The present invention relates to a locking device for connecting two end loops of a jewellery strand, such as a chain of a necklace or a bracelet, comprising a clip member comprising two half shells hinged together at respective outer peripheries and a snap lock allowing for the two half shells when being hingedly rotated to be releasably snap-locked to each other to form an assembled clip member with a through-going hole.

Such locking devices are known from the prior art in a variety of forms. One of the most common variations is sometimes referred to as an S- lock in which the strand retainer consists of a metal wire that has been bent to assume the shape of an S that "lies down". The two ends of the wire abut a centre part of the S-shape in an unloaded position of the S-lock, whereby a retainer loop is established at each lateral side (i.e., a top and a bottom, respectively, of the S-shape). An entrance to each loop is thus provided oppositely in the transverse up-down direction between each end of the wire and the centre part. An end loop of a jewellery strand may be inserted through each entrance by forcing the respective wire end and centre part apart from each other against an inherent elastic force of the metal wire. Subsequently, due to the elasticity the wire ends return to abutting the centre part whereby the end loops are retained to the S-lock and hereby also to each other, thus forming a jewellery lock of a necklace or a bracelet.

An example of a prior art variation of a like locking device is dis- closed in DE 9206259 U l, in which the strand retainer assumes a more or less ring-formed shape made from a bend metal wire, each half of the ring forming a retainer loop. A common entrance for end loops of a jewellery strand to enter the retainer loops is provided between the wire ends at a top of the strand retainer.

These prior art jewellery locks have a number of drawbacks. It is essential to design such locking devices so that a relatively strong mechanical force need be overcome between two strand retainer portions in order to ensure that the loop ends do not escape from the retainer loops of the strand retainer in a locked position of the locking device. It may be difficult for a user or wearer, especially one with relatively weak or large fingers, to force the loop ends through the locking device entrance(s) since the user has to overcome a relatively strong force at the entrance to push apart two abutting portions. If a locking device is designed so that a smaller force needs to be exerted when attaching the end loops to the retainer loops, this entails a risk of the end loops in a use position escaping through the entrances, whereby the jewellery may be lost. In any case, there is a substantial risk that the end loops will escape since the release force has, in practise, to always be so small that it is possible for a user to release them. Another drawback is that in time the inherent tensions of the strand retainer will loosen up so that risk of the end loops escaping from the retainer loops is increased, thus also increasing the risk of dropping a potentially valuable piece of jewellery.

Another prior art locking device is disclosed in US 229,257. A necklace fastening is composed of two parts hinged together using a spring and a projection. Hooks attached to the upper part of the fastening are used for retaining the necklace.

On this background it is the object of the present invention to provide a locking device with improved retaining of end loops of a jewellery strand and ease-of-use as regards engaging and disengaging end loops to and from the locking device.

This object is achieved in that the locking device as described in the introduction further comprises a strand retainer provided separately from the clip member, the strand retainer comprising two end parts connected by means of a centre part, each end part forming a retainer loop for retaining an end loop of a jewellery strand, each retainer loop comprising an entrance for connecting the respective end loop, the centre part in a released position of the clip member being able to be placed between the half shells such that when the half shells are subsequently snap-locked together to assume a locked position of the clip member, the centre part extends through the through-going hole, and the retainer loops of the end parts extend out of the clip member on each side of the through-going hole, the clip member being adapted such as to in the locked position prevent any jewellery strand end loops attached to the retainer loops from escaping the strand retainer through the retainer loop entrances.

