BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to a weft holding device in a fluid jet loom, and more
particularly, to a weft holding device disposed on a non-weft-inserting side.
Description of Prior Art
[0002] As a weft holding device in a fluid jet loom, techniques described in patent documents
1 and 2 are known.
[0003] Both prior arts described in patent documents 1 and 2 have a mechanism such as a
so-called hinge in which one of a pair of weft holding members angularly rotates about
a rotation shaft.
[0004] In both prior arts, the length of a weft holding portion, especially the length of
a portion capable of holding exceeds a swinging range of a reed (between the most
forward position and the most backward position of the reed).
[Patent Document 1]
Japanese Patent Appln. Public Disclosure No. 10-130999
[Patent Document 2]
Japanese Patent Appln. Public Disclosure No. 2000-199152
[0005] In such prior arts, an axis of a support point which is the axis of a rotation shaft
being out of a swinging range of a reed, the distance from the axis of the support
point of a pair of holding members to a weft holding position is-long. For this reason,
in both prior arts, if the swinging range of the holding members is small, it becomes
difficult to receive the weft between the holding members, while if the swinging range
of the holding members is large, a difference in time from when a command to hold
is outputted until when the weft is actually held is great, which results in bad responsiveness
of the weft holding device.
[0006] Also, in both prior arts, since the weft is only sandwiched by a pair of the holding
members, the weft tends to come off the holding members at the time of swinging motion
of the reed, particularly when the reed moves ahead of the weft holding members.
[0007] An object of the present invention is to provide a high responsiveness to a command
to hold and to catch hold of the weft surely.
SUMMARY OF THE INVENTION
[0008] The weft holding device according to the present invention is one to be attached
to a member different from a reed sley of a fluid jet loom, and comprises: a pair
of holding members which have a weft holding portion for receiving and holding a weft,
which moves together with a reed, between the most forward position and the most backward
position of the reed, the weft holding portion having a length in the moving direction
of a warp shorter than the length of a swinging locus of the reed, and which are moved
selectively and relatively by a drive unit in the directions to approach each other
or part from each other; and an engaging member for engaging the weft received in
the weft holding portion and positioning the weft relative to both holding members.
[0009] Since the length of the holding member in the moving direction of the warp is shorter
than the length of the moving locus of the reed, even in case of a linear movement
or an angular rotational movement of holding member, a difference in time from when
a command to hold is outputted until when the weft is actually caught hold of becomes
small, thereby improving responsiveness.
[0010] Also, in case of a weft holding device wherein holding members receive the end portion
on a non-inserting side of the weft inserted into a warp shed as the reed advances,
and holding the weft with both holding members moved linearly by the drive unit, the
weft can be surely received in the weft holding portion even if the moving range of
the holding members is smaller than a device for holding a weft wherein both holding
members are angularly rotated to catch hold of the weft. Therefore, a difference in
time from when the command to hold is outputted until when the weft is actually caught
hold of becomes small, thereby improving the responsiveness.
[0011] The tension of the weft after insertion usually gets smaller toward the non-weft-inserting
side, but the weft is beaten as it is to cause a flaw in a cloth. If, however, the
weft holding portions are positioned within the swinging range of the reed, both holding
members, besides being linearly moved, catch hold of the weft extending immediately
after the weft insertion instantaneously and can keep the tension of the weft. Therefore,
after the weft is caught hold of by the holding members, the reed is further advanced,
by which the part of the weft on the non-inserting side is stretched and beaten by
the reed. As a result, the tension on both end portions of the weft becomes equal,
thereby preventing generation of a flaw in a cloth.
[0012] The weft received in the weft holding portion is engaged with an engaging member
and positioned relative to both holding members. Therefore, the weft is surely held
by the holding members, and is prevented from coming out of the holding members with
the advance of the reed.
[0013] Also, at this time, a certain tension can be applied to the weft, and by further
adjusting the position of the engaging member forward or backward, the applied tension
can be adjusted.
[0014] The length of the weft holding portion in the moving direction of the warp can be
made smaller than the length of the swinging locus of the reed. Thus, the holding
members can be made small, thereby improving the responsiveness.
[0015] The weft holding portion may be located, as viewed from the running direction of
the weft, at the height position of the weft swinging locus connecting the weft running
paths respectively at the most forward position and at the most backward position.
By doing' so, the weft can be surely received by the weft holding portion and more
surely held.
