IMPROVEMENTS IN MACHINES FOR USE IN THE MANUFACTURE OF WOOD SCREWS
Year: 1883

page_text: LETTERS PATENT to William Robert Lake of the firm of Haseltine, Lake
I
& Co., Patent Agents, Southampton Buildings London for an Invention of
"IMPROVEMENTS IN MACHINES FOR USE IN THE MANUFACTURE OF WOOD
SCREWS". communicated to him from abroad by Edward Nugent of Brooklyn,
New York, United States of America
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 20th July 1883.
"
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, and Co Patent Agents,
Southampton Buildings, London, IMPROVEMENTS IN MACHINES FOR USE IN
THE MANUFACTURE OF WOOD SCREWS," [a communication to hiin from abroad
by Edward Nugent of Brooklyn, New York, United States of America]
This invention relates to machines for automatically cutting screw threads upon
blanks for wood screws and more particularly to that class of machines known as
group screw cutting machines. The said invention comprises improvements (1) in
the hopper and means for delivering the blanks therefrom to the guide ways.
(2) in the means for regulating the feed and delivery of the blanks to the
clamping jaws and (3) in the mechanism by which the movements of the bars that
carry the cutter foriners or pattern cams and the movable portions of the jaws are
controlled; it also comprises other features hereinafter described.
In the following description as each of the four sets of screw-cutting mechanism
that compose the group is the counterpart of the others both in construction and
in the mode of operation. I shall only describe one set
In carrying the said invention into practice I provide a hopper for holding the
blanks which before being put into it have their heads finished and notched. The
bottom of the said hopper is curved from front to rear and in it is formed a slot
which extends likewise from front to rear, and is at the front bounded by ridges
which gradually rise from the bottom of the hopper and ineet guide-ways between
which the blanks from the hopper pass to the mechanism for cutting the screw-
1071

page_text: thread. The distance between the said guide-ways is equal to the width of the
slot, and the width of the latter is such as to permit only the shank or body of the
blank to pass through it, so that blanks which may happen to fall therein will hang
suspended by the heads
.
If
Within the hopper, and in line with the slot, is a finger which is attached to,
and projects from, a slowly rotating shaft driven by any suitable means.
desired I may use more than one finger, although in practice I have found that one
will answer every purpose. The said finger is arranged eccentrically to the slot,
that is to say, the slot is so formed and the axis of rotation of the finger is so
placed relatively thereto that the finger. will, at the rear of the hopper, enter or
project into and through the slot, and will, as it travels towards the front of the
hopper, gradually emerge from the said slot, until as it reaches the point where the
slot joins the guide-ways, its point will be out of the slot or thereabouts and
tangential to the end of the said guide-ways. The action of the said finger is to
tilt the blank over the ends of the guide-ways into the passage between them,
avoiding all contact with the blank save at its head. When once the blank is
fairly in the guide-ways the finger leaves it and the blank descends by the force
of gravity between the downwardly inclined guide-ways to the point whence it
passes therefrom to the jaws.
At the point where the guide-ways pass through the front of the hopper there is
an opening of sufficient size to permit the passage of the head of the blank that
hangs between them. In order to prevent the liability of the blanks choking or
jamming in the slots during the operation of the machine give the finger a
curved form whereby it is caused to act on the blanks which are in the slot with
the point or tip only and to put the rest of it in a position where it cannot
interfere with those blanks and where it will keep the slot clean of others. The
finger also acts as a stirrer during its passage through the mass of blanks in the
hopper thus causing one or more of them to fall into the slot so as to be in readiness
for the finger when it next comes around.
The guide-ways extend downwards in a sinuose path from the hopper to a point
just above the dies and are so formed and arranged that at this point the blanks
will lie points foremost, one above the other, in a horizontal plane or parallel with
the dies.
