Patent CA-2258986-A1 (CA)
Title: Slackless drawbar
Inventor: DAIGLE MARIO
IPC: B60D1/52
Filed: 1999-01-28
Abstract: Field of the invention The present invention is concerned with trailer hitches and towing. More particularly, it concerns a slackless drawbar for use with a vehicle hitch of the type comprising a receiver tube for receiving an end portion of the drawbar.        Prior art Already known in prior art, there is the drawbar connector for interconnecting a vehicle hitch to a trailer hitch, comprising an enlarged end portion adapted to be positioned in a receiver tube formed in the vehicle hitch and a forwardly extending plate adapted to mount a trailer hitch ball associated with the trailer hitch. Traditionally, the enlarged end portion is fixed into the receiver tube by means of a transversal bolt. In order to ease the engagement of the drawbar into the receiver tube, the transversal cross section of the enlarged end portion of the drawbar is slightly smaller in size than the transversal cross section of the receiver tube, thereby forming a small gap or looseness between these two elements. That looseness causes a lot of vibrations or movements between the receiver tube and the drawbar as the vehicle is put in motion. This also causes the joint to be very noisy and furthermore, it may cause rapid braking of the drawbar by fatigue failure.       Description of the invention It is therefore an object of the present invention to provide a slackless drawbar which will overcome the above-mentioned drawbacks.   In accordance with the present invention, and referring to figures 1 and 2, this object is achieved with a slackless drawbar for interconnecting a vehicle hitch to a trailer hitch. The drawbar comprises a trailer ball mounting (12) having a forward end plate (14) provided with a ball mounting hole (16) adapted to receive a trailer hitch ball (18) associated with the trailer hitch, and an enlarged end portion (20) for engagement into a receiver tube (21) of the vehicle hitch. The drawbar (10) is characterised in that the enlarged end portion (20) is hollowed and comprises two pieces, a trailer piece (22) and a hitch piece (30). The trailer piece (22) has a first end (24) fixed to a transversal wall (26) of the trailer ball mounting (12) and a second free bevelled end (28). The hitch piece (30) has a first end (32) adapted for engagement into the receiver tube (21) of the vehicle hitch and a second bevelled end (33) matching with the bevelled end (28) of the trailer piece (22). A screw receiving plate (34) is transversally mounted in the hitch piece (22).    The hitch piece (30) and the trailer piece (22) are connectable together by longitudinally inserting an adjusting bolt (36) through the first end (22) of the trailer piece (22) and then into the screw receiving plate (34) of the hitch piece (30).       As can be appreciated and as best seen in figure 1, by adjusting said bolt (36), the hitch piece (30) is brought closer to the trailer piece (22) and thanks to the bevelled ends of the two pieces, the hitch part (30) rises or lowers down with respect to the trailer piece (22), depending on the direction of the bevelled cut, and thereby increases the height of the enlarged end portion (20) from h1 to h2 at the joint formed by the trailer piece (22) and the hitch piece (30).   As can also be appreciated, in use, the hitch piece (30) of the drawbar (30) is engaged into the receiver tube (22) and fixed therein by means of a transversal screw (38). Then the trailer piece (22) is connected to the hitch piece (30) by means of the adjusting bolt (36), which causes an increase in the height of the enlarged end portion (20), thereby eliminating the slack between the receiver tube (22) and the enlarged end portion (20) and the vibrations of the assembly as the vehicle is put in motion.        Although a preferred embodiment of the invention has been described in detain herein and illustrated in the accompanying drawings, it is to be understood that the invention is not limited to this precise embodiment and that various changes and modifications may be effected therein without departing from the scope or spirit of the invention.