*****??SR??????R. May 19, ,638, Sheets-Sheet 1. Attorneys. Filed Sept. 21, Inventor T, HNOLE

Transcription

1 May 19, 1953 Filed Sept. 21, 1950 T, HNOLE WEFT DETECTOR AND STOP MOTION FOR WEAVING LOOMS *****??SR??????R 2,638,942 3 Sheets-Sheet 1 VA.V. AYAYAY S. SY N S SL SS S SS SS SS SSSSSLSSSSS S N I y Inventor Attorneys

2 May 19, 1953 T. HINDLE 2,638,942 WEFT DETECTOR AND STOP MOION FOR WEAVING LOOMS Filed Sept. 21, Sheets-Sheet 2 Attorneys

3 May 19, 1953 T. HNOLE 2,638,942 WEFT DETECTOR AND STOP MOTION FOR WEAVING LOOMS filed Sept. 21, Sheets-Sheet 3 Inventor?????????????????? By??????)???htt Attorneys

4 Patented May 19, ,638,942 UNITED STATES PATENT OFFICE This invention relates to looms for weaving and more particularly to improvements in weft detectors and loom stop-motions. The object of the invention is to provide an in proved Weft detector which is sensitive to the ten Sion of the weft as this is laid in the warp shed by the moving shuttle. According to the invention, when the shuttle enters the shed, the weft is caused to loop round a Sensitive detector pin temporarily positioned ciosely adjacent to or actually amongst the Selvage Warp threads near the fell of the cloth, the pull exerted by the weft on the said pin being utilised to close the contacts. Of an electric Switch against the pressure of a light Spring acting to Open them. The invention is illustrated in and Will be de Scribed with reference to the accompanying drawings. In these drawings Fig. 1 is a front elevation, partly in section, of the improved weft detector, which is shown in the detecting position in relation to the Selvage of the cloth being woven; Fig. 2 is a partial cross-section through a loom showing one suitable form of mechanisin for ac tuating the arms which support the Weft detec tors; Fig. 3 is an electric circuit diagram illustrating the action of the detector switches; and Fig. 4 is a timing diagram based on One-revolu tion of the loom crankshaft. Referring to Fig. 1, which illustrates the Weft detector and the manner in which it functions, an approximately vertical detector-pin i, tapered or pointed at its lower end is suitably clamped by screws 2b in a holder 28, which is pivoted at 2 on the inner end of a horizontal holder-bar 3, fixed stops 4 and 4a being provided to restrict the rocking movement of the holder 2 and the detec tor-pin to a Small angle. An electric switch 5 is mounted on the outer end of the holder-bar 3, preferably adjustably, as for instance by means of the collar 5, which forms part of the switch casing, and the Screw 5b. The switch 5, which may be of any suitable type provided with a light spring acting to Sep arate the switch contacts, is actuated by the de tector-pin through a push-rod 6, the inner end of which bears on the detectorspin, or as shown, on its holder 28, a short distance above the pivot 2, and the outer end of which bears on the plung er : 5e of the switch i 5. The push-rod 6 slides, in bushes 3b inserted in a central passage-3 in the holder bar 3. when the weft pull is absent on the detector WEFT DETECTOR AND STOP MOTION FOR WEAVING LOOMS Thomas Hindle, Blackburn, England Application September 21, 1950, Serial No. 185,990 In Great Britain September 25, Claims. (Cl ) pin the contacts of the switch 5 are opened by the switch-spring, and the detector-pin, by rea Son of its unbalanced weight in relation to pivot 2, assumes its natural position, as shown by the centre-line a-b, in which the lower end of the holder 28 rests against the stop 4a. The pull of the weft W looped round the de tector-pin at the picking end of the loom dis places the bottom end of the pin in the direction of the moving shuttle (indicated by arrows in Fig. 1) with the result that the pin then rocks to the position shown in Fig. 1, corresponding to centre-line C-d. Such displacement is trans mitted on a reduced scale by the push-rod 6 to the plunger 5e of the switch 5, so as to close the SWitch contacts, which then remain closed pro vided that the weft continues to exert the neces Sary pull on the detector-pin f. throughout the remainder of the shuttle's flight. When the Weft has pulled the detector, pin to position C-d, so that the holder, 2a, bears firm ly against stop 4, the pin in such position is rigid ly Supported and is well adapted to withstand Without further displacement any snatch or ab normal pull exerted by the weft. The inproved Weft-detector possesses, there fore, the incidental advantage of preventing, in well-known manner, the cloth selvage being pulled in unevenly by irregular weft. tension. In Fig. 1, the WOven clothis indicated in cross section at C, E being one selvage. Wprepresents the warp threads forming the shed, through which the weft W is being laid by the shuttle travelling in the direction indicated by the ar "OWS. In Fig. 2, the Weft W is shown extending be tween the cloth-fell F and the shuttle S passing through the shed formed by the warp threads WP. The weft Wt loops round the detector-pin. The slay is shown in solid lines at Lb in its fully back position, in dotted lines at If in its fully forward position. The horizontal holder-bar 3, is clamped by a Screw 7 approximately midway in its length - at the end of an arm or lever 7, Secured so as to rock With a rocking shaft 8, which is parallel to and is Supported in bearings8 fixed on the front-rest R. Of the loom,. A mechanism constructed and arranged as so far described is provided at each selvage side of the loom and both arims 7 are given a suitable rocking movement in Synchronism with the for. ward-and backward movements of the slay. The rocking shaft 8 may be actuated through any suitable mechanism connected to the slay or its

