IMPROVEMENTS IN THE MANUFACTURE OF SCREWS
Year: 1853

page_text: LETTERS PATENT to Alfred Vincent Newton, of the Office for Patents,
66, Chancery Lane, in the County of Middlesex, Mechanical Draughts-
man, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
SCREWS." A communication.
Sealed the 4th April 1854, and dated the 29th December 1853.
PROVISIONAL SPECIFICATION left by the said Alfred Vincent Newton
at the Office of the Commissioners of Patents, with his Petition, on the
29th December 1853.
I, ALFRED VINCENT NEWTON, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF SCREWS" to be as fol-
lows:
The first part of this Invention relates to a machine for arranging the blanks
with their heads all in one direction, and feeding them one by one into the
machines which give them the proper shape and finish. This branch of the
Invention consists, first, in arranging screw blanks, pins, and other like or
similarly headed articles (so as to present them with the points or heads all in
the same direction) by means of oppositively inclined bevelled or curved sur-
faces, with sufficient space between them to receive freely the shanks of such
articles whilst they hang suspended by their heads, operated essentially in the
manner herein-after described.
Second, in making one of the said inclined, bevelled or curved surfaces in

page_text: two parts, one above the other, to aid in giving to the screw blanks or other
articles the required tendency towards the space between the said surfaces.
Third, in combining with the said oppositely inclined bevelled or curved
surfaces, a fence or guard plate placed across from one to the other, and over
the space in which the screw blanks or other articles are suspended to prevent
the passage of any which I may not be properly suspended.
Fourth, in combining with the oppositively inclined bevelled or curved
surfaces, revolving arms, wings, or beaters, to knock or beat back the surplus
screw blanks or other articles, and prevent any but such as are properly
suspended from passing towards the point of delivery.
And, lastly, in combining with the said oppositively inclined bevelled or
curved surfaces, a checking and delivering apparatus for delivering out in
succession the screw blanks or other articles. It consists of a horizontal slide
plate suitably sustained at the lower edge of the hopper, and caused to
slide towards and from the axis of a conic frustrum set in the middle of the
hopper.
a!
The second part of the Invention relates to shaving the heads of the blanks,
and to mechanism for holding the blanks while the tools operate on them, and
to mechanism for feeding the blank to the holding mechanism. This branch
of the Invention relates, 1st, to the method of transferring screw blanks one
by one from a hopper or other receptacle to jaws, by which they are held while
undergoing certain of the operations of finishing, and it consists of a feeding
trough with a close bottom and open top, and composed of yielding sections
held together by springs or otherwise into which the blank drops from the
hopper, and arranges it itself in the proper position before a traversing rod,
which pushes it out of the trough in between the jaws...
Second, to the method of setting the blank in a position at which the cutting
instrument can act upon it with the best effect, and it consists in operating the
instrument that transfers the blank from the feeder into the griping jaws by a
spring, or its equivalent, and making the instrument that gauges the distance
which the blank is permitted to enter between the jaws, adjustable so that more
or less of the blank will be left projecting. beyond the jaws as may be found
expedient.
Third, to the manner of griping and holding the blank in a rotating
mandril, and it consists in a method of operating. the jaws of the mandril, and
closing them upon the blank with sufficient force to hold it firmly under the
action of the cutter without producing end strain upon the mandril by means
of toggle or knuckle joint levers, which are thrown past centers when the jaws
:

page_text: are closed to hold them closed in connection with a pair of long shanked
nippers, which by their elasticity admit of the toggle being thrown past centers
without releasing the gripe of the jaws upon the blank.
Fourth, to a spring detaching punch constructed and arranged in such manner
that the same shall be compressed by the entrance of the blank between the
griping jaws, and shall throw the blank out of the jaws the instant they relax
their hold of it sufficiently to permit it to pass out, such pushing out of the
blank depending upon such relaxation of the jaws, and the action of the spring
punch being entirely independent of the motion of any other part of the
machine.
These improvements, besides being applicable to a machine specially adapted
to the shaving of the heads of screw blanks, greatly improve the operation of
machines by which various other operations in the manufacture of screws are
effected. Thus, for example, the feeding may be adapted to receiving the
screw blank with its head towards the griping jaws, and the latter may be
constructed to admit and gripe the heads of screw blanks, thus holding them
firmly while their shanks are being shaved or threaded.
The mechanism for imparting motion to the several moving members of the
machine; and for directing their movements may likewise be varied.. Thus
for example, the feeder may have a longitudinal alternating movement instead
of a lateral alternating movement, and the hopper will also have in such case
to be adapted to this arrangement. Instead of the knuckle joint levers to open
and close the jaws of the nippers, various other devices may be used with very
good effect, although these above indicated are deemed the best.
These and other modifications of the mechanism will be readily carried into
effect by skilful mechanicians, if circumstances should ever render it necessary
to make them.
The next branch of this Invention relates to the pointing of the blank, and
cutting a screw thread thereon. This branch of the Invention consists in
pointing the blank and threading it by means of different cutters held in and
operated by the same tool-holder, and having a common motion, whereby the
pointing and threading of the blank are performed at a single operation.
The thread is formed on the blank by a succession of cuts of the chasing
tool, made successively deeper by changing the position of a conical cam, and
bringing radii of gradually increasing length to act upon the cutters.
For the further improvement of this branch of the manufacture, a machine
of tlic following construction for threading the blank (which machine for
certain purposes I deem superior to all others) may be employed.

page_text: This branch of the Invention relates, 1st, to a cutter for threading screw
blanks of soft material, such as iron or brass. This cutter is made of hard
material, such as tempered steel, and in form is a screw, the counterpart of
that which is to be produced by it, but of much greater diameter. This
cutting screw is of unequal depth of thread, of uniform pitch of thread, and of
unequal diameter, so that portions of the thread of the cutter which have
the greatest amount of material to reduce or cut away in threading the blank
have also the greatest circumferential motion and the greatest cutting capacity,
while those parts which have the least material to cut away have the least
circumferential movement and the least cutting capacity, whereby a screw
blank can be reduced to any required shape and threaded at the same opera-
tion, with the advantage among others of not subjecting either the blank or
cutter to undue strain or excessive wear by the increased depth of cut at
particular parts.
Secondly, to arranging the axis of the rotating cutting serew, and of the
rotating blank to be threaded by it, parallel to each other, so that the cutter
may run smoothly and steadily, and that its threads may not bind in the
grooves of the blank and strain the metal between them.
Thirdly, to the rotating of the axis of the cutting screw and the axis of the
blank in the same direction during the operation of threading, in order that
the metal may be cut from the grooves of the blank from the bottom outwards
towards the periphery, whereby the chips detached from the blank by the
cutter are prevented from wedging in between the two and creating great
strain and friction, as they would do if the cut was from the periphery towards
the centre, which would force the chip, from a wider to a narrower space,
instead of forcing it from a narrower to a wider, as by this arrangement.
Fourthly, to the combination of a cutting screw with a rest to support the
blank while being threaded, the cutter and rest being so arranged and operated
that while the blank is firmly supported against the pressure produced by the
action of the cutter, the axes of the two are caused to approach gradually, so
that the helical groove may be formed in the blank by a spiral cut commencing
at the circumference of the rough blank, and winding round and round to form
the groove by the removal of a shaving, turning a greater or less number of
times around the blank, as the approach of the axis of the latter and the cutter
is more or less rapid.
Fifthly, to the feeding of the blanks one at a time and shank foremost into
the rest, where they are held under the action of the cutter and threaded.
A screw driver is arranged to pass and repass through a feeding box in

page_text: moving towards and from the rest, the trough receiving one blank upon the
screw driver, while the latter in its forward position is holding another to be
threaded, so that when the driver is drawn to its backward position to liberate
the threaded blank, the unthreaded one will drop down in front of it in the
proper position to be caught on its return movement, and pushed forward into
the rest, to be there held and threaded."
Sixthly, to the discharge of the threaded blank from the rest and from the
mechanism by which it is rotated.
For this purpose a vibrating arm or the equivalent thereof, which detach
the head of the screw from the driver or holder, acts in combination with a
reciprocating punch to force the blank out of the rest.
The combined operation of these two instruments ensure the discharge of one
blank before the introduction of another, thus avoiding the danger of breaking
the machine, which is always imminent when an unthreaded blank is presented
before the threaded one is discharged.
Seventhly, to the operation of the screw driver by which the blanks are
turned while under the action of the cutter. The bit of the screw driver bears
with a light yielding pressure against the lead of the blank, until it finds and
enters the nick, and then a heavier pressure is applied to keep it engaged with
the blank while the latter is turned to be threaded.
A modification of tlie burr cutter forms the last part of this Invention. For
threading screw blanks a rotating concave annular burr cutter is used, a com-
bination with suitable rests and turn screws for presenting the blank to the
cutter, and rotating it while being threaded.
This part of the Invention also includes a combination of a vibrating rest
to support the screw blank, and a rotating turn screw vibrating with the rest
to turn the blank.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alfred Vincent Newton in the Great Seal Patent Office on
the 29th June 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I. ALFRED
VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane, in the County
of Middlesex, Mechanical Draughtsman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of December, in the year of our
Lord One thousand eight hundred and fifty-three, in the seventeenth year of

