EP1791992A1

EP1791992A1 - Rotating bobbin holder

Info

Publication number: EP1791992A1
Application number: EP05796479A
Authority: EP
Inventors: Sam Ravi
Original assignee: Titan Paints & Chemicals Ltd
Current assignee: Titan Paints & Chemicals Ltd
Priority date: 2004-09-03
Filing date: 2005-09-02
Publication date: 2007-06-06
Anticipated expiration: 2025-09-02
Also published as: EP1791992B1; ATE486982T1; JP4585569B2; JP2007534852A; DE602005024582D1; WO2006025073A1

Abstract

A rotating bobbin holder comprising a stud member (25) with a head (25a), a body (25c) of variable length and with a substantially non-circular cross section, said body (25c) further extended as a threaded profile (25d), said stud member (25) disposed to pass through a smaller opening of the expanded barrel (11), a brake shoe (17) permitted to pass through said stud member and disposed on the outer-upper surface of the barrel (11) to provide a variable a brake force by means of a brake tensioner (19), said tensioner (19) connected to the brake shoe (17) on one side and the other side of the tensioner (19) is abutted by a tensioner support member (20) , a skirt member (18) is permitted to pass through the stud member and disposed on the upper extended barrel (11), a relative surface profile on top inner surface of the skirt member (18) corresponding to the outer profile of the tensioner support member (20) to provide a non-rotatable functional support to the skirt member (18), and at least a spacer member (26) disposed on the body of the stud member to compress and decompress said tensioner (19) and to generate variable braking force on said bobbin hanging tube.

Description

ROTATING BOBBIN HOLDER

Technical Field

The present invention is in the field of bobbin holders. The present invention relates to a rotating bobbin holder with variable brake force. Background and related art

A bobbin holder is a principal functional component indispensable for roving and spinning processes in a spinning factory. It is a suspension type rotating bobbin holder in which standard type bobbins for thread, sliver or roving are releasably suspended for free rotation from the creel rails of spinning machines or the like.

The conventional bobbin holder used chiefly for spinning machines has two principal functions. The first one is that it has the capability of securing and releasing the roving bobbins without difficulty. Towards this end a self-securing and self-releasing mechanism is housed in the barrel body of the bobbin holder, which when inserted into the bobbin supporting hole provided in the upper part of the bobbin, supports the bobbin at a shoulder lying" between the bobbin supporting hole and a large diametrical hollow part extended at the depths thereof through the medium of two or more fingers or levers projecting in plurality of directions from the lower part of the barrel body. The second principal function of the bobbin holder is to make the suspended bobbin holder rotate smoothly and uniformly. To this end, almost all the bobbin holders make use of rolling contact ball bearings hung on creel rail of the spinning machines. In a spinning frame up to 1200 bobbin holders are required to hang from the creel rail. It is therefore imperative to make them as light and cost effective as possible. Therefore metal is used only for the balls of the. ball bearing section and the remaining parts are made up of synthetic resinous material of good abrasion resistance. This rolling bearing structure disposed axially of the bobbin holder cooperates with, the bearing itself to have a rotating resistance value of substantially zero in order to ensure smooth and uniform rotation. During operation, a rotating bobbin holder is required to provide not only an absolute free rotation but also a controlled and regulated rotation. The speed of rotation of the bobbin holder must correspond with the feeding rate of the roving yarn into the spinning machine. Maintaining a uniform roving tension is necessary for obtaining the best yarn quality parameter.

The controlled rotation is achieved by providing a braking system in which a brake shoe is pressed against a rotating part of bobbin holder by means of a coiled spring. Accordingly, unless the pressing force by the coiled spring is changed, the braking torque (T/,) on the bearing side is substantially constant.

When the bobbin holder is in operation, the braking torque on the bearing side (T/,) maintains a close equivalence to the rotating torque (T₇-) on the roving bobbin side induced by the roving withdrawing tension F exerted on the rotating part as the roving is withdrawn. If this equivalence is not maintained the roving either unwinds more than required causing sagging in the roving yarn and possible multiple breaks in the yam due to free rotation or stretching and/or snapping of the roving yarn due to tight rotation. The choice of the spring is such that when it is compressed to a fixed distance (d) its stiffness .(k) exerts the required compression force (C), which in conjunction with the ^' friction factor (μ) will produce such braking torque (T_b) as to maintain equilibrium with the rotating torque (T₇-),

