DESCRIPTION

The present invention relates to a recessed handle. In particular, the present invention relates to a recessed handle installable on a sliding leaf of a door or window coiranutable between a closed and an open position in relation to a fixed portion of the door or window. In more detail, the present invention refers to a recessed handle installable on a sliding leaf of a door or window commutable between a locked and an open position in relation to a fixed portion of the door or window and a protected anti-forcing device for preventing accidental commutation of the handle itself to the open position. BACKGROUND TO THE INVENTION

In the field of sliding windows and doors the practice is known of using elongated handles which include an elongated casing or body installable in a slot formed in a face of the leaf transversely to the direction of sliding and having a flat plate which remains visible externally on the face of the leaf. Such handles include a plurality of devices, each one of which is associated with a specific function, as is seen in US patent 6050617 in the name Ferco, in which are described a plurality of such devices for a handle for sliding leaves and doors, recently devised.

It is known that such handles include an L or T shaped bolt to engage transversely a slot formed laterally in a stile of a fixed portion of the window or the door. The bolt is connected rigidly to a slider which is longitudinally movable and usable for commuting the bolt between the open and locked positions. The slider normally presents a longitudinal hollow portion usable by the fingertips of one hand for longitudinal activation of the

slider. Some handles present an anti-forcing device connected with the slider to avoid accidental commutation of the bolt from the closed position. On the other hand, in some cases, the slider is connected with an activation unit including an operating key, capable of effecting, in succession, the unlocked condition the anti-forcing device and the slider itself by the transfer from the locked position. In the case of Patent ^Λ 617, the anti-forcing device includes a pair consisting of a step created by a projection which the slider presents on the face turned towards the respective plate of the casing and extends for a determined height, to function as a shoulder. When the projection of the slider and the lateral edge of the slot are facing towards each other and in contact, the anti- forcing device is armed or operational, and to disarm it, it is necessary to displace the two edges transversely, in such a way as to allow the respective sliding of the edge of the slider over a flat internal face of the plate itself. To keep the anti-forcing device armed, in many cases the slider has internally, on the same side as the longitudinal hollow portion of the slider, an elastic strip having one end freely sliding over a determinate surface. This surface can be the flat internal surface of the plate or be formed and profiled similarly to a ramp. The strip and the profile constitute a device called a positioner. If this surface is smooth, as in the case of Patent ^λ 617, then the strip performs only the function of keeping the anti- forcing device armed. Alternatively, the positioner is also useful in opposing the accidental commuting of the slider, for example by gravity. In any event, the anti-forcing device is effectively armed only when the snap engagement of the slot in the casing of the handle is brought about by the projection on the slider.

With reference to the activation unit provided with an

operating key, this is capable of acting on the slider through a mechanism having two bodies coupled together by a toothed coupling. These teeth are delimited by planes facing each other and inclined in such a way that a longitudinal movement of one of the two towards the other causes a reduction in their mutual distance measured transversely. In particular, the mechanism includes a longitudinally sliding carriage mounted on side members of the casing which extend internally. This carriage, activatable by a rotatable tappet on the activating unit presents internally at least one tooth delimited by an inclined face which is longitudinally opposed to a similar tooth carried internally by the slider. Once engagement/clutch of the teeth on the slider and carriage is brought about, further sliding of the carriage can cause, in succession, sliding of the two inclined faces against each other, which in its turn brings about the return inwards of the projection on the slider and therefore the disarming of the anti-forcing device, and the commutation of the bolt . The scraping of the two faces over each other is accompanied by scraping between the projection on the slider and the lateral edge of the slot.

As has been seen, recessed handles of recent design include a considerable collection of devices cooperating with each other. On the other hand, in order to comply with the needs of the designer, such handles must also be couplable with stiles of limited width. This imposes the need to miniaturise the devices described and the respective components both to exploit internal spaces in increasingly narrow casings, and also to limit the weight of the handles and therefore their cost. In any event, this necessity must not compromise the reliability of the devices mentioned, which must be precisely designed and must have robust and reliable components. This contributes

to limiting the extent of maintenance operations, but also to limiting the capacity for resisting attempts at break- in, at least in the case of the anti-forcing device.

