Patent Publication Number: US-9431749-B2

Title: Electrical connector assembly comprising an array of elongated electrical contacts

Description:
BACKGROUND 
     The subject matter herein relates generally to an electrical connector assembly that has an array of electrical contacts and is configured to mate with another connector having a corresponding array of electrical contacts. 
     Electrical connectors may be used to transfer data and/or electrical power between different systems or devices. Electrical connectors are often designed to operate in challenging environments where contaminants, shock, and/or vibration can disrupt the electrical connection. For example, automobiles and other machinery utilize electrical connectors to communicate data and/or electrical power therein. At least some known electrical connectors include a connector housing that has a cavity configured to receive another electrical connector (hereinafter referred to as a “mating connector”). The cavity opens to a front end of the connector housing and extends a depth into the connector housing. The electrical connector includes an array of electrical contacts, and the mating connector includes a complementary array of electrical contacts (hereinafter referred to as “mating contacts”). As the mating connector is received within the cavity, the electrical contacts are received within corresponding socket openings of the mating connector. Each socket opening may include one of the mating contacts that engages the corresponding electrical contact to establish an electrical connection. 
     Although the connector housing partially surrounds the electrical contacts within the receiving cavity, the electrical contacts may be exposed to the ambient environment through the open front end. During shipping or handling of the electrical connectors, contaminants may enter the receiving cavity through the front end. In addition, the front end may permit objects to enter the receiving cavity and engage the electrical contacts thereby moving and/or bending the electrical contacts. If an electrical contact is not positioned properly within the receiving cavity, the electrical contact may improperly engage the mating connector, an incident referred to as stubbing, which can damage the electrical contact. In some cases, the damage may require the electrical contact or, potentially, the entire electrical connector to be replaced. 
     Accordingly, there is a need for an electrical connector assembly having a mechanism for reducing exposure of the electrical contacts to the surrounding environment. 
     BRIEF DESCRIPTION 
     In an embodiment, electrical connector assembly is provided that includes a connector housing having a front end and a receiving cavity that opens to the front end. The receiving cavity is sized and shaped to receive a mating connector therein that is inserted into the receiving cavity along a central axis. The electrical connector assembly also includes a contact array of electrical contacts that is disposed within the receiving cavity. The electrical contacts have elongated bodies that extend generally parallel to the central axis through the receiving cavity. The electrical connector assembly also includes a movable guard that is configured to be slidably held by the contact array within the receiving cavity. The movable guard includes a dielectric sheet that extends transverse to the central axis and has an array of thru-holes. Each of the thru-holes is shaped by a corresponding inner edge of the dielectric sheet. The thru-holes include clearance thru-holes and frictional thru-holes. The inner edges of the frictional thru-holes engage corresponding electrical contacts of the contact array to hold the movable guard at a forward position within the receiving cavity. The clearance thru-holes permit corresponding electrical contacts of the contact array to move freely therethrough when aligned with the corresponding electrical contacts. The movable guard is configured to slide along the central axis from the forward position to a deeper position within the receiving cavity when engaged by the mating connector. 
     Optionally, the inner edges of the frictional through-holes of the electrical connector assembly are shaped to include projections that extend toward and directly engage the corresponding electrical contacts. In some embodiments, the electrical contacts of the electrical connector assembly are contact blades having a thickness and a width. The width may be greater than the thickness. 
     In some embodiments, the frictional thru-holes and the clearance thru-holes of the movable guard are distributed across the dielectric sheet to provide a substantially uniform mating resistance as the movable guard slides toward the deeper position. Optionally, the array of thru-holes may include a first section and a second section. The thru-holes of the first and second sections may be configured to receive electrical contacts having different first and second cross-sectional profiles, respectively. Optionally, the array of thru-holes includes multiple columns in which each column includes at least one of the frictional thru-holes. 
     In an embodiment, a communication system is provided that includes an electrical connector having a connector housing with a front end and a receiving cavity that opens to the front end. The electrical connector includes a contact array of electrical contacts within the receiving cavity. The electrical contacts extend parallel to each other along a central axis of the electrical connector. The connector housing has an interior rear wall that faces along the central axis and at least partially defines the receiving cavity. The communication system also includes a mating connector that is configured to be inserted into the receiving cavity in a mating direction along the central axis. The mating connector has a front wall and an array of passages that open to the front wall. Each of the passages includes a mating contact that engages a corresponding electrical contact of the contact array. The communication system also includes a movable guard that is configured to be slidably held by the contact array within the receiving cavity. The movable guard includes a dielectric sheet that extends transverse to the central axis and has an array of thru-holes. Each of the thru-holes is shaped by a corresponding inner edge of the dielectric sheet that engages a corresponding electrical contact of the contact array. The inner edge collectively holds the movable guard at a forward position within the receiving cavity and permits the movable guard to slide in the mating direction from the forward position to a deeper position within the receiving cavity. The movable guard is disposed between the rear wall and the front wall during operation. 
     Optionally, the thru-holes are frictional thru-holes and the array of thru-holes also includes clearance thru-holes that are shaped to permit corresponding electrical contacts of the contact array to move freely therethrough. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an electrical connector assembly in accordance with an embodiment. 
