IMPROVEMENTS IN ENGRAVING MACHINES
Year: 1882

page_text: LETTERS PATENT to Frank Wirth of the firm of Wirth and Company
Patent Solicitor's at Frankfort on the Main in the Empire of Germany for an
Invention of "IMPROVEMENTS IN ENGRAVING MACHINES" a. communication
from Ludwig Limbert and Maximilian Salm persons resident at Hanan in
the Empire of Germany
PROVISIONAL SPECIFICATION left by the said. Frank Wirth at the Office
of the Commissioners of Patents on the 13th December 1882.
"
"
FRANK WIRTH, of the firm of Wirth and Company, Patent Solicitors, at Frankfort
on the Main in the Empire of Germany "IMPROVEMENTS IN ENGRAVING
[A communication from Ludwig Limbert and Maximilian Salm
persons resident at Hanan in the Empire of Germany]
MACHINES
-
4
This invention relates to machines designed to produce artistic objects in hard
and soft stone, glass, metal, ivory, wood or other suitable material (without any
artistic ability) similar to given model and either of the same size, smaller or
larger as desired. Moreover models can be reproduced by the said machines in
counterparts and existing reliefs can be transposed or transferred in sunk work
and vice versa.
In carrying the said invention into practice I provide a vertical spindle which
passes through a bearing in a table or plate. This spindle is also guided by
corresponding bearings in a bridge piece and a cross piece so that it can be easily
rotated upon its axis and can also be moved upwards or downwards in a vertical
direction, being always kept vertical by the said bearings: A pantograph is fixed
at its central portion on this spindle above the said table or plate.
On the said table or plate are raised parts which are provided with longitudinal
slots having at the top dove-tailed grooves, which form guides for sliding blocks.
These sliding blocks are provided with screw threads in their lower part, through
which pass screws connected at three corners of the table by mitre wheels, one of
the screws being continued and projecting beyond the front edge of the table and
D.

page_text: :
carrying a hand-wheel by which the screws can be turned, and by this means the
sliding blocks can be shifted simultaneously through equal distances.
The material from which the copies have to be made is fixed in any well known
manner to three of the said sliding blocks, while the model which has to be copied
or reproduced is fixed to the fourth sliding block; The three corners of the
pantograph which lie above the material to be operated upon are provided with
drills. The latter are connected to small pulleys which by means of a cord or band
are connected to another pulley in such a manner that when the latter is set in
motion the three drills commence to rotate. At the fourth corner of the
pantograph a guide pin is fixed.
The operation of the machine is as follows that is to say after the material to
be operated upon has been fixed upon the said sliding blocks and the model upon
the fourth block, drills are set in motion by means of the said pulleys. By the
weight of the central spindle and the panograph, the drills are pressed upon and
caused to enter the material below them. As soon however as the said guide pin
touches the model below it the spindle and the pantograph fixed to it are
prevented from being pressed further down. By this time the said drills have at
the parts operated upon removed so much of the material fixed upon the said three
sliding blocks, that the thickness of the said parts is equal to that of the model at
that part where the guide pin touches it.
The spindle of the pantograph is now raised and by altering the position of the
pantograph the adjoining parts of the material are removed in a similar manner.
The movement of the pantograph which is regulated by the guide pin must take
place only in one direction, that is to say, if the grinding or drilling
commenced
at the foot of a model or figure the guide pin is to be moved in a straight line
towards the head of the figure.
11
A straight groove is in this manner formed in the material at the places
operated upon, the depth of which groove is in inverse proportion to the height of
that part of the model over which the guide pin is caused to move. As soon as
such a groove is formed in the entire length of the model, the sliding blocks are
shifted by a partial rotation of the aforesaid hand wheel, so that the drills now
operate upon and remove the material on one side of the said groove and thus
widen the same. The guide pin can then be moved in a direction exactly
opposite to the previous one. By this gradual and repeated to-and-fro movement of
the guide pin over the model in connection with the shifting of the sliding blocks,
the superfluous material is removed by the drills, and a figure is produced on each
of the three sliding blocks which corresponds exactly with the model...
L
the
When, in working, on very hard materials the pressure which is exerted on t
point of operation by the weight of the spindle and the pantograph is not
sufficiently great, it can easily be increased by shifting a ring on the lower part of
the central spindle a little higher up, whereby a spiral spring between the said ring
and the table is compressed, and by its elasticity increases the pressure in the
manner desired.
If on the contrary the pressure resulting from the weight of the spindle and
pantograph is too great, then the said spiral spring is removed from the lower end of
the said spindle to the upper end of it, and is placed between an adjustable collar and
the aforesaid bridge piece. According to the position of the said collar the spring
will be more or less compressed and the pressure caused by the spindle and the
pantograph will be counteracted according to its position.
