Abstract:
A ceramic card having a thick film network, with conductive vias formed as part of the card. Each of the vias is in electrical communication with both sides of the thick film network, allowing the pads and the pad senders to be formed on both sides of the card. This configuration maintains the contact when one of the connectors is subjected to bending force or is otherwise displaced, maintaining contact with at least one of the pads, and allowing the system to still function. The double sided thick film network allows for each connector to touch both sides of one of the pads, and still maintain electrical communication with the level sender, thus eliminating the failure mode of intermittent contact with the thick film network resulting from movement of the connector.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/001,996 filed May 22, 2014. The disclosure of the above application is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates generally to a connector for a double-sided thick film network card for a level sender in a fuel module. 
       BACKGROUND OF THE INVENTION 
       [0003]    Level senders in fuel modules are generally known, and are disposed in gas tanks of vehicles for detecting the level of fuel in the fuel tank. Typical fuel modules have a level sender with some type of circuit disposed on a network card. There is also a float connected to a lever assembly, and the lever assembly is connected to some type of bracket that is in contact with the network card. As the float changes position within the gas tank as the fuel level changes, the bracket changes position relative to the card, and therefore changes the configuration of the circuit, producing a signal corresponding to the level of fuel in the fuel tank. 
         [0004]    It is common for these types of cards to have the circuit disposed on one side of the card, where a connector is in contact with one of the pads that is part of the circuit. The connector therefore only contacts one side of the pad. The connector has a wire that extends into another connector, which is connected to the flange of the fuel module. 
         [0005]    The connection between a connector and a pad on the network card is subject to becoming disconnected due to the connector moving out of position, and losing contact with one of the pads. There is very little support for maintaining the proper location of the connector relative to the corresponding pad. When the connector is exposed to various bending forces, the connector may temporarily lose contact with the pad, or become disconnected from the pad completely. 
         [0006]    Accordingly, there exists a need for a connector which maintains contact with a thick film network card even when exposed to bending forces. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention is a ceramic card having a thick film network, with conductive vias formed as part of the card. Each of the vias is in electrical communication with both sides of the thick film network, allowing the pads and pad senders to be formed on both sides of the card. This configuration maintains the contact when one of the connectors is subjected to bending force or is otherwise displaced, maintaining contact with at least one of the pads, and allowing the system to still function. 
         [0008]    The double sided thick film network allows for each connector to touch both sides of one of the pads, and still maintain electrical communication with the level sender, thus eliminating the failure mode of intermittent contact with the thick film network card resulting from movement of the connector. 
         [0009]    In one embodiment, the present invention is a sensor assembly, which includes a card, a circuit disposed on the card, and a first pad and a second pad located on the card, where the first pad and the second pad are part of the circuit. There is a first connector connected to the first pad, and a second connector connected to a second pad. A first arcuate portion and a second arcuate portion are also located on the card, and the first arcuate portion and the second arcuate portion are both part of the circuit. A first pad sender is part of the circuit and located on the card, and places the first pad in electrical communication with the first arcuate portion. A second pad sender is also part of the circuit and located on the card, and places the second pad in electrical communication with the second arcuate portion. The circuit also includes a first via and a second via, where the first via is in communication with the first pad sender such that the first via provides communication between portions of the first pad sender on both sides of the card, and the second via is in communication with the second pad sender such that the second via provides communication between portions of the second pad sender on both sides of the card. 
         [0010]    A bracket assembly is in sliding contact with the first arcuate portion and the second arcuate portion of the circuit. As the bracket assembly changes position relative to the first arcuate portion and the second arcuate portion, the resistance of the circuit changes such that a signal indicative of the position of the bracket assembly is generated by the circuit. 
         [0011]    The sensor assembly also includes a lever assembly connected to the bracket assembly, and a float connected to the lever. As the float changes position, the lever assembly pivots relative to the bracket assembly and the float, and the bracket assembly pivots relative to the first arcuate portion and the second arcuate portion such that the configuration of the circuit changes, and the circuit generates a signal indicating the position of the float. The signal is then used to provide an indication of how much fuel is in a fuel tank. 
         [0012]    The sensor assembly also includes a housing, and a cover connected to the housing. The bracket assembly is located between the cover and the housing, such that the bracket assembly is pivotally connected to the cover and the housing. 
