Background Art It is known to lock the zip fastener of an article by securing the toggle of the zip fastener slide to the rest of the article, thereby preventing the slide from being moved. If the article includes two slides, then the toggles of the slides can be secured together to prevent the fastener being opened. Such an arrangement usually requires a separate lock with its own key. The present invention provides a slide for a zip fastener that has an integral lock.

GB 658 573 describes a zip fastener having a slide moveable along a pair of interengageable rows of teeth to open and close the fastener. In order to prevent the slide catching on adjacent fabric, the slide is formed by two hinged plates that can be released from their normal operating position to open the slide and remove any fabric caught. The toggle acts to hold the plates together in their normal operating position and to release the plates to open the slide.

GB 462 489 discloses a zip fastener having a slide incorporating a lock, a toggle and a key insertable into a keyhole for opening and closing the lock.

GB 949 986 discloses a zip fastener having a lock with a removable key.

GB-A-2022688 discloses a zip fastener with a slide incorporating a lock, a toggle and a key for locking the slide.

EP 0512402 discloses a zip fastener with a slide that can be secured in a desired position ; the fastener includes a spring-biased member that can be (a) inserted between the teeth (stringers) of the zip fastener to lock the slider and (b) removed from between the teeth to allow the slider to move along the teeth to open and close the zip fasteners. The securing member is moved between positions (a) and (b) by a rotatable eccentric cam on one end of a rotatable post to which the zip toggle is also secured.

Disclosure of the Invention According to the present invention, there is provided a lockable slide for a zip fastener comprising a slide body having a pair of opposed channels through which the two chains of teeth of the zip fastener can pass to open and close the fastener, a toggle that is detachably secured to the slide body, a lock for releaseably engaging the zip fastener to prevent the slide body moving along the chains of teeth of the fastener, wherein the lock can be moved by the toggle from a locking position in which it engages the zip fastener and prevents the slide body moving along the chains of teeth of the fastener and a released position in which it does not engage the zip fastener and so allows the slide body to move along the chains of teeth of the fastener to open and close it and wherein toggle can be detached from the slide body when the lock is in the locked position.

As is usual in the prior art of zip fasteners, the term"toggle"denotes a part (or a series of connected parts) pivotally attached to the slide (usually pivotable at least about an axis orthogonal to the fastening/unfastening direction of the zip fastener) that can be grasped to move the slide to open and close the zip fastener.

The slide body may comprise a housing and a slider held within the housing and containing the pair of opposed channels through which the two chains of teeth of the zip fastener can pass to open and close the fastener.

The lock may include a locking member that, when the lock is in the locked position, is in a position in which it engages at least one end of the zip fastener to prevent the slide body from moving along the chains of teeth of the fastener and, when the lock is in the released position, is in a position away from the ends of zip fastener and so allows the slide body to move along the chains of teeth of the fastener to open and close it.

The lock is preferably moved between the locked position and the released position by turning the toggle. The toggle may have a barrel that engages with an opening in the lock and wherein the barrel has at least one rib and the opening has at least one groove that engage with each other to move the lock between the locking position and the released position.

Alternatively, the toggle barrel has at least one groove and the opening has at least one rib that engage with each other to move the lock.

Description of the drawings There will now be described, by way of example only, three embodiments of a lockable slide for a zip fastener in accordance with the present invention by reference to the accompanying drawings in which: Figure 1 (a) to (d) shows a zip fastener having a lockable slide according to the present invention and illustrating its mode of operation; Figure 2 is an exploded view of the slide of Figure 1 ; Figures 3 a and 3b are perspective views of a second lockable slide for a zip fastener in an unlocked condition (Figure 3a) and a locked condition (Figure 3b) ;

