Improvements in Machinery for Screw-threading Bolts and the like.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Machinery for Screw-threading Bolts and the like.
I, Hio PETER EILERS, of 92, Pear Street, Cleveland, Ohio, United States
of America, Manufacturer, do hereby declare the nature of this invention
to be as follows:-
My invention has for its object the improvement of threading heads of bolt
threading machines and consists of means hereinafter described.
The barrel of the threading head is formed with a longitudinal bore, and an end
flange by means of which it may be secured to the rotating spindle of the thread-
ing machine. Four radial slots are cut in the end of said barrel, the distance
from each other of whose centers is ninety degrees. In each lateral face of each
slot are cut two tongues.
Four slides or die holders are each of a thickness such as to cause them to
snugly slide into the radial slots above mentioned, and are formed on each
lateral face with two grooves adapted to receive the tongues on the lateral face of
each slot. The grooves are both formed nearer one end of the slide than the
other, whereby the latter, when in position in the slots, are caused to project
beyond the end of the barrel. The slides are thus held rigidly against dis-
placement in either direction of the barrel axis, and are capable of radial retrac-
tion only.
The outer end face of each slide is inclined with reference to the face
opposite, such inclination being toward the inner end of each slide. An undercut
or inverted tee-groove is formed in each slide parallel with, and cut from, the
middle of the inclined face thereof.
In the outer lateral end of each slide is cut a groove into each of which fits a
cutter or die which is removably secured by means of a set screw threaded in a
bushing suitably secured in the slide.
Bearing upon, and projecting beyond, the end of the barrel is a die ring upon
whose inner surface are secured four tongues of tee-cross section and distant from
each other ninety degrees. Said tongues are given an inclination equal to that
of the tee-grooves in the slide and made to fit and slide in said grooves. The
ring may hence be slipped upon the barrel and the tongues caused to engage
the grooves whereby the retraction of the ring will cause the said slides to
radially retract toward and from the barrel axis.
The inner projecting surface is of bevelled or inclined formation.
Diametrically opposite each other nearer the opposite end of the barrel are
formed or secured two racks. A retractible sleeve has sliding bearing upon
said barrel and is formed with grooves whereby it may pass said racks. Said
sleeve has formed upon it two pairs of lugs, in each pair of which is, secured a
pin, journalling one arm of a toggle. Said. toggle arm has formed upon it,
concentric with its bearing, a set of gear teeth forming a segment meshing with
the rack. The opposite end of the toggle is journalled upon a screw bolt which
is screwed into an elongated nut having an outer thread whose trend is in a

page_text: direction opposite that of the inner thread. Said nuts are screwed into threaded
bores diametrically opposite each other in the die ring.
When the sleeve, and hence the toggle arm bearing, is retracted to the right,
the toothed toggle arm will be engaged by the rack, whereby the toggle will be
actuated, causing it to rotate on its bearing, and to 'imove in a cycloidal path;
such movement of the toggle operates the die ring, causing it also to retract to
the right and hence radially retract and open the dies themselves, such operation
taking place when it is desired to release a bolt upon which a thread has been
cut. It will thus be seen, that a given linear movement on the part of the sleeve
produces more than twice the same amount of movement in the die ring, by
virtue of the cycloidal movement imparted to the toggle. This feature permits
the use of a degree of inclination in the groove of the slides, less than that which
would otherwise be required to cause a given amount of opening movement on the
part of the dies for a given amount of movement on the part of the sleeve. The in-
clination being thus less, it is obvious that a nicer adjustment of the dies may be
obtained. The adjustment of the dies is brought about by turning a nut which
is provided in its end with a slot for the insertion of a screw driver for that
purpose. When the sleeve is in its extreme position to the left, the middle of the
toggle rests upon the barrel and a line drawn through the centre of the left
hand pin, through the centre of the middle pin will intersect the pitch line of
the teeth of the gear and rack, perpendicularly below the centre of said gear.
