Technical Field
[0001] The present invention relates to a flatbed knitting machine which feeds a knitting
yarn to a knitting needle that carries out knitting motion and knits a knit fabric,
and to its yarn feeding method.
Background Art
[0002] Hitherto, in a flatbed knitting machine, knitting needles arranged in parallel on
a needle bed is selectively driven by a cam mounded on a carriage that runs along
the needle bed and a knit fabric is knitted. In a V-bed type flatbed knitting machine,
a pair of needle beds is arranged in front and back in such a manner as to be opposed
to each other with a needle bed gap in-between. The needle bed gap extends in a horizontal
direction of the flatbed knitting machine, and each needle bed is tilted with the
needle bed gap side raised and the far back side lowered as it departs from the needle
bed gap. A knitting needle which is selectively driven on each needle bed advances
to and retreats from the needle bed gap, and receives a knitting yarn fed from above
the needle bed gap to form a stitch. The knitting yarn fed to the knitting needle
is supplied from a yarn feeder port which is provided to a carrier such as a yarn
feeder, etc. running along a thread guide rail disposed above the needle bed gap.
By installing a plurality of carriers and selectively hauling a carrier by a carriage,
the knitting yarn can be changed over and a knit fabric can be knitted.
[0003] Fig. 3 shows an example of arrangement of cams mounted to a carriage. To a base board
1 of the carriage, for example, two sets of cam systems 2 and 3 are respectively mounted
on left and right sides of a center line 1a. The cam systems 2 and 3 each include
knitting cams 2a and 3a for driving knitting needles and needle selecting cams 2b
and 3b for selecting knitting needles, and have the same configuration on both sides.
The number of cam systems mounted to carriages may be one set or may be three or more
sets. The cam system with a plurality of sets has each set in the same configuration
or in different configurations. Knitting needles driven by the cam systems 2 and 3
of this kind of configuration are latch needles, which have a hook on a head end that
advances to and retreats from the needle bed gap, the hook opened and closed by a
latch, and have a needle-selecting butt on the tail end side. Between the head end
and the tail end of the knitting needle, a driving butt on which the knitting cams
2a and 3a work on is provided.
[0004] Knitting cams 2a and 2b guide a driving butt of a knitting needle along a butt passage
4. On the needle bed, needle grooves extending in the direction corresponding to the
vertical direction in Fig. 3 are formed in such a manner that they line up at predetermined
intervals in the horizontal direction in Fig. 3. Each of the knitting needles is housed
in each of the needle grooves, and slides and displaces in the needle groove in the
needle-groove extending direction. The butt passage 4 is formed between the upper
edge of a needle raising cam 5 and the lower edge of a needle guide cam 6. On both
sides of the butt passage 4, stitch cams 7 and 8, also called as knitting cams, are
disposed.
[0005] For example, let's assume a case in which the carriage runs so as that the base board
1 moves rightward shown by arrow mark 1R. When a knitting needle reaches a yarn catching
position 4a by the guide of the butt passage 4, the knitting yarn is supplied to the
hook of the knitting needle from the yarn feeder port 9 of the carrier which goes
ahead by a lead "X0" only with respect to the yarn catching position 4a. The driving
butt of the knitting needle guided along the butt passage 4 begins lowering again
at the yarn catching position 4a after the driving butt passes the center chevron
zone 4b and moves to a horizontal shoulder zone 4c. A knitting needle located on the
left side of the yarn catching position 4a, which has already received the yarn has
the driving butt dragged down along an inclined plane of the stitch cam 8. On the
occasion of this drag-down, an old loop whose knitting yarn was caught in the hook
and is hanging on the needle shank side is knocked over. On the occasion of the knock-over,
the hook is closed by the latch. In the event that there is any knitting needle which
received the yarn fed in advance and had a stitch formed on the following side of
the yarn catching position 4a, a knitting yarn extending from the knitting yarn caught
in the knitting needle hook on the following side to the yarn feeder port 9 is caught
by the hook of a knitting needle at the yarn catching position 4a. In the event that
there is no knitting needle which receives the yarn in advance of the knitting needle
at the yarn catching position 4a, the knitting needle at the yarn catching position
4a serves as an entry-side knitting end, and the knitting yarn extending from the
old loop latched on the needle shank side of this knitting needle itself to the yarn
feeder port 9 is caught by the hook.