         FIG. 2  is another perspective view of the electrical connector assembly shown in  FIG. 1 . 
         FIG. 3  is a plan view of a movable guard that may be used with the electrical connector assembly of  FIG. 1 . 
         FIG. 4  is an enlarged plan view of a portion of the movable guard of  FIG. 3  slidably engaged to electrical contacts of the electrical connector assembly. 
         FIG. 5  is a cross-section of the electrical connector assembly of  FIG. 1  prior to engaging a mating connector. 
         FIG. 6  is a perspective view of the mating connector that may engage the electrical connector assembly of  FIG. 1 . 
         FIG. 7  is a cross-section of a communication system in accordance with an embodiment that includes the electrical connector assembly of  FIG. 1  and the mating connector of  FIG. 6 . 
         FIG. 8  is a perspective view of an electrical connector assembly formed in accordance with an embodiment that is communicatively coupled to a circuit board. 
         FIG. 9  is a perspective view of a movable guard that may be used with the electrical connector assembly of  FIG. 8 . 
         FIG. 10  is a perspective view of an electrical device formed in accordance with an embodiment. 
         FIG. 11  is a cross-section of the electrical device of  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 and 2  illustrate different perspective views of an electrical connector assembly  100  formed in accordance with an embodiment. The electrical connector assembly  100  includes an electrical connector  102  and a movable guard  140  that is slidably coupled to the electrical connector  102  as described herein. The electrical connector assembly  100  is configured to engage a mating connector  106  (shown in  FIG. 6 ) during a mating operation. The electrical connector  102  includes a connector housing  108  having a front end  110  and a back wall  112  ( FIG. 1 ) that face in generally opposite directions. The connector housing  108  also includes housing sides  113 ,  114 ,  115 ,  116  that extend between the front end  110  and the back wall  112 . As shown in  FIG. 1 , the electrical connector assembly  100  is oriented with respect to mutually perpendicular axes, including a central axis  191 , a first lateral axis  192 , and a second lateral axis  193 . Although the electrical connector assembly  100  shown in  FIGS. 1 and 2  has a particular orientation, the electrical connector assembly  100  is not limited to a particular orientation during operation. 
     The connector housing  108  defines a receiving cavity  118  that opens to the front end  110 . The receiving cavity  118  is sized and shaped to receive the mating connector  106  ( FIG. 6 ) during the mating operation. During the mating operation, the electrical connector assembly  100  and the mating connector  106  are moved, relative to one another, such that the mating connector  106  is received within the receiving cavity  118 . For example, the mating connector  106  may be inserted into the receiving cavity  118  as the electrical connector  102  is held in a stationary position. Alternatively, the mating connector  106  may be stationary as the electrical connector  102  is moved such that the mating connector  106  is received within the receiving cavity  118 . In other embodiments, both the mating connector  106  and the electrical connector  102  are moved during the mating operation. 
     The connector housing  108  includes interior sidewalls  121 ,  122 ,  123 , and  124  that define the receiving cavity  118 . The sidewall  124  is shown in  FIG. 2 . In the illustrated embodiment, the interior sidewalls  121 - 124  are shaped to include keying features  126 . The keying features  126  may assure that the electrical connector assembly  100  and the mating connector  106  are properly oriented with respect to one another during the mating operation. The receiving cavity  118  may also be defined by an interior rear wall  128  ( FIG. 2 ). The interior sidewalls  121 - 124  generally face toward the central axis  191 . The rear wall  128  faces in a direction along the central axis  191 . In some embodiments, each of the interior sidewalls  121 - 124  may interface with the mating connector  106  ( FIG. 6 ). 
     The electrical connector  102  includes a contact array  130  of electrical contacts  132 ,  133  that are disposed within the receiving cavity  118 . The electrical contacts  132 ,  133  include respective elongated bodies  134 ,  135  (shown in  FIG. 2 ) that extend generally parallel to the central axis  191  and to one another. The elongated bodies  134 ,  135  extend from the rear wall  128  ( FIG. 2 ) to a respective distal tip  138 . 
     The movable guard  140  is configured to protect the contact array  130  prior to the mating operation. For example, the movable guard  140  may shield the electrical contacts  132 ,  133  from objects that inadvertently enter the receiving cavity  118 . In some embodiments, the movable guard  140  may align and/or hold the electrical contacts  132 ,  133  in designated positions to reduce the likelihood of stubbing during the mating operation. Optionally, the movable guard  140  may be configured to function as a cover that reduces the likelihood of contaminants (e.g., dust) entering the receiving cavity  118 . The movable guard  140  is configured to be held at a designated forward position, as shown in  FIGS. 1 and 2 , and move to a deeper position (shown in  FIG. 7 ) during the mating operation. The movable guard  140  may remain within the receiving cavity  118  during the lifetime operation of the electrical connector assembly  100 . As shown, the movable guard  140  may include an array  142  of thru-holes  144 . The array  142  is patterned to match the contact array  130  such that the electrical contacts  132 ,  133  extend through the thru-holes  144 . 
