GB2202728A - Earring - Google Patents

Abstract

A gold circular earring 1 of hollow construction has two hollow arc-shaped portions 2, 3 joined in end to end relationship by hinge 4. A clasp 5 is diametrically opposed to the hinge 4. The hollow portions 2, 3 of the earring may be formed from seamed tubing drawn from sheet or strip stock, in which case the earring cross-section is 0.76-1 mm and the wall thickness of the hollow portions is 0.05-0.07 mm. In an alternative embodiment the tubular portions may be formed by electrodeposition of metal on a mandrel or model. Optionally, the earring is of gold and the caratage is controlled by a computer-controlled electroforming process which controls or varies current density or temperature of the plating solution. <IMAGE>

Description

EARRING This invention relates to an earring more particularly made of precious metal such as gold, silver or platinum and which is of a type known in the art as a 'sleeper'. 'Sleeper' earrings are of generally circular form and may be passed through a pierced hole in the earlobe.

Earrings of this type are generally formed with a clasp diametrically opposite a hinge. Once the clasp is opened the ear lobe may be introduced into the open ring and one end of the earring passed through the pierced hole; the clasp is then fastened thus retaining the ring to the ear and giving the appearance of a completely uniform thin ring. Such earrings have to be intricately made and usually have a thin solid circular cross section of thirty to forty thousands of an inch (.76 mm to 1 mm) diameter. The diameter of the earring itself may be twelve to fifteen millimetres.

It is an object of the present invention to provide earrings comparable in appearance with those of the prior art but which are less expensive and/or require less precious metal.

According to the present invention there is provided a generally circular earring of hollow construction having one or more of the following features a) a clasp and a hinge generally diametrically opposed to the clasp, b) two hollow arc-shaped portions joined in end to end relationship by a hinge, c) the hollow construction is formed from seamed tubing drawn from sheet or strip stock, d) the cross section of the earring is about thirty to forty thousands of an inch thick (.76 mm to lmm), and e) the wall thickness of the hollow earring is about 2 to 3 thousands of an inch (.05 mm to .07 mm), and is a minimum thickness of about 2 thousands of an inch (.05 mm).

Further according to the present invention there is provided a method of making a circular earring of hollow construction comprising one or more of the following features:a) making the earring with a clasp and a hinge generally diametrically opposed to the clasp, b) making two hollow arc-shaped portions and joining them in end to end relationship by a hinge, c) forming the hollow construction from seamed tubing drawn from sheet or strip stock, d) making the earring with a cross section of about thirty to forty thousands of an inch thick (76 mm to 1 mm), and e) making the wall thickness about 2 to 3 thousands of an inch (.05 mm to .07 mm), and of a minimum thickness of about 2 thousands of an inch (.05 mm).

In a preferred embodiment, the earring is comprised of two hollow, generally opposed, arc-shaped portions (preferably almost semicircular) formed from seamed tubing, adjacent ends of the arcshaped portions being joined by a hinge having ends (milled and ground) which are soldered or bonded into associated ends of the arcshaped portions, Additionally, the clasp may have ends which are soldered or bonded into associated ends of the arc-shaped portions.

In the manufacturing process the drawn seamed tube stock is, preferably, immediately coiled on a mandrel and two arc-shaped portions are then cut substantially simultaneously from a generally circular coil before being integrated into the earring structure with the seam arranged on the inside of the earring. Preferably, solder or brazing paste is induced to flow along the seam to strengthen the structure in an advantageous manner.

The present invention represents a very significant advance in the art since savings in weight of 60 to 709Ó of precious metal are possible over conventional solid constructions representing huge savings in costs.

Further advantageous features of the earring and method of manufacture will be evident from the following description and drawings.

An embodiment of a sleeper earring and method of making same in accordance with the present invention will now be described, by way of example only, with reference to the simplified drawings in which: FIGURE 1 shows a part sectional view of the earring; FIGURE 2 shows a detail of a hinge of the earring looking in direction of arrow A; FIGURE 3 shows a modified form of clasp, and FIGURE 4 shows a stage in the manufacturing process of the earring.

Referring to the FIGURES in the drawings, a generally circular earring 1 known in the art as a 'sleeper' earring is formed of precious metal and of hollow construction.

The earring 1 is composed of two hdllow, generally opposed, arcshaped (almost semi-circular) portions 2, 3 joined in end to end relationship by hinge 4. The hinge 4 is arranged generally diametrically opposed to a clasp 5.

The centre portion 4a of the hinge is generally of known form but is provided with milled and ground ends 4b, which have pips 4c. The hinge ends 4b plug as a close, force fit into adjacent, open ends 2a, 3a of the hollow arc portions 2, 3. The ends 4b are soldered into the arc portions 2, 3 in a secure manner.

