New or Improved Machinery for Engraving or Sinking Dies and Matrices and other Objects in Relief or Intaglio.
Year: 1891

page_text: Date of Application, 21st May, 1891
Complete Specification Left, 22nd Feb., 1892-Accepted, 26th Mar., 1892
PROVISIONAL SPECIFICATION.
New or Improved Machinery for Engraving or Sinking Dies and
Matrices and other Objects in Relief or Intaglio.
We, LUIGI FILIPPO CAMPI, of 16 Cross Street, Hatton Garden, London,
Engineer, and ROBERT ELSDON, of Highlands, Burnt Ash Hill, Lee, in the
County of Kent, Gentleman, do hereby declare the nature of the said invention to be
as follows:-
-
This invention relates to new or improved machinery for engraving or sinking
dies and matrices and other objects in relief or intaglio, in which the cutting or
engraving tool is caused to follow a path which is defined by the movements of a
pointer or tracer which is kept in contact, with the surface of a template, pattern,
or model, while the latter is passed in front thereof, and the arrangements are such
that the object engraved or sunk may be made the same size as, less than, or larger
than, the template, pattern, or model, from which it is copied, and either right-
handed or left-handed as may be required.
The new or improved machinery consists of the following arrangements :-
On a suitable table or bed are mounted two spindles or shafts adapted to revolve
in bearings which can be adjusted and secured in any desired position on the said
table or bed. These spindles or shafts are usually placed parallel to each other,
but at distances apart dependent upon the proportion that the size of the object to
be engraved bears to that of the template, pattern, or model, from which it is to be
copied. These spindles or shafts are caused to rotate slowly in the same, or
opposite, directions by means of worm gearing or otherwise. On the end of one
of these spindles is mounted the template, pattern or model, which it is desired to
copy, and on the end of the other of these spindles is mounted the piece of material
which is to be engraved or sunk in imitation of the aforesaid template, pattern, or
model. Opposite the pattern and piece of material to be operated upon, is placed
a bar or arin, one end of which is furnished with a kind of universal joint which
allows of the said bar or arm being moved round such joint as a fulcrum in vertical
and horizontal planes. On this bar or arm are secured adjustably, first, a pointer
or tracer the front end of which comes opposite the pattern mounted on one of the
spindles so that it can be pressed against the surface of the said pattern as it
revolves slowly in front of it; secondly, a revolving cutting tool, which comes
opposite the piece intended to be operated upon and which is mounted on the
other spindle so that as the pointer or tracer follows the projections and hollows
of the pattern, so the cutting tool acts correspondingly upon the piece which is
intended to be a copy of the pattern.
The revolving cutting tool may be driven by a band or otherwise, and is mounted
in any suitable bearing, preferably one composed of hard material such as glass for
example. The spindle carrying the cutting tool is preferably formed with conical
journals, somewhat like those employed for lathe spindles, and these journals are
kept against their conical bearings by spring pressure.
The outer end of the bar or arm, carrying the pointer or tracer and the cutting
tool, is guided and supported by devices which, while allowing free movement to
the said bar or arm in a horizontal direction so as to enable the pointer or tracer
to follow all the irregularities of the surface of the pattern as the latter revolves
in front of it, only allows the said bar or arm to extend automatically to a certain
slight extent for each revolution of the spindles carrying the pattern and the piece
to be operated upon.
It will now be understood that if the two spindles, carrying the pattern and

page_text: piece to be operated upon respectively, be caused to rotate, and the pointer or
tracer on the aforesaid bar or arm is brought in contact with the pattern, the
cutting tool on the said bar will act on the piece on which the copy is to be made
and will cut it away to a depth proportionate to that of the corresponding part
of the pattern. In practice, the operation of engraving or sinking may be com-
menced by placing the pointer or tracer in the centre of the pattern, then at each
revolution of the pattern and piece being operated upon, the bar or arm, with the
pointer and cutter, is lowered slightly, so that the pointer or tracer passes over
a succession of circles, or in a spiral line, over the surface of the pattern as the
latter revolves, and the cutting tool passes over a similar path on the piece being
operated upon as it revolves. As, however, the circumference of the circles
described becomes larger as the pointer and cutter are moved away from the
centres of the pattern and copy respectively, it is necessary to proportionally
reduce the speed of the spindles carrying the pattern and copy, so that the space
passed over by the tool in a given time shall be about the same whatever part of
the copy it may be operating upon. This may be effected by any suitable
nechanism; for example the said spindles or shafts may be driven by a pair of
cone pulleys, the strap of which is gradually shifted along from the larger to the
smaller end of the driving cone, as the pointer and cutting tool are moved away
from the centre of the pattern and copy respectively.
