US1309160A - George a - Google Patents

Description

G. A. THORNTON.

METHOD AND APPARATUS FOR MARKING METAL.

APPLICATION FILED 056.18, 1911.

1,309, 160. I Patented July 8, 1919.

UNITED sTATEs PATENT OFFICE- GEORGE A. THORNTON, OF CLEVELAND, OHIO, ASSIGNOR TO ADAMS-BAGNALL ELECTRIC COMPANY, OF CLEVELAND, OHIO, A CORPORATION.

METHOD AND APPARATUS FOR MARKING METAL.

Specification of iLetters Patent.

Patented July 8, 1919.

Application filed December 18, 1917. Serial No. 207,769.

Cleveland, in the county of Cuyahoga and- State of Ohio, have invented certain new and useful Improvements in Methods and Apparatus for Marking Metal, of which the following is a specification.

This invention relates to the method and apparatus for marking metal by electricity, the object of the invention being to provide a method and apparatus for printing or writing or branding metal by marking the same electrically.

In the drawings accompanying and forming a part of this specification Figure 1 illustrates a form of apparatus which may be used to carry out this improved method, this figure illustrating a piece of thick metal being marked by electricity and connected with a transformer. Fig. 2 illustrates this improved method when used in connection with a thin metal plate connected with the same transformer Fig. 3 is a perspective view of the apparatus as it is built for commercial use.

Similar characters of reference illustrate the same parts in the several figures of the drawings.

This improved method is particularly adapted for printing, writing or branding tools and ot er articles of iron or steel. Heretofore in order to brand tools or pieces of metal workit has been necessary to coat the article with asphalt, aint or wax to protect all those portions 0 the articles that were not to be etched, then etch the article, then apply an acid thereto to eat away the etched ortion of the article, then clean off the aci and then clean oil the wax or asphalt used to protect the work around the etched portion thereof. Aside from the length of time required to etch in this way the results were unsatisfactory because of the resultant rust, acid marks and smudgy work. By the present improvement tools and metal articles may bemarked in about onefifth the time heretofore required, the work left clean, as there is no cleaning required after the marking is finished elther of an acid or a protective coat ofasphalt or wax. Not only this but any desired style or size of letters or fi res or designs maybe written, printed or randed upon the metal.

The use of electricity however for marking has not heretofore been found practicable for various reasons among others that it was not found possible to obtain the desired voltage for various qualities or thicknesses of metal or to steady the current to enable the article to be properly marked.

In carrying out this improved method I provide a transformer 2, a metal plate 3 such as a copper plate suitably connected to the transformer according to the quality and characterof the metal plate or article to be marked and a marking tool formed of metal such as copper also connected with the transformer 2. The transformer is connected to a suitable source of electricity having preferably an alternating current, as it has been found that an alternating current is more desirable than a direct current for the reason that the latter has a tendency to burn and cannot be as easily controlled as an alternating current although in some instances a direct current may be used. The transformer is efi'ective to give the proper voltage according to the thickness and quality of the plate and to steady such current to en- .able the plate to be properly marked. It has been found by experiment that in order to mark a thin piece of metal less voltage is required than is necessary with a thicker piece of metal of the same grade and quality and having the same depth or type of mark or printing thereon.

In Fig. 2 a thin plate 5 .is illustrated as being marked. In this instance the marking tool 4 and the plate 3 upon which the metal plate 5 is located are connected to a smaller section of the secondary coil 6 of the transformer 2 whereby a lower voltage is obtained for use on the particular thickness of plate shown. In Fig. 1 a thicker metal plate is illustrated as being marked and in this instance the plate 3 and marking tool 4 are connected with both ends of the sec ondary coil of the transformer so that a higher voltageis obtained as is necessary in view of the greater thickness of the plate.

In practice if desired the plate 3 could be dispensed with and the article to be etched be directly connected with the transformer but the present form of apparatus is more practicable since it permits any age to be obtained from the source of electricity byreducing the voltage to the required amount, according to the article to be marked, while increasing the current and steadying the same to obtain a uniform marking. In other words the use of the transforn'ler enables the voltage to be reduced sufliciently low to produce a heavy current and steady the same.

In Fig. 3 the apparatus as it is commercially used is illustrated, the source of electricity in this instance being an alternating current light socket to which the apparatus may be readily connected or disconnected as occasion requires.

By the present improvement steel and similar metal may be marked practically as fast as writing with a pen, no acid or waxes are used, there are no parts to wear out except the copper marking tool or pencil which may be readily replaced with ordinary copper wire, so that without the use of an etching acid or a protecting asphalt, paint or wax all that is necessary by means of the present improvement is to write upon the article to be marked in the ordinary way of using a pencil or pen.

