Improvements in Dobbies and in Weft Stop Motions employed in Looms for Weaving.
Year: 1891

page_text: Date of Application, 12th Oct., 1891
Complete Specification Left, 19th Jan., 1892-Accepted, 27th Feb., 1892
PROVISIONAL SPECIFICATION.
Improvements in Dobbies and in Weft Stop Motions employed in
Looms for Weaving.
I, CHARLES BEDFORD, of 63 Alexandra Road, Shipley, Yorkshire, Machine
Shop Manager, do hereby declare the nature of this invention to be follows:-
The first part of my invention has reference to that class of dobby in which
the heald shafts or heddles are raised by a combination of levers, catches, and draw
bars. One of the levers, which is commonly called a balk lever, has a long catch
hinged to it at each end. In the middle of the balk lever is a pivot or a hole, by
which it is hinged onto a second lever, to which the heddles are attached.
In the above class of dobby it is found that, when the shed has been opened, and
the shuttle is passing therethrough, the healds run back or have back-lash, whereby
the shed is contracted or reduced. The cause of the healds running back or having
back-lash is as follows, viz. :-In a non-positive dobby where the heddles are
required to remain up for several picks or shoots in succession, the catches at each
end of the balk levers are allowed by the pegging mechanism to fall and engage
with their respective draw-bars, each having a reciprocatory motion so that as one
bar moves forward the other bar moves backward. Behind each end of the balk
lever there are stop bars, against which the balk lever rests (or is held by the weights
or springs used to draw down the heddles) when the heddles are down.
When one catch which we will name a, falls, its draw bar b (when moving
forward) takes the said catch forward, and this acts on the second lever so as to
raise the heddle. If it be required to keep up this heddle for several picks, then a
catch on the other end of the balk lever is allowed to fall by the pegging
mechanism, and so be taken forward, along with its end of the balk lever, by a
draw-bar d, in its forward movement. At the same time the draw-bar b is moving
backward with the catch a and its end of the balk lever; thus the balk lever is
oscillating upon the pivot of the second lever and thus holding the heddle up.
When the bar b is near the end of its backward movement, that end of the balk
lever comes in contact with the stop bar, thus preventing any further backward
movement of the catch a; but the bar 6 continues to move backward, in order to
clear the catch a and leave it free to be acted on by the pegging mechanism.
Whatever distance the bar b travels backward after leaving the catch a, the bar
travels the same distance forward, taking with it the catch e and its end of the
balk lever, and so raising the heddle still higher than is necessary for the passage
of the shuttle through the shed. When the bar d begins to move back, it allows
the heddle to fall again, until the barb takes hold of the catch a, and oscillates the
balk lever upon the pivot on the second lever, thus holding the heddle in its normal
position when up, until the bar b comes to the end of its forward movement, when
it again raises the heddle higher than its normal position, letting it down again to
its normal position, and thus causing the back-lash alluded to.
The object of my invention is to prevent the back-lash of the parts, and the con-
sequent running back of the healds, and this I accomplish in the following manner :-
Instead of the draw-bars being connected direct by rod to the ordinary bell
crank lever which operates the said draw-bars, I attach the said draw-bars to
another lever, jointed in the middle. The bell crank lever, which has hitherto
operated the draw-bars, is now provided at each end with a bowl, entering slots
in the jointed lever, which jointed lever is caused to oscillate backwards and
forwards by the said bell crank lever, whereby the draw-bars are made to recipro-
cate backwards and forwards as formerly, but the slots in the jointed lever are
so formed, that when the shed is being opened, one half of the jointed lever dwells,

page_text: and so does its draw-bar, whilst the other half of the jointed lever is giving the
necessary increased motion to its draw-bar so as to release the catch, and as the
opposite draw-bar is being rigidly held, the back-lash or running back of the healds
is entirely prevented. By the employment of the mechanism herein described, the
greatest disadvantage in the working of the Hattersley dobby is overcome; the size
of the shed may also be lessened, consequently less tension is put upon the warp, and
fewer breakages follow.
The second part of my invention consists of an improved arrangement of parts to
form a positive dohby. In carrying out this part of my invention, I use a bell
crank shaped harness lever, the two arms of which are notched or have a number
of grooves or recesses in them. One of these recesses in the upper arm (which is
in an oblique or nearly vertical position) is attached by means of bands, chains,
and wire, to the top part of the heddles; grcoved pulleys being placed in suitable
positions for the bands or chains to pass over and guide them to the top of the
heddle.
