BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Further advantages and characteristic features of the device according to the present invention will emerge from the following detailed description of an embodiment thereof provided by way of a non-limiting example with reference to the accompanying plates of drawings in which:
FIG. 1 is a longitudinally sectioned view of a buckle according to the present invention;
FIG. 2 is a view, similar to that of FIG. 1, showing a different stage of operation of the buckle according to the present invention; and
FIG. 3 is a cross-sectional view along the line III-III of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an embodiment of the buckle according to the present invention; 1 denotes the body of the said buckle. Said body 1 has two side walls which at one end converge in a head 401 having, extending therefrom, the pin 501 which allows connection to the sports equipment, i.e. in this case the goggles 3, by means of insertion inside the eyelet 113 in the portion 103; the pin 501 is fastened to the eyelet 113 by means of the introduction of the mushroom-shaped end 511 of the same pin 501 inside the hole 104 of the button 4 provided with snap-engaging walls 114.
At the opposite end the side walls 101 of the body 1 carry the drive roller 201 over which the strap 2 with reliefs 102 slides; said reliefs engage with the engaging tooth 321 projecting from the free end of the tongue 301 and provided with the inclined wall 341, said tongue at the opposite end being connected to the head 401 of the body 1 and having, in the vicinity of the engaging tooth 321, the slit 311 provided with inclined transverse walls 331. The slider 5 is arranged on the body 1 and has a wide central opening 305; at one end it is provided with a pin 205 which engages inside the cavity 411 formed in the head 401 of the body 1, while in the vicinity of the opposite end said slider has a lug 105 which is inclined with respect to the sliding plane of the strap 2 at an angle similar to that of the transverse walls 331 of the slit 311 and engaged inside the said slit 311.
As can be seen from FIG. 2, where the same parts are indicated by the same number, when the slider 5 is displaced forwards towards the head 401 of the body 1, the lug 105 of the slider comes into contact with the wall 331 of the slit 311 and, as a result of this co-operation, the engaging tooth is released from its engagement with the relief 102 of the strap 2.
FIG. 3 shows a cross-section along the line III-III in FIG. 1; identical parts are indicated by the same numbers. The way in which the slider 5 is guided on the body 1 can be seen more clearly in this figure; the side walls 405 of the slider 5 are provided, on the side directed towards the body 1, with longitudinal reliefs 415 which co-operate with the grooves 111 formed on the side walls 101 of the said body 1.
The operating principle of the device according to the present invention will become clear from the description below. As mentioned above, the buckle as shown in FIG. 1 has the effect that the engaging tooth 321 allows sliding of the strap 2 only in the direction of the arrow 10, namely so as to shorten the strap around the diver's head. This operation, which is in fact common for most of the types of buckle which are commercially available, is allowed by the form of the engaging tooth 321, which has an inclined wall 341 so as to favour travel of the reliefs 102 in the predetermined direction. When, instead, the diver intends adjusting the strap so as to lengthen it, the slider 5 must be displaced towards the head 401 of the body 1 so that the inclined lug 105 comes into contact with the inclined wall 331 of the slit 311 and causes raising of the end of the tongue 301 which has the engaging tooth 321. In this way, as is clear from FIG. 2, the strap is able to slide in the direction of the arrow 20 and its length may therefore be conveniently adjusted.
As can be noted, the buckle according to the present invention has an extremely small dimensional volume and does not have any projecting part able to create an obstruction or likely to get tangled in any way with other parts of the diver's equipment. The movement which allows release of the engaging tooth is completely guided, as can be seen in FIG. 3, and balancing of the forces makes it completely symmetrical, so as to prevent sticking which with other types of devices would be attributable to not properly distributed application of the force.
Advantageously this type of buckle may be easily adapted to different types of equipment for water sports, such as diving and swimming goggles preferably, and in particular may be easily coupled with a lug projecting directly from the face-piece of the diving or swimming goggles.