Abstract:
An anti-sway trailer hitch connection is provided for use between a towing vehicle and a trailer and includes structure whereby slight left and right lateral movement of the forward end of the towing vehicle will not be translated into right and left lateral movement, respectively, of the forward end of the trailer, and thereby eliminates the tendency of a trailer to sway back and forth while a towing vehicle changes lanes on a highway or is acted on by cross-wind gusts from the passing of a large vehicle.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   The present application is a continuation-in-part of U.S. application Ser. No. 10/908,672 filed May 23, 2005 now U.S. Pat. No. 7,137,643, entitled “Anti-sway Trailer Hitch”, which is incorporated herein by reference in its entirety. 

   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not applicable. 
   REFERENCE TO A MICROFICHE APPENDIX 
   Not applicable. 
   TECHNICAL FIELD 
   The present invention relates generally to trailer hitches, and more particularly to an improved anti-sway trailer hitch. 
   BACKGROUND INFORMATION AND DISCUSSION OF RELATED ART 
   Inasmuch as most passenger vehicles and the like include rear overhang portions, which project considerably rearward of the rear wheels of the vehicle, and trailer hitches are constructed in a manner such that the forward tongue portion of a trailer towed behind such vehicles are actually coupled to the vehicles at a point spaced slightly rearward of the rear bumpers of the vehicles, any slight left and right lateral shifting of the forward end of the towing vehicle results in right and left lateral shifting, respectively, of the forward end of the trailer. 
   This operational feature of the combination of a passenger vehicle and a trailer being towed there behind can be very dangerous, especially when the vehicles are moving at highway speed, such that the vehicles are having momentums such that a sudden lateral changing of direction of the towing vehicle can cause a serious swaying problem of the trailer. 
   Because the towing vehicle rearward end displaces to the side that is opposite to its forward end, it is especially dangerous when vehicles are in a down hill situation such that the weight of the trailer adds to the momentum of the trailer and the trailer has the tendency to push the towing vehicle rearward end off the moving course. 
   The towed vehicle-swaying problem is also pronounced when the towed vehicle has a large side elevation area upon which crosswind gusts and slip stream blasts may act on the towed vehicle for creating a sudden unstable condition. 
   Accordingly, a need exists for a hitch connection between a vehicle and a trailer that eliminates the swaying tendencies of the vehicle and trailer combination as a result of slight lateral shifting of the forward end of the towing vehicle. 
   Various solutions to the problem of trailer swaying have been proposed with anti-sway trailer hitches that include at least some of the general structural and operational features of the instant invention are disclosed in U.S. Pat. Nos. 2,201,660, 2,913,256, 3,254,905, 3,785,680, 3,787,077 and 3,825,282. 
   The most closely related improvement in anti-sway trailer hitch assemblies was disclosed in U.S. Pat. No. 6,485,046, by the present inventor. But, the &#39;046 patent hitch assembly has a limitation for limiting the towing vehicle turning angle, such that, at a larger turning angle, the control rod that connects the hitch beam to the control beam will move closer to and interfere with the intermediate bar on the hitch assembly, thus limiting the towing vehicle turning angles. 
   SUMMARY OF THE INVENTION 
   An anti-sway trailer-hitch assembly for connecting a towing vehicle to a towed vehicle having symmetrical anti-sway features. 
   The vast majority of passenger vehicles include a substantial vehicle mass that projects rearward from the back wheels of the vehicle. With a conventional trailer hitch installed on the rearward end of the towing vehicle, a slight left and right lateral shifting of the forward end of the towing vehicle results in concomitant right and left lateral shifting of the connecting towed vehicle forward end. 
   With the present anti-sway trailer hitch invention installed on the rearward end of the towing vehicle, a slight left and right lateral shifting of the forward end of the towing vehicle will result in a concomitant lateral shifting left and right, respectively, of a hitch ball affixed to a hitch beam on the anti-sway trailer hitch. 
   The hitch ball lateral left and right shifting displacements cancel out the towing vehicle rearward end lateral right and left shifting displacements respectively, so that the hitch ball remains at the same location and does not shift laterally. 
