INTEGRATED INSERT TYPE POLYURETHANE BOOT SEAL FOR MAINTENANCE-FREE BALL JOINTS

FIELD OF INVENTION

The present invention relates to a boot seal for vehicle steering ball joint. Specifically, the present invention relates to a "press-on" type polyurethane boot seal for enhanced sealing of vehicular steering ball joint to increase durability. More specifically, the present invention relates to a polyurethane boot seal, which is introduced with an integrated insert to avoid external damage and dislocation of boot seal during assembly process and intended service period. Further, the present invention aids in the ease of manufacturability and assembly process of the vehicle by reduction of parts.

DESCRIPTION OF BACKGROUND ART

The steering mechanism in automobiles is provided with steering ball joints, which enables to steer road wheels based on the rotational motion given by vehicle driver to steering wheel. One of the most important requirements of the ball joint, especially those used in automotive steering links is to sustain ball joint for a long service life and intended period, one of the primary requirement being to have good sealing which is achieved by a boot seal.

Sealing function in serviceable type ball joint was earlier achieved by various advancements such as open boot seal made of nitrile material or open boot seal made of neoprene material.

Further, global improvements transformed from serviceable type to maintenance-free ball joint to improve the durability. Sealing function in maintenance-free vehicle ball joint was achieved by various advancements such as clip-on type with neoprene material, clip-on type with polyurethane material or external u-ring type with polyurethane material.

The maintenance-free ball joint assembly having sealing with u-ring type with polyurethane material has following limitations:

• Higher parts count
• Separate surface protection for metallic components
• Low productivity / process complexity
• Process rejections
• Dislocation of boot seal during intended service period.

Some of the approaches for improvement in sealing of a vehicle steering ball joint known in the art are as follows:

US5092704 disclosed an invention for the corrosion protection of a ball joint in the motor vehicles by means of sealing cuff arrangement mounted on a boot seal with external spring rings.

CN201487218 relates to an invention for improved service life of automobile steering ball joint by means of dustproof device constructed as a locking seat on the side of socket housing and a retaining ring on the side of ball pin rod.

CN201553198 disclosed a heat-proof dust cover in an automobile steering system located between steering connector and a steering knuckle. Heat-proofing is achieved by means of an additional protective layer arranged at the periphery of the dust cover.

GB1043778 provide a sealing to a ball joint in the steering linkages of motor vehicles by means of an external annular shaped pre-stressed plug of elastic material such as polyurethane, polyamide or poly tetra fluoro ethylene.

GB1154168 relates to an improvement in ball and socket joints where sealing is improved by external constructive means of polyurethane sleeve introduced in contact with ball head neck which keeps the sealing boot in position during operation.

Therefore, there exists a need for improving the sealing on maintenance free ball joint performance, i.e. the construction is to be modified accordingly, which enhances the characteristics of ball joint like:

1. Enhanced sealing
2. Increased durability
3. Increased productivity
4. Reduction in parts
5. Reduction in process cost.

OBJECTS OF INVENTION

One or more of the problems of the conventional prior art may be overcome by various embodiments of the system and method of the present invention.

Accordingly the primary object of the present invention is to improve sealing and service life in a vehicular steering ball joint by introduction of an integrated insert type boot seal.

It is another object of the present invention, wherein the integrated insert type boot seal is of polyurethane material.

It is yet another object of present invention, wherein metal insert/inserts are integrated with boot seal to form a single piece member.

It is another object of the present invention, wherein the integrated insert type polyurethane boot seal provides longer service life of vehicular steering ball joint.

It is another object of present invention wherein the integrated insert type polyurethane boot seal helps to avoid additional surface protection process.

A further object of the present invention is to aid manufacturability and assembly process.

SUMMARY OF INVENTION

Thus according to the basic aspect of the present invention there is provided a vehicle steering ball joint with enhanced sealing and increased durability comprising integrated insert type polyurethane boot seal.