If it be desired to make figures either larger or smaller than the model, I proceed
in the following manner, that is to say-After the pantograph has been set for
enlarging or reducing in the well known manner, the drills at two of the sides are
thrown out of gear and only that drill which is opposite to the guide pin is
employed as the side drills in this case would not produce figures corresponding
with the model.. The operation is effected in the manner above described but it is
not necessary to adhere to a certain definite, direction of the guide pin which can if
desired be moved over the model in an irregular manner, while the figure whether

page_text: its outline is enlarged or diminished is always correctly reproduced. But the
enlargement or reduction of the outline of the model requires a similar enlargement
or reduction with regard to the raised or sunk parts of the picture which is
attained by the following contrivance that is to say ;-On a head piece which can
be fixed on the central spindle by means of screws a double armed lever is
pivotted. This lever can be fixed in a horizontal position by means of set screws
whereby its up and down movement can also be regulated within certain limits.
On the said double armed lever are sliding pieces which can be shifted easily. A
forked piece is connected with the first sliding piece by a link in which the drill
rotates.
One of the said sliding pieces is connected by means of links with a guide pin
and indirectly with the pantograph by means of a connecting piece. "The said guide
pin can easily be moved up or down in a hollow. boss, which connects two
pantograph bars with each other. The said connecting piece, the lower end of
which is connected by a link with the pantograph, can at the other end be moved
to and fro in an open link and can be fixed thereon by means of a crew on which
it is free to oscillate.
If now for instance it is desired to reproduce the model in question Vialf size, then
the pantograph is set to the required position and the said double rmed lever is
fixed in a horizontal position by the set screws. The said connecting piece is then
fixed in the open link by the said screw, so that it can vibrate on the same as a
centre. After the drill has been put in rotation by the motive power the guide
pin is moved freely across the model. The pantograph must now follow the
movements of the guide pin with which it is connected by means; of the, slotted
link and the connecting piece, whether it is moved in a vertical or aghorizontal
direction.
If it is desired to enlarge the model then the drill is fitted on the side where the
guide-pin was fitted in the above described operation for, reducing the model, and
the guide pin is fixed in the place of the drill.
:
If it is desired to work from negative to positive and vice versa for instance to
convert a negative engraved coat of arms into, raised work, then the said double
armed lever is allowed to work freely by slackening the set screws. The central
spindle is moreover fixed in such a manner that it can rotate but, cannot alter its
position vertically. If the guide pin is brought into a recessed part in the
engraving then a raised part will be produced on the drill side because the said
lever turning on its pivot will be raised as much on the working side as it is
lowered on the other side. In working from positive to negative the reverse takes
place.
11. I w
"
In order to be able to produce an even smooth surface another contrivance is
applied by means of which the central spindle with the pantograph can always'be
kept at the same height, without preventing it from turning freely. A head-piece
is fixed on the said spindle by means of a screw. On its upper end it has a groove
extending around it. In a bearing on the aforesaid bridge piece are screws which
are screwed so far into the said head that they do not prevent the same and with
it the said spindle from turning freely, but yet prevent them from descending.".
As the said head piece can be fixed in any position on the said spindle the
surface worked upon can be of any desired thickness.
The drill or tool does not in this case cut from above downwards but from side
to side like planing and the necessary pressure is not obtained, by the weight of
the spindle but by the hand directing the guide pin.
This machine can be used as a substitute for a rose engine lathe.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Frank Wirth in the Great Seal Patent Office on the 13th June
1883.
FRANK WIRTH of the firm of Wirth and Company Patent Solicitors at Frankfort-
on-the-Main in the Empire of Germany "IMPROVEMENTS IN ENGRAVING 5
MACHINES A communication from Ludwig Limbert and Maximilian Salm,
persons resident at Hanan, in the Empire of Germany
وو
. This invention relates to machines designed to enable a person, without any
artistic ability, to produce artistic. objects similar to a given model, in hard and
soft stone, glass, metal, ivory, wood or other suitable material, and either of the 1
same size, smaller, or larger as desired. Moreover, models can be reproduced by the
said machines in counterpart, and existing reliefs can be transposed or transferred
into sunk work and vice versa.
In the accompanying drawings
Figure 1 is a sectional plan of a machine constructed according to this 1
invention..
i
Figure 2 is a sectional elevation of the same, and
Figure 3 is a detail view drawn to an enlarged scale.
