Patent Publication Number: US-2009229090-A1

Title: Slide Fastener and a Top Stop for a Slide Fastener

Description:
FIELD OF APPLIATION 
     The present invention refers to a slide fastener and to a top stop of a slide fastener. The invention relates in particular to fluid-tight slide fasteners and top stops of fluid-tight slide fasteners. 
     PRIOR ART 
     A slide fastener, in essential terms, comprises a pair of tapes bearing respective rows of teeth, top and bottom stops, and a slider for opening and closing the fastener by engaging and disengaging the teeth. The slider is operated by a puller (or pull-tab) which is usually connected to the slider by a ring or a ring shaped end portion of the same puller. 
     The top and bottom stops are at opposite ends of the slide fastener, which is completely closed when the slider reaches the top stop. 
     Fluid-tight slide fasteners, in particular, are used in sports and outdoor activity items, diving or sailing suits, camping tents and the like, and are required to securely prevent the passage of a liquid and/or gas, e.g. water and/or air. In some cases, a fluid-tight fastener must ensure fluid-tightness even under a significant pressure difference between the interior and the exterior, for example up to about 2 bars. 
     Fluid-tight slide fasteners are realized for example with layered tapes made of a textile core with a waterproof coating layer, and injection-molded teeth. 
     The slider of a slide fastener, more in detail, comprises upper and lower blades, lateral flanges and a central portion, called diamond, connecting the upper and lower blades. In known slide fasteners, especially fluid-tight slide fasteners, the top stop is a substantially U-shaped element with leg portions defining a front opening for the diamond of the slider, and a seat for receiving said diamond when the slide fastener is fully closed. It is known technique to provide a suitable shape of the lateral flanges of the slider so that they act on the sides of said leg portions of the U-shaped top stop, in order to close said front opening in a fluid-tight manner when the slider reaches the full-closed position. 
     It can be understood that, in order to guarantee the fluid-tightness of the closed slide fastener, during the use, the slider should be kept in position and prevented from moving away from the top stop. In fact, an accidental displacement of the slider, even of few tenths of a millimeter, may compromise the fluid-tightness of the fastener at the region of the top stop and/or between the teeth. 
     Nevertheless, the user must always be able to open the slide fastener quickly, also for safety reasons. These needs are felt, in particular, in the field of fluid-tight slide fasteners for waterproof items such as diving suits, military or fireman suits, and the like. 
     SUMMARY OF THE INVENTION  
     The technical problem underlying the invention is to provide a reliable and safe closure of a slide fastener as defined above, avoiding the slider from leaving the position where the fastener is fully closed, allowing at the same time a quick and easy opening of the fastener itself. 
     This problem is solved by a slide fastener comprising a pair of tapes, carrying respective teeth, a top stop and a slider comprising a puller, the slider being movable up to a closing position of the fastener where said slider is in contact with said top stop, characterized in that the top stop comprises at least one retaining element adapted to retain the slider in said closing position. 
     According to a further aspect of the invention, said at least one retaining element is integrally formed with the top stop. 
     According to another aspect of the invention, said retaining element is disposed to act as a stop means for the slider when the puller is fitted on the top stop in a determined locking position. Preferably, said locking position is a position where the puller is lying on the top stop, substantially parallel to the sliding direction of the slider. 
     In a preferred embodiment, a retaining element is integrally formed with the top stop, having a surface disposed to act as a stop means against a contact face of the puller, when the puller is fitted on the top stop in said locking position. 
     According to further aspects of the invention, the top stop further comprises at least one locking element, adapted to a snap engagement with a suitable seat or portion of the puller, to retain the puller in said locking position. Preferably, said seat or portion of the puller is a ring or a ring portion connecting the puller to the slider. 
     In a preferred embodiment, said at least one locking element is an elastically deformable element adapted to snap on the ring connecting the puller to the slider. Preferably, said locking element has an elastically deformable stem portion and a head portion projected from top of the stem portion, defining an undercut recess for receiving the ring of the puller. 
     Said locking element(s), according to the invention, are able to engage/disengage the ring of the slider by elastic deformation induced by contact with the ring itself when the puller is locked or unlocked on the top stop. Preferably, the head portion of the locking elements has a suitably profiled surface to allow deformation of the element by contact with the ring of the slider, while the puller is pressed down to the locking position, or lifted from that position. Thanks to said profiled surface, contact with the ring of the puller results in a force directed to deform the locking element(s) in such a way to receive or, respectively, to free the ring of the puller, as will be clearer hereinbelow with the help of an example. 
     According to a particularly preferred embodiment, said at least one retaining element of the top stop is formed as a wall of the top stop, comprising a base part with a surface adapted to act as a stop means against a contact face of the puller, and two locking elements formed as elastically deformable toothed elements projecting upwards from said base part and each defining an undercut recess for receiving the ring of the puller. 
