IMPROVED MACHINERY FOR MANUFACTURING SCREWS AND STUD AND OTHER PINS
Year: 1879

page_text: LETTERS PATENT to Charles William Parker, of Leeds, in the County of York,
Machinist, for the Invention of "IMPROVED MACHINERY FOR MANUFACTURING
SCREWS AND STUD AND OTHER PINS."
Sealed the 1st July 1879, and dated the 10th January 1879.
PROVISIONAL SPECIFICATION left by the said Charles William Parker at
the Office of the Commissioners of Patents on the 10th January 1879.
CHARLES WILLIAM PARKER, of Leeds, in the County of York, Machinist.
"IMPROVED MACHINERY FOR MANUFACTURING SCREWS AND STUD AND OTHER
PINS."
This Invention relates chiefly to an arrangement of machinery for manufacturing
what are known as machine screws, and other similar forms used in all kinds
of metal work. The machine is automatic and continuous in its action, discharging
the screws in a finished state.
The machine consists, 1stly, of a hollow coned pulley or head which contains
the feed apparatus, and is itself rotated by a band from any prime mover; 2ndly,
of a tool holder and die holder, both of which obtain their motions from cams
operated by gearing attached to the hollow head; 3rdly, of a gripper or fingers
which seize the article previous to its being cut off from the stock, rod, or wire,
and convey it necessarily under the nicking saw and milling or finishing tool,
after which it will drop the finished article and prepare it to seize another; 4thly
of a nicking saw operated directly by gear from the head; 5thly, of the milling
or finishing tool actuated by a band direct from the head; and lastly, of a break
apparatus and its appurtenances which controls the various parts of the machine,
and causes them to act at their proper times and in their respective places.
A face plate of this driving cone serves to connect it with a hollow mandril
through which the wire is fed, and to this mandril it imparts rotary motion.
Mounted loosely on a boss carried by the mandril is a worm box enclosed within
the cone. On the hub of this box is a spur wheel which by means of differential
gearing receiving its motion from the mandril drives the worm box in the same
direction as the mandril, but at a slightly different speed. In the inner periphery
of this worm box a worm is cut for the purpose to be presently explained.
The feed apparatus contained within the head or cone consists of nipping rollers
(say three), which are mounted in rocking frames tending to a common centre.
To one side of these feed rollers is secured a spur wheel which gears into and is
I Drine 10 271
'

page_text: turned by a second spur wheel loose on the fulcrum of the rocking frame. It is into
these wheels that the worm of the worm box gears, and by the rotation of this box at
a speed slightly differing from that of the cone that the feed motion for the adjustment
of the rollers is obtained. To provide for the adjustment of these rollers to grip
different diameters of stock wire, their frames are embraced by a ring which has
internal cam shaped surfaces. This ring fits into the cone and is provided on a
portion of its external periphery with rack teeth to receive a pinion, the rotation
of which by a key will cause the cam ring to turn in its bearing and advance
the rollers towards the wire, or permit of their receding to receive an increased
diameter of wire between them. In order to form a screw blank the extremity
of the wire is fed past a set of cutters (say two) placed side by side; when these
are brought up into position, the foremost cutter will turn down the wire to the
desired gaugo for the head of the screw, the cutter which follows will turn down
that portion of the wire which is to receive the thread to the desired diameter,
and by approaching the work at an incline will finish the shoulder of the head
leaving it slightly concaved. When this operation is completed the holder carrying
these cutters is forced back by means of an advancing rod carrying a pair of
grippers to make room for the advance of the threading die. This die is carried by
a holder consisting of a socketed round rod mounted in bearings on a sliding frame
in which it is capable of moving endwise. The sliding frame is caused to advance
by means of a rocking lever, and is caused to retire or be withdrawn by a helical
spring attached at one end to the sliding frame, and at the other to the main
framing of the machine.
Affixed to the die holder between its bearings is a double clutch, formed with an
annular groove to receive a finger which is carried by a second slide mounted on
the sliding frame. Running free upon the die holder is a wide spur pinion, on the
boss of which is formed a clutch to take into one end of the double clutch before
mentioned, and affixed to the sliding frame in line with the double clutch is a
retaining clutch for arresting the rotary motion of the die when it has completed
the threading of the blank, as will be presently explained. Attached to the upper
side of the small slide is a rocking lever or trigger, ono end of which is formed with
an incline, and the other end with a double catch.