Hereby, it is no longer necessary to design the strand retainer so that a large force needs to be exerted on it when attaching or releasing end loops of a jewellery strand. Instead, the clip member prevents the end loops from escaping, e.g. by abutting the strand retainer, compressing a resilient strand retainer or by blocking any end loop escape routes. Since any releas- ing or opening movement of the clip member is unrelated to movements of or forces exerted on the end loops, strength and security of the lock is greatly improved. Furthermore, it is no longer necessary that the strand retainer be designed so that a substantial force needs to be overcome in order to attach or detach the end loops. Instead, entrance dimensions corresponding to or being larger than a diameter or thickness of material of the end loops in an unloaded position are possible, making it easy for any user to guide the end loops through the respective entrances. Generally the locking clip may be easily snap-locked to form a closed locking clip enclosing at least the centre part of the strand retainer, and it may similarly be easily snapped out of the locked, closed position so as to release the end loops from the locking device.

The locking device according to the invention further has the added advantage that freedom as regards the design and appearance of the locking device is improved. Thus, the clip member may assume a large number of different shapes and may comprise ornaments in many different variations.

Preferred embodiments of the invention are defined in the dependent claims 2 to 9.

In one embodiment the retainer loops have larger dimensions than the through-going hole, whereby in the locked position of the locking device they are prevented from entering the through-going hole. If the retainer loops abut a peripheral edge of the through-going hole or are positioned at a distance from a peripheral edge of the through-going hole smaller than a material thickness of the end loops, the end loops are prevented from entering the clip member, thus being firmly locked to the closed locking device.

In another embodiment the strand retainer is formed so that the en- trance to each retainer loop is positioned at the centre part and/or so that in the locked position of the clip member the entrance to each retainer loop is positioned within the through-going hole. This ensures that in the locked position the end loops do not escape through the entrances.

In another embodiment the strand retainer is symmetrical over an inclined symmetry line. Hereby, the entrance to each retainer loop can be provided at opposite sides of the centre part, making it possible to easily and securely attach the end loops to each of the retainer loops of the strand retainer in the unlocked, open position of the clip member, the end loops not interfering with each other during attachment.

In another embodiment the strand retainer is formed from a thread, preferably a piece of metal wire, the thread having been bent into shape. This ensures easy and low-cost manufacture of a suitable strand retainer.

In another embodiment each retainer loop comprises two loop ends, each loop end extending into a leg that extends, preferably in parallel, into the centre section such as to be contained within the through-going hole in the locked position of the clip member. Hereby, the clip member can readily be firmly closed with a periphery of the clip member or the through-going hole being positioned over the legs while allowing for the retainer loops to extend out on each side of the clip member. In a development of this em- bodiment a first leg on each side is connected with each other by means of a connector member, preferably said first legs are an upper and a lower leg, respectively, so that the connector member extends, preferably inclined, in a transverse up-down direction. In a further development of this embodiment the entrance to the retainer loops on each side is formed between a second leg on each side and the connector member. These features provide a strand retainer with oppositely (up/down) positioned entrances, to which the end loops can be easily attached and detached. Furthermore, in combination with the closed clip member the strand retainer and end loops are firmly attached to the locking device.

In another embodiment the locking device further comprises a chain, preferably of the anchor type, comprising a number of connected chain links, preferably substantially elliptical, oval or circular in shape, a chain link at each end of the chain being adapted for being positioned in a respective retainer loop.

The invention also relates to a method for providing a locking device, preferably according to any one of the previous claims, connecting two end loops of a jewellery strand, such as a chain of a necklace or a bracelet, comprising the steps of

providing a strand retainer comprising two end parts connected by means of a centre part, each end part forming a retainer loop for retaining an end loop of a jewellery strand, each retainer loop comprising an entrance for connecting the respective end loop,

providing a clip member comprising two half shells hinged together at respective outer peripheries and a snap lock allowing for the two half shells when being hingedly rotated to be releasably snap-locked to each other to form an assembled clip member with a through-going hole,

providing a jewellery strand with two end loops,

attaching the jewellery strand end loops to the retainer loops through the respective entrances,

in a released, open position of the clip member positioning the centre part between the two half shells,

snap-locking the half shells together such that the clip member assumes a locked position, the centre part extending through the through-going hole, the loops of the end parts extending out of the clip member on each side of the through-going hole, the clip member in the locked position preventing the jewellery strand end loops attached to the retainer loops from escaping the strand retainer through the retainer loop entrances.

