Abstract:
A zip slider comprises: a body ( 200 ) having two channels through which opposing rows of zip teeth may be respectively fed into a single channel in which the zip teeth are forced into interdigitation; upper and lower jaw members ( 114, 140 ) mounted on the body ( 200 ) and defining a slot between them; a biasing member ( 180 ), pivotally mounted on the body ( 200 ), and being pivotable in a first direction between a rest position and a deflected position, wherein pivoting of the biasing member ( 180 ) out of the rest position permits insertion of a loop of a pull tab into the jaws ( 114, 140 ) and, in the rest position, the biasing member ( 180 ) prohibits removal of the pull tab from the jaws ( 114, 140 ).

Description:
BACKGROUND TO THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a zip fastener, and more particularly to a zip slider. 
         [0003]    Typically, a zip comprises two rows of mutually-opposing teeth. The fastening action of the zip is achieved by interdigitating the teeth of opposing rows with each other, thereby causing the rows to knit together along their lengths. This interdigitation is achieved by means of a zip slider. Motion of the zip slider is guided along the length of the teeth by virtue of its engagement with the teeth. Simultaneously, the zip slider comprises a pair of channels through which opposing teeth pass when the slider is moved along the length of the zip; and it is by means of these channels that the teeth are forced into mutual engagement (or, in the case of un-zipping by reversing the motion of the slider relative to the teeth, disengagement) as the slider moves. Motion of the zip slider is most usually powered manually. To facilitate this, a pull tab is typically pivotally mounted on the slider to enable easy gripping of the slider. 
         [0004]    2. Description of Related Art 
         [0005]    The present invention relates to a zip slider which comprises a detachable pull tab. Detachable pull tabs, that is to say pull tabs which may be applied to the zip slider after manufacture of the zip (and, where required, a garment in which the zip has been incorporated) are known per se. For example, EP 1987730, JP2131704 and GB 2165583 both show zip sliders with detachable pull tabs. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention provides alternative forms of zip slider. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0007]      FIG. 1  is a perspective view of a zip slider according to an embodiment of the present invention; 
           [0008]      FIG. 2  is a cutaway perspective view of the slider shown in  FIG. 1 ; 
           [0009]      FIG. 3  is a plan view of the slider shown in  FIGS. 1 and 2 ; 
           [0010]      FIG. 4  is a section on A-A in  FIG. 3 ; 
           [0011]      FIG. 5  is a cutaway perspective view of a zip slider according to an embodiment of the present invention with a pull tab attached; 
           [0012]      FIG. 6  is a side view of the slider shown in  FIG. 5 ; 
           [0013]      FIG. 7  is a perspective side view of a zip slider body according to an embodiment of the present invention; 
           [0014]      FIG. 8  is a perspective side view of the zip slider body of  FIG. 7  from the opposite side; 
           [0015]      FIG. 9  is an exploded perspective view of the zip slider of  FIGS. 7 and 8  in conjunction with additional components to provide locking and retention of a pull tab; 
           [0016]      FIG. 10  is a section through the slider of  FIG. 9 ; 
           [0017]      FIG. 11  is an assembled perspective view of a modified version of the slider of  FIGS. 7 to 10 ; 
           [0018]      FIG. 12  is a section through shown the zip slider of  FIG. 11 ; and 
           [0019]      FIG. 13  is a perspective side view of a further embodiment of zip slider according to the present invention which does not incorporate any locking mechanism. 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0020]    Referring now to  FIGS. 1 to 4 , a slider comprises a body  10  having a base part  12  made of two mutually opposing plates  14 ,  16  which, in common with a standard zip slider, are formed to create two angled entry channels  18  into which the teeth of the two opposing parts of an unfastened zip (not shown) are fed. The entry channels feed into a single mating channel  20  and, as the slider is moved along the zip the forces applied to the zip teeth by the side walls  22  of the plates  14  urge the teeth to interdigitate thereby to knit together and cause the zip to fasten when the zip slider is moved relative to the zip in the direction of arrow F in  FIG. 4  or, when moved in the opposite direction, to disengage and cause the zip to unfasten. Referring additionally to  FIGS. 5 and 6 , movement of the slider relative to the zip teeth is actuated by means of a pull tab  100 . 