     More in detail, the base part of the wall integrally formed with the top stop has a front surface facing the slider and a rear surface adapted to act as a stop means against a bottom face of the puller, to retain the slider when the puller is in the locking position. 
     According to another aspect of the invention, the top stop comprises at least one pin adapted to engage a corresponding hole of the puller, to retain the puller from lateral movement. 
     In further embodiments of the invention, the retaining element is adapted to cooperate with a corresponding locking element of the slider. As an example, the top stop has a suitable seat or recess for receiving a locking element projecting from the front of the slider, the locking element of the slider being engaged in said seat or recess of the top stop when the slider reaches the top stop. In these further embodiments, a disengagement system, e.g. by pressing a disengagement button, can also be provided on the top stop, to unlock the slider. 
     An object of the invention is also a top stop for a slide fastener, the slide fastener comprising a pair of tapes, carrying respective teeth, and a slider comprising a puller, the slider being movable to a closing position where said teeth are fully engaged and the slider is in contact with the top stop, the top stop being characterized by comprising at least one retaining element(s) as described above. 
     In particular, the invention provides a top stop for a slide fastener wherein said at least one retaining element is formed as a front wall of the top stop, the top stop being adapted to receive the puller of the slider in a locking position, said front wall comprising a surface adapted to act as a stop means against a contact face of the puller when the puller is fitted in said locking position. 
     The invention has the advantage that the slider is securely kept in the closing position. It should be noted that the snap-on engagement between the locking elements and the slider, namely the puller thereof, provides a quick and simple locking/unlocking action, so that the slider of the fastener is securely kept in the closing position and prevented from accidental opening even under intensive use, but the user can open the fastener rapidly and easily at any time. 
     The invention is particularly useful in a fluid-tight fastener, where a small deviation of the slider from the full-closing position may compromise the fluid-tightness. Hence, an item fitted with a slide fastener according to the invention, such as a sports garment or the like, gives reliable fluid-tight performance with easy and safe use. 
     Further advantages and characteristics of the slide fastener according to the invention will be more evident from the detailed description and examples provided here below, with indicative and not limiting purpose. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         FIG. 1  is a perspective view of the top end of a slide fastener according to an embodiment of the invention. 
         FIG. 2  is a side view of the fastener of  FIG. 1 . 
         FIG. 3  is a side view of the fastener of  FIG. 1 , with the puller of the slider in a different position. 
         FIG. 4  is a top view of the fastener, in the position of  FIG. 3 . 
         FIGS. 5 and 6  are cross-sectional views according to lines V-V and VI-VI of  FIG. 4 . 
         FIG. 7  is an enlargement of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT  
       FIG. 1  shows a top portion of a slide fastener  1 , in accordance with a preferred embodiment of the invention, comprising a pair of tapes  2 , equipped with teeth  3 , a top stop  4 , and a slider  5  with a puller  6 . The puller  6  is connected to the slider  5  by a ring  7 . 
     The slider  5  is movable in a sliding direction, parallel to tapes  2 , up to a closing position where the slide fastener  1  is fully closed, i.e. all teeth  3  are engaged and the slider  5  is in contact with the top stop  4 . Said closing position is shown in  FIG. 1 . 
     Details of tapes  2  an teeth  3  can be according to known art and are not discussed in detail. For example, in a fluid-tight sliding fastener, tapes  2  are made of a textile core layer fully coated on both sides by a suitable waterproof layer and teeth  3  are injection-molded on tapes  2 . The top stop  4 , in a fluid-tight slide fastener, can also be injection-molded on tapes  2 . 
     The slider  5  ( FIG. 2 ) substantially comprises upper and lower blades  8 ,  9  with lateral flanges  10 ,  11  on both sides, and a diamond connecting said upper and lower blades  8 ,  9 . Flanges  10  and  11 , in use, act on suitable contact faces of teeth  3  in order to bring the facing teeth of the tapes  2  to reciprocal engagement, according to known art. When the slide fastener  1  is fully closed, i.e. the slider  5  is in the position of  FIG. 1 , the diamond can be received in a seat between leg portions  12  of the top stop  4 . 
     The puller  6  can be fitted from the position of normal use, as seen in  FIGS. 1 and 2 , to a locking position on the top stop  4 , shown in  FIGS. 3 and 4 . In said locking position, the puller  6  is lying on the top stop  4 , substantially parallel to the sliding direction of the slider  5 . 
     A front wall  20  is integrally formed in the top stop  4 , acting as a stop means against a bottom contact face  30  of the puller  6 . The wall  20  has a rear surface  32  ( FIG. 2 ) acting as a stop means against the contact face  30  of the puller  6 , when in position of  FIGS. 3-4 . Opposite to the surface  32 , the wall  20  has a front surface  31  facing the slider; advantageously, there is a gap between said front surface  31  and the slider  5  for clearance recovery. The contact face  30  may be slightly curved and, in this case, the rear surface  32  of wall  20  is curved accordingly ( FIG. 4 ). 
