US2970790A

US2970790A - Pressure thread guide

Info

Publication number: US2970790A
Application number: US770649A
Authority: US
Inventors: Richard D Neal
Original assignee: American Enka Corp
Current assignee: Akzona Inc
Priority date: 1958-10-30
Filing date: 1958-10-30
Publication date: 1961-02-07
Anticipated expiration: 1978-02-07

Description

Feb. 7, 1961 R. D. NEAL PRESSURE THREADGUIDE Filed Oct. 30, 1958 INVEN TOR.

RICHARD D. NEAL A OR EY.

PRESSURE THREAD GUIDE Richard D. Neal, West Asheville, N.C., assignor to American Enka Corporation, Enka, N.C., a corporation of Delaware Filed Oct. 30, 1958, Ser. No. 770,649

4 Claims. (Cl. 242-157) This invention relates generally to traversing thread guides, and more particularly to a pressure guide assembly for controlling the placement of thread onto spools or other winder type take-ups.

While not limited in its application, this invention is particularly useful for guiding thread fed from an uptwisting mechanism to a package rotating about a horizontal axis. In the operation of this type equipment, it has been observed that a faulty package is often produced when the traversing guide used to place the twisted yarn onto the package lacks precision either through poor thread control or insufficient weight. For purposes of this application, a faulty package is one which has been over-wound at the ends. In other words, the thread is allowed to wind over the ends of the package during reversal of the traversing guide. This over-wound thread may be tight against the ends of the package or loose enough to twist back upon itself in the form of a loop. In either event, these overwinds frequently cause broken filaments or other thread damage during subsequent processing, as in coning or warping.

A twisting guide which lacks proper control may place the aforesaid random coils or loops over the package edge because of excessive backlash or play at the traversing reversal points. Moreover, aguide which is too light has been found to bounce about erratically and thereby lose control of the thread, especially at these reversal points. It was heretofore generally felt that guides having sutficient weight to produce firm or densely wound packages would deleteriously affect the thread filaments. Consequently, light-weight guides have been used in general practice. The conventional type guides not only provide poor thread control but also are found to produce undesirably loosely-wound packages. Additionally, special tension devices and undesirably high tensions are frequently needed'when conventional guides are used in an effort to offset the control and package density limitavtions.

One of the objects of the present invention is to-provide a guide assembly not having the disadvantages of known guides.

Another object of this invention is to provide a pressure guide assembly having precision lateral control over the thread passing therethrough. r

A further object of the present invention is to provide a traversing pressure guide assembly of sufiicient Weight to enable the production of more firmly wound packages than heretofore possible without damage to the thread filaments.

Still another object of this invention to provide a traversing thread guide assembly having sufiicient thread control to prevent thread overwinds at the traverse reversal points.

A further object of the present invention is to provide a twisting guide assembly for laying up thread in package form which may be easily threaded but which in States Patent ice operation maintains precision placement of thread on the package.

Another object of this invention is to provide a traversing pressure guide assembly for controlling the introduction angle of thread to a package whereby consistently uniform packages containing more thread than heretofore possible may be produced.

These objects are accomplished in accordance with the present invention by utilizing a composite pressure guide assembly having a rounded control head provided with a V-shaped notch pointing in the direction of pack age rotation and a positioning bar connected to the control head for maintaining a predetermined angle of approach of thread to the V-shaped notch.

The assembly is pivotally mounted about a horizontal axis in order to rise as package build-up progresses and is urged by gravity toward the thread package although actual contact with the package during operation is prevented by virtue of a specific location of the V-shaped notch with respect to a tangent on the periphery of the package at the point of thread engagement. The guide assembly preferably is disposed with respect to the package in such a manner that the vertex of the notch in the control head coincides with the aforesaid point of tangency. Consequently, the assembly normally is spaced above the package by the thickness of thread passing therethrough. The pressure exerted by the assembly therefore is applied to the thread being wound onto the package, and not directly to the package.

Other objects and advantages will become apparent upon study of the following detailed disclosure taken in conjunction with the accompanying drawings, wherein Figure 1 is an elevational view, partly in section, illustrating the invention as applied to a conventional uptwisting machine;

Figure 2 is a plan view of part of the guide assembly, taken along the lines 2-2 of Figure 1; and

Figure 3 is a perspective view of the composite pressure guide assembly.

With attention now directed to Figure 1, wherein only that portion of an uptwisting machine necessary to a complete understanding of the present invention has been shown, reference numeral 10 represents a spinning spool or supply package mounted for rotation about a vertical axis and driven by known means in order to impart twist to thread 11 withdrawn therefrom. During withdrawal, thread 11 balloons about supply package 10 and passes upwardly to a gathering guide 12. From this guide the thread is fed in serpentine fashion over

tension rails

13, 14 to a preliminary thread aligning or pre-positioning guide 15 mounted on traverse rail 16. Rail 16 is reciprocated in known manner by means not shown to shift thread 11 laterally along the periphery of thread collection means or take-up spool 17. In a conventional uptwisting machine of the type under consideration, the spool 17 is surface driven and rotates in the direction of the arrow about a horizontal axis to collect thread 11 without imparting additional twist thereto.

Pivotally mounted to pre-positioning guide 15 and extending generally horizontally therefrom is the novel pressure guide assembly 18 constituting this invention. The assembly 18 comprises an elongated and generally U-shaped positioning bar 20, a control head 24, and a pair of supporting

arms

27, 28. The bar 20 has legs 21,

bar 29 and to one side of the control head 24 and thereby secures the latter in spaced relationship to the former.

Threading up may be accomplished through the lateral slot 32 defined by the control head and leg 22.