page_text: Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Alfred Vincent Newton, Her special license that I, the said Alfred
Vincent Newton, my executors, administrators, and, assigns, or such others as
I, the said Alfred. Vincent Newton, 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, usé, exercise, and vend, within the United Kingdoin of Great Britain
and Ireland, the Channel Islands and Isle of Man, an Invention for "IMPROVE-
MENTS IN THE MANUFACTURE OF SCREWS;" being a communication from abroad,
upon the condition (amongst others) that. I, the said Alfred Vincent Newton,
by an instrument in writing under my hand and seal, 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 Alfred Vincent- Newton, 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 fol-
lowing statement, reference being had to the Drawings hereunto annexed,
and to the letters and figures marked thereon (that is to say):-
The manufacture of wood screws involves a series of processes which are
performed wholly or mainly by automatic machinery. A coil of annealed wire
of suitable diameter is received in a machine cut into pieces of the proper
length to form the required screw, and each piece so cut has one of its ends
enlarged by compression to form the head of the screw about to be made. The
piece of wire thus cut off and headed is called the headed blank, and the
machine by which it is made is called a "header" or "heading machine."
After the blanks are headed they are discharged promiscuously into any
suitable receptacle or into a heap on the floor, but in this promiscuous order
they cannot be fed into any machine to perform subsequent operations upon
them in the process of converting them into finished screws. These blanks
must therefore be assorted and presented one by one with their heads all
arranged in the same direction to succeeding machines; this arrangement and
feeding of the blanks is effected by means of a machine contrived for the
purpose, called the arranging and feeding machine. The third operation is to
smooth the rough heads of the blanks and reduce them to an uniform size and
shape. This operation is performed on a machine called a " shaver" or "head
shaver." The fourth operation is forming a nick or groove across the head of

page_text: the blank to receive the bit of a "turn screw" or screw driver. The machine by
which this operation is performed is called a "nicker." The fifth operation is
to shape the point of the blank and cut a thread thereon and on the shank.
These operations may be performed in the same or in distinct machines, or if
in the same machine, it will be by a turning tool for dressing or rough shaping
the point and shank, and by a chasing tool for cutting the thread, the latter
performing its function after the former has prepared the shank and point for
threading. Each of these several operations may be performed by machines
variously modified, but constructed and acting upon the same general principles.
The best form of inachine and its most valuable modifications will, in each
case, be described where an improvement claimed; but where a machine
known in the manufacture is employed to perform any of the operations of
finishing a screw, it will merely be referred to, as the knowledge of every
person of competent skill in the art will supply the necessary information to
construct such machine.
Any ordinary or approved "header" may be used, as the Invention does not
relate to that branch of the manufacture, but as great improvements have been
effected in other branches subsequent to the heading, the machines relating to
these branches will be described in detail.
The first is the machine for arranging the blanks with their heads all in one
direction, and feeding them one by one into the machines which give them the
proper shape and finish. The following is a full and exact description of this
machine, reference being had to the accompanying Drawings, in which Fig. 1,
A, is a top view; Fig. 2, A, a front elevation; Fig. 3, A, a longitudinal,
vertical; and central section; Fig. 4, A, a transverse vertical section; and
Fig. 5, A, an inverted horizontal section, taken just below the check motion
which governs the feed-motion.
This branch of the Invention consists, first, in arranging screw-blanks,
pins, and other like or similarly headed articles, so as to present them with the
points or heads all in the same direction by oppositely inclined, bevilled, or
curved surfaces, with sufficient space between them to receive freely the shanks
of such articles whilst they hang suspended by their heads, operated essentially
in the manner herein-after described:
Second, in making one of the said inclined, bevilled, or curved surfaces in
two parts, one above 'the other, to aid in giving to the screw-blauks or other
articles the required tendency towards the space between the said surfaces.
Third, in combining with the said oppositely inclined, bevilled, or curved
surfaces, a fence or guard plate placed across from one to the other, and over

page_text: the space in which the screw blanks or other articles are suspended to prevent
the passage
of any
which may not be properly suspended.
Fourth, in combining with the oppositely inclined, bevilled, or curved
surfaces revolving arms, wings, or beaters to knock or beat back the surplus
screw-blanks or other articles, and prevent any but such as are properly
suspended from passing towards the point of delivery.
And, lastly, in combining with the said oppositely inclined, bevilled, or curved
surfaces, a checking and delivering apparatus to deliver out in succession the
screw-blanks or other articles.
In the above-mentioned Figures, A represents a conical hopper sustained in
position by a suitable frame-work B. Two couic frustra C, D, are disposed
within the said hopper, the one above the other, and sustained above the shafts
or bearings, having the same axis of motion as seen in the Drawings. The
said conic frustra should revolve in contra directions, as denoted by arrows in
the Figures. The diameter of the base of the lower frustrum is somewhat less
than the diameter of the lower. part of the interior of the hopper, there being a
circular space E left between them of a width to correspond with the diameter
of the shank of each of the screw-blanks, &c., and permit them to move freely
through it, as will be herein-after described. The exterior surfaces of the two
conic frustra should be roughened or indented in such manner as to act upon
the screw or pin blanks, &c., and cause them to revolve; generally speaking, the
angles of inclination of the exterior edge of the two conic frustra and the interior
edge of the hopper with respect to a horizontal plane are to be equal, or about
equal, as denoted in Figures 3 and 4. Between the inner face of the hopper
and the outer faces of the two frustra, I extend a partition, plate, fence, or
guard F, which I secure to the hopper and permit to approach as near as pos-
sible towards the frustra, so as not to interfere with their revolving movements;
and at a suitable distance from or on the right of the said fence or guard,
and between the interior face of the hopper and exterior faces of the frustra, I
arrange a revolving beater G. The said beater consists of one or more triangular
or other suitably shaped plates H, affixed to a horizontal shaft I, which extends
into the hopper, and is sustained in bearings L and M. The said beater may
be revolved by an endless band N, which may pass around a grooved pulley O,
placed upon the shaft P, of the upper conic frustrum, and thence over guide
pulleys Q and R, and under a small pulley S, fixed upon the shaft of the
beater. The lower conic frustrum should have a pulley T, fixed upon its axis.
From the said pulley an endless belt U, proceeds to and around a pulley V,
fixed upon a vertical shaft W. The said shaft has another pulley X, fixed upon

page_text: its upper end, the said pulley communicating with another (viz.), Y, upon the
shaft of the upper conic frustrum by a crossed band Z.
Instead of the aforesaid mode of giving motion to the several parts any
suitable gear work may be adopted.
The screw or other blanks of the kind are to be thrown promiscuously into
the hopper on the left hand side of the partition or fence F. As the upper
conic frustrum C, revolves from left to right, and the lower one D, from right
to left, they will disturb the screw blanks which come in contact with them in
such manner as to cause them to move successively downwards towards the
circular space E, before mentioned, through which the shanks will fall until
arrested in vertical positions by the heads of the blanks coming into contact
with the adjacent inclined surfaces of the lower conic frustrum and the hopper.
As the lower frustrum continues to revolve, it will advance each screw-blank
through the circular space E, in the direction in which it (the frustrum) travels.
The circular space E will thus be filled with screw-blanks, whose shanks stand
in vertical positions, as denoted at a, a. The object of the beater is to prevent
any one of the screw-blanks from over-riding the others, or passing towards the
delivery if they are not in a proper position in the space E. The object of the
upper conic frustrum is to prevent the blanks from being carried around towards
the beater in too great a body. It also facilitates the downward movement of
the blanks towards the space E. The triangular wings or arms of the beater;
shaped as seen in Fig. 3, revolve in the opposite direction to that of the lower
conic frustrum; they therefore throw or keep back such blanks as are not
properly suspended in the space E.
The next part of the apparatus to be described is that by which the blanks
are regularly delivered or freed from the circular space E. It consists of a
horizontal sliding plate b, shewn best at Fig. 5, which represents a view of the
under sides of the hopper and lower conic frustrum D, affixed to the lower
edge of the hopper just on the right of the partition F. This plate is suitably
sustained so as to slide towards and from the axis of the lower conic frustrum.
It is forced inwards or towards the axis of the frustrum by means of a sping c,
applied to it and attached to the hopper. The said check plate has a circular
aperture d, cut through one end of it, and a passage e, into the said aperture
ent through the side of the plate, the whole being as seen in the Drawings.
The inner end of the plate is cam-shaped as seen at f, so that when a stud g,
projecting from the under side of the lower frustrum is brought into contact
with it the stud shall press the slide outward or in a direction away from the
frustrum, and bring the passage e, into line or so as to correspond with the

