IMPROVEMENTS IN MACHINERY FOR FORMING THE THREADS OF METAL SCREWS
Year: 1869

page_text: LETTERS PATENT to William Robert Lake, of the "International
Patent Office," No. 8, Southampton Buildings, Chancery Lane,
London, Consulting Engineer, for the Invention of "IMPROVEMENTS
IN MACHINERY FOR FORMING THE THREADS OF METAL SCREWS."- A com-
munication from abroad by Treat Timothy Prosser, of Chicago,
Illinois, United States of America.
Sealed the 13th July 1869, and dated the 17th May 1869.
PROVISIONAL SPECIFICATION left by the said William Robert Lake
at the Office of the Commissioners of Patents, with his Petition,
on the 17th May 1869.
I, WILLIAM ROBERT LAKE, of the "International Patent Office," No.
8, Southampton Buildings, Chancery Lane, London, Consulting Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
MACHINERY FOR FORMING THE THREADS OF METAL SCREWS," a communication,
to be as follows:-
This Invention relates to machines for forming screw threads upon

page_text: bolts or metallic rs of any TUU
in forming such threads by compression between plates having concentric
projections upon their faces set at an angle to one another and revolving
upon axes in different planes.
The frame of the machine, which may be constructed in any suitable 5
manner, is provided with suitable boxes for the recoption of the
shafts of the driving gear and with proper receptacles for the screw-
forming discs or cups and for the wheels; it may also be provided with
a reservoir for water as shown, so that the screw-forming discs may
enter such water as they rotate. The shafts to which are secured the 1
larger gear wheels and the screw-forming discs or cups are fitted
to revolve in boxes formed in or secured to the frame at an angle to
each other. The arrangement of these shafts and the screw-forming
discs or cups which are secured thereto, is such that when the bolt or
bar upon which the thread is to be formed is placed in the guido
provided for the purpose, the axis of one of such shafts will be above
the axis of such balt or rod, while the axis of the other or opposite shaft
will be as much below the axial line of the bolt. Gear wheels are
secured to the said shafts for the purpose of communicating motion
to the same, and toothed pinions are secured to shafts which are
mounted in bearings formed in the under side of the frame. These
pinions mesh with and rotate the said gear wheels. Pulleys are secured
to the outer ends of the shafts upon which these pinions are secured,
and on these pulleys are placed the belts which are to drive the machine.
These machines may be arranged upon a table or frame, and be driven
by belts passing down through such table to a shaft below. When
each of the pulleys is driven from one driving shaft, it will be necessary
to cross one of the belts, as it is necessary that one of the discs or cups,
which form the threads should rotate in one direction, and the other in
the opposite direction. These discs may be constructed in the form of
plates having a hole for securing them to the shafts and an overhanging
or projecting flange upon their edges for the reception of the concentric
grooves which alternate with the concentric projections thercon for
the purpose of forming the screw, or they may be made in the form of
semi-spheres and have the grooves and projections-formed upon their outer
edges, while the revolution of the discs arranged as set forth would cause a
forward feed to the bar placed between them; this motion would be

page_text: irregular but when the projections from the faces have taken hold of
the bar and compressed the thread, the concentric projections succeeding
the first one bearing against the sides of the thread will serve to control
the movement of the bolt, and cause it to be fed regularly forward so
as to form a thread of a uniform pitch. The guide herein-before
mentioned for the rod or bolt upon which the screw is to be formed consists
of a thin piece of metal which may have a slot through its centre of the
width of the diameter of the bolt to be threaded. Upon each end of
this flattened and slotted guide there is to be formed a tubular pro-
jection, it being fixed in place by boxes formed in or secured to the
frame. Through these hollow journals the rod or bolt to be threaded
passes. The socket of the guide has on its inner face the thread of a
femalo screw of the same pitch as that to be cut on the rod or bolt.
This screw when it receives the thread on the bolt serves to control the
3 movement of the latter, a function which becomes essential when in
cutting taper pointed bolts the innermost of the concentric projections
on the disc cease to bear upon the thread which is being formed. As
the thread is raised in part above the original surface of the rod or
bolt, the latter will pass through the guide and the threads only will
engage those of the female screw. In order that the outermost of the
concentric projections may act upon the rod the edge of the disk should
be beveled. When it is desired to form the threads of a given length
upon a number of bolts or rods, a gauge rod may be inserted into one
of the hollow journals of the guide. The rod or bolt to be threaded is
to be passed through the opposite journal, and pushed forward until
its inner end comes in contact with such gauge rod. This gauge rod
may be set so as to allow a thread of any desired length to be formed
and may be held in the desired position by means of a set screw.
handle or lever is formed with an aperture in each of its ends to receive
the ends of screws, it being so formed as to extend from one end of
the machine to the other, and it may be furnished with a guide in which
to move and by which it may be held in any desired position. The said
screws are hollow and pass through projections formed upon boxes in
which the disc shafts rotate. These screws bear against the ends of the
shafts, and are actuated by the handle or lever to force the thread
forming discs or cups nearer together, so that when they commence to
act проп the bolt or rod to form the thread thereon, only a slight inden-
tation will be made, but so that they may be forced together gradually
A