   With the towed vehicle forward end connected to the hitch ball, the towed vehicle forward end does not shift laterally when the towing vehicle forward end shifts laterally, and thus the towed vehicle remains stable and does not sway. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a plan view of the trailer hitch according to the present invention of connecting a towed vehicle in the form of a trailer to a towing vehicle. 
       FIG. 2  is a side view of the trailer hitch according to the present invention of connecting the trailer to the towing vehicle. 
       FIG. 3  is an enlarged plan view of the trailer hitch according to the present invention. 
       FIG. 4  is an enlarged side view of the trailer hitch according to the present invention. 
       FIG. 5  is an enlarged plan view of the trailer hitch showing components details according to the present invention. 
       FIG. 6  is an enlarged side view of the trailer hitch showing components details according to the present invention. 
       FIG. 7  is a plan view of the trailer hitch showing the vehicles are making a bigger turn. 
       FIG. 8  is a plan view of the trailer hitch according to another embodiment of the present invention of connecting a towed vehicle in the form of a trailer to a towing vehicle. 
       FIG. 9  is a side view of the trailer hitch according to another embodiment of the present invention of connecting a towed vehicle in the form of a trailer to a towing vehicle. 
       FIG. 10  is a plan view of the trailer hitch according to the present invention of connecting the trailer to the towing vehicle without individual components indication numbers. 
       FIG. 11  is a prospective view of the trailer hitch assembly, according to the second embodiment of the present invention, connecting a towed vehicle in the form of a trailer to a towing vehicle. 
       FIG. 12  is a prospective view of the trailer hitch assembly according to the second embodiment of the present invention. 
       FIG. 13  is a prospective view of the trailer hitch&#39;s frame assembly according to the second embodiment of the present invention. 
       FIG. 13A  is a prospective view of the frame assembly components according to the second embodiment of the present invention. 
       FIG. 13B  is a prospective view of the frame assembly installed on to the rearward end of the towing vehicle according to the second embodiment of the present invention. 
       FIG. 14  is a prospective view of the trailer hitch&#39;s center beam assembly according to the second embodiment of the present invention. 
       FIG. 14A  is a prospective of the center beam assembly components according to the second embodiment of the present invention. 
       FIG. 14B  is a prospective view of the center beam assembly installed onto the frame assembly according to the second embodiment of the present invention. 
       FIG. 15  is a prospective view of the trailer hitch&#39;s center beam extension assembly according to the second embodiment of the present invention. 
       FIG. 15A  is a prospective view of the center beam extension assembly components according to the second embodiment of the present invention. 
       FIG. 15B  is a prospective view of the center beam extension assembly installed onto the center beam assembly and the frame assembly according to the second embodiment of the present invention. 
       FIG. 16  is a prospective view of the trailer hitch&#39;s hitch beam assembly according to the second embodiment of the present invention. 
       FIG. 16A  is a prospective view of the hitch beam assembly components according to the second embodiment of the present invention. 
       FIG. 16B  is a front view of the hitch beam assembly installed onto the frame assembly according to the second embodiment of the present invention. 
       FIG. 17  is a front view of the trailer hitch assembly connecting a towed vehicle in the form of a trailer to a towing vehicle according to the second embodiment of the present invention. 
       FIG. 17A  is a front view of the trailer hitch assembly connecting a trailer to a towing vehicle, with the trailer is in a straight line with the towing vehicle, according to the second embodiment of the present invention. 
       FIG. 17B  is a top view of the trailer hitch assembly connecting a trailer to a towing vehicle, with the trailer is at an angle with the towing vehicle, according to the second embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   As illustrated in  FIG. 1  and  FIG. 2 , A hitch assembly of the present invention is generally designated by reference numeral  10  and articulately connects a towing vehicle  80  and a towed vehicle  90 . The towing vehicle  80  includes a frame  80   a , rear wheels  80   b  and rear axle  80   c . The towed vehicle  90  is in the form of a trailer having supporting wheels  90   a  at opposite ends of an axle  90   b . Various supporting wheel and axle arrangements may be provided for the trailer  90 , and the forward end of the trailer is provided with a tongue or frame structure  92  that extends forward and includes a trailer hitch coupler  94  at forward end thereof. 