Figure 4 is an exploded view of the slide of Figure 3; Figure 5a is a cross-sectional view along the line 5-5 of Figure 3a with the slide in an unlocked condition; Figure 5b is a perspective view of the slider but without a cover, showing the slider in an unlocked condition; Figure 6a and 6b are similar to Figures 5a and 5b but show the slider in a locked condition; Figure 7 is a sectional view similar to Figure 6a, i. e. showing the slider in a locked condition, but with the toggle removed and showing a row of teeth of a zip fastener; Figure 8 is a side view of a boss pin of the slider of Figures 3-7; Figure 9 is a sectional view similar to Figure 5a but showing a slight modified locking mechanism; and Figure 10A and 10B are a side view and a perspective view (respectively) of a third embodiment of the present invention showing the slide without a cover and in an open position allowing the slide to move over a zip fastener to open or close it; Figures 1 lA and 11B correspond to Figures 10A and 10B but show the slide in a locked condition preventing it from being moved up and down a zip fastener to open and close the fastener; Figures 12A-D are, respectively, a top view, an end view, a side view and an orthogonal view of a locking member that prevents the slide of Figures 10 and 11 from opening and closing a zip fastener; and Figure 13 is a side view of a fastener of the present invention.

Best Mode for Carrying out the Invention Referring initially to Figure 1, there is shown a zip fastener having a slide 10 provided with a toggle 12. The zip fastener includes a pair of strips of material 16, which, in use, are secured to an article on either side of an opening to be

closed, and two chains of teeth 18 that can be inter-engaged to close the fastener. By moving the slide 10 downwardly along the chains of teeth, the zip fastener can be opened and by moving the slide 10 upwards along the chains of teeth, the zip fastener can be closed again.

The toggle 12 forms part of a key 14 that is rotatably held within an opening 15 in the slider. In the position shown in Figure la, the lock 14 is held captive within the opening 15 and, as indicated, the slide can move along the chain of teeth.

At one end of the two chains of teeth 18, the textile strips 16 are provided with a metal sheath 20 that can engage the slide 10 in the region around the key 14 to prevent the lock within the slide 10 being tampered with (see Figure lb). The key 14 may be turned through 180° by the toggle 12 (see Figure I c) to lock the slide and prevent it from moving along the chains of teeth 18. In the locked position, the key (including the toggle) can be removed (see Figure ld).

Referring now to Figure 2, the interior workings of the slide 10 are shown. The slide has a pair of faceplates 22,24. The faceplate 24 has an opening 25 that is generally circular but has a groove 27 in it. The key 14 includes a boss 26 that is pivotally connected to the toggle 12 and to a hollow barrel 28 having a bar 30 formed at one end. The boss 26 can be pushed onto the bar 30 to secure the toggle 12 and the boss 26 to the barrel 28. The'outer surface of the barrel 28 has a rib 29 of corresponding size and shape to the groove 27 in the opening 25 such that the barrel can be inserted into the opening 25 in the face plate 24. A slider 32 is held between the faceplates 22 and 24 and includes two opposed channels 34 (only one channel shown, the other being formed on the side of the slider 32 that is not visible). In a known manner, the slider can slide along the chains of teeth 18 with the chains being held within the channels 34 ; the

channels converge towards the base of slider 32 so that, by sliding the slider 32 along the chains of teeth, the zip fastener can be opened or closed in a known manner.

Located immediately above the slider 32 is a locking member 36 having a hollow cylinder 35 and a crosspiece 37. The width of the crosspiece 37 is smaller than the separation between the channels 34 and so, when in the position shown in Figure 2, the crosspiece does not interfere with the movement of the slider 32 along the teeth. The interior of the cylinder 35 includes a groove (not visible) that can mate with the rib 29 on the lock barrel 28. The lock member 36 is held on a post composed of a wide section 39 having a diameter corresponding to the internal diameter of the cylinder 35 and a narrow section 38 having a diameter corresponding to the internal diameter of the barrel 28 of the key 14. The locking member 36 is mounted on the section 39 such that it can rotate until the crosspiece 37 engages with stops 40.

When the slide 10 is at the upper extremity of the zip fastener shown in Figures 1 (b) to (d), the end section of the chains of teeth 18 are located at the top of the channel 34 below the cross member 37. The slide can be locked by pivoting the lock member 36 clockwise from the position shown in Figure 2 so that the cross member 37 is located above the end section of one of the chains of teeth 16.

The slide 10 cannot be moved along the chains of teeth 18 to open the fastener since the cross member 37 prevents this. The stop 40 prevents the cross member 37 from turning too far since if it were allowed to turn to 180°, it would again free up the movement of the slider 32.