The anti-forcing device described with reference to Patent ^λ 617 has the disadvantage of operating only after it has been armed. Furthermore, according to the teaching of that patent, the anti-forcing device is exposed to the risk of early damage to the step of the slider which determines the grip of the anti-forcing device, through the scraping which it brings about at each activation between the external projection of the slider and the lateral edge of the slot. Furthermore, still with reference to the said patent, the anti-forcing device is easily accessible from the outside, and for this reason the result is that it is both accidentally commutable, and exposed to voluntary or involuntary damage .

SUMMARY OF THE PRESENT INVENTION

The present invention relates to a recessed handle. In particular, the present invention relates to a recessed handle installable on a sliding leaf of a door or window commutable between a closed and an open position in relation to a fixed portion of the door or window. In more detail, the present invention refers to a recessed handle installable on a sliding leaf of a door or window commutable between a closed and an open position in relation to a fixed portion of the door or window and a protected anti-forcing device for preventing accidental commuting of the handle itself, or for limiting problems which can be caused by inattention or improper use of the handle itself.

An object - of the present invention is to create a recessed handle which will allow the disadvantages explained above to be resolved, and which will have an anti-forcing device protected from interference and capable

of satisfying a series of requirements which are still unanswered in the present state of affairs. Therefore, a handle of this type is such as to represent a new and original source of economic advantage, capable of altering the current market for recessed handles. According to the present invention, a recessed handle is created whose principal characteristics will be described in at least one of the claims which follow.

BRIEF DESCRIPTION OF THE DRAWINGS Further characteristics and advantages of the recessed handle according to the present invention will appear more clearly from the following description, explained with reference to the attached drawings which illustrate at least one non-limiting example of embodiment, in which identical or corresponding parts of the said device are identified by the same reference number, barring instructions to the contrary. In particular:

- figure 1 is a schematic lateral view of the handle according to the present invention represented in a first operating position;

- figure 2 is a plan view, and with parts removed for clarity, of figure 1;

- figure 3 is a schematic lateral view, on an enlarged scale and with parts removed for clarity, of the handle in figure 1; figure 4 is a schematic lateral view, with parts removed for clarity, of the handle in figure 1 represented in a second operating position;

- figure 5 illustrates the handle from figure 1 in a third operating position ; and

- figure 6 shows a particular extract from figure 5.

DETAILED DESCRIPTION OF THE PRESENT INVENTION In figure 1, no. 1 indicates, in its entirety, a recessed handle, validly installable on leaves 2 of sliding

doors or windows. As is known, such leaves 2 have housing slots 3 for this purpose formed in respective vertical stiles and usually delimited by annular edges elongated transversely to the direction of sliding which, at their respective ends, are substantially circular. Recessed handles usually grip the respective slots 3 by means of suitable clamping members. To this end, every handle of this type has a casing 10, which is provided with a flat plate 11 of elongated form substantially similar geometrically to housing slot 3. Furthermore, handle 1 includes a pair of longitudinal sides 14 which extend from a flat internal face 12 of plate 11 and transversely to it, to delimit laterally a determinate volume V of substantially paralleliped form. Furthermore, the handle includes two clamping members 15, each of which is housed in an end position between sides 14, and is provided with a projection 17 which cooperates with face 12 of plate 11 to snap into position and clamp the ends of casing 10 to slot 3 of leaf 2. Handle 1 has a slider 20 including an elongated body which extends for at least half the length of sides 14. Slider 20 is housed inside volume V in longitudinally sliding manner and selectively in contact with face 12 of plate 11, in a respective locking operating position P. In this position, slider 20 is capable of keeping a bolt 21 housed within a moving element integral with slider 20, in a position of engagement with a transverse housing known and not illustrated, formed in a rebate in a frame known and not illustrated of the sliding door or window to which leaf 2 belongs. With reference to figure 3, the handle includes an anti-forcing device 30 which includes an axial striker 16 integral with the clamping member 15, which is represented on the left in figure 3. Device 30 has, connected with slider 20, a longitudinal stop member 22 carried in end

