PATENT ABSTRACT
A sliding hitch with a self-arming latch is described. The hitch includes a carriage slideably mounted on a base. The base includes a latching pin on a pivot arm that is biased to extend toward engagement with the carriage and a rotatable shaft with an arming member and a locking member. Rotation of the shaft to an unlocked orientation, cams the pivot plate away from the carriage to withdraw the pin and enable sliding of the carriage on the base. An arm of the arming member is also rotated into the path of a protuberance associated with the carriage. Contact between the protuberance and the arm during sliding of the carriage along the base causes rotation of the shaft to a locked orientation enabling extension of the pin toward engagement with the carriage and engaging the locking member with the pivot plate to restrict withdrawal of the pin.

PATENT DESCRIPTION
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. provisional patent application Ser. No. 61/719,095, filed Oct. 26, 2012, under 35 U.S.C. §119(e). 
    
    
     BACKGROUND 
     A fifth-wheel hitch is a common apparatus for coupling a trailer to a truck for towing. The fifth-wheel hitch is preferably positioned over or spaced forward of the rear axle of the truck. In trucks with short-beds, due to the shorter distance between the rear axle and the back of the cab, positioning the fifth-wheel hitch over or in front of the rear axle significantly limits the turning radius of the trailer without damaging the cab. To provide additional clearance between the cab and the trailer, a variety of moveable fifth-wheel hitch assemblies have been developed which permit sliding of the hitch rearward behind the rear axle in situations in which tight turns between the truck and the trailer are likely to be required. 
     For example, U.S. Pat. No. 7,871,096 to Colibert-Clarke et al. describes a displaceable fifth-wheel hitch assembly that includes a platform mounted in the bed of a truck with a pair of tracks mounted along each side thereof. A hitch assembly is slideably mounted between the tracks and includes a spring-biased locking pin that extends from the hitch assembly into holes aligned along the center of the platform. The locking pin is biased toward engagement with the platform by a spring disposed between a clip attached to the pin and a support member of the hitch assembly. A rod extends through a slotted flange extending from the platform and is coupled to the locking pin. The slotted flange acts as a fulcrum about which the rod can be pivoted to raise the locking pin and to allow the hitch assembly to move along the platform track. The rod can be engaged with a hook to maintain the locking pin in the raised position. Movement of the hitch assembly on the platform track can disengage the rod from the hook to allow the locking pin to engage the holes in the platform track and lock the hitch assembly in place. 
     U.S. Patent Publication No. 2011/0109061 to Peterson et al. describes a sliding hitch assembly mounted on a pair of elevated rails. A locking mechanism is provided that employs a cable actuated cam member and a pair of locking pins. One of the locking pins is associated with a forward position of the hitch assembly and the other is associated with a rearward position. A handle coupled to the cable is pivoted between a forward engagement position and a rearward engagement position to slide the cam member between a sidewall of the rails and a portion of the locking pins. The cam member thereby draws one locking pin out of engagement with the hitch assembly and allows the second locking pin to extend from the rail for engagement with the hitch assembly in the second position. 
     There remains a need in the art for a self-arming latching mechanism for a sliding-hitch assembly that is easily operable by a user. There is also a need for an automatic-arming latching mechanism with a locking feature that prevents disengagement of the latching mechanism. Some solutions employ spring biased members, but no mechanical engagement is provided to further prevent such disengagement. Additionally, a self-arming latching mechanism that is simple and compact for incorporation substantially within a base or hitch carriage would improve on prior designs. 
     SUMMARY 
     Embodiments of the invention are defined by the claims below, not this summary. A high-level overview of various aspects of the invention are provided here for that reason, to provide an overview of the disclosure, and to introduce a selection of concepts that are further described in the Detailed-Description section below. 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 isolation to determine the scope of the claimed subject matter. In brief this disclosure describes, among other things, a sliding fifth-wheel hitch with a self-arming latching assembly. 
     The fifth-wheel hitch includes a base assembly that is coupleable to a vehicle. The base assembly includes a pair of longitudinally extending legs disposed along opposite edges thereof and a cross-member disposed therebetween. The legs each include a rod or a sliding surface on which a hitch carriage is slideably mounted. 
