US2613692A - Textile detecting device - Google Patents

Description

Oct. 14, 1952 w. c. ANDERSON TEXTILE DETECTING DEVICE 2 SHEETS-SHEET 1 Filed Dec. 2. 1948 M HER p. Qwzrassw Oct. 14, 1952 w. c. ANDERSON TEXTILE DETECTING DEVICE 2 SHEETS-SHEET 2 Filed Dec. 2, 1948 INVENTOR WILMER C. ANDERSON Patented Oct. 14, 1952 2,613,692 TEXTILE DETECTING DEVICE Wilmer C. Anderson, Greenwich, Conn, assignor to Deering Milliken Research Trust, Greenwich, Conn., a nonprofit trust of Maine Application December 2, 1948, Serial No. 63,177

14 Claims. 1

The present invention relates to weft detectors for looms and comprises a novel device of this character which is particularly adapted for use in the weaving of very fine yarns or of yarns of low or zero twistf When a shuttle carried bobbin is nearly depleted of weft, it is important, in order to avoid the running out of the weft in the middle of a pick, that the loom be stopped or that the weft supply be replenished either-by substitution of a fresh bobbin for the exhausted bobbin in the shuttle or by substitution of a shuttle carryin a fresh bobbin.

Modern high speed looms are equipped with fingers or feelers which detect near exhaustion jof the weft supply by physical engagement with the bobbin when the lay is in the forward position. When very fine yarn is used for the weft, the yarn is unduly damaged by this repeated contact with the feelers. If the damage causes breakage of theyarn, there will be a large numberof loom stops during the weaving. If the yarn does not break but is damaged, inferior fabric will be woven.

To'avoid physical contact of feelers with the yarn various arrangements involving the use of photoelectric devices have Previous to the presentinvention, however, no

been suggested.

commercially feasible photoelectric Weft detector has been developed, as each of the previously suggested arrangements failed to meet one or more of the following essential qualifications for a practical construction of weft detector.

There should be a relatively large change in incident light on the light sensitive element of the photoelectric cell as weft nears depletion.

'The detector should operate with bobbins or quills of substantially standard construction. Slotted quills are relatively weak and tend to crimp the yarn in contact with the slots. Special jforms of quills add to the cost of the equipment. The construction should be compact and have .no parts mounted on the law for movement therewith.

invention meets each of the above requirements as will be apparent as the description proceeds. The detector signifies weft depletion when the intensity of light incident on the sensitive element of a photoelectric cell decreases sufficiently light is obtained for signifyin weft depletion. The detector includes blanking means for preventing actuation of the device when the shuttle is not in viewing position. These means, in the preferred embodiment of the invention, comprise a mirror positioned to reflect light to the photocell except when the shuttle is in viewing position and a shuttle engaging finger for automatically movin the mirror from light reflecting position when the shuttle is in the left hand box and the lay approaches the extreme forward position.

The detector is of compact, simple and sturdy construction, can be readily mounted on the frame of a loom and has a relatively long useful life. The circuit requires but few elements and is readily adjustable for change of sensitivity. As two lamps are preferably included in the circuit, either one of which alone provides sufficient light for illumination of the photoelectric cell, the possibility of false indication of weft depletion is rendered almost nil. In the event of failure of any other part of the circuit the weft on the bobbin will run out and the loom will stop under its regular stop motion.

For a better understanding of the invention reference may be had to the accompanying drawings in which one specific and preferred embodiment of the invention is illustrated.