5 ....? 3 swords, or by a can or cams revolving at crank shaft speed. In the case of very wide looms, the rocking shaft 8 may be in two parts, each actu ated independently, but in unison. Referring to Fig. 2, as the slay retires from its forward position L in anticipation of the next picking operation, the arms 7 swing down to carry the detector-pins into their detecting posi tion, that is, as shown in Fig. 1 and in full lines in Fig. 2, closely adjacent to or actually amongst the selvage warp threads near the fell F of the cloth, with the bottom or pointed end projecting slightly below the plane of the bottom shed. The detector-pin remains in this position until at a suitable time as the slay is again ad vancing towards its front position, shown by dotted lines at Li, the arms 7 swing up, first with drawing the engaged detector-pin in an upward direction from the weft loop, and then swinging both arms and detectors upward and forward out of the way of the slay which is then advanc ing to beat up the weft. The time at which the detector-pin f is withdrawn from the weft loom does not occur until after the shuttle has arrived in the opposite box, so that the detector is sen sitive to the tension of the weft during the major and final portion of the shuttle's passage across the slay. One suitable arrangement of actuating the rocking shaft 8 and hence the arms 7 fixed there on is shown in Fig. 2. In this arrangement the loom crankshaft 9 is provided with a negative cam or cams fo, co-acting with roller if on a follower-lever i?, pivoted at a on the loom framing. The displacement of the lever by the cam O is transmitted by a link 2 to a two arm lever 13 which is pivoted at 3a on the loom framing. A spring 6 anchored at one end to the frame of the loom and at the other end to one arm of the lever 3 acts on the latter to main tain the roller fb carried by the follower-lever in contact with the cam 0. - The upper arm of the lever 3 is connected by link 14 to lever f5 which is fixed to the rocking 2,638,942 shaft 8, on which the arms 7 are secured. Instead of employing a negative cam 0 for 45 actuating the follower-lever? a positive cam may be employed in which case the spring 6 is not required.????. - --? As applied to a wide loom in which the slay 50 movement includes appreciable "dwell'in or near. the back position to allow of the shuttle's pas sage through the shed, the profile of the cam 0 is preferably such that the arms remain up for about one-quarter of the crankshaft's revolu 55 remaining tion and remain two-eighths down sufficing for about for pne-half, the up' and the down movements. The arms 7 supporting the weft-detectors are adjustable along their shaft or shafts - 8 to suit the exact width of cloth being woven. A flexible cable 5e connects each swinging switch 5 to a terminal box or plug 5 mounted underneath the front-rest R The details of the mounting and actuation of each switch may be varied if desired. For ex ample the switches may be mounted on or below the front-rest and be actuated through mechani cal linkage from the detector-pins 1. - The weft-detector mechanism hereinbefore de scribed can be used either to close an electric circuit. or, as is preferred, to maintain an elec tric circuit which would otherwise be broken, as an indication that the weft is intact from the Japp round the detector-pin?? --!?...????....??????????? to????? the... : moving shut :::?????? tle. It may be employed to indicate whether the weft is intact right across the loom's reeded width at or just before the time when the shuttle Com pletes its passage, or at any desired earlier stage in the shuttle's flight after the Weft Should nor mally have looped round and actuated the de tector-pin at the picking end. Such indication may be adapted to control any form or loop stop notion. So as to cause the loon to be stopped in the event of Weft failure. The Weft detector switches 5 act by controlling the circuit of an electro-magnet, the basic prin ciple... being that. Such electro-magnet must be energised, or continue to be energised at the crucial moment if the loom is to continue run ning. Thus if the weft fails to make or to main tain the circuit of the electro-magnet, the loom stops. The loom also stops should the electric supply for the detector circuit fail for any reason. The aforesaid electro-magnet may be con trolled by a pair of weft detector switches, op erating in combination with a cam-actuated weft try-switch, such cam revolving at slay crank shaft speed. Alternatively, the weft try-switch may be actuated by a can or cams mounted on any other shaft, or by an oscillating cam or equivalent linkage connected to the slay or slay Swords, the essential requirement being that the weft try-switch shall open and close at the de sired times in each successive revolution of the loom crankshaft. The two Weft detector switches and the weft try-switch are all three connected in parallel with the electro-magnet and a suit able Source of electric current. Fig. 3 shows Such a circuit arrangement in diagrammatic form, the weft-actuated detector Switches 5 being connected in parallel with the cam-actu ated weft try-switch 7, and then in series with the electro-magnet 8. The cam-actuated weft try-switch T maintains the circuit for part of the crankshaft's revolution, but opens the cir cuit at any desired point during the period the shuttle is normally passing through the shed, during which period one or the other of the de tector switches 5 normally should be closed due to the pull of the weft exerted on the corre sponding detector-pin. In Fig. 4 which shows a timing diagram typical for a wide loom, I represents the crank position at beat-up when the slay is fully forward and W represents the crank position when the slay is fully back. The arms remain up out of the path of the reed from VIII to III. From II to III the arms are lowered to carry the detector-pins into their detecting position, where they remain until WII. From WII to VIII, the arms are lift ing. The picking impulse normally commences at III and the shuttle passage takes place from IV to VI. The weft try-switch opens at about W and remains open until about WI, after which it re-closes and remains closed for the remainder of the cycle. If the weft runs out or breaks so that the ap propriate detector switch 5 is not closed when the weft try-switch fl opens the circuit at about W, then the electro-magnet is promptly de-ener gised and the loom thereby caused to be stopped automatically. Similarly, if the weft is intact when the weft try-switch opens at about V, but subsequently fails before it re-closes at about VI, then the appropriate detector-switch 5 opens with the result that the electro-magnet is de-en ergised and the loom thereby caused to be stopped automatically. -...

