IMPROVED MACHINERY FOR MAKING SCREW BOLTS AND NUTS
Year: 1859

page_text: LETTERS PATENT to William Sellers, of Philadelphia, in the State of
Pennsylvania, United States of America, Engineer and Machinist, for
the Invention of "IMPROVED MACHINERY FOR MAKING SCREW BOLTS AND
NUTS,"
Sealed the 29th September 1859, and dated the 3rd May 1859.
PROVISIONAL SPECIFICATION left by the said William Sellers at the
Office of the Commissioners of Patents, with his Petition, on the
3rd May 1859.
I, WILLIAM SELLERS, of Philadelphia, in the State of Pennsylvania, United
States of America, Engineer and Machinist, do hereby declare the nature of
the said Invention for "IMPROVED MACHINERY FOR MAKING SCREW BOLTS AND
NUTS," to be as follows:-
The object of this Invention is to avoid the necessity of reversing the
motion of the cutting dies, or of stopping the machine to change the bolts,and
to so arrange the die and top holder as to admit of greater facility in changing
from one size thread to another. The same arrangement of machinery with
suitable modifications in some of the working parts may be used both for
cutting the threads of screw bolts and for tapping the nuts.
To this end
I place the dies in a cylindrical piece of metal called the die box, and which is
provided with radial grooves of such size as to receive the dies and to allow
them to slide freely in a radial direction. The die box is securely attached to
the face plate of a hollow spindle which carries a spur wheel that receives
motion from the pulley shaft; this spindle is placed within another hollow
027

page_text: spindle, having a face plate or flanch at one end; this latter spindle is bolted
to and is supported by a tubular, piece of the frame. Three excentric or
scroll cams of equal eccentricity are securely bolted to the face plate, leaving
spaces between them of sufficient width to admit the dies to pass freely. On
the outer surface of the cams I bolt a covering plate having on its inner
surface other cams parallel with the first-mentioned.cams. Three springs are
provided for the purpose of keeping the dies from sliding out of the openings
whenever they are opened for the purpose of removing the bolt, and alto to
govern the position of the dies. On the spur wheel and moving freely, a
suitable distance around the hub thereof is placed an adjustable stop, which
may be securely attached to the wheel by means of a bolt, and having near
its centre a projection, which is of such length as to come in contact with a
similar projection on a wheel on one of the hollow spindles. The dies may be
opened or closed by communicating to them a radial motion by means of their
cams. A thread having been cut on a bolt the dies are opened and the bolt
withdrawn, it not being necessary to unscrew the threaded bolts from the dies
as is usually the case. The cutting edge of the dies is formed so as to cut a
full thread by once passing over the bolt; this is accomplished by first cutting
a thread in the dies perfectly true and cylindrical, and of such size as to fit the
bolt when it has the thread cut upon it, the tops of the threads in the dies are
then dressed off,commencing at the base of the thread where the bolt is entered
and terminating at the top of the thread, about four threads from the point of
entrance, they are at the same time to be dressed back from the cutting edge
so as to give a clearance, each thread of the dies will thus form a cutting edge
and the thread upon the bolt will be formed by a series of cuts, each one
deeper than its predecessor until the perfect thread is developed. To fit the
machine for tapping nuts I provide a cylindrical piece of metal which is turned
to fit accurately in the hollow spindle and die box, having a square hole
through its centre to receive the shank of the tap. In its outer surface I cut
a square recess of the same width as the grooves in the die box which receive
the dies. Having removed the dies 1 insert in the place of one of them a
piece of metal of the same shape and size as the die, having the end nearest
the centre of the die box made square so as to fit in the recess of the
cylindrical piece, and which serves as a key to prevent the piece from turning
in its place. The piece being forced into the recess by the operation of the
cam as described in the process for cutting bolts, the square shank of the tap
is slipped into a hole of the same shape. The nut to be operated upon by the
tap may be held by any of the numerous devices now in use for that purpose.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Sellers in the Great Seal Patent Office on the
3rd November 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
SELLERS, of Philadelphia, in the State of Pennsylvania, United States of
America, Engineer and Machinist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of May, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-second year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said William Sellers, Her special license that I, the said William
Sellers, my executors, administrators, and assigns, or such others as I,
the said William Sellers, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVED MACHINERY FOR MAKING SCREW BOLTS
AND NUTS"
upon the
condition (amongst others) that I, the said William Sellers, by an instrument
in writing under my hand and seal, should particularly describe and ascertain
the nature of the said Invention,. and in what manner the same was to be
performed, and cause the same to be filed in the Great Scal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said William Sellers, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formned, to be particularly described. and ascertained in and by the following
description thereof, reference being had to the Drawings bereunto annexed,
and to the letters and figures marked thereon (that is to say):-
The object of this Invention of improved machinery for making screw
bolts and nuts, is to prevent the necessity of reversing the motion of the
cutting dies, or of stopping the machine to change the bolts, and to so arrange
the die and top holder, as to admit of greater facility in changing from one
size thread to another. The same arrangement of machinery, with suitable
modifications in some of the working parts, may be used both for cutting the
threads of screw bolts and for tapping the nuts.
In the accompanying Drawings, Fig. 1 is an end view of the improved
machinery; Fig. 2.is, a vertical section through the centre of the spindle ;

