FIELD OF THE INVENTION
[0001] The present invention relates to a loop cutting apparatus for circular knitting machines
and particularly to a loop cutting apparatus for circular knitting machines that cuts
a pile loop immediately after it is formed.
BACKGROUND OF THE INVENTION
[0002] Fabrics with fine pile provide the look and touch feel of furs or pelts, hence are
appealing to consumers. Conventional circular knitting machines that can knit fine
plush fabrics, like
U.S. patent Nos. 7,146,829 and
7,127,920, include a cylinder with a plurality of latch-less needles located thereon, a needle
dial contained a plurality of latch needles and a plurality of sinkers. The sinkers
are located on a sinker holder circulating the cylinder. Each sinker has a cutter
at the front end. The sinker is driven by a cam on the sinker holder to slide toward
the cylinder, and the cutter on the sinker severs a pile loop formed by a yarn to
form a pile. References of other types of circular knitting machines that can knit
fine pile fabrics also can be found in PRC patents Nos.
CN201136946 and
CN201546011, Germany patent No.
DE19518490,
U.S. patent Nos. 4,592,212 and
6,094,944. However, the conventional circular knitting machines that can produce fine pile
fabrics require to add a sinker holder around the cylinder, hence significantly increase
the total size of the circular knitting machines and the number of components required.
As a result, the circular knitting machines are complex in structure, and fabrication
and assembly also are more difficult.
[0003] Aside from severing the pile loops via the sinkers, the circular knitting machine
can also be equipped with blade-contained needles to cut the pile loops. For instance,
R.O.C. patents Nos.
205255 and
208294 disclose a pile cutting apparatus. It has multiple sets of vertical cutter needles,
horizontal knitting needles and horizontal sinkers located on a cylinder of a knitting
machine. These three sets of elements can be moved in collaborated displacements so
that the knitting needles can pick up yarns to form loops in cutter needle slots,
then the sinkers move forwards to press the surface of the loops and the cutter needles
are moved upwards to the apex, and the blades at the lower end of the slots sever
the pile loops. However, in order to push the cutter needle to the apex its travel
path has to increase, that means that the time to cut each pile loop is longer, that
adversely affects the knitting efficiency of the fine pile fabrics.
SUMMARY OF THE INVENTION
[0004] The primary object of the present invention is to solve the problems of the conventional
knitting machines for knitting fine pile fabrics of requiring an additional and complex
pile loop cutting apparatus and lower efficiency in knitting the fine pile fabrics.
[0005] To achieve the foregoing object the present invention provides a loop cutting apparatus
for circular knitting machines adopted for use on a circular knitting machine. The
circular knitting machine has a circular cylinder and a yarn conveying system to provide
a plurality of yarns to the circular cylinder. The circular cylinder has a plurality
of first needle slots parallel with the axis of the circular cylinder and a plurality
of knitting needles located in the first needle slots and movable independently. The
loop cutting apparatus includes an upper needle dial and a plurality of yarn cutting
needle sets. The upper needle dial has a plurality of second needle slots radially
centered about the axis of the circular cylinder and corresponding to the first needle
slots. Each yarn cutting needle set includes a first cutter needle and a second cutter
needle in parallel with the first cutter needle and movable against the first cutter
needle in a first yarn cutting displacement thereof. The first cutter needle is located
between two neighboring knitting needles. The first cutter needle has a yarn holding
section leaned by the yarn and collaborated with the abutting knitting needles at
two sides to pick up and draw the yarn to form a pile loop and a first cutter section
connected to the yarn holding section. The second cutter needle has a second cutter
section staggered against the first cutter section in the first yarn cutting displacement
to cut the pile loop.
[0006] In one embodiment the first cutter section of the first cutter needle inclines away
from the knitting needles, and the second cutter section of the second cutter needle
is bent towards the first cutter needle.
[0007] In another embodiment the first yarn cutting displacement includes a first middle
displacement with a closed yarn cutting space among the first cutter section, second
cutter section and yarn holding section to hold the yarn.
[0008] In yet another embodiment the first cutter section inclines towards the knitting
needles, and the second cutter section is bent towards the first cutter needle.
[0009] In yet another embodiment the first yarn cutting displacement includes a second middle
displacement with an open yarn cutting space between the first cutter section and
second cutter section that has an upper opening to hold the yarn.
