US3083414A

US3083414A - Forming funnel and method of forming sliver

Info

Publication number: US3083414A
Application number: US55295A
Authority: US
Inventors: Gasser Hermann
Original assignee: Luwa Ltd
Current assignee: Luwa Ltd
Priority date: 1959-09-12
Filing date: 1960-09-12
Publication date: 1963-04-02
Anticipated expiration: 1980-04-02

Description

April 2, 1963 H. GASSER 3,083,414

FORMING FUNNEL AND METHOD OF FORMING SLIVER Filed Sept. 12, 1960 FIG. 1

ATTOK/VEY United States Patent land Filed Sept. 12, 196i Ser. N 55,295 Qlaims priority, application Switzerland Sept. 12, 195% 18 Claims. (Ci. l9--l5ll) The present invention relates to a novel method of and means suitable for continuously grouping together into a desired configuration the fibers of a flat web or roving and, more particularly, to a novel construction of a funnel-shaped tubular member serving as a forming member for the fibers of the webs received at the delivery side of a drawing frame or like machine. The present invention is particularly suitable for use in conjunction with a drawing frame and is adapted to be positioned beveen the draw rollers thereof and a conventional trumpet member, as for example, in the arrangement shown by Hendrickson United States Letters Patent 2,355,071, granted August 8, 1944, for Sliver Can Motion.

As is well known when employing drawing frames and like machines, the fibers of the webs are passed between banks of rotatable draw rollers or cylinders. The drawing operation is carried out by virtue of the different number of revolutions imparted to the grouped pairs of draw rollers which are serially arran ed in the direction of web travel to define an upper and lower draw roller bank. The web or roving delivered by the drawing frame possesses a substantially rectangular cross-section. In view or the fact that the thus formed web is not suitable for further processing and handling, it must first be formed or reshaped so as to have imparted thereto a desired configuration, as for example, possessing a ubstantially circular cross-section. It is known to arrange a funnelshaped forming member at the delivery side of the drawing frame and before entry to a condenser member for a coiler head assembly. The forming member picks up the fibers of the web at its narrow end and forms it into a web of smaller width. The forming member may be formed of a completely or partially closed length of conical tubing. If, however, the velocity of the web is increased to approximately 200 m./min. and beyond, certain types of these tunnel-shaped members will cause disturbances which adversely efiect the web to be handled. On the one hand, the fibers leaving the drawing frame which are attenuated and in parallel condition are partially returned to their disordered state, and in some instances, the fibers may even be removed from the web bulk; whereas on the other hand, an undesirable and non-permissible ballooning of the fibers occurs when the web leaves the funnel-shaped forming member.

Such disturbances are particularly observed in forming members of the type wherein the fibers of the web are subjected to an intensive shaping operation eiiecting its cross-section and density, and wherein there is provided an accurate guiding of the web. In such forming members, the effective length thereof is a multiple of the diameter of its smallest cross-section. The elfective inlet or supply cross-section, that is to say, the cross-section wherein the web initially contacts the side walls of the funnel-shaped forming member, is also a multiple of said narrowest cross-section. Such funnel-shaped forming members are, therefore, comparatively lengthy and extended in form. The disturbances acting on the fibers of the web increase with increasing web velocity. The present invention is directed at overcoming these difiiculties by providing a forming member which permits the fibers of the web to pass therethrough Without encounter- 3,083,414 Patented Apr. 2, 1&5?

2 ing difiiculties or being subjected to undesirable disturbances even when the velocity of the web is high.

To this end, the present invention contemplates the provision of a funnel-type forming member formed by a tube which tapers or converges between the inlet or supply side and the outlet or discharge side and, wherein at least, the discharge portion of the tube possesses a substantially circular cross-section. The funnel-shaped forming member is provided with a throat portion of narrowest cross-section which is arranged upstream and prior to reaching the outlet of said forming member. The design of the cross-section of the tube is uniform at least in the delivery portion thereof which has the narrowest cross-section. A number of experiments and tests performed with forming funnels of this type have clearly revealed that the adverse effects experienced by the fibers of the web is due to the air which surrounds the web and also which is located between its fibens. As the speed of the web increases, this entrained air cannot be removed and emerge from between the fibers of the web prior to entry into the forming funnel so that said air is carried along into the interior of the forming member where it undergoes a slight pressurization. This observation was made mainly by virtue of the behavior of the fibers of the web when delivered from the forming member, wherein the sudden expansion of the air emerging therefrom was apparently the cause of the sometimes very pronounced ballooning or swelling of the web. The method of handling the fibers of the web by use of a forming member constructed in accordance with the teachings of the present invention obviates these undesirable eflects.

