Improvements in anchoring anti-skid members to soles provided with retractable anti-skid means and related manufacturing methods

Abstract

An improved anti-slip device for a sole in which anti-slip or non-slip means, such as nails or hooks, are provided, which are not directly fixed to the sole, but are fixed to rigid or semi-rigid means which can be folded into grooves formed in the sole itself, wherein each anti-slip component (10) and its component (24) fixed to the sole and provided with its own latching means (25) are connected to each other in a non-removable manner by means of a joint (14) provided with a double-ended steel pin (15) having protruding ends forming an axis of rotation about which the anti-slip component (10) can be rotated 180 DEG, the joint is provided on opposite sides with projecting appendages (16) having eyelets (18) and forming a 90 DEG center of rotation of the shaft (26) of the member (24) anchored to the sole, perpendicular to the steel pin (15), so that the anchoring member (24) cannot be separated from the anti-slip member (10). In molding from a suitable plastic material, the joint (14) is joined by overmolding using another plastic material having a different melting point so as to obtain a single member together with the anchoring member (24) and the anti-slip member (10), avoiding any accidental separation of the assembly, but maintaining the degree of freedom of movement of the different parts.

Description

Technical Field

[0001] The present invention relates to an improvement in an anti-skid device for a shoe sole and a related method for its manufacture, in which an anti-skid or anti-slip device, such as a spike or a hook, is provided, which is not fixed directly to the sole but to a rigid or semi-rigid device which can be folded into a groove obtained in the sole itself.

[0002] More particularly, the present invention relates to an improvement, and an associated method of manufacture, involving anchoring a support member of an anti-slip device to a shoe sole, which for brevity will be referred to below as an anti-slip member, which may be used in several of the scenarios described in the background section. Background Art

[0003] In the anti-slip device disclosed in Italian Patent 102017000024298, the anti-slip device is fixed to a reversible rigid or semi-rigid member, which is preferably made of a semi-rigid plastic material and is able to transition from a first groove or recess obtained on the sole to a second groove that is mirror-symmetrical to the previous groove, wherein the catch is accommodated in a suitable cavity obtained at the bottom of the groove, which accommodates the rigid member, and wherein the reversal / lifting of the supporting member (rod, arch or even more complex shape) occurs around an axis coplanar with the sole, by means of pins protruding from opposite sides of the lower end of the member, which are snap-fastened into a corresponding rotating seat obtained in the shape of a cube, which is provided with a mushroom-shaped pin, which is fixed in a special cavity obtained in the side sole of the groove of the support member accommodating the anti-slip device.

[0004] Or about the anti-skid device disclosed in patent EP1558103 of the same applicant, in which the anti-skid device is fixed to a rigid or semi-rigid supporting member, which is hinged to the sole like a flag so that it can be raised and lowered relative to the sole and can be rotated at least 180° relative to the symmetry axis of the supporting member, which is different from the hinge / lifting axis relative to the sole and is not parallel to the hinge / lifting axis, so as to use a single groove to retract the surface with the grab hook when the grab hook does not need to be in contact with the ground.

[0005] In both cases, the articulated / rotating seat of the anti-slip element is not obtained integrally with the element itself, but on an auxiliary element (in this case in the form of a parallelepiped or a cube) which acts as a foot anchored to the sole by means of mushroom-shaped elements with which they are provided, which snap-fasten into corresponding seats arranged to be molded in the sole, close to the groove which accommodates the reversible supporting element after its reversal, without disturbing the integrity of the sole itself, avoiding disintegration and loss of the sole due to a simple twisting of the bottom.

[0006] However, it has been stressed that any replacement of the reversible anti-slip element due to breakage, loss or wear caused by accidental causes or due to wear and tear caused by constant and prolonged use is rather inconvenient, since the pulling action that makes it possible to extract the reversible element from its fixed seat often leaves behind the mushroom and the cube anchored to the sole. This is because, when interference on the sole forces the anti-slip element to be elastically extracted, the greatest stress occurs precisely at the rotating seat of the reversible anti-slip element obtained in the form of a cube, which is not integral with the body of the same reversible element but can be easily detached therefrom, which remains anchored to the sole.

[0007] This obviously leads to a longer replacement time, since the cube also needs to be removed manually from the receiving seat of the support member in the sole.

