1. Field of the Invention
This invention relates to hinge constructions, especially for items of jewellery of precious metals or their alloys. The invention may be applicable more generally, but it was devised in connection with the manufacture of items of jewellery, in particular items of jewellery known as creole earrings.
Therefore, in the following reference is made mainly to creole earrings, as such reference: best explains the nature of the invention, but it is to be borne in mind that it may have application in other fields, and the applicants do not wish to be prevented from coverage of the invention in such other fields. It must be stated however, that having regard to the nature of the invention, it has particular advantage and application in the field of items of jewellery which have hinge constructions of a delicate nature, and of a relatively small size. In other fields, where hinges are more robust and are of greater dimension, the advantages of the invention may not be as great.
2. Description of Related Art
A creole earring comprises basically a looped body of part round, oval or other shape defining two ends which are adjacent, but are bridged by a hinge bar or hasp which passes through the user""s ear. The hinge bar is hinged to a hinge pin at one end of the body, and may be a stamping with a hole therein through which the pin passes, or a length of wire bent to shape around the pin. On the other end of the body is a clasp into or onto which the hinge clips. On the end where the hinge bar hinges, there is a U-shaped mounting bracket formed from a plate pressing and which is soldered or brazed to the body, and the bracket carries the hinge pin on which the hinge bar is pivotally mounted.
Such earrings each comprise six components, namely two body halves which are soldered or brazed together to form the body, the mounting bracket, the clasp, the hinge pin and the hinge bar.
Such earrings are notoriously difficult to make mainly because of the size, and typically are entirely hand made. The difficulties include that
i) it is difficult to locate the hinge pin in the hole of the hinge bar when such bar is a plate pressing, and it is difficult to form the wire around the hinge pin when the hinge bar is of wire
ii) the pin, which is of the order of 10-20 thousandths of an inch in diameter, is cut (usually with hand operated wire cutters) from wire and it may have burrs or flashings on the ends which have to be removed, and is difficult to handle, and after it has been inserted in the bracket and is engaged by the hinge bar, has to be swaged at its ends to keep it in position. The pin is a weak spot in the earring, and will pull out easily, especially if the swaging is not performed perfectly,
iii) the formation of the bracket from a flat plate (again of only 10-20 thousandths of an inch thickness) is a difficult operation, and if not performed perfectly, can cause difficulties in the hinge construction regarding the location of the hinge pin
iv) generally, the current method of construction is slow, difficult and expensive.
The present invention, which has a number of aspects, was conceived to address the difficulties indicated above, and the various aspects overcome, at least in part, the aforesaid problems.
According to the invention, in a first aspect, there is provided a method of forming a hinge comprising a hinge component which is hinged to a hinge pin, and in which method a hinge component is attached to the hinge pin to pivot thereon by having a portion of Y-shape, and the attachment is by positioning the pin between the arms of the Y-shape, followed by the bending of at least one of the arms around the pin so that it will be retained by the arms enabling the component to hinge on the pin.
This method provides that the attachment of the component to the pin is simplified, as compared to the conventional method described above, in that there is no aligning of pin and hole, and nor is there any need to form a wire member around the hinge pin.
Preferably, both arms of the Y-shape may be bent around the pin to the same extent, and also the extremities of the arms may be shaped to be complimentary to each other, so that they abut and neatly inter-fit when bent around the pin. For example, if one end has a convex shape, the other end may be concave. The ends may alternatively be squared off, or cut on an angle. Another alternative is that the ends may overlap after the bending, but in the case of fine jewellery, this is not preferred.
Such a hinge construction can easily be made strong by making the Y-shaped end of sufficient robustness and thickness. This is easily achievable in the case of delicate items of jewellery.
As will be understood, it is preferred that the method be applied to a creole earring, and the said component is the hinge bar, which at the other end is adapted to engage the clasp in the conventional way.
The component is preferably a stamping from sheet material, such as a precious metal or its alloys, which does not require any additional processing before being applied to the hinge pin.
In jewellery manufacture, such a method can be effected by machinery much more readily than the conventional method, providing a main advantage of the first aspect of the invention.
In the first aspect of the invention, the hinge pin can be one of conventional configuration, mounted in a conventional bracket, as described above, but this is not preferred, and a second aspect addresses replacing the conventional hinge pin arrangement.
The second aspect of the invention may be applicable outside the field of items of jewellery, but is less likely to be so than the first aspect above.
In the second aspect of the invention, which can be in combination with or independent of the first aspect of the invention, to provide a hinge pin for a hinge in an item of jewellery, a mounting plate is provided, which has a shaped portion, such as an H-shaped portion defining a cross bar which extends between two support legs, of which the cross bar forms a hinge pin in a hinge of the item of jewellery.
With this second aspect, a wire can be used for the hinge bar or hasp, in that the wire can be bent round the cross bar to become hinged to the hinge pin, but we prefer that the first and second aspects be combined, in an item of jewellery, so that the hinge component has the Y-shaped end as discussed above, and can be applied to the mounting plate to become hinged thereto.
The second aspect of the invention provides a means of overcoming or reducing the disadvantages of using a separate hinge pin, and provides for a strong hinge easily constructed using machine techniques. It may be desirable to further form the pin to circular cross section to enhance the functioning of the hinge, but it is preferred that the stamping of the mounting plate be the only operation involved in producing the mounting plate, in which case the pin would have a square cross section. It all depends upon whether or not the hinge can be made to work smoothly with a square cross sectioned hinge pin. It is believed that such a hinge pin can be made to work smoothly in items of jewellery, especially earrings, in which loadings are small.
The mounting plate preferably has a section parallel to the cross bar and also joining the legs, which section is shaped to enable it to be connected to the body of an earring.
For the application of the aspects of the invention to items of jewellery and specifically to creole earrings, the mounting plate and the clasp are plate stampings, and additionally the body may be notched to provide locations for the stamped clasp and mounting plate, which will lie with their planes at right angles to the plane of the body. This notching of the body to provide for easy location of the clasp and/or the mounting plate forms in itself another a third aspect of the present invention which can be in combination with or independent of the first and/or second aspect of the present invention. The advantage of such notching enables the simpler locating and fixing of the clasp and/or mounting plate.
A further advantage of the invention in the first and second aspects is that by using these aspects, not only does a simpler, quicker and less expensive construction method for creole earrings result, but also the number of separate parts to make an earring is reduced due to the fact that the pin and mounting bracket are merged into a single mounting plate.
The invention also provides hinges and items of jewellery produced by the methods of the aspects of the present invention.