CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF SCREWS
Year: 1847

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Civil Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twelfth day of July, in the eleventh year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said.
William Edward Newton, Her especial license, full power, sole privilege
and authority, that I, the said William Edward Newton, my executors,
administrators, and assigns, and such others as I, the said William Edward
Newton, my executors, administrators, or assigns, should at any time agree
with, and no others, from time to time and at all times during the term of
years therein mentioned, should and lawfully might make, use, exercise, and
vend, within England, Wales, and the Town of Berwick-upon-Tweed, and.
in all Her Majesty's Colonies and Plantations abroad, and in the Islands
of Guernsey, Jersey, Alderney, Sark, and Man, an Invention of "CERTAIN
IMPROVEMENTS IN THE MANUFACTURE OF SCREWS," being a communication from a
Foreigner residing abroad; in which said Letters Patent is contained a pro-
viso obliging me, the said William Edward Newton, by an instrument in
writing under my hand and seal, particularly to describe and ascertain the
nature of the said Invention, and in what manner the same is to be per-
formed, and to cause the same to be enrolled in Her Majesty's High Court
of Chancery within six calendar months next and immediately after the date

page_text: of the said in part recited Letters Patent, as in and by the same, reference
being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
William Edward Newton, do hereby declare that the nature of the said
Invention, and the manner in which the same is to be performed, is particu-
larly described and ascertained in and by the following description thereof,
reference being had to the Drawings hereunto annexed, and to the letters and
figures marked thereon (that is to say):-
:-
This Invention of Improvements in the Manufacture of Screws relates to
that kind of screws known as "wood screws," and in the machinery for
manufacturing the same.
The first part of the Invention relates to the form of the screw.
The second part relates to the method of forming the heads of blanks to
be manufactured into wood screws, but which may also be employed for the
making of rivets.
And the last part of the Invention relates to the method of cutting or
forming the threads of wood screws.
The improvement in the screw will be best understood by referring to the
accompanying Drawings; in which Fig. 1 is an elevation of one of the
improved screws; and Fig. 2, is a similar view of the core thereof without
the thread.
Screws have heretofore been, and are now generally made of equal dia
meter from end to end, or with a very slight taper along the threaded part.
When thus formed they hold with great force, each turn of the thread having
its full hold, and each turn of the thread formed in the wood being fully
sustained by those above it.. But such a screw cannot be inserted without
first boring a hole in the wood; and if by chance the hole be not bored deep
enough, the difficulty of penetrating the solid wood will strain the thread
already formed therein, and be liable to break it, a result often experienced by
those who use wood screws. With the view to avoid this, and to produce a
screw that could penetrate the wood without boring, the screw has hitherto been
made tapering at the point, or from end to end of the threaded part, but in
these cases the thread has either been made of the same depth along the
conical part, or gradually tapering, that' is, gradually decreasing in depth
towards the point; but when made of a gradually less depth towards the
point the distance between the turns of the threads has always: been gradually
diminished towards the point, and in the same or nearly the same ratio, in
this way producing what is well known as the "
gimlet point." These two
methods of making pointed screws are objectionable. When the thread has

page_text: the same or nearly the same depth at the point that it has along the body
it presents a long lip projecting from the point of the core, which renders
it: difficult to insert. the screw at any point required, for the same reason that
a hole cannot be bored at any desired point with a bitt having a side lip
without a centre point; and although the gimlet-pointed screw avoids this
difficulty it gives rise to another equally bad, if not worse. The turns of the
thread at the point being nearer together than along the body, they will not
travel so fast; that is to say,, the turns of the thread along the body being
farther apart than at the point, for every turn they will force the body of the
screw faster than those at the point, because those at the point become
useless the moment the body enters the wood, and, as a necessary consequence,
after the screw has entered it would continue to penetrate with more ease
without a thread on the point. The object of the first part of the Invention
is, to produce a pointed screw that will avoid the objections above pointed
out; and to this end the first improvement consists in making the thread of
pointed, screws of the same pitch along the body and point, that is, all the
turns at equal distances apart, irrespective of the reduction of the diameter
towards the point, when this is combined with the making of the thread of a
gradually reduced depth along the conical part, that the core and spiral of
the thread may end at one and the same point, or nearly so.
A
In Figs. 1 and 2 in the accompanying Drawings, a represents the head of
the screw and b the shank, both made in the usual manner.
The core c is
made cylindrical, or nearly so, with a conical point d, and the thread e is
made with all the turns equally distant from each other, and gradually
reduced in depth towards the apex of the cone into which it is merged;
the cylindrical part should run into the conical part by a gradual curve.
screw thus formed, it will be seen, will penetrate the wood without the
necessity of previously boring a hole, unless, indeed, the wood be very hard;
it can be inserted at any point desired, and will continue to penetrate in the
line in which it is started, and every portion of the thread will have the same
progress, and the thread formed in the wood by that portion of the thread
which is on the conical point will be adapted in pitch to receive the thread
on the body of the, screw, and therefore the thread on the point of the screw
will tend to penetrate the wood;when turned.
What I claim as new in this part of the Invention, and desire to secure
under the herein-before in part recited Letters Patent, is, making the thread
of pointed screws of the same, pitch along the body and point, that is, all that
turns at equal distances apart; irrespective of the reduction of the core at the
point, when this is combined with the gradual reduction of the depth of the

