BACKGROUND OF THE INVENTION 1. Field of the Invention.

The present invention relates to hinges capable of holding a pivoting object in a predetermined position and, in particular, to friction hinges wherein friction is used for holding a pivoting object in a predetermined position.

2. Brief Description of the Prior Art.

Hinges and friction hinges are known in the art. For example, an adjustable plastic friction hinge is described in U. S. Pat. Nos. 4,630,332 and Des. 284,931, issued to Robert Bisbing on Dec. 23,1986 and Aug. 5,1986, respectively. This hinge includes an odd number of resilient leaves joined by a resilient pin. The pin includes a head dimensioned and configured to engage a screwdriver, and a threaded end dimensioned and configured to mate with threads inside the corresponding leaf. Friction washers fit inside the leaves. The coefficients of kinetic and static friction are similar to prevent squeaking. Tightening the pin increases the level of friction within the hinge.

U. S. Pat. Nos. 4,490,884,4,630,333, and Des. 278,309, issued to James H. Vickers on Jan. 1,1985, Dec. 23,1986, and April 9,1985, respectively, describe another adjustable friction hinge. This hinge comprises three leaves joined by a pin, with the pin having noncircular ends corresponding to the knuckles of the two end leaves. The central leaf has a knuckle with an adjustable diameter for controlling the degree of friction.

An example of a detent hinge is described in U. S. Pat. Nos. 5,412,842 and Des. 344,667, issued to Allen Riblett on May 9,1995 and March 1,1994, respectively. This hinge has three leaves and a pin. The pin has a slot which is press-fitted over a boss in each end leaf, and a plurality of apertures. The central leaf includes a plurality of members which are spring biased towards the pin, and dimensioned and configured to fit within the pin's apertures.

There is a continuing need for a friction hinge that has the concealability, range of motion, and ability to be installed on a wide a variety of pivoting objects.

SUMMARY OF THE INVENTION The invention is a hinge using friction to hold a door, armrest, or other pivoting object in a predetermined position. The hinge is particularly suited for objects pivoting on a horizontal axis.

The friction hinge includes a pair of hinge leaves pivotally joined by a pair of pivot pins, with a friction washer and spring element therebetween the hinge leaves and each corresponding pivot pin. Each spring element, preferably a spring washer, fits on a corresponding pin and is adjacent to one leaf. The preferred location being between the corresponding pin's head and one hinge leaf. Each spring washer thereby pushes that hinge leaf towards the corresponding friction washer and the other hinge leaf. A third washer and an end washer preferably fit over the end of each corresponding pin opposite the corresponding spring washer, preferably between the end of the corresponding pin and the other hinge leaf. Each end washer is secured to the end of the corresponding pin, thereby securing the hinge together. Although the preferred embodiment described herein includes the pair of pivot pins between the two hinge leaves, with one pivot pin at each end, a single pivot pin may be used for appropriate applications to better conceal the hinge.

It is therefore an object of the present invention to provide a hinge capable of holding a pivoting object in a predetermined position.

Another object of the invention is to provide a hinge using friction to hold the hinge leaves in the desired position relative to each other.

A third object of the invention is to provide a concealable hinge.

A fourth object of the invention is to provide a hinge having greater durability than past hinges.

These and other objects of the invention will become apparent through the following description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a friction hinge according to the present invention.

FIG. 2 is an exploded perspective view of the friction hinge of FIG. 1.

FIG. 3 is a perspective view of a second hinge leaf of the friction hinge of FIG. 1.

FIG. 4 is a rear view of a second hinge leaf of the friction hinge of FIG. 1.

FIG. 5 is a top view of a second hinge leaf of the friction hinge of FIG. 1.

FIG. 6 is a right side view of a second hinge leaf of the friction hinge of FIG. 1.

FIG. 7 is a bottom view of a second hinge leaf of the friction hinge of FIG. 1.

FIG. 8 is a front view of a second hinge leaf of the friction hinge of FIG. 1.

FIG. 9 is a left side view of a second hinge leaf of the friction hinge of FIG. 1.

FIG. 10 is a front view of a first hinge leaf of the friction hinge of FIG. 1.

FIG. 11 is a bottom view of a first hinge leaf of the friction hinge of FIG. 1.

FIG. 12 is a right side view of a first hinge leaf of the friction hinge of FIG. 1.

FIG. 13 is a top view of a first hinge leaf of the friction hinge of FIG. 1.

FIG. 14 is a rear view of a first hinge leaf of the friction hinge of FIG. 1.

FIG. 15 is a left side view of a first hinge leaf of the friction hinge of FIG. 1.

FIG. 16 is a perspective view of a first hinge leaf of the friction hinge of FIG. 1.

FIG. 17 is a perspective view of a friction washer of the friction hinge of FIG. 1.

FIG. 18 is a side view of a friction washer of the friction hinge of FIG. 1.