     The electrical connector assembly  100  may be constructed in various manners. For example, in some embodiments, the electrical contacts  132 ,  133  are inserted through passages  146  ( FIG. 2 ) of the back wall  112  that open to the receiving cavity  118  along the rear wall  128 . The electrical contacts  132 ,  133  are advanced through the passages  146  into the receiving cavity  118  in a direction that is parallel to the central axis  191 . Prior to inserting the electrical contacts  132 ,  133 , the movable guard  140  may be disposed within the receiving cavity  118 . As the electrical contacts  132 ,  133  are inserted through the back wall  112  and the rear wall  128 , the distal tip  138  of the electrical contacts  132 ,  133  is inserted through corresponding thru-holes  144 . In other embodiments, the movable guard  140  may be positioned within the receiving cavity  118  after the electrical contacts  132 ,  133  are assembled into the contact array  130 . For instance, each and every electrical contact  132 ,  133  may be operably positioned for engaging a corresponding mating contact of the mating connector  106 . The movable guard  140  may then be disposed within the receiving cavity  118  such that the thru-holes  144  receive the corresponding electrical contacts  132 ,  133 . 
     In the illustrated embodiment, the electrical connector assembly  100  includes a latching actuator  150  that is configured to engage the mating connector  106  and couple the mating connector  106  and the electrical connector assembly  100  to each other such that the mating connector  106  and the electrical connector assembly  100  remain secured to each other during operation. The latching actuator  150  may include a pair of rotatable levers  152 ,  154  and an operator-controlled panel  156  that extends between and joins the rotatable levers  152 ,  154 . In  FIG. 1 , the latching actuator  150  is shown in a first rotational position. In  FIG. 2 , the latching actuator  150  is shown in a second rotational position. To move to the second rotational position, the latching actuator  150  may be rotated about an axis of rotation  158  ( FIG. 1 ) such that the operator-controlled panel  156  is positioned adjacent to the housing side  115  as shown in  FIG. 2 . As described in greater detail below, the latching actuator  150  moves the mating connector  106  further into the receiving cavity  118  when the latching actuator  150  is rotated. 
     The electrical connector assembly  100  and the mating connector  106  ( FIG. 6 ) may be wire-to-wire connector assemblies that each couple to and hold a bundle of wires. For example, the electrical contacts  132 ,  133  may be electrically coupled to or be parts of insulated wires  195  (shown in  FIG. 5 ). The insulated wires  195  may include insulative jackets  196  (shown in  FIG. 5 ) and wire conductors (not shown) that extend along a length of the corresponding wire. When the electrical connector assembly  100  and the mating connector  106  are mated, each insulated wire  195  may be electrically coupled, through the corresponding electrical contacts, to a corresponding insulated wire (not shown) of the mating connector  106 . As such, the electrical connector assembly  100  and the mating connector  106  electrically connect different bundles of wires. In some embodiments, the electrical connector assembly  100  and the mating connector  106  are not secured to a structure such that the mated connectors (i.e., the electrical connector assembly  100  and the mating connector  106  secured to each other) are free-floating. In such embodiments, the mated connectors may be moved when either of the wire bundles is pulled. 
       FIG. 3  is an isolated plan view of the movable guard  140 . The movable guard  140  includes a dielectric sheet  160  having a first sheet side  162  and an opposite second sheet side  164  (shown in  FIG. 5 ). The first sheet side  162  is configured to engage or interface with the mating connector  106  ( FIG. 6 ), and the second sheet side  164  is configured to engage or interface with the rear wall  128  ( FIG. 2 ). In some embodiments, the movable guard  140  may function in either orientation such that the dielectric sheet  160  may be flipped and the first sheet side  162  engage or interface with the rear wall  128 . The first and second sheet sides  162 ,  164  may be separated by a thickness  166  (shown in  FIG. 5 ) of the dielectric sheet  160 . By way of example, the thickness  166  may be between about 0.1 millimeters (mm) to about 0.5 mm. In more particular embodiments, the thickness  166  may be between about 0.15 mm to about 0.40 mm. In yet more particular embodiments, the thickness  166  may be between about 0.20 mm to about 0.30 mm. In an exemplary embodiment, the thickness  166  is substantially uniform throughout the dielectric sheet  160 , except for the thru-holes  144 , such that the dielectric sheet  160  constitutes a substantially planar body that is sheet-like or film-like. 
     The dielectric sheet  160  may comprise one or more non-conductive materials that are sufficiently rigid to function as described herein. By way of example only, the non-conductive material may include polyester or polyethylene. In particular embodiments, the dielectric sheet  160  includes biaxially-oriented polyethylene terephthalate (boPET). In some embodiments, the dielectric sheet  160  may be stamped from a dielectric film, such as a film that includes polyester or polyethylene. A single stamping operation may provide the array  142  of thru-holes  144  as shown in  FIG. 3 . 
     However, it should be understood that the dielectric sheet  160  is not limited to a particular material or materials, and that various other materials may be used to form the movable guard  140 . In an exemplary embodiment, the dielectric sheet  160  is etched to form the array  142  of thru-holes  144 . However, the array  142  may be formed by other methods. For instance, the dielectric sheet  160  may be stamped, molded, or 3D-printed to form the array  142  of thru-holes  144 . 