In practice there are several qualities of yarn used for various applications of fabrics. Each of these types of yarn induces roving tension of different magnitude. The setting of the roving tension is based on many factors. The quality of the raw material used, the spindle speeds, the twist factor in the roving and spinning, the count spun, the age and make of the spinning frame. The roving tensions vary from 2 to 8 gms depending upon the application and the bobbin holder is required therefore to offer many different braking forces/torques. Therefore, a different set of bobbin holders with different brake springs to suit the various applications are currently being used. Generally, three different brake systems are used; one for coarse counts of yarn, a second for medium counts and the third for finer counts of the yarn. However, in many cases the count of yarn is not the only determining parameter in ascertaining change of a particular bobbin holder. The other parameters such as change in speeds, twist factors, raw material quality and a host of other conditions also force a user to use different bobbin holders to achieve variable brake forces. It is also a practice to use different spring systems to customize the brake system for different applications. Usually these are distinguished by designated colour codes on the skirt member. For instance, if a user wishes to change the count spun due to market demands the bobbin holders have to be changed entirely. Alternatively, brake springs need to be changed by opening up the bobbin holder, which may significantly alter the original manufacturers' settings of the bobbin holders. Moreover these modifications may also affect the production in textile mills. It has been a long standing need felt by the spinning industry that there should be a universal bobbin holder which will have provision for adjusting the Braking Torque (T_A) under variable spinning conditions wherein the Rotating Torque is altered considerably. In a known bobbin- holder the compressed length of a spring, which provides a braking torque is constant, since it is fixed on both ends, one end resting on the brake shoe and the other end on the inner surface of the skirt or cap.

An attempt was made to develop an adjustable braking bobbin holder. This is explained in the Patent No: EP0547712. This version uses two slidable cylindrical members one inside the other and both mounted on a stud member, which rotatably supports one of the known bobbin locking finger systems. The outer cylindrical member comprises a helical projection on its inner circumferential surface and also comprises a lower edge of helical or stepped profile provided with notches uniformly spaced apart. The inner cylindrical member comprises a helical groove in its circumferential top surface and also comprises at its lower end a circular rim, the upper edge of which has a helical or stepped profile provided with teeth which match said notches. By rotating the cylindrical members, relative to each other, the inner cylindrical member is made to move axially downwards or upwards relative to the outer cylindrical member because of the contact between the helical profiles. Downward movement of the inner cylindrical member compresses the helical spring thereby increasing the brake force. Another spring is provided coaxially inside the brake spring in order to prop up the inner cylindrical member and keep it always in contact with the inner upper surface of the outer cylindrical member.

However in this embodiment of the adjustable brake force system, the setting is not clearly visible. The position is, of course, marked by letters embossed on the surface of the one of the cylindrical members, which is not visible from a distance. This means should there be differential settings in different bobbin holders it will not immediately be delected and corrected.

Objects of the present invention

The main object of the present invention is to provide a rotating bobbin holder with variable brake force whose settings are clearly visible.

An object of the present invention is to provide a rotating bobbin holder with a variable brake forces by using a single torque spring.

Another object of the present invention is to provide a rotating bobbin holder with a variable brake force by using removable and non-removable spacers to create the desired brake force.

Summary of the invention

Accordingly, the present invention provides a rotating bobbin holder with a bobbin hanging tube having an upper expanded barrel and a lower narrow trunk with a pair of bobbin holding fingers to hold and release bobbins, said bobbin holder connected to textile ring spinning machine comprising a stud member with a head of a curvaceous surface profile to receive bearing assembly, a smooth neck portion of said stud member extending from the head and terminating in a substantially barrel-shaped bulge, a body portion of variable length of said stud member extending from the neck portion, with a substantially non-circular cross section, said body portion further extended as a threaded profile, said stud member disposed to pass through a smaller opening on the top surface of the expanded barrel, and the head with bearing assembly rotatably impinging on the upper inner surface of the barrel to provide a rotary motion to the bobbin hanging tube, a brake shoe with a central opening permitted to pass through said stud member, said brake shoe disposed on the outer-upper surface of the barrel to provide a variable a brake force by means of a brake tensioner, said tensioner functionally connected to the upper surface of the brake shoe on one side and the other side of the tensioner is abutted by a tensioner support member having a profile corresponding to the body of the stud member, an enlarged skirt member with a smaller opening on its upper surface, said opening having a corresponding profile of the body of the stud member and an opened lower end, said skirt member is permitted to pass through the stud member and disposed to envelope the upper extended barrel, a relative surface profile on top inner surface of the skirt member corresponding to the outer profile of the tensioner support member to provide a non- rotatable functional support to the skirt member, and at .least a spacer member of desired thickness is disposed on the body of the stud member and arranged on the upper surface of the skirt member to compress and decompress said tensioner and to generate desired variable braking force on said bobbin hanging tube.