In carrying the said invention into practice I provide a vertical spindle W which
passes through a bearing in the table or plate T. This spindle is also guided by 2
corresponding bearings in the bridge piece E and the cross-piece H, so that it can
be easily rotated upon its axis and can also be moved upwards or downwards,
being always kept vertical by the said bearings. The pantograph P is fixed at its
central portion on this spindle above the said table or plate.
On the said table or plate are raised parts N which are provided with 2
longitudinal slots having at the top dovetailed grooves, which form guides for the
sliding blocks K. These sliding blocks K are provided with screw-threads in their
lower part, through which pass the screws D. The latter are connected at the
three corners of the table C by mitre wheels, one of the screws 'being continued
and projecting beyond the front edge of the table and carrying a handwheel R, by 3
which the screws can be turned and by this means the sliding blocks can be shifted
simultaneously through equal distances.
"
+
The material which has to be engraved is fixed in any well known manner, to
three of the said sliding blocks, while the model B¹ (Figure 1) which has to be
copied or reproduced is fixed to the fourth sliding block. The three corners of the 3
pantograph, which lie above the material, to be operated upon are provided with
drills b. The latter are connected to small pulleys r, which by means of a cord or
band are connected to the pulley S in such a manner, that when the latter is set in
motion the three drills commence to rotate. At the fourth corner of the pantograph
the guide pin ¹ is fixed.
4
The operation of this machine is as follows, that is to say ;-After the material B
to be operated upon has been fixed upon the said three sliding blocks K, and the
model B upon the fourth block the drills are set in motion by means of the said
pulley S. By the weight of the central spindle W and the pantograph P, the
drills are pressed upon and caused to enter the material below them. As soon 4
however as the said guide pin touches the model below it, the spindle and the
pantograph fixed to it are prevented from being pressed further down. By this
time the said drills have at the parts operated upon removed so much of the
material fixed upon the said three sliding blocks K, that the thickness of the said

page_text: parts is equal to that of the model at that part where the guide pin touches it.
The. spindle of the pantograph is now raised, and by altering the position of
the pantograph the adjoining parts of the material are removed in a similar
manner.
The movement of the pantograph, which is regulated by the guide pin, must
take place in only one direction, that is to say, if the grinding or drilling is
commenced at the foot of the model B¹ (Figure 1) representing the figure to be
copied the guide pin is to be moved in a straight line towards the head of the
figure. The drills fixed at the other three corners of the pantograph are then also
moving in straight lines.
A straight groove is in this manner formed in the material at the places
operated upon, the depth of which groove is in inverse proportion to the height of
that part of the model over which the guidè-pin is caused to move.
As soon as
such a groove is formed in the entire length of the model, the sliding blocks are
shifted by a partial rotation of the aforesaid hand wheel R, so that the drills now
operate upon and remove the material on one side of the said groove, and thus
widen the same. The guide pin can then be moved in a direction exactly opposite
to the previous one. By this gradual and repeated to-and-fro movement of the
guide-pin over the model in connection with the shifting of the sliding blocks, the
superfluous material is removed by the drills and a figure is produced on the
material on each of the three sliding blocks, which corresponds exactly with the
model.
When, in working on very hard materials, the pressure which is exerted on the
point of operation by the weight of the spindle and the pantograph, is not
sufficiently great, it can easily be increased by shifting the ring G on the lower
part of the central spindle W a little higher up, whereby the spiral-spring F
between the said ring and the table T is compressed and by its elasticity increases
the pressure in the manner desired. If on the contrary the pressure resulting from
the weight of the spindle and pantograph is too great then the spiral spring F is
removed from the lower end of the spindle W to the upper end of it and is placed
between an adjustable collar G' and the bridge piece E. According to the position
of the said collar G¹ the spring will be more or less compressed, and the pressure
caused by the spindle and the pantograph will be counteracted according to its
position. I am thus enabled to regulate the pressure exactly according to
requirements
The copies thus produced are, as already stated exactly like the model and form
two counterparts of it.
If it be desired to make figures either larger or smaller than the model, I proceed
in the following manner, that is to say; After the pantograph has been set for
enlarging or reducing in the well known manner, the drills at two of the sides are
thrown out of gear, and only that drill which is opposite to the guide pin is
employed, as the side drills in this case would not produce figures corresponding
with the model. The operation is effected in the manner above described, but it
is not necessary to adhere to a certain definite direction of the guide pin, which
can if desired be moved over the model in an irregular manner, while the figure,
whether its outline is enlarged or reduced, is always correctly reproduced. But
the enlargement or reduction of the outline of the model requires a similar enlarge-
ment or reduction with regard to the raised or sunk parts of the picture, which is
attained by the following contrivance, that is to say; On the head piece U, which
can be fixed on the central spindle W by means of the screws f, the double armed
lever L is pivotted. This lever L can be fixed in a horizontal position by means of
the set screws g, g, whereby its up and down movement can also be regulated
within certain limits. On the said double armed lever are sliding pieces w and x
which can be shifted easily. The forked piece P is connected with the first sliding
piece by a link, in which the drill rotates.
