IMPROVEMENTS IN MACHINERY OR APPARATUS FOR BRONZING, DUSTING, OR POWDERING
Year: 1877

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in
the County of Middlesex, Gentleman, for the Invention of "IMPROVEMENTS
IN MACHINERY OR APPARATUS FOR BRONZING, DUSTING, OR POWDERING."
A communication from abroad by Charles Georges Legrand, of Paris, in the
Republic of France, Envelope Manufacturer.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 22nd November 1877.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN MACHINERY OR APPARATUS FOR BRONZING,
DUSTING, OR POWDERING." A communication from abroad by Charles Georges
Legrand, of Paris, in the Republic of France, Envelope Manufacturer.
This Invention relates to machines for bronzing or applying dust or powder to
impressions of every description, and it consists of improvements in the general
construction, arrangement, and combination of the parts of the said machines; also
in the construction of the powder box; further, of an arrangement of bands which
prevent the effacing or rubbing off of the mordant; and lastly, in the application
to the cylinder of the machine of india-rubber, in order to facilitate the drawing
forward of the sheets.
The machine is supported by a frame carrying a cylinder, by preference of cast
iron, covered with a layer of soft india-rubber.
The sheets are caught between the fingers of a gripper, which are opened and
closed by a cam, and a finger is also provided for pushing off the sheets. Over two
or more (say three) sets of rollers arranged round a portion of the circumference of
the cylinder, and at a suitable distance therefrom, pass respectively bands of india-
rubber covered with chamois leather, which are cleaned by rotating brushes.
The bronze powder is contained in a powder box or sieve having a reciprocating
motion imparted to it by means of cams. The sheets are laid upon a table
G

page_text: provided with a carrier, serving to push the sheets forwards, and to which are
secured projections adjusted according to the length of the sheets; the carrier is
actuated by a cam through the intervention of a connecting rod and suitable levers.
The bands and powder box are covered by a case to prevent waste of bronze, and
the cylinder is contained in a case provided with a drawer, into which the excess of
bronze falls, and where it may be collected. The india-rubber surface of the
cylinder is cleaned by a brush.
On leaving the bands the sheets are guided by a shelf and deposited upon a
table. The supply of bronze powder is regulated by adjustable plates.
The machine may be actuated by hand, or be connected to a printing machine by
a wheel fixed upon the cylinder of the latter, such wheel driving the bronzing
machine by means of an endless chain carried round the shaft of the cylinder of the
bronzing machine in such a manner as to cause the latter to make one revolution
to every revolution of the printing machine.
Assuming that this latter arrangement is adopted, the taker off of the printing
machine receives the sheet printed with the mordant and places it upon the table
in front of the projections before referred to. The sheet is then pushed into the
gripper of the cylinder, which at this movement is open. As the cylinder rotates
the gripper closes, drawing the sheet under the first band, which receives the bronze
from the powder box. At this moment all the parts covered with the mordant are
covered with bronze powder, and it only remains to wipe off the excess of bronze
deposited upon the sheet. This operation is performed by the cylinder continuing
to rotate and carrying the sheet under the other bands.
As soon as the end of the sheet reaches the extremity of the last band the gripper
opens, causing the finger to project and push up the edge of the sheet and direct it
on to the shelf, which guides it until it falls on to the receiving table.
The powder box is composed of a brass frame constructed after the manner of a
sieve with a fine silken fabric, underneath which there are provided the plates
before mentioned, which are arranged side by side, and so as to be capable of
sliding when required in order to adjust the size of the opening for the passage of
the bronze powder contained in the sieve or box, according to the quantity which it
is required to distribute, and the direction in which it should be distributed. The
bronze falling upon the band collects on the soft or velvety surface of the chamois
leather, whence it is deposited as the band is carried round upon the sheet printed
with the mordant. The powder box has a jerking to-and-fro motion imparted to
it by cams, so as to be constantly shaken.
Each band is carried upon two rollers, which guide it in such a manner as only
to exert a very slight pressure upon the sheet of paper, and thus obviate the
liability of rubbing off the mordant. The bands travel in the opposite direction to
that of the motion of the cylinder, so as to rub the sheet gently. Above the bands
there are provided the brushes before referred to, which rotate in the opposite
direction to that of the motion of the bands for the purpose of removing the powder
which collects on their velvety surfaces by their wiping off the excess of bronze
deposited on the sheet.