Screwed to the framing of the machine and projecting above the level of the
small slide is an adjustable stop, which is intended to catch against the inclined
end of the rocking lover or trigger. Projecting up from the sliding frame and
passing through a slot in the small slide is a second projection or stop, on to which
the inner catch on the before mentioned trigger takes.
In order to insure the connection between the catch on the trigger and tho
projection on the sliding frame, a small spring latch is fixed to the frame of the
machine, and at the proper time this latch will force the catch into connection with
the aforesaid projection, and thus secure by the engagement of the proper clutches
the requisite rotating motion to the die holder.
Motion is communicated to the die holder from a spur pinion keyed on to the
front end of the cone. This spur pinion gears into a spur wheel keyed on to a
shaft placed below, but parallel with the centre of motion of the machine. On
the opposite end of this shaft is another hollow spur wheel, which gears into
the broad spur pinion already described as mounted loosely on the die holder.
When the rear face of the double clutch locks into this pinion, rotary motion will be
communicated to the dio holder. The rotation of the die and cone will be in the
same direction, but the die will over run the rotating blank, and thus when once it
lays hold of the blank, it will screw itself forward, cutting the thread as it
advances.
It is to provide for the release of the screw from the die that the above described
contrivance is adopted, thus, when the die has reached the end of its course and
the latch is tripped by the fixed stop on the frame the double clutch will be thrown
out of gear with the pinion on the die holder, and the rotation of the die will con-

page_text: The
sequently cease. The cut screw by continuing to rotate will thus draw itself clear
of the die ready for the next operation. The grippers having by their advance
thrust back the set of cutters, as before explained, will by that same act advance a
cutter, which will commence the operation of severing the thread screw from the
stock wire, and practically complete that severance. The grippers will now come
into action and take a firm hold of the screw immediately below the head.
rod which carries the grippers slides in a metal block, which has a limited motion
in a line parallel with the axis of the machine. This limited motion is controlled
by the operator for the purpose of setting the gripping device to the varying thick-
nesses of the heads of the screws to be made. The end of the gripper rod next the
centre of the machine is flattened to receive two screws, which constitute the
centres of motion for the grippers or jaws of the gripping device. These jaws are
furnished with ears or projecting pieces, which at the proper time will catch against
stops to open the jaws and cause them to drop the finished screw.
The front part
of the gripper rod is split so us to be adjustable to any sized screw it is desired to
make, and this split opening is made larger or smaller by an adjusting screw.
Behind the grippers and encircling the gripper rod is a loose collar, having a cam
face on the side next the gripping jaws. This collar when rotated (as hereafter
explained) will close the gripping jaws firmly on the screw. Cam followers or
antifriction rollers aro attached one to the gripper rod and the other to the looso
collar that encircles the gripper rod. These two cam followers take into cam
grooves formed in the interior of the before mentioned metal block, the object of
the cam grooves being to cause the gripper rod and collar to turn axially, the one
to close the grippers, as just explained, and the other to turn the severed screw
with its head upwards ready for the nicking operation.
This is effected by means of a rotary saw, which is mounted on a short shaft
carried by an adjustable sleeve parallel with the axis of the machine. When it is
desired to adjust the saw to the varying positions of the gripper (which is deter-
mined by the depth of the head of the screw) the adjustable sleeve is loosened on
one side and tightened on the other, and by this meaus the saw is moved to the
desired position. The saw derives its motion from the first spur wheel on the
cam front of the cone through an intermediate and adjustable pinion, the object of the
adjustable pinion being to admit of the saw being adjusted to the varying depths
of the heads of the screws.
The last operation is performed by a milling or finishing tool, which is attached
to the lower end of a rod mounted in a vertical adjustable bearing. Keyed loosely
on to the milling tool rod, but capable of sliding on it, is a band pulley, which
derives its motion from a band on the conc. The requisite vertical motion is com-
municated to the milling tool rod by a lover, which is actuated by a cam provided
for that purpose on a cam shaft, from which various other motions are derived.