[0008] It is also emphasized that in previous technical solutions, a joint has been used, which forms a rotating and / or flipping support for the anti-slip member, the joint being provided with a double-headed through pin made of steel to allow the anti-slip member to rotate 180°, and another protruding pin made of steel being provided perpendicular to the double-headed through pin, which alternatively forms a 90° rotation axis of the same anti-slip member: therefore, after the entire system is completed, a special machine is used to insert the mushroom-shaped coupling through the joint.

[0009] However, this technical solution is complex and significantly increases production time and costs. Summary of the invention

[0010] A first task of the present invention is to overcome all the disadvantages of the prior art described above, by providing a member of an anti-slip member to be anchored to the sole, which member:

[0011] forming a single body with means, such as a mushroom-shaped member, which allow the member to be fixed to the sole itself; and

[0012] It is connected in an irremovable manner to a rigid or semi-rigid material element which forms a rotation and / or tilting seat for the anti-slip element, for which purpose an innovative joint is provided which forms a single body with the anti-slip element, avoiding any possible splitting of the assembly.

[0013] Another task of the present invention is to overcome all the drawbacks of the prior art described above, providing a connection between a member of rigid or semi-rigid material which, when moulded, obtains the element to be anchored to the sole and which forms the rotation and / or turnover seat of the anti-slip element, also introducing, by overmoulding, a suitable innovative joint made of the same material from which the element is obtained, which allows moulding a single body, maintaining freedom of movement of the different parts but avoiding accidental separation of the assembly.

[0014] Therefore, even when a traction force required to extract the sole is applied to the sole, the member anchored to the sole cannot be detached from the anti-slip member.

[0015] According to a preferred embodiment of the invention, this result is achieved by providing a joint molded from plastic material, provided with a first steel pin protruding above along its axis of symmetry for forming an axis of rotation about which the anti-slip member can be rotated by 180° to flip over, switching from a rest position to an operating position, and below which an eyelet-shaped perforated attachment is provided, which forms a seat for shaping the member to be anchored to the sole relative to the axis of rotation during the subsequent overmolding, about which the joint can be rotated by 90° relative to the anchoring plane, and which is perpendicular to the aforementioned first axis of rotation of 180°, so that the anti-slip member can travel a sufficient angular travel to rise from the receiving impression to allow complete flipping. With this configuration, once molded, the joint is reloaded on a mold that is unique to the entire structure and includes both the shape of the anti-slip member and the shape of the member provided with the sole anchoring means, so as to position the joint between the shape of the anti-slip member and the shape of the anchoring member.

[0016] According to a unique feature of the invention, a plastic material is used for the subsequent moulding of the entire structure, which plastic material has a melting point different from that of the material from which the joint is made.

[0017] By molding two components and simultaneously overmolding the joint, an integral structure is obtained, which includes a support member for the anti-slip device, the aforementioned joint and a member provided with one or more fastening devices for positioning and anchoring the member on the sole. Therefore, the entire structure allows the anti-slip member to be raised and lowered relative to the member in the housing impression obtained by anchoring the anti-slip member in the sole, and the same anti-slip member to be rotated 180° relative to the same anchoring member so as to flip the anti-slip member when it is intended to switch from a working position to a static position, and vice versa. At the same time, any accidental release is avoided. This is because, as described below, the two different materials of the parts of the structural member, such as TPU and nylon, are not bonded to each other in any way, allowing the parts to be connected by overmolding with the help of a steel pin, which protrudes from the joint embedded in the anti-slip member, and by forming a horizontal axis, which is perpendicular to the previous horizontal axis that connects the member anchored to the sole to the same joint, but since there is no bonding between the two materials forming the parts, the parts are free to rotate relative to each other.

[0018] It should be noted that the materials of which the joint and the member anchored to the sole are made are nylon and TPU and are shown here as preferred exemplary embodiments, but this choice is not limiting, as it is sufficient to use suitable plastic materials with different melting points and which do not stick together when overmolded.

[0019] The use of the described joint and subsequent overmolding enables:

[0020] The operation of loading steel pins when molding a traditional joint is avoided, this operation being replaced by pins obtained in an overmolding step, integral with the member anchored to the sole, while reducing production time and costs;

[0021] Since when the joint is overmolded with another plastic material having a different melting point (in this example, nylon and thermoplastic polyurethane TPU), the entire structure of the finished reversible member with the coupling device is obtained, the separate molding of the mushroom-shaped coupling is eliminated;

[0022] Then after the system is completed, the assembly of the mushroom coupling is omitted; and

[0023] Avoid accidental detachment of the mushroom coupling from the steel pin.

