Improvements in Electrical Warp Stop-motions for Looms.
Year: 1899

page_text: Date of Application, 24th May, 1899- Accepted, 22nd July, 1899
COMPLETE SPECIFICATION.
Improvements in Electrical Warp Stop-motions for Looms.
We, WILLIAM HENRY BAKER, of Central Falls, in the County of Providence, and
State of Rhode Island, United States of America, Electrician, and FREDERIC
ELLSWORTH KIP, of Montclair, in the County of Essex, and State of New Jersey,
United States of America, Manufacturer, 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 electrically controlled warp stop-motions, and it
has for its object, in part, to provide a loom for weaving pile-fabrics with a
stop-motion for the pile-warps as well as for the main or back warps; in part
to provide for stopping the loom when a warp-thread breaks without disengaging
the take-up pawl or pawls, the loom being provided with a weft stop-motion
which is adapted to release the take-up pawl simultaneously with the stopping
of the loom; and in part to provide an improved construction of circuit closing
gravity drop.
Respecting the first named feature of the invention it may be well to state
preliminarily that in the class of electrical warp stop-motions, an electric circuit
is completed, when a warp-thread breaks, by the falling of a metallic drop,
normally supported by an unbroken warp-thread; this completion of the circuit
excites an electro-magnet therein, and this magnet acts through mechanical
devices to stop the loom. Such devices have been applied to the flat warps of
looms, but in looms for weaving pile-fabrics the pile-warps are carried up
through the flat or back warps, at an incline from the let-off rolls or beams to
easing rods above, and the said warps are let off intermittently to an extent
sufficient to provide enough of the pile-warps to float between the two back
webs of the fabric. This makes the application of circuit-closing drops to the
pile-warps quite difficult, and necessitates the devising of special means for effect-
ing the object, and it is in this special means or mechanism that the first part of
the present invention lies.
Most looms are provided with mechanical weft stop-motions, wherein the
carriage on which the weft-fork is mounted acts, when the weft fails, to drive
back a horizontally arranged knock-off lever, and through this lever to free the
shipper-lever so that it may stop the loom; but the knock-off lever acts at the
same time to disengage the back pawl of the take-up beam and allow the latter
to run back. This release of the take-up beam is not desired when a warp-
thread breaks, and one of the features of the present invention is to provide a
means for stopping the loom independently of the main knock-off lever.
In this class of warp-stop-motions, and especially where the drops are mounted
on pile-warp threads, it is desirable that the drop shall be open-slotted from
the bottom thereof up to the thread-aperture, for convenience in threading them.
but at the same time it is desirable that they shall be so constructed that the
riding drop cannot be thrown up and unseated by the twitching of the warp-
threads and one of the purposes of the present invention is to provide such
adron

page_text: In the accompanying drawings which illustrate an embodiment of the
invention-
Figure 1 is a somewhat diagrammatic side view, on a small scale, of a loom
for weaving pile-fabrics, embodying the invention; and Fig. 2 is a plan of the
loom-stopping mechanism seen at the right in Fig. 1.
Figure 3 is an enlarged detail view of an easing bar or rod for the pile-
warps, showing the improved drop; and Figure 4 is an edge view of the drop,
detached, and illustrating the manner of spreading the branches thereof.
Figures 5 and 6 are enlarged detail views illustrating the loom-stopping
mechanism seen on a smaller scale in Figures 1 and 2.
Figure 7 is a side view and Figure 8 a plan, illustrating the construction and
manner of mounting the easing bars or rods for the pile-warps.
Figure 9 is a view illustrating a modified construction of the easing bar.
Referring primarily to Figure 1, which shows the parts of the loom in a
somewhat diagrammatic manner; W is the main warp-beam and to the main or
back warps; P is the pile-warp beam, and p the pile-warps; R are the let-off
rolls or beams for the pile-warps; A A represent, in general, the improved easing-
rod devices, which will be more minutely described hereinafter; H indicates the
usual heddles and harness for producing the sheds in the warps; is the whip-
roll L is the lay; R¹ is the reed; B is the breast-beam; K is the main knock-
off lever, and S is the shipper-lever. All of these parts are common in looms in
some form, except as to the special form of easing-rod device A, and said common
or usual parts are merely indicated diagrammatically in Figure 1.
G represents any form of electrical generator and the conductors of a nor-
mally open controlling circuit fed thereby. This circuit is adapted to be com-
pleted, when a warp-thread breaks, by the falling of a metallic drop, normally
supported by the said warp-thread, upon or into contact with terminals of said
circuit. In Figure 1 three sets or series of such drops are shown at D, mounted
on the threads of the back warps; and at A, two series of such drops are shown
mounted on the threads of the pile-warps.
Figure 3 illustrates the preferred form of contact drop and circuit terminals. lis
a terminal bar connected with the conductor c, and 2 is a terminal strip connected
with the terminal, and mounted in the upper edge of the bar 1, but insulated
therefrom. 3 is the drop which is an elongated strip of thin metal, slotted to
fit over and straddle the compound terminal, and provided with an aperture, 3,
to receive the warp-thread. When the thread breaks, the drop falls into contact
with the strip 2; and being normally in contact with the bar 1, it thus com-
pletes the circuit.
In the ordinary loom for weaving pile-fabrics the pile-warps are supported
cach by an easing-rod or bar (sometimes called a monkey tail), and the taking
up of the slack warp is effected by a cam similar to those operating the loom
harness, the bar being supported by a spring which serves as a cushion or ease-
ment. The present construction, which adapts the device to the electrical stop-
motion, is best illustrated in Figures 3, 7 and 8, and this construction will now
be described.
Each of the pile-warps p passes over two parallel rods (or rolls), 5, mounted
at their respective ends in plates or end-pieces, 6, the two rods and their end-
pieces forming the bar. Only one end of the device is herein shown, but both
ends will be alike. The end-piece 6 has mounted in it the compound terminal, 12,
which will be properly insulated. The electrical connections may be made as
shown in Figure 7, through the medium of binding posts, 7 and 7. The end-
piece is guided in its up and down movements in a slot in a fixed plate or
bracket, 8, on the loom-frame.
The space between the rods 5 will be sufficient to receive the drop 3, which is
supported on the short length of warp-thread which extends across and bridges
the space between the rods. The compound terminal will be situated below the
rods, and at about the middle of the space between them. The easing bar is