         [0021]    To provide for connection of the pull tab  100  to the slider body  10 , the slider has an upper body  40  (sometimes referred to as a ‘bridge’) mounted on the base  12  of the slider which, in conjunction with the upper plate  14  of the base  12  forms a pair of jaws  50  into which a window section  110  of the pull tab  30  may be inserted and by means of which the pull tab  100  may be retained on the slider  10 . In the design of the present embodiment enables the upper body  40  to be cast solidly with the other elements of the slider body, unlike existing locking sliders which are are formed from several pieces. The upper body  40  retains a locking member  60  which comprises a prong  62  that projects through an aperture  70  in the upper plate  14  and into the mating channel  20 . In this way the prong  62  thereby is able to bear against the knitted teeth of the zip in the mating channel to provide a force to retain the slider in position relative to the zip. The locking member  60  is movable relative to the upper body  40  to provide for projection of the prong  62  into the mating channel  20  and retraction of the pawl out of the mating channel  20 . In the present embodiment the locking member  60  is mounted on the upper body for pivoting motion relative to the upper body  40  about its point of contact  64  and by virtue of a clearance  66 . 
         [0022]    The prong is biased into a position where it projects into the mating channel  20  (and thereby into a position of engagement with the knitted zip teeth) by means of a biasing spring, which in the present embodiment is provided by a wire loop spring  80  having two limbs  82  which extend from a loop  84  at its base, which sits in a slot  67  formed in the locking member  60 . The loop spring  80  further has two spigots  86  which project outwardly from the upper ends of the limbs  82  and which extend into apertures  88  in the upper body  40  thereby to locate the spring in the upper body  40  in a manner permitting pivotal motion of the loop  84  at its lower extent relative to the upper body  40 . The spring is formed in such a manner that, when in its relaxed state, the limbs  82  of the spring extend at different angles from the loop  84  which, in turn, means that the two spigots  82  are offset relative to each other. Because, by contrast, the apertures  88  in the upper body lie in register with each other, when the spigots  86  are located in the apertures  88 , the tendency of the wire spring to seek to adopt its relaxed configuration therefore has the effect of biasing the loop  84  of the spring to rotate anti-clockwise (as viewed in  FIG. 4 ) about the points of engagement of the spigots  86  with the apertures  88 . This rotational biasing of the loop  84  causes it to bear against the slot  67  in the prong and bias the pawl  62  to pivot and thereby project further through the aperture  70 . Conversely, the engagement of the loop  84  against the slot  67  defines what is effectively a rest position for the spring  80 , when no external forces act on it. 
         [0023]    In addition to biasing the prong of the locking member into the aperture  70 , the wire loop spring  80  performs the further function of retaining the pull tab  100  in engagement within the jaws  50 . Referring additionally to  FIGS. 5 and 6 , the pull tab  100  has a window section  110  at one end which terminates in a substantially cylindrical bar  112 . To connect the pull tab  100  to the slider the bar  112  of the window section  110  is inserted between the jaws  50 . As it is inserted, the bar  112  first comes into contact with the limbs  82  of the loop spring, the surfaces of which are angled relative to the vertical as a result firstly of the rotational biasing action of the loop spring  80  and secondly engagement of the loop  84  in the slot  67  which therefore prevents further rotation of the limbs  82  and loop  84 . Further force applied to the pull tab  100  after it has come into contact with the limbs  82  of the wire spring  80  will act to cause the limbs  82  and loop  84  of the spring  80  to pivot in a clockwise direction (as viewed in  FIG. 4 ) and thereby continue to permit insertion of the bar  112  into the jaws. This pivoting of the limbs  82  and loop  84  will continue until the bar  112  is inserted to a point where it passes beyond the loop  84 , whereupon the bar  112  will no longer bear against either the limbs  82  or the loop  84  of the wire spring  80  and so the biasing action of the spring  80  will cause it to return to its rest position bearing against the slot  67 . However, because the bar  112  now lies within the jaws and has passed beyond the wire spring  80 , when the spring is in its rest position, the limbs  82  of the wire spring now operate to prevent the bar  112  from being removed from the jaws  50 , since motion of the bar  112  in the reverse direction will merely urge the limbs  82  to push the loop  84  more forcefully into engagement with the slot  67 . Since the locking member  60  has only a limited capacity for movement in the reverse direction before it comes into contact with an abutting surface  74  on the upper plate  14 , motion of the limbs  82  in the anti-clockwise direction is therefore limited, with the result that the limbs  82  therefore act to retain the pull tab  100  in engagement with the body  10  of the slider. 
         [0024]    The pull tab  100  is therefore now securely retained in the jaws  50  so that pulling forces applied to the pull tab  100  by a user will cause the entire body  10  of the slider to move relative to the zip teeth and, thereby fasten or unfasten the zip. It will be noted that the locking member  60  further comprises a recess  68 . A fastening force, applied in the direction of arrow F, will cause the bar to bear against the groin  68 A of the recess and this will have the effect, to some extent, of counteracting the biasing force applied by the wire spring  80  urging the pawl  62  into engagement with the zip teeth thereby enabling easier motion of the zip slider to fasten the zip. Conversely, an unfastening force applied by the pull tab  100  will initially cause the bar  112  to bear against the limbs  82  which will, in turn, urge the pawl  62  to bear more forcefully against the zip teeth and thereby act to prevent motion of the slider body  10  to unfasten the zip. However, as the unfastening force applied to the pull tab  100  increases, the bar  112  will be urged upwards by the angle of the limbs  82 , and will then engage the upper limb  69  of the locking member. This will then have the effect of causing the prong  62  to lift away from the teeth so that further force applied by the pull tab  100 , via the bar  112  will then unfasten the zip. 