     The dielectric sheet  160  includes an outer edge  170  that defines a perimeter of the dielectric sheet  160  when viewed along the central axis  191 . In some embodiments, the outer edge  170  may interface with one or more of the interior sidewalls  121 - 124 . For example, the outer edge  170  may be located immediately adjacent to, at least, the interior sidewall  122  ( FIG. 1 ) and the interior sidewall  124  ( FIG. 2 ). More specifically, the outer edge  170  may slidably engage the interior sidewalls  122 ,  124  and/or have a nominal gap therebetween. The interior sidewalls  122 ,  124  may position or locate the movable guard  140  within the receiving cavity  118  ( FIG. 1 ) so that the thru-holes  144  may receive the corresponding electrical contacts. As the movable guard  140  moves to the deeper position, the interior sidewalls  122 ,  124  may engage the outer edge  170  to facilitate maintaining the movable guard  140  in a proper orientation. In some embodiments, the outer edge  170  may be located immediately adjacent to each of the interior sidewalls  121 - 124 . 
     The perimeter (or profile) formed by the outer edge  170  may define a cover area of the movable guard  140  and may have a shape that is similar to an opening  240  ( FIG. 5 ) defined by a leading edge  148  ( FIG. 5 ) of the connector housing  108 . As such, the dielectric sheet  160  may be sized and shaped to cover a substantial portion of the receiving cavity  118  ( FIG. 1 ). In such embodiments, the dielectric sheet  160  may reduce the level of contaminants that enter the receiving cavity  118 . In some embodiments, the cover area is at least 60% of a profile of the receiving cavity  118 . In more particular embodiments, the cover area is at least 75% of the profile of the receiving cavity  118 . The profile of the receiving cavity  118  may be defined by a cross-section of the connector housing  108  taken transverse to the central axis  191 . 
     As described herein, the array  142  of thru-holes  144  is patterned to match the contact array  130  of electrical contacts  132 ,  133 . More specifically, each of thru-holes  144  is configured to have a corresponding electrical contact  132  or  133  extend therethrough. As such, each of the thru-holes  144  is sized and shaped relative to the corresponding electrical contact  132  or  133 . The thru-holes  144  may be defined by corresponding inner edges  174  of the dielectric sheet  160 . For embodiments that are stamped from a film, the outer edges  170  and the inner edges  174  may be stamped edges. Stamped edges may have structurally different properties than edges of other dielectric sheets. For example, a dielectric sheet that is formed from an injection-molding process may have edges that exhibit different qualities or properties than edges that were formed through a stamping operation. The dielectric sheet that is formed from plastic may be more rigid than a dielectric sheet stamped from a film. The different qualities or properties of the different dielectric sheets may be identified by inspecting the dielectric sheets (e.g., using a microscope) or through other tests. As described herein, the array  142  of thru-holes  144  may facilitate assembling the electrical connector  102  by locating the electrical contacts  132 ,  133  within the receiving cavity  118 . After assembly, the movable guard  140  may also substantially hold the electrical contacts  132 ,  133  within designated positions relative to one another. 
     The thru-holes  144  include clearance thru-holes  180 A,  180 B and frictional thru-holes  182 A,  182 B. Each of the thru-holes  180 A,  180 B,  182 A,  182 B have different sizes and shapes that are defined by the corresponding inner edges  174 . For example, the inner edges  174  of the clearance thru-holes  180 A,  180 B are configured to permit the respective electrical contacts  132 ,  133  ( FIG. 1 ) to move freely therethrough as the movable guard  140  within the receiving cavity  118  ( FIG. 1 ). The inner edges  174  of the clearance thru-holes  180 A,  180 B may have a profile that is similar to, but larger than, a cross-sectional profile of the corresponding electrical contact. The inner edges  174  of the frictional thru-holes  182 A,  182 B, however, are configured to engage the respective electrical contacts  132 ,  133 . For example, the inner edges  174  of the frictional thru-holes  182 A,  182 B may have at least one dimension that is smaller than a similar dimension of the corresponding electrical contacts such that the inner edges  174  must engage the corresponding electrical contacts. 
     In an exemplary embodiment, the frictional forces generated between the inner edges  174  of the frictional thru-holes  182 A,  182 B and the respective electrical contacts  132 ,  133  are sufficient to hold the movable guard  140  within the receiving cavity  118 . For example, the movable guard  140  may be retained at the forward position in any orientation with respect to gravity and, in some embodiments, may remain at the forward position even if the electrical connector assembly  100  is dropped from a distance of 20 millimeters or less. In particular embodiments, the movable guard  140  may remain at the forward position even if the electrical connector assembly  100  is dropped from a distance of 1 meter or less. 
     As shown in  FIG. 3 , the array  142  may include a first section  186  and a second section  188 . The first section  186  of the array  142  is configured to receive the electrical contacts  132 , and the second section  188  of the array  142  is configured to receive the electrical contacts  133 . The first section  186  includes the clearance thru-holes  180 A and the frictional thru-holes  182 A. The second section  188  includes the clearance thru-holes  180 B and the frictional thru-holes  182 B. In other embodiments, the array  142  may include only one section or more than two sections. In alternative embodiments, the thru-holes  144  are not separated into different section but, instead, are mixed within the array  142 . 