When in the locked position, the rib 29 is in register with the groove 27 and so the key can be removed. However, when the lock is in the open position, the rib 29 is not in register with the groove 27 and accordingly the lock 14 is held

captive within the slide 10.

The faceplates 22 and 24 include grooves 42 that fit outside the sheath sections 20 at the end of the pieces of fabric 16.

Instead of having ribs on the outside of the barrel 28, ribs can be provided within the cylinder 35 that engage with grooves in the barrel 28. However, such an arrangement is not as advantageous as that illustrated since with such an arrangement, the key 14 can be removed at any time, which means that it could be removed accidentally and lost.

Many alternative locking mechanisms for preventing the slide 10 from moving down the chains of teeth 18 may be used instead of the mechanism described in connection with Figures 1 and 2 but all will operate on the basis that the toggle, acting as a removable"key", can activate and deactivate the locking mechanism. For example, the locking mechanism could be formed by a pair of spring-loaded jaws provided within the faceplates 22,24 ; the jaws will normally be held apart to allow the slider to move up and down the chain of teeth 18 but when the key 14 is removed they are released so that they grip or clamp the material strips 16 or the chain of teeth 18, thereby preventing the slide 10 from moving. An alternative locking mechanism is for the toggle to engage a worm screw that opens and closes a clamp that, when closed, clamps on the material 16 or the teeth 18 and so prevents movement of the slider to lock the zip fastener. Yet another alternative way is for the toggle to move a pin (or other locking member) into and out of a recess in the sheath 20 to lock and unlock (respectively) the fastener.

The lock could be more sophisticated than as shown in Figures 1 and 2; for example, instead of the single rib 29, several ribs could be provided that are

spaced radially about barrel 28, 113. By varying the height, width and annular spacing between ribs, a large number of key configurations could be provided.

Obviously the grooves 27,119 in the opening 25 and recess 117 will correspond in shape and spacing to the ribs.

A second embodiment is shown in connection with Figures 3 to 9 and includes a slider 101 provided with a toggle 102. The slider 101 includes a body portion 103 and a top cover 104. The body portion 103 includes a"Y"shaped channel 105 through which the rows of teeth (not shown) can pass to open and close the zip fastener in a known manner. The arms of the"Y"channel are separated by a diamond or neck 106; channels 107 are provided for accommodating the strips of material (such as 16 shown in Figure 1) that support the chains of teeth of the zip fastener (such as teeth 18 shown in Figure 1); only one channel 107 is shown in Figure 3a and 3b.

The toggle 102 is pivotally attached to a boss 108 by means of a pivot pin 109 extending between bifurcated arms 110 of the toggle 102. The boss 108 forms one end of a hollow key barrel 113 having a rib 112 on its outer surface. Above the barrel 113 are a pair of rings 114 and 115, each ring being formed with facets. The barrel 113 and the toggle 102 together form a key 111.

The top cover 104 includes an opening 116 leading to a recess 117 provided in the body portion 103. A pin 118 is located within the recess 117 that can engage with a hollow bore 137 (see Figure 7) within the barrel 113 of the key.

The recess 117 includes a groove 119 into which rib the 112 of the key can slide when the key 111 is pushed into the opening 116 and recess 117.

Referring now to Figure 4, it can be seen that the body 103 of the slide includes

a circular raised wall 120 that is concentric with the recess 117. A cam 200 is provided that includes a cam ring 121 and a cylindrical body 125 around which the ring 121 is secured. The outside surface of the body 125 is cylindrical and has a diameter such that it can fit snugly within the circular wall 120; the inside surface of the body 125 includes a first and a second body section 122,123 having facets matching, in shape and size, the facets of rings 114 and 115 respectively of the key 111. The cam ring 121 includes an elevated cam surface 124 and a lower cam surface 126. The lower cam surface 126 has, at its lowest section, a hole 127 whose function will be described later. As will be appreciated, the cylindrical body 125 of cam 200 is placed within the circular wall so that the cam 200 including cam ring 121 can be rotated on the slide body portion 103.

The body portion 103 can move within channel 129 and, at the upper limits of its movement, it is held within the channel by the wall 128. The locking member 130 also includes a further wall 128 surrounding, on three sides, a rectangular-sectioned channel 129 that extends into the slide body portion'103 and the neck and/or diamond 106.