         [0013]    A first notch is formed as part of the housing, and a second notch is formed as part of the cover. The connection between the cover and the housing also forms a plurality of cavities. The first notch is located in proximity to the second notch, and the first notch and second notch are located in proximity to at least one of the plurality of cavities when the housing is connected to the cover. Each connector includes a connector housing, and a first retention feature and a second retention feature are integrally formed with the connector housing. There is also a first flange portion and a second flange portion integrally formed with the connector housing. The first retention feature is in contact with the first notch and the second retention feature is in contact with the second notch, maintaining the first flange portion and second flange portion in contact with both sides of the pads. 
         [0014]    Each connector also includes a first protrusion integrally formed with the first flange portion creating a first inflection point, and a second protrusion integrally formed with the second flange portion, creating a second inflection point. The first protrusion and the second protrusion contact the card when the connector is being connected to the card such that the force applied to the connector causes the first flange portion, second flange portion, first protrusion, and second protrusion to deflect, allowing the card to be placed between the first inflection point and the second inflection point, placing the connector in electrical communication with the pad. The connection between each connector and a corresponding pad is substantially similar. 
         [0015]    In an embodiment, the circuit is made of conductive ink. Portions of the conductive ink are disposed on both sides of the card such that a portion of the first pad, a portion of the second pad, a portion of the first pad sender, and a portion of the second pad sender are formed on both sides of the card. In an embodiment, the card is made of ceramic material, but it is within the scope of the invention that other materials may be used. 
         [0016]    Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
           [0018]      FIG. 1  is a first perspective view of a fuel module having a sensor assembly, according to embodiments of the present invention; 
           [0019]      FIG. 2  is a second perspective view of a fuel module having a sensor assembly, according to embodiments of the present invention; 
           [0020]      FIG. 3  is an exploded view of a sensor assembly, according to embodiments of the present invention; 
           [0021]      FIG. 4  is an exploded view of a housing, a cover, and a bracket assembly, which are part of a sensor assembly, according to embodiments of the present invention; 
           [0022]      FIG. 5  is a perspective view of a plurality of connectors located in proximity to a plurality of cavities, which are part of a sensor assembly, according to embodiments of the present invention; 
           [0023]      FIG. 6A  is a perspective view of a bracket, which is part of a bracket assembly used as part of a sensor assembly, according to embodiments of the present invention; 
           [0024]      FIG. 6B  is a perspective view of a spring, which is part of a bracket assembly used as part of a sensor assembly, according to embodiments of the present invention; 
           [0025]      FIG. 6C  is a perspective view of a contact spring, which is part of a bracket assembly used as part of a sensor assembly, according to embodiments of the present invention; 
           [0026]      FIG. 7  is a perspective view of a contact spring in contact with a card, used as part of a sensor assembly, according to embodiments of the present invention; 
           [0027]      FIG. 8A  is a perspective view of a first side of a card used as part of a sensor assembly, according to embodiments of the present invention; 
           [0028]      FIG. 8B  is a perspective view of a second side of a card used as part of a sensor assembly, according to embodiments of the present invention; 
           [0029]      FIG. 9A  is a perspective view of a first side of a card used as part of a sensor assembly, with connectors attached to the card, according to embodiments of the present invention; 
           [0030]      FIG. 9B  is a perspective view of a second side of a card used as part of a sensor assembly, with connectors attached to the card, according to embodiments of the present invention; 
           [0031]      FIG. 10  is a partial side view of a card used as part of a sensor assembly, according to embodiments of the present invention; 
           [0032]      FIG. 11  is a perspective view of a sensor assembly and a connector, according to embodiments of the present invention; 
           [0033]      FIG. 12  is a sectional view taken along lines  12 - 12  of  FIG. 11 ; and 
           [0034]      FIG. 13  is an enlarged view of the rectangular portion of  FIG. 12 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0035]    The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
         [0036]    A fuel module having a thick film network (TFN) sensor card is shown in the Figures generally at  10 . Referring to the Figures generally, the fuel module  10  includes a flange  12 , where the flange  12  has a connector  14  integrally formed as part of the flange  12 , and a port  16  which is also formed as part of the flange  12 . The fuel module  10  also includes a fuel pump  18  located in a reservoir  20 , along with a filter  22 , and various connectors and hoses. The fuel pump  10  functions to transfer fuel from the reservoir  20  through the various connectors and hoses, and out of the port  16 . 