6 2,688,942 5 claim: 1. A weft detector motion for controlling the stop motion of a loom comprising the combina tion with an electric switch of a Sensitive de tector-pin, means for temporarily positioning said pin in close relationship to the Selvage Warp threads near the fell of the cloth during the passage of the shuttle across the slay, and a member between said pin and Switch for con trolling the Switch, the movement of the shuttle O causing the weft to loop around the detector pin and exert a pull thereon to move it into a posi tion to operate said member to close the Switch and maintain the Switch closed. So long as the pin remains in close relationship to the Selvage warp threads and the weft Continues to exert a pull on the pin. 2. In a weft detector motion as in claim 1, the combination with the Sensitive detector-pin of a pivot on which it is mounted in a slightly un 20 balanced condition, and wherein Said member comprises a push rod adapted to be engaged by the detector-pin when it is moved out of its neu tral position by the pull of the weft, and said electric Switch has Spring controlled contacts 25 which are closed by the movement imparted to the push rod by the detector-pin due to the pull of the weft, and including an electric circuit containing the Switch and controlling the stop motion of the loom In a weft detector motion as in claim 2, the combination with the Sensitive detector-pin, of a holder rotatably mounted on said pivot and in which the detector-pin is adjustably mounted, a holder-bar in which the push rod is slidably 35 mounted, the holder being pivotally mounted at 6 the end of the holder bar so that the holder and the pin are out of balance, and a housing for the Switch at the opposite end of the holder bar to that at which the holder for the pin is pivotally mounted. 4. In a weft-detector motion as in claim 3, the combination with the detector-pin, the holder therefor, and the holder bar of a rocking arm in Which the holder bar, is carried, and a cam mak ing one revolution for each revolution of the Crank Shaft of the loom, Said can controlling the rocking arm to lower the detector-pin into the detecting position in close relationship to the Selvage warp threads and to raise it therefrom at the appropriate points in the weaving cycle of the loom. 5. In a Weft detector motion as in claim 4, the Combination with the detector-pin, the holder therefor, the holder bar, the rocking arm and the actuating cam of a pivoted follower-lever which is actuated by the cam, a rotatably mount ed Shaft on which the rocking arm is affixed and a lever and link mechanism connecting the foll lower-lever to the shaft. HOMAS HINDLE. References Cited in the file of this patent UNITED STATES PATENTS Nurnber Name Date Buell et al Aug. 15, 1939 FOREIGN PATENTS NUOer Country Date Great Britain May 7, ,855 Germany Aug. 28, 1930