Abstract:
A coupler assembly for coupling a trailer to a towing vehicle hitch ball includes a coupler housing with an interior that defines a coupler socket adapted to receive a hitch ball. The coupler housing also includes a sight hole that communicates with the coupler socket and allows a user to see into the coupler socket to confirm proper engagement of the hitch ball and coupler.

Description:
BACKGROUND 
       [0001]    This invention relates to couplers. More particularly, it relates to a coupler mechanism having a sight hole that allows a user to visually determine when a hitch ball is properly positioned within the coupler socket. 
         [0002]    Trailer couplers are known. Typically, trailer couplers consist of a conformally-shaped socket that is close-fitting around a spherical hitch ball. The coupler also has securing means by which separation of the coupler and hitch ball is blocked. 
         [0003]    One problem that sometimes occurs when a coupler is placed over a hitch ball is that the hitch ball does not properly enter into the socket portion of the coupler, but rather, components within the coupler assembly come to rest on the top of the hitch ball rather than allowing the hitch ball to pass through to establish a conformal close fit between the hitch ball and coupler. When this occurs, the coupler installer can be unaware, and may engage the coupler securing means thinking it is functional, when in reality, it is not. 
         [0004]    There is a need, therefore, for a coupler that addresses the foregoing problem. It is an object of the present invention to provide such an apparatus. 
         [0005]    Additional objects and advantages of the invention will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations pointed out in the appended claims. 
       SUMMARY OF THE INVENTION 
       [0006]    To achieve the foregoing objects, and in accordance with the purposes of the invention as embodied and broadly described in this document, there is provided a coupler assembly for coupling a trailer to a towing vehicle hitch ball. The coupler assembly includes a coupler housing with an interior that defines a coupler socket adapted to receive a hitch ball. The coupler socket includes a bottom socket opening adapted to allow the insertion of the hitch ball into the coupler socket. The socket opening has a partially circumferential retaining rib. A ball clamp is disposed within the interior of the coupler housing and is movable toward and away from the coupler socket. The ball clamp has a clamping portion that cooperates with the socket opening retaining rib to retain the hitch ball within the coupler socket with the ball clamp is positioned toward the coupler socket in a hitch ball retention position. The coupler housing includes a sight hole that communicates with the coupler socket and allows a user to see into the coupler socket. In this configuration, the sight hole allows for visible inspection of the hitch ball in the coupler socket to confirm the proper engagement of the hitch ball and coupler. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate the presently preferred embodiments and methods of the invention and, together with the general description given above and the detailed description of the preferred embodiments and methods given below, serve to explain the principles of the invention. 
           [0008]      FIG. 1A  is a side sectional view of a prior ball clamp trailer coupler showing the hitch ball secured within the coupler socket with the ball clamp positioned in contact with the hitch ball in a retention position. 
           [0009]      FIG. 1B  is a side sectional view of the coupler of  FIG. 1A  showing the hitch ball within the coupler socket with the ball clamp positioned away from the hitch ball in a release position. 
           [0010]      FIG. 1C  is a side sectional view of the coupler of  FIG. 1A , showing the ball clamp jammed into the socket by the hitch ball, resulting in the insecure engagement of the ball and socket. 
           [0011]      FIG. 2  is a side sectional view of a coupler assembly in accordance with one embodiment of the present invention, showing the ball clamp in a retention position securing the hitch ball within the coupler socket. 
           [0012]      FIG. 3  is a bottom perspective view of the housing of the coupler assembly of  FIG. 2 . 
           [0013]      FIG. 4A  is a front top perspective view of the coupler assembly of  FIG. 2 , showing the sight hole with no hitch ball engaged in the coupler socket. 
           [0014]      FIG. 4B  is a front top perspective view of the coupler assembly of  FIG. 2 , showing the hitch ball properly engaged in the coupler socket and visible through the sight hole. 
       
    
    