The object of covering the cylinder with a layer of soft india-rubber is partly to
provide an elastic surface under the sheet, but principally to enable the cylinder to
continue to draw on the sheet when the gripper is open on passing the last band,
notwithstanding that the bands travel in the opposite direction. This result is
obtained owing to the property which india-rubber possesses of resisting the slipping
of the sheet, which the greater the pressure it receives has an increased tendency to
allow the bands which travel in an opposite direction to slip over.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 21st
May 1878.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. 'IMPROVEMENTS IN MACHINERY OR APPARATUS FOR BRONZING,
DUSTING, OR POWDERING." A communication from abroad by Charles Georges
Legrand, of Paris, in the Republic of France, Envelope Manufacturer.
The said Invention relates to machines for bronzing or applying dust or powder
to impressions of every description, and it consists of improvements in the general
construction, arrangement, and combination of the parts of the said machines, also
in the construction of the powder box; further, of an arrangement of bands which
prevent the effacing or rubbing off of the mordant; and lastly, in the application to
the cylinder of the machine of india-rubber, in order to facilitate the drawing for-
ward of the sheets.
And in order that the said Invention may be fully understood, I shall now pro-
ceed more particularly to describe the same, and for that purpose shall refer to the
several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
Figure 1 of the accompanying Drawings represents a longitudinal section of the
bronzing machine having applied thereto the improvements which form the subject
of the said Invention.
Figure 2 is a transverse section of the same taken along the line 1, 2, Figure 1.
Figures 3 and 4 are details drawn to a larger scale, showing the construction of
the powder box; Figure 3 also shews one of the bands, together with an apparatus
employed for attaching by pressure to the cylinder, the sheet of paper bearing the
impression to be bronzed or powdered.
A is the frame of the machine, in which is mounted a cylinder B, by preference
of cast iron, covered with a layer of soft india-rubber C. The edges of the sheets
prepared to receive the dust or powder are caught under a moveable jaw or finger
D, forming a gripper, which is opened and closed by a cam E, and a flange Fis
also provided for pushing off the sheets; H are rollers carrying bands G, G¹,
of india-rubber, covered with chamois leather, and maintained in a state of tension
by means of small rollers h; oue of the journals of each of these tension rollers
works in a bush or collar r, secured to the frame by a screw v, on removing which
the rollers h may be drawn out lengthwise for the purpose of facilitating the
removal of the bands when required. Revolving brushes u are provided for
cleaning the said bands while the machine is in operation.
J is the powder box or sieve (shown in detail in Figures 3 and 4, containing the
bronze powder, which box has a to-and-fro motion imparted to it by means of
cams K, Figure 4. The sheets of paper to be operated upon are deposited on a
table L, and propelled by a carrier M, provided with projections N, capable of being
adjusted to suit the lengths of the sheets; motion is imparted to this carrier by
means of a cam O acting on a connecting rod P and lever arms Q, Q. The bands
and powder box are covered by a casing R to prevent any waste of the brouze
powder in this direction; and a casing S surrounding the lower part of the
cylinder B serves to collect any surplus bronze powder which may fall from the
paper, and direct the same into a drawer T.
A cylinder U is provided for the purpose of pressing the paper before it leaves
the apparatus, in order to fix the bronzing thereon, and fluted rollers V then seize
the paper and draw it from the apparatus, causing it to pass over guides X, whence
it falls upon a table Y.
The supply of bronze powder is regulated by means of a cylinder J', having
a portion of its periphery cut away, and provided at one extremity with a toothed
sector j, which is in gear with a corresponding sector j', the latter being actuated
by means of a lever J2, carrying a pointer J³, by moving which over a graduated

page_text: scale on the outside of the case, the cylinder J can be partially rotated, and the
extent of the opening for the passage of the powder regulated at will. The sieve
m of wire gauze is provided within the box J for the purpose of sifting the bronze
powder before it is deposited upon the impression.
The brushes u before referred to serve to remove any powder that may adhere
to the bands G, and deposit the same in drawers on coming in contact with
blades l.
