Weft holder for selvedge tuck-in device

Textiles: weaving – Weft manipulation – Weaving with stationary weft supply

Reexamination Certificate

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Reexamination Certificate

active

06289942

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a weft holding device that transfers a weft to a tuck-in device, capable of avoiding cutting a weft with a weft cutter when a command signal is given thereto by a loom controller.
2. Description of the Related Art
A shuttleless loom capable of properly removing a mispicked weft is disclosed in JP-U No. Hei 3-45975. This prior art shuttleless loom is provided with a mispicked weft removing device, a tuck-in device and a tuck-in escaping device. The mispicked weft removing device removes a mispicked weft (improperly picked weft) continuous with a yarn package disposed on the picking end of the shuttleless loom when a weft stop motion operates. The tuck-in device cuts a picked weft at least at a position near the picking end of the loom during a weaving operation and tucks an end portion extending in the picking end in a cloth fell for the next pick to form a tuck selvage. The tuck-in escaping device moves a mispicked weft (improperly picked weft) away from the working position of a tuck-in needle included in the tuck-in device when a weft stop signal is given thereto to avoid tucking an end portion of the faultily picked weft in the selvage.
The tuck-in escaping device of the prior art shuttleless loom has an air nozzle through which compressed air is jetted, and moves a mispicked weft outside of the working region of the tuck-in needle of the tuck-in device by jetting compressed air through the air nozzle against the mispicked weft and, at the same time, avoids cutting the mispicked weft with the weft cutter.
Air jetted through the air nozzle of the tuck-in escaping device diffuses widely, and a large amount of compressed air is necessary to move the mispicked weft effectively. Hence, a large amount of energy is consumed to move the mispicked weft. Since the air nozzle must be disposed near the tuck-in device, a wide selvage is formed unavoidably and, consequently, wefts and a picking fluid are wasted.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a weft holding device for a tuck-in device disposed adjacent to a weft cutter, capable of surely moving a mispicked weft away from the working region of the weft cutter by a jet of air in response to a command signal given there to by a loom controller when a weft stop motion operates or when necessary and of reducing air consumption.
According to one aspect of the present invention, a weft holding device for a tuck-in device for transferring a weft to the tuck-in device disposed adjacent to a weft cutter that is driven in synchronism with the rotation of a main shaft of a loom in order to tuck an end portion of a picked weft cut by the weft cutter in a shed of warps. The weft holding device comprises a block member provided with a slit for receiving an end portion of the weft beaten up by a reed, opening toward the reed, toward the warps, and toward the weft cutter, and a releasing hole formed in the depth of the slit and opening toward the front of the slit to blow backward the end portion of the picked weft received in the slit. Air is jetted through the releasing hole in response to a command signal provided by the loom to move the end portion of the picked weft away from at least a cutting region in which the adjacent weft cutter operates.
When the command signal is provided by the loom controller, air is jetted through a space defined by upper and lower surfaces defining the slit into the shed so that the jet of air may not diffuse and may act effectively on the picked weft. Consequently, cutting of the picked weft by the weft cutter disposed adjacent to the tuck-in device can be avoided with reliability and only a small amount of air is consumed. An air jetting hole formed in the needleless tuck-in device may be used as the releasing hole to simplify the weft holding device. A mispicked weft can be removed by a low force when the mispicked weft is separated from the cloth fell by jetting air through the releasing hole when the mispicked weft is released from the cloth fell by a mispicked weft removing operation and hence the mispicked weft can be surely removed.
More concretely, air jetted through the releasing hole in response to the command signal provided by the loom controller flows through the space defined by the upper and the lower surface defining the slit toward the shed, the diffusion of the air is suppressed and the air acts effectively on the picked weft. Therefore, cutting of the picked weft yarn by the weft cutter disposed adjacent to the tuck-in device can be prevented with reliability by using a relatively small amount of air. When the air jetting hole of the needleless tuck-in device (air-jet tuck-in device) is used as the releasing hole, any special hole is not necessary and the construction of the weft holding device can be simplified. When the mispicked weft is separated from the cloth fell after the mispicked weft has been released from the cloth fell when the weft stop motion operates or during work for removing a mispicked weft, the mispicked weft can be surely removed by exerting a relatively low force thereto. The present invention is applicable to removing a picked weft yarn when the loom is stopped upon the detection of the breakage of the picked weft and to removing a weft picked in a weaving cycle immediately before warp breakage to prevent the formation of filling bars.
Preferably, the block member provided with the slit is provided with a retaining hole opening into a plane including the slit to retain an end portion of the picked weft by a jet of air acting on the retaining hole.
Since the picked weft tucked up by a jet of air acting on the retaining hole is caught, the picked weft can be surely and securely caught and held by the weft holding device.
Preferably, the releasing hole is formed so as to extend toward the shed and to extend obliquely backward with respect to a direction in which the warps are advanced to form the tuck-in device. Air is jetted through the releasing hole in synchronism with the rotation of the main shaft of the loom to tuck the end portion of the picked weft in the shed after the picked weft has been cut.
Since the releasing hole is formed so as to extend toward the shed and to extend obliquely forward with respect to a direction in which the warps are advanced and the end portion of the picked weft is tucked into the shed by jetting air after cutting the picked weft, any guide hole is not necessary and the block unit is simplified.
Preferably, the command signal provided by the loom is a stop signal that causes the loom to stop and air to be jetted through the releasing hole when the stop signal is provided. The stop signal is, for example, a weft stop signal that is provided when a weft is mispicked.
Since air is jetted through the releasing hole when a stop signal is provided by the loom controller, cutting of the picked weft is prevented when a stop signal is provided.
Preferably, the command signal provided by the loom is a tuck-in inhibition signal to inhibit the execution of a tuck-in operation during the weaving operation of the loom. The weft holding device jets air through the releasing hole when the tuck-in inhibition signal is provided.
Since a weft stop signal is provided as a stop signal when a weft is mispicked, the mispicked weft is not cut and hence work for removing the mispicked weft is facilitated.
Preferably, the tuck-in device is of either a needle type or a needleless type (air-jet type). The releasing hole may be either a hole formed specially for the foregoing purpose or a hole formed for another purpose.
Since the command signal provided by the loom controller is a tuck-in inhibition signal to inhibit the execution of a tuck-in operation during the weaving operation of the loom, cutting of the picked weft can be avoided and weft tuck-in operation can be inhibited.


REFERENCES:
patent: 4957145 (1990-09-01), Verclyte et al.
patent: 5193591 (1993-03-01), Nicolini
patent: 5718267 (1998-02-01), Kawabata et al.
patent:

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