In order to produce a left-hand copy from a right-hand pattern, or nice versi, the
two spindles carrying the pattern and copy respectively, are caused to rotate in
opposite directions. An intaglio copy can be made from a pattern in relief, or
vice versû, by arranging the universal joint or fulcrum of the bar or arm carrying
the pointer or cutter in a position between the said pointer and cutter, and by
causing the said joint or fulcrum and the entire bar or arm to descend slowly in
the same way as the outer end of such bar or arm is caused to descend in the
arrangement above described.
The size of the copy, relative to that of the pattern, can be varied by suitably
adjusting the relative positions to each other of the spindles carrying the pattern
and copy, and of the position of the fulcrum of the bar or arm carrying the pointer
and cutter with reference to those two spindles.
The said spindles are preferably made with conical journals and bearings, the
journals being pressed against their corresponding conical bearings by spring
pressure in order to prevent unsteady action of such spindles as they rotate.
Dated this 21st day of May 1891.
COMPLETE SPECIFICATION.
New or Improved Machinery for Engraving or Sinking Dies and
Matrices and other Objects in Relief or Intaglio.
We, LUIGI FILIPPO CAMPI of 16 Cross Street, Hatton Garden, London
Engineer, and ROBERT ELSDON of Highlands Burnt Ash Hill, Lee, in the County
of Kent, Gentleman do hereby declare the nature of the said invention and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement, that is to say:-
This invention relates to new or improved machinery for engraving or sinking
dies and matrices and other objects in relief or intaglio, in which the cutting or
engraving tool is caused to follow a path which is defined by the movements of a
pointer or tracer which is kept in contact with the surface of a template, pattern,
or model while the latter is passed in front thereof, and the arrangements are such
that the object engraved or sunk may be made the same size as, less than, or larger

page_text: And in order that the said invention may be fully understood we will now pro-
ceed to describe the same with the aid of the accompanying two sheets of drawings,
in which
Figure 1 is a front elevation,
Figure 2 a plan and
Figure 3 an end elevation of a machine constructed in accordance with the said
invention.
Figures 4 and 5 are sectional elevations taken on the lines 1-1 and 2-2
respectively of Figures 1 and 2, and
Figure 6 shews detail views of certain parts.
On a suitable table or bed A mounted on standards Bare arranged two spindles
or shafts C C adapted to revolve in bearings in the headstocks D D¹ which can
be adjusted to any desired position on the said table or bed A, and secured thereto
by means of bolts passing through slots A in the said table or bed. These spindles
or shafts CC are usually placed parallel to each other as shown, at distances
apart dependent upon the proportion that the size of the object to be engraved
bears to that of the template, pattern, or model, from which it is to be copied.
These spindles or shafts are caused to rotate slowly in the same or opposite
directions by means of worm wheels C2 C3 fixed thereon and driven by worms C₁ C³
on the shaft E, which revolves in bearings in the headstocks D D', and carries at
one end the speed pulley E which is driven by the band E2 from the speed pulley F
on the countershaft F. The worm C is adapted to slide longitudinally on the
shaft E to enable it to adjust itself to the position of the headstock D' on
the table A but is caused to turn with the said shaft by means of a feather taking
into a groove formed longitudinally in the said shaft.
If preferred however the aforesaid spindles or shafts may be driven by spur or
bevil gearing or otherwise. On the end of one of these spindles is mounted in a
suitable chuck C the template, pattern, or model C7 which it is desired to copy,
and on the end of the other of these spindles is mounted also in a suitable chuck C
the piece of material C which is to be engraved or sunk in imitation of the afore-
said template, pattern, or model C. Opposite the pattern and piece of material
to be operated upon, is placed a bar or arm G, one end of which is furnished with
a kind of universal joint which allows of the said bar or arm being moved round
such joint as a fulcrum in vertical and horizontal planes. In the machine illustrated
in the drawings this universal joint is constructed as follows:-H is a kind of head-
stock fixed adjustably on the table or bed A. His a spindle adapted to turn in
bearings in the headstock H. H is an arm formed with or secured rigidly to the
front end of the spindle H. The upper and lower edges of this arm H2, are pro-
vided with several holes or recesses H³ into either pair of which the points of the
fulcrum screws I of a fork I' may be adjusted. The fork I can be fixed in any
desired position on the bar or arm G by means of the boss 12 and set screw 13. Ou
this bar or arm G are secured adjustably, first, a pointer or tracer J the front end
of which comes opposite the pattern C7 mounted on the spindle C so that it can be
pressed against the surface of the said pattern as it revolves slowly in front of it;
secondly, a revolving cutting tool K which comes opposite the piece C³ intended
to be operated upon, and which is mounted on the other spindle C, so that as the
pointer or tracer J follows the projections and hollows of the pattern C7 so the
cutting tool K acts correspondingly upon the piece C which is intended to be a
copy of the pattern.