The toggle, when in this position is effectually locked, and the trend of the
threads on the inside and outside of the adjusting nut being in opposite directions,
it is seen that it is impossible for the nut to turn itself,-through the pressure
of the work or jar of the machine, and hence change the position of the dies,
so that while the thread is being cut the dies are absolutely rigid and inde-
pendent of any jars which would tend to alter the relation of the parts. But
when the thread is not being cut it is possible to adjust the nut at any time,
and the turning of the nut will produce a corresponding movement of the die
ring, which hence alters the relation between the said sleeve and the die ring
and the dies held therein.
The slides projecting beyond the end of the barrel make it possible to permit
the dies to be located beyond the said end and further permits the sides of that
part
of the slides which directly support the dies to be free. The slides always
bear against the die ring and hence a plane perpendicular to the barrel axis and
passing through the end portion of a die will intersect the outer bearing surface
of the slide holding such die, said ring thereby forms a supporting or backing.
to receive radial outward thrusts exerted upon the dies during the cutting
operation, the greater amount of cutting being performed by the outer teeth of
the dies forming the throat, and hence the greatest strain being imposed upon
said throat. The outer lateral face of each slide is free and thus the outer lateral
face of each die may be free.
The sides of the slides being free as described, the chips formed during the
cutting operation find a free exit between the slides, and the possibility of
clogging up the inside of the head is avoided; the inner surface of the die ring
being bevelled as described and shown, the chips are not permitted to remain
in the die throat but are discharged from the ring as soon as they drop upon it,
thus still further contributing to the freedom from damage by the clogging or
interference of the chips.
The outer lateral face of the die being free it is possible to bring the said
dies completely up under the head of the bolt upon which a thread is being
cut.
My improvement thus combines the advantages of nicety of adjustment,
absolute rigidity of parts during the cutting operation, freeness from clogging,
ability to cut a thread through the entire length of a bolt, and simplicity of
construction, without unduly increasing its size. Inasmuch as the dies them-
selves are independent of and removable from the slides, the back-stock may be

page_text: used, thus eliminating expense occasioned by dressing and finishing the hard die
steel, an item of considerable economical importance in the construction of boit
threading machinery.
Dated this 28th day of November 1899
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
Improvements in Machinery for Screw-threading Bolts and the like.
I, HIO PETER EILERS, of 92, Pear Street, Cleveland, Ohio, United States
of America, Manufacturer, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement: —
My invention has for its object the improvement of threading heads of boit
threading machines and consists of means hereinafter described.
In the accompanying drawings I have shown one embodiment of the invention:
Figure I represents a perspective view of my improved threading head;
Figure 1 represents a section taken upon the axial plane indicated by line
2-2 in Figure I;
Figure III represents a section taken upon the axial plane indicated by the
said line 2-2, illustrating the relative position of the parts when the head is
open;
Figure IV represents a section taken upon the axial plane indicated by
line 4 4 in Figure I, showing portions of the mechanism in elevation;
Figure represents a sectional view taken upon the axial plane indicated by
said line 4-4, showing the relation of the parts when said parts are in the
position shown in Figure III; and
Figures VI, VII, VIII and IX and X are detail views.
The barrel A is formed with a longitudinal bore a, and an end flange a¹ by
means of which it may be secured to the rotating spindle of the threading
machine. Four radial slots a are cut in the end of said barrel Figure X, the
distance from each other of whose centres is ninety degrees. In each lateral
face of each slot are cut two tongues a³, Figures II III and X.
Four slides or die holders B, Figures II, III, IV, V, and IX are each of a
thickness such as to cause them to snugly slide into the slots a², and are formed
on each lateral face with two grooves b adapted to receive the tongues a³. The
grooves are both formed nearer one end of the slide than the other, whereby the
latter, when in position in the slots, are caused to project beyond the end of the
barrel. The slides are thus held rigidly against displacement in either direction
of the barrel axis, and are capable of radial retraction only.
The outer end face 6' of each slide is inclined with reference to the face opposite,
such inclination being toward the inner end of each slide. An undercut or
inverted tee-groove 62 is formed in each slide parallel with, and cut from, the
middle of the inclined face thereof.