page_text: thread on the conical part, and towards the apex thereof, substantially as
described.
The improved method of forming the heads of screw blanks, rivets, or other
like articles, is shewn in the accompanying Drawings in Sheets 1 and 2, in
which Fig. 1 is a plan of the machine; Fig. 2, a longitudinal vertical
section taken at the line A, a, of Fig. 1; Fig. 3, a front elevation, with the
middle part of the machine broken out; Fig. 4, an elevation of the left-hand
end; Fig. 5, vertical cross section at the line D, d, of Fig. 1; Fig. 6, a
cross vertical section taken at the line C, c, of Fig. 1; Fig. 7, an end view
of the headers and punches; Fig. 8, a section taken at the line Y, y, of
Fig: 6; Fig. 9; an enlarged section taken at the line X, x, of Fig. 6; and
Fig. 10, a section taken at the line Z, z, of Fig. 1. The same letters indi-
cate like parts in all the Figures of Sheets 1 and 2. The wire is to be
formed into screw blanks or rivets, is fed by a pair of reciprocating tongs
through the shears into griping dies which gripe the length required; the
shears then cut it off, and the solid plate to which they are attached forms
the rest against which the griping jaws rest with that end of the wire which
is to form the point of the screw blank or rivet, so that the header can strike
the head on the other end. When this is completed the rest plate and shears
are drawn back, the jaws opened, and the wire again fed in by the tongs which
forces the headed blank out of the jaws into a pair of spring fingers, by
which it is shifted and presented to a second die called the gauge, into which
it is forced by a punch that moves with the header during the operation of
heading another blank. The gauge die is for the purpose of trimming off
the surplus metal of the head, and smoothing by pressure the levers formed
on the under surface thereof by the open space between the jaws, the die
being made in a single piece with the countersunk part cylindrical for a short
distance, so that when the head is forced in by the punch the edge of the
die will trim off the surplus metal, and leave the edge concentric with the
On the return motion of the header a rod pushes the blank out of the
gauge die into a second pair of spring fingers, while the motion of the feed
tongs forces the second blank into the first pair of fingers; and then, by the
shifting of these fingers the second blank is carried to the gauge die, and
the first from the gauge die to a second heading die, made similar to-the
gauge die, except that the countersink is of the exact form intended to be
given to the head of the blank, and there the head is struck up again by a
second header to spread out the metal and reduce to an edge all round.
finally, on the return motion of the headers the blank is by a second rod
pushed out of the second heading die into a third spring fingers to be shifted to
stem.
And

