Antislip apparatus for footwear

Abstract: The object of the invention is an antislip apparatus for footwear which is made up of a structure (1) able to fit on a region (2) of the sole and/or the heel of a shoe in contact with the ground and comprising ground-gripping means (50) made up of one or more crampon-like prongs (50), means (6) for moving the grip means (50) and able to dispose the latter to either a grip or rest positions in which, respectively, the prongs protrude from the lower surface (20) of the shoe or result inwardly of the same surface, and means (7) for operating the driving means (6) being accessible from the same lower surface (20) of the shoe.

Description: It is known to be quite difficult to walk on surfaces having low coefficient of friction, such as frozen grounds, roadways and sidewalks. To overcome this problem, the prior art has provided shoes with rubber soles with marked protrusions or engravings. Such shoes, although having a sufficient grip on fresh snow, do not provide a safe hold in case of frozen surfaces. An alternative to this solution is represented by metal, crampon-like prongs to be applied to the shoes. This solution provides a good grip but' results bulky and makes it necessary to add an accessory to the shoes which thus cannot be uses as such. The documents DE-A-1957191, FR-A-1521753, US-A-1487976, FR-A-2567004, FR-A-1116046 and US-A-5870838 describe antislip apparatus for footwear with ground gripping means comprising cramp-like prongs protruding of the lower surface of the shoe surface. These apparatus have means for moving the grip means and able to dispose the latter to either a grip or rest positions in which, respectively, the prongs protrude from the lower surface of the shoe or result inwardly of the same surface, and operating means for operating the driving means. The known antislip apparatus provide a suitable grip on the ground but they are not completely integrated with the shoe and, for this reason, they are visible during the use of the shoes. Furthermore, in the known antislip apparatus, the means for operating the driving means is constituted by a lever o similar element protruding out of the body of the apparatus. This feature is a drawback in the manufacturing of the shoe because it increases the production time and the relevant cost. The object of the present invention is an apparatus able to provide a a sufficient grip on slippery grounds for footwear of sport type as well of traditional type for everyday use. This result has been achieved, according to the invention, by providing an apparatus having the characteristics described in claim 1. Further characteristics being set forth in the dependent claims. The advantages of the present invention lie in that the antislip apparatus provides a suitable grip on the ground and is fully integrated with the shoe, that the apparatus is undetectable by anyone looking at the shoe so that it can be used on traditional and/or elegant footwear, that the apparatus is of simple and ready utilization, exhibits a robust structure and is able to maintain its features also after a prolonged wear. These and other advantages and characteristics of the invention will be best understood by anyone skilled in the art from a reading of the following description in conjunction with the attached drawings given as a practical exemplification of the invention, but not to be considered in a limitative sense, wherein: Figs. 1a, 1b shows an embodiment of the invention associated to a heel of a footwear article, in front view and plan view, respectively, with cutaway parts to show others more clearly; Figs. 2a, 2b are, respectively, a side view and a top view of a detail of the embodiment shown in Figs. 1a and 1b, relating to an operating rotor element; Figs. 3a, 3b are, respectively, a top view and a sectioned view on line III-III in Fig. 3a, of a detail of the embodiment illustrated in Figs. 1a and 1b, relating to a driving plate; Figs. 4a, 4b are, respectively, a top view and a sectioned view on line IV-IV in Fig. 4a, of a detail of the embodiment illustrated in Figs. 1a and 1b, relating to a cover; Figs. 5a, 5b are, respectively, a top view and a sectioned view on line V-V in Fig. 5a, of a detail of the embodiment illustrated in Figs. 1a and 1b, relating to a box-like element; and Figs. 6a, 6b are, respectively, a side view and a top view of a detail of the embodiment illustrated in Figs. 1a and 1b, relating to a support for prongs; Fig. 6b illustrating also a detail in sectional view relating to the shape of a slot. An apparatus constructed according to the present invention and designated by (1) in its entirety, can be associated to a footwear article at a region thereof which faces the lower surface in contact with the ground. In this embodiment, the apparatus (1) is fitted on a heel (2) of a traditional shoe for men, the lower surface of the same shoe being indicated by (20). The apparatus may also be associated to other types of footwear such as sport shoes, mountaineering boots, ski-boots, woman shoes, etc. In the illustrated example, the apparatus (1) comprises a box-like holding element (3) closed by a cover (4). The box-like holding element (3) has a substantially cylindrical, upwardly open shape on the base (30) of which there are provided a central through hole (39) and four through slots (38) angularly equidistant. The cover (4) is of circular shape and exhibits a central through hole (40) and a pin (49) which protrudes from the lower face (48), the latter remaining inside when the cover (4) closes the box-like element (3) upon the assembly of the apparatus. Provided inside the box-like element and inwardly of cover (4) is a prongs support (5), a driving plate (6), an activation rotor (7) and a spring (8). The prongs support (5) defines the means for gripping the ground and consists, in the illustrated example, of an annular, substantially flat body from which four angularly equidistant prongs (5) protrude orthogonally (that is, disposed at 90° to each other). The prongs (50) are made up of laminae having serrated free ends (59) with such longitudinal development and thickness allowing them to be introduced into straight slots (38) of the box-like element (3) previously described. The support (5) for the prongs is also provided with four slots having curved development (55) and disposed angularly equidistant along a circular crown (54). In particular, the four slots (55) are offset by 45° to the prongs (50) and are separated by solid lengths (58). Possibly provided between the solid lengths (58) and the slots (55) are flaring ramps (56) likewise those more clearly visible in the enlarged sectional view of the detail in Fig. 6b. The flaring ramps (56) are provided in pairs on the sides of each slot (55) and exhibit a profile extending towards the side of the adjacent solid length (58). The driving plate (6) is circular in shape and has a square through hole (60) in the middle, and a slot (65) develops along an arc under a preset angle and around the central hole (60) at a distance from the centre corresponding to the spacing between the central hole (40) of cover (4) and the pin (49) provided on the same cover. The width of the slot (65) is such as to allow the insertion of the pin (49) into the same slot. Also provided on the lower side (69) of plate (6) are four cams (61) having an arcuate convex profile. The operating rotor (7) is made up of a substantially cylindrical body with different sections along its height. In its upper end, the rotor (7) has a cylindrical portion (70) of such a diameter as to result insertable into the central hole (40) of cover (4). Under said cylindrical portion (70), the rotor (7) exhibits a square portion (75) which can be inserted into the square hole (60) of the driving plate (6) so as to result solid to the latter during the rotational movement. Provided below the square portion (75) are a central portion (78) of larger cross-section and a lower portion (76) of a diameter corresponding to that of the central hole (39) provided on the box-like element (3). The lower portion (76) has a seat (77) at its free end, which seat is defined by a groove or cut disposed diametrally with respect to the rotor (7). The seat (77) results thus accessible through the central hole (39) also when the apparatus is assembled. Once assembled, the apparatus (1) may have the configuration shown in Figs. 1a and 1b. In practice, the box-like element (3) results closed on top by the cover (4) which has its pin (49) extending downwards. Disposed just below the cover (4) is the driving plate (6) into the slot (65) of which the pin (49) goes through, while the square portion (75) of rotor (7), disposed centrally in the apparatus (1), goes through the square hole (60) thereof. The plate (6) has its cams (61) facing downwards and resting on the support (5), the latter being urged upwards by the spring (8) which is made to act between the inner face of the box-like element (3) and the same support (5). The prongs (50) of support (5) are disposed in correspondence of straight slots (38) of the box-like element (3) and are able to come out thereof when the apparatus (1) is in operative condition, that is, with the prongs (50) in gripping position. As previously mentioned, the rotor (7) is disposed centrally, solid with the plate (6), and its portions interact with the other structural components of the apparatus (1) as described later on. The upper cylindrical portion (70) is inserted into the central hole (40) of the cover (4); the central portion (78) is disposed inwardly of the prongs support (5), it is not solid with the latter, and the periphery of its lower face (79) is in contact with the upper (inner) face of the cover (3), so that it can rotate relative to the latter; finally, the lower portion (76) has the seat (77) turned downwards so as to allow the rotor (7) to be rotated with ease by means of a coin or a screwdriver or the like. By rotating the seat (77) and thus the whole rotor (7), the latter drives into rotation the driving plate (6) solid thereto. The rotation of the plate (6) causes the cams (61) to slide along the crown (54) defined by the sequence of slots (55) and solid lengths (58) of the support (5). When the cams (61) are inserted into the slots (55), the apparatus (1) is pack-closed and the prongs (50) do not protrude from the lower surface of the shoe because the spring urges the support (5) upwards. When, on the other hand, the cams (61) interact with the solid lengths (58), the support (5) is urged downwards and the prongs (50) result in a gripping condition, as shown in Fig. la. The return of prongs (50) to the retracted or rest position is caused by the spring (8) urging the support (5) upwards, as the latter is no longer subject to the downwardly directd action of the cams (61). The movement between the solid lengths (58) and the slots (55) of the crown (54) is made more smmothly in both directions by the presence of the flaring ramps (56) previously described. The rotation of the rotor (7) and of plate (6) solid thereto is limited by the extension of the curved slot (65) of plate (6) within which the pin (49) of cover (4) is made to slide. The association of the apparatus (1) to the footwear article may be made in various ways. In fact, it is possible either to mount the apparatus (1) inside the heel when manufacturing the shoe, or to provide a heel having the apparatus already inside it and associate the heel to the shoe afterwards. In case of ski-boots or shoes with plastics or rubber soles, it is possible to embed the apparatus (1) within a portion of the sole. For example, reference being made to what is illustrated in Fig. 1a, the structure (1) will result inside the heel (2) and, on the lower surface (20) thereof, slots will be provided allowing the passage of prongs (50) in case of activation of the latter. In any case, a shoe will be obtained which, when looking at it laterally or from above will not exhibit any aesthetical differences to a corresponding shoe non equipped with the apparatus.