[0006] The carrier is hauled being latched to a hauling pin which pops in and out from the
carriage. The yarn feeder port 9 of the carrier being hauled by the carriage stopped
at the yarn feeder position 9a relatively with respect to the carriage cam system.
The yarn feeder position 9a is located ahead by the lead "X0" from the yarn catching
position 4a.
[0007] In the event that a plurality of carriers are used with switching by the use of pop-in
and out control of the carriage hauling pins, the relevant yarn feeder ports 9 occupy
the same space in the vicinity of the needle bed gap and may interfere with one another.
Evacuating the carrier to be used to the outside of the knitting width before switching
and hauling the carrier to be used after switching can avoid interference, but a running
distance of the carriage increases. In addition, in the event that a plurality of
carriers are held in the vicinity of the boundary where the zone knitted by the knitting
yarn from relevant carriers is finished in the knitting width and the carriers are
repeatedly used as in the case of knitting intarsia patterns or Jacquard patterns,
carriers are unable to be evacuated to the outside of the knitting width. In order
to hold and switch a plurality of carriers inside the knitting width, the yarn feeder
port 9 needs to be movable vertically in the direction hanging from the carrier (for
example, see Patent Citation 1). Furthermore, a carrier that has the yarn feeder port
9 capable of displacing in a swing motion to change over from yarn feeding to evacuation
and vice versa may be used (for example, see Patent Citation 2).
[0008] If the carrier is not hauled by the carriage to move but is self-propelled, it is
expected that the running of the carriage which is required only for changing over
carriers can be omitted and the productivity can be improved. It is disclosed a pattern
producing mechanism of a flatbed knitting machine which knits intarsia patterns, etc.
while a plurality of self-propelled carriers are changed over and used while the carriage
runs in one stroke (for example, see Patent Citation 3). From the 5th line to the
16th line in column 4 of Patent Citation 3, it is described that the portion corresponding
to the yarn feeder port 9 "is free to slide vertically" and "is constantly energized
with upward elasticity by coil springs and slightly moves vertically as required according
to patterns." This description is interpreted in the light of Fig. 8, etc. of Patent
Citation 3 that yarn feeder ports used for knitting a plurality of zones of intarsia
patterns are held to a high position by spring energizing to avoid interference, and
only the yarn feeder port used for knitting of each zone is lowered by vertical movement.
Patent Citation 1: Japanese Patent No. 3044370
Patent Citation 2: International Publication WO02/079556 pamphlet
Patent Citation 3: Japanese Examined Utility Model Publication No. 3-54150
Disclosure of the Invention
Technical Problem
[0009] It is preferable to keep it lower the height at the needle bed gap of the yarn feeder
port 9 of a carrier that supplies knitting yarn for allowing the knitting yarn hook
to catch the yarn even above the knitting needle because of less knitting yarn deflection.
However, there could be problems that yarn feeder ports 9 interfere with one another
or a knitting needle used for knitting erroneously catches the knitting yarn extending
from the stopped yarn feeder port 9 when intarsia patters or Jacquard patterns, etc.
are being knitted. The vertical moving mechanism of the yarn feeder port 9 as described
in Patent Citation 1 and Patent Citation 2 is installed to prevent this kind of problem.
[0010] However, installing a vertical movement mechanism of the yarn feeder port 9 makes
the carrier configuration complicated and increases the manufacturing cost. Furthermore,
in a self-propelled carrier as described in Patent Citation 3, an increase of weight
by equipping the vertical movement mechanism increases drive loads for running, too.
[0011] It is an object of the present invention to provide a flatbed knitting machine that
enables proper yarn feeding without vertically moving the yarn feeder port and its
yarn feeding method.