The blanks are maintained in this position by receiving and delivering
mechanism which feeds the blanks, one by one, at the proper intervals to the
clamping jaws. One jaw is stationary and has in its face a half round horizontal
groove which extends from front to rear thereof. The jaw is movable and has a
corresponding half round groove and is mounted upon a slide bar which, by
suitable mechanism, has a reciprocating movement imparted to it at proper
intervals so as to move the said movable jaw up to, and away from, the stationary
jaw. When the two jaws come together their two half grooves meet and form a
cylindrical hole of a size to receive and fit the shank of the screwblank, the
movable jaw being of a width from front to rear to embrace only that portion of
the shank which is to remain unscrew-threaded
The slide bar is mounted in proper bearings so as to be capable of sliding
longitudinally and is caused to reciprocate in this direction by mechanism
hereinafter described
The receiving and delivering mechanism consists of two parts a vibratory or
reciprocating blank receiver and a stop or cut off. The receiver is a hook-like arm
which extends downward from the outer end of a rod which is fastened to, and
projects forward from, a rock shaft supported in proper bearings in the frame of the
machine., The 'receiver normally stands with its bent or hook-like lower end
extending across the end of the passage between the guideways so as to intercept
and sustain the screw blanks that lie therein. It will be noted here that the inner
or acting vertical face of the stationary jaw is in line with, or on prolongation of
the side of the passage opposite that on which the receiver is placed. The receiver
occupies this position so long as the jaws are closed as soon however as the jaws

page_text: are opened the said receiver descends and gradually lowering that blank which
rests directly upon it, guides it into the half groove in the stationary jaw and
maintains it there until the movable jaw again moves up and closes around the
blank; at which time it, rises and resumes its first position. There is no
interference between the movable jaw and the receiver, as the said jaw is of less
length than the stationary jaw, and the receiver is situated so as to work in front
of the movable jaw in connection with that portion of the stationary jaw which
extends further to the front than its fellow.
It is necessary to prevent the mass of the blanks above the lowermost one from
following its movement when it is lowered by the receiver as just explained, so
that only one blank at a time, and at proper intervals, shall be fed to the jaws.
To this end I make use of the said stop or cut off. This device consists of a
horizontal cross pin or plate which works through a hole in the guide ways and is
mounted on the end of a spring arm attached to the frame. This spring arm has
on it an incline, and upon the vertical portion of the receiver is a projection
intended to act in connection with the said incline. The distance between the
cross pin and the bent lower end of the receiver is about equal to the diameter of
the screw blank, so that, when the lowermost blank rests upon the receiver, the
point of the cut-off or cross pin will stand opposite to the line of contact between
that blank and the one next above. The cross-pin normally stands out of the path
of the blanks with the projection just meeting the machine. The consequence of
this arrangement is, that, as soon as the receiver commences to descend, the cross
pin, by the action of the projection upon the said incline, will be moved against
the stress of the said spring arm so as to extend across the guideways and cut off
all of the blanks save the lowermost one, thus permitting but one blank to be
delivered by the receiver, and upholding the others until the receiver resumes its
original position, at which time the cut off will return also to its first position
and permit the blanks to drop until they stop against the receiver. This feed
mechanism is very simple in construction and entirely effective in operation.
In order to cast a screw-thread upon a blank, I provide a cutter and a cutter-.
stock. The said cutter is placed in a recess or socket in the stock and is then held
by a cap A stop gauge on the head of the stock is provided for the purpose of
determining accurately the position of the cutter. The said cap is fastened in
place by a screw. The cutter-stock is designed to vibrate upon a horizontal axis
towards, and away from, the screw blank in the dies, and for this purpose it is
provided on its rear face with a short horizontally projecting stud or axle mounted
in bearings on a carrier bed or plate, which latter, by suitable mechanism herein-
after described, has imparted to it a reciprocating movement from front to rear, so
as to impart the requisite traverse motion to the cutter. The vibrating movement
of the cutter-stock is for the purpose of causing the cutter to approach, and recede
from, the blank at proper times. In order to cause the cutter to follow the taper
of the blank, I employ a pattern-cam or former mounted on a longitudinally
reciprocating bar to which proper movements are imparted by mechanism herein-
after described. The said former is intended to act on the. tail or lower end of
the cutter stock which is held against it by the stress of a spring. The straight
portion of the former is traversed by the cutter stock while the cutter is working
on the cylindrical part of the blank-and it traverses the inclined part of the former
while working on the tapering point of the blank as will be understood without
further explanation. The cutter is intended to traverse the blank several times,
cutting into it a little deeper each time, so as finally to cut a thread of the proper
depth. For this purpose one end of the former-bar is prolonged beyond the end of
the machine, and has rigidly attached to this end a rearwardly extending arm
provided in its inner face with a stud or projection that works against an annular
cam formed on the side of a power driven revolving cam wheel; a spring serves to
pull the former-bar in the direction requisite to hold the rearwardly extending arm
with yielding pressure against the cam. This cam is formed with several rises
(corresponding to the number of times the cutter has to traverse the blank to cut

page_text: a thread) each a little in advance of its fellow and with a corresponding number of
intervening notches. The rises are the surfaces which act to hold the former-bar
up in position for the cutter-stock; the notches permit the bar at the conclusion of
each forward movement of the cutter during its traverses to move far enough to
allow the tail of the cutter-stock to move a distance requisite to enable the cutter.
