AN UNIVERSAL MACHINE FOR MANUFACTURING CIRCULAR CUTTERS AND MILLING TOOLS OF ANY FORM OR OUTLINE WITH EITHER A RECTANGULAR OR A HELICOIDAL
Year: 1867

page_text: LETTERS PATENT to Paul François Tranchat, Engineer, of 13, Rue
Gaillon, Paris, in the Empire of France, for the Invention of "AN
UNIVERSAL MACHINE FOR MANUFACTURING CIRCULAR CUTTERS AND MILLING
TOOLS OF ANY FORM OR OUTLINE WITH EITHER A RECTANGULAR OR A HELICOIDAL
Sealed the 23rd June 1868, and dated the 24th December 1867.
PROVISIONAL SPECIFICATION left by the said Paul François Tranchat
at the Office of the Commissioners of Patents, with his Petition, on the
24th December 1867.
I, PAUL FRANÇOIS TRANCHAT, Engineer, of 13, Rue Gaillon, Paris, in the
Empire of France, do hereby declare the nature of the said Invention for
"AN UNIVERSAL MACHINE FOR MANUFACTURING CIRCULAR CUTTERS AND MILLING
TOOLS OF ANY FORM OR OUTLINE WITH EITHER A RECTANGULAR OR A HELICOIDAL
DIRECTION OF CUT," to be as follows:-
This machine is composed of two parts, one of which is for the circular
cutter or milling tool to be cut, and the other for the tool which makes or
cuts the cutter.
}
In the first part the cutter to be made is fixed on a spindle, the rotation of
which can be divided into any number of parts, and which remains stationary'

page_text: for straight cutting, whilst it receives a slight rotary motion for helicoidal or
curvilinear cutting; this spindle is fitted on a diso capable of turning in
order to present either the side or the end to the working cutter, which
disc is fitted to two cross slides capable of moving at right angles with one
another.
In the second part I adapt the rotating tool which cuts the cutter on two
cross slides working at right angles one with the other; for straight work I
make use of one or the other of these slides according to whether the cutter
has to be cut on its edge or its end face, and for helicoidal, curvilinear, or
irregular outline cutting I give motion to these two slides by means of one or
more cams, the shapes of which are calculated to impart to the working
cutter such a compound motion as will coincide exactly with the outline of
the cutter to be cut.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Paul François Tranchat in the Great Seal Patent Office on the
24th June 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PAUL
FRANÇOIS TRANCHAT, Engineer, of 13, Rue Gaillon, Paris, in the Empire of
France, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of December, in the year of our
Lord One thousand eight hundred and sixty-seven, in the thirty-first year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Paul François Tranchat, Her special licence that I, the said
Paul François Tranchat, my executors, administrators, and assigns, or such
others as I, the said Paul François Tranchat, 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 UNIVERSAL MACHINE FOR MANUFACTURING CIRCULAR CUTTERS AND MILLING
TOOLS OF ANY FORM OR OUTLINE WITH EITHER A RECTANGULAR OR A HELICOIDAL
DIRECTION OF CUT," upon the condition (amongst others) that I, the said Paul
François Tranchat, 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

page_text: 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 Paul François Tranchat, 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 thereof, reference being had to the accompanying Sheet
of Drawings (that is to say):-
This machine is composed of two parts, one of which is for the circular
cutter or milling tool to be cut, and the other for the tool which makes or
cuts the cutter.
In the first part the cutter to be made is fixed on a spindle, the rotation of
which can be divided into any number of parts and which remains stationary
for straight cutting, whilst it receives a slight rotary motion for helicoidal
or curvilinear cutting; the spindle is fitted on a disc capable of turning,
in order to present either the side the end to the working cutter, which
disc is fitted to two cross slides capie of moving at right angles to one
another.
In the second part I adapt the rotating tool which cuts the cutter on two
cross slides working at right angles one with the other; for straight work I
make use of one or the other of these slides according to whether the cutter
has to be cut on its edge or its end face, and for helicoidal, or curvilinear, or
irregular outline cutting I give motion to these two slides by means of one or
more cams, the shapes of which are calculated to impart to the working
cutters such a compound motion as will coincide exactly with the outline of
the cutter to be cut.
In order that my Invention may be more fully understood I will proceed to
explain it conjointly with the four Figures of the accompanying Sheet of
Drawings, in which Fig. 1 is a plan of the machine complete; Fig. 2, a front
elevation; Fig. 3, a lateral elevation in section through A, B, Fig: 2, shewing the
left or passive part of the machine, viz., that which contains the blank or cutter
to be operated on or cut, and Fig. 4 the same section shewing the right or
active part of the machine, viz., that which cuts the cutter.
"
My machine is composed of a bed or table a supported on legs b, b, and
carrying the two main or constitutive parts, which I'will describe separately,
commencing with the stationary or passive' part; this machinery consists of a
borizontal spindle. c, on one extremity of which the cutter to be cut (d) is
fixed, whilst its other extremity is provided with a worm wheel c, whereby.
an intermittent rotary motion is imparted to the spindle and cutter by means