For the most satisfactory operation of the guide assembly 18, it has been found that the V-shaped notch 25 in control head 24 should point in the direction of package rotation, as shown. Moreover, it is very important that the vertex 33 of this notch coincide with the point of tangency 34 in order to determine where thread 11 initially engages the take-up spool or convolutions already in package form. Additionally, the base 35 of the slot 23 in bar 2i) should be disposed not only in alignment with the pre-positioning guide 15 and control head 24 but also at such a height above member 24 that angle alpha (or) is maintained in the range of 42 to 55". Further, at least the lateral curvature of the lower surface 26 on control head 24, that is, the curvature when viewed at right angles to the Figure 1 position, should have a radius of between 0.4 and 1.1 inches in order to achieve maximum thread control with minimum side roll of the assembly at the traverse reversal points. Finally, it is obvious that the assembly 1% should be pivotally supported to permit thread control during all stages of package build-up. in this connection, it is pointed out that the angle alpha, once determined by the spacing between bar it! and head 24, remains within the specified range during package formation since the positioning bar 26 and control head 24 rise as one unit about the pivotal axis, and since point of engagement 34 between thread 11 and the take-up spool remains substantially at the vertex 33. This latter condition exists because the vertex 33 applies pressure to thread 11 and forces the same against the package. This is in contrast to the usual operation where the guide corresponding to control head 24 actually rests on the take-up spool and therefore does not directly control the point of engagement between thread and package during build-up.

In the operation of the device described above, thread is passed from the spool through the gathering guide, over tension rail 13 and under rail 14. The thread next is usually wrapped around take-up spool 17, after which the same may be set in motion by the drive means mentioned earlier. The running thread 11 may easily be inserted through lateral slot 32 into the vertex 33 and base 35, and passed through the slot provided in prepositioning guide 15. The guide 15 and entire pressure guide assembly 18 are reciprocated by traverse rail 16 to produce the desired package build.

The positioning bar 20, control head 2 and connecting pin 31 are conveniently formed from ceramic material such as 'Heanium, but any other wear-resistant material, such as Alsimag or steel, of course could be used. The supporting

arms

27, 28 may be formed from steel wire or any material having sufiicient resilient properties to enable springing for the purpose of mounting shafts 3t) onto guide 15.

Aithough many thread guides currently available on the market are similar in overall design to the assembly 18, none of these guides provide the precision control precision thread control was maintained throughout the package formation. Since the assembly 18 applies pressure during thread winding, smaller packages of greater density and solidity can be obtained. Moreover, no damage to the thread has been found as a result of this in creased pressure.

Inasmuch as other modifications embodying the principles discussed herein will become apparent to those skilled in this art, it is intended that the scope of this invention be limited only to the extent set forth in the following claims.

What is claimed is:

l. A thread collection device comprising a take-up spool mounted for rotation about a horizontal axis, a pre-positioning guide mounted for reciprocation parallel to the axis of said take-up spool, a positioning bar pivotally supported from said pro-positioning guide and extending outwardly therefrom to overlie said take-up spool, said positioning bar having legs defining a longitudinal slot open at one end, a control head having a V-shaped notch secured to said positioning bar and suspended in spaced relationship therebelow, and V-shaped notch facing the open end of said longitudinal slot, and supply means from which thread may be passed through said pre-positioning guide, the longitudinal slot in said positioning bar and the V-shaped notch in said control head to said take-up spool.

2. A thread collection device comprising a take-up spool mounted for rotation about a horizontal axis, a prepositioning guide mounted for reciprocation parallel to the axis of said take-up spool, a positioning bar pivotally supported from said pre-positioning guide and extending outwardly therefrom to overlie said take-up spool, said positioning bar having legs defining a longitudinal slot open at one end, a control head having a V-shaped notch secured to said positioning bar and suspended in spaced relationship therebelow, said V-shaped notch facing the open end of said longitudinal slot and one face of said control head being curved with a radius of curvature of between 0.4 and 1.1 inches, and supply means from which thread may be passed through said prepositioning guide, the longitudinal slot in said positioning bar and the V-shaped notch in said control head to said take-up spool, said control head determining the point of thread engagement with the take-up spool.

3. A thread collection device as set forth in claim 2 wherein the angle of introduction of thread through said positioning bar and control head is maintained within a range of 42 to 55 with respect to a tangent drawn at the point of thread engagement with said take-up spool.

4. A thread collection device comprising a take-up spool mounted for rotation about a horizontal axis, a prepositioning guide mounted for reciprocation parallel to the axis of said take-up spool, a positioning bar pivotally supported from said pre-positioning guide and extending outwardly therefrom to overlie said take-up spool, said positioning bar having legs interconnected at a base and defining therebetween a longitudinal slot open at one end, a control head secured to one leg of said positioning bar and suspended in spaced relationship therebelow, said control head having a V-shaped notch and a face curved with a radius of curvature of between 0.4 and 1.1 inches, and supply means from which thread may be passed through said vpreepositioning guide, over the base of said positioning bar and through the V-shaped notch of said control head to said take-up spool, said V-shaped notch facing the open end of said longitudinal slot and the vertex thereof coinciding with the initial point of thread engagement on said take-up spool, the spacing between said positioning bar and said control head being such that the angle of introduction of thread to said take-up spool is'mai ntained within a range of 42-55 at said point of initial engagement.

5 6 References Cited in the file of this patent 2,160,780 Kennedy May 30, 1939 UNITED STATES PATENTS 2,293,983 7 Jackson Aug. 25, 1942 1,049,798 Babcock Jan. 7, 1913 FOREIGN PATENTS 2,052,226 Holley Aug. 25, 1936 5 636,934 Great Britain May 10, 1950