Thus the sliding out of gear of the clutch which ensures the action of the differ-
ential motion before mentioned is effected by a cam on the cam shaft. In like
manner the starting motion of the sliding frame which carries the die holder is
obtained through a rock lever operated by a cam on the cam shaft, and the endway
motion of the gripper rod is obtained by a bowle carried by a sliding rod attached
to the gripper rod working in a grooved cam on the cam shaft. The cam shaft is
driven from the cone head through a worm wheel loose on the shaft, which derives
its motion through intermediate gearing from No. 1 spur pinion on the front of
the cone. This worm wheel imparts motion to a dished wheel which is loose on
the cam shaft. Keyed to the cam shaft is a block of metal of suitable form, to
which is hung a friction block, which is controlled by a spring. This friction
block acts excentrically to the centre of motion of the cain shaft, and together with
the dished wheel before mentioned forms the break of the machine. This friction
clutch is held permanently in contact with the inner periphery of the dished wheel
by the spring before mentioned, and so causes the cam shaft to rotate at the same
speed as the worm wheel. The rotation of the cam shaft is stopped by with-

page_text: drawing the friction clutch from contact with the dished wheel. This is effected
by means of a hook on the end of a rocking lever, which is controlled by another
lever, which is caused to rise on being touched by the end of a screw blank as it is
fed out from the cone. By throwing out of action the threading die and fitting
suitable cutters to the cutter holder the stock wire instead of being converted into 5
screws may without further alteration of the machine be manufactured into stud
and other pins.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles William Parker in the Great Seal Patent Office on the 10th
July 1879:
"
CHARLES WILLIAM PARKER, of Leeds, in the County of York, Machinist.
IMPROVED MACHINERY FOR MANUFACTURING SCREWS AND STUD AND OTHER
PINS."
This Invention relates chiefly to an arrangement of machinery for manufacturing
what are known as machine screws; but it is also applicable to the manufacture of
other similar forms used in all kinds of machinery, such as pins and studs.
The machine which is automatic and continuous in its action is provided with
a novel construction of feed apparatus that maintains its hold upon the stock wire
from the starting to the stopping of the machine. The advance of the wire (on a
sufficient length to form a screw, having been fed forward) will bring into action
the thread cutting die and simultaneously stop the feed. The dic in advancing will
thread itself onto the screw blank, the two rotating together in the same direction,
and when the thread is cut the rotation of the die will be arrested and the screw
continuing to rotate will worm itself out of the die, after which the nicking and the
polishing of the head will take place and the screw will be discharged in a finished
state from the machine.
In the accompanying Drawings, Fig. 1, Sheet I., shews in plan view an arrange-
ment of automatic screw cutting machinery constructed according to my Invention ;
Fig. 2, Sheet II., is a longitudinal vertical section of the same taken in the line 1, 2,
of Fig. 1; Fig. 3, Sheet III., is an elevation of the right hand end of the machine;
and Fig. 4 is a sectional elevation looking in the same direction as Fig. 3 and taken
in the line 3, 4, of Figures 1 and 2.
In these Figures A is the bed plate, and A¹ to A are standards bolted thereto
and constituting the fixing framing of the machine; B is a hollow coned pulley or
head which contains the feed apparatus, and is itself rotated by a band from any
prime mover.
This hollow head is closed at one end by a disc B¹ which is made fast thereto,
and is formed with a hollow concentric sleeve that enters the bearing of the
standard A' and serves to carry the hollow head. Fitted to the inner face of the
disc B' are bearing pieces a for receiving rocking frames a¹, in which are mounted
three rollers a for feeding the stock wire forward.

page_text: The internal arrangement of the head is best shown in the detached view, Fig. 5
which represents the parts in position, the disc B¹ being for the purpose assumed to
bo transparent or absent.
On the axles which constitute the fulcrums of the rocking frames are mounted
pinions a³, which gear into spur pinions a' made fast to their respective feed rollers.
Surrounding this feed mechanism (within the hollow head) is a worm box C, having
a worm c on its inner periphery which gears into the pinions a³ as into worm
wheels, in order that they may be caused through the axial motion of the worm
box to impart slow rotary motion to the feed rollers. This worm box is mounted
loosely on the boss of a disk C', which is made fast to a hollow shaft C² through
which the stock wire is led into the machine. The disc c' is attached by screws to
the ends of the bearing pieces a of the plate B', and thus the hollow shaft C and
the sleeve of the disc B are firmly connected together. The shaft C is supported
in a bearing on the standard A, which with the standard A¹ carries the hollow
head and the parts in connection therewith.
Fitted concentrically to the worm box C is a spur pinion C³, into which gears a
pinion keyed to a short shaft c³, having its bearing on the standard A². On the
outer end of this shaft is mounted loosely a pinion e, which gears into a pinion c³
on the hollow shaft C. This loose pinion is made fast to its shaft by a sliding
clutch which is thrown out of action at the moment that a sufficient length of
wire is fed forward to form a screw blank, as will be hereafter explained. The
arrangement of genring just described is intended to impart the feed motion to the
stock wire and is set in action by the rotation of the hollow shaft C, which rotates,
as already indicated, at the same speed as the hollow head. This gearing is so
timed as to cause the worn box to turn slowly on its axis, and thereby to rotate
the feed rollers a² through the pinions a³, a*.