page_text: of a worm c³ rotating in a small head e' made fast by a set screw c³; the
worm is rotated by a wheel c keyed. to its shaft and put in motion by a
second wheel provided with a handle, one turn of the wheel being made
for each pass of the-cutting tool; wheels c³ of different diameters are adapted
to the machines, so as to subdivide one rotation of the spindle c according to
the diameter of the cutter to be cut or the desired pitch of the cuts, and in
order that the wheels should always gear into the wheel & whatever its
diameter may be:; it is fitted in a slot projecting from the head e', as shewn.
The spindle c rotates in a head stock-e mounted on the cross slide e³, which
latter is mounted on the longitudinal slide es; the stock.e can be rotated
horizontally round the bolt e³ as a centre by the spindle and worm gearing
into a worm wheel, a dial s attached to e3 and an indicator s¹ attached to e
serving to denote the angle required, whilst by means of the handles e and e
and the slides e and e³ it can be adjusted horizontally to the working cutter.
For purposes hereafter described the head e is also provided with teeth o
gearing into similar teeth on the extremity of a horizontal lever o' attached
by friction to the upper end of a vertical stud o turning in a bearing o³ fixed
to the head e, and the lower extremity of which is provided with a lever or
arm o attached to the same by a frictional connexion. .
The active part of my machine, or that designed to give motion to the
working cutter, is composed of a tool holder f, in which is adapted a vertical
spindle f, the lower extremity of which carries the working cutter g, to which
a rapid rotary motion is imparted by a cord or gut f³ running round the
driving pulley fs and the guide pullies f, f*; this tool holder is attached by
bolts f, f, to a plate ; which can traverse on a slide f8 attached by a
horizontal bolt f to the head stock f10. For purposes of adjustment the tool
carrier f can be set in five different ways, the first vertically by means of the
screw f, the screws f serving to fix it at the required height; the second in
an inclined position on a vertical plane by turning it on the bolts f",f", which
serve to fix it at the required angle; the third by inclining both the holder
and the plate f8, in which case the traversing motion of the cutting tool, here-
after described, follows the inclination given; fourthly, in a horizontal
direction by means of the slide h, and fifthly, in a transverse direction by
the slide i. Besides the rotary motion imparted to the cutter g by the gut f
it receives a traversing motion, which is transmitted to it in two different
manners, the first of which for operating on cutters, the profiles of which are
straight lines, by means of the vertical lever j¹ working with its shaft jin
bearings, its other extremity being provided with an armijs connected to
the platej by a link j; and the second for operating on cutters, the profiles

