US2531944A - Textile machine - Google Patents

Description

Nov. 28, 1950 A. G. B. METCALF 2,531,944

TEXTILE MACHINE Filed Feb. 4, 1946 3 Sheets-Sheet 2 ELECTRONIC RELAY mow 6 r Nov., 28, 1950 A. G. B. METCALF 2,531,944

TEXTILE MACHINE Filed Feb. 4, 1946 3 Sheets-Sheet 3 26 0: 11 ALARM ELECTRONIC g I RELAY I 1 4; P H

ELECTRONIC RELAY II Z ELECTRONIC RELAY Patented Nov. 28, 1950 UNITED STATES PATENT OFFICE TEXTILE MACHINE Arthur G. B. Metcalt, Milton, Mass. Application February 4, 1946, Serial No. 845,410

11 Claims.

The present invention relates in general to textile and similar thread-handling machines, and in particular to the combination with such machines of electrical apparatus for detecting the breakage of a thread.

Heretofore, it has been known to provide travelling threads, filaments, and the like, as for example the threads of warping frames or creels in textile machines, with so-called drop wires or equivalent contactor devices which stop the machine or give an alarm signal by completing an electrical circuit upon the breakage of a thread. Such arrangements are complicated, dangerous, and uncertain in operation due to the fact that the currents involved are usually large, so that the closing of a circuit by a drop wire contactor causes considerable sparking, which, with the lint and dust normally present in the atmosphere around the machine, creates an ever-present hazard of fire and dust explosion. Furthermore the contacts frequently become fouled resulting in failure of the device and the machine may continue to function even though a thread may have been broken.

In the present invention, it is proposed to provide an electronic relay-amplifier between the contactor device and the alarm or motor stop mechanism, so that an extremely minute current is sufiicient to efiect operation, thus greatly reducing the hazard of fire or explosion, and providing reliable filament-break detection and stop motion even upon poor contact of the drop wire contactor.

It is accordingly an object of this invention to provide in a machine for weaving, spinning, or the like, a filament-break detection apparatus which operates positively and reliably under any conditions in which it may normally be used.

It is another object of this invention to provide such filament-break detection apparatus which requires only a very minute current to effect operation, thereby minimizing the dangers oi fire and explosion.

It is a further object of this invention to provide such apparatus for simultaneously indicating the breakage of a filament, and shutting down the machine.

It is a still further object of this invention to provide thread-break detection apparatus of the type described for a loom or the like having more than one bank of travelling threads which will permit ready identification of the bank in which a broken thread exists.

It is still another object of this invention to provide such thread break detecting apparatus in loom a multi-bank loom or the like which will permit ready identification of the bank in which a broken thread exists and simultaneously interrupt the operation of the loom.

Other objects and features of the present invention will become apparent from the following description. The description refers to the drawings in which:

Fig. 1 illustrates partly in electrical scheme and partly in perspective the essential elements of the invention;

Fig. 2 illustrates the invention as applied to a having three banks or warp-forming threads? Fig. 3 illustrates the invention as adapted to provide an indication of the bank in which a broken thread exists in the loom of Fig. 2;

Fig. 4 illustrates the invention as further adapted to provide simultaneously an indication of the bank in which the broken thread exists and interruption of the motor power to the loom;

Figs. 5 and 6 illustrate other types of circuit completing devices that may be used in place or the drop contactors illustrated in Fig. 1.

While it will readily be apparent that this invention will provide improved filament-break detection for any filament-handling machine, the description is directed only to the application of the invention to a textile machine as a convenient illustration. Accordingly, in Fig. 1, thread-break detection apparatus 15 as commonly found in a loom is shown enclosed in a dotted line box and comprises first and second bars of conductive material, l0 and H respectively, substantially parallel and separated from each other by suitable insulating material H. The bars run across the loom beneath threads I4, and conductive drop contactors I3, made of as copper, are supported each upon an individual thread. The contactors l3 are each in constant slideable contact with the first bar l0 and are supported above the second bar ll so that when a supporting thread l4 breaks, the associated contactor l3 will fall and establish electrical contact between the bars I 0 and H.

