IMPROVEMENTS IN MACHINERY FOR MANUFACTURING SCREWS
Year: 1878

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
A com-
& Co., Patent Agents, Southampton Buildings, London, for the Invention of
" IMPROVEMENTS IN MACHINERY FOR MANUFACTURING SCREWS."
munication from abroad by Charles Dake Rogers, of Providence, Rhode Island,
United States of America.
Sealed the 18th April 1878, and dated the 28th February 1878.
COMPLETE SPECIFICATION filed by the said William Robert Lake at the
Office of the Commissioners of Patents on the 28th February 1878.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN MACHINERY FOR MANU-
FACTURING SCREWS." A communication from abroad by Charles Dake Rogers, of
Providence, Rhode Island, United States of America.
My improvements relate to that class of machines in which fine threaded screws
are made, and which embody threading dies; and in which improved machine the
threading operation can be performed alone or simultaneously therewith. The
blanks may be so milled as to be properly pointed, their bodies made truly cylin-
drical, with a precise and uniform diameter, and their heads squared upon the under
side; or either one of these last-named operations may be performed, they depending
wholly upon the character of the milling tool employed.
The first part of my Invention consists in the combination with a pair of jaw
spindles, which are capable of revolving on their own axes, and also on an inter-
mediate axis common to both spindles of threading dies, and a milling tool, which
accurately adjusts the blank axially in the jaw of one of the spindles while pointing,
reducing in diameter, and squaring up the head of the blank, or performing either
one of said operations, whereby no blank can be presented to the threading dies
unless held absolutely coincident with the axis of the jaw spindle. Jaw spindles of
the character named have heretofore been employed in combination with "shaving'
and nicking tools, as in the well-known "Sloan" machine, and also in connection
with threading dies and an edge tool for pointing, but that class of tool does not
possess the above-described centreing capacity of a milling tool, which is provided
"

page_text: with an axial opening for receiving the whole or a portion of the body of the blank.
With a milling tool which operates on the shank of a blank and determines its
diameter it is impossible for the dies and other portions of the machine to be
injured, as might be the case when a larger blank by accident is encountered among
those of a size to which the threading dies have been adjusted.
In this improved machine I have embodied a novel organization of mechanism
which constitutes a portion of my Invention, and consists, broadly stated, in the
combination with revolving griping jaw spindles for holding the blanks, mounted
in an intermittingly revolving yoke frame and threading dies, of a main and counter-
shaft, two cam sleeves loosely mounted on the countershaft and driven by it inter-
ittingly, and a clutch for each sleeve, connected with and controlled by the
threading dies. It is not new to control the changing movements in such machines
by the threading dies, but the novel combination of mechanism thus generally
stated is thoroughly efficient with the intermediate mechanism for causing the jaws
of one of the spindles to open and close, the threading dies to close and advance,
open and retreat, and the spindles to change position with reference to the threading
dies, and can be employed with or without the milling tool.
Another part of this Invention relates to the yoke frame in which the griping
jaw spindles are mounted. As heretofore constructed the yoke frame has been
provided with a central shaft, longer than the spindles, and provided with a bearing
at each end. This central shaft being long is liable to spring, and its presence
renders it necessary that long yokes should be used and the said spindles widely
separated. The stopping and starting of these yoke frames has therefore been here-
tofore attended with considerable concussion, and a consequent liability to undue
wear and breakage of the operative mechanism. The object of my improvement in
this connection is to so mount the spindles that they will be closely adjacent to each
other in order that when the frame revolves it will be smoothly and without shock,
and my Invention therefore further consists in a pair of griping jaw spindles, mounted
rotatively at one end in a circular head plate, which has a peripherical journal in
an annular bearing on the frame of the machine, and is connected to a yoke and
axis for supporting the rear ends of the spindles.
The front end of the spindle is smaller than the central portion owing to the
enclosed complex mechanism (which must have considerable bulk and strength to
properly operate the griping jaws) but the rear ends of the spindles are of such
small size as will permit them to be properly geared, even though the central surfaces
of the spindles are barely separated). This portion of my improvements is applicable
to "shaving and nicking" machines, and to others, in which the griping jaw spindles
and yoke frame are of value.
