IL25990A - Pneumatic false twister - Google Patents

Description

ί I" i ¾ 1 1 Patents Form No. 3 PATENTS AND DESIGNS ORDINANCE.

SPECIFICATION.

"PNEUMATIC FALSE TWISTER" I / WE, QHSAHTO. COl!PAilif^ a Jorp©patibn pg niaeft a . elating, unto..--^ states of . A^ Louie, Misaoupi, United States of America do hereby declare the nature of this invention and in what manner the same is to be performed, to be particularly described and ascertained in and by the following statement : - The present invention relates to apparatus for imparting a false twist or coiling action to continuous filaments. More particularly this invention relates to an improved pneumatic false twister, In the preparation of yarns and fabrics for textile manufacturing purposes, the imposition of false twist on the fibers being processed is a very important and essential step in most operations. False-twist devices are commonly used in yarn bulking processes, core and sheath-core spinning processes, and production of non-woven structures. The false-twist may be produced by a , mechanical or pneumatic type false twister. Recently there has been an increased amount of effort devoted to the improvement of the existing pneumatic false twisters because of an increased demand for non-woven structures. The pneumatic twisters are preferred over the mechanical twisters in the formation of various networks from continuous filament yarns since the air stream imparts a coiling action to the yarn and forwards it to a collection means where the yarn coils are bonded together to form a non-woven structure.

Heretofore, the pneumatic false-twist devices have been composed of air ejectors or aspirators having complicated design features which increase the difficulty of reproducing other units having similar operating performance. Therefore, it is difficult to reproduce a controlled condition where several of the devices are employed. Another disadvantage with the presently known devices is the high velocities that are required in With the foregoing in mind, it is an object of the present invention to provide a device for imparting false twist to continuous filament yarn.

Another object of the invention is to provide an improved pneumatic false twisting device having simple design features and controllable operating efficiency.

A further object of the invention is to provide a device which forwards yarn under low tension and imparts false twist thereto at a predetermined rate ranging preferentially from a low twist to an ultra-high twist.

Still another object of the invention is to provide an improved pneumatic false twister capable of imparting a high degree of false twist to yarn under a considerable amount of tension.

Another object of the invention is to provide an improved pneumatic false-twist device capable of operating at low velocities to achieve low false twist.

Other objects and advantages of the invention will become apparent from the following detailed specification and the accompanying drawing.

The present invention comprises an elongated tubular body member having a hollow insert concentrically disposed in said body member and being characterized by a spiral-helical rib or fin extending around the outer surface of the insert and an inlet passageway through the wall of the body member for inroducing a stream of air or other gaseous medium onto the spiral-helical fin which imparts a spiraling motion to the air as it passes over the fin on the insert to further impart a twisting action The invention will be more clearly understood by reference to the drawings, in which: Figure 1 is a side elevation of an embodiment of the invention, partly in cross-section, to show the internal passageways of the device.

Figure 2 is a cross-sectional view of the device shown in Figure 1 at 2-2.

Figure 3 is a cross-sectional view of another embodiment of the invention wherein the air stream enters the body member intermediate the longitudinal axis thereof and is divided to flow in opposite directions.

Referring to Figure 1 , there is shown a tubular member 10 which is designed to have a length substantially greater than the inside diameter. The member 10 has a counter-bore at one end to provide an annular shoulder 12 for accommodating an insert II . disposed concentrically therein and supported by an enlarged disclike portion 16 which is secured against the shoulder 12. The insert extends through a major portion of the tubular member 10, but terminates at a point from the end opposite from the support flange 16 for reasons that will be explained later herein.

A spiral-helical rib l8 circumscribes the outer surface of insert II . over the entire length thereof. The apex of the rib or fin l8 generally extends to within close proximity to the inside wall 20 of tubular member 10. It should be apparent however that the distance will be determined by the geometrical configuration of the fin l8 and its overall length, in conjunction with the preferred it is to be understood also that the depth, shape, and pitch of the fin 18 may be varied to give a wide range of twisting action whereby control of the twisting action can be attained at a predetermined air flow.