position facing striker 16. This member 22, which henceforth will be more simply indicated with the term boss 22, is carried by slider 20 in end position in such a way that when slider 20, in use, is positioned in the respective locking position P, boss 22 is facing and scarcely any distance from striker 16, as may be seen in figure 2. This prevents attempts at forcing through the displacement of slider 20 from the respective position P in the direction of striker 16, given that contact between striker 16 and boss 22 causes the longitudinal arrest of slider 20. This striker 16 has a determinate thickness, sufficient to provide rigid support to boss 22 with pressure compatible with the material from which the latter is made . Still with reference to figure 3, anti-forcing device 30 includes, in addition, a positioning device 70 of elastic type, capable of applying a transverse force on slider 20, oriented towards plate 11, to maintain slider 20 in the respective position P visible in figures 1, 2 and 3, with boss 22 facing and scarcely any distance from striker 16. This is in order to prevent accidental disengagement of slider 20 from face 12 of plate 11, and the possible resulting release of slider 20 from the locked operating position. In particular, this thrust is exercised on slider 20 by positioning device 70 through a respective profile-cam pair 71 which includes an elastic body 19 carried by striker 16 in the direction of slider 20, and a profile 72 carried by slider 20 in an end position in the direction of striker 16. Body 19 and profile 72 are both fork-shaped and therefore provided with respective prongs 73 and 75. In particular, with reference to figures 1 and 2, prongs 73 are provided with respective portions of free end 74, rounded on the side facing slider 20, and prongs 75 are

provided with respective seats 76 capable of receiving and housing selectively ends 74, as may be seen clearly in figure 3. In virtue of what is described above, ends 74 and housings 76 are capable of exchanging with each other the above-mentioned transverse thrust both in static conditions, when ends 74 are housed in seats 76, and in dynamic conditions in which, as will be seen below, slider 20 is rotated clockwise in figure 1 until it takes up position P' in figure 4, and subsequently transferred towards striker 16 to take up position P'' in figure 5, in which slider 20 is at the end of its movement. Ends 74 and seats 76 therefore are capable of operating in mutual sliding contact to prevent accidental disengagement of slider 20 from plate 11, and the consequent release of slider 20 from locking operating position P; in order to constantly counterbalance the thrusts exerted on prongs 75 by ends 74, and to avoid twisting of the corresponding portion of slider 20.

It should be observed that boss 22 of slider 20 is constantly and completely contained within volume V, both when slider 20 is arranged in the respective position P, and during all the activations which are operationally imposed on it because of operational necessities connected with the commutation of bolt 21 from the position of engagement with the seat known and not illustrated, and in order to be able subsequently to open leaf 2 by sliding. This circumstance has notable importance given that in this type of handle the anti-forcing device 30 is for this reason protected from the outside and is inaccessible to attempts at forcing or violence, and exempt from problems which may be brought about by inattention or improper use of the handle itself.

In addition, the anti-forcing device 30 includes an unlocking device 40 capable of releasing slider 20 from

striker 16 to permit, in succession, the longitudinal activation of slider 20 from the respective locked operative position P, and the superimposition of boss 22 on striker 16, as may be seen in sequence in figures 4 and 5. Device 40 includes a guide 42 contained completely within volume V which presents, on the opposite side from plate 11, a surface 45 profiled in such a way as, in use, to transform a longitudinal thrust imposed on slider 20 towards striker 16 into a thrust composed of a longitudinal component and a transverse component towards the inside of volume V. It should be noted that, if handle 1 is activated from inside, and therefore from the bottom of figure 1, the commutation of slider 20 between the respective positions P and P' ' must necessarily be preceded by the application of a transverse thrust on slider 20 itself towards the inside of volume V in such a way as to release boss 22 from the corresponding striker 16. Only at this point will it be possible to exploit the function of guide 42 as has been described above. In this way it is possible to avoid accidental contact and/or impact of boss 22 against striker 16, following which the integrity of the less hard element could be compromised, and with it the proper operation of handle 1 in its entirety. To this end, slider 20 presents at least one slide 24 couplable in sliding manner to guide 42 in the vicinity of the respective surface 45, and arranged above the latter in figure 3 on the opposite side to striker 16. Naturally, guide 42 can even be eliminated, but, in the absence of this part, it is necessary operationally to commute handle 1 acting with extreme care on slider 20 to avoid contacts and/or impacts between boss 22 and striker 16.

