IMPROVEMENTS IN MACHINERY OR APPARATUS FOR FORMING SCREW THREADS
Year: 1857

page_text: LETTERS PATENT to George Léonard Doelling of 2, Rue Drouot, Paris,
for the Invention of "IMPROVEMENTS IN MACHINERY OR APPARATUS FOR
FORMING SCREW THREADS."
Sealed the 21st July 1857, and dated the 27th January 1857.
PROVISIONAL SPECIFICATION left by the said George Léonard Doelling
at the Office of the Commissioners of Patents, with his Petition, on the
27th January 1857.
I, GEORGE LÉONARD DOELLING, of 2, Rue Drouot, Paris, do hereby declare
the nature of the Invention for "IMPROVEMENTS IN MACHINERY OR APPARATUS
FOR FORMING SCREW THREADS," to be as follows:-..
This. Invention has for its object improvements in machinery or apparatus
for forming or cutting screw threads. For this purpose the screw cutters or
dies are arranged to slide. in radial grooves cut in a circular plate, which is
fixed to a handle. Over this fixed plate is a moveable circular plate, which is
fixed to a handle, and the two plates are connected by means of a flange on:
the moveable plate fitting into a groove on the outside of the fixed plate. In:
the moveable plate there are eccentric grooves, in which projections on the
screw cutters or dies slide. On to the fixed plate is: formed a projection in
which a screw turns; the end of this screw coming against the handle, of
the moveable plate, regulates the relative positions of the two plates, and con-
sequently the distance that the cutters or dies are from each other. "By these

page_text: means, when the screw has been cut the apparatus will be readily released
therefrom by moving the handle. fixed to the moveable plate away from the
regulating screw; or the cutters. or dies may be arranged to slide in grooves
in a square frame fixed to a handle, the grooves being at right angles to each
other. The movement of two of the cutters is regulated by projections on
the cutters entering inclined grooves in a plate which slides against the sides
of the frame, and the movement of the other two cutters is regulated by their
projections entering grooves in smaller plates which are at right angles to the
first-mentioned plate. The movement of these cross-plates is caused by their
ends fitting in inclines cut in the first-mentioned sliding plate, and the move-
ment of the first-mentioned sliding plate is caused by the end of a lever,
which is hinged to the frame, passing through a slot in the said sliding plate,
and the position of this hinged lever is regulated by a catch on such lever
entering a rack on the fixed handle. By this arrangement, by moving the
lever away from the fixed. handle the cutters may be withdrawn, as in the
former case. The sliding. plates. are held in the frame by a suitable cover
screwed on the top of the frame, there being a hole.in the centre of the cover
for the rod to pass through on which the screw is to be cut.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by 'the said "George, Léonard, Doelling in the Great Seal Patent Office
on the 25th July 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
LEONARD DOELLING, of 2, Rue Drouot, Paris, send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by. Her. Letters
Patent, bearing date the Twenty-seventh, day of January; in the year of our
Lord One thousand eight hundred, and fifty-seven, in the twentieth year of
Her reign, did, for Herself, Her, heirs and-successors, give and, grant unto
me; the said George Léonard+ Doelling, Her special licence that I, the said
George Léonard Doelling, my executors, administrators,,and, assigns,, or such
others as: I; the said George)-Léonard, Doelling, 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
öf Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention, for IMPROVEMENTS IN MACHINERY OR APPARATUS FOR FORMING SCREW
THREADS," upon, the condition. (amongst others) that I, the said George

page_text: Leonard Doelling; 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 George Leonard Doelling,, do hereby
declare the, nature of the 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, that is to say:-
This Invention. has for its object improvements, in machinery or apparatus
for.forming or cutting screw threads. For this purpose the screw cutters or
dies are arranged to slide in radial grooves cut in a circular plate, which is
fixed to a handle. Over this fixed plate is a moveable, circular plate which
is fixed to a handle, 'and the two plates are connected by means of a flange on
the moveable plate fitting into a groove on the outside of the fixed plate. In the
moveable plate, there are excentric grooves, in which projections on the screw
cutters or dies slide... On to the fixed plate is formed a projection in which a
screw turns; the end of the screw coming against the handle of the moveable
plate regulates the relative positions of the two plates, and consequently the
distance that the cutters or dies are from each other. By these means, when
the screw has been cut, the apparatus will be readily released therefrom by
moving the handle fixed to the moveable plate away from the regulating
screw; or the cutters or dies may be arranged to slide in grooves in a
square frame fixed to a handle, the grooves being at right angles to each
other. The movement of two of the cutters is regulated by projections. on
the cutters entering inclined grooves in a plate which slides against the sides
of the frame, and the movement of the other. two cutters is regulated by their
projections entering grooves in smaller plates which are at right angles to
the first-mentioned plate. The movement of these cross: plates is caused by
their ends fitting in inclines cut in the first-mentioned sliding plate, and the
movement of the first mentioned sliding plate is caused by the end of a lever,
which is hinged to the frame, passing through a slot in the said sliding plate,
and the position of this hinged lever is regulated by a catch on such.. lever,
entering a rack on the fixed handle. By this arrangement; by moving the
lever away from the fixed handle the cutters may be withdrawn, as in the
former case. The sliding plates are held in the frame by a suitable cover
screwed on the top of the frame, there being a hole in the centre of the
cover for the rod to pass through' on which the screw is to be cut.