         [0025]    Removal of the pull tab may be undertaken, if desired, by inserting a suitable tool into the jaws  50  to displace the limbs  82  in a clockwise direction to a sufficient extent that the bar  112  may then pass back beyond the loop  84 . This is a preferred method since it then enables easy re-insertion. Alternatively, the spigots of the wire spring. 
         [0026]    In a modification of the embodiments described above, the zip slider is a non-locking zip slider and, accordingly, there is no mechanism to lock the zip teeth in place relative to the slider body. One embodiment of such a modification would simply be for the locking member  60  not to incorporate a prong  62  that projects onto the zip teeth. Another embodiment would be for the upper plate of the body to be formed such that a suitable slot is formed within it, having a similar shape to that of the slot  67  in the locking member. 
         [0027]    Further, alternative embodiments of the present invention will now be described which include alternative spring configurations whereby no forces applied during movement of the slider can be applied to the locking prong. 
         [0028]    Referring now to  FIGS. 7 to 10 , a slider comprises a body  200  having a base part  112  made of two mutually opposing upper and lower plates  114 ,  116  which, in conjunction with side walls  122 , depending downwardly from the edges of the upper plate  114 , are formed to create two angled entry channels which open onto the end  118  of the slider and into which the zip teeth (not shown) of the two opposing parts of an unfastened zip (not shown) are fed. The entry channels feed into a single mating channel which opens onto end  120 . As the slider is moved along the zip in the direction of arrow F, the forces applied to the zip teeth by the side walls  122  urge the teeth to interdigitate and knit together, fastening the zip; the fastened zip exiting the slider via the mating channel at end  120 . Movement of the slider relative to the zip teeth is actuated by means of a pull tab not shown. 
         [0029]    To provide for connection of a pull tab to the slider body  200 , the slider has an upper body  140  (sometimes referred to as a ‘bridge’) mounted on the base of the slider which, in conjunction with the upper surface of the upper plate  114  of the base forms a pair of jaws into which a window section of the pull tab may be inserted and by means of which the pull tab may be retained on the slider. In the design of the present embodiment enables the upper body  140  to be cast solidly with the other elements of the slider body, unlike existing locking sliders which are formed from several pieces. 
         [0030]    Typically, a zip slider will include a mechanism which operates to lock the position of the slider relative to the zip teeth. Usually, this is a prong located on the zip slider and which projects into the mating channel to bear against the upper surface of the interdigitated zip teeth and, by virtue of that engagement, prohibit the relative motion of the slider and teeth. Evidently, any locking prong is desirably disengagable from the zip teeth in order to facilitate relative motion of the slider and zip teeth. In the present embodiment a locking prong  160  is provided at one end of an elongate, folded leaf spring  162 . The leaf spring is folded in such a manner as to create two functional elements: a locking element  164  which is configured in a G shaped configuration with the locking prong  160  as the downward facing tail of the G; and a C shaped biasing element  166  from the lower part of which the locking element  164  depends. In use, the biasing element  166  urges the locking prong  160  of the locking element  164  downwardly and into engagement with the interdigitated zip teeth. The leaf spring  162  is retained on the upper body  140  by means of an end cap  142  which can be clipped into place after insertion of the leaf spring  162 . 
