CS198167B2 - Apparatus for detecting malfunction of weft feeler in weaving looms - Google Patents

Abstract

1510214 Weft detectors NISSAN MOTOR CO Ltd 1 May 1975 [8 May 1974] 18160/75 Heading DIE A weft detector for a loom comprises a detecting means such as finger 128 which will detect the presence of a weft and produce an electric signal and electronic circuitry which if said signal persists for a time shorter than a predetermined period allows the loom to operate but if longer than said period stops the loom. As shown an arm 126 is pivotable by means of a solenoid 142 and a detector 128 pivotable on the arm opens a switch 130 if a weft holds detector 128 as arm 126 turns, a timer circuit 150 compares the pulse length of signal produced by a NOT circuit 148 to a standard and if the signal is shorter, an AND circuit 152 operates. A second AND circuit operates from the output of AND circuit 152 and a reed operated output 156.

Description

The present invention relates to a device for detecting a malfunction of a weft detector of a loom.

Modern weaving. the state is normally provided with a weft detector that senses the end of the weft yarn that is swept to the opposite side. shed than where the weft clogging device lies. When the weft thread reaches after. the second one. on the side of the shed, the pracuje state continues to work, while the weft detector stops the state when it is under arrest.

However, when the weft detector malfunctions, for example by the action of a loose fiber adhering to the electrodes, or when the detector components are damaged or dropped, it works. the condition continues even if the weft thread does not reach the other side of the shed, which results in the fabric being fabricated to be defective.

It is an object of the present invention to overcome this disadvantage and to detect an actual malfunction of the weft detector.

The object of the invention is a device for detecting a malfunction of a weaving loom detector, whose output signal changes from first level to second level during each operating cycle of the state from the beginning of the beam movement from the starting position through the bump to the return of the beam to the starting position. it returns to the first level, while in the case of a weft detector malfunction it changes from the first level 'to the second' level and remains on the second level throughout the weft detector malfunction; of the invention. characterized in that an electrical control circuit is connected to the weft detector in which a comparison timing circuit is connected to compare the length of the output signal from the weft detector. with a predetermined time interval, the interval being longer than the time for which the output signal is in the second level when the weft is correctly inserted into the shed, and to output the output signal for the duration of the second level signal for a period exceeding predetermined time. a predetermined time interval, and a pulse generator to transmit a signal once every cycle of which. the outputs are connected to. the inputs of the logic circuit to transmit an error signal when the signal comes from the comparison timing circuit and the pulse. generator.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of the electro-mechanical portion of the first embodiment of the ' device ' of the invention; FIG. 2 is a diagram of the electrical control circuit that forms the electrical portion of the first embodiment;

198187 FIG. 3 is a schematic view of a second embodiment of the device according to the invention.

Referring to FIG. 1, the cordless jet condition is provided with a metering roller 10 which is driven by a drive (not shown) from the condition and engages the pressure roller 16, thereby pulling the weft yarn 12 from the bobbin 14 at a predetermined speed; The weft yarn 12 passing between the metering roller 10 and the pressing roller 14 is fed through the inlet tube. 18 into the tubular storage chamber 20, where it is temporarily looped by the action of an air stream 21 that flows through the tubular storage chamber 20 to its outlet end 22. The clamping device 24 serves to temporarily clamp the weft yarn 12, which exits through the outlet 26 from the tubular storage chamber 20. Once the weft yarn 12 is released by the clamping device 24, it is entrained by the pressure medium jet through the nozzle 28 into the shed 30 between the planes 36. 38 strained. warp threads. 32, raised and lowered by the first healds 34. The weft yarn 12 introduced into the shed 30 is stamped to. The second healds 44 form, in synchronism with the first healds 34, a control shed 46 of the warp threads 48. The twisting device 50 serves to twist the control warp threads 48 so that the end of the weft thread 12 is firmly engaged in the shed after the stroke. . 46 between the warp threads 48. The twisting device 50 is driven by a pulley 52 which is driven by a belt 54 of a drive pulley 56 mounted on a drive shaft 58 of the condition. The cutting device 60 positioned between the fabric 40 being fabricated and the twisting device 50 serves to cut the end of the weft yarn 12 trapped between the check warp yarns 48.

