Improvements in Book-sewing Machines
Year: 1897

page_text: Date of Application, 6th Oct., 1897-Accepted, 11th Dec., 1897.
COMPLETE SPECIFICATION.
66 Improvements in Book-sewing Machines."
I, ALFRED GERLACH; of 33 Moor Lane London, Engineer and Manufacturer, do
hereby declare the nature of this Invention (which has been communicated to me
fron abroad by Friedrich Rehwoldt of Leipzig-Plagwitz in the Empire of Germany,
Manufacturer) 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 book-sewing machines particularly of the class in or by
which the various packets or bundles of sheets to be sewn (which packets or bundles
are hereinafter termed "signatures") are connected together by a row, or two or
more rows of chain stitches.
Among the special features of the invention may be mentioned the following viz:-
(1). The arrangement of mechanism by which the thread in consecutive signatures
is carried in respectively opposite directions to the right and left of the chain
stitching whereby the swelling caused by the accumulation or superposition of the
different stitches or portions of thread at the back of the book is reduced to a
minimum.
(2) The employment of mechanism for automatically preventing the ends of the
signatures from being moved out of line with each other by the pull or tension on the
thread and
(3) The employment of improved take-up mechanism for tightening the stitch of
each signature last previously sewn.
The invention is not limited to these special features neither is it limited to the
particular class of machine above mentioned as certain parts of it. are applicable to
machines of other construction.
The invention will be best understood by reference to the accompanying Drawings-
in which
t
Figure 1 is an elevation of the left hand side of sufficient of one of the improved
book-sewing machines to illustrate the invention.
Figure 2 is a view similar to Figure 1 with the left hand end-frame or standard
removed.
Figure 3 is a front elevation.
Figure 4 is an elevation looking from the right hand side of the machine.
Figure 5 is a front elevation of the upper part of the machine provided with one
set of sewing devices as distinguished from two sets as shewn in Figure 3.
Figure 6 is a transverse section of part of Figure 5.
Figure 7 is a plan of a portion of Figure 5.
Figures 8 to 23 inclusive are views of detached portions of the machine.
Figures 24 to 40 inclusive are views shewing various stages of the sewing or stitch-
forming operation.
Figures 41 and 42 are views shewing two different ways of sewing according to this
Invention and

page_text: Figures 43, 44, 45 and 46 are views illustrating a modification of certain parts of
the machine represented in Figures 1, 2, 3 and 4.
Like letters of reference indicate like or corresponding parts throughout the various
Figures of the drawings.
In a machine constructed as shewn in the drawings the main framing comprises two
vertical frames or standards A A² rigidly connected together by a bridge rail A³ and
also if desired by suitable tie-rods or their equivalent, and supporting a table A*
whereon the work to be sewn may be placed.
In the standards A A² are provided bearings for supporting a main shaft B on the
outer end of which is mounted a driving pulley B2 which may be thrown into and out
of gear with the said shaft by means of a friction clutch B3 Figure 3 actuated by the
operator through the medium of a spring-controlled treadle B4.
On the shaft B are secured two cain discs B5 B each of which is provided with two
cam grooves b b Figure 2, and two cam projections b³ b* or 6' 6" respectively. The
cams or cain grooves b engage with anti-friction rollers c each pivotted on the rear-
ward end of a link or bar c² the forward end of which is pivotted to an arm c³ capable
of rocking on a shaft c' secured in the standards A A². The links c² are slotted near
their rearward ends as shewn in dotted lines in Figures 2 and 4 so as to allow the
main shaft B to pass through them and thereby serve to guide them at these parts.
To the upper ends of the two swinging arms c³ is secured a bar or rail C, hereinafter
termed the saddle bar," on which the signatures are placed during the sewing
operation, and which arms by means of the before mentioned cams are at the
proper times moved outwards or forwards, as indicated by the dotted lines c³ in
Figure 2 to enable the unsewn signatures to be placed on the saddle-bar C, and
inwards or backwards to bring the signatures into the position wherein they are
sewn.
