IMPROVEMENTS IN THE MANUFACTURE OF SCREWS, SCREW-BOLTS, AND SCREW-NAILS, AND IN MACHINERY THEREFOR
Year: 1881

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention
of "IMPROVEMENTS IN THE MANUFACTURE OF SCREWS, SCREW-BOLTS, AND
SCREW-NAILS, AND IN MACHINERY THEREFOR." A communication from
abroad by the Harvey Screw Company, Incorporated, of Jersey City, New
Jersey, United States of America.
COMPLETE SPECIFICATION filed by the said William Robert Lake at the
Office of the Commissioners of Patents on the 12th October 1881.
"
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN THE MANUFACTURE OF
SCREWS, SCREW-BOLTS, AND SCREW-NAILS, AND IN MACHINERY THEREFOR.'
A communication from abroad by the Harvey Screw Company, Incorporated,
of Jersey City, New Jersey, United States of America.
The said improvements relate to the manufacture of screws, screw-bolts, and
screw-nails, and to that class of machines for rolling screw-threads in which a
spiral groove is impressed upon the body of the blank by the impingement upon it
of parallel ribs formed with a suitable inclination upon the concave face of a
stationary die, and similar ribs oppositely inclined formed upon the periphery of a
rotating cylindrical die, by the action of which the blank is rolled along the curved
face of the stationary die, that is to say, to such a machine, for instance, as that
described in the Specification of former Letters Patent, dated June 20th, A.D. 1879,
No. 2465.
It is essential to the successful operation of this class of machines that when the
blank is to have a single thread formed upon it the ribs upon the face of one die
at their point of engagement with the blank shall occupy elevations midway
between the elevations occupied by the ribs of the other die at their points of
engagement with the blank; or, if a double thread is to be formed the apices of the
ribs upon the opposed faces of the two dies at the point where they first acquire
ו.
71

page_text: contact with the blank must occupy the same elevations respectively. In other
words it is essential that at the time of the first engagement of the blanks by the
dies the parallel ribs upon the opposed faces of the dies respectively shall occupy
prescribed relative positions in the same radial plane.
The blank having been engaged by the dies at the instant when the ribs at their
points of engagement respectively with the opposite sides of the blank occupy
their proper relative positions, enters upon and pursues its journey through the
space between the stationary die and the rotating die. When the cylindrical dio
has rotated to such an extent as to have rolled the blank once around, the ribs upon
the cylindrical die again acquire the proper position with relation to the ribs upon
the stationary die at the point where the blank is introduced.
It will be readily understood that if the blank is to have a double thread formed
upon it, a rotation of the cylindrical die sufficient to roll the blank half way around
will again bring the ribs into the proper relative positions.
The first part of this Invention relates to making a section of the concave die
movable toward and from the rotating die and suspending in front of the concave
face of such sectional die one or more blanks, which are held by their heads at the
required distance from each other, so that when the sectional die moves up toward
the rotating die the blanks are simultaneously engaged by the ribs on the faces of
the two dies at the instant when the points of engagement of the ribs with the
blanks respectively are those which are required to enable the dies to form upon
the blank either a single or a double thread, as the case may be.
To enable the blanks to be rolled along the face of the sectional die, and from that
to the stationary concave die, the forked holders in which the blanks are suspended
by their heads are permitted to oscillate in a plane at right angles to the axis of
the blank. This is accomplished by pivoting the forked holders upon vertical pins
carried by the sectional die and by providing them with light springs which yield,
allowing the holders to sway inward from the edge of the sectional die when the
blanks have been engaged between the face of the sectional die and the cylindrical
die, thus permitting the blanks to be rolled along out of the holders and into the
space between the cylindrical die and the stationary concave die.
This mode of feeding machines of this character may be employed to feed
blanks one at a time, or two or more blanks at a time, according to the length of
the sectional die.
In the accompanying Drawings representing a machine for rolling the threads of
screws provided with this improved feeding apparatus the sectional die is
represented as being of suitable length to feed three blanks at a time, requiring
three independent sets of ways, which are supplied with blanks from the same
hopper and from the lower ends of which respectively the blanks are successively
cut off and dropped one by one into the forks by mechanism of peculiar construc-
tion, which also forms a feature of the present Invention.
This first part of the said Invention is illustrated in Figures 1 to 6 of the
Drawings, in which
Figure 1 is a plan or top view of a machine, having two rotating cylindrical
dies and two stationary concave dies, and provided with a hopper having triple
ways, and
Figure 2 is a side elevation of the same.
Figure 3 is a plan or top view, partly in horizontal section, showing the
rotating primary die and a portion of the checking mechanism, the section being
taken on the line x, x, Figure 4, and portions of some of the parts represented as
broken away.
Figure 4 is a vertical section through the line v, v, Figure 3.
Figure 5 is a plan or top view of the primary rotating die and a portion
of the sectional die showing the oscillating forked plates for receiving the blanks
from the checks, the blanks being represented in horizontal section taken imme-
diately under their head and the sectional die represented as drawn back.
Figure 6 represents the same parts as those shown in Figure 5 in the positions

page_text: they occupy just after the sectional die has been pushed forward into position to
cause the engagement of the blanks by the rotating die.
Figures 3 to 6 are drawn to a larger scale than Figures 1 and 2.