     Collectively, the frictional thru-holes  182 A,  182 B may provide a mating resistance during the mating operation. For example, the frictional forces generated between the inner edges  174  and the corresponding electrical contacts  132 ,  133  impede movement of the movable guard  140  toward the rear wall  128  ( FIG. 2 ). The number of frictional thru-holes  182 A,  182 B may be configured such that the mating resistance does not exceed a designated force. As shown, the dielectric sheet  160  includes  30  the frictional thru-holes  182 A,  182 B out of a total of 48 thru-holes  144 . In an exemplary embodiment, the mating resistance does not change based on a depth of the dielectric sheet  160 . 
     The clearance thru-holes  180 A,  180 B and the frictional thru-holes  182 A,  182 B may be distributed across the dielectric sheet  160  to provide a substantially uniform mating resistance during the mating operation. For instance, the clearance thru-holes  180 A,  180 B and the frictional thru-holes  182 A,  182 B may be positioned relative to each other so that the frictional thru-holes  182 A,  182 B are not overly concentrated within one or more particular portions of the array  142 . 
     In some embodiments, the mating resistance may also include frictional forces generated between the outer edge  170  and one or more portions of the connector housing  108 . For example, the outer edge  170  may engage one or more of the interior sidewalls  121 - 124  ( FIGS. 1 and 2 ). In some embodiments, the dielectric sheet  160  includes thru-holes  190 . The thru-holes  190  may receive one or more projections from the mating connector  106 . Alternatively, the thru-holes  190  may receive one or more projections from the connector housing  108 . Such projections may be used to align the movable guard and/or provide a designated mating resistance during the mating operation. 
       FIG. 4  is an enlarged plan view of a portion of the dielectric sheet  160  slidably engaged to corresponding electrical contacts  132 . In an exemplary embodiment, the electrical contacts  132  are configured to transmit data signals and the electrical contacts  133  ( FIG. 1 ) are configured to transmit electrical power. In alternative embodiments, both of the electrical contacts  132  and  133  may transmit data signals or, alternatively, both of the electrical contacts  132  and  133  may transmit electrical power. Although the following is with specific reference to the electrical contacts  132  and the clearance and frictional thru-holes  180 B,  182 B in  FIG. 4 , the description may be similarly applied to the electrical contacts  133  and the clearance and frictional thru-holes  180 A,  182 A ( FIG. 3 ). 
     With respect to the clearance thru-hole  180 B, the inner edge  174  of the clearance thru-hole  180 B is shaped relative to the corresponding electrical contact  132  such that a gap or clearance  202  exists between an outer surface  215  of the electrical contact  132  and the inner edge  174 . More specifically, when the clearance thru-hole  180 B is aligned with the corresponding electrical contact  132 , the gap or clearance  202  exists and the electrical contact  132  is permitted to move freely therethrough. The clearance thru-hole  180 B has a width  204  and a height or height  206 . The electrical contact  132  has a width  208  and a thickness  210 . In an exemplary embodiment, the electrical contact  132  is a contact blade such that the width  208  is substantially greater than the thickness  210 . For example, the width  208  may be about two times (2×) to four times (4×) greater than the thickness  210 . As such, the electrical contact  132  has opposite broad sides  212 ,  214  and opposite short sides  216 ,  218 . The short sides  216 ,  218  may have a curved contour as shown in  FIG. 4 . The width  204  and the height  206  of the clearance thru-hole  180 B may be dimensioned such that the shape of the inner edge  174  is similar to a cross-sectional profile of the electrical contact  132 . More specifically, the width  204  may be slightly greater than the width  208  and the height  206  may be slightly greater than the thickness  210 . 
     In  FIG. 4 , the electrical contact  132  has an ideal, central position within the clearance thru-hole  180 B. In the central position, the gap  202  surrounds an entirety of the electrical contact  132 . It should be understood that, due to tolerances in the assembly process, the electrical contact  132  may have a different position. For example, the electrical contact  132  may be closer to one or more segments of the inner edge  174  or, in some cases, the outer surface  215  of the electrical contact  132  may directly engage the inner edge  174 . As shown, electrical contact  132  reduces or tapers in size at the distal tip  138 . As the electrical contact  132  is received through the clearance thru-hole  180 B, if the electrical contact  132  engages the inner edge  174 , the tapered distal tip  138  may operate to re-direct the electrical contact  132  to a sufficiently aligned position. 
     The frictional thru-hole  182 B has a different shape than the clearance thru-hole  180 B. The inner edge  174  is configured to directly engage the electrical contact  132 . As shown, the frictional thru-hole  182 B has a width  224  and a varying height that changes between a first height  226  and a second height  228 . The width  224  may be substantially equal to the width  204  of the clearance thru-hole  180 B. Unlike the height  206 , however, the frictional thru-hole  182 B has a varying height. As shown, the first height  226  is greater than the height  206  and the second height  228  is less than the height  206 . In such embodiments, the inner edge  174  of the frictional through-hole  182 B may be shaped to include projections  232 ,  234  that extend toward and directly engage the corresponding electrical contact  132 . The projection  232  engages the broad side  212  of the corresponding electrical contact  132 , and the projection  234  engages the broad side  214  of the corresponding electrical contact  132 . 
