Patent Publication Number: US-10326238-B2

Title: Systems and devices for maintaining an electrical connection

Description:
BACKGROUND 
     Background and Relevant Art 
     Use of computing devices is becoming more ubiquitous by the day. Computing devices range from standard desktop computers to wearable computing technology and beyond. One area of computing devices that has grown in recent years is the hybrid computers. Hybrid computers may act as a both a conventional computer with conventional user interaction devices, such as a keyboard, a mouse, a trackpad, trackball, stylus, or other input peripherals, as well as a touch-sensitive computing device that allows for direct interaction with information by a user&#39;s input on the display device. 
     Hybrid computers, therefore, experience more movement than conventional computers. The movement of the computer introduces additional challenges to electrical connections from a reliability standpoint, a power continuity standpoint, and a safety standpoint. Conventional electrical connectors rely upon friction fits that may loosen during movement of the device, or rely upon mechanical locking methods that are difficult to engage and disengage in the restrictive spaces behind the devices. In addition to difficulty of use, the conventional mechanical locking methods are disruptive to the Industrial Design. 
     The subject matter claimed herein is not limited to implementations that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one exemplary technology area where some implementations described herein may be practiced. 
     BRIEF SUMMARY 
     In an implementation, an electrical connector includes a locking plug, a lock actuator, a strain relief, and an exterior mating surface. The locking plug includes a locking mechanism and the lock actuator is coupled to the locking mechanism. The strain relief is coupled to the locking plug and the exterior mating surface is coupled to the locking plug and axially moveable relative to the locking plug to move the lock actuator. 
     In another implementation, an electrical connector includes an electrical plug, a cable, and an exterior mating surface, a biasing element, and a strain relief. The cable is in electrical communication with the electrical plug. The exterior mating surface is moveable in an axial direction relative to the electrical plug. The biasing element is configured to bias the exterior mating surface axially toward the electrical plug. The strain relief is positioned circumferentially about the cable. 
     In yet another implementation, a system for making an electrical connection includes an electronic device having an appliance inlet connector and an appliance coupler connector configured to engage with the appliance inlet connector. The appliance inlet connector has an appliance inlet connector surface. The appliance coupler connector includes an electrical plug, a strain relief, and an exterior mating surface. The strain relief is coupled to the electrical plug. The exterior mating surface is coupled to the electrical plug and moveable in an axial direction relative to the electrical plug. The exterior mating surface is biased toward the appliance inlet connector surface. The exterior mating surface has a shoulder abutting the appliance inlet connector surface in a plugged configuration. 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
     Additional features and advantages will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the teachings herein. Features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. Features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to describe the manner in which the above-recited and other features of the disclosure can be obtained, a more particular description will be rendered by reference to specific implementations thereof which are illustrated in the appended drawings. For better understanding, the like elements have been designated by like reference numbers throughout the various accompanying figures. While some of the drawings may be schematic or exaggerated representations of concepts, at least some of the drawings may be drawn to scale. Understanding that the drawings depict some example implementations, the implementations will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
         FIG. 1  is a perspective view of an implementation of a system for forming an electrical connection between an electrical connector and an electronic device; 
         FIG. 2A  is a perspective view of an implementation of an electrical connector; 
         FIG. 2B  is a perspective view of the implementation of an electrical connector of  FIG. 2A  with a cover removed; 
         FIG. 2C  is a top view of the implementation of an electrical connector of  FIG. 2B ; 
         FIG. 2D  is a side view of the implementation of an electrical connector of  FIG. 2B ; 
         FIG. 2E  is a side cross-sectional view of the implementation of an electrical connector of  FIG. 2B ; 
         FIG. 3A  is a perspective view of an implementation of another electrical connector; 
         FIG. 3B  is a perspective view of the implementation of an electrical connector of  FIG. 3A  with a cover removed; 
         FIG. 3C  is a top view of the implementation of an electrical connector of  FIG. 3B ; 
         FIG. 3D  is a side view of the implementation of an electrical connector of  FIG. 3B ; 
         FIG. 3E  is a side cross-sectional view of the implementation of an electrical connector of  FIG. 3B ; 
         FIG. 4A  is a perspective view of an implementation of another electrical connector; 
         FIG. 4B  is a perspective view of the implementation of an electrical connector of  FIG. 4A  with a cover removed; 
         FIG. 4C  is a top view of the implementation of an electrical connector of  FIG. 4B ; 
         FIG. 4D  is a side view of the implementation of an electrical connector of  FIG. 4B ; and 
         FIG. 4E  is a side cross-sectional view of the implementation of an electrical connector of  FIG. 4B . 