[0024] Other characteristics and advantages of the invention will become apparent from the accompanying drawings which show, by way of non-limiting example only, a preferred embodiment of the invention in which there are two mushroom-shaped members of the member anchored to the sole. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In the accompanying drawings, Figure 1 5E to 5E relate to systems in use according to the prior art:

[0026] Figure 1 A first anti-slip member of a known type is shown, in which there is a joint connected to the sole by two separately moulded mushrooms;

[0027] Figure 2 Shown with Figure 1 Two mushrooms assembled manually by the same joint, which in their working position will be anchored to the sole;

[0028] Figure 3 and Figure 4 shows the step of extracting, by traction, the anti-slip member of the previous figures from its fixing seat on the sole, highlighting a defect often found in practice, namely that one of the fixing mushrooms, not being integral with the rest of the structure, remains anchored to the sole, thus prolonging the replacement time;

[0029] Figure 5A is an exploded view of the different parts of a joint forming another updated anti-slip member, showing the need for a complex and laborious assembly of its different parts, including a nylon joint with a double-headed pin rotated 180°, a steel pin inserted and rotated 90°, and a Figure 5B The TPU arch is overmolded. Figure 5BA side view of the anti-slip member is shown with the catch hook facing upward;

[0030] Figure 5C Shows the installation Figure 5D A perspective view of the same anti-slip member before the mushroom-shaped coupling is shown, and

[0031] FIG. 5E finally shows a side view of the anti-slip member of the grab hook coupling facing downward after manual assembly of the mushroom coupling;

[0032] Fig. 6A is a view of the parts forming a joint according to the invention, wherein the joint is provided on one side with an attachment having an eyelet, while on the opposite side a part of a double-headed pin projects for a 180° rotation of the anti-slip member;

[0033] Figure 6B is a partial cross-sectional view of an entire structure or complex according to the invention which has been obtained by overmolding with a plastic material having a melting point different from that of the material from which the joint is made. Fig. 6A The mushroom-shaped coupling is made of the same material as the 90° rotation pin of the anti-slip member when the entire composite is molded;

[0034] Figure 6C is with Figure 6B a perspective view of the same structure or complex, with an anti-slip member, a joint and an anchoring member, which, by way of non-limiting example only, is provided with a single mushroom-shaped coupling;

[0035] Fig.6D yes Figure 6C a side view of the middle complex with the grappling hooks of the anti-slip member facing downward;

[0036] Figure 7 and Figure 8 It is shown how the removal of the anti-slip member with the grab hook according to the invention can be easily performed with a simple traction which allows the anti-slip member to be completely extracted from its fixing seat together with the fixing mushroom(s) since they are an integral part of a single structure;

[0037] Fig. 9 and Fig.10 shows, in different embodiments, the complex composed of the anti-slip member, the joint and the anchoring member of FIG. 6 , when it is positioned separately in the impression of a shell in the sole and, once lifted from the same impression, partially rotated relative to the member connecting it to the sole, the complex being obtained in one piece after overmolding;

[0038] The following figures illustrate the different steps of the method for manufacturing the anti-slip element of the invention, which steps can obviously take the most completely different forms depending on the mould used. In particular:

[0039] Fig.11 A top plan view of a multi-imprint mold for molding a nylon connector is shown, and a double-ended steel pin is manually loaded for 180° rotation prior to molding the nylon connector;

[0040] Fig.12 A nylon connector including a steel pin is shown. Fig.11 Exit from the mold;

[0041] Fig.13 Shows the reloading of the pinned nylon connector onto a multi-imprint die of a simple circular design prior to TPU overmolding of the entire anti-slip system;

[0042] Fig.14 It is shown that once the structural coating made of TPU is overmolded on the nylon joint, the entire anti-slip system equipped with the joint is completed;

[0043] Fig.15A and Fig. 15B They are shown respectively by Fig.14 Vertical cross-sectional plan view and horizontal cross-sectional elevation view of the structure or composite consisting of anti-slip members, joints and anchoring members. DETAILED DESCRIPTION

[0044] like Figure 3 and Figure 4 As shown, since the technical products currently sold on the market are not obtained in one piece, in addition to involving several manual assembly steps, they have the serious drawback of separating from each other if subjected to strong traction, whereby it often happens that during replacement, some fixing components remain in place, thus requiring further intervention and with considerable loss of time.