page_text: a second gange die, by which any burr that may have been formed thereon
by the second header may be trimmed off, this last operation being performed
at the same time that the operations are performed on other blanks, and the
finished blank being discharged from the last gauge or trimming die in the
same manner as it was discharged from the previous dies.
The improvements connected with this part of the Invention consist in
combining with the first operation of striking up the head either or any two
or all three of the other operations, that is, the first gauging, the second
heading, and the third gauging or trimming operations.
In the accompanying Drawings A represents the frame of the machine
properly adapted to the purpose, but which may be variously changed to suit
At one end there is a
the purpose, according to the fancy of the constructor.
crank shaft B, which is connected by a joint link C with a sliding bar D, which
it actuates to give the required back and forward motions to the headers and
punches that it carries; and on the other end of the frame, and parallel with
the crank shaft, there is a main cam shaft E, the two being connected and
caused to rotate with equal velocity by means of a long shaft F, and the bevel
cog wheels G, G, and H, H. The wire to be formed into screw blanks or
being
rivets is fed in by means of a pair of sliding tongs a, a', the one jaw a
adapted to slide in a groove in a part 6 of the frame, and the other a¹ being
jointed thereto and provided with an arm c, and spring d, which tends to open
and therefore to keep the arm against the face of a face came on the main
cam shaft. This cam is so formed that during one half of the rotation (or
thereabouts) it permits the tongs to be open as they are drawn back
preparatory to seizing the wire; and during the other half it keeps them
closed to feed in the wire. The tongs are moved in to feed the length of wire
This
required for a blank or rivet by a cam f, on the main cam shaft E.
cam facts against the end of the slide a of the tongs, as seen in Fig. 1*; and
so soon as the wire is griped by the griping jaws the smaller radius of the cam
comes round so as to allow the tongs to be forced back by a spring g,
Fig. 2, preparatory to another operation. The extent of motion of the tongs
is regulated for the different lengths of blanks and rivets by a set screw h,
which limits their back motion, the cam being so formed as to give the
range of motion required for the greatest length of screw blank or rivet
The wire is carried through a hole
3 intended, to be made in the machine.
i in the head block I of the frame, and through the cutting die j to the griping
jaws k, k, seen on an enlarged scale at Fig. 9. The cutting die j slides in
front of the head block I, and between it and the griping jaws k, and in a
recess in a plate J. The die j slides obliquely, as shown by dotted

page_text: lines in Fig. 6, so as to shear off the wire by a draw cut, the 'hole in
the head block I being enlarged to allow the wire to be carried up by the
motion of the cutting die, the cutting edge of which is formed on the lower
edge of a recess in the cutting die, as shown separately in Fig. 11. The
shearing motion of the cutting die is given to it by a 'cam b, Fig. 6, on the
periphery of a wheel 'm on the lined shaft, and it is forced back after the cam
has passed by a spring n. The griping jaws k, k, Fig. 6, that gripe the wire
to be headed, are fitted in a recess in a plate J, the one half k being per-
manently attached therein, and the other adapted to slide, and being for
this purpose connected with a rod p that passes out beyond the frame, and is
acted upon to close the jaws and gripe the wire by a wedge-formed. slide 9
that is worked by a cam K on the crank shaft, and forced back to open the
jaws and liberate the blank by a spring The dies of the griping jaws are
formed in the usual manner, with the countersink for the head of the 'blank
or rivet.
So soon as the griping jaws are closed the header's fitted on the
end of the sliding bar D, shewn detached at Fig. 7, is forced up to upset the
iron and form the head, and as the header moves back the jaws are opened,
the feeding tongs feed in a fresh length of wire, which forces 'the headed blank out
of the griping jaws into a pair of spring fingers t, see Fig. 5, formed of two
steel plates attached to a rocker L, that vibrates on a fulcrum pin u, the said
rocker being provided with an arm v, which is acted on by a spring w to
vibrate the rocker to the distance required to shift the blank from the die of
the griping jaws to a gauge die X, fitted in the plate J below the jaws, as seen
in Figures 6 and 9. This die x is formed with a cylindrical hole to receive the
shank of the blank, countersunk at the front end to receive the head, the
countersunk part being cylindrical for a short distance, and made with a cut-
ting edge to cut off the jagged part and surplus metal of the head, and make
it concentric with the shank. As the header 'moves forward to head another
blank a punch y, fitted on the end of the slide bar D below the header, forces
the blank out of the fingers into the gauge die, and turns off the surplus
metal of the head. On the return motion of the sliding "bar D, the fingers
are carried back to their original position by a cam N on the line shaft,
and as the tongs feed in the wire a rod a (attached to an arm 62 of the slide
that carries the tongs), fitted to a hole in the head block I, as seen in Fig. 9,
pushes the blank out of the gauge die into a second pair of fingers c², similar
to the first pair, and attached to the same rocker, by the vibration of which
the gauged blank is shifted from the gauged die to a second heading die d², as
the first pair of fingers shift a headed blank from the jaws to the gauge die.
This second heading die is similar in every respect to the gauge die, except that