[0016] The drive unit includes a drive source which relatively moves the pair of holding
members in one of the directions to approach each other and to part from each other,
a spring which relatively moves the pair of holding members in the other of the directions
to approach each other and to part from each other, and adjusting means for adjusting
the energizing force of the spring may be included. By doing so, since the holding
force can be set at an appropriate value by adjusting the energizing force of the
spring, applying excessive tension to the weft can be prevented. Further, the energizing
force may be adjusted by replacing the springs.
[0017] The weft holding device can further include a blow nozzle for jetting a pressure
fluid toward the weft held by the pair of holding members. Thus, the weft can be surely
discharged from the holding members by the pressure fluid jetted from the blow nozzle,
thereby preventing tangling of the weft with the weft holding device.
[0018] The weft holding device can further include a weft anti-tangling member disposed
near the weft holding portion in the running direction of the weft. As a result, a
guide port for the weft into the weft holding portion is formed by the weft anti-tangling
member, so that the weft can be surely guided to the holding member when the reed
swings, thereby preventing the weft from tangling with the holding member. Also, even
if the weft anti-tangling member is disposed near the non-weft-introducing side of
the holding member, entanglement of the weft with the holding member is prevented.
[0019] The weft anti-tangling member may be a plate-like member disposed opposite to both
sides of the jet nozzle of the blow nozzle. Since thereby the weft anti-tangling member
regulates diffusion of jetting of the pressure fluid to be jetted from the blow nozzle,
even if the pressure fluid of the blow nozzle has a low pressure, the pressure fluid
acts on the weft in a state strong enough to blow off the weft, so that the fluid
compression equipment of the blow nozzle can be made small.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020]
Fig. 1 is a side view of the first embodiment of the weft holding device according
to the present invention.
Fig. 2 is an enlarged view of the weft holding device shown in Fig. 1
Fig. 3 is an enlarged front view of the weft holding device shown in Fig. 1.
Fig. 4 is a plan view of the weft holding device shown in Fig. 1.
Fig. 5 is a typical front view of the second embodiment of the weft holding device
according to the present invention.
Fig. 6 is a typical side view of the weft holding device shown in Fig. 5.
PREFERRED EMBODIMENT OF THE INVENTION
[0021] Referring to Figs. 1 - 4, a weft holding device 10 is disposed on the non-weft-inserting
side of an air jet loom and is used for holding a weft 80 (see Fig. 4) to be inserted
and advanced from a reed 12 toward a cloth fell.
[0022] The weft holding device 10 is disposed nearer the non-weft-inserting side than the
reed 12 which beats the inserted weft 80, and removably assembled by a support arm
14 into a member different from a reed sley (not shown), for example, a temple base
18 which rotatably supports a temple 16. However, the position and state of assembly
of the weft holding device 10 is optional.
[0023] The reed 12 has a plurality of strip-like dents 20 at intervals in the direction
of the weaving width. Each dent 20 has, near the longitudinal center, a convex portion
22 projected toward the cloth fell, and at the center of the convex portion 22, a
concave portion 24 opening toward the cloth fell side. The reed 12 having the dents
20 arranged in parallel in its thickness direction forms a groove formed by the concave
portions 24 of the dents 20 as a running path of the weft 80.
[0024] The reed 12 has a coiled fine line 26 disposed at each end portion of the reed 20,
with the end portions of each dent 20 inserted into adjoining turn portions of the
fine lines 26 to keep the adjoining dents 20 at certain intervals and prevents relative
displacement of the dents 20 by upper and lower caps 28. The reed 12 is attached to
a reed sley (not shown) by the lower cap 28.
[0025] The weft holding device 10 holds the weft 80 to be advanced together with the reed
12 accompanying the forward motion of the reed 12 with a pair of holding members 32,
34 to be moved selectively so as to approach and part from the drive unit 30, and
assembles a pair of plate-like support members 36 arranged in front of and behind
the holding members 32, 34 in the weaving width direction (running direction of the
weft) into the support arm 14 by a plurality of screw members 38.
[0026] Both support members 36 are shaped like an inverted L-letter, and the holding members
32, 34 are removably attached to the support arm 14 at the upper portions at an interval
in the direction of the weaving width (weft running direction) in the upper portion
so as to be located there between in the weaving width direction, and furthermore,
a bracket 40 is removably assembled into the upper portion by a plurality of screw
members 42.