to clear the blank during the rearward movement of the stock
One of the notches is deeper and is intended at the conclusion of the last cut, to
permit the former-bar to move a greater distance for the purpose of withdrawing.
at this time the movable jaw whose sliding bar is connected with the former-bar
by lever mechanism
"
This mechanism consists of a two-part lever hung on a pivot on the frame of
the machine, the main portion of the said lever has its lower end forked so as to
straddle a pin on the former-bar and its upper end is situated between the machine
frame, and a downwardly projecting lip. or flange on the end of the sliding bar;
with the upper end of the main portion of the lever is combined the other part
which is held thereto by a headed rod or bolt passing loosely through the front
part and having on that part of it which projects a spiral spring confined between
the head of the rod and the lever. A part of the slide bar is held between the
two parts of the lever. When the former-bar is drawn out by the cam the sliding
bar is, by the second part of the lever, pushed inwards so as to close the movable
jaw against its fellow, and the movement is sufficient to carry the upper end of
the second part of the lever some distance away and to put a spring under
considerable compression. Consequently when an arm drops into one of the
notches the pivot lever-part can move without disturbing the sliding bar, which,
by the action of a compensating spring on the second part, is held firmly up in
place, but when the arm drops into the deeper notch, then both jaws, the sliding
bar, and the former-bar will move simultaneously so as to open the jaws and remove
the formers from an operative position
By the combination with the cam-wheel and the former and carrying bars of
the two-part spring-lever, I am enabled to materially simplifly the machine and
reduce the number of working parts.
The reciprocating movements of the cutter carrier or plate are imparted to it by
scroll cams on a rotating shaft. The carrier is held in yielding contact with these
cams by a stiff rectracting spring.
The rising and falling movement of the receiver is obtained from a cam-wheel
through an arm fixed to, and projecting from, a shaft and provided with a friction
wheel or roller which is held in contact with the periphery of the said cam-wheel
by a spring
The cam wheel has on its periphery an enlargement or rise which acts to rock a
shaft at the proper time during each revolution of the cam-wheel.
+
I will now describe what is known in machines of this class as the screw driving
mechanism, that is to say, the mechanism by which the screw blank is rotated
during the time it is operated on by the cutter.
The screw-driver proper is a two part driver consisting of the shank and stem
which latter fits in a socket in the front end of the former and is pushed forward
by a spring. The stem is united to the shank by a cross pin whose ends extend
into a longitudinal slot in the shank.. The stem is thus permitted to have a limited
longitudinal movement independently of the shank but both must revolve together
and in unison. The object of the former provision is to enable the point of the
screw-driver to more readily find and enter the nick in the head of the screw-blank
in line with which the screw-driver is placed. The shank is mounted in a rotary
power-driven tubular shaft or sleeve with which it is connected by a pin and slot
connection; the object being to render the screw-driver capable of moving
to-and-fro in the tubular sleeve by which it is rotated so as to bring it into and
out of engagement at proper times with the head of the blank.
In order to impart to the screw-driver this to-and fro-movement the head of the
shank is formed with an annular flange which engages and runs in a groove in the

page_text: top of a vibratory lever pivotted to the machine frame and provided at its lower
end with a stud that bears upon the periphery of a cam with which it is held in
yielding contact by a spring."
The cam is fixed on, and revolves with, a shaft. In the upper end of the
vibratory lever is a bearing screw which can be set up against the head of the
screw-driver and is held in that position by a set-screw
The shafting and driving gearing are suitably arranged.
In this group-screw cutting machine, the cutter stocks are placed side by side
parallel with one another on a carrier which moves from front to rear of the
machine; and also the former and jaw carrying bars, the range of whose movement
is comparatively short, move laterally or from side to side of the machine. Each
cutter stock also is mounted upon the carrier on its own pivot or axle inde-
pendently of the others and has its own separate former or pattern cam. By this
arrangement I am enabled to reduce the size of the machine and also to adjust
and change any one of the cutter stocks or formers without interfering with or
changing the adjustment of the others
It is, obvious that the form and construction of the parts may be varied
considerably without departure from the nature of this invention

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Robert Lake in the Patent Office on the 19th January
1884.