page_text: Fig. 3 is a plan of the whole machine; Fig. 4 is a plan of the dye holder and
cam box with the cover removed; Fig. 5 is a vertical section of the cam
box; Fig. 6 is a section through the centre of the tap holder; Fig. 7 is an
end view of the tap holder; Fig. 8 is an edge view of the key for the tap
holder; and Fig. 9 is a side view of the same.
In carrying out the Invention, the dies A, A, are placed in a cylindrical
piece of metal B, which may be called the dye box, and which is provided
with radial grooves of such size as to receive the dies, and to allow them to
slide freely in a radial direction. The dye box B is securely attached to the
face plate C of the hollow spindle D, which carries a spur wheel F, that
receives motion from the pulley shaft E by means of a pinion G. Surrounding
and sustaining the spindle D is another hollow spindle H, having a face
plate or flanch I at one end. This latter spindle H is bolted to, and is sup-
ported by the tabular piece J of the frame. On the face I there are three
excentric or scroll cams M, M, M, of equal excentricity; they are securely
bolted to the face plate, leaving spaces N, N, N, between them of sufficient
width to admit the dies A, A, A, to pass freely. On the outer surface of the
cams M, M, M, is bolted a covering plate O, having on its inner surface three
cams P, P, P, parallel with the cams M, M, M, and three springs Q, Q, Q,
which springs are so placed as to form one side of the openings N, N, N,
through which the dies are inserted, and having also projections R, R, R, which,
form a continuation of the cams P, P, P. These springs Q, Q, are provided
for the purpose of keeping the dies from sliding out of the openings N, N, N
whenever the dies are opened for the purpose of removing the bolt, and also
to govern the position of the dies when first entered, so as to guide them
upon the cams P, P, P. The face plate I, cams M, M, M, and cover O, with
its cams P, P, P, are called the cam box. On the spur wheel F, and
moving freely a suitable distance around the hub thereof, is placed an adjust-
able stop S, which may be securely attached to the wheel F by means of the
bolt T, and having near its centre a projection U, which is of such length
as to come in contact with a similar projection on the wheel K, thereby
conveying motion to the wheel K and spindle H.
To put the machine in operation, it is necessary, first, to move the die box
Binto such a position that the grooves to receive the dies shall correspond
with the openings N, N, N, between the cams M, M, M. Into these openings
the dies are then inserted, and pushed forward until the projection R on the
spring Q (Fig. 5) falls into an opening in the edge of the die, which is made
to receive one of the cams P, which cams are for the purpose of with-
drawing the die from the centre. The dies now being in the die holder, the