As hereinabove stated, it has hitherto been customary to employ the drop contactors I3 as switches in a circuit having relatively high current and thereby to close the circuit to operate a relay or other operator device. In accordance with the present invention, an electronic relay Ii, shown enclosed in a dotted line box, which may be 01' any suitable type, as for example that disclosed in Patent No. 2,357,371, to William F. Wolfner, II, dated September 5, 1944, is interposed bea suitable material, such tween the detecting apparatus and the operator means, which may comprise a magnetic relay 29 controlling a contact 35, so that a relatively small current controlled by the contactors 13 will effect operation of the operator means, through the electronic relay. The electronic re lay apparatus 16 comprises generalh' an electronic discharge device or tube 20 having at least an anode 2i, a cathode 22 and a control grid 23. The electron tube 20 is supplied with alternating potent'al at terminals and 26. Bar In may be connected to terminal 26 or both bar and terminal may be grounded as shown. The energizing coil of the relay 29 is connected in the anode, cathode circuit of tube 29. The second bar I l is connected to the grid 23 through the grid terminal 28. As long as an open circuit exists between terminals 28 and 26, condenser 8| is charged by grid current flowing during the half cycles when terminal 25 is positive and the charge provides a suflicient negative grid bias to maintain tube 20 non-conductive during the half cycles when terminal 26 is positive. Relay 29 is, therefore, deenergized. When terminal 28 is connected to terminal 26, or the resistance between the terminal is substantially reduced, as by the dropping of a contact member i3 due to thread breakage, the current through resistance 82 is substantially increased, and the potential drop across the resistance, during the half cycles when terminal 26 is positive, overcomes the bias applied by condenser 81 and renders the tube conductive. Relay 29 is then energized and closes contact 35. It is thus apparent that, upon breakage of a thread M, the associated drop contactor l3 closes a circuit between the input terminals 26 and 28 and effects operation of the electronic relay l8, and therefore of the relay 29 and the switch 35. This switch may control alarm or motor circuits involving relatively great current and power, examples of which are hereinafter set forth in detail.

Referring now to Fig. 2, there is illustrated in part a loom havin vertical supporting columns and 4| and a plurality of contactor devices I5, each including the elongated conductive bars l0 and H. Groups of threads I 4, which may be warp-forming threads, are arranged in banks, of which only one is here illustrated, and supported between the vertical columns 40 and 4| by horizontal runners 42. A pair of conductor bars 10 and H is arranged beneath each bank of threads l4 and upon each thread is suspended a drop contactor 13, as illustrated in greater detail in Fig. 1. Each first bar [0 is grounded and the second bars H are all connected in parallel to the grid input terminal 28 of an electronic relay [6, again as shown in Fig. l. The second bars H may be connected together in parallel as shown, or in series if desired, there being no difference in the result of either of these connections, since the drop contactors l3 all cause switching action in parallel, and if any one of them drops, a switching action will take place and cause the electronic relay IE to become operative. To the output terminals 44 and 45 of the switch 35 there is connected an alarm 46, which may have any desired characteristics, so that upon the dropping of any drop contactor I3 a circuit is closed causing operation of the alarm 46 through the relay l6 and switch 35. A particular type of alarm that is suitable for use with a loom is discussed hereinafter in connection with Fig. 4. s

Fig. 3 illustrates another arrangement of electronic relays\l6 and alarms 46 which may be adopted to provide a signal that will enable one not only to stop the loom, but also to identify the bank in which the broken thread exists. The left hand half of the loom of Fig. 2 is shown in part, including one vertical supporting column 40 and the appropriate ends of the three sets of contactor bars in and II. As heretofore, the first conductive bar in is grounded. However, each second conductive bar H is connected to the input grid terminal 28 of an individual associated electronic relay 16, the relays being distinguished by Roman numerals I, II and III. The negative terminal 25 of each electronic relay is grounded, so that the signal input circuit for each electronic relay is the same as in Fig. l. A separate alarm 46 I, II or III is operated by each relay. Thus, when a thread breaks in any bank, the alarm 46 of that bank will operate, and in addition to giving an alarm, will indicate in which bank the breakage occurred.

To illustrate how the invention may be adapted to indicate the bank in which a thread breakage occurs and simultaneously automatically stop the loom, reference is made to Fig. 4. There in dotted line boxes is enclosed the apparatus of three identical suitable alarms 46 which are adapted to accomplish these purposes. The alarms 46 are distinguished by Roman numerals I, II and III in accordance with the plan of Fig. 3. In each alarm 46 there is included a normally closed switching relay 50 and a lamp 5i. The normally closed relays 50 are all arranged so that their switches 52 are in series with the power to a motor M, which may provide the driving power for the loom. Power is brought to the motor M through appropriate input terminals 54 and 55 and wires 58 and 59, and to these terminals there are also connected in parallel two wires 56 and 51 to carry power for energizing the relays 59 in the alarms 46 In series connection with each relay 50 is the switch 35 of the associated electronic relay I6, I, II or III (illustrated in Fig. 3), and a lamp 5i. The alarms 46 are all connected in parallel to the power input terminals 55 and 55.