[0010] In yet another embodiment the first cutter needle includes a first distal end towards
the knitting needles that contains the first cutter section.
[0011] In yet another embodiment the first cutter needle has a first yarn laying displacemen
moved towards the knitting needles to lean on the yarn.
[0012] The invention further provides a loop cutting apparatus for circular knitting machines
adopted for use on a circular knitting machine. The circular knitting machine has
a circular cylinder and a yarn conveying system to provide a plurality of yarns to
the circular cylinder. The circular cylinder has a plurality of first needle slots
parallel with the axis of the circular cylinder. The loop cutting apparatus includes
an upper needle dial on the circular cylinder and a plurality of yarn cutting needle
sets. The upper needle dial has a plurality of second needle slots radially centered
about the axis of the circular cylinder corresponding to the first needle slots and
a plurality of knitting needles located in the second needle slots and movable independently.
The yarn cutting needle sets are located in the first needle slots. Each yarn cutting
needle set includes a first cutter needle and a second cutter needle in parallel with
the first cutter needle and movable against the first cutter needle in a second yarn
cutting displacement. The first cutter needle is located between two neighboring knitting
needles. The first cutter needle has a yarn holding section leaned by the yarn and
collaborated with the abutting knitting needles at two sides to pick up and draw the
yarn to form a pile loop and a first cutter section connected to the yarn holding
section. The second cutter needle has a second cutter section staggered against the
first cutter section in the second yarn cutting displacement to cut the pile loop.
[0013] The yarn cutting apparatus of the invention can have the yarn cutting needle sets
selectively mounted onto the circular cylinder or the upper needle dial. Through the
movable first cutter needle and second cutter needle in each yarn cutting needle set,
the yarn of the pile loop is in contact at the same time with the first cutter section
of the first cutter needle and second cutter section of the second cutter needle,
and is shorn at two sides to sever the pile loop. Compared with the conventional circular
knitting machines for knitting fine pile fabrics, the invention does not need an extra
sinker holder to guide the sinkers and also does not need to extend the travel path
of the cutter needle, thus space utilization of the circular knitting machine is more
efficient and the efficiency of knitting the fine pile fabrics also improves.
[0014] The foregoing, as well as additional objects, features and advantages of the invention
will be more readily apparent from the following detailed description, which proceeds
with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015]
FIG. 1 is a holistic view of an embodiment of the invention adopted on a circular
knitting machine.
FIG. 2 is a perspective view of an embodiment of the loop cutting apparatus of the
invention.
FIG. 3 is a fragmentary perspective view of an embodiment of the loop cutting apparatus
of the invention.
FIG. 4 is a perspective view of an embodiment of the yarn cutting needle set of the
invention.
FIGS. 5A through 5D are schematic views of an embodiment of the yarn cutting needle
set of the invention in loop cutting processes.
FIGS. 6A through 6D are schematic views of another embodiment of the yarn cutting
needle set of the invention in loop cutting processes.
FIGS. 7A through 7D are schematic views of yet another embodiment of the loop cutting
apparatus of the invention in loop cutting processes
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] Please refer to FIGS. 1 through 4 for an embodiment of a loop cutting apparatus of
the invention adopted on a circular knitting machine. The loop cutting apparatus 20
of the invention is used on a circular knitting machine 10 to knit fine pile fabrics
which have a pile surface and a ground fabric to hold the pile surface. The circular
knitting machine 10 has a circular cylinder 11 with an axis A and a yarn conveying
system 14 to provide a plurality of yarns to the circular cylinder 11. The yarns include
at least one first yarn 51 (generally called pile yarn) to form the annular yarn surface
and at least one second yean 52 (generally called ground yarn) to form the ground
fabric. The circular cylinder 11 has a plurality of first needle slots 111 parallel
with the axis A of the circular cylinder 11 and a plurality of knitting needles 112
located in the first needle slots 111 and movable independently. In this invention
the knitting needles 112 can be moved and controlled through a lower cam set 15 at
the periphery of the circular cylinder 11 like the conventional techniques do. The
lower cam set 15 has a corresponding control track (not shown in the drawings) corresponding
to a protrusion 113 of each knitting needle 112 (also referring to FIG. 5A). The lower
cam set 15 can move against the circular cylinder 11, and the protrusion 113 is driven
by the control track so that the knitting needle 112 also is moved in one first needle
slot 111. The loop cutting apparatus 20 includes an upper needle dial 21 located on
the circular cylinder 11 and a plurality of yarn cutting needle sets located on the
upper needle dial 21. The upper needle dial 21 has a plurality of second needle slots
211 radially centered about the axis A of the circular cylinder 11 corresponding to
the first needle slots 111. Each yarn cutting needle set is held in one second needle
slot 211.