. Fig. 1 'is a circuit diagram detector; g Fig. 2 is a side view of the detecting unit, outlet box and the supportin bracket therefor;

Fig. 3 is a bottom plan view of the detecting unit showing the mounting of the reflecting mirror and control finger therefor;

" Fig. 4 is a view of the detector unit taken'from the left of Fig. 2 with part of the casing broken away to show the relative locations of the exciting lamps and photoelectric cell; some strucof the new weft 'tural parts being omitted for simplicity;

Figs. 5 and 6 are side views, partly diagrammatic showing how the mirror is retracted when tector includes a step down transformer 2, the

ends of the primary of which are connected, through suitable fuses t0 t prongs, 5a and 6b, of a three-pronged plug 6. A pair. of parallel connected low voltage exciter lamps, 8 and I0, are connected in series with a resistor ll across the secondary of transformer 2. A gas filled tube 12, indicated as a tetrode, has its anode conheated through the windings of a relay M and one of the fuses to prong 6a and its cathode connected through a resistor 16 and the other fuse to prong 6b. The cathode heater is connected across the secondary of the transformer and the control grid is connected through a resistor l8 to 3 a movable tap 26 on a resistor 22. Resistors 22 and I6 and a third resistor 24 are connected in series across the prongs 6a and 6b. A photoelectric cell 28 has its anode connected to the control grid of tube [2 and its cathode connected to the prong 6b. The third prong 6c of the plug 6 is connected to a front contact 1411 associated with the armature 30 of relay 14, a suitable condenser 32 being connected across the leads to the armature and front contact of the relay to prevent sparking. A condenser 34 is connected across the relay winding.

The plug 6 is adapted to be inserted into a socket 36 with its prongs 6a, 6b and 60 connected, respectively, to terminals 36a, 66b and 360 of the socket. Terminals 36a and 36b are connected, respectively, to lines L1, L2, which may be, and preferably are, 60 cycle 115 volt supply lines, line L2 being the grounded line. A solenoid 38 is connected across terminals 360 and 36b of the socket.

With the above described circuit, when the plug 6 is inserted in the socket 36, the lamps 8 and ID will be lighted as alternating voltage from the power lines will be impressed across the transformer primary through the mating terminals of the plug and socket. The cathode heater of tube [2 will receive current from the secondary of the transformer and the anode of the tube will be connected through the winding of relay l4 and the plug and socket to the ungrounded power line.

The voltage of the power lines will appear also across the series connected resistors 24, 22 and I6, raising the potential of the control grid above that of the cathode and causing tube [2 to pass current if the photoelectric cell 28 is not conducting current. The control grid of tube l2 will be biased to cut-01f if the photoelectric cell is rendered conductive by light from the lamps 8 and H1. As will be described in connection with Figs. 2 through 6, the photoelectric cell is positioned out of the path of the direct beams of light from the lamps but is kept illuminated by reflected light except when weft nears depletion. When the tube I2 is biased to cut-off the circuit of solenoid 38 is open at contact l4a of relay l4. When however the cell 28 is rendered non-conducting, that is when light is not reflected thereto, relay I4 is energized to pick up its armature 30 and thereby close the circuit of the solenoid 38, the circuit being from the line L1, terminal 36a of socket 36,

prong 6a of plug 6, armature 36, contact Ma, prong 6c of the plug, the terminal 360 of socket 36, and solenoid 38 to the ungrounded power .line L2.

All of the elements of the circuit of Fig. 1 with the exception of the plug 6, socket 36 and solenoid 36 are adapted to be mounted within a relatively small housing and supported as a. unit on a bracket which also carries an outlet box for the socket 36. In Figs. 2 to 4 to which reference may now be had constructional features of the unit are shown. In Fig. 2 the reference numeral 40 indicates the housing within which are positioned the various elements of the circuit heretofore described. The housing has rigidly secured thereto a pair 'of'angle pieces 42 and these pieces are supported above a plate 44 by means of shock proof tubular mounts 46. The plate 44 is mounted on the upper end 48a of an inverted L-shaped bracket 48 by means of a bolt 50 and a nut 52, the bolt passing through an elongated open ended slot 54 in the bracket end 48a which permits of horizontal adjustment of the position of the housing 40. A flexible conductor 55 connected across the angle piece 42 and the plate 44 provides a ground connection for the casing. The plate 44 extends only part way across the bottom of the casing (see Fig. 3) and a window 56 is provided in that part of the lower wall of the casing which is unobstructed by the plate 44. As shown best in Fig. 4, the lamps 8 and I6 and the photoelectric cell 28 are mounted .in the casing above the window. Mounted in the casing beneath each lamp is a small spherical lens 58 which confines the light from the lamp into a relatively narrow beam and prevents direct illumination of the cathode of the photoelectric cell.

