IMPROVEMENTS IN PENTAGRAPH ENGRAVING MACHINES
Year: 1876

page_text: LETTERS PATENT to Thomas Nixon, Pentagraph Engraver to Messrs. John Orr
Ewing and Company, of Alexandria, in the County of Dumbarton, North
Britain, for the Invention of "IMPROVEMENTS IN PENTAGRAPH ENGRAVING
MACHINES."
Sealed the 25th July 1876, and dated the 29th January 1876.
PROVISIONAL SPECIFICATION left by the said Thomas Nixon at the Office of
the Commissioners of Patents on the 29th January 1876.
THOMAS NIXON, Pentagraph Engraver to Messrs. John Orr Ewing and Company,
of Alexandria, in the County of Dumbarton, North Britain. "IMPROVEMENTS IN
PENTAGRAPH ENGRAVING MACHINES."
This Invention relates to multiple pentagraph engraving machines of certain well
known kinds heretofore used for engraving rollers or cylinders, and has for its object
the adapting of such machines for engraving flat plates.
In one machine to which the improvements are applicable the movement of the
tracer over the enlarged design is communicated to bars or frames moving at right
angles to each other, and these bars carry adjustable inclined pieces which transmit
the separate rectangular movements in reduced proportions, depending on their
degrees of inclination, to a second set of bars or fraines mounted so as to move at
right angles to each other. Those bars of the second set which move transversely
give motion to a frame carrying the diamonds or engraving points, whilst the bars
moving backwards and forwards give a rotatory motion to the roller or cylinder; and
the combination of the two movements causes the diamonds to engrave the design
on the roller surface on a reduced scale, the design being repeated by each diamond.
In adapting the machine for engraving a plate instead of a roller those bars of
the second set which have a transverse movement are provided with small pedestals
or studs, to which the plate to be engraved is fixed in a horizontal position by
means of screws admitting of its level being accurately adjusted. Then to those bars
of the second set which mové backwards and forwards there are attached lateral
brackets to carry a transverse bar or frame which is entirely above the plate to be
engraved, and which has attached to it the holders for the diamonds or engraving
points, together with the appliances for adjusting the holders and for putting the
diamonds or points into or out of action. The lateral brackets carrying the
engraving points are bowed or shaped so as to admit of the desired amount of

page_text: transverse movement of the plate without its touching the brackets. The trans-
verse bar carrying the engraving points can be shifted backward or forwards on
the side brackets for repeating the engraving on different parts of the plate; and
the bar is also made in two parts, with provision for adjusting the part actually
carrying the engraving points at any desired inclination to the part which is
attached to the side brackets. The parts for adapting the machine for engraving
plates are fitted and attached so that they can be applied or removed in a very
short time accordingly as it may be required to engrave a plate or a cylinder.
In another machine, to which the improvements are applicable in a modified
form, the enlarged design is on a concave cylindrical surface, and the tracer in
moving over it gives a direct angular movement to a lever frame having discs, which
support and turn the roller or cylinder to be engraved. When adapted for engraving
a plate a frame to carry the plate is mounted on antifriction rollers, so as to move
horizontally backwards and forwards over the lever frame, and the discs of the lever
frame are connected to the plate frame by steel bands.
The diamonds or engraving points are carried above the plate by a transverse bar
connected by brackets to a bar in the position of that which carries the diamonds or
engraving points when arranged for engraving a cylinder.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Nixon in the Great Seal Patent Office on the 28th July
1876.
THOMAS NIXON, Pentagraph Engraver to Messrs. John Orr Ewing and Company,
of Alexandria, in the County of Dumbarton, North Britain. "IMPROVEMENTS IN
PENTAGRAPH ENGRAVING MACHINES."
My said Invention relates to multiple pentagraph engraving machines of certain
well known kinds heretofore used for engraving rollers or cylinders, and has for its
object the adapting of such machines for engraving flat plates.
In one machine the plate to be engraved is fixed to the part ordinarily carrying
the engraving points, which last are carried by an adjustable frame connected to the
parts ordinarily turning the cylinder. In another machine the parts ordinarily
turning the rollers are connected by steel bands to a horizontally moving frame
carrying the plate, and the engraving points are carried by an added bar connected
to the ordinary bar.
And in order that my said Invention, and the manner of performing the same, may
be properly understood, I hereunto append two Sheets of explanatory Drawings, to be
herein-after referred to, and representing one modification of pentagraph engraving
machine arranged with my improvements. In these Drawings the same reference
numerals are used to mark the same or like parts wherever they are repeated.
Figure 1, on Sheet 1 of the Drawings, is a plan, Figure 2, on Sheet 2, is an cad
elevation, and Figure 3 is a sectional side elevation of a pentagraph engraving
machine adapted for engraving flat plates. In this machine, which comprises two
side frames or standards 1, supporting the parts carrying the operating mechanism,
the movement of a tracer 2 over the enlarged design placed on a table 3 extending
across the standards is communicated to bars or frames 4, 5, moving at right angles
to each other, and these bars carry adjustable inclined pieces 6, 7, which transmit
the separate rectangular movements in reduced proportions, depending on their
degrees of inclination to a second set of bars or frames 8, 9, mounted so as to move
at right angles to each other.
When the machine is intended for engraving rollers or cylinders those bars of the
second set which move transversely give motion to a frame carrying the diamonds
or engraving points, whilst the bars moving backwards and forwards give a rotatory
motion to the roller or cylinder, and the combination of the two movements causes
the diamonds to engrave the design on the roller surface on a reduced scale, the

