OPTICAL ACCESSORY FOR USE WITH SPECTACLE FRAME

Abstract: There is disclosed an improved optical accessory (10) of the sun shade type for use with a pair of prescription spectacles (12). The accessory (10) includes a releasable securing structure (54) which releasably cooperates with a bridge assembly (30) of the spectacles to inhibit movement of the accessory (10) relative thereto.

Description: The invention relates to an optical accessory for mounting to a spectacle frame. Optical accessories for use in combination with spectacles exist for a wide variety of reasons. Sunglass accessories, for instance, generally permit optimum use of the spectacles under varying lighting conditions. Other optical accessories provide, for example, eye shielding and vision correcting functions. A number of factors are considered important in constructing such accessories. In this regard, it is desirable to have the optical elements of the accessory positioned in correct superposed relationship to the optical members of spectacles for proper usage and convenience. In many instances, it is highly desirable to avoid unnecessary movement of the accessory relative to the spectacle frame assembly. Moreover, facilitating quick, easy and reliable mounting and demounting of the accessory are of practical importance. Significantly, it is desirable to have these mounting arrangements as aesthetic as possible. Unaesthetic mounting arrangements, of course, detract appreciably from the commercial appeal of such accessories. Furthermore, in the highly competitive spectacle accessory field, need exists to provide the foregoing features as simply, economically and efficiently as possible. Mounting arrangements for releaseably attaching optical accessories to spectacle frames are significant components of the accessories. The following are exemplary of prior art optical accessories and their releasable mounting arrangements: US Patent Specification Nos. 2,580,859; 2,607,919; 2,696,141; 2,949,609; 2,981,956; 3,092,838; 3,345,121; 3,555,563; 3,604,013; 3,741,634; 4,012,129; 4,176,921; 4,253,745; 4,402,577; 4,402,578; and 4,405,214. Known optical accessories exhibit a number of deficiencies in connection with the foregoing enumerated design factors. Moreover, most accessories must have specially constructed frames to be attached to. Accordingly, the accessories are not compatible with many kinds of existing frames. Furthermore, these specially constructed spectacles often appear unattractive whether the accessories are attached or removed. In accordance with the present invention, we provide an optical accessory for mounting to a spectacle frame of the kind having a central opening defined by a brow bar, a nose bridge, both of which are generally horizontally extending and spaced apart from each other, and the portions of the lens frame extending between the brow bar and the nose bridge, the accessory comprising a pair of spaced apart optical members connected by connection means and configured to be positioned in front of the optical elements of the spectacle frame in use, and mounting means to mount the accessory to the frame, said optical accessory being characterised in that said mounting means are fixed to said connection means for releasably fitting to said opening and comprise a resilient retaining member the dimension of which is so configured relative to the dimension of the central opening that when the retaining member is inserted through the opening a resilient engagement is obtained. The present invention provides an improved optical accessory for use in combination with a spectacle frame. In this regard, the optical accessory may be used with a spectacle frame of the type for mounting a pair of optical elements and having a brow bar and a nose bridge holding the optical elements in spaced apart relationship. Such means has surfaces intermediate the optical elements which are cooperable with the releasable mounting means. Means may be provided for blocking the view of the cooperable surfaces and the releasable mounting means from the front of the spectacles when the accessory is attached. For example, the connecting means may include an opaque assembly adapted to cover the opening of the spectacle frame when the accessory is mounted thereto. Preferably, the mounting means includes a pair of portions which converge toward and merge into said second resilient portion. Preferably the mounting means yieldably biases the accessory to the frame so as to provide a releasable connection therewith which substantially prevents movement of the accessory in all directions in a plane defined by the opening and which limits movement in directions generally transverse to the plane, when the accessory is attached. Conveniently, the opening defined by the spectacle frame has a pair of spaced apart corners and an edge spaced from the corners, the mounting means being adapted to engage the corners and edge in use. Preferably, one of the nose bridge and brow bar defines with other parts of the frame the pair of corners and the other of the nose bridge and brow bar defines the spaced edge. Some advantages of the invention and subsidiary features of the invention are an improved optical accessory for use in combination with spectacles wherein the accessory is easily attached and detached therefrom; the provision of an improved optical accessory having releasable securing means which are hidden from view when attached to the spectacles; the provision of an improved optical accessory which is accurately positioned and securely mounted to inhibit undesired relative movement of the accessory with respect to the spectacles; the provision of an optical accessory having an improved mounting arrangement which is simple in construction and economical to manufacture; and, the provision of an optical accessory which is compatible with a large number of frames. An example of