Improvements in Embossing Sheet Metal and other Materials and in Means or Apparatus employed therein.
Year: 1892

page_text: Date of Application, 16th Nov., 1892
Complete Specification Left, 16th Sept., 1893-Accepted, 11th Nov., 1893°
PROVISIONAL SPECIFICATION
Improvements in Embossing Sheet Metal and other Materials and in
Means or Apparatus employed therein.
We ROOKES EVELYN BELL CROMPTON Engineer, of Mansion House
Buildings in the City of London, and RICHARD CHARLES of 3 Dorea Road
Fulham in the County of Middlesex, and WILLIAM CLARKE FISHER of
3 Horbury Crescent in the County of Middlesex do hereby declare the nature of
this invention to be as follows:-
Our invention relates to certain improvements in and connected with the manu-
facture of rollers intended for embossing various materials such as sheet metals,
paper, millboard, asbestos sheet, leather and the like and relate more particularly
to further improvements in connection with the invention described in the Speci-
fication of Letters Patent granted to Richard Charles No. 14826 bearing date the
20th of September 1889. In that Specification certain improved methods of
preparing models to facilitate the manufacture of such rollers is described.
Our present improvements consist in substituting for the stencil, sheet of lead
and handwork thereon described as necessary for the production of the model, a
model design prepared on the flat in either clay or plaster cast from a design
modelled in clay or a wood carving or a design worked by hand in sheet lead or
other soft material. From this flat design we take a cast in an elastic material
such as that which is commonly used by printers to cover the surface of their
printing rollers. This elastic cast in then bent round and secured to a plain
supporting roller made of wood or other suitable material and a cast of the roller
thus covered is then taken in plaster or other suitable material the said cast can be
in one piece or can be separated into three or more parts according to the nature
of the relief of the required design the arrangement and dividing up for removal
of the plaster cast being such as is well understood by those accustomed to make
plaster casts so that after removal of the plaster cast from the elastic covered
roller the moulded surface of the plaster cast can be coated with blacklead or
suitable metallic facing and can again be, when necessary, fastened accurately
together so as to form a hollow cylinder on which by electro processes an electro
type roller can be deposited. Our improvements. are more particularly applicable
to the production of rollers intended to emboss materials in high relief. In such
cases when a design modelled in high relief is transferred from a flat surface to a
curved or roller surface in such a manner that the said roller shall when used for
embossing the desired materials reproduce exactly the original flat design it is
necessary to somewhat distort the original flat design when applying it to the
surface of the cylinder. Such distortion however cannot be easily calculated and
allowed for and is one of the causes why the preparation of embossing rollers for
high relief is extremely expensive and difficult. In our improvement however the
mere act of: bending the elastic cast from its flat form to the cylindrical form of
itself produces a sufficiently approximate distortion in the pattern as is required to
produce a satisfactory result. It is evident that for certain purposes rollers can
be produced by casting from the plaster models obtained as above but for the most
partiwe prefer to use electro depositing to produce the embossing rollers of the
desired fineness of finish. In some cases we can obtain the desired result of
increasing the hardness and hence the durability of the working surface of the
embossing rollers by making our electro deposit, take the form of successive layers
of metal the first layer of which forms the exterior surface and is harder and better
calculated to resist such wear than the tougher and more rigid layers which can be