[0017] Each yarn cutting needle set includes a first cutter needle 22 and a second cutter
needle 23 parallel with the first cutter needle 22 and movable against the first cutter
needle 22 in a first yarn cutting displacement P thereof. The first cutter needle
22 has a first distal end 221 towards the knitting needles 112 and a yarn holding
section 222 leaned by the first yarn 51, a first cutter section 223 located at the
first distal end 221 and connected to the yarn holding section 222 and a first control
bump 224. The second cutter needle 23 has a second cutter section 231 staggered against
the first cutter section 223 in the first yarn cutting displacement P and a second
control bump 232. In this invention the first cutter needle 22 and second cutter needle
23 can be moved and controlled by an upper cam set 24 on the upper needle dial 21
like in the conventional techniques do. The upper cam set 24 has a plurality of control
tracks (not shown in the drawings) corresponding to the first control bump 224 and
second control bump 232. When the upper cam set 24 is moved against the upper needle
dial 21 the first control bump 224 and second control bump 232 are driven by the control
tracks to move the first cutter needle 22 and second cutter needle 23.
[0018] In this embodiment, referring to FIGS. 3, 4 and 5A, the first cutter section 223
of the first cutter needle 22 inclines away from the knitting needles 112, and the
first cutter section 223 and yarn holding section 222 form a first included angle
a smaller than 90 degrees between them. The second cutter section 231 of the second
cutter needle 23 is bent towards the first cutter needle 22, even can be bent in contact
with the first cutter needle 22.
[0019] Please refer FIGS. 5A through 5D for an embodiment of the loop cutting apparatus
of the invention in loop cutting processes. First, the yarn conveying system 14 guides
the first yarn 51 and second yarn 52 to the circular cylinder 11; the first cutter
needle 22 is controlled by the upper cam set 24 to move towards the knitting needles
112 to proceed a first yarn laying displacement S1; the first yarn 51 leans on the
yarn holding section 222 of the first cutter needle 22 as shown in FIG. 5A; the second
yarn 52 passes through below the yarn holding section 222. Since each first cutter
needle 22 is located between two abutting knitting needles 112, when the knitting
needles 112 are driven by the lower cam set 15 to move downwards as shown in FIG.
5B, the first yarn 51 leaned on the yarn holding section 222 and the second yarn 52
located below the yarn holding section 222 are picked up together by the knitting
needles 112 at the two sides; because of the distance between the yarn holding section
222 and the first yarn 51 picked up by the knitting needles 112 a pile loop 53 is
formed, and the second yarn 52 winds around and holds the bottom of the pile loop
53; next, the second cutter needle 23 is controlled by the upper cam set 24 to proceed
the first yarn cutting displacement P. During the second cutter needle 23 is in the
first yarn cutting displacement P, namely, the first cutter section 223 and second
cutter section 231 start in a staggered manner, as shown in FIG. 5C, the first cutter
section 223, second cutter section 231 and yarn holding section 222 form a first middle
displacement P1 with a closed yarn cutting space 30 among them to hold the first yarn
51. When the second cutter needle 23 continuously proceeds the first yarn cutting
displacement P, the first cutter section 223 and second cutter section 231 are in
contact respectively to two sides of the first yarn 51 to form two-side cutting like
scissors. After the second cutter needle 23 has finished the first yarn cutting displacement
P to sever the pile loop 53 a pile 54 is formed as shown in FIG. 5D. In this embodiment
first yarn 51 is held in the closed yarn cutting space 30 formed among the first cutter
section 223, second cutter section 231 and yarn holding section 222, hence can be
securely shorn to form the pile 54.
[0020] Please refer to FIG. 6A for another embodiment of the invention. The first cutter
section 223a of the first cutter needle 22 inclines towards the knitting needles 112,
and the first cutter section 223a and yarn holding section 222 form a second included
angle β greater than 90 degrees between them. The second cutter section 231a of the
second cutter needle 23 is bent towards the first cutter needle 22, or even bent in
contact with the first cutter needle 22.