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London "IMPROVEMENTS IN MACHINES FOR USE IN
THE MANUFACTURE OF WOOD SCREWS a communication to me from abroad by
Edward Nugent of Brooklyn, New York, United States of America
"
This invention relates to machines for automatically cutting screw threads
upon blanks for wood screws and more particularly to that class of such machines
known as "group screw cutting machines."
The said invention comprises improvements in the hopper and means for
delivering the blanks therefrom to the guideways; in the means for regulating the
feed and delivery of the blanks to the clamping jaws; and in the mechanism by
which the movements of the bars that carry the cutter-formers or pattern-cams
and movable portions of the jaws are controlled. It also comprises other
improvements all as hereinafter described.
În the accompanying drawings.
Figure 1 is a plan of a machine in which are grouped four sets of screw cutting
mechanism. Two hoppers only are represented, the other two together with their
supporting-frame and the rotating feed fingers which work in them, being removed
in order to disclose parts of the machine situated beneath them.
Figure 2 is a front elevation of the machine with one of the cutter stocks
removed.
Figure 3 is a rear elevation of the machine.
Figure 4 is an elevation of that side of the machine on which is placed the cam
which controls the movements of the jaw carrying and cutter former bars and the
blank receiving and delivering arm.
Figure 5 is a section on the line 5, 5, Figure 1.
Figure 6 is a horizontal section, partly in elevation the plane of section passing
just above the reciprocating cutter carrier. In this Figure a portion of the carrier
is broken away so as to disclose one of the formers or patterns, together with that
portion of the stock of the cutter that works against it.
Figure 7 is a sectional front elevation drawn to an enlarged scale, of one set of
clamping jaws, together with the cutter and cutter stock and blank feeding and
delivering mechanism which co-operate with the said set of jaws. In this Figure
the parts are represented in the position which they occupy when the cutter is
operating on a blank contained in the jaws
Figure 8 is a front elevation of the same parts in the position which they
assume when the blank receiving and delivery mechanism has just delivered a
blank to the stationary jaw and the movable jaw is about to advance toward the
other so as to close upon the blank.
Figure 9 is a diagram showing the formation of the cam which controls the
movement of the former or pattern bar and the jaw carrying bar.
Each of the four sets of screw cutting mechanism that compose the group is the
counterpart of the others, both in construction and in mode of operation, so that a
description of one will answer for all.
A indicates the blank holding hopper. It can best be understood by reference to
Figures 1 and 5.. The blanks before being put into it have their heads finished
and nicked. The bottom of the hopper is curved from front to rear and in it is
formed a slot a, which extends likewise from front to rear, and is at the front

page_text: bounded by ridges a' which gradually rise from the bottom of the hopper and
meet the guideways B, between which the blanks from the hopper pass to the
mechanism for cutting the screw thread. The distance between the guide-ways is
equal to the width of the slot a, and the width of the latter is such as to permit
only the shank or body of the blank to pass through it, so that blanks which may
happen to fall therein will hang suspended by the head, as indicated in Figure 5.
Within the hopper, and in line with the slot, are one or more fingers b which are
attached to and project from a slowly-rotating shaft 1, driven from any suitable
source. In the arrangement shown in the, drawings only one finger is employed
to each hopper, which in practice will answer every purpose. The finger is placed
eccentrically to the slot that is to say, the slot is so formed, and the axis of rota-
tion of the finger is so placed relatively thereto that the finger will at the rear of
the hopper enter or project into and through the slot for some distance and will
then, as it travels toward the front of the hopper, gradually emerge from the slot
until as it reaches the point where the slot joins the ways B, its point will be out
of the slot or thereabout, and tangential to the end of the ways, as indicated in
Figure 5, where it is represented in the act of lifting a blank by the head out of
the slot into the passage formed by the guide-ways, its action being to tilt the
blank over the ends of the guideways into the passage between them, avoiding all
contact with the blank save at its head. When once the blank is fairly in the
guide-ways the finger leaves it, and the blank descends, by force of gravity between
the downwardly-inclined guide-ways to the point whence it passes therefrom to the
jaws. At the point where the guideways pass through the front of the hopper
there is an opening above the guideways of sufficient size to permit the passage of
the head of the blank that hangs between them. I have found it essential, in
order to prevent liability of the blanks choking or jamming in the slot during the
operation of the machine to give the finger a curved form, substantially like that
shown in the drawings, by this means acting on the blanks which are in the slot
with the point or tip only of the finger, and putting the rest of it in a position
where it cannot interfere with those blanks and where it will keep the slot clean
of others. The finger also acts as a stirrer during its passage through the mass of
blanks in the hopper, thus causing one or more of them to fall into the slot so as
to be in readiness for the finger when it next comes around.