   The hitch assembly  10  includes a hitch frame  20  having a forward end  20   a  and a rearward end  20   b , a center beam  30  having a forward end  30   a , a middle portion  30   b  and a rearward end  30   c , a center beam-extension  50  having a forward end  50   a , a middle portion  50   b  and a rearward end  50   c , a hitch beam  60  having a forward end  60   a , a middle portion  60   b  and a rearward end  60   c , and a rear support  70 . 
   Hitch frame  20  forward end  20   a  installs onto towing vehicle  80  rearward-end. 
   Center beam  30  forward end  30   a  is pivotally connecting to hitch frame  20  rearward-end  20   b  through a pivotal connection  31 . Pivotal connection  31  allows center beam  30  to swing an arc horizontally around pivotal connection  31 . 
   Hitch beam  60  forward end  60   a  is pivotally connecting to hitch frame  20  rearward-end  20   b  through a pivotal connection  61 . Pivotal connection  61  allows hitch beam  60  to swing an arc horizontally around pivotal connection  61 . 
   Center beam  30  rearward end  30   c  is pivotally connecting to center beam-extension  50  forward end  50   a  by a pivotal connection  51 , which includes a removable pin  52 . Pivotal connection  51  allows center beam-extension  50  swings an arc vertically around pivotal connection  51 . 
   Center beam-extension  50  rearward end  50   c  is pivotally connecting to rear support  70  upper-end by a pivotal connection  53 . Pivotal connection  53  includes a hitch coupler  54  affixing on center beam-extension  50  rearward end  50   c  and a hitch ball  72  affixing on rear support  70  upper end. Hitch coupler  54  engages with hitch ball  72 . 
   The rear support  70  lower-end is affixed firmly to trailer  90  body and frame  92 . 
   The center beam-extension  50  mid portion  50   b  is hollow inside such that the rearward end  50   c  forward section is able to slide inside mid portion  50   b . This sliding feature together with pivotal connections  51  and  53  compensates for the constantly-changing distances between the two vehicles due to road conditions and vehicle turning. Besides, this sliding feature can further accommodate different trailers being towed because trailer frame  92  varies in lengths for different trailers. 
   Hitch beam  60  rearward end  60   c  including a hitch ball  64  is engaged by hitch coupler  94  affixed to the towed vehicle  90  forward end. 
   When connecting the towed vehicle to the towing vehicle by connecting trailer hitch coupler  94  to hitch ball  64 , to make the connection easier, it is better first to remove the center beam-extension  50  completely so that it will be out of the way. For this reason, pin  52  can be removed from pivotal connection  51  on center beam-extension  50  forward end, and hitch coupler  54  can be disengaged from hitch ball  72  on rear support  70 , so that center beam extension  50  can be removed completely. 
   Referring to  FIG. 3  and  FIG. 4 , hitch frame  20  forward end includes a hitch tongue  24 , and hitch frame rearward end includes an upper member  21  having a rearward end  21   b , a middle member  22 , and a lower member  23 . 
   Hitch tongue  24  inserts into a hitch bar receptacle  84  existing on rearward end of towing vehicle  80 . A removable pin  86  inserts through a hole on receptacle  84  and a hole on hitch tongue  24  to keep hitch tongue  24  inside receptacle  84 . A spring pin  86   a  inserts through a hole on pin  86  to keep pin  86  in place. 
   An upwardly extending roller  28  has a pivotal connection with the upper member  21  rearward end  21   b  by a pivotal connection  27 . 
   Hitch beam  60  middle portion  60   b  has a slot  62 , and rearward end has a cavity  63 . 
   Center beam  30  middle portion includes a vertically-positioned center shaft  34  in pivotal connection with center beam  30  by a pivotal connection  35 . Center shaft  34  includes an upper end  34   a  and a lower end  34   b  that upper end  34   a  affixing a slot  37  extending forwardly that roller  28  on upper member  21  interposing inside slot  37 . 
