BACKGROUND OF THE INVENTION

This invention relates in general to ball joints, such as are commonly used in vehicular steering and suspension applications to transmit force between a steering mechanism and a steered wheel of a vehicle. In particular, this invention is aimed at avoiding accidental separation of the ball joint assembly due to wear of both the ball and the socket. The design includes a retainer/ safety nut for preventing accidental separation of the components of the ball joint as a result of such wear.

Ball joints are well known structures that are used in a variety of mechanical linkages. For example, ball joints are commonly used in vehicular steering and suspension assemblies to allow front wheels to turn sideways and also to transmit force between a steering mechanism and a steered wheel of a vehicle. A typical ball joint includes a ball stud that is received within a lubricated socket. The ball stud includes a spherically- shaped head portion having an elongated shaft portion extending therefrom. The spherically- shaped head portion of the ball stud is received within and cooperates with a corresponding spherically- shaped recess formed in the socket. This arrangement positively connects the ball stud to the socket so as to permit some forces to be transmitted therethrough. This arrangement also allows the ball stud to pivot in any direction relative to the socket.

It has been found that after a period of use, the cooperating portions of the ball stud and the socket of the ball joint will experience wear. Such wear can create undesirable looseness between the ball stud and the socket of the ball joint, resulting in the generation of noise and misalignment between the ball stud and the socket. In extreme cases, such wear can contribute to or cause the accidental separation of the ball stud from the socket, resulting in a total failure of the ball joint. Accidental separation of the ball stud from the socket is common in areas with bumpy roads. Unfortunately, because the spherically- shaped head portion of the ball stud is received within the corresponding spherically-shaped recess formed in the socket, it is often difficult to determine how much wear has occurred within the ball joint without removing the ball joint from its application and disassembling the ball stud and the socket for inspection. Such removal and disassembly is time consuming and expensive. In extreme cases, wear of the ball stud from the socket can lead to motor vehicle accidents that are caused by the accidental separation of the ball joints or tie rod ends. Thus, it would be desirable to provide a device that prevents accidental separation of the ball joint as a result of such wear.

Description

SUMMARY OF THE INVENTION

This invention relates to a retainer/ safety nut that prevents the separation of the ball stud from the socket as a result of wear of the ball stud or socket. The improved ball joint design includes a shaft on the other side of the ball stud. The shaft has threads for fitting of a retainer/ safety nut. The retainer/ safety nut ensures that the ball does not leave the socket. The retainer nut is bell-shaped so as to allow for sideways movement of the shaft. The retainer/safety nut and the whole ball joint assembly are protected from dust and natural elements by rubber boots. Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, when read in light of the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a ball joint with a retainer/ safety nut in accordance with this invention. FIG. 2 is a perspective view of the ball with shafts on either side showing preferred embodiments.

FIG. 3 is a perspective view of a ball joint with a retainer/ safety nut and coil spring in accordance with this invention.

FIG. 4 is a perspective view of the tie rod assembly with a retainer/ safety nut in accordance with this design.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (refer to Fig 2)

• The invention relates to ball joint assembly having a ball (1) with studs/shafts on both sides of the ball (2 &3). The main stud/shaft ( 2 ) is the same as the as the stud found in conventional ball joints. The auxiliary stud (3) is shorter than the main stud and is for holding the retainer/safety nut that prevents accidental separation.

• Both shafts have holes for cotter/safety pins (4&5). The main shaft ( 2 ) holds the castle nut as in conventional ball joints.

• The retainer nut (6) is bell shaped so as to allow the ball and studs to move in all directions.

• The ball (1) and socket (7) function as a typical ball and socket.

• A polymer bearing (8) is injected into the socket. Press fitting of the ball joint assembly or

screwing-in of the socket cap ensures that the polymer bearing is tightly packed. The polymer bearing absorbs impact thereby protecting the ball and socket. When the polymer bearing is worn, some up and down movement in the ball will result. This movement is a sign of wear and can be felt by shaking the wheel up and down.

• The end of the socket with the retainer nut can either be closed by way of pressing a cap or by way of a screw-in cap that can be adjusted inwards as the ball wears (see Fig 3&4).

• The ball and socket are protected on both sides by rubber boots (9 & 10). The boots are held firmly in place by rings as in conventional ball joints.

• As the ball wears, the ball moves in the direction of the main shaft bringing the retainer nut gets into contact with the socket, thereby preventing accidental separation of the ball and socket.

• Grease is placed inside the rubber boots to facilitate lubrication. The ball has some grooves that facilitate movement of grease from the rubber boots (Fig 2).

• The present invention may be used as a substitute for a conventional ball joint or may be installed in new vehicles.

A coil spring can be added to this design to reduce impact which may result from wear of the ball and socket.