     As the corresponding electrical contact  132  is inserted through the frictional thru-hole  182 B, the projections  232 ,  234  may engage the broad sides  212 ,  214 , respectively. In some embodiments, such as those that are stamped from a dielectric film, the projections  232 ,  234  may function as flaps that bend slightly away from the first sheet side  162  to permit the electrical contact  132  to slide therethrough. Resistance to bending by the projections  232 ,  234  may be based, in part, on the differences between the heights  226 ,  228 . Nonetheless, the projections  232 ,  234  directly engage the electrical contact  132  and generate the frictional forces therebetween. In the illustrated embodiment, the projections  232 ,  234  extend toward each other. In other embodiments, the projections  232 ,  234  do not extend toward each other. Yet in other embodiments, the inner edge  174  defines only one projection or more than two projections that engage the electrical contact. 
     For embodiments in which the projections  232 ,  234  are permitted to bend slightly, the frictional forces that initially hold the movable guard  140  within the receiving cavity  118  may be greater than the frictional forces that resist movement of the movable guard  140  after the movable guard  140  has been displaced during the mating operation. Likewise, for embodiments in which the dielectric sheet  160  is a dielectric film, the frictional forces that resist movement of the movable guard  140  may be less than the frictional forces that are generated by plastic plates in known systems. Accordingly, compared to known systems, embodiments set forth herein may allow movement of the movable guard  140  when a lower mating force is applied. 
     The inner edges  174  of the frictional thru-holes  182 A,  182 B directly engage the corresponding electrical contacts  132 ,  133  to hold the movable guard  140  at the forward position within the receiving cavity  118 . For example, the projections  232 ,  234  may pinch the corresponding electrical contact therebetween such that each of the projections  232 ,  234  presses against the corresponding electrical contact. In some embodiments, when the electrical contacts  132 ,  133  are aligned with the frictional thru-holes  182 A,  182 B, the electrical contacts  132 ,  133  must engage the inner edges  174  of the frictional thru-holes  182 A,  182 B. In other words, the electrical contacts  132 ,  133  are not permitted to move freely through the frictional thru-holes  182 A,  182 B without engaging the inner edges  174 . 
     The forces provided by the projections  232 ,  234  may oppose each other. The inner edges  174  of the clearance thru-holes  180 A,  180 B, however, may not provide opposing forces. Under certain circumstances, the inner edges  174  of the clearance thru-holes  180 A,  180 B may inadvertently or nominally engage the corresponding electrical contacts  132 ,  133 . In some embodiments, however, the frictional forces between the inner edges  174  of the clearance thru-holes  180 A,  180 B may be insubstantial compared to the frictional forces generated by the inner edges  174  of the frictional thru-holes  182 A,  182 B. 
       FIG. 5  is a cross-section of the electrical connector assembly  100  prior to engaging a mating connector  106  ( FIG. 6 ). The front end  110  has an opening  240  to the receiving cavity  118  that is defined by the leading edge  148 . The opening  240  and the receiving cavity  118  are sized and shaped relative to the mating connector  106  to receive the mating connector  106  during the mating operation. As shown, the electrical contacts  132 ,  133  of the contact array  130  are disposed within the receiving cavity  118 . 
     As shown, the movable guard  140  (or the dielectric sheet  160 ) extends transverse to the central axis  191  and to the elongated bodies  134 ,  135  of the electrical contacts  132 ,  133 , respectively. For example, the central axis  191  may be orthogonal or perpendicular to the dielectric sheet  160 . The first sheet side  162  faces toward the front end  110  in a direction that is along the central axis  191 . The second sheet side  164  faces the rear wall  128 . In  FIG. 5 , the movable guard  140  is disposed at a forward position. In the forward position, the movable guard  140  is located at a height  242  that is measured from the rear wall  128  and at a depth  244  that is measured from the opening  240  (or the leading edge  148 ). Also shown, the electrical contacts  132 ,  133  have a common height  246  measured from the rear wall  128  to the distal tips  138 . The height  246  is greater than the height  242 . In alternative embodiments, the electrical contacts  132 ,  133  may not have a common height. As described herein, the frictional forces generated between the electrical contacts  132 ,  133  may collectively hold the movable guard  140  in the forward position prior to the mating operation. 
       FIG. 6  is a perspective view of the mating connector  106 . The mating connector  106  has a connector housing  302  that includes a front wall  304 . The front wall  304  is configured to engage the first sheet side  162  ( FIG. 3 ) of the movable guard  140  ( FIG. 1 ) during the mating operation. The connector housing  302  includes an array  306  of passages  308 ,  309  that open to the front wall  302 . The mating connector  106  may include an array of mating contacts  310 ,  311  ( FIG. 7 ). For example, the passages  308 ,  309  may include mating contacts  310 ,  311 , respectively. 