Brief Description of the drawings

Fig.l is a cross sectional view of the bobbin holder of the present invention depicting exemplary variable brake force elements. Fig.2 is an exploded view of Fig 1 depicting the arrangement of the variable brake force elements.

Fig.3 is an exploded view of the bobbin holder of the present invention with a alternate embodiment in the form of a pin disposed on the body of the stud member acting as a spacer to provide a desired braking force. Fig.4 provides an isometric view of the stud member of the present invention along with other suitable geometric profiles.

Fig.5 depicts exemplary profiles of spacer members used in the bobbin holder of the present invention.

Fig.6 is a partially cut view of the skirt member of the bobbin holder of the present invention depicting the fitment of the body of the stud member and an inverted view showing the hexagonal recess.

Fig.7 is a graph showing the stiffness characteristics of the new spring and the exemplary settings for achieving desired results in various counts of yarn.

Detailed Description of the invention Accordingly, the present invention provides a bobbin holder with variable brake force to exert a variable braking force corresponding to the spinning conditions such as the yarn count. The representative embodiments of the present invention are described hereinafter with reference to the accompanying diagrams.

Referring to Fig 1, the Bobbin holder of the present invention in a cross-sectional view, has an upper expanded barrel 11 and a narrow rotatable trunk 8. The narrow trunk 8 is connected and suspended to the upper expanded barrel 11 by riveting means 13 in a known manner, to form a single rotatable unit along with the expanded barrel 11. A weight collar 3 is floating on the trunk. The trunk 8 houses the actuator 9 at the bottom end of which are two fingers 1 pivotably connected to the actuator by means of the actuator pin 4. On the upper portion of the actuator 9 houses a ratchet 6. The ratchet also has two wings on its body, which is connected to the actuator 9 by means of the ratchet pin 7. A 'Z' type flat spring 5 with one leg located in a slot in the actuator 9 and the other end resting on the ratchet 6 acts as the operating lug for the ratchet 6. On top of the actuator 9 is located the actuator spring 10. The top end of the actuator spring 10 abuts the top cap 12, which in turn is fixed to the top of trunk through the rivet 13.

During operation of the bobbin holder, when the weight collar is pushed up once, the flat spring 5 rotates the ratchet 6 by 90 degrees. The two wings of the body of the ratchet 6 now occupy a horizontal position thereby resting on the shoulder portion of the trunk 8. In this position the bobbin holding fingers are shrunk to release the bobbin. When the weight collar 3 is pushed up by the bobbin for the second time by the bobbin, the operating lug of the flat spring 5 rotates the ratchet 6 again by 90 degrees when the wings of the ratchet 6 assume a vertical disposition which allows the actuator 9 to clear the shoulder of the trunk 8 and fall further down. The fingers 1 are now swung apart aided by the dowel pin 2, thereby holding the bobbin in position. Now by specifically referring to Figures 1, 2 & 4, in an embodiment of the present invention, a stud member 25 with a head 25a having a curvaceous surface profile on its either side, is used as non-rotatable pivot to mount the rotatable upper expanded barrel 11. The rotation of the upper expanded barrel is performed by means of a bearing race 14 with balls 15 rotatably disposed on it. A neck portion 25b, which has a general smooth circumference, of said stud member 25 extending from the head 25a and terminating in a substantially barrel-shaped bulge 25e. The barrel shaped bulge 25e acts as a bottom dead centre for the movement of tensioner 19 the description of the tensioner 19 is hereinafter provided. A body portion (which is formed out of 25c and 25f) of said stud member 25 extending from the bulge 25e, said body portion of variable length with a substantially non-circular cross section. The variable length of the body portion corresponds to the length and tensile strength of the brake tensioner 19. The Variable length of the body portion of the stud member 25 is proportional to free length of the tensioner 19. In the present invention, as an exemplary embodiment, the cross sectional geometry of the body portion 25c of the stud member 25 is chosen from the shapes such as an ellipse, a square, a star, a cross, a hexagon, a diamond, a polygon or a substantially circular body with a peripheral wing profile as depicted in Fig 4 of the accompanied diagrams. These cross sectional geometries permit linear motion of the skirt member together with tensioner support member 20 during- operation and prevent the rotary motion of said skirt member 18. However, it is understood that any other suitable cross sectional geometries for said body portion 25c can be adapted in the present invention that can arrest the rotary motion of the skirt member 18. In the present invention, the cross sectional geometry that is used is substantially a circular body 25f with a peripheral wing profile 25c as depicted in Fig 4. The cross sectional geometry as of the stud member 25 as described above is further vertically extended by a threaded profile 25d. The threaded profile area 25d of the stud member is used to suspend said bobbin holder to the rail (not shown in the Figs) of the ring spinning or similar textile machine by means of intermediate fitting arrangements 22-24. The stud member 25 with the bearing race 14 mounted on its head is functionally disposed to pass through the smaller opening of expanded barrel with the bearing race 14, bearing balls 15 and cage 16 impinging on the upper inner surface profile of the expanded barrel, in known manner, to provide a slight swing action and rotation to the barrel 11 and the trunk 8.