Heretofore in this class of machines the blank receiving slot has been concentric
with the axis of rotation of the finger. My improvement in this direction is found
in the eccentric arrangement of these parts, as above described by which I obtain
material advantages over the old arrangement, the finger acting on the blank in
the slot with greater ease and less liability of jamming and also operating with
entire certainty to tilt the blanks over the end of the slot into the guide-ways.
The guide-ways extend downward in a sinuous path from the hopper to a point just
above the dies and are so formed and arranged that at this point the blanks will
lie, point foremost one above the other, in a horizontal plane, or parallel with the
dies, as indicated in Figures 1, 2, 5, and 7 in which last-named figure the blanks
are represented by dotted lines. The blanks are maintained in this position by a
receiving and delivering mechanism which feeds the blanks one by one at the proper
intervals to the clamping jaws.
The clamping mechanism has two jaws C C¹. The jaw C is stationary, and has
in its face a half round horizontal groove, c, which extends from front to rear of
the jaw. The jaw C¹ has a corresponding half-round groove c¹, and is mounted
upon a slide bar D which, by suitable mechanism has a reciprocating movement
imparted to it at proper intervals so as to move the jaw C up to and away from
the stationary jaw When the two come together as indicated in Figure their
two half grooves c c¹ meet and form a cylindrical hole of a size to receive and fit
the shank of the screw-blank, the movable jaw C being of a width from front to
rear to embrace only that portion of the shank which is to remain unscrew-
threaded.. The bar D is mounted in proper bearings so as to be capable of sliding

page_text: lengthwise and is caused to reciprocate in this direction by mechanism which will
be hereinafter described..
The receiving and delivering mechanism consists of two parts, a vibratory or
reciprocating, blank receiver E and a stop or cut off F, whose construction and
arrangement can best be seen in Figures 1, 2, 4, 7, and S. The receiver E is a
hook like arm, which extends downward from the outer end of a rod E¹ fastened
to and projecting forward from a rock shaft supported in proper bearings in the
frame of the machine. The receiver normally stands as shown in Figure 7, in
which position its bent or hook-like lower end extends across the end of the passage
between the guide-ways B so as to intercept and sustain the screw blanks that lie
therein. It will be noticed that the inner or acting vertical face of the stationary
jaw C is in line with or on prolongation of the side of the passage opposite that on
which the receiver is placed. The receiver occupies this position so long as the
jaws are closed. As soon however as the jaws are opened the receiver descends
and gradually lowering that blank which rests directly upon it guides it into the
half groove in the stationary jaw as shown in Figure 8 and maintains it there until
the movable jaw C¹ again moves up'and closes around the blank; at which time it
rises and resumes its first position (shown in Figure 7) There is no interference
between the jaw C¹ and the receiver for that jaw is of less length than the stationary
jaw and the receiver is situated so as to work in front of the jaw C¹ in connection
with that portion of the stationary jaw C which extends farther to the front than
its fellow.
