Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF THE IN~7ENTION
Field of the Invention:
The present invention relates to an apparatus for
crimping textile fibrous materials such as filaments,
yarns, tows for staple fibers and the like.
Prior art:
There have been known various crimping apparatus of
the type described in which a tow of paralleled continuous
filaments is nipped between rotating rolls and is forced
into a stuffing box disposed adjacent to the rolls, whereby
the Eilaments increase their bulkiness. In a high-speed
operation of such known apparatus, a textile fibrous
material tends to intrude into a gap or cle~rance between a
stationary part and a movable part of the apparatus, i.e.
into a clearance between one of the rolls and a
corresponding doctor blade or a side plate of the stuffing
box, and also into a clearance between the doctor blade and
the side plate.
Japanese Patent Laid-Open Publicatiorl (Kokai) Nos.
53-90453 and 54-131065 published on August 9, 1978 and
October 11, 1979, respectivelyl and assigned to the present
assignee disclose somewha-t successful apparatus, wherein a
pressurized fluid chamber is disposed on each doctor blade
of a stuffing box, and a fluid ejected therefrom is sent
toward the inside of the stuffing box while the outflow
leakage of the fluid is prevented with a gasket or the
like. According to the disclosed system, the stuffing box
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is liable to be de~ormed by heat or pressure, and the
gasket may cause con-tamination of the rolls.
SUMMARY OF THE INVENTION
_
It is therefore an object of the present invention to
provide an apparatus for crimping a textile fibrous
material, which comprises a mechanism Eor preventing
intrusion of the textile fibrous material by exterting a
pressurized fluid thereon without any contamination of nip
rolls or any deformation of a stuffing box that may
otherwise be induced by heat or pressure.
According to the present invention, an apparatus for
crimping a textile fibrous material, comprises a pair of
nip rolls, a stuffing box disposed adjacent to and
downstream of the nip rolls for the passage -therethrough of
the textile fibrous material and having a pair of spaced
doctor blades. Each of the doctor blades has an end
surface confronting with the-perlpheral surface of a
corresponding one of the nip rolls with a clearance
therebet~een, the clearance having an inner end opening to
said stuffing chamber and an outer end opening to the
outside air. A channel defining means extends in each
doctor blade for the passage therethrough of a pressurized
fluid and has an outlet opening to the end surface near the
inner end of the clearance. The crimping apparatus further
includes a means for substantially preventing leakage of
the pressurized fluid from the stuffing chamber through the
clearance to the outside air. The leakage preven-ting means
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comprises a recess extending in the end surface
transversely of the doctor blade and disposed between the
outlet and the outer end of the clearances, a plug loosely
received in the recess, and means acting between the recess
and the plug to urge the latter against the peripheral
surface of the nip roll. The end surface of the doctor
blade preferably is formed into an arcuate complementary in
contour with the peripheral surface of the roll so as to
form jointly with the latter an arcuate clearance
therebetween.
Many other advantages and features of the present
invention will become manifest to those versed in the art
upon making reference to the detailed description and the
accompanying sheets of drawings in which preferred
structural embodiments incorporating the principles of the
present invention are shown by way of illustrative example~
BRIEF DESCRIPTION OF T~IE DRA~INGS
-
FIG. 1 is a schematic front elevational view, partly
in cross section, of a crimping apparatus according to the
present invention;
FIGo 2 is a fragmantiary side elevational view,
partly in cross section, of the apparatus of FIG~ l;
FIG~ 3 is a plan view of FIG~ l;
FIGc ~ is an enlarged view showing a portion of -the
apparatus of FIGo l;
FIGSo 5 and 6 are views similar to FIG. ~, showing
different modifications;
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FIG. 7 is a cross-sectional view taken along line VII
- VII of FIGo 5;
FIG. 8 is a cross-sectional view taken along line
VIII - VIII of FIG. 6;
FIG. 9 is a view similar to FIG. 6, showing another
modiEication;
FIG. 10 is a fragmentary front elevational view
showing a modified apparatus;
FIG. 11 is an enlarged fragmentary side elevational
view of FIG. 10; and
FIG. 12 is a diagram showing a pressure distribution
in the clearance among the individual poin-ts shown in FIG~
4.
DETAILED DESCRIPTION
As shown in FIGS. 1 to 3, an apparatus 20 comprises a
pair of upper and lower nip rolls 21, 22 cooperating in
exerting pressure on a textile fibrous material 23 passing
therebetween along a longitudinal path, and a stuffing box
24 disposed downstream of and adjacent to the nip rolls 21,
22 for crimping the textile fibrous material 23 supplied
therein by the nip rolls 21, 22. The tex-tile fibrous
material 23 to be crimped includes filaments, yarns, tows
for staple fibers and the like.