page_text: design being repeated by each diamond; but in adapting the machine for engraving
a plate instead of a roller the bars 8 which have a transverse movement are
provided with small pedestals or studs 10 on which the plate 11 to be engraved is
laid or fixed in a horizontal position, and its level is accurately adjusted by means
of screws 12. Then to those bars 9 of the second set which move backwards and
forwards there are attached lateral brackets 13 to carry a transverse bar or frame 14
which is entirely above the plate 11, and has attached to it the holders 15 for the
diamonds or engraving points. The engraving points are carried by sinall bars 16
suspended near their centres by the holders 15, and are kept out of action by
adjusting screw pins 17 bearing against a transverse bur 18 hinged to the frame 14.
When it is wanted to bring the engraving points into action the bar 18 is lifted up
by a wire 19 attached to it and to a lever 20 on the end of a rocking spindle 21
supported over the frame 14, and having on its other end a wiper 22 resting on
a longitudinal rod 23. From this ro: 23 two vertical rods 24 extend down to a
bar 25 held by levers 26, one of which is a bell-crank lever, and has fixed to its
arm a rod 27 reaching down to and acted on by a foot treadle. The lateral
brackets 13 carrying the bar 14 with the engraving points are bowed or shaped so
as to admit of the desired amount of transverse movement of the plate 11 without
its touching the brackets. The transverse bar 14 carrying the engraving points can
be shifted backwards or forwards on the side brackets 13 for repeating the engraving
on different parts of the plate; and the bar is also made in two parts, the upper
part having formed on it arcs or arms 28, through slots in which bolts 29 pass and
are screwed into the lower part, thus permitting of the adjustment of the part
actually carrying the engraving points at any desired inclination to the part which
is attached to the side brackets 13. The parts for adapting the machine for
engraving plates are fitted and attached so that they can be applied or removed
in a very short time, accordingly as it may be required to engrave a plate or a
cylinder.
In another machine, to which the improvements are applicable in a modified
form the enlarged design is on a concave cylindrical surface, and the tracer in
moving over it gives a direct angular movement to a lever frame having discs, which
support and turn the roller or cylinder to be engraved. When adapted for engraving
a plate a frame to carry the plate is mounted on antifriction rollers, so as to move
horizontally backwards and forwards over the lever frame, and the discs of the lever
frame are connected to the plate frame by steel bands.
The diamonds or engraving points are carried above the plate by a transverse bar
connected by brackets to a bar in the position of that which carries the diamonds or
engraving points when arranged for engraving a cylinder.
Having thus particularly described my said Invention, and the manner of
performing the same. I have to state that I do not restrict myself to the precise
details herein described or delineated, but that what I believe to be novel and
original, and claim as the Invention secured to me by the herein-before in part
recited Letters Patent is, the adapting of certain kinds of pentagraph engraving
machines for engraving flat plates, substantially in the manner herein-before
described.
In witness whereof, I, the said Thomas Nixon, have hereunto set my hand
and seal, this Twenty-seventh day of July, in the year of our Lord One
THOMAS NIXON. (L.S.)