Improvements in and relating to Die Heads for Screw Cutting.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in and relating to Die Heads for Screw Cutting.
I, WILLIAM JOHN SMITH, of The Geometric Drill Company's Factory, West-
ville, Connecticut, United States of America, Engineer, do hereby declare the
nature of this invention to be as follows:-
:--
This invention relates to die heads for screw cutting.
The object of the invention is to produce a simple and easily operated device
capable of use on a turret lathe or on an automatic screw cutting machine
whereby a screw of any desired length with limits may accurately be cut and
in which the cutting operation can automatically be stopped when a screw of any
predetermined length has been cut and the dies disengaged from the work.
Also the die holders and dies can be reinstated in their working position
either by hand or in the movement of the turret or part of the machine in
which the die head is mounted.
"
Also means is provided for adjusting the parts for depths of cut to suit the work
to be produced and also for attaining a roughing" cut and a "finishing" cut
without disturbance of the adjustment just referred to.
The screw thread cutting dies may vary in number and the holders of course
correspond as well as the guideways therefor and corresponding parts, but for an
example I will describe the invention as applied to a die head with four cutters.
These cutters and holders are held in the carrier portion of a skeleton sleeve
in corresponding guideways formed with grooves to engage ribs on the holders
and are capable of a radial motion therein controlled as will be described. The
parts of this carrier are held together by a flange like extension from a shank of
tubular form. From the rear of the cutter holders project lugs which I prefer
to be integral therewith and these lugs engage in grooves in a cam piece or
ring mounted on the carrier shank in rear of the carrier parts and cutter holders.
The cam ring is designed to fit accurately against the rear face of the carrier
and it is provided in its front face with the cam grooves referred to. By rotating
the cam ring in one direction or the other the holders and the cutting dies carried
thereby are moved towards or away from the centre of the carrier to regulate the
space between the cutting edges of the dies and consequently the diameter of the
screw cut and also to separate the dies to allow withdrawal of the work after a
screw of the desired length has been cut. This cam ring has handles to turn
it by, either using the hands or allowing one handle or pin to contact with a
part of the tool slide in the course of any rotative motion given to the turret
or part supporting the die carrier by its shank, whereby the cam ring will be
caused to rotate relatively to the other parts connected to it and so reinstate them
in the cutting position. The cam ring has at back a recess in which is located
a coiled spring one end of which abuts against a fixed piece from the cam
and the other end of the spring abuts against a projection entering said groove
from a locking and releasing flanged short cylindrical piece or sleeve mounted
on the shank of the skeleton carrier.

page_text: The locking sleeve has mounted on it an index plate which is adjustably
clamped to the sleeve and to an inner and similar plate by counter-sunk bolts
passing therethrough and secured by nuts and on the index plate is mounted an
recentric bolt which passes through these clamped parts and is partially rotatable
by means of a handle lockable by a screwed bolt mounted in a threaded hole
in the handle said screwed bolt entering one, or other of two holes located at either
extreme of the movements of the said handle, in the index plate as it is operated
by a milled head.
The eccentric end of the bolt enters a bolt hole in the cam piece and according
as the eccentric projects to right or left so by the bolt hole therein the cam
piece is pushed round and the cutters made to give a roughing" cut or a
finishing" cut at will by this simple movement of this handle to right or to
ieft without disturbance of the general or fixed adjustment of the cam ring and
carrier.
This flanged sleeve encloses a ring or collar screwed to the shank of the carrier
and serving to keep said piece in place as well as serving as an abutment against
the pressure of certain springs which press the flanged sleeve against 'the cam
piece..
The shank of the carrier is provided with elongated openings through which
project screws retaining the locking and releasing sleeve and a stop by which the
length of the screw is limited.
A
At the intersection of the carrier portion and the shank portion is the ring
or flange referred to this serves to strengthen the frame and also to guide the
cam ring.
The sleeve is provided with a longitudinal opening through which projects
a screw threaded into the collar. This opening has a portion reduced in diameter
providing a shoulder against which bears a coil spring the other end of which bears
against the head of the screw. With the parts arranged and this screw pro-
jecting through the sleeve and into the opening in the collar a space is left
between the shoulder and the head of the screw so that reciprocations of the
sleeve to and from the collar can take place.
The spring causes the sleeve to move towards the cam ring and to bring the
locking stop already described into the opening in the, cam ring when the two
are opposite each other by the operation of the coiled spring.
A stop piece hollowed out and having a head by preference is held in position
in the shank by screws which secure the sleeve to the shank.
This stop is arranged in the shank according to length of work to be cut
either head or the open end towards the cutting dies. In the latter case the work
will enter this open end and thus a longer screwing can be cut.
The length of screw is determined by a gauge and scale. Movement of the
stop to and fro, after the screws have been loosened enables the length of screw
to be regulated and predetermined.
When in operation a screw is cut to desired length and the work contacts with
the head the locking and releasing sleeve will be pushed rearward moving said
lock stop from, the opening in the cam ring. Then the spring rotates the cam
ring and the die holders and dies are moved to separate the dies from the work.
Dated the 4th day of October 1899.
WM. BROOKES & SON,
55/56, Chancery Lane, London,
Agents for the Applicant.