page_text: until they shall penetrate the bolt a sufficient distance to form a perfect
thread. Through each of these screws a rod passes which is secured to
the shafts and extends beyond the ends of the screws for a distance
sufficient to receive a collar outside of the handle or lever, so that when
the said handle is turned in a direction opposite to that which forces the
discs together it will cause the screws to be turned in an opposite
direction, and thus draw the discs apart preparatory to receiving another
bolt to be threaded.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Robert Lake in the Great Seal Patent
Office on the 16th November 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the "International Patent Office," of No. 8,
Southampton Buildings, Chancery Lane, Consulting Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of May, in the
year of our Lord One thousand eight hundred and sixty-nine, in the
thirty-second year of Iler reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said William Robert Lake,
Her special licence that I, the said William Robert Lake, my
executors, administrators, and assigns, or such others as I, the said
William Robert Lake, 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 mako, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "IMPROVEMENTS IN MACHINERY FOR FORMING THE
THREADS OF METAL SCREWS," upon the condition (amongst others) that I,
the said William Robert Lake, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the

page_text: said Invention, and in what manner the same was to be performed,
and cause the same to bo filed in the Great Seal 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 Robert Lake, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying
Drawing forming a part of this Specification:-
My Invention relates to machines for forming screw threads upon
bolts or metallic bars of any kind adapted to the purpose, and consists
in forming such threads by compression between plates having concentric
projections upon their faces, set at an angle to one another and revolving
upon axes in different planes.
DESCRIPTION OF THE DRAWING.
Figure 1 is a plan of the top of the said machine; Figure 2 is a vertical
longitudinal section of the same; Figure 3 is a perspective view thereof;
Figure 4 illustrates a detached portion of the said Invention. Like
letters in all of the Figures refer to corresponding parts.
A, represents the frame of the machine, which may be constructed as
shewn or in any other suitable manner, it being provided with suitable
boxes for the reception of the shafts of the driving gearing, and with
proper receptacles for the screw-forming discs or cups, and for the wheels;
and it may also be provided with a reservoir for water as shewn in
Figure 3, so that the screw-forming discs may enter such water as they
rotate. B, B', represent the shafts to which are to be secured the larger
gear wheels C, C, and the screw-forming discs or cups F, F. These
shafts are fitted to and revolve in the boxes b and 6', formed in or secured
to the frame A at an angle to each other as clearly shewn in Figure 1.
The arrangement of these shafts and the screw-forming discs or cups
which are secured thereto is such that when the bolt or bar upon which the
thread is to be formed is placed in the guide G provided for the purpose
the axis of one of such shafts will be above the axis of the said bolt or bar,
while the axis of the other or opposite shaft will be as much below said
axial line of the bolt. C, C', represent gear wheels which are to be secured

page_text: to the said shafts B, B', for the purpose of communicating motion to
the same; D, D', represent pinions which in the present case are secured
to shafts which are mounted in bearings c, c', formed in the under side of
the frame A, as shown in Figures 2 & 3. These pinions mesh with and
rotate the wheels C, C', as clearly shewn in Figure 2; E, E', represent
pulleys which are to be secured to the outer ends of the shafts upon
which the pinions D, D', are secured. On these pulleys the belts aro
placed which are to drive the machine. Figure 3 shows how theso
machines may be arranged upon a table or frame and driven by belts
passing down at the ends of the table to a shaft below. When both of
the pulleys are driven from one driving shaft it will be necessary to cross
one of the belis, as it is necessary that one of the discs or cups which
form the threads should rotate in one direction and the other in the
opposite direction. F, F, are the thread-forming discs or cups which
are to be secured to the shafts B, B'. These discs may be constructed
in the form of plates having a hole for securing them to the shafts, and
an overhanging or projecting flange upon their edges for the reception
of the concentric grooves which alternate with the concentric projections
thereon for the purpose of forming the screw, or they may be made in the
form of semispheres, or as shown in the Drawing, and have the grooves
and projections formed upon their outer edges. These discs or cups
being attached to the shafts B, B', it follows that the effects above
described as resulting from the arrangements of such shafts in connection
with these discs will be produced while the revolution of the discs arranged
as set forth would cause a forward feed to the bar placed between them,
this motion would be irregular, but when the projections from the faces
have taken hold of the bar and compressed the thread, the concentric
projections succeeding the first one, bearing against the sides of the
thread will serve to control the movement of the bolt and cause it
to be fed regularly forward so as to form a thread of an uniform pitch.
G represents the guide for the rod or bolt upon which the screw is to
be formed. It consists of a thin piece of metal which may be of the
form shown in the Drawing, and have a slot through its centre of the
width of the diameter of the bolt to be threaded. Upon each end of this
flat turned and slotted guide there is to be formed a tubular projection,
it being fixed in place by boxes formed in or secured to frame A.
Through these hollow journals the rod or bolt to bo threaded passes as
shown in Figure 3. The socket G₁ of the guide has cut on its inner face

