Jewelry clasp

This invention is related to a clasp used in jewelry. The clasp includes a first element having a main body and a jaw in the shape of a hook which is integrally formed with the main body; a second element, also having a main body and a jaw in the shape of a hook which is integrally formed with its main body. The jaws of both the first and second elements are tapered, one to the left and the other to the right, thereby mutually lapping each other. A rod and a spring are provided to pivot the bodies of the first and second elements relative to one another, such that the tapered surfaces of the jaws form contacting faces.

FIELD OF THE INVENTION 
The present invention relates generally to clasps, more specifically to a 
miniature clasp of the type adapted to attach small chains for wearing 
jewelry. 
BACKGROUND OF THE INVENTION 
It is well known in the art of jewelry-making to attach the two ends of a 
small chain worn around the neck or arms by means of a clasp. Such clasps 
are also used to attach security chains to jewelry. 
The clasp which is most known and used commercially comprises a hollow ring 
in which is mounted a plunger which slides inside the ring and is biased 
by means of a spring, also located inside the ring, to close a small open 
arc formed in the ring. This kind of clasp, however, has major 
disadvantages. For example, the plunger and the spring, which are located 
inside the ring, do not receive sufficient ventilation and corrode easily 
due to the humidity of the skin. The ring itself is also subject to be 
easily flattened or twisted out of shape. The result is that the plunger 
becomes stuck and the clasp stays half or fully open, leading possibly to 
the loss of a valuable piece of jewelry. 
Another type of clasp used in jewelry has the form of pincers having a jaw 
provided with several pairs of teeth which overlap each other to partially 
surround the ring at the end of the chain. This ring can easily be caught 
in a single pair of teeth and, if too much tension is applied to the 
chain, the pair of teeth may break. 
OBJECT OF THE INVENTION 
Accordingly, it is the object of this invention to provide a jewelry clasp 
which is completely safe and whose constituent parts are well exposed to 
air, thereby not corroding easily. 
SUMMARY OF THE INVENTION 
The above and other objects and advantages of the present invention are 
realized according to a preferred embodiment comprising a first element 
having a main body and a jaw in the form of a hook which is integrally 
formed with the main body of this first element, and a second element, 
also having a main body and a jaw in the form of a hook integrally formed 
with the main body of the second element. The jaws of both the first and 
second elements are tapered: one to the left and the other to the right, 
thereby mutually lapping each other. Means are provided to pivot the main 
bodies relative to each other, such that the tapered surfaces of the jaws 
define contacting faces. A spring means is provided to bias the jaws of 
the first and second elements into movement towards each other. 
The interior portion of the hook of each jaw has a radius of curvature 
corresponding to the radius of curvature of a ring normally provided at 
one end of small jewelry chains, and the width of each of the jaws is 
sufficient to receive a substantial portion of the circumference of the 
ring. Such construction prevents the deformation of the ring as well as 
breakage of the jaws when excessive tension is applied to the ring and 
also prevents wearing-out of the latter. 
The cavity formed by the hooks of the jaw is of such construction that the 
hooks surround opposite surfaces of the ring in taut configuration of the 
chain, thus preventing the opening of the clasp in such configuration. The 
clasp is therefore very safe. 
In accordance with a preferred embodiment, the tip of each hook is 
externally rounded, such that the jaws will automatically close even if 
the ring is already retained under tension by one of the hooks.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to the drawings, the clasp comprises a first elongated planar, 
element 10 having a main central body 12 and a jaw 14 at one end defining 
a hook 16; and a second similar elongated, planer, element 18 having a 
main central body 20, as well as a jaw 22 at one end defining a hook 24. 
The main body of each element 10 and 18 has a cross-sectional U-shape and 
the legs 26 of main body 12 lap the legs 28 of main body 20, one being 
interiorly located and the other exteriorly, as clearly shown in FIG. 5 of 
the drawings. A rod 30 extends through the legs of the two elements and 
functions as a pivot in the clasp assembly. The jaws of the elements are 
tapered, one leftwardly and the other rightwardly, such that they can lap 
each other and define contact surfaces 32 in a plane which is inclined 
relative to the axis of rod 30. A spring 34 is mounted on rod 30 to bias 
the jaws into closing relationship at their respective contact surfaces 
32. Spring 34 is of a spiral shape, being inserted between one leg 26 and 
one leg 28 of the elements 10 and 18, respectively, to prevent the legs 
from sliding laterally on rod 30. 
It is to be noted that jaws 14 and 22 are tapered so that, when in closed 
lapped configuration, the sum of their widths does not exceed the maximum 
width of the clasp. 
Referring now specifically to FIGS. 4 and 7 of the drawings, the inner ring 
contacting surfaces of hooks 16 and 24 are each concavely rounded in a 
plane perpendicular to pivot rod 30, thus forming a circular arc having a 
radius of curvature which corresponds with that of the cross-section of 
rings normally used in jewelry chains. Moreover, these ring contacting 
surfaces are convexly rounded in the plane containing said pivot rod and 
have a radius of curvature substantially equal to that of the inner 
circumference of said ring. Finally, the width of each jaw 14 and 22 is 
such that the jaws surround a substantial portion of the chain ring. Also, 
the web portion of each hook is much thicker than the tip of said hook. 
This design effectively prevents the deformation of the ring or of the 
jaws even if substantial tension is applied to the chain considering that 
the clasp is normally made of malleable precious metal, such as gold. 
The cavity formed by closed hooks 16 and 24 is of such dimension so as to 
completely surround the ring when the chain is taut. In this manner, the 
clasp cannot open by itself because the two hooks 16 and 24 surround 
opposite surfaces of the ring. To open the clasp, it is thus necessary to 
push the ring out of the cavities formed by the hooks 16 and 24. 
Elements 10 and 18 are provided with rearwardly-extending projections 36 
and 38, which are used to open the clasp and disengage the ring as 
illustrated in FIGS. 2 and 3. Projection 38 is longer than projection 36 
to allow attachment of another ring 40. The latter attaches the clasp to 
the other end of the chain without obstructing the movement of projection 
36. The latter is formed with a small slot 42 adapted to receive a 
fingernail to facilitate the opening movement of the clasp. 
Referring finally to FIG. 8 of the drawings, there is shown a refinement of 
the clasp as described above; instead of having a straight outside surface 
at the tip of hooks 16 and 24, the outside surface is substantially 
rounded, as shown by the tips of hooks 16' and 24' of FIG. 8. Such 
particular construction obviates the need to push the ring out of the 
cavity formed by the hooks to close the clasp. Thus, when the ring is 
already inserted in one of the hooks, it will slide of itself on the 
rounded exterior surface at the tip of the other hook 16' or 24' when the 
latter is biased into closing position by spring 34. This other hook can 
thus close automatically without having to push the ring towards 
projections 36 or 38. 
Although the invention has been described in terms of the above-preferred 
embodiment, it is to be understood that variations thereof are also 
envisioned, as set forth in the appended claims.