When a switch 35 closes, the relay 50 of the associated alarm 46 will operate and open itsswitch 52, thus interruptin power to the motor M and shutting down the loom. Simultaneously, the power for the relay 50 will flow through the associated lamp 5|, and the lamp will light and indicate that the thread bank with which the particular alarm 46 and switch 35 are asso ciated has in it a broken thread. A current return path is provided for each alarm 46 to the terminal 54 through a direct wire 56. An alternative return path may be had to terminal 54 through the unlighted lamps 5i and non-energized relays 50 of the remaining alarms 46 However, this alternative return path offers a relatively large impedance to the flow of electrioal current, and therefore the major portion of return current will fiow through the direct wire 56, and the remaining lamps 5i will not be lighted nor will the other relays 50 be operated. Thus the apparatus of Fig. 3 may be adapted simultaneously to shut off the loom and indicate the bank in which a thread-breakage exists, whenever the breakage of a thread l4 occurs.

As hereinabove stated, relay apparatus "3 of the electronic type is adapted to become operative not only when a positive connection is made between the grid terminal 26 and terminal 26, but also when the resistance between terminals tive switching apparatus as illustrated in Fig. 6.

The apparatus of Fig. comprises an elongated fixed condenser plate 60, and a plurality of movable smaller condenserplates 6|. As illustrated in cross section-holes 63 are provided in each movable plate SI for guiding the plate upon vertical poles 62 mounted on the fixed plate 60. The

poles 62 may be 01' any suitable insulating materiaT such as hard rubber or polystyrene. The

- movable plates 8| are adapted to fall toward the fixed plate Blifand to come to rest on the enlarged base portions 84 of the poles 62. A hook 85 is provided on each movable plate 6| for attachment to a thread M in substantially the same manner as the drop contactors iii are so attached in Fig. 1. Flexible partly coiled wires 68 furnish conductive contact between the movable plates 6| and a bus bar 61 which is further connected to a terminal 68. This last-mentioned terminal 68 is adapted to be connected to the input grid terminal 28 of the electronic relay apparatus IE or similar apparatus. The fixed condenser plate 80 is grounded, or may be connected to the second input terminal 26.

When the hooks 65 are attached each to a thread (not shown), the movable plates 6| are each'held a predetermined distance away from the fixed plate 60. However, when a thread breaks, the associated movable condenser plate GI falls until it comes to rest on the base portions 6| of the guiding poles 62, thus decreasing the distance between the two condenser plates 60 and 6|. This decrease in distance will effect a reduction in the capacitive reactance of the apparatus, and likewise in the impedance of the input circuit of an electronic relay l6 to which it may be connected, thus having an efiect of the same nature as the dropping of a conductive contactor ii to Fig. 1 and causing operation of the electronic relay apparatus in the same manner as discussed above. It is to be noted that there is no conductive contactbetween the plates 60 and BI and hence no possibility of sparking between those plates, and thus the hazard of fires and explosion caused by sparking in the presence of lint, is completely eliminated inthis apparatus.

The switching mechanism of Fig. 6 which is illustrated mainly in electrical scheme, comprises a transformer 10 having a primary winding H and a short-circuited secondary winding 12. The primary H has one end grounded and the other end connected to a terminal 18 which, like the terminal 6! of the apparatus of Fig. 5 is adapted to be connected to the grid input terminal 28 of the electronic relay apparatus IS. A thread-engaging hook 13 is provided on the short-circuited secondary 12 and has the same purpose as the hook .65 of the capacitor switching apparatus in Fig. 5. The short-circuited secondary 12 is adapted to rotate about a point 14 as an axis and is normally maintained in the vertical position illustrated in Fig. 6 when the hook I! is resting on a thread (not shown). The weight of the secondary is preferably so distributed about the point ll-that it will tend to fall to a disposition in which it is substantially parallel to the primary Ii when not otherwise constrained.

When alternating current fiows in the primary has a relatively .low impedance, and a relatively 1 6 winding II and whenthe secondary winding It is disposed substantially p p ndicularly thereto, a relatively high impedance is offered to thefiow or current in the primary winding. However,

when the short-circuited secondary I2 is substantially parallel to the primary 1 I, the primary than large current may be permitted topass. Thus, upon the breakage of a supporting thread (not shown) with which the hook I! may have been engaged, the short-.circuited secondary 12 will fall and permit the passage of a larger current through the primary H by lowering its inductive reactance. Like the capacitive switch 01' Fig. 5, the apparatus of Fig. 6 is adapted to lower the impedance of the input circuit of electronic relay apparatus l6 whenv properly connected thereto. This apparatus also will permit I spark-tree thread-break detection.

Obviously various changes may be made in the above-described articles and different embodiments of the invention can be made without departing .from the scope thereof. It is therefore intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only, and not in a limiting sense, and that the invention is to be limited only by the prior art and the spirit or the appended claims.