     
    
    
     DETAILED DESCRIPTION 
     This disclosure generally relates to electrical connection apparatuses, systems, and methods. More particularly, this disclosure generally relates to locking apparatuses, systems, and methods for securing computing devices. 
     An electrical connection includes a positive terminal, a negative terminal, and a ground terminal. The electrical connection includes an appliance inlet connector and an appliance coupler connector that mate together to provide electrical communication. A plurality of prongs of the appliance inlet connector is received in a plurality of receivers in the appliance coupler connector. In some implementations, at least one of receivers of the plurality of receivers includes a locking mechanism to lock the prong in the receiver. 
     In some implementations, such as shown in  FIG. 1 , an appliance coupler connector  100  is an end of an electrical cable  102 , and the appliance coupler connector  100  connects to an appliance inlet connector  104  on an electronic device  106 . For example, the appliance coupler connector  100  may be a C13 plug and the appliance inlet connector  104  may be a C14 plug in accordance with the International Electrotechnical Commission (IEC) 60320 standard. In other examples, the appliance coupler connector  100  and the appliance inlet connector  104  may be other mating pairs of connectors according to the IEC 60320 standard. In yet other examples, the appliance coupler connector and the appliance inlet connector may be a mating pair of connectors according to another standard. 
     The appliance coupler connector  100  may have an exterior mating surface  108  with a proximal-facing surface configured to mate against or proximate to an appliance inlet connector surface of the appliance inlet connector  104 . For example, the proximal-facing surface may be oriented toward the electronic device  106  including the appliance inlet connector  104 . In some implementations, the proximal-facing surface may be moveable in an axial direction relative to (e.g., movement away from) the appliance inlet connector  104 . The appliance coupler connector  100  includes a biasing element configured to bias the axial position of the proximal-facing surface in the axial direction toward the distal end of the appliance coupler connector  100  (i.e., away from a user when connected to the appliance inlet connector  104 ). For example, an outer housing or exterior mating surface  108  of the appliance coupler connector  100  may have a predetermined range of axial movement relative to the plug of the appliance coupler connector  100 . 
     The appliance coupler connector  100  may be a locking plug that has a locking mechanism configured to grip, latch, pinch, frictionally engage, or otherwise mechanically resists the axial movement of the locking plug relative to one or more prongs of the plurality of prongs on the appliance inlet connector. In some implementations, the locking mechanism may engage with a prong of the appliance inlet connector  104  to limit and/or prevent the axial movement relative to the appliance inlet connector  104 . In other implementations, the locking mechanism may engage with a plurality of prongs of the appliance inlet connector  104 . 
     In some implementations in which the appliance coupler connector  100  includes a locking plug, as described herein, a lock actuator operably coupled to the locking plug to bias the locking plug in a locked position, and a moveable exterior mating surface  108 . The movement of the moveable exterior mating surface  108  may move the lock actuator to actuate the lock mechanism and move the locking mechanism to an unlocked state, allowing the disengagement of the appliance coupler connector  100  from the appliance inlet connector  104 . 
       FIG. 2A  illustrates an implementation of an appliance coupler connector  200 . The appliance coupler connector  200  includes an electrical plug  210  with a cover  211  thereon, an exterior mating surface  208 , and a strain relief  220 . The cover  211  may enclose one or more components of the electrical plug  210 . For example, the lock actuator (such as lock actuator  230  shown in  FIG. 2B ) may be at least partially internal to (e.g., within) the cover  211 . The appliance coupler connector  200  is configured to mate with an appliance inlet connector to provide electrical communication between an electrical cable  202  in electrical communication with the appliance coupler connector  200  and an electronic device in electrical communication with an appliance inlet connector. 