The strand retainer and clip member are preferably provided as in any of the above embodiments of the locking device, the method providing respective advantages similar or comparable to those described above.

The invention will now be explained by means of examples of embodiments with reference to the schematic drawings in which

Fig. 1 is a front view of a detail of a piece of stranded jewellery showing a strand retainer of an embodiment of a locking device according to the present invention connected to two respective end loops of a chain,

Fig. 2 is a view corresponding to that of Fig. 1 in which the locking device is in a locked position, a clip member of the locking device in a closed position being attached to the strand retainer,

Fig. 3 is a front view of the clip member of Fig. 2 shown in a closed, locked position,

Fig. 4 is a view corresponding to that of Fig. 3 showing the clip member of Fig. 2 in an open, unlocked position,

Fig. 5 is a side view corresponding to that of Fig. 3 showing the clip member of Fig. 2 from an end side in the closed, locked position,

Figs 6 and 7 are views corresponding to those of Figs 3 and 4 show- ing a modified embodiment of the clip member of Fig. 2,

Figs 8a to 8c show three steps of assembly of the locking device of

Fig. 2,

Figs 9 and 10 are views corresponding to Figs 1 and 2 of a modified embodiment of a locking device according to the invention,

Figs 11a to 11c are views corresponding to Figs 8a to 8c of the embodiment of Figs 9 and 10,

Fig. 12 is a view of the strand retainer of Fig. 1 shown connected to three different chains on one side,

Figs 13a and 13b are views corresponding to Figs 8a and 8b, respectively, of another embodiment of a strand retainer and locking device according to the invention, and

Figs 14a and 14b are views corresponding to Figs 8a and 8b, respectively, of yet another embodiment of a strand retainer and locking device ac- cording to the invention.

Generally in the drawings, in different embodiments similar or like elements are provided with similar reference signs.

Figs 1 to 5 and 8a to 8c show different parts and views of an embodiment of a locking device 1 according to the present invention as used in a piece of stranded jewellery comprising also a jewellery strand in the form of a necklace or bracelet chain 2 of which only part is shown in Figs 1 and 2. In Figs 1 and 2 the locking device 1 connects two end loops 3, 4 of the chain 2.

The locking device 1 comprises a strand retainer 5 comprising two end parts connected by means of a centre part 6, each end part forming a retainer loop 7, 8 each for retaining and holding one end loop 3, 4 of the chain 2. Each retainer loop 7, 8 comprises an entrance 9, 10 for connecting the respective end loop 3, 4. The opening or entrance 9, 10 to each retainer loop 7, 8 is positioned at or near the centre part 6. The strand retainer 5 is symmetrical over an inclined symmetry line. Hereby, the entrance 9, 10 to each respective retainer loop 7, 8 is provided at opposite sides (top/bottom side, respectively, in Fig. 1) of the centre part 6, making it possible to easily and securely slide the end loops 3, 4 onto each of the retainer loops 7, 8. The strand retainer 5 is bent into shape from a piece of metal wire, e.g. silver or gold wire. In other embodiments the strand retainer may for instance be punched out from a metal plate to form a similar shape. Metal may be re- placed by for example plastic. The metal wire is circular in cross-section, but may have other shapes, such as elliptical or rectangular, the latter being a possibility if the strand retainer is punched out from a plate. The strand retainer may in principle also for example be moulded to form a suitable shape. In this context it is noted that, although preferred, the strand retainer needs not comprise any specific resilience characteristics or inherent pre-stressed forces. Some resilience might however be of advantage for preliminarily holding the loop ends 3, 4 in the retainer loops 7, 8 before locking the locking device (i.e. closing the clip member, see below).