page_text: circular opening E. When this takes place tlie movement of the lower
frustrum will carry one of the screw blanks through the passage e, and cause
it to drop out of the machine, the circular aperture & being larger in diameter
than the head of the blank.
The inner periphery of the conical hopper is formed with a recess just
under the check slide (not seen in the Drawings) of sufficient capacity for
the free passage of the heads of the screw-blanks or other articles when
delivered by the check slide. There is a small stud h, fixed on the rear side
of the entrance e of the, slide, which stud when the slide is pressed outward
enters between the screw-blank which is to be discharged and the one next
to-it, and thereby prevents the escape of the latter. As soon as the blank is
discharged, the side plate should be moved inward by its spring to close the
passage e, as shewn in Fig. 5. The screw or pin or other blank thus dis-
charged may be received by or into any apparatus calculated to hold or dispose
of it for any other operation necessary to be next performed. It will be
obvious from the foregoing that instead of the two central conical fustra, a
single one may be used; as the upper one is only to facilitate the arrangement
of the serew-blanks, &c: that they may freely enter the space E below; that
the inclined surfaces instead of being a rotating cone within a surrounding
hopper, either of them may consist of a chain belt having their surfaces
arranged relatively, so as to be the equivalent of the cone and hopper. And
as to the beater it may be used in combination with any other arrangement of
two inclined bevilled or curved, surfaces adapted to the arrangement of the
screw-blanks, &c. with their shanks hanging down between the inclined
surfaces and moving forward towards a point of delivery, the object of such
rotating beaters being. to knock back and prevent the passage towards the
point of delivery of any of the screw-blanks, &c. until they are properly
arranged with their shanks hanging down and suspended by their heads on
the lower edges of the inclined bevilled or curved surfaces. Nor do I wish to
limit the combination of the central frustrumi and surrounding conical hopper
and check, or delivery apparatus, to the special kind of sliding check herein
specified as any other kind of check or delivery apparatus which will prevent
the delivery of the screw blanks, &c. except at the required periods, will fulfil
the requirements of this part of the Invention, as I have simply described the
mode of applying this combination which is deemed the best.
What I claim as new under this head of the Invention is,
First, the method substantially as described of arranging screw-blanks, &c.
by the motion of oppositely inclined-bevilled or curved surfaces, with sufficient

page_text: space between them to receive freely the shanks of the blanks whilst they
hang suspended by their heads, the. said motion of such surfaces being in the
direction of the space between them, substantially as described.
Second, making one of the said inclined, bevilled, or curved surfaces in two
parts one above the other, substantially in the manner and for the purpose
specified.
Third, combining with the said oppositely inclined, bevilled, or curved
surfaces, a fence or guard plate placed across from the one towards the other
and over the space in which the blanks are suspended, substantially in the
manner and for the purpose specified.
Fourth, in combining with oppositely inclined, bevilled, or curved surfaces,
revolving arms, wings, or beaters; substantially in the manner and for the
purposes specified.
And, lastly, in combining with the said. oppositely inclined, bevilled, or
curved surfaces, a checking and delivering apparatus, substantially in the
manner and for the purpose specified.
The next part of the improvements relates to shaving or trimming the
heads of the blanks, and to inechanism for holding the blanks while the tools
operate on them, and to imechanism for feeding the blank to the holding
mechanism, of which the following is a full, clear, and exact description,
reference being had to the accompanying 'Drawings, in which: Fig. 1, B, is a
side elevation of the machine; Fig. 2, B, an 'end elevation, and Fig. 3, B, a
plan of the same; and Fig. 4, B, represents an elevation on an enlarged scale
of the mechanism for holding and liberating the blank, a portion of the hollow
mandril being removed to expose its interior; and Fig. 5, B, represents a
transverse section through the rear end of the mandril at the line X, X, of
Fig. 1, B.
This branch of the Invention relates, firstly, to the method of transferring
screw-blanks one by one from a hopper or other receptacle to jaws by which
they are held while undergoing certain of the operations of finishing, and it
consists of a feeding trough with a close bottom and open top, and composed
of yielding sections held together by springs or otherwise, into which the blank
drops from the hopper and arranges itself in the proper position before a
traversing rod which pushes it out of the trough in between the jaws.
This part of the Invention relates, secondly, to the method of setting the
blank in à position at which the cutting instrument can act upon it with the
best effect, and it consists in operating the instrument that transfers the blank
from the feeder into the griping jaws by a spring or its equivalent, and making
the instrument that guages the distance which the blank is permitted to enter

page_text: between the jaws adjustable, so that more or less of the blank will be
left projecting beyond the jaws as may be found expedient.
This part of the Invention relates, thirdly, to the griping and holding of the
blank in a rotating mandril, and consists in operating the jaws of the mandril
and holding them closed upon the blank with sufficient force to hold it firmly
under the action of the cutter without producing end strain upon the mandril,
by means of toggle or knuckle joint levers, which are thrown past centres
when the jaws are closed to hold them closed, in connection with a pair of long
shanked nippers, which by their clasticity admit of the toggle being thrown
past centres without releasing the gripe of the jaws upon the blank.
This part of the Invention consists, lastly, of a spring detaching punch con-
structed and arranged in such manner that the same shall be compressed by
the entrance of the blank between the griping jaws, and shall throw the blank
out of the jaws the instant they relax their hold of it sufficiently to permit it to
pass out, such pushing out of the blank depending upon such relaxation of the
jaws and the action of the spring punch being entirely independent of the
motion of any other part of the machine.
The machine represented in the Figures marked B, consists mainly of a
hollow mandril which carries a pair of griping jaws to grasp a screw blank to
hold it while under the action of the cutter, and to liberate it when the opera-
tion is finished; of a reciprocating tool holder which carries the tool forward to
shave the head of the blank and withdraw when the shaving is completed;
and of driving and cam shafts with pullies, cams, and other mechanism, to
give motion to the several acting members of the machine. The different parts
of the machine are mounted upon a strong bench whose form and construction
may be made to suit the place in which the machine is to be used.
Upon the bench A, two puppet heads B, are secured, which support the
revolving mandril C, in suitable boxes. That portion of the mandril between
the puppet heads is enlarged and turned into the proper form to act as a pulley
for the belt which puts the mandril in motion. This mandril carries the griping
nippers D, which are supported between a pair of lugs C', that project from the
front extremity of the mandril, and are secured thereto by joint pins a, which
pass through both the lugs and the limbs of the nippers. The shanks D' of
the nippers are made long to give them considerable elasticity, and they pass
through the mandril to its rear end; they are forced towards each other by
springs b, to keep the jaws open at all times when they are not pressed together
to grasp a blank. The jaws of the nippers are shut by forcing their shanks
apart, and this is effected in this instance by means of a pair of knuckle joint
levers E, which diverge from a central block F. The latter has two armse, at

page_text: right angles with the levers, which are fitted to slide longitudinally in corre
sponding grooves formed in the hinder extremity of the mandril to direct the
block in moving. This block forms the head of a rod F, whose axis is in line
with that of the mandril and whose hinder extremity is swivelled to a cross
head F, between a pair of standards G, which are fixed at the hinder extremity
of the bench. The inner sides of these standards have grooves formed in theni
on a level with and parallel to the axis of the mandril, so that the cross head,
may slide freely therein towards and from the end of the mandril. The inner
extremities of the knuckle jointed levers are fitted into sockets in the head F.
Their outer extremities are received in boxes g, seated in sockets formed in the
hinder extremities of the shanks of the griping jaws, and are fitted with set
screws g', by means of which the positions of the boxes can be adjusted to
cause the jaws to approach within a greater or less distance to adapt them to
griping blanks of different sizes and with varying degrees of pressure.
Beneath the cross head F of the rod F¹, an elbow lever H is pivotted to the
bench. One arm of this lever enters a hole made in the cross head to receive
it, so that whenever the arm is vibrated, the cross head F, with the rod F',
will be moved to and fro. The other arm of the lever enters a hole in the
upper extremity of a rod I, which slides up and down in suitable guides, and
whose lower extremity has an anti-friction wheel / pivoted to its side in such
a position that it comes within the range of two revolving cams J, J', on the
shaft K, by which it is alternately elevated and depressed to raise and lower
the rod I, and vibrate the bent lever II.
The horizontal rod F1, when moved backwards, will flex the knuckle joint
levers E, and allow the springs b, to force the shanks of the nippers together
to open the jaws, and when the rod F is moved forward, the levers E will be
forced into a line with each other to separate the shanks D', and close the
jaws with great force upon a screw blank placed between them. Mechanism
for discharging the screw blank after it is shaved is arranged within the griping
jaws. This mechanism consists of a straight rod or punch L, whose front
extremity is arranged to slide in the same grooves in which the blank is held
in the adjacent faces of the jaws of the nippers. The hinder extremity of this
rod enters a socket in the head block F, which guides it in moving; a collar or
stop is formed near the front extremity of the punch, to prevent it from pro-
truding beyond the jaws when the blank is discharged. A spring is coiled
upon the punch which constantly tends to force it forward endwise between the
griping jaws.
Immediately in front of the griping nippers, the feeding apparatus is placed.
It consists of a stock M, mounted upon the upper extremities of a pair of arms

