IMPROVEMENTS IN MACHINERY FOR THE MANUFACTURE OF SCREWS
Year: 1878

page_text: LETTERS PATENT to Edward Thomas Periam, of Birmingham, in the County
of Warwick, Manufacturer, for the Invention of "IMPROVEMENTS IN MACHINERY
FOR THE MANUFACTURE OF SCREWS."
Sealed the 13th December 1878, and dated the 9th October 1878.
PROVISIONAL SPECIFICATION left by the said Edward Thomas Periam at
the Office of the Commissioners of Patents on the 9th October 1878.
EDWARD THOMAS PERIAM, of Birmingham, in the County of Warwick, Manu-
facturer. “IMPROVEMENTS IN MACHINERY FOR THE MANUFACTURE OF SCREWS."
My Invention has reference to that part of the machinery for the manufacture
of screws, by which the screw thread is cut upon a headed screw blank.
In constructing machinery for the manufacture of screws according to my
Invention I mount by preference four cutting tools in a rotating holder worked in
a lathe.
The said tools are situated in a plane at right angles to the rotating shaft, and
are carried by the short arms of four levers jointed to the rotating shaft.
The said levers are situated equidistantly around the said shaft. The longer
arms of the said levers are connected by short links to a sliding collar on the
rotating shaft.
When the said collar is moved towards the cutting tools the said
tools close upon one another, and when the said collar is moved in the opposite.
direction the said tools separate by the action of the links upon the levers carrying
them. The blank to have a screw thread cut upon it is placed in a holder working
in a slide in a line with the rotating shaft, and by means of a lever the end of the
blank is advanced to the rotating cutting tools. The said tools seize the said blank,.
causing it to advance at the required rate between them and cut upon it the
desired thread.
The distance to which the blank is drawn between the cutters and the length of
the screw cut on the blank is determined in the following manner :-A rod parallel

page_text: with the sliding holder as an adjustable stop on it, against which a finger carried
by the said slide comes when the blank has advanced sufficiently. The said rod
then commences to move at the same rate as the blank. A projection on the end of
the said rod engages in a groove in a sliding collar on the rotating shaft, and when
the said rod is moved towards the cutting tools it slides the said collar on the
rotating shaft until the links connecting the collar with the levers are passed their
centres, when the cutting tools suddenly open and cease to act on the blank. The
screwed blank is now withdrawn by the contrary motion of the lever by which it
was advanced, when the workman removes the screwed blank from the holder and
places another therein. The backward motion of the lever causes the closing of the
cutting tools readily for operating upon another blank by means of a second
adjustable stop on the sliding rod.
In the backward motion, the holder, the finger described, strikes against the
second stop on the sliding rod and thereby moves the sliding collar in the direction
proper to close the cutting tools. The cutters are formed in the machine itself by
fixing blank cutters in the levers and a screw tap in the holder. The sliding
rod carrying the adjustable stops is thrown out of gear, and by means of a lever
connected with a fork which takes into the groove in the sliding collar the work-
man gives the desired pressure to the blank cutters as the screw tap passes between
them.
By repeating the action of the tapping tool upon the blank cutters a sufficient
number of times the required teeth are formed on the said cutters. The said
cutters are then hardened and tempered in the ordinary way.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Edward Thomas Periam in the Great Seal Patent Office on the
26th March 1879.
EDWARD THOMAS PERIAM, of Birmingham, in the County of Warwick, Manu-
facturer. "IMPROVEMENTS IN MACHINERY FOR THE MANUFACTURE OF SCREWS."
My Invention has reference to that part of the machinery for the manufacture
of screws by which the screw thread is cut upon a headed screw blank or
other rod.
In constructing machinery for the manufacture of screws according to my
Invention I mount three or four cutting tools in a rotating holder worked in a
lathe. The said tools are situated in a plane at right angles to the rotating shaft,
and are carried by the short arms of three or four levers jointed to the rotating
shaft. The said levers are situated cqui-distantly around the said shaft. The
longer arms of the said levers are connected by short links to a sliding collar on the
rotating shaft. When the said collar is moved towards the cutting tools the said
tools close upon one another, and when the said collar is moved in the opposite
direction the said tools separate by the action of the links upon the levers carrying

