IMPROVEMENTS IN PANTOGRAPH ENGRAVING MACHINES
Year: 1875

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine,
Lake, & Co., Patent Agents, Southampton Buildings, London,
for the Invention of "IMPROVEMENTS IN PANTOGRAPH ENGRAVING
MACHINES." -A communication from abroad by John Hope, of
Providence, Rhode Island, United States of America.
Sealed the 18th February 1876, and dated the 29th December 1875.
COMPLETE SPECIFICATION filed by the said William Robert Lake
at the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 29th December 1875, pursuant to the 9th
Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
PANTOGRAPH ENGRAVING MACHINES," and have petitioned Her Majesty to
grant unto me, my executors, administrators, and assigns, Her Royal

page_text: Letters Patent for the same, and have made solemn Declaration that
it has been communicated to me from abroad by John Hope, of
Providence, Rhode Island, United States of America.
NOW KNOW YE, that I, the said William Robert Lake, do hereby
declare that the following Complete Specification, under my hand and
seal, fully describes and ascertains the nature of the said Invention, and
in what manner the same is to be performed, in and by the following
statement, reference being had to the accompanying Drawing forming a
part of this Specification :-
A pantographic mechanical engraving machine is to be understood
to be a machine capable of multiplying upon either a curved or plain
surface in proportion to the numbers of gravers employed any figure
from a single pattern sketch. It is also expected to be able to produce
a full regular geometrical figure, or one of a complex ornamental
character from a pattern which contains only a single complete set of
the elements, which by repetition will make up such figure.
Machines of this class consist of a number of diamond-pointed gravers
fixed upon a bar at stated distances apart, and capable by means of a
foot treadle of being brought to bear at pleasure upon
the copper
roller
or other article to be engraved. The surface of the metal to be engraved
is coated with a prepared varnish, which will resist the action of acids,
but can be readily etched by the diamond points. The pattern sketch
which is usually made nine times the size of the intended figure when
otched is placed upon the flat surface of a table in front of the operator.
Over the sketch is a stylus or metallic pointer which as it is moved over
the figure upon the pattern sheet causes a movement corresponding in
direction but reduced in extent to be given to the table or frame which
supports the article to be engraved by means of intermediate connecting
mechanism, and thus the pattern is reproduced upon the varnished
coating as many times as there are fixed gravers.
Prior to this Invention these machines were complicated in structure,
and consequently defective in operation, owing to the want of exact
correspondence between the movements of the object table and those of
the stylus, induced by disturbances from the slipping of friction wheels
and variations in the length of pulley bands used in transmitting motion
from one to the other. It is sought by the present Invention to
overcome all the objections which have existed in a machine of this

page_text: showing the lever by which longitudinal motion is transmitted.
Figure 4 is a horizontal view of the traversing carriage, showing the
lever by which the transverse or rotative motion is imparted to the shell
or roller.
Figure 5 is a plan of the reciprocating standard showing the carriage.
supporting the same; Figure 6 is an elevation of the conical standard
and the carriage supporting the same.
A, A, are the standards forming the ends of the frame of the machine
on which the mechanism is supported; B is the object table upon which
the pattern sketch is secured; C is the pointed stylus or tracer, hinged
to the longitudinal traverse carriage D; E is the reciprocating transverse
carriage provided with suitable rails, forming ways on which the
longitudinal traverse carriage D may freely and accurately move;
F, F, are the ways or rails on which the carriago E moves from front
to rear, forward and backward, as the stylus is moved forward or
backward.
As the two carriages D and E are the principal moving parts, it is
important that their relation to the other parts should be distinctly
understood. The stylus C is hinged to the carriage D, this carriage is
mounted on grooved wheels running on longitudinal rails. The carriage
may therefore freely follow the motion of the stylus to the right or left
longitudinally on the line of the rails, but cannot move forward or
backward transversely to the frame. Therefore the carriage E is also
mounted on grooved wheels at its ends supported on fixed rails secured
to the frame, so that the said carriage E can freely move backward and
forward transversely. Every motion of the stylus is thus transferred to
the carriage D and E, and if either the gravers or the shell herein-after
described are by suitable mechanism connected to these carriages,

page_text: shell.
To produce fine work and allow the operative to follow the pattern,
the same is made several times larger than the figure desired, and the
motion transmitted either to the shell or the gravers must be corro-
spondingly reduced. For this purpose, levers turning on a fulcrum and
arranged with one long and fixed arm and a shorter adjustable arm are
secured to each of the carriages D and E, and so connected with tho
same that the movement of the carriages is only communicated to the
lever in one direction.
The lever G is supported on the standard secured to the carriage 9,
the rollers of which run in the groove made in the carriage D. Any
forward or backward motion of the carriage E will not affect the
lever G, as the standard and carriage 9 can freely roll along the groove
in the carriage D; but the slightest lateral motion of the carriage D is
at once communicated to the lever G, and transmitted on a diminished
scale to the shell to be engraved. The lever G¹ is supported on the
standard secured to the carriage g¹, whose rollers run in a groove made
in the bracket e, which is secured to the carriage E and forms a right
angle with the groove on the carriage D. Any forward and backward
motion of the carriage E is therefor transmitted by the lever G¹ to the
shell, causing the same to rotate on the same diminished scale. Every
motion of the stylus is thus transmitted to the shell to be engraved on
the desired diminished scale, and the pattern is reproduced by the
gravers manifold and accurate in every detail and of the desired size.
Before the present Invention the standard giving motion to the
levers G and G' was made to slide in a groove, which either caused
considerable friction or necessitated considerable lost motion by allowing
sufficient play; such lost motion prevented the exact reproduction of
the pattern and caused irregular and zig-zag lines to be made by the
gravers. By mounting the standard on the carriages 9 and g¹ the whole
moves with the least possible resistance without any lost motion, nor
will the wearing of the parts by use produce any lost motion as was the
case in the older machines.
g
H is a cylindrical shell, such as are used by calico printers. This
shell is mounted on the arbor h, to which the index wheel H' is also
secured. The shell H is supported on the discs i, i, which are again

