WO1994029680A1

WO1994029680A1 - Jewellery gauge

Info

Publication number: WO1994029680A1
Application number: PCT/GB1994/001264
Authority: WO
Inventors: Bernard David Shindler
Original assignee: Bernard David Shindler
Priority date: 1993-06-14
Filing date: 1994-06-13
Publication date: 1994-12-22
Also published as: AU6932794A; GB9312192D0

Abstract

A device for assisting in measuring or visually estimating the weight of precious stones, comprising an open ended (16) tubular body (8) which is of suitable internal diameter to fit slidably over the body of a conventional jeweller's 'loupe' (2) and which is axially slotted to accommodate the shape of the body (8) of the loupe (2). The other end carries a transparent scale or graticule (24) through which the article to be measured is then viewed, with the aid of the lens (6) of the loupe (2).

Description

Jewellery Gauge"

This invention relates to a device for examining and estimating the value of precious stones mounted in jewellery, and in particular to a measuring gauge which aids in visually estimating the weights of gemstones.

Various kinds of hole gauges and calipers for estimating the weights of gemstones, on the basis of their physical size have been known for many years, but they are difficult to use, particularly in the case of stones which are already mounted in pieces of jewellery (other than solitaires) .

A considerable improvement on the system of such devices, is the combined magnifier and graticule device known as the "Shindler scale", devised by the present inventor some years ago. This comprises a folding magnifier having a lens in one side, and a graticule containing size gauges in the other side (Fig. 1) . In use, the article of jewellery is measured by holding it immediately behind the graticule of the magnifier, which is located at a fixed distance from the lens so that it is viewed through the graduations of the graticule, and by matching each stone against a suitable set of graduations, its weight can be estimated.

In practice, because users have different eyesight characteristics, and also, often have favourite magnifiers which they prefer to use, the device has not gained universal acceptance, and the present invention therefore seeks to overcome these particular disadvantages.

Accordingly, the present invention provides a measuring instrument having a tubular body, one end of which ( is open so as to slide over the outer surface of a

_\ jeweller's magnifier or "loupe", and the other end of which carries a graticule or gauge for measuring or estimating the weight of precious stones. Preferably, the gauge is of the "Shindler Scale" type.

The most common type of jeweller's "loupe" is, in fact, of a fairly standard configuration, comprising a main body 2 (Fig.2) which is generally "tear drop" shaped in cross-section and is pivotally connected to a cover member 4 of the same shape into which it can be folded. The main body carries a lens 6 which is typically of ten times magnification.

In accordance with a preferred feature of the present invention, therefore, the tubular body of the instrument comprises a first section, extending from the open end, which has an axially extending opening to allow it to be slid over the cylindrical portion of the body of a loupe whilst allowing the non circular portion of the loupe body to project through the opening. Preferably, additional circumferentially extending slots are also provided, so as to allow the body of the tube to flex resiliently, to fit around the body of the loupe. In this way, the position of the graticule at the other end of the tube can be varied, relative to the magnifying lens, so as to accommodate different strengths of eyesight.

One embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 illustrates a graticule;

Figure 2 is a perspective view of a typical jewellers loupe;

Figure 3 is a perspective view of the device of the invention;

Figure 4 is a plan view of the device of Figure 3;

Figure 5 is an axial end view of the righthand end of the device of Figure 4; and Figure 6 is an axial end view of the lefthand end of the device of Figure 4.

Referring to the drawings, the main body of the device comprises a piece of tubing 8 which may for example be PVC tubing, having an axially extending opening 16 which is formed by making two axial cuts (10, 12) and one circumferentially extending cut (14) through the material. It will be appreciated from a consideration of the perspective view of Figure 3, that this provides two resilient "flap" members 18 and 20, which will allow the body 8 to be slid over another cylindrical body of suitable external diameter, whilst gripping on to it by virtue of the resilience of the material. If one considers the type of magnifier or loupe illustrated in Figure 2, it will easily be appreciated how the tubular body of Figure 3, which is shown, for clarity, inverted in the Figure, can be slid over the body of the magnifier, if the relative sizes are suitably related. In the preferred and illustrated embodiment, the device of the invention is made from a 50mm length of PVC tubing having an internal diameter 19mm and an external diameter of 22mm, which has been found suitable to fit onto a wide range of commercially available magnifiers. The axial opening 16 is 40mm long.

The lefthand end of the device (as seen in Figure 4) is closed by a clear window 22 of plastics material which carries a measuring scale 24 of the kind illustrated in more detail in Figure 1, and it will be appreciated that because of the "telescopic" slidable fitting of the body 8 onto the magnifier 2, the position of scale 24 can be adjusted, relative to the position of the lens 6, so as to allow users having various different optical prescriptions to focus clearly through the device. In this way, it is possible to provide a versatile measuring instrument which can be used together with a magnifier of the user's own preference.

Claims

1. A device for measuring or visually estimating the weight of precious stones, comprising: a tubular body one end of which is open and is adapted to fit over the body of a jeweller's magnifier or "loupe" and the other end of which carries a transparent graticule or scale through which a precious stone can be viewed with the aid of the lens of the magnifier, in use.

2. A device according to claim 1 in which the body is made from a resilient material and has at least one slot extending axially from the open end, whereby the body can be flexed slightly to fit slidably over the body of the loupe.

3. A device according to claim 2 in which the said body comprises a first cylindrical portion at the open end, which is axially slotted, and a second continuous cylindrical portion at the scale end, additional part circumferentially extending slots being provided which extend from the axial slot, so that the said first cylindrical portion forms at least one pair of resilient flaps which grip the body of a loupe inserted in the device.

4. A device according to claim 3 in which the said first cylindrical portion is sufficiently long to allow the body of the loupe to be slidable therein, to provide a focussing effect.

5. A device according to any preceding claim in which the tubular body has an internal diameter of 19mm