US2458871A - Marking device - Google Patents

Description

H. E. OLES MARKING DEVICE Jan. 11, 1949.

Filed July 12, 1945 INVENTOR. fezerf E (/71 5 HTTORNEY Patented Jan. 11, 1949 umren PATEN 0F F E. om, fimuan R. Mallory, $130., acorporationcflnela This 1 invention: relates: tomarkingdevices and method and has particular" reference to electrimily: forming: characters or "designs on: metal;

An; object" of. this invention is to'r'provide improved meuns and methcdofforming characters Impresent; there'rarer several methods of providing'marking, such astnameplates; identifl oationrserial numbers; etc:, onmeta'llic objects; These include hardened: steel stamps which imposethe characters in the metal and have'the disadvantage oi suhjectingitheipiece toshockand possible distortion: Anothermethod' ls tdwrite on themwith av so-calle'd "electric pe'ncill This has the disadvantagevtha'ti it: is slow: andfdoes not give uniform! work. Another method is on the market whereby a special stencil is made and then by means-Ora solution"andelectrolytic action the characters are etched into the surface. This has the disadvantage that the" stencils are expensive, not readily made, and'asolution must be employed,- which is inconvenient.

The present invention utilizes a method which has none: of the disadvantages of the foregoing. The invention. comprises. the. application the output of" a high. frequency electrical impulse generator toiagroupofmetal projections;- preferably flnaorsharp. metal points and soar-ranging these points that. sparks will jump from; them through the characteror desisn openings 'of a stencil to a metal object to be marked. The burning caused by the sparks produces the desired marking. The stencils can be produced out of paper from any stenciling machine. No solutions are employed and the operation is rapid and simple, producing a permanent mark.

As in Figure 1, the device comprises mainly a high frequency electrical impulse generator II); a metal object II to be marked, connected to the impulse generator by a lead I2; 8. stencil sheet I3, mounted on the object II; and a marking device ll, connected to the impulse generator by a lead apolis, 1nd,, yassignor to Inc., Indianapolis, Ind.,

ware Application-Jilly 1-2; 1945,S erial-No. 6043811 3 Claims.- (01. 219-45) I5. .In operativezposition, the marking device 14 rests on thestencil sheet I3, and marking impulse gaps I6: are thus provided between the marking deviceildandithe. object lLthrough the perforations of the stencil sheet l3.

The circuitof the impulse generator I0 is shown in Figure 5. While relatively low frequencies may be useduitls preferable to provide frequencies of the order of radio frequencies in the output of the impulse generator particularly since such high frequencies present no danger to a-ntoperator-"of the device of this invention. A relatively high voltage is preferable so that the sparkingrate through the marking impulse gaps i is?-high.n0ugh t0 providea substantial and uniformdensity of. dots or marks on the object l I.

The impulse generator circuit has a D. 0. supply and comprises-two oscillatory circuits A and B, The DC. supply to circuit A builds up a charge in a condenser-I1 which breaks down a spark gap- Ill. The oscillation of the circuit A, with a 2000 volt:D. C. supply, provides a sparking frequency across thegap I8 of the order cuit Bi to oscillate; and at a higher frequency, through thecharging of a condenser I9 and the breaking downof I I and the markin The-gap I6, that is, the thickness of the stencil I3, is taken into consideration with respect to'the voltage and the electrical characteristics of vtheimpulse circuits, the object II, and the marking device l4, so that the gap I6 is short enough to permit arcing in sufiicient stl'cngth to efil'ciently burn the object II.

Referring to Figures 1 and 2, the object I I is formed ofmetal, for example, steel, and is provid'e'd'wl'th a convex upper surface to be marked, in a curvature to which a rolling cylinder may conform. in continuous overall contact. It is withinithescope' of this invention that the surmay-be flat, or may be of any desired curvature and configuration, as long as the markin device is so formed as to be able to conform to such curvature and configuration.

The stencil I3 may be formed of paper or other suitable non-conducting material, and with perforations defining Whatever character is desired to be formed on the object II.

The marking device ll, of Figures 1 and 3, comprises a roller unit with metal spark points 20. The marking is accomplished by running the roller, in this case manually, back and forth over the stencil sheet I3 as it lies on the object I l.