FIG. 19 is a front view of a friction washer of the friction hinge of FIG. I.

FIG. 20 is a perspective view of a spring washer of the friction hinge of FIG. 1.

FIG. 21 is a front view of a spring washer of the friction hinge of FIG. 1.

FIG. 22 is a side view of a spring washer of the friction hinge of FIG. 1.

FIG. 23 is a rear view of a spring washer of the friction hinge of FIG. 1.

FIG. 24 is a perspective view of a third washer of the friction hinge of FIG. 1.

FIG. 25 is a side view of a third washer of the friction hinge of FIG. 1.

FIG. 26 is a front view of a third washer of the friction hinge of FIG. 1.

FIG. 27 is a perspective view of an end washer of the friction hinge of FIG. 1.

FIG. 28 is a side view of an end washer of the friction hinge of FIG. 1.

FIG. 29 is a front view of an end washer of the friction hinge of FIG. 1.

FIG. 30 is a perspective view of a pivot pin of the friction hinge of FIG. 1.

FIG. 31 is an end view of a pivot pin of the friction hinge of FIG. 1, viewed from the end including the pin's head.

FIG. 32 is a side view of a pivot pin of the friction hinge of FIG. 1.

FIG. 33 is an end view of a pivot pin of the friction hinge of FIG. 1, viewed from the end opposite the pin's head.

FIG. 34 is a perspective view of a semi-tubular pivot pin of the friction hinge of FIG. 1.

FIG. 35 is an end view of a semi-tubular pivot pin of the friction hinge of FIG. 1, viewed from the end opposite the pin's head.

FIG. 36 is a side cross sectional view of a semi-tubular pivot pin of the friction hinge of FIG. 1.

Like reference numbers denote like elements throughout the drawings.

DETAILED DESCRIPTION The present invention is a hinge 10 using friction to hold a door, armrest, or other pivoting object (not illustrated) in a predetermined position. Referring to FIGS. 1-36, the hinge 10 includes a first hinge leaf 200, a second hinge leaf 100, pivotal attachment means for joining the hinge leaves 100,200, means for creating friction between the hinge leaves 100,200, biasing means for creating friction between the hinge leaves 100,200, and means for securing the hinge 10 together.

The first hinge leaf 200 is best illustrated in FIGS. 2-9. The first hinge leaf 200 includes a central elongated mounting bracket 202 and a pair of pivot brackets 204. The mounting bracket 202 has a substantially rectangular shape, and a plurality of holes 206 for facilitating the attachment of the first hinge leaf 200 to a desired surface, such as a door, armrest, or other pivoting object (not illustrated). The pivot brackets 204 are elongated, extend in opposed relationship, and are substantially identical to one another. Each pivot bracket 204 has an aperture 208, a dished region 210 surrounding the aperture 208, and a reinforcement rib 216 along the length of the pivot bracket 204. Each pivot bracket 204 is attached to a corresponding end of the mounting bracket 202. Each pivot bracket 204 initially extends away from the plane defined by the mounting bracket 202, and then curves back toward the plane defined by the mounting bracket 202 such that a hook-shaped structure is formed. The end portion of each hook-shaped pivot bracket 204 having the aperture 208 is located closer to the plane defined by

the mounting bracket 202 as compared to the curved medial portion of the hook-shaped pivot bracket 204. Each dished region 210 has a convex surface 212 facing outwardly away from the opposing pivot bracket 204, and a concave surface 214 facing the opposing pivot bracket 204.

Each reinforcement rib 216 has a convex surface 218 facing outwardly away from the opposing pivot bracket 204, and a concave surface 220 facing the opposing pivot bracket 204. The pivot brackets 204 are in superimposed relationship relative to one another when the first hinge leaf 200 is viewed from one end of the mounting bracket 202.

The second hinge leaf 100 is best illustrated in FIGS. 2 and 10-16. The second hinge leaf 100 includes a central elongated mounting bracket 102 and a pair of pivot brackets 104. The mounting bracket 102 is dimensioned and configured to bring the pivot brackets 104 adjacent to the pivot brackets 204 of the first hinge leaf 200, preferably by being either slightly longer or slightly shorter than the mounting bracket 202 of the first hinge leaf 200. The mounting bracket 102 has a substantially rectangular shape, and a plurality of holes 106 for facilitating the attachment of the second hinge leaf 100 to a desired surface, such as a door, armrest, or other pivoting object (not illustrated). The pivot brackets 104 extend in opposed relationship and are substantially identical to one another. Each pivot bracket 104 has an aperture 108, a dished region 110 surrounding the aperture 108, and a reinforcement extension 122 for helping the second hinge leaf 100 to maintain its shape under stress. Each pivot bracket 104 is attached to a corresponding end of the mounting bracket 102. Each dished region 110 has a convex surface 112 facing the opposing pivot bracket 104, and a concave surface 114 facing outwardly away from the opposing pivot bracket 104. Each reinforcement extension 122 is located at or about the attachment point of the corresponding pivot bracket 104 and the mounting bracket 102. The pivot brackets 104 are in superimposed relationship relative to one another when the second hinge leaf 100 is viewed from one end of the mounting bracket 102.