The frames a' in which the feed rollers are mounted are made adjustable on their
fulcrums to suit various sizes of stock wire, and the rollers are caused to grip the
wire by means of a cam shaped ring a³, which embraces projections on the free
ends of the rocking frames a¹. This cam shaped ring is fitted with a sector rack,
into which gears a pinion 6 carried by an arbor b, having its bearings in the
disc B¹ and the pulley B. The outer end of this arbor is squared to receive a key,
the turning of which will give an axial motion to the cam ring and thereby cause
the feed rollers to bite the stock wire that is placed between them, or slacken their
hold thereon when wire of a larger gauge is required to be supplied to the machine.
On the outer face of the disc B₁ and concentric therewith is a pinion b³, which
transmits motion to the operating tools of the machine through the longitudinal
horizontal driving shaft D. As the wire is fed forward it comes under the action
of one or more turning tools, which reduce it to the form of a screw blank. In
Fig. 1 I have shewn three of these tools contained in a tool holder E, which holder
is also shewn detached, and in end view at Fig. 6, Sheet III. The first tool e
which comes into action is for the purpose of trucing the wire and bringing it to
the required diameter for the head. The second e' is for reducing the diameter of
the wire in rear of the head and finishing the shoulder of the head, and the third e
is for completing the blank and reducing it to the required diameter for receiving
the thread. The slide E is carried by a bracket projecting from the standard A',
and it moves over a dovetail guide thereon which is set at an angle inclining
towards the hollow head, as shewn at Fig. 1. This slide receives a tendency
forwards from the pressure spring E, and its advance is controlled by an adjustable
stop These turning tools it will be understood operate as the stock wire is
advancing, and when the feed is complete they are pushed out of action by the
partial advance of a gripper, as will be hereafter explained. When the screw blank
is thus freed from the turning tools the threading die is ready to come into
operation. This die which is mounted in the line of the axis of the screw blank
is shewn at fas fitted to the end of a spindle f¹, which spindle turns in bearings
on a slide F. On the under side of this slide is a dovetail projection running
longitudinally thereof and fitting into guides formed in the standards A³, A'. In

page_text: the centre of this slide is a rectangular opening to receive a broad pinion f³ which
is loose upon the die spindle f¹. This pinion on its forward end is formed with a
ring of clutch teeth, and the end of the rectangular opening opposite this end of the
pinion is fitted with a similar ring of clutch teeth.
Between these rings of clutch teeth is a double clutch f³ which is made fast to
the die spindle, and is furnished with clutch teeth at its opposite ends for the
purpose of taking alternately into one or other of the rings of clutch teeth before
mentioned. This clutch is furnished with an anuular groove into which takes a
finger projecting from a small slide G carried by the slide F.
This slide G is intended when locked to the slide F to hold the clutch in gear
with the pinion f³, and thereby to maintain the rotation of the die f. Mounted on
the slide G is a trip latch G¹ which is notched at its rear end to catch on to a stud
gwhich projects upwards from the slide F through a slot made for the purpose in
the slide G. The forward end of the trip latch G₁ carries an incline, which, as the
threading die with its slide is advanced, will approach to and press against a fixed
stop g' on the standard A³. The effect of this will be to trip the latch G¹ and
unlock the slide G.
Supposing now that the threading die has completed its action on the screw
blank, which will occur at the moment that the latch G¹ is tripped, the power of
the finger g to hold the clutch in contact with the pinion will cease, and the slide F
which has a tendency to move from an advanced position to the drawn position of
Fig. 2, through its connection with a draw spring F¹, will now be free to movo
back and engage its ring of clutch teeth with the forward end of the double clutch
f. The effect of this will be to lock the die spindle to the slide and stop the
further rotation of the threading die. The screw by continuing its rotation will now
run itself out of the die, leaving the die free to retire under the drag put upon the
slide F. The broad pinion f³ receives its motion from a pinion on the shaft D,
which as before explained, is driven from the hollow head B.