Griping jaw spindles in a yoke frame, as heretofore constructed, are alternately
placed in gear for revolving one of them, while the other spindle (if they are revolved
simultaneously) is driven by a jockey pulley. In my machine both spindles con-
tinuously revolve when in working position, and they also in fact revolve during the
rotation of the yoke frame; and another feature of my Invention consists in a pair
of revolving griping jaw spindles mounted in a yoke frame, in combination with an
intermediate sleeve on the axis of the frame, which is geared to both spindles and
continuously driven. This portion of my Invention is also applicable to other
machines.
"
The jaw spindles employed in this machine are provided with a sliding sleeve and
"compound or thrusting levers, which move with the sleeve for operating the jaws
substantially as heretofore. As formerly constructed, however, if the jaws be
adjusted to hold a blank head of a certain size they will not engage firmly with
a smaller head; and if by accident a blank with a larger head be fed to the jaws
there is liability of breakage or injury to the whole or some portion of the jaw
operating mechanism, including all of that through which the requisite movements
of the jaws are obtained. Another object sought is a firm gripe of the jaws on
heads of different sizes, which at the same time shall be yielding to that extent that
no injury will be liable to result from the accidental feeding of a larger blank than

page_text: those for which the jaws are generally adjusted, and therefore my Invention further
consists in the combination with a spindle containing the griping jaws, thrusting
levers and sliding sleeve of cam levers, which are pivoted to the sleeve, and bear
upon the rear ends of the thrusting levers with yielding pressure when the sliding
sleeve is moved forward. It is important that this yielding pressure be adjustable
and to that end my Invention further consists in the combination with the griping
jaws, thrusting levers, and yielding cam levers, of springs which bear upon the
levers and are adjustable to varied pressure.
The rear ends of the thrusting levers when pressed by the cam lovers (all being
in their most rearward position) would be liable to be thrown to one side or the
other of the axial line of the spindle, and therefore when next moved forward the
heads of the thrusting levers would fail to properly engage with the rear ends of
the griping jaws, and this would inevitably be the result if one cam lever spring
should be more powerful than the other; for obviating this difficulty, and to always
maintain the rear ends of the thrusting levers in the same relations to each other
and to the axial line of the spindle, the said Invention further consists in the com-
bination with the griping jaws, thrusting levers, yielding cam levers, and sliding
sleeve, of a parting block or guiding block, which is interposed between the two rear
ends of the thrusting levers, and is provided with a spring that forces it forward, so
that it moves in that direction with the thrusting levers until no longer required,
and also so that it may retreat when the levers move backward, meantime main-
taining with its wedge-shaped head its guiding or parting capacity.
Certain portions of my Invention relate to the thread-cutting dies. For
threading fine machine screws by machinery, solid dies have heretofore been gene-
rally used, and although sectional or open dies have been successfully employed in
bolt-threading machines, their application to the threading of small "machine"
screws has heretofore been objectionable to such an extent as to result in the
almost exclusive use either of solid dies or of sectional dies secured in solid
heads.
It is well known to be difficult to work a thread close up under a squared head,
with dies as generally heretofore constructed, and also that those dies are frequently
broken when such work is attempted by reason of chips being interposed between
the face of the die and the head of the screw, and open bar dies for hand plates have
been heretofore inclined in their holders to obviate this difficulty.
It is also well known that solid dies are costly and liable to twist in hardening,
and that these, as well as open dies rigidly set in a head when used in screw-
threading machines require reverse rotation, or an equivalent action for release from
threads cut by them, and also that solid dies cannot be relied upon for cutting fine
machine screws to scale, because in proportion as the dies are used they become
worn and deliver screws of larger diameter than when new. With sectional or
open dies, and a novel adjustable feature herein-after described, I am enabled to so
adjust the counterpart sections as to secure uniformity in the diameters of the screws
cut by them, regardless of the wear of the dies.