a pair of spectacles and an optical accessory in accordance with the present invention will now be described with reference to the accompanying drawings, in which:- FIG. 1 is an exploded perspective view of an example of an optical accessory of the present invention shown in combination with a pair of spectacles; FIG. 2 is an elevational view showing structure forming the releaseable connection between the accessory and the spectacles; FIG. 3 is a cross-sectional view taken along section-line 3-3 appearing in FIG. 2; FIG. 4 is a view showing cooperation between the spectacles and the accessory; and FIG. 5 is a fragmented elevational view better showing other details of the accessory structure. Reference is now made to the drawings for showing an improved optical accessory 10 of the present invention for use with a pair of spectacles 12, such as of the type shown in FIG. 1. In this embodiment, the optical accessory can be of the sun shade type. As illustrated, the spectacles 12 can be of the prescription glasses type and include prescription lenses 14 which are secured to a frame assembly 16. Other optical elements could, of course, be used instead. In particular, the frame assembly 16 is a conventional wire-framed type and includes a pair of lens frames 18. These lens frames 18 are spaced apart and connected by a central bridging assembly 20. Attached as by temple hinges and lugs, generally indicated at 22, to outward lateral sides of the lens frames 18 are conventional temple pieces 24 which have ear tips 25 engageable with the ears of a wearer. Attached to inward lateral sides of the lens frames 18 is a pair of conventional opposing nose pads 26. Reference is again made to the central bridging assembly 20 which in the present embodiment includes a central opening 28, in part, defined by a brow bar and nose bridge 30 and 32 respectively which are generally horizontally extending and spaced apart from each other. Also defining the central opening 28 are generally vertical portions 34 of the lens frames 18 extending between the brow bar and nose bridge 30, 32, respectively. The brow bar 30, nose bridge 32 and the vertical portions 34 converge to define retaining corners 36. Although the illustrated embodiment depicts the central opening 28 having four-sides defined by the brow bar 30, nose bridge 32, and vertical portions 34, it will be appreciated that such a central opening 28 can be formed from other structural features so long as such structure provides an opening similar in structure and function to opening 28. Reference is now made to FIGS. 1, 3 and 4 for showing the optical accessory 10. Included in the optical accessory 10 is a pair of spaced apart and adjacent sun shade type optical elements 38 made of a suitable plastic material. The optical elements 38 are held in a horizontally space apart orientation by a connecting assembly 40. In this embodiment, the connecting assembly 40 includes an elongate and resilient metallic backing bar 42, lens retaining segment 44 made of resilient plastic material, and releaseable attaching means 46 integral with the backing bar 42. The lens retaining segment 44 defines a pair of spaced apart and arcuately shaped recessed shouldered portions 50 upon which peripheral portions of the optical elements 38 are supported in abutting relationship. An outer pair of plastic rivets 52 secure the backing bar 42 to the optical elements 38 while the inner pair secure the backing bar 42 to both the optical elements and the segment 44, as shown in FIG. 5. In this fashion, the optical elements 38 are firmly maintained in a fixed and spaced apart relationship and the accessory 10 is a self-supporting and resilient member. The lens retaining segment 44 is opaque. This is for hiding from view, the releaseable attaching means 46 which is attached to the backside thereof as well as the spectacle surfaces to which it is attached. Hence, aesthetics of the optical accessory 10 is enhanced since the attaching means 46 is not seen when the accessory 10 is worn. Reference is now made in particular to FIGS. 1-3 for showing the releaseable attaching means 46. In this embodiment, the attaching means 46 is formed by a resiliently deformable, unitary wire-like, retaining member 54 which has a snap-fit connection to the spectacles. More particularly, the retaining member 54 has a rounded cross-section and its opposite end portions 54a extend rearwardly and generally perpendicularly from the backing bar 42. In this embodiment the end portions 54a are adapted to snugly and resiliently engage the retaining corners 36. The releaseable retaining member 54 has two generally converging and descending portions 54b. Corners are formed by the junction of portions 54a,b which corners are in general alignment with retaining corners formed by the bridge assembly. The portions 54b merge together in a laterally forwardly extending and generally U-shaped tongue-like portion 54c. Such a merging of portions 54b,c form another set of corners. The tongue portion 54c is configured to have a snap-fit cooperation with the nose bridge 32, much as in the manner indicated in FIG. 3. The releaseable retaining member 54, when joined to the bridging assembly 20 through the central opening 28, provides a three point type of resiliently firm snap-fit engagement. For effecting this resilient engagement the configuration of the retaining member 54, in the unstressed condition, is slightly larger than the dimension of the central opening 28. Thus, when, the retaining member 54 is inserted through the opening 28, the former deforms resiliently, and as it attempts to return to its unstressed condition creates a resiliently tight or yieldably biased engagement which restricts movement of the accessory 10. Because of the configuration of the retaining member, the tongue section 54c is in tight resilient engagement with the nose bridge 32 while