page_text: i, which project from a rock shaft m, at the side of the bench. This shaft is
operated by a cam m', and a spring Q', in such manier as to vibrate the stock
from the middle of the bench in a line with the axis of the mandril to the side'
of the frame, where it passes under the hopper or other receptacle. for the
blanks to be dressed. On the front extremity of the stock M, a pair of nippers
m' is secured by means of pivots o, on which they turn to open and shut. These
jaws are constantly pressed together by means of spiral springs p, inserted
between an arm on each jaw and, a corresponding projection of the stock:
The upper side of these jaws is hollowed or scooped out, so as to form a trough
for the reception of a screw blank, and the adjacent faces of the front ex-
tremities of the jaws have semi-cylindrical grooves cut. in them.. of sufficient
size to admit the shank of a screw blank. Behind the jaws M', and in a line
with the aperture through. their front extremity, a hole is formed through the
stock M, to admit and guide a rod M², which when moved towards the jaws
M', will push the blank shank foremost out of the trough through the aperture
formed in its end. The jaws M are pressed upon the blank as it passes out
to guide and steady it, by the springs which yield to allow the jaws to open to
permit the head of the blank to pass through on its transit from the trough to
the griping nippers. This operation takes place when the trough is over the
middle of the bench, so that the blank and the pusher will be in a line with
the axis of the mandril, that the blank may enter between the jaws and force
the punch L back to compress its spring. After a blank has thus been trans-
ferred from the feeder, the latter is immediately moved by suitable mechanism
over to the side of the bench beneath a hopper to receive therefrom another
blank, which in turn is carried into line with the axis of the mandril and
transferred into the nipper. simultaneously with the movement of the feeder
towards the hopper. A bent tube P. is moved towards the nippers until its
upper extremity is brought into line with the blank under operation to receive
the latter when dressed, and conduct it into a box or other suitable receptacle.
Neither the hopper to contain the supply of blanks nor the mechanism for
delivering the blanks therefrom to the feeder are described, as they form no
part of this Invention.
The pushing rod M² has a boss r, depending from its under side, which has a
recess formed in it to receive the upper extremity of a lever Q, whose lower
extremity is pivoted to a bracket 9, on the leg of the bench. This lever is
connected near its middle with one extremity of a horizontal rod Q', whose
opposite extremity is forked to embrace the shaft K, which guides it, and on
which it is free to slide back and forth. The front or guided extremity of the
rod has a short lateral arm Q², depending from it, which is within the range_ of

page_text: motion of a cam Q, on the upright shaft K, so that as the cam turns it will
push back the rod Q, and with it,the lever Q, and the pushing rod M², from
the griping nippers D, in which position they will be held until the cam has
passed the arm Q, when a spring Q, which is coiled around a rod sliding. at
one end in a bracket attached to the leg of the frame, and at the. other end
connected with the rear end of the rod Q, will cause. the lever Q, and pusher
M², instantly to return into the position whence they were moved by the cam
Q, and to discharge the blank from the feeder into the jaws. of the griping
nippers. A set screw. R is passed through a lug projecting from the top of the
bench at the front extremity of the slot Q, tlirough which the lever Q passes,
that gives motion to the pushing rod M. This set screw limits the movement
of the lever Q, and that of the pusher, M, and consequently gauges the depth
to which the shank of the screw blank is made to enter: between the griping
jaws and the distance which its head is left projecting therefrom. This is a
point of very considerable importance, as it admits of the head of the blank
being set exactly in range with the cutter that dresses it, so that the cutter,
may be clamped firmly to the holder, instead of being made, adjustable at the
expense of firmness and solidity....
The tool holder consists of an upright oscillating shaft S, mounted in a
bracket on the side of the bench, and carrying at its upper end an arm S', on the
extremity of which the cutter. T is secured by clamp screws or otherwise. The
lower extremity of the shaft. carries a second arm S2, upon which a cam S, on
the shaft K acts, to force. the tool T against, the screw. blank to be dressed:
This arm has a set screw t, in its end, by the adjustment of which the tool will
be caused to approach within a greater or less distance of the axis of the blank,
or in other words, it will dress it down more or less. When the most pro-
tuberant part of the cam S" is not acting against the armS, the latter is
pulled inwards by a spring S, to turn the upper arm S! outward,; to remove
the cutter out of the way of the feeder and of the receiving tube P, so as to
allow both to perform their functions properly.
The tool when mounted. in a holder thus constructed and arranged, will
approach the head of the blank to shave it at about the angle of forty-five
degrees to its axis of rotation. This mode of operating a tool of the proper
form to shape the head, as shewn in Figs. 1 and 3 of the Drawing, will cause
the under or inclined side of the head to be shaved first, and then the top,
so that the tool will press.mainly in the direction of the length of the blank
and towards the mandril, so that the pressure.of the tool will have but little
tendency to wrench the blank out of the jaws. By this means the blank can be
held while being shaved with sufficient firmness, without the use of a rest to

page_text: support it against the pressure of the cutter, and will constantly rotate freely
on its axis, so that when finished its head will be round, whether in its rough
state it were round or not.
This oblique movement of the cutter may be produced by carrying the tool
holder towards and from the nippers, on ways or guides inclined to their axis
of rotation, instead of employing the swinging or oscillating arm to carry it;
but I do not deem it necessary to describe in detail the various means which
might be used to carry the tool obliquely to the blank.
On the lower part of the bench a driving shaft is mounted in suitable boxes
and carries a pulley that drives the mandril by means of a belt which encircles
both. On the rear end of the mandril behind the puppet a second pulley is
formed that drives a pulley on a counter shaft by means of a belt. The
counter shaft carries a worm or endless screw which gears into a worm wheel
by which the cam shaft is turned.
When the machine is put in operation it will perform the various move-
ments required to shave the head of a blank in the following order. The
knuckle joint levers are flexed by the backward movement of the horizontal
rod to open the jaws. The feeder which meanwhile has received a blank from
the hopper is brought into line with the axis of the mandril, and the blank is
forced by the pusher out of the feeder between the jaws of the nippers and
against the punch, which yields to permit it to enter. The knuckle joint levers
are now by the return movement of the rod extended to close the jaws upon
the blank, and the movement of the rod is continued until the levers are
pushed slightly beyond a straight line to cause them to lean against the corners
a, of the sockets in the shanks, in which position they stand to hold the shanks
apart and the jaws together, to grasp the blank firmly without any tendency
to produce endwise pressure of the mandril against its bearings, the clasticity
of the long shanks preventing any relaxation of the grasp of the jaws upon the
blank when the toggles are past centres. The feeder now moves to one side,
and the cutter is gradually borne against the blank, which is revolving rapidly
with the mandril, until its head is shaved down to the required size and shape,
when the cutter is withdrawn and the jaws are opened again by the flexing
of the knuckle joint levers to liberate the blank which is ejected from them
into the receiving tube by the punch. The machine is now ready to receive
another blank to shave it by a repetition of this operation.
I have described the improvements as applicable to a machine especially
adapted to the shaving of the heads of screw-blanks, but it will be evident to
the skilful mechanician that some of the most important of them are applicable
to, and would greatly improve the operation of machines by which various

page_text: other operations in the manufacture of screws are effected. Thus, for example,
the feeder may be adapted to receive the screw blank with its head towards the
griping jaws, and the latter may be constructed to admit and gripe the heads
of screw blanks, thus holding them firmly while their shanks are being shaved
'or threaded."
The mechanism for imparting motion to the several moving members of the
machine, and for directing their movements may likewise be varied. Thus,
for example, the feeder may have a longitudinal alternating movement instead
of a lateral alternating movement, and the hopper will also have, in such case,
to be adapted to this arrangement. Instead of the knuckle joint levers to open
and close the jaws of the nippers various other devices may be used with very
good effect, although these are deemed the best. These and other modifications
of the mechanism will be readily carried into effect by skilful mechanicians, if
circumstances should ever render it necessary to make them.
Having thus described this branch of the improved machinery for the
manufacture of screws, I wish it to be understood that I claim,
First, the feeder composed of a sectional trough with a close bottom and open
top into which the blank drops and arranges itself before a traversing rod which
pushes it into the griping jaws, substantially as described.
Second, the combination of the traversing rod actuated substantially as
described, with an adjustable stop for the purpose of setting the blank between
the jaws in the exact position required, as herein set forth.
Third, the method of operating the jaws and holding them closed with the
requisite force to hold the blank firmly between them without end strain upon
the mandril, by means of toggle or knuckle joint levers acting upon the
shanks of the nippers, the levers being thrown slightly past centres when
the jaws are closed to hold them closed, whereby all end strain of the mandril
against its bearings is prevented during and by the griping and holding of the
blanks.
Fourth, the spring discharging punch, constructed and arranged in such
manner that the same shall be compressed by the entrance of the blank
between the griping jaws, and shall throw the blank out of the jaws the instant
they relax their hold of it sufficiently, such pushing out depending upon such
relaxation and the force of the spring, and being entirely independent of the
motion of any other part of the machine.
And, lastly, I claim the method of shaving the heads of screw blanks by
causing the cutter to approach the blank obliquely, and in a line or nearly so
with the under side of the head, whereby the use of a rest to support the blank
B