     DESCRIPTION 
       [0015]    Reference will now be made in more detail to presently preferred embodiments of the invention, as illustrated in the accompanying drawings. While the invention is described more fully with reference to these examples and drawings, the invention in its broader aspects is not limited to the specific details, representative devices, and illustrative examples shown and described. Rather, the description which follows is to be understood as a broad, teaching disclosure directed to persons of ordinary skill in the appropriate arts, and not as limiting upon the invention. 
         [0016]    For purposes of explanation, and to further assist in the understanding of this invention, a brief description of the operation of a standard previously-known ball and socket coupler mechanism follows. Referring to  FIGS. 1A-B , a hitch ball  22  is commonly affixed to the rear end of a tow vehicle, such as a truck or sport utility vehicle, utilizing a standard mounting device that can support the tongue weight of the trailered vehicle. Similarly, a coupler  20  is affixed, by commonly known techniques, e.g. welding, bolting, etc., to the frame of the vehicle that is to be towed, e.g. a trailer, thus forming an integrated frame unit. The coupler  20  has a housing  34  with a ball-shaped socket  24  for receiving the hitch ball  22  when the trailer is hitched to the tow vehicle. In operation the trailer coupler socket  24  is lowered, from an elevated height, relative to the hitch ball  22 , onto the hitch ball  22  such that the socket  24  engulfs the hitch ball  22 . 
         [0017]    Still referring to  FIGS. 1A-B , the ball and socket coupler further includes a user rotatable handwheel  26 . The handwheel  26  is rotatably mounted upon a threaded member  29  such that rotation of the handwheel  26  draws or urges the threaded member  29  and a ball clamp  25  depending from the member  29  either toward or away from the hitch ball  22 . The ball clamp  25  has a curved surface that conforms to the curved surface of the hitch ball  22 . Upon rotation of the handwheel  26  in the appropriate direction (usually clockwise), the ball clamp  25  is drawn upward and toward the hitch ball  22 , thereby decreasing the effective opening dimension of the socket  24  until the ball clamp  25  contacts the hitch ball  22  and secures it within the coupler socket  24 . In this retention position, as shown in  FIG. 1A , the ball clamp  25  cooperates with the socket  24  to prevent removal of the hitch ball  22  from the socket  24 . Similarly, upon rotation of the handwheel  26  in the opposite direction (typically counterclockwise), the ball clamp  25  is moved downward and away from the hitch ball  22  to a release position, shown in  FIG. 1B , which allows the hitch ball  22  to be released from the socket  24 . 
         [0018]    As shown in  FIGS. 1A-B , a spring loaded retaining tab  30  is usually provided in ball and socket hitches in order to maintain the ball clamp  25  in the retention position. The tab  30  has a projection  31  that engages recesses  27  formed in the periphery of the handwheel  26 . The tab  30  exerts a biasing force against one of the wheel recesses  27  to maintain the tab  30  in engagement with the handwheel  26 . When engaged, the tab  30  prevents rotation of the handwheel  26 , rotation being permitted only when the projection  31  of tab  30  is pivoted away from the recess  27  in the handwheel periphery. 
         [0019]    During the rotation of the handwheel  26 , the retaining tab  30  is continually depressed by the operator. The depression of the tab  30  disengages the tab projection  31  from the recesses  27  formed in the periphery of the handwheel  26 . Upon positioning the handwheel  26  such that the coupler assembly  20  is in a coupled condition, the operator releases the tab  30  so that it engages one of the recesses  27  formed in the lower periphery of the handwheel  26 , thus securing the handwheel  26 . Minor additional rotation of the handwheel  26  may be required to properly align the tab  30  in one of the recesses  27 . Proper alignment of the tab  30  in one of the recesses  27  helps prevent the handwheel  26  from becoming inadvertently loosened by vibrations, or other unexpected forces. 
         [0020]    In the operation of the previously-known coupler illustrated in  FIG. 1 , the trailer/coupler assembly is first aligned over the hitch ball  22  with the ball clamp  25  in the release position. The trailer is then lowered so that the socket cavity  24  engulfs the hitch ball  22 , as shown in  FIG. 1B . After the hitch ball  22  is positioned in the socket cavity  24 , the handwheel  26  is then rotated to move the ball clamp  25  into the retention position shown in  FIG. 1A . In this position, the ball clamp  25  reduces the effective opening of the coupler socket  24  so that the hitch ball  22  can no longer be readily retracted from the coupler socket  24  and the coupler assembly  20  is securely coupled. 
         [0021]    As shown in  FIG. 1C , during installation of the hitch ball  22  into the coupler socket  24 , the hitch ball  22  can strike the ball clamp  25  from below and jam the ball clamp  25  upward into the coupler socket  24  and in an insecure relationship with the hitch ball  22 , which can result in unwanted separation of the hitch ball  22  from the coupler socket  24 . 
         [0022]    Having described the operational characteristics of a typical ball and socket coupler mechanism, the features of an improved coupler assembly according to the present invention will now be described. In accordance with the present invention, disposed within the coupler socket  24  is a sight hole  40 . The sight hole  40  gives the user simple and effective visual means by which full entry of the hitch ball  22  into the coupler socket  24  can be confirmed. 
         [0023]      FIGS. 2-4  depict a coupler assembly in accordance with a presently preferred embodiment of the invention. In one preferred embodiment, the sight hole  40  is located on the front upper portion of the coupler housing, as best shown in  FIGS. 4A and 4B . Upon reading this disclosure, it will be understood that the sight hole  40  can be located in the coupler housing in any suitable location for viewing the interior of the coupler socket  24 . This location also can be, for example, the top or the side of the coupler housing around the coupler socket. The sight hole  40  can be formed in the coupler housing by any suitable means, including drilling, punching or stamping. 
         [0024]    In the operation, the coupler  20  is first aligned over the hitch ball  22  which is attached to the vehicle. The trailer is then lowered so that the coupler comes into contact with the hitch ball  22 . If the hitch ball  22  enters fully into the coupler socket  24  such that the socket cavity  24  engulfs the hitch ball  22  therein (see  FIG. 2 ), the user will be able to observe this through the sight hole  40 , as shown in  FIG. 4B . If, on the other hand, the hitch ball  22  contacts the ball clamp  25  from below and the ball clamp  25  prevents the hitch ball  22  from fully entering the coupler socket  24  (see  FIG. 1C ), the user will be able to observe through the sight hole  40  that the hitch ball  22  is not properly positioned within the coupler socket  24 . 
         [0025]    After the user confirms via the sight hole  40  that the hitching ball  22  is properly positioned in the socket cavity  24 , the handwheel  26  is then rotated, as previously described, thereby drawing the ball clamp  25  upward and forward toward the hitch ball  22  until the ball clamp reaches the retention position shown in  FIG. 2 . In this position, the ball clamp  25  reduces the effective opening of the coupler socket  24  and contacts the hitch ball  22  so that it cannot be readily retracted from the coupler socket  24 . The operator then aligns the tab projection  31  in one of the recesses  27  and releases the tab  30  to secure the handwheel  26  as previously described. 
         [0026]    Upon reading this disclosure, those skilled in the art will appreciate that various changes and modifications may be made to the preferred embodiments of the invention and that such changes and modifications may be made without departing from the spirit of the invention. Therefore, the invention in its broader aspects is not limited to the specific details, representative devices, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general inventive concept.