     A latching assembly is disposed within the base assembly substantially within the cross-member. The latching assembly includes a shaft extending along the length of the cross-member and rotatable about its length. A handle is fixedly coupled to an end of the shaft to enable a user to rotate the shaft. A flange or lever arm extends radially outward from the shaft and is coupled at a distal end thereof to a spring. The spring is further affixed to the base assembly such that an over center condition is created in which the shaft is rotated by the spring in either a first direction toward a locked orientation or in a second direction toward an unlocked orientation. 
     A latch release and arming member extends from the shaft in a plane perpendicular to the length of the shaft. The latch release and arming member comprises a cam presenting a cam surface that contacts a plate to pivot the plate about a coupling with the base assembly and between the locked and unlocked orientations. A latching pin is coupled to the plate and is extended into engagement with the hitch carriage when the shaft is rotated to the locked orientation in which the cam is oriented to allow the pivot plate to pivot upward. The latch pin is withdrawn from such engagement when the shaft is rotated to the unlocked orientation in which the cam is rotated to pivot the pivot plate downward. 
     A trigger arm projects radially outward from the cam on the latch release and arming member. When the shaft is rotated to the unlocked orientation, the trigger arm extends upward through the base assembly and into the path of a portion of the hitch carriage such as a protuberance or boss. Subsequent engagement of the distal end of the trigger arm by the boss, pivots the trigger arm downward, rotating the latch release and arming member into an armed orientation with the lever arm on the shaft pivoted below the center position and biasingly urged toward a locked orientation. 
     A locking member comprising a finger is also formed on the latch release and arming member or is separately mounted on the shaft. The finger engages the plate to prevent pivoting of the plate when the shaft is rotated to the locked orientation. 
     The hitch carriage can thus be moved from a forward position to a rearward position, and vice-versa, along the base assembly by actuating the handle to rotate the shaft from the locked orientation to the unlocked orientation. The locking member is disengaged from the plate and the latching pin is withdrawn from engagement with the hitch carriage. During movement of the hitch carriage along the base assembly, the arming member is contacted by the protuberance to automatically rotate the shaft toward the locked orientation. Upon alignment of the latching pin with a receiver in the hitch carriage, the latching pin engages the receiver and the finger of the locking member engages the plate to lock the latching pin in place. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Illustrative embodiments of the invention are described in detail below with reference to the attached drawing figures, and wherein: 
         FIG. 1  is a perspective view of a sliding fifth-wheel hitch assembly depicted in accordance with an embodiment of the invention; 
         FIG. 2  is a top plan view of the sliding fifth-wheel hitch assembly; 
         FIG. 3  is a front elevational view of the sliding fifth-wheel hitch assembly; 
         FIG. 4  is a side elevational view of the sliding fifth-wheel hitch assembly; 
         FIG. 5  is front elevational view of a base of the sliding fifth-wheel hitch assembly depicted with a hitch carriage removed; 
         FIG. 6  is a bottom plan view of the base of the sliding fifth-wheel hitch assembly; 
         FIG. 7  is perspective bottom view of a central portion of the base of the sliding fifth-wheel hitch assembly depicted with pivot arms and a central brace removed; 
         FIG. 8A  is a bottom perspective view of the sliding fifth-wheel hitch assembly depicting a latching assembly in a locked orientation in accordance with an embodiment of the invention; 
         FIG. 8B  is a cross-sectional elevational view taken along the line  8 B- 8 B shown in  FIG. 6  depicting the latching assembly in the locked orientation; 
         FIG. 8C  is a cross-sectional elevational view taken along the line  8 C- 8 C shown in  FIG. 6  depicting the latching assembly in the locked orientation; 
         FIG. 9A  is a bottom perspective view of the sliding fifth-wheel hitch assembly depicting the latching assembly in an unlocked orientation in accordance with an embodiment of the invention; 
         FIG. 9B  is a cross-sectional elevational view taken along the line  9 B- 9 B shown in  FIG. 6  depicting the latching assembly in the unlocked orientation; 
         FIG. 9C  is a cross-sectional elevational view taken along the line  9 C- 9 C shown in  FIG. 6  depicting the latching assembly in the unlocked orientation; 
         FIG. 10B  is a cross-sectional elevational view similar to  FIGS. 8B and 9B  depicting the latching assembly in an armed orientation; 
         FIG. 10C  is a cross-sectional elevational view similar to  FIGS. 8C and 9C  depicting the latching assembly in the armed orientation; 
         FIG. 11  is a cross-sectional side elevation along the line  8 C- 8 C shown in  FIG. 6  depicting the hitch carriage in a forward position in solid lines and a rearward position in phantom lines; 
         FIG. 12A  is a partial cross-sectional view of the sliding fifth-wheel hitch assembly taken along the line  12 A- 12 A shown in  FIG. 2  depicting guide rollers on the hitch carriage for coupling to the base assembly; and 
         FIG. 12B  is a partial cross-sectional view of another embodiment of the sliding fifth-wheel hitch assembly shown in  FIG. 12A  depicting glide blocks on the hitch carriage for slideably coupling to the base assembly. 