One of the corresponding recesses in the other arm of the harness lever (which is
nearly in a horizontal position) is similarly attached to the bottom or under portion
of the heddle. To this recessed harness lever I attach (to a suitable part of the
vertical arm) a balk lever with its two catches, which catches are operated upon by
two draw-bars in the ordinary manner.
I also use two extra moving bars to operate on the ends of the balk lever to force
them back to the fixed stop bars. I use also two retaining bars to hold (by means
of notches on the top part of the catches) the ends of the balk levers near to the
stop bars when it is requisite to do so.
The third part of my invention has reference to that class of weft stop motion
employed in the middle of the loom and commonly applied to broad looms, the
object of my invention being to simplify the parts. Accordingly I attach to the
head of the feeler or weft fork, a catch made to lift up and down at each beat
up of the slay, by a suitably shaped cam fixed upon a short horizontal rod,
carried by brackets in front of the slay. This rod also carries a dagger to act
upon the belt fork mechanism. The rod is made to rock each time the slay
beats up, causing the cam to raise the feelers, and if weft be absent, the feelers
descend into a groove cut in the slay, the effect of which would be, that a catch
on the cam would be caught by the catch formed at the head of the feelers; this
meeting of the catches would prevent further moving of the cam, bringing the
dagger into position to strike the knocking off apparatus, at the further beating up
of the slay.
Dated this 9th day of October 1891.
TASKER & CROSSLEY,
Halifax, Agents.
COMPLETE SPECIFICATION.
Improvements in Dobbies and in Weft Stop Motions employed in
Looms for Weaving.
I, CHARLES BEDFORD, of 03 Alexandra Road, Shipley, Yorkshire, Machine
Shop Manager, 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 :-
The first part of my invention has reference to that class of dobby in which the
heald shafts or heddles are raised by a combination of levers, catches, and draw-
bars. One of the levers, which is commonly called a balk lever, has a long catch
hinged to it at each end. In the middle of the balk lever is a pivot or a hole,
by which it is hinged on to a second lever to which the heddles are attached or
connected.
In the above class of dobby it is found that when the shed has been opened, and

page_text: the shuttle is passing therethrough, the healds run back or have back-lash, whereby
the shed is contracted or reduced.
In order to explain why and how the healds run back or have back-lash, I will
make reference to the accompanying sheets of drawings, wherein Fig. 1 is an
elevation without framework of the parts composing a non-positive dobby as at
present constructed on the Hattersley system. A is the ordinary rocking or bell
crank lever, receiving its motion from the tappet or other shaft of the loom.
As this lever oscillates, it imparts a to and fro motion to the drawbars and d
In a
which are used for the purpose of pulling forward the catches a and c.
non-positive dobby where the heddles are required to remain up for several picks
or shoots in succession, the catches a and c carried at each end of the balk levers B
are allowed by the pegging mechanism to fall and engage with their respective
drawbars bd each having a reciprocatory motion, so that as one bar moves forward
the other bar moves backward. Behind each end of the balk lever B there are
stop bars C, against which the balk levers rest (or are held by the weights or
springs used to draw down the heddles) when the heddles are down.
When the catch a falls, its drawbar 6 takes the said catch forward as shewn by
the arrow, and this acts on the jack lever D so as to raise the heddle. If it be
required to keep up this heddle for several picks, then the catch c on the other end
of the balk lever B is allowed to fall by the pegging mechanism, and so be taken
forward, along with its end of the balk lever, by the drawbar d in its forward
movement. At the same time the drawbar bis moved backwards with the catch a
and its end of the balk lever, causing the balk lever to oscillate upon the pivot E
of the jack D, thereby holding up the heddle. When the bar d is near the end
of its backward movement, that end of the balk lever will come into contact with
the stop bar C and thus prevent any further backward movement of the catch c;
but the drawbar d continues to move some short distance backward in order to clear
the catch c and leave it free to be acted on by the pegging mechanism; but what-
ever distance the bar d travels backward after leaving the catch e the bar 6 travels
the same distance forward, taking with it the catch a, together with its end of the
balk lever, and thereby raising the heddles still higher than is necessary for the
passage of the shuttle through the shed; then as the bar d moves forward to take
hold of the catch c, the bar & is moving backward with its catch a, thus permitting
the springs or other devices employed to pull the heddles down, to operate the said
heddles some little distance, causing the various levers to assume the positions
shewn in dotted lines of Fig. 1 thus allowing the back-lash complained of causing
the shed to contract or become less at the very time when it is required to be
greatest, that is, when the shuttle is passing through.