At or near their upper parts the standards, A A2 incline from back to front as shewn
in Figures 1, 2 and 4 and on these parts, in suitable guides, is mounted a frame D
connected by links d and levers d² with the before mentioned cams or cam grooves 62
which engage with anti-friction rollers pivotted on the rearward ends of the
levers 2 by this arrangement the frame D is caused at the proper times to descend
and ascend as hereinafter more particularly described. In some of the Figures for
example Figures 5 to 11 parts which in the actual machine are inclined, are for
convenience represented as vertical. The frame D is provided with suitable guides
for accommodating a bar E which, while participating in all upward and downward
movement of the frame D is also capable of being moved in a horizontal direction
independently of the said frame. This horizontal movement is imparted to it through
a lever E2 pivotted by a pin or fulcrum e, to lugs a, on the standard A, from a cam E³
mounted on a stud a² rigidly secured to the standard A. The cam Es is geared with
the main shaft B by spur wheels e² e the relative diameters of which are such as to
cause the cam E³ to rotate once for every four revolutions of the main shaft B.
connection between the bar E and the lever E2 is such as to admit of it remaining
undisturbed throughout the descent and ascent of the bar, in which movements the
lever E2 does not participate; for this purpose the forward end of the lever E2 may, as
shewn in Figure 7, be forked and engage with a rib or projection extending backwardly
from the adjacent end of the bar E, or the reverse of this last described arrangement
may be employed. To enable the throw or longitudinal travel of the bar E to be
varied for a purpose hereinafter described the lever E2 and lugs a are provided with
two or more holes e as shewn in Figures 1, 3 and 7 to admit of the pin or fulcrum e
being inserted in either of them according to the particular result to be obtained.
The
To the front of the bar E are secured one or more pairs of similar brackets F
hereinafter termed "needle carriers" which are arranged so that they may be moved
to, and secured in any desired position on the bar E. Between each pair of needle
carriers F is a hook carrier G which is fastened on the frame D. In the lower ends
of the needle carriers Fare secured sewing needles ff2 and from their upper ends
extend arins pivotted to the rearward ends of levers f the forward ends of which
are forked and pivot upon a rod a³ supported by brackets A secured to main framing

page_text: of the machine. Each of the levers fis provided with a number of holes through
either of which the thread is passed according to the degree of tension desired to be
put upon the said thread.
In each of the arms as shewn most clearly in Figures 8, 9 and 10 is pivotted a
short spindle f having secured on one end a toothed wheel or disc f and the other
end of which is encircled by a helical spring. One end of the spring is rigidly
secured to the spindle fo and the other end thereof projects forward and constitutes.a
spring arm which terininates in an eye f10; and which arm, when in its norinal
position, bears upon a pin f" projecting sidewise from the bracket arın f³. Above
the toothed wheels or discs fare provided pins or bolts 12 capable of being raised
and lowered in lugs f³ projecting sidewise from the bracket arms f³ and the lower
ends of these pins or bolts fare adapted to engage with the wheels or discs f" so as
to lock thein in any desired position, by which means the tension of the springs and
consequently the tension exerted by the spring arins f; f¹ on the thread, may be
varied to suit different requirements.
Within the before mentioned bearing G as shewn most clearly in Figures 9 and 11
is journalled a vertical spindle g in the lower end of which is secured a hook y² of
substantially the shape shewn in Figures 30, 31, 32 and 34. On the upper end of
the spindle g is secured a spur wheel which gears with a rack gt adapted to slide in
the direction of its length in the before described rising and falling frame D. The
longitudinal motion of the rack g is derived from the before described cam projec-
tions b³ 64 which respectively operate on anti-friction tollers gs go the cam projection bs
and the roller g on which it operates being situated in a plane differing from that in
which are situated the other cain projection band roller go as most clearly shewn in
Figure 3. The rollers are pivotted to two arms of a three-armed lever G²
connected by a link g
pivotted to the standard A2, and the third arm of this lever
to an arm of a bell-crank lever g g the other arın g of which is slotted or forked
to engage with a block or anti-friction rollér g10 pivotted to the rack g¹; the lever
arm is slotted or forked to allow of the descent and ascent of the block or roller g10
when the frame D is lowered and raised, in which inotion the bell-crank lever g³ g",
being pivotted to the standard A²; does not participate. The cam projections 63 64
and the levers G² and y³ ³ are of such shape and size as, when operated, to cause the
spindle and hook g² to be turned through an angle of 180° first in one direction
and then in the opposite direction, one of the carii projections serving to turn the
front of the hook g² towards the back of the inachine and the other to turn it back so
as again to face towards the front of the machine.
