AN IMPROVED MODE OF FORMING STRAINERS, AND AN IMPROVED TOOL FOR PREPARING PERFORATED METAL PLATES FOR THE SAME.
Year: 1874

page_text: LETTERS PATENT to Louis Deny, of Paris, in the Republic of France,
for the Invention of "AN IMPROVED MODE OF FORMING STRAINERS, AND
AN IMPROVED TOOL FOR PREPARING PERFORATED METAL PLATES FOR THE
SAME.
""
Sealed the 19th June 1874, and dated the 1st January 1874.
PROVISIONAL SPECIFICATION left by the said Louis Deny at the
Office of the Commissioners of Patents, with his Petition, on the
1st January 1874.
I, LOUIS DENY, of Paris, in the Republic of France, do hereby
declare the nature of the said Invention for "AN IMPROVED MODE OF
FORMING STRAINERS, AND AN IMPROVED TOOL FOR PREPARING PERFORATED METAL
PLATES FOR THE SAME," to be as follows:-
The object of this Invention is to produce in a more economical
manner, and with greater facility than heretofore, a straining or filtering
surface consisting of a number of long narrow slits. The improved
mode of forming such straining or filtering surface is as follows:-Take
a sheet of metal, either copper, zinc, sheet iron, or other suitable metal

page_text: of the desired.thickness, and with a tool having a sharp or chisel-shaped
edge I punch or indent the metal to about the depth of the thickness of
the sheet. This will produce in the metal a V shaped indentation of
any desired length according to the length of the indenting tool, and on
the under side of the metal there will be a corresponding projection.
When the sheet of metal has been indented all over in this manner
the projecting parts on the under side are planed or grooved off so as to
leave a perfectly flat even surface in which will be formed a series of
narrow slits or long perforations, such as are required in various straining
surfaces employed in the arts.
In order to facilitate the manufacture of the improved strainer I have
devised an improved tool for producing the indentations in the metal. This
tool consists of two parts, namely, a countersunk bed plate on which the
metal sheet to be operated upon is placed, and a compound punch or
indenting tool consisting of a number of punches (with V shaped edges)
which are combined and secured in a holder which is capable of being
raised and lowered at pleasure in suitable guides.
When the sheet of metal is placed on the bed plate the compound
punching tool is brought down with considerable force with a number of
blows, which must be repeated until the indentations are produced of
the proper depth in the metal sheet, and the metal on the under side is
driven into the countersunk recesses in the bed plate. From two to
three dozen indentations may be made in this way simultaneously with
ease, so that a large filtering surface may be quickly produced with
great facility by merely afterwards planing off the projecting parts of
the under side as already explained.
If it be desired to produce cylindrical filtering or straining surfaces,
the sheet of metal, after being perforated in the manner above explained,
must be bent round into the form of a cylinder and soldered or brazed
at its edges.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Louis Deny in the Great Seal Patent Office on
the 1st July 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, LOUIS
DENY, of Paris, in the Republic of France, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of January, in the year of our Lord.
One thousand eight hundred and seventy-four, in the thirty-seventh
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Louis Deny, Her special licence that I, the
said Louis Deny, my executors, administrators, and assigns, or such
others as I, the said Louis Deny, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should
and lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "AN IMPROVED MODE OF FORMING STRAINERS, AND AN
IMPROVED TOOL FOR PREPARING PERFORATED METAL PLATES FOR THE SAME,"
upon the condition (amongst others) that I, the said Louis Deny, my
executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
"
NOW KNOW YE, that I, the said Louis Deny, do hereby declare,
the nature of my said Invention, and in what manner the same is to.
be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawing hereunto
annexed and to the letters and figures marked thereon (that is to
say) :-
1
.
The object of this Invention is to produce in a more economical
manner, and with greater facility than heretofore, a straining or filtering
surface consisting of a number of long narrow slits. The improved mode
of forming such straining or filtering surfaces is as follows:-Take a
sheet of metal, either copper, zinc, sheet iron, or other suitable metal of