To economize in steel and in the labor of making the die, as well as in the
hardening thereof, I take a strip of steel of proper width, bevel its two edges by
planing or milling, then drill and countersink at proper intervals holes for the centre
of each of the sections so that a screw may secure them to a die block, jaw, or
holder; I then saw the bar into squares, and bevel each end at the sawed portion,
and then while the sections are in pairs properly secured I drill and tap them
successively on each of their four sides, so that one pair of sections will be equiva-
lent to four solid dies. The distribution of metal in these sections of die is such
that in hardening it is seldom if ever that one will be injured by warping or
twisting. These items of economy are of great practical value, and one feature of
the said Invention consists in a square sided sectional threading die, inwardly
bevelled, at each edge centrally drilled for a holding screw, and provided with a
threaded recess on each side, so that when two of them are attached to suitable
jaws or a holder with coincident recesses, the die as a whole will have a front face,

page_text: sented to the threading dies C perfect uniform threading is attained, and the dies
are not liable to be injured. When the head is squared and the body of the blank
milled while in the jaw no damage accrues to the dies if a larger blank by accident
should be fed to the jaw, because the milling tool determines the diameter, and is in
size adapted to co-operate with the threading dies. These parts are so geared and
driven that when a blank is fed to spindle A, Figure 1, the jaw closes both spindles
meantime revolving. After closing, the milling tool B advances and performs its
duty of milling and correctly centreing the blank, and then retires. The spindles
then change position, the blank being thereby presented to the threading dies C,
which advance and close upon the tip of the blank, and then by the lead of the
thread are drawn forward to or near the head of the blank, as may have been pre-
determined; and when the proper length of thread has been cut the threading dies
open and promptly recede. During this threading operation another blank has been
meantime presented by feeding mechanism, not shown, to the fellow spindle and
milled, and after threading the spindles again revolve on their common axis to their
former positions, the threaded screw released from the jaw, and the same operations
automatically repeated.
The jaw spindles are continuously revolved by a chain of gearing from the main
shaft D, Figures 5 and 8, commencing with gear wheel a on said shaft, thence
by larger gear wheel a¹ above to gear wheel a² on an intermediate sleeve a³
carrying gear wheel at which meshes on each side with gear wheels a" on the jaw
spindles.
The spindles continuously geared to the main shaft constitute one feature of my
Invention. The spindles near their front ends have bearings in a circular head
plate A2, journalled at its periphery in an annular portion of the frame of the
machine. This head plate at its rear side is provided with two rearward projecting
arms a, which connect at their rear end by a yoke a7 which has an axis a which
extends through sleeve a³ to the rear end of the machine. The axis as is
coincident with the centre of the head plate A2, and its bearing is in a vertical
portion of the frame F. The circular head plate and the axis, connected as described,
constitute a yoke frame of novel construction, and it will be seen that the spindles
may be therein mounted in close proximity to each other, and that they may there-
fore be revolved by and with the frame with a minimum of shock in starting and
stopping. The rotation of the revolving spindles with their head plate on axis a³ is
effected by gearing from the main shaft through gear wheels b and b' on a stud to
gear wheel 62 on countershaft E within cam sleeve E', which is in turn revolved
by shaft E at certain intervals, as hereafter described, and communicates motion at
said intervals through gear wheel 3 on said sleeve to an upper gear wheel b on a
stud connected with a mutilated or segmental gear wheel 65, which in turn meshes
at intervals with the gear wheel 60 on the outer end of the axis as on which
both spindles revolve. The axis a inside of its gear wheel has a four-sided
locking plate c, which revolves with the axes, and has on its opposite sides or
edges a concave surface which corresponds in outline with the periphery of the
smooth portion of segmental gear wheel 63, which is as wide on its rim as the
combined thickness of gear wheel 6 and plate c. Alongside of its teeth the
rim of the segmental or broken gear wheel is cut away, forming an opening or
recess c¹, Figure 1, into which the advanced corner of the squared plate c is pro-
jected the moment that the broken gear teeth engage with the spindle axis gear
wheel b and commence to revolve it; but by the time a half revolution of the yoke
frame axis is made the opposite concave surface of the plate c comes in contact with
the periphery of the broken gear wheel. By this construction the spindles are
absolutely locked in truly accurate positions from which there can be no possible
variation. The combination of this concave-sided plate with the mutilated gear
wheel constructed as described constitutes one portion of my Invention.
To prevent longitudinal movement of the spindles when revolving at their work
an abutting plate c² at the rear end of each is provided on the end of a threaded
stem secured to the standard on the frame F, so that said plate may be accurately

page_text: adjusted. The rear end of each spindle is also provided with an adjusting screw c³,
the head of which is in contact with the abutting plate. The combination with
the spindles of these adjustable abutting plates constitutes one feature of my
Invention.