     
    
    
     DETAILED DESCRIPTION 
     The subject matter of select embodiments of the invention is described with specificity herein to meet statutory requirements. But the description itself is not intended to necessarily limit the scope of claims. Rather, the claimed subject matter might be embodied in other ways to include different components, steps, or combinations thereof similar to the ones described in this document, in conjunction with other present or future technologies. Terms should not be interpreted as implying any particular order among or between various steps herein disclosed unless and except when the order of individual steps is explicitly described. 
     With reference to  FIGS. 1-12 , a sliding-hitch assembly  10  is described in accordance with an embodiment of the invention. The description herein is provided with respect to a standard orientation of the sliding-hitch assembly  10  disposed in a vehicle. As such, terms such as forward, rearward, front, rear, variations thereof, and terms of similar import are used with respect to common understandings of forward and rearward travel of a vehicle. The terms longitudinal and transverse indicate orientation along the length of the vehicle and along the width of the vehicle, respectively. 
     The sliding-hitch assembly  10  is configured for installation in the bed of a vehicle, such as a pick-up truck, but the assembly  10  can be configured for installation on tractors or in other heavy-duty or light-duty applications without departing from the scope of embodiments described herein. The sliding-hitch assembly  10  comprises a hitch assembly  12  that is slideably coupled to a base assembly  14 . The hitch assembly  12  includes a hitch carriage  16  on which a hitch support  18  and a fifth-wheel hitch  20  are mounted. 
     The fifth-wheel hitch  20  is of a type useable to receive and maintain a pivotal coupling with a kingpin of a trailer. A wide variety of such hitches are known in the art including for purposes of illustration only the hitch shown in U.S. Pat. No. 6,170,850 to Joseph Works. The fifth-wheel hitch  20  can also be configured to provide a ball-hitch, draw bar, or other trailer-coupling apparatus without departing from the scope described herein. 
     The hitch support  18  supports the fifth-wheel hitch  20  above and couples it to the hitch carriage  16 . The hitch support  18  includes a pair of legs  22  extending upwardly from opposite sides of the hitch carriage  16 . A generally rectangular plate with a center section removed is formed or folded about its transverse dimension to form a cross-member or saddle  24  with a U-shaped profile. The saddle  24  is disposed on and between distal ends of the legs  22  and is pivotally coupled thereto. The saddle  24  is thus pivotable about an axis extending between the legs and transverse to the sliding-hitch assembly  10 . A base  26  of the fifth-wheel hitch  20  is coupled centrally along the width of the saddle  24 . The coupling enables the base  26  and fifth-wheel hitch  20  to pivot side-to-side about a longitudinal axis extending through the coupling. As such, the fifth-wheel hitch  20  can pivot transversely and longitudinally during coupling of the hitch  20  with a trailer and/or during towing of the trailer. 