   An arm  44  has a forward end  44   a  and a rearward end  44   b  that forward end  44   a  affixes on center shaft lower end  34   b . A downwardly extending roller  46  is in pivotal connection with arm  44  rearward end  44   b  by a pivotal connection  45 . Roller  46  interposes inside slot  62  on hitch beam  60 . 
   A hitch bar  67  having a forward end and a rearward end that forward end fits inside cavity  63  on hitch beam rearward end  60   c . A pin  65  inserts through a hole on cavity  63  and a hole on hitch bar  67  of keeping hitch bar  67  in place, and a spring pin  65   a  inserts through a hole on pin  65  to keep pin  65  in place. Hitch bar  67  rearward end affixes to a hitch ball  64 . 
   Trailer hitch coupler  94  on forward end of the trailer  90  engages hitch ball  64  on hitch beam  60 . 
   Referring to  FIG. 5  and  FIG. 6 , roller  28  pivotal connection  27  includes an upwardly extending pin  29  affixing on upper member  21  rearward-end  21   b . Roller  28  is able to rotate on pin  29  through a bearing  28   a  interposed between the upper surface of member  21  and the lower end of roller  28 . A washer  28   b  is inserted onto pin  27  and a spring pin  28   c  is inserting through a hole on pin  29  to keep roller  28  in place. 
   Center beam  30  forward end pivotal connection  31  includes a vertical positioned sleeve  32  extending through and affixed firmly to center beam forward end  30   a . Two bearings in the form of flange bushings  32   a  and  32   b  fit tightly inside sleeve  32  at the top and bottom. Upper bearing  32   a  is against upper member  21  and lower bearing  32   b  is against middle member  22 . A pin  25  inserts through a hole on upper member  21 , bushing  32   a , bushing  32   b  and a hole on middle member  22 . A spring pin  25   a  inserts through a hole on upper member  21  and a hole on pin  25  to keep pin  25  in place. Sleeve  32  allows center beam  30  to swing in an arc horizontally around pin  25 . 
   Center shaft  34  pivotal connection  35  includes a vertically-positioning sleeve  36  extending through and affixed firmly to center beam  30 . Two bearings in the form of flange bushings  36   a  and  36   b  fit tightly into sleeve  36  at the top and bottom. Center shaft  34  is inserting through slot  38 , bushings  36   a ,  36   b  and arm  44  with upper bushing  36   a  against slot  38  lower surface and lower bushing  36   b  against arm  44  upper surface. A pin  34   c  is inserted through slot  38  and center shaft  34 , and a pin  34   d  is inserted through arm  44  and center shaft of securing slot and arm to center shaft. Center shaft  34  is able to rotate vertically inside sleeve  36 . 
   Roller  46  pivotal connection  45  with arm  44  includes a downwardly extending pin  47  affixed on arm  44  rearward end  44   b . Roller  46  is able to rotate on pin  47  through a bearing  46   a  in the form of a flange bushing inserted through roller  46 . A washer  47   a  is placed onto pin  47 , and a spring pin  47   b  is placed through a hole on pin  47  to keep washer  47   a  and roller  46  in place. Roller  46  is interposed inside slot  62  on hitch beam  60 . 
   Pivotal connection  51  on center beam rearward end  30   c  includes a horizontally-positioned sleeve  38  extending through and affixed firmly to center beam  30 . Two bearings in the form of flange bushings  38   a  and  38   b  fit tightly into sleeve  38  ends. 
   Pivotal connection  51 , on center beam-extension  50  forward end  50   a , includes a left fork  55  and a right fork  56  such that each fork has a hole, and center beam  30  rearward end  30   c  fits between the left fork and the right fork. A removable pin  52  is placed through the hole on left fork  55 , bushing  38   b , bushing  38   a  and right fork  56 , and a spring pin  52   a  is placed through a hole on pin  52  to keep pin  52  in place. Sleeve  38  allows center beam-extension  50  to swing in an arc vertically around pin  52 . 