On the before mentioned bridge rail A³ is secured a bar H in or, to which are
secured as many vertical pins H' as there are sewing needles employed in the
machine, thus in Figure 5, where two sewing needles are represented, there are pro-
vided two of the pins H2, only portions of which are shewn in this Figure, and in
Figure 3, where four sewing needles are shewn, there are provided four of the
pins H2. Each of the pins H2 as shewn particularly in Figures 13, 14, 15 and 16 is
provided with a shoulder h, and is forked or provided with a deep recess h² extend-
ing in a plane running from back to front of the machine and reaching down to
slightly below the shoulder h. On the upper or thinner portions of the pins H2 are
provided weights h³ which are free to slide vertically thereon, and which normally
rest on the shoulders ; or springs may be employed instead of the weights h³. On
the lower or thicker poftions of tlie pius He is fitted a bar H³ which is lowered and
raised in unison with the frame D to which, for this purpose, it is connected at its
ends by two links hª. The sewing threads J, before reaching the needles f f², are
passed through the recesses h² and are älternately gripped and drawn upwards, and
released by the last previously described devices, that is to say they are gripped be-
tween the bar H3 and weights h³ and drawn upwards when the bar H³ is raised and
caused to lift the weights off the shoulders h, and released when the bar has descended
5 sufficiently to allow the weights to rest on the shoulders h at which lattër juncture
the threads are left free to move between the under side of the weights h³ and the
lower ends of the recesses h².

page_text: At the back of the before described rising and falling frame D and pivotted in
stationary bearings k is a horizontal rocking shaft K to which oscillatory motion is
imparted by means of a lever arm 2 secured on the said shaft, link or rod k³,
pivotted to the lever arm k², a cam k Figures 2 and 3 secured on the main shaft B
and an anti-friction roller 5 pivotted on the link or rod ³. The lower end of the
link or rod 3 is preferably forked or slotted as represented in dotted lines in Figure 2
so as to embrace the main shaft B which is thereby caused to guide it in its longi-
tudinal movement. The rocking shaft K also has two lever arins 6 rigidly secured
to it, and these arms carry a perforated or slotted rod through which the threads
are passed after leaving the before described slotted pins H2 as shewn particularly in
Figures 8 and 10.
Below the rod 7 is provided a stationary perforated or slotted rod k³ suitably
supported by the before mentioned brackets A5 or in any other convenient manner.
In suitable guides L secured to the front face of the before described saddle-bar C
are mounted two generally-cylindrical rods L² L³ which are capable of being moved
longitudinally in these guides. On each of the rods L2 L is secured a hooked
looper 2 or 3 respectively, each facing in a direction opposite to that in which the
other faces. The hooked ends of the loopers (2 13 are adapted, throughout the greater
part of their stroke, to travel close in front of the saddle-bar C, in the front face of
which are formed a number of vertical grooves c5 and a horizontal groove c³, the
former for receiving the needles ff and hook g² after the said needles and hook have
pierced the signature, and the latter for allowing each thread-loop to be moved
rearwards so as to hold it close against the front of the then-depressed hook g² and
thereby ensure that when the hook is next raised it shall engage with the said
thread-loop. For effecting this rearward movement of the thread-loops the
rods L L are each provided with a stud carrying a substantially-spherical
anti-friction roller 15 (see particularly Figure 17) which is adapted to travel in a
cam-slot each formed in one of the before described bearings L. These cam-slots 10
are so shaped that at the proper part of the longitudinal movement of each of the
rods L2 L3 and corresponding movement of the looper 12 or 13 appertaining thereto
(which looper at that juncture has engaged the thread-loop) the said rod is slightly
turned on its axis so as to press the thread-loop rearwards against the front of the
then-depressed hook g².