[0027] The drive unit 30 uses an electric actuator such as a solenoid, a motor or the like
as a drive source 44, and removably assembles the drive source 44 into the bracket
40 with a plurality of screw members 48 such that its movable pin 46 projects downward.
Consequently, the drive source 44 as well as the drive unit 30 is firmly assembled
through the bracket 40, the support member 36 and the support arm 14 into the temple
base 18 so as to adjust the position, and removably.
[0028] As the drive source 44, it is possible to use a one-way excitation type solenoid
which incorporates a coil spring. An excitation command (drive command) to this solenoid
is supplied from a control unit (not shown) to a drive circuit (not shown). By this,
excitation current (drive current) is supplied to the drive circuit to excite (drive)
the drive source 44.
[0029] The movable pin 46 of the solenoid is applied downward force by the built-in coil
spring of the drive source 44 when the solenoid is not excited (not driven), while
it is sucked upward against the spring force of the built-in coil spring when the
solenoid is excited.
[0030] A plate-like weft anti-tangling member 50 is removably attached to the lower end
portion of each support member 36 by a plurality of spring members 52. Both weft anti-tangling
members 50 are L-shaped as viewed in the direction of the weaving width and assembled
into the support member 36 at the upper end portion.
[0031] Both weft anti-tangling members 50 are spaced apart in the direction of the weaving
width, interposing the holding members 32, 34, and each has a U-shaped guide port
54 opening toward the non-cloth-fell side (the upstream side in the moving direction
of the warp) at the front end portion so as to receive the front end portion of the
weft 80 which is advanced together with the reed 12. The interval between the upper
and lower parts of the portion from the guide port 54 toward the non-cloth-fell side
(the front end side) is made larger toward the non-cloth-fell side so as to surely
receive the end portion of the weft 80 which is advanced together with the reed 12.
[0032] The holding member 32 is shaped like a bracket with a one-side open rectangular or
a U-like shape opening toward the non-cloth-fell side and acts as a fixed side holding
member attached immovably to the support member 36.
[0033] On the other hand, the holding member 34 is immovably attached to the lower end portion
of a movable shaft 56 which is independent from the holding member 34 and which extends
vertically through the holding member 32, and acts as a holding member on the movable
side. The movable shaft 56 abuts at its upper end face on the lower end face of the
movable pin 46. The holding member 34 is located below the holding member 32 at an
interval. Either one of the holding members 32 and 34 or both may be made movable.
[0034] The movable shaft 56, on which the weft 80 advancing with the reed 12 abuts, acts
as an engaging member for preventing the weft 80 from advancing further. The axis
of the movable shaft 56 coincides with the axis of the movable pin 46.
[0035] The weft holding portion is formed by the horizontal lower end face 58 and the horizontal
upper end face 60 of the holding member 32, and opens toward the non-cloth-fell side.
The height positions of the weft holding portions 58, 60 are the height position of
the guide port 54 (See Fig. 2).
[0036] A position nearer the non-cloth-fell side than the weft holding portions 58, 60 is
adapted to be a weft inlet, the distance between the upper and lower parts of which
is made larger toward the non-cloth-fell side so as to surely receive the end portion
of the weft advancing together with the reed 12.
[0037] The length L (the distance from the position of the movable shaft 56 to the front
end portion of the non-cloth-fell side of the weft holding members 58, 60) of the
weft holding members 58, 60 in the swinging direction of the reed 12 is shorter than
the length (the distance between the most forward position and the most backward position)
of the swinging locus (actually, the swinging locus of the weft running path accompanying
the swinging of the reed 12) of the reed 12 in the moving direction of the warp.
[0038] A guide shaft 62 for the holding member 34 and the movable shaft 56 penetrates the
holding member 32 not to move up and down in a state of extending vertically parallel
with the movable shaft 56.
[0039] The holding springs 64 and 66 to apply the weft holding force to the holding members
32, 34 are compression coil spring in the illustration, and each of them is within
a one-side open rectangular or U-shaped area formed by the holding member 32 and disposed
around the movable shaft 56 and the guide shaft 62.
[0040] The movable shaft 56 and the guide shaft 62 penetrate a spring force adjusting member
68 so as to move vertically and are connected by the spring force adjusting member
68 and an adjusting screw 70. The spring force adjusting member 68 is disposed above
the holding springs 64 and 66 so as to adjust the energizing force of the holding
springs 64 and 66, and assembled by the adjusting screw 70 into the movable shaft
56 so as to be able to change the attached position.