In the outer lateral end 63 of each slide is cut a groove 64 into each of which
fits a cutter or die C which is removably secured by means of a set screw B¹
threaded in a bushing suitably secured in the slide.
Bearing upon, and projecting beyond, the end of the barrel is a die ring D
upon whose inner surface are; secured four tongues D¹ of tee-cross section and

page_text: distant from each other ninety degrees. Said tongues are given an inclination
equal to that of the tee-grooves in the slide and made to fit and slide in said
grooves. The ring may hence be slipped upon the barrel and the tongues caused
to engage the grooves whereby the retraction of the ring will cause the said slides
to radially retract toward and from the barrel axis.
The inner projecting surface is of bevelled or inclined formation, as shown in
Figure IV.
Diametrically opposite each other nearer the opposite end of the barrel are
formed or secured two racks E. A retractible sleeve F has sliding bearing upon
said barrel and is formed with grooves f whereby it may pass said racks. Said
sleeve has formed upon it two pairs of lugs, f¹ in each pair of which is secured a
pin journalling one arm g of a toggle G. Said toggle arm has formed upon it,
concentric with its bearing, a set of gear teeth forming a segment g¹ meshing
with the rack E. The opposite end of the toggle is journalled upon a screw
bolt H which is screwed into an elongated nut having an outer thread whose
trend is in a direction opposite that of the inner thread. Said nuts are screwed
into threaded bores diametrically opposite each other in the die ring.
When the sleeve and hence the toggle arm bearing, is retracted to the right
from the position shown in Figure IV, the toothed toggle arm will be engaged by
the rack, whereby the toggle will be actuated, causing it to rotate on its bearing,
and to move in a cycloidal path; such movement of the toggle operates the
die ring, causing it also to retract to the right and hence radially retract and
open the dies themselves, such operation taking place when it is desired to
release a bolt upon which a thread has been cut. The relation of the parts when
the dies are open, is illustrated in Figures III and V and it will be seen, that a
given linear movement on the part of the sleeve produces more than twice the
same amount of movement in the die ring, by virtue of the cycloidal movement im-
parted to the toggle. This feature permits the use of a degree of inclination in the
groove 62 of the slides, less than that which would otherwise be required to cause a
given amount of opening movement on the part of the dies for a given amount of
movement on the part of the sleeve. The inclination being thus less, it is obvious
that a nicer adjustment of the dies may be obtained. The adjustment of the dies
is brought about by turning a nut J which is provided in its end with a slot for
the insertion of a screw driver for that purpose. When the sleeve is in its
extreme position to the left as shown in Figure IV, the middle of the toggle
rests upon the barrel as shown and a line drawn through the centre of the left
hand pin, through the centre of the middle pin will intersect the pitch line of
the teeth of the gear and rack, perpendicularly below the centre of said gear.
The toggle, when in this position is effectually locked, and the trend of the threads
on the inside and outside of the adjusting nut being in opposite directions, it is
seen that it is impossible for the nut to turn itself, through the pressure of the
work or jar of the machine,-and hence change the position of the dies, so
that while the thread is being cut the dies are absolutely rigid and independent
of any jars which would tend to alter the relation of the parts. But when the
thread is not being cut it is possible to adjust the nut at any time, and the
turning of the nut will produce a corresponding movement of the die ring, which
hence alters the relation between the said sleeve and the die ring and the dies
held therein.
The slides projecting beyond the end of the barrel make it possible to permit
the dies to be located beyond the said end and further permits the sides of that
part of the slides which directly support the dies to be free. The slides always
bear against the die ring and hence a plane, perpendicular to the barrel axis and
passing through. the end portion of a die will intersect the outer bearing surface
of the slide holding such die, when in the position shown in Figure I, said ring
thereby forms a supporting or backing to receive radial outward thrusts exerted
upon the dies during the cutting operation; the greater amount of cutting being
performed by the outer teeth of the dies forming the throat, and hence the

page_text: greatest strain being imposed upon said throat. The outer lateral face of each
slide is free and thus the outer lateral face of each die may be free.
