1. Field of the Invention
The present invention relates generally to jewelry clasps and, more particularly to a single-action double clasp for attaching bracelet and necklace chains in a loop using a single spring.
2. Description of the Background
Clasping devices for necklaces, bracelets and other looped jewelry are well known in the art. They range from a very simple split-ring construction and operation, to more complex double-locking clasps. Most all such jewelry clasps are used to connect the free ends of necklace chains, bracelet chains, ankle chains, and the like. The very nature of these clasps and their use with delicate aesthetic chains commands a very small, delicate ornamental appearance, with tiny but stable and secure double-locking means for both ends of the chain. Security is paramount because these clasps in many cases hold extremely valuable diamond, silver, gold, pearls, etc. The delicate nature of these clasps makes opening and closing difficult, and struggling with the clasp can easily break the jewelry chain under the strain of opening. The locking mechanism must therefore achieve a balance between simple and delicate aesthetics, versus high-strength and simple and easy operation
For example, U.S. Pat. No. 4,314,389 to Sauer et al. issued Feb. 9, 1982 shows a double fold over jewelry clasp for securing opposite ends of a necklace chain, and more particularly to a double fold over jewelry clasp providing two sets of interlocking fastening means. However, each set of interlocking fastening means is completely independent of the other, and as such requires double the effort to remove both ends of the chain. There are twice as many moving parts to break, and double the complexity and obtrusiveness in appearance. Moreover, the two interlocking fastener are compression fittings which require significant dexterity to manipulate. Compression fittings are not well suited for very fine smaller jewelry. If the metal yokes fail are too small they tend to break.
U.S. Pat. No. 6,604,381 by Haber issued Aug. 12, 2003 shows a jewelry clasp having two members secured to one another. Similarly, U.S. Pat. No. 2,462,425 to Pratt, et.al. discloses a clasp for securing the ends of a flexible strand of jewelry such as a snake chain to each other. In both cases the locking element of the clasp is hinged and more easily manipulated, but only for one side of the chain to be clasped. What is needed is a jewelry clasp for securing opposing ends of a chain with a single spring-biased hinge and double-locking clasp.
It is, therefore, a primary object of the present invention to provide a jewelry clasp that uses a single-pivot spring-biased hinge for double-sided locking of opposing ends of a chain together. Another object of the present invention is to provide a double-sided jewelry clasp with a fine, delicate and ornamental appearance, but which is highly stable and secure.
It is still another object of the present invention to provide a double-sided jewelry clasp with a simplified mechanism using minimal moving parts (four), and which is simple and efficient to manipulate.
It is still another object to provide a double-sided jewelry clasp with no fragile parts or stress points prone to breakage.
In accordance with the foregoing objects, the present invention is a double-sided jewelry clasp having a rocker plate pivotally mounted to a base plate at a spring-biased hinge. The hinge comprises a pair of opposing yokes extending from the center of each of the rocker plate and base plate. With the rocker plate facing the base plate, the yokes align and a pin is inserted through distal apertures in all of the yokes to pivotally secure them together. A torsion spring is carried on the pin to bias the rocker plate versus the base plate. Further, the base plate has a hook at one end and a post at the other. The post acts as a stop against the pivoting of the rocker plate, and as a yoke for insertion of one end of a necklace or other chain. Thus, when the rocker plate is pivoted tight against the necklace chain is held captive on the post. The hook loops around to the backside of the rocker plate, and thereby acts as a stop against the counter-pivoting of the rocker plate. Likewise, the hook serves as a yoke for insertion of the other end of the necklace. Thus, when the rocker plate is counter-pivoted tight against the hook the necklace chain is held captive on the hook. Given a spring-bias the rocker plate will seat against both the post and hook, locking the necklace chain at both ends. A user need only depress the rocker plate to counter-bias it open at both ends, and thereby release both ends of the necklace chain. The foregoing configuration accomplishes a double-ended yoke/release with just a single-spring-biased hinge, minimal parts (four), and no stress points prone to breakage. The result is a double-sided jewelry clasp that is highly stable and secure, yet which presents a fine, delicate ornamental appearance. Moreover, it is simple and efficient to manipulate.
Other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments and certain modifications thereof when taken together with the accompanying drawings in which:
The present invention is a jewelry clasp with a more efficient single-pivot spring-biased hinge for double-sided locking of opposing ends of a chain together.
In operation, given the spring-bias of spring 20 the rocker plate 4 will naturally seat against both the post 8 and hook 9, locking the necklace chain at both ends. A user need only depress the rocker plate 4 by clamping the distal ends (proximate hook 9) together in their fingers, thereby counter-biasing the clasp 2 open at both ends. Both ends of the necklace chain can be conveniently released and removed from the hook 9 and post 7.
The foregoing configuration accomplishes a double-ended yoke/release with just a single-spring-biased hinge 8, minimal parts (four), and importantly, no stress points prone to breakage. The result is a double-sided jewelry clasp 2 that is highly stable and secure, yet which presents a fine, delicate ornamental appearance. Moreover, the clasp 2 is extremely simple and efficient to open and close.
One skilled in the art should readily understand that features of the double-sided jewelry clasp 2 may be altered without sacrificing the utility of the jewelry clasp 2. For example, the hook 9 and/or post 7 may be extended from either the base plate 6 or rocker plate 4, or one from each of the base plate 6 and rocker plate 4.
As an example,
The above-described embodiments are for the purpose of promoting an understanding of the principles of the invention. It should nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alternations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated herein being contemplated as would normally occur to one skilled in the art to which the invention relates.
The present application derives priority from U.S. provisional application 61/336,996 filed 29 Jan. 2010 which is incorporated herein by reference.
Number | Date | Country | |
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61336996 | Jan 2010 | US |