An Improved Method of Making Split Needles.
Year: 1896

page_text: Date of Application, 29th Sept., 1896-Accepted, 20th Mar., 1897
[Communicated from abroad by HELEN AUGUSTA BLANCHARD, of the
Buckingham Hotel, Fifth Avenue and Fiftieth Street, New York,
United States of America, Inventor.]
An Improved Method of Making Split Needles.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, 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 that class of needles in which the body of the needle is
longitudinally divided throughout a portion of its length, one of the divisions being
a thin and narrow spring separated from the main part of the needle at a distance
from the point thereof, so that a thread may be inserted into the slot between the
divisions and moved down into the eye of the needle. Heretofore the narrower
division or spring has either been made in a separate piece and soldered or otherwise
secured to the main body of the needle, or has been formed by cutting a slot in the
body of the needle after the formation of the eye. The first-named construction is
objectionable in that it is difficult and expensive, and further in that it is difficult
to provide a needle with a smooth surface at the point where the spring is united
to the body of the needle, near the point thereof. The second method above
alluded to has not been successful, because of the difficulty experienced in cutting
a slot in the body of a cylindrical needle and giving the proper proportions to the
spring and the main body of the needle, the metal removed in forming the slot
necessitating the formation of a very attenuated spring, which is liable to be
irregular in thickness and generally undesirable. My invention has for its object
to enable a desirable and practical needle of this class to be made, by cutting a
slot in the body of the needle, thus making the spring integral with the needle and
avoiding a rough surface at the junction of the spring and needle.
The invention also has for its object to provide an improved construction of a
split needle, particularly with respect to the guard which is attached to the shank
of the needle and projects over the free end of the spring.
To these ends, my invention consists in the improvements which I will now proceed
to describe and claim.
Of the accompanying drawings, forming a part of this specification,-
Figure 1 represents a side view of the incipient needle, in an early stage of its
manufacture.
Figure 2 represents a section on line 2-2 of Figure 1.
Figure 3 represents a view showing the form produced by the next step in the
method of making the needle.
Figure 4 represents a section on line 4-4 of Figure 3.
Figure 5 represents a view of the incipient needle shown in Figure 3, taken from
a different point.
Figure 6 represents a section on line 6-6 of Figure 5.
Figure 7 represents a view similar to Figure 3, showing a slot cut in the body
of the needle.

page_text: Figure 8 represents a section on line 8-8 of Figure 7, showing the same to two
scales, the lower view being to the same scale as Figure 7.
Figure 9 represents a side view, showing the needle reduced to a cylindrical
form.
Figure 10 represents a section on line 10-10 of Figure 9, showing the same to
two scales, the lower view being to the same scale as Figure 9.
Figure 11 represents a view showing the needle provided with an eye, and the
upper portion of the spring cut away.
Figures 12 and 14 represent side views, showing the completed needle.
Figure 13 represents a section on line 13-13 of Figure 12, showing the same
to two scales, the lower view being to the same scale as Figure 12.
Figure 13 represents a section on line 13-13 of Figure 12, showing the
same to two scales, the lower view being to the same scale as Fig. 12.
Figure 15 represents a section on line 15-15 of Figure 14.
Figure 16 represents a side view of the guard, before its application to the
needle, and
Figure 17 is an end view of the said guard.
The same letters of reference indicate the same parts in all the figures.
In carrying out the invention, I first form a cylindrical needle blank, the body
portion a of which is of greater diameter than the body portion of the completed
needle, the said body portion having therefore an excess of material over that
required or desirable in the finished needle. I then compress the body portion a in
such manner as to form two flat sides or faces a' a' thereon, as shown in Figures 3,
4, 5, 7, and 8, this operation displacing portions of the metal and making the body
oblong in cross-section. This compression takes place while the metal is comparatively
soft, or in other words, while it is soft enough to permit of the body being readily
flattened by compression.
I then cut a longitudinal slot a² in the flattened body portion, said slot being
nearer one edge than the other, as shown in Figures 7 and 8, so that the portion a³
of the body left at one side of the slot is considerably narrower than the portion a
left at the other side, the narrower portion constituting the spring above mentioned.
After cutting the slot a², I subject the needle body to the action of dies, or by
other suitable means reduce the body to a cylindrical form, as shown in Figures 9
and 10. The removal of metal involved by the formation of the slot a² causes a
considerable reduction of the diameter of the needle body, as compared with that
of the blank shown in Figure 1, the body being thus reduced to the diameter desired
for the finished needle. The reduction of the needle body to cylindrical form brings
together the sides of the slot, and leaves the needle in substantially the same form as
an ordinary solid needle, the only difference being that the needle is longitudinally
divided from a point near its penetrating end to a point at or near the base of its
shank. The pressure necessary to return the body to cylindrical form and close
the sides of the slot partially hardens it, and places it in better condition for final
tempering.
The spring may now be completed by cutting away the upper portion of the
narrower division of the needle body, as shown in Figure 11, thus forming a free
end or tongue as, which is preferably slightly bent or curved outwardly to facilitate
the introduction of the thread into the slot. I prefer to cut out some of the
material of the body of the needle, at the point where the spring is cut through,
thus forming a recess to facilitate the insertion of the thread, The eye c is
formed in the needle at one side of the spring, the eye being so arranged that it
opens into the slot between the main body of the needle and the spring.
For sewing-machine use, the needle is or may be provided with the usual
longitudinal groove c¹ (Figures 11, 12, and 13) extending from the eye c and below
it to the upper portion of the needle body.
d represents a guard, which is a small metal plate, preferably of oval form
and concavo-convex in cross-section, said guard being provided with an elongated
stem d'. The sbank of the needle is provided with a longitudinal slot (Figures