A relatively thick sheet 60 of hard rubber or the like, cut in a generally U-shaped form, is mounted on the under side of the plate 44 by means of screws 62 which pass through elongated slots in the sheet. A block 64, also of hard rubber or the like, is mounted on the plate 44 between the ends of the legs of the piece 65 so as to 'form therewith a rectangular opening 66. The block 64 and the end of the piece 613 remote therefrom have pairs of aligned passages therethrough and a pair of rods 68 extend through the passages in the block 64 and into the passages in piece 60, the size of the passages being large enough'to permit the rods to slide freely therein. An arm 76 is fixedly mounted on the rods 68 within-the opening 66. Biasing spring 12, surrounding the rods and confined between the arm 10 and the part of the piece 66 corresponding to the'base of the U, urge the arm against the block 64. A mirror 14 is secured to the ends of rods 68 so as normally to underlie the window 56. At the lower end of the arm 10 is screw threadedly mounted a horizontally projecting finger '16 having a rounded head 18 adapted to engage the side wall of a shuttle during operation of the device. A nut 86 permits of ready horizontal adjustment of the finger 16.

The front wall of the casing 40 is provided with an outlet 82 for a cable 84 comprising the leads to the plug 6. On the same wall of the casing 46 is an adjusting screw 86 which is connected, inside the casing, with the tap 20 on the resistor 22 so that the sensitivity of the unit may be adjusted externally of the casing.

Bolted to the L-shaped bracket 48, adjacent the lower end thereof, is an outlet box 88 for accommodation of the socket 36. The box 88 has a suitable opening in the side thereof for admission of power leads and leads from a solenoid such as solenoid 38 of Fig. 1. An elongated slot 9| is formed in the bracket 48 for accommodation of a bolt 93 by means of which, and of a nut 95, the bracket may be adjustably mounted on the frame of a loom.

The above described unit is so mounted on a loom with reference to the lay and the shuttle boxes carried thereby that when the lay is in the extreme forward position, the head 18 of finger l6 protrudes into the side opening in a shuttle box as indicated in Figs. 5 and 6, wherein the left hand shuttle box of a loom is indicated at 89, a shuttle at 9| and a bobbin at 33. When the shuttle is not in'the box the head 18 does not meet any obstruction, as shown in Fig. 5, and hence the mirror [4 remains in place beneath the window 56 of the housing. When, however, the shuttie is in the box, as indicated in Fig. 6, the head [8 is engaged by the side wall of the shuttle, finger 16 and arm I6 are moved forwardly (to the right as shown in Fig. 6) carrying the rods 68 and mirror '14 therewith and compressing the springs 12. The light from the lamps 3 and I0, assuming that the weft is not depleted, is then reflected fromt he weft on the bobbin 93 back to the cell heretofore indicated, the quill is painted-black,

the light deflected thereby will be insufficient to render the cell 28 conducting. Consequently the potential on the control grid of tube l2 will rise and the tube will pass current to energize the relay I4 and close the circuit of solenoid 38.

Energization of the solenoid 38 may initiate a actuation of quill changing or shuttle changing mechanism or may effect loom stoppage as desired. In a Draper rayon loom, for example, the movable element of the solenoid may be attached tothe lifting lever connecting rod of the quill changing mechanism. Fig. 7 illustrates such an arrangement. In Fig. '7, the conventional lifting 1 lever connecting rod of a quill changing mechanism is indicated by the reference numeral 92 and the movable element of the solenoid 38 is shown as connected thereto. In such type of loom the casting, indicated at 94, ordinarily provided for themounting of the conventional finger ,type' weft detector can be conveniently used for mounting thereon. of the L-shaped bracket 48 andyalso for mounting thereof the solenoid 38.

