An Improved Method of and Apparatus for Marking and Ornamenting Cutlery and other Metal Articles.
Year: 1895

page_text: Date of Application, 26th Feb., 1895--Accepted, 22nd June, 1895
COMPLETE SPECIFICATION.
An Improved Method of and Apparatus for Marking and Ornamenting
Cutlery and other Metal Articles.
I, CHARLES LOUIS BURDETT, of No. 188 Sigourney Street, in the City of
Hartford, County of Hartford, and State of Connecticut, United States of
America, Civil Engineer, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
The object of my invention is to provide an improved means and apparatus for
marking articles of table ware and of cutlery, the process involving the use of
stamps for outlining and of electricity for etching the letters, figures or characters
to be delineated on the surface marked. To this end my invention consists in the
method or process of marking metallic articles and in the several devices and
combination of devices for marking, as more particularly hereinafter described and
pointed out in the claims :
Referring to the accompanying drawings:
Figure is a detail top or plan view of an apparatus for practicing my
invention.
Figure 2 is a detail view in vertical transverse section through the apparatus.
Figure 3 is a detail view in end elevation of the apparatus, some of the parts
being shown in section.
According to my improved method the marking of metallic articles is effected as
hereinafter described, that is to say :-The surface to be marked is first covered
with a suitable varnish or other resist or protecting medium and the mark imprinted
thereon by removing this resist or protecting medium along the lines forming the
said mark. The surface is then washed with water and treated with a solution of
sal-ammoniac or equivalent substance and a metallic block connected to the
negative pole of a battery is placed close to, but out of contact with the said
surface, the article to be marked being connected to the positive pole of the said
battery; a current is then allowed to pass and electrically cut away or etch the
metal along the outline of the mark. When the said cutting away or etching has
proceeded to the required depth the current is stopped and the articles are cleaned
in any convenient manner.
In the accompanying drawings the letter a denotes a table or base preferably of
wood, a support for holding the article to be marked, the support in this case
consisting of the rods,, having shallow sockets in their upper surfaces to
receive and hold a table knife, as my invention is described herein in connection
with an apparatus particularly adapted for marking cutlery, although the invention
is equally applicable for marking and ornamenting other articles whether of cutlery
or table ware, or for ornamental purposes.
The rods,, are of metal and are insulated, the former resting on strips of
insulating material c which are held on the guides d on the table. A metallic
conductor e is removably supported at a slight distance above the surface at the
point where the mark is to be etched, and in the form of device shown these
conductors, consisting each of a small block of copper, are supported from a rod
by the arms g which project from the standards h fixed on a carriage i. This
carriage is secured to a slide k that by means of a feed screw is movable toward
and from the row of knives. This form of device is convenient where a number of
articles as knives are to be marked with the same character, symbol or subject
LP 71

page_text: matter and for other articles any convenient form of carriage may be provided, it
being necessary that the conductor e should be held for a certain time immediately
over the surface of the article where the mark is to be etched by the action of
electricity, as already described.
A conducting wire m from a battery o, or like source of electrical energy, is
connected from the positive pole (+) to the rods b', 62 on which the article to be
marked is supported, and a wire from the negative (-) pole of the battery is
connected to the rod, on which the conductor or conductors e are supported.
In a convenient position, preferably along the front of the table, there is a
guide pon which a slide is movably supported, an adjustable armi extending
from this slide supporting a stamp g. By means of this stamp the character or
figure to be etched is outlined on the surface of the blade by pressing the stamp
down upon the surface which has been treated with a special varnish, the surface
of the stamp having been wiped with a solution as hereinafter described. The
copper conductors e are withdrawn at the time the articles are successively stamped
and then the stamp being moved out of the way, as indicated in Fig. 1 of the
drawings, the carriage is moved forward and the conductors arranged directly over
the imprint of the stamp on the surface.
The marking upon the surface of the metallic article is accomplished by the use
of an electric current as hereinafter described, and to prepare the article for
marking by this process the surface is treated with a varuish preferably made of
the following ingredients:
To one gallon of naptha add two ounces bi-sulphide of carbon, two pounds of
pulverized resin, and one and one-half pounds of chlorile of copper.
A thin layer
of this varnish is spread across the surface and the stamp having been washed
with a weak solution of wood potash is then pressed down onto the varnished
surface.
The surface of the varnish where the stamp has touched it is then washed with
water and treated with a weak solution of sal-ammoniac by means of what is termed
in the trade a goose, which is an implement allowing small quantities of the
solution to be dropped upon the surface. The copper conductors are then arranged
as described and the current turned on with the result that the surface of the
liquid lying on the plate is lifted into contact with the copper conductor and the
surface of the steel or other metal cut away hy the action of electricity. Chloride
of sodium is an equivalent of the sal-ammoniac in this process. The etching
operation is one of comparatively brief duration and the current being turned off
the knives are removed and dipped into a solution of caustic potash or sal-soda to
wash off the varnish. The knives or like articles are then ready for the plating
room or for such subsequent treatment as may be desired.
By means of the process described the surface of an article may be cut to a
sufficient depth to clearly outline any desired figure which may be delineated by
means of a stamp, the design being cut into or etched on the surface by the action
of the electricity.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :
1. The improved method of marking metallic articles which consists in treating
the surface to be marked with a protecting varnish, then printing upon the
varnished surface with a stamp treated with a solution of wood potash, then
washing the stamped surface with water, then treating the stamped surface with a
solution of sal-ammoniac, then connecting up the article to the positive pole of a
battery and placing a metallic conductor which is connected to the negative pole
of the battery in close proximity to the varnished surface where the mark is
imprinted and subjecting it to the action of an electric current, all substantially as
described.
2. The improved method of marking cutlery which consists in treating the

page_text: surface of the article with a resinous varnish, then imprinting a mark on the
varnished surface by means of a stamp treated with an alkaline solution, then
washing the surface with water, and then applying a solution of sal-ammoniac to
the marked surface, then placing the article in an electric circuit, the negative wire
terminating in a block of copper placed adjacent to but out of contact with the
surface to be marked, the said article being connected to the positive pole of
the battery, and then washing off the varnish with an alkaline solution, all
substantially as described.
3. The improved method of marking and ornamenting cutlery and other articles
of metal which consists in applying a resist or protecting medium to the surface,
imprinting the outline of the mark by removal of the resist or protecting medium,
treating the surface with a solution of sal-ammoniac and then placing a metallic
block connected to the negative pole of a battery close to but out of contact with
the surface and connecting the article to the positive pole of the battery while the
latter is in action, all substantially as described.
4. An improved apparatus for marking cutlery which comprises a table or stand,
metallic supports for the article, a metallic conductor, as a copper block, supported
on a movable carriage and adapted to be held near the surface of the article, and
an adjustable stamp for imprinting the surface, all substantially as described.
Dated this Sixth day of February 1895.
777 ARAMA
CHARLES LOUIS BURDETT.
D. Young & Co.,
11 & 12 Southampton Buildings, London, W.C.,
Agents for the Applicant.