Patent Publication Number: US-2005141955-A1

Title: Towing hitch for connecting a trailer to a wheeled vehicle

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a towing hitch, and more particularly to a towing hitch for connecting a trailer to a wheeled vehicle, such as a car or the like.  
      2. Description of the Related Art  
      A conventional towing hitch  1  in accordance with the prior art shown in  FIGS. 13 and 14  is used for connecting a towing bar  3  of a trailer  2  to a towing bar  5  of a wheeled vehicle  4  (such as a car or the like). As shown in  FIG. 14 , the conventional towing hitch  1  comprises a fixing bar  11  having a first end formed with a threaded face  13  for screwing a nut  14  and a washer  15 , a mediate portion integrally formed with a stepped seat  12 , and a second end integrally formed with a fixing ball  16 . A mounting space  18  is formed between the washer  15  and the stepped seat  12 , so that the conventional towing hitch  1  can be mounted on the towing bar  3  of the trailer  2 . The fixing ball  16  is directed upward to mount a bushing (not shown) of the towing bar  5  of the wheeled vehicle  4  to form a joint structure.  
      However, the fixing bar  11  is integrally formed with the threaded face  13 , the stepped seat  12  and the fixing ball  16 , so that it is necessary to work and align the fixing bar  11 , the threaded face  13 , the stepped seat  12  and the fixing ball  16 , thereby greatly increasing difficulty of the working process, and thereby increasing costs of fabrication.  
     SUMMARY OF THE INVENTION  
      The primary objective of the present invention is to provide a towing hitch for connecting a trailer to a wheeled vehicle, such as a car or the like.  
      Another objective of the present invention is to provide a towing hitch, wherein the fixing bar is formed with a mounting shaft for detachably mounting the fixing ball or the fixing bar, so that the towing hitch has a detachable structure, thereby facilitating assembly of the towing hitch, and thereby decreasing costs of fabrication.  
      A further objective of the present invention is to provide a towing hitch, wherein the mounting hole of the fixing ball is exactly aligned with the mounting shaft of the fixing bar, so that the fixing ball is mounted on the fixing bar easily and conveniently.  
      A further objective of the present invention is to provide a towing hitch, wherein the abutment of the fixing ball is closely rested on the stepped seat of the fixing bar, so that the fixing ball is integrally combined with the fixing bar rigidly and stably.  
      In accordance with one embodiment of the present invention, there is provided a towing hitch, comprising a fixing bar, and a fixing ball, wherein: 
          the fixing bar has a first end formed with a threaded face for screwing a nut and a washer, a mediate portion integrally formed with a stepped seat, and a second end formed with a threaded rod and a mounting shaft; and     the fixing ball is detachably mounted on the fixing bar and has a first end formed with a mounting hole mounted on the mounting shaft of the fixing bar and a second end formed with a screw bore screwed on the threaded rod of the fixing bar.        

      In accordance with another embodiment of the present invention, there is provided a towing hitch, comprising a fixing bar, a fixing ball, and a stepped seat, wherein: 
          the fixing bar has a first end formed with a threaded face for screwing a nut and a washer and a second end formed with a mounting shaft;     the fixing ball is integrally formed on the second end of the fixing bar and has an end having a periphery formed with an abutment; and     the stepped seat is detachably mounted on the second end of the fixing bar and has an inside formed with a mounting hole mounted on the mounting shaft of the fixing bar.        

      Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is an exploded perspective view of a towing hitch in accordance with the preferred embodiment of the present invention;  
       FIG. 2  is a plan cross-sectional view of a fixing ball of the towing hitch as shown in  FIG. 1 ;  
       FIG. 3  is an exploded perspective view of a towing hitch in accordance with another embodiment of the present invention;  
       FIG. 4  is a plan cross-sectional view of a fixing ball of the towing hitch as shown in  FIG. 3 ;  
       FIG. 5  is an exploded perspective view of a towing hitch in accordance with another embodiment of the present invention;  
       FIG. 6  is an exploded perspective view of a towing hitch in accordance with another embodiment of the present invention;  
       FIG. 7  is an exploded perspective view of a towing hitch in accordance with another embodiment of the present invention;  
       FIG. 8  is an exploded perspective view of a towing hitch in accordance with another embodiment of the present invention;  
       FIG. 9  is an exploded perspective view of a towing hitch in accordance with another embodiment of the present invention;  
       FIG. 10  is a partially plan cross-sectional assembly view of the towing hitch as shown in  FIG. 9 ;  
       FIG. 11  is an exploded perspective view of a towing hitch in accordance with another embodiment of the present invention; and  
       FIG. 12  is a partially plan cross-sectional assembly view of the towing hitch as shown in  FIG. 11 ;  
       FIG. 13  is a schematic plan view of a conventional towing hitch for connecting a trailer to a wheeled vehicle in accordance with the prior art; and  
       FIG. 14  is a perspective view of the conventional towing hitch in accordance with the prior art. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring to the drawings and initially to  FIGS. 1 and 2 , a towing hitch in accordance with the preferred embodiment of the present invention is used for connecting a trailer (not shown) to a wheeled vehicle (not shown), such as a car or the like.  
      The towing hitch comprises a fixing bar  20 , and a fixing ball  50 .  
      The fixing bar  20  has a first end formed with a threaded face  21  for screwing a nut  41  and a washer  42 , a mediate portion integrally formed with a stepped seat  30  having a larger diameter, and a second end formed with a threaded rod  22  and a mounting shaft  23  located between the stepped seat  30  and the threaded rod  22 . A mounting space (not shown) is formed between the washer  42  and the stepped seat  30 . The mounting shaft  23  has a diameter greater than that of the threaded rod  22 .  
      The fixing ball  50  is detachably mounted on the fixing bar  20  and has a first end formed with a mounting hole  52  mounted on the mounting shaft  23  of the fixing bar  20  and a second end formed with a screw bore  51  screwed on the threaded rod  22  of the fixing bar  20 . Preferably, the second end of the fixing ball  50  has an open side and the screw bore  51  of the fixing ball  50  is extended through a whole length of the second end of the fixing ball  50  as shown in  FIG. 2 . In addition, the first end of the fixing ball  50  has a periphery formed with an annular abutment  53  rested on the stepped seat  30  of the fixing bar  20 .  
      Thus, the mounting hole  52  of the fixing ball  50  is exactly aligned with the mounting shaft  23  of the fixing bar  20 , so that the fixing ball  50  is mounted on the fixing bar  20  easily and conveniently. In addition, the abutment  53  of the fixing ball  50  is closely rested on the stepped seat  30  of the fixing bar  20 , so that the fixing ball  50  is integrally combined with the fixing bar  20  rigidly and stably.  
      Referring to  FIGS. 3 and 4 , the second end of the fixing ball  50  has a closed side and the screw bore  51  of the fixing ball  50  is not extended through the whole length of the second end of the fixing ball  50 .  
      Referring to  FIG. 5 , the nut  410  has another shape.  
      Referring to  FIG. 6 , the washer  420  is a substantially C-shaped elastic washer.  
      Referring to  FIG. 7 , the towing hitch further comprises an O-ring  54  mounted on the fixing bar  20  and clamped between the stepped seat  30  of the fixing bar  20  and the abutment  53  of the fixing ball  50  to provide a buffer effect.  
      Referring to  FIG. 8 , a towing hitch in accordance with another embodiment of the present invention comprises a fixing bar  20 A, a fixing ball  50 A, and a stepped seat  30 A.  
      The fixing bar  20 A has a first end formed with a threaded face  21 A for screwing a nut  41 A and a washer  42 A and a second end formed with a mounting shaft  23 A. The mounting shaft  23 A has a diameter greater than that of the threaded face  21 A.  
      The fixing ball  50 A is integrally formed on the second end of the fixing bar  20 A and has an end having a periphery formed with an abutment  53 A located adjacent to an end of the mounting shaft  23 A of the fixing bar  20 A. Preferably, the mounting shaft  23 A of the fixing bar  20 A is located between the threaded face  21  A of the fixing bar  20 A and the fixing ball  50 A.  
      The stepped seat  30 A is detachably mounted on the second end of the fixing bar  20 A and has an inside formed with a mounting hole  31 A mounted on the mounting shaft  23 A of the fixing bar  20 A. The stepped seat  30 A has an end having a periphery formed with a lip  32 A rested on the abutment  53 A of the fixing ball  50 A. A mounting space (not shown) is formed between the washer  42 A and the stepped seat  30 A.  
      Referring to  FIGS. 9 and 10 , the fixing ball  50 A has an end having a periphery formed with a positioning groove  55 A located adjacent to an end of the mounting shaft  23 A of the fixing bar  20 A, and the stepped seat  30 A has an end having a periphery formed with a lip  32 A inserted into the positioning groove  55 A of the fixing ball  50 A.  
      Referring to  FIGS. 11 and 12 , the positioning groove  55 A of the fixing ball  50 A has a periphery formed with a locking hole  56 A, and the lip  32 A of the stepped seat  30 A has a periphery formed with a locking stub  33 A locked in the locking hole  56 A of the fixing ball  50 A.  
      Accordingly, the fixing bar is formed with a mounting shaft for detachably mounting the fixing ball or the fixing bar, so that the towing hitch has a detachable structure, thereby facilitating assembly of the towing hitch, and thereby decreasing costs of fabrication.  
      Although the invention has been explained in relation to its preferred embodiment(s) as mentioned above, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention. It is, therefore, contemplated that the appended claim or claims will cover such modifications and variations that fall within the true scope of the invention.