[0041] The holding springs 64 and 66 constantly apply the upward the force to the spring
force adjusting member 68. However, the spring force of the holding springs 64 and
66 is smaller than the spring force of the built-in coil spring of the drive source
44.
[0042] As a result, when the drive source 44 is not driven, the holding member 34 is applied
the downward spring force by the built-in coil spring and can be changed by changing
the position assembling the spring force adjusting member 68 into the movable shaft
56.
[0043] A blow nozzle 72 for removing the weft from the weft holding device 10 is disposed
between both weft anti-tangling members 50 and on the cloth fell side of the weft
holding portions 58, 60 so as to jet a pressure fluid like the compressed air from
a nozzle 74 horizontally relative to the weft holding members 58, 60 toward the non-cloth-fell
side. The blow nozzle 72 is air-tightly connected to a hose 76 extending over the
support arm 14.
[0044] A stretch nozzle 78 for sucking the end portion of the inserted weft 80 is disposed,
as shown in Fig. 4, on the non-weft-insert side of the holding members 32, 34 so as
to form an air flow to suck the end of the weft 80. The height position of the weft
80 is kept approximately at the height positions of the weft holding portions 58,
60, because the end portion of the weft 80 is sucked by the stretch nozzle 78.
[0045] The above-mentioned weft holding device 10 acts as follows.
[0046] Firstly, with the drive source 44 not driven, weft insertion is started. When the
drive source 44 is not driven, the movable pin 46, by the spring force of the built-in
coil spring of the drive source 44, presses down the movable shaft 56 and the movable-side
holding member 34 against the spring force of the holding springs 64, 66, whereby
the weft holding portions 58, 60 are spaced apart so as to receive the weft 80.
[0047] Then, with the stretch nozzle 78 driven, the reed 12 is advanced from the most backward
position as shown in the upper part of Fig. 4 toward the most forward position as
shown in the lower part of Fig. 4. By this, the inserted weft 80 is advanced together
with the reed 12 to be introduced between the weft holding portions 58 and 60, while
the front end portion on the non-insert side is sucked into a stretch nozzle 78.
[0048] At this time, since the guide port 54 and the vertical distance of the position of
each non-cloth-fell side of the weft holding portions 58, 60 become larger toward
the non-cloth-fell side positions, the weft 80 is surely received by the guide port
54 and the weft holding portions 58, 60. However, the weft 80, abutting on the movable
shaft 56, is prevented from advancing further.
[0049] Then, after the weft 80 is engaged with the movable shaft 56, the drive source 44
is driven. Since the movable pin 46 is raised by this, the movable shaft 56 and the
weft holding member 34 are raised by the spring force of the holding springs 64, 66,
and the weft 80 is held by the weft holding members 58, 60. At this time, since the
weft 80 abuts on the movable shaft 56, the weft 80, positioned relative to both holding
members 32, 34, is surely held by the holding members 32, 34.
[0050] The timing to start driving the drive source 44 is set beforehand together with the
timing of weft insertion, the timing to start warp shed motion, the timing to start
the reed beating motion and the like, on the basis of the rotation angle of the main
shaft of the loom.
[0051] In the weft holding device 10, since the motion of the holding member 34 at the time
of holding the weft 80 is a linear motion, the weft 80 can be surely received into
the weft holding portions 58, 60, even if the range of moving of the holding member
34 is small in comparison with a device in which a holding member is angularly rotated
to hold the weft. As a result, a difference in time from when a command to hold is
outputted until the weft 80 is actually held becomes smaller, thereby improving the
responsiveness.
[0052] Since the weft holding portions 58, 60 are located at the height position of the
weft swinging locus of the weft running path connecting the most forward position
and the most backward position of the reed 12, as viewed from the weft running direction,
the weft 80 is more surely received in the weft holding portions to be held more surely.
[0053] Then, the reed 12 is further advanced, and the weft 80 is beaten against the cloth
fell. Due to such a further advance of the reed 12, further tension is applied to
the weft 80. At this time, since the weft 80 is surely held by the holding members
32, 34, the weft 80 is prevented from coming off, accompanying the advance of the
reed 12, from the holding members 32, 34.
[0054] Also, as the energizing force by the holding springs 64, 66 is adjusted, a constant
tension is applied to the holding member 34.