page_text: against the pressure of the cutter is dispensed with, substantially as herein
set forth.
The next branch of the improvements relates to the pointing of the blank
and cutting a screw head thereon, and the following is a full, clear, and exact
description thereof, reference being had to the Drawings of the same..
Fig. 1, C, represents a front elevation of a machine, with the improvements
applied thereto; Fig. 2, C, is also an elevation of the side of the machine, on
the left of the view represented in Fig. 1,, C, .with a portion of the frame
removed; and Fig. 3, C, is a horizontal section looking downwards from the
line X, X, of Fig. 1, C.
This branch of the Invention and improvements consists in the particular
construction and arrangement of the mechanism for pointing the blank and
threading it by means of different cutters in the same machine; held in and
operated by the same tool holder, and having a common motion, whereby the
pointing and threading of the blank are performed at a single operation.: Such
parts of this machine as are not particularly claimed will only be referred to
briefly, the description in detail being restricted to the parts that constitute and
more immediately relate to the subject matter of the claims."
The Drawing represents a strong frame A, which supports the other parts of
the machine, among which B is the tubular rest for supporting the blank while
under the action of the cutters. C is the discharging rod, which at the proper
time enters the rest in the manner of a piston and discharges the finished screw,
and is then immediately withdrawn to permit a rough blank to be placed in the
rest to be in its turn pointed and threaded. D is the screw driver or turn
screw, by means of which the blank iş rotated while under the action of the
cutters. The mandril Da of the turn screw is made the driving shaft. It
receives motion from the driving pulley E, and transmits this motion through
a pinion F, mounted near its middle, and through the reducing gear wheels:
F, F, F, to the cam shaft G, which by means of its cam M, regulates, and
controls the longitudinal movements of the cutters along the blank so as to
determine the pitch of the thread. H is a turning and sliding bar, which
carries the tool holder I, and traverses the cutting tool lengthwise of the blank,
as will be presently described. Beneath the wedge formed cam M, for deter-
mining the pitch of the thread, a conical or conoidal cam N is mounted on the
shaft G, for determining the depth of the successive cuts by which the thread
is formed by acting at each successive cut with a greater radius. This cam
regulates the position of the tool holder through a lever J, which at one end
carries a shoe to bear upon the face of the cain, and at the other end carries a

page_text: gauge plate j, in which the arm K slides, and which turns the shaft H with its
tool holder I towards or from the rest as it is moved forward or back, and thus
causes the cutter to approach towards and recede from the axis of the blank.
The cam N has a portion n of its periphery (which is designed to control the
chasing tool when acting upon the point of the blank) excentric to its axis of
rotation, and more protuberant than the rest, in order that the tool may by this
sudden elongation of the radius of the cam which controls its position be caused
to approach suddenly towards the axis of the blank, and produce upon it a short
blunt point, as represented....
The thread is formed by a succession of cuts of the chasing tool, made suc-
cessively deeper by changing the position of the conical cam N, and causing. it
to act by. radii of gradually increasing length. The position of this cam is
changed as follows:-A wiper L on the cam shaft acting through the long
arm L'of a lever actuates a pawle L² on its shorter arm, that takes into a
ratchet wheel O on a counter shaft P. The latter carries a wedge-shaped cam
Q, which acting upon a lever R raises the conical cam N, so as to bring suc-
cessive sections of its length of gradually increasing radius to act upon the
treadle J, to turn the shaft H, and move the cutter towards the axis of the
blank. The acting face of the cam Q has different degrees of inclination to its
axis, so that by the turning of the ratchet wheel O one notch at each revolution
of the cam shaft G, which corresponds to one cut of the chaser, the latter will
at the commencement of the operation of threading a blank take rank hold and
remove the surplus material rapidly, while towards the end of the operation.
or during the last cuts of the chaser it will make shallow cuts and operate to
trim and so give a smooth finish to the Screw.
A spring L³ is attached by a strap 1, passing over a pulley, to the arm L'
of a lever on the sleeve L', on the shaft P, to hold it against the cam L, and
to return or draw back the pawle L' after it has been advanced to turn the
ratchet wheel O one notch. At the end of the stroke of the cutter S is a disc
also mounted on the counter shaft P, that supports an arm S', connected with
a shifting rod T', that holds the mandril D in connection with the driving
power during the operation of pointing and threading a blank, by means of a
clutch D and arm D; but when the screw is threadled, the arm S' is permitted
to drop into a notch of the disc S to shift the clutch, and thus disconnect the
operating parts of the machine.from the driving power. T is a hand lever to
raise the shifting rod T to lift the arm S¹ to unlock the machine, and at the
same time to raise the arm D2 and clutch D' to throw the latter into the gear
with the driving power and set, the, machine in, motion. U is a lever handle,
that by turning in one direction bears. against an arm U₁ of a rock shaft and

page_text: depresses the same, and simultaneously depresses a second arm U2, that clutches
by its forked extremity a collar U on the mandril D* of the turn screw.
By reversing the movement of the lever handle U, the turn screw is raised
to liberate the blank. The former of the movements just described takes
place at the beginning, and the latter at the end of the operation of threading
and pointing a screw. A spring U is connected with the arm U¹ of the rock
shaft in such manner as constantly to tend to keep the turn screw raised from
the rest. The sliding and turning bar H (that carries the tool holder I) is
held in contact with the face of the wedge-formed cam M that traverses
it by a spring II. The tool holder I is a standard secured to the sliding
and turning bar H. The head of this standard is perforated to receive the
chasing tool b, and the pointing tool c; the chasing tool is clamped in its scat
by a screw c. The tools thus arranged in the head of the holder stand at
right angles to both the sliding bar H and axis of the screw blank h, and they
also stand at a distance from each other equal or thereabouts to the length of
he screw thread to be cut on the blank. The pointing tool c projects further
from the holder towards the blank than the chaser, in order that it may come
into contact with the blank, and perform its office before the chaser begins to
act; and that this may be done conveniently, the chaser is brought very
slightly nearer to the head of the blank than usual, and is not pressed inwards
by the action of the conical cam to commence its cut until the holder has
moved far enough towards the point of the blank to remove the cutting edge
of the pointing tool far enough from the surface of the blank to prevent it
from cutting while the chaser is acting. The sliding bar on which is the tool
holder receives two motions, one longitudinal and derived from the wedge-
shaped cam M, and the other an oscillating or rocking motion at right angles
to the first, and derived from the conical cam N. These motions thus derived
are communicated to the tools, the longitudinal traverse giving the pitch to the
thread, and the transverse traverse or oscillation regulating the depth of the
thread. The wedge-formed and conical cams have each a dead motion
between the completion of one cut and the commencement of another, and the
dead motion of each is of uniform radius throughout its whole length, so that
the cutters will fall back both transversely and longitudinally to the same point
after each cut.
These cams are also so shaped that by a given angular motion they will
impart a transverse movement to the tool holder, that will bring its cutters at
the commencement of each stroke to the same distance from the blank at the
instant the longitudinal movement commences, in order that the pointing
cutter may by a transverse movement of the holder be caused to perform its

page_text: office before the chaser begins its first cut; and then as the wedge-shaped cam
M. begins to act, giving a longitudinal movement to the holder that the
pointer may be carried out from the point of the blank, so that it can no
longer cut, the instant the movement of the cams exceed the said given
angular distance, by which means the chaser is free to cut deeper and deeper
at each successive cut without bringing the pointing cutter into action after
the first cut. The edge of the pointing tool should be bevilled off until it is
parallel to the side of the point required to be made by it, as represented in
Fig. 1, C, and the distance to which the cutting edge of this tool should be
advanced beyond the point of the chaser, as before stated, should be equal to
the difference, being the depth of the thread and the radius of the blank, so
that the thread may run to a point. If a sharp point is not required, then
the projection of the cutter beyond the chaser must be correspondingly
diminished. By this arrangement a separate cutter in the same tool post is
made to relieve the chaser of the severe duty of reducing the end of the blank
to a point without increasing the number of cam movements, or otherwise
adding to the complexity of the machine beyond the mere affixing of a pointing
cutter to the tool post which carries the chaser:
What I claim as new in this branch of the Invention is pointing and
chasing the blank in the same machine by different cutters, substantially as
herein set forth.
For the further improvement of this branch of the manufacture, the
Inventor has devised an improved machine for threading the blank, which
for certain purposes he deems superior to all others.
The following is a full, clear, and exact description of this machine, reference
being had to the annexed Drawings, in which Fig. 1, D, represents a view in
perspective of one of the improved machines adapted to the manufacture of wood
screws; Fig. 2, D, represents a plan of the same; Fig. 3, D, represents an
elevation of the side of the machine opposite to that which is seen in the per-
spective view; Fig. 4, D, represents an elevation of that end of the machine
at which the cutter is situated; and Fig. 5, D, represents a horizontal section
taken through the axis of the cutter (the blank being threaded) and through
the adjacent parts of the machine.
In this method of threading screw blanks it is necessary that they should
receive the same previous preparation that they receive to fit them for being
threaded by the machine previously described for that purpose.
In the operation of threading the points of wood screws by means of a
chaser, as heretofore practised, the axis of the point is deflected by the pressure
of the chaser to a greater or less extent, as the cutting edge of the latter is