In order to engage the threading die with the screw blank, it is necessary to
advance the slide F in which the die spindle is mounted against the backward
drag of the spring. This is effected in the following manner:
Projecting from the rear end of the slide F is a stud upon which bears a horizontal
rock lever which receives motion froin a tappet cam F3 bearing on the side
thereof. This cam is mounted on the cam shaft H which is carried by standards
A. As this tappet cam F³ comes into action, it causes the rock lever F3 to press
forward the slide F, and thereby to bring the threading die into contact with the
screw blank.
As the rotary motion of the pinion ƒ³ and the clutch of the die spindle is at this
time in contact with the clutch teeth of the pinion, the die will be rotated and in
the same direction as the screw blank.
A slightly superior speed is however given
to the threading die, which is thereby caused to run on to the screw blank and
draw forward the slide F. It will now be understood that the operation of cutting
the screw thread will be comparatively slow, and therefore no undue wear will be
put upon the die. When the die has advanced sufficiently far to complete the
thread, the unlocking of the slides G and F will take place as already explained,
and the draw spring F coming into action, the rotation of the threading die will
be arrested, and the screw will worm itself out of the dic.
The thread having been cut upon the screw blank, the next operation is to sever
the partially formed screw from the stock wire, this is done simultaneously with
the advance of the gripper which is intended to seize the screw and present it
successively to the action of the nicking saw and milling tool.
i, Figures 1 and 4, is the parting tool carried by a rock lever I, having its
fulcrum on the side of the bed. The tool is moved forward to its work by means
of a horizontal rock lever 1¹ actuated by the recession of the tool holder E, such
lever being caused to bear against the rear end of the tool holder by means of a
spring.
K. is the gripper rod which moves endwise in a box bearing K¹ secured to the

page_text: bed plate. It is the forward end of this rod which projects beyond and below the
level of the grippers that serve to force back the tool holder E as before explained,
and thereby to bring into action the parting tool . This gripper rod receives its
endway motion from a grooved cam K on the cam shaft H, which cam is shewn
detached at Fig. 7, Sheet III. The groove of this cam receives a bowle carried
by a sliding rod K³, which at its forward end enters a square groove provided to
receive it in the box bearing. Attached to this rod is also a collar which fits into
an annular groove turned in the gripper rod. It will now be seen that as the cam
K rotates, the gripper rod will be advanced and drawn back as required. The
forward end of this gripper rod is forked and slit longitudinally to form adjustable
supports for a pair of gripping levers k, k', which are pivotted to the prongs of the
fork near the outward ends thereof.
Figures 8, Sheet III., shew in plan, side view, and end view this gripper rod and
the part connected thereto. The free end of the lever kit will be seen, is bent
round and overlaps the back of the lever for the purpose of pressing thereon and
bringing the jaws of these levers opposite each other, so as to grip the screw
between them. The back of the lever is intended to receive the pressure of a
sleeve cam which is mounted loosely on the gripper rod, and is retained in position
by a fixed collar. As the gripper is turned axially, the cam which is relatively
stationary will press upon the lever k, and thus bring the gripping surfaces or jaws
of those levers together.
The gripper as it is advanced to seize the work makes a quarter turn in order to
bring the gripping levers into the position for seizing the screw, this motion is
obtained by means of a bowle³ carried by the gripper rod working in a suitably
cut groove running longitudinally through the box bearing K¹; similarly an axial
motion is obtained for the sleeve cam which closes the gripper on to the screw at
the moment that the jaws come into coincidence with the screw, and causes the
release of the screw when the head is finished. The groove in the box bearing
which controls the action of the sleeve cam is straight for the greater part of its
length, to permit of the cam travelling with the gripper rod, without making any
axial motion. When however the gripper rod turns to bring the jaws into this
position for gripping the screw, the sleeve cams being relatively quiescent, will force
the jaws towards each other. And immediately before the gripper completes its
advancing motion, a slight twist in the groove in which the bowle of the cam
works will tighten the jaws upon the screw. A twist in the opposite end of this
groove will, when the bowle enters that part of the groove, open the jaws and
allow the screw to fall from between then. So soon as the screw is severed from
the wire, the cam draws back the gripper which now makes a back quarter turn
and brings the screw from a horizontal to a vertical position, the head being brought
under the action of a nicking saw L, which stands in the line of motion of the
gripper rod and cuts the nick in the head during the back motion of the gripper.
The further recession of the gripper rod brings the now nicked head under the
action of a milling tool m, carried by a vertical spindle M to which a rapid rotary
motion is given; by this means the screw is finished, and the gripper still moving
backward, is now caused to discharge the screw from the machine. This is dono
by lugs on the backs of the gripping levers striking against the face of the box
bearing K, and thus causing the jaws to open and release their grip of the screws.