     The appliance coupler connector  200  has an exterior mating surface  208  that is moveable in an axial direction (i.e. in the direction of a longitudinal axis of the electrical connector). In some implementations, the exterior mating surface  208  has a proximal-facing surface  212  oriented toward the electrical plug  210  with a shoulder  214  extending laterally away from and/or beyond the electrical plug  210 . In some implementations, the shoulder  214  is rectangular about the electrical plug  210 . In other implementations, at least a portion of the shoulder  214  is elliptical, circular, otherwise round, polygonal, irregular, or combinations thereof. 
     The shoulder  214  extends laterally away from and beyond the electrical plug by an amount relative to the width of the electrical plug  210 . A shoulder ratio is the ratio of the width of the shoulder  214  relative to a width of the electrical plug  210 . In some implementations, the shoulder  214  extends laterally away from and beyond the electrical plug  210  by a shoulder ratio in a range having an upper value, a lower value, or upper and lower values including any of 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, or any values therebetween. For example, the shoulder ratio may be less than 2.0. In other examples, the shoulder ratio is between 1.0 and 2.0. In at least one example, the shoulder ratio is about 1.5. In at least one example, the shoulder ratio may comply with an IEC 60320 specification. 
     The exterior mating surface  208  may have a distal-facing surface  216  that is oriented in the opposite direction from the proximal-facing surface  212  and toward the cable  202 . In some implementations, the distal-facing surface  216  is curved in profile. In other implementations, the distal-facing surface  216  is planar in profile. 
     In some implementations, a distal projection  218  of the exterior mating surface  208  projects distally from the distal-facing surface  216 . The distal projection  218  may flank and/or encircle at least a portion of the cable  202  and/or at least a portion of a strain relief  220  about the cable  202 . 
     Referring now to  FIG. 2B , the appliance coupler connector  200  of  FIG. 2A  is illustrated with the cover of the electrical plug  210  removed. The electrical plug  210  illustrated in  FIG. 2B  is a locking plug with a positive receiver  222 , a negative receiver  224 , and a ground receiver  226 . The ground receiver  226  has a locking mechanism  228 , operably coupled to a lock actuator  230 . The lock actuator  230  is connected to a tab  232  of the exterior mating surface  208 . 
     As shown in  FIG. 2C , a biasing element may be a spring  234  or other resilient member that biases the locking mechanism  228  and lock actuator  230  in the proximal direction. The exterior mating surface  208  is slidable in an axial direction relative to the electrical plug  210 . Distal motion of the exterior mating surface  208  moves the tab  232  in the distal direction away from the electrical plug  210 , which, in turn, moves the lock actuator  230  in the distal direction. 
     In some implementations, the biasing element may apply a biasing force to the lock actuator  230  that is in a range having an upper value, a lower value, or upper and lower values including any of 0.20 Newtons (N), 0.30 N, 0.40N, 0.50 N, 0.60 N, 0.70 N, 0.80 N, 0.90 N, 1.00 N, 1.10 N, 1.20 N, 1.30 N, 1.40 N, 1.50 N, 1.60 N, 1.70 N, 1.80 N, 1.90 N, 2.00 N, of any values therebetween. For example, the biasing force may be greater than 0.20 N. In other examples, the biasing force may be less than 2.00 N. In yet other examples, the biasing force may be between 0.20 N and 2.00 N. In further examples, the biasing force may be between 0.40 N and 1.50 N. In at least one example, the biasing force may be about 0.50 N. 
     The force applied to the exterior mating surface  208  to actuate the locking mechanism  228  and move the locking mechanism  228  to an unlocked state, therefore may be equal to or greater than the biasing force of the biasing element. 
       FIG. 2D  illustrates a side view of the appliance coupler connector  200 . The electrical plug  210 , the cable  202 , and the strain relief  220  are fixed axially relative to one another, while the exterior mating surface  208  is slidable a predetermined distance  235  in the axial direction. In some implementations, the predetermined distance  235  is in a range having upper values, lower values, or upper and lower values including any of 1 millimeter (mm), 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, or any values therebetween. For example, the predetermined distance  235  may be less than 10 mm. In other examples, the predetermined distance  235  may be greater than 1 mm. In yet other examples, the predetermined distance  235  may be in range from 1 mm to 10 mm. In further examples, the predetermined distance  235  may be in a range of 3 mm to 8 mm. In at least one example, the predetermined distance  235  is about 5 mm. 