The loom comprises two electrodes 66, 68 which form part of a device for detecting a weft detector malfunction and at the same time serve to monitor weft picking. The first electrode 66 is fixed by the bracket 70 to the beam 42 and is grounded therethrough, the second electrode 68 is fixed by an insulating means. The electrodes 66, 88, between which there is a gap, form part of a weft detector (not shown) which it senses. at each weft introduction cycle. the end of the weft yarn 12 on the opposite. the end of the shed 30 than where the nozzle 28 is located, and stops the state when the weft thread 12 has not passed through the entire shed 30.

FIG. 2 shows an electrical control circuit 74 that forms a second portion of the device of the invention. In the electrical control circuit 74. both electrodes 66, 68 and a DC power supply 76, such as a battery, are connected. The second electrode 68 is connected to one of the two input terminals of the preamplifier 78, the second input terminal of which is connected to a DC source 76. The electrodes 66, 68 serve as fixed contacts, while the weft thread 12 forms a movable contact so that the electrodes 68, 68 and the weft thread 12 together form a switch. When the electrodes 66, 68 come into contact with the weft yarn 12, it passes through them to the preamplifier 78. an electrical signal indicating the presence of the weft yarn 12. In the preamplifier 78, the electrical signal is amplified and outputted. in the preamplifier 78, a rectangular signal of a predetermined level appears. The preamplifier 78 is connected to the input terminal of the comparison timing circuit 82, which produces an output signal when the output signal of the preamplifier 78 is shorter than a predetermined time interval, and conversely stops outputting the output signal. when the preamplifier output signal 78 applied to its input lasts longer than a predetermined time interval. In this case, the predetermined time interval is longer than the time for which the electrodes 66, 68 contact the weft yarn 12, i.e. the time from. touch. weft yarns. 12 - and electrodes 66, 68. until the end of the beat. The comparison timing circuit 82 is connected to the input terminal of the negator 84, which does not output the output signal or, as will be explained below, does not produce an output signal when the input signal from the comparison timing circuit 82 is present, The negative 84 is connected to one of the two input terminals. the logic circuit 86, which in a particular case is a product circuit. The apparatus further comprises a pulse generator 88 that generates a pulse signal at a predetermined time while the beam 42 moves from a prone to an opposite position. The predetermined moment lies beyond said time interval. The pulse generator 88 consists of a rotary arm 90 that rotates synchronously according to the working condition. A permanent magnet 92 is attached to the free end of the rotary arm 90. In close proximity to the permanent magnet 92 is a coil 94 with an iron core (not shown). When the rotary arm 90. rotates ,. a pulse signal is generated in the coil 94 each time the permanent magnet 92 is positioned against the iron core. The pulse generator 88 is connected to a second input terminal of the circuit 88. One terminal of the coil 94 of the pulse generator 88 is grounded.

The output circuit 86 generates an output signal only when the output signal from the negator 84 and the pulse signal from the pulse generator 88 are present at the input. The output circuit 86 is output connected to the input terminal of the pulse extender 96, which is the output connected to · input terminal · power amplifier 98. Na. output power. amplifier 98 is connected. · Relay 100. This relay. 100 controls a switch 102 which interrupts the supply line 104 supplying. whole. state and 'stop state' when relay 100 energizes.

The pulse expander 96 serves to increase the width of the output circuit product signal 86 which is itself too small to energize relay 100 because it takes, for example, 10 ms, and produces an output signal with sufficient width to energize relay 100, for example 100 ms. . In order to stop the excitation of the relay 100, a memory circuit (not shown) that is set by the output signal of the circuit 66 may be provided to produce an output signal, and reset by an output signal from a suitable source (not shown) so that it stops transmitting the output signal. Power amplifier 96. the amplifier output signal 96 is amplified so that its output signal has sufficient energy to energize relay 100.

The described apparatus operates as follows: When the weft yarn 12 is punched into the shed by beam 42, the electrodes 66 and 66 are joined at the end thereof. When no foreign material, such as the remainder of the fiber, adheres to the electrodes 66, 66, an electrical signal 106 is generated which lasts for less than a predetermined period of time, i.e., only while the electrodes 66 and 66 are touching the weft yarn 12. the signal 106 is amplified in the preamplifier 76, whose rectangular output signal 106 is applied to the comparison timing circuit 62.