         [0031]    As with the previous embodiment, a pull tab (not shown) is retained within the jaws by means of a wire loop spring  180 . The loop spring has two limbs  182  which extend from a loop  184  at its base  186 . The loop spring  180  further has two spigots  188  which project outwardly from the upper ends of the limbs  182  and which extend into apertures  190  in the upper body  140  thereby to locate the spring in the upper body  114  in a manner permitting pivotal motion of the loop  184  at its lower extent relative to the upper body  114 . The spring  180  is formed in such a manner that, when in its relaxed state, the limbs  182  of the spring extend at different angles from the loop  184  which, in turn, means that the two spigots  188  are offset relative to each other. Because, by contrast, the apertures  190  in the upper body  114  are positioned such that, when the spigots  186  are located in the apertures  190  the limbs  182  lie in register with each other or, in other words, are mutually aligned, the tendency of the wire spring  180  to seek to adopt its most relaxed configuration therefore has the effect of biasing the loop  184  of the spring  180  to rotate clockwise (as viewed in  FIG. 13 ; anti clockwise in  FIGS. 8 and 9 ) about the points of engagement of the spigots  188  with the apertures  190 . This rotational biasing of the loop  184  causes it to bear against an abutting surface  200  (seen in  FIG. 13 ) on the body of the slider. Connection of a pull tab therefore involves inserting the end of the pull tab between the jaws formed by the bridge  140  and upper surface of the body  114 . This motion causes the pull tab to bear against the limbs  182  of the loop spring  180 , the facing surfaces of which are angled relative to the vertical as a result firstly of the rotational biasing action of the loop spring  180  and secondly engagement of the loop  184  with the surface  200  and, against the natural biasing action of the spring  180  arising as a result of the offset limbs  182 , causes them and the loop  184  to rotate anti-clockwise in  FIG. 13  (clockwise in  FIGS. 2 and 3 ). Continuing force applied to the pull will cause the limbs  182  and loop  184  of the spring  180  to pivot until the bar of the pull tab is inserted to a point where it passes beyond the loop  184 . Once the bar of the pull tab is clear of the loop  184 , the biasing action of the spring  180  will cause the limbs  182  and loop  184  to snap back into abutment with the surface  200 . Because the bar of the pull tab now lies within the jaws and has passed beyond the wire spring  180 , when the spring is in its rest position, motion of the bar in the reverse direction will merely urge the limbs  182  to push the loop  184  more forcefully into engagement with the surface  200  with the result that the limbs  182  of the loop spring  180  now operate to prevent the pull tab from being removed from the jaws. 
         [0032]    In order to move relative to the zip teeth, the locking prong  160  must be disengaged from the zip teeth. This occurs as a result of the pulling action of the pull tab during unzipping. The action which is to be described can more readily be appreciated when viewing the section of  FIG. 10 . Pulling of the pull tab perfectly horizontally against the loop spring causes it first to bear against the angled limbs  182  of the locking spring  180  whereupon it will ride up the angled surfaces of the limbs  182  and bear upwardly against the upper surface of the locking element  164 . That upward force acts against the downward biasing action of the biasing element  166  to cause upward, disengaging motion of the locking element  164  thereby bringing the locking prong  160  out of engagement with the interdigitated zip teeth (not shown) which, in turn then permits movement of the zip slider body. In practice, because users almost always pull a zip slider from a point somewhat outwardly displaced from the zip, almost all forces applied by the pull tab on the slider body will additionally involve some upward component. When the zip slider is pull with such an additional upward component, the result is a yet greater disengaging force applied to the locking element  164  and against the action of the biasing element  166 . 
         [0033]    A feature of the present embodiment is that the loop  184  of the spring  180  bears against an abutting surface  200  on the slider body and therefore no forces applied to the loop spring can cause any increase in force applied to the locking prong. 
         [0034]    Referring now to  FIGS. 11 and 12 , a modification of the embodiment of  FIGS. 7 to 10  is now illustrated. In addition, the angle of illustration of this modification enables the mating channel indicated by reference numeral  120 M to be more clearly seen as well as one of the entry channels  118 E a modification, the locking element  164  and biasing element  166  are two separate structures. The locking element  164  is formed as a relatively rigid monolithic metal structure (typically die cast from aluminium) and the biasing element is a leaf spring  166  which bears against a hook  168  in the rear of the locking element  164  and downwardly against a shoulder  169  in the upper surface of the locking element  164  to urge the locking prong  160  into engagement with the interdigitated teeth. Disengagement of the locking prong  160  occurs in precisely the same way as a result of the same mechanism as described previously in connection with  FIGS. 7 to 10 . 
         [0035]    Referring now to  FIG. 13 , in yet a further modification, a zip slider is provided without any locking capability. The zip slider of this embodiment therefore merely includes the loop spring  180  to retain the pull tab. 
         [0036]    In each of the foregoing embodiments, removal of the pull tab may be undertaken, if desired, by inserting a suitable tool into the jaws to displace the limbs  182  to a sufficient extent that the bar of the pull tab may then pass back beyond the loop  184  whereupon the pull tab may be removed. This is a preferred method since it then enables easy re-insertion. 
         [0037]    The embodiments of the present invention described above therefore provide the ability to latch a pull tab onto the slider yet with a simple and low-cost construction. The ability to attach a pull tab to a slider in this way is advantageous for a number of reasons. It enables manufacturers to use different designs of pull tab in dependence upon the style of garment in which the zip is to be used, without having to purchase different zips in order to do so. Further, it permits the entire construction of the garment, including stitching and dyeing to be completed before attaching the pull tab, thereby minimising the risk of damage to the garment or zip slider as a result of the need to subject the zip with a pull tab attached to the rigours of those processes. 
         [0038]    The various modifications to embodiments disclosed herein are not limited in their applicability to the embodiment in connection with which they were first described and, unless specifically stated otherwise, any modification is equally applicable to all other embodiments described herein.