page_text: it has not the cylindrical cavity in front of the countersink, but is so formed
that on the forward motion of the header a second header e, attached also to
the forward end of the sliding bar D, strikes it, and completes the upsetting of
the head, and when this is done another rod f, similar to a, fitted in the
head block I, and actuated in like manner, forces the blank out of this die
into a third pair of fingers.g, similar to the others, and connected with the
same rocker, by which it is shifted to another die h², called the second gauge
or trimming die, and made similar to the first gauge die, into which the blank
is forced from the third pair of fingers by another punch i², to trim off the
edge of the head, and from this die the blank, with the head finished, is
discharged by a third rod of the head block I, made and actuated in manner
similar to the other two already described. In this way all the blanks' are
carried in succession through the four operations, and all four operations are
carried on at the same time, and each on separate blanks.. The two headers
and the two punches are each fitted in holes in the end of the sliding
bar, and rest against wedge pieces k², Fig. 7, provided with nuts 1, by
means of which they can be adjusted with accuracy and facility. The arm of
the jointed part of the feeding tongs should be made long and thin enough to
bend slightly, that the jaws of the tongs may adapt themselves to any slight
inequality in the wire. It will be obvious, from the foregoing, that any or all
of the operations succeeding the first gauging operation may be dispensed
with, and that, if it be desired, the header alone may be worked to do rough
work; but by means of the heading and first gauging operation heads of good
quality may be made by so regulating the motion of the feeding tongs that
the head formed will only require to be slightly trimmed in the first gauge die.
When the machine is to operated with only the header and first gauge die, then
the second and third pair of fingers must be removed, that the blank may be
at once discharged from the first gauge die, and when the header alone is
used then all the fingers must be removed.
What I claim as new in this the second part of the Invention is, the first
gauging operation, the second heading operation, and the third gauging or
trimming operation, all three, or any one or any two of them in combination
with the first heading operation, substantially as described, whether the
mechanical devices and arrangements herein described for performing the
various functions be employed, or the equivalents, thereof be substituted.
The machine for cutting or forming the threads of that kind of wood screws
described above as constituting the first part of the Invention, parts of which
are applicable to the making of other kinds of screws, is shewn in the accom-
panying Drawings in Sheets 3, 4, 5, and 6, in which Fig. 1 is a plan of the

page_text: machine; Fig. 2, a back elevation; Fig. 3, a front elevation; Fig. 4, an
elevation of the right-hand end; Fig. 5, an elevation of the left-hand end;
Fig. 6, a cross vertical section taken at the line A, a, of Fig. 1, and
looking in the direction of the arrow; and Fig. 7 a like section, taken at the
line B, b, of the same Figure, also looking in the direction of the arrow.
The same letters indicate like parts in all the Figures of Sheets 3, 4, 5, and 6.
These Drawings are made full size for a machine for threading screws of the
size known as "three eighths threes." The main object of this part of the
Invention is to cut the threads of that kind of wood screws in which the point
is made conical with the turns of the thread at equal distances apart along the
body and point, and gradually reduced in depth along the conical part, and
towards the apex thereof. As in this kind of screws the line of the thread has
the same pitch at the conical point as it has along the body, and the thread is
gradually reduced in depth and thickness towards the apex of the conical
part, it becomes necessary to have the motions which give the pitch to the
tbread varied as the cutters arrive at the conical part to form the thread, so
that the cutting edges that form the under and upper faces of the thread on
the conical part may gradually approach the pitch line of the thread, and
coincide with it at the apex of the cone, and thus form the thread with all the
turns at equal distances apart, and gradually reduced in depth towards the
apex of the conical point. This part of the Invention consists,―
First, in giving such motions to the cutting edges that form the upper and
under faces of the thread along the conical part, relatively to the motion of
the blank, that they shall approach the line of the spiral that forms a thread,
the turns of which are at equal distances apart.
Second, in feeding the blanks to the mandril or spindle from a tube by
means of spring fingers made with two enlargements, the upper one to receive
the blank from the end of the tube by gravity, to be thence transferred by a
catch combined therewith to the second enlargement to be presented to the
mandril or spindle, this shifting of the blank being effected by sliding the
fingers down a short distance until the head of the blank passes under the
catch, and then sliding them up that the catch may force the blank down from
the upper to the lower enlargement preparatory to the presentation of the blank
to the end of the mandril; and,
Third, in holding the screw blank on to the end of the mandril or spindle
(by which it is made to rotate) by means of a thimble that embraces the under
surface of the head, and which, when drawn back, gripes and holds the blank
on to the end of the mandril provided with a fillet that fits into the nick of the
blank. The said thimble is connected with and is actuated by a rod within.