[0021] Please refer FIGS. 6A through 6D for the another embodiment of the loop cutting apparatus
of the invention in loop cutting processes. First, the yarn conveying system 14 guides
the first yarn 51 and second yarn 52 to the circular cylinder 11; the first cutter
needle 22 is controlled by the upper cam set 24 to move towards the knitting needle
112 to proceed a first yarn laying displacement S1; the first yarn 51 leans on the
yarn holding section 222 of the first cutter needle 22 as shown in FIG. 6A; the second
yarn 52 passes through below the yarn holding section 222. Since each first cutter
needle 22 is located between two abutting knitting needles 112, when the knitting
needles 112 are driven by the lower cam set 15 to move downwards as shown in FIG.
6B, the first yarn 51 leaned on the yarn holding section 222 and the second yarn 52
located below the yarn holding section 222 are picked up together by the knitting
needles 112 at the two sides; because of the distance between the yarn holding section
222 and the first yarn 51 picked up by the knitting needles 112 a pile loop 53 is
formed, and the second yarn 52 winds around and holds the bottom of the pile loop
53; next, the second cutter needle 23 is controlled by the upper cam set 24 to proceed
the first yarn cutting displacement P. During the second cutter needle 23 is in the
first yarn cutting displacement P, namely, the first cutter section 223 and second
cutter section 231 start in a staggered manner, as shown in FIG. 6C, the first cutter
section 223, and second cutter section 231 form a second middle displacement P2 with
an open yarn cutting space 40 between them with an upper opening to hold the first
yarn 51. When the second cutter needle 23 continuously proceeds the first yarn cutting
displacement P, the first cutter section 223 and second cutter section 231 are in
contact respectively to two sides of the first yarn 51 to form two-side cutting like
scissors. After the second cutter needle 23 has finished the first yarn cutting displacement
P to sever the pile loop 53 a pile 54 is formed as shown in FIG. 6D.
[0022] Please refer to FIG. 7A for yet another embodiment of the invention. The upper needle
dial 21 includes a plurality of knitting needles 212 in the second needle slots 211
that are movable independently. The circular cylinder 11 has a plurality of yarn cutting
needle sets located in the first needle slots 111. Each yarn cutting needle set includes
a first cutter needle 12 and a second cutter needle 13 parallel with the first cutter
needle 12 and movable upward against the first cutter needle 12 in a second yarn cutting
displacement Q. The first cutter needle 12 has a first distal end 121 towards the
knitting needles 112 and a yarn holding section 122 leaned by the first yarn 51, a
first cutter section 123 located at the first distal end 121 and connected to the
yarn holding section 122 and a first control bump 124. The second cutter needle 13
has a second cutter section 131 staggered against the first cutter section 123 in
the second yarn cutting displacement Q and a second control bump 132. In this embodiment
the first cutter needle 12 and second cutter needle 13 can be moved and controlled
by a lower cam set 15 at the periphery of the circular cylinder 11 like in the conventional
techniques. The lower cam set 15 has control tracks (not shown in the drawings) corresponding
to the first control bump 124 and second control bump 132. Movements of the knitting
needles 212 can be controlled by the upper cam set 24 on the upper needle dial 21.
The upper cam set 24 has a plurality of control tracks (not shown in the drawings)
corresponding to the bump 213 of the knitting needles 212.
