Improvements in or relating to Book Sewing Machines.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in or relating to Book Sewing Machines.
I, CHARLES WELCH, of 184, Heywood Road, Castleton, Rochdale, in the
County of Lancaster, Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention relates to book sewing machines, and has reference more particu-
larly to machines of the kind or class described in the Specification of prior
British Letters Patent, No. 11,673 of 1895, and the object of the present improve-
ments is to render such machines more certain, reliable, and serviceable than
those previously constructed.
In the machine described in the said specification, means were provided for
adjusting the needles to different distances apart, but such adjustment necessarily
altered their distance from the ends of the thread take-up levers employed for
drawing the stitches tight. Consequently, the stitches were apt to be irregular
on account of the amount of slack there was in the thread if short stitches were
being made.
To overcome this objection, I provide automatic tension devices, which allow
only the proper amount of thread to pass to the needles. The operation of these
devices is controlled by means of forks or pressers adapted to act on the
tension springs, such forks or pressers being carried on a rocking shaft which is
divided in the middle, so that one part can operate independently of the other.
The two parts of the shaft are, however, worked by separate cams, so as to operate
the tension devices in two pairs or sets alternately.
To further facilitate the delivery of the thread to the needles, I also provide
a special arrangement for drawing, from the bobbins, the proper quantity of
thread, instead of leaving this to be done by the mere drag or pull of the threads
themselves.
For this purpose, the threads are led from the bobbins, in a rearward direction,
over a bar arranged lengthwise of the machine. Between this bar and the bobbins,
a second bar is arranged to work up and down, being actuated by suitable cams.
At each depression, the threads are drawn down in loops in sufficient quantity to
serve for the next stitch.
I also provide for giving greater stiffness to the take-up levers, and this I do
by forming them of a single piece, having a forked or branched extremity, so that
one lever will serve the purpose of two in the former machine, and will be more
rigid on account of the absence of all joints except that where the fork is
connected to the main part, which, however, does not tend to weaken it.
In the former machine, a lack of rigidity was found in the feeding table, box,
or carrier on which the work was placed, so that at the moment the needles were

page_text: piercing the paper, the said table was liable to yield slightly thus throwing the
parts out of truth.
To overcome this difficulty I provide a pair of short strong levers actuated by
cams, so that they close up behind a pair of projections at the ends of the feeding
table when in the stitching position, and thus hold the same absolutely rigid.
In the said former machine moreover, a central needle was employed which is
worked first in conjunction with a needle on one side of it, and then with one
on the other side of it. This led to an objectionable crossing of the loops at the
middle of the stitching. To avoid this, I employ two needles arranged close
together and working independently of one another, one serving for the left
hand set of stitches and the other for the right hand set.
Dated this 92nd day of Novamban 1908
I, CHARLES WELCI, of 184, Heywood Road, Castleton, Rochdale, in the
County of Lancaster, 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, reference being had to the
accompanying drawings and to the letters and figures marked thereon, that is to
say:-
This invention relates to book sewing machines and has reference more par-
ticularly to machines of the kind or class described in the Specification of prior
British Letters Patent No. 11673 of 1895, and the object of the present improve-
ments is to render such machines more certain, reliable, and servicable than
those previously constructed.
I have found in practice that machines of this kind are unreliable in their
action and get out of order suddenly, without warning, so that for these reasons
they cannot be worked at a high speed, or be driven by power.
"
One great difficulty has been that the feed table or box" could not be made
sufficiently rigid to properly withstand the thrust of the needles.
Furthermore, no means were provided to compensate for the different positions
of the adjustable needles relatively to the take-up levers for drawing the stitches
tight. Consequently, when short stitches were being made they were very
apt to be irregular on account of the amount of slack in the thread.
"
Now, according to this invention, I construct these machines so that the feed
table or "box is held absolutely rigid while in its closed or working position;
that the tension of the threads is so controlled that the said threads are rendered
tight or slack, automatically as required, during the formation of the stitches;
and also that the take-up levers are specially constructed to secure greater stiff-
ness, and that the delivery of the threads from the spools is effected in a positive
manner instead of depending simply on the pull of the threads themselves.
I furthermore now provide the machine with two central needles instead of
one, as heretofore, so as to avoid twisting or entanglement of the stitches in the
middle of the work.