page_text: fully to describe the same.
DESCRIPTION OF THE DRAWINGS.
Figure 1 (Sheet 1) is a plan of a screw-cutting apparatus arranged
according to my Invention. A is a circular plate, in which are cut the radial
grooves a, a', a", a". This plate is shewn separately at Figure 2 (Sheet 1).
D is a circular plate (shewn separately at Figure 3 (Sheet 1), in which
are cut excentric grooves d, 'd', d", d"". The circular plate A is attached to
a bandle B, and the circular plate D is attached to a handle E. G, G,
G", G", àre the cutters or dies, which slide in the grooves a, a', a", a","in
the plate A. On the cutters or dies there are projections 9, 9', 9", 9", as
shewn at Figure 4 (Sheet 1). These projections enter the excentric
d, d', d", d, in the plate D. The circular plate A and D are connected
together by means of a flange on the plate D, fitted into a groove 'in
the plate A.) On the plate A there is a projection C, through which
a screw c passes. The end of the screw C comes against the handle E of
the plate D, and regulates the relative position of the two plates, as shewn by
the red lines in Figure 1, and by reason of the projections g, g', 9", 9", on the
cutters or dies sliding in the excentric grooves d, d', d", d", of the plate D,
the position of the screw c regulates the distance that the cutters or dies are
from each other, and, for the same reason, when a screw has been cut, the
apparatus will readily be removed therefrom by moving the handle E away
from the regulating screw c, and so causing the cutters or dies G, G', G", G",
to be drawn back.
Figure 1 (Sheet 2) shews a screw-cutting apparatus where the cutters or
dies are arranged to slide in grooves in a square frame attached to a handle;
Figure 2 is a section of the same, taken through the dotted line 1, 2, Figure 1.
A is the square box or frame (shewn separately at Figure 4), in the centre of
which there is a projection B, through the centre of which there is a hole for
the passage of the articles on which the screw is to be- cut; through the pro-
jection B are cut four grooves a, a', a","a", at right angles to each other, in
which the cutters or dies O, O', O", O'", slide; there are projections o, o', o", o"",
as shewn at Figure 6. The motion of the cutters O', O"", is regulated by their
projections o, o", entering the inclined grooves 7, "; in the plate I, which
slides against the sides of the frame A. The motion of the cutters O, O", is
regulated by their projections o, o", entering the grooves i, ", in the plates
K, L, shewn separately at Figure 7.) The movement of these plates is regulated
by their ends fitting on inclines 1, l, k, k', in the plate I. D is a lever, hinged

page_text: to the frame A at G; the end of this lever passes through a hole d in the
frame I, and the position of the lever D is regulated by the catch H on the
lever D entering a rack F on the handle E, fixed to the frame A. By this
means, when the lever D is moved away from the handle E the end of the
lever in the hole d moves the plate I, and by reason of the grooves 2, 21, cut
therein being inclined, the cutters or dies o', o"" are drawn inwards, and by
reason of the inclines l, l', k, l, in the plate I moving, the sliding plates K, L,
in which are the inclined grooves i, ", the cutters or dies O, O", are also drawn
inwards. The sliding plates and the cutters or dies are held in the frame A
by a suitable cover, held down by means of the plates C screwed on the top of
the frame, there being a hole in the centre of the cover for the rod to
pass through on which the screw is to be cut. This is not shown in the
Drawing.
Having thus described the nature of my Invention, and the manner of per-
forming the same, I would have it understood that I do not confine myself to
the precise details herein shewn; but what I claim is the arrangements or
combination of apparatus herein described.
In witness whereof, I, the said George Leonard Doelling, have hereunto
set my hand and seal, this Twenty-fourth day of July, in the year of
our Lord One thousand eight hundred and fifty-seven.
GEORGE LEONARD DOELLING. (L.S.)
Witness,
T. BASSET,
14, Bd Montmartre,
à Paris.