The nicking saw L is mounted on a horizontal shaft L' carried by a bracket arı
projecting from the standard A', and it receives motion through spur gearing from
the hollow head B. The milling tool m is driven by a band from a grooved
pulley B* on the hollow head B, which is led to and from a grooved pulley on the
milling tool shaft by guide pullies b³ and b, and it receives an advancing motion
towards its work by means of a cam m³ on the cam shaft H, the rod M being made
capable of moving endwise in its bearings both for the purpose of being fed to its
work and of being adjusted to various kinds of work. The motion of the cam m
is transmitted to the spindle through a rock lever m², which pulls down a vertical
guide rod connected by a cross head to the spindle. When released from the
pressure

page_text: of the cam m¹ the milling tool is raised out of action by means of a coiled
spring m³.
I have stated that the feed of the stock wire is arrested when a sufficient length
is fed forward to form a screw blank. This is effected by means of a coiled spring
contained within the clutch cª, Figures 1 and 2, which spring, so soon as it is freed
from a counter pressure, will draw back the clutch from contact with the ring of
clutch teeth carried by the boss of the pinion c*. A forward pressure is imparted
to this clutch by means of a cam N on the left hand end of the cam shaft H. The
tappet on this cam bears against the tail end of a rock lever N', the forward end of
which engages with a slido rod N" supported in a guide rod on the standard A*.
The rear end of this slide rod is nt right angles to and is caused to press on the rear
end of the clutch c. So long therefore as the pressure of the tappet cam N is
maintained on the rock lever N¹ the clutch will engage with its pinion, but so soon
as this pressure ceases the clutch co will be withdrawn, and the pinion c¹ being left
loose on its shaft the feed will be arrested. This will be caused to tako place imine-
diately the cam shaft commences its rotation.
It now only remains to explain how the advance of the stock wire is caused to
put the cam shaft H in action, and thereby to follow up the operations which
succeed to the formation of the screw blank.
In front of this wire stands an elastic arm O keyed to a short horizontal shaft O¹,
which is mounted in bracket bearings attached to the bed of the machine. On the
shaft O' is keyed a second arm 02, which terminates in a hook, and by means of a
coiled spring connected with the bed plate a tendency is given to this lever to take
the dotted position of Fig. 9, which is a detached view of this rock lever and the
friction clutch in connection therewith. The hooked arm 0° when in its raised
position nets as a stop on a friction clutch P, which is pivotted to an armed boss
keyed to the cam shaft H. Surrounding this armed boss and mounted loosely on
the cam shaft is a friction bar P₁, against the inner periphery of which the friction
clutch P is caused to bear by means of a presser spring p. This friction clutch is
formed with a lateral projection p', which as the clutch is rotated is arrested by
the hook of the arm O³, and thus the rotation of the cam shaft is stopped.
This shaft receives motion from the shaft D in the following manner :--On the
end of this shaft is keyed a bevil pinion, which gears onto a bevil pinion on a
transverse shaft h', which shaft carries at its opposite end a worm ³ in gear with
a worm wheel ³ loose on the cam shaft H. This worm wheel h³ is made fast to the
friction box P¹; when therefore this box is held fast by the action of the friction
clip a slow rotary motion will be imparted to the cam shaft. The arm O of the
compound rock lever is held in the position shewn in Figures 1 and 9 by a stop k
projecting from the box bearing K', and it is by the end pressure of the stock wire
upon this elastic arm disengaging it from the stop that causes the friction clutch to
come into action and set the cam shaft rotating. To restore the compound rock
lever to this position against the drag of the spring before mentioned, a travelling
stud pin projecting from the sliding rod K³ is caused to press down the arm of
the compound rock lever as the gripper advances to its work, and thereby to engage
it with the stop latch k'.
On the back motion of the gripper this stud pin will move out of the way, and
thus leave the arm 0 free to rise when disengaged from the stop, as already
explained. From the foregoing it will be understood that my Invention is not only
applicable to the manufacture of screws, but also to studs and other pins, by simply
removing the threading mechanism from the machine, and in some cases the gripper,
the nicking saw, and the milling tool may be dispensed with.