page_text: A book sewing machine embodying these improvements will be found to do
better work than formerly, besides which, it will work more efficiently and
reliably, even at a high rate of speed, so that it is now quite practicable to drive
it by power which was not possible hitherto, owing to the above mentioned
difficulties.
And in order that my invention may be readily understood, I will describe the
same fully with reference to the annexed drawings, in which:
Figure 1 is a front elevation of a machine constructed according to the inven-
tion.
Figure 2 shews the upper part of the machine in vertical central section;
whilst the lower part is a section on the line A, B, of Figure 1.
Figure 3 shews in detail the tension controlling mechanism.
Figures 4 and 5 are respectively a side elevation and plan of one of the levers
for drawing the stitches tight.
Figures 6 and 7 are respectively a vertical section and plan of the take-off
arrangement for drawing the threads off the bobbins and delivering them to the
needles.
The detail figures, viz. 3 to 8, are drawn to a larger scale than are Figures 1
and 2.
a is the feed table or "box" upon which the sheets or signatures a* to be
sewn are placed, as shewn in Figure 2, and which is operated in the ordinary
manner. At its ends are pins or studs a¹, against which a pair of pressers 6 are
adapted to bear when the table is in its closed position, so as to support it and
enable it better to resist the thrust of the needles.
The pressers are worked by an arm b¹ on a shaft 62 operated by a second arm 63
whose outer end bears on a cam 64 on a shaft b. When the feed table swings
outward, the pressers 6 turn into the position shewn in Figure 2 to allow the
pins or studs a to clear them, and they remain in this position until the table
has returned to its normal position, whereupon they close up behind the pins or
studs so rendering the table absolutely rigid.
c are the tension devices, of which there are four worked from a rocking shaft
formed in two parts d, d, in line with each other and hereinafter referred to as
shafts. Each shaft works two of the tension devices corresponding to the
pair of needles (i, k, or i, k,) that are operating at that moment.
dare short arms or forks on the shafts which, by compressing the springs c¹
of the tension devices, control the pressure between the discs 2. The
regulation of this pressure is effected by the movements of the shafts d, d', each
of which carries an arm d³ connected (see Figure 3) by a rod d with a lever d
on which acts a grooved cam do.
The said cam do is so arranged that the pressure between the discs c³ ceases and
they release the threads during the time the loopers ? require thread, whilst
when the stitches are being tightened up the pressure is again applied and the
discs grip the threads. The pressure is also applied at the time the take-off
arrangement hereinafter described is operating.
e are stays or supports which are provided for the hooked needles e¹, suitable
eyes being formed in the lower ends of these stays for the needles to work through.
The purpose of these stays is to prevent the hooked needles bending and getting
out of truth during the time they are drawing the loops sidewise, as in the
former patent, so as to throw them across the binding cords f which are supplied
from reels f¹ situated above the frame of the machine, as are also the thread
bobbins g.
The thread take-off arrangement comprises a pair of bars h, h¹, the former of
which is fixed to some suitable portion of the framing, say the rails h² carrying
the reels and bobbins, while the latter, viz. h, is carried by a pair of arms h³
which impart to it a rocking motion from a cam *. Each rocking motion of the
bar draws out, (as indicated in dotted lines Fig. 6) the proper length of thread
required to form the stitch. Such thread is thus ready to pass freely to the

page_text: needles when the bar h¹ rises, so relieving the threads of the strain or tension
required to unwind them from the bobbin.
At the time the thread is being drawn off the bobbins, the tension devices
are closed and are holding the threads with their greatest pressure, and this
takes place at the time the hooked needles are descending. The pressure is
however released at the time the other needles are descending, and at this latter
time the take-off bar h¹ is coming back into its original position, so giving ample
slack to the threads and avoiding any strain whatever on the needles which might
tend to pull them out of truth.
i, i, are the two central needles which are employed to avoid the twisting of the
stitches that was apt to occur with a single central needle, as in the former
machine. These needles, like the outside needles k, ¹, are plain, that is they
are not hooked like the intermediate needles e¹. They are arranged to work
independently of each other, but in pairs with the outside needles, the needles i
and forming a pair, and the needles and another pair. They operate
substantially in the same manner as the needles of the former machine, but
instead of both hooked needles receiving a loop from a single central needle by
the action of the loopers 1, each takes its loops from one of the needles i, i,
only.
The construction of the take-up levers by which the stitches are drawn tight,
is shewn more clearly in Figs. 4 and 5. They are arranged to be actuated directly
by their operating cams instead of by means of a system of levers such as shewn
in Fig. 10 of the former patent. Each lever consists of a main part or lever
proper m having a friction roller m' at its upper end for the thread to run freely
over, whilst its other end has a truck m³ engaging in the cam m³. The lever
also carries an arm m forming a forked or branched extremity. This arm
is secured rigidly to the lever at m5 and itself serves also the same purpose as
a lever. By this construction one lever will serve the purpose of two such as
were in the former arrangement, and the looseness and irregularity of working of
the parts in that arrangement are entirely obviated.
In cases where the binding is done by cords f, as shewn, the parts are adjusted
so that the stitches will loop into one another centrally above the cords on which
they lie, but if tapes are used instead of cords, the stitches are carried right over
them from one edge to the other. Moreover, in order to make the various levers
and cams work better at high speeds, I employ cams which are grooved after the
manner of box cams, so as to hold the trucks or rollers on both sides, instead of
edge cams which only act on one side of them.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. A book sewing machine, of the kind referred to, provided with means for
keeping its feed table or box rigid during the thrust of the needles, substantially
as and for the purposes described.
2. In a book sewing machine of the kind referred to, the means for auto-
matically relieving the tension on the threads whilst the loopers are operating,
but gripping them whilst the stitches are being tightened and during the
operation of the take-off arrangement, substantially as described.
3. In a book sewing machine of the kind referred to, the employment of two
independent central needles acting alternately to prevent twisting of the stitches,
and co-operating with the outside needles, substantially as described.
4. In a book sewing machine of the kind referred to, the thread take-off
arrangement for drawing the threads from the bobbins in proper quantities and
relieving them from strain or tension, substantially as described.
5. In a book sewing machine of the kind referred to, the special construction
of forked or branched take-up levers substantially as described with reference to
Figs. 4 and 5 of the drawings, and for the purposes set forth.

page_text: 6. My various improvements in book sewing machines, whether used singly
or in combination, substantially as hereinbefore described and as shewn in the
annexed drawings.
Dotal 17
T
1900
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, London, & 5A, Market Street, Nottingham,
Agent for the Applicant.