Patent Publication Number: US-9850090-B2

Title: Drum intermediate storage device for a textile machine

Description:
TECHNICAL FIELD 
     The invention relates to a drum intermediate storage of yarn of a textile machine, which comprises a driven rotary drum with a working surface and a movable compensatory rotary arm in which the driven rotary drum is coupled with a first drive and the compensatory rotary arm is coupled with a second drive, both drives are composed as motors and are connected to a control system of the textile machine. 
     BACKGROUND ART 
     In the devices for drawing-off and winding yarn in an open-end spinning machine, it is difficult to meet all the technological requirements for the formation of a cross wound cylindrical, particularly conical bobbin, and to make sure that the construction of the machine is simple from the point of view of spinning-in yarn. In an open-end spinning machine, yarn is produced in the rotor of the spinning unit and is drawn-off by a pair of draw-off rollers, in which the yarn is led onto a bobbin leaning on a winding roller with the distribution of yarn. However, during the cross winding of the yarn on the bobbin, different lengths of the yarn travel path arise when the yarn is being distributed from one extreme position to another, and, as a result, the yarn is wound under unequal tensions. 
     CZ 303880 discloses a drum intermediate storage of yarn for a textile machine which comprises a driven rotary drum with a compensatory rotary arm, where the driven rotary drum is coupled with a first drive composed of an electric motor and the compensatory arm is coupled with a second drive composed of an electric motor, whereby both motors are connected to a control system of the spinning machine. The outlet portion of the driven rotary drum is provided at its end, i.e. by the compensatory rotary arm, with an extension that restricts or prevents undesired yarn slipping from the working surface of the driven rotary drum outside the movable compensatory arm. The movable compensatory arm is provided at its free end with a yarn guide which runs around the outer circumference of the outlet portion of the drum and acts on the yarn in a defined manner. 
     However, there is a disadvantage that limits the applicability of this drum intermediate storage of yarn—namely the presence of the extended portion of the drum near the movable compensatory rotary arm, which means that it is necessary to construct the yarn guide on the movable rotary arm substantially in the shape of a bent elongated body of a circular cross section, such as a wire. 
     The goal of the invention is to eliminate or at least minimize the disadvantages of the background art, and, above all, to improve the applicability of the drum intermediate storage of yarn. 
     SUMMARY OF THE INVENTION 
     Additional objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention. 
     The aim of the invention is achieved by a drum intermediate storage of yarn, whose principle consists in that the radial rotary arm is provided with a yarn guide, whose working portion upholds the yarn radially in relation to the axis of the drum rotation. 
     The advantage of this embodiment is the fact that it enables to improve the exploitation of the drum intermediate storage of yarn for individual processes at an operating unit of a textile machine while preserving the advantages of the drum intermediate storage of yarn and its high efficiency. 
    
    
     
       DESCRIPTION OF DRAWINGS 
       The invention is schematically shown in the drawings, where: 
         FIG. 1  shows a side view of an arrangement of a drum intermediate storage of yarn with a radial rotary arm; 
         FIG. 2  provides a skew view of an arrangement of a drum intermediate storage of yarn with a radial rotary arm; 
         FIG. 3  shows a detail of an arrangement of the working portion of a yarn guide of the radial rotary arm and the drum; and 
         FIG. 4  represents an arrangement of a radial rotary arm. 
     
    
    
