GB2172047A

GB2172047A - A bow-spring lock

Info

Publication number: GB2172047A
Application number: GB08528699A
Authority: GB
Inventors: Olavi Antero Ranta
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-11-23
Filing date: 1985-11-21
Publication date: 1986-09-10
Also published as: FI844602L; SE8505489L; SE8505489D0; NL8503205A; SE463798B; GB8528699D0; DE3541058A1; FI71659B; FI844602A0; GB2172047B; FI71659C

Abstract

A body portion (1) of the lock is formed by a link member (3) of the ornamental chain, a hinge link (4) of which is replaced with a shaped combination of a hinge and a locking bow (2', 2), whereby the lock differs in shape from the other link members of the chain as little as possible. In addition, a point portion of the bow spring (2) is in the locking position protected against any outside contacts. Being integral in construction, the lock enables chains to be shortened without any laborous soldering step, because even a shortened chain can be connected to the bow spring (2). When chains are joined together, the bow spring portion (2) of the lock (1) is scarcely noticeable in most chain types. The bow-spring lock (1) is also as a separate lock adaptable to all chain types by the use of linking rings. <IMAGE>

Description

SPECIFICATION A bow-spring lock The invention relates to a bow-spring lock for ornamental chains, wherein a lock portion having an integral structure comprises a link or a ring hinge for the connection of the lock portion to one end of the chain as a member thereof, the other end of the lock portion being provided with a hinged locking tongue which is shaped of a wire material and is inserted into a link or ring hinge provided at the other end of the chain in an upright position with respect to the lock, whereafter said tongue is displaced adjacent a bow bent in the spring to form the hinged portion and then turned to extend in parallel with the chain, whereby the chain is in the locking position, wherefrom it can be released by the above steps in reverse order.

Such hook locks are limitedly used mainly in ornamental chains made of basic metals. The structure of the known hook lock is based on a separate hook bent from a metal wire or band or cut out of a sheet. A disadvantage of the use of this kind of hook is that the free end thereof easily gets caught in the objects of contact, whereby it is liable to open and thus unreliable. The hook is seldom used in chains made of noble metals as the design thereof is unsuitable for most ornamental chains and as it produces an impression of cheapness.

The object of the invention is to improve a hook lock of the above type in such a manner that the hook is attached to a link member of the chain as a structurally integrated part in order to protect the point of the hook; that it can be manufactured by a casting method up to an operative state; and that the lock is reliable as well as easy to use.

For the achievement of the object, the bowspring lock mentioned above is characterized in that the body portion of the lock is formed by a link member of the ornamental chain, said link member being provided with a bow spring in place of a ring hinge, which bow spring is made of a wire material by bending and shaping so that the bow replaces the ring hinge, that an extension thereof forming a locking arm is bent inside the body portion is such a manner that the point portion is protected against any outside contacts and that the bow spring provides a secure locking which is releaseable only by turning a link member of one end of the chain into a perpendicular position with respect to the body portion of the lock and by displacement thereof so as to be released through the point of the bow spring, said point acting as an elastic retainer.

Besides being reliable and easy to use, the one-part bow-spring lock having an integral structure and which can be brought into an operative state by casting is applicable as a separate lock in different kinds of chains. As it is attached to one link member of the chain, it in most cases scarcely differs from the other members and is ready to operate even if parts are removed from the other end of the chain. Further, several chains can be almost unnoticeably joined by means of the lock.

Certain working examples of the invention will be more closely described in the following with reference to the attached drawing, wherein Figures 1 and ib illustrate a side view of the bow-spring lock according to the invention and one link member at one end of the chain when locked within a bow spring 2 from a link 1'.

Fig. 1a illustrates the locking step of the chain shown in Fig. 1.

Figures 2 and 2b illustrate a bottom view of the lock according to Fig. 1 and one link member at one end of the chain when locked within the bow spring 2 from the link 1'.

Figure 2a is a cross-sectional view of the lock 1 along the line a-a in Fig. 2 at the initial stage of the locking operation.

Figures 3 and 3b illustrate a side view of a bow-spring lock according to another embodiment of the invention in the locking position and one link member of one end of the chain when locked within the bow spring 2 from a hinge link 4.

Figure 3a illustrates the locking step of the bow spring arrangement shown in Fig. 3.

Figures 4 and 4b illustrate a bottom view of the bow-spring lock according to Fig. 3 in the locking position and one link member of one end of the chain when locked within the bow spring 2 from the hinge link 4.

Figure 4a is a cross-sectional view of the lock shown in Fig. 3a.

Figures 5 and 5b illustrate a side view of the bow-spring lock according to still another embodiment of the invention in the locking position and one link member at one end of the chain when locked within the bow spring from the hinge link 4.

Figure 5a illustrates the bow-spring lock of Fig. 5 when released from the spring locking and one link member at one end of the chain when removed from within the bow spring 2.

Figures 6 and 6b illustrate the bow-spring lock of Fig. 5 in the locking position and one link member of one end of the chain when locked within the bow spring from the hinge link 4.

The bow-spring lock shown in Figs. 1, la, 1b, 2, 2a and 2b is fastened on a link 1' of one end of the ornamental chain in the same way as the other chain members. Depending on the manufacturing technique, the joint of the hinge link can be left open or soldered.