The two rods L2 L3 are alternately reciprocated in a longitudinal direction by
means of a cam I mounted on a stud as rigidly secured to the standard A2, this cam
being geared with the main shaft B by spur-wheels 17 the relative diameters of which
are such as to cause the cam LA to rotate once for every two revolutions of the main
shaft. Motion is transmitted from the cam L to the rod L2 by means of a lever 18
pivotted as shewn in Figure 4 by a fulcrum pin l to lugs a' on the standard A. The
lever 18 at its rearward end, is provided with an anti-friction roller entering the groove
of the cam L' at the upper side of the latter, and, at its forward end the said lever is
provided with a fork (10 as shewn in Figures 7 and 20 for engaging with a pin or
projection on the rod L2, the arms of the fork 10 being splayed to admit of the
pin or projection readily entering it during the rearward movement of
the saddle-bar C it being here explained that when the said saddle bar is moved
forwards for receiving a fresh or unsewn signature, the pin or projection 11 leaves the
fork 10, and that during this disengagement neither the rod L2 nor the lever 18 receives
any motion which disturbs the alignment of the pin or projection with the fork (10.
As the cam L is employed for longitudinally reciprocating both of the rods 12 L³
and as these rods are reciprocated in respectively opposite directions, that is to say
as the rod L2 is moved first towards the right and afterwards towards the left, and the
rod L³ is moved first towards the left and afterwards towards the right it is necessary
to interpose a lever 12 Figures 4 and 21 between the cam L and the lever 18 which
engages with the rod L³ so as to provide for the necessary reversal of motion; the
lever engages with the underside of the cam L so that the reciprocations of
the rod L³ may alternate with those of the rod L². In respects other than those last
reviously described the devices connecting the cam L* with the rods L2 and L³ are

page_text: substantially similar. The levers 18 and 11s and the lugs at in or to which they are
pivotted, are provided with a number of holes, see Figures 4, 20 and 21 to admit of
the position of the respective fulcrum pins 19 being adjusted to suit the motion to be
imparted to the loopers 2 13 the amplitude of this motion depending upon the
distances from the hook g² at which the needles f f are adjusted to work.
Before the needles ff and hook g², during their descent, reach the signatures,
they pass through the perforations or slot m Figure 22 of a bar M secured to the
before mentioned brackets A", which bar thereby serves to prevent bending of the
said needles and hook when they are piercing the signatures. The bar M as shewn in
Figures 22 and 23 is also provided with perforation m² in which a plunger m³ or two
or more such plungers m³ is or are free to be moved up and down, each such plunger
at its lower end being provided with a cam surface m adapted, when the plungers
are depressed, to move backwards the previously sewn signatures as will be readily
understood by referring to Figure 22. The upper end of the plunger or of each of
the plungers m³ is pivotted to a lever arin m³ secured adjustably, as for example by
means of a screw me Figure 22, to a rocking shaft M2 mounted in bearings in the
brackets A5. The rocking motion of the shaft M² is derived from the before
mentioned cam projections 65 60 which operate respectively on anti-friction
rollers mm pivotted on a three-arm lever M³ connected by a link me to a lever
arın m10 secured on one end of the shaft M2; the operation of the cam projections 65 be
on the lever M3 is substantially similar to that previously described in connection
with the cam projections 63 64 and lever G2 and will therefore be sufficiently well
understood without special description thereof.