     Two toothed elements  22 ,  23  project upwards from the central portion of base part  21  of the wall  20 , adapted to mechanically engage the ring  7  in order to “lock” the puller  6  in the position of  FIGS. 3-4 . Each of said elements  22  and  23  has an elastically deformable stem portion projecting upwards from the base  21 , and a head portion defining an undercut recess  22  for receiving the ring  7  when the puller is in the locking position. 
     As seen in the cross-sectional view of  FIGS. 5 and 7 , each of elements  22 ,  23  has a stem portion  24  projecting upwards from base part  21  of the wall  20 , and carrying a head portion  25  projecting laterally and outward from the top of the stem  24 , defining inclined surfaces  26  and  27  converging to an edge  28 , and the undercut recess  22  below said edge  28  and between the base  21  and the head  25  itself. 
     Pressing the ring  7  against faces  26  or  27  has the effect of bending laterally and inwards the stem portion  24  of the toothed elements  22  and  23 , thus engaging the ring  7  in the recess  22  or vice-versa disengaging the same ring  7  and puller  6  from the locking position. 
     In the shown embodiment, the top stop  4  also comprises a pin  40  which is received in a corresponding hole  41  of the puller  6 , when the puller  6  is in said locking position. Said pin  40 , received in the hole  41 , retains the puller  6  from lateral movement. 
     In the example, the pin  40  is elliptical and frusto-conical, with a cross section decreasing from base to top. However, the pin  40  may also be cylindrical in simpler embodiments. 
     The invention is open to many variants. In other (not shown) embodiments, for example, the toothed elements  22 ,  23  or equivalent locking elements can engage a suitable seat (e.g. a recess) of the puller, rather than the ring connecting the puller to the slider. Clearly, the position of said locking elements can be different according to the needs and/or the design of the top stop. 
     The puller  6  may also be shaped in a different manner, for example with a hole in the bottom part defining a ring portion connecting the puller with the slider  5 . 
     The retaining element, rather than wall  20 , may be realized in different ways, including a plastic or metal element not integrally formed with the top stop itself. 
     In a further variant, the slider  5  may be equipped with a locking element, adapted to cooperate with another engagement element provided in the top stop  4 , so that when the slider  5  reaches the top stop  4 , said slider is locked to the top stop and prevented from sliding away. An unlocking system may be incorporated in the top stop. 
     Referring to said further variant, the slider for example has a first coupling element protruding from the front of the slider itself, adapted to snap on a second coupling element or recess of the top stop when the slider reaches the top stop. Said second coupling element or recess may be provided e.g. on face  31  or equivalent part of the top stop  4 . The top stop has an unlocking button associated to said second coupling element of the top stop, so that acting on said button the user can move the second coupling element to a disengaging position, freeing the slider from the top stop. 
     Referring back to embodiment of the figures, the invention operates as follows. 
     When closing the slide fastener  1 , the user pulls the slider  5  up to the position of  FIG. 1 , where all the teeth  3  are mutually engaged and the slider  5  reaches the top stop  4 . 
     To secure the fastener, the user lowers the pull-tab  6  from the position of use of  FIGS. 1-2  to the locked position of  FIGS. 3-4 . As the ring  7  contacts the upper surfaces  26  of teeth  22 ,  23  ( FIG. 2 ), and due to inclination of said surfaces  26 , the stems  24  are deformed until the ring  7  can overcome the edge  28 , and reach the undercut recesses  22 . 
     When the ring  7  is received in said undercut recesses  22  ( FIG. 5 ), it is locked by elements  22 ,  23 . The contact between surfaces  30  and  32  prevents the slider  5  from sliding away from the top stop  4 , thus keeping the fastener  1  closed and ensuring fluid-tightness at the region of the top stop  4 . The puller  6  is safely prevented from leaving the locking position, by lateral outward projections of the heads  25  of elements  22  and  23 , locking the ring  7  as seen in  FIGS. 5 and 7 . This is sufficient to avoid undesired unlock due to the use, plying of the fastener, etc. The pin  40  is a further help to maintain the puller  6  in the correct locking position, preventing the puller from lateral movement. 
     The fastener is unlocked by lifting the puller  6 , so that the ring  7  bends the elements  22 ,  23  pressing against the contact surfaces  27 , until the ring  7  itself reaches the edge  28  and is freed to the use position of  FIGS. 1-2  again. Then, the user can open the slide fastener  1  as usual. 
     It should be appreciated that the puller  6  is locked and unlocked manually and in a quick and immediate way by lowering or, respectively, lifting the puller. Notwithstanding this, when the puller  6  is locked the slider  5  is firmly secured on the top stop  4 , and accidental opening of the fastener and/or loss of the fluid-tightness is prevented in a reliable way. 
     Of course, a person skilled in the art can bring modifications and variants to the invention in order to satisfy specific requirements, all of which are in any case covered by the scope of protection of the following claims.