page_text: operated through the medium of wires, 9, in which are springs, 9, as in the usual
construction.
The preferred form of drop 3, is best illustrated in Figures 3 and 4. The slot
in these figures is nearly closed at the lower end of the drop by an inwardly
projecting part or parts, 3b, which effectually prevent the drop from being unseated
by the jerking or twitching of the thread as the projections 3b will catch under the
terminal bar 1. But these projections will not interfere with the placing of the drops
on the terminal bar. as the drops are made of thin, spring steel and the branches
thereof may be sprung apart laterally at their lower, free ends (see Fig. 4) to an
extent sufficient to pass the drop down over said bar, after which they will spring
back again to their original positions. It is preferred to form a projection 36
on each branch or leg of the drop, but obviously the desired result will be
attained if the slot be narrowed at the lower end of the drop, or nearly closed,
by any suitable projection or projections 3b.
The loom-stopping mechanism is seen at the right in Figure 1, and in plan
in Figure 2, and in detail in Figures 5 and 6. The knock-off lever K, is coupled
at its free end to the slide, F, which carries the weft-fork, f. When the weft
fails the weft-hammer (not shown) shifts the knock-off lever K, and the latter
acts to force the shipper-lever S from engagement with its retaining shoulder, s,
and allows it to act and stop the loom. This mechanically controlled weft stop-
mechanism is well known and will require no more minute description.
The warp stop-mechanism comprises an auxiliary knock-off lever, k, which rests on
the knock-off lever K, and may be pivoted or fulcrumed at the same point, ", on
the supporting bracket B. On the lever kis mounted an electro-magnet, M.
By preference the lever k will have a pendent bracket, b, and the magnet will be
secured to this bracket so as to be capable of vertical adjustment. The arma-
ture, m, of the magnet, is carried by an armature lever, 7, which projects out
toward the lay, and on the lay is fixed a tappet, t, which, normally, when the lay
makes its beating up movement, plays over the free end of the armature lever;
but the coils of the electro-magnet M are in the circuit c, c, and when a warp-
thread breaks and the drop 3 thereon falls and closes said circuit through said
magnet, the latter will be excited and attract its armature, (see Figure 5) thus
putting the end of the armature lever 7, into the path of the tappet t, so that when
the lay next advances in beating up, said tappet will strike the lever 7, and
through it shift the knock-off lever k. This lever acts on the shipper-lever S
precisely as in the case of the lever K, before described, and through the shipper-
lever stops the loom.
The object of having two superposed and independently operating knock-off
levers will now be explained. As before stated, it is desired that when the loom
is stopped from failure of the weft or filling, the take-up of the cloth beam shall
be let off so that the beam may run back a little and slack the warp and web;
and to effect this, a let-off lever, N, is provided. This lever is fixed on a rock-
shaft, u, on the loom-frame, and is adapted to lift the back-pawl of the take-up
ratchet when the lever N is impinged upon by the knock-off lever K. The upper
end of the lever N projects upward into the path of the lower knock-off lever K,
so that when the latter is shifted for stopping the loom, the cloth beam will be
freed and allowed to run back at the same time. This let-off construction is
known, and it has not been considered necessary to show herein more than the
lever N, and the rock-shaft n.
It has also been explained that when a warp-thread breaks, this letting off of
the cloth beam is not desired; and to enable the loom to be stopped without
actuating the lever N. the latter is shortened so as not to extend up above the
upper surface of the lever K, whereby the auxiliary knock-off lever k may be
displaced without impinging upon said lever N.
The form of pile fabric loom adapted for illustration herein shows the pile-warps
arranged to pass up through the back warps, and the easing rods arranged to move
up and down in straight lines; but the invention is equally applicable to other

