IMPROVEMENTS IN THE MANUFACTURE OF SCREWS AND SCREW BOLTS, AND IN MACHINERY THEREFOR
Year: 1879

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF SCREWS AND SCREW BOLTS, AND IN
MACHINERY THEREFOR" A communication from abroad by Hayward A.
Harvey, of Orange, New Jersey, United States of America, Mechanical
Engineer.
Sealed the 26th August 1879, and dated the 20th June 1879.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 20th June 1879.
"
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN THE MANUFACTURE OF
SCREWS AND SCREW BOLTS, AND IN MACHINERY THEREFOR' [A communication
from abroad by Hayward A. Harvey, of Orange, New Jersey, United States of
America, Mechanical Engineer.]
One part of this Invention relates to a ratchet thread screw with a conical point
and with bosses projecting from the face of the head, which bosses serve the double
purpose of adapting the head to the ordinary action of a screw driver, and of
presenting bearing places for receiving the impact of a hammer, by the blows of
which the screws can be driven in without destroying the head.
Another part of the said Invention relates to the machinery employed for the
manufacture of screws or bolta.
My improvements in connection with the last mentioned part of this Invention
comprise machinery for forming the threads of screws or bolts by the combined
action of a curved stationary die and a cylindrical rotating die upon a blank
introduced between the dies, and rolled along the face of the stationary die by
the friction of the rotating die.
In dies of this kind the screw threads are impressed upon the body of the
blank by parallel ridges of metal formed in the faces of the dies at the proper
angle of inclination with the plane of motion of the rolling die. I notch trans-
versely the parallel ridges on the faces of the dies at intervals so that they may
present a series of sharp points or corners which will have a cutting action upon

page_text: the blank. I combine with the rotating and stationary dies devices for automa-
tically presenting the blanks one by one and pushing them successively into the
space between the dies, and I employ series of pairs of dies, as hereinafter set
forth.
The various parts of the machine are mounted in a substantial frame which
affords bearings for a vertical shaft, upon which one of the rotating dies is mounted.
It also affords bearings for the intermediate shaft upon which the transfer wheel is
mounted, and for the shaft upon which the second rolling die is mounted. These
three shafts are geared together and are thus caused to rotate.
The first named die, which I call the primary rolling die, acts in conjunction
with a curved stationary die, and the transfer wheel acts in conjunction with a
curved guide wall, while the secondary die acts in conjunction with the curved
stationary die.
The vertical shaft is provided on its lower end with a cam or eccentric which
imparts a reciprocating motion to the cam bar. The cam bar is provided at the
end with a transverse pin which is inserted in the forked arm of a bell crank lever.
By reason of this connection, oscillating motion is transmitted to a lifter; this lifter
is composed of two parallel plates of segmental form pivoted to the upper end of
ways, and they reciprocate in a vertical path in the centre of the hopper. The
bottom of this hopper is slotted to allow the movement of the lifter.
Blanks are thrown indiscriminately into the hopper, which has converging side
walls.
Hoppers and lifters of this character are well known, but the lifter has not been
heretofore permitted to drop bodily below the mouth of the slot in the bottom of
the hopper, and this peculiarity of my lifter grently increases its efficiency in
picking up blanks.
At the bottom of the said ways there is the usual gate or check, which is thrust
outward by a tappet cam on the vertical shaft, and is returned to its normal
position by a spring. The gate or check in its reciprocating movement cuts off a
blank from the lower end of the row of blanks and permits it to drop through a
short tubo or guide into the space between the rolling die and the guide wall at
the end of the stationary die.
The blank is held in a vertical position by the guide wall, concave end of a
pusher, and a spring. The said pusher is affixed to a stud on the end of an oscil-
lating arm projecting radially from a loose hub on the vertical shaft, immediately
beneath the rotating die. Loosely hung on the said stud is a tripper, one of the
arms of which carries a roller which bears on a stationary guide. A pin, projecting
radially from the said hub, is connected to the end of a spiral spring. The under
side of the rotating die is provided with a pin which, as the die rotates, strikes
against one arm of the said tripper and carries the oscillating arm around until in
obedience to the action of the spiral spring the said arm moves back to its normal
position. In the act of moving forward, however, the pusher has delivered the
blank into the space between the rotating and stationary die, so that the said blank
is caught by friction and rolled forward around the face of the stationary die.
In some cases I may omit the transfer wheel and substitute in its place the
secondary dies, delivering from the primary dies directly to the secondary dies.
It will be understood that in tho caso of large screws, especially wood screws, in
which a deep thread is required, I may increase the number of pairs of dies in the
series.
I employ in connection with the secondary dies a milling wheel for cutting a
cone point on the end of the screw. This milling wheel has a bevelled cutting
edge, and is affixed to a pulley loosely mounted upon a hollow cylinder, through
which a shaft passes. The milling wheel is driven at a higher speed than the
rolling die, and has its axis out of line with the axis of the rotating die.
In certain cases, where only a shallow thread is required, only one pair of dies
may be necessary, and in such a case the primary rolling dio may be provided with

page_text: a milling wheel. The transfer wheel and its guide wall may be omitted and some
other transfer device may be substituted therefor.
The shape of the working faces of the dies will be varied according to the different
shapes of screw threads which it may be desired to make.
I form a ratchet screw which has a ratchet thread upon its body, a conical point
and two bosses projecting upward from the top of the head, on opposite sides of
the centre thereof. Sufficient space is left between the bosses to allow the intro-
duction of the blade of an ordinary screw driver, by means of which the screw may
be turned in the usual manner in either direction.
It is the object of this part of my Invention to adapt screws for being by the
blows of a hammer wholly or partially driven into the place in which they are to
be inserted. The desired adaptation of the screw to this purpose is effected by the
use of the conical point and the ratchet thread, the inclined surfaces of which
facilitate the driving-on of the crew while the bosses on the head present bearing
places for receiving the impact of the hammer.
In manufacturing these improved screws I form the bosses in the act of heading
the blanks by the use of a recessed heading punch, and in the case of screws of
considerable diameter I also partially form the conical point in the header by the
use of a countersunk female die or dies.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Robert Lake in the Great Seal Patent Office on the 20th
December 1879.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN THE MANUFACTURE OF
SCREWS AND SCREW BOLTS, AND IN MACHINERY THEREFOR." A communication
from abroad by Hayward A. Harvey, of Orange, New Jersey, United States of
America, Mechanical Engineer.
One part of this Invention relates to a ratchet thread screw, with a conical point
and with bosses projecting from the face of the head, which bosses serve the double
purpose of adapting the head to the ordinary action of a screw-driver, and of
presenting benring places for receiving the impact of a hammer, by the blows of
which the screws can be driven in without destroying the head.
The other part of the said Invention relates to the machinery which I employ,
and which for convenience I shall describe first.
My improvements in connection with the last mentioned part of this Invention
relato to machinery for forming the threads of screws or bolts by the combined
action of a curved stationary die and a cylindrical rotating die upon a blank intro-
duced between the dies, and rolled along the face of the stationary die by the friction
of the rotating die. In dies of this kind the screw threads are impressed upon
the body of the blank by parallel ridges of metal formed in the faces of the dies
at the proper angle of inclination with the plane of motion of the rolling die.
My Invention consists, first, in transversely notching the parallel ridges on the
faces of the dies at intervals, so that they may present a series of sharp points or
corners, which will have a cutting action upon the blank.
Another part of my Invention consists in combining with the rotating and
stationary dies devices for automatically presenting the blanks one by one, and
pushing them successively into the space between the dies.
Another and the most important part of my Invention consists in the combination
with each other of pairs of dies in series, the first pair of dies being adapted to
make a shallow indentation in the path of the thread around the blank, and the
next pair of dies being adapted to make such indentation deeper, either to the
extent of finishing the thread, or of partially finishing it preparatory to subjecting
the blank to the action of the third pair of dies, and so on until the screw is rolled
to the proper depth.
In carrying out this part of my Invention I may arrange the successive pairs of
dies in close proximity, so that the blank is fed directly from one pair of dies to the
next pair, or I may introduce between the pairs of dies a rotating transfer wheel
acting in conjunction with a concave guide wall for carrying the blank from the
pair of dies in which it is first operated upon to the pair of dies which next act
upon it.
Another part of my Invention consists in combining with the dies for forming or
finishing the screw thread a milling wheel for cutting or finishing a cone-point on
the end of the screw.
The accompanying Drawing illustrates a machine embodying my Invention.
Figure 1 is a front elevation, shewing the exposed portions of the faces of two
rolling dies mounted in suitable bearings, and geared to a central shaft carrying the
intermediate transfer wheel, the two systems of dies and the transfer wheel being
arranged in the same plane.
Figure 2 is an end elevation of the machine, shewing the hopper for carrying a
mass of blanks and ways, in which the blanks are conducted from the hopper to the
tube, from which they are permitted to drop into a recess at the end of the
stationary die.

page_text: Figure 3 is a transverse section through the machine on the line x, x, Figure 1
showing in section the shafting upon which the dies and the transfer wheel are
mounted, and also shewing the oscillating pusher, which pushes the blanks sidewise
successively into the space between the first pair of dies.
Figure 4 is a view in detail of the pusher and the oscillating arm upon which it
is mounted, shewing the tripping pawl which is affixed to the oscillating arm of the
lever, and which, after having been caught by a pin on the face of the die and moved.
a prescribed distance, is tripped from the pin, and thereby permits the oscillating
arm to spring back to its normal position.
Figure 5 is a section on an enlarged scale through the line y, y, Figure 3, showing
the shape of the working faces of the first pair of dies.
Figure 6 is a similar section through the line y', y', Figure 3, shewing the shape
of the working faces of the second pair of dies.
Figure 7 is a section through the lines, s, Figure 3, shewing the milling wheel
for cutting the cone upon a screw which is being operated upon by the second pair
of dies.
Figure 8 is a view on a still larger scale of the working face of one of the dies,
shewing the transverse notches in the parallel ridges formed in the face thereof.
Figure 9 is a transverse vertical section through the central portion of the hopper
and through the lifter, by means of which the blanks in the hopper are caught by
the head and lifted so that they fall by gravity into the ways which conduct them
to the check.
Figure 10 is an elevation of my improved ratchet thread screw; and
Figure 11, a top view of the head thereof.
The various parts of the machine are mounted in a substantial frame A, which
affords bearings for the vertical shaft B, upon which the rotating die b is mounted;
for the intermediate shaft C, upon which the transfer wheel a is mounted; and for
the shaft D, upon which the second rolling die d is mounted. These three shafts
are geared together, and are thus caused to rotate respectively in the directions
shown by the arrows in Figure 3.
The die b, which for convenience I will call the primary rolling die, acts in con-
junction with the curved stationary die b', and the transfer wheel cacts in conjunction
with the curved guide wall c³, while the secondary die d acts in conjunction with
the curved stationary die d'
The shaft B is provided on its lower end with a cam or eccentric B², which
imparts a reciprocating motion to the cam bar B. The cam bar B' is provided at
the end with a transverse pin B³, which is inserted in the forked arm of the bell
crank lever B. By reason of this connection the bell crank lever is caused to
Oscillate by the movement of the cam bar B³, and this oscillating motion is trans-
mitted by means of the pitman B³ to the lifter E.
The lifter is composed of two parallel plates e, e, of segmental form, which are
arranged at the desired distance from each other, and are fastened together and
pivotted to the upper end of the ways e¹. The two parallel plates of the lifter are
in line respectively with the two parallel sides of the ways, and reciprocate in a
vertical path in the centre of the hopper E¹. The bottom of this hopper is slotted
to allow the movement of the lifter, and the range of movement of the lifter is such
that the upper edges of the two parallel plates e, e, drop from the position in which
they are shewn in Figure 2 to a point slightly below the mouth of the opening in
the bottom of the hopper, as shown in Figure 9.
Blanks are thrown indiscriminately into the hopper, which has, as will be seen,
converging side walls. When the lifter falls to its lowest point the blanks are
permitted to drop into the opening in the bottom of the hopper, and are caught
between the parallel plates of the lifter, and when the lifter rises hang therein by
their heads, and slide therefrom by gravity into the ways.
Hoppers and lifters of this character are well known, but the lifter has not been
heretofore permitted to drop bodily below the mouth of the slot in the bottom of

page_text: the hopper, and wis pecuniarity or my miter greatly increases its emciency in picking
up blanks.
At the bottom of the ways there is the usual gato or check F, which is thrust
outward by a tappet cam on the shaft B, and is returned to its normal position as
the tappet cam continues its rotation by the spring f¹. The gate or check F in its
reciprocating movement cuts off a blank from the lower end of the row of blanks
hung by the heads in the ways, and permits it to drop through the short tube or
guide, indicated in dotted lines in Figures 1 and 2, into the space between the
periphery of the rolling die b and the guide wall 6' at the end of the stationary
die b¹.
The blank is held in a vertical position by the guide wall b², the concave end of
the pusher g, and the spring g', which is affixed to the pusher and partially embraces
the body of the blank. The pusher g is affixed to a stud on the end of the oscil-
lating arm H, projecting radially from a loose hub h on the shaft B, immediately
beneath the rotating die b. Loosely hung on the stud is the tripper H' in the form
of a bell crank lever, one of the arms of which points toward the hub h, while the
other stands at about a right angle with the first, and carries on its end a roller,
which bears on the stationary guide H. A pin h¹ projecting radially from the hub
h is connected to the end of a spiral spring, the opposite end of which is secured
to the frame of the machine, and the pull of this spring tends to hold the oscillating
arm H in the position in which it is shewn in Figure 3. The under side of the
rotating die b is provided with a pin H, which as the die rotates, strikes against
the inwardly turned arm of the tripper H, and carries the oscillating arm H around
until the roller on the end of the outer arm of the tripper has travelled to the end
of the concentric part of the guide H², at which point the tripper is free to turn on
its axis, and hence releases itself from the pin H³, while in obedience to the action
of the spiral spring h³ the arm H moves back to its normal position. In the act of
moving forward however the pusher g has delivered the blank caught on the recess
G so far into the space between the rotating and stationary die that the blank is
caught by friction and rolled forward around the face of the stationary die.
The action of the dies b and b¹ upon the periphery of the blank is to make a
shallow depression upon it in a spiral path corresponding to the path of the screw
thread. Having travelled to the opposite end of the stationary die b', the blank is
delivered to and caught by the transfer wheel c, which rolls it around the_guide
wall c², and delivers it to the secondary rolling die & and stationary die d. In
passing through the secondary dies the shallow impression upon the periphery of
the blank produced by the primary die, which is represented approximately in
Figure 5, is deepened so that the central longitudinal section of the screw presents
an approximation of the appearance indicated in Figure 6.
In some cases I may omit the transfer wheel, and substitute in its place the
secondary dies, delivering from the primary dies directly to the secondary dies,
which, except as to their size, would be represented by the transfer wheel o and the
stationary guide wall c'.
It will be understood that in the case of large screws, especially wood screws in
which a deep thread is required, I may increase the number of pairs of dies in the
series, employing each successive pair of dies to deepen the impression made by the
next preceding pair of dies until the thread is finished to the proper depth.
I have shewn in connection with my secondary dies a milling wheel for cutting a
cone point on the end of the screw. This milling wheel I has, it will be seen, a
bevelled cutting edge, and is affixed to a pulley i, loosely mounted upon the hollow
cylinder 1', through which the shaft D passes, and is driven by the belt i³, which is
carried by means of leaders to the pulloy on the driving shaft A' of the machine.
The milling wheel is driven at a higher speed than the rolling die d, and has its
axis out of line with the axis of the die d, so that its work on the point of the
screw will be progressively done, and also so that the edge of the milling wheel
will not project beyond the periphery of the rolling die at the place where the blank
is delivered.

page_text: In certain cases where only a shallow thread is required, only one pair of dics
may be necessary, and in such a case, as indeed in all other cases, the primary rolling
die may be provided with a milling wheel.
In the case of very large screws it may be desirable to divide the work of
cutting the conical point by providing milling wheels for each one of the rolling
dies.
It will be understood that the transfer wheel c and its guide wall c¹ may be
omitted, and some other transfer device be substituted therefor. If however the
transfer wheel is employed, it will be desirable to surround its periphery with rubber
or some other elastic material.
It will be understood that the shape of the working faces of the dies will be
varied according to the different shapes of screw threads which it may be desired
to make. The dies shown in the Drawing have working faces suitable for producing
a ratchet thread substantially like the thread shown in Figure 10, which is an
elevation of a screw embodying the first part of my Invention.
It will be seen that this screw has a ratchet thread upon its body K, a conical
point Land two bosses M, M, projecting upward from the top of the head N respec-
tively on opposite sides of the centre thereof. Sufficient space is left between the
bosses to allow the introduction of the blade of an ordinary screw driver, by means
of which it will be seen that the screw may be turned in the usual manner in either
direction.
But it is the object of this part of my Invention to adapt screws for being, by
the blows of a hammer, wholly or partially driven into the object in which they are
to be inserted. The desired adaptation of the screw to this purpose is effected by
the use of the conical point and the ratchet thread, the inclined surfaces of which
facilitate the insertion of the screw by driving, while the bosses on the head present
bearing places for receiving the impact of the hammer.
In manufacturing my improved screws I form the bosses in the act of heading
the blanks by the use of a suitably recessed heading punch, and in the case of screws
of considerable diameter, I also partially form the conical point in the header by the
use of a suitably countersunk female die or dies.
Machines for heading blanks are well known, and as this part of my Invention
consists solely in the screw having the characteristics set forth, I do not deem it
necessary to more fully describe the heading machine.
Having thus fully described the said Invention, as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,
First. Dies for rolling the threads of screws or bolts, in which dies the ridges for
impressing the thread upon the body of the blank are transversely notched at
intervals, substantially as and for the purpose set forth.
Second. In combination with a pair of dies, consisting of a rotating die and a
stationary curved die for rolling screw threads, an automatic feeding apparatus,
consisting of the hopper, the ways, the check, the guide tube, and the pusher,
adapted to feed blanks successively into the space between the rotating die and the
stationary die, substantially as set forth.
Third. In combination with the rotating die and stationary curved die, substan-
tially such as described, an oscillating pusher moving in a plane parallel or nearly
parallel with the plane of the rotating die, and having a movement toward the
space between the rotating die and the stationary die, for the purpose of feeding a
blank sidewise into such space, substantially as set forth.
Fourth. The hopper E' having a slotted bottom, in combination with an oscil-
lating lifter, having a range of downward motion sufficient to carry the upper edges
of its two parallel plates below the edges of the slot in the bottom of the hopper,
substantially as shown and described.
Fifth. In combination with each other two or more pairs of dies for rolling screw
threads, each pair consisting of a rotating die and a stationary curved dio, and the
pairs of dies having their working faces relatively so formed and proportioned as to

page_text: adapt the several pairs of dies for rolling and finishing the thread of a screw or
bolt by a series of progressive operations, the primary dies impressing a shallow
spiral groove upon the body of the blank, and the subsequently following pair or
pairs of dies, successively deepening and enlarging such impression until the thread
is finished, substantially as described.
Sixth. The combination of pairs of dies, substantially such as described, with
transferring mechanism adapted to transfer the blanks from one pair of dies to the
next following pair of dies, substantially as specified.
Seventh. The oscillating arm H. connected with the spring and provided with the
tripper in combination with the stationary guide Hand with the actuating pin,
all arranged and operating, substantially as and for the purpose set forth.
Eighth. In a machine operating automatically to finish the threads of screws or
bolts, the combination of dies for rolling such threads, and a cutting instrument
for cutting the conical point on the end of the screw or bolt, substantially as
described.
Ninth. The milling wheel provided with a bevelled cutting edge, in combination
with a rotating die and a stationary curved die, substantially as and for the purpose
set forth.
Tenth. The hollow cylinder, affording the bearing for the milling wheel, in
combination with the shaft carrying the rotating die d, substantially as shown and
described.
Eleventh. A ratchet thread screw, provided with a conical point, substantially as
shewn and described, and for the purpose specified.
Twelfth. Two or more bosses projecting outward from the head of a screw, sub-
stantially as and for the purpose set forth.
Thirteenth. A screw, having a ratchet thread and a conical point, and having
projecting bosses formed on its head, substantially as shewn and described, and for
the purpose specified.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Nineteenth day of December, in the year of our Lord
One thousand eight hundred and seventy nine.
WE RORT LAKE (L.S.)