AN IMPROVED MACHINE FOR CUTTING, DIVIDING, AND TURNING STRAIGHT AND CONICAL COGS OF WOOD OR OF METAL WITHOUT DISPLACING THE COG WHEEL
Year: 1869

page_text: LETTERS PATENT to Jean Denis, of No. 78, Rue St. Louis en l'Ilc,
and No. 37, Boulevard Bonne-Nouvelle, Paris, in the Empire of
France, Mechanic, for the Invention of "AN IMPROVED MACHINE FOR
CUTTING, DIVIDING, AND TURNING STRAIGHT AND CONICAL COGS OF WOOD OR
OF METAL WITHOUT DISPLACING THE COG WHEEL."
Sealed the 2nd October 1869, and dated the 9th April 1869.
PROVISIONAL SPECIFICATION left by the said Jean Denis at the
Office of the Commissioners of Patents, with his Petition, on the
9th April 1869.
I, JEAN DENIS, of No. 78, Rue St. Louis en l'Ile, and No. 37, Boule-
vard Bonne-Nouvelle, Paris, in the Empire of France, Mechanic, do
hereby declare the nature of the said Invention for "AN IMPROVED MACHINE
FOR CUTTING, DIVIDING, AND TURNING STRAIGHT AND CONICAL COGS OF WOOD OR OF
METAL WITHOUT DISPLACING THE COG WHEEL," to be as follows:-
This Invention may be applied to all kinds of lathes without changing
the system, all that is necessary being to make the face plate dividing
at its upper part, and to fit it with a moveable index to indicate the

page_text: required division. The cog wheel to be divided being turned without
displacing it from above the lathe it is fixed to the face plate so that
it follows all the movements of this latter. The tool which has served
to turn the toothing is then removed from the slide, the tool holder A,
shown separately Sheet II. of the accompanying Drawings (cutting
machine), substituted in a vertical position, and the tool B (shown
separately Sheet III.), which exactly forms the space intended to be left
between the cogs placed in the mortice of the vertical shaft of the
cutting machine, the index being in the desired division. The band is
passed over the pulley to give motion to the shaft which should make
two thousand eight hundred to three thousand revolutions a minute.
The tool B is advanced so as to make the tooth at a single traverse.
Being on the required division the tool is made to pravel parallel to the
toothing by means of the slide crank; the traverse being made the face
plate is turned and the cog wheel to be out being fixed to the face plate)
until the desired point is facing the index, and the tool B is brought
back, making its traverse quite as easily as in advancing. In many
cases to shorten the work the slide screw may be removed and the tool
run by hand. This kind of machine is not limited to diameter, and the
less so because the tool holder and the directing pulleys advance and
retire according to the diameter to be executed. A cog wheel of two
inches may be executed with the same facility as one of 10 yards.
To cut on the spot in any kind of factory the divider is made on the
crown of the cog wheel to be cut either right or left, so that it may be
visible and pointed with care. This division made (which serves for as
many teeth as may require to be renewed) a slide is pushed parallelly
to the toothing as for turning it, and in the axis of the cog wheel (its
height is therefore of little consequence) an index is placed on the
division. As it mostly happens that this cog wheel cannot be set in
motion to give it its teeth, the tool B is replaced by a tool wider than
the tooth and only cutting with its end. The machine is set in motion
and all the teeth are cut to length as if they were turned, and all the
teeth having undergone this operation the tool B is put in the place
prepared for forming the exact space between the teeth, and the teeth
are made as above set forth. To turn or shape the side of the cogs it is
only necessary to place the machine or tool holder flat or horizontal,
substituting in lieu of the tool B a tool cutting only on the side. The
tool being in motion the cog wheel is turned by hand one revolution

page_text: until one side is trimmed. To operate on the other side all that is
required is to pass the tool to the other face and to give another turn
to the cog wheel, which is then completely finished.
To make conical cogs the slide must be pushed so that the axis of the
mortice of the tool holder A is in the axis of the tooth to be cut, and
in that of the cone; the tool C (Sheet III.) cutting only in the axis,
and from to of an inch below the line of contact, and forming the
desired rounding of the tooth, another index being on the division, all
the cogs are made on one side. To execute the other side it is only
requisite to shift the tool upside down turning in the reverse direction
and to make this traverse to all the teeth on the inside. This operation
terminated the slide is set parallelly to the crown, that is to say, at the
bottom of the tooth and with the tool D (Sheet III.), the smooth part
of the teeth is finished first on one side and then on the other by
turning the tool upside down; the cog wheel is then completely finished.
The machine is composed of a tool holder A (Sheet II.), a steel shaft
with a 2-inch (55) rim pulley, two trestle heads one with two 5-inch
(120) rim pulleys on the same axle fixed by two bolts on the head of
the machine at the same height as the two-inch pulley below for the
under motion, and above for the top motion. The second head is
invariably held by the same two bolts, on this head are fixed two semi-
circular supports with round rods to receive the rim pulleys, each
secured at pleasure by two bolts and to be driven from the side or from
right or left. The two heads permit the machine to be driven from
all parts. The hand motor is moveable and may be shifted where
desired.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Jean Denis in the Great Seal Patent Office on
the 6th October 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JEAN
DENIS, of No. 78, Rue St. Louis en l'Ile, and No. 37, Boulevard Bonne-
Nouvelle, Paris, in the Empire of France, Mechanic, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of April, in the year
of our Lord One thousand eight hundred and sixty-nine, in the