It is requisite to prevent the mass of blanks above the lowermost one from
following its movement when it is lowered by the receiver as just explained so that
only one blank at a time and at proper intervals shall be fed to the jaws. To this
end I make use of the stop or cut off F. This device consists of a horizontal cross
pin or plate which works through a hole in the guide-ways, and is mounted on the
end of a spring arm F1 attached to the frame. This spring arm has on it a swell
or incline d and upon the vertical portion of the receiver is a projection d¹ intended
to act in connection with the swell or incline d. The distance between the cross
pin F and the bent lower end of the receiver is about equal to the diameter of the
screw blank so that when the lowermost blank rests upon the receiver, the point
of the cut-off or cross pin will stand opposite to the line of contact between that
blank and the one next above, as indicated in Figure 7. The cross-pin normally
stands out of the path of the blanks, in the position indicated in the Figure last
referred to, with the projection d¹ just meeting the swell d. The consequence of this
arrangement is that as soon as the receiver commences to descend, the cross-pin by
the action of the projection d' upon the swell d, will be pushed in against the stress
of the spring-arm F¹, so as to extend across the guide-ways and cut off all the blanks
save the lowermost one, thus permitting but one blank to be delivered by the
receiver, and upholding the others, as indicated in Figure 8, until the receiver
resumes its original position, at which time the cut-off will return also to its first
position (seen in Figure 7) and permit the blanks to drop until they stop against
the receiver. This feed mechanism is very simple in construction and effective in
operation.
The mechanism by which the screw-thread is cut upon the blank held in the
dies comprises the cutter G and the cutter stock G¹ The cutter is placed in a
recess or socket in the stock, and is there held by a cap e. A stop-gauge f on the
head of the stock is provided for the purpose of determining accurately the position
of the cutter. The cape is fastened in place by the screw e¹. The cutter-stock is
designed to vibrate upon a horizontal axis toward and away from the screw-blank
in the dies, and for this purpose it is provided on its rear face with a horizontal
projecting short stud or axle g, (see Figure 6) mounted in bearings g' on a carrier
bed or plate H, which latter, by suitable mechanism hereinafter described, has
imparted to it a reciprocating movement from front to rear, so as to impart the
requisite transverse motion to the cutter. The vibrating movement of the cutter-
stock is for the purpose of causing the cutter to approach and recede from the

page_text: blank at proper times. In order to cause the cutter to follow the taper of the
blank, I employ a pattern cam or former I mounted on a longitudinally-reciprocating
bar I to which proper movements are imparted by mechanism which will be
presently described. The former I is intended to act on the tail or lower end of.
the stock G¹, which is held against it by the stress of a spring G³, as indicated in
Figures 2 and 6. The straight portion of the former is traversed by the stock
while the cutter is working on the cylindrical part of the blank, and it traverses
the inclined part of the former while working on the tapering point of the blank,
as will be understood without further explanation.
The cutter is intended each time it traverses the blank to cut into it a little
deeper so as finally to cut a thread of the proper depth. For this purpose one end
of the former-bar T is prolonged beyond the end of the machine, and has rigidly
attached to this end, a rearwardly-extending arm I2, Figure 4, provided on its inner
face with a stud or projection that works against an annular cam J, formed on the
side of a power-driven revolving cam-wheel J¹. A spring.Is serves to pull the bar
in the direction requisite to hold the arm 12 with yielding pressure against the cam.
This cam as shown in Figure 9 has seven rises or projections h h', h², h³, h*, h³, hª,
each a little in advance of its fellow and seven intervening notches, i and ", The
rises, are the surfaces which act to hold the former-bar up in position for the cutter-
stock. The six notches permit the bar at the conclusion of each forward
movement of the cutter, during six of its traverses, to move to the left, (see
Figure 2,) far enough to allow the tail of the cutter-stock to move in like direction
a distance requisite to enable the cutter to clear the blank during the rearward
movement of the stock. The seventh notch ¹ is deeper, and is intended, at the
conclusion of the seventh and last cut to permit the bar I to move a greater
distance to the left for the purpose of withdrawing at this time the movable jaw C¹,
whose sliding bar D is connected with the former-bar by a lever mechanism, which
can best be seen in Figures 2 and 4. This mechanism consists of a two-part
lever K K hung on a pivot j on the frame of the machine. K indicates the main
portion of the lever. It has its lower end forked, so as to straddle a pin 7 on the
bar I¹, and its upper end is situated between the machine-frame and a downwardly-
projecting lip or flange D¹, on the right-hand end of the bar D. With the upper
end of the main portion of the lever is combined the other part K¹, which is held
thereto by a headed rod or bolt k passing loosely through the part K, and having
on that part of it which projects beyond the latter a spiral spring confined
between the head of the rod and the lever. The part D¹ of the slide-bar D is held
between the parts K and K' as shown. When the slide-bar I¹ is drawn out by one
of the rises h, the jaw-carrying bar D is by the part K¹ pushed inward, so as to
close the jaw C¹ against its fellow, and the movement is sufficient to carry the
upper end of the lever part K some distance away from the part D¹ of the bar, and
to put the spring under considerable compression, as indicated in Figure 2.