At the left hand end of the saddle-bar C, I secure a bracket N in which is free to
slide longitudinally a rod n provided at its inner end with a clamp n² Figure 5 in
which a gauge n³ may be secured in any desired position according to the length
of the signatures to be sewn. At or near its outer end, the rod n is pivotted to
one arm of a bell-crank lever N2 the other arm of which is pivotted to the upper end
of a link or rod nt. The lower end of the link or rod n is pivotted at n to one arm
of a bell-crank lever N³ Figure 1 which is pivotted to the standard A; the other
arm of the lever N³ is connected to one end of a rod n5 which, at or near its opposite,
or rearward end, is provided with an anti-friction roller no constantly maintained
by a spring or equivalent (not shewn in the drawings) in rolling contact with a cam N¹
formed conveniently in one part with the before described cam E³. The rod n³ at its
rearward end is slotted and guided in its longitudinal motion on the before described
stud a². The bell-crank lever N³ is situated in such a position that during the
time that the saddle-bar C is being moved forwards and backwards the point n' at
which the link n' is pivotted to the said lever, is co-axial with the before described
shaft c, so that although the link n moves along with the saddle-bar during such
operation the gauge n³ will not be moved independently of the saddle bar.
The before described machine may be used for sewing either with tapes ( as shewn
in Figure 41 or without such tapes as shewn in Figure 42. When sewing without
tapes the lever E2 Figures 1, 5 and 7 is either rendered inoperative say for example
by withdrawing the fulcrum pin e from it and the lugs a, or entirely detached from
the machine, or any other convenient means may be employed for the purpose.
When sewing with tapes these latter are wound on spools or reels 02 whence they
lead to a series of rods o over or between which they are passed first in one direction
and then in the reverse direction, more or less drag or tension being applied to the
tapes by pressing the latter a greater or smaller number of times between the rods o.
From the rods o the tapes O pass beneath the bar M whereon are mounted adjustable
guides o² which serve to prevent the tapes from moving edgewise the ends of the
tapes being secured by spring clips 03 Figure 22 or other suitable devices to a wooden
bar o supported at its ends on rails 05 along which the bar of travels as the
signatures are pressed backwards by the before described plungers m³.
The thread J for each of the needles ff2 passes from a reel or hobbin ; Figure 1
through the recess h² of the appropriate pin H2 between the weights on the said
pin and the bar H³ and then successively through the rod 7 one of the before

page_text: mentioned perforations f³, the eye f10 of the appropriate spring take-up arm ƒ³ the
rod, the guides 23 Figures 8 and 10 and the needle eye.
S is a horizontal plate (shewn in dotted lines in Figures 1 and 2) for sup-
porting the signatures after they are sewn; this plate is adjustably connected
to the frames A A2 or other suitable fixed part of the michine, so that it may be
raised or lowered according as the signatures are of less or greater width.
The operation of sewing without tapes may be described as follows:-
At starting the threads hang loosely a short length through the eyes of the
needles. The operator places one of the signatures Pastride the saddle-bar C, when
the latter is in its forward position, with one end of the said signature abutting
against the gauge 13. The saddle-bar then moves backwards and brings the
signature into proper position beneath the needles ff2 and hook g² which, through
the medium of the frame D, links d, levers d², and cams b², are immediately
thereafter caused to descend and penetrate the signature as shewn in front and side
elevation in Figures 24 and 25 respectively. The needles slightly ascend after
reaching their lowest position, so as to form loops in the thread as shewn in Figure 25
and at this stage the camn L moves one of the loopers 12 13, say for example the
looper 3, which it causes to travel from the right towards the left, during which
movement the said looper engages with the thread loop of the needle f2 and carries
it past the hook g2, which at this time is turned towards the front of the machine
all as shewn in front and side elevation in Figures 26 and 27 respectively. Near
the termination of its leftward travel the looper 13, through the medium of the
rod L3 and the roller and cam appertaining thereto, is tilted backwards so as
to press the thread forming the rear side of the loop, against the hook g², as shewn
in Figure 27 and in plan in Figure 25. The needles ff and hook g³ then commence
to ascend the hook being thereby caused to engage with the loop as shewn in
At this stage the cam
Figures 29 and 30 in respectively front and side elevation.