The sides of the slides being free as described, the chips formed during the
cutting operation find a free exit between the slides, and the possibility of
clogging up the inside of the head is avoided; the inner surface of the die ring
being bevelled as described and shown, the chips are not permitted to remain
in the die throat but are discharged from the ring as soon as they drop upon it,"
thus still further contributing to the freedom from damage by the clogging or
interference of the chips.
The outer lateral face of the die being free it is possible to bring the said
dies completely up under the head of the bolt upon which a thread is being
cut.
My improvement thus combines the advantages of nicety of adjustment,
absolute rigidity of parts during the cutting operation, freeness from clogging.
ability to cut a thread throughout the entire length of a bolt, and simplicity of
construction, without unduly increasing its size. Inasmuch as the dies them-
selves are independent of and removable from the slides, the black stock may be
used, thus eliminating expense occasioned by dressing and finishing the hard die
steel, an item of considerable economical importance in the construction of bolt
threading machinery.
I do not desired to limit my invention to the precise form of apparatus described
as the same may be modified without departing from the principal of the invention.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
I claim is
1. In a bolt threading machine, the combination of a barrel, slides fitted in
and projecting from the end of said barrel and provided with dies in said pro-
jecting portion, and supporting means, said slides having a bearing surface for
engaging said supporting means said surface intersecting a plane perpendicular
to the barrel axis and passing through the outer end portion of such die, sub-
stantially as set forth.
2. In a bolt threading machine, the combination of a barrel, die-holding slides
fitting in the end of the said barrel and engaging said barrel in tongue and groove
formation, supporting means, said slides provided with an undercut groove for
engaging a tongue having a cross section similar to the groove cross section
and secured to said supporting means, substantially as set forth.
3. In a bolt threading machine, the combination of a barrel, slides fitting in
and radially retractible in said barrel, and a supporting ring projecting beyond
the barrel end, the inner projecting surface of said ring having a bevelled or
inclined formation intermediate of said slides, substantially as set forth.
4. In a bolt threading machine, the combination of means for retracting the
dies, means for operating said retracting means, said operating means having a
cycloidal movement, and means for actuating said operating means, substantially
as set forth.
5. In a bolt threading machine, the combination of means for retracting the
dies, a toggle for operating said retracting means, said toggle having a cycloidal
movement, and means for actuating said toggle, substantially as set forth.
6. In a bolt threading machine, the combination of means for retracting the
dies, means for operating said retracting means, means for actuating said operat-
ing means and means for imparting the said operating means a cycloidal move-
ment, substantially as set forth.
7. In a bolt threading machine, the combination of means for retracting the
dies, a toggle for operating said retracting means, means for actuating said toggle
and means for imparting to said toggle a cycloidal movement, substantially as
set forth.

page_text: 8. In a bolt threading machine, the combination of means for retracting the
dies, a toggle for operating said retracting means, said toggle journalled solely
on said retracting means and on a retractible bearing, and means for imparting
a rotary movement to one of said toggle arms whereby the toggle has imparted
to it a cycloidal movement, substantially as set forth.
9. In a bolt threading machine, the combination of means for retracting the
dies, a toggle for operating said retracting means, one end of said toggle secured
to said retracting means and the other journalled on a retractible bearing said
journalled end formed with gear teeth and a rack engaging said gear teeth,
whereby said journalled arm is given a rotary movement when said bearing is
retracted thereby imparting a cycloidal movement to said toggle, substantially
as set forth.
10. In a bolt threading machine, the combination of means for retracting the
dies, means for operating said retracting means, and means for adjusting the
relation of said retracting and operating means, such adjusting means consisting
of a nut adapted to be screwed into the retracting means and provided with a
threaded bore adapted to receive the connecting portion of said operating means,
the trend of the inner and outer threads being in opposite directions, substantially
as set forth.
Dated this 28th dox of fontambon 1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.