[0045] In fact, the joint 4 is made by inserting, in addition to the double-ended steel pin 6, another steel pin 8 allowing a 90° rotation, into which the mushroom coupling 25 is inserted by a special machine after the system is completed. However, this does not ensure durability in position under significant stresses that could cause the pin 8 to release from the mushroom coupling 25.

[0046] In order to avoid this drawback, the views depicted forward in FIG. 6 have been implemented, which illustrate some embodiments of the invention, given purely by way of non-limiting example.

[0047] With reference to these figures, the object of the present invention is a structure comprising:

[0048] an anti-slip gripper holder 10 , preferably made of TPU, thermoplastic polyurethane, which is an elastic material with high abrasion and chemical resistance, in the form of a rod, an arch or even more complex shapes, on which spikes or grippers 12 adapted to grip snow and / or icy surfaces are distributed;

[0049] a nylon joint 14 incorporating a double-ended steel pin 15 for the 180° rotation of the grab holder 10, while at the opposite end 16 the joint 14 is provided with an eyelet 18 forming a seat for a 90° rotation axis 26 of a member 24 fixed to the sole, which instead of being perpendicular to the rotation axis of the grab holder 10, as shown, and

[0050] Part 24, anchored to the sole, is made of TPU, ie of the same thermoplastic material as the anti-slip member 10, adapted to be fastened by one or more fastening means (eg Figure 5D The mushroom-shaped pin 25 shown is fixed to the sole, the fastening means being snap-fastened into a corresponding seat arranged in the sole close to the groove which accommodates the reversible supporting member after reversal.

[0051] According to the invention, once the nylon joint 14 has been obtained by molding, it is reloaded onto the multi-imprinting mold used to mold the entire structure, positioned on the anti-slip member 10 with its steel pin 15 so that it is hinged like a flag, while at its opposite end, in the eyelet 18, a TPU shaft 26 is formed by overmolding, which connects the joint to the anchoring member 24.

[0052] Thus, the joint 14 is made integrally with both the anti-slip hook holder 10 and the member 24 anchored to the sole, obtained integrally with the mushroom-shaped pin 25, without preventing relative movements to each other, i.e. rotation and flipping, since there is no adhesion between nylon and TPU, which would also occur when using any other selected pair of suitable plastic materials with different melting points, which would not adhere to each other when overmolding.

[0053] Fig.11 The different steps of manufacturing the anti-skid system of the present invention are shown above, including:

[0054] a) First, a plastic material such as nylon is molded in a mold A ( Fig.11 ), in the case shown the mold A is multiple, the joint 14 is manually loaded with double-headed steel pins, so that each joint 14 carries a protruding steel pin 15, and at the opposite end, the joint is as Fig.12 shaped as shown so as to have a protruding appendix 16 with an eye 18 adapted to form, during subsequent overmolding, the centre of rotation of a shaft 26 obtained integrally with the anchoring member 24 , perpendicular to the axis of rotation of the anti-slip member;

[0055] b) providing a multi-imprinting mould B arranged for simultaneously moulding the anti-slip element 10 and its element 24 for anchoring to the sole, with the joint 14 interposed therebetween, wherein the element 24 has been provided with mushroom-shaped pins 25;

[0056] c) loading the joint 14 into the multiple-imprinting mold B, positioning the joint 14 between the imprints of the anti-slip member 10 and the imprints of the member 24 anchored to the sole, and performing a molding operation by selecting a plastic material having a melting point different from that of the molded joint 14, also overmolding the joint, so as to obtain the anti-slip member 10, the member 24 anchored to the sole and the joint 14 forming a single structure obtained in one piece. Thus, it is avoided that the member 24 anchored to the sole is integrated with its mushroom-shaped pin 25, and it can be detached from the anti-slip member 10 even if the elastic force required to extract the anti-slip member 10 is applied to the sole, as Fig. 9 and Fig.10 As shown, they do not prevent relative movement, i.e. rotation and tilting, with each other, because there is no adhesion between the materials forming them.

[0057] A preferred embodiment of the manufacture has been described herein. Obviously, numerous modifications and variations may be made by a person skilled in the art, particularly in terms of the number, position and shape of the fixing members carried by the member anchored to the sole, without departing from the scope of the invention as defined by the appended claims.