page_text: Improvements in and relating to Die Heads for Screw Cutting.
I, WILLIAM JOHN SMITH, of The Geometric Drill Company's Factory, West-
ville, Connecticut, United States of America, Engineer, 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:-
This invention relates to die heads for screw cutting.
The object of the invention is to produce a simple and easily operated device
capable of use on a turret lathe or on an automatic screw cutting machine
whereby a screw of any desired length within limits may accurately be cut and
in which the cutting operation can automatically be stopped when a screw of any
predetermined length has been cut and the dies disengaged from the work.
Also the die holders and dies can be reinstated in their working position
either by hand or in the movement of the turret or part of the machine in
which the die head is mounted.
"h
Also means is provided for adjusting the parts for depths of cut to suit the work
to be produced and also for attaining a roughing" cut and a finishing" cut
without disturbance of the adjustment just referred to.
The screw thread cutting dies may vary in number and the holders of course
correspond as well as the guideways therefor and corresponding parts, but for an
example I will describe and illustrate the invention as applied to a die head with
four cutters,
DESCRIPTION OF THE DRAWINGS.
Fig. 1 shows by a vertical section the construction of a dic head according to
the invention.
Fig. 2 is an external view of Fig. 1.
Fig. 3 is a front view of the same, showing the dies in their working position.
Fig. 4 is a similar view to Fig. 1, but with the dies in their released position
and sprung open to release the work.
Fig. 5 is a rear elevation.
Fig. 6 is a side view partly in section of the die holder, or skeleton carrier.
Fig. 7 is an end view of the same.
Fig. 8 is a face view of the cam plate or cam ring.
Figs. 9, 10, 11 and 12 show details illustrating parts of the mechanism
separately.
Fig. 13 is a cross section of the tool on the line A B Fig. 1 and,
Fig. 14 is a like cross section on the line CD of the same fig.
a is the skeleton carrier (see separate views thereof Figs. 6 and 7) having
front carrying parts 1, 2, 3 and 4, which form between them the slide ways for
the holders b, to which the cutting dies (herein illustrated as four in number),
marked respectively 5, 6, 7 and correspondingly formed to the parts holding
and guiding them, are attached but the invention is not restricted to such number
of cutters, holders and guideways.
a is the hollow shank of the carrier. This hollow shank has mounted on it
the spring actuated cam piece and the locking and releasing sleeve d.
The hollow shank a¹ may be entered into one of the holes of a turret of the
slide mounted on the bed of lathe, or the like, not shown.
These cutters 5, 6, 7, 8 screwed by screws k to holders bare held in the
carrier portion of the skeleton sleeve a in corresponding guideways formed as

page_text: shown with grooves, to engage ribs on the holders, and are capable of a radial
motion therein controlled as will be described. The parts 1, 2, 3, 4 of this
carrier a are held together by a flange like extension a³ from the tubular
shank. From the rear of the cutter holders b project lugs which I prefer
to be integral therewith and these lugs 62 engage in grooves c in a cam piece or
ring c mounted on the skeleton carrier shank in rear of the carrier parts and
cutter holders.
The cam ringe is designed to fit accurately against the rear face a² of the
carrier a, and it is provided in its front face with the cam grooves c¹ referred to.
By rotating the cam ring c in one direction or the other the holders b and the
cutting dies 5, 6, 7 & 8, carried thereby are moved towards or away from the
centre of the carrier c to regulate the space between the cutting edges of the
dies and consequently the diameter of the screw cut and also to separate the dies
to allow withdrawal of the work, after a screw of the desired length has been cut.
This cam ring c has handles c, c5 to turn it by, either using the hands, or
allowing one handle or pin to contact with a part of the tool slide in the course
of any rotative motion given to the turret or part supporting the die carrier a
by its shank a whereby the cam ring e will be caused to rotate relatively to the
other parts connected to it and so reinstate them in the cutting position. The
cam ring has at back a recess 2 in which is located a coiled spring i one end
of which abuts against a fixed piece c³ (shown by dotted lines in Fig. 4) extending
from the cam c and the other end of the spring i abuts against a projection h¹
(shown by dotted lines in Fig. 4) entering said groove and projecting from a
locking and releasing flanged short cylindrical piece or sleeve & mounted on the
shank of the skeleton carrier a.
This locking sleeve has mounted on it an index plate, m (see Figs. 10, 11
and 12) which is adjustably clamped to the sleeve d and to an inner and similar
plate located in groove a of sleeve d by counter sunk bolts c, c² passing
through the plates 1, d'and m and being therein secured by nuts c. These bolts
and nuts serve to clamp the three parts 1, d and m tightly together in their
adjusted position, the adjustment being assisted by the position of the index
point m relatively to the index graduations a³ cut or mounted on the periphery
of the flanged part of d, and on the index plate m is mounted a bolt g provided
with an eccentric end g³ which passes through these clamped parts and is partially
rotatable by means of a handle gl, (lockable by a spring actuated sliding bolt g*
located in a counter bored hole g2 in the handle g¹, said bolt g entering one or
other of two holes m2, m², (one of which is seen in Fig. 5) located in the under
plate mat either extreme of movements of said handle g¹).
cut or a
"
and
therein the
The eccentric end g³ of the bolt g enters a bolt hole c8 in the cam piece
according as the eccentric projects to right or left so by the bolt hole
cam piece e is pushed round and the cutters 5, 6, 7, 8, made to give a roughing."
finishing "cut at will by this simple movement of this handle to
right or to left without disturbance of the general or fixed adjustment of the
cam ring c and carrier a. This flanged sleeve d encloses a ring or collar h
screwed by screws at to the shank a of the carrier a. This sleeve d serves as
an abutment against the pressure of certain springs f¹ which press the flanged
sleeve against the cam piece c.
Said sleeve d is also provided with two fixed guide pins e which pass freely
into corresponding holes e in the fixed collar h before referred to.
Said pins e prevent the sleeved from revolving while admitting of longitudinal
movement and keeping said sleeve d in alignment with the body of the tool.
The shank a of the carrier a is provided with elongated openings through
which project screws d retaining the locking and releasing sleeve d and a stop p
by which the length of the screw is limited.
At the intersection of the carrier portion and the shank portion a¹ is the ring
or flange a referred to this serves to strengthen the frame and also to guide the
cam ring c.

