Improvements in Machinery for Forming the Thread of Screws,
Year: 1886

page_text: Date of Application, 30th Apr., 1886.
Complete Left, 19th Jan., 1887.
Complete Accepted, 30th Apr., 1887.
[Communicated from abroad by CAMILLE EMILE DESIRE WINSSINGER, of Brussels,
in the Kingdom of Belgium, Civil Engineer.]
Improvements in Machinery for Forming the Thread of Screws,
I, WILLIAM PHILLIPS THOMPSON, Fel. Inst. P.A. of the Agency for Foreign Patent
Solicitors, 6 Lord Street, Liverpool in the County of Lancaster, and 323 High Holborn
in the County of Middlesex, Civil Engineer do hereby declare the nature of this
invention to be as follows:-
Object. This machine effects, by cold rolling, and quite automatically, the threading
of wood-screws, eye-bolts, etc., or metal screws, bolts, etc., or any metal cylindrical
shanks whatever. It produces threads of any profile and, in the case of wood-screws,
it forms the screw known as
These last-named screws should be
gimlet point."
previously pointed by turning or milling.
"
Description. The principal organ of the machine consists of a pair of straight
screw-plates, one of which is fixed, while the other receives an alternate rectilinear
motion. Each screw is drawn along and rolls between these two screw-plates provided
with inclined grooves, the counterpart of which they form in the metal of the shank
to be screwed. The shanks are fed in at one end of the fixed screw-plate and fall out
at the other end. The moveable screw-plate receives its reciprocating motion from a
rod actuated by a crank.
Figs. 1, 2, 3 and 4-The screws, fed by a distributor along a groove K, fall on to

page_text: the upper face of the fixed screw-plate A, which is slightly inclined, as also is the
portion next the frame. A slide LL pushes each screw as it falls, one at a time, in
such a way as to make it rise on the inclined plane, thus bringing it into the space
between the two screw-plates, where it is drawn along by the friction of the moveable
plate. The motion of the slide L L is given by a lever G H, the arm H of which is
lifted by a stud Q fixed to the moveable plate F¹ which carries the screw-plate A¹.
A spring J draws back the slide L L as soon as the stud Q descends. The
screw-plate A is carried by a plate B', into which it is inserted by a dove-tail portion.
The plate B' is retained in a box F provided with two blocks which slide in the frame.
The wear of the guides is taken up by two set-screws P. It is the box F which
carries the fastening of the rod. The box B' rests on three bolts CCD which
permit of its assuming exactly the position it ought to have; while a fourth bolt E'
draws it against these three fulcra. The screw-plate A is similarly fastened in a box B,
which is attached directly to the frame F, drawn by the screw E against the three
bolts C, C, D. The travel and the length of the screw-plates should vary with the
diameter of the shanks to be threaded, the hardness of the metal to be operated upon,
the depth of the threads, etc. To this end, the crank consists of a slotted plate
in the slot of which the bolt fastening the rod may be shifted. The travel should
always be double the length of the working portion of the fixed screw-plate A.
The frame is formed of two pieces bolted to a base-plate, and firmly braced by the
cross stays M, N, N.
{
Screw-plates. The two screw-plates are perfectly identical. Figs. 5, 6, 7 and 8
shew the details of a screw-plate for forming wood-screws with gimlet point. Fig. 5
shews a screw-plate in plan, and fig. 6 an elevation of the outer left face turned down
towards the left. Fig. 7 gives a section through the pair of screw-plates, at the
moment when the threaded screw, which they are pressing between them, is about to
fall. Fig. 8 shews an elevation of the screw-plate A, as seen on the side of its
greatest width. Each of the two similar screw-plates is provided with straight grooves
making the same angle with the edge m m'as the screw-thread to be produced does
with its axis. In other words, the grooves are parallel with the line that would be
obtained by developing, on the plane mm²nn', the helix of the same pitch as the
screw-thread, described by a point (fig. 7) in the body of the finished screw.
The screw-plates are by no means parallel, and have a very irregular shape. I give a
correct idea of their form and of their motion with respect to each other, the position
of the lines may be referred to an auxilary plane TT (figs. 3, 4, 7, 8 and 9) made by
the axis of the screw during its rotation. This plan is parallel with the edges of the
slide-blocks of the box F. The surface m m' nn (fig. 5) is a plane, not parallel with
TT, but approaching it from m m³ to nn. It is in this surface that the grooves are
formed. The axis of the screw remains parallel with the plane mm² an while it is
being threaded. The portion ee" o'gis plane and parallel with T T but has no
grooves. The surface om o¹n is curved, and in it are the hollow prolongations of the
grooves of the surface mm²nn³¹. The surface om o¹n serves to form the thread at
the screw point. That portion of the surface y ddd' mo is a plane, and a prolongation
of the plane mm nn. The portion of surface deed is an incline plane which
descends from the plane e e¹¹¹o¹ to the plane ad do. Lastly the surface de d'e
is a curved surface connecting the lines de, ee with the plane m m¹n n'. Fig. 9 shows
by their main lines, the screw-plates A A¹, of which A is fixed, and A³ capable of
moving from the position A', to that of A¹. In order to show clearly the irregular
shape of the screw plates, I have, in this figure, reduced to one tenth the dimensions
which are parallel with the arrow, that is to say, with the length of the screw-plates
while preserving without alteration the dimensions perpendicular to the former.
The dimensions of the circles have not been altered in any way. This conventional
drawing (fig. 9) makes very apparent the irregularities above described. The grooves
of the screw-plates vary in width and in deptli, except from ab to o¹¹ where they are
both in constant section. The hollows deepen from ab to o m² while on the contrary,
the projections increase from o m³ to a b. "Each screw travels along the plate from