page_text: them. The blank or rod to have a screw thread cut upon it is placed in a sliding
holder working in a guide in a line with the rotating shaft, and by means of a
lever the end of the blank is advanced to the rotating cutting tools. The said
tools seize the said blank, causing it to advance at the required rate between them
and cut upon it the desired thread. The distance to which the blank is drawn
between the cutters and the length of the screw cut on the blank is determined in
the following manner :-A rod parallel with the sliding roller has an adjustable
stop on it, against which a finger carried by the said sliding holder comes when the
blank has advanced sufficiently. The said rod then commences to move at the
same rate as the blank. The said rod is connected with a fork, and studs on the
latter engage in a groove in the sliding collar on the rotating shaft; and when the
said rod is moved towards the cutting tools it slides the said collar on the rotating
shaft until the links connecting the collar with the levers are past their centres,
when the cutting tools suddenly open and cease to act on the blank. The screwed
blank is now withdrawn by the contrary motion of the lever by which it was
advanced, when the workman removes the screwed blank from the holder and
places another therein. The backward motion of the lever causes the closing of
the cutting tools ready for operating upon another blank by means of a second
adjustable stop on the sliding rod. In the backward motion of the holder the
finger described strikes against the second stop on the sliding rod, and thereby
moves the sliding collar in the direction proper to close the cutting tools. The
cutters are formed in the machine itself by fixing blank cutters in the levers and a
screw tap in the holder. The sliding rod carrying the adjustable stops is thrown
out of gear, and by means of a lever connected with the fork which takes into the
groove in the sliding collar the workman gives the desired pressure to the blank
cutters as the screw tap passes between them. By repeating the action of the
tapping tool upon the blank cutters a sufficient number of times the required teeth
are formed on the said cutters. The said cutters are then hardened and tempered
in the ordinary way.
I will now proceed to describe with reference to the accompanying Drawings
the manner in which my Invention may be performed.
Figure 1 represents a side elevation, and Figure 2 a plan of a machine for the
manufacture of screws containing my improvements, three cutting tools being
employed in the machine; Figures 3 and 4 are cross sections of the machine,
Figure 3 being taken on the line a, a, Figure 1, and Figure 4 being taken on the
line b, b, Figure 1; Figure 5 is a longitudinal section of the rotating spindle and
cutting tools and parts connected therewith; and Figure 6 is an end elevation of
the bearing plate to which the cutter levers are jointed; Figure 7 is a plan of a
machine provided with four cutting tools, and with a sliding holder modified to
hold headed screw blanks; Figures 8 and 9 represent longitudinal sections of the
rotating shaft or spindle of the machine, together with the cutting tools and their
levers and links, drawn to a larger scale, Figure 8 representing the cutters closed,
and Figure 9 the same open; Figure 10 represents an end elevation of Figure 8.
The same letters of reference indicate the same parts in the several Figures of the
Drawings.
c, c, are the cutting tools having toothed cutting ends of the ordinary kind, three
or four of the said cutting tools being employed, three being used in the machine
represented in Figures 1, 2, 3, 4, and 5, and four in the machine represented in
Figures 7, 8, 9, and 10. These cutting tools are carried by holders on the ends of
the short arms of the ievers d, d, the said levers being jointed at e to the bearing
plate f, which is screwed or otherwise fixed on the end of the rotating hollow shaft
or spindle g of the machine, the said spindle being driven by a band on the fast
pulley of the fast and loose pulleys h, i. The said cutter levers d, d, are situated
equidistantly around the rotating shaft or spindle g, as best seen in Figure 3.
The
longer arms of the cutter levers d, d, are connected by short links h, k, to a sliding
collar on the rotating shaft or spindle g of the machine.