page_text: and 6) formed to receive and closely fit the stem d', so that when said stem is
inserted in the slot it may be securely fastened to the needle by exerting pressure
upon the shank in such manner as to crowd the sides of the slot e inward against
the stem d. The elongated form of the stem d' giving it an extended bearing on
the shank of the needle, enables the guard to be very securely attached by the
described compression of the slot e. The guard projects below the free end of the
spring, as shown in Figures 12, 14, and 15, and is arranged so that the thread can
be readily slipped between it and the free end of the spring in an upward direction,
the thread then entering the recess b¹, from which it can be readily moved down-
wardly through the slot into the eye c.
It will be seen that by making the needle blank larger than the size required
for the finished needle, I am enabled to readily form a longitudinal slot in the
needle body in such manner as to make a practical and effective spring of uniform
width, without the difficulty that would attend the operation of slotting the body
if the latter were reduced to the diameter required for the completed needle before
the slotting operation. It will also be seen that by flattening the blauk to give it
oblong form in cross-section before cutting the slot, I greatly facilitate the slotting
operation, because the rotary saws which I use in cutting the slot can much more
readily enter flat surfaces than cylindrical ones; and secondly, because said saws
do not encounter as much metal in cutting through from one flat side to the other
as they would in cutting through a cylindrical body. The reduction of the needle
to a cylindrical form as stated gives the needle practically the same form as
that of an ordinary needle which is not slotted, so that the point of the needle
is as perfect and is adapted to penetrate as readily as that of an ordinary
needle.
I do not limit myself to the described improvements in connection with a sewing-
machine needle, although that is the only form of needle which I have here shown
and described. I desire, however, to apply my improvement to any needle to which
it is adapted to be applied.
In order to make a smooth cut, I run the needle between two saws arranged in
the same plane and having their teeth intermeshing like the teeth of a gear.
It is evident that this will make a perfectly smooth cut, and it is also evident that
if the teeth of the saws do not so intermesh, a burr will be left on the sides of the
needle forming the slot.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
The method of making split needles, which consists in first making a cylindrical
needle-body with an excess of metal diametrically; then, and while the metal is
in a comparatively soft state, partially flattening the body; then cutting a
longitudinal slot therein and thereby removing the surplus metal; and then
compressing the body to partially harden it preparatory to finishing, said
compression giving the body the desired cylindrical diameter and at the same time
closing together the sides of the slot.
Dated this 20th da
1
1000
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.