The present invention relates to eyeglasses . The invention more particularly, although not exclusively, relates to a hinge for eyeglasses providing resistance against pivotal movement between open and closed configurations of the arms of the eyeglasses.

Eyeglasses are known to comprise folding arms attached to the frame at each temple region. The standard hinges permanently affix the arms to the frame , whereas some hinges are designed to enable detachment of the arms from the frame to facilitate replacement of a damaged arm and/or replacement of alternative styles of arm.

The hinges of known eyeglasses allow the arms to pivot freely throughout an angle of about 90° between closed and open configurations. When the arms are folded into a closed configuration, they can inadvertently swing into an open configuration in which the glasses are susceptible to damage,

Qbjects of the Invention

It is an object of the present invention to provide an improved eyeglasses hinge which retains the arm of the eyeglasses in either an open or a closed configuration - providing resistance to pivotal movement between those configurations .

It is a further object of the present invention to provide an improved eyeglasses hinge to facilitate easy removal and replacement of the arms of the eyeglasses.

Disclosure of the invention

There is disclosed herein eyeglasses comprising: a pair of lenses ; a pair of temple portions flanking the lenses ; a pair of arms ; a hinge connecting each of the arms to a respective one of the temple portions, each hinge comprising: a recess formed in the temple portion, the recess having a cam surface; and a spring member attached to the arm and extending into the recess to pivotally connect the hinge block to the temple portion, the spring being movable to a release position whereat the arm is detachable from the temple portion, the spring member bearing against the cam surface of the recess to provide resistance against pivotal movement of the arm with respect to the temple portion between folded and extended orientations , Preferably, the eyeglasses further comprise a cylinder at the temple portion in which the recess is located, and wherein the spring member further comprises a resilient leg which passes into the recess and has a distally positioned pin that extends into the cylinder.

Preferably , the recess comprises a pair of opposed said cam surfaces and wherein the spring member comprises a pair of said legs with said pins at the distal end of each leg facing away from each other and mutually aligned.

Preferably, the eyeglasses further comprise a hinge block attached to or formed integrally with the arm and within which the spring is received, and a locking plate movably attached to the hinge block and having a boss extending therefrom to bear against the legs of the spring, the locking plate being movable between a release position whereat the boss engages the legs in such manner as to allow the pins to be withdrawn from the cylinder via the recess, and a locking position whereat the boss biases the arms against the cam surfaces so that the pins are retained by the cylinder .

Preferably, the legs comprise a contoured surface against which the boss bears, the contoured surface defining said release and locking positions.

Preferably, the hinge block is formed separately to the arm and wherein the spring extends from the hinge block into the arm to secure the hinge block to the arm.

Brief Description of the Drawings

A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings , wherein :

Fig. 1 is a schematic parts-exploded perspective illustration of a portion of a pair of eyeglasses including the hinge;

Fig. 2 is another schematic parts-exploded perspective illustration of the same portion of a pair of eyeglasses including the hinge;

Fig. 3 is a schematic elevation of a spring forming part of the hinge shown in Figs. 1 and 2 in an unlocked/release at configuration;

Fig. 4 is a schematic elevation of the spring of Fig. 3 in a locked configuration; Fig. 5 is a schematic perspective illustration of a pair of eyeglasses having two of the hinges shown in Figs. 1 and 2;

Fig. 6 is a schematic perspective illustration of the portion of a pair of eyeglasses shown in Figs . 1 and 2 including the hinge, with the spring in the locked configuration of Fig . 4 ; and

Fig. 7 is a schematic perspective illustration of the portion of a pair of eyeglasses shown in Figs. 1 and 2 including the hinge, with the spring in the unlocked/release configuration of Fig. 3.

Description of the Preferred Embodiment

In the accompanying drawings there is depicted schematically a pair of eyeglasses 10. The eyeglasses include a frame 14 having a pair of opposed temple portions 13. Arms 11 are attached respectively to each temple portion 13 by a hinge including a hinge block 12.

At the temple portion 13 , there is a vertically extending cylinder 16. A recess 24 extends laterally from the cylinder 16 and comprises upper and lower cam surfaces 17 which comprise a "bump" in the middle to be described later .

The hinge block 12 houses a spring member 15 which has a pair of resilient legs 20 each having a pin 21 extending from its distal end. Each pin 21 is to be received within the cylinder 16 of the temple piece 13. The spring member includes a pair of apertures 23 through which screws 16 pass to secure the spring on the one hand to the hinge block 12 and on the other hand to the arm 11.

A locking plate 18 is provided with a boss 19. The locking plate 18 is attached to the hinge block 12 so as to slide between a locking position and a release position. The boss 19 fits between the proximal portions of the legs 20« The boss 19 bears against contoured surfaces 22 of each leg 20 above and below it. The spring member 15 under its own resilience takes on the "release" configuration depicted in Fig. 3. In this position the pins 21 are positioned sufficiently closely to one another to enable their passage through the recess 24 between cam surfaces 17 en route to the cylinder 16, When the locking plate 18 is moved to the right to the position depicted in Fig. 4, it passes a notch in the contoured surfaces 22 of each leg en route to the locking position whereat the pins 21 are mutually separated and a locked behind the cam surfaces 17 in the cylinder 16 of the temple piece 13 above and below the respective cam surfaces 17. In this position, the hinge block 12 and arm 11 can pivot between open and closed configurations. To this end, the hinge block 12 is provided with a concave surface 25 which fits neatly around the external surface of the cylinder 16 of temple piece 13. During pivotal movement, the legs 20 are forced toward one another by the "bump" in the respective cam surface 17 against the resistance of boss 19. This provides a resistance to movement which can be felt by the user and retains the arm 11 in either the open or closed configuration unless user-force overcomes the resistance caused by the bump in the cam surfaces 17.

Should it be desired to remove the arm 11, the locking plate 18 can easily be moved to the left-most position as depicted in Fig. 3 whereupon the boss 19 also moves to the left to allow the pins 21 to move toward each other.

It should be appreciated that modifications and alterations obvious to those skilled in the art are not to be considered as beyond the scope of the present invention. For example, an alternative to providing both upper and lower cam surfaces and contoured surfaces might provide only singular equivalent features . Moreover , one of the legs 20 might be fixed and the other movable.