Background of the Invention The primary attachment system used today for lenses is a standard, full circumferential eyeglass frame, either of plastic or metal. The rim surrounds the lens, holding it in place. The lens itself will typically have a ridge around the full circumference to allow for the holding of the lens in place (Figs. 1 and 2). This system has been in place for hundreds of years and represents the basic state of the art.

Another system which has been in place for many years is the"three piece" fixation system. In this form, the eyeglass frame is actually in three pieces with "fingers"extending into the lens into which holes have been drilled and screws affixed (Figs. 3 and 4). This also has been used for hundreds of years and dates back to some of the earliest eyeglass uses. In addition to the traditional three piece with screws through the lens, a more recent adaptation is that by Air Titanium whereby folded metal rods are inserted through holes in the lens and the opening tension produced by the oversize, bent rods fixes the lens and frame, without the use of screws. This system, however, while reversible, does not provide sufficient structural integrity, and requires intrusion into the lens.

A newer connection system is that of a"half rim"where structural material is used such as in a full circumferential metal rim, but only through part of the

frame. The remainder of the lens is supported through a cord, or cable, typically of nylon, which, when put in tension, holds the lens in place by virtue of its fitting in a groove in the lens (Figs. 5 and 6). An example of this is the Essilor"rimless" frame, which patent issued around 1970.

Other lens systems have been proposed, which include permanently fixing the frame to the lens with pieces such as glue or epoxy. Those have not found significant applications because of their inability to be replaced, requiring full replacement of both the lens and the frame.

A newer method of attachment is described in U. S. Patent No. 4,894,438 which discloses the use of shape memory alloys to grab onto lens, thus providing a reversible positive connection without rims, cords, or screws (Figs. 7 and 8).

Summary of the Invention: The invention provides an eyeglass lens attachment arrangement comprising an eyeglass frame and a pair of lenses, each of the lenses including at least one shaped engaging portion, the shaped engaging portion cooperating with an attachment member which attaches a respective one of the lenses to the frame.

The shaped engaging portion can comprise a recess in the lens or a projection on the lens. Alternatively, the engaging portion can comprise a discrete part bonded to the lens. Although a single engaging portion could be utilized, more preferably first and second shaped engaging portions are provided on each lens. For instance, each lens can include first and second spaced apart recesses, first and second spaced apart projections or first and second spaced apart discrete parts bonded to the lens.

The attachment member can comprise a separate or integral part of the eyeglass frame removably attached to the shaped engaging portion. For instance, the attachment member can include a pair of fingers which engage the shaped engaging portion. Other attachment member configurations can be used such as a

C-shaped, V-shaped, triangular, or other shaped portions engaging the shaped engaging portion. With the arrangement according to the invention, the lens can be removably attached to the frame without screws, cords or rims.

Brief Description of the Drawings Figs. 1-8 show prior art arrangements for attaching lenses to eyeglass frames; Figs. 9-17 show various embodiments of shaped engaging portions in accordance with the invention; and Figs. 18-23 show various attachment member configurations in accordance with the invention.

Detailed Description of the Invention The invention provides a novel lens attachment arrangement. The arrangement utilizes material either on the lens itself or through attachment such as bonding (e. g., epoxying) of a special fitting to the lens which is specifically designed to accommodate various mechanical, reversible frame mating systems such as envisioned in the'438 patent and other non-shape memory alloy embodiments. These connection designs would preferably be the"male"end of a male-female fixation system. In one embodiment (Figs. 9-11), the lens material itself would be ground away leaving an exposed mating fixture such as a recess or projection which is integral with the lens. A male or female attachment member would then grab onto the protruding material either directly, or through a sliding motion such as in the vertical plane. A locking clip could then keep further sliding from taking place. In another mode, the material of the lens would be machined such that the male or female portion is inboard of the circumference of the lens. This could be accessed by techniques such as through the grabbing

motion defined in the'438 patent, or a snapping motion provided by an attachment member having an elastic grabbing portion (Figs. 12-14).

In yet another embodiment, a separate lens engaging portion, such as that made by a similar or dissimilar material, such as metal ceramic or plastic material could be permanently attached (e. g., epoxied) onto the lens itself and then attachment member of the frame could be directly attached to that lens engaging portion (Figs. 15-17). While the lens engaging portion can be permanently attached to the lens, the lens itself can still be removed and adjusted, coated and cleaned, unlike other permanent fixation methods.

The female and male portions of the attachment arrangement may also be formed in a round or angled pattern such that either adjustments or fixation are enhanced (Figs. 18 and 19). They may also be"forked"to open or close as in Figs. 20-22 or press fit or swaged on as shown in Fig. 23. In the Figs. 20-21 arrangement, the attachment member can be of materials such as stainless steel, titanium, Beta-titanium, shape memory alloy or other springy material.

In all the embodiments, screws and holes in the lens themselves are not necessary to provide a rimless, cordless, screwless attachment system for optical frames.

The foregoing has described the principles, preferred embodiments and modes of operation of the present invention. However, the invention should not be construed as being limited to the particular embodiments discussed. Thus, the above-described embodiments should be regarded as illustrative rather than restrictive, and it should be appreciated that variations may be made in those embodiments by workers skilled in the art without departing from the scope of the present invention as defined by the following claims.