     The distal-facing surface  216  of the exterior mating surface  208  is shown in profile in  FIG. 2D . As described herein, the profile of the distal-facing surface  216  may have different shapes including curves, planes, discontinuous angles, or combinations thereof. In some implementations, the distal-facing surface  216  is a continuous curve. For example, the profile of the distal-facing surface  216  may be a circular arc. In other examples, the profile of the distal-facing surface  216  may be an elliptical arc. In some implementations, at least a portion of the distal-facing surface  216  is a curve with a radius of curvature in a range having an upper value, a lower value, or upper and lower values including any of 0.20 inches, 0.30 inches, 0.40 inches, 0.50 inches, 0.60 inches, 0.70 inches, 0.80 inches, 0.90 inches, 1.0 inches, 1.1 inches, 1.2 inches, 1.3 inches, 1.4 inches, 1.5 inches, 1.6 inches, 1.7 inches, 1.8 inches, 1.9 inches, 2.0 inches, or any values therebetween. For example, at least a portion of the distal-facing surface  216  has a radius of curvature greater than 0.20 inches. In other examples, at least a portion of the distal-facing surface  216  has a radius of curvature less than 2.0 inches. In yet other examples, at least a portion of the distal-facing surface  216  has a radius of curvature in a range of 0.20 inches to 2.0 inches. In further examples, at least a portion of the distal-facing surface  216  has a radius of curvature in a range of 0.50 inches to 1.5 inches. In at least one example, at least a portion of the distal-facing surface  216  has a radius of curvature about 1.0 inches. 
       FIG. 2E  is a cross-sectional view of the side view of  FIG. 2D . The implementation of an appliance coupler connector  200  is depicted with a cross-section through the ground receiver  226  and illustrating the locking mechanism  228 . The locking mechanism  228  includes a bracket  236  that may tilt upon application of force by the spring  234 , thereby engaging a ground prong. The tilting of the bracket  236  may frictionally engage the bracket  236  with the ground prong, limiting and/or preventing movement of the appliance coupler connector  200  relative to the ground prong, when the appliance coupler connector  200  in coupled to an appliance inlet connector. In other implementations, the locking mechanism  228  may include a protrusion and detent or recess between the locking mechanism  228  and a ground prong that, when engaged, limits and/or prevents movement of the appliance coupler connector  200  relative to the ground prong. 
     The locking mechanism  228  is shown in the unlocked state in  FIG. 2E , with the bracket  236  substantially perpendicular to the axial direction. The spring  234  is compressed in  FIG. 2E  as the exterior mating surface  208  is moved toward a distal position away from the electrical plug  210 . The tab  232  of the exterior mating surface  208  pulls on the lock actuator  230 , which compresses the spring  234  and moves the bracket  236  to the substantially perpendicular position shown, positioning the locking mechanism  228  in an unlocked state. 
     In some implementations, the axial movement of the electrical plug  210  in a distal direction (i.e., unplugging the appliance coupler connector  200 ) may be limited and/or prevented by the locking mechanism  228  in the absence of external force applied to the exterior mating surface  208 . A distal force applied to the exterior mating surface  208  actuates the locking mechanism  228  and allows distal movement of the electrical plug  210 . The actuation of the locking mechanism  228  to an unlocked state and the axial movement of the electrical plug  210  may, therefore, be performed in a single motion and/or application of force by a user, rendering the locking mechanism transparent from the perspective of the user&#39;s experience. 
     The lock actuator  230  may be connected to the exterior mating surface  208  in various types of connections. In some implementations, the tab  232  is a hook or other mechanical interlocking feature that engages with an opening, a recess, or other complimentary interlocking feature in the lock actuator  230 . In other implementations, the exterior mating surface  208  is connected to the lock actuator  230  by a pin, clip, clamp, or other mechanical fastener. In yet other implementations, the exterior mating surface  208  is connected to the lock actuator  230  by an adhesive. In further implementations, the exterior mating surface  208  is connected to the lock actuator  230  by a combination of interlocking features, fasteners, and adhesives. 
