WO2000062115A1

WO2000062115A1 - An improved spectacles frame

Info

Publication number: WO2000062115A1
Application number: PCT/IT1999/000089
Authority: WO
Inventors: Vittorio Tabacchi
Original assignee: Safilo Societa' Azionaria Fabbrica Italiana Lavorazione Occhiali S.P.A
Priority date: 1999-04-14
Filing date: 1999-04-14
Publication date: 2000-10-19
Also published as: AU3532399A

Abstract

The spectacle frame described has open rims with rim-closing barrels each including a first half-barrel and a second half-barrel (4, 5) which are fixed to respective opposite free ends of the rim, spanning the opening in order to house a screw (17) the fastening of which has the effect of tightening the half-barrels (4, 5); in order to prevent accidental unscrewing of the screw, a bush (20) is associated with the threaded hole (10) of one of the half-barrels (4, 5) externally and as an extension thereof; the bush (20) houses with interference a portion of the threaded shank (18) of the screw (17) which projects beyond the threaded hole (10) of the barrel.

Description

An improved spectaclej frame Technical field

The subject of the present invention is a spectacle frame according to the preamble to the main claim. Technological background

In spectacles with metal frames, with lens-holder rims of the so-called open type, each rim has, in the region of the opening, a double-flanged clamping system known in the ophthalmology field as a "rim-closing barrel". Each barrel is composed of a first half-barrel and a second half-barrel which are fixed to respective opposite free ends of the rim, spanning the opening. Respective coaxial through-holes extend through the half-barrels in order to house a screw the fastening of which tightens the half-barrels towards one another in order to clamp the rim as a whole onto the lens.

Normally, only one of the holes is threaded so that the threaded shank of the screw can be engaged therein by screwing; the other hole, which has a smooth surface, has a larger diameter than the tips of the thread.

One of the problems encountered with spectacle frames of this type is that of loosening of the screws for clamping the barrels. The loosening of these screws first of all may bring about a general instability of the frame and, subsequently, may allow the lens to come out of the lens- holding rim.

To prevent this problem, according to the prior art, the screws of the barrels are locked in the respective threads by the application of glues, for example, of the type available commercially under the registered trade mark "LOCTITE". However, this solution has two considerable disadvantages. The first of these disadvantages is connected with the relative difficulty of applying the glue, particularly in view of the minute dimensions of the screw and of the holes in the barrels. Spillages may therefore occur and may soil the frame and, in any case, the operation leads to a considerable increase in assembly times. Another problem is connected with the fact that, once the screw has been locked with the glue, it becomes difficult to unscrew or, after it has been unscrewed, it has to be locked with glue again.

Without the application of further glue, performed with all the necessary care, the frame is subject to the loosening problems complained of above. As an alternative to glue, it is known to use self-locking systems such as, for example, that described in US patent No. 5508758. However, this solution is also quite complex and, as such, is not suitable for application for the clamping of the barrels . Description of the invention

The problem upon which the invention is based is that of providing a spectacle frame which is designed structurally and functionally to solve all of the problems complained of with reference to the prior art mentioned. This problem is solved by a spectacle frame formed in accordance with the following claims. Brief description of the drawings

The characteristics and advantages of the invention will become clearer from the detailed description of a preferred embodiment thereof, given below by way of non- limiting example with reference to the appended drawings, in which:

Figure 1 is a partially-exploded, perspective view of a spectacle frame formed in accordance with the invention, Figure 2 is a sectioned view of a detail of the frame of

Figure 1,

Figure 3 is a side elevational view of the same detail as

Figure 2,

Figue 4 is a section similar to that of Figure 2 with parts separated,

Figures 5 to 7 show three variants of a detail of the frame of the previous drawings.

Preferred embodiment of the invention

A lens-holding rim of a spectacle frame, which is not shown but is formed in conventional manner, is generally indicated 1 in the drawings.

The rim 1 is of the type conventionally used for metal frames. Identified therein are a groove 2 for housing the rim of the lens, an opening 3 in which the rim is interrupted, two half-barrels 4, 5 together defining a barrel for clamping the rim 1 onto the lens, and a shoulder 6 for the articulation of an arm 7.

The shoulder 6 is welded or otherwise fixed to the first half-barrel 4. The half-barrels 4, 5 have respective mutually facing surfaces 8, 9 with matching profiles, further preventing deformations of the lens-holder rim in the region of the opening 3 when the barrel is clamped.

The first half-barrel 4 has a threaded through-hole 10 which is widened, at the opposite end to the surface 8, to form a cylindrical and coaxial seat 12. _The second half-barrel 5 has a further hole 15 which is coaxial with the hole 10 and, at the opposite end to the surface 9, is flared to constitute a countersunk seat for the head 16 of a screw 17, the threaded shank 18 of which is engaged by screwing in the hole 10.

