US1101403A - Warp stop-motion for looms. - Google Patents

Description

T. A. B. CARVER.

WARP STOP MOTION FOR LOOMS.

APPLICATION FILED JUNE 8, 1912.

Patented June 23, 1914.

figgzzad ad 1? (ar UNITED STATES PATENT OFFICE.

THOMAS ALBERT BRIGGS CARVER, OI GLASGOW, SCOTLAND,

was? s'roraorron non ooms.

Specification of Letters Patent.

Patented J une 23, 1914.

Application filed June a, 1912. Serial No. 702,557.

This invention relates to an improved construction of the ordinary reed in weaving looms, whereby it is enabled to detect the breakage of a thread of the warp. In

. its simplest form the reed is constructed in the ordinary way, that is by grouping the metallic dents together between pairs of wooden slats at the two ends, the dents being separated by a cord soaked in pitch or similar compound so that they are electrically insulated one from the other.

According to the present invention the dents of the reeds are connected electrically in two groups and included in an electric circuit in such manner that should a dent in one group come into electric connection with a dent in the other group, a current will be established in the circuit which can be used to cause or control the operation of a knockofl mechanism. Each dent is provided with a contact piece which tends to establish this circuit by coming into engagement with an adjacent dent or a projection therefrom, but these contacts are normally held out of engagement either entirely by the warp threads or by a comb with insulating fingers which are withdrawn at one point of the movement of the reed so that the contacts are then held off by the warp threads only. Consequently should a warp thread break, the energizing or controlling circuit of the knock-off is established by the two adjacent dents coming into electric connection, and

section of the same taken on a plane between two dents; Figs. 4 and 5 are detail yiews drawn to an enlarged scale illustrating the operation of the detectors of the modified reed of Fig. 2; Fig. 6 is a diagrammatlc view showing the subdivision of the reeds into a number of groups, the electrical circuits of which are controlled by a commutator, and Fig. 7 is an end view of such a commutator; and Fig. 8 is a diagrammatic view of a differentially wound relay, the operation of which is controlled by the detector circuit.

As shown in Figs. 1 to 5 the dents of the reeds are connected electrically in two groups a and b and each group is connected in a circuit which includes a battery and preferably also a switch (not shown in the drawings) which is normally open until that period of motion of the loom at which the reed approaches its back position and the threads of the warp are raised to the full opening of the shed, the switch being then automatically closed so that, should a warp thread be broken, the circuit will be completed through the dents as hereinafter de scribed.

In the preferred construction of detectors of the above character each dent a (or b) of the reed is provided with a springy projection which may be in the form of a tongue (1 (or b) stamped out of the dent itself and of such length and set that if unrestrained it will touch its neighboring dent. These springy projections are so disposed that when the shed is opened and the reed is in its back position and when, if the warp is perfect, there is one thread (1 raised to the highest position in each split 6 of the reed, the threads of the warp are then in such position that they interpose themselves between the springy projecting tongues a, b and the neighboring dents b, a respectively, so that the threads themselves provide a breakage of connection between the springy projection of one dent and the neighboring dent. The tongues'are not central in the dents, those in one group of dents being toward one edge and those of the other group toward the opposite edge of the respective dents, so that each tongue will be opposed to a solid part of its neighboring dent, as shown in Fig. 3.

In weaving practice it is of course important to relieve the threads of the warp of any pressure in the reed, such as that which might be applied by the springy projections a, 6, described working without further provision, and in order to relieve thethreads of the warp from any undue friction, the springy projections are made of such a shape, 6. g. by having their free ends turned inward, that an insulating plate or fin er f disposed between each pair of dents 0 the warp raised to the full opening of the shed,

. for example as that the warp is so this comb of insulating fingers is moved in a direction lengthwise of the dents and awayfrom-the sprin s, so as to release the spring tongues a, b and permitthem, if unrestrained by a thread of the warp, to spring into contact with the ad acent dent.

The means for periodically moving the comb may be of any suitable nature, such that of the mechanism frequently employed for actuating the p1n rails in a lappet loom, and may comprise a cam member driven from the main shaft of the loom and co-acting with alever 's stem operatively connected with the com in such a manner that when the lever system 1s intermittently actuated by the cam the comb will be withdrawn and held out of engagement with the springs. The comb may be adapted to return under the action of gravity to a position wherein it presses against the springs, or it may be positively returned by cam actuated lever mechanism or other means.