In another embodiment of the present invention, a brake shoe 17 having a diametrical shape corresponding to the upper surface of the upper expanded barrel 11 having a central opening, is rotatably disposed and permitted to allow the stud member 25 to pass through the central opening to provide a variable brake force by means of a brake tensioner 19, which is operably connected to the brake shoe 17 during the operation of the bobbin holder.

The brake tensioner 19 is operably connected to the upper surface of the brake shoe 17 on one side and the other side of the tensioner is abutted by a tensioner support member 20 having a profile corresponding to the body of the stud member 25. It is observed here that the tensioner support member 20, which abuts the tensioner 19, rests on the top surface of the lensioner 19. In the present invention the tensioner support member 20 is in the form of a hexagonal washer. However, any other suitable profile can be applied to said tensioner support member 20. The tensioner 19 of the present invention is a tensioning device to provide compression and decompression forces on the brake shoe 17 during operation. In the present invention, tensioning devices in the form of a metallic spring, a rubberized spring or a rubber sleeve is adapted to act as a tensioner 19. However, the material objects that are disclosed, as tensioning devices are indicative and should not be construed as limiting the scope of such devices. Further, it is within the purview of the present invention to use variants of such tensioning devices including but not limited to hydraulic, pneumatic or thermally controlled metallic devices. In the present invention, as an exemplary embodiment, a metallic spring is used as a tensioner 19 to generate the variable brake force. Now, specifically referring to Fig 2 or Fig 3, wherein the arrangement of the tensioner 19 is depicted. The tensioner 19 in the form of a metallic spring is disposed about the body portion of the stud member 25 with end supports in the form of a brake shoe 17 and tensioner support member 20. The tensioner 19 is disposed to cover the area between the upper surface of brake shoe 17 and the beginning of the threaded profile 25d of the stud member 25. An enlarged skirt, member 18 with a smaller opening on its upper surface, said opening having a corresponding profile of the body of the stud member 25 and an opened lower end, said skirt member 18 is permitted to pass through the stud member 25 and disposed to envelope the upper extended barrel 11. While providing the enlarged skirt member 18, which corresponds to the variable length of the body portion 25c of the stud member 25, it is ensured that the basic function of the skirt member 18, which is to prevent fluff from entering into the bearing assembly, is retained.

In the present invention as an exemplary embodiment as provided in Fig 6, the skirt member 18 having a smaller opening with two slots 18a disposed diametrically opposite ends to provide non-rotatable movement relative to the body portion 25c of the stud member 25. A hexagonal threaded washer 21 is screwed on to the threaded portion of the stud member 25, which defines the top dead centre for the linear movement of the skirt member 18.

The upper-inner surface of the skirt member 18 is provided with a suitable profile 18b corresponding to the profile of the tensioner support member 20 to ensure the relative non- rotating connectivity between the stud member and the skirt member.