[0023] Please refer FIGS. 7A through 7D for the yet another embodiment of the loop cutting
apparatus of the invention in loop cutting processes. First, the yarn conveying system
14 guides the first yarn 51 and second yarn 52 to the circular cylinder 11; the first
cutter needle 12 is controlled by the lower cam set 15 to move towards the knitting
needle 112 and upward to proceed a second yarn laying displacement S2; the first yarn
51 leans on the yarn holding section 122 of the first cutter needle 12 as shown in
FIG. 7A; the second yarn 52 passes through below the yarn holding section 122. Since
each first cutter needle 12 is located between two abutting knitting needles 212,
when the knitting needles 212 are driven by the upper cam set 24 to move leftward
as shown in FIG. 7B, the first yarn 51 leaned on the yarn holding section 122 and
the second yarn 52 located below the yarn holding section 122 are picked up together
by the knitting needles 212 at two sides; because of the distance between the yarn
holding section 122 and the first yarn 51 picked up by the knitting needles 212 a
pile loop 53 is formed, and the second yarn 52 winds around and holds the bottom of
the pile loop 53; next, the second cutter needle 13 is controlled by the lower cam
set 15 to proceed the second yarn cutting displacement Q. During the second cutter
needle 13 is in the second yarn cutting displacement Q, namely, the first cutter section
123 and second cutter section 131 start in a staggered manner, as shown in FIG. 7C,
the first cutter section 123, second cutter section 131 and yarn holding section 122
form a first middle displacement Q1 with a closed yarn cutting space 30 among them
to hold the first yarn 51. When the second cutter needle 13 continuously proceeds
the second yarn cutting displacement Q, the first cutter section 123 and second cutter
section 131 are in contact respectively to two sides of the first yarn 51 to form
two-side cutting like scissors. After the second cutter needle 13 has finished the
second yarn cutting displacement Q to sever the pile loop 53 a pile 54 is formed as
shown in FIG. 7D.
[0024] The loop cutting apparatus of the invention can have the yarn cutting needle sets
selectively located on the circular cylinder or the upper needle dial. Through the
first cutter needle and second cutter needle of each yarn cutting needle set that
are movable against each other the first yarn of the pile loop can be in contact at
the same time with the first cutter section of the first cutter needle and second
cutter section of the second cutter needle, and the pile loop can be securely severed
from two sides to form the fine pile without the problem of forming some non-severed
pile loops. Compared with the conventional circular knitting machines for knitting
fine pile fabrics the invention does not need an extra sinker holder to guide the
sinkers, and also does not need to extend the travel path of the bladed knitting needles,
thus space utilization the circular knitting machines is more efficient and knitting
efficiency of the fine pile fabrics also improves.
[0025] As will become apparent to a person skilled in the art, the features as outlined
above and claimed by the appended claims may also be combined in other ways as specifically
claimed in the appended claims. Any such combinations shall be covered as well by
the scope of the appended claims.
1. A loop cutting apparatus for a circular knitting machine (10) which comprises a circular
cylinder (11) and a yarn conveying system (14) to provide a plurality of yarns (51)
to the circular cylinder (11), the circular cylinder (11) containing a plurality of
first needle slots (111) parallel with the axis (A) of the circular cylinder (11)
and a plurality of knitting needles (112) located in the first needle slots (111)
and movable independently, the loop cutting apparatus (20) being
characterized by:
an upper needle dial (21) which is located on the circular cylinder (11) and comprises
a plurality of second needle slots (211) radially centered about the axis (A) of the
circular cylinder (11) and corresponding to the first needle slots (111); and
a plurality of yarn cutting needle sets which is located in the second needle slots
(211), each yarn cutting needle set including a first cutter needle (22) and a second
cutter needle (23) parallel with the first cutter needle (22) and movable against
the first cutter needle (22) in a first yarn cutting displacement (P) thereof, the
first cutter needle (22) being located between two abutting knitting needles (112)
and including a yarn holding section (222) leaned by the yarn (51) and collaborated
with the abutting knitting needles (112) at two sides to pick up the yarn (51) to
form a pile loop (53) and a first cutter section (223) connected to the yarn holding
section (222), the second cutter needle (23) including a second cutter section (231)
staggered against the first cutter section (223) in the first yarn cutting displacement
(P) to cut the pile loop (53).
2. The loop cutting apparatus of claim 1, wherein the first cutter section (223) of the
first cutter needle (22) is inclined away from the knitting needles (112),
3. The loop cutting apparatus of claim 1 or 2, wherein the first yarn cutting displacement
(P) includes a first middle displacement (P1) which contains a closed yarn cutting
space (30) formed among the first cutter section (223), the second cutter section
(231) and the yarn holding section (222) to hold the yarn (51).
4. The loop cutting apparatus of claim 1, wherein the first cutter section (223) of the
first cutter needle (22) is inclined toward the knitting needles (112).
5. The loop cutting apparatus of claim 4, wherein the first yarn cutting displacement
(P) includes a second middle displacement (P2) which includes an open yarn cutting
space (40) with an upper opening and formed between the first cutter section (223)
and the second cutter section (231) to contain the yarn (51).
6. The loop cutting apparatus of any of the preceding claims, wherein the second cutter
section (231) of the second cutter needle (23) is bent toward the first cutter needle
(22).