In Fig. 7 theshuttle 9| is shown as boxed in the "leftghand box 89. The box is mounted on the lay 96 which reciprocates toward and away from the "detector unit as indicated by the double-ended -arro w-98. The picker is indicated at l00,'picker stick at I02 and shipper or starter handleat I04.

The various parts of. the weft replenishing mechanism controlled by the lifting lever connecting rod 92 have not been illustrated in Fig. '7 as they hold 38 may be considered as the relay controlling the weft replenishing mechanism of such looms. For details of such mechanism, see pages 17 and60 of thesection on Crornpton- 8: Knowles Rayon Looms inthe above cited textbook.

From the above description of one specific em bodiment of the invention, it willbe apparent that'the new weft detector comprises asimple positive acting device which may be economically constructed and readily mounted on a loom for control either of weft replenishing mechanism D er loom stop mechanism. The described construction permits of ready adjustment of the parts. The level of the detector unit with respect to the lay may be adjusted by means of the slot and bolt connection in the mounting bracket. The slot in the upper end of the bracket permits adjustment of the detector unit toward and away from the forward position of the lay. The screw 85 permits adjustment of the sensitivity of the circuit after mounting on the loom and the shock mounting between the plate M and casting protects the circuit elements from the vibrations'of are loom frame during operation. The provision of; the reflecting mirror with its actuating finger engageable by the shuttle ensures against false indications during the periods when the shuttle is not in viewing position. The casing enclosing. all circuit elements affords protection against should be provided with an opening for passage of the mirror controlling finger therethrough but shuttle boxes ordinarily are so constructed. As the operation of the above described device depends upon a decrease in reflection of light as weft nears depletion, it is, of course necessary that the detectorbe used only on looms weaving weft of greater defiective power than the bobbin upon which it is wound. This does not restrict the prime field of use of the new detector as fabric woven from fine yarns having low or "zero twist, such as low denier filament rayonfwhich is the type of yarn subject to injury when physically contacted by conventional feelers, is ordinarily dyed afterbeing woven and hence; the weft on the bobbin will be light in color and have high reflective power. By suitable adjustment of the sensitivity control, however, the detector can be made to operate satisfactorily when there is but relatively slight difference in reflectivity between the dull black bobbin and the surface of the weft. r

Obviously Various changes could'be'made in the specific construction illustrated and described and various features could be omitted without ideparting from thespirit of the invention'asdefined in the appended claims; for example instead of using a retractable reflecting mirror for I maintaining the solenoid deenergized during the periods when the shuttle is not in viewing'po'sition, switches operated by moving parts of the loom could be employed if desired either to maintain the control tube deenergized or 'to hold open the solenoid circuit, during such periods and such alternative arrangements is within the intended scope of the invention. Other modifications such as the omission of one of the excitingla'mps, or the inclusion of a pilot lampor othersignal to indicate normal or abnormal operation of the detector will occur to those skilled in the art. The following is claimed: l 1 1. The. loom having a shuttle carrying a supply of weft, the combination comprising a light sensitive element, means actuated in response to a change in the illumination of said element for signifying weft depletion, a source of light-for illuminating said element by reflection from the surface of the weft when the shuttle-is in one position and means including a reflector effective to direct light from said source to said element except when the shuttle is in said one position for preventing actuation of said signifyingmeans except when the shuttle is in said one position. 2. The combination according to claim 1 wherein said last mentioned means comprises a reflector, means normally biasing said reflector into a position to reflect light from said source to said element and a finger engageable by the shuttle as the shuttle moves into said one position for moving said reflector from said reflecting position.

