Improvements in Stitch-separating and Indenting Mechanism for Sewing Machines used in the Manufacture of Boots and Shoes.
Year: 1899

page_text: Date of Application, 27th Oct., 1899-Accepted, 16th Dec., 1899
[Communicated from abroad by FRANK WESTON WHITCHER, Merchant, and
HEBER CUSHING PETERS, Mechanical Engineer, both of Boston, County of
Suffolk, State of Massachusetts, United States of America.]
Improvements in Stitch-separating and Indenting Mechanism for
Sewing Machines used in the Manufacture of Boots and Shoes.
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:-
My invention has relation to the devices which are employed in certain kinds
of stitching and sewing machines for automatically separating, dividing or prick-
ing up, the stitches of the seams produced in such machines, and in some cases
indenting the work adjacent to the line of stitches simultaneously with the
operation of separating etc., the latter, the tool that effects the separating being
constructed suitably to effect the indenting as well. For convenience, the terms
stitch-separating mechanism," stitch-separating devices," and "stitch-separat-
ing tool," are employed hereinafter in the description and claims, but it is to be
understood that by such terms I intend equally either mechanism, devices, and a
tool which either only separate the stitches, or both separate the stitches and
indent the work.
" **
The general aim of the invention is to provide a stitch-separating mechanism
which shall act to transmit motion positively from a part of the actuating con-
nections for the thread-inserting tool or needle to the stitch-separating tool,
thereby ensuring that the latter shall act efficiently at every stroke, and enter
fully into the stock that is being operated on, regardless of variations in the hard-
ness or penetrability of the latter, as well as ensuring that the stitch-separating
tool shall act with great rapidity and force in penetrating the work. A further
aim of the invention is to enable the required action of the stitch-separating tool,
when required, to occur after the thread-inserting tool has completed the insertion
of the thread into the work, thereby obviating any excessive strain upon the said
actuating connections for the thread-inserting tool or needle, and providing that
there shall be no material increase in the rate of wear thereof.
The invention will first be described with reference to the accompanying draw-
ings wherein is shown an embodiment of the said invention in connection with
the head and a portion of the working mechanism of a fair-stitch machine operat-
ing to form its stitches by punching a series of loops of thread into the upper
surface of the work that is being operated on.
In the drawings, Fig. 1 is an end elevation of the parts of the machine which
is referred to just above. Fig. 2 is a side elevation of the same, viewed from the
left in Fig. 1.
Having reference to the drawings,
1 designates an awl 2 an awl-bar and 3 a swinging portion of the machine.

page_text: head. In the said swinging portion 3 the said awl-bar is received in bearings,
through which latter it is free to slide endwise, it being operated as heretofore or
in any preferred manner.
8 designates a bolt by means of which an upward extension 31 of the said
swinging portion of the head is connected pivotally with an upward extension 9
of the fixed portion 10 of the said head. In practice, the said swinging portion 3
is moved about its pivot at S in well-known manner in occasioning the lateral
movements of the awl, by which movements the work is fed through the machine.
11 designates the thread-inserting tool, and 12 the carrier-bar therefor, the
said carrier-bar 12 also being mounted to slide vertically in bearings in the said
swinging portion 3 of the head, and usually being operated in practice by means
of the link 121 connecting the same with the crank-pin 122 on the forward end
of the shaft G, the latter being indicated in dotted lines.
13 designates the presser-foot and 14 the presser-bar, the last being mounted to
slide vertically through bearings in the fixed part 10 of the head, and being pro-
vided at its upper extremity with stops herein shown adjustable on the said
presser-bar and constituted by nuts 15, 15. The upper end of the carrier-bar 12
for the thread-inserting tool is provided with a projection 16, which extends
underneath the lower nut 15 and makes contact therewith in the ascent of the
carrier-bar 12 thereby lifting the presser-bar and raising the presserlfoot from
the surface of the work. 141 designates the spring that depresses the presser-
bar and presser-foot.
All of the foregoing parts may be constructed as preferred.
17 designates the tool that is employed for the purpose of stitch-separating or
stitch-separating and indenting. Its working extremity is sharpened to an
edge, and in other respects is shaped to engage properly with the work between
the stitches, as shown most clearly in Fig. 1. The said tool 17 forms part of or is
attached to a stock or carrier 18, the latter herein being shown located at the
lower end of a stem 19. The upper reduced portion of the said stem is fitted to a
bearing in a fixed part 10 of the head, and projects somewhat at its free end above
the lower portion of the said part of the head, it receiving on its projecting upper
end a spiral spring 20. The spring is compressed between the head and a nut
or collar 21 on the said stem, whereby the tendency of the spring to expand
holds the stem 19, the stock or carrier 18 and the tool 17 normally upraised
from the work, the limit of the ascent thereof being determined by contact of the
said stock or carrier with the enlarged upper part 131 of the shank or stock of the
presser-foot 13. The working extremity of the tool 17 is extended forward and
downward into close proximity to the point at which the thread is driven into the
work by means of the thread-inserting tool 11.
23 is the bolt by means of which the tool 17 is held to the stock or carrier 18,
the threaded end of the said bolt entering a tapped hole in the said tool, and the
head 24 of the bolt being at the opposite side of the stock or carrier 18 from
the tool 17. When the bolt is turned up tightly the tool is clamped securely
against one side of the stock or carrier 18. The tool is held from slipping or
turning upon the stock or carrier in a vertical plane after having been set in
proper position thereon by being provided with a horizontal rib 231 entering
between ribs on the contiguous face of the stock or carrier. The said ribs form
slide-ways lying parallel with the slot 22 and consequently not interfering with
the adjustment of the bolt 23 in the said slot, shown in dotted lines.
The stitch-separating tool is guided in its vertical movements between the
adjacent flat side of the presser-foot and the flat under-side of the large head of
a screw 25 applied to the upper part or stock of the presser-foot, the said head
being sufficient in diameter to overlap the face of the said tool even in the lower-
most position of the latter. In the embodiment of the invention which is now
being described, the stitch-separating tool is confined to movement in a given
vertical plane and moves in a direct path toward and from the surface of the
work.

page_text: As will be apparent, the spring 20 acts to hold the tool 17 in an upraised
position above the upper surface of the work, and to lift the same after it has been
for down into the work by the depressing means about to be described.
One of the important characteristics of the said depressing means is the fact
that its action upon the stitch-separating tool is positive, and that it acts to
drive the working end of the said tool positively into the work. Thereby is
secured an efficient action of the tool, it being caused at every stroke toward the
work to enter fully into the stock that is being operated upon, regardless of
variations in the hardness and penetrability of the said stock. Whether the
stock is hard or soft the tool is driven into the stock to the same extent and
there are no differences in this respect due to differences or variations in the
hardness.
Another of the characteristics of the said depressing means is the fact that it
embraces a tappet, or the like, which is connected with part of the stitch-forming
devices of the sewing machine, the said tappet acting to drive the working end
of the tool positively into the work.
Another of the said characteristics is the fact that the depressing means for the
tool communicates a percussive blow to the tool, whereby to act with greater
certainty in causing the working end of the tool to enter the work to the required
extent. The said percussive blow is by preference secured by providing for lost
motion or play between certain of the members of the depressing means, allowing
the tool and a part of the train of connections to remain at rest until suddenly
started into motion by the impact of another part of the said train in full motion.
Preferably, though not in all cases necessarily, these characteristics are all
embodied in one mechanism.
In the drawings the arrangement shown is one in which the motion is taken
from the lower end of the link 121 which transmits movement to the carrier-
har 12 from the crank-pin 122 on the operating shaft 6.
The said lower end of
link 121 constitutes in this case the tappet aforesaid. Into the path of the said
lower end of the link 121 projects an arm 26, one end of which is sleeved loosely
upon a shaft 28, the said arm having a projection, herein constituted by a
screw 29, to engage with the upper end of the stem 19 of the stock or carrier 18
for the tool 17. The said screw 29 is fitted to a tapped hole in a portion of the
arm 26 and is adjustable vertically with respect to the said arm in order to enable
the extent to which the tool 17 is forced into the work to be varied as required.
30 designates a lock-nut or jam-nut on screw 29 for preventing loss of adjust-
ment. The said screw serves as an adjustable contact-piece for transmitting
the pressure of the arm to the stem 19. The weight of the arm 26 is sustained by
means of a spring 311 so as to relieve the spring 20 of such weight, the latter
spring being located so close to the shaft 28 that if it had to bear the entire
weight of arm 26 in addition to performing its other work, its stiffness and size
would be disadvantageous in the position in which it is placed. Normally, the
lower end of the contact-piece 29 is separated from the upper end of the stem 19
by a space as is shown in the drawings. The lower end of the link 121, when it
makes contact with the arm 26, strikes the latter downward, and the said arm
transmits to the stem 19 through the adjustable contact-piece constituted by
the screw 29, the sudden force which drives the working end of the tool 17 into
the work. The percussive blow that is transmitted through the tool may be
derived either from the striking of the lower end of link 121 upon arm 26, or
from the striking of contact-piece 29 upon the upper end of the stem 19, prefer-
ably the latter. 32 designates a stop by means of which the rise of the actuating
arm 26 under the action of the spring 11 is limited.
When it is desired that the action of the stitch-separating tool shall not occur
until after the completion of the thread-inserting movement of the thread-inserting
tool, the link 121 is provided with a projection 144 at the outer side of its lower
extremity, the right-hand side in Fig. 1, and the arm 26 is provided with a
co-acting shoulder or sloping portion 145 on its upper surface, whereby the

page_text: contact of the said parts does not take place until at or shortly after the moment
when the link 121 has drawn down the carrier-bar 12 to the lowest point in its
stroke, and hence until the thread-inserting tool of the machine has begun or
is about to begin its retraction or rise. Thereafter, during such rise, the con-
tinued movement of the link 121 causes the projection 144 to ride over the
shoulder 145, thereby depressing the movable arm 26 and driving the stitch-
separating tool into the work. Such depression has the percussive quality already
adverted to. It is to be observed that, in practice, either the projection 144 or
the shoulder 145 may be decreased in degree, the other of such parts being corre-
spondingly increased in degree, and in some cases it might be possible to entirely
dispense with one of such parts, the other being sufficiently increased in degree
to produce the necessary amount of depression of the arm 26 at the proper
moment. In practice, however, I prefer to retain both elements in about an
equal degree as I find that a superior result is obtained thereby.
The effect thus produced is the actuation of the stitch-separating tool after the
completion of the descent of the thread-inserting tool or during the retraction
of the latter, but without the interposition of any levers or other additional parts,
the peculiar positive and percussive quality of such actuation being preserved.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, as communicated to
me by my foreign correspondents, I declare that what I claim is:-
1. Devices arranged substantially as set forth to actuate both the thread-
inserter and the stitch-separating tool from the rotating crank.
2. The herein-described stitch-separating devices substantially as set forth.
3. The arrangement by which the stitch-separating devices are actuated from
the crank and link substantially as set forth.
4. Devices acting substantially as described to drive the stitch-separating tool
directly into the work by a percussive blow.
Dated this 27th day of October 1899.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.