page_text: subsequently deposited to provide the necessary rigidity and strength. As for
instance the first layer may be of a different metal to the succeeding layers we can
also form our electro roller entirely of copper and insure that the layer first
deposited is harder than succeeding layers by commencing at a slow rate of deposit
and using a low density of electric current. We can subsequently without changing
the bath increase the rate of deposit and the toughness of the copper by increasing
the density of the current and hence the rate of deposit. We can also ensure
that the first layer will be harder than the succeeding layers by placing the roller
first in a special depositing bath containing in addition to the usual solution a minute
quantity of gelatine or other matters which have the effect of so hardening the
deposit. We can then remove it and continue the deposit in a second bath in the
ordinary way so as to obtain the best results by depositing tough copper.
The electro rollers thus prepared may be mounted in any of the manners described
in the above mentioned Patent by being packed or filled in with type metal or other
suitable metals and then being mounted on a mandril made of cast iron, steel, or
other suitable material.
We use such rollers for embossing fibrous or semi fibrous sheets or millboards or
leather or other sufficiently soft materials as can be easily pressed into the design
on the roller either by a soft cylinder revolving in contact with the back of the
material to be embossed or by applying to the back of the material a sufficiently
thick sheet of soft or elastic material the required pressure being applied to the
back of this soft sheet by a hard roller; but in some cases when we desire to emboss
harder materials including sheet metals we find it necessary to provide embossing
rollers in pairs which may be called male and female rollers the relief parts in one
corresponding with the recessed parts in the counterpart roller. In order to readily
obtain such pairs of rollers we can prepare one of these rollers in the manner
already described but in order to prepare the counterpart we apply to the surface
of the original flat modelled design already described a sheet of soft metal such as
lead or of other material of a similar plastic and easily moulded nature and which
we call a filling sheet. We press and mould by hand or by tools this filling sheet
so as to make it lie in close contact with the entire modelled surface of our flat
modelled design.
This filling sheet must be of a thickness to correspond exactly with the finished
thickness of the material intended to be embossed by these rollers. From this new
surface thus obtained a first plaster cast must be made which will be the reverse of
the flat design and from the plaster cast we continue the process of first making a
gelatine cast and then applying it to the surface of a roller and eventually preparing
therefrom a second plaster cast and electro roller or a casting exactly as herein-
before described. It will be readily understood that the addition of the filling
sheet above described insures that the embossed surfaces of the two rollers when
placed and geared so as to revolve together and emboss the desired material will
maintain exactly that parallelism and distance apart of the two embossed surfaces
which is necessary to obtain clean and sharp results and without the danger of
cutting into the surface of the materials and distorting or damaging it.
Dated the 16th day of November 1892.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Embossing Sheet Metal and other Materials and in
Means or Apparatus employed therein.
We ROOKES EVELYN BELL Crompton, Engineer of Mansion House Buildings
in the City of London, and RICHARD CHARLES of Hanwell in the County of
Middlesex, Fireman at Hanwell Lunatic Asylum, Sole Administrator of Richard
Charles deceased late of 3 Dorea Road, Fulham in the County of Middlesex, and
€

page_text: :
WILLIAM CLARKE FISHER of 3 Horbury Crescent in the County of Middlesex
do hereby declare the nature of this invention and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement :-
Our invention relates to certain improvements in and connected with the
manufacture of rollers intended for embossing various materials such as sheet
metals, paper, millboard, asbestos sheet, leather and the .like and relate more
particularly to further improvements in connection with the invention described in
the Specification of Letters Patent granted to Richard Charles No. 14826 bearing
date the 20th of September 1889.
In that Specification certain improved methods of preparing models to facilitate
the manufacture of such rollers is described.
Our present improvements consist in substituting for the stencil sheet of lead and
handiwork thereon described as necessary for the production of the model, a model
design prepared on the flat in either clay, or plaster cast from a design modelled in
clay or a wood carving or a design worked by hand in sheet lead or other soft
material; and from this model, preparing an elastic cast which is then employed in
the manner and for the purpose herein after fully set forth in the manufacture of
rollers for embossing.
In order that the invention may be the better understood we have illustrated by
the accompanying figures the means employed in carrying out the invention in the
manner hereinafter described.
DESCRIPTION OF THE DRAWINGS.
Figure 1 indicates a diagrammatic section shewing a the elastic material and
b the model on the flat.
Figure 2 shews by a like view a roller c on to which the sheet of elastic material a
is being wound and separated from the model b.
0
Figure 3 shews by a perspective view the appearance of such a sheet a when
rolled around the roller o and with the meeting edges on the line a' fitted, and now
forming a complete roller with elastic composition in position ready for taking
plaster piece mould.
Fig. 4 shews a like view to that shewn in the last figure, of a piece mould taken
of the surface of the elastic composition as shewn wound on the roller c in Fig. 3,
here shewn as having 4 divisions or pieces 1, 2, 3, 4.
Figure 5 shews a modification for use when as hereafter explained a pair of male
and female rollers is required to be produced. b being the model on flat. d plaster
impression and ea "filling sheet."
Figure 6 shews an elastic mould f being taken from the plaster impression as d,
to form the counterpart roll.
The subsequent operations of rolling up, mounting correctly and moulding from
the roll, will in the case of Fig. 6 be merely a repetition of the operations indicated
by Figures 2, 3 and 4 for the manufacture of the primary roll.
From this flat design 6 shewn in Fig. 1, we take a cast in an elastic material a,
we use for this elastic material a thick sheet of gelatine or a combination of
gelatine with other materials such as is used by printers for their inking rollers.
But other materials not quite so elastic but sufficiently soft and pliable for this
purpose can be used.
This elastic cast is then bent round and secured to a plain supporting roller made
of wood or other suitable material see Fig. 2.
Care must be taken to insure that the abutting ends of the gelatine sheet fit
neatly together, and that they are secured in such a manner, that undue or
noticeable distortion of the pattern at this point is avoided.
One method of doing this is to back or support the gelatine sheet at these
points where it most needs such support during the act of bending by a backing
of canvas or similar material and a cast of the roller, thus covered is then taken in