The object of my invention is to prevent the back-lash, and the consequent
running back of the healds, and this I accomplish in the following manner, as
illustrated in Fig. 2 which is elevation of a non-positive dobby having my improve-
ments applied thereto, namely:-Instead of the drawbars b, d, being connected
direct by rod to the ordinary bell crank lever A, which operates the said drawbars,
I attach the said drawbars to another or immediate lever or levers F jointed in the
middle at G. The bell crank lever A, which has hitherto operated the draw-
bars b, d, is now provided at each end with a bowl H and I, entering slots J in the
jointed lever F, which jointed lever is caused to oscillate backwards and forwards
by the said bell crank lever A, whereby the drawbars are made to reciprocate
backwards and forwards as formerly, but the slots J in the jointed lever are so
formed, that when the shed has been opened, one half of the jointed lever dwells,
and so does its drawbar, whilst the other half of the jointed lever is giving the
necessary increased motion to its drawbar so as to release the catch, and as the
opposite drawbar is being rigidly held, the back-lash or running back of the healds
is entirely prevented.
I will now explain more fully the action of the slots J (of the jointed levers F)
upon the drawbars and catches. When the drawbars are in the positions shewn
in Fig. 2, the shed will be opened and the pegging mechanism or other indicating

page_text: apparatus will be about to lift up the bottom hook c, but to permit this to be freely
done, it is necessary to slacken the hold of the lower drawbar d from its hook Ć,
and to do this the slot J is so timed and shaped that (as will be seen on reference to
the drawing) when the bowl H in the upper slot J is near the bottom thereof, it
ceases to move the upper portion of the lever F and consequently the bar 6 and
hook a and the lower bowl I continues to move the lower portion of the jointed
lever F and bar d which is designedly done for the purpose of extending the move-
ment of the drawbar d so as to remove the said drawbar d a short distance from its
hook, thus leaving the hook free to be acted upon by the pegging mechanism, but
whilst such drawbar is moving that additional short distance, the upper drawbar is
stationary and rigidly holding its catch, which prevents the healds from running
back. The shape of the slots J is such that when the drawbars are in the reverse
position to that shewn in the drawing, the bottom drawbar will in turn remain rigid
or stationary, whilst the upper drawbar receives the extended motion for slackening
its hold on its hook, as already explained with regard to the lower drawbar. It will
be seen that by prolonging the lower end of the top slot J and the upper end of the
bottom slot J that the "shed" may be made to remain open for a longer period
or during a greater angular movement of the crank than has hitherto been
practicable by the ordinary form of dobby. A spiral spring K may be employed
to draw the jointed lever F together after having been opened by the bowls.
By the employment of the mechanism herein described, the greatest disadvantage
in the working of the Hattersley dobby is overcome; the size of the shed may also
be lessened, consequently less tension is put upon the warp, and fewer breakages
follow, and although I have referred to these improvements as being applicable for
operating the healds I would observe that the apparatus herein shewn and
described is equally applicable for raising and moving the shuttle boxes of looms.
The second part of my invention consists of an improved arrangement of parts
to form a positive dobby, i.e., a dobby which operates the healds both up and down
without the aid of weights or springs. In carrying out this part of my invention,
which is illustrated in Fig. 3 and end view Fig. 4 I use a bell crank shaped harness
or jack lever D, the two arms of which are notched or have a number of grooves
or recesses in them. To one of these recesses in the upper arm (which is in an
oblique or nearly vertical position) is attached by means of bands, chains, and
wires, the top part of the heddles T, grooved pulleys U being placed in suitable
positions for the bands or chains to pass over and guide them to the top of the heddle.
