IMPROVEMENTS IN MACHINERY FOR THE MANUFACTURE OF SCREWS
Year: 1877

page_text: LETTERS PATENT to Joseph Tangye, of Tickenhill, Bewdley, in the County of
Worcester, Gentleman, for the Invention of "IMPROVEMENTS IN MACHINERY
FOR THE MANUFACTURE OF SCREWS."
Scaled the 27th April 1877, and dated the 3rd February 1877.
PROVISIONAL SPECIFICATION left by the said Joseph Tangyo at the Office
of the Commissioners of Patents on the 3rd February 1877.
JOSEPH TANGYE, of Tickenhill, Bewdley, in the County of Worcester, Gentleman.
"IMPROVEMENTS IN MACHINERY FOR THE MANUFACTURE OF SCREWS."
My Invention consists of the improvements herein-after described in such
machinery for the manufacture of screws as effects the formation of the thread of
the screw by a rolling or impressing process.
I construct, arrange, and work the parts of the said machinery in the following
manner:-The rolls or rotating parts, by the action of which a screw thread is im-
pressed upon the screw blank, are of a disc-like form, that is, the said rolls are of a
diameter much greater than their length. These rolls have on their peripheries a
series of parallel threads of a size and figure similar to the size and figure of tho
screw thread to be formed on the blank. The said threads on the peripheries of the
rolls are in planes at right angles to the axes of the rolls, that is, they are not in-
clined like the threads of a screw. The axes of these rolls work in bearings carried
by hollow cylindrical frames capable of turning on the fixed framing of the machine.
The axes of the said hollow cylindrical frames are in the same line. By turning
these cylindrical frames in the required direction and to the required degree, the
rolls may be brought into the same plane or be made to cross each other at any
angle and in either direction. Besides being capable of rotating the said cylindrical
frames are capable of a sliding motion along their axes. They are forced towards each
other by strong springs or other equivalent means, and are separated for the intro-
duction of the blank between the edges of the rolls by means of a hand lever. By
turning the said lever through a considerable angle the frames and rolls are first
separated and afterwards allowed suddenly to close upon the blank to be
screwed. This action is effected by means of a suitably shaped cam actuated
by the lever.

page_text: Motion is given to the rolls by means of gearing contained within the hollow
cylindrical frames driven by shafts in the axes of the said frames. The said
frames having been set so as to cause the rolls to cross each other at the
required angle, they are fixed by means of clips tightened upon them.
I prefer to make the rolls of a slightly conical figure, so that the parallel
threads on them act progressively, the parts of the rolls first acting on the
blank making a shallow impression, which. is deepened by the parts of the rolls
which in succession operate upon it.
The blank to be screwed is supported in a hole in a fixed bush situated at the
opposed or acting parts of the rolls. This bush has grooves cut in it on opposite
sides, which grooves open into the cylindrical hole in it, in which hole the blank is
supported. The acting parts of the rolls work in these grooves and operate on
opposite sides of the blank, giving to it a rotatory motion, impressing a screw thread
upon it and causing it to recede out of the machine by a screwing motion.
The action of the machine is as follows:-The workman taking a blank in one
hand gives motion by his other hand to the hand lever described, and at the same
time introduces the blank into the hole in the bush, the distance to which the blank
is introduced being determined by a fixed stop. By the time the blank has reached
its proper position the hand lever has advanced so far as to permit the grooved rolls
suddenly to close upon the blank, upon which they immediately commence to operate
in the manner herein-beforo described.
Instead of operating the lover described and effecting the feeding of the blanks by
hand the said lever may be operated and the feeding effected automatically.
.
•
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Joseph Tangye in the Great Seal Patent Office on the 27th
July 1877.
JOSEPH TANGYE, of Tickenhill, Bewdley, in the County of Worcester, Gentleman
"IMPROVEMENTS IN MACHINERY FOR THE MANUFACTURE OF SCREWS."
My Invention consists of the improvements herein-after described in such
machinery for the manufacture of screws as effects the formation of the thread of
the screw by a rolling or impressing process.
I construct, arrange, and work the parts of the said machinery in the following
manner: The rolls or rotating parts, by the action of which a screw thread is im-
pressed upon the screw blank, are of a disc-like form, that is, the said rolls are of a
diameter much greater than their length. These rolls have on their peripheries a
series of parallel threads of a size and figure similar to the size and figure of the
screw thread to be formed on the blank. The said threads on the peripheries of the
rolls are in planes at right angles to the axes of the rolls; that is, they are not in-
clined like the threads of a screw. The axes of these rolls work in bearings carried
by hollow cylindrical frames capable of turning on the fixed framing of the machine.
The axes of the said hollow cylindrical frames are in the same line. By turning
these cylindrical frames in the required direction and to the required degree, the
rolls may be brought into the same plane or be made to cross each other at any
angle and in either direction. Besides being capable of rotating, the said cylindrical
frames are capable of a sliding motion along their axes. They are forced towards.
each other by a strong spring or other equivalent means, and may be separated for
the introduction of the blank between the edges of the rolls by means of a lever.
By turning the said lever through a considerable anglo the frames and rolls are first
separated and afterwards allowed suddenly to close upon the blank to bo
screwed. This action is effected by means of a suitably shaped cam actuated
by the lever.
Motion is given to the rolls by means of gearing contained within the hollow
cylindrical frames driven by shafts in the axes of the said frames. The said frames