In another embodiment of the present invention at least a spacer member (26, 27, 28, 29) is disposed in the area of the body portion of the stud member 25 to generate the desired -braking force. The size, type, shape and number of the spacer member (26, 27, 28 and 29) is determined considering the yarn count and desired amount of braking force that is required during the spinning of the yarn. The selected spacer member (26, 27, 28 and 29) is disposed on the body of the stud member 25 and arranged on the upper surface of the skirt member 18 to compress and decompress said tensioner 19 and to generate desired variable braking force, during operation, on the brake shoe 17 of the bobbin hanging tube. In yet another embodiment of the present invention the spacer member is a removable spacer of variable size corresponding to the braking and rotating torque of a corresponding count of the spinning yam.

In further embodiment of the present invention the locking means of the removable spacer member vis-a-vis the body of the stud member is by means of a snap fit or press-fit as a locking means. In another embodiment of the present invention, a non-removable spacer member, in the form of solid-spacer of variable sizes corresponding to the braking and rotating torque is also used. It is to be noted here that the inner profile of the non-removable spacer member is either threaded or non-threaded, subject to the surface profile of the stud member as adapted in the present invention. In another embodiment of the present invention, by referring to Fig 5, a spacer member of C-type with two extensions having holes on them, is disposed on the stud member 25 by means and locked by means of a dowel pin in the designated holes to secure its position on the stud member 25 above the skirt member 18. The dowel pin acts as an additional or optional locking means to the spacer member, during the operation of the bobbin holder. The selection of a suitable spacer member is exemplified in the form of following example.

However, this example should not be construed as limiting the scope of the invention.

Example 1

The adjustable braking force under variable spinning conditions is determined by 5 considering factors such as roving tension under various spinning conditions. In the conventional bobbin holders, at least three different brake tensioners (usually metallic springs) are used: one for fine counts of yarn, a second for medium counts and a third for coarse counts. On measuring the brake forces of several springs used for each count the following average values were found. 10 Count Brake force grams

Fine 10

Medium 20

Coarse 40

Several experiments conducted to determine by what distances the new spring should be 15 depressed to simulate the above brake forces. Table 1 provides the details of experiments done on 50 numbers of the said spring to arrive at an average value.

Table 1

Spring Force in grams .

Spπn Compressed Length inmm gNo: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1 2.3 4.6 7.3 9.7 12 14.6 17.1 19.4 21.8 24.5 26.8 29.9 32.6 35 37.6 40.2

2 1.8 4.1 6.4 8.7 11.3 13.8 16.6 18.7 21.2 23.8 26.5 29.1 31.7 34.2 37 39.8

3 1 3.6 6.1 8.4 10.7 13.5 15.8 18.2 20.8 23.1 25.5 28.2 30.9 33.3 35.7 38.1

4 2.5 5.1 7.4 9.7 12 14.9 17.4 20 22.4 25 27.5 30.6 33.2 35.7 38.6 41.5

5 2.1 4.9 7.5 9.9 12.3 14.9 17.6 19.9 22.2 24.7 27.3 30.3 32.8 35.8 38.6 41.4

6 2.1 4.2 6.9 9.2 11.3 14.3 16.5 18.9 21.3 23.7 25.8 28.8 31.5 34 36.8 39.6

7 1.4' 4.3 6.9 9.2 11.5 14.2 16.5 -22.1 21.5 24.1 26.5 29.3 32.4 35 37.5 40 l IπU.

8 2.9 5.4 7.8 2 12.5 15.1 17.7 20.4 22.4 24.9 27.8 30.3 32.9 35.7 39 42.3

9 1 3.9 6.2 8.8 li.3 13.5 16 18.5 22.6 23 25.3 27.6 30.4 32.8 34.8 36.8

10 1.1 3.8 6.3 8.8 11 13.4 16.1 19 21.2 23.7 26.3 28.8 31.5 34.4 37 39.6

10.