page_text: forms of such looms, and notably to those looms where the easing rods move in
a slightly curved path by reason of their having a rocking motion.
Where the drops embrace the transverse terminals as shown, so as to be held
and guided thereon, and the inclination of the pile-warp is not too great, one
of the rods of the easing device may be dispensed with and the apparatus will
still be operative. This construction is illustrated in Figure 9, which will re-
quire no special description. The construction with the two connected parallel
rods, is preferred.
Having now particularly described and ascertained the nature of our said in-
vention and in what manner the same is to be performed, we declare that what
we claim is:-
1. In an electrical warp stop-motion for looms for weaving pile-fabrics, the
combination with the easing device for the pile-warp, of terminals of the oper-
ating electric circuit carried by said easing device, and gravity, circuit closing
drops on the respective pile-warp threads at said easing device, each of said
drops being adapted to close the circuit between said circuit terminals when
its supporting warp-thread breaks.
2. In an electrical warp stop-motion for a loom for weaving pile-fabrics,
the combination with the easing device for the pile-warp, of a terminal bar fixed
to and carried thereby, and a series of circuit-closing drops embracing and
guided on said terminal bar, substantially as set forth.
3. In an electrical warp stop-motion for a loom for weaving pile-fabrics, the
combination with an easing bar composed of a pair of substantially parallel rods
for the pile-warps, and end-pieces connecting said rods, of the terminal bar
carried by such end-pieces, said rods being separated a distance sufficient to
allow space for a series of circuit-closing drops which embrace said terminal
bar, and the said drops, substantially as set forth.
4. In an electrical warp stop-motion for a loom for weaving pile-fabrics, the
combination with an easing bar or device for the pile-warps, consisting of two
rods, connected and moving together and properly spaced, terminal bars carried
by and moving with said easing device, an electric circuit including said ter-
minals and a generator, stop-mechanism controlled by said circuit, and a series
of drops carried by the pile-warp threads where they bridge the space between
the rods of the easing device, said drops adapted to close the circuit between
said terminals when their supporting warp-threads break, substantially as set
forth.
5. In an electrical warp stop-motion for a loom for weaving pile-fabrics,
the combination with an easing bar or device for the pile-warps, consisting of
two rods connected and moving together and properly spaced, terminals bars
carried by and moving with said easing device, an electric circuit including said
terminals and a generator stop-mechanism comprising the shipper-lever, a knock-
off lever, an electro-magnet in said circuit and carried by said knock-off lever, its
armature and armature lever, and a tappet carried by a going part of the loom and
adapted to impinge upon the armature lever when said magnet is excited, and drops
carried by the pile-warp threads where they bridge the space between the rods
of the easing device, substantially as set forth.
6. The combination with the end-pieces 6, and the pair of rods 5, fixed therein,
of the compound terminal fixed in said end-pieces below said rods, and slotted
drops embracing said terminal, substantially as set forth.
7. As an improved article of manufacture, a slotted drop for an electrical
warp stop-motion, having a thread-aperture, a guide-slot opening out at the
bottom of the drop, said guide-slot being contracted at the lower end of the
drop, substantially as and for the purposes set forth.
8. In a loom provided with a shipper-lever, a main knock-off lever for freeing
said shipper-lever, a weft-fork carried by the knock-off lever, and a let-off lever
for the warp adapted to be operated by the knock-off lever, the combination with

page_text: an independent, auxiliary knock-off lever k, mounted on the main knock-off
lever and adapted, when shifted, to actuate the shipper-lever only, a magnet
carried by said lever k, and its armature and armature-lever, of a normally open
electric circuit, including a generator and the coils of said electro-magnet, drops
mounted on the warp-threads and each adapted to fall and complete said circuit
when its warp-thread breaks, thus exciting said magnet, and a tappet carried by
the lay of the loom, the armature-lever being so placed that it is brought into
the path of the said tappet when the armature of the magnet is attracted,
substantially as set forth."
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