2,468,871 g ffaiif i smooth outer contact surface, and the ends of the sleeve are closed by centrally perforated plugs 23 of nonconducting material such as Bakelite. A support arm 24 is provided for the roller sleeve 2|, in the form of a metal rod bent back'on itself at its midpoint to form a handle portion with two portions of the rod extending along a substantial 1 distance together, then outwardly, then parallel,

and finally inwardly toward each other to terminate inside the sleeve 2| in the perforations of the end plugs 23. Thus, the sleeve 2| may be rotated on the ends of the support'arm -24. A handle 25 of Bakelite or other insulation material is mounted on the handle portion of the support arm 24. Electrical connection from the impulse generator In to the spark points 20 is made through the lead l5, and a contact arm 26 which is secured to the support arm at 21 and is in contact engagement with the roller sleeve contact portion 22. i

The alternate structure of Figure 4 is shown in out of operation position and comprises a substantially flat object 28 to be marked, a paper stencil sheet 29 lying on the body 28, and a marking plate 30,'comparable to the roller 2| of Figure 1. The plate 39 is substantially in the form of a metal disc with its operating face knurled to provide metal points 3| from which sparks are jumped through the perforations 32 of the stencil sheet 29 to mark the body 28. The desired length of the marking spark gap is provided by the thickness of the stencil sheet 29 so that in its position of operation, the marking plate rests on the stencil sheet 29.

The marking plate 30 is provided with a handle 33 for moving the plate into and out of operating position. With this structure, the marking plate 30 may be applied to the stencil 29 somewhat in the manner of a stamp instead of the rolling application of the structure of Figure 1. Thus, the structure of Figure 4 may be used in arrangements where no room is available for the lateral rolling action of the roller 2|.

The surface to be marked of the body 28 may be of any desired curvature or configuration, as long as the marking plate 30 is formed to a conforming curvature and configuration. Leads 34 and 35 are provided for connection with the impulse generator IB and correspond respectively to the leads I2 and I5 of Figure 1.

Many variations of material, form, and dimension come within the scope of this invention as disclosed in this specification and the following claims, taken in conjunction with the accompanying drawings, since the particular details provided are simply for illustration.

Having described my invention, I claim:

1. In an electric marking device, a metal object, a stencil mounted upon a surface of said object having openings therein defining a pattern to be marked onsaid surface,;'a metal marking member having projections extending therefrom constituting a continuous regular array of spark electrodes, and an impulse generator connected .to-said member and said object whereby, when the member is moved into contact with the sten cil, sparks pass between said object and said electrodes through the openings in said stencil therebymarking a'pattern on portions of said surface, the; body ,of the stencil preventing the passage of sparks between the said electrodes and the other portions of said surface.

2. In an electric marking device, an object to be marked which is formed of conductive-material, a stencil mounted upon a-surface of said object having openings therein defining a pattern to be marked on said surface, a"roller having'p'rojections extending therefrom constituting a con.- tinuous, regular array of spark electrodes, and an impulse generator-' connected to said, roller and said object whereby, when-the roller is passed over the stencil, sparks pass between said object and said electrodes through the openings in said stencil thereby marking a pattern on portions of said surface and the body of the stencil prevents the passage of sparks between said electrodes and the other portions of said surface. 1 a

3. In an electric marking device, an object having a metal surface to be marked, astencil mounted on said object having Openings therein defining a pattern to be marked on said surface, a metal marking member having a knurled face with a continuous series of spark points extending therefrom, said member being adapted for. con tact with said stencil whereby. spark :gaps are formed between said surface and the spark points overlying the openings in the stencil and the bodyof the stencil is interposed between said member and the other portions .of said surface, and an impulse generator connected to said metal surface and said marking membeng HERBERT E. OLESI.

REFERENCES orrnn The following references areof record in the file of this patent:

UNITED STATES PATENTS Number Name Date 498,973 Garnett June 6, 1893 1,068,774 Hutchison July 29, 1913 1,289,000 Robinson Dec. 24., 1918 1,651,074 Steffens Nov. 29, 1927 -1,'795,564 Korge Mar. 10, 1931

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