page_text: having been set so as to cause the rolls to cross each other at the required angle
they are fixed by means of clips tightened upon them.
I prefer to make the rolls of a slightly conical figure, so, that the parallel threads
on them act progressively, the parts of the rolls first acting on the blank making a
shallow impression, which is deeponed by the parts of the rolls which in succession
operate upon it.
The blank to be screwed is supported in a hole in a fixed bush situated at the
opposed or acting parts of the rolls. This bush has grooves cut in it on opposite
sides, which grooves open into the cylindrical hole in it, in which holo the blank
is supported. The acting parts of the rolls work in these grooves and operato on
opposito sides of the blank, giving to it a rotatory motion, impressing a screw thread
upon it, and causing it to recede out of the machine by a screwing motion.
The action of the inachino is as follows:-The workman, taking a blank in one
hand gives motion by his other hand to the hand lever described, and at the same
time introduces the blank into the hole in the bush, the distance to which the blank
is introduced being determined by a fixed stop. By the time the blank has reached
its proper position the hand lever has advanced so far as to permit the grooved rolls
suddenly to close upon the blank, upon which they immediately commence to
operate in the manner herein-before described.
Instead of operating the lever described by hand the said lever may be operated
automatically.
Having described the nature of my Invention, I will proceed to describe
the manner in which the same is to be perforined, reference being had to the
accompanying Drawing and to the letters and figures marked thereon.
Figure 1 represents in front elevation a machine for the manufacture of screws
constructed according to my Invention; Figure 2 is a section of the same taken on
the line C, D, Figure 1; and Figure 3 is a section of the same takon on the line A, B,
Figure 1.
The same letters indicate the same parts in the several Figures.
a, a, are the rotating parts or rolls by which a screw thread is impressed upon
the screw blank b. These rolls are of a disc-like form, that is, are of a diameter
much greater than their length, and are mounted upon axes c. The parallel threads
on the peripheries of the rolls, by which threads the scrow thread is formed on the
screw blank b, are seen in elevation in Figure 2, and in section in Figure 3.
These parallel threads, as will be seen by reference to Figure 2, arc at right angles
to the axes of the rolls, that is, are not inclined like the threads of a screw. The
rolls a, a, are made of rings of hardened and tempered steel or double case hardened
iron, and are fixed on their axes c by screw bolts as represented. Rings having.
threads of different pitch for making screws, having threads of different pitch, are
readily fixed on and removed from the axes c. The axes c of the rolls a work in
bearings d. These bearings are carried by the hollow cylindrical frames e; these
frames turn in the head stock f of the machine. By turning these cylindrical
frames the required inclination or crossing of the rolls can be effected and single,
double, treble, or multiple threaded screws be thereby produced.
The angle at which the rolls are inclined to one another must be varied to suit.
not only the pitch and number of screw threads to be produced but also to suit the,
diameter of the blank operated upon. By way of example, I remark, that in
order to produce a single threaded screw of one inch diameter, having eight threads
to the inch, the rolls require to be inclined or to cross each other at an angle of
twelve degrees; that is, the roll a, Figure 2, being inclined in the direction of the
dotted line a the other roll is inclined in the opposite direction, as indicated by the
lines, the rolls making with a vertical plane an angle of six degrees and conse-
quently with each other an angle of twelve degrees.
The sliding motion of the frames e, e, takes place on the bed g; his the sliding
base of the headstocks f; and i are caps for holding down the said sliding base h;
k, k, are packing pieces kept to their bearing by set screws (see Figure 2). The
headstocks fand frames e are pressed towards each other by the strong coiled