page_text: dull or sharp; and this deflection gives to the point à tendency to run into or
over-ride the chaser, which results when it takes place in either bending the
blank, breaking off its point, or otherwise damaging it so as to render it
unsaleable, and therefore a refuse piece of metal. Difficulties of this kind
constantly occur when unremitting attention is not exercised to keep the cutter
adjusted at the 'exact position above the axis of the blank, which compensates
for the deflection of the latter in the operation of cutting; and thus prevents
it from over-riding the chaser. And as the distance to which the blank is
deflected depends upon its rigidity and the amount of lateral pressure against
it, and as the latter depends upon the sharpness or dullness of the cutter, it
will be seen that it is an exceedingly nice and difficult operation to keep the
ordinary mechanism for threading the point of a wood screw in good working
order. A further difficulty in threading the point of a wood-screw arises from
the point of the blank being unsupported while the cutter is acting against it,
which permits a horizontal deflection of the point from the cutter, which is
greater or less as the shank of the screw is 'more or less flexible, and springs
more or less towards the cutter to permit the point to bend from it, so that a
compensating adjustment for the horizontal deflection is as difficult as that for
the vertical deflection..
To obviate these defects and to secure other advantages is the object of this
branch of the Invention, the first part of which relates to a cutter for threading
screw blanks of soft material, such as iron or brass. This cutter is made of
hard material, such as tempered steel, and in form is a screw, the counterpart
of that which is to be produced by it, but of much greater diameter. This
cutting screw is of unequal depth of thread, of uniform pitch of thread, and of
unequal diameter, so that portions of the "thread of the cutter which have the
greatest amount of material to reduce or cut away in threading the blank have
also the greatest circumferential motion and the greatest cutting capacity,
while those parts which have the least material to cut away have the least
circumferential movement and the least cutting capacity, whereby a screw
blank can be reduced to any required shape and threaded at the same operation,
with the advantage among others of not subjecting either the blank or cutter
to undue strain or excessive wear by the increased depth of cut at particular
parts.
The next part of the Invention consists in arranging the axes of the rotating
cutting screw, and of the rotating blank to be threaded by it, parallel to each
other, so that the cutter may run smoothly and steadily, and that its threads
may not bind in the grooves of the blank and strain the metal between
them.

page_text: The next part of the Invention consists in 'causing the axis of the cutting
-screw and the-axis of the blauk to: rotate in the same direction during the
operation of threading, in order that the metal may be cut from the grooves of
the blank from the bottom outwards, or- from the axis inwards towards the
periphery, whereby the chips detached from the blank by the cutter are
prevented from wedging in between the two and 'creating great strain and
friction, as they would do if the cut was from the periphery towards the centre,
which-would-force the chip from a wider to a narrower space, instead of forcing
it from a narrower to a wider, as by this arrangement.
The next part of. the Invention consists in the combination of a cutting
screw with a rest to support the blank while being threaded; the cutter and
rest being so arranged and operated, that while the blank is firmly sup-
ported against the pressure produced by the action of the cutter, the axes of
the two are caused to approach gradually, so that the helical groove may be
formed in the blank by a spiral cut conimencing at the circumference of
the rough blank, and winding round and round to form the groove by the
removal of a shaving, turning a greater or less number of times around
the blank as the approach of the axis of the latter and the cutter is more
or less rapid. By this arrangement, all the rigidity and smoothness of
cut which can be secured by placing the cutter and rest at a fixed distance
apart while the cut is being made are attained, together with all the facili-
ties: for presenting and discharging: the blank which the absence of a rest
affords.
The next part of the Invention relates to the feeding of the blanks, one at
a time, shank foremost, into the rest, where they are held under the action of
the cutter and threaded; and it consists in the use of a feeding box through
which the screw-driver is arranged to pass and repass in moving. towards and
from the rest, the trough receiving one blank upon the screw-driver, while
the latter in its forward position is holding another, to be threaded, so that
when the driver is drawn to its backward position to liberate the threaded
blank, the unthreaded one will drop down in front of it in the proper position
to be caught on its return movement and pushed' forward into the rest, to be
there held and threaded...
The next part of the Invention relates to the discharge of the threaded
blank from the rest and from the mechanisni' by which it is rotated; and it
consists of a vibrating arm, or the equivalent thereof, to detach the head of the
screw from the driver or liolder acting in combination with a reciprocating
punch to force the blank out of the rest. The combined operation of these two
instruments-ensuring the discharge of one blank before the introduction of

page_text: another, thus avoiding the danger of breaking the machine, which is always
imminent when an unthreaded blank is presented before the threaded one is
discharged.
The next part of the Invention relates to the operation of the screw-driver
by which the blanks are turned while under the action of the cutter; and it
consists in imparting to the bit of the screw-driver a light yielding pressure
against the head of the blank until it finds and enters the nick, and then
applying to it a heavier pressure to keep it engaged with the blank while the
latter is turned to be threaded.
'
"The machine represented in the accompaying Drawings shews one mode of
applying this Invention. It consists of two principal parts acting in combina-
-tion, the mechanism for cutting the thread or screw upon the blank, and the
mechanism for presenting the blanks in succession and in the proper manner
to the cutter. These I shall call respectively the cutting and the feeding and
.holding mechanism, both of which have one common prime mover to com-
municate to them the proper relative motion. These combined mechanisms
are supported upon a strong bed plate A, made, in this instance, of cast iron,
having several standards B, C, D, E, projecting from its upper side to support,
at the proper height, different parts of the mechanism which are secured to
them. This bed plate has suitable holes a made through it to receive bolts
for fastening it to a strong bench or other foundation.
On the standards B and C, puppet heads F and G are secured to support
the mandril H, which carries at its front extremity the cutter I. The rear
puppet head F has a fixed bearing made in it for the back journal of the man-
dril H to turn in, but the front puppet head G has an aperture bored through
it of considerably larger diameter than the journal of the mandril and excentric
thereto. This aperture is fitted with a cylindrical plug J, which is free to turn
therein. This plug has a flange b on its rear end, and is held in the puppet
head by a pin c, which projects from a hole in the adjacent part of the frame.
This cylindrical plug has an opening bored through it, both parallel and
excentric to its axis, and this opening constitutes the box or bearing for the
front journal of the mandril. An arm K extends in a downward direction
from the flange 6 of the excentric bearing J. The lower extremity of this arm
is fitted with a rubber or shoe d, which is adjusted by means of a screw e,
fitted with a jam nut to hold it in any position to which it may be set. This
shoe is held against a cam L, by the spring M, which presses on the arm K, so
that as the protuberant portions of the cam press the arm K outwards, the
excentric bearing in the plug J, with the mandril H, will be turned inwards,
while, as the less protuberant parts of the cam allow the spring M to press the

page_text: arm K inwards, the plug J will turn in such manner as to carry the mandril
outwards. The rear end of the mandril projects beyond the puppet head F
far enough to receive a belt pulley by which it is driven, and the mandril is
prevented from moving endwise by collars f and f¹ secured to it on either side
of the puppet head by set screws passing through them.
"
The front extremity of the mandril has a solid collar g formed on it, with a
wide shoulder to support the cutter which is clamped between this fixed roller
and a moveable one h by a nut i on the end of the mandril. The cutter I
is a disc of solid steel of about thirty times the diameter, and in thickness
equal to the length of the threaded portion of the shank of the screw it is
intended to cut.
The centre of this disc has a cylindrical opening made through it, which is
concentric with its axis, and which fits upon the mandril between the collars.
The periphery of this disc is, except in diameter, the exact counterpart in
outline of the screw required to be produced by it on the shank of the blank,
the counter thread on the disc being the exact counterpart in shape and pitch
of the thread to be cut. This counter thread is divided by oblique cuts into a
series of teeth, which in revolving in contact with the shank of the screw-
blank, reduce it to the required shape, thus forming the screw thereon. This
cutter is adapted to the formation of a gimlet-pointed screw, with both a
tapering body and a thread tapering at both extremities. The rear end or
head of this disc is the smallest in diameter and has the least cutting capacity.
And this part corresponds to the upper end of the thread which is shallow,
and therefore requires but little cutting action to produce it. The cutter at
this end increases in diameter somewhat abruptly at first for a short distance,
and then tapers gradually to near the front end or head of the disc, where it
again suddenly increases in diameter, so as to reduce the end of the blank to a
point, and thread it. Here the greatest amount of cutting action is required,
and here the cutter has the greatest capacity for cutting, as its cutting power,
other things being equal, is proportionate to its diameter.
A rest block N is secured to the standard D, opposite to the cutter I, and
barely clear of its periphery when the two are nearest together. The inner
end of this block has a flange l on its rear edge, which overlaps the inner head
of the cutter. Between this flange and its front edge, the face of this block is
transversely the counterpart in shape of the periphery of the cutter, and verti-
cally is coincident with the tangent to the periphery of the cutter. A trans-
verse cylindrical channel m is made in that part of the face of the rest which is
nearest the face of the cutter; this channel is parallel with the axis of the
cutter. That portion of it which passes through the flange is cylindrical, and