The clasp 5 is a solid three-dimensional form of clasp arranged to induce low stress on the hinge which is all the more important due to the hollow construction of the earring 1. The clasp 5 is formed with plug-in ends 5a which are similar to the ends 4b of the hinge already described. Each end 5a plugs into an associated end of the arc portions 2b, 3b as shown in FIGURE 1.

The diameter D is, in this instance, 12 to 15 mm, the cross section S is 30 to 40 thousands of an inch (.76 mm to 1 mm) thick and the wall thickness l is 2 to 3 thousands of an inch (.05 mm to .07 mm) thick. It is envisaged that to achieve a satisfactorily stable construction the minimum wall thickness W of the earring 1 wiil be about 2 to 3 thousandths of an inch.

Llost advantageously by virtue of the hollow construction of the earring 1 a 60% saving in weight of precious metal can be achieved with an earring of 12 mm diameter as compared with a solid earring of the same external size and configuration. For an earring of 15 mm diameter a 70% saving in weight can be achieved with the hollow construction.

FIGURE 3 shows an alternative form of clasp 5' which takes advantage of the hollow construction of the earring 1. The general form of this clasp should be evident; it has an end 5'a which plugs into end 2b of an arc-shaped portion 2 and an end E which is a releasable push-fit engagement into the open end 3b of arc-shaped portion 2. End E is provided with an annular recess r which is engaged as shown in FIGURE 3 by an internal annular locking rib R (or alternatively internal pips) on the arc end 3 to retain the end E thereto. Rib R is deformable as the end E is pushed into and out of engagement therewith.

It is a marked feature of this embodiment of the present invention that the earring 1 is formed from two arc-shaped portions of seamed tubing (no seam is shown) which is drawn from sheet or strip stock in a manner to be explained.

Production of the earring 1 from seamed tubing eases the manufacturing process considerably. The seam (not shown) will be arranged on the inside of the earring and it is envisaged that usually the bw paste solder used for securing the hinge and clasp in position will flow right down and around the seam thereby significantly strengthening the construction.

The seamed tube is formed in a conical die from sheet or strip stock in a manner known per se (see our copending British Patent Application No. 8617399). FIGURE 4 illustrates very simply the next step in the manufacturing process whereby the seamed tube T (represented in chain dotted lines) is wound on a mandrel M into a generally circular form (the seam being on the inside of the circle) and two arc-shaped portions (corresponding to portions 2 and 3 shown in FIGURE 1) are cut substantially simultaneously from the circle.

The arc-shaped portions are then soldered to the remaining earring parts in a manner already explained.

The whole manufacturing process is, of course, more labour intensive than the production of a similar earring of solid construction and on the whole is a very intricate process because of the very small dimensions involved. Nevertheless, despite these difficulties the Applicant has realised that such a production process is achievable and has great cost benefits whilst, to all intents and purposes, the article appears of the same or even of improved quality.

The Applicant has made additional improvements in the method of manufacture and, therefore, further according to the present invention there is ptrovided a method of making a circular earring of hollow construction comprising:a) depositing a layer of precious metal onto a mandrel or model by an electroforming process.

Usually, the earring will have a clasp arranged generally diametrically opposed to a hinge and usually, most advantageously, the whole article will be formed by the electroforming process with no subsequent bonding or soldering of parts then being necessary.

Where the earring is more particularly of gold, the Applicant envisages that the caratage will be accurately controlled by a computer controlled electroforming process which controls or varies the current density since the efficiency of the electrolyte solution varies with current density. The Applicant envisages the production of electroformed gold earrings, preferably of at least 2 thousands of an inch thick, with gold of only 14 to 18 carat and most importantly expects to be able to realise earrings of only 9 carat gold with an entirely homogeneous 9 carat gold layer being deposited on the mandrel or model (which model is usually subsequently destroyed by acid at a later stage).The computer controlled process maintains the variable parameters e.g. chemical composition of the solution, working conditions (e.g. temperature, racking method etc.) perfectly stable.

The material of the mandrel or model is, preferably, mazac (zamac) or possibly a fusible alloy (Sn-Pb-Bi) or brass or aluminium.

Hydrochloric acid may be used to dissolve mazac models, Nitric acid for dissolving brass and caustic soda for aluminium. The temperature will probably be in the range 400 - 6000C and the time taken for the electroforming process will probably be about 20 minutes.

The Applicant envisages the production of circular earrings in particular (and other jewellery items) by this electroforming process which allows advantageously, production: a) in a single operation b) in a short manufacturing cycle c) low reject rates d) good quality production of article with uniform thickness, few or no soldered joints and high mechanical strength.

It is envisaged that the computer will precisely control: a) the temperature of the plating solution to within +.1 C., b) the plating current to give a precise current density, c) calculation of the relation between fine gold content and current density to enable the operator to choose the correct current density.