page_text: spring. This spring is connected at one end to the fixed framing of the minchine,
and at its other end to the lever m. In its normal condition the spring is com-
pressed and tends to move the lever m in the direction of the arrow on the said
lever. Connecting rods o, p, are jointed at their distant or outer ends to the head-
stocks respectively, and their inner ends terminate in clips working upon eccentrics
on the axis of the lever m. When the spring can act on the arm m it causes the
headstocks to approach each other, as indicated by the arrows above the con-
necting rods 0, 2, and the peripheries of the rolls a, a, are pressed forcibly against
the screw blank b. The headstocks, and with them the rolls a, u, are separated for
the introduction of a fresh screw blank by means of the cam 7 and connecting rod q.
This connecting rod is jointed at one end to the lever m and carries at its other end
a roller which bears against the face of the enin 7. When the depressed part of the
face of the cam 7 is opposed to the roller on 7 the spring is at liberty to act, but
when a rise on the cam comes opposite to the roller on the rod g the said rod q
is urged towards the spring 1, the said spring is compressed and the rolls a, a,
separated. The cam may be operated by hand or by means of a lever; I prefer,
however, to make it act automatically by the mechanical arrangement represented
in the Drawing. The cam r is mounted on an axis, to which rotation is given from
the driving shaft v by means of the change gear at S.
Motion from a steam engine or other prime mover is communicated through the
fast pulley u on the shaft v; pinions on the said shaft v drive the toothed
wheels t, t, and motion is transmitted from the shafts of the wheels t, t, to the
rolls a, a, by means of the gearing *,,, and 15, as will be understood by an
examination of Figure 3.
I will now describe, with reference to the Drawing, the production of a screw thread!
on a screw blank b. The blank b to be threaded is fed by the workman into the
holder 2 during the time that the rolls a, a, are separated to their greatest distance by
a rise on the cam r, having come opposite to and acted upon the roller on the end of
the rod q. The holder 2 consists of a tube portions of which have been cut away
at opposite sides. The point end of the blank b is inserted in the holder 2. The
distance to which the blank is introduced into the holder may be regulated by a
stop fixed in the holder. By the motion of the cam the spring is permitted to
move the arm m in the direction of the arrow, and thereby to make the rolls a, a,
approach each other and press upon the blank. The rotation of the rolls gives a
rotary motion to the blank b, and screw threads are impressed upon the said blank.
As the blank rotates it is withdrawn from the holder 2, and passes from between
the rolls by a screwing motion falling from the rolls at the side at which it was
introduced. By an examination of Figures 2 and 3 it will be seen that the acting
or threaded surfaces of the rolls a have not the general figure of a cylinder but arc
slightly conical. By giving the rolls this configuration the action of the rolls on
the blank is made progressive, that is, the parts of the rolls which first act on the
blank impress only a shallow thread on the blank, which thread is gradually
deepened as it passes by the screw-like motion described out of the machine. The
length of the part of the blank on which a screw thread is formed is determined
by the distance to which the said blank is introduced into the holder 2 and the 4
change gear at 8, the said gear determining the rate of rotation of the cam r, and
consequently the greater or less number of rotations of the rolls a, a, between the
times at which the rolls are separated by the action of the rise on the said cam.
My Invention is applicable to the manufacture of screws of iron, brass, copper,
and such other metals and alloys as are suitable for the making of screws and to
the manufacture of left-handed as well as right-handed screws. In making iron
screws, by the use of my improved machinery, the blanks may either be operated
upon in a hot or cold state.
Having now described the nature of my Invention and the manner in which the
same is to be performed, I wish it to be understood, that I claim as my Invention
of Improvements in Machinery for the Manufacture of Screws,-
First. The employment in screw-making machinery of rolls of the kind herein-

page_text: before described and illustrated in the accompanying Drawing for impressing screw
threads on screw blanks, that is to say, rolls having on their periphery or acting
surface a series of parallel threads or depressions at right angles to the axis of the
roll, each of the said threads or depressions being independent of the others.
Secondly. The combination or arrangement of parts, herein-before described and
illustrated in the accompanying Drawing, for giving the desired inclination of the
rolls to one another.
Thirdly. The combination or arrangement of parts, herein-before described and
illustrated in the accompanying Drawing, for producing the required pressure of
the rolls on the blank to be screwed by means of a spring and for separating the
rolls at the required times to permit of the introduction of the blanks between
the rolls.
In witness whereof, I, the said Joseph Tangye, have hereunto set my hand
and seal, this Twenty-fourth day of July, in the year of our Lord One
thousand eight hundred and seventy-seven.
Witness,
•
RICHARD SKERRETT,
Clerk to George Shaw,
Birminghum.
JOSEPH TANGYE. (L.S.)