   Hitch beam  60  forward-end pivotal connection  61  (not shown in  FIG. 5 ) includes a vertical positioning sleeve  65  extending through and affixed firmly on hitch beam forward end  60   a . Two bearings in the form of flange bushings  65   a  and  65   b  are tightly fit into sleeve  65  at the top and bottom. Upper bushing  65   a  is against middle member  22  and lower bushing  65   b  is against lower member  23 . A pin  26  inserts through the hole on lower member  23 , bushing  65   b , bushing  65   a  and middle member  22 . A spring pin  26   a  inserts through a hole on lower member  23  and a hole on pin  26  of keeping pin  26  in place. Sleeve  65  allows hitch beam  60  to swing in an arc horizontally around pin  26 . 
   As shown, pivotal connections  31  and  61  are not coincidental, but pivotal connections  31  and  61  can be coincidental such that pin  25  and pin  26  can be coincidental and can become one single pin. 
   Refer back to  FIG. 1 ,  FIG. 2 ,  FIG. 3  and  FIG. 4  for illustrating the functions of the present invention. As shown, the towing vehicle is making a slight left turn causing the towing vehicle rearward end and hitch frame upper member  21  attaching roller  28  and roller-engaging slot  37  displacing to the right, which rotates center shaft  34  clockwise and displaces arm  44 , affixing roller  46 , roller-engaging slot  62 , hitch beam  60  and attached hitch ball  64  to the left, and displaces hitch ball-engaging hitch coupler  94  on trailer forward end to the left. As a result, when the towing vehicle is turning to the left slightly, the towed vehicle forward end is shifting to the left too. 
   In the above description, it is to be noted that because center beam  30  and center beam extension  50  are connected together by pivotal connection  51 , which is flexible vertically but is rigid laterally, center beam  30  and center beam extension  50  together are treated as one solid beam in the lateral direction which is the longest member in the hitch assembly. Therefore, the mid-portion of this member where center shaft  34  is affixed has less lateral movement than that of the roller  28  affixed on the hitch assembly when the towing vehicle is turning. The difference in lateral movement between roller  28  and center shaft  34  is thus able to turn the center shaft and create the subsequent movements of other components and at the end to produce lateral movement of hitch ball  64 . 
   The hitch ball  64  lateral movement shifting amount depends on the hitch assembly construction mainly depending on its component lengths being made, such that for a fixed amount of the towing vehicle forward end lateral shifting but with different component lengths, the resultant hitch ball  64  lateral displacement will be different. 
   When the towing vehicle makes small turn such as a lane change, in the case when the resultant hitch ball  64  lateral displacement amount is the same as the towing vehicle rearward end lateral displacement amount but opposite in direction, such that the two displacements cancel out each other, the hitch ball  64  and engaging trailer hitch coupler remain at the same location as that before the towing vehicle was turning. As a result, the towed vehicle forward end moving direction and moving momentum is not changed nor affected by the towing vehicle forward end lateral shifting, and thus the towed vehicle remains steady and does not swing. 
   In the case with the hitch assembly components made such that when the lateral shifting amount of hitch ball  64  and coupling hitch coupler  94  is more than the towing vehicle rearward end shifting amount but opposite in direction, hitch ball  64  and coupling hitch coupler  94  will shift to the direction as the towing vehicle forward end shifting direction. 
   In this case, the towed vehicle forward end is equivalent to a pivot at a point, which is the intersection of the towed vehicle center line extension and the towing vehicle center line, and is forward of the towing vehicle rear axle. 
   Because the pivot point is forward of the towing vehicle rear axle, when the towing vehicle turns, the towed vehicle moving momentum follows the towing vehicle forward end turning direction, and shifts to the same direction as the towing vehicle turning direction, such that when the vehicles are reducing speed, especially in a down hill situation, the towed vehicle momentum and weight are pushing toward a point forward of the towing vehicle rear axle in the towing vehicle mid-section rather than the towing vehicle rear-end, thus having less chance for pushing the towing vehicle rearward end off the road and creating a “jack Knife” situation. 