The action of the detecting arrangement in the loom as described of course assumes drawn into the heddles and drawn into the reed that at each period of the loom one thread in each splitis.

raised, and the action asdescribed provides a complete warp stop motion in suchinstances. Cases in which there one thread raised in each split at-eachperiod of the loom. may be met by connecting the I dents of the reed into suitable separate a number of,

groups, making one oup or another active or inactive by a simp e threads in the reeds. Such an arrangement with one group a of dents, group b is divided into I sub-groups which are "severally connected through a commutator g with the other pole of the battery 0. The commutator is provided with contact devices-'9", which are so disposed that by" bringing the commutator any desired number of the sub-groups of the dents may be connected with or disconnected irom the battery 0.

may not be" form of commutator. in accordance with the disposition of the one pole of the Electrical warp stop motions are of course well known and simplification is aiforded by electrical action, especially where contact is made, as in the a paratus described, in the immediate neighborhood of the threads themselves. 'But they are all subject to the disadvantage that the making and breaking of the circuit in the immediate neighborhood of the inflammable warp is dangerous on account of the inevitable spark. In order to reduce thls danger to a minimum, an electrical relay is provided in association with the circuit of the detecting apparatus, so that the circuit kept open by the thread is one which when closed need convey only a minute amount of electrical energy, but sufiicient to control by means of the relay the establishment of another circuit by which the knock-off mechanism is operated.

In one form of relay suitable for the purpose (illustrated in F i 8) a very small electromagnet h is wound differentially with two coils of fine wire one of which i is included in the detector circuit, while the other '21 is traversed by a current from a suitable source of just sufiicient strength. to .hold the armature against the action-of a spring or gravity, so long aswthe' detector circuit is not established. momentary closing oft-he latter, however, sufiices. to neutralize-mm magnet andjfthereby' 'rel-ea'se"gthearmature-to 7 close the circuitpwhich"controls-the knock ofi mechanism.

Having thus described my nvention and the best-meansI know ofcfarrying the same into practical efiect,fI'claim-:-=- I Q1}? 1; In warp stop, motionslffor lobms, the combination of knock ofif mechanism. a normally open electricalcircu' controlling-themechanism, a reed comp i ing to make. electrical-contact with an 'adja- I-y' cent. dent andthereby 'efiect closure 01. 1 the electrical clrcuit', each of said fcontacts being" adapted to be held, out of contact with the.

adjacent dentby a warp thread interposed v between'fthe contact Land the dent? and ,un

broken. I 2.1a warp stop. motions. for looms, the

y combmatlon of knock off mechanism, arnormally open'electrical circuit'c'ontrollingthef mechanism, a-reed comprising a number; of

dents, a, spring" contact formed integrally with each dent normally tending to make electrical contact withI-anadjacent dent and thereby effect. closure of the electrical circuit, each of said contacts being adapted to be held out of contact with the adjacent dent by. a warp thread interposed between the contact and the dent and'unbroke n.

3. In warp stop motions for looms, the combination of knock ofi mechanism, a normally open electrical circuit controlling themechanism, a reed comprising a number of V 105, ing ',a,,number, ,oi dents,- a contact'on each dentnormally tend posed between the contact and the dent and unbroken. Y j

4. In warp stop motions for looms, the

" 1 combination of-knock'oii mechanism, a norlow mally. open'electrical circuit controlling the mechanism, a reed comprising a plurality of dents arranged in pairs of'groups and a contact device on each dent, each contact in a group normally tendi'nglto make electrical contact with a neighboring dent of the felgroup of a pair so as to effect closure of theelectrical circuit, and adapted to be held out of contactwith the said neighboring dent by an unbroken warp thread interposed between the contact andthe dent.

5. In warp stop motions for looms, the combination of knock of! mechanism, a normally open electrical circuit controlling the mechan1sm,'a reed comprising a plurality of dents arranged in pairs of groups, a contact device on each dent, each contact 111 a group normally tending to make electricallcontact with a neighboring dent of the fellow group of a pair so as to efiect closure of the electrical circuit, and adapted to be held out of contact with the said neighboring dent by an unbroken warp thread interposed between the contact and the dent, and a comb with insulating fingers normally disposed between eachcontact device and its neighboring dent and means operating during the movement of the reed'to withdraw the fingers from their normal position as and for the purpose described.

6. In warp stop motions for looms, the combination of knock off mechanism, a normally open electrical circuit controlling the mechanism, a reed comprising a plurality of dents arranged in separate pairs of groups, a contact device on each dent, each contact in a group normall tending to make electrical contact with a neighboring dent of the fellow'group of a pair so as to effect closure of the electrical circuit, and adapted to be held out of contact with the said neighboring dent by an unbroken warp thread interposed between the contact and the dent,

and means adaptedto render a desired number of the separate groups of dents inactive with respect to the establishment of the electrical circuit."

7. In warp stop motions for looms, the combination of knock ofl mechanism, a normally open electrical circuit controlling the mechanism, a normally open electrical detector circuit, a differentially wound relay interpolated between the detector circuit and the said first circuit and controlling the said first circuit, a reed comprising a number of dents and contacts carried by each dent normally tending each to make electrical contact with an adjacent dent so as to eflect closure of the detector circuit whereby the relay'is actuated to close the first said circuit so as to operate the knock ofl" mechanism, each of said contacts adapted to be held out of contact with an adjacent dent by an unbroken warp thread interposed between the means and cooperating dent.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

THOMASALBERT BRIGGS CARVER. Witnesses:

WILLIAM LAMONT, ANDREW Soorr.

Images