Feb. 6, 1940. i A. E. SUNDERLAND 2,189,257
DEVICE FOR USE IN TWISTING THREADS Filed March 20, 1939 Patented Feb. 6, 1940 UNITED STATES 2,189,257 DEVICE FOR USE IN. TWISTING THREADS Alfred E. Sunderland, Asheville, N. 0., assignor to American Enka Corporation, Enka, N. 0., a corporation of Delaware Application March 20, 1939, Serial No. 262,976
The present invention relates to an improved system for handling threads during the twisting operation and more particularly involves a device for eliminating irregularities normally occurring in threads of synthetic character while the threads are being passed from a supply bobbin to a. take-up bobbing locatedon the well known type of up-sroke twisting machine.
In the twisting of threads on upward twisters, the thread, after being withdrawn overhead from a rapidly rotating supply bobbin, is passed through an adjacent pigtail guide and collected upon a take-up spool. The thread in this manner receives a definite number of turns per inch 15 depending upon the rate at which it is withdrawn. The rapid rotation of the supply bobbin causes the thread to balloon outwardly therefrom between the point of delivery of the thread from the bobbin and the pigtail guide, said guide serving to confine the thread at that point and impart a braking action thereto.
Certain disadvantages have heretofore been regarded as inherent in this method of twisting. For example, the centrigual force set up by the 5 rapid rotation of the supply bobbin causes displacement and entanglement of individual filaments in the thread layers in the package. Thus as the thread balloons from the supply bobbin certain of the individual filaments forming the 30 thread tend to separate, or become entangled with other layers of thread, or sticky substances remaining in the thread from previous treating steps may cause filaments to adhere to the thread package, the result being that the parallel rela- 35 tion of the filaments is disturbed and certain filaments are stretched and become looped about the thread mass. As a consequence, irregularities known in the art as loops and corkscrews are formed, the presence of which seriously impair the uniformity of the thread and lowers the quality for certain textile purposes. These irregularities appear to be largely dueto the high rate of speed at which modern twisting machines operate, and it has been suggested that their occurrence may be avoided to some extent, although not entirely, by reducing the speed of revolution of the supply package. However, to do so would be to retard the rate of production with consequent increase in the cost of operation.
Such irregularities are particularly noticeable in the twisting of rayon threads, inasmuch as rayon threads are made up of large numbers of individual filaments of a delicate character, which, prior to twisting, are in substantially parallel relation to each other. Heretofore. such defects as loops and corkscrews have been regarded as normal imperfections in rayon threads and. no means have been devised for their efiicient removal.
Therefore, an object of the present invention is i the provision of means for removing loops and corkscrews from the thread during the twisting operation and prior to delivery of the twisted ing disturbances therein prior to collecting the filaments on the take-up bobbin in a fixed and twisted condition.
The invention further contemplates a thread guide especially designed to remove objectionable loops and corkscrews from thread during the process of twisting.
These and other objects will be apparent from the following detailed description when 'considered in connection with the accompanying drawing, wherein:
Fig. 1 is a diagrammatic view of a side elev tion of a twisting assembly showing the mechanical features of my invention,
Fig. 2 is an enlarged elevation of the coilshaped guide shown in Fig. 1, and
Fig. 3 is a plan view of the guide shown in Fig. 2. a 36 Referring to the drawing, the numeral I indicates a whorl for driving a spindle 2 located on the base portion of a twisting machine (not shown) having a package 3 of untwisted thread mounted thereon. The thread 4 is withdrawn 40 from the package 3 in an overheadmanner by passing the same through a coil-shaped guide 5 rigidly afiixed to a crossbar 6. It is to be understood that any other suitable means for securing the guide in position may be employed. The thread is collected on a take-up spool 'l which is driven at a predetermined constant peripheral speed from a roller 8 in driving engagement therewith. As the thread is being collected, it is laid up in the form of a package by guiding the same back and forth across the face of the spool l by means of the traversing mechanism diagrammatically shown at 9.
, As shown more particularly in Figs. 2 and 3, the coil-shaped guide 5 is formed of a thin flat strip of metal such as steel or other hard, durable material. The coil itself consists of substantially one and one half convolutions of a metal band that is rectangular in cross section to provide a sharp, thread contacting surface along the lower edge II) thereof, the said lower edge being also very smooth and highly polished. Whereas the tip I I of the coil may be made integral at the base I2 thereof to form one closed convolution, it is preferable to project the said tip I I beyond the periphery of the convolution as shown in Figs. 2 and 3. Such a construction facilitates the threading up of the thread during the initiation of the twisting operation, and prevents the thread from becoming entangled around the said tip as will be hereinafter more fully explained. The thickness of the band forming the coil may vary although bands having a thickness of approximately .015 inch have produced excellent results. The convolutions making up the coil may be constructed at a uniform angle or the angle may vary beginning at the base I2 and ending at the tip II. For example, the angle that the said base forms with the center line through -the spindle 2, see Fig. 1, may be substantially 90 and the angle that the front portion of the convolution forms with the center line through thespindle may vary from 45 to 57.
In operation, the supply package is rotated clockwise (see Fig. 1) and the thread is withdrawn therefrom by first threading the same through the coil, and traversing guides and wrapping the thread around the twisting spool. The rate at which the thread is withdrawn from the supply bobbin is greater than the R. P. M.
of the said bobbin and accordingly the thread balloons around the bobbin also in a clockwise direction. 'When the twisting operation commences, the thread first contacts the highest point of the lower edge of the coil guide 'and convolutes clockwise downwardly around the coil guide for each complete revolution. It can be readily appreciated that unless the tip of the guide projects beyond the periphery, the thread may become entangled with the guide. If it is necessary to rotate the supply bobbin in a counter-clockwise direction, the position of the coil guide must be, of course, reversed with respect thereto.
The sharpened edge of the coil guide imparts to the thread the necessary braking action and provides suflicient friction to smooth and take out substantially all of the loops and corkscrews in the thread. It is rather remarkable that if the thread balloon is caused to rotate counter-clockwise while maintaining the guide in the position shown in Fig. 1, so that the thread convolutes upwardly around the lower edge of the coil, the improved results are not realized, Moreover, the use of conventional pigtail guides made from metal rods and having a circular cross-section, does not remove any of the loops and corkscrews normally occurring.
Whereas the invention has been described in its preferred form, various modifications may be made without departing from the spirit and scope thereof; and it is to be understood that the invention is only limited to the extent of the appended claims.
What is claimed is:
1. In an apparatus for twisting thread, a coil-shaped guide being relatively thin in cross section to provide a sharp, lower thread contacting edge.
2. In an apparatus for twisting thread, a coilshaped thread guide formed of at least one convolution, said convolution being rectangular in cross section to provide a relatively sharp, lower thread contacting surface. I
3. In an apparatus for twisting thread, a coilshaped thread guide formed of at least one convolution, said convolution being constructed of a hard durable material that is relatively thin and rectangular in cross section to provide a relatively sharp, lower thread contacting surface and said convolution forming an angle to the vertical between 45 and 90.
4. An apparatus for twisting thread which comprises a supply bobbin, a take-up spool driven at a constant peripheral speed and means located between said supply bobbin and take-up spool for guiding a thread therebetween and removing irregularities therein, said means consisting of a coil-shaped guide having approximately one and one half convolutions formed at an angle to the vertical of more than 45 and being rectangular in cross section to provide a relatively sharp, lower thread contacting surface.
ALFRED E. SUNDERLAND.-