A passageway 22 extends throughout the longitudinal centerline of the insert 11+ and support flange 16. The diameter of the passageway 22 is generally dimensioned to accommodate a continuous filament of the size normally used for fashioning non-woven structures. Positioned near the end of tubular member 10 which supports insert II4. is an inlet passageway 2I4. and a connecting conduit 26 for introducing a stream of air or some other gaseous medium into the bore of tubular member 10 from a source, not shown.

In operation of the embodiment described above, a filament is threaded through passageway 22. A gaseous medium such as air is introduced at inlet 21+ and directed upon rib 18 which channels the medium in a coherent stream along the spiral-helical path to the end of insert li+ where the stream leaves the surface thereof with a spiraling action which contacts the filament and imparts false twist thereto. Also, as the air stream passes the end of insert II4. a suction is created at the yarn inlet 28 and thereby forwards the filament through the device.

The amount of false-twist and magnitude of force imposed upon the yarn may be controlled by either regulating the amount of air or changing the surface conf guration of the insert li and its relationship with the inside wall 20 of tubular member 10. For example, when the an air stream having a low velocity will attain a 3piraling motion as the stream advances to the end of insert 1ί+ where the filament is entrained by a coherent stream of air which imposes a low degree of false twist and forwarding action on said filament.

Alternatively, if an ultra-high degree of false twist is desired for yarn being advanced by mechanical driven rollers, another embodiment of the invention as shown in Figure 3 may be employed wherein a tubular member 3,0 having hollow insert 32 disposed therein is provided with an inlet 3]+ at midpoint between the ends thereof. The surface of insert 32 is provided with spiral-helical ribs 36 which are contiguous with the inside wall 38 of tubular member 30. A divider plate i 0 is located opposite inlet 3I . between insert 32 and inside wall 38 for dividing a source of air introduced through inlet 3^· The ribs 36 and 37 circumscribe insert 32 in opposite directions to produce false twist on a filament advanced through passageway I4.2 at each end of tubular member 30 and thus impose an increased amount of twisting action on the yarn.

The invention is not to be limited to the exact details shown and described since obvious modifications will occur to those skilled in the art, and any departure from the description herein that conforms to the present invention is intended to be included as a part thereof.

Claims (1)

1. 25990/2 Claims *· Apparatus for Imparting false twist to a continuous strand* comprising: (a) a body member having an internal bore which Is substantially unobstructed at one end thereof* (b) a hollow member disposed in said bore* said member having a passageway for receiving a yarn to be false twisted* (o) a screw thread-like configuration circumscribing said hollow member* and (d) an inlet for Introducing a gaseous medium into the internal bore wherein said threadlike configuration is adapted for directing said medium in a coherent stream having a coiling motion whereby false twist is imparted to said yarn. 2» Apparatus as claimed in claim 1 wherein (a) the body member is a cylindrical member* (b) the hollow member le an insert concentrically disposed in the bore and having a passageway therein for receiving a continuous threadline, said Insert being seoured to the cylindrical member at one end but terminating a distance from the other end thereof to allow ballooning of the continuous threadline* (o) the screw thread-like configuration is a spiral helical fin which oiroumserlbes the length Of said insert in close proximity to the bore wall* and 25990/2 (d) the Inlet is located at said one end of the cylindrical member r introducing Into said bore the gaseous medium which imparts false twisting to the continuous thread!ine» An apparatus as claimed in claim 1 whereini (a) the body member is a tubular member having a passageway extending through the length thereof, (b) the hollow member is an insert disposed in the passageway for receiving a continuous threadline, said insert terminating a distance from one end of said tubular member* (o) the inlet is located through a wall of the tubular member or introduoing the gaseous medium, and (d) a surface configuration is provided on th© insert adapted for advancing the gaseous medium in a coherent stream over the surface configuration thereb impart* ing a potential twisting action to said stream upon departure from soldi surface configuration whloh Imposes false twisting on said continuous threadline. An apparatus as claimed in claim 1 wherein; (a) the body member is a cylindrical member having an internal bore, (b) the insert has a spiral-helical fin extending longitudinally around the surface thereof and in close proximity to the wall of the 25990/2 bore of the cylindrical member, are BEflYldedf (o) means (tat supporting the insert in the cylindrical member, said means and said insert having oo-extensively aligned passageways for receiving the continuous strand, and