       FIG. 7  is a cross-section of a communication system  320  in accordance with an embodiment after the mating operation. The communication system  320  includes the mating connector  106  and the electrical connector assembly  100 . During the mating operation, the front wall  304  engages the first sheet side  162  of the movable guard  140  and moves the movable guard  140  in a mating direction  322  along the central axis  191  ( FIG. 1 ) toward the rear wall  128 . As shown, the movable guard  140  is disposed between the front wall  304  and the rear wall  128 . During operation of the communication system  320 , the movable guard  140  may remain within the receiving cavity  118 . 
     In some embodiments, the latching actuator  150  completes the mating operation. For example, the mating connector  106  may be inserted into the receiving cavity  118  until the mating connector  106  is located at a designated position. The latching actuator  150  may then be rotated about the axis  158 . As the latching actuator  150  is rotated, the latching actuator  150  may drive the mating connector  106  and the movable guard  140  toward the rear wall  128  until the mating connector  106  and the movable guard  140  achieve the designated positions shown in  FIG. 7 . 
     When the electrical connector assembly  100  and the mating connector  106  are mated as shown in  FIG. 7 , the electrical contacts  132 ,  133  are directly engaged to the mating contacts  310 ,  311 , respectively. Accordingly, data and/or electrical power may be transmitted through the communication system  320 . 
       FIG. 8  is a perspective view of an electrical connector assembly  400  formed in accordance with an embodiment that is mounted to a circuit board  401 . The electrical connector assembly  400  includes an electrical connector  402  and a movable guard  440  that is slidably coupled to the electrical connector  402 . The electrical connector  402  and the movable guard  440  may have similar features as the electrical connector  102  ( FIG. 1 ) and the movable guard  140  ( FIG. 1 ), respectively. Although not shown, the electrical connector  402  is configured to engage a mating connector, which may be similar to the mating connector  106  ( FIG. 6 ). The electrical connector  102  includes a connector housing  408  having a front end  410  and a back wall  412  that face in generally opposite directions. 
     The connector housing  408  defines a receiving cavity  418  that opens to the front end  410 . The receiving cavity  418  is sized and shaped to receive the mating connector (not shown) during the mating operation. The connector housing  408  includes interior sidewalls  421 ,  422 ,  423 , and  424  that define the receiving cavity  418 . In the illustrated embodiment, the interior sidewall  421  is shaped to include keying features  426 . The receiving cavity  118  may also be defined by an interior rear wall  428 . The rear wall  428  faces in a direction toward the front end  410 . In some embodiments, each of the interior sidewalls  421 - 424  may interface with the mating connector when the mating connector and the electrical connector  402  are engaged. 
     The electrical connector  402  includes a contact array  430  of electrical contacts  432 ,  433  that are disposed within the receiving cavity  418 . The electrical contacts  432 ,  433  may be similar or identical to the electrical contacts  132 ,  133  ( FIG. 1 ). For example, the electrical contacts  432 ,  433  may be contact blades. The movable guard  440  is configured to protect the contact array  430  prior to the mating operation. For example, the movable guard  440  may shield the electrical contacts  432 ,  433  from objects that inadvertently enter the receiving cavity  418 . In some embodiments, the movable guard  440  may align and/or hold the electrical contacts  432 ,  433  in designated positions to reduce the likelihood of stubbing during the mating operation. Optionally, the movable guard  440  may be configured to function as a cover that reduces the likelihood of contaminants (e.g., dust) entering the receiving cavity  418 . Similar to the movable guard  140  ( FIG. 1 ), the movable guard  440  is configured to be held at a designated forward position and move to a deeper position during the mating operation. 
       FIG. 9  is a perspective view of the movable guard  440 . The movable guard  440  includes an array  442  of thru-holes  444 . The array  442  is patterned to match the contact array  430  ( FIG. 8 ) such that the electrical contacts  432 ,  433  ( FIG. 8 ) extend through the thru-holes  444 . The movable guard  440  may have similar features as the movable guard  140 . For example, the movable guard  444  includes a dielectric sheet  460  having a first sheet side  462  and an opposite second sheet side  464 . The first sheet side  462  is configured to engage or interface with the mating connector (not shown), and the second sheet side  464  is configured to engage or interface with the rear wall  428  ( FIG. 8 ). The first and second sheet sides  462 ,  464  may be separated by a thickness of the dielectric sheet  460 , which may be similar to the thickness  166  ( FIG. 5 ) described above. The dielectric sheet  460  may be manufactured in various manners, such as those described above with respect to the dielectric sheet  160 . In certain embodiments, the dielectric sheet  460  is stamped from a dielectric film. 
     The dielectric sheet  460  includes an outer edge  470  that defines a perimeter of the dielectric sheet  460 . In some embodiments, the outer edge  470  may interface with one or more of the interior sidewalls  421 - 424  ( FIG. 8 ). For example, the outer edge  470  may be located immediately adjacent to the interior sidewalls  422 - 424 . The interior sidewalls  421 - 424  may position or locate the movable guard  440  within the receiving cavity  418  ( FIG. 8 ) so that the thru-holes  444  receive the corresponding electrical contacts. As the movable guard  440  moves to the deeper position, the interior sidewalls  421 - 424  may engage the outer edge  470  to facilitate maintaining the movable guard  440  in a proper orientation. In some embodiments, the outer edge  470  may be located immediately adjacent to each of the interior sidewalls  421 - 424 . 
     The perimeter (or profile) formed by the outer edge  470  may define a cover area of the movable guard  440  and may have a shape that is similar to an opening  441  ( FIG. 8 ) defined by a leading edge  448  ( FIG. 8 ) of the connector housing  408 . As such, the dielectric sheet  460  may be sized and shaped to cover a substantial portion of the receiving cavity  418  ( FIG. 1 ). In such embodiments, the dielectric sheet  460  may reduce the level of contaminants that enter the receiving cavity  418 . In some embodiments, the cover area is at least 60% of a profile of the receiving cavity  418 . In more particular embodiments, the cover area is at least 75% of the profile of the receiving cavity  418 . 
     The thru-holes  444  may be defined by corresponding inner edges  474  of the dielectric sheet  460 . The thru-holes  444  include clearance thru-holes  480  and frictional thru-holes  482 . The inner edges  474  of the clearance thru-holes  480  may be configured to permit the electrical contacts  432  ( FIG. 8 ) to pass freely therethrough when the movable guard  440  is aligned with the contact array  430  ( FIG. 8 ). The inner edges  474  of the frictional thru-holes  482  are configured to engage the respective electrical contacts  433  ( FIG. 8 ). For example, the inner edges  474  may define opposing projections  461 ,  463  for each of the frictional thru-holes  482 . 
     Returning to  FIG. 8 , the electrical contacts  432 ,  433  may be stamped and formed. Each of the electrical contacts  432 ,  433  may extend lengthwise between a corresponding first end  472  and a corresponding second end  474 . The first ends  472  may represent distal ends of the electrical contacts  432 ,  433  that are inserted through corresponding passages (not shown) of the connector housing  408  such that the first ends  472  are exposed within the receiving cavity  418 . The second ends  474  may be inserted into plated thru-holes  476  of the circuit board  401 . In such embodiments, the electrical connector assembly  400  may be part of a device, such as an electrical device  500  shown in  FIG. 10 . 
       FIG. 10  is a perspective view of the electrical device  500 , and  FIG. 11  is a cross-section of the electrical device  500 . The electrical device  500  includes an electrical connector assembly  501 , a device housing  504 , and a circuit board  506  ( FIG. 11 ). The electrical connector assembly  501  includes an electrical connector  502  and a movable guard  540  that is slidably coupled to the electrical connector  502 . The electrical connector  502  may be similar to the electrical connector  102  ( FIG. 1 ) and the electrical connector  402  ( FIG. 8 ). The electrical device  500  is configured to engage a mating connector (not shown) during a mating operation. The electrical device  500  may be secured to a structure (not shown) through the device housing  504 . 
     With respect to  FIG. 11 , the electrical connector  502  includes a connector housing  508  that defines a receiving cavity  518  that opens to a front end  510  of the electrical connector  502 . The receiving cavity  518  is sized and shaped to receive the mating connector (not shown) during the mating operation. The connector housing  508  includes an interior rear wall  528  that defines a portion of the receiving cavity  518 . The rear wall  528  faces in a direction toward the front end  510 . 
     The electrical connector  502  includes a contact array  530  of electrical contacts  532  that are disposed within the receiving cavity  518 . The electrical contacts  532  may be similar or identical to the electrical contacts  132  ( FIG. 1 ) or  432  ( FIG. 8 ). The movable guard  540  is configured to protect the contact array  530  prior to the mating operation. Although not indicated in  FIG. 11 , the movable guard  540  includes an array of thru-holes that are patterned to match the contact array  530 . The movable guard  540  may have similar features as the movable guard  140  ( FIG. 1 ) or the movable guard  440  ( FIG. 8 ). 
     Similar to the electrical contacts  432 ,  433  ( FIG. 8 ), the electrical contacts  532  may be stamped and formed. As shown, each of the electrical contacts  532  extend lengthwise between a corresponding first end  572  and a corresponding second end  574 . The first ends  574  represent distal ends of the electrical contacts  532  that are exposed within the receiving cavity  518 . The second ends  574  are inserted into plated thru-holes  576  of the circuit board  506 . The electrical contacts  532  extend through a housing cavity  580  that is defined by the device housing  504 . The connector housing  508  is secured to the circuit board  506  and to the device housing  504  such that the connector housing  508  has a fixed position with respect to the circuit board  506  and the device housing  504 . 
     It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the various embodiments without departing from its scope. Dimensions, types of materials, orientations of the various components, and the number and positions of the various components described herein are intended to define parameters of certain embodiments, and are by no means limiting and are merely exemplary embodiments. Many other embodiments and modifications within the spirit and scope of the claims will be apparent to those of skill in the art upon reviewing the above description. The patentable scope should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. 
     As used in the description, the phrase “in an exemplary embodiment” and the like means that the described embodiment is just one example. The phrase is not intended to limit the inventive subject matter to that embodiment. Other embodiments of the inventive subject matter may not include the recited feature or structure. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means—plus-function format and are not intended to be interpreted based on 35 U.S.C. §112(f), unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.