11 2.8 5.4 7.8 7 13.5 16.2 18.6 21.2 23.7 26.9 29.9 32.8 35.5 38.3 41.5 44.7

12 1.8 4.3 6.9 9.2 11.8 14.4 17.1 19.4 18.9 24.4 30 29.8 32.3 34.9 37.6 40.3

13 2.4 5 7.3 9.7 12.5 14.9 17.3 19.5 21.9 24.6 27.3 29.7 32.4 34.8 36.5 38.2

14 2.3 4.7 7 9.2 12.1 14.5 17.2 19.4 21.8 24.4 27 29.6 32.1 34.6 36.6 38.6

15 1.4 4.1 6.3 8.6 11 13.6 16.1 18.4 20.7 23 25.7 28.3 30.8 33.4 36.5 39.6

16 1.3 4.1 6 8.6 11.3 14 16.6 18.9 22.2 24.6 27.7 30.7 33.7 36.7 40.6 44.5

17 1.7 4.4 6.9 9.2 11.9 14.8 17.4 19.9 22 25.1 28.3 30.9 33.7 36.4 39.8 43.2

18 1.3 4.1 6.4 9.1 12.3 14 16.5 18.7 20.9 23.5 26.2 28.6 31.2 33.6 36.6 39.6 19 1.3 3.7 6.2 8.5 Il 13.9 16.2 18.6 21.3 24 26.9 29.6 32.4 35.1 38 40.0

20 1.3 3.6 6.2 8.4 10.9 13.8 16.3 18.4 21.2 22 25.9 29.6 32.3 35 37.9 40.8

21 1.4 3.7 6.1 ^■8.5 11 13.7 16.2 18.5 20.8 23.3 26 28.7 30.9 35.5 37.7

22 2.8 5.2 7.7 10 12.6 15.3 17.2 20.5 22.4 25.1 27.7 30.6 33 35.3 38 40.7

23 1.4 4 6.4 8.7 11 13.3 15.9 18.4 20.2 23 25.6 28.1 30.5 32.7 35.5 38.3

24 2.5 4.7 7 9.4 ^' 12 14.6 16.9 19.5 21.8 24.5 26.8 29.8 31.9 34.7 37.5 40.3

25 2.5 5 7.4 9.7 12.3 15.3 18.1 20.5 22.9 25.5 28.3 31.1 33.5 36 38.7 41.4

26 1.5 4 6.3 S.6 11.1 13.6 16.2 17.9 20.8 23.6 26.1 28.6 30.9 33.3 36 38.7 10.

