US289642A - Anti-magnetic shield for watches - Google Patents

Description

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0. K. GILES.

ANTI-MAGNETIC SHIELD FOB, WATCHES.

No. 289,642. I Patented Dec. 4, 1888.

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ANTI-MAGNETIU SHIELD FOR WATCHES.

No. 289,642. Patented Dec. 4, 1883.

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CHARLES K. GILES, OF CHICAGO, ILLIXOIS.

ANTI-MAGNETIC SHIELD FOR \NATCHES.

SPECIFICATION forming part of Letters Patent No. 289,642, dated l'ieeember 4, 1883.

Application filed June 13,1883. (Modeh) To all whom it may 00720677 Be it known that I, OimnLns K. Guns, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Anti Magnetic Shields for 'Watches, which are fully set forth in the following specification, reference being had to the accompanying drawings, in which Figure 1 represents a side elevation of a watchanovement inelosed within my shield; Fig. 2, a vertical section of the same, taken on the linew 00, Fig. 1; Fig. 3, a side elevation of the two parts of the shield detached and separated from each other; Fig. 4, a back plan view, showing my shield applied to a case, the dome at the back being open and a portion of the shield broken away; and Fig. 5, a cross section of the same closed, taken 011 the line y 3 Fig. 4, and on an enlarged scale.

It is well known that when watches are brought near to powerful magnets their utility is entirely destroyed, as the many parts of the movement become magnetized, and so the regularity of th e movement is entirely destroyed. At the present time, when powerful dynamo-machines are in use all over the country for various purposes, the liability to this injurious disturbance in watches is greatly increased, for the magnets of these machines are frequently so powerful that persons coming very near these machines will find the watch they carry affected, as described, by the magnets. It is a somewhat difficult and expensive operation to demagnetize a watch thus affected, and of course until this is done the watch is practieallyworthless. It is also well known that the time-keeping qualities of a watch are very materially and deleteriously affected by the so-callec electric belts, pads, soles, and other electric devices now so commonly worn, and many persons are so-callec magnetic in person and temperament. Their persons and clothing are so impregnated with magnetic currents that they find it impossible to wear a watch and have it keep accurate time, as it will with another person not so affected with magnetism.

It is an object of myinvention to overcome this diffi culty and completely protect the watch from the deleterious influence of magnets, so that it may be carried into the presence of dynamo-machines, or into the presence of magnets elsewhere with perfect security against injury; also, to shield the watch from the magnetism and magnetic currents of the body. This result I accomplish by surrounding the works or the watch with a complete shield of highlyanagnetic metal, or an alloy or combination of metals, which, in common language, may be said to absorb or turn aside the mag netic currents, thereby preventing their reaching the works of the watch-movement.

1 will proceed to describe in detail the one way in which I have carried out my invention in a practical form, and will then point out definitely in the claims the special improvements which I believe to be new and wish to protect by Letters Patent.

In the drawings, A represents a box of size and form adapted to receive a watch-move ment, B, and to go inside my dust-proof box or any ordinary case without increasing the size or bulk of the watch. This box is made, preferably, of a thin sheet of iron, which, as is well known, is a highly-magnetic metal. Any other highly-magnetic metal or compound may, however, be used instead of iron. A thin sheet, 0, of the same metal is fastened to the top of the plate I) of the watch-movement. This sheet extends entirely over the movement-plate and projects beyond it all round, so that the edge may turn over and down to form a flange, 0, thus making a cover for the box A, as shown in Fig. 2 of the drawings. The relative diameter of the box and cover may be such as to admit the box within the cover, or vice versa, as may be desired, the former arrangement being preferred, however. The dial D is placed above the sheet of metal, 0, and fastened to the movement-plate in the usual way; or the same result or effect can be accomplished by enameling the dial on a thin sheet of iron instead of copper, as usually done.

In applying this device the thin plate which makes the cover is attached to the movement before the latter is mounted in the box, and then the movement is placed in the box, the cover fitting over or into the latter, and the movement being secured within the box in any suitable way. It will be seen that the] improvement is a device applied permanently movement will then be entirely incased by a thin sheet of iron or other highly-magnetic metal, and will present the appearance shown in Fig. 1 of the drawings. The box is constructed so that it is adapted to be received and mounted in an ordinary watch-case-for instance, as stated in my prior application for dust-proof box. This casing operates as a perfect shield to the works within whenever the watch is brought near to a magnet; or I would make the box, as in my prior application for. dust-proof box, of iron or any magnetic compound, as described, and to complete the surrounding of the movement I would make the dial-plate 011 which the dial-enamel is put of iron, or the magnetic compound, or put the thinsheet of metal under the dial, as described above, and inside of the box may be placed the thin sheet, as in the boxes described above, thus making the watch doubly shielded and protected against any outside magnetic effects. It is not necessary to enter upon a scientific statement of the reason; but, using common words, it may be said that the shield of highly-magnetic metal absorbs or turns aside the magnetic influence proceeding from the magnets, so that the watch-works within remain unaffected. Electricians will readily understand that this must be so, and I have found the efiect to be as stated above by prac tical experiment by holding a watch inclosed in one of these shields close to a powerful dynamomachine, and all round it, without magnetizing the works in the least.

This box may be made practically dustproof, as described in my prior application referred to above; or it may be provided with the necessary small openings for winding, regulating, and so forth. These small open- .ings, however, I h(ve found do not destroy the practical utility of the shield.

I have thus described one way in which my invention may be carried out practically but I do not limit my improvement to this particular mode of embodiment. The shield may be of any suitable form and construction, pro vided, only it so nearly incloses the watch as to accomplish the object explained, and it may be made of any metal or compound which is adapted to secure the result described. 7

It will be understood, of course, that my to a watch, the movement and its surrounding shield being mounted in and inclosed by an ordinary ease in the usual way.

In Figs. 4 and 5 of the drawings I have shown the shield mounted in a case which in this instance is an ordinary open-face case, E, consisting of a center, 6, a ring-bezel, e, hinged thereto, and adapted to receive and hold the crystal F, and a back plate or dome, 6 also hinged to the center. The watch-movement and the shield attached to and surrounding it are placed within the center, and fastened there in the same way in which the movement is applied in the ordinary construction without the shield, and which will be understood without further description here. It will be understood, of eouse, that I do not limit myself to any particular kind of case, as this shield may be applied to a watch-move ment intended for any case; but the shield becomes a permanent part of the watch within the case in all instances, and whenever it is necessary to reach the works for repairing or any other purpose the detachable portion of the shield is easily removed.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. A watch-movement, in combination with a shield of highly-magnetic metal or material, wholly or in part surrounding and inclosing the movement within the case, substantially as and for the purposes set forth.

2. Awatch-movement, in combination with a box of highly-magnetic metal or material and a cover of like material extending over the plate of the movement, whereby the movement is substantially inclosed in a magnetic shield within the case,as and for the purposes set forth.

3. A watch-movement, in combination with a box, A, of highly-magnetic metal or other material, and a cover, 0, of like material,supported from the dial, and extending over the plate of the movement, whereby the latter .is inclosed in a magnetic shield within the case, substantially as and for the purposes set forth.

CHARLES K. GILES. lVitnesses:

JNo. C. :MACGREGOR, A. M. Bnsr.

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