The jaws of the spindles are opened and closed by a sliding sleeve d on each
spindle, as heretofore; its flange d' enters a vertical recess in a vertical arm d
whenever the spindles change position with their jaws closed. The vertical arm has
a movement to and fro parallel with the spindle at proper intervals, and when
moved rearward the jaws are opened, and when moved forward the jaws are closed.
The sleeve operating arm is mounted on a sliding rod ³, to which motion is
imparted by the cam d' on the sleeve E', said cam being so shaped and timed as to
move the sleeve d to and fro immediately after the spindles change position.
The sleeve E¹ has a stop wheel e, provided with a notch in its periphery, into
which the toe of a spring lever el enters after the sleeve has made a complete revo-
lution for rotating the spindles on their common axis, and opening and closing their
jaws.
I will next describe how the milling tool B is operated. In this machino said
tool has only a movement toward and from the jaw of a spindle, but it may also be
made to revolve on its own axis by means of a continuously driven splined shaft in
a manner well known within the cross head, by which it is moved longitudinally.
The milling tool is mounted in the outer end of the cross head f, fitted to guides in
standards of frame F, and provided with tail rod f¹ projecting from its rear through
a guide in a standard at the end of the frame. To the tail rod is pivotted the upper
end of a lever f, provided with a retractile spring, not shewn, connected to the
standard before referred to, by which the milling tool is withdrawn after its work
is completed. The lever f" is centrally pivotted to a short standard on the top
plate of the frame, and its lower end projecting downward through the top plate
engages normally, by reason of its spring, with the side of a cam f³ on sleeve E,
within which is extended the countershaft E, before described. The cam f³ has an
easy gradual swell, by which the milling tool is advanced, and an abrupt drop,
which permits the retractile lever spring to act in promptly throwing the milling
tool backward.
Inasmuch as the length of thread in screws is largely varied according to their
size, and as the threading operation must in each case be fully completed, and the
dies withdrawn before the spindles can change position, the threading die block
occupies an intermediate controlling position between the main shaft and all the
moving parts of the machine, excepting only the continuous rotation of each jaw
spindle on its own axis, these being always free to revolve while all other operations
are suspended.
The threading dies have been already designated, as at C, and although there are
many novelties connected therewith hereafter to be set forth they will now be
referred to in general terms in order to describe their general mode of operation and
the manner in which they control the time at which other parts of the mechanism
shall operate.
The dies are contained within a holder g¹, shown fully in Figure 3, fitted like a
cross head to guides in standards of frame F, and provided with a tail rod g¹
(connected with the die jaws), which extends rearward through a guide bearing in
a standard at the rear end of the frame. On the tail rod near its junction with
the die holder is a cam g² which loosely encircles the rod, and is connected with the
die holder g also loosely mounted on the rod. Alongside the cam is a sleeved gear
wheel with a cam which corresponds with cam g2, their two faces being coincident
so that when the gear wheel 93 is turned on the tail rod y' the two cam faces will
force the shell of the holder sufficiently forward to close the dies. The gear
wheel is rotated by a segmental gear plate g* on the upper end of a lever g³,
which extends downward below its pivot through the top plate of the machine,
and thence curves toward the opposite side of the machine and ongages by means
of a finger and roller with a cam groove in the side of cam h on sleeve E2 on

page_text: countershaft E. This cam groove is so shaped and timed that the lever is vibrated
to and fro promptly once during the revolution of the cam, and this forward
vibration rotates gear wheel g³ forward, forcing the die holder forward and closing
the jaws, after which the lever vibrates rearward, leaving gear wheel g³ and its cam
ready to repeat the same movement.
After the
The combination of the geared lever g with the gear wheel and cam on the tail
rod, the dies, and the holder, constitutes one portion of my Invention.
die holder has thus far been slightly advanced it is then pressed forward with
yielding pressure so that the tip of the blank enters the threading dies. This
additional forward movement is effected by the arm h¹ secured to the die holder tail
rod gl at its upper end, and at its lower end to a sliding rod h, to which is con-
nected an arm h³ linked below the bed plate to the end of a centrally pivotted
lever h, Figure 8, the opposite end of which is pivotted to a sliding bar h mounted
in guides at the opposite side of the machine on the frame. This bar is provided
with a retractile spring, which so draws the bar that the tail rod and die holder is
normally held at its most rearward position. The bar is also provided with a
laterally projecting but slightly yielding spring finger ho, with which a side cam h
on sleeve E engages at proper intervals for forcing the die holder forward with
yielding pressure, as before stated. This sleeve E2 acting as it does intermittently
is provided with a notched stop wheel i and a spring plunger ¹, which enters the
notch in the wheel after each revolution, and secures the proper rest at the proper
moment. This combination with the die holder, the die's tail rod, its cam and
geared lever of the cam on sleeve E, the sliding bar and its spring finger, constitutes
one portion of my Invention.
From the description already given it will be clearly understood that the main
shaft D and the countershaft E are continuously revolved, and that the connter-
shaft E is within both cam sleeves E¹ and E2, and that these sleeves intermittently
make one complete rotation. The nature of the service performed by cam sleeve E¹
is such that when rotatively connected with the countershaft it revolves therewith
and at the same speed, but cam sleeve E is so geared that it revolves at a much
slower speed than the countershaft, because the milling tool and the threading dies
are necessarily moved at slow speed.
It has also before been stated that all of the intermittent movements of the
mechanism are controlled by the dies, and it has been shown how many of these
intermittent movements are executed by the alternate rotation of the sleeves E¹
and E⁹.
It is next in order to show how the two sleeves are rotatively connected with the
countershaft E. This shaft, about midway of its length, is splined and carries a
sliding clutch k, Figure 8, provided with laterally projecting pins for entering holes
in the side of a plate alongside, and attached to a gear wheel kl which is loosely
mounted on said shaft. When this gear wheel k¹ is by its clutch rotatively con-
nected with shaft E it communicates motion at slow speed to sleeve E2 by way of
the train of gearing mounted on studs, and an arm clearly shown at k³, k³, k', k³, to
gear wheel on said sleeve, as seen in Figures 5, 7, and 8.
The pin clutch k is provided with a central annular groove in its periphery,
which is occupied by a finger projecting laterally from a long spring shipper bar 7,
mounted in guides on that side of the frame of the machine. The spring of this bar
acts in the direction of the gear wheel k¹ and forces the pin clutch into engage-
ment therewith. When thus engaged sleeve E' is completely rotated, but just
before the stop wheel i and its plunger co-operate a side can l on said sleeve
commences to move the sliding bar against its spring, thereby disconnecting the
clutch from gear wheel k¹, and just before the disconnection is wholly effected the
spring plunger ¹ enters the V shaped notch in the stop wheel and accelerates the
disconnection by slightly rotating the sleeve. The sliding bar having been thus
moved against the spring it is securely held by a spring lever or catch m pivoted
to the frame of the machine near the opposite end of the bar, which engages with a
notch or shoulder in the side of the bar, when said notch reaches the end of the

page_text: catch, see Figure 8. The bar is thus securely held until such time as the sleeve E'
is rotated, whereupon, after it has made one complete revolution, a lateral stud m¹ in
the side of the stop wheel e trips the spring lever, releases the bar, and allows the
pins of the clutch k to move in contact with the smooth side of the gear wheel k¹
until the pin holes therein are reached and entered, thus rotatively connecting
shaft E with sleeve E².
I will next describe how sleeve E¹ is rotatively connected with its shaft E. On
the central splined portion of shaft E before described is another pin clutch n,
the pins of which engage with other pins projecting from the side of the adjacent
end of the sleeve E¹. When the pins are locked with each other the sleeve is
rotated with its shaft. A plunger n¹ is mounted within a shell on the sleeve,
parallel with it in line with one of its pins, and provided with a spring which forces
the plunger away from the side of the clutch, but it is forced against its spring and
made to disconnect the clutch from the sleeve pins by means of a stationary
inclined plane n² on the frame of the machine, the upper or thick end of which is
shown in Figure 8, which also shows the clutch n just disconnected thereby.
It has already been stated that the service performed by the cam sleeve E¹ consists
consecutively in rotating the spindles on their common axis, for changing position,
opening and closing the jaw of a spindle, and tripping the sliding bar which
rotatively connects cam sleeve E² with shaft E, this latter service being performed
a little prior to the moment the stop wheel e and its spring lever or finger e¹
co-operate.
The time of connection of sleeve E¹ and shaft E varies according to the length of
thread cut, or, in other words, the length of time required to properly cut a certain
thread, and I will here state that the combination with the countershaft and the
two cam sleeves of the clutch which connects sleeve E² with the countershaft, and
the spring shipper bar which engages with the clutch, and is moved longitudinally
by a cam on said sleeve, the spring lever or finger which holds the shipper bar
when thus moved, and the catch releasing device on sleeve E' for permitting the
shipper to again connect the countershaft with sleeve E², constitutes one feature of
my Invention.
I will next explain how the threading die executes its controlling power over
sleeve E'. In Figure 5, one of the two standards in which the die holder slides is
broken away, revealing a pendant arm o, which is attached to the shell of the die
holder, which has a sliding movement independent of the dies, but which, when the
dies are closed, move forward with them by the lead of the thread. The sliding rod
², before described, see Figure 5, is hare enclosed by a hollow rod o', provided with
n vertical arm o%, which extends upward for engagement with the pendant arm o,
and which also extends below the bed plate, where it loosely encircles the sliding
rod o³, which is provided with a collar o³, adjustable longitudinally thereon by a set
screw. The rod, before described, by which the dies are forced forward under
yielding pressure to the dies, imparts no movement to the hollow rod, but slides
freely therein. The hollow rod o' at its outer end is provided with a pendant arm
05, which is within the range of the edge of a side cam p, loosely mounted on main
shaft D. The lower sliding rod o³ at its end is connected with the lower arm of a
vertical bell-crank lever q. See Figure 5.
The upper or horizontal arm of the bell-crank lever q is connected with a vertical
spring pin q' housed within a bracket on the frame of the machine, in line with, but
nt right angles to, the centre of the main shaft D, and alongside of the face of an
automatic clutch plater, whick is keyed to the main shaft, and is provided within
its hub with a spring bolt and a radial spring latch bolt, these being so placed
with relation to each other that the inner end of the latch bolt enters a concave
recess in the side of the head of the bolt, and prevents said bolt from projecting
its head beyond the side of the clutch plate at all times, except when the upper arm
of the bell-crank lever q is so raised that an inclined cam surface on the lower end
of the vertical spring pin causes the laterally projecting finger on the spring latch 2,
clearly shown, to ride thereon as the clutch plate revolves, whereby the latch bolt

page_text: is moved outward radially, thereby releasing the spring bolt r', and permitting its
head to project and enter a recess in the side of a sleeve which carries the two canis
8 and p, and so to rotatively connect these cams with the main shaft throughout one
complete revolution. The spring bolt 1, when it next reaches the spring pin q', is
forced backward by a side incline on the spring rod out of engagement with the cam
sleeve, after which movement the latch 2 re-engages with the spring bolt, as before,
and maintains its control until the bell-crank lever q again raises the spring pin q',
which when in its normal depressed position permits the finger of the latch to pass
freely above it. The cams s and p having thus by the forward terininal movement
of the die holder been rotatively connected with the main shaft, perforin respectively
the following functions:-Cam p engages with the pendant arın o on the hollow
sliding rod o', and forces it and the die holder backward, and fully opens the
dies; this mechanism, by which the die block is moved backward, consisting in the
combination with the threading dies of the clutch r on the main shaft, controlled by
the forward terminal movement of the dies, the cam p on the main shaft driven by
the clutch and the sliding rod o¹ constitutes another portion of my Invention.
The side of cam 8 engages with a stud on a lever shipper s¹, the opposite end
of which occupies the annular groove in the pin clutch n, which being moved
rotatively connects the sleeve E' with shaft E for consecutively changing the position
of the spindles, opening and closing the jaws of one of them, and connecting sleeve
E' with the shaft E, as described; the cams 8 and p being connected together, but
loosely mounted on the main shaft; the cam 8' is provided with a recess in its
periphery, and after each revolution this recess is occupied by the stop pin, shewn,
in the bracket alongside the spring pin q', Figure 8.
The novel combination of mechanism described embracing the threading dies, the
main shaft, the countershaft, the two cam sleeves, and their clutches of the can s
loosely mounted on the main shaft, the clutch lever 8', clutch keyed to the main
shaft, the bell-crank lever q, and sliding rod o³ controlled by the threading dies
constitutes one portion of my Invention by which the dies at their terminal
forward movement rotatively connect one sleeve to the countershaft, which in
turn causes the spindles to change position, the jaws of one spindle to open and
close the disconnection of said sleeve from the countershaft, and the connection
with said shaft of the second sleeve, which imparts to the threading dies their
initial movements. The main shaft D is provided with the usual fast and loose
pulleys as at t, t¹.
With the general description of the effective movements of the spindles, milling
tool, and dies already given, and the detailed description of the mechanisin by
which each movement is attained, the operation of the machine will be fully
understood.
I will now refer particularly to Figure 2, which illustrates those portions of my
Invention which are contained within the jaw spindles.
The jaws, thrusting levers, and sleeve d are all as heretofore, but the pivoted
yielding cam lever u attached to the sleeve, their springs, and adjusting screws u¹
are novel.
It will be seen that when the jaws are closed the springs on the levers u operate
with a powerful but yielding pressure on the rear ends of the thrusting levers, so
that the jaws will be made to firmly hold blanks with heads of different sizes
without liability of injuring the jaw mechanism in case a larger head be inserted
than those which they have been particularly adjusted to receive. By turning the
screws u¹ the force of the springs may be graduated as desired.
It will be seen that after the sleeve d has been moved rearward for opening the
jaws, as indicated in dotted lines, that either spring might so far prevail over the
other as to throw the rear ends of the thrusting levers to the one side of a central
line, so that when next advanced to close the jaws they would not be moved truly,
and would fail to properly co-operate on the jaws; and I therefore introduce the
parting block v, which is wedge-shaped in front, spindle-shaped at its rear, centrally
located with its edge between the ends of the thrusting levers, and provided with a

page_text: spring which forces it forward when the levers move forward, but which permit it
to retire when the levers are moved rearward by the sleeve.
It will be seen that this parting or guiding block will prevent either spring
from forcing the rear ends of the thrusting levers to the one side or the other, and
invariably secure the proper position of the front ends of said levers with relation
to the rear ends of the griping jaws.
My improvements in the dies and their novel mode of adjustment are illustrated
in Figures 3 and 4.
The sections of die ware secured to jaws w¹, which are pivoted at their rear
ends to the tail rod g¹. The die holder casing g is capable of longitudinal move-
ment independently of the tail rod. The wedge blocks w² are pivoted to the
holder, so that the inclined planes on cach side of the holder, when this latter is
moved forward, causes the dies to close, and when moved backwards permits their
springs to throw them open, substantially as heretofore.
My improvement in this connection partially consists in the combination with
the jaw dies and holder of inclined planes or wedge blocks x, which are adjustable
longitudinally within the holder; they are well fitted to slide within the holder,
and are attached to a movable cross bar a¹ having an upward projecting lug which
extends through a slot in the top of the holder, and connects with a finely threaded
screw, which is tapped into a worm gear wheel actuated by a finely threaded thumb-
screw y in such a manner that by turning the thumbscrew the inclined planes
may be withdrawn or advanced, and thereby cause the threading dies to approach
more or less closely to each other.
It will be seen that this construction in no manner affects the time of the opening
or closing of the jaws, because the adjustment is offected without changing the
relations of the tail rod and holder.
It will also be seen that cach section of die w is square, has a central hole for
receiving a screw by which it is attached to its jaw, a threaded recess in each side,
and is inwardly bevelled on all sides, so that when two of these sections are placed
side by side for service the front face of each inclines rearward from the threaded
opening.
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 combination with a pair of revolving griping jaw spindles capable of
intermittent rotation on an axis common to both of threading dies, and a milling
tool, which in operating upon a blank will positively secure the axial adjustment in
the jaw of one of the spindles, whereby when the spindles change position the blank
is presented to the threading dies truly coincident with the axis of the spindle and
the centre of the die, as above set forth.
Second. The combination, with revolving gripping jaw spindles in an inter-
mittingly revolving yoke frame and with the threading dies of the countershaft, two
cam sleeves thereon driven by it intermittingly, and a clutch for each sleeve con-
nected with and controlled by the threading dies, whereby the cam sleeves alternate
n their movement and in regular order, cause the jaw of one spindle to open and close
the threading dies to close and advance, open and retreat, and the spindles are
changed with reference to the threading dies, as above set forth.
Third. A pair of jaw spindles mounted rotatively at one end in a circular head
plate, which revolves in an annular bearing, and is connected to a yoke and axis
which supports the rear ends of the spindles, the same constituting an improvement
in a yoke frame, whereby the spindles are placed closely side by side, and a smooth
and easy change of position is effected, as above set forth.
Fourth. A pair of jaw spindles mounted in a yoke frame, in combination with an
intermediate sleeve on the axis of the frame, which is geared to both spindles, and
continuously driven, as above described.
Fifth. The combination with the spindle containing the jaws, thrusting levers,
and sliding sleeve of cam levers, which bear upon the rear ends of the thrusting

page_text: levers with yielding pressure, whereby the jaws may be closed upon and made to
hold the heads of blanks of various sizes without danger of injury to the jaw-
operating mechanism, asabove set forth.
Sixth. The combination with the jaws, thrusting levers, sliding sleeve, and yielding
cam levers of springs for the cam levers, which are adjustable to varied pressure, as
above described.
Seventh. The combination with the jaws, thrusting levers, sliding sleeve, and
yielding cam levers of a parting block, which secures the proper relation of the
thrusting levers to each other and to the jaws, as above described.
Eighth. A four-sided sectional threading die inwardly beveled at each .edge,
centrally drilled, and provided with threaded recesses, as above described, and for
the purpose specified.
Ninth. The combination with threading dies mounted on jaws attached to a tail
rod of a die holder enclosing the die jaws, and provided with wedge blocks for
closing the dies of adjustable wedge blocks, for causing the dies to approach more or
less closely to each other without affecting the relations of the tail rod and holder,
and the time of opening or closing the dies, as above described.
Tenth. The combination with threading dies mounted on spring jaws sliding
within a die holder, and connected with a tail rod of a cam attached to the holder,
a gear wheel and cam on the tail rod, and a vibrating lever provided with a seg-
mental toothed plate, substantially as described, whereby the holder is advanced
independently of the tail rod and the dies closed, as above set forth.
Eleventh. The combination with the die holder, the dies, the tail rod, its cam,
and geared lever, with the cam on sleeve E, the sliding bar with spring finger, and
lever connecting with the tail rod, whereby the dies after being closed are advanced
with yielding pressure, as above set forth.
Twelfth. The combination with the threading dies, the main shaft, the counter-
shaft, the two cam sleeves, and their clutches, of the cam loosely mounted on the
main shaft, the clutch lever, the clutch keyed to the main shaft, the bell-crank lever,
and the sliding rod controlled by the threading dies, whereby the dies at the
terminal forward movement rotatively connect one of the sleeves to the counter-
shaft, which in turn causes the spindles to change position, the jaws of one spindle
to open and close the disconnection of said sleeve from the countershaft, and the
connection with said shaft of the second cam sleeve, as above set forth.
Thirteenth. The combination with the countershaft and the two cam sleeves of
the clutch which connects sleeve E2 with the shaft, a spring shipper bar which
engages with the clutch, and is noved longitudinally by a cam on said sleeve for
opening the clutch, a spring lever or catch which holds the shipper when thus
moved, and a catch-controlling device on sleeve El for permitting the shipper to
again close it clutch, and thereby connect sleeve E2 with the countershaft, as above
described.
Fourteenth. The combination with the threading dies of the clutch on the main
shaft, controlled by the forward terminal movement of the dies, the cam on the
main shaft driven by the clutch, and the sliding rod, which engages with the dic
holder, whereby the dies are opened, and the die holder or block moved backward
after the threading operation, as above set forth.
Fifteenth. The combination with a pair of revolving griping jaws mounted in a
yoke frame, having a geared axis common to both spindles, of a concave sided plate
secured to said axis, and a mutilated gear wheel, which engages with the axis gear
wheel, and is provided with a smooth periphery wider than the face of the toothed
portion, and which is cut away alongside the teeth thereof, whereby when the mutilated
gear wheel engages with the axis gear wheel the corner of the plate in half revolving
enters the recess, and then places its opposite concave side in close contact with the
smooth periphery of the gear wheel for locking the frame and spindles in position,
as above set forth.
Sixteenth. The combination with the revolving jaw spindles mounted in an
intermittingly revolving yoke frame of adjusting abutting plates for the rear ends

page_text: of the spindles to bear against when the spindles are in working position, as above
described.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Twenty-eighth day of February, in the year of our
Lord One thousand eight hundred and seventy-eight.
W. ROB. LAKE. (L.S.)