Claims

1. An improved anti-skid device for a shoe sole, wherein in an anti-skid device of this type, anti-skid or anti-slip means, such as spikes or hooks, are provided, said means being not fixed directly to the shoe sole, but to a rigid or semi-rigid means which can be folded into a groove provided in the shoe sole, characterised in that Each anti-slip member (10) and its component (24) are connected to each other in an undetachable manner by a joint (14) provided with a double-headed steel pin (15), the component (24) being anchored to the sole and provided with a locking fastening device (25) of the component (24) itself, the double-headed steel pin having a protruding end forming a rotation axis, the anti-slip member (10) being able to rotate 180° around the rotation axis, the joint being provided with a protruding attachment (16) on the opposite side, the attachment having an eyelet (18), the eyelet forming a 90° rotation center axis (26) of the component (24) anchored to the sole, the rotation center axis (26) being perpendicular to the steel pin (15), so that even if the elastic force required for separation from the anti-slip member (10) is applied to the sole, the anchoring part (24) cannot be separated from the anti-slip member (10).

2. The improved anti-slip device for the sole according to claim 1, characterized in that: The anti-slip member (10) and the anchoring member (24) with the fastening means (25) and the shaft (26) are made by molding into one part from the same plastic material, thereby forming a single overmolded part, so that a joint (14) is placed between the anti-slip member (10) and the anchoring member (24), the joint being molded from a plastic material having a melting point different from that of the overmolded part, so that the joint (14) is integral with both the anti-slip member (10) and the member (24) anchored to the sole, however, since the materials of the two members cannot adhere to each other, the movement of the two members relative to each other, i.e. rotational and flipping movements, cannot be hindered.

3. The anti-slip device for the sole according to claim 2, characterized in that: The anti-slip member (10) and the anchoring member (24) with its fastening means (25) are molded from TPU (thermoplastic polyurethane) so as to form a single body by overmolding, and a joint (14) molded from nylon is placed between the anti-slip member (10) and the anchoring member (24) so ​​as to make the joint integral with both the anti-slip member (10) and the member (24) anchored to the sole, however, since nylon has a different melting point from the thermoplastic polyurethane used in the overmolding, the materials of the two members cannot adhere to each other and thus cannot hinder relative movement, i.e. rotational and flipping movement, to each other.

4. An anti-slip device for a shoe sole according to any one of the preceding claims, characterized in that The fixing means of the member (24) anchored to the sole are shaped as one or more mushroom-shaped pins (25) fixed in suitable cavities provided in the sole on one side of the groove, which cavities accommodate the supporting member of the anti-slip means.

5. The anti-slip device for the sole according to claim 4, characterized in that: The fixing means for anchoring the member (24) to the sole are in the form of mushroom-shaped pins (25) aligned axially with the appendages (16) of the joint (14).

6. The anti-slip device for the sole of claim 4, characterized in that: The fixing means of the member (24) anchored to the sole are in the form of two mushroom-shaped pins (25) positioned symmetrically with respect to the attachment (16) of the joint (14).

7. A method for manufacturing the improved anti-skid device according to claim 1, characterized by the following steps: a) moulding of a joint (14) in plastic material, said joint (14) carrying a protruding steel pin (15), said joint being provided on opposite sides with protruding appendages (16) having an eyelet (18) and being able to form the centre of rotation of the shaft (26) of the anchoring member (24), said centre of rotation being perpendicular to the axis of rotation of the anti-slip member during subsequent overmoulding; b) providing a multi-imprinting mould (B) arranged for simultaneously moulding the anti-slip member (10) and its member (24) for anchoring to the sole and the fastening means (25) and the shaft (26) of the member (24), the joint (14) being placed between the anti-slip member (10) and the member (24); c) inserting the joint (14) into the multi-imprinting mold (B) and positioning the joint (14) between the imprint of the anti-slip member (10) and the imprint of the fixing member (24) anchored to the sole, and performing molding by selecting a plastic material having a melting point different from that of the material of the joint (14), and overmolding the joint so as to produce an integrated structure formed as a whole by the anti-slip member (10), the member (24) anchored to the sole by means of associated fixing means (25) and an axis (26), and the joint (14), thereby preventing the member (24) anchored to the sole by its fastening means (25) from being separated from the anti-slip member (10), even if the elastic force required for separation from the anti-slip member (10) is applied to the sole, however, without hindering the movement of the two members relative to each other, i.e. rotational and flipping movements, because the materials of the two members cannot adhere to each other.

8. The method for manufacturing an anti-slip device according to claim 7, characterized in that: The material selected for molding the joint (14) is nylon and the material selected for molding the entire structure is thermoplastic polyurethane TPU.

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