3. In a loom having a shuttle carried'weft supply, a fixed source of light, a light responsive element'in fixed position, reflecting'meansinormally positioned to reflect light from said source .to said element for illumination thereof, means responsive to a decrease in illumination of said element for signifying weft depletion; and-means actuated by normal operation of the loom for intermittently moving said reflecting means out of reflecting position for rendering the illuminationof said element dependent upon light reflected from the surface of the weft in the shuttle. 4. In a loom, the combination with a weft replenishing mechanism and a shuttle carried bobbin, of a device for initiating actuation of said mechanism comprising means for creating a fixed beam of light, a light sensitive element positioned to receive light reflected from the bobbin when the bobbin enters the beam, means controlled by said element for initiating actuation of the weft replenishing mechanism upon a decrease in the intensity of reflected light received by said element indicative of a depleted bobbin and means for preventing initiation of actuation of the weft replenishing mechanism by said last mentioned means except when the bobbin is illuminated by the beam.

5. The combination according to claim 4 wherein said element is a photoelectric cell-and said means controlled thereby includes an electronic tube which when energized initiates actuation of the weft replenishing mechanism and a circuit controlling energization of said tube, said circuit including said photoelectric cell. I

'6. The combination according to claim 5 wherein said tube has a control grid and said photoelectric cell is connected thereto to bias the same to cut-off when rendered conductive by illumination.

'7. A weft detector for actuation of an element of a loom which, when actuated, signifies deple- I tion of the weft on a shuttle carried bobbin, comprising in combination a circuit adapted when energized to actuate said element, a source of light, a photoelectric cell adapted when conductive to prevent energization of said circuit and positioned to be rendered conductive by light from said source reflected from the surface of weft on the bobbin in one position of the shuttle and means for preventing energization of said circuit except when the shuttle is in said one positi on,-said last mentioned means comprising a memberbiased into a position toreflect light from said source to said cell and means operative as the shuttle enters viewing position to move said member against its bias out of light reflecting position.

8. The weft detector according to claim 7 wherein said circuit includes a thermionic tube source of light, a light sensitive device fixedly positioned out of the direct path of light from said source, movable means biased into a position to reflect light from said source to said device, means controlled by said device and responsive to a substantial decrease in illumination thereof for actuating said element, and means responsive to normal operation of the loom for moving said reflecting means against its bias out of light reflecting position, said last mentioned means operating when the shuttle carried bobbin ated to signify weft depletion and with a shuttle carried bobbin having a surface of low reflective power, said unit comprising a bracket adapted to be mounted on the frame of the loom, a housing mounted on said bracket, said housing having a windowin one wall thereof, circuit elements including a lamp and a light sensitive device mounted within said housing adjacent said window, a light reflecting member carried by said bracket and movable into and out of position to reflect light from the lamp back through the window to illuminate said light sensitive device, means biasing said member into light reflecting position, a finger rigidly connected with said member for moving the same against said biasing means upon engagement with a regularly moving loom part, and means for connecting the circuit elements in said housing with the means for signifying weft depletion for actuation thereof upon a predetermined decrease in illumination of said light sensitive device.

12. The weft detecting unit according to claim 11 wherein the window is in'the lower wall of the housing and said bracket is so mounted on the frame of the loom that the window in the housing overlies the shuttle when the lay is in the forward position and wherein said finger is positioned for engagement by the shuttle as it moves into viewing position whereby the light sensitive device will be illuminated during the period when the reflecting member is moved out of reflecting position only when sufiicient weft is on the bobbin to reflect light thereto.

13. Theweft detecting unit-according to claim 11 wherein one of said circuit elements is a thermionic tube having a control grid, and said light sensitive device is a photoelectric cell connected to the control grid to bias the same to cut-off when rendered conductive by illumination.

14.'The weft detecting unit according to claim 11 wherein one of said circuit elements in said housing is adjustable for changing the sensitivity of the unit, and wherein means accessible from without the housing are provided for adjusting said last mentioned circuit element.

WILMER C. ANDERSON.

REFERENCES CITED 7 The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,026,146 Turner Dec 31, 1935 2,026,147 Turner Dec. 31, 1935 2,026,148 Turner Dec. 3 1, 1935 2,026,149 Turner Dec. 31, 1935 2,431,340 Payne ..4 Nov. 25, 1947 2,432,171 Payne Dec. 9, 1947 2,432,793 Payne Dec. 16, 1947 2,522,101 Dion et a1 Sept, '12, 19-50

Images