As is perhaps best seen in Fig. 8a, each retainer loop 7, 8 comprises two loop ends 11, 12; 13, 14, each of which extends into a leg 15, 16, 17, 18 that all extend in parallel towards an into the centre section 6. A first leg 16, 17 on each side is connected to each other by means of a connector member 19, said first legs 16, 17 being upper and lower legs, respectively, so that the connector member 19 extends inclined in a transverse up-down direction, i.e. with an angle in relation to the general leg direction of about 60-70°. It is preferred that this angle is within a interval of 30-80°. The connector member at each end extends somewhat further up and down, respectively, than the respective leg 16, 17 to improve the respective entrances 9, 10. The en- trances 9, 10 to the respective retainer loops 7, 8 are each formed between a second leg 15, 18 on each side and the extended end of the connector member 19. Oppositely positioned entrances 9, 10 make it easy to attach and detach the end loops 3, 4 without them having to touch or disturbing each other. Both of the second legs 15, 19 are at distal ends bend slightly away from (i.e., downwards and upwards, respectively) from the connector part 19 such as to improve ease of sliding of the respective end loops 3, 4 over the legs 15, 19 through the respective entrances 9, 10.

Referring to Figs 1 and 2, the chain 2 is in the form of an anchor chain comprising a number of connected chain links that are each substan- tially elliptical in shape. The respective end loops 3, 4 are each the endmost one of the chain links. The strand may be of any other suitable type as long as suitable end loops are provided, for example a leather strand with attached end loops could be used. In principle, the end loops need not be closed, they may instead be for example hook-shaped.

Referring especially to Figs 3 to 5, the locking device 1 further com- prises a substantially ball-shaped or spherical metal clip member 20 comprising two half shells 21, 22 hinged together by means of a hinge 23 positioned to connect respective outer periphery parts of the two half shells 21, 22. The used hinge 23 may be of any suitable type. Each half shell 21, 22 comprises an internal depression 24, 25 surrounded by a metal shell 26. When closed the clip member 20 thus comprises an inner, spherical cavity composed of the two depressions 24, 25 facing each other. The shell 26 at each lateral end (left and right ends of Fig. 3) comprises a circular aperture 27, 28 forming respective entrances to a through-going hole 29, the latter thus extending from left to right in Fig. 3 through the clip member 20 first via aperture 27, then the inner cavity (depressions 27, 28), then aperture 28. Two resilient plate-shaped, bend metal clips 30, 31 at the periphery of the lower half shell 22 snap into corresponding projections 30a, 31a of the upper half shell 21 to form a snap lock allowing for the two half shells 21, 22 when being hingedly rotated about hinge 23 to be releasably snap-locked to each other to form an assembled, locked, closed clip member 20, as shown in Figs 3 and 5, with a through-going hole 29. A small, transversely extending cut-out 20a at the top (Fig. 5) allows for insertion of a user's nail for separating the two half shells 21, 22 when opening the clip member 20 for release of the strand retainer 5. Other types of snap locks or different locks may fulfil the same purpose, e.g. a single plate-shaped, bend metal clip positioned centrally, or a hook-and- loop connector, which could be released by means of an external, spring- biased button for example positioned to replace the cut-out 20a.

Referring to Figs 8a to 8c, in accordance with the invention assembly and locking of the locking device 1 may be carried out in the following manner. The chain 2 end loops 3, 4 are attached to the retainer loops 7, 8 by sliding them through the respective entrances 9, 10. In a released, open position of the clip member 20 the centre part 6 is placed between the half shells 21, 22, more specifically on the lower half shell 22, cf. Figs 8a and 8c. The half shells 21, 22 are subsequently mutually rotated via hinge 23 to be snap-locked together by means of clips 30, 31 to assume a locked position of the clip member 20, cf. Fig. 8c. The centre part 6 now extends through the through-going hole 29, and the retainer loops 7, 8 extend out of the clip member 20 on each side of the through-going hole 29, whereby the clip member 20 will prevent the jewellery strand end loops 3, 4 attached to the retainer loops 7, 8 from escaping the strand retainer through the retainer loop entrances 9, 10.