The revolving cutting tool K may be driven by a band or cord K' which passes
round the pulley K on the shaft K³, then round the guide pulley K³, round the
pulley K of the cutter K, round the tightening pulley K, thence round guide
pulley K and back to pulley K². Motion is communicated to the shaft K³
and pulley K from the main driving shaft Lof the machine by the pulleys K³, L'
and strap L. The tightening pulley K is mounted on an arm K turning between

page_text: centres as shown, and drawn constantly towards the left hand in Figures 1 and 2
by the weight K10 acting on the arm K", whereby the band or cord K' is kept
sufficiently tight. The cutting tool K is mounted in the end of a spindle K12
revolving in any suitable bearing K¹³ preferably composed of hard material, such
as glass for example. The spindle K carrying the cutting tool is preferably
formed with a conical journal as shown somewhat like those employed for lathe
spindles and this journal may be kept against its conical bearing by spring
pressure. The spindle K and bearing K may be contained in a case K
secured adjustably to the carriage K clamped to the bar or arm G by the set
screw K
The other end of the bar or arm G carrying the pointer or tracer, and the cutting
tool is guided, and supported by devices which, while allowing free movement to
the said bar or arm in a horizontal direction so as to enable the pointer or tracer
to follow all the irregularities of the surface of the pattern as the latter revolves in
front of it, only allow the said bar or arm to descend automatically to a certain
slight extent for each revolution of the spindles carrying the pattern and the piece
to be operated upon. These devices are of the following character:-M is an arm
clamped on the bar or arm G, and having at its upper end an opening M in which
is mounted the friction roller M, revolving freely on centre screws as shown. The
end of the bar G is supported by the roller M2 bearing on a pin N projecting from
a slide N', which can be moved up and down in guides on the standard N by
means of a screw N³ taking into a nut in the said slide N¹. The lower end of the
screw N³ carries a worm wheel N, into which gears the worm N on the shaft N°
which turns in bearings secured to the table A, and is driven from the spindle C by
the speed pulleys N N and cord Nº. A weight M³ and cord M* draw the arm M
and end of the bar G constantly towards the back of the machine; such action
being limited and regulated however by the adjusting screw M5, screwed through
the arm M, and having its end bearing against a part of the slide N'. By these
arrangements the free end of the bar & is at liberty to move backwards and for-
wards horizontally as the pointer or tracer follows the clevations and depressions
of the pattern, and is allowed to gradually descend so as to carry the pointer or
tracer and the cutting tool towards the circumference of the pattern and of the
piece to be operated upon respectively.