It is another aspect of the present invention, wherein the ball joint comprising: socket housing with or without grease nipple provision; atleast one ball pin with a spherical head disposed in the socket housing; atleast one bearing cup disposed there between the ball pin with the spherical head and the socket housing; atleast one spring element positioned between the bearing cup and an end plate; and

press-on type polyurethane boot seal comprising one or more metal inserts required for mounting the boot seal onto the socket housing.

It is yet another aspect of the present invention, wherein the metal inserts are integrated with the polyurethane boot seal to form a single piece member.

It is further aspect of the present invention, wherein the press-on type boot seal with integrated metal inserts is mounted on the vehicle steering ball joint by the provision of top metal insert and bottom metal insert which encapsulate the ball pin spherical head.

It is another aspect of the present invention, wherein the boot seal is manufactured by insert type molding through injection molding process.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1: Illustrates a conventional ball and socket joint.

Figure 2: Illustrates a ball and socket joint according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING

DRAWINGS

As disclosed above, the present invention relates to an integrated insert type polyurethane boot seal for vehicular steering ball joint to improve the superior sealing and thus service life.

Reference is now invited to accompanying Figure 1 which illustrates conventional ball and socket joint for a vehicle steering system of an automobile comprising of socket housing (1) connected to a steering linkage (not shown), a ball pin (2) with a spherical head (3) is encapsulated in bearing cup (5) and the socket housing (1) and a spring element (6) is placed between the bearing cup (5) and end plate (4). All internal components are placed and crimp closed (8) at a load based on functional requirements to arrest the ball joint from disassociation during vehicle operation. A boot seal (7) is mounted on the vehicle steering ball joint by provision of retaining ring (9) and u-ring (10) which encapsulates ball pin head and prevents entry of contaminants.

Reference is now invited to accompanying Figure 2 which illustrates vehicular steering ball joint according to the present invention comprising of socket housing (1) with or without grease nipple provision connected to a steering linkage (not shown), a ball pin (2) with a spherical head (3) encapsulated in a bearing cup (5) and the socket housing (1) and a spring element (6) placed between the bearing cup (5) and an end plate (4). The end plate (4) is with or without grease nipple provision. All internal components are placed and crimp closed (8) at a load based on functional requirements to arrest the ball joint from disassociation during vehicle operation. A press-on type boot seal (12) of polyurethane material is mounted on the vehicle steering ball joint by the provision of top metal insert (13) and bottom metal insert (14) which encapsulate ball pin head and prevent entry of contaminants. The metal insert/inserts (13, 14) are integrated with the boot seal and hence the boot seal comprises of a single piece member. The integrated press-on type boot seal is manufactured by insert type molding through injection molding process thereby replacing external u-ring or external clips for retention of boot seal on vehicle steering ball joint. Further, the boot seal entity does not require surface treatment protection.

Thus the vehicular steering ball joint according to the present invention improves the sealing and service life. The construction is modified accordingly thereby enhancing the characteristics of ball joint like enhanced sealing, increased durability, increased productivity, reduction in parts and reduction in process cost.

WE CLAIM:

1. A vehicle steering ball joint with enhanced sealing and increased durability comprising integrated insert type polyurethane boot seal.

2. The ball joint as claimed in claim 1 comprising:

socket housing (1) with or without grease nipple provision;

atleast one ball pin (2) with a spherical head (3) disposed in the socket housing (1);

atleast one bearing cup (5) disposed there between the ball pin (2) with the spherical head (3) and the socket housing (1);

atleast one spring element (6) positioned between the bearing cup (5) and an end plate (4); and

press-on type polyurethane boot seal (12) comprising one or more integrated metal inserts (13, 14) required for mounting the boot seal (12) onto the socket housing (1).

3. The ball joint as claimed in claim 2, wherein the metal inserts (13, 14) are integrated with the polyurethane boot seal (12) to form a single piece member.

4. The ball joint as claimed in claim 3, wherein the press-on type boot seal (12) with integrated metal inserts is mounted on the vehicle steering ball joint by the provision of top metal insert (13) and bottom metal insert (14) which encapsulate the ball pin spherical head (3).

5. The ball joint as claimed in claim 4, wherein the boot seal (12) is manufactured by insert type molding through injection molding process.