         [0037]    Also partially disposed in the reservoir  20  is a holder assembly  24 , which is connected to a sidewall of the reservoir  20 . The holder assembly  24  supports a sensor assembly, shown generally at  26 . The sensor assembly  26  includes a housing  28  attached to a cover  30 , and disposed between the housing  28  and the cover  30  is a TFN card  32 . In this embodiment, the card  32  is made of a ceramic material, but it is within the scope of the invention that other materials may be used. Also located between the housing  28  and the cover  30  is a bracket assembly  34 , and connected to the bracket assembly  34  is a lever assembly  36 , and connected to the lever assembly  36  is a float  38 . 
         [0038]    The bracket assembly  34  includes a cylindrical support member  40  partly disposed within a recess  42   a  formed as part of the cover  30  and partly disposed in a corresponding recess  42   b  formed as part of the housing  28 , such that the bracket assembly  34  is able to pivot relative to the cover  30  and the housing  28 . The bracket assembly  34  also includes a spring  44  and a contact spring  46 , where the contact spring  46  is mounted to a bracket  48  and is in contact with the card  32 . The spring  44  is connected to an end portion  50  of the bracket  48 , and the contact spring  46  is connected to the spring  44  and the end portion  50 , best seen in  FIGS. 3-4  and  6 A. 
         [0039]    Formed as part of the bracket  48  is an extension  52 , which extends over a portion of the cover  30 . More specifically, the extension  52  moves with the bracket  48  relative to the cover  30  and housing  28 , and is selectively in contact with a first stopping surface  54  or a second stopping surface  56 . The surfaces  54 , 56  determine the maximum distance the bracket assembly  34  is able to pivot relative to the housing  28  and the cover  30 . The extension  52  contacts either surface  54 , 56 , preventing the bracket assembly  34  from pivoting beyond either surface  54 , 56 . 
         [0040]    The bracket  48  also includes an aperture  58  formed as part of a second end portion  60  of the bracket  48 . And end portion  62  of the lever assembly  36  is pivotally disposed in the aperture  58 , and allows the lever assembly  36  to pivot relative to the bracket  48 . 
         [0041]    The contact spring  46  includes two spring portions, a first spring portion  64   a  and a second spring portion  64   b  are in contact with the TFN card  32 . The card  32  includes a circuit, shown generally at  66 , made of conductive ink. The circuit  66  includes a first arcuate portion  68   a  which is in electrical communication with a first pad circuit  70   a , and a second arcuate portion  68   b , which is in electrical communication with a second pad circuit  70   b , where both the pad circuits  70   a , 70   b  are also part of the circuit  66 . The first arcuate portion  68   a  is in contact with the first spring portion  64   a , and the second arcuate portion  68   b  is in contact with the second spring portion  64   b . The spring portions  64   a , 64   b  are flexible, and are therefore able to compensate for variations in tolerance of the card  32 , and small changes in shape due to temperature variations as well. 
         [0042]    The circuit  66  also includes a first pad  72   a  which is part of the first pad circuit  70   a , and a second pad  72   b  which is part of the second pad circuit  70   b . The first pad  72   a  and first pad circuit  70   a  are in electrical communication with a first via  74   a , and the second pad  72   b  and second pad circuit  70   b  are in electrical communication with a second via  74   b . Portions of the circuit  66  are formed on both sides of the card  32 . More specifically, each of the pad circuits  70   a , 70   b  and the pads  72   a , 72   b  are formed on a first side  32   a  of the card  32  and a second side  32   b  of the card  32 . Each of the vias  74   a , 74   b  extend through the card  32 , to provide for electrical communication on both sides of the card  32 , such that the portions of the pad circuits  70   a , 70   b  are in communication with one another. There are also contacts  76  formed as part of the circuit  66 , which extend through the card  32  as shown in  FIG. 10 , which also provide for communication between the pad circuits  70   a , 70   b , such that the pad circuits  70   a , 70   b  are in electrical communication with one another. 
         [0043]    Referring now to  FIGS. 9A-10  and  12 - 13 , there is a first connector  78   a  connected to the card  32  in such that the connector  78   a  is in contact with the first pad  72   a . There is also a second connector  78   b  connected to the card  32  such that the second connector  78   b  is in contact with the second pad  72   b . In one embodiment, the connectors  78   a , 78   b  are clip-type connectors, but it is within the scope of the invention that other types of connectors may be used. 
