Abstract:
A trailer-hitch system comprises a hitch frame adapted to be secured to a vehicle and having a receiver for accommodating a foremost end of a mount unit. The mount unit has a member portion in mating engagement with the receiver of the hitch frame. A connector for connection with a trailer is provided at a rearmost end. The trailer-hitch system also comprises a mechanism actuated to press a portion of the member portion against the receiver for locking the mount unit into the mating engagement with the receiver. A method for locking a mount unit in a receiver of a hitch frame is also provided.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority on U.S. Patent Application Ser. No. 61/253,233, filed on Oct. 20, 2009, incorporated herein by reference. 
     
    
     FIELD OF THE APPLICATION 
       [0002]    The present application pertains to trailer-hitch systems and more particularly, but not exclusively, to trailer-hitch systems having a removable coupling mount such as trailer-hitch systems with a ball mount. 
       BACKGROUND OF THE ART 
       [0003]    Trailer-hitch systems are commonly used in non-commercial and recreational vehicles in order to attach a trailer to the vehicle. Trailer-hitch systems typically have a hitch frame that is secured to a frame of the vehicle, a coupling mount being provided on the hitch frame for interfacing with a corresponding coupler of a trailer. One well known type of connector for a trailer-hitch system is the hitch ball. The hitch ball is advantageously used in that it forms a joint with the coupler allowing at least two rotational degrees of freedom. This allows movements of the trailer with regard to the vehicle. Other types of connectors are usable as well with trailer-hitch systems. 
         [0004]    The connector ball (i.e., hitch ball) is typically provided on a removable mount. One of the reasons for the removable feature of the connector is that the connector typically projects rearwardly of the bumper. Therefore, if the connector is not removed from the vehicle, it may damage adjacent vehicles in case of a contact, for instance during parking. However, due to the loads on the mount, any space between the mount and a receiver of the trailer-hitch system may cause rattling or unwanted vibrations. Such vibrations may result in annoying noises, as well as premature damage to the mount. 
       SUMMARY OF THE APPLICATION 
       [0005]    It is therefore an aim of the present application to provide a trailer-hitch system that addresses issues associated with the prior art. 
         [0006]    Therefore, in accordance with the present application, there is provided a trailer-hitch system comprising: a hitch frame adapted to be secured to a vehicle and having a receiver for accommodating a foremost end of a mount unit; a mount unit having a member portion in mating engagement with the receiver of the hitch frame and having at a rearmost end a connector for connection with a trailer; and a mechanism actuated to press a portion of the member portion against the receiver for locking the mount unit into the mating engagement with the receiver. 
         [0007]    Further in accordance with the present application, there is provided a method for locking a mount unit in a receiver of a hitch frame, comprising: matingly engaging the member portion of the mount unit into a receiver of the hitch frame; threading a hitch pin through the receiver and the mount unit; and pressing the member portion radially against an inner surface of the receiver by actuating a mechanism to lock the mount unit in the receiver. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is an assembly perspective view of a trailer-hitch system in accordance with an embodiment of the present disclosure; 
           [0009]      FIG. 2  is a perspective view of a ball-mount unit of the trailer-hitch system of  FIG. 1 , with abutments in a retracted position; 
           [0010]      FIG. 3  is a perspective view, fragmented, of the ball-mount unit of  FIG. 2 , showing an interior thereof; 
           [0011]      FIG. 4A  is a perspective view of the ball-mount unit from another standpoint, with the abutments in the retracted position; 
           [0012]      FIG. 4B  is an enlarged view of the ball-mount unit of  FIG. 4A , emphasizing the abutments in the retracted position; 
           [0013]      FIG. 5A  is a perspective view of the ball-mount unit of  FIG. 4A , with the abutments in a projecting position; 
           [0014]      FIG. 5B  is an enlarged view of the ball-mount unit of  FIG. 5A , emphasizing the abutments in the projecting position; 
           [0015]      FIG. 6  is a perspective view of the trailer-hitch system of  FIG. 1 , with the ball-mount unit coupled to a receiver of the hitch frame; 
           [0016]      FIG. 7  is a perspective view of a trailer-hitch system in accordance with another embodiment of the present disclosure; and 
           [0017]      FIG. 8  is a perspective view of the trailer-hitch system of  FIG. 7 , with locking bolts locking a ball-mount unit coupled to a receiver. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    Referring to the drawings, and more particularly to  FIG. 1 , a trailer-hitch system in accordance with the present disclosure is generally shown at  10 . The trailer-hitch system  10  has a hitch frame  11 , that is shown sectioned at opposed ends. The hitch frame  11  is secured at opposed ends to a frame of a car. For simplicity purposes, the connector ends of the hitch frame  11  are not illustrated, but may be of any configuration as a function of the vehicle to which they are secured. The hitch frame  11  may have any shape so as to be secured to the vehicle. 
         [0019]    A receiver  12  is transversely positioned with respect to the hitch frame  11 . The receiver  12  accommodates an end of a connector mount. Therefore, the receiver  12  is preferably tubular. In  FIG. 1 , the receiver  12  is illustrated as being a generally square-section receiver, although other sectional shapes are considered as well. A throughbore is provided in the square-section receiver  12 , and is illustrated as  13 . The throughbore  13  receives a hitch pin  14  so as to lock a connector mount therein. 