page_text: the thread of a female screw of the same pitch as that to be cut on the
rod or bolt. This screw when it receives the thread on the bolt serves to
control the movement of the latter, a function which becomes essential
when in cutting taper pointed bolts, the innermost of the concentric
projections on the disc F cease to bear upon the thread which is being
formed. As the thread is raised in part above the original surface of the
rod or bolt the latter will pass through the guide, and the threads only
will engage those of the female screw. In order that the outermost of
the concentric projections may act upon the rod the edge of the disc
should be beviled. When it is desired to form the threads of a given
length upon a number of bolts or rods, a gauge rod may be inserted into
one of the hollow journals of the guide G. The rod or bolt to be
threaded is to be passed through the opposite journal and pushed forwards
until its inner end comes in contact with such gauge rod, when the
machine is to be put in motion, as a consequence of which the bolt will
be threaded from the point where the discs come in contact with it to its
end. This gauge rod may be set so as to allow a thread of any desired
length to be formed, and may be held in the desired position by means
of a set screw.
H represents a handle or lever which is attached to the screws K, K',
the latter being for a purpose herein-after described. This handle or
lever is to be formed with an aperture in cach of its ends to receive the
ends of the screws K, K', and is so formed as to extend from one end of
the machine to the other as shown in Figure 3, and it may be furnished
with a guide K' on which to move and by which it may be held in any
desired position. The said screws are hollow and which pass throughpro-
jections formed upon the boxes 6', in which the shafts B and B' rotate.
These screws bear against the ends of the shafts as shown in Figure 2
and are actuated by the handle or lever H to force the thread-forming
discs or cups nearer together, so that when they commence to act upon
the bolt or rod to form the thread thereon only a slight indentation will
be made, but so that they may be forced together gradually until they
shall penetrate the bolt a sufficient distance to form a perfect thread.
Through each of these screws a rod passes which is to be secured to the
shafts B, B, and is to extend beyond the ends of screws K, K³, for a
distance sufficient to receive a collar upon that portion which is outside
of the handle or lever, so that when said handle is turned in a direction

page_text: opposite to that which forces the dises together, it will cause the screws
to be turned in an opposite direction, and thus draw the discs apart. prc-
paratory to receiving another bolt to be threaded. Various arrangements
of belts may be adopted for driving these machines.
The operation of my improved screw-forming machine is as follows:-
The parts having been constructed and arranged as shown in Figure 3
the lever or handle H being in the position shown the bolt or rod is to
be inserted into the guide G and between the edges of the discs or
cups F, F, the machine is then put in motion through the above
described devices for that purpose, when the handle is to be turned to
the proper direction as far as may be found necessary to cause the discs
to approach near enough to each other to form the thread upon the bolt.
As a consequence of the above arrangement of the discs or cups which
form the threads, they will so soon as they come in contact with the bolt
or rod to be threaded cause the same to rotate within the guide, and a
scrow thread corresponding to the form and pitch of the depressions and
projections will be formed into which the projections nearer the inner
edge of the discs will enter and thus cause the required longitudinal
movement of the bolt or rod.
Having thus fully described the said Invention as communicated to
me by my foreign correspondent, and shewn how the same may be con-
veniently and advantageously carried into practice, I claim,-
First. An improved screw-forming machine constructed substantially
ns herein described, in which the spiral thread is formed upon a bar or
rod by the compression of two discs or cups cach having on its face con-
centric projections and grooves, the edges of said projections being on
each disc on the same plane, and the faces of said discs being set at an
angle to each other. And the said discs revolving in opposite directions
upon axes in different vertical and horizontal planes equidistant above
and below the axis of the rod or bar subjected to their action, sub-
stantially as set forth.
Second. In combination with the screw-threading discs F, F', con-
structed and arranged to operate substantially as set forth, I claim the
guide G having an internal thread at G', substantially as and for the
purpose set forth.
Third. The combination of the screw-threading disks, the tubular guide

page_text: and the adjustable rod placed in the latter for regulating the length of
the thread to be cut, substantially as set forth.
In witness whereof, I, the said William Robert Lake, have here-
unto set my hand and seal, this Sixteenth day of November,
in the year of our Lord One thousand eight hundred and sixty-
ninc.
WILLIAM ROBERT LAKE. (L.S.)