Devices of such type are known in the art and are such as to prevent the theft of spectacles or other objects equipped with arms of an elongated shape, since they are unmovably connected thereto (being able to be removed only by authorised personnel) and contain therein anti-theft members (of the electromagnetic, magneto-acoustic types and the like) adapted to trigger corresponding alarm circuits if they pass through the coverage area of these latter ones.

These devices however are unsatisfactory and have the following problems: - some devices have large sizes and weight and are therefore uncomfortable to be applied to articles with arms such as spectacles, and are as well uncomfortable when such articles are worn in order to try them on before purchasing them; other devices have a complex construction and are equipped with numerous elements that are mutually coupled or hinged, providing a costly arrangement to realise and that has not been favourably accepted by the market; the recent device disclosed in Patent Application No. T02000A000115 solves the above- mentioned problems, but cannot be applied to particular arrangements in which the spectacles must be inserted into suitable spectacles- holders equipped with two openings for inserting their arms therein; since these openings have a maximum size of 20 x 20 mm, this device is not able to penetrate into them.

Object of the present invention is solving the above prior-art problems, by providing an anti- theft device for articles equipped with at least one arm member, particularly spectacles, that is of small sizes, reduced weight and simple construction, employing the minimum number of component parts adapted to make it operate. The device is adapted to be inserted into openings for spectacles-holders whose maximum sizes are 20 x 20 mm.

A further object of the present invention is providing an anti-theft device of the above- mentioned type that guarantees a safe anti-theft function, without any chance of fraudulently, inadvertently or undesiredly removing it from the arm to which it is applied.

The above and other objects and advantages of the invention, as will appear from the following description, are obtained by an anti-theft device as claimed in Claim 1. Preferred embodiments and non-trivial variations of the present invention are claimed in the dependent Claims.

The present invention will be better described by some preferred embodiments thereof, given as a non-limiting example, with reference to the enclosed drawings, in which: - Figure 1 is a perspective view of an embodiment of the anti-theft device according to the present invention applied to a pair of spectacles ; - Figure 2 is an exploded perspective view of the component parts of the device of the invention; - Figure 3 is an exploded view of the device in Fig. 2 seen from the opposite perspective; Figure 4 is a perspective view of the device of the invention in its opening position; Figure 5 is a view similar to Fig. 4 with the device in its half-closed position ; and Figure 6 is a view similar to Fig. 4 and 5 with the device in its closing position.

With reference to the Figures, a currently- preferred embodiment of the anti-theft device 1 of the present invention for articles 3 equipped with at least one arm member 5 is shown, particularly for spectacles: in this embodiment, the anti-theft device 1 is configured in order to house therein electromagnetic labels, magneto-acoustic labels and the like (of an elongated shape, not shown since they are known), that is, anti-theft members adapted to trigger corresponding alarm circuits in case the article 3 is taken into the range of action of these latter ones, without having been previously detached from the article 3 through suitable detaching means (not shown) that are available for the authorised sales personnel in the place where such articles 3 are exposed and marketed. While the following description will refer to the article 3 as a pair or spectacles for an easy illustration, it is evident that the device 1 of the present invention can be applied to any article 3 comprising at least one arm 5 in order to provide it with the anti-theft functionality.

The anti-theft device 1 for articles 3 equipped with at least one arm member 5 of the invention substantially comprises one support body composed of two half-shells 9,9'adapted to be mutually coupled to realise a body with a commonly elongated parallelepiped shape, with the ends of the half- shells 9,9'that are mutually approaching till a shape is obtained with beveled ends: the support body 9,9'thereby obtained is attached to the arm 5 in parallel thereto and is of very small sizes (max 20 x 20 mm) such as not to be of a great encumbrance when the device 1 is assembled onto the spectacles 3 and when the arms 5 of the spectacles are inserted into the corresponding openings of the spectacles-holders for exhibition. In the embodiment in Fig. 1, the coupling is shown between device 1 and arm 5 of the spectacles 3 in which the device 1 is placed in parallel with the longitudinal extension of the arm 5, to allow also a user to comfortably wear the spectacles 3 in order to try them on. In order to realise such coupling, the half-shell 9 is equipped with a projection 11 that realises a recess 13 in which the arm 5 is made pass to join it to the device 1.

The device 1 of the invention is further equipped with tightening means 15 for tightening the device 1 against the arm member 5: such tightening means 15 are adapted to assume, through a sliding movement inside the support body 9,9', an opening position and a closing position of the anti-theft device 1.

Control and adjustment means 17 are then provided for the movement of the tightening means 15, housed inside the support body 9,9' : such control and adjustment means 17 are adapted to be manually actuated by rotating them around a movement axis of the tightening means 15 in order to push or pull them into their operating closing and opening positions, respectively.

The device 1 also comprises locking and unlocking means 19 of the control and adjustment means 17, housed inside the support body 9,9' : the locking and unlocking means 19 enable the control and adjustment means 17 to realise the two opening and closing positions of the tightening means 15.

Finally, the device 1 of the invention is equipped, in a known way, with at least one anti- theft member adapted to activate corresponding alarm circuits in case of unauthorised removal of the articles 3 from their exposure and/or sales place. In particular, such anti-theft element can be composed of a label of the electromagnetic or magneto-acoustic type, or still of a wound or non- wound wire.

According to the currently-preferred embodiment shown here, the tightening means 15 are composed of a plate 23 with such sizes as to substantially coincide with the sizes of the recess 13 obtained in a half-shell 9 of the support body 9,9'. In the embodiment shown, the plate 23 is shaped as a square, but other shapes are obviously possible (rectangular, circular, etc.) such as to allow the plate 23 itself to completely occupy the recess 13 in which it is housed, to guarantee the complete tightening functionality of the device 1 against the arm member 5.