     The hitch carriage  16  includes a pair of longitudinally extending support arms or side support assemblies  28  that slideably couple the hitch assembly  12  to the base assembly  14 . As best seen in  FIG. 12A , the side support assemblies  28  comprise a main support member  30 , an upper roller support member  32 , and a pair of lower roller support members  34 . The main support member  30  comprises an elongate tubular member with a generally inverted L-shaped, cross-sectional profile. As depicted in  FIG. 12A , the main support member  30  is manufactured from a plurality of formed plate sections that are welded or otherwise coupled together, but the main support member  30  might be otherwise formed from one or more component pieces such as by extrusion or molding without departing from the scope of embodiments of the invention. The leg  22  of the hitch support  18  is coupled along a vertical portion of the main support by one or more fasteners, welding, or the like. The main support member  30  may also include one or more reinforcing members  36  disposed therein to provide additional support for coupling with the legs  22  and/or the upper and lower roller support members  32 ,  34  as described below. 
     The upper roller support member  32  comprises an elongate channel that is oriented with an open face thereof directed downward. The upper roller support member  32  is disposed beneath a horizontal portion of the main support member  30  and against a side of the vertical portion opposite that of the leg  22 . The upper roller support member  32  extends a distance longitudinally and parallel to the main support member  30 . 
     A roller  38 , wheel, glide, bearing, or similar component is disposed within the open channel of the upper roller support member  32  adjacent each end thereof. A rod or axle  40  is disposed through sidewalls of the upper roller support member  32  and through the center of the roller  38  to rotatably couple the roller  38  within the channel of the upper roller support member  32 . The axle  40  may extend into the main support member  30  to couple the upper roller support member to the main support member  30 . The roller  38  is configured to roll along a guide bar  42  of the base assembly  14  (or slide or glide in the case of a bearing or glide) as discussed more fully below, and may include a profile that compliments the shape of the guide bar  42 . 
     The pair of lower roller support members  34 , only one of which is shown, comprise sections of channel with dimensions similar to that of the upper roller support member  32  but of shorter longitudinal length. The lower roller support members  34  are oriented with an open face thereof directed upward toward the open face of the upper roller support member  32  such that opposing edges of the upper and lower roller support members  32 ,  34  are abutted and may be coupled together, such as by welding or with mechanical fasteners. The lower roller support members  34  are placed at opposite ends of the upper roller support member  32  such that the pair of lower roller support members  34  are longitudinally spaced apart. Like the upper roller support member  32 , a roller  44  is disposed within the lower roller support member  34  and is rotatably coupled thereto by a rod or axle  46  extending through the sidewalls thereof. The axle  46  may couple the lower roller support member  34  to the main support member  30 . The rollers  38  and  44  may be the same or different, e.g. having the same or different profiles, materials, or the like. 
     As depicted in  FIG. 12B , the hitch carriage  16  can also be configured with glide blocks  48  that slide along a guide bar  50  instead of or in addition to the rollers  38 ,  44 . A glide block  48  can be disposed within one or both of the upper and lower roller support members  32 ,  34  and fastened to the upper and lower roller support members  32 ,  34  by one or more fasteners  52 . The glide blocks  48  comprise one or more pads or bearing blocks comprised of a low-friction material, such as nylon, Teflon®, polyethylene, or the like, that enable sliding of the hitch carriage  16  along the guide bars  50 . In an embodiment, a combination of rollers  38 ,  44  and glide blocks  48  might be employed, e.g. a roller  38  might be disposed within the upper roller support member  32  while a glide block  48  is disposed in the lower roller support member  34 , without departing from the scope of embodiments of the invention described herein. In addition, although the glide blocks  48  are shown as rectangular and sliding along a rectangular guide bar  50  it is understood that the glide blocks could be configured with a geometry that mates with the guide bar or rails  42 . 
     The hitch carriage  16  may include one or more enclosure plates  54  that extend between the support arms  28 . The enclosure plates  54  act as cross-member supports for the support arms  28  and at least partially enclose the hitch carriage for aesthetic reasons and/or to provide some protection from environmental elements, such as precipitation, dirt and debris. 