A locking member 130 includes a locking pin 131, whose function will be described in greater detail with reference to Figure 7. The locking member 130 also has a cam follower 132 that fits over the cam surfaces 124,126 so that, when the cam ring 121 is rotated, the locking member 130 is raised or lowered within channel 129.

The pin 118 within the recess 117 shown in Figure 3b is provided on a base 133 and is pushed up through the recess 117 from underneath (as viewed in Figure 4). It lies concentrically with the recess 117. The pin 118 is provided on a base 133 that is secured, e. g. by welding or gluing, on the underside of the slide body

portion 103 (see Figure 5a) by means of a rim 133a of the base 133 engaging in a groove on the underside of slide body portion 103. However, the pin 118 can be made integrally with the body as desired.

The cover 104 includes a lip 134 that engages with a cut out section 135 on slide body portion 103 ; a similar lip (not shown) is provided on the opposed edge of cover 104 and engages a second cut out section 136 on the body portion 103. The two lips are held within the cut outs by welding or gluing or some other permanent fixture that prevents the cover 104 being removed from the body portion 103. If permanent fixing of the cover 104 is unnecessary, a simple snap-fit connection between the cover and the slide body 103 is provided.

Referring now to Figure 5a, the key is shown within the recess 117 with the faceted rings 114,115 of the key fitting into the correspondingly facets in sections 122,123 on the inner surface of cylindrical cam body 200 (see also Figure 7).

The bore 137 within the barrel of the key 111 is shown fitted on the pin 118.

As can be seen, the cylindrical cam body 125 of the cam 200 is rotatable by the key 111 within the circular wall 120 by means of the engagement of the key facets 114,115 with the cam facets 122,123 to lock and unlock the slide. As seen in Figure 5a, the cam follower 132 is engaged on the raised cam surface 124 of the cam ring 121 and so the locking pin 131 is retracted from the channel 105' ; (105'indicates the"stem"of the Y-shaped channel 105). Thus, the channel 105 can slide over the rows of teeth (not shown in Figure 5a but indicated by reference number 118 in Figure 1 and 139 in Figure 7), thereby allowing the zip fastener to be opened or fastened, depending on which way the slide is pushed over the teeth.

Figure 5b shows a perspective view showing the cam follower 132 engaged on the raised section 124 of the cam ring 121.

Figure 6a is the same as Figure 5a but shows the position after the toggle 102 has been rotated through 180°. The cam follower 132 is now engaged on the lower section 126 of the cam ring 121, which pushes the locking member 130 downwards into the channel 129 (see Figure 4) so that the locking pin 131 is engaged within the stem section 105'of the Y-shaped channel 105. The position of the cam follower 132 within the channel as a result of its engagement on lower cam surface 126 is shown in Figure 6b.

Referring back to Figure 4, in the locked position, the hole 127 in the cam ring 121 engages with a pip 138 on the cam follower 132 to temporarily hold the cam ring 121 in a stable position when the slide is locked. In this connection, the arms of the cam follower 132 should be resilient to allow the engagement between the pip 138 and the hole 127 and the disengagement of the pip when it is desired to open the zip.

Figure 7 shows the slider in the locked position with the locking pin 131 engaged with teeth 139 of a zip fastener. Because of this engagement, the slide 101 cannot be moved up or down the teeth to open or close the zip fastener.

As described in connection with Figure 4, the cylindrical barrel 113 of the key 111 has a rib 112. An annular groove 140 between the base 133 and the recess 117 accommodates the rib 112 and allows the key 111 to turn within the lock.

A straight groove 119 is provided in the recess 117 to allow the key 111 to be pushed into or removed from the recess. The removal is only possible when the lock is in the closed position shown in Figure 7, in which the rib 112 is in

register with the straight groove 119.

The length of the pin 118 (length"X"shown in Figure 8) must match the length of the cylindrical barrel 113 of the key. If the barrel is too short, the rib 112 will not engage within the annular recess 140 and so it will not be possible to turn the key to open the lock. On the other hand, if the barrel is too long, the faceted rings 114,115 on the key will not engage with the corresponding facets in the first and second body sections 122,123 and, again, it will not be possible to turn the lock.

