MXPA99008830A - Closed cells foam insert for a pivot / arm adjustment assembly - Google Patents

Abstract

The present invention relates to a steering mechanism comprising: an axle bar having an almost vertical aligned bore, a central pivot extending longitudinally through the bore and having upper and lower portions extending from the axle bar a label having upper and lower yoke portions each with a rotationally aligned hole disposed about a corresponding hole in the upper and lower extending portions of the central pivot whereby a rotary connection is established between the ball and the bar of the shaft, closing means for closing each of the aligned holes of the yoke portions of the ball and retaining the central pivot, and at least one longitudinal insert disposed between the central pivot and one of the closing means for practically occupying a space between them, this insert engages with an internal surface of the closing means and a long end tudinal central pivot, the insert is compressed under a preload which adapts to expand and also compress to continuously reduce pressure fluctuations caused by the axial movement of the central pivot in relation to the rotu

Description

CLOSED CELLS FOAM INSERT FOR PIVOT ASSEMBLY / STEERING ARM DESCRIPTION OF THE INVENTION 1. Field of the Invention This invention relates to a pivot / ball arm assembly for a steering mechanism and is particularly directed to a closed-cell foam insert positioned between the pivot and steering arm. 2. Description of the Prior Art Numerous assemblies of the former pivot ball joints exist in the prior art US 5,213,352 to Chalin discloses a pivot shaft assembly comprising a shaft, a steering arm, a pivot pivotally connected to the shaft and steering arm in a top cover with a grease fitting that holds the pivot inside the steering arm. A thrust pressure is placed between the pivot and the steering arm to reduce friction and wear. Each of the patents of the United States The steering pivot arrangements of the prior art suffer from the disadvantage that the pivot has a certain degree of axial displacement. Said displacement in relation to the steering arm causes a change in the volume, in the volume of air / grease between the pivot and the pivot cover or the bottom of the end of the ball joint. These volume changes create negative and positive pressure fluctuations that act as a pumping mechanism to expel grease and ingest water or other contaminants from the sealing interface of the pivot to the ball joint. The object of the present invention, therefore, is to overcome the disadvantages of the prior art and to avoid pressure fluctuations in the empty space between the pivot and the pivot cover and / or the lower recessed portion of the end of the ball joint. . BRIEF DESCRIPTION OF THE INVENTION The present invention is directed to a closed cell foam insert provided between the pivot and the pivot cover or the lower recessed portion of the end of the ball joint. A pivot is connected between a steering axle of a vehicle and a steering arm. The pivot pins are pivotally connected to either end of an axle bar and pivotally connected to the steering knuckles, which in turn are connected to the rims. Each pivot is rotatably mounted within a cylindrical bore in the steering knuckle and is retained therein by a pivot cover disposed adjacent at least at one end. A closed cell foam insert is provided between the pivot and the pivot cover to occupy the space therebetween. The insert preferably is axially compressed so that it can further compress or extend to substantially or supplementally occupy the volume between the pivot and the pivot cover or the lower surface and the orifice at the end of the ball joint. An attachment for grease can be formed in the pivot cover and a grease passage formed between the insert and the pivot cover to facilitate lubrication.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a partial sectional view of the steering ball pivot arrangement according to the present invention.