7. The loop cutting apparatus of claim 1, wherein the first cutter needle (22) includes
a first distal end (221) which faces the knitting needles (112) and contains the first
cutter section (223).
8. The loop cutting apparatus of any of the preceding claims, wherein the first cutter
needle (22) includes a first yarn laying displacement (S1) movable towards the knitting
needles (112) to place the yarn (51).
9. A loop cutting apparatus for a circular knitting machine (10) which includes a circular
cylinder (11) and a yarn conveying system (14) to provide a plurality of yarns (51)
to the circular cylinder (11), the circular cylinder (11) including a plurality of
first needle slots (111) parallel with the axis (A) of the circular cylinder (11),
the loop cutting apparatus (20) comprising:
an upper needle dial (21) which is located on the circular cylinder (11) and includes
a plurality of second needle slots (211) radially centered about the axis (A) of the
circular cylinder (11) and corresponding to the first needle slots (111) and a plurality
of knitting needles (212) located in the second needle slots (211) and movable independently;
and
a plurality of yarn cutting needle sets located in the first needle slots (111), each
yarn cutting needle set including a first cutter needle (12) and a second cutter needle
(13) parallel with the first cutter needle (12) and movable against the first cutter
needle (12) in a second yarn cutting displacement (Q) thereof, the first cutter needle
(12) being located between two abutting knitting needles (212) and including a yarn
holding section (122) leaned by the yarn (51) and collaborated with the abutting knitting
needles (212) at two sides to pick up the yarn (51) to form a pile loop (53) and a
first cutter section (123) connected to the yarn holding section (122), the second
cutter needle (13) including a second cutter section (131) staggered against the first
cutter section (123) in the second yarn cutting displacement (Q) to cut the pile loop
(53).
10. The loop cutting apparatus of claim 9, wherein the first cutter section (123) of the
first cutter needle (12) is inclined away from the knitting needles (212).
11. The loop cutting apparatus of claim 9 or 10, wherein the second yarn cutting displacement
(Q) includes a first middle displacement (Q1) which includes a closed yarn cutting
space (30) formed among the first cutter section (123), the second cutter section
(131) and the yarn holding section (122) to place the yarn(51).
12. The loop cutting apparatus of any of claims 9 to 11, wherein the second cutter section
(131) of the second cutter needle (13) is bent toward the first cutter needle (12).
13. The loop cutting apparatus of any of claims 9 to 12, wherein the first cutter needle
(12) includes a first distal end (121) which faces the knitting needles (212) and
contains the first cutter section (123).
14. The loop cutting apparatus of any of claims 9 to 13, wherein the first cutter needle
(12) is movable towards the knitting needles (212) to place the yarn (51) to form
a second yarn laying displacement (S2).
Amended claims in accordance with Rule 137(2) EPC.
1. A circular knitting machine comprising a loop cutting apparatus, said circular knitting
machine (10) comprising a circular cylinder (11) with an axis (A) and a yarn conveying
system (14) to provide a plurality of yarns (51) to the circular cylinder (11), wherein
the circular cylinder (11) has a plurality of first needle slots (111) parallel with
the axis (A) of the circular cylinder (11) and a plurality of knitting needles (112)
located in the first needle slots (111) and movable independently, and
the loop cutting apparatus (20) has an upper needle dial (21), which is located above
the circular cylinder (11) and comprises a plurality of second needle slots (211)
radially centered about the axis (A) of the circular cylinder (11) and corresponding
to the first needle slots (111), and a plurality of yarn cutting needle sets located
in the second needle slots (211), wherein
each yarn cutting needle set includes a first cutter needle (22) and a second cutter
needle (23) parallel with the first cutter needle (22) and movable against the first
cutter needle (22),
the first cutter needles (22) are located between two abutting knitting needles (112)
and include a yarn holding section (222) for contact with one of the yarns (51) and
cooperating with the abutting knitting needles (112) at each side to pick up the yarn
(51) to form a pile loop (53) and a first cutter section (223) connected to the yarn
holding section (222), and
the second cutter needle (23) includes a second cutter section (231),
characterized in that the movement of the first cutter needles (22) and of the second cutter needles (23)
is controlled such that
the first cutter needle (22) is moved towards the knitting needles (112) to perform
a first yarn laying displacement (S1) to place the yarns (51), and
the second cutter needle (23) is moved towards the knitting needles (112) after the
first cutter needle (22) has finished the first yarn laying displacement (S1) to perform
a first yarn cutting displacement (P) so that the second section (231) of the second
cutter needle (23) moves towards the knitting needles (112) to stagger against the
first cutter section (223) of the first cutter needle (22) during the first yarn cutting
displacement (P) to cut the pile loop (53).
