Steering column boot

Abstract

A resilient boot assembly (10) of the type for containing a steering shaft (22) therein includes a tubular body portion (12) having a passageway (14) extending therethrough and first and second end portions (16,18). One end of the boot is adapted to attach to a steering gear housing (20). The assembly (10) is a unitary tubular member and includes at least one end having a resilient portion (24) and stiffened portions (26,28) at each end of the resilient portion for providing the flexible resilient portion (24) to roll up upon the body portion (12) to a retracted position to expose the connection between the steering shaft (22) and steering gear assembly and rolling down to an extended position to contain and perfect a seal with the steering gear housing (20).

Description

This application is a continuation-in-part of Ser. No. 095,570, filed Sept. 11, 1987, now abandoned.

TECHNICAL FIELD

The present invention relates to a resilient boot assembly of the type for containing a steering column therein, a method of manufacturing and assembling such a boot assembly, and to a vehicle including the resilient boot assembly. More particularly, the invention relates to a boot assembly for containing a portion of a steering column extending through a fire wall in a vehicle body and a portion of the steering column connected to the steering gear assembly.

BACKGROUND ART

In order to prevent corrosion and damage to a steering column caused by corrosive materials found on the road, such as dirt, stones, and salt, it is common for a resilient boot to be disposed over the steering column which extends through a fire wall in a vehicle. 50 60 to 70 75 durometer on the B D scale.

As shown in FIG. 2, a foam gasket generally indicated at 32 is integrally formed with the body portion 12. The gasket can be made from a restricted cell urethane. The gasket provides means for connecting the body portion 12 of the boot assembly 10 to a fire wall 34 by means of bolts 36.

The present invention provides a one piece boot assembly which eliminates or alleviates problems of alignment and leakage. Since the boot is a unitary structure, there is no longer the problem of leakage from between two part boot assemblies. The ability of the boot to be folded in upon itself and the flexibility of the end portion 16 assists in alignment of the boot and fitting of the boot to a particular steering column construction. Manufacturing efficiency is increased because what was formally two parts is now a single part.

During assembly, the boot assembly 10 is fixedly connected in the retracted position as shown in FIG. 3 and in solid lines in FIG. 5 to the fire wall 34 by the bolts fasteners 36 connecting the gaskets 32 to the fire wall 34. The steering shaft 22 is then disposed through the passageway 14 of the boot 12 and positioned to connect a connecting portion of the steering shaft 22 to the connecting portion of the steering gear assembly within the housing 20. The end portion 16,16' is then moved to the retracted position as shown in FIG. 3 and in solid lines in FIG. 5 to expose the connecting portions of the steering shaft 22 and the steering gear assembly. Upon operative connection of the steering shaft 22 to the steering gear assembly, the end portion 16,16' is rolled down to the extended position shown in FIG. 4 and in hatched lines in FIG. 5. The end portion 16 is then connected to the steering gear housing 20 to perfect a seal therewith. Thusly, the vehicle includes a steering column and gear connection totally contained within the boot assembly 10 and protected against environmental corrosion.

The present invention further provides a method of manufacturing the boot assembly 10. The method generally includes the steps of molding the unitary resilient boot 10 including the tubular body portion 12, and end portion 16 including two stiffened portions 26,28 and a more resilient portion 24 therebetween on tool, and removing the molded boot 10 from the tool. More specifically, and as shown in the flow diagram in FIG. 1, the stiffening portions of the boot assembly 10 are placed on a mold ring of a tool. The stiffened portions can be either the stiffening wires 33, the flange stamping and/or other harder plastic materials of the boot, or further stiffening wires 37,37' which stiffen other portions of the boot assembly 10. Alternatively, a partially cured harder plastic material which cures at a higher temperature to high durometer in the molding process can also be disposed on the tool. The tool is then preheated to between 275° and 350° F. The tool is dipped in a pot tank of soft plastic material for a period of time. The heated tool partially cures and adheres the adjacent soft plastisol to the tool during the dipping process. The exposure time of the tool within the pot tank is dependent upon the amount of material and end thickness of the boot desired. The longer the tool is dipped in the pottank, the thicker the material will be disposed on the tool. The tool is then removed from the pot tank and placed in a heat source to cure out all of the plastics, at a temperature of approximately 275° F. This temperature finally cures the soft plastisol, as well as the harder plastisol areas. The tool is then removed from the heat source and cooled down to handling temperature. The boot is then trimmed of material where plastic is not required. The boot is stripped from the tool and cooled down to ambient temperature if needed. The end portion of the boot is then rolled up to reduce its length for shipping and handling.

Alternatively, both ends 16,18 can be manufactured to roll up, depending upon the desired use of the boot assembly 10,10' in assembly.

The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims wherein reference numerals are merely for convenience and are not to be in any way limiting, the invention may be practiced otherwise than as specifically described.

Claims

1. A resilient boot assembly (10) of the type for containing a steering shaft (22) therein, said assembly (10) comprising; a tubular body portion (12) including a passageway (14) extending therethrough and first and second end portions (16,18), and attachment means for attaching at least one of said end portion (16) of said body portion (12) to a support structure (20), characterized by a said assembly (10) being a unitary tubular member and including roll-up means for rolling up and maintaining at least one of said end portions (16) upon said body portion (12) from an extended position defining a first axial length of said assembly (10) to a retracted seated position defining a second shorter axial length of said assembly (10) and rolling down said one end portion (16) to said extended position.

2. An assembly as set forth in claim 1 further characterized by said rolling up means including an annular flexible portion (24) adjacent one of said end portions (16) and a stiffened portion (26,28) adjacent each end of said flexible portion (24), one of either of said flexible portions (24) and said body portion (12) having a predetermined outer diameter and the other of said flexible portion (24) and body portion (12) having a predetermined inner diameter greater than said predetermined outer diameter.

3. An assembly as set forth in claim 2 further characterized by said body portion (12) having a predetermined wall thickness, said flexible portion (24) having a predetermined thickness which is less than said wall thickness of said body portion.

4. An assembly as set forth in claim 2 further characterized by said body portion (12) comprising a plastisol plastic material having a predetermined hardness, said flexible portion (24) comprising a plastisol plastic material having a predetermined hardness which is less than said predetermined hardness of said plastisol plastic material of said body portion (12).

5. An assembly as set forth in claim 2 further characterized by said stiffened portions including at least one annular metallic ring member embedded in said tubular member (12) on each side of and adjacent to said flexible portions (24).

6. An assembly as set forth in claim 2 further characterized by said stiffened portions (26,28) including at least one annular bead (35,37) on each side of and adjacent to said flexible portion (24).

7. An assembly as set forth in claim 2 further characterized by said inner diameter of said body portion (12) being greater than said outer diameter of said flexible portion (24) so that said flexible portion (24) telescopes into said body portion (12).

8. An assembly as set forth in claim 2 further characterized by said inner diameter of said flexible portion (24') being greater than said outer diameter of said body portion (12') so that said flexible portion (24') telescopes over said body portion (12').