page_text: its rear end is countersunk to receive the head of the blank; the remainder of
the channel is semi-cylindrical or thereabouts. The cylindrical portion of the
channel receives the shank' of the blank, and as the two are of such relative
diameters that the latter will barely turn without binding in the former, it is
supported with great steadiness and firmness in the same manner as a shaft in
its box.
..
The blanks are inserted into the rest one at a time and shank foremost by
means of a reciprocating feeding trough (), and a reciprocating and rotating
screw-driver P, which passes through the trough when it moves forward, and
repasses through the trough when it moves back, so that if a blank is dropped
into the trough in front of the driver when the latter is in its most back-
ward position, it will be pushed forward from the trough O into the channel
m in the rest, when the driver again moves forward. A screw blank is
fed into the trough O, by a suitable feeder of the usual or any approved
construction, every time the screw-driver P is carried forward towards the
rest N.
:
This blank lies upon the stem of the screw-driver while the latter remains
forward, so as to be ready to drop down into the bottom of the trough in front
of the driver the moment the latter is drawn back. The screw-driver P is secured
to the front extremity of a mandril Q, which is supported in bearings in puppet
heads R and S, secured to the standard E. The rear end of this mandril
projects beyond the puppet head S, through a pinion n, in the eye of which is a
feather that enters the longitudinal groove p on the mandril, by which arrange-
ment the mandril may slide freely through the eye of the pinion, while neither
can turn without rotating the other. This arrangenient allows the screw-driver,
while being continuously rotated by the pinion, to be alternately moved from
and towards the rest to discharge a threaded blank and present an unthreaded
one.
The rear extremity of the mandril Q has a collar 7 formed on it, which
turns between the forks at the upper extremity of a lever T. This collar is
rather narrower than the space between the forks of the lever T, so as to allow
the mandril a little end play. A spring shewn in red lines in Fig. 3 is inserted
in a socket formed in the end of the mandril, which bears against the rear
limb of the fork, and constantly presses the collar ġ formed on the mandril
against the front limb of the fork. The object of this spring is to allow the
screw-driver to yield slightly when pressed against the head of a screw blank,
to enable the bit with the greater facility to find and enter the nick, and to
avoid the bruising of the head, which results when a screw-driver rigidly held
is pressed while turning against the head of a blank in a fixed and solid rest.

page_text: The front extremity of the screw-driver Ppasses through the 'trough O, and
out at its "front end when in its most forward position (as shewn in Fig. 5),
and when in its most backward position (as shewn in red lines in the same
Figure,) it is withdrawn into a socket in the rear end of the trough. The bit
of the screw-driver'should be of the proper size to enter the nick in the heads.
of the blanks.
On that portion of the mandril Q between the puppet heads a grooved
collar is secured, which embraces the arms that projects up from a bar t; the
latter slides in bearings in the legs of the puppet heads R and S, so as to move
parallel to the mandril Q. By the side of the bar t, and in the same bearings
another sliding bar is placed; the two bars are of uniform breadth and
thickness, and their adjacent sides fit smoothly together. The bar u has a
longitudinal slot v made in it; through which a round arm 'w projects from the
bar t: This arm has coiled round it a spring, which at one end bears against
a washer which slides against the. bar u, and at the other end presses against
à pin in the outer end of the arin w, so that the bars u and tare clamped
together with a force equal to thic tension of the spring. The object for which
these bars are thus clamped together is, that the bar t may, when moved back
and forth by the collar, carry with it the bar by friction until the latter is
arrested by a stop, while the former is free to move on. The front end of the
bar has a standard a projecting up from it which carries the feed trough o,
and as the motion of the latter is more limited in its range in both directions
than the screw-driver, the movement of the latter carries it back or forward by
sliding the two bars à ánd:t together, until the trough strikes a stop, when the
bar u is arrested; but the bar tislides on until 'the screw-driver has attained the
extremity of its range of motion.
The bar textends forward beyond the standard D, and is then bent upwards
to the proper height to support a punch y, whose axis is in line with the axis
of the cylindrical channel m.in the rest. Whenever the screw-driver is drawn
backward, 'the punch y will also be moved in the same direction. The
end of the punch is placed at such a distance. in advance of the rest that it
does not enter the groove m to push out the threaded screw until the screw-
driver has moved back far enough to give room for the free discharge of the
screw. When the screw-driver inoves forward it carries the discharge punch
with it, which is moved out of the front end of the groove m before the blank
enters its rear end.
To prevent the adhesion of the head of the screw to the bit of the driver, a
vibrating arm U is arranged at the side of the rest N, and is suddenly
depressed at the instant the screw-driver is passing into the trough O, so as to

page_text: strike the screw and detach it from the driver. This arm projects upwards
from a shaft U, which is supported in bearings formed in brackets U². A
spring U³ is secured on the shaft U'; a second arm U projects downwards
against the periphery of a cani V, on which a tappet or pin V projects, which
strikes the arm U', and turns it suddenly outward once at each revolution of
the cam.
This movement outward of the arm U turns the end of the arm U
suddenly in towards the screw-driver to detach the blank.
The cams L and V are mounted upon. the opposite extremities of a shaft,
supported in a long bearing in a puppet head W, secured by bolts to the bed
plate A. Between the cam V and the rear end of the puppet head W, a cog
wheel X is secured to the cam shaft. This cog wheel receives motion from a
pinion X' on a counter shaft above it, and this pinion is connected with and
moved by a wheel X3, which is driven by a pinion X3, secured to and turned
by the mandril H of the cutter. The wheel X2 gears into and drives the
pinion n on the mandril of the screw-driver, which pinion is of equal diameter
with the pinion X3, so that the pinions X3 and n will at all times turn with
equal velocity to rotate the blank and the cutter simultaneously with equal
speed and in equal times.
The cam V has a narrow ring formed on the outer edge of its front side,
against which a shoe or arm T¹ projecting from the inner side of the lever T
bears.
This ring on the cam for about ten-twelfths of its circumference is parallel
to its plane of rotation, and therefore does not move the lever T. About two-
twelfths of this ring are depressed into the face of the cam to allow the
lever T to be drawn back by the spring T, for the purpose of moving the
screw-driver back to discharge a threaded blank, and to bring an unthreaded
blank into range with the rest, ready to be pushed forward on the return of
the screw-driver. This depression in the ring of the cam has both its ends
inclined; the inclination at that end of the depression which allows the screw-
driver to fall back has a step in it, which causes the driver to stop for a
moment about the middle of its backward movement, while the arm U strikes
to detach the screw.
The inclination at that end of the depression which causes the screw-driver
to move forward is gradual, so that the bit of the driver may have time to find
and engage with the nick in the head of the blank before it is pressed forward
by the flat portion of the ring on the face of the cam with the requisite force
to hold and turn the blank under the action of the cutter. This depression in
the cam V is shewn in red lines in Fig. 3.
The cam L, on the front end of the cam shaft, is turned simultaneously with