   During ordinary operations of the vehicles, due to road conditions being uneven and moving vehicle direction changes, with hitch coupler  94  engaging hitch ball  64  as the main connection and controlling the distance between the two vehicles, and the other connection between the two vehicles being the connection of center beam  30  and center beam-extension  50  between pivotal connection  31  and pivotal connection  53 , the distance between the two vehicles is constantly changing, and the changing distance is compensated by the center beam-extension mid portion  50   b  sliding mechanism, while the elevation differences between the two vehicles is compensated by pivotal connections  51  and  53 . 
   Also to be noted is that pivot joint  35  on center beam  30  keeps center shaft  34  vertical in center beam  30 , so that slot  37  and arm  44  are maintained horizontally parallel to center beam  30 . As upper member  21 , middle member  22 , lower member  23 , center beam  30  and hitch beam  60  are all horizontally parallel, roller  28  is able to stay in slot  37 , and roller  46  is able to stay inside slot  62  at all times. 
   As shown in  FIG. 7 , when the towing vehicle is making a bigger turn, as roller  28  displaces more, the angle forming between upper member  21  and slot  37  reduces and becomes closer to  90  degrees. The effective displacement of roller  28  against slot  37  is reducing, and an increasing roller  28  lateral movement produces a proportionally lesser angular movement of slot  37 . Thus, the towed vehicle forward end does not proportionately displace laterally with the towing vehicle-turning angle. 
   As a result, the hitch assembly is most effective when the towing and towed vehicles are moving in a path closer to a straight line. One example is in the case when vehicles are moving on highways and have a higher speed such that a small degree of turning of the towing vehicle creates a large lateral movement of the towed forward end to make the towed vehicle forward end follow the towing vehicle turning direction. On the other hand, when the towing vehicle makes a big turn normally at lower speed, the towed vehicle forward end does not over-shift laterally, thus avoiding the case of forcing the towed vehicle forward end toward a non-ideal path. 
   Referring to  FIG. 8  and  FIG. 9 , according to another embodiment of the present invention, the center beam-extension  50  includes a center section  50   b , which is hollow inside, such that a center beam-extension rear section  50   c  is able to slide inside center section  50   b . Center section  50   b  includes a through-hole  56  going through both walls, and rear section  50   c  includes a plurality of holes  55  such that a pin  57  is placed through hole  56  and one of the holes  55 , and a spring pin  58  is placed through a hole in pin  57  to keep pin  57  in place. 
   Rear section  50   c  rearward end affixing a hitch coupler  54  connects to a rear support  70  upper end  70   a  affixing hitch ball  72 , and rear support  70  lower end  70   b  is pivotally connected to the towed vehicle frame  92  by a pair of pivotal connection  73  connecting to a pair of brackets  74  affixed to the towed vehicle frame  92 , such that rear support  70  is able to swing fore and aft around pivotal connection  73 . In this structure, the swinging fore and aft of the rear support  70  compensates the changing distance between the towing vehicle and the towed vehicle when vehicles are moving, and pluralities of holes  55  on center beam-extension rear section  50   c  allows different hole  55  to be used to align with hole  56  on center beam-extension mid-section  50   b  for pin  57  to push through, such that center beam-extension lengths can be adjusted to suit for different towed vehicles to be towed. 
   Refer to  FIG. 11 , according to another embodiment of the present invention, a hitch assembly of the present invention is generally designated by reference numeral  110  and articulately connects a towing vehicle  80  and a towed vehicle  90 . 
     FIG. 12  shows hitch assembly  110  including: a hitch frame assembly  130 , a center beam assembly  140 , a center beam extension assembly  150 , and a hitch beam assembly  160 . 
     FIG. 13  shows frame assembly  130  having a forward end  130   a , pivot point  130   b  and pivot point  130   c.    
     FIG. 13A  shows frame assembly  130  components including; a frame body  131  having holes  131   a ,  132   a ,  132   b ,  132   c ,  133   a ,  133   b , and  133   c , a pin  134  having a hole  134   a , a spring pin  135 , a pin  136  having a hole  136   a , a pin  137 , a pin  138  having a hole  138   a , and a pin  139 . 