Accordingly, it is an important object of the present invention to provide a novel construction of a forming funnel permitting unhampered advance of a web and the like therethrough without subjecting the same to undesirable conditions tending to adversely efiect said web.

It is another important object of the present invention to provide means permitting gradual expansion of air entrapped between the fibers of the web and carried along therewith into a forming funnel.

Still a further object of the present invention is the provision of a novelly constructed forming funnel adapted to impart a desired configuration to the fibers of a web without subjecting the latter to adverse effects.

Another important object of the present invention is the provision of a novel forming funnel which is simplified in construction, easy to manufacture, and may under certain conditions be employed as a fiber compressing member.

These and still further subjects of the present invention and its entire scope and applicability will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illus tration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

In the drawings:

FIG. 1 is a diagrammatic view of a funnel-shaped member for the continuous forming of the fibers of a fiat fiber web;

FIG. 2 is a sectional view of the forming member shown in FIGURE 1 taken along the line II-II;

FIG. 3 is a sectional view of a further embodiment of a forming member for forming a flat fiber web; and

FIG. 4 shows the details of the delivery or outlet portion of a further embodiment of a funnel-shaped forming member similar to that shown in FIGURE 1 and pursuant to the present inventionframe enters the forming member which may, by way of example, be arranged upstream of the entrance to a compressor or trumpet 7 cooperable with a coiler head assembly (not shown). The forming tunnel 1, located downstream and directly adjacent the outlet of the drawing frame for the advancing web is in the illustrated embodiment formed from a funnel-shaped converging-diverging tubular member possessing an annular cross-section, as

forfexample a fiat oval at its inlet end 2 as best seen in FIGURE 2. This flat oval-shaped cross-section isconstituted by a pair of semicircular diametrically opposedside portions 3 interconnected by a pair of straight intermediate wall portions 4. The inner Walls 8 of the tubular funnel 7 defined by'said semicircular opposed side portions 3 and said interconnecting wall-portions 4 converge toward one another downstream and in the longitudinal direction of the inlet 2 so that a substantially circular cross-section is obtained ata throat'portion 5 where the cross-section of the tubular' funnel 1 is narrowest. As shown in FIGURE 1, the discharge portion 5a approaching the outlet 6 of the funnel -1 is somewhat flared or diverging with'respect 'to'the throat portion Shaving the narrowest cross-section.

The inner'walls of the discharge portion 6 of the tubular funnel form an angle a, which is preferably smaller than The curvature and extension of the side walls 3 down the length of'the tubular forming tunnel is as uniform as possible and they substantially describe a parabola. Upon emerging from the outlet 6 of the funnel, the web may be supplied toa condensor or trumpet 7 in a known manner, the latter of which cooperates with a coiler headassembly (not shown).

The disclosed configuration of the tubular forming funnel 1 enables the initially flat web band of substantially rectangular cross-section to be continuously bent over and rolled in at its side edges as it moves down the length of the funnel. The fiat fiber band is thus shaped in such a manner that the web leaving the outlet 6 of the funnel-shaped member 1 has imparted to its now substantially circular cross-section a somewhat spiral twist substantially along the length of the fiber strands. 'It is readily to be appreciated that the Web of circularcross- {section and previously fed through the funnel-member 1 displays a substantially better cohesion than a web produced simply by pushing together the fiat lateral edges thereof. The distances between the inlet 2 and the throat portion 5 of narrowest cross-section is'preierably larger than ten times the value of the diameter 'of said throat portion 5, and the ratio of the respective cross se'ctional areas of the inlet 2 and 'throatportion 5 is not less than 5:1.

The tapering or widening of the funnel-shaped member 1 at the discharge portion 5a prevents the fibers of the web band and the entrained air carried along therewith from suddenly expanding. It alSO allows the superfluous air to gradually emerge from the web without causing the fibers to be removed and separatedfrom the bulk of the web and further, prevents an undesirable ballooning of the fibers. The effect of the tapering of the discharge portion 5a of the tubular funnel member 1 can be compared 'to' that of a Venturi tube. The diverging discharge por- 'tion 5:: results in the advantage that the danger of eddy and transverse currents in the interior of the funnel member can be greatly minimized or reduced in comparison to a purely cylindrical delivery-portion, and further, it

permitsa'gradual-desirable expansion or "the air. It 'is to be appreciated, howeverythat a certain degree of ad- "vantageoils results'have' been achieved where the discharge portion'of the formingffunnel was formed as a cylindrical member.