     With continued reference to  FIGS. 1-6 , the base assembly  14  comprises a pair of longitudinally extending elongate base members  56  and a cross-member  58  extending therebetween. The longitudinal base members  56  each include a foot  60  adjustably mounted on an underside thereof and extending along the length thereof. The foot  60  may be configured for receipt in recess or corrugation found on the floor of a bed of a vehicle and is adjustable side-to-side or transversely for adaptation to variations in spacing between such recesses in a variety of vehicles. The foot  60  is formed of a rubber, plastic, or similar material to aid in reducing damage or wear between the longitudinal base members  56  and the bed of the vehicle. 
     Mounting brackets  62  are coupled to ends of the base members  56  for supporting the guide rails  42 . The guide rails  42  are disposed parallel to the longitudinal base members  56  and spaced inwardly from the respective base member  56 . As discussed previously, the guide rails  42  are configured to support the rollers  38  or can be configured as guide bars  50  for supporting glide blocks  48 . 
     The cross-member  58  extends between the longitudinal base members  56  and generally medially therewith. The cross-member  58  comprises a channel or C-shaped member oriented with an open face of the channel directed downwardly. As depicted in  FIG. 5 , a pair of guide rail support plates  64  are disposed on a top portion  65  and at opposite ends of the cross-member  58  for receiving and supporting the guide rails  42  generally medially relative to the ends which are supported by mounting brackets  62 . 
     A coupling member or coupler  66  is affixed to the center of the cross-member  58  and extends vertically downward from the bottom thereof. The coupling member  66  is configured for receipt within a mating receiver mounted in the bed of a vehicle. A preferred coupler  66  has a square or non-circular cross-section for mating with a receiver having a complimentary cross-section. The mating geometry between the coupler  66  and receiver preventing rotation of the hitch assembly  10  relative to the truck bed. 
     The coupling member  66  and the receiver include one or more transversely oriented through holes  68  that are aligned to receive a pin and thereby fixedly couple the member  66  to the receiver. The mating receiver is typically mounted beneath and/or extending through a floor of the bed and is attached to the frame of the vehicle. As such, the sliding-hitch assembly  10  can be installed in the bed of the vehicle via a single connection point. The assembly  10  is further supported by the feet  60  contacting the floor of the bed. The sliding-hitch assembly  10  is also configurable for coupling to a vehicle in a variety of other ways, e.g. the assembly  10  might be configured for bolting or welding directly to the frame of a vehicle with or without a bed, among other methods, without departing from the scope of embodiments of the invention described herein. 
     With additional reference to  FIGS. 6 and 7 , a latching assembly  70  is disposed on an underside of the cross-member  58 . The latching assembly  70  comprises a shaft  72  extending along the length of the cross-member  58  with a first end  74  of the shaft  72  extending from an end of the cross-member  58  and into a respective one of the longitudinal base members  56 . A pair of support brackets or tabs  76  extends from the underside of the cross-member  58  near opposite ends thereof to rotatably support the shaft  72 . A handle  78  is fixedly coupled to the first end  74  of the shaft  72  and extends upwardly out of the base  56  through an elongate slot  80  in a top surface thereof as best seen in  FIGS. 1 and 2 . 
     A flange or lever arm  82  extends radially outward from a second end  84  of the shaft  72 . A tension spring  86  is coupled between a distal end of the lever arm  82  and a sidewall of the cross-member  58 . As best seen in  FIGS. 8B and 9B , the coupling of the spring  86  and the lever arm  82  is configured to provide an over-center condition in which the spring  86  biases rotation of the shaft  72 , via the lever arm  82 , in a first direction or in a second direction depending on which side of a center position the lever arm  82  lies; the center position comprising the position in which the spring  86  extends across second end  84  of the shaft  72  and is aligned with an imaginary line representing the lever arm formed between the axis of rotation of the shaft  72  and the distal end of the lever arm  82 . 
     A pair of latch release and arming members  88  is disposed about the shaft  72  near each end of the cross-member  58 . The latch release and arming members  88  are each longitudinally aligned with a latch pin support plate  90  and a hinge  92 , as depicted in  FIG. 7 , which are positioned generally vertically below each of the side support assemblies  28  of the hitch carriage  16 . A pivoting plate  94  is pivotally coupled to the hinge  92  at a first end and retains a latch pin  96  in a second end thereof, as shown in  FIGS. 6 , and  8 - 11 . 