projection 63, through the lever G2, link g, lever g³, g° rack and pinion g³,
causes the book g² to turn through 180° as shewn in Figures 31 and 32, and the
looper 3 returns to its original position and releases the loop. As soon as the
hook g2 has drawn the loop, which is then engaged with it, through the last
previously formed loop or stitch j the cam projection 6' and the above named
parts G2 g, g, go, g' and g³ cause the hook g² to turn backwards through 180°
so that it again faces towards the front of the machine as shewn respectively in front
and side elevation in Figures 33 and 34 thus completing the stitch; throughout.
this operation the looper 12 has remained inoperative. The saddle-bar then moves
forward, and after the next signature has been placed astride it, it again moves
backwards to bring this unsewn signature beneath the needles f f2 and hook g².
After this the sewing is effected in a manner similar to that before described the
only substantial difference being that the looper 12 is caused to engage the loop formed
by the needle f while the looper 13 remains inoperative as shewn in front elevation in
Figures 35 and 36.
By referring to Figure 42 which represents a series of signatures sewn together in
the manner previously described; it will be seen that the thread loops in successive
signatures extend in opposite directions, the thread loop in one signature being at
say the right hand of the chain-stitches and the thread loops in the adjacent
signatures being at say the left hand of the chain stitches.
The operation of sewing with tapes after these latter have been attached to the
bar o as hereinbefore explained is carried out in a manner similar to the sewing
without tapes but at every alternate signature the cam E³, lever E2, and bar E cause
the needles ff2 to inove towards the right or left so that, the loop in one signature
is shorter, by the extent of this movement, than that in the next adjacent signature;
the loops in alternate signatures on each side of the chain stitching being alternately
longer and shorter as shewn in Figure 41; their length may be varied by changing
The above described
the position of the fulcrum pin e in the lever F2 and lugs a.
lateral displacement of the needles is indicated in Figures 24, 26, 29, 33 and
Figures 35 to 40.

page_text: In a machine as previously described both of the needles ƒ ƒ descend simul-
taneously and as the thread of only one of them is utilized for forming a stitch at
each such operation the other needle perforates the signature unnecessarily and if
desired may be prevented from so operating by mounting the two needle holders F
and the bearing G on three separate plates or frames capable of being independently
operated one above another and causing the two frames carrying the needle-holders
to operate alternately and the frame carrying the bearing G to operate in conjunction
with each of the other two frames.
As the thread loops in consecutive signatures are drawn in opposite directions and
the holes formed in the signatures are slightly larger than the diameter of the thread
there is a tendency of the signatures to shift in the direction of the drawing of the
loop, which, if not prevented, will result in the "head" or end of the book being
uneven, each alternate signature standing out a little beyond the neighbouring ones.
The before described gauge n³ and the parts connected therewith overcome this
difficulty because at the time at which the pull on the thread-loop tends to move the *
signature toward the left side of the machine the cam N* causes the gauge N³ and
consequently the signature to move slightly in the opposite direction.
Instead of employing the before described plungers m³ for moving the sewn
signatures towards the back of the machine this result may be obtained by the
apparatus shewn in Figures 43, 45 and 46. In this arrangement a shaft Q, pivotted
in suitable bearings in the brackets A5, is fitted with two arms 9 carrying a bar or
plate 10 and is oscillated in its bearings, through the medium of two cam-
projections q2q3, a three-armed lever q*, a link q³ and a lever arm q, the movement
of the bar q10 from the position shewn in Figure 43 to that shewn in Figure 46 taking
place when the saddle-bar is in its forward position and the tension on the thread is
released, the bar q₁ remaining in its rearward position, as shewn in Figure 46 until
the saddle-bar nearly reaches it with the next unsewn signature.