It will now be understood that if the two spindles C C', carrying the pattern C
and the piece to be operated upon C respectively, be caused to rotate, and the
pointer or tracer J on the aforesaid bar or arm G is brought in contact with the
pattern C the cutting tool K on the said bar will act on the piece C on which
the copy is to be made and will cut it away to a depth proportionate to that of
the corresponding part of the pattern. In practice the operation of engraving or
sinking may be commenced by placing the pointer or tracer J in the centre of the
pattern, then at each revolution of the pattern C' and piece being operated
upon C the bar or arm G with the pointer J and cutter K is lowered slightly by
micans of the screw N³ operated from the spindle C as above described, so that the
pointer or tracer passes in a spiral line over the surface of the pattern as the latter
revolves and the cutting tool passes over a similar path on the piece being operated
upon as the latter revolves. It will be obvious that if preferred the screw N³ may
be moved intermittently instead of continuously by any suitable arrangement of
mechanism, such as a ratchet wheel and pawl for example, whereby the tracer and
cutting tool will follow a succession of circles on the pattern and copy instead of
a spiral line. As however the circumference of the circles or spirals described
becomes larger as the pointer and cutter are moved away from the centres of the
pattern and copy respectively, it is necessary to reduce the speed of rotation of
the spindles carrying the pattern and copy, so that the surface speed of the part
of the copy passing in front of the tool shall not be too great, whatever part of
the copy
the tool may be operating upon. This may be effected by any suitable
mechanisin, for example, the said spindles or shafts may be driven as shown in the
drawings by a pair of cone pulleys P, Q the strap R of which is gradually shifted

page_text: along from the larger to the smaller end of the driving cone Pas the pointer..J
and cutting tool K are moved away from the centre of the pattern and copy
respectively. This shifting of the strap R is effected in the following manner :-
S is a cord connected at one end to a pin N* fixed to the back of the slide N' and
after passing under the guide pulley S, over the guide pulley S and under guide
pulley S3 is secured at the other end to the strap fork T which is adapted to slide
on the bar T connecting the two standards B. U is a cord connected at one end
to the strap fork T and, after passing over the guide pulley U¹, has its other end
connected to the weight V. As the slide N' is carried down by the screw N³ the
cord S is relaxed and the weight V draws the strap fork T to the left in Figure 1,
gradually traversing the strap R in the same direction, whereby the speed of the
countershaft F and consequently that of the worm shaft E and spindles CC¹ is
gradually reduced.
In order to produce a left hand copy from a right hand pattern, or nice versú,
the two spindles carrying the pattern and copy respectively, are caused to rotate
in opposite directions by making the worm and worm wheel of one of the
spindles C C right handed, and those of the other spindle left handed. An intaglio
copy can be made from a pattern in relief, or nice versa, by arranging the head-
stock H and fork I forming the universal joint or fulcrum of the bar or arm G in
a position between the spindles C C'. In order to produce a copy the same size
as the pattern or model an apparatus similar to that indicated by the letters of
reference N to N' inclusive may be substituted for the headstock H, a piece W
shown in Figure 6 being secured on the end of the pin N of such apparatus for
the fork I to take its bearing upon. By these means the entire bar or arm G is
caused to descend parallel to itself in the same way as the outer end of such bar
or arm is caused to descend in the arrangement above described, the said bar or
arm being still free to oscillate horizontally on the fulcrum screws of the fork I'
to enable the tracer to follow the elevations and depressions of the pattern.
The size of the copy relative to that of the pattern can be varied to a certain
extent by suitably adjusting the relative positions to each other of the spindles C C¹
carrying the pattern and copy, and of the position of the fulcrum of the bar or
arm G carrying the pointer J and cutter K with reference to those two spindles..
In the arrangements shown in the drawings the copy is produced smaller than the
pattern; when it is desired to make the copy larger than the pattern the latter
is mounted on the spindle C, and the piece, on which the copy is to be made, on
the spindle C.
When it is desired to adjust the fork I nearer to the spindle C₁than can be
effected with the arm H2 in the position shown in Figures 1 and 2 the said
arm may be reversed so as to project towards the said spindle C' instead of away
therefrom.
The spindles C C are preferably made with conical journals and bearings,.
the journals being pressed against their corresponding conical bearings by springs.
such as that shown at C* for example in Figure 5, in order to prevent unsteady
action of such spindles as they rotate.
The point of the tracer J should be made of hardened steel, diamond ruby or
other very hard material to prevent wear and tear as much as possible.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed we declare that what we:
claim is
First. The new or improved machinery for engraving or sinking which consists
of two spindles caused to rotate at the same speed in the same or in opposite
directions, one of such spindles carrying the pattern or model, and the other the
piece of material on which the copy is to be produced; a bar or arm on which are
mounted a pointer or tracer and a revolving cutting tool; mechanism for enabling
the said bar or arm to turn in a horizontal plane in order to allow the pointer or
tracer to follow the elevations and depressions of the pattern or model; and

page_text: mechanism for moving the said bar or arm vertically in order to traverse the
pointer or tracer and the cutting tool across the faces of the said pattern or model
and piece of material respectively, as the said pattern or model and piece of material
revolve, combined, arranged and operating substantially as hereinbefore described
and illustrated in the drawings.
Second. The new or improved machinery for engraving or sinking constructed
and operating substantially as hereinbefore described and illustrated in the
drawings.
Dated this 22nd day of February 1892.
L. F. CAMPI.
R. ELSDON.
Per W. H. Beck,
115, Cannon Street, London, E.C., Agent.