As best illustrated in FIGS. 2 and 30-36, the pivotal attachment means are preferably a pair of pivot pins 300,800. Each pin 300,800 includes a shaft 302,802 that is dimensioned and configured to pass through the apertures 108,208 of the hinge leaves 100,200, a head 304,804 having a diameter larger than the diameter of the apertures 108,208, and a deformable end 306, 806. The pin 800 is semi-tubular and has a central bore 808 about its end 806. The central bore 808 is coaxial with the shaft 802 and facilitates the deformation of the end 806 by a deforming

tool. Such deforming tool is well known in the art. The pins 300,800 are interchangeable, so any combination of the pins 300,800 may be used within the hinge 10.

As best illustrated in FIGS. 2 and 17-19, the means for creating friction between the hinge leaves 100,200 is preferably a pair of friction washers 400. Each friction washer 400 has a central aperture 402 that is dimensioned and configured to accept the shaft 302,802 of the corresponding pin 300,800. Each friction washer 400 is preferably made from a fluorocarbon resin, such as the one marketed under the trademark, TEFLON, or a phosphor bronze. Either of these materials, or other materials, may be selected to achieve a desired coefficient of friction between the friction washers 400 and hinge leaves 100,200.

The biasing means for creating friction between the hinge leaves 100,200 is preferably a pair of spring elements. As best illustrated in FIGS. 2 and 20-23, the spring elements are preferably a pair of spring washers 500. Each spring washer 500 has a central aperture 502 that is dimensioned and configured to accept the shaft 302,802 of the corresponding pin 300,800.

Each spring washer 500 is dished, and has a convex surface 504 and a concave surface 506.

Compressing a spring washer 500 will cause at least some flattening of that spring washer 500, and cause that spring washer 500 to exert an opposing force such that friction between the hinge leaves 100,200 is created.

As best illustrated in FIGS. 2 and 24-29, the means for securing the hinge 10 together are preferably a pair of third washers 600 and a pair of end washers 700. Each washer 600,700 has a central aperture 602,702 that is dimensioned and configured to receive the shaft 302,802 of the corresponding pin 300,800. Each aperture 702 may be dimensioned and configured to frictionally engage the shaft 302,802 of the corresponding pin 300,800, thereby making removal of the corresponding end washer 700 difficult once it is installed. Each third washer 600 is preferably made of a fluorocarbon resin, such as the one marketed under the trademark, TEFLON, or a phosphor bronze. Each end washer 700 is preferably made of steel.

The assembly of the hinge 10 is illustrated in FIGS. 1 and 2. Each pin 300 passes through the corresponding apertures 108,208 of the hinge leaves 100,200. Each friction washer 400 is located on a corresponding pin 300 and between the hinge leaves 100,200. Each spring washer 500 is located on a corresponding pin 300 and adjacent to one of the hinge leaves 100, 200. Each third washer 600 is located on a corresponding pin 300 and adjacent to the opposing hinge leaf 100,200. Each pin 300 terminates at one end with its head 304 and at the other end

with the corresponding end washer 700. Each pin 300 may be deformed at its end 306 to retain the corresponding end washer 700. A preferred assembly of the hinge 10 is made by first inserting each pin 300 through the corresponding spring washer 500. Next, each aperture 208 of the first hinge leaf 200 is passed over the corresponding pin 300. Each friction washer 400 is then placed on the corresponding pin 300, followed by the second hinge leaf 100. Lastly, the third and end washers 600,700 are placed on the corresponding pin 300. Each end washer 700 is secured on the corresponding pin 300 to hold the hinge 10 together, preferably by a friction fit or by deforming the end of the pin 300.

In use, one of the hinge leaves 100,200 is fastened to a nonmoving object, and the corresponding hinge leaf 100,200 is fastened to a moving object, such as a door or an armrest (not illustrated). Each spring washer 500 will bias the first hinge leaf 200 towards the corresponding friction washer 400 and first hinge leaf 100, thereby creating friction and holding the two hinge leaves 100,200 in the desired position relative to each other. When a rotational force sufficient to overcome the friction is applied to one of the hinge leaves 100,200, the hinge leaves 100,200 pivot relative to each other, thus holding the next user-selected position once the force is no longer applied. The degree of force required to move the hinge leaves 100,200 relative to each other may be varied by varying the strength of the spring washers 500.

It is to be understood that the invention is not limited to the preferred embodiments described herein, but encompasses all embodiments within the scope of the following claims.