Note: Descriptions are shown in the official language in which they were submitted.
1037273
It is an object of the invention to provide a more
efficient circular knitting machine which will allow the
production of large rolls of fabric which can be more readily
doffed from the knitting machine.
According to one broad aspect, the present invention
provides a circular knitting machine comprising: means to -~
produce a knitted fabric, means to take up the knitted fabric
produced and a semi-automatic means to mechanically doff the
fabric from the means to take up the fabxic, said semi-automatic
- 10 means including a pair of spaced lever arms pivotally connected
to said machine, a handle means extending between and connected `~-
to said lever arms, said lever arms each having a groove on the
inside surface thereof with one side of said groove on each
lever arm being longer than the other side of each groove, said
means to take up the knitted fabric including a shaft adapted -
to be slidably mounted at each end in said grooves.
Other objects and advantages of the invention will
; become clearly apparent as the specification proceeds to
i describe the invention with reference to the accompanying
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20 drawings, in which: ¦
Figure 1 is a front elevation partially schematic view
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` of a circular knitting machine incorporating the novel doffing ~ -
~- apparatus.
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Figure 2 is a view taken on line 2-2 of Figure 1
showing one side of the take-down and take-up arrangement;
Figure 3 is a view taken on line 3-3 of Figure 1
showing the other side of the take-down and take-up apparatus;
Figures 4 and 5 are views taken on line 45-45 of
Figure 1 showing the take-up roll partially doffed (Figure 4)
and In the full doffing position (Figure 5);
Figure 6 i3 a top section view taken on line 6-6 of
Figure 3; and
Figure 7 is a top view of the secondary spreader bar.
Looking now to Figure 1 there is shown a conventional
double knit circular knittlng machine 10 supplied with a
plurality of yarns from an off-side creel (not shown). The
,,~ yarn is supplied through the yarn guide ring 12 to the rotating ~ `
needle cylinder 14 whereat it is knit into a tube of fabric F.
The fabric F from the needle cylinder 14 passes downwardly
- over a conventional spreader bar 15 to spread it into a flat
- ~ shape and then passes under the oxbow shaped rod 16 and over
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; the secondary spreader bar 17 to the driven take-down rolls
; 20 18 and 20 which are off-set rearwardly from the centerline of
the knitting machine. From the take-down rolls 18 and 20 the
; flattened fabric F is delivered to the take-up roll 22 which i6 -
driven by surface drive roll 24 which is also off-set rear-
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wardly from the centerline of the knitting machine.
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` The fabric take-down structure, generally designated
26 and shown in detail in Figures 2-6, is supported by the
upright frame members 28 and 30 and rotates on track 32 in
synchronism with the rotation of the needle cylinder 14 via :~
5 wheels 34 rotably connected to the frame members 28 and 30.The oxbow shaped rod 16 is suspended for vertical ~ ;
movement by arms 36 which are pivotally secured to lever ~-
arms 38, 39, 40 and 41, pivotally mounted to the frame ~ -
. members 28 and 30 substantially parallel to one another. To
`` 10 bias the rod 16 in the downward position another lever arm
: 42 is fixed to each of the arms 36 and has a spring member
~ 44 connected thereto with the other end of the spring being
.~.; connected to each of the frame members 28 and 30.
As described briefly above, the rod 16 is oxbow
shaped and is located between the needle cylinder 14 and the
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. take-down rolls 18 and 20 so that the fabric F passes under
the rod 16 as it passes to the take-down rolls 18 and 20. For
the most efficient operation of the machine it is desired to - `
~i; maintain the`tension between needle cylinder 14 and the
` 20 take-down rolls 18 and 20 substantially the same across the
. width of the fabric F. Since the fabric length adjacent the
... - center of the fabric F is longer than the fabric length
adjacent the ends of the fabric when the cylinder of knit
fabric at the cylinder needles 14 is spread and flattened under
the same thec~retical tension, it is necessary to decrease the ~: :
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~1037Z73
length of travel of the center of the flattened fabric F between
the needle cylinder 14 and the take-down rolls 18 and 20
relative to the path of travel of the flattened fabric outward
of the center of the fabric to maintain a constant tension
across the width of the fabric since the take~down rolls apply
a substantially even pull across the width of the flattened
fabric F. Therefore, the rod 16 is oxbow shaped to decrease
the path of travel of the fabric at the center of the rod and
increase the path of travel of the fabric slightly outward of
the center of the fabric to compensate for the differential
; fabric lengths developed when the cylinder or tube of fabric
is spread and flattened prlor to delivery to the take-down
rolls 18 and 20. As noted briefly before, a secondary spreader
bar 17 is located inside the flattened fabric tube F to control
~ - 15 the width of the tube. The secondary spreader bar 17 has a
`~ ~ pair of wheels 82 and 84 pivotally mounted on each end
thereof to roll inside the fabric as the fabric is drawn by the
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take-down rolls 18 and 20. Bar 17 basically consists of two ; ~-~
, threaded po~tions 86 and 88 with a turnbuckle 90 mounted
therebetween to vary the width of the fabric F. The spreader
bar 17 is secured to the spreader bar 15 by means of cables
92 which pass under the oxbow shaped rod 16 inside the fabric.