page_text: om to on. The screw-plates A and A¹ are identically the same as stated above, but
they are placed in inverse directions. While being threaded, therefore, the screw
receives the impression of feathers or ribs, which penetrate to a constantly increasing
depth, while they also become more and more widened out. It follows that the screw-
thread undergoes a lateral pressure which progressively reduces and polishes it at the
same time. From ab to on the profile of the screw is no longer modified, this last
distance to be traversed only giving a supplementary polishing. The circumference s
is that of the original shank before being rolled the circumference t is that of the
main body of the screw as completely threaded; the circumference T is the apparent
The
external contour of the thread as existing on the body of the finished screw.
screw-plates for metal screws, bolts or cylindrical shanks only differ from those of wood
screws in the suppression of the projecting portions mo o¹m which are only necessary
for screwing the points of wood screws.
WM. P. THOMPSON & Co.,
Agents for the Applicant.

page_text: A communication from abroad by CAMILLE EMILE DÉSIRE WINSSINGER, of Brussels,
in the Kingdom of Belgium, Civil Engineer.
J, WILLIAM PHILLIPS THOMPSON, F.C.S. of the Agency for Foreign Patent Solicitors,
6 Lord Street, Liverpool, in the County of Lancaster, and 323 High Holborn, in the
County of Middlesex, Civil Engineer, 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:--
Object. This machine effects, by cold rolling and quite automatically, the threading
of wood screws eye-bolts etcetera, or metal screws, bolts, etcetera, or any metal
cylindrical shanks whatever. It produces threads of any profile and in the case of
wood-screws it forms the screw known as "gimlet point." These last-named screws
should be previously pointed by turning or milling.
Description. The principal organ of the machine consists of a pair of straight
screw-plates, one of which is fixed, while the other receives an alternate rectilinear
motion. Each screw is drawn along and rolls between these two screw-plates
provided with inclined grooves, the counterpart of which they form in the metal of the
shank to be screwed. The shanks are fed in at one end of the fixed screw-plate and
fall out at the other end. The moveable screw-plate receives its reciprocating motion
from a rod actuated by a crank.
Referring to the drawings left with the provisional specification :
Figures 1, 2, 3, and 4. The screws fed by a distributor along a groove K fall on to
the upper face of the fixed screw-plate A, which is slightly inclined as also is the
portion next the frame. A slide L, L, pushes each screw as it falls, one at a time, in
such a way as to make it rise on the inclined plane, thus bringing it into the space
between the two screw-plates where it is drawn along by the friction of the movable
plate. The motion of the slide L, L, is given by a lever G H, the arm H of which is
lifted by a stud Q fixed to the movable plate F¹ which carries the screw-plate A¹.
A spring J draws back the slide L, L, as soon as the stud Q descends. The screw-
plate A is carried by a plate B₁ into which it is inserted by a dove-tail portion.
The plate B is retained in a box F provided with two blocks which slide in the frame.
The wear of the guides is taken up by two set screws P. It is the box which
carries the fastening of the rod. The Lox B' rests on three bolts (",("¹, D', which
permit of its assuming exactly the position it ought to have, while a fourth bolt E¹
draws it against these three fulera. The screw-plate A is similarly fastened in a box B,
which is attached directly to the frame F drawn by the screw E against the three
bolts C, C, D. The travel and the length of the screw plates should vary with the
diameter of the shanks to be threaded, the hardness of the metal to be operated upon,
the depth of the threads etcetera. To this end the crank consists of a slotted plate in
the slot of which the bolt fastening the rod may be shifted. The travel should
always be double the length of the working portion of the fixed screw-plate A. The