The bow spring 2 shown in said figures is bent into the final position within the body of the lock, the point portion being thus pro tected against any outside contacts. When a chain member 3 is modified to act as a lock, a transversal bar positioned in the middle of said member is removed, the member being widened so that the link 1' of the member 3 can be pushed inside the body portion 1 when the locking according to Fig. 2a is being effected, a tongue 2 acting as an elastic retainer. The member 3 is displaced in an upright position to a hinge point 2' of the bow spring and then turned to be in parallel with the chain, whereafter the locking step is completed.In order to be released from the lock, the chain member 3 is turned into a position perpendicular to the body portion 1 of the lock and then displaced towards the point portion of the spring 2, whereby the point portion acting as an elastic retainer must finally yield, thus releasing the chain from the locking.

The basic structure of the bow-spring lock 1 of the chain type illustrated in Figs. 3, 3a, 3b, 4, 4a and 4b is the same as in the lock of the preceding chains type. A gap 1' of the lock portion 1 of this ornamental chain enables locking of the point of the bow spring 2, wherefore it does not act as an elastic retainer. The spring 2 is released when it is detached from the body portion 1 in a manner shown in Fig. 3a. When a hinge link 4 of the member 3 is passed within the bow spring 2 which is in the opening position and then turned so as to be in parallel with the chain, the thickened end portion of the bow spring 2 is pressed into the gap 1" of the body portion 1.As the walls are resilient in the outward direction, the point portion of the bow spring 2 snaps into a locking position which prevents the point from getting caught, said point portion being thereby positioned in a locking recess provided within the walls of the body portion. To be released from locking, the point portion of the bow spring 2 is lifted e.g. by means of a finger nail from the locking recess and the member 3 is removed from within the bow spring 2 in a position perpendicular to the body of the lock 1. A stationary hinge link 4 is positioned at that end of the lock portion which is opposite to the bow spring, whereby the lock can be used as a separate lock in different kinds of chains by using a linking ring.

The basic structure of the bow-spring lock 1 of the chain type illustrated in Figs. 5, 5a, 5b, 6 and 6b is similar to those described above. The spiral-shaped body 3 of this chain type requires that the bow spring 2 is bent to correspond to the shape of said body. Passing in place of the other end of the chain is effected in the same way as in the preceding lock, whereafter a tip 2" of the spring 2 is locked into a spiral position when pressed in the direction of the spiral, whereby the point does not get caught.

Claims

1. A releasable link for a chain, comprising a looped body having a tongue which extends initially away from a root on the body and then back towards the body to a free end shielded by the body, the tongue forming a loop external to the body for reception of a further chain link into which the free end of the tongue can be passed so that the further link can be fed along the tongue for reception in the external loop.

2. A link according to claim 1, in which the body and tongue are formed integrally.

3. A link according to claim 2, in which the body and tongue are cast.

4. A link according to any preceding claim, in which the tongue is resilient.

5. A link according to any preceding claim, in which the tongue is engageable with the body adjacent its free end.

6. A link according to any preceding claim, in which the body forms a closed loop.

7. A link according to claim 6, in which the loop has a twisted configuration.

8. A link according to any preceding claim, in which the free end of the tongue lies within an interior space of the body defined by the looped shape thereof.

9. A one-part bow-spring lock adaptable to a type of an ornamental chain, which bowspring lock is manufactured by casting up to an operative state and connectable to the ornamental chain in the same way as the other link members of the chain, a link of one end of the ornamental chain being passed within a bow spring of the lock in the inner space of the body portion of the lock in an upright position, whereafter it is displaced to the point of the spring and further to a link point and then turned to be in parallel with the chain, whereby the chain is in the final locking position thereof and is reieaseable from the locking by turning the member along the bow into a position perpendicular to the body of the lock and by displacing it through the point of the bow so as to be released, wherein the body portion of the lock is formed by a link member of the ornamental chain, said link member being provided with a bow spring in place of a ring hinge, which bow spring is made of a wire material by bending and shaping so that the bow spring replaces the ring hinge, and that an extension thereof forming a locking arm is bent inside the body portion in such a manner that the point portion is protected against any outside contacts, which point portion can also alternatively be locked in place by pressing it into a secured locking within the body, and that the bow spring provides a secure locking which is releaseable only by turning the link member of one end of the chain into an upright position with respect to the body portion of the lock and by displacement thereof so as to be released through the point of the bow which acts as an elastic retainer.

10. Bow-spring lock according to Claim 9, wherein a hing link is attached to the other end of the lock as an internal part thereof and that a thickened point portion of the bow spring can be pressed into a gap of the body, whereby it is in a locking position which prevents it from getting caught.

11. Bow-spring lock according to the alternative of Claim 9, wherein a hinge link is attached to the other end of the lock as an integral part thereof and that the point of the spiral-shaped bow spring is bent to form a tip which is locked when pressed in the direction of the spiral.

12. A releasable link for a chain, substantially as hereinbefore described with reference to Figs. 1, 1a, ib, 2, 2a and 2b, 3, 3a, 3b, 4, 4a and 4b or 5, 5a, 5b, 6 and 6b of the drawings.

13. A chain having a releasable link according to any preceding claim, the external loop of the releasable link receiving a looped body of an adjacent link.