page_text: The sleeve is provided at two opposite points with a longitudinal opening f
through which projects a screw f threaded into the collar h. Each opening has a
portion reduced in diameter providing a shoulder against which bears a coiled
spring the other end of which bears against the head of the screw. With the
parts thus arranged and these screws projecting through the sleeve and threaded
into the openings in the collar h space is lett between the shoulders and the
head of each screw so that reciprocations of the sleeve to and from the collar can
take place.
The spring causes the sleeve d to move towards the cam ring and to
bring the locking stop already described into the opening in the cam
ring c when the two are opposite each other by the operation of the coiled spring i.
Pis a stop piece (hollowed out and having a head of lesser diameter for the
purpose of contacting when a screw of smaller diameter or of shorter length is
being cut or screwed,) is held in central position by screws d', d, d threaded in
hub of sleeve and passing through slots in shank.
The object of the said stop piece is to disengage the eccentric bolt from the
cam piece e by carrying back the sleeve d.
By means of the hexagon headed screw the stop piece p may be released
from the sleeve d and adjusted longitudinally to any desired position for such
length of screw as may be predetermined.
This stop is arranged in the shank according to length of work to be cut
either head or the open end towards the cutting dies. In the latter case the
work will enter this open end and thus a longer screwing can be cut.
The length of screw is determined by a gauge and scale. Movement of the
stop p to and fro, after the screws have been loosened, enables the length of
screw to be regulated and predetermined.
When in operation a screw is cut to desired length and the work contacts with
the head the locking and releasing sleeve will be pushed rearward moving said
lock stop from the opening in the cam ring. Then the spring rotates the cam
ring and the die holders and dies are moved to separate the dies from the work.
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 claim is:-
1. A die head for screw cutting in a lathe or screw cutting machine, in which
cutters, their holders, a spring actuated cam ring controlling the motions of those
holders, a sleeve having a lock adapted to engage and hold in adjusted position
said cam ring and cutting and cutter holders controlled by it during cutting and
an adjustable stop piece carried by said sleeve adapted to contact with the work
and thereby disengage the locking parts and permit the cutters to be released
from the work, are combined with a skeleton frame piece a, a¹, all substantially
as and for the purpose set forth and shown by the accompanying drawings,
2. In a die head for screw cutting in a lathe or screw cutting machine the
combination of parts for supporting the cutters and cutter holder parts in
adjusted and locked position during work and automatically releasing and
removing them therefrom as soon as a predetermined length of screw has been
cut such release of the locked and locking parts being effected by the contacting
of the finished work with an adjustable stop picce carried by the locking part
in the path of said work within a hollow skeleton frame-piece which serves as
the support for the die head, as set forth.
3. The construction and use, in combination with the mechanism described in
Claim 1, of means whereby the screw cutting die holders and dies can be re-
instated in their working position, either by hand, or contact of a part in the
movement of the turret or other part of the machine in which the die head
is mounted, as described and shown by the drawings.
4. The use in die heads of the kind described in Claim 1, of means for

page_text: "
adjusting the cutting parts of die heads to required depths of cut and enable a
roughing" cut and a finishing cut to be effected without disturbing the
adjustment of the depth of cut suited to the work in hand to which the die
head has been adjusted, substantially as set forth and shown by the drawings.
Dated the 3rd day of July 1900.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London,
Agents for the Applicant.