page_text: the mandril in such manner as to admit of the turning of the thimble on
the mandril when the blank is not griped thereon, that the said thimble
may be held and prevented from turning with the mandril during the opera-
tion of inserting a blank.
In the accompanying Drawings A, A, A, represents the frame of the.
machine properly adapted to. the purpose, but which may be varied at
the pleasure of the constructor. The screw blanks to be threaded are fed
by hand into an inclined tube a, Fig. 3, Sheet 4, down which they descend
by-gravity, points foremost, to enter a recess b in the feeding fingers c (see
also Section 8, Sheet 6, which is drawn to double the scale). These fingers c.
are formed of two springs, which keep them closed, and the recess b, which is
formed by a bend in each, which is sufficiently large to permit the blanks one
by one to fall in. At the lower end the two fingers, are again bent to form
another recess d, and from the swell of the bent part project two lips, e to
embrace the head of the blanks. The upper end of these fingers is secured to
a vertical slide f, which works in ways or grooves in a standard B of the
frame; and to the upper end of the slide is attached a bent arm 9, see
Figures, 2 and 3, that rests on the periphery of the feed cam c, attached to the
shaft D, Fig. 1, that makes one entire revolution for each complete operation
of the machine, that is, from the taking of the blank to the delivery of the
threaded screw. The form of this cam is shewn separately in Fig. 9, Sheet 6,
where it will be seen that from the point 1 nearest the centre to the point 2
the cam runs out from the centre for the purpose of raising the fingers c to
bring the recess of the fingers opposite the end of the feed tube a, and from
2 to 3 it is concentric to retain the fingers in that position that a blank may
fall into the recess from the feed tube. From 3 to 4 it runs in towards the
centre by a curve to depress the fingers, and carry the head of the blank below.
the point of a spring catch h, on a spring i, attached to the standard B, as
seen at Fig. 8. At 4 the cam by a gentle curve again runs out from the
centre to the point 5, to elevate the fingers, that the blank which is kept
down by the spring catch h may be transferred from the recess 6 to the one d
at the lower end of the fingers, the spring of the fingers permitting them to be
opened by the blank for. this purpose, and from the point 5 to 6 the cam.is
concentric, to hold the fingers in this position until the time required for the
5 insertion of the blank into the spindle, and from 6 to 1 the cam runs towards
the centre by a line nearly radial, to permit the fingers to descend for this
purpose. This completes the feeding operation, and by the repetition of these
motions the fingers are lifted out of the way to permit the other operations to
take place. The blank to be threaded. is held on the end of a hollow spindle

page_text: or mandril E, shewn detached and in section at Fig. 10, Sheet 6. This
spindle causes the blank to rotate by means of a belt from some first mover
passing around a pulley. F, near its rear end. The forward end of the spindle
E is in the form of a frustrum of a cone, the outer extremity of the diameter
of the head of the blank to be threaded, and there provided with a screw-
driver, which fits in the nick of the screw. Over the head k of the spindle,
which is made cylindrical, is fitted a thimble l, see Fig. 1, which slides on it
freely, but yet without play. In the outer end of this there is a hole which
receives the shank of the screw blank m, and the inside is conical to corre-
spond with the under side of the head of the blank and the conical end of the
spindle, so that when this thimble is drawn tight over the screw blank and
the head of the spindle, with the screw-driver in the nick of the blank, the
whole will turn together. The head of the spindle has a longitudinal slot n,
in which slides a key o, (see Fig. 10) the ends of which fit an annular groove.
(shewn by dotted lines) inside of the thimble, and the keyo also passes through
a hole in the head of a rod 7 that runs through the lower spindle, and
extends out beyond the back end thereof, where it has the necessary
connections for sliding it backward and forward at the required time, so
that when this rod is moved the connection of its former end with the
thimble, by means of the key, will cause the thimble to slide on the head
of the spindle to gripe or liberate the blank, while at the same time it is
free to turn by reason of the annular groove in which the ends of the key o
lie; but when this thimble is drawn back tight to gripe the blank it is
prevented from turning on the spindle by the contact of the surfaces.
The inner end of this rod q is connected by a joint link s (see Fig. 10)
with a rol, the end of which turns freely in a sliding bar t, so that the
said link shall perform the functions of a lever when the rod is drawn back,
by reason of a shoulder n made on the end of it below the pin which joints
it to the rod, this shoulder being brought against the end of the spindle,
which is bevilled off around the hole to form a rest, which becomes the fulcrum
of the lever, when the link acts as such, to make the thimble gripe the blank
on the end of the spindle. The various motions for griping and liberating the
blank are given to the sliding bart by a cam G on the rear shaft D, that
carries the feed cam C, the end of the sliding bar being adapted to the surface
of the cam. This cam G is made on the back edge of a rim, on the outer
periphery of which is a rim of cogs H, by which the shaft of this and the
feed cam is actuated by means of a pinion I on the shaft J of the threading
cain, to be hereafter described. The form of the cam G is represented in
elevation and in section in Fig. 11, Sheet VI., and as developed in Fig. 12,

