Patent Publication Number: US-11388960-B2

Title: Snap button, and a female component for such snap button

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Italian Patent Application No. IT102019000016394 filed on Sep. 16, 2019, the entire contents of which are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to a snap button, also referred to as a snap fastener or press stud. 
     The invention has been developed with particular regard for a female component of a snap button, comprising a resilient member for selective connection to a corresponding male component of the same snap button. 
     TECHNOLOGICAL BACKGROUND 
     Snap buttons are widely used to keep fastened two edges of a generic substrate, for example, fabric, plastics material, pelts in various sectors, such as clothing, upholstery and leather goods, to name only the most significant areas. 
     Snap buttons comprise a male component and a female component. The female component has a housing with an opening, in which the male component can be inserted in order to carry out the closure of the snap button. There is arranged in the housing of the female component at least one resilient member which is configured so as to retain the male component in the female component until the two components are separated by applying thereto a force sufficient to release the male component from the resilient member in the female component. 
     An extremely large number of configurations of the male and female components of the snap buttons are known. Among them, there are known configurations in which the female component has a system of resilient retention which is constructed by means of two metal wires which are arranged parallel with the sides of a hole in which there is inserted the head of a male component. This type of snap button is subjected to wear as a result of the repeated friction of the head, which is metal, on the metal wires in the female component. Furthermore, the catch action of this snap button during the closing and opening operation is particularly “hard”, that is to say, it requires an effort which is relatively high with respect to the travel. This behaviour of the snap button is not appreciated in the sector of leather goods, wherein there are instead required snap buttons which have a soft opening and closing action. In fact, it is known that, in the field of leather goods, there are appreciated magnetic buttons, precisely for the softness characteristics thereof. However, magnetic buttons have a number of disadvantages which make it suitable to replace them with snap buttons. In fact, magnetic buttons have a poor reliability during closing and are weakly resistant to transverse traction forces. 
     STATEMENT OF INVENTION 
     An object of the present invention is to overcome the disadvantages of the prior art and to provide a snap button which is reliable and does not suffer significantly from the phenomenon of wear, including for continuous use. Another object of the invention is to provide a snap button which is economical and simple to construct and to fix to a substrate. Furthermore, the invention is intended to provide a snap button which withstands transverse separation forces well. 
     In order to achieve these objects and other objects, the invention relates to a snap button as defined in the appended claims. The invention also relates to a female component which is particularly suitable for use in a snap button. 
     According to a first aspect, there is described a snap button comprising a male component and a female component. The two male and female components are intended to couple and uncouple in order to fasten and unfasten the button. The coupling and uncoupling are brought about as a result of an effort in a main axial direction. This ensures that the opening and closing of the snap button are carried out only in a substantially axial manner, preventing accidental opening if the button in the fastened condition is subjected to a traction in a transverse direction. In this manner, there is obtained good reliability of coupling between the male component and the female component. 
     The male component comprises a base. A head protrudes from the base. The head, which may be rounded, is provided with a neck which is narrower than the head. The female component comprises a hollow body. The hollow body has an opening which has such dimensions that the head of the male component can be introduced therein. Two flexible bars are arranged in the hollow body. The flexible bars may have a circular cross-section or a cross-section which is shaped differently, an asymmetric shape. The flexible bars are of a plastics material. The flexible bars are mounted in the hollow body, with the ends thereof blocked in housings formed in the hollow body so as to be able to bend in a central zone thereof. The distance between the two flexible bars is less than the dimension of the head of the male component so that they can be flexibly forced away from each other when the head is forced between the two flexible bars. After the head of the male component has passed the flexible bars, therefore, they can move back towards each other resiliently. Particularly when the button is coupled, the flexible bars can resiliently move back towards each other at the neck of the male component. 
     For the same pushing or pulling force necessary for engaging or disengaging the male component from the female component, respectively, the flexible bars of plastics material can be produced with a much greater diameter than similar components produced from a metal wire. This brings about the increase of the percentage of deformation which can be withstood by the flexible bars while remaining in a resilient range. The use of flexible bars of plastics material, particularly though not exclusively of acetal resin, is particularly advantageous with respect to using flexible bars of metal. In fact, using flexible bars of plastics material brings about greater flexion of the flexible bars and therefore a greater travel which is available during the insertion and withdrawal operation of the head of the male component into/out of the female component. 
     From another perspective, for the same diameter the flexible bars of plastics material require a smaller effort in order to engage and disengage the male component from the female component with respect to similar bars of metal material. An important advantage is the great reduction of the occurrences of friction and the greater resistance to wear of the snap button which uses bars of plastics material, in comparison with conventional systems in which the friction of metal on metal during use generates early wear of the components. The reduction of problems of wear is ensured in the present description by the friction of the head, which is made of metal, on elements of plastics material, that is to say, the flexible bars. The friction is reduced not only as a result of the difference of the materials, but also because the flexible bars of the female component have a greater range of deformability than similar metal bars, and therefore generate during use substantially smaller occurrences of friction than metal bars. 
