Apparatus for crimping textile fibrous materials

Abstract

 An apparatus (20) for crimping a textile fibrous material (23), includes a pair of nip rolls (21, 22), a stuffing box (24) disposed adjacent to and downstream of the nip rolls, and a channel (44) disposed in a doctor blade (27, 28) of the stuffing box for the passage therethrough of a pressurized fluid and having an outlet (45) opening to an end surface (32) of the doctor blade through which the pressurized fluid is sent into a clearance (33) between the peripheral surface of each roll and the arcuate surface, the apparatus includes a seal block or plug (47) received loosely in a recess defined in the end surface between the outlet (45) and an outer end of the clearance. The plug (47) is urged mechanically or fluidically against the peripheral surface of the roll (21,22) to prevent leakage of the pressurized fluid from a stuffing chamber (31) in the stuffing box (24) through the clearance (33) to the outside air.

Description

[0001] The present invention relates to an apparatus for crimping textile fibrous materials such as filaments, yarns, tows for staple fibers and the like.

[0002] 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 filaments increase their bulkiness. In a high-speed operation of such known apparatus, a textile fibrous material tends to intrude into a gap or clearance 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.

[0003] Japanese Patent Laid-Open Publication (Kokai) Nos. 53-90453 and 54-131065 published on August 9, 1978 and October 11, 1979, respectively, and assigned to the present assignee disclose somewhat 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 is liable to be deformed by heat or pressure, and the gasket may cause contamination of the rolls.

[0004] The present invention seeks to provide an apparatus for crimping a textile fibrous material, which comprises a mechanism for 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.

[0005] According to the present invention, there is provided an apparatus for crimping a textile fibrous material, comprising: a pair of nip rolls cooperating in exerting pressure on the textile fibrous material passing therebetween along a longitudinal path; a stuffing box disposed adjacent to and downstream of said nip rolls and having a pair of spaced doctor blades and a pair of side plates defining jointly with said doctor blades a stuffing chamber for the passage therethrough of the textile fibrous material, each of said doctor blades having'an end surface confronting with the peripheral surface of a corresponding one of said nip rolls with a clearance therebetween, said clearance having an inner end opening to said stuffing chamber and an outer end opening to the outside air, characterized by means defining a channel extending in each said doctor blade for the passage therethrough of a pressurized fluid, said channel defining means including an outlet opening to said end surface and communicating with said clearance near said inner end thereof; and means for substantially preventing leakage of the pressurized fluid from said stuffing chamber through said clearance to the outside air, said leakage preventing means comprising a recess extending in said arcuate end surface transversely of said doctor blade and disposed between said outlet and said outer end of said clearances, a plug loosely received in said recess, and means acting between said recess and said plug to urge the latter against the peripheral surface of said nip roll.

[0006] 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.

Figure 1 is a schematic front elevational view, partly in cross section, of a crimping apparatus according to the present invention;

Figure 2 is a fragmantiary side elevational view, partly in cross section, of the apparatus of Figure 1;

Figure 3 is a plan view of Figure 1;

Figure 4 is an enlarged view showing a portion of the apparatus of Figure 1;

Figures 5 and 6 are views similar to Figure 4, showing different modifications;

Figure 7 is a cross-sectional view taken along line VII - VII of Figure 5;

Figure 8 is a cross-sectional view taken along line VIII - VIII of Figure 6;

Figure 9 is a view similar to Figure 6, showing another modification;

Figure 10 is a fragmentary front elevational view showing a modified apparatus;

Figure 11 is an enlarged fragmentary side elevational view of Figure 10; and

Figure 12 is a diagram showing a pressure distribution in the clearance among the individual points shown in Figure 4.

[0007] As shown in Figures 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 textile fibrous material 23 to be crimped includes filaments, yarns, tows for staple fibers and the like.

[0008] 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 (Figure 1) at a predetermined peripheral speed. The upper nip roll 21 is fixedly supported on a shaft 26 which is movably-supported for vertical movement toward and away from the shaft 25 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 direction (Figure 1) at the same peripheral speed as the nip roll 22.

[0009] The stuffing box 24 is in the form of 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 31. 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 textile fibrous material 23 off the peripheral surface of the respective nip roll 21, 22 while the latter is rotated. The lower doctor blade 28 is fixed in position, while the upper doctor blade 27 is movable in both horizontal and vertical directions 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.

[0010] The side plates 29, 30 are secured to opposite side surfaces of the stationary lower doctor blade 28 with clearance 36, 36 therebetween. Each 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.

[0011] As shown in Figure 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 by the source through the holes 43, 44 and the slot 45 or the orifices into the arcuate clearance 33. The slot 45 or the orifices are disposed near the knife-edge 35 as at A so that the stream of pressurized fluid can flow mostly into the stuffing chamber 31, effectively preventing intrusion of the textile fibrous material into the arcuate clearance 33.

[0012] As best shown in Figure 4, the arcuate clerarance 33 is open at its inner end B 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 47 has an arcuate outer side surface 49 complementary in contour with the peripheral surface of the roll 21.

[0013] With this arrangement, the fluid flowing 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 plug 47. As shown in Figures 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 of 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.