Since the output signal 106 of the preamplifier 76 lasts for less than a predetermined time interval, the comparison timing circuit 86 outputs an output signal 110 that arrives at the input of the negator 64. Thus, the negator 64 does not produce any output signal. The pulse generator 66 creates a pulse signal 112 in ^advance: set point during · when the beam 42 moves from the assignment to the opposite position. The pulse signal 112 of the pulse generator 66 is routed to the product circuit 66. Since there is no signal at the output of the negator 64, the product circuit 66 will not produce an output signal. Thus, the relay 100 does not wake up so that the state can continue to operate uninterrupted.

When foreign material such as loose broken fiber adheres to the electrodes 66 and 66, an electrical signal 113 is generated which lasts longer than a predetermined time interval, i.e. even after the weft yarn 12 has arrived. This electrical signal 113 is amplified. in the preamplifier 76, whose amplified output signal 113 is fed to the comparison timing circuit 62. Since the output signal 114 of the preamplifier 72 lasts longer than a predetermined time interval, the comparison timing circuit 62 stops transmitting the output signal. As a result, the negator 64 outputs an output signal 116 that arrives at the input of the circuit 66. The pulse generator 86 generates a pulse signal 112 at a predetermined time as the beam 42 moves from the stowed position to the opposite position. Since the output signal 116 and the pulse signal · 112 arrive at the input of the product circuit δ6 simultaneously, they appear at its output. A signal 116 that is fed to a pulse expander 96, whose output signal 120 has a pulse waveform and an increased width. The output signal 120 is amplified in a power amplifier 9δ whose output signal 122 has a sufficient level to energize the relay 100. The relay 103 actuates a switch 102 that interrupts the power line 104 and thereby stops the state.

Giant. 3 shows a second embodiment of a fault detection or malfunction detection device according to the invention. The device 124 of FIG. 3 comprises an arm 126 that is pivoted at one end. At the other end of the arm 126 is a pivoted weft detector 126 in the form of a curved pin which can be captured by the weft thread pricked by the beam 144. The apparatus further comprises a switching device 130 having a fixed contact 132. The movable contact 134 is mounted on the weft detector 126 and may be in contact with the fixed contact 132. The weft detector 12δ is normally biased clockwise to the position shown in FIG. 3 by a dashed line with a biasing device, for example a spring (not shown) or a permanent magnet so that the movable contact 134 contacts the fixed contact. . so that the switching device 130 emits an electrical signal. After the weft yarn 136 has been introduced into the shed, the weft detector 136 is pivoted by the weft yarn 136 counterclockwise and is clamped between the weft yarn 136 and the previous weft yarn 136 which has been pinned to the edge of the fabric 140 prior to the weft yarn. thread 136; this position is shown by the solid line in Fig. 3. furthermore, the movable contact 134 moves away from the fixed contact 132 and the switching device 130 ceases to emit an electrical signal. The solenoid 142 serves to rotate the arm 126 clockwise as shown in Fig. 3 to eject the weft detector 126 from the space between the weft yarns 136 and 13β. The solenoid 142 is excited at a first predetermined time during the movement of the beam 144z assigned to the opposite position.

The detection device 124 further comprises an electrical control circuit 146 to which the switching device 130 is connected. The switching device 130 is connected to the input terminal of the negator 146, which sends an output signal when the switching device 130 does not send a signal, and the device 130 transmits a signal. Negator 146 is connected to the input terminal of comparison timing circuit 150, which does not output an output signal when. when the output signal from the negator 146 supplied to its input is shorter than a predetermined time interval, and sends an output signal when the output signal from the negator 146 is longer than a predetermined time interval. It should be noted that the predetermined time interval 199187 val is longer than the time the weft detector 128 contacts the weft yarn 136, or the interval between moving the 'movable contact 134 from the fixed' contact 132 and energizing the solenoid 142. also connected to one of the two input terminals of the first product circuit 152, the second input terminal of which is connected to the comparator timing circuit 150. The first product circuit '152 produces an output signal only when the input from the negator 148 and the comparator timing signal are present. The pulse generator 156, which is analogous to the pulse generator 88 of FIG. 2, emits a pulse signal at a second predetermined time during the movement of the beam 144 of the pulse generator. thrust into the opposite position. Second predetermined. the moment is later than the first predetermined excitation time of the solenoid 142 and lies beyond the predetermined time interval. The pulse generator 156 is connected to the second input terminal of the second product circuit 154.