27 2.8 5.4 7.6 I 12.5 15 17.4 19.8 22.1 24.5 27.3 30 32.8 35.4 38.3 41.2

28 1.4 4.1 7 9.2 11.7 14.3 17.1 19.5 22.1 24.4 27.3 30.1 32.9 35.3 38 40.7

29 2.3 4.5 6.9 9.3 11.9 14.2 17.6 18.9 21.5 24 27.1 29.9 32.4 35 38.5 42

30 1.3 4.1 6.3 8.6 11 13.3 16.1 18.4 20.2 22.7 25.4 28.1 30.4 33 36.2 39.4

31 1.7 4.1 6.8 9 π.5 13.9 16.4 18.7 21.1 23.7 26.4 28.6 31.3 33.8 37 40.2

32 1.3 3.9 6.1 8.5 10.7 13.3 16.6 17.9 20.1 22.5 .25 27.8 30.3 32.7 35.6 38.5

33 1.3 3.6 6.1 8.2 10.4 12.8 15.1 17.7 19.9 22.5 24.3 27.3 30 32.4 34.5 36.6

34 2.4 4.8 6.9 9.6 11.9 14.5 16.6 19.2 21.5 24.2 27.3 30 32.9 35.4 38.5 41.6

35 2.5 4.8 7.4 9.7 12.! 14.9 17.1 19.9 21.9 24.1 26.5 29.4 31.7 34.2 37 39.8

36 1.3 3.7 5.6 8.2 10.7 13.2 15.6 17.8 20.2 22.7 25.1 27.6 30.1 32.5 35.5 38.5

37 2.3 4.5 6.9 9.2 11.5 14.3 17.1 19.3 22.1 24.3 27.1 29.9 32.9 35.6 38.3 41

38 ^'2.2 4.1 6.4 8.2 11.2 14.5 16.1 17.9 20.1 23 25.4 27.6 30 32.3 35.4 38.5

39 1.3 ^■ 3.9 6.3 8.8 11 13.3 16 18.5 21.1 23.9 26.3 28.8 31.7 34.1. 36.7 39.3

40 2 4.7 7.4 9.6 12 14.8 17.1 19.7 22.1 24.5 27.2 29.8 32.2 34.7 37.7 40.7

41 2.8 5 7.4 9.6 12 14.3. 16.6 18.7 20.7 23.3 25.8 28.6 30.9 33.2 35.7 38.2

42 1.3 3.9 6.1 8.7 11.6 14 16.5 19.4 22.2 24.5 27.3 29.6 32.1 35.2 38.6 42

43 1.5 3.9 6 8.2 10.9 13.3 16.1 18.7 21.2 23.8 26.5 29.1 31.7 34.2 37.6 41

44 2.8 4.7 7,1 9.7 12.5 15.3 18.1 20.8 23.2 26.1 28.8 32 34.9 37.7^" 41 44.3

45 2.4 4.7 7.4 9.7 11.9 15 17.3 19.8 22.2 24.7 27.5 30.2 33.1 35.7 38.5 41.3

46 1.3 3.8 6.1 8.6 π 14.2 16.1 18.4 21.1 23.4 26.2 29.1 31.7 34.3 37.9 41.5

47 1.3 3.8 5.9 8.2 10.5 13.2 15.9 17.8 20.2 23 25.5 28 30.7 33.2 36.2 39.2

48 2 4 6.2 8.5 11.3 13.6 16.1 18.6 21 23.2 25.9 28.6 31.4 34 36.7 39.4

49 2.3 4.6 7 9.2 11.9 14.1 16.6 18.7 21.1 23.8 26.7 28.8 31.6 34.2 37 39.8

50 1.3 3.7 . 6.1 8.2 10.8 13.5 15.8 18.4 20.8 23.3 25.8 28.6 31.2 33.6 36.3 39

Aver age 1.9 4.3 ^• 6.7 9.1 11.6 14.2 16.7 19.1 21.4 24.0 26.7 29.3 32.0 34.5 37.4 40.2

It was observed that the new spring gives brake forces matching those required for fine, medium and coarse counts as above when they are depressed by 4mm, 8mm and 16mm. When the tensioner is assembled without any spacer it gets compressed by 4mm, which is 5 suitable for fine counts. When an additional spacer of 3 mm is introduced it gets compressed by 7mm. The thickness of the upper surface of the skirt member contributes to another 1 mm. Hence the total compression is 8mm. This setting is used for medium counts. Another spacer of 8 mm will provide the setting for the coarse counts with a total compression of 16 mm. The results graphically depicted in Fig 7. The graph shows the stiffness characteristics, through which the settings for fine, medium and coarse counts are clearly inferred.

Spacers of variable thicknesses ^"such as 3mm and 7mm are selected for achieving the variable brake force in the tensioner. The thickness of the spacer dictates the distance by which the spring is compressed and in turn the increase in the brake force exerted by the spring. Spacers of other thicknesses can also be used depending upon the spinning conditions in the mill.

Flexibility in brake force exerted by the-tensioner can be brought about only by making one end of the tensioner free and providing a means to set the compressed length at different levels. Since the lower end of the tensioner has to necessarily rest on the brake shoe 17 the top end must me made free. It must be capable of being progressively compressed so as to give variable brake force.

This arrangement gives the power to the operating persons in the spinning factory to fine tune and set the bobbin holder brake system to the required condition of their machines. Besides, adding and removing the washer is externally done without opening the bobbin holder, which ensures that the factory settings are not tampered with. The spacers are given bright colours so that they will be visible from a distance and it can be ascertained that all the spindles are running in the same setting. Any alteration can be immediately detected and therefore an element of tamper proofing is in-built. However, if the factory requires more degree of tamper proofing, solid spacers 27 or 29 can be used in place of the special snap fitting spacers 26 or 28. In this case adding and removing spacers can be done only by removing the bobbin holder from the creel, which provides additional fool-proofing. In another embodiment of the variable brake force bobbin holder of the present invention, which is pictorially represented in Fig.3, a pin 31 is adapted in place of spacers to generate the desired braking force. A set of two small holes 32 & 33 are provided on the stud member 25 to permit the pin pass through them. The pin 31 is inserted into said holes 32 & 33 after depressing the skirt member 18, as shown in Fig.3, to achieve a higher brake force. In the present invention two such holes are provided so as to give two different settings. However, the number of holes can be varied suitably to achieve the desired brake force corresponding to the yarn count.

During the operation the bobbin is mounted on the bobbin holder by pushing it up the weight collar. During the mounting stroke after the shoulder in the inner hole of the bobbin has passed the fingers, the mechanism acts to swing the fingers apart to retain the bobbin.