[0014] Figures 5 and 7 show a modification according to the invention, wherein a pair of coiled compression springs 53, 53 is 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.

[0015] Figures 6 and 8 show another 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 54 into the pressure chamber 48. The plug 47 thus can be pressed 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 54 may be modified as the one shown in Figure 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.

[0016] Referring back to Figures 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 in the groove 56, 57 and urged against the opposite surface of the side plate 29 or the doctor blade 28. The groove 56, 57 is disposed at a position closer to the outside than the transverse through-hole 43 (Figure 4) through which the pressurized fluid is sent into the clearance 36. With this arrangement, a required amount of the pressurized fluid is effectively reduced.

[0017] Likewise, as shown in Figures 10 and 11, a substantially U-shaped groove 60 is formed in an inner 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, 62 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.

[0018] 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 lublicating filler or anti-friction agent, an antifriction alloy or the like.

[0019] 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 applied to the plug behind the same.

Claims

1. An apparatus (20) for crimping a textile fibrous material (23), comprising: a pair of nip rolls (21, 22) cooperating in exerting pressure on the textile fibrous material passing therebetween along a longitudinal path; a stuffing box (24) disposed adjacent to and downstream of said nip rolls (21, 22) and having a pair of spaced doctor blades (27, 28) and a pair of side plates (29, 30) defining jointly with said doctor blades a stuffing chamber (31) for the passage therethrough of the textile fibrous material, each of said doctor blades (27, 28) having an end surface (32) confronting with the peripheral surface of a corresponding one of said nip rolls (21, 22) with a clearance (33) therebetween, said clearance having an inner end (B) opening to said stuffing chamber (31) and an outer end (C) opening to the outside air, characterized by means (43 - 45) defining a channel extending in each said doctor blade for the passage therethrough of a pressurized fluid, said channel defining means including an outlet (45) opening to said end surface (32) and communicating with said clearance (33) near said inner end (B) thereof; and means (46 - 48; 53; 54;.55; 56 - 59; 60, 61) for substantially preventing leakage of the pressurized fluid from said stuffing chamber (31) through said clearance (33) to the outside air, said leakage preventing means comprising a recess (46) extending in said end surface (32) transversely of said doctor blade (27, 28) and disposed between said outlet (45) and said outer end (C) of said clearance (33), a plug (47) loosely received in said recess (46), and means (53) acting between said recess (46) and said plug (47) to urge the latter against the peripheral surface of said nip roll (21, 22).

2. An apparatus according to claim 1, said end surface (32) of said doctor blade (27, 28) being arcuate complementary in contour with the peripheral surface of said roll (21, 22) and forming jointly with the peripheral surface of said roll an arcuate clearance (33) therebetwen.

3. An apparatus according to claim 1, said plug (47) and said recess (46) jointly defining therebetween a pressure chamber (48), said plug urging means comprising the pressurized fluid supplyed through said outlet (45) into said clearance (33) and then introduced therefrom into said pressure chamber (48).

4. An apparatus according to claim 1, said plug urging means comprising at least one compression spring (53) disposed in said recess (46) behind said plug (47) and normally urging the latter against the peripheral surface of said nip roll (21, 22).

5. An apparatus according to claim 1, each said doctor blade (27, 28) including a passage (54) opening at one end to said recess (46), said plug (47) and said recess (46) jointly defining therebetween a pressure chamber (48) communicating with said passage (54), said plug urging means comprising a pressurized fluid supplied through said passage (54) into said pressure chamber (48).

6. An apparatus according to claim 1, each said doctor blade (27, 28) including a passage (55) opening at one end to said recess (48) and communicating at the other end with said channel (44), said plug (47) and said recess (46) jointly defining therebetween a pressure chamber (48) communicating with said passage (55), said plug urging means comprising the pressurized fluid supplied through said channel (44) and said passage (55) into said pressure chamber (48).

7. An apparatus according to claim 1, said plug (47) having a surface (49) engageable with and complementary in contour with the peripheral surface of said roll (21, 22).

8. An apparatus according to claim 1, said plug (47) being made of one of plastics, plastics including a lubricating filler and an antifriction alloy.

9. An apparatus according to claim 1, each said doctor blade (27, 28) and each said side plate (29, 30) having a pair of confronting surfaces (38, 39)with a clearance (36) therebetween, said channel defining means including a through-hole (43) extending transversely across said doctor blade (27, 28), said leakage preventing means comprising a groove (56, 57) extending in one of said confronting surfaces (38, 39) at a position closer to the outside air than said through-hole (43), a plug (58, 59) loosely received in said groove (56, 57), and means acting between said groove and said plug to urge the latter against the other confronting surface.

10. An apparatus according to claim 1, each said side plate (30') having an extension (37') extending beyond said end surface (32) of said doctor blade (27, 28) over the nipping point between said nip rolls (21, 22), said side plate having an inner surface (38) confronting to one end surfaces (39) of said nip rolls with a clearance (40) therebetween, said leakage preventing means comprising a groove (60) extending in said inner surface (38) of said side plate (30') in the vicinity of the nipping point, a plug (61) received loosely in said groove (60), and means acting between said groove and said plug to urge the latter against said one end surfaces (39) of said nip rolls (21, 22).

Drawing