As discu~sed briefly, the needle cylinder 14 and the
take-down apparatus 26 are rotated in synchronism by a drive
` 25 means (not shown). The take-down rolls 18 and 20 and the
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. surface drive roll 24 are driven by a separate variable speed
drive motor 46 mounted on the knitting machine. The drive
motor 46 drives both the roll 20 and 24 through a suitable
drive belt 47 connected to the sprocket 48 operably associated
with the shaft of the drive motor, the sprocket 50 on the shaft
of take-down roll 20 and the sprocket 51 on the shaft of the
. surface drive roll 24. To maintain nip pressure between
rolls 18 and 20, tXe roll 18 is spring located by means of a
spring 52 toward the roll 20 and can be adjusted by adjust-
ment of the nut 54. When the nip pressure between the take-
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: down rolls 18 and 20 has been adjusted the speeds of the
take-down rolls 18 and 20 and the surface roll are automati-
cally and simultaneously adjusted in accordance with the pull
. down tension in the fabric F by the vertical position of the
rod 16. The vertical position of the rod 16 through the arm
` 36 and the lever 41 controls the vertical position the rod 56
. connected to the lever 41 which in turn adjusts the speed of
the variable speed motor 46.
As noted above, the take-down rolls 18 and 20 are
Z0 off-set from the centerline of the machine toward the rear
. thereof to allow the production of a larger roll 22. When
- ~ producing such a roll it is necessary to provide a means to ~ :
readily doff same, especially when using female knitting
~: machine operators. To this end the doffing mechanism
cons-isting of a pair of lever arms 58, a pair of bell cranks
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60, and a doffing handle mechanism 62 is employed. The
doffing mechanism basically consists of a doffing handle 64
connected to a pair of elongated lever arms 66 each of which
has a groove 68 therein facing toward the take-up roll 2Z.
- 5 Each of the lever arms 58 is pivotally connected to one of the
lever arms 66 at 70 and to the inner wall of the respective
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frame member 28 or 30 at 71. Each of the bell cranks 60 is
also pivotally connected to one of the elongated lever arms 66
at 72 and to the inner wall of the respective frame member 28
; 10 or 30 at 74. Rigidly secured to each of the elongated lever
arms 66 is a bracket member 67 which has a roll support rod
- 69 therebetween.
Looking now primarily to Figures 4 and 5 the doffing
operation will be explained. As is well known the take-up `~
roll winds up the fabric F on a tube 76 in which is inserted a
, core 78. As shown in Figures 4 and 5 the core 78 is slidably ,
mounted in the groove 68 so that as the roll grows in diameter
the core and tube will move upwardly. When the desired
diameter rol~ is wound the doff handle 64 is grasped and
moved in a counterclockwise direction to unroll the roll 22
somewhat to provide a fabric tail and to rotate the support 69 -~ - ~
, counterclockwise into engagement with the roll 22 to aid in ~ ;
causing the roll to be lowered onto the buggy 80. The core is
guided by the links 58 and 60 to raise the center approximately
Z5 4" before the roll is lowered toward the buggy 80. As the
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handle is being rotated to a horizontal position it is pulled to
the left (Figures 4 and 5) to aid in depositing the roll Z2 on the
buggy 80. Then the doff handle is pushed to the right until the
core 78 drops out of the groove 68 to disengage the roll 22.
; 5 The core 78 is then disengaged from the tube 76, the fabric
cut and the buggy moved to a remote position. Then the doffing
mechanism is in position to be loaded with a new tube and be
threaded up with more fabric.
It is obvious that an improved circular knitting
machine has been provided that can roll up large rolls of knit
fabric and which at the same time can be readily doffed with
-- a minimum of effort.
Although the preferred embodiment of the invention
has been described, it is contemplated that many changes may
be made without departing from the scope or spirit of the
invention and it is desired that the scope of the invention be
limited only by the claims.
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