Technical Solution
[0012] The present invention is a flatbed knitting machine for knitting a fabric, provided
with
a plurality of tracks installed above the needle bed gap side of the needle beds on
which knitting needles are installed side by side,
each track having a carrier equipped with a yarn feeder port and self-propelled,
knitting yarn fed from the yarn feeder port to the knitting needles for carrying out
knitting operation by successively advancing to and retracting from the needle bed
gap, driven by a carriage running along the needle bed,
wherein heights of the yarn feeder ports of the carriers are set to such heights that
even if the yarn feeder ports of carriers on different tracks intersect, the yarn
feeder ports do not interfere with a knitting needle that advances to the needle bed
gap for knitting operation, and
the flatbed knitting machine further provided with a controller for controlling running
speed of carriers in one knitting course and adjusting a lead of a carrier to be larger
than the knitting needle at the entry side end of the knitting width, with respect
to knitting needles within the knitting width except the entry side end, and a height
of the yarn feeding position from yarn feeder port to the knitting needle to be a
proper yarn catching height in accordance with the conditions at the time of knitting.
[0013] In the flatbed knitting machine according to the present invention,
wherein said controller adjusts the lead of said carrier to be increased in a zone
where knitting needles to which no knitting yarn is fed continuously exist within
said knitting width.
[0014] In the flatbed knitting machine according to the present invention,
wherein said controller adjusts the lead of said carrier by varying its speed to the
speed of said carriage.
[0015] Furthermore, the present invention is a method for feeding knitting yarn from a yarn
feeder port above a needle bed gap to knitting needles, when a knit fabric is knitted
with varying the position of the knitting needle to carry out knitting motion by advancing
to and retracting from the needle bed gap, is being successively transferred to one
side of a needle bed in a flatbed knitting machine,
wherein a lead in which the yarn feeder port advances on the one side of the needle
bed with respect to a knitting needle is adjusted so that a yarn catching height at
a knitting needle that receives the knitting yarn becomes appropriate in accordance
with knitting conditions.
Advantageous Effects
[0016] According to the present invention, the height of a self-propelled carrier is set
to the height at which a yarn feeder port does not interfere with a knitting needle
that advances to the needle bed gap for knitting even when yarn feeder ports of carriers
of different tracks intersect. Thus interference with knitting needles can be avoided
even when plural carriers are used. Since the yarn feeder port is located high, a
problem of a knitting needle used for knitting to erroneously catch a knitting yarn
extending from a stopped yarn feeder port could be made less likely to occur. In addition,
even when yarn feeder ports come into contact with each other due to their interference,
damage would not be caused and knitting can be carried out without any trouble. For
the knitting needle of the knitting end on the knitting width entry-side, a lead of
the carrier is reduced and the yarn feeder port located at a high position comes close
to the knitting needle, and therefore even when the knitting yarn is pulled out at
a lower position with respect to a hook from an old loop hanged on the needle shank
side, the knitting yarn can be allowed to be caught by a hook at a proper height in
the middle of ascending to the yarn feeder port at a high location. For other knitting
needles inside the knitting width, the lead of the carrier is increased, and therefore,
the height of knitting yarn to be caught by a hook is made lower than the height of
the yarn feeder port, thereby enabling the proper yarn feeding. Since proper yarn
feeding is enabled even if a vertical movement mechanism is not installed to a carrier
to vertically move the yarn feeder port, the cost can be reduced and drive loads for
running can be reduced, too.
[0017] In addition, according to the present invention, the lead of the carrier is adjusted
within the knitting width to be increased at a zone where knitting needles to which
no feed yarns are fed continuously exist. Therefore, for knitting needles to which
knitting yarn is fed, hooks are allowed to catch knitting yarns at a proper height
in the middle of ascending to the yarn feeder port at a high location. Since the knitting
yarn height is made lower, knitting needles which are not used for knitting need not
be used, and proper yarn feed is achieved by adjusting a carrier lead.
[0018] In addition, according to the present invention, the lead of the carrier is adjusted
by varying speed in accordance with the running of a carriage that drives a knitting
needle for knitting. Therefore, knitting yarn is able to be properly fed in accordance
with the knitting motion of the knitting needle.
[0019] Furthermore, according to the present invention, the lead with respect to the knitting
needle at the yarn feeder port is adjusted in such a manner that the yarn catching
height at a knitting needle which receives the yarn is made appropriate in accordance
with the knitting conditions. Therefore, appropriate yarn feeding is enabled even
if the yarn feeder port is not moved vertically.
Brief Description of Drawings
[0020]
[Fig. 1] Fig. 1 is a diagram showing a basic concept of a yarn feeding method of a
flatbed knitting machine as one embodiment of the present invention.