   When frame assembly  130  components are assembled, pin  134  is placed into hole  131   a , and spring pin  135  is placed into hole  134   a  to keep pin  134  therein, pin  136  is placed into holes  132   a  and  132   b , and pin  137  is placed into holes  132   c  and  136   a  to keep pin  136  therein, pin  138  is placed into holes  133   a  and  133   b , and pin  139  is placed into holes  133   c  and  138   a  to keep pin  138  therein. 
     FIG. 13B  shows the rearward end of towing vehicle  80  having a hitch receptacle  81  having a hole  81   a , and hitch frame assembly  130  is placed into hitch receptacle  81 , and pin  134  is placed through hole  81   a  on hitch receptacle  81  and the hole on hitch frame body  131 , and spring pin  135  is placed through the hole on pin  134  to keep pin  134  in place. 
     FIG. 14  shows center beam assembly  140  having a forward end having a pivot point  140   a , a mid portion having a pivot point  140   b , and a rearward end having a pivot point  140   c.    
     FIG. 14A  shows center beam  140  components including: a center beam body  141  having holes  141   a ,  141   b ,  141   c  and  141   d , a sleeve  142  having a hole  142   a , a sleeve  143  having a hole  143   a , a pin  144  having a hole  144   a  and a groove  144   b , a roller  145  having a hole  145   a , four of bearings in the form of bushings  146 , a washer  147 , and a shaft spring clip  148 . 
   When center beam  140  components are assembled; sleeve  142  is placed into hole  141   a  and affixed firmly thereto, two of bearings  146  are placed on the ends of hole  142   a  and affixed firmly thereto, sleeve  143  is placed into hole  141   c  and affixed firmly thereto, pin  144  is placed into hole  141   b , and pin  149  is placed into hole  141   d  and hole  144   a  to keep pin  144  firmly affixed to center beam  141 , two of bearings  146  are placed on the ends of hole  145   a  and affixed firmly thereto, roller  145  and washer  147  are placed onto pin  144 , and shaft spring clip  148  is placed onto groove  144   b  to keep roller  145  and washer  147  on pin  144 . 
     FIG. 14B  shows center beam assembly  140  installed onto hitch frame assembly  130 . Pin  136  is placed through hole  132   a , sleeve  142  and hole  132   b , and pin  137  is placed through holes  132   c  and hole on pin  136  to keep pin  136  in place. Center beam assembly  140  is able to rotate laterally around pin  136 . 
     FIG. 15  shows center beam extension  150  having a forward end having a pivot point  150   a , a mid portion  150   b , and a rearward portion  150   c.    
     FIG. 15A  shows center beam extension  150  components including: a front-section  151  having a forward end having a left prong  156  having a hole  156   a  and a right prong  157  having a hole  157   a , and a rearward end having a rectangular hole  151   a , a mid-section  152  having a forward end  152   a  having a rectangular shape, a rearward end  152   b , a rear-section having a ball receptacle  153  having a forward end  153   a  and a rearward end  153   b  having a ball shape cavity, a pin  154  having a hole  154   a , a spring pin  155 , a hitch ball  158  having a threaded end  158   a , a bracket  159  having a hole  159   a , and a nut  158   b.    
   When center beam extension  150  components are assembled; mid-section  152  forward end  152   a  is placed and slidably inside front-section  151  rearward end  151   a , mid-section  152  rearward end  152   b  is firmly affixed to ball receptacle  153  forward end  153   a , pin  154  is placed through holes  157   a  and  156   a , spring pin  155  is placed through hole  154   a  to keep pin  154  in place, hitch ball  158  threaded end  158   a  is placed through hole  159   a  on bracket  159 , nut  158   b  is placed on threaded end  158   a  to keep hitch ball  158  attached to bracket  159 , and hitch ball  158  is removably attached to ball receptacle  153 . 
