Field of the Invention

The present invention relates to the field of towing equipment. More particularly, the invention is designed to prevent decoupling of a trailer coupler from the hitch ball of the towing vehicle.

Background of the Invention

Towing equipment includes devices and accessories fitted on a towing vehicle and on a trailer such as a camper, caravan, flatbed trailer, and utility trailer that assist in attaching the trailer to the towing vehicle. Towing equipment includes fifth wheels, hitches, gooseneck hitches, and wiring harnesses for drawbars, weight distribution systems, crossbars, tow sling, tow dollies, ball mounts, towbars, and other towing accessories such as chains, straps, hitch locks, hitch covers, hitch aligners, hitch adapters, fifth- wheel hitch adapters, and anti-rattles.

Fig. 1 (below) schematically illustrates a conventional arrangement for coupling a towing vehicle 109 and a trailer 106. A coupler 104 connected to trailer 106 is adapted to be coupled to a hitch ball affixed to towing vehicle 109 by means of hitch 108. Coupler 104 is generally configured with a socket 102 having a downwardly opening ball receiving cavity and with a locking mechanism 107 for coupling to the hitch ball so that the coupler will remain in place while the trailer is being towed. While the socket 102 clamps down on the hitch ball, vertical movement of the socket is inhibited but swinging or rotating movement in a substantially horizontal direction is not. The trailer 106 is accordingly able to move along a turn and to absorb some of the shocks that are prevalent during a towing operation. An electrical harness 113 is used to provide electricity to the back lights of trailer 106. Safety chains 111 connecting the trailer 106 and towing vehicle 109 are often used as a security measure in case a coupler decouples from a hitch ball. However, users often neglect to correctly apply the safety chains 111, resulting in trailer separation and severe road accidents.

A coupler is also liable to be decoupled from a hitch ball, potentially resulting in hazardous conditions, due to wear of the hitch ball or the socket resulting from high friction between the hitch ball and the socket surfaces during the relative pivotal motion, the wear being exacerbated during infiltration of sand or mud to the socket surfaces.

Fig. 2 below shows a typical coupling mechanism in use today (note that there are also other mechanisms in use). The surfaces that are prone to excessive wear and tear are marked by red circles.

Another cause of potential decoupling of a coupler from the hitch ball is shown is Fig. 3 below. This figure shows a rotatable tri-ball mount on the left. Each of the balls is of different size (large, medium and small). The three couplers on the right are of three sizes as well (large, medium and small). These 3 sizes are standard and in common use in the USA. The user should make sure that he/she always uses a coupler that matches the size of the ball. For example, put a large coupler on a large ball. However, a user may - by mistake - put a large coupler on a small ball. This may lead (and already did lead) to coupler separation and road accident.

Indeed, the Fatality Analysis Reporting System (FARS) revealed 736 fatalities during the years 1975-2015 that have been caused in the United States by hitch ball related failures.

BRIEF SUMMARY

According to an aspect of the present invention a hitch ball decoupling prevention device, comprising of: a pivot mount connected to the underjaw in a permanent manner; a fork member that hangs from the pivot mount by means of the pivot; and a pivot that connects the pivot mount with the fork member in a way that allows the fork member to rotate to a limited degree around the pivot.

It is further within provision of the invention to be wherein the pivot mount moves with the underjaw; when the underjaw is moved to the locked position the pivot mount moves with it and causes the fork member to also move to the locked position; and when the underjaw is moved to the unlocked position the pivot mount moves with it and causes the fork member to also move to the unlocked position It is further within provision of the invention to be wherein the axis of the rotation of the fork member about the pivot is aligned with the geometrical center of the hitch ball.

It is further within provision of the invention to be wherein the forward part of the fork member comprises of two prongs; when the decoupling prevention device is in the locked position, these two prongs touch the lower part of the hitch ball and prevent it from moving down and separating from the coupler; and when the decoupling prevention device is in the unlocked position, the two prongs are moved downward and allow the coupler to be separated from the hitch ball.

It is further within provision of the invention to be wherein the fork member can rotate to a limited degree about the pivot which allows the fork member to be always aligned with the hitch ball even when the coupler performs a rolling motion to the right or to the left while keeping the two prongs always in their position on the lower part of the hitch ball where they prevent the hitch ball from moving downward and separating from the coupler.

It is further within provision of the invention to be wherein the coupler will be modified to include two secondary sockets protruding upwardly from the front plate of the coupler body and also protrude laterally and discontinuously from the ball receiving socket while these secondary sockets are used to receive the corresponding prongs of the fork member when the fork member is in the locked position.

It is further within provision of the invention to be wherein an opening is provided in the upper part of the coupler body to allow the underjaw the range of motion required to move the device to the unlocked position.