The machine may be worked by hand, or driven by means of a bevel wheel, by
gearing connected with a printing machine, and it may be mounted on sinall
flanged wheels, as shown at Z, in Figures 1 and 2. In operating with this improved
machine, the sheet bearing the impression to be bronzed, printed in mordant, is
placed upon the table L in front of the projections N, and is then propelled towards
the cylinder B, and its front edge is brought under the movable finger or jaw D of
the gripper, which is held open by a lever x, one end of which bears against the
fixed cam E. As the cylinder rotates, the lever a being no longer supported by the
cam E, the finger or jaw D will nip the edge of the sheet of paper under the action
of a spring, and draw it round with the cylinder. The sheet is then drawn under
the first band G¹ (receiving powder from the powder box J) and becomes covered
with bronze powder on all parts, which are impregnated with mordant.
The excess of bronze powder is removed by the sheet coming in contact with the
three other bands G, G, G, and the sheet is then passed under the roller U, which
performs the function of a press. After passing under this roller, and just before it
arrives opposite the guide X, the lever a comes again in contact with the cam E,
and the finger D is raised so as to release the edge of the paper whilst the finger F,
which is connected to the finger D, is caused to project at the same time from the
recess in the periphery of the cylinder B, in which it slides, and detach the paper
from its surface; the sheet is then seized by the fluted cylinders V which direct it
through the guides X, whence it falls on to the table Y.
The motions of these different parts are obtained by the means herein-after
described. Z is a shaft carrying a fly wheel I, provided with a crank handle I'; for
the convenience of operating it; on this shaft is secured a pinion a in gear with a
wheel b, keyed upon the shaft Z of the cylinder B, whereby rotatory motion is
imparted to the said cylinder.
The wheel b drives a toothed wheel c fast on the shaft Z3, on which is also
secured a wheel d, which is in gear with a wheel e, of double its width, carried on
an axis fixed to the frame of the machine; the wheel e imparts motion to a wheel
f, mounted loose on the shaft Z2 of the cylinder B so as to be capable of turning
freely thereon, and serving to transmit the motion to a series of toothed wheels g
fixed respectively on the axes of the rollers H, carrying the bands G and G¹.
Rotatory motion is imparted to the brushes u which serve to remove the surplus
powder adhering to the bands G by means of toothed wheels i fast upon the axes
of the said brushes, the said wheels being actuated by intermediate wheels / in gear
respectively with one of the wheels g of each pair of rollers H.
The powder box J consists of a copper frame arranged after the manner of a sieve,
with a wire gauze bottom m for this purpose of purifying the bronze powder
collected in the drawers t, consisting of the surplus powder which has been removed
from the surface of the sheet of paper.
The bronze powder falling through the sieve which has a reciprocating motion
imparted to it by the cam K is received upon the cylinder J¹, having a portion of
its periphery cut away as herein-before described so as to form an inclined plane
down which the bronze powder is allowed to slide.
The amount of bronze powder which it is desired to deposit upon the paper is
regulated as required by giving a greater or less degree of inclination to the flat
surface on the cylinder by means of the lever J and sector wheels j and j¹. The
bronze powder falls upon the band G¹, being retained in the soft velvety surface of
the chamois leather, and is subsequently deposited upon the design imprinted in
mordant upon the sheet.

page_text: Each band is carried upon two cylinders H and a tension roller h in such a
manner as to cause it to press very lightly upon the surface of the paper in order
not to rub off the mordant. The bands travel in an opposite direction to that of
the cylinder as indicated by the arrows.
The rotating brushes u before referred to, which respectively work above the
three bands G, and turn in an opposite direction thereto, are provided for the
purpose of removing by friction the surplus bronze powder collected on the surfaces
of the bands G, and depositing the same in the drawers t by contact with the
blades 7.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention secured to me by the berein-before in part
recited Letters Patent is,-
First. The general arrangement and combination of parts forming a machine for
bronzing, dusting, or powdering, substantially as herein-before described.
Second. The construction and arrangement of sifting powder box, substantially
as herein-before described.
Third. The arrangement of bands, substantially as and for the purpose herein-
before described.
Fourth. The application of india-rubber to the cylinder conducting the sheets,
substantially as and for the purpose herein-before described.
In witness whereof, I, the said John Henry Johnson, have to this my
Specification set my hand and seal, this Eighteenth day of April, One
thousand eight hundred and seventy-eight.
TATAYAN
J. HE
HENRY JOHNSON. (L.S.)