     The latch pin  96  extends upward from the second end of the pivoting plate  94  and slideably passes through a hole in the latch pin support plate  90  and a hole in the top portion  65  of the cross-member  58 . The latch pin  96  comprises a generally cylindrical pin that includes an upper section  98  having a first diameter and an intermediate section  100  having a second diameter smaller than the first. The larger first diameter of the upper section  98  forms a shoulder  102  or annular flange. A coil spring  104  is disposed around the intermediate section of the latch pin  96  between the shoulder  102  and the latch pin support plate  90  and biases the latch pin  96  to extend through the top portion  65  of the cross-member  58 . A washer  106  or similar component having an central aperture larger than the second diameter of the latch pin  96  but smaller than the first diameter can be disposed between the shoulder  102  and the spring  104  to provide a larger contact surface for the spring  104 . Or the shoulder  102  might include a flange or tabs extending radially outward beyond the first diameter to provide the larger contact surface for the spring  104 . 
     The latch pin  96  shown includes an annular recess  108  adjacent a lower end and configured for receipt in a slot  110  (See  FIG. 9A ) in the pivoting plate  94  for coupling thereto. The coupling between the latch pin  96  and the pivoting plate  94  restricts vertical movement between the latch pin  96  and the pivot plate  94  such that their upward and downward movements are maintained in unison. The coupling also allows the latch pin  96  to slide and/or pivot with respect to the coupling so that the latch pin  96  can move linearly while second end of the pivoting plate  94  to which the latch pin  96  is coupled is pivoted along an arc. The sliding and/or pivoting of the latch pin  96  about the coupling with the pivoting plate  94  avoids binding between the components as the latching assembly  70  is actuated. 
     Each of the latch release and arming members  88  is formed as a cam  117  with a cam surface  118  extending radially outward from the shaft  72  with an increasing radius along an arc of approximately sixty degrees. The cam surface  118  contacts the respective pivoting plate  94  to pivot the plate  94  downward about the hinge  92  when the shaft  72  and the latch release and arming members  88  are rotated using handle  78  from a locked or latched position as depicted in  FIG. 8C  to an unlocked or unlatched position as depicted in  FIG. 9C . 
     In the latched position, the narrowest portion of each cam  117  extends between the latching assembly shaft  72  and the respective pivoting plates  94  which allows latch pins  96  to be biased upward through the openings in the top portion  65  of the cross member  58  and into one of at least two aligned receivers  124  and  126  formed in a bottom surface  114  of a respective side support assembly  28 , including for example, in the bottom surface  114  of a respective main support member  30 . The receivers  124  and  126  on the respective side support assemblies  28  comprises first and second aligned pairs of receivers  124  and  126  for retaining the carriage in a forward position (in solid lines in  FIG. 11 ) and a rearward position (in phantom lines in  FIG. 11 ) respectively. As best seen in  FIGS. 8B and 8C , when the latch release and arming members are in the latched position, the lever arm  82  extends below the center position and the tension spring  86  draws the lever arm  82  downward and toward the rear of the cross member  58  (clockwise in  FIG. 8B ) thereby biasingly resisting rotation of the latch release and arming members  88  out of the latched alignment. 
     In an unlatched position, the widest portion of each cam  117  is rotated to extend between the shaft  72  and the respective pivoting plates  94 , pivoting the plates  94  downward such that the latch pins  96  are withdrawn from receivers  124  or  126  against the biasing force of springs  104 . As best seen in  FIGS. 9B and 9C , when the latch release and arming members  88  are in the unlatched position, the lever arms  82  extend above the center position and the tension spring  86  draws lever arm  82  upward and toward the rear of the cross member  58  (counter-clockwise in  FIG. 9B ) thereby biasingly resisting rotation of the latch release and arming members  88  out of the unlatched alignment. 