The half-barrels 4,5 are thus tightened towards one another by screwing of the screw 17 into the hole 10 in order to close the rim 1 onto the lens . To prevent accidental unscrewing of the screw 17, when the screw is fully tightened into the half-barrel, a portion of the threaded shank 18 projects from the hole 10 in order to engage a bush 20, preferably made of plastics material . The bush 20 has an axial hole 21 the diameter of which is initially smaller than that of the threaded shank 18 and which initially has no thread. The hole 21 is threaded by the shank 18 when the shank is engaged in the bush 20 with interference with the rim clamped. The bush 20 has a cylindrical portion 23 which is coaxial with the hole 21 and can be housed in the seat 12 with radial clearance and a flange 24 which projects relative to the cylindrical portion and which can abut the surface 25 surrounding the seat 12. The flange 24 has operating means enabling the bush to be screwed onto and/or unscrewed from the threaded shank 18. The operating means are produced in the form of a slot 26 for a screwdriver 28 (Figure 5) , in hexagonal form 29 for a hexagonal wrench 30 (Figure 6) , or with a different geometrical shape 31 for a special key 32 (Figure 7) . The frame can be assembled by three methods which are described in detail below. _According to a first method, the frame is assembled by inserting the lens in the rim 1 and clamping the barrel 4, 5 by means of the screw 17. Once the lens-holder rim 1 is closed onto the corresponding lens, the bush 20 is screwed onto the portion of the shank 18 which projects into the seat 12 until it is fully tightened. The thread thus produced in the hole 21 brings about coupling of the bush 20 with the screw 17 with interference, preventing subsequent accidental unscrewing thereof. According to a second method, the frame is assembled by inserting the lens in the rim 1 and tightening the barrel 4, 5 by means of the screw 17. Once the lens-holder rim 1 is closed onto the corresponding lens, the bush 20 is force-fitted onto the portion of the shank 18 which projects into the seat 12 until the bush abuts the barrel. The threaded shank of the screw 17 brings about a deformation along the bush and results in a coupling with interference, preventing subsequent unscrewing thereof. According to a third method, the frame is assembled by inserting the lens in the rim 1, after which the bush 20 is inserted in the corresponding seat 12 by force. Once this operation has been performed, the rim is closed by means of the screw 17. During the screwing, the threaded shank of the screw meets the pre-fitted bush 20 and produces therein a thread with forced interference, preventing accidental unscrewing thereof .

In order to remove the screw 16, it suffices to slacken the bush 20 and then to unscrew the screw 17 from the hole 10. The bush 20 can be repositioned and continues to have its original anti-unscrewing effect. In practice, it acts both as a self-locking system, owing to the friction developed relative to the screw 17, and as a lock nut in relation to the screw itself.

The invention thus achieves the object set by simple and inexpensive means which, above all, permit reversible locking and release of the screw for easy maintenance of the spectacles .

Although the technical solution which is the subject of the invention has been described with reference to the preferred application for locking the barrel-clamping screw, it may also be used in other parts of the spectacles, for example, for preventing accidental unscrewing of the screws for the articulation of the arms to the front portion of the frame, or for other parts connected by screws.

Claims

1. A spectacle frame comprising at least one lens-holder rim (1) of the open type, a rim-closing barrel in the region of the opening (3) of the lens-holder rim, the barrel including a first half-barrel and a second half barrel (4, 5) which are fixed to respective opposite free ends of the rim, spanning the opening (3) , each half- barrel (4, 5) having a respective hole (10, 15), the holes being coaxial and being intended together to house a screw (17) the fastening of which has the effect of tightening the half-barrels (4, 5) towards one another in order to clamp the rim (1) onto the lens, the hole (10) of the first half-barrel (4) being threaded in order to house the threaded shank (18) of the screw (17) , anti-unscrewing means being associated with the first half-barrel (4) and with the screw (17) to prevent accidental unscrewing thereof, characterized in that the anti-unscrewing means comprise a bush (20) which is associated with the threaded hole (10) externally and as an extension thereof, and in which a portion at least of the threaded shank (18) of the screw (17) is engaged with interference when the rim is clamped.

2. A frame according to Claim 1, in which the bush (20) initially has no thread and is threaded by the shank (18) of the screw (17) during screwing.

3. A frame according to Claim 1 or Claim 2 , in which the bush (20) is rotatable relative to the half-barrels (4, 5).

4. A frame according to any one of Claims 1, 2 and 3, in which operating means are provided on the bush (20) for enabling the bush to be screwed onto and/or unscrewed from the threaded shank (18) of the screw (17) .

5. A frame according to one or more of the preceding claims, in which a seat (12) for at least partially housing the bush (20) is formed on the axially opposite end of the first barrel (4) to the second barrel (5) .

6. A frame according to Claims 4 and 5, in which the operating means are accessible outside the seat (12) .

7. A frame according to one or more of the preceding claims, in which the bush (20) is made of plastics material .

8. A frame according to one or more of the preceding claims, in which the half-barrels (4, 5) have mutually facing surfaces (8, 9) with matching profiles.

9. A frame according to one or more of the preceding claims, in which the bush (20) is housed in the corresponding seat (12) of the first half-barrel (4) with the ability to rotate relative thereto.

10. A frame according to one or more of the preceding claims, in which the bush (20) has a cylindrical portion

(23) coaxial with the seat (12) and the hole (10) , and a flange (24) projecting from the cylindrical portion (23) at one end thereof.

11. A frame according to one or more of the preceding claims, in which the bush (20) constitutes a lock nut for the screw (17) .

12. A spectacle frame including at least two portions coupled to one another by means of a screw (17) having a threaded shank (18) which can engage by screwing in a threaded hole (10) formed in one of the portions, and in which a portion of the shank (18) projects beyond the threaded hole, anti-unscrewing means being associated with the portion having the threaded hole (10) and with the screw (17) for preventing accidental unscrewing thereof, characterized in that the anti- nscrewing means comprise a bush (20) which is associated with the threaded hole (10) , externally and as an extension thereof, the projecting portion of the threaded shank (18) of the screw (17) being engaged in the bush (20) with interference.