[0055] Also, the weft 80 abuts the weft anti-tangling member 50 while abutting the movable
shaft 56 to be prevented from advancing further, so that the weft 80 is prevented
from tangling with the vicinity of the weft holding portions 58, 60.
[0056] Furthermore, since the weft holding portions 58, 60 are located within the swinging
range of the reed 12 and the holding members 32, 34 are linearly moved, the weft stretched
immediately after the weft insertion can be instantaneously held, and the tension
of the weft 80 can be maintained. As a result, after the weft 80 is held by the holding
members 32, 34, the reed 12 is further advanced, so that the portion of the non-weft-insert
side of the weft 80 is extended and beaten. Thereby, the tensions at both ends of
the weft 80 become equal, thereby preventing generation of a defect in cloth.
[0057] Thereafter, the drive source 44 is stopped, the holding of the weft 80 by the holding
members 32, 34 is released, the reed 12 begins to withdraw, and the next weft insertion
is started. At this time, by the swinging motion of the reed, the weft 80 is removed
from the holding members 32, 34, and before the next weft arrives, the pressure fluid
is jetted from the nozzle 74 of the blow nozzle 72 to the weft holding portions 58,
60.
[0058] The pressure fluid from the nozzle 74 is jetted substantially horizontally from the
cloth fell side to the non-cloth-fell side relative to the weft holding portions 58,
60, and passes the weft holding portions 58, 60. Thereby, the weft holding portions
58, 60, the weft 80 and dust tangling in both weft anti-tangling members 50 are removed
from the weft holding device 10.
[0059] Also, since diffusion of jetting of the pressure fluid from the nozzle 74 is restricted
by the plate-like weft anti-tangling members 50 arranged to face each other on both
sides of the nozzle 74, even if the pressure of the pressure fluid from the blow nozzle
72 is low, the pressure fluid acts on the weft 80 strongly enough to blow off the
weft 80, so that a fluid compressor of the blow nozzle 72 can be made small.
[0060] According to the weft holding device 10, the drive unit 30 includes: the drive source
44 for linearly move the holding members 32 and 34 relatively in one of the direction
to approach each other and the direction to part from each other; holding springs
64 and 66 for linearly moving the holding members 32 and 34 relatively in the other
of the direction to approach each other and the direction to part from each other;
the spring force adjusting member 68 for adjusting the energizing force of the holding
springs 64 and 66, and the adjusting screw 70, so that, by adjusting the force of
the holding springs 64, 66, the energizing force to hold the weft can be adjusted
to a proper value, thereby preventing the weft 80 from being applied an excessive
tension.
[0061] Also, it is possible to provide the drive source 44, for example, out of the swinging
range of the reed and also in front of and behind the weft holding device 10, to move
the movable pin 46 horizontally, to move horizontally the movable shaft 56 abutted
by the movable pin 46 and to connect the movable shaft 56 with the holding member
34 through a mechanism for converting the horizontal motion of the movable shaft 56
into an angular rotation of the holding member 34.
[0062] Referring to Figs. 5 and 6, a weft holding device 90 differs from the weft holding
device 10 shown in Fig. 1 in that the former uses a stick-like weft anti-tangling
member 92. The weft anti-tangling member 92 is disposed in front of and behind the
weft holding portions 58, 60 in the running direction of the weft 80 so as to extend
upward and downward.
[0063] The weft holding device 90 disposes the weft holding portions 58, 60 and the weft
anti-tangling member 92 between the reed 12 and the stretch nozzle 78. The weft holding
device 90 is attached to the loom through a bracket not shown, like the weft holding
device 10 shown in Fig. 1.
[0064] In the embodiments shown in Figs. 5 and 6, one end portions of the holding springs
64, 66 are attached to a bracket 94, but the spring force may be made adjustable like
the holding springs 64, 66 of the weft holding device 10.
[0065] In the embodiment shown in Fig. 6, as shown by a dashed line, the weft anti-tangling
member 92 may be disposed near the non-weft-introducing side of the holding members
32, 34. It also prevents the weft 80 from tangling with the holding members 32, 34.
[0066] Also, it is possible to provide a holding spring not in the holding member which
is driving in the foregoing embodiment but in the other holding member.
[0067] The timing to drive the drive source 44 and the jet timing of the blow nozzle 72
can be freely controlled by a command from an operation panel and the like not shown.
[0068] The present invention is not limited to the foregoing embodiments but can be variously
modified without departing from its spirit.