Thus, in the locked position of the clip member 20 the entrance 9, 10 to each retainer loop 7, 8 is positioned within the through-going hole 29. The diameter of each aperture 27, 28 (each being substantially circular, but may assume any other suitable shape, such as elliptical or quadratic) in this embodiment corresponds substantially to the distance (measured from the outside) between each pair of legs 15, 16; 17, 18, whereby the loop ends 3, 4 are prevented from entering through the apertures 27, 28 such as to be locked to the locking device 1. Thus, part of or all of each leg 15, 16, 17, 18 extends in parallel with the other legs 15, 16, 17, 18 towards and into the centre section 6 such as to be contained within the through-going hole 29 in the locked position of the clip member 20. Hereby, the clip member 20 can readily be firmly closed with a periphery of the clip member shell 26 being positioned over the legs 15, 16, 17, 18 while allowing for the retainer loops 7, 8 to extend out on each side of the clip member 20.

The retainer loops 7, 8 have larger dimensions (diameter, in this case) than the apertures 27, 28, whereby in the locked position of the locking device 1 they are prevented from entering the through-going hole 29. And, as mentioned, the retainer loops 7, 8 abut a peripheral edge of the through- going hole 29 (or are positioned at small a distance from a peripheral edge of the through-going hole 29 smaller than a material thickness of the end loops), whereby the end loops 3, 4 are prevented from entering the clip member 20, thus being firmly locked to the assembled locking device 1.

Another embodiment of the clip member 20 is shown in Figs 6 and 7.

Whereas in the previous embodiment the surface of each half shell 21, 22 is smooth, in this case the substantially spherical surface has been provided with an ornamental triangle pattern. In other embodiments the surface and shape of the clip may be further varied as desired. For example the overall shape may be circular cylindrical or non-circular cylindrical (for example being rectangular or triangular in cross section), cube-shaped or a parallelepiped instead of spherical while either comprising an inner cavity or not. The inner cavity may thus also in the previous embodiment be dispensed with such that the though-going hole (in that case a "tube") has the same diame- ter all the way through the clip member. However, presence of the inner cav- ity is preferred since this provides more freedom of designing the strand retainer as regards size and dimensions. Examples of clip members that may be used in the context of the present invention are disclosed in applicant's EP 1657991 Bl, the contents of which are hereby included in their entirety herein.

Figs 9 to 11c show another embodiment of a locking device 1 according to the invention. Only differences from the previous embodiment will be explained in the following. Thus, the strand retainer 5 in this modified embodiment comprises somewhat larger, half-circle-shaped or ear-shaped re- tainer loops 7, 8. As can be deduced from Figs 11a to 11c this provides enhanced security as regards the risk of the retainer loops 7, 8 being drawn into the clip member 20 during use of the piece of jewellery in question.

Fig. 12 is a view of the strand retainer 5 of Fig. 1 shown connected to three different chains 2 of the same type as that shown in Figs 1 and 2 on one side instead of being connected to one single chain 2 as shown in Figs 1 and 2. Each of the retainer loops 7, 8 may thus be attached to more than one chain 2, such as two, three or more chains, to vary the resultant piece of jewellery.

Generally, with the locking device according to the invention the user may thus exchange both clip members and strands and even vary the number of strands so that large variations of the appearance of the piece of jewellery in question may be achieved. It is thus preferred that the locking device according to the invention is in the form of a set of parts comprising a number of different clip members and preferably a number of chains. It may also comprise different strand retainers, e.g. made from different materials such as silver and gold. It is also noted that further variation may provided in that one piece of jewellery or one jewellery strand may be composed of several locking devices connecting several chains.