     As shown in  FIG. 2E , the strain relief  220  may include a plurality of portions. For example, the plurality of portions may include portions including or made of different materials. In some implementations, the different materials include a rigid material  238  and a soft material  240  to provide strain relief to the cable  202 . For example, the soft material  240  may be distal of the rigid material  238 . In other examples, at least a portion of the soft material  240  may longitudinally overlap a portion of the rigid material  238 . As shown in  FIG. 2E , the soft material  240  and the rigid material  238  may be co-molded to produce a mechanical interlock therebetween to retain the soft material  240  and rigid material  238  relative to one another. 
     It should be understood that “soft” and “rigid” are relative to one another. For example, the soft material  240  may have a Young&#39;s modulus that is less than the rigid material  238 . In some implementations, the soft material  240  has a Young&#39;s modulus that is less than 1.0 gigapascals (GPa) and the rigid material  238  has a Young&#39;s modulus that is greater than 1.0 GPa. In other implementations, the soft material  240  has a Young&#39;s modulus that is less than 0.50 GPa and the rigid material  238  has a Young&#39;s modulus that is greater than 0.50 GPa. In yet other implementations, the soft material  240  has a Young&#39;s modulus that is less than 0.10 GPa and the rigid material  238  has a Young&#39;s modulus that is greater than 0.10 GPa. 
     The strain relief  220  may be substantially the same longitudinal length as the exterior mating surface  208 . In other implementations of an appliance coupler connector  200 , a longitudinal length of the exterior mating surface  208  is greater than a longitudinal length of the strain relief  220 . In yet other implementations, a longitudinal length of the exterior mating surface  208  is less than a longitudinal length of the strain relief  220 . 
     The axial movement of the exterior mating surface  208  relative to the strain relief  220  (or other portions of the appliance coupler connector  200 ) may be at least partially constrained by a mechanical interaction of the exterior mating surface  208  and the strain relief  220 . For example, the exterior mating surface  208  may include a recess  242  that receives a portion of the strain relief  220 . The recess  242  may limit the axial movement of the exterior mating surface  208  relative to the strain relief  220 . In some implementations, the recess  242  may also rotationally key the exterior mating surface  208  to the strain relief  220 , limiting and/or prevent the rotation of the exterior mating surface  208  relative to the strain relief  220 . 
     In other implementations of an appliance coupler connector, an exterior mating surface and strain relief may be the same component, may be integrally formed, or may be co-molded such that the strain relief is configured to move axially relative to an electrical plug.  FIG. 3A  is a perspective view of another implementation of an appliance coupler connector  300  with a cable  302  in electrical communication with an electrical plug  310  and an exterior mating surface  308  that is axially moveable relative to the electrical plug  310  and cable  302 . 
     The exterior mating surface  308  has a distal projection  318  positioned circumferentially about the cable  302 . The implementation of a distal projection  318  illustrated in  FIG. 3A  includes a flare  344  at the distal end to provide strain relief to the cable  302 . The flare  344  may reduce the need for a portion of the strain relief to project distally from the exterior mating surface  308 . 
     As shown in  FIG. 3B , the strain relief  320  is co-molded with the exterior mating surface  308  such that the strain relief  320  is not visible from the exterior of the assembled appliance coupler connector  300 . With the cover of the electrical plug  310  removed, the strain relief  320  is visible radially within the exterior mating surface  308 . 
     In the depicted implementation, the tab  332  is integrally formed with the strain relief  320 . As mentioned herein, the strain relief  320  is moveable in the axial direction with the exterior mating surface  308  such that the tab  332  of the strain relief  320  applies a force to actuate the locking mechanism  328  of the electrical plug  310 . 
     Referring now to  FIG. 3C , in some implementations, an axial force is applied against the spring  334  through the tab  332 . The tab  332  includes a hook or other mechanical interlocking feature that engages with another hook, an opening, a recess, or other complimentary interlocking feature in the lock actuator  330 . In other implementations, the tab  332  is connected to the lock actuator  330  by a pin, clip, clamp, or other mechanical fastener. In yet other implementations, the tab  332  is connected to the lock actuator  330  by an adhesive. In further implementations, the tab  332  is connected to the lock actuator  330  by a combination of interlocking features, fasteners, and adhesives. 
