Improvements relating to the Manufacture of Screws and to Apparatus therefor..
Year: 1887

page_text: Improvements relating to the Manufacture of Screws and to
Apparatus therefor..
I, HORACE KIMBALL JONES, of 35 Spring Street, Hartford, Connecticut, United
States of America, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to screws upon which the threads are produced by means of
rollers, three of which are usually employed and between the peripheries of which the
rod or wire whereon the screw-thread is to be formed is rotated.
My said invention is more especially applicable to screws of this kind or class
provided with ratchet-threads, that is to say, with screw-threads having one side thereof
inclined relatively to the axis of the screw and the other side perpendicular to
said axis.
The rollers heretofore employed in the manufacture of screws of the kind or class
above mentioned, are so made that the periphery or working edge of each roller
corresponds in shape or configuration to the groove which it is desired to form in
the screw-blank. For instance, for producing the aforesaid ratchet-threads, the
periphery or working edge of the roller has one side thereof inclined to the axis
of the roller and the other side thereof perpendicular to the said axis. The screw-
threads formed by means of rollers made in this manner are always defective; and it
has heretofore been found impracticable to roll a properly shaped screw-thread of the
kind above mentioned.
Now I have discovered that the defect in these screws as heretofore made is due to
the deformation of one side of each convolution of the groove by the pressure of
the rollers in the operation of rolling the succeeding convolution thereof, that is to
say, by the flow or bending of the unsupported metal away from the inclined side
of the roller.
I have, therefore, devised a novel method of producing the said screw-threads by
forming each convolution of the groove in the blank with its sides at a greater angle
to each other than that required in the finished screw-thread, and then causing the

page_text: metal to flow, during the rolling of the succeeding convolution of the groove, suffi-
ciently to impart the desired shape or configuration to the screw-thread. For this
purpose, in making screws with the aforesaid ratchet-threads, I employ rollers the
peripheries or working edges of which are inclined on both sides, so that each convo-
lution of the groove formed in the screw-blank will have both sides thereof inclined,
but, in the operation of rolling the succeeding convolution of the said groove, the
pressure of the rollers will cause the flow of the metal in such a manner as to cause
one of the said sides of the preceding convolution of the groove, viz. that nearest
the pointed end of the screw, to assume a position perpendicular to the axis of the
screw.
When the side of the groove nearest the point of the screw is, in the first part of
the operation, made inclined as above described, considerable resistance is offered to
the pressure of the rollers in the second part of the operation, thus ensuring the flow
of the metal in such a manner that, when the screw-thread is completed, it will have
the proper shape or configuration, and will have a sharp edge.
I am thus enabled to form screw-threads free from the defects herein before
referred to.
בד
1
1007
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements relating to the Manufacture of Screws and to
Apparatus therefor.
I, HORACE KIMBALL JONES, of 35 Spring Street, Hartford, 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 :-
My invention relates to screws the threads of which are produced by forming a
spiral or helical groove in the screw-blank by means of rollers subjected to pressure
and thus forcing outward the metal between the convolutions of the said groove.
My said invention is more especially applicable to screws of the kind or class
provided with a ratchet-thread, that is to say, with a screw-thread having one side
thereof inclined relatively to the axis of the screw and the other side perpendicular to
the said axis. Screws of this kind, as produced by the rollers hitherto used for the
purpose, have always had defective screw-threads and it has heretofore been found
impracticable, for the reason hereinafter explained, to roll such screw-threads with
sharp edges.
Now the object of my invention is to provide for the production of perfect ratchet-
screw-threads. I accomplish this result by a novel method of forming the said screw-
threads by means of rollers with peculiarly shaped peripheries or working edges as
hereinafter described.
The rollers hitherto employed in the manufacture of screws with ratchet-threads are
so made that the periphery or working edge of each roller corresponds in shape in
transverse section to the groove which it is desired to form in the screw-blank.
In the accompanying drawing,
Figure 1 is an edge view of part of a roller as heretofore made for producing
ratchet-screw-threads, showing in section a part of a screw-blank in which one con-
volution of the groove has been formed.
Figure 2 is a similar view showing the shape of the screw-thread after the roller
bas formed the succeeding convolution of the groove.
Figure 3 shows in longitudinal central section part of a finished screw.
Figure 4 is an edge view of part of a roller made in accordance with any present
invention, showing in section a part of a screw-blank in which one convolution of the
groove has been formed by the said roller.
Figures 5, 6 and 7 are similar views illustrating different steps or stages in the
manufacture of a screw according to my said invention.
Figure 8 shows in longitudinal central section part of my improved screw, and
Figure 9 is a side elevation of the said screw partly in longitudinal central
section.
All the Figures, with the exception of Figure 9, are drawn to a greatly enlarged
scale.
a is the roller, 6 the screw-blank.

page_text: Referring to Figures 1, 2, and 3, it will be seen that the periphery or working
edge a¹ of the roller a has the side a inclined to its axis and the other side a per-
pendicular to the said axis.
I have discovered that, in the production of screw-threads by means of rollers made
in this manner, although each convolution of the groove, when first formed, has the
same shape in transverse section as the working edge of the roller, as shown in Figure 1,
the pressure of the rollers, in forming the succeeding convolution of the groove,
causes the deformation or displacement of the side c of the groove, that is to say,
the unsupported metal of the screw-thread is bent or caused to flow away from the
inclined side a of the roller a; the angle formed by the two sides of the groovo is
thus reduced so that the screw-thread has the form shown in Figure 3, the side c of
the groove being at an angle of less than ninety degrees to the axis of the screw, and
the edge of the thread being blunted or flattened.
I have, therefore, devised a novel method of producing the said screw-threads by
forining each convolution of the groove in the blank with its sides at a greater angle
to each other than that required in the finished screw-thread as shown for instance in
Figure 4, and then causing the metal to flow (during the rolling of the succeeding
convolution of the groove) sufficiently to impart the desired ratchet shape or con-
figuration to the screw-thread. For this purpose I make the sides a³ as well as the
sides a² of the working edges a¹ of the rollers a inclined to the axis of the roller
as shown in Figures 4, 5, 6 and 7, so that each convolution of the groove, when first
formed, will have both sides thereof inclined as shown in Figure 4, but, in the
operation of rolling the succeeding convolution of the said groove, the pressure of the
rollers will cause the flow of the metal in such a manner as to cause the side c of
the groove to gradually assume a position perpendicular to the axis of the screw, as
indicated in Figures 5, 6 and 7.
The side c of the groove being (in the rolling of one convolution thereof) made
inclined as above described, considerable resistance is offered to the pressure of the
rollers in rolling the succeeding convolution of the said groove, thus ensuring the
flow of the metal in such a manner that, when the screw-thread is completed, it will
have the proper shape or configuration, with a sharp edge, as shown at d in Figures 7, 8
and 9. I thus produce a finished-screw having a ratchet-thread,.as shown in Figure 9,
free from the defects hereinbefore referred to.
The head and point of my improved screw are made in the usual or other suitable
manner.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed 1 wish it understood
that I claim :-
First. The improved method of producing a screw-thread upon a rod or wire,
consisting in forming therein by pressure a spiral or helical groove having its sides at
a greater angle to each other than that required in the finished screw, and then causing
the metal to flow in such a manner that the said groove and the screw-thread will
assume the desired shape or configuration, substantially as set forth.
Second. A roller for the purpose above specified, the periphery or working edge of
which is inclined on both sides, as above set forth.
Third. A screw formed with a ratchet-thread in the manner hereinbefore
described.
Tate this and dose of T... 1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.