Claims: Antislip apparatus for footwear, consisting of a structure (1) to be fit on a region (2) of the sole and/or the heel of a shoe in contact with the ground and comprising ground-gripping means (50) made up of one or more crampon-like prongs (50) disposed on a support (5), cam means (6) interacting with said support (5) so as to vertically move said one or more prongs (50) to dispose the latter to either a grip or rest positions in which, respectively, the prongs protrude from the lower surface (20) of the shoe or result inwardly of the same surface, and means (7) for operating the cam means (6), said support (5) for said one or more prongs (50) being made up of a body on which said prongs (50) are disposed perpendicularly, said cam means comprising a plate (6) disposed substantially parallel to said support (5) and being provided with one or more cams (61) intended to interact either with the support (5) so as to vary the distance between said support (5) and said plate (6) thereby moving said one or more prongs (50), antislip apparatus characterized in that said means (7) for operating the cam means (6) consist of a substantially cylindrical rotor (7) integral to said plate (6), disposed perpendicularly to said support (5) and having - at a lower end thereof accessible from the lower surface of the shoe - a seat (77) defined by a groove or cut and in that said structure (1) comprises a holding box-like element (3) provided below - on the lower surface of said element to be disposed in correspondence of the lower surface of the shoe (20) - with a centrally drilled region (39), allowing access to said operating means (7), and one or more slots (38) which said prongs (50) are able to go through. Apparatus according to claim 1, characterized in that said support (5) is made up of an annular body having one or more slots (55) as well as one or more solid lengths (58) located along a circular crown (54), angularly correlated to said prongs (50). Apparatus according to claims 1, characterized in that said plate (6) and support (5) are disposed inside said box-like element (3), with the plate (6) being located above, elastic means (8) being provided acting between said box-like element (3) and said support (5), which means are able to impart a thrust in a direction opposite to the action exerted by said one or more cams (61) on said support (5) upon their interaction with said solid lengths (58). Apparatus according to claims 1, characterized in that it comprises a cover (4) closing said box-like element (3) and exhibiting a pin (49) on its lower face (48), that is, inwardly of the structure (1), said plate (6) being able to rotate relative to said cover (4) and exhibiting a curved slot (65) inside which said pin (49) in inserted to define a travel of such angular displacement corresponding to a preset rotation of the cover (4) with respect to the plate (6). Apparatus according to claim 1 characterized in that said driving plate (6) features a central square bore (60) and that said rotor (7) features a corresponding square portion (75) for a stable coupling with said plate (6). Apparatus according to the preceding claims, characterized in that said rotor (7) is made up of a substantially cylindrical body provided with a cylindrical portion (70) located above said square portion (75) and of a diameter suitable for insertion thereof into a central hole (40) of said cover (4), and. with a central portion (78) of larger cross-section and a lower portion (76), the latter having a diameter corresponding to the one of the central hole (39) formed on said box-like element (3) and being provided with said seat (77). Apparatus according to claim 3, characterized in that said support (3) is made up of a substantially flat body from which said angularly equidistant prongs (50) extend perpendicularly, and on which, along a circular crown, said slots (55) and solid lengths are connected between them through flaring ramps (56).

Inventors: CALABRESE ANTONINO, GUIZZARDI SERGIO
Applicants: CALABRESE ANTONINO, SAMET PLAST S R L, CALABRESE, ANTONINO, SAMET PLAST S.R.L
Application year: 1999
Main classification: A43C15
IPC codes: A43C15