page_text: Tame 15
}
UT two pieces Dotted to a base plate and nrmy braced by me
cross-stays M, N, N.
Screw-plates. The two screw-plates are perfectly identical. Figures 1, 5, 6, 7 and 8
shew the details of a screw-plate for forming wood-screws with gimlet point.
Figure 5 shews a screw-plate in plan, and Figure 6 an elevation of the outer left face
turned down towards the left. Figure 7 gives a section through the pair of screw
plates at the moment when the threaded screw, which they are pressing between them,
is about to fall. Figure 8 shews an elevation of the screw-plate A as seen on the side
of its greatest width. Each of the two similar screw-plates is provided with straight
grooves making the same angle with the edge m, m', as the screw-thread to be produced
does with its axis. In other words, the grooves are parallel with the line that would
be obtained by developing on the plane m, m², n, n', the helix of the same pitch as the
screw-thread, described by a point (in Figure 7) in the body of the finished screw.
The screw-plates are by no means parallel, and have a very irregular shape. I give a
correct idea of their form and of their motion with respect to each other, the position
of the lines may be referred to an auxilary plane T, T (Figures 3, 4, 7, 8 and 9) made
by the axis of the screw during its rotation. This plane is parallel with the edges of
the slide-blocks of the box. F. The surface m, m³, n. n', (Figure 5) is a plane, not
parallel with T, T', but approaching it at n'. It is in this surface that the grooves are
formed. The axis of the screw remains parallel with the plane m, m', n, n', while it
is being threaded. The portion e elogis plane and parallel with T, T, but has no
grooves. The surface o, m, o¹, n, is curved, as shewn in Figs. 5 & 6, and in it are the
hollow prolongations of the grooves of the surface m, m³, n, n². The surface o, m, 0¹, 1,
serves to form the thread at the screw point. That portion of the surface g,d',d', d',m,o,
is a plane, and a prolongation of the plane m,m²,,'. The portion of surface ("
led
is an incline plane which descends from the plane e col to the plane y, o, d", d.
Lastly the surface dede is a curved surface connecting the lines deee with the
plane m, m, n, n. Figure 9 shews by their main lines, the screw plates A A' of which
A is fixed and A capable of moving from the position A¹ to that of A'. In order to
shew clearly the irregular shape of the screw plates I have in this figure reduced to
one tenth the dimensions which are parallel with the arrow, that is to say, with
the length of the screw plates while preserving without alteration the dimension
perpendicular to the former. The dimensions of the circles have not been altered in
any way. This conventional drawing (Figure 9) makes very apparent the irregularities
above described. The groove of the screw plates vary in width and in depth except
from ab to on where they are both in constant section. The hollows deepen from
ab to o m² while on the contrary the projections increase from m² to ab. Each screw
travels along the plate from o m³ to on. The screw plates A and A' are identically the
same as stated above, but they are placed in inverse directions. While being threaded,
therefore, the screw receives the impression of feathers or ribs, which penetrate to a
constantly increasing depth, while they also become more and more widened out. It follows
that the screw-thread, progressively reduces and polishes it at the same time. From
ab to on the profile of the screw is no longer modified, this last distance to be
traversed only giving a supplementary polishing. The circumference s is that of the
original shank before being rolled; the circumference t is that of the main body of the
screw as completely threaded; the circumference is the apparent external contour of
the thread as existing on the body of the finished screw. The screw plates for metal
screws, bolts or cylindrical shanks only differ from those of wood screws in the
suppression of the projecting portions mo on which are only necessary for screwing
the points of wood screws.
ין
"
Having now particularly described and ascertained the nature of the said invention,
and in what manner the same is to be performed, as communicated to me by my
foreign correspondent, I declare that what I claim is :-
1. In machines for threading screws, bolts, eye-bolts or shanks of any kind, the use
of two identically similar screw plates straight but not parallel with each other, of
which one is fixed and the other actuated by a reciprocating motion in a straight line.

page_text: 2. The special form of the screw plates provided with inclined grooves, causing a
progressive penetration of the feathers or edges, and at the same time a progressive
lateral compression of the threads as above described and shown.
3. In combination with the fixed screw plate, the movable plate and a suitable
distributor, a slide pushing the screws one by one, by means of an inclined plane
between the two plates.
4. The method of fastening the fixed and movable screw-plates by means of a
dovetailed groove and three bolts, as described and for the purposes above mentioned.
5. The screwing machine as described, in its ensemble and in each of its parts, as
described and figured and for the purposes set forth in the preceding specification.
Dated this 18th day of January 1887.
WM. P. THOMPSON & Co.,
Agents for the Applicant