page_text: the desired thickness, and with a tool having a sharp or chisel-shaped
edge I punch or indent the metal to about the depth of the thickness of
the sheet. This will produce in the metal a V shaped indentation of any
desired length, according to the length of the indenting tool, and on the
under side of the metal there will be a corresponding projection.
When the sheet of metal has been indented all over in this manner
the projecting parts on the under side are planed or ground off so as to
leave a perfectly flat even surface, in which will be found a series of
narrow slits or long perforations, such as are required in various strain-
ing surfaces employed in the arts.
In order to facilitate the manufacture of the improved strainer I have
devised an improved tool or apparatus for producing the indentations in
the metal and in the accompanying Drawings I have shown various
views of the same. This tool consists of two parts, namely, a counter-
sunk bed plate on which the metal sheet to be operated upon is placed,
and a compound punch or indenting tool consisting of a number of
punches (with V shaped edges) which are combined and secured in a
holder which is capable of being raised and lowered at pleasure in
suitable guides.
'
When the sheet of metal is placed on the bed plate the compound
punching tool is brought down with considerable force with a number of
blows which must be repeated until the indentations are produced of the
proper depth in the metal sheet and the metal on the under side is driven
into the countersunk recesses in the bed plate. From two to three
dozen indentations may be made in this way simultaneously with ease,
so that a large filtering surface may be quickly produced with great
facility by merely afterwards planing off the projecting parts of the
under side as already explained.
If it be desired to produce cylindrical filtering or straining surfaces
the sheet of metal after being perforated in the manner above explained
must be bent round into the form of a cylinder and soldered or brazed at
its edges.
In the accompanying Drawing Fig. 1 is a longitudinal vertical section
of the stamp or punch carrier showing a number of punches secured
therein; Fig. 2 is a similar view of the matrix or bed plate upon which
the sheet of metal to be operated upon is placed; Fig. 3 is a plan view of

page_text: the same; Fig. 4 is a transverse vertical section of the punch holder
taken in the line 1, 2, of Fig. 1; Fig. 5 is a transverse vertical section
of a metal plate after it has been subjected to the punching operation;
Fig. 6 is a similar view of the plate after its under side has been planed
down level; Fig. 7 is a plan or top view of part of the finished plate;
Fig. 8 is a longitudinal section of the punched metal plate taken through
a view of the indentations made by the punches; and Fig. 9 is a similar
view of the plate after it has been finished by planing off the projecting
parts from the under side. In all these Figures, which are drawn full
size, similar letters of reference indicate the same parts. A is a kind of
box made of steel and provided at its upper side with a rod B, whereby
it is secured to the end of the operating lever, whereby it is moved up
and down. The box A. is hollowed out at its under side, and in this
recess are placed the punches C, C, the upper ends of which bear against
a steel plate D. They are so arranged as not to be capable of shifting
or moving in the box, and in order to secure them more perfectly therein
they are tightly pressed by a steel plate E, against which acts a screw e,
which is prevented by means of a tightening uut e' from coming
unscrewed. Should any of the punches become broken the tightening
nut e¹ is loosened, and then the screw e may be unscrewed and the plate
E loosened, so that the defective punch may be withdrawn with facility
and a fresh one of the same size introduced in its place. Any other
convenient and suitable mode of securing the punches in the box A may
be employed. As the object to be attained by the use of this tool is to
produce in a sheet or plate of metal a number of slits or grooves of a V
form, and about one-tenth of a millimetre in width, by a considerably
greater length, the working edge of the punch will be formed of an'
angle, the two sides of which will be inclined so as to obtain the greatest
width of groove that may be required. The required length of the slits
will determine the width of the punches. On the under side of the box
A there are holes F, F, into which enter the guide pins K, K, for the
purpose of ensuring the accurate working of the punches. G, G, is the
bed block or die, in the face of which the cavities g, 9, 9, are made to
receive those parts of the metal plate which are forced up by the
punches. H, H, are steadying pins on which the metal plate to be
operated upon is placed, two holes having been made therein for the
purpose. The operation of the several parts is as follows:-The sheet of
metal to be operated upon must be rolled to an even thickness through-
out, the edges must be made smooth and straight, and the holes