     All the factors set out above result in a greater ease of use of the snap button, particularly in the coupling step, that is to say, fastening, wherein a smaller application pressure is required, which is particularly appreciable in the sector of leather goods, where a soft catch action is required and appreciated for the closure, for example, of a flap of a bag. 
     According to a specific aspect, the flexible bars are made from acetal resin. This material is particularly suitable for processing, is resistant and is suitable for constructing buttons with a predetermined hardness of catch action which can be repeated and readily modified during design. 
     According to a particular feature, the distance between the two flexible bars substantially corresponds to the transverse dimensions of the neck of the male component. In this manner, the flexible bars are not subjected to deformation in the condition in which the snap button is fastened, with resultant greater reliability and durability over time. 
     According to another feature, the hollow body of the female component comprises a basin-like body which is shaped to house the flexible bars with their ends being locked. The construction of a basin-like body which integrally comprises the housings of the flexible bars simplifies the production and the assembly of the female component. 
     According to another feature, the hollow body of the female component is closed by a plate opposite a wall on which the opening is formed for the introduction of the head of the male component. The closure plate simplifies the assembly of the female component and in particular the positioning of the flexible bars inside the basin-like body, which are then retained in position by the closure plate. 
     According to another feature, on the closure plate of the basin-like body there is provided an opening which is coaxial with the opening on the basin-like body. This opening in the closure plate is advantageous for the at least partial introduction of the head of the male component when it is introduced into the female component when the two components are coupled to each other when the snap button is fastened. This allows the production of a snap button which is quite compact in an axial direction while producing the head of the male component with dimensions which are relatively extensive for easier engagement and disengagement of the two components. 
     According to another feature, the opening in the hollow body of the female component is a hole. The distance between the flexible bars is less than the diameter of the hole. This configuration simplifies the coupling of the male component and the female component and is particularly simple to produce, as well as being aesthetically pleasing. 
     According to another feature, the male component and the female component comprise connection members for connecting to a respective plate for fixing on a substrate. Preferably, the connection members are pins which engage in housings arranged on the respective plate. The connection of the male component and the female component is thereby very secure, which is especially appreciated for use on leather substrates and the like in the sector of leather goods, wherein the substrates to which the snap buttons are intended to be applied are relatively thick and rigid. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Additional features and advantages will be appreciated from the following detailed description of a preferred embodiment, with reference to the appended drawings, given by way of non-limiting example, in which: 
         FIG. 1  is a view of a snap button incorporating aspects of the present invention, in the unfastened configuration in which the male component and the female component which are fixed to respective substrate edges are separated from each other; 
         FIG. 2  is a cross-section of the snap button of  FIG. 1  in the fastened configuration, wherein the male component and the female component are joined together, and wherein the depiction of the substrate edges has been omitted for clarity of illustration; 
         FIG. 3  is an exploded, perspective view of the male component and the female component of the preceding figures, wherein the members for anchoring to the substrate edges can be seen in greater detail; 
         FIG. 4  is an exploded, perspective view of a first embodiment of the female component of the snap button of the preceding figures, wherein the resilient retention elements of the male component can be seen in greater detail; 
         FIG. 5  is an exploded, perspective view, which illustrates similarly to  FIG. 4  a second embodiment of the female component of the snap button, with shaped resilient retention elements of the male component; 
         FIG. 6  is a plan view of the female component of  FIG. 5 , without the covering plate in order to show the internal components and in particular the positioning of the shaped resilient retention elements of the male component; 
         FIG. 7  is a plan view of the female component also without the covering plate similarly to  FIG. 6 , with an alternative form of resilient retention elements of the male component; 
         FIG. 8  is an exploded, perspective view, which illustrates another embodiment of the female component of the snap button; and 
         FIGS. 9 and 10  are perspective views of two variants of shaped resilient retention elements of the male component. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     With reference now to  FIGS. 1 to 4 , a snap button  10 , which is also known as a press stud or snap fastener, comprises a male component  12  and a female component  14 . The male component  12  and the female component  14  are provided to be fixed to respective substrate edges S 1 , S 2 . The fixing is carried out with systems of the type generally known in the sector. By way of example, the figures illustrate anchoring members  13 ,  15  in the form of plates, for example, a metal plate or a plate of another aesthetically pleasing material, which are arranged at the side opposite the substrate edges S 1 , S 2  with respect to the male component  12  and the female component  14 , with which they are engaged, for example, by means of pins  16  which are press-fitted in metal tubes  17 . Naturally, there may be provided different engaging members, such as nails, screws, rivets and other similar systems. The anchoring solution illustrated is particularly advantageous when the substrate to which the snap button is fixed is a hide or other substrate which is relatively thick. In this case, the substrate is drilled beforehand at the pins  16 , using, for example, a drilling jig or an equipment item which is provided for the purpose. The anchoring members  13 ,  15  are preferably, but not necessarily, identical to each other, from the aesthetic perspective and/or functional perspective. Naturally, the shape, dimensions and materials of the anchoring members  13 ,  15  may be of different types, on condition that the functionalities of good anchoring are preserved. 
     The male component  12  comprises a base  18 . A head  20  projects from the base  18  at the side opposite the pins  16 . The head  20  is preferably, but not necessarily, spherical, with a narrower neck  22  which is arranged near the base  18 . A collar  24  widens from the neck  22  and is supported on the base  18 . A handle  26 , which is fixed to the base  18 , projects from the collar  24 , for example, with an interference fit, by means of welding, threading, clinching or other known means. 
     The female component  14  comprises a basin-like body  28  with a wall  30 , which is preferably but not necessarily planar. There is formed in the wall  30  a hole  32  which is intended to receive the head  20  of the male component  12  in the fastened configuration of the snap button  10 . Preferably, the hole  32  widens in a manner complementing the conicity of the collar  24  of the male component  12  in order to improve the stability of the connection in the fastened configuration of the snap button  10 . Inside the female component  14 , in the basin-like body  28 , there are provided two flexible bars  34 , which are mutually parallel and arranged to be equidistant from the centre of the hole  32 . The distance which separates the two flexible bars  34  is less than the diameter of the head  20  of the male component  12  and substantially corresponds to the diameter of the neck  22 . The basin-like body  28  which contains the flexible bars  34  is closed by a plate  36 , for example, which is screwed to the basin-like body  28  or fixed thereto in another known manner. The plate  36  has a hole  38  which is aligned with the hole  34  in the basin-like body  32 , from which the head  20  of the male component  12  can project in the fastened configuration of the snap button  10 , which is thereby particularly compact in an axial direction. In order to further reduce the axial spatial requirement of the snap button  10  in the fastened configuration, it is also possible to construct in the substrate edge S 2 , on which the female component  14  is fixed, a hole or housing in which the head  20  can be partially received. To this end, there can project from the anchoring member  15  a cup-like body  40  which is intended to be introduced into the hole of the substrate edge S 2  in order to receive the head  20  therein. 
     Inside the basin-like body  28  there are provided two pairs of opposing recesses  42 , in which the ends of the flexible bars  34  are received. Two supporting extension pieces  44  of the central zone of the plate  36  project from the wall  30 , at the side of the hole  32 . The pins  16  project from the basin-like body  28  and extend through respective holes  48  which are formed in the plate  36 . 
     The flexible bars  34  are constructed from plastics material, for example, an acetal resin or other synthetic materials. The diameter of the flexible bars  34  is selected to provide predetermined resilient behaviour in accordance with the hardness of fastening and unfastening which is intended to be carried out in the specific snap button. In fact, when the snap button  10  is fastened, the insertion of the head  20  of the male component  12  in the hole  32  of the female component  14  initially brings about the mutual movement apart of the two flexible bars  34  which return to resiliently approach each other, substantially taking up the rectilinear configuration by being compressed on the neck  22  of the male component  12  in order to thus keep the snap button  10  fastened. The resilient behaviour of the flexible bars  34  when they are moved apart from the head  20  of the male component  12  determines the fastening and unfastening hardness, that is to say, the force necessary to couple or uncouple the two male  12  and female  14  components of the snap button. 
       FIGS. 5 and 6  illustrate another embodiment of the female component. The female component comprises a basin-like body  128  with a wall  130 , which is preferably but not necessarily planar. There is formed in the wall  130  a hole  132  which is intended to receive the head  20  of the male component  12  in the fastened configuration of the snap button  10 . Preferably, the hole  132  widens in a manner complementary to the conicity of the collar  24  of the male component  12  in order to improve the stability of the connection in the fastened configuration of the snap button  10 . Inside the female component, in the basin-like body  128 , there are arranged two flexible bars  134 , which are mutually parallel and arranged to be equidistant from the centre of the hole  132 . The flexible bars  134  have a generally flattened formation, except in a central zone  135  thereof, where they engage with the head  20  of the male component  12 , in which they have an enlarged portion having a substantially semi-cylindrical or in any case rounded form in order to promote the engagement with the male component. 
     The distance which separates the two flexible bars  134  in the central zone  135  is less than the diameter of the head  20  of the male component  12  and substantially corresponds to the diameter of the neck  22 . The basin-like body  128  which contains the flexible bars  134  is closed by a plate  136  which is, for example, screwed to the basin-like body  128  or fixed thereto in another known manner. In the embodiment of  FIGS. 5 and 6 , the plate  136  is closed, even though it can take up the formation of the plate  36  described above. 
     There are provided inside the basin-like body  128  two pairs of opposing recesses  142  in which the ends of the flexible bars  134  are received. Each flexible bar  134  has near each of the ends thereof a planar protuberance  138  which is smoothed or rounded and which projects towards a corresponding protuberance  138  on the opposite flexible bar  134 . The protuberances  138  provide for the flexible bars  134  to rotate about the longitudinal axis thereof when the head  20  of the male component  12  is introduced into or withdrawn from the female component. Two plates  140  are fixed to the basin-like body  128 , for example, with screws or rivets, in order to block the ends of the flexible bars  134 . Two supporting extension pieces  144  of the central zone of the plate  136  project from the wall  130 , beside the hole  132 . 
     As in the previously described embodiment, in this case the flexible bars  134  are also constructed from plastics material, for example, an acetal resin or other synthetic materials. The dimensions of the flexible bars  134 , and particularly the cross-section, width thereof and the enlarged portion in the central zone  135  thereof, are selected to provide a predefined resilient behaviour in accordance with the hardness of fastening and unfastening which is intended to be brought about in the specific snap button, which interacts with the flexible bars  134  in a similar manner to that described above. 
     With reference now to  FIG. 7 , there is illustrated a variant of the embodiment of  FIGS. 5 and 6 , wherein identical numerals correspond to identical elements. In this variant, there are provided two flexible bars  134 ′ which are joined to each other at the planar projections  138 ′ which merge in order to generally form a closed ring-like structure which is very resistant to the torsion applied to the bars  134 ′ during the action of insertion and withdrawal of the head  20  of the male component  12 . 
       FIG. 8  illustrates an embodiment of the female component which differs from the one in  FIGS. 5-7  in that the basin-like body is narrower and more compact. In this case, the plates  140 ′ which clamp the ends of the flexible bars  134  are fixed to the basin-like body  128  with a single central screw or rivet. The plate  136  is also fixed to the basin-like body  128  only with two screws or rivets which are located on a line of central symmetry of the female component. The flexible bars  134  are closer together than in the embodiment of  FIGS. 5-7  and are suitable for use in buttons having dimensions which are very small. 
     The resilient bars can take up other configurations with respect to the ones described above. For example, as can be seen in  FIG. 9 , each resilient bar  134 ″ may comprise an elongate cylindrical member, from which there projects laterally an elongate extension piece  150  which serves both to reinforce the resilient bar  134 ″, partially determining the resilient flexion behaviour, and to prevent the rotation thereof following the torsion applied by the head  20  of the male component  12  during the action of introduction and withdrawal from the female component. 
       FIG. 10  shows another example of a resilient bar  134 ′″ which can be used in a female component. The resilient bar  134 ′″ comprises an elongate member with a rectangular cross-section, from which there laterally projects an elongate extension member  152  which also in this case serves to reinforce the resilient bar  134 ′″, partially determining the resilient flexion behaviour. 
     For the same pushing or pulling force necessary for engaging or disengaging the male component from the female component, respectively, of any one of the above-described embodiments, the flexible bars of plastics material have a diameter or cross-section which is far greater than similar components constructed from a metal wire, which also determines the increase of the percentage of deformation which can be withstood by the flexible bars while remaining in the resilient range. The use of flexible bars of plastics material, particularly though not exclusively of acetal resin, is particularly advantageous with respect to using metal material because with the first material there is obtained during use a greater flexion of the flexible bars, and therefore a greater available travel during the insertion and withdrawal operation of the head of the male component in the female component. Accordingly, for the same diameter or cross-section of the flexible bars of resin with respect to bars of metal, a smaller force is necessary to engage and disengage the male component from the female component. 
     An important advantage is the strong reduction of the friction and the greater resistance to wear of the snap button which uses resilient bars of synthetic material, plastics material or resin, when compared with conventional systems where the friction of metal on metal during use generates early wear of the components. The reduction of problems of wear is ensured in the present invention by the friction of the head of the male component, which is made of metal, on the flexible bars of the female component, which are plastics material elements. Not only is the friction reduced as a result of the diversity of the materials, but also because the flexible bars, having a range of deformability which is greater than similar metal bars, generate during use friction which is substantially less than them. 
     All the factors set out above result in a greater ease of use of the device, particularly during closure, that is to say, fastening, which requires a smaller application pressure, which is particularly appreciable in the sector of leather goods, where the closure, for example, of a flap of a bag, preferably has to require a soft catch action. 
     The present invention further ensures that both the opening and the closing of the snap button are carried out only in a substantially axial manner, preventing the accidental opening if the button in the fastened condition is subjected to a traction in a transverse direction. 
     Naturally, the principle of the invention remaining the same, the forms of embodiment and details of construction may be varied widely with respect to those described and illustrated, without thereby departing from the scope of the present invention.