     FIG. 15B  shows center beam extension  150  installed onto center beam  140 , such that pin  154  is placed through holes on prongs on center beam extension  150  forward end and the hole on center beam  140  rearward end, and spring pin  155  is placed through the hole on pin  154  to keep pin  154  therein. Center beam extension  150  is able to rotate around pin  154  vertically. 
     FIG. 16  shows hitch beam assembly  160  having a forward end having a pivot point  160   a , a mid portion having a slot  160   b , and a rearward end having a pivot point  160   c.    
     FIG. 16A  shows hitch beam  160  components including: a body  161  having holes  161   a ,  161   b , and  161   c , a sleeve  162  having a hole  162   a , two of bearings in the form of flange bushings  163 , a slot  164 , a block  165  having holes  165   a  and  165   b , a pin  166  having a hole  166   a , a spring pin  167 , a hitch ball  168  having an threaded end  168   a , and a nut  169 . 
   When hitch beam  160  components are assembled; sleeve  162  is placed into hole  161   a  and affixed firmly thereto, two of bearings  163  are placed into the ends of hole  162   a  and affixed firmly thereto, slot  164  is firmly affixed to hitch beam body  161 , block  165  forward end is placed inside hole  161   c , and pin  166  is placed through holes  161   b  and  165   a , and spring pin  167  is placed through hole  166   a  to keep pin  166  in place, hitch ball threaded end  168   a  is placed though hole  165   b , and nut  169  is placed onto threaded end  168   a  to secure hitch ball  168  firmly to block  165 . 
     FIG. 16B  shows hitch beam assembly  160  installed onto hitch frame assembly  130 . Slot  164  on hitch beam  160  is aligned with roller  145  on center beam  140 , such that roller  145  is positioned inside and slidably engaged with slot  164 , sleeve  162  is aligned with holes  133   b , pin  138  is placed through hole  133   b , sleeve  162 , and hole  133   a , and pin  139  is placed through a hole on frame assembly  130  and a hole on pin  138  to keep pin  138  in place. Hitch beam  160  is able to rotate around pin  138  laterally. 
     FIG. 17  shows hitch assembly  110  installed between towing vehicle  180  and trailer  190 , such that hitch frame assembly  130  forward end installed onto towing vehicle  180  rearward end as was shown in  FIG. 13B , hitch beam  160  rearward end hitch ball  168  is coupled to trailer  190  forward end coupler  194 , and center beam extension  150  rearward end bracket  159  is firmly affixed to trailer  190  body. 
   When towing vehicle  180  and trailer  190  are moving, due to road conditions and vehicles turning, the elevations and distances between the vehicles are constantly changing. Pivot point  140   c  allows center beam extension  150  rearward end  159  to follow trailer  190  elevations to compensate for the differences in elevations, while the sliding engagement between center beam extension body  151  and body  152  compensates for the varying distances between the vehicles. 
     FIG. 17A  shows when towing vehicle  180  and trailer  190  are in a straight path, such that trailer hitch assembly  110  is functioning as a regular trailer hitch. 
     FIG. 17B  shows towing vehicle  180  has turned to the left at an angle and pivoted around vehicle rear axle center  180   c . Since pivot point  130   c  is further away from axle center  18   c  than pivot point  130   b , pivot point  130   c  has displaced more lateral movement than pivot point  130   b . Center beam  140  connected to center beam extension  150  has formed the longest member in hitch assembly  110 , such that with this longest member forward end is pivoting at pivot point  130   b  and rearward end is pivoting at coupler  158 , such that pivot point  140   b  on center beam  140  where roller  146  (also was shown on  FIG. 14 ) is attached has less lateral displacement than pivot point  130   c . Since roller  146  is positioned inside slot  164 , lateral displacement differences between pivot point  130   c  and pivot point  140   b  causes slot  164  to slide against and to turn around roller  146 , such that hitch beam  160  rearward end hitch ball  168  and coupled hitch ball socket  194  on trailer  190  forward end displaces laterally toward the direction that towing vehicle  180  is turning, such that trailer  190  has less tendencies to sway.