Consequently when the arm 12 drops into the shallow notches i, the lever part K
can move without disturbing the jaw-carrying bar D, which, by the action of the
compensating springs k on the part K', is held firmly up in place; but when the
arm drops into the deeper notch , then both jaw-carrying bar and former-bar will
move simultaneously, so as to open the jaws and remove the formers from operative
position.
By the combination with the cam-wheel and the former and jaw carrying bars
of the two-part spring-lever, I am enabled to materially simplify the machine and
reduce the number of working parts.
The reciprocatory movements of the cutter carrier or plate H are imparted to
it by scroll-cams H¹ on a rotating shaft 3, as indicated in Figures 5 and 6. The
carrier is held in yielding contact with these cams by a stiff retracting spring 1,
Figure 6.
The rising-and-falling movement of the receiver E is obtained from the cam-
wheel J¹ through the intermediary of an arm E, fixed to and projecting from
shaft E', and provided with a friction wheel or roller E³, which is held in contact

page_text: with the periphery of the cam-wheel J' by a spring m, as seen in Figure 4. The
cam-wheel has on its periphery a swell or rise n which acts to rock the shaft E¹ at
the proper time during each revolution of the cam-wheel.
I will now describe what is known in machines of this class as the "screw-driving
mechanism," that is to say, the mechanism by which the screw-blank is rotated
during the time it is operated on by the cutter. This mechanism is shown plainly
in Figures 1 and 5. The screw-driver proper is a two-part driver consisting of
the shank L and stem L', which latter fits in a socket in the front end of the
former and is pushed forward by a spring o. The stem is united to the shank
by a cross-pin 2 whose ends extend into a short longitudinal slot p³, in the shank.
The stem is thus permitted to have a limited longitudinal movement independently
of the shank, but both must revolve together and in unison. The object of the
former provision is to enable the point of the screw-driver to more readily find
and enter the nick in the head of the screw-blank, in line with which the screw-
driver is placed.
The shank L is mounted in a rotary power-driven tubular shaft
or sleeve M, with which it is connected by a pin-and-slot connection 2 71, similar
to that shown at ppl, the object being to render the screw-driver capable of
moving to and fro in the tubular sleeve by which it is rotated, so as to bring it
into and out of engagement at proper times with the head of the blank. In order
to impart to the screw-driver this to and fro movement, the head of the shank L
is formed with an annular flange s. The said. flange engages and runs in a
groove in the top of a vibratory lever N, pivoted to the machine-frame at t, and
provided at its lower end with a stud or teat that bears upon the periphery of a
cam N with which it is held in yielding contact by a spring v. The cam is fixed
on and revolves with a shaft 4. In the upper end of the lever N is a bearing
screw w, which can be set up against the head of the screw-driver and is held in
that position by a set-screw x.
The shafting and driving-gearing may be briefly described as follows: The
main or driving shaft communicates a rapid movement of continuous rotation to
the several screw-drivers through bevelled gear-wheels 6, 7. A shaft 3 is driven
from the shaft 5 through the intermediary of the pinion 8 and the spur-wheel 9.
The shaft 4, on which are mounted both the cam-wheel J¹ and the cams which
operate the screw-driver levers is driven from the shaft 3 by the pinion 10 and
spur-wheel 11. The shaft 1 derives its movement from the shaft 3, through the
intermediate pulleys 12 and 13, and belt 14. The shaft 3 makes seven revolutions
for each revolution of the cam wheel J'. The parts are so proportioned, arranged,
and timed in their movements relatively to one another as to operate in the
following manner. Suppose the last cut to have been made upon the screw-blanks
held in the dies, and the arm 12 to have just dropped into the deep notch i¹ of
cam-wheel J; the effect will be to cause the jaws C, C¹ to open and release the
finished screws (which drop into the discharge spouts or chutes 3,) and simul-
taneously to move the former-bar in a direction which will permit the cutter-stocks
to turn on their pivots, far enough to remove the cutters from the path of the
blanks. The screw-drivers at the same time withdraw far enough to be disengaged
from the nicks in the heads of the screws. The receivers E now descend, and each
lowers to its appropriate jaw. C one screw, the others being retained during this
time by the cut-offs F. As soon as this takes place the jaws C¹ move up and close
upon the blanks in the stationary jaws C, and simultaneously the former-bar
moves to bring the formers up into operative position, and the cutter-carrier recedes
to the point from which the cutters start to cut the thread, the receiver E rising in
time to clear the cutters, while by the time the cutters are in position to commence
work the screw-drivers have advanced and found the nicks in the heads of the
blanks, and the latter are consequently in rapid rotation in their jaws. The
cutters now move forward, and make the first cut, the depth of which is determined
by the rise on cam-wheel J¹. The arm 12 then drops into the first notch i, which
permits the former-bar to move a little toward the left without disturbing the
jaw-carrying bar, as hereinbefore explained, and simultaneously the cutter-carrier

page_text: returns to its first position. By the second rise h¹ the former-bar is put in a
position to cause the cutters as they advance to make a deeper cut, and so on,
progressively, until the final cut is completed, when the arm I³ drops into the
deep notch and the operations hereinbefore described are repeated in the order
recited.