page_text: h, h1, h2, h3, and 4, Fig. 7, to receive the steadying pins H, H, Fig. 1,
must be made near each side of the sheet opposite to the middle of each
line of slits or perforations. The sheet of metal being thus prepared it
is placed on the matrix or die, the steadying pins H when passed
through the holes h, h, in the sheet serving to hold it in place and
prevent it from shifting. The stamp A is then brought down with a
smart blow, and the punches C, C, will force down the metal into the
cavities g, g, in the bed plate or die, and will produce on the upper face
of the metal plate a row of grooves or recesses of a V form, as shewn at
Figures 5 and 8. If one blow be not sufficient the operation must be
repeated until the grooves are of the proper depth. The metal plate is
then moved forward and the holes h¹, h, Fig. 7, placed over the steady-
ing pins H, when a second row of grooves or recesses may be made by
bringing down the punches with sufficient force on the fresh part of the
sheet. These operations are to be repeated until the entire sheet has
been completed with the proper number of rows of grooves. The sheet
of metal is then placed face downwards on the table of a planing
machine, and all the projecting parts which were driven into the
recesses of the matrix are planed off or otherwise removed. As the
working or operating part of the punches has been carefully adjusted to
the thickness of the metal the planing operation will open the slits to
the required width, and will produce a plate such as that shewn at
Figures 6, 7, and 9.
If the metal sheet thus completed is to remain flat nothing further is
required to be done, but if it is desired to be converted into a cylindrical
straining surface the sheet must be turned up into the form of a cylinder,
and the two ends must then be brazed or soldered together, then the
slits may be made therein by turning off the projecting parts in a lathe,
in which it may be mounted on a divided chuck.
The filtering or straining surfaces thus produced are employed either
in the form of sheets or cylindrical or curved surfaces, according to the
purposes to which they may be applied. They may be advantageously
employed in place of the ordinary gauze or metallic filtering surfaces
used in filtering beetroot syrup or straining the pulp from the juice, or
for straining paper pulp, or for use in breweries, and for other analogous
purposes. The improved filtering surface may also be employed as the
filtering surfaces of centrifugal turbines. Its thickness is such that it
may be employed in place of the perforated sheet iron of which the

page_text: cylinder is formed, or for the thin perforated sheet as well as instead of
the different gauzes heretofore used as filtering surfaces. It may also be
used to form the end of the cylinders of these same turbines and make
them answer as filtering or straining medea, or for drying fabrics. It
will be obvious that instead of long narrow slits the sheet of metal may
be perforated with round holes at the bottom of conical recesses.
Having now described the improved mode of forming strainers and
the improved tool for preparing perforated metal plates for the same, and
having explained the manner of carrying the same into effect as com-
municated to me by my foreign correspondent, I would observe that
what I claim as the Invention secured to me by Letters Patent as
aforesaid is, forming metal straining or filtering surfaces by making
depressions or indentations in the face of the sheet of metal by means of
punches, and then planing, grinding, cutting off, or otherwise removing
the metal that has been forced up on the opposite side, so that by
removing such forced up or extraneous metal narrow slits or perforations
may be produced in the sheet of metal as herein set forth. I also claim
the construction and arrangement of the tool or apparatus herein shewn
and described or any mere modification thereof for punching or forming
the recesses or grooves in the metal sheets.
In witness whereof, I, the said Louis Deny, have hereunto set
my hand and seal, the First day of July in the year of our Lord
One thousand eight hundred and seventy-four.