IMPROVEMENTS IN ELECTRO ENGRAVING MACHINES
Year: 1876

page_text: LETTERS PATENT to Ernest de Pass, of Fleet Chambers, 68, Fleet Street, in the
City of London, Patent Agent, for the Invention of "IMPROVEMENTS IN
ELECTRO ENGRAVING MACHINES." A communication from abroad by John C.
Guerrant, of Danville, State of Virginia, in the United States of America.
PROVISIONAL SPECIFICATION left by the said Ernest de Pass at the Office
of the Commissioners of Patents on the 29th March 1876.
ERNEST DE PASS, of Fleet Chambers, 68, Fleet Street, in the City of London,
Patent Agent. "IMPROVEMENTS IN ELECTRO ENGRAVING MACHINES." A communica-
tion from abroad by John C. Guerrant, of Danville, State of Virginia, in the
United States of America.
Heretofore electro-engraving machines have been made with a bed which is
moved beneath the engraving tool and carries the article to be engraved, and in
this instance the plaster or other non-conducting material inserted in the spaces
between the types is apt to be injured, and the point of the tracer to accumulate
particles of such plaster and prevent the electrical action. Besides this the electrical
contact is not sharp and reliable in consequence of the junction of the conducting
and non-conducting portions not being sharp and uniform, hence there will be
imperfections in the engraving.
Now this Invention relates to a tracer used to close a circuit to an electro-magnet
which lifts the engraving tool when such tracer comes in contact with the metallic
surface of the form or pattern. This tracer is formed as a fine wire of conducting
material surrounded by a non-conducting case having preferably a tapering end
which prevents the tracer falling into the spaces between the types or other
pattern employed, but which tracer is efficient, inclosing the circuit to the electro-
magnet when the fine wire comes in contact with the metallic surface of the types
or pattern, and I combine with such circuit closing tracer a pantograph and a bed
upon which the material to be engraved is placed, thereby dispensing with any
non-conducting fillings in the faces of the types or patterns, the tracer running
freely over them without catching.
A stationary bed is provided for the reception of the pattern and a bed for the
article to be engraved. The bed which carries the article to be engraved is

page_text: moveable in the ways that form part of the carriage, which carriage can be moved
cudwise in slides upon the bed by revolving or operating the screw.
A shaft passes through the slide ways, and is provided with a pinion which acts
upon the rack beneath the bed, and to this bed one joint of the pantograph is con-
nected; the stationary fulcrum of this pantograph is upon the bed, and the tracer
is connected at the moving end of such pantograph by a hinged yoke, so as to rest
upon the surface as it is moved over the pattern by the motions given to the bed
in one direction by the rack and pinion, and in the other direction by the carriage
and screw.
The engraving tool is upon the arm and is so pivoted as to move
slightly up and down, and it is caused to cut by pressure derived from a weight or
spring it is raised by an electro-magnet acting upon the armature of the lever
when the circuit is closed from a battery, through said electro-magnet by the
contact of the tracer with the metallic surface of the pattern. If the electro-
magnet be on the other side of the pivot it may bring the engraving tool to its
work, and a spring or weight may be employed to raise it.
The article to be engraved is secured to the bed, if flat, but if circular it is
attached to a shaft either upon the surface thereof if convex, or within a chuck if
concave, and the engraving tool is positioned accordingly so as to reach the surface
to be engraved. It will be apparent that the shaft having partially or entirely
revolved moves the rack, tracer, and pantograph at the same time that the article
is moved, thereby a flat pattern is transferred to the convex or concave engraved
surface.
A pin on the shaft gives motion to a pawl and moves a ratchet wheel and screw,
and each revolution or oscillation of the shaft moves the carriage the distance
required between one engraved line and the next.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Ernest de Pass in the Great Seal Patent Office on the 29th September
1876.
ERNEST DE PASS, of Fleet Chambers, 68, Fleet Street, in the City of London,
Patent Agent. "IMPROVEMENTS IN ELECTRO ENGRAVING MACHINES." A communica-
tion from abroad by John C. Guerrant, of Danville, State of Virginia, in the
United States of America.
Heretofore electro-engraving machines have been made with a bed which is
moved beneath the engraving tool, and carries the article to be engraved, and the
plaster or other non-conducting material inserted in the spaces between the types is
apt to be injured, and the point of the tracer to accumulate particles of such plaster,
and prevent the electric action. Besides this the electric contact is not sharp and
reliable in consequence of the junction of the conducting and non-conducting
portions not being sharp and uniform; hence, there are imperfections in the
engraving.
Now this Invention relates to a tracer which is used to close a circuit to an
clectro-magnet, which lifts the engraving tool when the tracer comes in contact with
the metallic surface of the form or pattern. This tracer is formed of a fine wire of
conducting material, and it is surrounded by a non-conducting case having pre-
ferably a tapering end, which prevents the tracer falling into the spaces between
the types or other pattern employed, but which tracer is efficient in closing tho
circuit to the electro-magnet when the fine wire comes in contact with the metallic
surface of the types or pattern, and I combine with such circuit closing tracer a
pantograph and a bed upon which. the material to be engraved is placed, thereby
dispensing with any non-conducting fillings in the faces of the types or patterns, the
tracer running freely over them without catching.
A stationary bed is provided for the reception of the pattern and a bed for the

page_text: article to be engraved. The bed which carries the article to be engraved is moveable
in the ways that form part of the carriage, and such carriage can be moved end wise
in slides upon the bed by revolving or operating the screw.
A shaft passes through the slideways, and is provided with a pinion which acts
upon the rack beneath the bed, and to this bed one joint of the pantograph is con-
nected. The stationary fulcrum of this pantograph is upon the bed, and the tracer
is connected to the moving end of such pantograph by a hinged yoke so as to rest
upon the surface as it is moved over the pattern by the motions given to the bed in
one direction by the rack and pinion, and in the other direction by the carriage and
screw. The engraving tool is upon the arm, and is so pivoted as to move slightly
up and down, and it is caused to cut by pressure derived from a weight or spring;
it is raised by an electro-magnet acting upon the armature of the lever when the
circuit is closed from a battery through said electro-magnet by the contact of the
tracer with the metallic surface of the pattern. If the electro-magnet be on the
other side of the pivot it may bring the engraving tool to its work, and a spring or
weight may be employed to raise it.
The article to be engraved is secured to the bed, if flat, but if circular it is
attached to a shaft either upon the surface thereof if convex, or within a chuck if
concave, and the engraving tool is positioned accordingly so as to reach the surface
to be engraved. It will be apparent that the shaft having partially or entirely
revolved moves the rack, tracer, and pantograph at the same time that the article
is moved, thereby a flat pattern is transferred to the convex or concave engraved
surface.
A pin on the shaft gives motion to a pawl, and moves a ratchet wheel and screw,
and each revolution of the shaft moves the carriage the distance required between
one engraved line and the next.
I now proceed with reference to the accompanying Drawings to describe a machine
constructed according to the Invention.
Figure 1 is a perspective view of the whole machine.
Figure 2 is a plan.
Figure 3 is a sectional view of the spring which gives pressure to the engraving
tool.
And Figures 4 and 5 are enlarged views of the tracer.
a is the conductor of the tracer, which is a fine wire, and is made preferably of
platina; it passes through a case or stock a of ivory or other non-conducting
material, and the tracing point comes preferably out at the apex of an obtuse cone,
so that the tracer shall run freely over the surfaces of the types without catching,
thereby dispensing with any non-conducting filling in the face of the types or
pattern. A stationary bed b is provided for the reception of the pattern, and a bed c
for the article to be engraved. The bed c is moveable in the ways d, forming part
of the carriage e. The carriage can be moved endwise in slides fupon the bed g by
revolving the screw . i is a shaft passing through the slideways d, and provided
with a pinion which operates upon a rack X beneath and attached to the bed c, and
to which bed c one joint j of the pantograph is connected. The stationary fulcrum
of this pantograph is upon the bed g, and the tracer a is connected to the moving
end of the pantograph by the hinged yoke m, so as to rest upon the surface as it is
moved over the pattern by the motions given to the bed c in one direction by the
rack and pinion, and in the other direction by the carriage e and screw h.
The engraving tool and holder n is upon the arm o, and this holder is adjustablo
both to the engraving tool and the article to be engraved. The arm o is pivoted
at p so as to be moved up and down sligtly. The pressure upon the engraving
tool to cause it to cut is derived from a weight or spring r, and the tool is raised by
the electro-magnets acting upon the armature t of the arm o when the circuit is
closed from a battery u through said electro-magnet by the contact of the tracer v.
If the electro-magnet is upon the other side of the arın o it may bring the engraving
tool to its work, and a spring or weight will be employed to raise it. The articlo

page_text: to be engraved is secured to the bed c if it is flat, but if the article is circular it
is attached to the shaft i either upon the surface thereof if convex, or within
a chuck wif concave, and the engraving tool is positioned accordingly so as to
reach the surface to be engraved, as shown in Figure 2. It will be apparent
that the shaft i being partially or entirely revolved moves the rack X, tracer a,
and pantograph at the same time that the article is moved, thereby a flat pattern
is transferred to the concave or convex engraved surface.
The operation of engraving upon the outside and upon the inside of a ring
requires a change of motion of the pantograph. This change of motion is effected
by the addition of a rack X, which travels under the pinion of the shaft i, so that
when the bed c is moved in one direction the rack X travels in the opposite. When
the pantograph is attached to this lower rack at X¹ then the engraving done upon
the outside of a ring reads properly. The same result would follow if engraving
work was being done upon the flat surface of an article placed upon the bed c. By
attaching the pantograph to the bed the pattern would be duplicated, and would
read as type or engraving from which it is printed. For engraving upon the inside
surface of a circular piece or ring the ring would be held by the chuck w, and the
pantograph would be attached to the bed at j. This would make the engraving
work read right, for by this connection the motion is reversed between the revolving
shaft and the bed, which is arranged and shown in Figure 2. For holding the type
or pattern an ordinary frame similar to that used by printers is employed, and is
placed upon a portable table b, which is arranged to secure the pattern firmly. This
table is supported by one or more screws, forming legs, and which admit of the
table being adjusted so as to bring the pattern into proper place for contact with
the tracer. This is fully shown in Figures 1 and 2.
The feeding mechanism is produced in the following manner-When the bed c
is moved by means of the shaft, rack, and pinion, pins or projections 6, 61, come in
contact with two pieces d', d, which are adjustable to a small sliding rod g. This
rod, as shown in Figure 1; has firmly attached to it an arm u¹ carrying a pawl,
which works on the ratchet wheel and nut w, the nut being revolved and the
screw / being stationary. This feeds the carriage e in a direction from the operator.
To regulate the amount of feed required the lock nuts should be turned so as to
give the sliding bar more movement. This adjustment admits of the pawl taking
one or more teeth on the ratchet which turns the nut ¹, all of which equally
advance the article being engraved and the tracer over the pattern employed. To
bring the bed back into position after the piece is engraved the operator must
unloose the pawl and turn the screw by hand, the nut remaining stationary. By
this arrangement of parts the operator is able to regulate the exact amount of
movement required for the bed c, pantograph k, and tracer a.
Having now described the nature of the said Invention and in what manner the
same may be performed, I declare that I claim,-
First. In an engraving machine a tracing point made of metal surrounded with a
case of non-conducting material, and preferably with a slightly conical surface, in
combination with an electro magnet and engraving lever, as set forth and substan-
tially as shewn in the Drawings.
Second. The combination in an engraving machine of a reciprocating bed carrying
the article to be engraved, a pantograph and tracer connected with and moved by
such bed, a stationary pattern, an engraving tool moving vertically, and a lever and
electro-magnet for operating such engraving tool, as set forth and substantially as
shewn in the Drawings.
Third. The combination in an engraving machine of a revolving chuck for holding
the article to be engraved, a rack and pinion, a pantograph and a tracer receiving
motion from the mechanism revolving the chuck, a stationary pattern and
engraving tool, and a lever and electro-magnet for operating the same, as set forth
and substantially as shewn in the Drawings.
Fourth. A portable table for supporting the frame holding the pattern, such table

page_text: being provided with adjusting screws, as set forth and substantially as shown in
the Drawings.
In witness whereof, I, the said Ernest de Pass, have hereunto set my hand
and seal, this Twenty-third day of September, in the year One thousand
eight hundred and seventy-six.
ERNEST DE PASS. (L.S.)
Vitness,
S. J. A. McLORG.