One of the corresponding recesses in the lower arm of the harness or jack
lever D (which is nearly in a horizontal_position) is similarly attached to the
bottom or under portion of the heddle. To this recessed harness or jack lever
I attach a balk lever B carrying two catches a and c, which catches are operated
upon by the drawbars b, d connected to two separate slotted levers F and Fl
made to oscillate upon shaft G in manner already described with regard to the
non positive dobby. I also use two extra moving bars L and M connected to
the extended arms of levers F and F made to operate on the ends or extremities
of the balk levers B for the purpose of forcing them back against the fixed stop
bars C and the notches e and in the catches a and c to clear the retaining
bars N and O and so leave the catches a and c (Fig. 3) free to engage with the
moving bars 6 and d, or to be retained by the retaining bars N or O, according
to the design or indications on the peg lags or cards. I use also the two retaining
bars N O, to hold (by means of the notches e, f, on the top part of the catches) the
ends of the balk levers near to the stop bars C, when the catches a and c are not
required to move with the moving bars b and d.
The catches a and c are selected by the pegging barrel P, carrying lags with
pegs g, which, if present, raise the weighted end of the fork R, the prongs of
the fork acting on the toes of the catches a c, as indicated in Fig. 3.
The third part of my invention has reference to that class of weft stop motion
employed in the middle of the loom, and commonly applied to broad looms, the

page_text: head of the feeler or weft fork, a catch made to lift up and down at each beat
up of the slay, by a suitably shaped cam fixed upon a short horizontal rod,
carried by brackets in front of the slay. This rod also carries a dagger to act
upon the strap fork mechanism. The rod is made to rock each time the slay
beats up, causing the cam to raise the feelers, and if weft be absent the feelers
descend into a groove cut in the slay the effect of which would be, that a catch
on the cam would be caught by the catch formed at the head of the feelers; this
meeting of the catches would prevent further moving of the cam, bringing the
dagger into position to strike the knocking off apparatus, at the further beating
up of the slay. This part of my invention is illustrated on Sheet 4 where Fig. 5
is an end elevation of my improvements in a weft stop motion and Fig. 6 is front
elevation of same.
A represents the lathe sword and B the slay board which are made to oscillate
backwards and forwards by the connecting arm as is well understood. C represents
the feelers to the head of which is attached a cam D. These feelers together
with the said cam are mounted upon a short stud E mounted in brackets F,
attached to the front of the slay board B. To the front of the slay board there
are also fixed suitable brackets G and H, for carrying and supporting the short
horizontal rod I, on one end of which I fix a hanging lever arin J, which, as the
"going part" moves backwards the said lever arm J which is in contact with the
fixed stud L is made to assume positions as shewn in dotted lines of Fig. 1 in
doing which, the point a of the lifting cam M fixed upon the said horizontal shaft,
rides underneath the cam D connected to the head of the feeler C, whereby the
said feeler is raised so as to permit the shuttle to be sent across the loom for the
purpose of leaving another shoot of weft, and on the return motion of the going
part the lifting cam M moves away from the cam D at the head of the feelers
allowing the said feelers to descend and if weft is lying over the groove out in the
slay board, the feelers rest upon the said weft and the loom proceeds as usual but
if weft is absent from any cause, the feelers would descend into the groove made
for it, and place the point of the cam D lower than is the case when weft is present,
whereby the catch of the lifting cam is caught hold of so that further oscillation
of the horizontal shaft I is prevented, which places the dagger N in such a position.
that as the slay board advances towards the breast beam the dagger strikes or acts
upon any well known form of mechanism, which transfers the driving strap from
the fast to the loose pulley for the purpose of stopping the loom.
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 believe to
be new and claim is :—
Firstly. In a non-positive dobby employed either for operating the healds or
shuttle boxes, the use of a jointed lever F or two separate levers formed with
slots J for actuating the drawbars, all operated substantially as herein shewn and
described.
Secondly. In a positive dobby the combination of the recessed harness levers D
with the balk lever B, together with catches a and c and drawbars 6 and d, all
arranged as shewn in Fig. 3 and employed for the purpose herein described.
Thirdly. In a positive dobby the use of slotted levers F and F¹ for actuating
the drawbars b. d, L and M, in combination with the operating lever A, all
arranged in the manner and employed for the purpose substantially as herein shewn
and described.
Fourthly. In a weft stop motion for looms the combination of feelers C, cams D
and M, with catch 6 together with lever J and fixed operating stud L, all arranged
and operated as described.
Dated this 18th day of January 1892.