2. The loop cutting apparatus of claim 1, wherein the first cutter section (223) of
the first cutter needle (22) is inclined away from the knitting needles (112).
3. The loop cutting apparatus of claim 1 or 2, wherein the first yarn cutting displacement
(P) includes a first middle displacement (P1) which contains a closed yarn cutting
space (30) formed among the first cutter section (223), the second cutter section
(231) and the yarn holding section (222) to hold the yarn (51).
4. The loop cutting apparatus of claim 1, wherein the first cutter section (223) of
the first cutter needle (22) is inclined toward the knitting needles (112).
5. The loop cutting apparatus of claim 4, wherein the first yarn cutting displacement
(P) includes a second middle displacement (P2) which includes an open yarn cutting
space (40) with an upper opening and formed between the first cutter section (223)
and the second cutter section (231) to contain the yarn (51).
6. The loop cutting apparatus of any of the preceding claims, wherein the second cutter
section (231) of the second cutter needle (23) is bent toward the first cutter needle
(22).
7. The loop cutting apparatus of claim 1, wherein the first cutter needle (22) includes
a first distal end (221) which faces the knitting needles (112) and contains the first
cutter section (223).
9. A circular knitting machine comprising a loop cutting apparatus, said circular knitting
machine (10) comprising a circular cylinder (11) with an axis (A) and a yarn conveying
system (14) to provide a plurality of yarns (51) to the circular cylinder (11), wherein
the circular cylinder (11) has a plurality of first needle slots (111) parallel with
the axis (A) of the circular cylinder (11), and
the loop cutting apparatus (20) has an upper needle dial (21), which is located above
the circular cylinder (11) and comprises a plurality of second needle slots (211)
radially centered about the axis (A) of the circular cylinder (11) and corresponding
to the first needle slots (111), a plurality of knitting needles (212) located in
the second needle slots (211) and movable independently, and a plurality of yarn cutting
needle sets located in the first needle slots (111), wherein
each yarn cutting needle set includes a first cutter needle (12) and a second cutter
needle (13) parallel with the first cutter needle (12) and movable against the first
cutter needle (12),
the first cutter needles (12) are located between two abutting knitting needles (212)
and include a yarn holding section (122) for contact with one of the yarns (51) and
cooperating with the abutting knitting needles (212) at each side to pick up the yarn
(51) to form a pile loop (53) and a first cutter section (123) connected to the yarn
holding section (122), and
the second cutter needles (13) include a second cutter section (131),
characterized in that the movement of the first cutter needles (22) and of the second cutter needles (23)
is controlled such that
the first cutter needle (22) is moved towards the knitting needles (112) to perform
a second yarn laying displacement (S2) to place the yarns (51), and
the second cutter needle (23) is moved towards the knitting needles (112) after the
first cutter needle (22) has finished the second yarn laying displacement (S1) to
perform a second yarn cutting displacement (Q) so that the second section (231) of
the second cutter needle (23) moves towards the knitting needles (112) to stagger
against the first cutter section (123) of the first cutter needle (22) during the
second yarn cutting displacement (Q) to cut the pile loop (53).
9. The loop cutting apparatus of claim 8, wherein the first cutter section (123) of
the first cutter needle (12) is inclined away from the knitting needles (212).
10. The loop cutting apparatus of claim 8 or 9, wherein the second yarn cutting displacement
(Q) includes a first middle displacement (Q1) which includes a closed yarn cutting
space (30) formed among the first cutter section (123), the second cutter section
(131) and the yarn holding section (122) to place the yarn(51).
11. The loop cutting apparatus of any of claims 8 to 10, wherein the second cutter section
(131) of the second cutter needle (13) is bent toward the first cutter needle (12).
12. The loop cutting apparatus of any of claims 8 to 11, wherein the first cutter needle
(12) includes a first distal end (121) which faces the knitting needles (212) and
contains the first cutter section (123).