In Sheets IV., V., and VI., I have shewn some modifications of certain parts of
the machine, the object being to simplify their construction and to ensure certainty
of action; Fig. 10 is a plan view of the screw cutting machine with the modifi-
cations adapted thereto, and illustrating particularly a simplification of the working
parts of the die holder slide, and of the arrangement for working the milling tool;
Fig. 11 is a transverse section taken in the line 1, 2, of Fig. 10, and illustrating a

page_text: modification whereby the construction and action of the gripper is simplified;
Fig. 12 is a right hand end elevation of the machine shewing a modification of the
mechanism for starting and stopping the rotation of the cam shaft.
In explaining these Figures it will be unnecessary to recapitulate the various
operations of the machine or to refer at all to the feed apparatus, as the feed
mechanism which is not brought within view differs in no respect from that
illustrated in the longitudinal section, Fig. 2. I have explained that the cam shaft
receives its motion through a worm wheel which is made fast to the shaft by a
friction clip. In the modification shown best in Fig. 12 the friction box P₁ is
converted into a carrier for a pawl p, which under the pressure of a spring takes
into the teeth of a ratchet wheel P cast with or attached to the boss of the loose
worn wheel, the pawl carrier P' is keyed to the cam shaft H, and the tail of the
pawl p projects outwards from the box to permit of the tripping of the pawl when
the rotation of the cam shaft is to be arrested. Mounted loosely on a short fixed
axle is an arm P2 furnished with a stud p¹ which is capable of being brought within
the circuit described by the tail of the pawl p. Underlying this arm p³ is an arm t
of a rock lever P³ which has for its fulcrum a fixed axle carried by a standard on
the bed plate, and to this arm is connected a spring or weight which will give it a
tendency to retire from the arm P². An arm 2 of this rock lever P has an
elastic extension p which during the feeding action of the machine stands opposite
the end of the stock wire; in this position it is retained by a stop p³ projecting
from the standard A³. In this position of the rock lever the arm P' is held in such
a position that its stop p' will project within the circuit of the pawl p and serve to
retain it out of action. When however the stock wire by its advance is caused to
press against the elastic extension på of the arm 2 of the rock lever, this elastic
extension will be thrust out of contact with its stop and the rock lover will then be
drawn clear of the arm P3 by the spring or counterweight with which it is connected.
The arm P will then drop clear of the tail of the pawl, and the connection between
the box P¹ and the ratchet P being established the cam shaft will recommence
rotating. In order to restore the rock lever to the drawn position of Fig. 12, it is
provided with a third arm 3 which lies in the path of a stud p' standing out from
the back of the box P'; as, therefore, the cam shaft rotates, this stud coming under
the arm 3 will rock the lever P2 into the drawn position of Fig. 12 ready to act
again to stop the cam shaft when it has completed a rotation.
Instead of giving the tool holder E its back motion from the advancing gripper
rod, a special cam E¹ is provided, which through a rock lever E2 gives an endway
motion to a sliding rod E³ that abuts against the forward end of the tool holder E.
As the larger radius of this cam comes round, which will take place as the screw
blank is completed, the tools will be thrust back out of action to make room for
the advance of the threading die. The return motion of the tool holder will be
effected as before explained.
As a simplification of the threading die slide I substitute for the slide G a cranked
lever G which is pivotted to the slide and serves to control the action of the double
clutch f. On the side of the standard A³ is a longitudinal projection or rib g
which terminates at either end with an incline. This projection as the slide F
advances engages with a lateral projection on the rear end of the rock lever and
serves to retain it in such a position that the shorter arm of the rock lever will
press the clutch f³ into gear with the clutch teeth on the pinion f², thereby insuring
the rotation of the die spindle. When the cutting of the screw thread is completed
the slide F will have sufficiently advanced to clear the tail of the rock lever G from
the rib g, and the clutch being now freed from the pressure of the rock lever the
draw spring of the slide F will pull the clutch teeth of the pinion clear of the
clutch, and thus the rotation of the die spindle will be arrested. On the back
motion of the slide it will be requisite to bring the rock lever G into a position to
bear upon the rib g on the next advance of the slide. For this purpose an elastic
finger g' is fitted to the rock lever to bear against a fixed incline g³ on the standard A*,
as the slide F moves to its back position. By the pressing of this finger against the

page_text: Instead
incline the rear end of the lever G will be rocked outwards, and as the slide F
advances it will slide over the rib g, as before, throwing the clutch f³ into gear with
the clutch of the pinion f' and thus start the rotation of the die holder.
of actuating the parting tool i through the back motion of the tool holder E,
I have shown in Figures 10 and 11 a special cam 1' for advancing the tool holder I.