It is further within provision of the invention to be wherein an opening is provided in the fork member to allow access to the nut that controls the level of friction between the hitch ball and the underjaw. BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be implemented in practice, a plurality of embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

FIG. 1 illustrates typical arrangement of towing equipment;

FIG. 2 illustrates typical coupling mechanism in use today;

FIG. 3 illustrates three standard ball sizes in use in the USA;

FIG. 4 illustrates elements of the invention in the“locked” position;

FIG. 5 illustrates prevention of separation of the coupler from the hitch ball;

FIG. 6 illustrates two secondary sockets - front view;

FIG. 7 illustrates two secondary sockets - side view;

FIG. 8 illustrates two secondary sockets - side view;

FIG. 9 illustrates rear view;

FIG. 10 illustrates operation when coupler is tilted up;

FIG. 11 illustrates pivot axis;

FIG. 12 illustrates unlocked position; FIG. 13 illustrates an opening in the coupler body; and

FIG. 14 illustrates an opening in the fork member.

Detailed Description of the Invention

It is an object of the present invention to provide a device that prevents decoupling of a coupler from a hitch ball even if the hitch ball or socket is severely worn or its size was incorrectly selected. Other objects and advantages of the invention will become apparent as the description proceeds.

The directional terms included herein, such as "forward", "rear", "upper" and "lower", refer to driving conditions whereby the forwardly positioned towing vehicle and the trailer located behind the towing vehicle are advancing along level terrain. The scope of the invention, however, also includes other dispositions and relative positions as well.

The invention is built of three elements that are added to the coupler, as shown in figure 4 below:

1. A pivot mount 202 (in red color). The pivot mount 202 is connected to the underjaw 204 (in green color) in a permanent manner (e.g. by welding or any other suitable manner). When the underjaw is moved to the locked position (as is shown in figure 4) the pivot mount moves with it and causes the fork member 201 to also move to the locked position as is shown in figure 4.

2. A fork member 201 (in yellow color) that hangs from the pivot mount by means of the pivot 203.

3. A pivot 203 that connects the pivot mount 202 with the fork member 201 in a way that allows the fork member to rotate to a limited degree around the pivot 203. The axis of the rotation (the pivot 203) is aligned with the geometrical center of the hitch ball 205 (in blue). This axis of rotation is shown in figure 11 below.

Figure 5 below shows how the fork member 201 - when in the locked position shown in figure 5 - holds hitch ball 205 and prevents it from separating from the coupler. Fork member 201, in its forward part, consists of two prongs 207. These prongs touch the lower part of the hitch ball and prevent it from moving down relative to the coupler and separating from the coupler. This prevention is achieved even if the coupler or the underjaw are badly worn, or even if a large coupler is put on a smaller ball, since the distance between the prongs is smaller than the diameter of the ball.

Figure 6 below shows the prongs 207 and the hitch ball 205 from the front side of the coupler. This figure shows how the two prongs touch the lower part of the hitch ball and prevent it from any downward movement that may separate it from the coupler.

In addition, as shown in figure 7 below, the coupler will be modified to include two secondary sockets 210 protruding upwardly from a front plate 211 of the coupler body and also protrude laterally and discontinuously from ball receiving socket 212. These secondary sockets 210 are used to receive the corresponding prongs 207 of the fork member when the fork member is in the locked position.

Figure 8 below shows the same elements from a side view:

Figure 9 below provides a rear view of the coupler and the decoupling prevention device. It shows how the fork member 201 rotates about the pivot 203. This rotation allows the fork member 201 to always stay aligned with the hitch ball, even when the coupler body and the underjaw 204 are rolled right or left. This allows the prongs 207 to keep in touch with the lower part of the hitch ball 205.

Figure 10 below shows how the decoupling prevention device operates also when the coupler is tilted up or down. Fork member 201 is attached to the underjaw 204 (by means of the pivot 203 and pivot mount 202). This allows prongs 207 to always touch the bottom part of the hitch ball 205 and prevent it from separating from the coupler.

It is important to emphasize that the pivot 203 is on the same axis (shown in red) as the center of hitch ball 205, as shown in figure 11 below.

Figure 12 below shows how the decoupling prevention device is moved to the unlocked position. Safety lever 220 is pulled and this allows latch 221 to be moved up. This movement of the latch 221 pushes on rod 222 and allows spring 223 to push on the underjaw 204 to the unlocked position. All these operations are part of the normal operation of the coupler before the invention is added.

The downward movement of the underjaw 204 moves with it the fork member 201 and the associated prongs 207. The prongs 207 are thus moved away from the hitch ball 205 and allow to raise the coupler above hitch ball 205 thereby releasing the coupler from the hitch ball.

Moving the coupler and the decoupling prevention device from the unlock position to the locked position is done by doing the above activities in the reverse order, resulting in the locked position described in figure 4.

To allow the underjaw 204 the range of motion required to move the device to the unlocked position, it may be necessary to make an opening 224 in the upper part of the coupler, as shown in figure 13 below.

An opening 225 is also provided in the fork member 204. This opening is required to allow tightening or loosening of nut 226 that determines the level of friction between the underjaw 204 and the hitch ball 205. Nut 226 is part of the existing underjaw mechanism. Figure 14 below illustrates the opening in the fork member.