The tightening means 15 further comprise a ball 25 connected to the major side of the plate 23 that does not engage the arm member 5 ; the ball 25 engages the control and adjustment means 17 in order to allow the control and adjustment means 17 themselves, when they are actuated and operatively rotate, to vertically move the tightening means 15 along their axis without making them in turn rotate.

In practice, then, the tightening means 15 can be further equipped with shock-absorbing means 27 placed on a side of the tightening means 15 in contact with the arm member 5: the shock-absorbing means 27 prevent the tightening means 15 from distorting or damaging the arm member 5 when they are in tight contact with the arm member 5 when the device 1 is closed.

In order to better perform their function, the shock-absorbing means 27 are preferably composed of a plate whose sizes are the same as the sizes of the plate 23 and that is made of resilient and soft material, for example rubber.

Always according to the preferred embodiment shown, the control and adjustment means 17 are composed of a small wheel 29 that is partly projecting from the support body 9,9'for its manual operation ; such wheel 29 comprises a central hole 31 in which an hollow cylinder 33 is placed, and the hollow cylinder 33 houses therein the ball 25 and operates for pushing and pulling the tightening means 15.

The wheel 29 can be equipped with a plurality of small teeth 35 placed around its external circumference to facilitate a manual operation of the wheel 29.

The wheel 29 is equipped with at least one (and preferably two) control projection 37 adapted to be inserted into a corresponding groove 39 obtained into the cylinder 33 and is equipped with an internal spiral-shaped groove 41 placed next to the hole 31 housing the cylinder 33. The control projection 37 and the internal spiral-shaped groove 41 allow the wheel 29, when it is rotatingly operated, to control the cylinder 33 to be moved along its axis to assume the opening and closing positions of the device 1.

In order to complete its functionalities, the wheel 29 is equipped, on its side opposite to a side cooperating with the tightening means 15, with a plurality of step-shaped notches 43 obtained within a circular crown 45 inside the wheel 29: the step-shaped notches 43 cooperate with the locking and unlocking means 19 in order to prevent, when closing the device 1, the wheel 29 from rotating along an opening direction of the device 1, and in order to allow, when the locking and unlocking means 19 are disengaged from the step-shaped notches 43, the wheel 29 to rotate along the opening direction of the device 1 in order to free it from the arm member 5.

In the preferred configuration, the locking and unlocking means 19 are composed of an elongated plane-band spring 19 housed in a corresponding recess of a half-shell 9'of the support body 9, 9' : such spring 19 is adapted to be attracted through detaching means (not shown) along a direction oriented outside the support body 9,9' into an unlocking position of the control and adjustment means 17, while in its rest position the spring 19 is adapted to cooperate with and lock the control and adjustment means 17 preventing them from sliding inside the support body 9,9'along a rotation direction that allows opening the tightening means 15.

As a skilled person in the art will immediately understand, Fig. s 2 and 3 provide exploded perspective views of the component parts of the device 1 to make their respective coupling clear.

It is obvious, as also appears by examining Fig. s 4 to 6, that, when assembling, the tightening means 15 and the related shock-absorbing means 27 will be assembled next to the recess 13, making the cylinder 33 pass inside an hole 47 obtained in the half-shell 9, and it is therefore clear that Fig. s 2 and 3 are not an indication of the assembling sequence of the device 1.

The operation of the device 1 of the present invention will now be described.

When assembling, the device 1 is placed, in the opening configuration shown in Fig. 4, around an arm 5, for example of a pair of spectacles 3. The small wheel 29 is then manually rotated so that the tightening means 15 are progressively lifted along their axis, more and more closing the recess 13 (as shown in Fig. s 5 and 6) and taking the plate 23 in contact with the arm member 5. In case of particularly thin and/or delicated arms 5, the shock-absorbing means 27 with which the plate 23 is often equipped allow realising the unmovable contact of device 1 to arm 5 without anyway bending or otherwise damaging it. The advancement of the tightening means 15 consequent to the rotation of the wheel 29 occurs"by snaps", that can also be controlled acoustically given the characteristic noise that they make when the wheel 29 is rotated.

Such snaps are caused by the small spring of the locking and unlocking means 19 that comes, upon every progressive rotation of the wheel 29, to engage a subsequent step-shaped tooth 43, abutting against one of its sides and preventing the wheel 29 from inversely rotate, such inverse rotation undesirably opening the device 1. Once having performed the contact between tightening means 13 and arm 5, the spectacles 3 can be placed in their suitable exhibition spectacles-holder, making their related arms 3, and also the device 1 connected thereto, pass into the holes provided therefor.

When it is necessary to remove the device 1 from the spectacles 3 (for example after a customer has tried them on and has decided to purchase them), the device 1 is taken in contact with the magnetic detaching means, that attract the locking and unlocking means 19 towards them, freeing them from the engagement against the step-shaped teeth 43 of the wheel 29: in this way it is possible to manually rotate the wheel 29 itself in the opening position of the device 1, progressively moving the tightening means 15 away from the arm member 5, until it is possible to withdraw the device 1 from the arm member 5 itself.

As already previously seen, thanks to the above- described arrangement, the device 1 of the invention, in addition to the other advantages which it possesses with respect to similar prior art devices, is therefore adapted to be inserted into openings for spectacles-holders whose maximum sizes are 20 x 20 mm.