page_text: where it will be seen that from the point 1 to 2, in the direction the reverse
of the arrow, it runs in a plane at right angles with the axis of the shaft for
a short distance to give time to the feeding fingers to introduce a blank, the
sliding bar t being then forced forward by a helical spring v, that lies in a
hollow in the bar, as seen in Fig. 10, and rests against a standard w, and thie
thimble being thrown forward in a position ready to receive a blank from
the feeding fingers at 2 (see Fig. 12), the cam runs out at an inclination as
far as the point 3, for the purpose of drawing back the thimble'l far enough
to pass on to the end of the blank to hold it, that the fingers may spring open
when elevated, and leave it in the thimble, the cam running for a short dis-
tance from 3 to 4 in a plane at right angles with the axis of motion; and
then from the point 4 to 5 it runs diagonally to draw back the thimble, l, and
gripe the blank; and then from 5 to 6 it continues in a plane at right angles
to the axis of motion to retain the thimble in that position during the thread-
ing operation, and at 6 it runs back to 1, the place of beginning, in a line
nearly parallel with the axis of motion, to permit the spring to force the bar
forward to liberate the screw and receive another blank. As the spindle
rotates continuously (all the motions being derived from it and the thimble
being carried by it, but free to turn on it when the blank is not griped), it
becomes necessary to hold the thimble 1, and prevent it from turning during
the time that the fingers are introducing a blank. This is done by means of
a pina (Figures 10 & 11) on the thimble 1, which, as the thimble is thrown
open, comes in contact with a helix y, (shewn by dotted lines) attached to the
standard B, and extending around the thimble along which the pin passes
until it reaches the end, where it is held to prevent the further rotation of the
thimble; but when the thimble is drawn back to gripe the-blank then the pin
x runs clear of the helix, and permits the thimble to rotate with the spindle E.
The moment that the blank is griped the threading operation begins, and to
sustain the blank while under the operation of the chaser a rest z, Figures 3
and 1, on an arin a¹ that projects upwards from a tumbling shaft-L, is carried
forward to rest against the shank of the blank by a wedge-formed projection
6 on the sliding bar t, which, as before described, operates the thimble to
gripe the blank. The wedge-formed projection acts against the back of the
arm of the rest to push it forward the required distance against the blank.
The motion of the sliding bar for this purpose is the same that actuates the
thimble ; but the cam G is made of greater elevation from the point 5 to 6
than is necessary for the griping operation, and to allow the additional motion
'to the sliding bar after the griping operation (for the rest must not be brought
forward until after the blank is griped), the rod r that forms the connection

page_text: between the thimble and the sliding bar passes through a hole in the part p of
the bar t, in which there is a helical spring (shewn by dotted lines) which yields
to allow the additional motion to the bar for moving the rest. Immediately
succeeding the forward motion of the rest just described the threading opera-
.tion commences, and is produced by moving the chasing tool towards the axis
of the blank to cut in and along the shank of the blank to give the pitch of
the thread. These motions are produced in the following manner :--The
chasing tool c', Fig. 1, is made and held in the tool head d¹ in the usual
manner, and the tool head is attached to a sliding and rock shaft L', that, by
rocking, the chaser may be made to move towards and from the axis of the
blank, and by its sliding motion give the pitch to the thread. The motion for
giving the pitch to the thread is produced by a face cam M, at the other end
of the machine, shown as developed in Fig. 13, and in face and elevation in
Fig. 14. The cam M is on the shaft J of the pinion I, seen best in Fig. 6.
This cam M communicates motion to the shaft of the feed cam, so that the
relative sizes of the pinion I and wheel H will determine the number of cuts
to be made by the chaser for the completion of the thread of the screw, and
the shaft J receives motion from the spindle or mandril E by means of a
train of cog wheels O, P, Q, R. In Figures 13 and 14 it will be seen that
from the point 1, to 2, in the direction the reverse of the arrow, the cam is
a regular inclination from the plane of motion to move the chaser from that
part of the shank where the thread is commenced to the point. The face of
the cam acts on a roller e¹ (see Fig. 6) that has its bearings in a slide f¹, so
fitted to the end of the rock shaft that it (the rock shaft) may vibrate on its
.axis without turning the slide. The roller e¹ is held against the face of the
cam by the tension of the helical spring g' within the rock shaft (as shewn by
dotted lines in Fig. 3), so that the rotation of the cam shall give the required
motion to the chaser to give the pitch to the thread, and the spring carries it
back, the cam from the point 2 to 1 (the place of beginning) being a sudden
inclined plane for this purpose. At the back of the chaser head there is an
adjustable piece h', which, as the chaser is moved to give the pitch to the
thread, passes along a curved plane i, called the mould, the curved face of
, which is shewn in the detached sectional view, Fig. 15. This mould is so
formed that when the chaser begins to move, it first passes
from 1 to 2 to commence the thread, and then from 2 to 3.
the body of the screw is to be generated on a cylinder; but if it is to be
slightly conical, the face from 2 to 3 should be a slight inclined plane, and
;then from 3 to 4 it is inclined to move the chaser up to the centre to form
the conical point; but this part, it will be seen, is a curved plane to give a
along the curve
It is straight if

page_text: slight rounding to the junction of the conical point and the body of the thread.
This, however, only gives the motion to the chaser which is required to deter--
mine the form of the screw; but at the commencement of the operation it is
necessary to move the chaser forward against the blank, and at each succes-
sive cut to withdraw it enough to run back clear of the thread, and to make it
cut deeper. The mould is fitted by adjusting screws ",, to the head h¹, the
arms , l, of which (see section 16) embrace the chaser shaft, and are free to
vibrate thereon, and are prevented from sliding with it by means of a collar m²..
When, at the commencement of the threading operation, the chaser is to be
moved up, a blunt wedge n' on a sliding and rock shaft S is brought in con-
tact with the back of the head h¹, and moves the chaser up to the blank far-
enough to make the first cut, the sliding and rock shaft S receives the move--
ment just named from that face of the cam G opposite to the face which con-
stitutes the griping cam. This face cam acts on an arm o' of the shaft S, and
when, by the rotation of this cam, which is shewn developed at Fig. 12, the
inclined face from 8 to 9 acts on the arm, the wedge n¹ forces forward the
mould and chaser head to bring the chaser into action. The part of
the wedge on the shaft S is very sudden, to give the first forward motion to
the chaser; but, as after that, the chaser for each new cut has to be moved.
forward only a little, the wedge from n¹ to p₁is very gradual, and the cam is
composed of a series of faces 10, 12, 14, 16, 18, 20, which are in the line
of motion, so that as each of these pass the arm of the rock shaft the
wedge shall be stationary; and these planes are connected by a series of.
inclined planes 11, 13, 15, 17, and 19, each to move forward the wedge
sufficiently for every additional cut; and at the point 21 the cam, by a
sudden inclination, runs back to the point 7 to permit the tension of a helical
spring (shewn by dotted lines), within the hollow shaft S, to draw back the
wedge, and allow the chaser head to be thrown back by the tension of a
spring qattached to the shaft L', and bearing against the frame. The chaser
must of course be thrown back at the end of each cut, in order that it may
pass the threads for the repetition of the threading operation. This is done by.
the wedge pieces n', p¹, the circumference of which, from 1 to 2 (as shown
by dotted lines in Fig. 5), runs out slightly from a circle. The shaft S is pro-
vided at the opposite end with another arm r¹, which, by a springs, is kept
against the periphery of the cam N on the shaft J, which, as before
stated, makes one rotation for each series of cuts on the thread; and. this
cam (see Fig. 14), which from the point 1 to 2 is concentric, has a recess
from the point 2 to 1 in the direction the reverse of the arrow, to permit
the arm to fall in and to vibrate the shaft S, and with it the wedge piece, to
allow the chaser to fall back just before the chasing cam permits the chaser