The lower nip roll 22 is fixedly supported on a shaft
25 adapted to be driven by a suitable drive means (not
shown) to rotate the roll 22 in the crockwise direction
(FIGo 1 ) at a predetermined peripheral speed. The upper
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nip roll 21 is fixedly supported on a shaft 2~ which is
movably supported for vertical movement toward and away
from the shaft 2~ to adjust a nipping force at the nipping
point between -the nip rolls 21, 22. The nip roll 21 is
driven by a suitable drive means (not shown) in the
counter-crockwise direc-tion (FIG. 1) at the same peripheral
speed as the nip roll 22.
The stuffing box 24 is in the form oE substantially
hollow rectangular box with opposite ends open for the
passage therethrough of the fibrous textile material 23.
The box 24 is composed of pair of spaced upper and lower
doctor blades 27, 28 and a pair of side plates 29, 30
disposed one on each side of the superposed doctor blades
27, 28 to define jointly therewith a stuffing chamber 310
Each of the doctor blades 27, 28 has, at one end adjacent
to a corresponding one of the nip rolls 21, 22, an arcuate
end surface 32 complementary in contour with the peripheral
surface of the corresponding nip roll 21, 22 and facing to
the same with an arcuate clearance 33 therebetween. The
arcuate end surface 32 and a flat inner surface 34 of each
doctor blade 27, 28 jointly define a knife-edge 35 which
serves to scrape the tex-tile fibrous material 23 off the
peripheral surface of the respective nip roll 21, 22 while
the latter is rotated. The lower doctor blade 23 is fixed
in position, while the upper doctor blade 27 is movable in
both horizontal and vertical direc-tions so as to keep the
arcuate clearance 33 constant even when the upper nip roll
21 is vertically displaced with respect to the lower nip
roll 22.
The side plates 29, 30 are secured to opposite side
surfaces of the stationary lower doctor blade 28 with
clearance 36, 36 therebetween. ~ach side plate 29, 30 has
a tapered extension 37 projecting beyond the end surface 32
of the doctor blade 27, 28 and having an inner surface 38
extending parallel to one of opposite end surfaces 39 of
the respective rolls 21, 22 with a clearance 40
therebetween. The extension 37 of one side plate 30
includes a presser plate 41 movably supported on a base 42
and movable toward the end surfaces 39 of the respective
nip rolls 21, 22.
As shown in FIG. 1, each of the doctor blades 27, 28
has a transversely extending through-hole 43 adjacent to
the arcuate end surface 32, a supply hole 44 communicating
at one end with the through-hole 43 and having the opposite
end adapted to be connected to a source (not shown) for
supplying a pressurized fluid such as compressed air or
pressurized steam, and a transversely extending slot 45
opening at one side to the arcuate end surface 32 along the
length thereof and at the other side to the through-hole
43. Alternatively, each doctor blade 27, 28 may have a
series of orifices (not shown) instead of the slot 45, each
orifice opening at one end to the arcuate end surface 32
and at the opposite end to the through-hole 43. A stream
of pressurized fluid is supplied b~ the source through the
holes 43, ~4 and the slot 45 or the orifices in-to the
arcuate clearance 33. The slot 45 or the orifices are
disposed near the kniEe edge 35 as at A so tha-t the stream
of pressurized fluid can flow mostly into the stuffing
chamber 31, effec-tively preventing intrusion of the textile
fibrous material into the arcuate clearance 33.
As best shown in FIG. 4, the arcuate clerarance 33 is
open at its inner end s to the stuffing chamber 31 while
being open at its outer end C to the outside air. Each
doctor blade 27, 28 has a transversely extending recess 46
disposed in the arcuate end surface 32 between the outer
end C of the arcuate clearance 33 and the slot 45 or the
orifices. A sealing block or a plug 47 is loosely received
in the recess 46 with a pressure chamber 48 defined
therebetween, and partly projects from the arcuate end
surface 32 into the clearance 33. The plug 47 is normally
held in light contact or nearly out of contact with the
peripheral surface of the nip roll 21. Preferably, the
recess 46 has a transverse axis X - X' extending across the
axis of the roll 21, and the plug A7 has an arcuate outer
side surface 49 complementary in contour with the
peripheral surface of the roll 21.