page_text: the cam V. The acting portion of this cam is its periphery, which for about
nine-twelfths of its circumference is excentric to its axis; for about one-twelfth
more it is concentric at its most protuberant part with its axis; and for the
remaining two-twelfths of its circumference it is concentric at the least protu-
berant part with its axis.
The concentric portion of the least protuberant part of the cam corresponds
to the depression of the two-twelfths of the acting ring face of the cam V, so
that while the screw-driver is kept in its backward position by the latter cam,"
the cutter wheel is held by the former cam at its greatest distance from the
rest, and when the cam V has forced the screw-driver forward, and with it a
blank into the channel m of the rest, the cam L, at the commencement of its
excentricity at the least protuberant point, begins to push the lower end of the
arm K gradually outward, and moves the cutter gradually towards the blank
which it begins to cut. As the cam continues to turn, the radius of its surface
acting against the lever gradually increases, and presses the cutter nearer and
nearer towards the axis of the blank until the cam has made nine-twelfths of
a revolution, when the thread of the screw will be cut to the required depth.
As the cam turns during the next one-twelfth of a revolution the cutter will
not approach any nearer to the axis of the blank, but will repass over the cut
it had previously made to remove any protuberance that might have been
left to render the screw smoother and give it a better finish. When this is -
accomplished, the radius of the cam which acts upon the lever K is con-
tracted by a sudden step to its shortest limit to permit the cutter to fall back
and allow the threaded blank to be discharged, and an unthreaded one to be
presented, which is in turn threaded by a repetition of the before-described
operations.
While the cams L and V are making one revolution, the cutter and the
blank make ten revolutions in contact, and the cutter makes two revolutions
while the blank is being inserted and discharged. As the surface motion of the
cutter is about thirty times greater than the surface motion of the blank, it acts.
upon the latter and cuts it in the same manner that a saw or file would act
upon a fixed piece of metal held in a vice, and will remove the surplus metal
by a drawing cut, and this drawing action will be greater as the diameter of
the cutter is greater than that of the blank.
As the peripheries of the blank and cutter move in opposite directions, the
teeth of the latter cut from the bottom of the groove in the blank outwards, or
from the axis towards the circumference, so that the chips always pass from
a narrow into a wider space, which causes the tool to clear itself with great
ease.

page_text: What I claim in this branch of the Invention is, a counter screw cutter for
threading screw blanks of unequal depth of thread, of uniform: pitch of thread,
and of unequal diameter, substantially as herein set forth.
I also claim the, arrangement of the axes of the cutting. counter screw,
and of the rotating blank to be threaded parallel or thereabouts to each other,
so that the cutter may run smoothly and steadily, and that its threads, may
not bind in the grooves of the blank and strain the metal between them,
substantially as specified.
I also claim the arrangement of the cutter and blank in such manner that
the adjacent portions of their peripheries shall move in opposite directions
during the operation of threading, so that the metal may be. cut from the
grooves in the blank from the bottom outwards, to allow the chips to be freely
discharged, substantially as herein, set forth.
:
I also claim the combination of a.counter screw cutter with a rest to support
the blank and mechanism to cause the axes of the cutter and blank to approach
gradually until the thread is cut to the proper depth, and. then cause them to
diverge or separate, substantially as herein set forth..
I also claim the combination of the feeding trough and screw-driver arranged
in such manner that, while the driver is pushed forward to turn a blank while.
being threaded, an unthreaded blank may lie in the trough upon the driver,
ready to drop into place before it, the instant it is drawn back to allow the
previous blank to be withdrawn from the cutter.
I also claim the combination of the vibrating arm, or its equivalent, to
detach the head of a threaded blank from the bit of the screw-driver with a
discharging punch or its equivalent to eject the threaded blank from the rest,
the two thus operating insuring the discharge of one blank before another is
presented.
Lastly, I claim giving to the screw-driver a slight yielding pressure against:
the head of the blank to enable it to find and enter the nick before the greater
pressure required to gripe and turn the blank under the action of the cutter is
applied, substantially as herein set forth.
.1
I will now describe a further modification and improvement of the burr
cutter last described, and which for certain purposes possesses many adyan
tages. Fig. 1, E, represents a side elevation of a machine for the threading of
screws, having the improvements applied thereto; Fig. 2, E, represents a top
view of the same; Fig. 3, E, represents an elevation of that end of the machine
which is at the right hand in Fig. 1, E; Fig. 4, E, represents a transverse
vertical section at the line X, X, of Fig. 1, E; and. Fig. 5, E, represents a
view in perspective of the concave burr cutter.

page_text: This modification of the Invention and improvement consists of a rotating
concave annular burr cutter for threading screw blanks, and of a combination
thereof with suitable rests and turn screws for presenting the blank to the
cutter and rotating it while being, threaded...Likewise of a combination of a
vibrating rest to support the screw blank and a rotating turn screw vibrating
with the rest to turn the blank.
The accompanying Drawings represent one of the many arrangements of
machinery by means of which this part of the Invention may be carried
practically into effect. I propose to give a full and detailed description
of such portions of the machine as I claim, and only to refer briefly to
the rest.
The Drawing represents a strong iron frame A, for the support of the
working mechanism. A shaft B, is mounted on the top of this frame in
suitable bearings, and carries the cutter C on its inner extremity, and a
pinion D on its outer extremity. The pinion D gears into a wheel E, which
is mounted upon and drives a shaft. F, supported in suitable bearings in
brackets at the side of the frame. This shaft carries a pinion G, near its
middle which gears into a wheel E, mounted on a cam shaft I, which it turns.
On the left extremity of the shaft F, as shewn in Fig. 1, E, a wheel J is mounted
which gears into and rotates a pinion K, mounted on a stud pin n, projecting
from the adjacent end of the frame. This pinion gears into the pinions L
and L', on the mandrils m and m' of the turn-screws, by means of which the
blanks are rotated while under the action of the cutter.
The cam. N on the shaft I, beneath the cutter, is for the purpose of pressing
the blank against the cutter to thread it, and again withdrawing it from the
cutter after being threaded, in order that it may be discharged to make way
for another to be submitted to the same operation. The cam in performing
this duty works in connection with a system of levers and other devices. The
levers are pressed directly by the cam to force the blank against the cutter to
sink the thread upon it, and are moved by a spring in the opposite direction
when the cam has ceased to act to withdraw, the. blank. A friction roller
wiper O for the cam to act against is attached to the side of the lever O,
which is vibrated by the reciprocal action of the cam and spring.
The lever thus vibrated engages at its upper extremity with a sliding bar
P (Fig. 2, E), giving the latter a corresponding vibratory motion. When the
bar P is moved towards the cutter C, it extends a pair of toggle joint levers Q,
which are linked at their inner ends to the head of the bar P, and at
their outer extremities to the rests R, which support the blanks. When..the
bar P is moved from the cutter it flexes the levers Q, and draws the rests R,

page_text: towards each other and from the concave surface of the cutter, and thus
permits of the discharge of the blank by mechanism not here shewn, but
which as well as mechanism for feeding blanks into the rest may be con-
veniently constructed upon the same plan as the discharging and. feeding
apparatus of the screw cutter threading machine before mentioned. The
turn screws T vibrate with the rests R, as both are mounted upon the radius
bars S, which turn on pivots S', projecting upward from the end bar of
the frame.
It will be seen that the rotation of the cutter and the rotation of the blanks,
as well as the movements of the rests and feeding and discharging apparatus,
are all effected simultaneously and with the proper relative velocitics by means
of a single train of wheels, the cutter and blanks turning with their adjacent
moving surfaces going in opposite directions but with equal angular velocity,
and as the two blanks are threaded simultaneously by being pressed radially
against opposite sides of the cutter, the pressure of one blank against the cutter
in one direction is counterbalanced by that of the other in the opposite
direction, which prevents the axis of the cutter from being strained by lateral
pressure, and causes the machine to operate smoothly and steadily.
The cutter is composed of a cylindrical ring or annulus a, closed at one end
by a dise b, which is secured upon the end of the shaft B. The ring should
be made of cast steel well tempered, and have on its inner or concave surface
a serrated helical thread c, formed the counterpart or thereabouts of the
thread to be cut on the blank and of the same pitch, the outline of a section
of the cutter in a plane passing through the axis corresponding in shape with
the outline of the longitudinal axial section of the finished screw which this
cutter is designed to form. Instead of threading one pair of blanks only,
two, three, or more pairs may be threaded at a time if it is deemed expedient,
by simply increasing the number of turn screws and rests, and of the feeding
and discharging apparatus, and without adding to the number of cams.
As the numerous modifications of construction and arrangement of mechanism
by means of which this form of the improved screw threading machines may
be carried into effect, will be quite obvious to any competent and skilful
mechanician, I deem it unnecessary to give a detailed description thereof.
What I claim under this head of the Invention is,-
First, an annular concave burr cutter for threading screws having a helical
or conical serrated thread, substantially as described.
Second, the combination of two moving rests on opposite sides of a revolving
screw cutter with the mechanism herein described or the equivalent thereof,
for. operating the same in such manner as to move them simultaneously

page_text: towards and from the cutter, to press the blanks against the latter to be
threaded, and so that the pressure of one blank in one direction may be
counteracted by the pressure of another blank in the opposite direction, as
set forth.
Third, the combination of the vibrating rests with the vibrating rotating
turn screws, substantially in the manner herein described, so that the blank
may be rotated steadily and with regularity while the rest is carrying it
towards the cutter to sink a screw thread upon it.
In witness whereof, I, the said Alfred Vincent Newton, have hereunto
set my hand and seal, this 29th day of June, in the year of our Lord
One thousand eight hundred and fifty-four.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
A. V. NEWTON. (L.S.)