page_text: supported on antifriction rollers, supported on suitable bearings con-
nected with the table K, and this table is free to reciprocate longi.
tudinally on the rollers K', so that any motion imparted to the table K
is also communicated to the shell H.
The lever G is connected to the spindle L, as shown in Figure 1, on
the upper end of which spindle is the adjustable slide M that forms the
short arm of the lever. This slide may be adjusted to any desired point
to produce any desired dimension of the pattern. At the end of the
slide M a standard in all respects like that in Figures 5 and 6, but
placed with the spindle downward, is supported turning freely on the
spindle while the wheels or rolls of the carriage 9³ run in a groove of the
arm N. This arm is, hinged to the longitudinal reciprocating table K,
on which the shell H is supported,
Any longitudinal reciprocation of the carriage D is therefore com-
municated to the table K and shell H, diminished in the same ratio as
the distance from the centre of the standard 9 on the end of the
adjustable slide M, to the centre or axis of the spindle L, is to the
distance from the latter to the centre of the standard g on the other end
of the lever G, and in this proportion any motion of the stylus longi-
tudinally with the machine is transmitted to the shell H.
To communicate rotative motion to the shell the rollers i, ¹, having
roughened faces bear against the shell H, and are connected with the
traversing carriage N' by steel bands, so that any motion of the
carriage N¹ imparts a corresponding rotative motion to the shell H.
The end of the lever G¹ is secured like the lever G to a spindle L', at
the upper end of which the adjustable arm M¹ carries the standard and
carriage g³, running freely in a longitudinal groove on the under side of
the table N¹. Any motion therefore of the table E transversely is
communicated through the lever G¹, spindle L', and adjustable arm M¹
to the table N', in the proportion of the two arms of the lever G¹ and
M', and by means of the steel bands to the rollers, , and thus to the
shell H

page_text: In the machine above described, it will be observed that by the means
employed for connecting the stylus with the shell to be engraved, every
motion of the stylus will be followed by a corresponding motion on a
diminished scale of the shell, that the relative size of the etching to the
pattern can be regulated at pleasure, and that if desired by simply
adjusting the arms M and M' upon one side or the other of the spindles
L and L' respectively, the etching will be the same in position as the
design on the pattern sketch or the reverse thereof, as the case may be,
it being quite evident that in whatever direction the tables will move
in correspondence with the movements of the stylus the same motion
will be performed by the shell to be etched on a diminished scale.
Instead of one set of gravers two or more sets may be employed and
operated in the same manner as shown in Figure 1.
For engraving cylinders for calico printers it is often necessary to
change the position of the roller upon its axis by angular movements of
equal extent. For this purpose an index plate and finger are employed,
the said plate being secured to a shaft put through the axis of the
cylinder. It is however often found desirable to adjust the index plate
more accurately with the surface of the cylinder by reason of the axis
of the shaft to which the index plate is attached, from inequalities in a
the thickness of the shell of the cylinder not coinciding exactly with
the axis of the outer surface. A convenient device in such cases is
shown in Figures 1 and 2; H is the copper shell, and h the mandrel
placed through the axis of the same. A flanch is clamped to the
mandrel, and the index wheel H¹ which has a hole through its centre of
greater diameter than the mandrel is arranged to bear against the flanch.
A washer which may be dome shaped and of spring steel is then placed
upon the end of the mandrel, and secured and adjusted to the index
wheel H, so that the periphery of the index wheel corresponds exactly
with the periphery of the shell.
Having thus fully described the said Invention, as communicated to
me by my foreign correspondent, and the manner of performing the
same, I wish it understood that I claim,--
First. The reciprocating standard 9 supported on a carriage as above
described and for the purpose set forth.
Second. Combining the carriage of the tracer or stylus in a panto-
13

page_text: described.
Third. The adjustable index plate in combination with the shell, as
above specified and for the purpose set forth.
Fourth. The combination with the stylus and carriage D, provided
with a groove or way of the pivoted reciprocating standard g, supported
on wheels or rollers and arranged to run freely at right angles with the
motion of the carriage while transmitting all motions of the same to the
shell to be engraved.
Fifth. The combination of the roughened rolls i, , with the table N¹
connected with the same to impart rotative motion to the sholl H, as
above specified and for the purpose set forth.
Sixth. In a pantograph engraving machine the combination with the
levers G, G³, of the reciprocating standards g and g¹, arranged to support
the long end of the lever and supported on carriages running on ways
at right angles to each other, as above described and for the purpose set
forth.
Seventh. A pantographic engraving machino with the various parts
of its mechanism, constructed, combined, arranged, and mounted upon
a suitable stand or frame, as shewn in the accompanying Drawing and
operating as herein set forth.
In witness whereof, I, the said William Robert Lake, have here-
unto set my hand and seal, this Twenty-ninth day of December,
in the year of our Lord One thousand eight hundred and seventy-
five.
Witness,
JA. EDWARDS,
8, Southampton Buildings,
London.
WN. ROBT. LAKE. (L.S.)