page_text: next operation will be to adjust them to the size of the bolt to be cut; this is
accomplished by slacking the set bolt T on the adjustable stop S, and then
moving the die box B by means of the pulley shaft E.pinion G,and wheel F;
the wheel K, with the cams M, M, M, being held stationary. As this is
done, the dies A, A, A, will be gradually forced with the cams M, M, M
towards their common centre, and closed upon any finished bolt or other
object to which it may be desired to set them. Whilst the wheels are in this
position, the adjustable stop!S(Fig.2) is moved so as to bring the projection U
near its centre in contact with a similar projection on the wheel K, when the
set bolt T may be secured. If now the wheel F be turned in the same
direction as before, it will carry with it the wheel K and cams M, M, M, and
as the dies A, A, A,(Fig. 4) and cams M,M,M, wil 1 be then moving in the
same direction,and at the same velocity, there will be no further movement
of the dies in a radial direction. To open the dies for the purpose of with-
drawing the bolt, the pulley shaft E being in motion, the pinion L must.be
moved by means of the loose collar a' and handle V; so as to tighten the
friction clutch G,L, which will give an equal velocity to the two pinions G
and L; but as the pinion L is larger than the pinion G,the wheel K, which
is driven by L, will move faster than the wheel F, which is driven by G,
thereby causing the cambox to move around the dies in the opposite direction
to that first described, and the cams P, P, P, will force the dies from the
centre. To close the dies preparatory to or during the operation of cutting
the bolt, the pulley shaft E being in motion, the pinion L is forced by means
of the loose collar a¹ and handle V against the leg 2, which is here covered
by a piece of leather so as to create friction; this will cause the pinion to
stop, together with the wheel K and cains M, M, M; the motion of the
wheel F and die box D will, however,continue, thus causing the dies A,A,A,
to revolve as first described, thereby closing the dies until the projection on
the stop S comes in contact with the similar projection on the wheel K,com-
pelling it to move at the same velocity, when no further movement of the dies
in a radial direction will take place.
The cutting edge of the dies may be formed so as to cut a full thread
by once passing over the bolt; this is accomplished by first cutting a thread
in the dies perfectly straight and cylindrical, and of such size as to fit the
bolt when it has the thread cut upon it. The tops of the threads in the dies
are then dressed off,commencing at the base of the thread where the bolt is
entered, and terminating at the top of the thread about four threads from the
point of entrance; they are at the same time to be dressed back from the
cutting edge so as to give a clearance. Each thread of the dies will thus

page_text: form a cutting edge, and the thread upon the bolt will be formed by a
series of cuts, each one deeper than its predecessor, until the perfect thread
is developed.
To fit the machine for tapping nuts, I provide a cylindrical piece of
metal W, which is turned to fit accurately in the hollow spindle D and die
box B having a square hole through its centre to receive the shank of the
tap. In its outer surface I cut a square recess X of the same width as the
grooves in the die box B, which receive the dies A,A,A. Having removed
the dies, I insert in the place of one of them a piece of metal Y, of the same
shape and size as the die, having the end nearest the centre of the dye box
made square so as to fit in the recess X of the cylindrical piece W, and
which serves as a key to prevent the piece W from turning in its place.
The piece Y is forced into the recess X by the operation of the cam M, as
described in the process for cutting bolts, and the square shank of the tap is
slipped into a hole of the same shape in the piece W, and the nut to be
operated upon by the tap may be held by any of the numerous devices now in
use for that purpose.
Having thus fully described my Invention of improved machinery for
making screw bolts and nuts, what I claim as new, and desire to secure by
Letters Patent, is the use of rotating dies in combination with cams or their
equivalent, both being so arranged as to be capable of revolving about a
common centre at different velocities for the purpose of opening and closing
the dies.
I claim the arrangement of cams with open spaces between them in com-
bination with the die box, and dies to facilitate the changing of the dies.
I also claim the use of dies, having their cutting edges formed as described
when they are arranged so as to be opened or closed whilst revolving about a
common centre.
I also claim the mode of attaching the tap holder to the revolving die box.
In witness whereof, I, the said William Sellers, have hereunto set
my hand and seal, the First day of October, in the year of our
Lord One thousand eight hundred and fifty-nine.
WM. SELLERS. (L.S.)