     Each of the latch release and arming members  88  includes an arm  112  that extends generally radially outwardly from the cam  117 . The arm  112  is of sufficient length to at least partially extend through an aperture  113  in the top portion  65  of the cross-member  58  when latch release and arming member  88  is rotated to the unlocked orientation depicted in  FIG. 9C . In the unlocked orientation, a distal end of the arm  112  is spaced apart from and below a bottom surface  114  of the main support member  30  of the hitch carriage  16  or may contact and/or slide along the bottom surface  114 . The distal end of the arm  112  is configured to be contacted and displaced downward by a boss  116 , protuberance, flange, nub, rib, or other portion or feature of the carriage  16  extending downwardly from the bottom surface  114  of the main support member  30 , as described more fully below. Arm  112  is displaced downward by boss  116  far enough to rotate the lever arm  82  below the center position such that tension spring  86  now pulls or urges the latch release and arming member  88  toward the latched position. Until the carriage  16  is slid far enough to bring one of the pairs of receivers  124  or  126  back into alignment with the latch pins  96 , abutment of the latch pins  96  against the bottom surface  114  of the main support member prevents the latching assembly  70  from advancing from the unlatched orientation to the latched orientation and this orientation of the latching assembly  70  may be referred to as an armed orientation. 
     A locking member  120  extends from each of the arming members  88  between the arm  112  and the cam surface  118 . The locking member  120  comprises a generally L-shaped finger that extends radially outward from the shaft a first distance before turning to extend a second distance in a direction away from the arm  112  and spaced radially outward from the cam surface  118 . The locking member  120  is configured to protrude through an aperture  122  in the pivoting plate  94  to capture a portion of the pivoting plate  94  between the locking member  120  and the cam surface  118  when in the locked orientation and to be substantially withdrawn from the aperture  122  when in the unlocked orientation. It is foreseen that the locking member  120  may be formed as a separate component mounted on the shaft  72  adjacent to the latch release and arming member  88 . 
     With reference now to  FIGS. 8-11 , operation of the sliding-hitch assembly  10  is described in accordance with an embodiment of the invention. As depicted in  FIG. 11 , the sliding-hitch assembly  10  is slideably and/or rollably moveable along the guide rails  42  from a forward position (depicted by solid lines) to a rearward position (depicted in phantom) to enable additional clearance between a trailer and a cab of a tow vehicle, among other advantages. 
     As depicted in  FIGS. 8A-C  and  11 , in the forward position, the latching assembly  70  is initially in the locked orientation. In the locked orientation, the shaft  72  and the latch release and arming members  88  are rotated to position the arm  112  within the cross-member  58 . The cam  117  is rotationally oriented to enable the pivoting plate  94  to pivot about the hinge  92  upward toward the cross-member  58 . The coil spring  104  on the latch pin  96  biases the latch pin  96  upward through the top portion  65  of the cross-member  58  and thus draws the pivoting plate  94  upward toward the cross-member  58 . The locking member  120  is extended through the aperture  122  in the pivoting plate  94  and to a position that is below a portion of the pivoting plate  94  to prevent downward movement of the pivoting plate  94  and thus the latch pin  96 . 
     In the locked orientation, the latch pin  96  extends from the top portion  65  of the cross-member  58  and into the aperture or receiver  124  in the bottom surface  114  of the main support member  30  of the hitch carriage  16 . As such, the latch pin  96  prevents rolling or sliding movement of the hitch carriage  16  along the guide rails  42 . Also, in the locked orientation, as depicted in  FIG. 8B , the lever arm  82  on the second end  84  of the shaft  72  is positioned above the center position and biased by the spring  86  to rotate the shaft  72  toward the locked orientation and thereby to maintain the locked orientation. 
     To move the latching assembly  70  to the unlocked orientation, the handle  78  is operated by a user to rotate the shaft  72  and the latch release and arming members  88  toward the unlocked orientation. As the shaft  72  is rotated, the lever arm  82  moves past the center position and is then biased by the spring  86  in an opposite direction toward the unlocked orientation. The user may continue to move the handle  78  to rotate the latch release and arming members  88  toward the unlocked orientation or the spring  86  may complete the rotation. 