The roving yarn from the bobbin is fed into the spinning machine through rollers in the machine. The yam is drawn by the machine from the bobbin thereby making the bobbin to rotate to unwind the bobbin. This pulling force on the yarn is commonly called as the roving tension. When the counts change this pulling force or the roving tension changes thereby requiring a change in the braking force. This is achieved by depressing the skirt member down and inserting a suitable spacer on top of the skirt member. When there is no spacer the skirt member assumes its top dead centre position and the tensioner is compressed by about 4 mm. This setting is suitable for fine counts. When medium counts are required to be spun a smaller spacer an example of which is given as item 28 or 29 in Fig.5 is inserted on to the stud member above the skirt member. When coarse counts are spun, this setting is changed either by inserting another spacer on top of this spacer or by removing this spacer completely and adding a thicker spacer depicted as item nos 26 or 27 in Fig.5. By this method the desired brake force is achieved. Advantages: 1. The rotating bobbin holder of the present invention provides options from lighter brake force to harder brake force by means of single tensioner member used in conjunction with spacers or a pin.

2. The change- over from one. count to another count during the spinning operation is achieved without either opening the bobbin holder or changing the tensioner or a replacing the bobbin holder.

3. In the present invention a set of bright colours are provided to the spacers to provide high visibility even from a long distance as to the setting at which the different spindles are running to incorporate an element of fool proofing or tamper proofing.

Claims

We Claim:

1. A rotating bobbin holder with a bobbin hanging tube having an upper expanded barrel and a lower narrow trunk with a pair of bobbin holding fingers to hold and release bobbins, said bobbin holder connected to textile ring spinning machine comprising;

(a) a stud member with a head of a curvaceous surface profile to receive bearing ^' assembly, a smooth neck portion of said stud member extending from the head and terminating in a substantially barrel-shaped bulge,

(b) a body portion of variable length of said stud member extending from the neck portion, with a substantially non-circular cross section, said body portion further extended as a threaded profile,

(c) said stud member disposed to pass through a smaller opening on the top surface of the expanded barrel, and the head with bearing assembly rotatably impinging on the upper inner surface of the barrel to provide a rotary motion to the bobbin hanging tube,

(d) a brake shoe with a central opening permitted to pass through said stud member, said brake shoe disposed on the outer-upper surface of the barrel to provide a variable a brake force by means of a brake tensioner, said tensioner functionally connected to the upper surface of the brake shoe on one side and the other side of the tensioner is abutted by a tensioner support member having a profile corresponding to the body of the stud member.

(e) an enlarged skirt member with a smaller opening on its upper surface, said opening having a corresponding profile of the body of the stud member and an opened lower end, said skirt member is permitted to pass through the stud member and disposed to envelope the upper extended barrel,

(f) a relative surface profile on top inner surface of the skirt member corresponding to the outer profile of the tensioner support member to provide a non-rotatable functional support to the skirt member, and

(g) at least a spacer member of desired thickness and with a locking means is disposed on the body of the stud member and arranged on the upper surface of the skirt member to compress and decompress said tensioner and to generate desired variable braking force on said bobbin hanging tube.

2. The bobbin holder as claimed in claim 1, wherein the variable length of the body of the stud member corresponds to the length and tensile strength of the brake tensioner.

3. The bobbin holder as claimed in claim 1, wherein the cross sectional geometry of the body of the stud member is an ellipse, a square, a star, a substantially circular body with peripheral wing profile, preferably a substantially circular body with a peripheral wing profile.

4. The bobbin holder as claimed in claim 1 , wherein the brake tensioner is a metallic spring, a rubberized spring or a rubber sleeve.

5. The bobbin holder as claimed in claim 1, wherein the tensioner is disposed to cover the area between the upper surface of brake shoe and the beginning of the threaded profile of the stud member.

6. The bobbin holder as claimed in claim 1, wherein the spacer member is a removable spacer of variable size corresponding to the braking and rotating torque of a corresponding count of the spinning yarn.

7. The bobbin holder as claimed in claim 6, wherein the locking means of the removable spacer member is a snap fit or press-fit with or without additional locking pin.

8. The bobbin holder as claimed in claim 1, wherein the spacer member is non-removable solid-spacer of variable size corresponding to the braking and rotating torque.

9. The bobbin holder as claimed in claim 8, wherein the inner profile of the non¬ removable spacer member is either threaded or non-threaded.

10. The bobbin holder as claimed in claim 1, wherein a stopper pin is disposed on the stud member in place of a spacer.