         [0044]    The first connector  78   a  includes a connector housing  80 , and formed as part of the connector housing  80  is a first flange portion  82  and a second flange portion  84 . Formed as part of the first flange portion  82  is a first protrusion  86 , and formed as part of the second flange portion  84  is a second protrusion  88 . The flange portions  82 , 84  are curved toward one another, and the each protrusion  86 , 88  is curved away from one another, as shown in FIGS.  5  and  12 - 13 . The difference in curvature of the flange portions  82 , 84  and protrusions  86 , 88  forms first and second inflection points  90 , 92 , respectively. When the first connector  78   a  is not connected to the card  32 , the flange portions  82 , 84  are positioned such that the inflection points  90 , 92  are very close, but not touching one another, best seen in  FIG. 5 . 
         [0045]    When the first connector  78   a  is connected to the card  32 , the first flange portion  82  is in contact with one side of the pad  72   a  at the first inflection point  90 , and the second flange portion  84  is in contact with a second side of the pad  72   a  at the second inflection point  92 . During assembly, the first connector  78   a  is moved toward the card  32 , such that each of the protrusions  86 , 88  contact the card  32  first. When enough force is applied to the connector  78   a , the flange portions  82 , 84  and protrusions  86 , 88  deflect, and the card  32  moves between the inflection point  90 , 92  and contacts the pads  72   a , 72   b , respectively, as shown in FIGS.  10  and  12 - 13 . The deflection of the flange portions  82 , 84  causes force to be applied to the card  32 , ensuring an adequate connection between the connector  78   a  and pad  72   a  of the card  32 . 
         [0046]    Also integrally formed with the connector housing  80  is a first retention feature  94  and a second retention feature  96 . The retention features  94 , 96  extend at an angle away from the connector housing  80 . There is also a first notch  98  formed as part of the housing  28 , and a second notch  100  formed as part of the cover  30 . The distance  102  between the inner surfaces of the two notches  98 , 100  when the housing  28  and the cover  30  are connected together is less than the maximum distance  104  between the portions of the retention features  94 , 96  that are furthest away from one another. The housing  28  and cover  30  form several cavities  106 , and the notches  98 , 100  are located in the cavities  106 . During assembly, the connector  78   a  is inserted into one of the cavities  106 , as shown in FIGS.  5  and  12 - 13 . As the connector  78   a  is inserted, the part of the cavity  106  that is narrower than the distance  104  causes the retention features  94 , 96  to deflect, and once the connector  78   a  is inserted into the cavity  106  such that the retention features  94 , 96  have moved beyond the notches  98 , 100 , the retention features  94 , 96  are no longer deflected, and move back to their original positions such that the maximum distance  104  between the portions of the retention features  94 , 96  is greater than the distance  102  between the inner surfaces of the two notches  98 , 100 . Once this occurs, if there is force applied to the connector  78   a  to attempt to remove the connector  78   a  from the cavity  106 , the retention features  94 , 96  move and contact the notches  98 , 100 , respectively, and the connector  78   a  is therefore prevented from being removed from the cavity  106 . 
         [0047]    The second connector  78   b  has similar components to the first connector  78   a , and functions in a similar manner, and therefore does not need to be described. There is a first wire  108   a  connected to the connector housing  80  of the first connector  78   a , and a second wire  108   b  connected to the connector housing  80  of the second connector  78   b . Each of the wires  108   a , 108   b  are connected to a connector  110 , and the connector  110  is then connected to the portion of the connector  14  that extends downwardly from the flange  12 , as shown in  FIGS. 1-2 . 
         [0048]    Because there is conductive ink used on both sides of the card  10  to create the pad  72   a , there is electrical communication between both flange portions  82 , 84  and the circuit  66 . In addition to the connector  78   a  remaining in contact with the card  32  if a force is applied to the card  32  to pull the connector  78   a  away from the card  32 , the connector  78   a  is also able to remain in contact with the pad  72   a  when other forces, such as rotational forces, are applied to the connector  78   a . If a rotational force is applied to the connector  78   a  in the direction of the first arrow  112 , such that the second flange portion  84  is no longer in contact with the pad  72   a , the first flange portion  82  remains in electrical contact with the pad  72   a . Additionally, if there is a rotational force applied to the connector  78   a  in the direction of the second arrow  114  such that the first flange portion  82  is no longer in contact with the pad  72   a , the second flange portion  84  remains in electrical contact with the pad  72   a . This also applies to the connector  78   b  connected to the second pad  72   b  as well. 
         [0049]    The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.