  132 , causing power to be dissipated in all four of the resistors  94 ,  120 ,  130 , and  132 , thereby heating them and both the first electrical connector  30  and the second electrical connector  32 . 
     As an alternative to the embodiment shown in  FIG. 3 , the resistors  120  and  130  could be deleted (with the wire  106  being electrically connected directly to the female contact  62  and the wire  86  being electrically connected directly to the male contact  46 ), leaving the resistors  94  and  132  effectively connected in parallel, with each getting the full voltage of the power source  96 . 
     Turning now to  FIG. 4 , a fourth embodiment of the heated electrical connector of the present invention is illustrated. The embodiment of  FIG. 4  is identical to the embodiment of  FIG. 2 , with several differences. Instead of using the resistor  94  electrically connected between the male contact  42  and the wire  82 , three resistors  140 ,  142 , and  144  are instead electrically connected in parallel between the male contact  42  and the wire  82 . Instead of using the resistor  120  electrically connected between the female contact  62  and the wire  106 , three resistors  146 ,  148 , and  150  are instead electrically connected in parallel between the female contact  62  and the wire  106 . The six resistors  140 ,  142 ,  144 ,  146 ,  148 , and  150  have a greater heating capacity than the two resistors the resistor  94  and the resistor  120  used in  FIG. 2 . 
     When the first electrical connector  30  and the second electrical connector  32  shown in  FIG. 4  are matingly connected together, the circuit including the power source  96 , the three parallel resistors  140 ,  142 , and  144 , and the three parallel resistors  146 ,  148 , and  150  will be connected together. This circuit begins at one side of the power source  96  and includes the wire  82 , the three parallel resistors  140 ,  142 ,  144 , the male contact  42 , the female contact  62 , the three parallel resistors  146 ,  148 , and  150 , the wire  106 , the wire  108 , the female contact  64 , the male contact  44 , and the wire  84 , and ending at the other side of the power source  96 . This will energize three parallel resistors  140 ,  142 , and  144  which are in series with the three parallel resistors  146 ,  148 , and  150 , causing power to be dissipated in all of the resistors  140 ,  142 ,  144 ,  146 ,  148 , and  150 , thereby heating them and both the first electrical connector  30  and the second electrical connector  32 . 
     Turning now to  FIG. 5 , a fifth embodiment of the heated electrical connector of the present invention is illustrated. The embodiment of  FIG. 5  is identical to the embodiment of  FIG. 2 , with one difference. Instead of having the wire  82  electrically connected between the resistor  94  and the one side of the power source  96 , the wire  82  is electrically connected between the resistor  94  and one end of a resistor  160 , the other end of which is electrically connected to the one side of the power source  96 . By appropriately selecting the resistance of the resistor  160  with respect to the resistances of the resistors  94  and  120 , the proportion of the power that will be dissipated in the resistors  94  and  120  can be established. 
     When the first electrical connector  30  and the second electrical connector  32  shown in  FIG. 5  are matingly connected together, the circuit including the power source  96 , the resistor  160 , the resistor  94 , and the resistor  120  will be connected together. This circuit begins at one side of the power source  96  and includes the resistor  160 , the wire  82 , the resistor  94 , the male contact  42 , the female contact  62 , the resistor  120 , the wire  106 , the wire  108 , the female contact  64 , the male contact  44 , and the wire  84 , and ending at the other side of the power source  96 . This will energize both the resistor  160  and the resistors  94  and  120 , causing the selected proportion of power to be dissipated in each of the resistors  94  and  120 , thereby heating them and both the first electrical connector  30  and the second electrical connector  32 . This design allows a voltage lower than that of the power source  96  to be placed across the resistors  94  and the resistor  120 . 
     Turning now to  FIG. 6 , a sixth embodiment of the heated electrical connector of the present invention is illustrated. The embodiment of  FIG. 6  is identical to the embodiment of  FIG. 5 , with one difference. Instead of having the resistor  160  electrically connected between the one side of the power source  96  and the wire  82 , a thermistor  170  is electrically connected between the one side of the power source  96  and the wire  82 . The thermistor  170  is a positive temperature coefficient (PTC) thermistor in which the resistance increases with increasing temperature. As the ambient temperature decreases, it is necessary to dissipate more power in the resistors and  120  in order to heat the first and second electrical connectors  30  and  32 , respectively, in order to prevent snow or ice from building up on the outside of the first and second electrical connectors  30  and  32 . By appropriately selecting the thermistor  170  and the resistances of the resistors  94  and  120 , the proportion of the power that will be dissipated in the resistors  94  and  120  will increase as the ambient temperature on the thermistor  170  decreases. 
     Finally, with reference to  FIGS. 7 and 8 , an exemplary mating pair of first and second electrical connectors  30  and  32  is illustrated which may be, for example, a 10-pin set of mating male and female connectors that are commercially available from FCI in Westland, Mich., and which are as shown, for example, in U.S. Pat. No. 7,303,447, which is hereby incorporated herein by reference. The first and second electrical connectors  30  and  32  are cut away in  FIG. 8  to show the resistor  94  in the first electrical connector  30  and the resistor  120  in the second electrical connector  32 . The first and second electrical connectors  30  and  32  may each have housings with integrated sealing elements to sealingly engage each other with a seal being formed therebetween to protect the contacts contained therein from exposure to the ambient environment. The first and second electrical connectors  30  and  32  may also have a locking mechanism such as an integral releasable locking latch to prevent them from coming apart when the locking mechanism is engaged. It will be appreciated by those skilled in the art that the principles of the heated electrical connector of the present invention could be applied to any of a wide number of different types and configurations of connectors without departing from the spirit of the present invention. 
     It may therefore be appreciated from the above detailed description of the preferred embodiment of the present invention that it improves the characteristics electrical connectors exhibit in cold ambient weather conditions by heating the electrical connectors. Such heated electrical connectors exhibit the capability of inhibiting the buildup of snow and ice on the exterior surface of the electrical connectors. Further, such heated electrical connectors are substantially easier to disconnect from each other even in very cold ambient weather conditions. 
     The heated electrical connector of the present invention is of a construction which is both durable and long lasting, and which will require little or no maintenance to be provided by the user throughout its operating lifetime. The heated electrical connector of the present invention is also of inexpensive construction to enhance its market appeal and to thereby afford it the broadest possible market. Finally, all of the aforesaid advantages and objectives of the heated electrical connector of the present invention are achieved without incurring any substantial relative disadvantage. 
     Although the foregoing description of the heated electrical connector of the present invention has been shown and described with reference to particular embodiments and applications thereof, it has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the particular embodiments and applications disclosed. It will be apparent to those having ordinary skill in the art that a number of changes, modifications, variations, or alterations to the invention as described herein may be made, none of which depart from the spirit or scope of the present invention. The particular embodiments and applications were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such changes, modifications, variations, and alterations should therefore be seen as being within the scope of the present invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.