Referring to Figure 9, the locking member 130 is shown to be spring biased into the locking position by a spring 141 acting between the locking member 130 and the cover 104. Such an arrangement can assist with the movement of the locking member 130 within the channel 129.

Because the rib 112 is only in register with the groove 119 in recess 117 when the lock is closed, the key 111 and the toggle 102 are held captive by the body portion 103 while the lock and the zip fastener is open.

A slot 142 (see Figure 4) is provided between the cylindrical outer wall 125 of the cam ring 121 and the lower cam surface 126. This allows a certain amount of flexibility of the lower cam surface so that the locking pin 131 can find its way between the teeth 139 of the zip fastener and hence lock the slide 101. In this connection, the cam surfaces 124,126 could be made from acetal or nylon (if the cam 200 were made as a single moulding) or it could be made from spring steel.

The presence of the pin 118 within the recess 117 prevents the cam ring 121 being turned merely by inserting a screwdriver into the opening 116 and

engaging the cam 200.

The facets on the ring 114,115 and the corresponding facets on first and second sections 122,123 of the cam ring 121 can be varied from lock to lock so that a large number of combinations of keys and locks can be produced to reduce the risk that the lock can be opened by a key not originally supplied with the lock, i. e. improperly.

Referring now to Figures 10 to 12, there is shown a third embodiment of a slide of the present invention. The third embodiment is similar to that of Figures 3 to 9 except the locking member 130 is replaced by a locking member 201.

Accordingly, the reference numbers used in connection with Figures 3 to 9 will be used in the description of the third embodiment to indicate corresponding parts.

Referring initially to Figure 12, the locking member 201 is a flexible metallic strip (e. g. made of spring steel) ; it may be stamped and folded into shape. It includes a central section 210 and a hook 212 that is bent to overlie the central parts 210 and be separated from the central part by a gap 202.

The locking members include a pair of anchoring legs 203 and a pair of locking prongs 205,206. The locking member 201 is incorporated into the slide body 103, which has a cam 200 having a cam ring 121 arranged annularly around a cylindrical body 125. As described in connection with Figures 3 to 9, the cam ring 121 has an upper and a lower cam surface 124,126.

The locking member 201 is fastened onto body 103 by means of the legs 203, 204 engaging in a recess 220. As shown in Figure 10A, the cam ring 121 fits into the gap 202 between the hook 212 and the central part 210. The locking

prongs 205,206 are also located in a recess 222 within the body 103. The natural resilience of the locking member tends to keep it in the configuration shown in Figures 10A and 10B. However, when the cam ring 121 is rotated by a key (not shown) that engages in opening 117 in a manner described above, the lower cam surface 126 engages the central portion 210 of the locking member 201 and pushes it down to the position shown in Figures 1 lA and 11B against the natural resilience of the locking member. In the position shown in Figures 11A and 11B, when the lower cam surface 126 pushes down on the locking member 201, the prongs 205,206 and the legs 203,204 are pushed into the channel 105,105'and engage the teeth of the zip fastener or the surrounding fabric, thereby preventing the body 103 from moving up and down the fastener.

In this condition, the fastener is locked in position. It can, however, be released by turning the cam 200 through a further 180° to the position shown in Figures lOA and lOB, where the natural resilience of the locking member 201 removes the legs and prongs 203,206 from the channel 105, 105', thereby allowing the body 103 to move on the fastener and thereby also allowing the fastener to be opened and closed.

Referring finally to Figure 13, the distance Y is critical to the operation of the zip fastener. If it is too large, the act of pulling on the toggle to open and close the zip fastener will cause the body 101 to tilt excessively, thereby making it difficult to move the slide body 101 over the teeth of the fastener. However, the arrangement of the present invention allows the distance Y to be kept at a minimum.

The materials from which the lock are made will depend on the degree of security required. If a high degree of security is required, the parts could be made from cast/machined metal whereas, if a relatively lesser degree of security is acceptable, the parts can be moulded from plastic, e. g. nylon, which may

optionally include reinforcing fibres.

The lock may be used in any circumstances in which it is desired to lock a zip fastener, for example to lock a zipped pocket, a suitcase, a camera case or a bag.