With this arrangement, the fluid flowiny out through
the slot 45 or orifices into the clearance 33 is sent
toward the inner end B to prevent intrusion of the textile
fibrous material into the clearance 33. In the meanwhile,
the fluid flowing toward the outer end C is impeded by the
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plug 47. As shown in FIGS. 4 and 12, the pressure in the
clearance 33 at a position D immediately inside the plug 47
becomes higher than that in the clearance 33 at a position
E immediately outside the plug 47 due to the fluid pressure
and the rotation of the nip roll 21. Such higher pressure
is applied from the pressure chamber 48 to a rear or inner
side surface of the plug 47 via a narrow gap existing
between a lower surface of the plug 47 and a lower wall o~
the recess 46, thereby automatically pressing the plug 47
lightly against the peripheral surface of the nip roll 21
to substantially close a gap therebetween or to maintain
the gap at a further reduced spacing. The width or
thickness of -the plug 47 is so selected as to obtain such a
minute gap spacing, and the recess 46 is so formed as to
have a proper width in accordance therewith.
FIGS. 5 and 7 show a modification according to the
invention, wherein a pair of coiled compression springs 53,
53 ]s received in the recess 46 behind the plug 47 and acts
between the doctor blade 27 and the plug 47 to urge the
latter against the peripheral surface of the nip roll 21.
Thus, the sealing effect is further ensured.
FIGS. 6 and 8 show ano-ther modification in which -the
doctor blade 27 includes a supply passage 54 communicating
at one end with the recess 46 and having the opposite end
adapted to be connected to a source (not shown) for
supplying a pressurized fluid through the passage 5~ into
the pressure chamber 48. The plug 47 thus can be pressed
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by the fluid against the peripheral surface of the nip roll
21. With this arrangement, the pressure of fluid supplied
to the pressure chamber 48 is adjusted at a proper value.
The supply passage S4 may be modified as the one shown in
FIG. 9 at 55. The supply passage 55 communicates at one
end with the pressure chamber 48 and at the opposite end
with the supply hole 44 through which the pressurized fluid
is supplied to the slot 45 or the orifices and then to the
arcuate clearance 33. When the pressurized fluid is
introduced through the supply passage 55 by way of the
supply hole 44, a pressure slightly higher than that in the
clearance 33 at the position E immediately outside the plug
47 is created in the pressure chamber 48 so that the plug
47 is pressed lightly against the peripheral surface of -the
nip roll 21.
Referring back to FIGS. 1 and 2, a groove 56, 57
extends in one of confronting surfaces of each doctor blade
27, 28 and each side plate 29, 30, and a plug 58, 59 is
loosely received ln the groove 56, 57 and urged against the
opposite surface of the side plate 29 or the doctor blade
2~. The groove 56, 57 is disposed at a position closer to
the outside than the transverse through-hole 43 (FIG. 4)
through which the pressurized fluid is sent into the
clearance 36O With this arrangement, a required amount of
the pressurized ~luid is effectively reduced.
Likewise, as shown in FIGS. 10 and 11, a
substantially U-shaped groove 60 is formed in an inner
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surface of a side plate 30' in the vicinity of the nipping
point between the rolls 21, 22. A complementary plug 61 is
loosely received in the groove 60 and urged against the end
surfaces 39 of the rolls 21, 22 across the clearance 40. A
pair of supply holes 62, 6~ is formed in the side plate 30'
one on each side of the nipping point and is surrounded by
the U-shaped plug 61. With this arrangement, a required
amount of the pressurized fluid further can be reduced.
Throughout the embodiments mentioned hereinbefore,
the sealing block or plug 47, 58, 59, 61 preferably is made
of a proper material not impairing or contaminating the nip
rolls 21, 22, such as plastics containing or not containing
a lublic~ting filler or anti-friction agent, an
antifriction alloy or the like.
With the apparatus constructed in accordance with the
present invention, leakage of the presurized fluid from any
of the clearances 33, 36, 40 toward the outer end of the
stuffing box 24 is minimized or substantially prevented by
loosely holding the plug 47, 58, 59, 61 in the recess 46 or
groove 56~ 57, 60 such that the plug 47, 58, 59, 61 is
urged against the confronting surface of the opposed member
21, 22, 27, 28, 29, 30 by means of a mechanical or fluidic
force app~ied to the plug behind the same.
Although various minor modifications may be suggested
by those versed in the art, it should be understood that we
wish to embody within the scope of the paten-t warranted
hereon, all such embodiments as reasonably and properly
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come within the scope of our contribution to the art.
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