The sliding piece x is connected by means of the open link x' and other links
with the guide pin P1, and indirectly with the pantograph by means of the
21

page_text: connecting-piece. The said guide pin can easily be moved up or down in the
hollow boss, which connects two pantograph bars with each other. The said con-
necting piece the lower end of which is connected by a link with the pantograph;
can at the other end be moved to and fro in the open link x¹, and can be fixed
thereon by means of a screw y on which it is free to oscillate.
If now for instance it is desired to reproduce the model in question half size;
then the pantograph is set to the required position and the lever L is fixed in a
horizontal position by the set screws g, g, The connecting piece x is then fixed
in the open link x' by the screw y so that it can vibrate on the same as a centre;
as shown in Figure 3 After the drill has been put in rotation by the motive
power, the guide pin is moved freely across the model. The pantograph!P must now
follow the movements of the guide pin, with which it is connected by means of the
slotted link and the connecting piece all whether it is moved in a vertical or a
horizontal direction.
As it has been set to reproduce the model reduced to half size, the outline of the
picture is cut by the drill to the desired reduced scale, and the raised and sunk
parts of the model are at the same time correspondingly reduced.
The movement of the guide pin as above stated is not transferred direct to the
pantograph, but is effected by the slotted link x¹ and the connecting piece x¹¹.
The relative position of these parts to one another, as shown in the drawing, allows
the pantograph to follow the movements of the guide pin in the desired direction,
but reducing it at the same time to one half, so that when the guide pin is pushed
two centimetres up, the pantograph with the drill is only raised one centimetre..
This operation will be readily understood and therefore does not require further
description.
The further the connecting piece xli is fixed to the left on the slotted link x'
the more the copy will be reduced.
If it is desired to enlarge the model, then the drill is fitted on the side, where
the guide pin was fitted in the above described operation for reducing the model,
and the guide pin is fixed in the place of the drill.
If it is desired to work from negative to positive and vice versa, for instance to
convert a negative engraved coat of arms into raised work, then the double armed
lever L is allowed to work freely by slackening the set screws g. 9, The central
spindle W is moreover fixed in such a manner that it can rotate but cannot alter
its position vertically. If the guide pin is brought into a recessed part in the
engraving, then a raised part will be produced on the drill side, because the lever L
turning on its pivot f¹ will be raised as much on the working side, as it is
depressed on the other side. In working from positive to negative the reverse
takes place.
In order to be able to produce an even smooth surface another contrivance is
applied by means of which the central spindle W with the pantograph can always
be kept at the same height, without preventing it from turning freely. The head
piece U (Figures 2 and 3) is fixed on the spindle W by means of a screw f. On
its upper end it has a groove extending around it. In the bearing on the bridge
piece E are the screws e, e, (Figure 2) which are screwed so far into the groove in
the head U, that they do not prevent the latter and with it the spindle W from
turning freely, but yet prevent them from descending
As the head piece U can be fixed in any position on the spindle W the surface to
be operated upon can be of any desired thickness.
The drill or tool does not in this case cut from above downwards but from side
to side as in the operation of planing, and the necessary pressure is not obtained
by the weight of the spindle, but by the hand directing the guide pin.
This machine can be used as a substitute for a rose-engine lathe.
Having thus fully described the said invention and the manner of performing
the same, I wish it understood that I claim :-In an engraving-machine.
..
First. The spindle W, in combination with the pantograph P, the drills b and
guide pin 21, the pulleys r, the head piece-U, the collars Ğ, G' provided with set-

page_text: screws, the spiral spring F, the table T with the raised parts N having slots in
them, the sliding blocks K, the screws D connected by mitre-wheels, and the hand-
wheel R, substantially as described and for the purpose specified.
Second-The collar or head piece U, in combination with the set-screws g, g, the
screw, the lever L capable of oscillating on the pivot f¹, the sliding pieces wand x,
the slotted link xl, and the connecting piece x substantially as described and for
the purpose specified.
In witness whereof I the said Frank Wirth have hereunto set my hand
and seal this fifth day of June in the year of our Lord One thousand
eight hundred and eighty three.
FRANK WIRTH (L.S.)