The machine represented in these Figures of the Drawings has a substantial
frame A, which affords bearings for the vertical shafts B and C, upon which the
primary and secondary rotating dies b and c are carried. The primary and
secondary stationary dies b' and c¹ are securely fastened to the frame in such
relation to the rotating dies as to form the external boundaries of the sinuous
path, along which the screw-blanks are rolled by the action of the rotating
cylindrical dies.
The device for introducing the blanks successively into this path consists of a
sectional concave die D, which is seated in suitable guides and has a reciprocating
movement in a horizontal plane toward and from the primary rotating die b. The
movement of the said die D away from the rotating die is effected by the spring d,
which yields and allows it to be moved toward the rotating die by the action of
the cam d affixed to the shaft B of the primary die. As the shaft B rotates,
projections d' upon the face of the cam d' successively engage with one end of the
sliding bar d³, to the opposite end of which is pivoted the lower end of the rocking
lever d; the upper end d³ of this lever plays in a slot do in the reciprocating
sectional die D.
The top of the sectional concave die is provided with three oscillating
plates E, F, G, which swing in a horizontal plane upon the vertical pivots e, f, g.
The pivot for the central oscillating plate F is inserted in the top of the sectional
die D. The other pivots e and g are inserted in the plates e and g³, let into the
top of the sectional die D and made adjustable toward and from the centre of the
sectional die by means of the slotted holes 2 and g³, through which the screws es
and g³ are inserted, which screws confine the said plates to the sectional die. The
object of this adjustability is to facilitate the employment of the forked plates or
blank-holders as gauges for accurately fixing the relative positions of the several
blanks, so that a timing of the motion of the sectional die D with reference to the
rotating cylindrical die which is suitable for affecting the proper engagement of
the blank suspended in the forked end F¹ of the central blank-holder will also be
suitable for effecting the proper engagement of the other blanks.
Pressure is exerted upon the said oscillating plates by springs e, f, and g*, affixed
to posts e, f, and go, which serve as stops to arrest the movement of the said
oscillating plates in one direction, that is to say, when their forked ends project
over the face of the sectional die, as shown in Figure 5.
The forked ends E, F, G', of the oscillating plates are chamfered upon an angle
corresponding with that of the underside of the head of a flat-headed screw, and
are hence adapted for the suspension of that class of screws by their beads. This
chamfering of the forked ends is not however essential, especially in the case of
round-headed screws, the undersides of the heads of which are flat and perpen-
dicular to the axis of the screw.
The three oscillating plates are equidistant from each other, and when at rest
project as shewn over the front edge of the concave sectional die, so that the screw-
blanks suspended in them by their heads hang down between the face of the
sectional die and the face of the rotating primary die.
The face of the concave sectional die is provided with parallel ribs corresponding
in their inclination with the parallel ribs upon the face of the stationary curved
die, and so arranged as to be in alignment with the inclined ribs upon the face of
the stationary die when the sectional concave die has been pushed sufficiently
toward the rotating die to compress the blanks suspended in the forks against the
face of the said die.
The movement of the sectional die toward the rotating die is so timed that the
blanks are compressed between the two dies at the instant when the ribs upon the
opposed faces of the dies at their points of engagement with the blanks occupy the
prescribed relative positions.

page_text: The sectional die is held in position by the cam d' until the three blanks have
been rolled along the face of the sectional die and into. the space between the
rotating die and the stationary concave die. When the blanks arc seized by the
rotating die and commence to move the springs e, f, g, yield, permitting the
plates to swing inward and the blanks to be rolled out of the forked ends E¹, F', G¹,
as shewn in Figure 6. The oscillating plates immediately spring outward and the
sectional concave die is then drawn backward so far as to bring the forked ends of
the plates under the lower ends of the vertical tubes H, H, H. These tubes are of
slightly greater diameter than that of the heads of the screw-blanks, and are
affixed to the lower ends of the ways h, h, h, down which the blanks are conducted
from a hopper H₁ of suitable construction.
The upper ends of the tubes H are partially covered by horizontally reciprocating
plates I, I, I; the edge of each of these plates is provided with the notch i, having
the same width as the space between the parallel sides of the ways h, so that when
the edge of the plate I abuts against the lower end of the ways, the sides of the
notch form a continuation of the two parallel paths along which the blanks
hanging by their heads have been conducted by their own gravity from the hopper.
So long as the plate I remains in contact with the end of the ways, the sides of
the notch serve to support the screw blank with its shank hanging downward in
the tube H.
The reciprocating plates I are connected by the curved bar I' to the carriage J
provided with a horizontal stem J', the end of which is caused to constantly bear
against the cam K by the expanding spiral spring ; which bears at one end against
the side of the frame in which the reciprocating carriage slides and at the other
end upon the shoulder formed upon the end of the stem J'.
The concentric faces k of the projections k¹ on the cam while in contact with
the end of the stem J¹ hold the carriage back, and consequently hold the notched
edges of the slides I, I, I, against the lower ends of the ways in position to support
the screw blanks by their heads with their shanks hanging in the tube H. As
the cam K rotates, withdrawing one of the projections from contact with the
end of the stem J', the carriage is retracted by the expansion of the spiral spring j,
and the notched plates I are drawn inward, thus removing the supports upon
which the blanks have been suspended in the tubes H, and the blanks then fall by
their own gravity into the forked ends of the oscillating plates E, F, G.
In order to hold the notched plates I down upon their seats, I provide the cap L
which extends transversely across the plate I, and is secured at its ends to the side
pieces L' of the frame of the machine. This cap L is provided with the notches
to afford clearance for the heads of the blanks hanging in the plates, and the
sides of the said notches act as strippers against which the edges of the heads of
the blanks bear when the plates are withdrawn.
During the operation of dropping the blanks through the tubes by the with-
drawal of the plates I the reciprocating stops or gates M, M, M, are thrust
transversely across the lower ends of the ways, and hold back the column of
blanks resting in the same. The motions of each of these transverse reciprocating
stops M are imparted to it by means of a vertical pin m, which plays in a bent or
inclined slot 1, formed in each of the sliding plates I, the shape and direction
of these slots being such that as the sliding plates move back and forth the
gates M are thrust to and fro across the ways.
This mechanism taken in connection with the reciprocating concave die
constitutes what is termed a multiple feed, which for screw-machines of the
character to which it is applied has great importance by reason of the unusual
capacity of the machine to operate on a number of blanks at the same time, and
the consequent necessity, if the machine is to be used to its full capacity, for
feeding the blanks with a degree of rapidity far beyond that called for in the case
of screw machines of ordinary character.
The sectional die is shewn as provided with three forked holders for the
reception of screw-blanks, for the purpose of illustrating its. employment as a

page_text: multiple feed for delivering screw-blanks to the action of a rotating die, and a
stationary concave die. It will however be readily understood that the sectional
die may be employed to feed either one or more blanks to a similar machine by
varying the number of forked holders, checks, and ways accordingly. Instead of
the sectional die D adapted to move toward and from the rotating die, the ordinary
concave die b¹ of the machine may be arranged to move toward and from the said
rotating die, for the purpose of permitting the introduction of a blank or blanks
between the two dies preparatory to submitting such blanks to the action of the
dies for the purpose of forming the threads upon them, in which case the shorter
die D can be dispensed with. In either case the blanks will be suspended by the
heads with their shanks or barrels extending downward into the space between the
working faces of the dies, and the instrumentalities upon which the blanks are
thus suspended will have the capacity of yielding in a plane at right angles to the
axis of the blanks, so that when the blanks are seized between the dies and rolled
along they will easily extricate themselves from the forked holders in which they
have been suspended by their heads.
Another part of this Invention relates to the combination with a pair of dies,
such as are herein described, of an adjustable deliverer moving in a path parallel
or concentric with the path of movement of the working face of the moving die
for the purpose of ensuring the seizing of the blank by the dies at the time when
the ribs on the opposed faces of the two dies respectively occupy prescribed relative
positions. This part of the said Invention also relates to devices for carrying or
guiding the screw-blank by the head during its transfer from one pair of dies from
which it is delivered to the next following pair of dies by which it is received, and
for holding the screw-blank against the face of the rotating receiving die with an
elastic pressure.
This part of the said Invention is illustrated in Figures 7 to 14 of the Drawings,
in which
Figure 7 is a plan or top view of a machine containing three series of rolling
dies, and
Figure 8 is a front elevation of the same.
Figure 9 is a plan or top view of the dies with the exception of the first rotating
die which is removed for the purpose of disclosing the mechanism of the pusher
that delivers the blanks to the first pair of dies.
Figure 10 is a plan or top view of the spring holding-jaws, with which the said
pusher is provided.
Figure 11 is a plan or top view of the primary rotating die, shewing three
equidistant adjustable pins which extend vertically through concentric slots in
the said die, and successively operate the pusher.
Figure 12 is a horizontal section on a plane immediately beneath the primary
rotating die, showing the manner in which the vertical pins operate the pusher.
Figure 13 is a plan or top view, drawn to an enlarged scale, of portions of the
dies and the transferring device for transferring the blanks from the first pair of
dies to the second pair of dies, and represents in horizontal section a similar
transferring device for transferring the blanks from the second pair of dies to the
third pair of diea.
Figure 14 is an elevation of the transferring device, and represents the second
pair of dies in vertical section through the line 3, y, Figure 13.
The machine represented in these Figures of the Drawings has a suitable frame A,
which supports a horizontal driving shaft B driven by a belt on the pulley B'.
The cylindrical dies are mounted upon the upper ends of parallel vertical shafts.
These vertical shafts are geared together by suitable cog-wheels 63, and are rotated
by power transmitted from the driving shaft by means of the bevel gearing B³.
The arrows in Figure 7 indicate the direction of rotation of the primary rotating
die C, the secondary rotating die D, and the finishing rotating die E
The machine is also provided with a suitable form of feeding mechanism, con-
sisting of the hopper F, the ways F¹, and the check F³, for cutting off the lowermost

page_text: .
blank from the row of blanks hanging by their heads in the said ways, and
dropping it through the tube F³ into the cylindrical space between the jaws h, h¹,
of the pusher H. This pusher consists of a curved metallic plate affixed to the vertical
post g, inserted in the free end of the oscillating arm G, by which it is moved in
the arc of a circle between the face of the rotating die C and the stationary curved
die C¹.
A spring arm g¹ is hung upon the lower part of the post g immediately above
the arm G, and is therefore adapted to oscillate in a plane parallel with the plane
of oscillation of the said arm. The position of the spring arm gl relatively to the
arm G, upon which it oscillates, is governed by the stationary tripping cam g³, the
face of which affords a bearing for the vertical pin g³ inserted in the outer part of
the arm g¹. This pin gå is held against the face of the stationary tripping cam g²
by the force of the leaf spring g' affixed to the arm g¹, and bearing at its free end
upon the nose of the trigger g³ when the latter is in engagement with either of the
pins I. As these pins I are disengaged from the trigger g³ the arm G is retracted
by the spring G₁. The upper edge of the pusher H projects slightly above the
upper surfaces of the dies, and has fixed to it the stationary jaw h and the pivoted
spring jaw ¹. For clearness of illustration the pusher jaws h and h¹ are omitted
from Figure 9, but are shewn detached in Figure 10.
As the primary die C rotates the projecting lower ends of the vertical pins I are
successively swept against or brought in contact with the trigger go, thus causing
the arm G to swing upon its axis and push into the space between the rotating
die C and the stationary die C a blank which may have been deposited in the
jaws h and h¹ of the pusber. It will be seen that the vertical pins I are inserted
through the concentric slots i in the stationary die C, and are held therein by the
clamping nuts i¹. The length of the concentric slot i is so proportioned as to afford
a sufficient range of lateral adjustment for the vertical pins I to enable them to be
fixed at the exact points required, in order that they may commence to actuate the
oscillating arm G at the instant when the ribs upon the face of the rotating die
occupy, relatively to the ribs upon the face of the stationary die, the desired
positions.
Thus if the machine is to be employed for rolling a single threaded screw the
relative positions of the dies should be such that the apices of the ribs bisected
by a radial plane shall occupy elevations midway between the elevations occupied
by the apices of the ribs of the other die in the same radial plane. As one die is
stationary and the other is movable it will be understood that these relations are
constantly changing, and hence that it is of the utmost importance that the blank
should be seized by the dies at the instant when the ribs of the dies occupy the
proper relative positions.
The machine may also be employed to roll a double thread, that is to say, to
form two independent spiral threads upon the body of the blank, in which case the
apices of the opposed ribs on the vertical plane wherein the screw is first seized
should occupy the same elevations. If desired therefore sufficient range of adjust-
ment may be given to the vertical pins I to enable the machine to roll one or two
spiral threads upon the body of the blank.
The mechanism for transferring the blank from one pair of dies to the next
succeeding pair of dies consists of the spring guide-plates K and k, the jaws K¹
and of which are suitably curved to correspond with the curved faces of the dies
toward which they spring by the rotation, for example, of the die D (see
Figure 13).
The blank is introduced between the two spring guide-plates K and k, wherein
it is held by the head. As the guide-plate K is forced toward the die C by its
spring K³, the rotation of the said die causes the screw-blank to roll along the
edge K³ of the guide-plate K to the rounded end thereof, where it is released from
the lateral pressure of the guide-plate K, but is subjected to the lateral pressure in
the opposite direction of the guide-plate k.
The mechanism for transferring the partially formed screws from one pair of dies

page_text: to the next following pair of dies consists of the two spring plates K³ and L, the curved
edges of which respectively constitute portions of the concentric paths along which
the partially formed screw is rolled by the action of the rotating dies. The spring-
plate K³ is affixed to the vertical shaft K', having its bearings in the frame M,
which extends diagonally across the space between the rotating dies. This spring-
plate Ks is arranged to have a small range of oscillation in a horizontal plane
immediately above the surface of the dies. The concave edge ³ of the said spring-
plate K³ is curved upon substantially the same radius as the stationary die, from
which the partially formed screw is delivered, and which for the purposes of illus-
tration is called the delivery die. This concave edge ³ forms a continuation of the
curved path afforded by the stationary delivery die, along which the screw in
process of formation is rolled progressively by the action of the rotating die. The
spring-plate K³ is pressed toward the rotating delivery die by the spring k*, and is
rounded at its free end and extends to a point immediately above those parts or
points of the two adjacent rotating dies which are nearest together.
The spring plate L affixed to the vertical shaft L¹, and having a limited range of
oscillation in a horizontal plane immediately above the dies, is formed with a
sinuous edge, the convex portion of which is immediately opposite the concave
edge of the spring-plate K³, while the concave portion is so curved as to consti-
tute a portion of the curved path along which the partially formed screw is rolled
by the receiving rotating die, the remainder of that path being afforded by the
receiving stationary die. A spring presses the free end of the said plate L
toward the plate K³.
Is
When the machine is in operation, the partially formed screw as it is rolled
along the curved edge of the spring plate K³ presses back the free end of the
spring plate L, this result being secured by making the spring * more powerful
than the spring 12. When however the blank has been rolled to the end of the
spring-plate K, the spring-plate L pushes the blank laterally against the face of
the receiving rotating die and the curved edge of the spring-plate L affords
the exterior path along which the partially finished screw is rolled to the entrance
of the passage between the receiving rotating die and the receiving stationary die.
This passage however will not permit the entrance of the partially formed screw
until the apices of the ribs upon the working faces of the receiving stationary die,
and the receiving rotating die at the place where the screw is to enter occupy the
proper relative elevations, so that they may respectively engage the parallel
recesses which are presented upon the opposite sides of the screw, and which
result from the formation upon the blank of a spiral groove by the preceding pair
of dies. It will be understood that this transferring mechanism is adapted for
employment between any two adjoining pairs of dies.
Another function performed by the spring plates K³ and L is the suspension of
the partially formed screw by the head during its transfer from one pair of dies to
the next following pair of dies. The partially finished screw is prevented from
dropping by the engagement of its shank or barrel beneath the head with the
edges of the spring plates K³ and L, and the presentation of the partially finished
screw to the receiving dies upon the proper level is thereby ensured, so that the
ribs on the faces of the receiving dies will engage that part only of the barrel upon
which the thread is to be formed. This control of the vertical position of the
screw-blank by its head is especially important in the manufacture of rolled screws,
having the threaded portions of their barrels of the same diameter as the
unthreaded portions, in which case the portion of the barrel which is to be
threaded is first reduced in diameter, as more fully described in another part of
this Specification.
Another part of this Invention relates to the employment of an intermittently
rotating feed wheel having notches in its periphery, into which screw blanks are
deposited from any required number of guide channels or ways extending from a
hopper or hoppers to the edge of the said feed-wheel, the distances between the
discharge ends of the ways being the same as the distances between the notches.

page_text: Thus when the feed-wheel is stationary some one of its notches stand opposite the
discharge-end of each of the ways, and if empty may receive a blank discharged
from the said ways, or if it fails to receive a blank from one pair of ways it will
have other opportunities of being supplied as it is brought by the step by step
rotation of the feed-wheel successively opposite the discharge ends of the other
ways.
The blanks are held in these notches by a curved guard extending around the
edge of the feed-wheel to the place where the blanks are successively pushed
outward from the notches against the working face of one of the dies, which being
in motion rolls the blank off the face of the pusher into the space between the two
dies.
By suitably increasing the number of guide channels or ways the notches in
the feed-wheel may be placed near together, so that after a blank has been
delivered to the dies a very small range of movement of the said feed-wheel will
be sufficient to bring another blank into position for delivery, and the operation of
feeding can thus be carried on with great rapidity.
This part of the said Invention is illustrated in Figures 15, 16, and 17 of the
Drawings, in which-
Figure 15 is a plan or top view of the portion of the machine showing the feed-
wheel and portions of the guide channels or ways for conducting blanks from a
hopper or hoppers, and
Figure 16 is a side elevation of the same with a portion of the feed-wheel-guard
broken away to show the edge of the said feed-wheel.
Figure 17 is a horizontal section on the line x, x, Figure 16.
In this machine a suitable frame A affords the bearings for the vertical shaft B
of the rotating cylindrical die C, which in conjunction with the stationary curved
die D performs the preliminary operation of impressing a spiral groove upon the
body of the screw-blank.
The mechanism for feeding the blanks to the action of the dies consists of the
horizontal feed-wheel E, having the equidistant notches e formed in its edge.
Screw-blanks deposited in these notches from the lower ends f of the inclined
guide-channels F or ways are prevented from slipping out by the curved guard E¹
until they successively arrive at a point adjacent to the end D' of the stationary
die D. The blank having arrived at this point is held in its notch by the movable
spring-guard e¹ which is affixed to the end of the curved guard E¹. The inclined
ways F are supplied with blanks from a hopper or hoppers of ordinary construction.
The blanks hanging by their heads in these ways slide down by their own gravity,
and slip from the ends of the ways into the notches e in the feed-wheel. The
delivery of the blanks successively from the notches e to the dies is effected by
the pusher G upon the upper end of the rocking lever g; the lower end of this
lever is kept against the face of the rotating cam G₁ by the spiral spring g².
This cam G¹ has projections G2 formed upon its periphery, and is provided with
means of adjustment for accurately seating the cam G¹ upon the shaft B in the
proper relation with regard to the die C, so that when the projections G³ strike
against and push out the lower end of the said lever g, and the pusher G con-
sequently pushes a blank out of one of the notches e against the face of the
rotating die, and the rotating die rolls such blank into the space between the two
dies, the ribs upon the stationary die, at their points of first engagement with the
blank, will occupy elevations midway between the elevations occupied by the ribs
of the rotating die, at the same time in engagement with the opposite side of the
blank. The movable guard e¹ yields as the pusher G pushes the blank out of its
notch against the face of the rotating die, and after the blank has been engaged
by the latter and rolled away from the face of the pusher the guard e¹ springs
back into position to perform its functions for the blank in the succeeding
notch.
The circumference of the rotating die is made substantially a multiple of the
circumference of the shank of the screw blank which is intended to be operated

page_text: upon, and what may be termed the feeding points upon the rotating die equal in
number the number of times which the circumference of the blank is contained in
the circumference of the die.
The projections G³ upon the cam G¹ equal in number the feeding points upon
the die, and as these projections are equidistant it follows that an adjustment of
the cam with relation to the die which properly times the feeding of a blank to
one of the feeding points likewise properly times the feeding of blanks to all the
feeding points successively.
The feeding, wheel is intermittently rotated by means of the pawl E2 projecting
rearward from the upper end of the lever g and engaging the teeth upon the cog-
wheel E. The range of backward movement of the pusher-lever and its pawl
and the diameter of the cog-wheel E³ are calculated to give sufficient rotation to
the feed-wheel to bring the notches e successively over the space in front of the
pusher and to ensure the bringing of the feed-wheel to rest at the proper point.
A detent or projection e' is also affixed to and projects backward from the pusher G
in position to enter one of the spaces between the teeth of the cog wheel E³ and
stop its further rotation when the actuating pawl E' has completed its backward
movement. Any reverse rotary movement of the feed-wheel E is prevented by
the stationary spring detent pawl E³. Whenever the feed-wheel E is stationary
one of the notches e is held immediately opposite the discharge end of each of the
ways F, and if empty may receive a blank therefrom. If for any reason an empty
notch passes the end of one pair of ways, it may receive a blank from the discharge
end of one of the other pairs of ways, in front of all of which it will be succes-
sively brought to rest during the operations of delivering the blanks from the
notches in the feed-wheel to the dies. It will be seen that by this organization of
the feeding mechanism a very small range of movement suffices to effect the
delivery of a blank from the feed-wheel to the dies, and a very slight movement
of the feed-wheel suffices to bring another blank into position to be delivered, and
bence the feeding operation can be performed with a degree of rapidity com-
mensurate with the requirements of the class of screw-threading machines in
which the thread is formed by rolling the blank between the dies.
In the operation of this class of screw-threading machines the metal dislodged
from the cavities of the threads is thrown laterally outward, and the result is that
the diameter of the threaded part of the shank is thus increased beyond the
diameter of the unthreaded part.
In this particular the rolled screw differs from the screws made by cutting the
thread, wherein the diameter of the threaded part of the shank is the same as the
diameter of the unthreaded part.
Another part of this Invention, whereby screws are made with rolled threads of
the same diameter as that of the unthreaded part of the shank relates to preparing
the blank to receive the thread by rolling down that portion of the shank upon
which the thread is to be formed until its diameter is so far reduced that in the
subsequent rolling operation the threads will be thrown out from its surface to
such a distance that the length of the radius of the thread will be the same as the
length of the radius of the unthreaded part of the shank. The reduction of the
diameter of that portion of the blank which is to be threaded may either be
performed in a separate machine, or it may be performed by a pair of dies, con-
sisting of a rolling die and a stationary curved die with smooth working faces,
which may be incorporated in a machine containing other pairs of similar dies
having their working faces ribbed for the purpose of forming the threads.
This part of the said Invention is illustrated in Figures 18 to 23 of the Drawings,
in which
Tins 18 is a plan as ton rings of nont of the machine and

page_text: that portion of the shank upon which the thread is to be formed suitably reduced
in diameter, and
Figure 22 is a similar view of the finished screw made by rolling the thread upon
the reduced part of the blank shewn in Figure 21.
Figure 23 is a plan or top view of the portion of the machine in which the dies
are located, with the reducing die and a portion of the first rotating threading die
removed in order to exhibit the mechanism employed to operate the pusher, which
effects the delivery of the blank from the reducing dies to the first pair of threading
dies.
In the machine constructed according to this part of my Invention a suitable
frame A supports a horizontal driving shaft B. The several rotating dies C, D, E,
and F of the machine are mounted upon the vertical shafts C', D', E¹, and F',
which are geared together by means of the cog-wheels C, D, E, and F¹, so that
motion imparted to one of the vertical shafts from the driving shaft B by means
of the bevel gearing B¹ is imparted to all the said vertical shafts.
The machine is provided with the usual feed-mechanism, consisting of the
hopper G, the inclined ways G¹, the cheek G³, and the tube G³, through which
the blanks are successively dropped into the deliverer G, by the operation of which
they are at the proper time successively thrust forward bodily, so that that portion
of the body of the blank which it is desired shall be reduced in diameter is intro-
duced between the face of the rotating reducing die and the face of the stationary
curved reducing die. The stationary curved die is provided with the usual
facilities for adjustment, and is set in a position slightly excentric to that of the
rotating reducing die, so that as the body of the blank is rolled across the face of
the stationary die by the rotation of the rotating die, it is gradually rolled down
until it acquires the shape shown in Figure 21, wherein the portion H of the blank
is represented as having been suitably reduced in diameter. Having passed
through the reducing dies the blank is at the proper time delivered to the action
of the primary threading dies by a pusher moving in the arc of a circle concentric
with the rotating threading die. By means of adjusting devices this pusher is
adapted to deliver the blank to the threading dies at the instant when the parallel
ribs upon the face of the rotating die bisect a vertical radial plane at elevations
midway between the points at which the ribs of the stationary curved die bisect
the same radial plane. From the primary threading dies the blank is transferred
to the second pair of threading dies which perform the next step in the operation
of impressing the spiral thread upon the body of the blank, and so on.
The transferring device consists of spring-guides, between which the blank is
suspended by the head, and by which it is held with elastic pressure against the
face of the rotating threading die. Other transferring devices may also be used.
As the adjustable delivering device and the transferring device shown are similar
to those hereinbefore described with reference to other Figures of the Drawings, it
is not necessary to further describe them in detail.
It is not essential to the practice of this method of rolling the threads of screws
or screw-bolts that the operation of reducing the shank of the blank shall be per-
formed in the same machine as that in which the rolling of the threads is performed.
The blanks may have their shanks reduced in diameter in a separate machine,
employing only reducing dies, and may then be deposited in a hopper and fed in
the ordinary manner to a machine for rolling the threads.
Instead of reducing the diameter of the portion of the shank which is to be
threaded by rolling, as last above described, the pieces of wire of which the blank
is to be formed may be compressed longitudinally in a counter-bored heading die,
thereby enlarging the diameter of so much of the upper portion of the shank as is
to remain unthreaded, and the thread then rolled upon the unenlarged portion of
the shank, which in its extreme diameter will be the same as that of the enlarged
unthreaded portion. The advantage of this method is that the threading dies are
enabled to perforin their work upon material which has not been previously
compressed or hardened by rolling in order to reduce its diameter.

page_text: This method of compressing the blank constitutes another part of this Invention,
and is illustrated in Figures 24, 25, and 26 of the Drawings, in which
Figure 24 is a section of the counter-bored heading die, and
Figure 25 is an exterior view of the shouldered blank as it comes from the
said die.
Figure 26 is a central longitudinal section of the finished screw.
Referring to these Figures of the Drawings, it will be seen that the heading
die A is provided with the hole a, the upper portion of which is enlarged in
diameter by the counter bore b, and has the usual counter sink c to form the head
of the screw-blank. The blank B is formed from wire of substantially the same
diameter as that of the smaller portion a of the hole in the die. The lower portion a¹
of the shank of the blank is that which is to be threaded. The upper portion 6¹
of the shank has the enlarged diameter of the counter bore b, and is surmounted
by the usual flaring head c¹ which is formed by the longitudinal compression of
the wire in the die
In forming the threads by rolling, the ribs upon the faces of the dies impress a
spiral groove upon the body of the blank, and in so doing form the outer portion
of the thread by throwing the metal of the blank laterally outward.
In practice it will be found that when the difference in the diameters of the
upper and lower portions of the shank is equal to about one half of the depth of
the finished thread, the effect of rolling the thread will be to make the diameter
of the threaded portion as the same as the diameter of the unthreaded portion 6* of
the shank. The finished screw is provided with the usual nicked head c³, and with
the usual conical point d.
It will be understood that the head of the screw or bolt may be of any desired
shape.
Screw-nails or screws, which are intended for insertion by driving, are provided
preferably with ratchet-threads. It is desirable that the edges of the threads shall
project transversely outward beyond the body or shank of the blank.
By the use of the mechanism herein described the threads are formed partly by
abrasion and partly by the displacement of the metal, and its rearrangement in
the form of a rib extending spirally around the body of the blank.
It is found that by making the longer side of the thread, that is to say, the side
toward the point of the screw-nail concave, which as will be obvious may be effected
by making the ribs of the dies correspondingly convex, the metal displaced by the
impress of the die flows more easily outward, and the rolled thread not only
acquires a sharp edge but its edge is thrown further outward from the body of the
blank. The side of the thread toward the head of the screw nail may be
a spiral plane, which in cross section is at or nearly at a right angle with the axis
of the screw, or if desired it may be slightly concave in cross section. In either
case the concavity of the under side of the thread, or in other words, the corre-
sponding convexity of the rib or die which impresses that part of the thread is the
principal factor in inducing the outward flow of the metal and the complete filling
of the depressions in the dye, and thus the formation of a sharp edged projecting
thread.
Figure 27 is a central longitudinal section of my improved ratchet-threaded
screw-nail, and
Figure 28 is a similar view of a screw-nail, illustrating the application of my
improvement to those forms of ratchet threads in which the upper side of the
thread is either outwardly and downwardly inclined, or is slightly concave in
cross section.
For the purpose of the present case either of the forms of thread illustrated in
the said Figures may be called ratchet-threads, the distinguishing characteristic
of the class of threads to which this Invention applies being that their
lower sides form a more acute angle with the side of the body than their upper
sides.
It will be seen on reference to the Drawings that the heads A of the screw nails

page_text: are provided with the projections or nipples a, a, which are intended to receive the
impact of the hammer by which the screw-nail is driven into an object; and
which serve to engage the screw-driver employed to withdraw the screw-nail.
The body B is provided with a projecting spiral thread G, the distinguishing
characteristic of which is that its underside C is concave in cross section. The upper
side D of the thread may in cross section occupy a plane at right angles to the
axis of the screw-nail, as shewn in Figure 27, or the thread may be provided with
an outwardly and downwardly inclined upper face E, as shewn in the upper
portion of the body in Figure 28; or the thread may be provided with a concave
upper face F, as shewn in the lower portion of the body in Figure 28. In either
case it will be seen that the edges of each convolution of the thread have such an
outward projection that the diameter measuring from the edge of the thread on
one side, to a point in line with the edges of the thread on the other side, is
considerably greater than the diameter of the shank A. of the blank.
Driven screw-nails are held in position by the swelling or springing of the wood
into the depressions in the periphery of the body, and it has heretofore been
proposed to turn down the upper part of the shank of a wood screw to make room
for such swelling or springing of the wood.
Having thus fully described the said Invention as communicated to me by my
foreign correspondents, and the manner of performing the same, I wish it understood
that I do not claim broadly a screw having the unthreaded portion of its shank of
less diameter than the diameter of a cylinder capable of containing the unthreaded
portion of the body, but I claim,―
First. A reciprocating concave die, and one or more oscillating forked plates or
holders for the suspension of screw blanks, in combination with a rotating
cylindrical die and means for periodically moving the concave die toward and
from the working face of the rotating die, all substantially as above set forth and
for the purpose specified.
Second. In a machine for rolling the threads of screws by the combined action
upon the blank of a rotating cylindrical die and a fixed concave die, the opposed
faces of which are provided with parallel ribs suitably inclined in opposite
directions, the sectional die D, and means for periodically moving the same toward
and from the working face of the rotating die, one or more forked holders pivoted
upon or moving with the said sectional die, and having a range of oscillating-
movement in a plane parallel with the path of movement of the sectional die
sufficient to enable the forked end or ends of such holder or holders to swing
inward within the curved edge of the sectional-die, and outward to overhang the
concave face of the sectional die, in position to hold a blank or blanks by the
head with the shank or shanks of such blank or blanks hanging down between the
concave face of the sectional die and the working face of the rotating cylindrical
die, and means for ensuring the passage of the blanks one by one successively into
the said holder or holders when the sectional die is drawn backward, substantially
as above set forth and for the purpose specified.
Third. A pair of ways for conducting screw-blanks from a hopper, and a gate
or check-slide moving transversely across the lower part of the said ways in
combination with a notched plate moving toward and from the lower end of the
ways and across the upper end of a vertical tube into which screw-blanks are
dropped from the said ways, and means for periodically reciprocating the said
notched plate and gate, substantially as above set forth and for the purpose
specified.
Fourth. In a machine for rolling the threads of screws, a movable die and a
stationary die, the opposed faces of which are provided with parallel ribs inclined
respectively in opposite directions in combination with multiple feeding apparatus
consisting of two or more pairs of inclined ways for supplying screw-blanks from a
hopper or hoppers, and means for conveying the said blanks from the ways and
for simultaneously feeding two or more blanks against different parts of the working
face of the movable die, substantially as above described.

page_text: Fifth. In a machine for rolling screw-threads, a pair of suitably ribbed dies, one
of which is a moving die, and a pusher for pushing a screw-blank into one end
of the space between the working faces of the said dies, in combination with
adjustable mechanism for periodically actuating the said pusher at the times when
the ribs upon the opposed working faces of the dies occupy prescribed relative
positions, whereby a series of ribs upon the opposed dies respectively engage the
same spiral path or paths upon the shank of the blank, substantially as above
described.
Sixth. The circularly adjustable pins I secured to the rotating die C for actuating
the oscillating arm which carries the pusher H, substantially as above described.
Seventh. The pusher H provided with the jaws h, h¹, substantially as above set
forth and for the purpose specified.
Eighth. In combination with adjacent pairs of dies, each pair consisting of a
rotating cylindrical die and a stationary curved die, the transferring mechanism
herein described, consisting of the spring-plates operating substantially as above
Bet forth.
Ninth. In a machine for forming screw-threads, by rolling blanks between the
faces of two dies having systems of parallel ribs inclined respectively in opposite
directions, an intermittently rotating feed-wheel provided with notches in its
periphery, in combination with a pusher for pushing the blanks successively out
of the notches when the said feed-wheel is at rest against the face of the moving
die, substantially as above described.
Tenth. An intermittent rotating feed-wheel provided with notches in its
periphery, and two or more pairs of ways for conducting blanks from a hopper or
hoppers into the notches of the said feed-wheel which are successively brought to
rest opposite the discharge ends of such ways, in combination with a curved
guard for holding the blanks in the notches during the rotation of the wheel in
carrying the blanks from the points where they are deposited in the said notches
to the point where they are successively delivered from the same against the face
of the moving die, substantially as above set forth.
Eleventh. The feed-wheel provided with the notches e in its periphery, and the
toothed wheel E³ affixed to the shaft of the said feed-wheel in combination with
the pawl E, the detent e, the rocking lever g, and the cam G', substantially as
above set forth and for the purpose specified.
Twelfth. The herein described method of manufacturing screws and screw-bolts
with rolled threads of substantially the same diameters as the unthreaded parts of
their shanks, which consist in first reducing the diameter of the part of the shank
which is to be threaded, and in then rolling up threads upon such reduced part of
the shanks by means of suitable dies, substantially as above set forth.
Thirteenth. In a machine for rolling the threads of screws or screw-bolts by a
series of progressive operations performed by pairs of dies, each pair consisting of a
rotating die and a stationary die having their opposed faces provided respectively
with systems of parallel ribs of relatively opposite inclinations, the combination of
such threading dies with a pair of reducing dies consisting of a rotating die and a
stationary curved die having their working faces smooth, and suitable transferring
devices for transferring the blanks successively from the pair of dies by which
they are first operated upon to the pair of dies by which they are next operated
upon, and so on, substantially as above described.
Fourteenth. The above described improvements in the manufacture of screws
and bolts with rolled threads, which improvements consist in heading the blanks
in a counterbored heading die, and thereby enlarging the diameter of the upper
portion of the shank which is to remain unthreaded, and in subsequently rolling up
upon the unenlarged lower portion of the shank a thread of the same diameter
as the previously enlarged portion of the shank which is to remain unthreaded,
substantially as above described.
Fifteenth. A rolled screw-nail provided with a sharp edged projecting thread,

page_text: one or both sides of which is or are concave in cross section, substantially, as above
described and as shewn in the accompanying Drawings.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Fifth day of September, in the year of our Lord One
thousand eight hundred and eighty one.
1111
DAR
TATT