In Figures 43, 44 and 45 I have represented my improved devices for drawing up
In this
the thread so as to give tension to it in the signature last previously sewn.
arrangement each thread after leaving the before described forked or recessed pin H2
(which is not shewn in these Figures) is passed through or beneath the rods and
through a hole r in a forked lever R or R2 and thence through the guides 23 to the
needle eye. The levers R R2 are pivotted to the bracket arms f which in this
example are formed one longer than the other, and the forked ends of the said levers
engage with rods 72 73 carried in levers 74 connected by links or rods 5 to two
cams R3 R4 rotating at the same speed as the before described cam L to which as
shewn in Figure 45 they may be connected. These two cams are alike, but, as
regards their parts of greater radius, are disposed diametrically opposite to each other.
By the cams R R the fork levers R R2 are operated alternately, each such operation
taking place when the needle to which it appertains, makes its blind or ineffective
stroke, in consequence whereof the thread loop of the signature last sewn by that
needle is drawn tight and extra tight sewing results, and at the same time a further
supply of thread for the following stitch is drawn from the reel. The rods are
caused to alternately descend simultaneously with the forward movement of the
saddle-bar C so that the tightening of the loops always takes place after the completion
of each sewing operation. In Figure 43 the needles are shewn in their highest
position, when they descend as shewn in Figure 44, the rods act as fulcra for the
levers R R and consequently the distance between the points and becomes less
and the threads for the stitches can thus follow the needles and loopers without undue
friction.
For sewing books in the manner shewn in Figures 41 and 42, only two needles ƒ ƒ2
and one hook g² are necessary as shewn in Figure 5 but if desired two or more of
such sets of needles and hooks may be employed as shewn for example in Figure 3,
these various sets being either used for sewing separate books or for sewing different
parts of one and the same body which may subsequently serve as one book or be
divided into a number of books.
The needles ƒ ƒ2 and hook g² and the various parts operating in conjunction

page_text: therewith or the various sets of such apparatus may be adjusted to any desired
part of the machine to suit the size of the books to be sewn.
I desire it to be understood that I do not restrict myself to the precise details
of construction herein before described, as various modifications may be made
without departing from the essential features of the invention, and it is also to
be understood that I do not herein claim anything disclosed in the Specification
of Letters Patent No. 13917 of 1892.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed I declare that what
I claim is
1. A book-sewing machine for producing outside or at the back of the book a
continuous row of chain stitches, and inside the consecutive signatures, stitches or
loops extending alternately to the right and left of the row of chain stitches
substantially as hereinbefore described.
2. In a book-sewing machine having two needles and a hook and two loopers
operating in conjunction therewith for forming a row of chain stitches .at the
outside or back of the book, mechanism whereby the thread-loops or stitches
within the signatures are formed or disposed at alternately opposite sides of the
chain stitches substantially as hereinbefore described with reference to the
accompanying drawings.
3. In a book-sewing machine the combination with two loopers and a cam for
operating them of a single lever for transmitting motion from the cam to one of the
loopers and compound levers such as 12 [13 for transmitting motion from the cam to
the other of the loopers substantially as hereinbefore described with reference to the
accompanying drawings.
4. The combination with a book-sewing machine of a gauge such as n³ and
mechanisin operating in conjunction therewith for automatically counteracting the
tendency to move the signatures out of line, substantially as herein before described
with reference to the accompanying drawings.
5. In a book-sewing machine the combination with a hook such as g2 and a
reciprocating looper such as 12 or 13 of mechanism for tilting the looper towards the
hook substantially as and for the purpose herein before described with reference, to
the accompanying Drawings.
6. In a book-sewing machine mechanism for tightening the stitch of a previously
sewn signature substantially as hereinbefore described with reference to Figures 43,
44 and 45 of the accompanying drawings.
7. The combination with a book-sewing machine of a bar or plate such as q10 and
mechanism for moving it towards and away from the sewn signatures substantially
as and for the purpose hereinbefore described with reference to Figures 43, 45 and 46
of the accompanying drawings.
8. The combination and arrangement of parts constituting the book-sewing
machine substantially as herein before described and illustrated in Figures 1, 2, 3
and 4 of the accompanying drawings.