page_text: When the collar is moved towards the cutting tools c, c, (in the manner herein-
after described) the said tools close upon oue another by the action of the links k, l,
upon the levers d, d, carrying them as represented in Figures 1, 2, 3, 8, and 9; and
when the collar is moved in the opposite direction the said cutting tools separate
by the action of the links upon the cutter levers, as seen in Figures 8 and 9. The
collar is moved on the rotating shaft or spindle, automatically or by hand, for
opening and closing the cutting tools in the manner herein-after explained; m is a
sliding holder, square in section, in which the screw blank or rod n, the end of
which is to be screwed, is fixed, the said sliding holder working in the fixed guide p
on the bed of the machine.
This holder m is moved in the guide p, so as to advance the screw blank or rod
held in it towards the cutters c, c, or withdraw it from the said cutters by the
action of the hand lever q, to which the holder is jointed at q². The end of the
lever is jointed by the link q³ to the arm q' on the bed of the machine. When a
plain rod is to be screwed it is fixed to a holder m by a set screw n³ (Figures 1
and 2), and when a headed screw blank is to be screwed the end of the sliding
holder is furnished with a socket n³, into which the head of the blank is dropped
(see Figure 7). By the advance movement of the hand lever q the end of the blank
or rod in the holder m is advanced between the closed rotating cutting tools c, c,
which seize the said blank or rod and carry it between them and cut upon it the
required thread. After the blank or rod has been sufficiently advanced between
the cutting tools, and the required length of screw cut upon it, the cutting tools
open automatically and release the screwed blank or rod, which is withdrawn from
between them by means of the hand lever q. The cutting tools c, c, are opened
and closed at the proper times, and the length of screw cut upon the blank or rod
is determined by the following combination of parts:- is a horizontal rod situated
parallel to the rod or blank to be screwed, the said horizontal rod having fixed upon
it two adjustable stops 8, 83; and between the said stops is a horizontal finger u³,
the eye end of which slides freely on the said rod r. The said finger us is fixed to
and partakes of the motion of the sliding holder m carrying the rod or blank n to
be screwed. One end of the rod is supported in the eye bracket 72, and its
opposite end is jointed at to the arm or lever t, the axis u2 of which carries the
fork u.
Pins or studs on the branches of the said fork u engage in the groove in
the sliding collar on the rotating spindle or shaft of the machine, so that the
motion of the said collar in one or other direction causes the links to which the
collar is jointed to act upon the cutter levers c, d, and open or close the cutting
tools c, c.
The opening of the cutting tools c, c, is effected automatically, and the
closing of the said tools is effected by the action of the hand lever q in the following
manner :- When the rod or blank n being operated upon has advanced sufficiently
between the cutting tools to form on its end a screw of the required length the
finger carried by the sliding holder m strikes against the stops, and a sliding
motion is thereby given to the rod. The fork is by the motion of the rod
turned through the required angle by the action of the arm t and axis u², and the
said fork made to slide the collar & upon the hollow rotating shaft or spindle from
the cutting tools c, c. By this sliding motion of the collar 7 the cutting tools c, c,
open in the manner before described and release the rod or blank under treatment,
the said rod or blank coming to rest. By now giving a backward movement to
the hand lever q the screwed rod or blank is withdrawn from the cutting tools.
In making its backward movement the finger u³ on the holder m strikes the second
stop 82, and thereby moves the sliding rod in the direction proper to cause it to
close the cutting tools c, c, through the operation of the arm t, fork u, collar l,
link, and levers d. A fresh rod or blank having been fixed in the holder in the
end of the said rod or blank is introduced by the advance of the hand lever q
between the closed cutting tools c, c, which seize it and advance it between them
and effect the cutting of a thread upon its end in the manner herein-before
described. Thus the opening of the cutting tools is automatically effected after the

page_text: proper length of rod or blank has been screwed, and the closing of the said cutting
tools is effected by the back movement of the hand lever to remove the screwed
rod or blank from between the cutters.
The opening and closing of the cutting tools may be effected when required by
means of the hand lever w connected to the fork u. This hand lever is principally
useful for making the cutting tools by the machine itself. To effect this blank
cutters are fixed in the levers d, d, and a screw tap is fixed in the holder m. The
sliding rod r is ungeared from the fork w by removing the joint pin at By
means of the hand lever q the screw tap is advanced between the blank cutters in
the levers d, d, and the required pressure is put on the said blank cutters by means
of the lever was the said screw tap passes between them. By repeating the action
of the screw tap upon the blank cutters the required teeth are formed on them, the
said cutters being finished by being hardened and tempered in the ordinary way.
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 do not limit myself to
the precise details herein described and illustrated, as the same may be varied
without departing from the nature of my Invention.
But I claim as my Invention of improvements in machinery for the manufacture
of screws:
First. The construction and combination of parts herein-before described, and
illustrated in the accompanying Drawings, for opening and closing the cutting tools
of the machinery.
Secondly. The construction and combination of parts, substantially as herein-
before described, and illustrated in the accompanying Drawings, for automatically
opening the cutting tools when the required length of screw has been cut upon the
screw blank or rod, and for closing the said cutting tools by the act of withdrawing
the screwed blank or rod from the cutters.
Thirdly. The combination of the mechanical arrangements claimed in claims 1
and 2 in a machine for the screwing of screw blanks or rods, substantially as
described and illustrated.
In witness whereof, I, the said Edward Thomas Periam, have hereunto set my
hand and seal, this Twelfth day of March, in the year of our Lord One
thousand eight hundred and seventy-nine.
Witness,
GEORGE SHAW.
EDWARD THOMAS PERIAM. (L.S.)