It will be noted that in this group screw-cutting machine the cutter-stocks are
placed side by side, parallel with one another, on a carrier which moves from front
to rear of the machine, and also that the former and jaw carrying bars, the range
of whose movement is comparatively short, move laterally, or from side to side of
the machine. It will also be noted that each cutter-stock is mounted upon the
carrier on its own pivot or axle, independently of the others and has its own
separate former or pattern-cam. By this arrangement I am enabled to reduce the
size of the machine and also to adjust and change any one of the cutter-stocks or
formers without interfering with or changing the adjustment of the others.
In the foregoing description I have described what I believe to be the best
embodiment of my invention; but it is obvious that the form and construction of
the parts may be varied considerably without changing the principle or mode of
operation of the machine and without departing from the nature of this Invention
I do not therefore confine myself to the special construction herein shewn and
described
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, The hopper, provided in its curved bottom with a blank-receiving slot, in
combination with the rotating-feeding-finger placed eccentrically to the slot,
substantially in the manner and for the purposes set forth
Second, The combination, substantially as set forth, of the hopper, provided in its
curved bottom with a blank-receiving slot, the guide-ways having a passage
between them forming a continuation of the said slot, and the rotating feeding-
finger placed eccentrically to the slot and adapted to operate on the blanks
contained therein, substantially as described.
Third. The eccentrically-placed rotating feed-finger, curved as described, in
combination with the hopper provided in its curved bottom with a blank-receiving
slot, substantially as set forth."
Fourth. The combination with the blank-holding jaws and the guideways or
receptacle from which the blanks pass to the said jaws, of the receiver E, arranged
and operating substantially as described to receive a blank from the guide-ways or
receptacle and deliver it to the jaws, substantially as set forth.
Fifth. The combination of the blank holding jaws, the guide-ways or receptacle
from which the blanks pass to the said jaws, the receiver E which receives and
delivers to the jaws from the guide-ways the lowermost blank contained in the
latter, and the independent cut-off or stop for sustaining in the guideways the other
blanks while the receiver is delivering its blank to the jaws, these parts being
arranged and operating substantially as set forth
Sixth. The spring-controlled cut-off pin and the receiver, in combination with
the guideways and the blank-holding jaws, for joint operation substantially as
set forth.
Seventh. The jaw-carrying bar and the former-bar, in combination with the two-
part spring-lever and its actuating cam-wheel, for joint operation substantially as
set forth.
Eighth. The cam-wheel J¹, provided with a side cam. for controlling the movement
of the jaw-carrying bar and former-bar, and with a peripheral cam for actuating
the receiver-carrying shaft, in combination with the jaw-carrying bar, the former
bar, the two-part spring-lever, and the receiver-carrying shaft, arranged and
operating substantially as set forth.
Ninth. The series of vibrating cutter-stocks having independent axles, which
extend from front to rear of the machine and are mounted on a carrier which

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reciprocates in a similar direction, in combination with a corresponding series of
jaws having their acting faces extending from front to rear, a series of independent
formers or pattern-cams one for each cutter-stock, and laterally-reciprocating jaw
and former-carrying bars, these parts being timed in their movements relatively to
one another, and adapted to, co-operate substantially in the manner set forth.
In witness whereof I the said William Robert Lake have hereunto set my
hand and, seal this nineteenth day of January in the year of our Lord one
thousand eight hundred and eighty four,
DAD T