In the case of a handle 1 activatable only from the inside, and therefore by acting on slider 20 from the bottom in figure 1, guide 42 can be maintained fixed with

respect to casing 10 through a simple mortise known and not illustrated which by its shape engages U-shaped housing 18 by at least one of the sides 14, but can also be movable. Alternatively, when it is required that handle 1 should be activatable from the outside also, and therefore from the top of figure 1, unlocking device 40 is set up to cooperate selectively with an actuating device 50 on slider 20 activatable from the opposite side of plate 11 from sides 14, and guide 42 can be formed by means of a lever which, for convenience of description and representation, will be indicated by the same identification number 42, considering also that the shape of the active part of the object is substantially identical with reference to the relative surface 45. This actuation device 50 is clearly of reversible type as will be easily understood from what follows .

Still with reference to figure 3, lever 42 can be pivoted on casing 10 in the vicinity of the same U-shaped seat 18 around a respective transverse axis 43. Lever 42, furthermore, is provided with a first driven arm 44, which is located to the left of axis 43 in figure 3, and a second driving arm 46, which is located to the right of axis 43 in figure 3, and is delimited in an upwards direction in figure 3 by surface 45. In addition, the actuation device 50 includes a cam-tappet pair 52 in which a tappet 54 is rotatable with respect to a transverse axis 55 and the cam 56 is formed, in its turn, in a driver 58 movable longitudinally, connected in sliding manner with sides 14 and the first end 44 of lever 42. The driver 58 presents, on the side facing plate 11, a convex surface 59, rounded at the ends to take up contact gradually with arm 44 of lever 42 and start off the raising of boss 22.

Tappet 54 can be activated in a known way by a lock 80 provided with a respective operating key 81.

In particular, with reference to figures 5 and 6, driver 58 presents centrally a slot 60 which is delimited longitudinally by two projections 62. This slot 60 has a width sufficient to house a tooth 26 carried rigidly by slider 20 on the opposite side from plate 11. Projections 62 are capable of functioning as end-stops for coupling alternatively with tooth 26, and for dragging the slider 20 longitudinally, and slot 60 has an extension which exceeds in length the distance L between the position of the end of boss 22 when slider 20 is in the operating locking position P shown in figures 1, 2 and 3 and the position of the end of boss 22 when the slider 20 is in the position shown in figure 5, below the prongs of elastic body 19. This distance L represents substantially the longitudinal stroke of slider 20, and is visible only in figure 5. This allows the dragging of slider 20 to occur only with boss 22 already raised, and therefore allows slider 20 to be maintained in pause for as long as is necessary for the complete raising of boss 22 above striker 16. Finally, it is clear that modifications and variations may be made to the recessed handle here described and illustrated without for this reason departing from the protective compass of the present invention. By virtue of what is described above, anti-forcing device 30 does not require the presence of steps in association with slider 20, given that the latter is completely contained within volume V at every stage of the commutation of handle 1. For this reason slider 20, besides having a shape fairly easy to obtain by moulding, and besides being constantly protected from outside interference, voluntary or accidental, is not exposed to the problem of friction in its ordinary operation, but, if at all, only in the case of attempts at forcing, which furthermore it is capable of resisting effectively, since dismantling of handle 1 is necessary for

access to device 30 itself. For this reason, every handle equipped with an anti-forcing device similar to device 30 allows resolution of the disadvantages of known recessed handles, and satisfies a series of requirements still unanswered in the current state of affairs, among them also a lower cost of production. Therefore, every handle equivalent to handle 1 is such as to represent a new and original source of economic advantage, capable of altering the current market for recessed handles. In addition, it should be noted that the procedure for manual actuation of anti-forcing device 30, or for actuating the latter through device 50, allows the definition of an innovative and original method for the commutation of slider 20, which could also be implemented in recessed handles dissimilar to handle 1. The introduction of a lifting phase which precedes the phase of longitudinal activation of slider 20 from the respective locking operating position P, allows the said striker 16 and boss 20 to be kept constantly apart in use, and allows frontal contact and the consequent deterioration by friction, to be avoided. Naturally the principal means of achieving this result is lever 42, which can be kept fixed or installed rotatably with respect to casing 10, on the basis of commercial choices, which lie outside the purposes of what has been described. By virtue of what has been described above, anti- forcing device 30 is of universal use, and can be implemented on recessed handles provided with locking devices different from device 40 and possibly similar to the type described with reference to US Patent 6050617.