page_text: plaster or other suitable material the said cast can be in one piece or can be separated
into three or more parts see. Fig. 4 according to the nature of the relief of the
required design tlie arrangement and dividing up for removal of the plaster cast
being such as is well understood by those accustomed to make plaster casts so that
after removal of the plaster cast from the elastic covered roller the moulded
surface of the plaster cast can be coated with blacklead or suitable metallic facing
and can again be, when necessary, fastened accurately together so as to form a
hollow cylinder on which by electro processes an electro type roller can be deposited.
Our improvements are more particularly applicable to the production of rollers
intended to emboss materials in high relief. In such cases when a design modelled
in high relief is transferred from a flat surface to a curved or roller surface in
such a manner that the said roller shall when used for embossing the desired
materials reproduce the original flat design with sufficient exactness for decorative
purposes it is necessary to somewhat distort the original flat design when applying
it to the surface of the cylinder. Such distortion however cannot be easily
calculated and allowed for and is one of the causes why the preparation of
embossing rollers for high relief is extremely expensive and difficult.
In our
improvement however the mere act of bending the elastic cast from its flat form
to the cylindrical form of itself produces a sufficiently approximate distortion in
the pattern as is required to produce a satisfactory result. It is evident that for
certain purposes rollers can be produced by casting from the plaster models
obtained as above but for the most part we prefer to use electro depositing to
produce the embossing rollers of the desired fineness of finish. In some cases we
can obtain the desired result of increasing the hardness, and hence the durability
of the working surface of the embossing rollers by making our electro deposit take
the form of successive layers of metal the first layer of which forms the exterior
surface and is harder and better calculated to resist such wear than the tougher and
more rigid layers which can be subsequently deposited to provide the necessary
rigidity and strength. As for instance the first layer may be of a different metal
'to the succeeding layers we can also form our electro roller entirely of copper and
insure that the layer first deposited is harder than succeeding layers by commencing
at a slow rate of deposit and using a low density of electric current.
We can
subsequently without changing the bath increase the rate of deposit and thus
increase the toughness of the copper by increasing the density of the current and
hence the rate of deposit. We can also ensure that the first layer will be harder
than the succeeding layers by placing the rollers first in a special depositing bath
'containing in addition to the usual solution a minute quantity of gelatine or other
matters which have the effect of so hardening the deposit. We can then remove
it and continue the deposit in a second bath in the ordinary way so as to obtain the
best results by depositing tough copper..
The electro rollers thus prepared may be mounted in any of the manners described
in the above mentioned Patent by being packed or filled in with type metal or other
suitable metals and then being mounted on a mandril made of cast iron, steel, or
other suitable material. We use such rollers for embossing fibrous or semi-fibrous
sheets or millboards or leather or other sufficiently soft materials as can be easily
pressed into the design on the roller either by a soft cylinder revolving in contact
with the back of the material to be embossed or by applying to the back of the
material a sufficiently thick sheet of soft or elastic material the required pressure
being applied to the back of this soft sheet by a hard roller; but in some cases
when we desire to emboss harder materials including sheet metals we find it
necessary to provide embossing rollers in pairs which may be called male and
female rollers the relief parts in one the male-corresponding with the recessed
parts in the counterpart or female roller. In order to readily obtain such pairs of
rollers we can prepare one of the pair of rollers in the manner already described
but in order to prepare the counterpart we apply to the surface of the original flat
modelled design already described a sheet of soft metal such as lead or of other
material of a similar plastic and easily moulded nature and which we call a filling

page_text: sheet see Fig. 5. We press and mould by hand or by tools this filling sheet so as
to make it lie in close contact with the entire modelled surface of our flat modelled
design.
This filling sheet must be of a thickness to correspond exactly with the finished
thickness of the material intended to be embossed by these rollers. From the new
surface thus obtained on the reverse side of this filling sheet a first plaster cast
must be made which will be the reverse of the flat design and from the plaster cast
we continue the process of first making a gelatine cast see Fig. 6. and then applying
it to the surface of a roller and eventually preparing therefrom a second plaster
cast and electro roller or a casting exactly as herein before described. It will be
readily understood that the addition of the filling sheet above described insures
that the embossed surfaces of the two rollers when placed and geared so as to
revolve together and emboss the desired material will maintain exactly that
parallelism and distance apart of the two embossed surfaces which is necessary to
obtain clean and sharp results and without the danger of cutting into the surface
of the materials and distorting or damaging it.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
:-
1. The use of the herein described elastic cast as a means of transfering embossed
patterns from flat to curved surfaces or vice versa, substantially as herein before
described.
2. The manufacture or production of embossing rollers by the succession of
operations herein described of preparing a flat model, transferring by an elastic
cast to a cylindrical roller, taking a plaster cast therefrom and casting or electro
depositing the working roller in the mould thus obtained as and for the purpose set
forth.
3. The production of embossing rollers in pairs by the use of the filling sheet in
combination with the processes described in Claim 2. substantially as hereinbefore
set forth.
1
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicants.