Year: 1889

page_text: I, JAMES HERVEY STERNBERGH, Iron Manufacturer, resident at 530 North 4th
Street, in the city of Reading, the county of Berks, state of Pennsylvania, United
States of America, do hereby declare the nature of my invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :-
This invention relates to improvements in the die-heads of machines adapted for
cutting screws, and in mechanism for automatically effecting the opening and closing
of the dies.
In screw cutting machinery separate cutting tools of different forms have heretofore
been secured to the front of the die-head and adapted to be moved towards or away
from the center either radially or by an oscillating movement. My die-head is adapted
more particularly to that form of cutter which is provided with a longitudinally
grooved face held at a tangent to the blank. This cutter is very easily sharpened by
grinding, thus effecting a great saving in the maintenance of good cutters and my
main object is to provide a simple mechanism for holding and operating them which
will insure satisfactory results by positively and firmly maintaining the cutters in any
desired and easily regulated position, and thus forming clean cut threads of standard
size. To this end I avoid the use of screws and gearing with their necessary lost
motion.
The features of my die-head include parallel axial bars passing through the
die-head and engaging holders movably secured to the front of the same, as many bars
being used as there are holders. The front end of each bar is preferably made to
engage opposite sides of two adjacent holders in such a manner that a movement of
the bar will press one holder out from the centre and at the same time release the other
which is pushed out by another bar, all of the latter being connected at the rear end
and operated simultaneously.
"
The part of my invention which relates to means for automatically opening and
closing the dies which are adjustably held in the die-heads, has for its principal object
the effecting of this function by positive and prompt action. The automatic with-
drawal of cutting dies has been heretofore effected by a spring action. Such action

page_text: however is not satisfactory especially in connection with the form of cutter referred to
above as the preferable form for my die-head the sharp cutting edge being not easily
withdrawn from the work. In this invention the rotation of the spindle which
carries the cutting dies is made to positively release them from the work at the desired
point and it consists in the combination with the cutter head of the machine and the
mechanism for withdrawing the cutters, of a rod arranged to operate said mechanism,
the rod itself being moved by a lever which is thrown into engagement with the
machine spindle by the movement of the carriage to which the work is secured. It
consists further in the combination with the machine of a spring arranged to assist in
the withdrawal of the cutters from the work and also of the work from the cutter head.
The features of the invention are fully set forth herein and indicated in the claims.
Referring to the annexed drawings,
Fig. 1, is a full front view of the die-head with the retaining ring removed. The
two lower cutters are represented as open while the two upper are closed to a working
position. Only two of the axial bars are in position.
Fig. 2, is a longitudinal section through XY of figure 1, showing also the retaining
ring and guard in section through V W of figure 5.
Fig. 3, is a perspective view of 'the cutter holder with a longitudinally grooved
cutter in position.
Fig. 4, is a perspective view of one of the axial bars.
Fig. 5, is a view of the retaining ring and removable guard, a section of which is
shown in figure 2.
Figs. 6 and 7 and 8 and 9, show modified arrangements of the axial bars and cutter
holders.
Figs. 10 and 11, show a modified holder provided with a grooved wheel adapted to
form a thread by rolling.
Fig. 12, is a full elevation of a portion of a screw cutting machine showing the
mechanism involving my invention partly in section.
Fig. 13, is a stop view of the sleeve operating rod or pipe with collars and sleeve
yoke attached.
Fig. 14, is a separate view of the lever operating rod with lifter attached.
Fig. 15, is a section through X Y of Fig. 12.
Eig. 16, shows a modified mechanism, applied to a machine as in figure 12.
The die-head A is secured to the end of the mandrel B which may be hollow, or
partly hollow as shown to permit the threading of any length of bolt. The enlarged
front of the head has cutter holders of the form shown in figure 3, pivoted thereto,
trunnions on the holders fitting into holes A in the head, which latter may be
recessed at A¹ to let the holders in flush with the projecting portion of the head to
which the retaining ring hereafter described is secured. The cutters Care flat bars
of steel having one side C grooved longitudinally to suit the form and size of thread
which it is desired to cut. They fit snugly in slots ( formed in the rectangular.
holders Cand are clamped therein by means of face screws at C which project from
the outer ends of the holders. The base of the slot C is not parallel with the base of
the holder but is inclined so as to make the position of the cutter correspond with the
angle of the thread, as indicated more clearly in figure 2. The trunnions (, before.
referred to, project, one from the slotted face of the holder and another from the
opposite face near the outer end. Reversed inclines or wedge shaped projections C'
and C are formed opposite each other on the remaining two faces of the holder near
the inner or cutter end but at different distances from the trunnions.
Bars E formed with square heads or ends E2 having reversed wedge-shaped adjoining.
sides E3 and E, are passed axially through parallel openings A' in the head and are
secured to a sleeve D sliding on the mandrel B in the rear of the head. These
openings. A are so arranged as to bring the wedges E3 and E on the ends of the axial
bars E. in contact respectively with the corresponding inclines C of one holder'
and C of another adjacent holder. For convenience in referring to the different
holders they are marked respectfully 1, 2, 3 and 4 in figure 1, in which it will be

page_text: noticed that the head E³ of one bar engages the holder marked 1 on its incline C
nearer the pivotal point and also the adjacent holder marked 4 on its incline C
farther from the pivotal point, and the holder marked 2 and 3 are similarly engaged
by the inclines on the head of the cutter bar shown. The two bars which are omitted
in the figure are arranged in the same way, so that each holder is held between
oppositely inclined wedges. As these wedges are all moved backward simultaneously
by means of the sliding sleeve D, to which their rear ends are connected the head of
each bar forces one of the holders away from the centre of the head and at the same
time releases the adjacent holder as rapidly, and only as rapidly as another bar forces
the latter holder away from the centre, so that each holder is turned on its trun-
nions C to a position similar to holders marked 2 and 3, yet is constantly and firmly
held between the oppositely inclined wedges at every point of its movement.
forward movement of the sleeve D will in a similar manner force the cutters simulta-
neously towards the centre.
The nut J, upon the rear of the head serves as an adjustable stop for the sleeve D
by means of which the diameter of the thread to be cut can be regulated to the greatest
nicety. As soon as the cutters get to work their inclination to "dig in" to the blank
presses the inclined sides of the holders against the wedge shaped ends of the axia!
bars E tending to move the latter, which are positively stopped however when the
sleeve D is pulled tight against the nut J, so that threads of uniform size are
assured.
The retaining ring F shown in figures 2 and 5, is fastened to the head by means of
screw bolts K passing through holes F while the outer trunnions C on the holders
are supported in boles F in the ring, the holders being free to swing upon them
but without lost motion. In order to protect the operator and at the same time to
serve as a guide for the blank in entering the die, a guard G consisting of a central
ring with opening G₁ and arms reaching to the periphery of the ring F, is removably
secured to the latter by screws H, thus permitting its ready removal when desired
without interfering with the ring itself.
It is evident that in the construction described the incline E4 of the bar E and 07
of the holder should be somewhat less than the inclines E3 and C owing to their
being nearer the centre of rotation C. I do not however limit myself to the con-
struction set forth as it may be readily modified without departing from the spirit
of my invention, which consists essentially in the use of movable cutter holders and
an equal number of parallel adjusting bars passed axially through the head. Fig. 6,
illustrates a modified form in which a single incline is employed on both the holder
and the end of the axial bar E, springs L being employed to press the holders
outward instead of the inclines E of the bar and C7 of the holder, already described.
Fig. 7, indicates another modification in which an ordinary cutter M, having the
desired thread cut on the end has a radial movement in the front of the head,
instead of an oscillating movement as before described, motion being communicated
to it from the axial bar E by means of a projection E³ on the end of the latter
engaging an oblique slot in the side of the holder.
Figs. 8 and 9, are an irregular section and a front view of another modified
arrangement in which the axial bars E are arranged to oscillate the pivoted
holders C by means of a rotary movement instead of an axial movement as pre-
viously described, cams E' and E on the front end of the bars engaging adjacent
holders, (as those marked 1 and 4 in Figure 9,) on opposite sides and at different
listances from the centre of rotation C². The cam E is somewhat smaller than E8
for the same reason that the incline E' is less than E in the construction first
described, the principle of operation and the function of the two devices being
evidently similar. These rotary bars may also be operated by means of a sliding
sleeve D as shown in figure 8, spiral grooves E* near the rear end of the bars being
engaged by pins D which give the bars a rotary motion as the feathered sleeve is
moved axially. It is obvious that other modifications may be devised and I do not
limit my invention to those shown.
Instead of using cutting tools in the holders the thread may be formed by means of

page_text: a wheel N mounted in the end of the holder as shown in figures 10 and 11. The
surface of this wheel is provided with parallel grooves corresponding in form and
spacing with the thread to be cut and angled to the proper pitch, and the thread is
rolled on the heated blank by pushing the latter into the centre of the revolving
head A, the rollers N being rotated with the head and their distance from the centre
regulated in the same manner as the cutters. This revolution of the head A and the
contact of the rollers N,-preferably three or four in number with the blank, gives
the rollers a secondary movement around their own shafts P and the blank is fed
inward until the thread is rolled to the proper point, when the rollers may be with-
drawn in the manner already described for the cutters. I do not claim that the use of
a grooved wheel for rolling screw threads is new but so far as I am aware such
rollers have not heretofore been applied to adjustable holders secured to the revolving
head of a screw forming machine, as herein described.
Recurring to that part of my invention which relates to the automatic operation of
the dies, as illustrated in Figs. 12 to 16, it will be observed that the die-head A, and
connections, which have just been fully described, are merely represented in outline,
the present purpose being to fully describe my automatic mechanism and its positive
action upon a die-head of that or an equivalent form. The spindle B is supported
in bearings M and M¹ forming the head stock of the machine, and carries a belt pulley
and a cai B¹ the purpose of which will be hereafter described. A carriage W
provided with a vice in which the blank to be cut is fastened, can be moved in its tail
stock by means of a slotted lever Q¹.
The rod N to which the sleeve yoke O is secured, is represented in figure 12, as a
tube passing loosely through the head and tail-stocks and enclosing a square rod P
the ends P of which are rounded to loosely fill the tube N. The latter is provided
with slots N and N³ near opposite ends and also with collars N¹ and N. The rod P
has a projection P2 which reaches upward through the slot N³ and rests in a recess W2
formed in an attachment W on the bottom of the carriage with which the rod P is
thus compelled to move.
A lever T is pivoted intermediately to a jaw piece S secured to the rear bearing M
of the head stock between the mandrel B and the rod N. Its lower end has arms T³
forming a yoke which spans the rod N between the collars N' on the latter, and its
upper end T¹ is adapted to clear the cam faced sleeve B¹ on the mandrel when in its
normal position.
A slot T in which it is pivoted to the jaw piece S permits it however
to be raised when the end R2 of the lever lift R,-which is adjustably secured to the
rod P and projects upward through the slot N2, is pushed under its yoke and by the
movement of the carriage, and the end T is thus brought in contact with the cam-
faced sleeve the rotation of which pushes it forward and the lower end backward, the
latter carrying with it the rod N and the sleeve D which withdraws the cutters.
The lifter I can be adjusted by means of the slot R' so as to raise the lever into
engagement with the cam when the thread has been cut to any desired distance on
the blank, which latter pulls the carriage and the rod P with it as the thread is cut.
The bolt having been threaded and released by the withdrawal of the cutters,
the carriage W is pulled back by means of the lever Q', or pressed back by the
spring N hereafter described-carrying with it the rod P and lifter R until the
face of the carriage attachment" W touches the collar N on the rod N which
latter is then carried along by means of the lever Q until the sleeve D is closed
against the stop-nut J, which brings the cutters into position for a new blank and the
lever T into its normal position below the cam B. To retain the rod N in this
position the latch U may be pivoted to a jaw V which latter is secured to the machine
so that the shoulder U₁ of the latch engages one of the collars N' which serves as a
stop to prevent any movement of the rod N. An arm U of this latch rests upon an
offset T of the pivoted lever T which latter when raised by the lifter R² elevates the
shoulder U¹ until it clears the stop collar N¹ before the top T" of the lever engages
the cam B. The end R2 of the lifter R may be shaped, as shown, to form a spring
which will yield somewhat before lifting the latch and when the latter is released will
tend to lift the lever rapidly into engagement with the cam B¹.

page_text: The spring n is strung upon the rod n between a collar nº and the extension W* of
the carriage attachment W through which the rod passes. The movement of the
carriage W towards the die-head compresses this spring which thus tends to move
the rod N as soon as the latch has been raised and assists the cam B' in completing
the movement of the sleeve D. This movement however is positively effected by
the cam, and the spring is not essential to its accomplishment. The latter however
has another function to perform. When the cutters are withdrawn from the work
the latter is released and the resilience of the spring which presses against the attach-
ment W¹ of the carriage, moves it automatically away from the die-head, thus leaving
a minimum of work to be done by the operator.
It is obvious that the placing of the rod P within the tubular rod N is not essential
and also that the means employed to effect the engagement of the sleeve operating
rod N with the mandrel B, as well as other details of the construction above described
may be considerably modified without departing from the spirit of my invention which
consists broadly in mechanism adapted to withdraw the cutters positively from the
work substantially as set forth, and which prevents the possibility of their holding
fast to the work as is apt to occur when a spring alone is depended upon to withdraw
then. Fig. 16, illustrates a modification such as may be devised and which is an
equivalent of the construction already described. In this arrangement the rod p is not
enclosed by the rod n. It is fastened to the carriage attachment w and is provided
with a lifter having a spring 72. The lever t is pivoted to a bracket s, its lower end
engages the rod n and the top is represented as a yoke spanning the cam B¹ to prevent
side movement, one arm being broken away to show in full the end of a pin t which
is raised and lowered in the levert by means of the supplemental lever t³ which is
connected by a rod t to the latch pivoted to the lower end of the lever t. This
latch, when the cutters are closed, rests upon a stop X secured to the machine. The
spring is shown wholly within the tail-stock Q under the carriage W, which it is
adapted to press away from the die-head. It is obvious that the operation of this
mechanisin is substantially the same as that already described, the pin t' being lifted
instead of the whole lever T and the stop X being the equivalent of N¹. The spring
of the lifter may be used to effect the object mentioned in describing R2, that is
to promptly raise the pin t into engagement with the cam B' after the latch has
been raised to clear the stop X.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
:-
(1) In a die-stock or head the combination with the movably secured cutter holders,
of separate bars passing through the head and having ends engaging said holders, and
means for simultaneously operating said bars, all substantially as set forth.
(2) In a die-stock or head the combination with the pivoted cutter holders of
separate bars passing through the head, the front end of each har engaging opposite
sides of two adjacent holders, and means for simultaneously operating said bars, all
substantially as set forth.
(3) In a die-stock or head the combination with the movably secured cutter holders,
of separate bars connected to a sliding sleeve and passing through the head, the free
ends of said bars engaging said holders, and all adapted to operate substantially as set
forth.
(4) In a die-stock or head pivoted cutter holders each having a bevelled side in
combination with axial bars passing through said die-head and each having a bevelled
surface engaging the bevelled side of a holder, and means for simultaneously operating
said bars substantially as and for the purpose set forth.
(5) In a die-stock or head, pivoted cutter holders having oppositely bevelled sides
substantially as described, in combination with axial bars passing through said die-head
and having correspondingly bevelled surfaces each of which engages a bevelled side
of a bolder, and means for simultaneously operating said bars substantially as and for
the purpose set forth.
0

page_text: (6) In a die-stock or head the cutter holders with inclined slots C³ pivoted to said
head by trunnions, and the rectangular longitudinally grooved cutters adjustably
secured in said slots substantially as described, in combination with means for
oscillating said holders, substantially as and for the purpose set forth.
(7) In a die-stock or head the cutter holders with trunnions C' pivoted to the head
and provided with cutters and adjusting screws, in combination with a retaining ring
secured to the head and having bearings for said trunnions, substantially as set
.forth.
(8) In a die-stock or head the combination with cutter holders secured thereto and
a retaining ring, of a guard G with central opening removably secured to said ring,
substantially as and for the purpose set forth.
(9) In a die-stock or head the combination with the adjustable cutter holders
secured thereto, and a sliding sleeve and connected mechanism for operating said,
holders, of a stop for said sleeve adjustably secured to the head, substantially as and
for the purpose set forth.
(10) In a die-stock or head the combination with the adjustable cutter holders
secured thereto and a sliding sleeve and mechanisin substantially as described, for
operating said holders, of a nut J adapted to serve as a stop for said sleeve, substantially
as and for the purpose set forth.
(11) In a screw forming head the combination with adjustable holders secured
thereto and mechanism for operating said holders substantially as described, of grooved
rollers journalled in said holders and adapted to operate substantially as set forth.
(12) In a screw cutting machine the combination with the die-head, sliding sleeve
and tail-carriage, of a sleeve operating rod, a lever engaged by said sleeve rod and a
lever rod moving with the carriage and arranged to throw said lever into engagement
with the machine spindle substantially as and for the purpose set forth.
(13) In a screw cutting machine the combination with the die-head, sliding sleeve,
tail-carriage and cam on the machine spindle, of a sleeve operating rod, a pivoted
lever engaged by said sleeve rod, and a lever rod and connected mechanism substan-
tially as described arranged to throw said lever into engagement with said cam all
substantially as and for the purpose set forth.
(14) In a screw cutting machine the combination with the die-head, sliding sleeve
and tail-carriage, of a sleeve operating rod, a lever engaged by said sleeve rod, a lever
rod arranged to throw said lever into engagement with the machine mandrel and a
stop latch also operated by said lever rod, all substantially as and for the purpose set
forth.
(15) In a screw cutting machine the combination with the die-head, sliding sleeve
and tail-carriage of the sleeve operating rod, a pivoted lever, a lever rod arranged to
throw said lever into engagement with the spindle, a stop latch operated by said lever
rod, and a spring arranged to move said sleeve rod, all substantially as and for the
purpose set forth.
(16) In a screw cutting machine the combination with the die-head, sliding sleeve
and tail-carriage, of a slotted tubular sleeve operating rod with collars N' a pivoted
lever engaging said collars, a lever rod within said tubular rod provided with an
adjustable lifter and attached to the carriage, and a cam on the machine spindle, all
arranged and adapted to operate substantially as set forth.
(17) In a screw cutting machine the combination with the die-head, sliding sleeve
and tail-carriage, of a slotted tubular sleeve operating rod with collars N¹ a pivoted
lever engaging said collars, a lever rod within said tubular rod provided with an
adjustable lifter and attached to the carriage, a cam on the machine spindle, a
spring arrangement to move said sleeve rod, and a stop latch, all adapted to operate
substantially as set forth.
(18) In a screw cutting machine the combination with the die-head, sliding sleeve
and tail-carriage, of a sleeve operating rod, with lever collar N¹ and carriage collar N*
a pivoted lever, a lever rod provided with an adjustable lifter and attached to the
carriage, and a cam on the machine spindle, all arranged and adapted to operate
substantially as set forth.

page_text: (19) In a screw cutting machine the combination with the die-head, sliding sleeve,
sleeve operating rod, and tail-carriage, of a spring adapted to press said carriage and
rod in opposite directions, all arranged substantially as and for the purpose set forth.
(20) In a screw cutting machine the combination with the die-head, tail-stock and
carriage, of a spring located in said tail-stock and adapted to retract said carriage,
substantially as set forth.
(21) In a screw cutting machine substantially as described the combination with
the sleeve operating rod the lever engaging said rod and the lever rod attached to the
carriage, of a lifter adjustably secured to said lever rod and provided with a spring, all
adapted to operate substantially as set forth.
Dated this 1st day of March 1889.
JAMES HERVEY STERNBERGH.