As shown in FIG. 3, the cross-section of the funnelshaped member 1 at the inlet end 2 does not necessarily haveto be a flat oval. In the embodiment according to FIG. 3, the interconnecting side walls 4' disposed between the diametrically opposed arcuate and semicircular side edges 3 are also given a slight curvature so that the overall cross-section is substantially oval. The configuration of the cross-section of'the inlet 2 selected in the individual case depends upon the particular conditions of operation, that is to say, the initial shape of the web, its speed of passage and so forth. 7

As clearly shown in FIG. 4, the outlet 6 of the funnel shaped member may be laterally displaced with respect to the axis of the compressor 7, which according to the invention improves the passage of the web through said compressor.

FIG. 4 further discloses a funnel-shaped member 1 which continuously changes in cross-section from its inlet 2 through its throat 5 and thence to the value of the diameter D of the throat 5. The length 1 of the discharge portion 5a of the funnel member 1 and disposed between the throat 5 and the outlet 6 is advantageously about three times the value of the diameterD. This enables the air entrained by the fibers of the web and carried into the funnel interior to gradually expand and the pressure to be correspondingly reduced so that no adverse ballooning effects will be exerted on the emerging fibers of the web even if the velocity of said web reaches or exceeds 4 or 5 meters per second.

It will thus be readily appreciated that the teachings of the present invention provide a novel type forming funnel wherein the web emerging therefrom may be supplied to a compressor or the like in a slightly precompressed condition and without the inclusion of substantial quantities of air between its fibers, said compressor being coopera-ble with a coiler head assembly. Under certain circumstances the compressor may be entirely dispensed with and the desiredcompression of the fibers can already be imparted by the forming funnel itself, the degree of compression of said fibers being controlled in accordance with the degree of tapering and generalshape of the forming funnel.

Having thus described the present invention what is desired to be secured by United States Letters'Patent is:

1. A method of forming'the fibers of a web travelling at high speeds into a predetermined configuration, comprising the steps of feeding the fibers of a web of extended cross-section into the inlet of a forming member, thereafter'continuously grouping together said fibers to form a substantially annular web cross-section which substantially fills at least the smallest crosssection of said forming member, while simultaneously permitting gradual expansion of air entrained between said fibers and surrounding said web prior to discharge of said web from said forming member.

2. A method of forming the fibers of a web travelling at high speeds into a predetermined configuration, comprising the steps of feeding the fibers of a web of extended cross-section into a converging inlet of a forming member, thereafter continually grouping together said fibers internally of said forming member to form a substantially annular web cross-section which substantially fills theinterior of said forming member at least in the region where said fibersare most intensively grouped, while permitting a gradual expansion of air entrained between the fibers and surrounding said web prior to discharge of said Web from a diverging portion of said forming member.

7 3. A forming funnel adapted to guide webs and the like therethrough, comprising a tubular member having an inlet andoutlet, said tubular member having an an nular cross-section and provided with inner walls exwalls of said tubular member converging and diverging between said inlet and outlet.

4. A forming funnel adapted to guide webs and the like therethrough, comprising a tubular member having an inlet and outlet, said tubular member having inner walls extending between said inlet and outlet defining a passageway through which a web may be advanced, said inner walls of said tubular member converging and diverging between said inlet and outlet to define intermediate said inlet and outlet a throat portion of narrowest crosssection.

5. A forming funnel adapted to guide webs and the like therethrough, comprising a tubular member having an inlet and outlet, said tubular member having inner walls extending between said inlet and outlet defining a passageway through which a web may be advanced, said inner walls of said tubular member converging between said inlet and outlet to define intermediate said inlet and outlet a throat portion of narrowest cross-section, at least the portion of said tubular member between said throat portion of narrowest cross-section and said outlet being substantially circular in cross-section to thereby group to gether the fibers of said webs so as to assume an annular configuration.

6. A forming funnel adapted to guide the fibers of webs and the like therethrongh according to claim 5, wherein the distance between said throat portion and said outlet is a multiple of the diameter of said throat portion.

7. A forming funnel adapted to guide the fibers of webs and the like therethrough according to claim 6, wherein said distance between said throat portion and said outlet is approximately three times the value of the diameter of said throat portion.

8. A forming funnel adapted to guide the fibers of webs and the like therethrough according to claim 5, wherein the diameter of said outlet is a multiple of the diameter of said throat portion.

9. A forming funnel adapted to guide the fibers of webs and the like therethrough according to claim 8, wherein said diameter of said outlet is approximately 1.5 times the value of said diameter of said throat portion.