Figs 13a and 13b show another embodiment of a strand retainer 5 that is used with a clip member 20 similar to that shown in Figs 3 to 5. This strand retainer 5 is a modification of the strand retainer 5 shown for example in Fig. 1. In this embodiment each retainer loop 7, 8 again has two loop ends 11, 12; 13, 14, each of which extending into a leg 15, 16, 17, 18 that all again extend in parallel towards and into the centre section 6. A first leg 15, 17 on each side is connected to each other by means of a connector member 19, the first legs 15, 17 in this embodiment both being the lower of the four legs so that the connector member 19 extends linearly and horizontally, in practice forming an extension of the legs 15, 16. The entrances 9, 10 to the retainer loops 7, 8 are thus each formed between a second, upper leg 16, 18 on each side and the connector member 19 (or the legs 15, 17). The entrances 9, 10 are thus both positioned on the upper side. Note that it is preferred, however, that the entrances 9, 10 are positioned on opposite sides such as shown in the above embodiments since this makes it easier to attach and detach the end loops 3, 4 separately from each other without them dis- turbing each other. Further, the retainer loops 7, 8 in this embodiment are substantially elliptical.

Figs 14a and 14b show yet another modified embodiment of a strand retainer 5 that is used with a clip member 20 similar to that shown for example in Fig. 3. In this embodiment the strand retainer 5 is identical to that shown for example in Fig. 3 except for the following differences. The connector member 19 extends linearly and horizontally, i.e. parallel with the legs 15-18. Further, the legs 15, 18 have been extended such that when properly positioned in the clip member 20 the entrances 9, 10 are located outside the outer periphery of the clip member 20, see Fig. 14b. The dimensions of the parts of the strand retainer 5 positioned outside of the clip member 20 as well as the dimensions of apertures 27, 28 are again adapted such that the end loops 3, 4 cannot exit through the entrances 9, 10 and the through-going hole 29 in the locked position of the clip member 20. Note that at least for aesthetic reasons it is, however, generally preferred that the entrances 9, 10 are positioned within the clip member 20. This is also a more simple solution.

Disclosed is a locking device for connecting two end loops of a jewellery strand, such as a chain of a necklace or a bracelet, is provided, comprising

a strand retainer comprising two end parts connected by means of a centre part, each end part forming a retainer loop for retaining an end loop of a jewellery strand, each retainer loop comprising an entrance for connecting the respective end loop,

wherein it further comprises a clip member comprising two half shells hinged together at respective outer peripheries and a snap lock allow- ing for the two half shells when being hingedly rotated to be releasably snap- locked to each other to form an assembled clip member with a through-going hole,

the centre part in a released position of the clip member being able to be placed between the half shells such that when the half shells are subse- quently snap-locked together to assume a locked position of the clip member, the centre part extends through the through-going hole, and the retainer loops of the end parts extend out of the clip member on each side of the through-going hole, the clip member being adapted such as to in the locked position prevent any jewellery strand end loops attached to the retainer loops from escaping the strand retainer through the retainer loop entrances.

Disclosed is a method for providing a locking device, preferably as described on the previous pages, connecting two end loops of a jewellery strand, such as a chain of a necklace or a bracelet, comprising the steps of providing a strand retainer comprising two end parts connected by means of a centre part, each end part forming a retainer loop for retaining an end loop of a jewellery strand, each retainer loop comprising an entrance for connecting the respective end loop,

providing a clip member comprising two half shells hinged together at respective outer peripheries and a snap lock allowing for the two half shells when being hingedly rotated to be releasably snap-locked to each other to form an assembled clip member with a through-going hole,

providing a jewellery strand with two end loops,

attaching the jewellery strand end loops to the retainer loops through the respective entrances,

in a released, open position of the clip member positioning the centre part between the two half shells,

snap-locking the half shells together such that the clip member assumes a locked position, the centre part extending through the through-going hole, the retainer loops of the end parts extending out of the clip member on each side of the through-going hole, the clip member in the locked position preventing the jewellery strand end loops attached to the retainer loops from escaping the strand retainer through the retainer loop entrances.