page_text: of which curved concavely or convexly by the simultaneous action of the
slides h and i, in which case the small slide is set stationary by the screws jo.jo,
and the motion is imparted' to the slides h and i by rotating the small upright
shaft k by means of the handle k; this shaft bearing two cams h¹ and.i¹; tlie
former of which actuates the longitudinal slide h through the lever / turning
on, a weight serving to maintain the outer arm of the said lever against
the face of the cam, and the latter (1) actuates the transverse slide i by its
contact with the roller, a weight serving to maintain the two constantly
in contact.
22
For. cutting cylindrical cutters the cutter to be cut (d) being fitted on its
spindle c I place in its slot a wheel: provided with a number of teeth corre
sponding with the number of cuts to be made on the circumference of the
said cutter, and I set the screws t and t so as to render stationary.the
slides h, i, of the working cutter g; I then bring the cutter to be cut (d)
opposite the working cutter g by means of the slides e, e, and after déter-
mining the enetration of the cut, also set these slides by means of screws
adapted for that purpose, and then by means of the lever pass the working
cutter, rotated by the gut across the blank d and return it to its starting point:
I give one turn to the wheel c³, pass the cutter once. more across the blank
and back again, and so on until the entire circumference of the same is cut.;
}
For cutting conical cutters the blank cutter is set at the requisite angle by
turning its head stock.e until the side of the said cutter is parallel with the
traversing motion of the working cutter g, the operation can then be proceeded
with, as above stated in the case of cylindrical cutters.
For cutting end, cutters the head stock e should be turned at right angles,
or nearly, so, and in other respects the machine is worked as above stated.
::The manner of cutting cylindrical, conical, or end cutters with a helicoidal
or curvilinear cut differs. frem those above described, in so much that the
blank receives a slight rotary motion whilst the cutter is passing over it; for
this purpose the slide j is connected with the spindle.c by the rods and u', as
it is shewn more clearly in Fig. 1, the screw being previously slackened so as
to admit of the heade turning, and in order to regulate the extent of rotary
motion transmitted the levers 0, 0, 0, to which these rods are jointed,.are
slotted so that they can be set at different distances from their centres. Where
the inclination or the curve is rapid it is necessary to incline the working
cutter g in its carrier f in the direction of such curve.
For cutting round and irregular edged cutters, either concave or convex,.
with either a straight or a curvilinear; cút, instead of imparting a rectilinear
motion to the working cutter g by means of the vertical lever j¹ and horizontal,

page_text: slide j, I give to the same such a curved or irregular motion as may be
required by means of the compound motion of the slides h and i actuated by
the cams h¹ and which are rotated by the handle ; for this kind of work
the lever with its accessory parts are superfluous, as well as the slide j, which
must therefore be set by means of the screws je, j°. The cams h¹ and 1 are
made in two different ways; in the first, that indicated in the Drawing, one
entire rotation is required to produce the traversing motion in one direction,
and after such rotation they have to be returned in the opposite direction,
which brings the cutter back to its starting point and causes it. to pass a
second time on the cut, after which the wheel c is rotated, bringing a fresh
part of the blank opposite the cutter; in the second about one-half or three-
quarters only of a revolution of these cams is required to produce the cutting
traversing motion, and the remaining half or quarter brings back the cutter to
its starting point, thus one revolution is caused to give both the to-and-fro
motion of the cutter, avoiding the necessity of turning back the cams, and
when in such case it is desirable that the cutter on returing does not touch
the blank I give to those parts of the cams causing the return motion of the
cutter an enlargement sufficient for that purpose. When it is required to
cut such cutters with a helicoidal or curvilinear cut the process is the same as
that described with regard to the cylindrical, conical, or end cutters, by con-
necting, as it is there explained, the spindle c with the tool carrier f. It
will thus be seen that this machine can cut all kinds of cutters or milling
tools of whatever size or shape, either with a straight or curvilinear cut; also
spur wheel teeth, either straight or curved, as well as bevil gears; also that it
can groove or cut all kinds of boring tools, drills, or augurs, whether cylindrical
or tapered and with any desired number of cuts, either straight or curvilinear.
Having thus described the nature of my Invention and the best means that
I am acquainted with for putting it into practise, I claim,-
Firstly. The mechanism above described for holding, adjusting, and
rotating the blank or cutter, to be cut, both as regards its intermittent
rotation by hand for submitting successively, the entire circumference of the
blank to the action of the cutter, as well as its rotary motion whilst being
cut.
Secondly. The mechanism described for holding, adjusting, rotating,
and traversing the working cutter by the upright lever j' and its accessory
parts.
Thirdly. The use of cams constructed and applied as above described
for cutting round edged cutters either concave, or convex, and of any shape
or form.

page_text: Fourthly. The mechanism described for making cutters either with a
straight or a curvilinear cut.
In witness whereof, I, the said Paul François Tranchat, have hereunto
set my hand and seal, this Seventeenth day of June, in the year of
our Lord 1868.
Witness,
D. H. BRANDON,
13, Rue Gaillon, Paris.
P. f. TRANCHAT. (L.8.)