What is claimed is:

1. For machines for the weaving, spinning and the like of filamentary material, filament-break detecting means comprising: an electron discharge device having an anode, cathode, and con- 'trol electrode; an output circuit including said anode and cathode; and an input circuit including said cathode and control electrode; a plurality of electrical reactance controlling means arranged in mutually parallel connection in said input circuit and each supported by an individual filament in a predetermined disposition but adapted upon breakage of the supporting filament to assume? and maintain a new disposition and thereby alter the electrical character 01' said input circuit; and operator means adapted to be energized by said output circuit.

2. In combination with a machine for operatingupon a filament, means for detecting the breakage of said filament comprising: an electron discharge device having an anode, cathode and control electrode; an output circuit including said anode and cathode; a variable capacitance comprising, a movable member supported by said filament, and a fixed member; an input, circuit including said cathode, control electrode, and

capacitance, and adapted to render and maintain said discharge device conductive upon the breakage of said filament; and operator means adapted to be energized by said output circuit.

3. In combination with a machine for operating upon a filament, means for detecting the breakage of said filament comprising: an electron discharge device having an anode, cathode and control electrode: an output circuit including said anode and cathode; a variable inductance having a movable member the position of which is altered upon breakage of said filament; an input circuit including said cathode, control electrode and inductance, and adapted to render and maintain said discharge device conductive upon the breakage of said filament and operator means adapted to be energized by said output circuit.

4. A thread break detection device comprising: an electron discharge device having an anode,

contact with said bar; an input circuit including 30 said cathode, a device for storing electrical energy, and said detecting impedance, and adapted to render and maintain said discharge device conductive upon thread breakage; and operator means adapted to be energized by said output circuit. s

5. A thread break detection device comprising: an electron discharge device having an anode, cathode, and control electrode; an output circuit including said anode, said cathode; a variable capacitance comprising a movable member adapted to be supported by a thread, and a fixed member; an input circuit including said cathode, control electrode, and capacitance, and adapted to render and maintain said discharge device conductive upon thread breakage; and operator means adapted to be energized by said output circuit.

6. A device according to claim in which said capacitance comprises a pair of parallel plates maintained in alignment byinsulating studs.

'7. A thread break detection device comprising: an electron discharge device having an anode, cathode, and control electrode; an output circuit including said anode, said cathode; a variable inductance having a movable member, the position of which is altered on thread breakage; an input circuit including said cathode, control electrode and inductance, and adapted to render and maintain said discharge device conductive upon thread breakage; and operator means adapted to be energized by said output circuit.

8. A device according to claim '1 in which said inductance comprises a fixedinductance coil, and a movable coil rotatable with respect to said fixed coil.

9. For machines for the weaving, spinning and the like of filamentary material, filament-break detecting means comprising; an electron discharge device having an anode, cathode and control electrode; an output circuit including said anode and cathode; an input circuit including said cathode, said control electrode, and a capacitance; a plurality of electrical impedance controlling means arranged in mutually parallel connection in said input circuit and each supported by an individual filament in a predetermined position but adapted upon breakage of the supportingiilament to assume and maintain a new disposition and thereby alter the electrical character of said input circuit; operator means adapted to be energized by said output circuit upon breakage of any one of said filaments; and means controlled by said operator means ior interrupting a power circuit independent of said output circuit and for providing a thereafter continuing indication thatsaid breakage has occurred.

10. In combination with a machine for operation upon \filaments, means or detecting the breakage of any of said filaments comprising: I

an electron discharge device having an anode, a cathode and control electrode; an output circuit including d anode and cathode; an input circuit lnciu ing said cathode, said control electrode, and a capacitance; a plurality of impedance controlling means arranged in mutually parallel connection in said input circuit, each 0! said controlling means being supported by one of said filaments in a predetermined disposition,

but adapted upon breakage of its supporting filament to assume and maintain a new disposition and thereby alter the electrical character of said input circuit; and operator means adapted to be energized by said output circuit, said operator means consisting in means for. indicating the breakage of said filament and means for interrupting a power circuit independent of said output circuit, and being adapted upon the breakage 01 said filament to interrupt said power circuit and simultaneously to provide a thereafter continuing indication that said breakage has occurred.

11. In combination with a machine for operating upon filaments, means for detecting the breakage oi any of said filaments comprising: an electron discharge device having an anode, cathode and control electrode; an output circuit including said anode and cathode; an input circuit including said cathode, said control electrode, a capacitance and a plurality of parallel connected detecting impedances, and adapted to render and maintain said discharge device conductive upon the breakage of any of said filaments; and operator means adapted to be energized by said output circuit and when eners zed to interrupt the power supply to said ma chine and to actuate indicating means.

ARTHUR G. B. METCALF.

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

UNITED STATES PATENTS Number OTHER REFERENCES Textile World, July 1945, pa es 83-90, "Elec- 5 tronics at Work for Textiles, by H. E. Reed.

(Copy in Scientific Library.)

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