This cam presses against the upper end of a rocking arm I which is connected to
the rear end of tho tool holder and thus the tool holder is advanced to its work.
The tool holder rests upon a stud projecting from the face of the standard A', and
its connection with its rocking arm is such as to permit of its ready detachment
therefrom for the purpose of sharpening or replacing the parting tool i.
As a simplification of the gripper K I propose to employ the contrivance shewn
best in Figures 11 and 11 where K is a vibrating gripper holder receiving its
motion from a grooved face cam K' through a radius arm K' which is pendant from
a stud carried by a bracket on the standard A, and is furnished with a bowle which
takes into the grooved cam. This radius arm is jointed to a connecting rod K³, the
opposite end of which is pivotted to the gripper holder. The rotation thereof of
the cam will cause the gripper holder to rock and advance the gripper jaws to the
screw and move backwards to present the gripped screw first to the nicking saw
and then to the milling tool, as above explained. The gripper holder has fitted
loosely in its head two gripper bars K, K', the former of which has its outer
extremity bent at right angles to bring it opposite the end of the bar . These
opposing surfaces constitute the gripping jaws which approach to and recede from
each other by the bars k, k, sliding over each other. The contact surfaces of the
bars near their inner ends are hollowed out to permit of a fulcrum pin for a rock
lever passing between them without interfering with their freedom of motion.
The bars, k¹, are slotted at right angles to the fulcrum pin to permit of the
rock lever being pressed through them, and the gripper holder is similarly slotted
to receive the ends of the rock lever. When this lever is in place it is secured by
the fulcrum pin, which is passed through pin holes made for it in the gripper
holder.
It will now be understood that by rocking this lover the jaws of the gripper rod
may be drawn together or thrust apart as desired. In order to obtain this motion
a cam K is provided, which acting directly on a bell crank K³ having its fulcrum
on a short standard on the bed plate, and connected through a link rod k' with
the rock lever, will impart to that lever the gripping motion. The point of con-
nection between this rod and the bell crank lever is so arranged as to permit of the
rocking of the gripper holder without affecting the bite of the gripper jaws. When
the gripper is advanced to the screw by the action of the cam K₁ the cam K* will
close the gripper jaws on to the screw; and the further motion of this cam will
cause the gripper to raise the disengaged screw and bring it under the action of the
nicking saw L, which in this arrangement is mounted on a vertical spindle L¹
receiving rotary motion from a band below the bed plate. This spindle is carried
by a support L, which is free to yield to the pressure of a rock lever L³ held
against a faco cam L by a helical spring L³. This permits of the saw entering to any
desired depth into the head of the screw, which depth may be regulated by an
adjusting screw on the end of the rock lever L³. When the nicking operation is
completed the gripper continuing its back motion presents the head of the screw to
the action of the milling tool m, which is mounted on a horizontal spindle M. in
suitable bearings, in which it is free to receive a slight endway motion from a face
cam M' through a rock lever M² bearing on the end of the spindle M. This cam M
serves to advance the milling tool to its work, and when its work is completed a
coiled spring m' serves to draw back the tool from the finished head. The spindle M
is driven directly from the head B by a driving band.
In Sheet VII. I have shewn the cams for working the tool holder E, the parting
tool i, and the gripper K in side view. The relative positions of these cams being
retained to illustrate the timing of the machine.

page_text: Having now set forth the nature of my Invention of "Improved Machinery for
Manufacturing Screws, and Stud and other Pins," and explained the manner of
carrying the same into effect, I wish it to be understood that under the above in
part recited Letters Patent I claim,—
First. Feeding the stock wire up to and past the turning tools by rollers, which,
maintaining a continuous grip on the wire during the action of the machine, and
are automatically started and stopped, as above explained, to give an intermittent
feed.
Secondly. Starting the cam shaft of the machine through the agency of a friction
clip or its equivalent, the same being actuated by the end pressure of the screw
blank, stud, or other pin, bearing upon and causing the release of an elastic arm, as
above explained.
Thirdly. The arrangement above described, whereby the threading die is
advanced to the rotating screw blank and caused to take a hold thereon, draw
itself forward in the act of cutting the thread, and when the thread is cut remain
stationary in its slide to allow the screw to run itself out of the die.
Fourthly. The arrangement of screw cutting machinery above described, whereby
at one continuous operation screws may be formed and finished automatically.
In witness whereof, I, the said Charles William Parker, have hereunto set
my hand and seal, the Eighth day of July, in the year of our Lord One
thousand eight hundred and seventy nine.