FIELD OF THE INVENTION

The present invention relates to an arrangement for sealing a pivot joint formed by a pin rotating in a tubular sleeve providing relative pivotal movement between two components so to retain lubricating grease inside and dirt/debris outside the joint, and more specifically to an arrangement of this type using simple toroidal gaskets to form a relatively simple seal to trap grease inside a pivot joint.

BACKGROUND

Pivot joints are commonplace in dynamic mechanical structures where two parts of a structure are pivotally joined so that one can move in pivotal motion relative to the other about an axis defined by the joint. This is often formed by providing a pin which is mounted to a first component and which passes through a bore formed in a second component, where the pin defines the pivot axis of pivotal movement of one component in relation to the other.

Typically lubricant in the form of lubricating grease is disposed at an interface defined between the pin and an interior surface of the bore so as to reduce friction at this interface and enable smooth pivotal movement.

Oftentimes the mechanical structures employing these types of joints are used in environments where they are subject to dirt and debris, which material can contaminate the lubricant so as to cause wear of the components at the pivot joint.

Conventionally there is no barrier for trapping the lubricating grease inside the pivot joint and keeping contaminants such as the dirt/debris outside of same.

SUMMARY OF THE INVENTION

According to an aspect of the invention there is provided a pivot joint comprising:

a pivot pin;

a first member carrying a pair of upstanding sides opposite one another with inner surfaces in transversely spaced relation to one another so as to define a space therebetween;

each of the upstanding sides defining an aperture receiving the pivot pin spanning transversely across the space such that the pivot pin is operatively mounted to the first member;

a second member carrying a housing defining a bore which receives the pivot pin so that the pivot pin defines an axis of pivotal movement of the second member relative to the first member;

the housing being located in the space between the opposite upstanding sides of the first member;

opposite ends of the housing which face away from one another being spaced from the inner surfaces of the upstanding sides;

the bore being defined from one of the opposite ends of the housing to the other one thereof;

a circumferential gap formed along a length of the bore between an outer surface of the pivot pin and an inner surface of the bore that is suited for receiving lubricant;

a resilient toroidal gasket at each of the opposite ends of the housing located in the bore at axially spaced positions of the pivot pin;

a circumferential recess receiving each gasket in fixed axial location along the pivot pin, the recess being defined in one of the pivot pin or the housing;

the recess including a base recessed from the circumferential gap in a radial direction of the pivot pin;

the gasket spanning radially of the pivot pin from the base of the recess and across the gap so as to form a sealed interior of the bore closed at either end by the respective gasket.

This arrangement provides a relatively simple arrangement for sealing the lubricated area of a pivot joint so as to keep lubricant in and dirt/debris out. Thus the lubricant may have an extended operating life when it is not lost by leakage out of the bore as well as when it is not degraded by contamination with foreign contaminants such as dirt or debris.

Preferably, there is provided a washer substantially sandwiched between each opposite end of the housing and an adjacent one of the inner surfaces of the first member. The washer acts as a seal on an outside of the housing, keeping larger dirt/debris and other contaminants away therefrom so as to reduce exposure of an outer side of the toroidal gasket seated in the bore to such contaminants. Finer contaminants may still penetrate the seal of the washer, however the toroidal gasket acts to keep these out of the interior of the bore.

In one embodiment, the recess is defined in the pivot pin so that the pivot pin comprises a pair of circumferentially extending grooves oriented perpendicularly transversely to the axis defined by the pivot pin.

In one embodiment, the recess is defined in the housing so that the bore comprises a pair of circumferentially extending grooves oriented perpendicularly transversely to the axis defined by the pivot pin.

Preferably, the gasket is fastened to the housing so as to rotate therewith around the pivot pin while an inner annular periphery of the gasket is disposed in sliding contact with the pivot pin.

Typically, the gasket defines a plane, and the gasket is symmetrically shaped on either side of the plane.