[Fig. 2] Fig. 2 is a block diagram showing a schematic electric construction of a
flatbed knitting machine 20 in a simplified manner, which can feed knitting yarn in
accordance with the yarn feeding method as shown in Fig. 1.
[Fig. 3] Fig. 3 is a diagram showing an example of an arrangement of cams mounted
to carriages hitherto.
Explanation of References
[0021]
10. Yarn feeder port
10a, 10b, 10c, 10d, 10e, 10f, ..., 10s. Yarn feeding position
11, 11a, 11b, 11s Knitting yarn
12, 12a, 12b, 12c, 12d, 12e, 12f, 12s Knitting needle
14. Old loop
20. Flatbed knitting machine
21. Needle bed
22. Needle bed gap
23. Carriage
33. Carrier
40. Controller
41. Main controller
Best Mode for Carrying Out the Invention
[0022] Fig. 1 shows a basic concept of a knitting yarn feeding method of a flatbed knitting
machine as one embodiment of the present invention. Fig. 1(a) shows a criterion for
setting a lead of a yarn feeder port with respect to a knitting needle in the middle
of knitting width. Fig. 1(b) shows a criterion for a yarn feeder port to adjust an
advancing lead with respect to a knitting needle subject to yarn feed so that the
proper yarn catching height is achieved in accordance with knitting conditions.
[0023] As shown in Fig. 1(a), applying the concept of the present invention enables a hook
of a knitting needle 12 to catch a knitting yarn 11 under the conditions nearly equivalent
to the conventional even when a height of the yarn feeder port 10 is made higher than
the optimum height of a yarn feeder port 9 which serves as a conventional criterion.
For example, in a conventional example of Fig. 3, it is based on the condition in
which feeding a knitting yarn from a yarn feeder port 9 of a yarn feeding position
9a advancing by a lead "X0" only to a knitting needle at a yarn catching position
4a can achieve proper yarn catching. Fig. 1(a) shows that feeding a knitting yarn
11 to a knitting needle 12 from the yarn feeder port 10 located at a position only
"y" higher than the criterion of the conventional feeder port 9 provides the same
gradient to the knitting yarn 11 if a lead "X2" of the yarn feeder port 10 is increased
by "x" from the lead "X0" of the yarn feeder port 9. The knitting yarn 11 extends
from a hook of a knitting needle which receives knitting yarn ahead of, for example,
the knitting needle 12 to yarn feeder ports 9 and 10, provided, however, that the
optimum lead which achieves proper yarn catching height varies in accordance with
the knitting conditions relevant to the knitting needle 12. Incidentally, for the
knitting needle 12, the present invention is able to be applied not only to a latch
needle which is driven by a cam as shown in Fig. 3 but also to a composite needle
as disclosed, for example, in Japanese Patent
2946323.
[0024] When a plurality of yarn feeder ports 10 are used, a plurality of tracks on which
the yarn feeder ports 10 run are arranged. Allowing yarn feeder ports 10 that run
on different tracks to intersect with each other expands a range of space where the
yarn feeder port 10 passes at the needle bed gap and makes it likely to interfere
with a knitting needle that advances to the needle bed gap, even though a contact
of the yarn feeder ports 10 themselves which may not cause damage is admitted. By
making the height of the yarn feeder port 10 only "y" higher than the conventional
yarn feeder port 9, interference between the yarn feeder port 10 and a knitting needle
that advances to the needle bed gap can be avoided when the yarn feeder port 10 passes
the needle bed gap, etc.
[0025] Fig. 1(b) shows that it is desirable to vary the optimum lead in accordance with
the knitting conditions of each of knitting needles 12a, 12b, 12c, 12d, 12e, 12f...,
12s when a zone in which the knitting needles 12a, 12b, 12c, 12d, 12e, 12f..., 12s
are arranged is knitted. In the event that the zone of knitting needles 12a, 12b,
12c, 12d, 12e, 12f..., 12s is knitted while the yarn feeder port 10 moves rightward,
the knitting needle 12a on the left end serves as an entry side. This kind of the
rightward knitting course takes place following the leftward knitting course. The
carriage turns around the running direction as shown by the arrow mark 13. When a
hook is advanced to the needle bed gap in the rightward knitting, in the knitting
needle 12a on the left end, a stitch formed by leftward knitting is moved from the
hook to the needle shank as an old loop 14.
[0026] In order to form a stitch as a new loop on a hook of the knitting needle 12a on the
left end, which serves as the start of rightward knitting, the knitting yarn 11a fed
from the yarn feeder port 10 at the yarn feeding position l0a is pulled out from the
old loop 14 moved to the needle shank. The old loop 14 is hanged on the needle shank
of the knitting needle 12a and therefore, the position from which the knitting yarn
11a is pulled out becomes lower than the position of the hook of the knitting needle
12a. Feeding the knitting yarn 11 from the yarn feeder port 10 which is advanced only
by lead "X2" as shown in Fig. 1(a) to the knitting needle 12a, too, lowers the position
from which the knitting yarn 11 is pulled out, and therefore lowers the yarn catching
height, too. When the yarn catching height lowers, in the knitting needle 12a, the
knitting yarn may be fed to the needle shank side on which the old loop 14 is hanged
and the knitting yarn may be knocked over together with the old loop 14 without being
caught in the hook, or in the case of a latch needle, the knitting yarn gets stuck
on the head end of the latch and the knitting needle 11 may be split off. Consequently,
for the knitting needle 12a on the entry side end, it is desirable to set the lead
"X1" of the yarn feeding position l0a to be smaller than the lead "X2" at the yarn
feeding positions 10d, etc. for intermediate knitting needle 12d, and to allow the
knitting yarn 11a to be fed at a high position. In the knitting needle 12a on the
knitting end on the entry side of the knitting width, the lead "X1" of the yarn feeding
position l0a is reduced, whereby the feeder l0a at a high position approaches to the
knitting needle 12a, and the knitting yarn 11a can be caught by a hook at a proper
height in the middle of ascending to the yarn feeder port 10 at a high position even
if the knitting yarn 11a is pulled out from the former loop latched on the needle
shank side at a low position with respect to a hook.
[0027] Following the entry-side knitting needle 12d, for the knitting needle 12a in the
middle of the zone of knitting needles 12b, 12c, 12d, 12e, 12f, ... which continuously
form stitches, the knitting yarn caught on a hook of the knitting needle 12c which
receives the knitting yarn in advance is supplied to a hook. Consequently, the yarn
feeder port 10 is advanced so as to obtain the yarn feeding position 10d with the
lead "X2" as shown in Fig. 1(a). The change from the lead "X1" of the yarn feeding
position 10a with respect to the knitting needle 12a on the knitting end to the lead
"X2" of the yarn feeding positions 10d, etc., with respect to knitting needles 12b,
12c, 12d, 12e, 12f, ... of the continuous knitting zone is achieved by varying the
self-propelling speed of the yarn feeder port 10, provided, however, that it is difficult
to instantaneously change the lead from "X1" to "X2" for the knitting needle 12b adjacent
to the entry-side knitting needle 12a. Consequently, when a carrier enters the zone
of knitting needles 12b, 12c, 12d, 12e, 12f..., which continuously form stitches,
the lead is changed from "X1" to "X2" by continuously controlling the speed of the
carrier.
[0028] In the event that a knitting yarn 11s is fed to a hook of the knitting yarn 12s after
unused knitting needles 12e, 12f... continue, the lead "X3" at a yarn feeding position
10s is increased from "X2". Since the portion corresponding to the length of the knitting
yarn 11 up to a hook of a knitting needle which has already received the knitting
yarn on the left side of the knitting needle 12 in Fig. 1(a) extends, keeping the
lead of the portion corresponding to the right side to "X2" increases the height of
the knitting yarn to be fed to the knitting needle 12. In order to allow the hook
of the knitting needle 12s to definitely catch the knitting yarn 11s, the lead "X3"
at the yarn feeding position 10s of the yarn feeder port 10 needs to be increased
from "X2".
[0029] Incidentally, when the knitting yarn 11 is first used for set-up, etc., the left
end of the figure is held by, for example, a gripper, etc. installed at the end portion
of the needle bed. A height for holding the knitting yarn 11 at the end of the needle
bed becomes lower than the yarn hanging height at the needle shank of the knitting
needle 12 which serves as the entry side on the way of repeated knitting. In the event
that the knitting yarn 11 is first fed to the knitting needle 12, the lead of the
yarn feeder port 10 is set in accordance with a space between the holding position
of the knitting yarn 11 at the end of the needle bed and the knitting needle 12 located
at the entry-end of the knit width. When the height of the knitting yarn 11 to be
fed is increased, the lead should be decreased, and when the height is lowered, the
lead should be increased.
[0030] Fig. 2 shows a schematic electric structure of a flatbed knitting machine 20 that
can feed knitting yarn in accordance with the yarn feeding method as shown in Fig.
1 in a simplified form. The flatbed knitting machine 20 has a needle bed 21 that extends
in the horizontal direction in the figure. The needle bed 21 is installed so as to
make a pair in front and rear. The needle beds 21 in the front and in the rear stand
face to face with a space provided in-between, and in-between formed is a needle bed
gap 22. To the needle beds 21, a large number of knitting needles are arranged in
parallel at a predetermined pitch, though their illustrations are omitted. Selective
drive of knitting needles is conducted while a carriage 23 equipped with a cam advances
and retires back and forth along the needle bed. To the needle beds 21 or its vicinity,
a carriage rail 24 that guides running of a carriage 23 is installed. The running
drive of the carriage 23 along the needle beds 21 is conducted by a motor 25 via a
timing belt 26. For the motor 25, for example, a servo motor is used. To an output
shaft of the motor 25, a pulley 27 is mounted, and the endless-form timing belt 26
is installed over the pulley.
[0031] The yarn feeder port 10 hangs from a carrier 33 which is guided by a track of a carrier
rail 31 installed above the needle bed gap 22 and is self-propelled transversely.
The height of the feeder port 10 can be made higher than the height which was conventionally
believed to be appropriate. When the height of the yarn feeder port 10 is increased,
interference of yarn feeder ports 10 can be avoided and crossing of yarn feeder ports
10 is possible, even if a plurality of carrier rails 31 are arranged and the yarn
feeder port 10 is used by each carrier rail. Furthermore, interference of the yarn
feeder port 10 with a knitting needle that advances to the needle bed gap 22 can be
avoided, too. In the figure, only one yarn feeder port 10 is shown, but on the back
side of the carrier rail 31, the similar carrier 33 can be guided. In this case, on
the back and the front of one carrier rail 31, tracks on which a carrier 33 is self-propelled
are installed, respectively. In addition, plural similar carrier rails 31 are able
to be arranged in a direction perpendicular to the paper surface.
[0032] The carrier 33 is able to be run with a timing belt 36 driven by a motor 35. To an
output shaft of the motor 35, a pulley 37 is installed and the timing belt 36 is installed
over the pulley 37. In the event that plural carriers 33 are used, the same construction
may be used for each carrier 33. The carrier 33 does not include a mechanism to vertically
move the yarn feeder port 10 and therefore, the carrier 33 can be reduced in size
and weight. The load of the motor 35 can be alleviated to enable the carrier 33 to
run at high speed. For the motor 35, a servo motor and a stepping motor may be used.
[0033] The yarn feeding method as shown in Fig. 1 may be achieved by running control of
the carriage 23 and the carrier 33 by the use of a controller 40. The controller 40
for carrying out overall control of the flatbed knitting machine 20 includes a driver
42 of the motor 25 that drives running of the carriage 23 and a driver 43 of the motor
35 that drives running of the carrier 33. A main controller 41 sets a plurality of
knitting courses on which the carriage 23 runs and decides knitting needles used for
knitting for each knitting course in accordance with the pattern data of knit fabrics
knitted by the flatbed knitting machine 20. Furthermore, the main controller 41 carries
out control over the drivers 42 and 43 to make the carriage 23 and the carrier 33
to run so that the proper lead is achieved at the yarn catching timing for each knitting
needle used for knitting.
[0034] Furthermore, in Fig. 1(b), in one knitting course, the lead at the yarn feeding positions
10a, 10d, and 10s of the yarn feeder port 10 is changed from "X1" to "X2", and then
to "X3", but the lead may be changed from "X1" to "X3" or "X3" to "X2". All the changes
in leads can be achieved by changing the speed of the yarn feeder port 10.