     SPECIFIC DESCRIPTION 
     Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example features illustrated or described as part of one embodiment can be combined with another embodiment to yield still another embodiment. It is intended that the present invention include these and other modifications and variations to the embodiments described herein. 
     The drum intermediate storage of yarn is situated at an operating unit of a textile machine. Ideally, the textile machine comprises a row of identical operating units, arranged next to each other. At the operating unit are arranged individual devices for yarn formation from staple fibers, for example from staple fibers arranged in the form of a sliver or fiber band etc., and for subsequent winding the produced yarn on a bobbin. 
     Between the device for forming yarn and the device for winding yarn onto a bobbin is arranged a draw-off mechanism, which serves to draw-off the produced yarn from the yarn forming device. 
     The drum intermediate storage  1  of yarn is arranged between the draw-off mechanism and the device for winding yarn onto a bobbin. In the yarn path between the draw-off mechanism and the front portion  100  of the drum intermediate storage  1  of yarn  0  is arranged an unillustrated input guiding means of yarn  0  from the draw-off mechanism to the working surface  1000  of the drum  10  of the drum intermediate storage  1  of yarn  0 . In the yarn path between the end edge  1010  of the drum intermediate storage  1  of yarn  0  and the yarn winding device is arranged an output guiding means of yarn  0 . The yarn  0  during routine operation, i.e. when being formed and wound onto a bobbin, moves in a direction S, whereby also the drum  10  moves in this mode and rotates in the same direction, as will be explained further on. The working surface  1000  of the drum  10  is designed as a continuous rotary surface or it is made up of a group of segments forming a substantially continuous rotary surface or it is made as an enveloping area of a wire body etc. Therefore, in essence, it is not important which particular type of construction of the drum  10  is used. 
     The drum intermediate storage  1  of yarn  0  comprises a rotatably mounted drum  10 , which is coupled with a drive connected to an energy source and to a control device. 
     In an illustrated example of embodiment, the working surface  1000  of the drum  10  is in the front portion  100  of the drum  10  formed by a conical surface which is sloping downwards from the front portion of the drum  10  towards the rear portion of the drum  10 . Behind the conical front portion  100 , the working surface  1000  of the drum  10  continues as the main area  101 , which is also conical, sloping downwards from the front portion of the drum  10  towards the rear portion of the drum  10 , preferably with the size of the slope ranging from 0.5 to 5°, yet more preferably from 1 to 2° in relation to the rotation axis A of the drum  10 . In another embodiment, the drum  10  has a different suitable profile, for example a profile shaped as a continuous curve or it could have a profile of any other suitable shape with a gradually diminishing distance R of the generatrix X from the axis A of rotation of the drum  10 , conceived in the direction from the front portion to the rear portion of the drum  10 . In another unillustrated embodiment, the drum  10  has a cylindrical shape or there is an extension at the end of the drum  10 . 
     The end edge  1010  of the main area  101  of the working surface  1000  at the end of the drum  10  is rounded or chamfered. 
     A radial rotary arm  11  is mounted on an independently rotatable shaft (not shown), whose axis of rotation is in the illustrated embodiment identical to the axis A of rotation of the drum  10 . The radial rotary arm  11  is coupled with a separate drive which is independent of the drive of the drum  10 . The independent drive of the arm  11  is connected to a source of energy and to a control device, as is the case of the drive of the drum  10 . In an unillustrated embodiment, the rotation axis of the radial rotary arm  11  is different from the axis A of rotation of the drum  10 . 
     The arm  11  is at its free end  110  provided with a rigid or replaceable guide  111  of yarn  0 , which radially upholds the yarn  0  above the perpendicular projection onto the main area  101  of the drum  10 . The working surface  1110  of the guide  111  of yarn  0 , i.e. that part against which the yarn  0  rubs when passing from the main area  101  of the working surface  1000  of the drum  10  to the outlet guide of yarn  0 , is situated in the direction of the motion of yarn  0  before the end edge  1010  of the working surface  1000  of the drum  10 , i.e. as is shown in the drawing, it is situated above the main area  101  of the working surface  1000  of the drum  10 . 
     As is shown in  FIGS. 1 to 3 , the radial rotary arm  11  comprises a bent portion with a free end  110  and a guide  111  of yarn  0 , whose working portion  1110  (of the guide  111  of yarn  0 ) is situated above the main area  101  of the working surface  1000  of the drum  10 . This arrangement enables to prevent effectively unwanted slipping of yarn  0  from the main area  101  of the working surface  1000  of the drum  10 , since, in the illustrated embodiment, the yarn  0  is from the main area  101  of the working surface  1000  removed by the guide  111  under an acute angle α in the distance Z before the end edge  1010  of the main area  101  of the working surface  1000  of the drum  10 . Another advantage of this arrangement is that in the case of the unwinding of yarn  0  from the bobbin to the drum intermediate storage  1  of yarn  0  the yarn  0  is guided and wound reliably on the working surface  1000  of the drum  10 . 
     In the embodiment shown in  FIG. 3 , the working portion  1110  of the guide  111  of yarn  0  is made as a groove in the body of the guide  111 , whereby in the direction B of rotation of the drum  10  when winding yarn on the bobbin, i.e. in the mode of forming yarn  0 , on the rear part of the working portion  1110  is arranged a retention projection  11101 , which exceeds the inlet projection  11102  of the groove arranged on the front part of the working portion  1110 . In an unillustrated embodiment, the working surface  1110  of the guide  111  of yarn  0  is created in another suitable method which ensures reliable and safe capturing of the yarn  0  by the guide  111  and subsequent reliable and safe guidance of the yarn  0  over the working surface  1110  of the drum  10  to the outlet guiding means of yarn  0  in all modes of the motion of the arm  11  in relation to the drum  10 , including the case, when the arm  11  moves against the direction of the rotation of the drum  10 , thus ensuring reliable and safe radial support of yarn  0  above the main area  101  of the drum  10 . 
     In an illustrated embodiment, the guide  111  of yarn  0  is designed as a replaceable unit displaceably mounted on the arm  11 , so that in case of need it is only this small unit that has to be replaced and this operation can be performed readily and quickly. In an illustrated embodiment, the guide  111  of yarn  0  is designed as part of the arm  11 , which is easily and readily removable from the construction of the device and, consequently, is easily and readily replaceable. 
     So as to improve the durability of the device and reduce the abrasion of the produced yarn  0 , at least the working portion  1110  of the guide  111  of yarn  0  is equipped with wear-resistant means, especially resistant to wear caused by the abrasion of the yarn  0 , by which means that at least this portion of the guide  111  of yarn  0  is more wear-resistant than the material of the arm  11 . These wear-resistant means consist of, for example, a protective coating and/or a rolling means and/or another suitable means. 
     In an unillustrated embodiment, the guide  111  is constructed as an integral part of the arm  11  and when it is necessary the whole arm  11  including the guide, is replaced. In this case the guide  111  can be also made of material other than the basic material of the arm  11  or the guide is made of the basic material used to make the arm  11 , optionally provided with a protective coating. 
     In the example of embodiment in  FIG. 4 , there is a view of an embodiment of a drum  1  with a radial rotary arm  11  and a guide  111  of yarn, whereby the arm  11  has an optimized shape in order not to impede the removal of the yarn from the intermediate storage, or, to be precise, from the drum  1 . For these purposes, the arm  11  in the illustrated example of embodiment has skew surfaces  1101  for yarn slipping, whereby the arm  11  is, during the removal of the yarn, located between the guide  111  in the direction in which the yarn is removed. The opposite end  112  of the arm  11  is situated substantially in the inner space of the drum  1 , i.e. it is hidden beyond the end edge  1010  of the drum  1 , and so it does not hinder free motion of the yarn during the removal of the yarn. 
     Modifications and variations can be made to the embodiments illustrated or described herein without departing from the scope and spirit of the invention as set forth in the appended claims.