         [0020]    A hook  15  may be provided, for instance to lock a trailer to the trailer-hitch system  10 . A lock (not shown) connects into the hook  15  and therefore blocks the hitch pin  14  in the throughbore  13 . 
         [0021]    Referring concurrently to  FIGS. 1 and 2 , a ball-mount unit  20  is sized so as to be matingly received in the square-section receiver  12 . The ball-mount unit  20  has a member  21  that is complementarily shaped so as to be accommodated in the receiver  12 . A bracket  22 , herein a right-angle bracket, is secured to a rearmost end of the member  21 . The bracket  22  supports a connector, such as hitch ball  23 . Other types of connectors may be used as alternatives to the hitch ball  23  with the mount unit  20 . As illustrated in  FIG. 2 , the hitch ball  23  is connected to the bracket  22  by a bolt. 
         [0022]    Referring to  FIG. 2 , the member  21  is preferably a tube having a pinhole  25 . The pinhole  25  is positioned and sized so as to be aligned with the throughbore  13  when the unit  20  is in the receiver  12 , for the hitch pin  14  to be passed therethrough. A pair of openings  26  are also defined in the member  21 , so as to allow radial movement of abutments with respect to the member  21 , as will be described hereinafter. 
         [0023]    Referring to  FIG. 3 , a wedge bar  30  is inserted into the member  21 , and may move axially therein. More specifically, the wedge bar  30  is in threaded relation with an actuator bolt  31 , with the actuator bolt  31  being idled to the bracket  22 . Therefore, rotation of the actuator bolt  31  results in the axial movement of the wedge bar  30  in the member  21 . The wedge bar  30  features a pair of wedge surfaces (i.e., at least one), with the wedge surfaces  32  being in a wedged orientation with respect to a longitudinal axis of the wedge bar  30 . Other actuation configurations are considered in alternatives to the threading engagement to actuate the translation movement of the wedge bar  30  in the member  21 , such as pistons, levers, two-bar linkages or the like. 
         [0024]    Abutments  33  are in sliding engagement with the wedge surfaces  32 . Moreover, the abutments  33  are held captive in the member  21 . Therefore, a translation of the wedge bar  30  with respect to the member  21  will cause a radial projection or retraction of the abutments  33  as a result of the sliding engagement of the abutments  33  on the wedge surfaces  32 . Referring concurrently to  FIGS. 4A and 4B , it is shown that the abutments  33  are in a retracted position. Referring to  FIG. 5A and 5B , it is observed that the abutments  33  are in a projecting position. The abutments  33  may have a resilient coating (e.g. rubber, polymers), with the resilient coating being of relatively high hardness for the use of the abutments  33 . 
         [0025]    Still referring to  FIG. 3 , it is shown that slot  34  has an oblong section. The oblong section is provided so as to allow the translational movement of the wedge bar  30  in the member  21 , despite the pin  14  ( FIG. 1 ) being in the pinhole  25 . 
         [0026]    Now that the various components of the trailer-hitch system  10  have been described, a method for using the trailer-hitch system is set forth. Firstly, the ball-mount unit  20  is inserted into the receiver  12 . More specifically, the member  21  is matingly fitted into the square-section receiver  12 . In order to insert the ball-mount unit  20  into the receiver  12 , the abutments  33  must be in the retracted position, as shown in  FIGS. 4A and 4B . When the pinhole  25  is aligned with the throughbore  13 , the hitch pin  14  is inserted into the throughbore  13  to lock the ball-mount unit  20  in position in the receiver  12 . When the hitch pin  14  is in the throughbore and pinholes  25 , the abutments  33  are moved to their projecting position ( FIGS. 4A and 4B ). More specifically, a tool such as a wrench or ratchet is used to rotate the actuator bolt  31  in the appropriate direction. This will cause a translation of the wedge bar  30 , and thus the radially outward movement of the abutments  33  to the projecting position. The abutments  33  will press against an inner surface of the receiver  12 , thereby blocking the member  21  to the receiver  12  by friction. The trailer may then be hitched to the hitch ball  23 , although the trailer may also be hitched at any appropriate moment after the member  21  is received in the receiver  12 . 
         [0027]    In order to remove the ball-mount unit  20 , the actuator bolt  31  is rotated in the opposite direction, so as to cause a radially inward movement of the abutments  33 . The trailer may be unhitched from the ball-mount unit  20  before the removal of the ball-mount unit  20 . 
         [0028]    In  FIGS. 7 and 8 , there is illustrated an alternative to the wedge mechanism shown in  FIGS. 1 to 6 . In  FIGS. 7 and 8 , nuts  40  are provided on an exterior surface of the receiver  12 . Accordingly, bolts  41  are screwed through the nuts  40  and into the receiver  12 , so as to press the member  21  against an inner surface of the receiver  12 . The free ends of the bolts  41  may be provided with a resilient tip, in a fashion similar to that of the resilient coating of the abutments  33 . As a result, the ball-mount unit  20 ′ is locked to the receiver  12 . Any similar mechanism may be used as well.