the end portions 54a are tightly and resiliently bearing against the retaining corners 36. The tongue section 54c during insertion will cause a compression of the retaining member 54 and serves to transmit the force of the nose bridge thereon through the retaining member to urge the portions 54a into alignment with the retaining corners. Although the portions 54a resiliently deform to form a snap-fit connection, it is within the present invention to have the portions 54a have a snug-fit with the corners 36 or be constructed such that they are displaced into engagement with the corners when the retaining member 54 is compressed during insertion. Although in this embodiment, the tongue section 54c engages the nose bridge, it can contact the brow bar, providing of course, that the portions 54a engage an opposite pair of retaining corners to form said three-part engagement. As a result of the foregoing the optical accessory 10 when attached is prevented substantially from movement horizontally, vertically and rotationally in a plane defined by the opening. The optical accessory 10 is, when assembled, unable to move transversely to the central bridging assembly 20. Accordingly, the optical accessory 10 is securely and correctly positioned as well as is easily insertable and removable from the spectacles 12. FIG. 4 shows another aspect of the present invention. This takes advantage of the resilient nature of the accessory 10. In this regard, portions of each of the sun-shades are configured and arranged to engage respective lens frames 18 in the general vicinity of their furthermost spaced apart portion when accessory 10 is releasably attached to the spectacles 12 to act in a spring-like manner, at such time, so as to exert a yieldably resilient force on the snap-fit connection in a direction away from the spectacles, thereby further urging the accessory into a tight fit. Such an arrangement is effective to limit any play in the snap-fit connection. Hence, a more stable position for the accessory 10 is achievable. Although the releaseable retaining member 54 has the configuration shown, it will be appreciated that more than a single member might be used provided they would substantially prevent horizontal, vertical and rotational movement of the accessory 10 in the plane of the opening and restrict movement of the accessory 10 transverse to the plane of the opening, when attached.

Claims: An optical accessory (10) for mounting to a spectacle frame (12) of the kind having a central opening (28) defined by a brow bar (30), a nose bridge (32), both of which are generally horizontally extending and spaced apart from each other, and the portions of the lens frame extending between the brow bar and the nose bridge, the accessory comprising a pair of spaced apart optical members (38) connected by connection means (42, 44) and configured to be positioned in front of the optical elements (14) of the spectacle frame in use, and mounting means (54) to mount the accessory to the frame, said optical accessory being characterised in that said mounting means (54) are fixed to said connection means (42,44) for releasably fitting to said opening and comprise a resilient retaining member (54) the dimension of which is so configured relative to the dimension of the central opening (28) that when the retaining member is inserted through the opening a resilient engagement is obtained. An accessory according to claim 1, wherein the mounting means (54) comprises at least three resilient portions (54a, 54b, 54c) adapted to cooperate with the opening (28) of the spectacle frame. An accessory according to claim 2, wherein at least some of the portions cooperate such that when the accessory is mounted to a spectacle frame, forces exerted on one portion of the mounting means are transmitted to at least one of the other portions to increase the strength of the resilient engagement. An accessory according to any of the preceding claims, wherein the mounting means (54) is adapted to engage a pair of corners and an opposed, spaced edge of the opening (28) in use. An accessory according to any of the preceding claims, wherein the mounting means comprises a wire-like member (54) including first, end portions (54a) attached to the connection means (42) and extending away therefrom, the first portions being connected to respective second portions at a first pair of bends, the second portions extending at substantially 90° to the first portions, and the second portions being connected at a pair of second bends to a third, U-shaped portion extending at substantially 90° to the second portions and adjacent the first portions. An accessory according to any of the preceding claims, wherein the connecting means (42) further comprises an opaque assembly (44) adapted to cover the opening (28) of the spectacle frame when the accessory is mounted thereto. In combination: a pair of spectacles (12) having a frame to which a pair of optical elements (14) are mounted, the frame including a brow bar (30) and a nose bridge (32) for bridging and holding the optical elements (14) in spaced apart relationship and for defining an opening (28); and an optical accessory according to any of the preceding claims, the mounting means (54) of the optical assembly being adapted to be mounted in the opening (28) of the pair of spectacles. A combination according to claim 7, wherein the opening (28) has a pair of spaced apart corners (36) and an edge spaced from the corners, the accessory being constructed in accordance with at least claim 4. A combination according to claim 8, wherein one of the nose bridge and brow bar defines with other parts of the frame the pair of corners (36) and the other of the nose bridge and brow bar defines the spaced edge.

Inventors: GAZELEY, ALBERT E.
Applicants: POLAROID CORPORATION
Application year: 1986
Main classification: G02C9
IPC codes: G02C7, G02C9