page_text: to be run back. Thus far all the parts and motions have been described
which are necessary to the cutting of the thread on a screw; but it now
remains to shew how the thread is to be cut on the conical part or point of
the same pitch, and of a gradually reduced depth. As the chaser reaches that
part of the screw which is to be made conical, it, during, one cut, must be
moved with a gradually retarded motion, and during the next with a gradually
accelerated motion, so that the cutting edges that form the under.. and upper
surfaces of the thread may gradually approach the pitch line of the thread,
and be merged into it at the apex of the conical point. This is done in the
following manner:-The roller e (Fig. 6) that is interposed between the
chasing cam M and the sliding shaft of the chaser head is conical, and has
an.end play in its bearings.. The end of the journal runs against; the face t
of a slide which moves backwards and forwards for every two backward
and forward motions of the chaser. On the shaft J there is a cog wheel
U, which engages the cogs of another wheel V of double the number of
teeth, and on the shaft of this last wheel there is a cam W, so formed that,
from the point 1 to 2, in. the direction the reverse of the arrow, it is con-
centric, that the motion of the chaser may be regulated as it cuts along the
cylindrical part of the blank.. At 2 it. runs out for a short distance from
the circle, to push the slide u' back, the slide being provided with a pin
that bears on the periphery of the cam by the tension of a spring w, in
order that the larger diameter of the roller e! may be gradually interposed
between the chaser cam. and the shaft of the chaser head, and thus acce-
lerate the motion of the chaser as it passes along the conical point, that
the chaser may gradually approach the pitch line of the thread, and be merged
therein at the apex of the cone. The cam then runs back to the same
diameter at the point 3, that the conical roller.may be moved back to the
same place preparatory to the next cut. From the point 3 to 4 the cam is
again. concentric, to give the second cut along the cylindrical part, and from
4 to 5 it gradually runs towards the centre for a short distance, in order that
the conical roller may be moved in the opposite direction to produce the
reverse effect from the previous operation; and: gradually retard the motion of
the chaser, so that it may cut the under face of the thread, and gradually
approach the pitch line thereof as it approaches the apex of the cone. In
this way it will be obvious that during one cut the motion of the chaser. is
accelerated, cutting the thread along the conical point, the next cut retarded,
and so on alternately until the thread is completed..
It will be obvious from the foregoing that the mechanical elements, combi-
nations, and arrangements above described for applying the first and leading part
of the Invention for cutting or forming the threads on wood screws with conical

page_text: points may be greatly varied without changing the principle or departing from
the nature and object thereof, which consists, as stated above, in giving to the
cutting edges that form the upper and lower surface of the thread motions, rela-
tively to the motions of the blank that will cause them gradually to approach
the pitch line of the thread as they approach the apex of the cone, although
the mode of applying this principle which I have described and represented
has been found in practice to answer the best purpose; as, for instance, instead
of one cutter moving with an alternate accelerated and retarded motion, two
cutters may be employed, one having an accelerated and the other. a. retarded
motion, the spindle having a continuous and regular motion; or, instead of
this, the two cutters may remain stationary while cutting the tlireads on the
cylindrical part of the stem, the blank being moved longitudinally to give the
pitch to the thread, and then, as the cutters form the thread on the conical
part causing the two cutters to move in opposite directions towards a line at
right angles to the axis of the blank; or, instead of this, a single fixed cutter
may be used by giving a longitudinal motion to the blank for determining the
pitch of the thread, and alternately accelerating and retarding this motion to
form the thread on the conical part. What I claim, therefore, as new in this
part of the Invention is,-
First, giving to the cutting edges which form the upper and under surfaces
of the thread on the conical part a motion or motions relatively to the motion
of the blank on which the thread is to be formed, so that they shall gradually
approach the line of a spiral that generates the thread, the turns of which are
at equal distances apart, and thereby gradually reduce the depth of the thread
as it approaches the apex of the cone.
Second, I claim the method of feeding or presenting the blanks to the
mandril or spindle by means of spring fingers having two enlargements as
herein described in combination with the catch, by which the blank is shifted
from the upper to the lower enlargement preparatory to the presentation of it
to the mandril, substantially as described.
And finally, I claim the method of holding or griping the blank, and holding
it on the end of the mandril, by combining with the mandril the sliding
thimble that embraces the under face of the head of the blank, and. the parts
by which it is connected with the mandril, and operated substantially as
5 herein described.
In witness whereof, I, the said William Edward Newton, have hereunto
set my hand and seal, this Twelfth day of January, in the year of our
Lord One thousand eight hundred and forty-eight.

page_text: AND BE IT REMEMBERED, that on the Twelfth day of January, in the
eleventh year of the reign of Her Majesty Queen Victoria, the said William
Edward Newton came before our said Lady the Queen in Her Chancery, and
acknowledged the Instrument aforesaid, and all and every thing therein con-
tained and specified, in form above written. And also the Instrument afore-
said was stamped according to the tenor of the Statute made in the fifty-
fifth
year of the reign of His late Majesty King George the Third.
Inrolled the Twelfth day of January, One thousand eight hundred and