In the present improvement, the mark- ;ing of the iron or steel plate or analogous 30.

article is obtained by maintaining the pencil or marking tool in close contact with the article to be marked, thus maintaining a closed circuit during the marking of the article, the marking of the article being due to the proper resistance established at the point of the marking tool and not bythe formation of an arc, such as is used for the cutting of metal.

In marking steel and a like material, by electricity as used by applicant, the markingis caused by a current passing through the material to be marked and producing a burning temperature at the point of contact rather than a series of minute arcs. This burning causes a mark by eating away the material slightly and is done fast enough so as not to affect the metal which is not at the point of contact. Naturally the material whichis marked has the higher resistance to the electrical current andis heated higher than the pencil which in the case of the applicant, is a material of high conductivity.

I claim as my invention:

1. The method of electrically marking upon a steel or iron article which consists in providing a conducting medium and connecting the same together with the article to be marked to a suitable source of electricity through the medium of steadying means and then marking the article by the conducting medium while maintaining a close contact therewith.

2. The method of electrically marking upon a steel or iron article which consists in providing a conducting medium and con- .source of electricity b necting the same together with the article to marked to a suitable source of electricity through the medium of steadying means, which steadying means is also effective to provide the proper voltage for the article to be marked, and then marking the article by the conducting medium while maintaining a close contact therewith.

3. The method of electrically marking upon a steel or iron article which consists in providing a conductin medium connected together with the artic e to be marked to a suitable source of electricity through a means for reducing the voltage and steadying the current and then markino the article by the conducting medium while maintaining a close contact therewith.

l. The method of electrically marking upon a steel or iron article which consists in providing a. conductin medium connected together with the artic e to be marked to a suitable source of electricity by means of a transformer effective to reduce the voltage and steady the current, and then marking the article by the conducting medium while maintaining a close contact therewith.

5. The method of electrically marking upon a steel or iron article which consists in providing a conducting medium and a supporting metal plate, the conducting medium and plate bein connected to a suitable source of electricity y means of a transformer effective to reduce the voltage and steady the current, then placing the article to be marked upon the metal plate and then marking the article by the conducting medium while maintaining the conducting medium in close contact with the article.

6. The method of electrically marking upon a steel or iron article which consists in providing a conducting medium and a supporting metal plate, the conducting medium and plate being connected to a suitable means of a transformer effective to re uce the voltage and steady the current, the connection of the supporting plate and conducting medium with the secondary coil of the transformer being determined by the thickness and qualit of the article to be marked and then mar ring the article by the conducting medium while maintaining the conducting medium in close contact with the article.

7. An apparatus for electrically marking upon a steel or iron article, comprising a transformer and a metal pencil, the pencil and the article to be marked being electri- -ca1ly connected with a suitable source of electricity through the medium of a transformer.

8. An apparatus for electrically marking a steel or iron-article, comprising a transformer, a conducting pencil, and a supporting conducting plate for the article to be marked, the pencil and the plate being 0100- trically connected to a source of electrical energy through a transformer.

9. n apparatus for electrically marking upon a steel or iron article, comprising a transformer and a metal pencil, the pencil and the article to be marked being electrically connected with a suitable source of electricity through the medium of a transformer, the connections with the secondary coil of the transformer being determinedby the thickness and quality of the article to be etched.

10. An apparatus for electrically marking.

a steel or iron article, comprising a trans former, a conducting pencil and a supporting conducting plate for the article to be marked, the pencil and the plate'being electrically connected to a source of electrical energy through a transformer, the connections with the secondary coil of the transformer being determined by the thickness and quality of the article to be marked.

11. The method of electrically marking a steel or iron article which consists in connecting the article to be marked by a conducting medium with a heavy electric current oflow voltage transmitted through a transformer and then using said conducting medium to mark upon the article to be marked while maintaining the conducting medium in close contact with the article.

12. The method of electrically marking a steel or, iron article Which consists in providing a transformer effective to reduce the voltage low enough so as to produce a heavy and steady current and utilizin the terminals of the low voltage side 0% the transformer as electrodes one thereof forming the pencil for markin the article while maintaining the conducting medium in close contact with the article.

18. The method of electrically marking a steel or iron article which consists in providing a transformer having its primary terminals connected WlllhSJl alternating cur rent supply and having its secondary terminals connected one With a marking penoil and the other With the article to be marked and then, by means of the pencil, marking upon the article While maintaining the conducting medium in close contact with the article.

Signed at Cleveland, county "of Cuyahoga,

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