     As depicted in  FIGS. 9A-C , rotation of the shaft  72  rotates the cam surface  118  on the arming member  88  against the pivoting plate  94  to pivot the pivoting plate  94  downwardly about the hinge  92 . Downward movement of the pivoting plate  94  withdraws the latch pin  96  from the receiver  124  in the bottom surface  114  of the main support member  30  and compresses the coil spring  104  between the washer  106  and the latch pin support plate  90 . The distal end of the arm  112  of the arming member  88  is rotated upwardly to protrude from the top portion  65  of the cross-member  58  and into the path of the boss  116  on the bottom surface  114  of the main support member  30 . 
     The hitch carriage  16  is thus free to slide or roll along the guide rails  42  from the forward position to the rearward position or vice-versa. The hitch carriage  16  might also be moved to one or more intermediate positions between the forward and rearward positions. As the hitch carriage  16  moves along the guide rails  42 , the boss  116  contacts the distal end of the arm  112  protruding from the top portion  65  of the cross-member  58 . The contact is sufficient to depress the arm  112  downwardly and to rotate the lever arm  82  past the center position, e.g. automatically arming the latching assembly to latch the hitch carriage  16  in position. As such, the spring  86  again biases the lever arm  82  toward the locked orientation thereby, rotating the cam surface  118  against the pivoting plate  94 . The pivoting plate  94  is thus enabled to pivot upwardly to extend the latch pin  96  from the top portion  65  of the cross-member  58  via the bias provided by the coil spring  104 . However, the latch pin  96  may not yet be aligned with a second receiver  126  associated with the rearward position, because, for example, the hitch carriage  16  may have not yet moved completely to the rearward position. As such, the latch pin  96  is biased into contact with the bottom surface  114  of the main support member  30  and slides therealong until achieving alignment with the second receiver  126  (or with the first receiver  124  again). 
     The pivoting plate  94  and the shaft  72  generally will not achieve full rotation toward the locked orientation until the latch pin  96  aligns with the first or second receiver  124 ,  126 . The bias provided by the spring  86  on the lever arm  82  and by the coil spring  104  on the latch pin  96  maintains the latching assembly  70  in an intermediate state or armed orientation, biased toward the locked position. 
     Upon alignment of the latch pin  96  with the first or second receiver  124 ,  126 , the latch pin  96  moves further upward and out of the cross-member  58  to engage the receiver  124 ,  126  and thereby prevent further sliding or rolling movement of the hitch carriage  16 . And the spring bias continues upward pivoting of the pivoting plate  94  and continues the rotation of the shaft  72  to engage the locking member  120  with the pivoting plate  94 . The handle  78  is also reset to an original position via its coupling to the shaft  72 . 
     As shown, a single boss or protuberance  116  projects downward from the bottom surface  114  of each of the side support assemblies  28 . Each of the bosses  116  is positioned in closely space relation in front of the second receiver  126  a distance less than the spacing between the latch pin  96  and the aperture  113  in the top of cross member  58 . When the carriage  16  is slid rearward after advancing the latch release and arming members  88  to the unlatched position, withdrawing latch pins  96  from first receivers  124 , the bosses  116  engage the arms  112  of the arming members  88  just before the second receivers  126  are brought into alignment with the latch pins  96  such that the arming members  88  are rotated to the armed orientation just prior to alignment of receivers  126  with latch pins  96 . When the carriage  16  is latched in the rearward position (as shown in phantom lines in  FIG. 11 ), the bosses  116  are positioned in closely spaced relation behind apertures  113  in the top of cross member  58 . Upon advancing the latch release and arming members  88  to the unlatched position, the end of each arm  112  extends through respective aperture  113  and just in front of the associated boss  116 . When the carriage  16  is then slid forward, the bosses  116  almost immediately engage arms  112  of the arming members  88  such that the arming members  88  are rotated to the armed orientation prior to subsequent alignment of receivers  124  with latch pins  96 . It is foreseen that multiple bosses  116  could be included on and project downward from each of the side support assemblies  28 . 
     Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the scope of the claims below. Embodiments of the technology have been described with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to readers of this disclosure after and because of reading it. Alternative means of implementing the aforementioned can be completed without departing from the scope of the claims below. Certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations and are contemplated within the scope of the claims.