The second product circuit 154 outputs an output signal only when. when both signals from the first product circuit 152 and the pulse generator 156. are input at the same time. The second product circuit 154 is connected to the input terminal of the alarm circuit 158. At the output of the alarm circuit 158 it is connected. a warning lamp 160 that lights up when energized while being connected to the positive terminal of a DC power supply 161, such as a battery, the negative terminal of which is grounded.

The device of FIG. 3 operates as follows: When the weft yarn 136 is spiked by the beam 144 and the weft detector 128, the movable contact 134 and the solenoid 142 function correctly, the weft detector 128 is pivoted by the weft yarn 136 in FIG. between the two weft yarns 136 and 138 as shown in solid line in FIG. At the same time, the movable contact 134 moves away from the fixed contact 132 so that the switching device 130 stops transmitting an electrical signal. This condition lasts until the solenoid 142 is energized, so that the weft detector 128 slides out of the gap between the weft yarns 136, 138, and the movable contact 137 hits the fixed contact 132 again.

Because the switching device 130 does not send an output. signal, the negator 148 outputs an output signal 162 that is routed from the comparison timing. Since the output signal 162 lasts less than a predetermined time interval, the comparison timing circuit 150 does not send an output signal. As a result, the warning lamp 160 does not receive voltage and does not light up.

When the movable contact 134 remains distant from the fixed contact 132. due to a malfunction of the 'weft detector' 128 and / or solenoid 142, or due to the faulty dropping of the movable contact 134, the switch 130 does not emit an electrical signal for a period longer than the predetermined time interval. Consequently, the negator 148 sends an output signal 164 to the comparison timing. 150 and the first product circuit 152, the signal lasting longer than a predetermined time interval. The comparison timing circuit 150 outputs an output signal 166 that is input to the first product circuit 152. The first product circuit 152 outputs an output signal 168, since at its input are output signals 164 and 166 from the negator 148 and the timing circuit 150, and this the output signal 168 arrives at the second product circuit 154. The pulse generator 156 transmits the pulse signal 170 at a predetermined time when the beam 144 returns from the aligned position to the opposite position. Because at the input of the second product circuit 154 there is simultaneously an output signal 168 'from the first product circuit 162. . and a pulse signal 170 from the pulse generator 156 is generated. at its output, an output signal 172 that arrives at the warning circuit 158. The warning bulb 160 is lit.

Instead of the electrodes 66, 68 and the combination of the arm 126, the weft detector 128, the switching device 130, and the solenoid 142, it can be used as a weft detector of the center or end fork of the weft stop.

The weft detector may be located on the same side of the shed 30 as the nozzle 28 or directly in the shed instead of on the opposite side of the shed than where the nozzle 28 lies.

Although the invention has been described in connection with a cordless state, it is also applicable to gripper states.

Claims (3)

A device for detecting a malfunction of a weaving loom detector whose output signal. during each operating cycle of the state from the beginning of the beam motion. the starting position through the beat until the beam returns to the starting position when the weft is correctly picked changes from the first level to the second level and returns to the first level while. when the weft detector malfunctions, it changes from the first level to the second level and remains at the second level for the duration of the weft detector malfunction, characterized in that an electrical control circuit (74, 146) is connected to the weft detector in which it is connected a comparison timing circuit (82, 150) for comparing the length of the weft detector output signal to a predetermined time interval, which is further than the time the output signal is at the second level when the weft is correctly inserted into the shed and outputting the output signal for the duration of the signal with the second level INVOLVING a predetermined time interval, and a pulse generator (88, 156) to transmit a signal once. for each cycle whose outputs are connected to the inputs. a logic circuit (86, 154) to transmit an error signal while receiving a signal from the comparison timing circuit (82, 150) and the pulse generator (88, 156). Device according to claim 1, characterized in that a pulse expander (96) is connected to the output of the logic circuit (86) to increase the error signal width and a relay (100) is connected thereto via a power amplifier (98). connected in the supply line (104) of the state. Device according to claim 1, characterized in that a negator (84) is connected downstream of the comparison timing circuit (82) and the logic circuit (86) is formed by a product. a circuit whose one input is connected to. a second input to the pulse generator (88).