It is to be appreciated that the present invention offers many improvements at least some of which might be patentable individually or in combination. Any individual feature as aforementioned or as shown or implicit herein or combinations thereof, or functions or methods appertaining thereto, may be patentably inventive and any specific term as used herein should not be construed as unnecessarily or unduly limiting; the scope of such term should extent to, and may be replaced or supplemented by, any reasonable equivalent or generic expression.

Claims (20)

1. A generally circular earring of hollow construction having one or more of the following features:a) a clasp and a hinge generally diametrically opposed to the clasp, b) two hollow arc-shaped portions joined in ena to end relationship by a hinge, c) the hollow construction is formed from seamed tubing drawn from sheet or strip stock, d) the cross section of the earring is about thirty to forty thousands of an inch thick (.76 mm to 1 mm), and e) the wall thickness of the hollow earring is about 2 to 3 thousands of an inch (.05 mm to .07 mm), and is a minimum thickness of about 2 thousands of an inch (.05 mm).

2. An earring as claimed in Claim 1 which is comprised of two hollow, generally opposed, arc-shaped portions (preferably almost semicircular) formed from seamed tubing, adjacent ends of the arcshaped portions being joined by a hinge having ends which are soldered or bonded into associated ends of the arc-shaped portions.

3. An earring as claimed in Claim 2 in which a, or the, clasp has ends which are soldered or bonded into associated ends of the arc shaped portions.

4. An earring substantially as herein described and illustrated with reference to FIGURES 1 and 2 of the accompanying drawings or substantially as modified in accordance with FIGURE 3 of the accompanying drawings.

5. A method of making a circular earring of hollow construction comprising one or more of the following features:a) making the earring with a clasp and a hinge generally diametrically opposed to the clasp, b) making two hollow arc-shaped portions and joining them in end to end relationship by a hinge, c) forming the hollow construction from seamed tubing drawn from sheet or strip stock, d) making the earring with a cross section of about thirty to forty thousands of an inch thick (76 mm to 1 mm), and d) making the wall thickness about 2 to 3 thousands of an inch (.05 mm to .07 mm), and of a minimum thickness of about 2 thousands of an inch (.05 mm).

6. A method as claimed in Claim 5 in which, when the earring is made in accordance with paragraph 6(c), the tube stock is immediately coiled on a mandrel and two arc-shaped portions are then cut substantially simultaneously from a generally circular coil before being integrated into the earring structure with the seam arranged on the inside of the earring.

7. A method as claimed in Claim 6 in which solder or brazing paste is induced to flow along the seam to strengthen the structure.

8. A method as claimed in Claim 5 and substantially as herein described.

9. A method of making a circular earring of hollow construction comprising: a) depositing a layer of precious metal onto a mandrel or model by an electroforming process.

10. A method as claimed in Claim 9 in which the earring has a clasp arranged generally diametrically opposed to a hinge.

11. A method as claimed in Claim 9 or 10 in which the whole article is formed by the electroforming process with no subsequent bonding or soldering of parts then being necessary.

12. A method as claimed in any one of Claims 9 to 11 in which the earring is of gold and the caratage is accurately controlled by a computer controlled electroforming process which controls or varies the current density.

13. A method as claimed in Claim 12 in which the earring is preferably of at least 2 thousands of an inch thick, with gold of only 14 to 18 carat or even of only 9 carat gold.

14. A method as claimed in Claim 13 in which the computer controlled process maintains stability of the variable parameters e.g. chemical composition of the solution, working condition (e.g. temperature, racking method etc

15. A method as claimed in any one of Claims 9 to 14 in which the material of the mandrel or model is mazac (zamac) or a fusible alloy (Sn-Pb-Bi) or brass or aluminium.

16. A method as claimed in Claim 15 in which hydrochloric acid is used to dissolve mazac models, Nitric acid for dissolving brass and caustic soda for aluminium.

17. A method as claimed in any one of Claims 9 to 15 in which the temperature for the electroforming process is in the range 400 - 600 C and the time taken for the process is about 20 minutes.

18. A method as claimed in any one of Claims 9 to 17 in which the computer controls one or more of the following:a) the temperature of the plating solution to within +.1 C., b) the plating current to give a precise current density, c) calculation of the relation between fine gold content and current density to enable the operator to choose the correct current density.

NEW CLAIMS

19. A generally circular earring of hollow construction having two hollow arc-shaped portions joined in end to end relationship by a hinge, and a clasp to releasably fasten said arc-shaped portions to one another.

20. A method of making a circular earring of hollow construction comprising: a). depositing a layer of precious metal onto a mandrel or model by an electroforming process, and b). said earring having two hollow arc-shaped portions joined in end to end relationship by a hinge, and a clasp to releasably fasten the arc-shaped portions to one another.