10. A forming funnel adapted to guide the fibers of webs and the like therethrough according to claim 5, wherein the ratio of the area of the inlet and throat is greater than 5:1.

11. A forming funnel adapted to guide the fibers of webs and the like therethrough according to claim 5, wherein the distance between said inlet and said throat portion is greater than times the diameter of said throat portion.

12. A forming funnel adapted to guide the fibers of webs and the like therethrough according to claim 5, wherein said inlet of said tubular member is oval in crosssection, said inner walls of said tubular member including longitudinally extending side portions approaching said throat portion in a substantially uniform convex curvature.

13. A forming funnel adapted to guide the fibers of webs and the like therethrough according to claim 12, wherein said convex curvature of said side portions substantially define a parabola.

14. A forming funnel adapted to guide webs and the like therethrongh, comprising a tubular member having an inlet and outlet, said tubular member having an inner wall extending between said inlet and outlet defining a passageway through which a web may be advanced, said inner wall of said tubular member having a converging portion and a diverging portion between said inlet and outlet, said converging portion of said inner wall beginning at said inlet and terminating at a point remote from said outlet to define a throat portion having the narrowest cross-section of said funnel, said diverging portion of said inner wall beginning at said throat portion and terminating at said outlet.

15. In combination with a drawing frame and the like feeding web bands of substantially rectangular crosssection at a high rate of speed; the improvement or" a forming funnel comprising a tubular member having an inlet and outlet, said tubular member having an inner wall extending between said inlet and outlet defining a passageway through which said web may be advanced, said inner wall of said tubular member having a converging portion and a diverging portion between said inlet and outlet, said converging portion of said inner wall beginning at said inlet and terminating at a point remote from said outlet to define a throat portion having the narrowest cross-section of said funnel, said diverging portion of said inner wall beginning at said throat portion and terminating at said outlet.

16. A forming funnel adapted to guide webs and the like therethrough, comprising a tubular member having an inlet and outlet, said tubular member having inner walls extending between said inlet and outlet defining a passageway through which a web may be advanced, said inner walls of said tubular member converging between said inlet and outlet to define intermediate said inlet and outlet a throat portion of narrowest cross-section, at least the portion of said tubular member between said throat portion of narrowest cross-section and said outlet being substantially circular in cross-section to thereby group together the fibers of said webs so as to assume an annular configuration, said inner walls of said tubular member diverging between said throat portion and said outlet.

17. A forming funnel adapted to guide webs and the like therethrough, comprising a tubular member having an inlet and outlet, said tubular member having inner walls extending between said inlet and outlet defining a passageway through which a web may be advanced, said inner walls of said tubular member converging between said inlet and outlet to define intermediate said inlet and outlet a throat portion of narrowest cross-section, at least the portion of said tubular member between said throat portion of narrowest cross-section and said outlet being substantially circular in cross-section to thereby group together the fibers of said webs so as to assume an annular configuration, said inner walls of said tubular member diverging between said throat portion and said outlet in a uniform manner.

18. A forming funnel adapted to guide webs and the like .therethrongh, comprising a tubular member having an inlet and outlet, said tubular member having inner walls extending between said inlet and outlet defining a passageway through which a web may be advanced, said inner walls of said tubular member converging between said inlet and outlet to define intermediate said inlet and outlet a throat portion of narrowest cross-section, at least the portion of said tubular member between said throat portion of narrowest cross-section and said outlet being substantially circular in cross-section defining a substantially cylindrical extension to thereby group together the fibers of said webs so as to assume an annular configuration.

References Cited in the file of this patent UNITED STATES PATENTS 2,206,232 Martin July 2, 1940 2,858,577 West Nov. 4, 1958 FOREIGN PATENTS 587,095 Great Britain Apr. 14, 1947

Claims

1. A METHOD OF FORMING THE FIBERS OF A WEB TRAVELLING AT HIGH SPEEDS INTO A PREDETERMINED CONFIGURATION, COMPRISING THE STEPS OF FEEDING THE FIBERS OF A WEB OF EXTENDED CROSS-SECTION INTO THE INLET OF A FORMING MEMBER, THEREAFTER CONTINUOUSLY GROUPING TOGETHER SAID FIBERS TO FORM A SUBSTANTIALLY ANNULAR WEB CROSS-SECTION WHICH SUBSTANTIALLY FILLS AT LEAST THE SMALLEST CROSSECTION OF SAID FORMING MEMBER, WHILE SIMULTANEOUSLY PERMITTING GRADUAL EXPANSION OF AIR ENTRAINED BETWEEN SAID FIBERS AND