Figure 2 is a cross-sectional view of the closed cell insert according to the present invention. Figure 3 is a partial cross-sectional view of a steering knuckle pivot arrangement of an alternative embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Figure 1 represents a partial cross-sectional view of an assembly of a front axle for a vehicle. A rigid shaft 1 has a substantially cylindrical hole 2 having a substantially vertical axis 5. The alignment of the cylindrical hole 2 may be slightly angled to provide a curvature. A substantially cylindrical pivot 3 is provided within the bore 2. A steering knuckle 4 is mounted to perform a pivotal movement about the pivot axis 5. The steering knuckle 4 comprises a main shaft of outwardly extending wheels (not shown). ) on which a rim attached to the floor (not shown) is mounted rotatably. The steering ball 4 comprises upper and lower yokes arms 4a4b each has cylindrical holes 6a, 6b for receiving the end portions extending from the pivot 3. A steering end is connected to the ball joint in a conventional manner to facilitate steering. The upper ends of the pivot 3 extend into each hole 6a, 6b or ball joint 4 and are rotatably fitted within a sleeve 7 to facilitate easy relative rotation between the steering arm 4 and the shaft rod 1. Flexible annular seals 8 they are mounted inside the hole 6a. A first seal is mounted around the pivot between the pivot and the hole of the ball joint. A secseal is mounted between the bore of the ball and a pivot cover 9. These seals prevent the ingress of dust and moisture as well as the grease outlet to protect the contact surfaces between the pivot 3, the hole 6a, 6b of the ball joint 4 and the sleeve 7. At the upper end of the hole 6a, a pivot cover 9 tightly closes the hole by threadably coupling the ball joint 4. A seal 8 has provided between the pivot cover 9 and the hole of the ball joint to form a tight seal between them. An attachment for grease 11 is formed in the pivot cover 9 to allow the lubricant to be introduced between the pivot cover and the pivot to lubricate the contact surfaces between the pivot 3, the ball joint 4 and the sleeve 7. An insert of Closed cell foam 10 is provided between the pivot 3 and the pivot cover 9 to substantially fill the space therebetween. The insert 10 is preferably slightly compressed to allow expansion and compression as the pivot 3 moves axially. The insert 10 serves to eliminate a change in the volume of air / grease as the pivot 3 moves axially relative to the patella. Such an arrangement avoids positive / negative prevention fluctuations, which would otherwise act as a pumping mechanism to expel fat and ingest water and other contaminants from around the sealing interface of the pivot to the ball joint. The insert 10 is preferably made in the form of a disc to substantially fill the space between the pivot 3 and the pivot cover 9. A notch 13 can be formed in the insert 10 to reduce or eliminate contact of the insert with the rotation interface between the pivot 3 and the sleeve 7 with which the wear is reduced.

The closed cell foam insert is easily installed. After the steering arm 4, the pivot 3, and the shaft rod 1 have been assembled, the insert is placed within the hole 6a against the upper portion of the pivot 3. The pivot cover 9 is then screwed into the threads 12 of the hole 6a of the steering arm 4. The pivot cover 9 is tightened to closely engage the seal 8 and slightly compress the insert 10. The ligament understanding of the insert 10 acts to pre-load the insert 10 thereby allowing the insert expands without the distance between the pivot 3 and the cover 9 increases. The pre-load also counteracts any understanding that occurs to the insert during normal operation. The insert can be used at either end of pivot 3 whether a pivot cover 9 is used or not. Referring to Figure 2, a passage of grease 14 can be formed between the interface of the pivot cover 9 and the insert 10 to facilitate the passage of the lubricant from the grease fitting 11 to the contact surfaces between the pivot 3, the steering arm 4 and sleeve 7. The grease passage may be formed as a slot in either the pivot cover 9 or the upper surface of the insert 10. The lower end of the steering arm is preferably formed as the upper portion previously Description of the steering arm 4. However, it should be noted that a second pivot cover can be replaced by a solid portion of a ball joint having a closed depression to receive the extended lower portion of the pivot. When only one pivot cover is contemplated, a closed-cell foam insert can be placed within the lower depression of the lower portion of the steering arm between the steering arm and the pivot. Since the above invention has been shown and described with reference to a specific preferred embodiment, it should be understood by those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

Claims (6)

1. A steering mechanism comprising: an axle bar having a substantial and vertically aligned hole; a pivot extending through the hole and having upper and lower portions extending from the shaft bars. a ball joint having upper and lower yoke portions, each having a hole aligned and rotatably disposed about a corresponding portion of the up and down portions of such pivot whereby a rotary connection is established between the ball and the shaft rod; a closing means for closing each of the aligned orifices of the yoke portions of the patella and retaining the pivot therein; at least one insert provided between such a pivot and such a closing means to sustically occupy a space therebetween.

2. The steering mechanism according to claim 1, wherein the closing means comprises at least one pivot cover removably secured to one of the yoke portions to close a corresponding hole.

3. The steering mechanism according to claim 2, wherein the pivot cover further comprises a grease fitting adopted for introducing lubricants into the corresponding hole.

-4. The steering mechanism according to claim 3, wherein at least one insert is provided between the pivot and the pivot cover, wherein a grease passage is formed along an interface between the insert and the cover pivot to facilitate the distribution of the lubricant for a second interface between the ball and the pivot.

5. The steering mechanism according to claim 1, wherein at least one insert is made of closed cell foam, the insert is compressed under a pre-load with which it adapts as it expands and compresses to continuously reduce the fluctuations of pressure caused by the axial movement of the pivot relative to the ball joint.

6. The steering mechanism according to claim 5, wherein the closing means comprises a pivot cover removably secured to each of the yoke portions to thereby close each of the holes; each of the pivot caps has a grease fitting for introducing lubricant into the holes; and at least one insert comprising two inserts each, provided between the pivot and the orientation caps and having a grease passage formed at an interface between each of the pivot caps and the insert.