page_text: thirty-second year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Jean Denis, Her special
licence that I, the said Jean Denis, my executors, administrators, and
assigns, or such others as I, the said Jean Denis, 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 MACHINE FOR
CUTTING, DIVIDING, AND TURNING STRAIGHT AND CONICAL COGS OF WOOD OR OF
METAL WITHOUT DISPLACING THE COе WHEEL," upon the condition (amongst
others) that I, the said Jean Denis, 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 Jean Denis, 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 accompanying Sheet of
Drawing, and to the figures and letters of reference placed thereon:-
This improved machine fits on to all kinds of lathes without
changing their system, all that is necessary being to make the face plate
of the lathe dividing at its upper part, and to fit it with a moveable
index to indicate the required division. The cog wheel to be divided
being turned without displacing it from above the lathe, it is fixed to the
face plate so that it follows all the movements of this latter. The tool
which has served to turn the toothing is then removed from the slide, the
tool-holder A (cutting machine) substituted in a vertical position with
the tool B, which exactly forms the space intended to be left between the
cogs placed in the mortice of the vertical shaft of the cutting machine.
The index being on the desired division the band is passed over the shaft
pulley to give motion to the shaft, which should make from two thou-
sand eight hundred to three thousand revolutions a minute. The tool B
is advanced so as to make the tooth at a single pass or traverse. Being
on the required division the tool is made to travel parallelly to the

page_text: toothing by means of the slide crank; directly the pass is made
the face plate is turned (as also the cog wheel to be cut, it being
fixed to the face plate,) until the desired point is facing the index,
and the tool B is brought back, making its pass quite as easily as
in advancing. In many cases to shorten the work the slide screw may
be removed and the tool run by hand. This kind of machine is not
limited to any diameter, inasmuch that the tool holder and the directing
pulleys advance and retire according to the diameter to be executed. A
cog wheel of two inches may be executed with the same facility as one
of ten yards or more.
To cut on the spot in any kind of factory the division is made on the
actual crown of the cog wheel to be cut either right or left, so that it be
visible and pointed with care. This division made (and it serves for as
many teeth as may require to be renewed) a slide is set parallelly to
the toothing as for turning it, and in the axis of the cog wheel (its
height is therefore of little consequence) and an index is placed on the
division. As it mostly happens that this cog wheel cannot be set in
motion to give it its teeth the tool B is replaced by a tool wider than
the tooth, and only cutting with its end. The machine is set in motion
and all the teeth are cut to length as if they were turned. All the
teeth having undergone this operation the tool B is put in its place
ready to form the exact space between the teeth, and the teeth are made
as above set forth. To turn or shape the side of the cogs it is only
necessary to place the machine or tool holder flat or horizontal, substi-
tuting in lieu of the tool B a tool cutting only on the side. The tool
being in motion the cog wheel is turned by hand one revolution, when
one side will have been trimmed; to operate on the other side all that
is required is to pass the tool to the other face, and to give another turn
to the cog wheel, which is then completely finished.
To make conical cogs the slide must be set so that the axis of the
mortice of the tool holder A is in the axis of the tooth to be cut, and in
that of the cone; the tool C cutting only in the axis and from 1 to
of an inch below the line of contact, and forming the desired rounding of
the tooth, the index being on the division, all the cogs are then made
on one side. To execute the other side it is only requisite to turn the
tool upside down, make it turn in the reverse direction, and to pass over
all the teeth as for the preceding. This operation terminated, the slide
is set parallelly to the crown, that is to say, at the bottom of the tooth

page_text: and with the tool D, the smooth part of the teeth is finished first on one
side and then on the other, also by turning the tool upside down; the
cog wheel is then completely finished.
The machine is composed as follows:-Of a tool holder A, a steel shaft
with a 2-inch (55/m) rim pulley, two shifting supports or head pieces
("têtes de cheval) E, one with two 3-inch (120m/m) rim pulleys on the
same axle, fixed by two bolts on the head of the machine at the same
height as the two-inch pulley below for the under motion, and above for
the top motion. The second head piece ("tête de cheval) F is invariably
held by the same two bolts. On this head are fixed two semicircular
supports with round rods to receive the 3-inch rim pulleys, each secured
at pleasure by two bolts, and to be driven from the side or from right or
left. The two head pieces permit the machine to be driven from all
sides. The hand motor with its driving band is moveable, and may be
shifted wherever desired.

page_text: The distinctive characteristic of my Invention consists in the fact that
with my machine every kind of toothed gearing may be made on the
spot in the most restricted space; in other words my machine is easily
carried wherever it is desired to make toothed gearing on the spot,
without it being necessary to remove the cogs or toothed wheels from
their axle.
As an economiser of labour my machine offers the following
advantages:-A cog or toothed wheel made on the spot by the processes
now in use and by the most skilful workmen, and exacting twenty-five
hours work, will be executed by my machine in three hours, and the
work will be better executed than by hand.
In witness whereof, I, the said Jean Denis, have hereunto set my
hand and scal, this Second day of October, in the year of our
Lord One thousand eight hundred and sixty-nine.