     Referring now to  FIG. 3D , some implementations of an appliance coupler connector  300  may include one or more grip features  346  on or in the exterior mating surface  308 . For example, a grip feature  346  may be a recess in the exterior mating surface  308  that enhances a user&#39;s grip of the exterior mating surface  308 . In other examples, a grip feature  346  may be a protrusion in the exterior mating surface  308  that enhances a user&#39;s grip of the exterior mating surface  308 . 
     In some implementations, a grip feature  346  may visually communicate instructions to a user regarding how to unlock and unplug the electrical plug  310 . For example, the grip feature  346  shown in  FIG. 3D  is an arrow that communicates to a user to grip the exterior mating surface  308  and pull the exterior mating surface  308  in the direction of the arrow, as opposed to simply pulling on the cable  302 . 
     As can be seen in the side view, the exterior mating surface  308  is over-molded on the strain relief  320 . In some implementations, the exterior mating surface  308  includes or is made of a soft material and the strain relief  320  includes or is made of a rigid material. 
       FIG. 3E  illustrates a cross-section of the side view of  FIG. 3D . The strain relief  320  may be radially within the exterior mating surface  308 . The rigid material  338  of the strain relief  320  may have a longitudinal length less than the longitudinal length of the soft material  340  of the exterior mating surface  308 . The rigid material  338  of the strain relief  320  may provide radial support to soft material  340  of the exterior mating surface  308 . For example, a user may radially compress the soft material  340  manually and thereby increase friction between the moveable exterior mating surface  308  and the cable  302 . Compression of the exterior mating surface  308  against the cable  302  may limit and/or prevent the axial movement of the exterior mating surface  308 , preventing the unlocking of the locking mechanism. 
     In some implementations, the coefficient of friction of the soft material  340  may be greater than the rigid material  338 . Positioning rigid material  338  or other material with a lower coefficient of friction than the soft material  340  of the exterior mating surface  308  radially within the soft material  340  of the exterior mating surface  308  may ease the axial movement of the exterior mating surface  308 . 
     The exterior mating surface  308  may supplement the strain relief  320  or be the strain relief supporting the cable  302 . In some implementations, the exterior mating surface  308  has a flare  344  in which an inner diameter of the exterior mating surface increases to provide a curved surface to guide the flexion of the cable  302  and limit and/or prevent kinking of the cable  302 . For example, the exterior mating surface  308  may have an inner diameter  348  and the flare  344  may have a flare diameter  350  that are related through a flare ratio describing the proportion by which the flare  344  increases in diameter (i.e., the flare diameter  350  to the inner diameter  348 ). 
     In some implementations, the flare ratio is in a range having an upper value, a lower value, or upper and lower values including any of 1.0, 1.1., 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, or any values therebetween. For example, the flare ratio may be greater than 1.0. In other examples, the flare ratio may be less than 2.0. In yet other examples, the flare ratio may be between 1.0 and 2.0. In further examples, the flare ratio may be between 1.25 and 1.75. In at least one example, the flare ratio may be about 1.5. 
       FIG. 4A  illustrates yet another implementation of an appliance coupler connector  400 . The appliance coupler connector includes an electrical plug  410  in electrical communication with a cable  402  and an axially movable exterior mating surface  408  positioned circumferentially about and axially overlapping a strain relief  420 . In the depicted implementation, at least a portion of the strain relief protrudes distally from the exterior mating surface  408 . 
       FIG. 4B  is a perspective view of the implementation of an appliance coupler connector  400  with a gasket  451  on the proximal-facing surface  412  of the exterior mating surface  408 . In some implementations, the proximal-direction bias of the biasing element urges the exterior mating surface  408  in a proximal direction with a sufficient force to provide a seal against an electronic device or other device with an appliance inlet connector. For example, the gasket  451  may be an O-ring that is moved and compressed proximally by the exterior mating surface  408  to form a seal. The seal may reduce or prevent the entry of liquids, dust, or other materials potentially harmful to an electrical connection from entering the electrical connection. 
     In implementations where the strain relief  420  protrudes distally from the exterior mating surface  408 , a distal projection  418  of the exterior mating surface  408  may include a grip feature  446 , such as a ridge or other tactilely identifiable feature to allow tactile identification of the distal end of the exterior mating surface  408  and improve a user&#39;s grip on the exterior mating surface  408 . For example, a user reaching behind an electronic device and pulling on the strain relief  420  mistaking the strain relief  420  for the exterior mating surface  408  may damage the strain relief  420 . 
     Referring now to  FIG. 4C , the distal axial movement of the exterior mating surface  408  relative to the strain relief  420  and electrical plug  410  may be limited by the axial movement of the lock actuator  430 . For example, the lock actuator  430  is biased in the proximal direction by a spring  434  of other biasing element and the distal movement of the exterior mating surface  408  may act against the spring  434  to move the lock actuator  430  distally. The distal axial movement of the lock actuator  430  may be limited by an interaction with a stop  452  on or in the electrical plug  410 . In such implementations, the predetermined distance (e.g., distance  235  described in relation to  FIG. 2D ) that the exterior mating surface  408  may move in the axial direction is limited by the distance the lock actuator  430  may move axially before contacting the stop  452  of the electrical plug  410 . 
     In some implementations, the strain relief  420  may protrude distally from the exterior mating surface  408  by an amount related to the longitudinal length of the exterior mating surface  408 . As shown in  FIG. 4D , the exterior mating surface  408  has an exterior mating surface length  454 . A protrusion length  456  of the strain relief  420  may be related to the exterior mating surface length  454  by a protrusion ratio. In some implementations, the protrusion ratio (protrusion length  456  to exterior mating surface length  454 ) is in a range having an upper value, a lower value, or upper and lower values including any of 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, or any values therebetween. For example, the protrusion ratio may be greater than 0.5. In other examples, the protrusion ratio may be less than 1.5. In yet other examples, the protrusion ratio may be between 0.5 and 1.5. In further examples, the protrusion ratio may be between 0.7 and 1.3. In at least one example, the protrusion ratio is about 1.0. 
     Referring now to  FIG. 4E , the appliance coupler connector  400  is shown in side cross-sectional view. The strain relief  420  may be positioned radially within the exterior mating surface  408 . At least a portion of the exterior mating surface  408  may not longitudinally overlap the strain relief  420 . For example, and as shown in  FIG. 4E , the strain relief  420  protrudes distally from the exterior mating surface  408  and is longitudinally displaced from the electrical plug  410 . In such implementations, the strain relief  420  may be longitudinally fixed relative to the cable  402  or longitudinally fixed relative to the exterior mating surface  408 . 
     The articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements in the preceding descriptions. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one implementation” or “an implementation” of the present disclosure are not intended to be interpreted as excluding the existence of additional implementations that also incorporate the recited features. For example, any element described in relation to an implementation herein may be combinable with any element of any other implementation described herein. Numbers, percentages, ratios, or other values stated herein are intended to include that value, and also other values that are “about” or “approximately” the stated value, as would be appreciated by one of ordinary skill in the art encompassed by implementations of the present disclosure. A stated value should therefore be interpreted broadly enough to encompass values that are at least close enough to the stated value to perform a desired function or achieve a desired result. The stated values include at least the variation to be expected in a suitable manufacturing or production process, and may include values that are within 5%, within 1%, within 0.1%, or within 0.01% of a stated value. 
     A person having ordinary skill in the art should realize in view of the present disclosure that equivalent constructions do not depart from the spirit and scope of the present disclosure, and that various changes, substitutions, and alterations may be made to implementations disclosed herein without departing from the spirit and scope of the present disclosure. Equivalent constructions, including functional “means-plus-function” clauses are intended to cover the structures described herein as performing the recited function, including both structural equivalents that operate in the same manner, and equivalent structures that provide the same function. It is the express intention of the applicant not to invoke means-plus-function or other functional claiming for any claim except for those in which the words ‘means for’ appear together with an associated function. Each addition, deletion, and modification to the implementations that falls within the meaning and scope of the claims is to be embraced by the claims. 
     It should be understood that any directions or reference frames in the preceding description are merely relative directions or movements. For example, any references to “front” and “back” or “top” and “bottom” or “left” and “right” are merely descriptive of the relative position or movement of the related elements. 
     The present disclosure may be embodied in other specific forms without departing from its spirit or characteristics. The described implementations are to be considered as illustrative and not restrictive. The scope of the disclosure is, therefore, indicated by the appended claims rather than by the foregoing description. Changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.