GB2210637A

GB2210637A - Ball yarn tensioner device, in particular for double-twist spindles

Info

Publication number: GB2210637A
Application number: GB8823201A
Authority: GB
Inventors: Domenico Giudici; Virginio Giudici; Luigi Giudici
Original assignee: Giudici Davide & Figli
Current assignee: Giudici Davide & Figli
Priority date: 1987-10-07
Filing date: 1988-10-04
Publication date: 1989-06-14
Also published as: FR2621603A3; IT8722496V0; FR2621603B3; ES1007893Y; DE8812675U1; GB8823201D0; ES1007893U; IT211858Z2

Abstract

The device comprises a substantially cylindrical support (17) for receiving a yarn bobbin (18), and a plurality of yarn-guide elements (19) aligned along the axis of the support (17) inside therewith and having respective funnel-shaped portions (20) for respectively housing balls (21) for yarn tensioning. The yarn-guide elements (19) are positioned inside a housing body (25) borne by the support (17), and inside the support (17) an axial yarn-guide tube (30) is positioned, which has an end capable of laterally displacing the balls (21), when either the housing body (25) or the axial tube (30) are axially shifted relatively to each other such that in a yarn threading position the tube (30) runs through the yarn-guide elements (19) and keeps the balls (21) moved away from the axis of the yarn-guide elements (19), placing a yarn inlet (22) in communication with a yarn outlet (23), and in at least one work position the tube (30) leaves free at least a portion of the balls (21). <IMAGE>

Description

BALL YARN TENSIONER DEVICE, IN PARTICULAR FOR DOUBLE TWIST SPINDLES" The present invention relates to a ball yarn tensioner device, in particular for double-twist spindles.

It is known that in the devices of this type, a plurality of balls are housed inside respective yarnguide elements essentially having a funnel shape, positioned superimposed to one another inside the support for the yarn bobbins. The balls, which have a diameter' smaller than the maximum diameter of the funnels, but larger than the diameter of the bottom openings of the funnels, rest by gravity on the bottom of the funnels, in correspondence of the openings.

The yarn to be tensioned is guided through these openings and is tensioned by the weight of the balls, while it is being unwound from the bobbin in order to be twisted. In practice, the balls oblige the yarn to run along a tortuous path, simultaneously stopping the twists which occur downstream the yarn tensioner device, due to the effect of the revolutionary motion of the spindle.

These yarn tensioner devices result however not very convenient, in that when the processing is started up, the operation of yarn threading has to be carried out. In fact, in order to accomplish this operation, the balls have to be displaced from their position of rest in correspondence of the openings, in order that the yarn may be orderly inserted through the openings.

The threading is generally carried out by means of a semirigid nylon needle, an end of which is inserted inside the support, whilst to the other end of it an end of the yarn to be threaded is knotted. The needle is made pass through the successive openings, displacing the balls as it runs through them, which then return back into their initial position after that the needle has passed.

Anyone will easily understand that this operation is toilsome and slow, and has to be carried out by hand, with an economic burden owing to the long stop of the spindles, and to the labour costs.

An automatic threading of the type performed by suction cannot in fact be accomplished, in that the suction, which should take place at the outlet side of the yarn tensioner support, would cause the balls to remain in their position of closure of said openings, rather than them to move away in order to make it possible the yarn to pass through.

The purpose of the present invention is to provide a ball yarn tensioner device, in particular for doubletwist spindles, which makes it possible the yarn end to be automatically threaded through the support for the bobbins.

In order to accomplish said purpose, a ball yarn tensioner device, in particular for double-twist spindles, is proposed according to the present invention, which comprises a substantially cylindrical support capable of receiving a yarn bobbin, and provided, in its interior, with a plurality of yarn-guide elements having respective funnel-shaped portions and lined-up along the axis of the support, with said portions respectively housing balls for yarn tensioning and the end yarn-guide elements respectively being in communication with a yarn inlet and a yarn outlet, characterized in that the yarnguide elements are positioned inside a housing body borne by the support, and that inside the support an axial yarn-guide tube is positioned, which has an end suitable for laterally displacing the balls, with the housing body or the axial tube being substantially shiftable relatively to each other between a yarn threading position, in which the tube runs through the yarn-guide elements and keeps the balls moved away from the axis of the yarn-guide elements, placing the yarn inlet in communication with the yarn outlet, and at least one work position, in which the tube leaves free at least a portion of the balls.

Advantageously, in a device of such a type, a short and simple relative axial movement between the housing body and the yarn guide tube, preferably an axial movement of the housing body relatively to the yarn guide tube makes it possible all of the balls to be moved away from their position of covering of the openings of the funnel-shaped portions of the yarn-guide elements of the device, in that the axial tube, by penetrating these openings, laterally shifts the balls, and establishes a direct communication between the inlet and the outlet of the device, which makes it possible the yarn to be easily and rapidly threaded. This threading can be easily carried out by suction through the same axial tube which has liberated the passages of the yarn guide elements. In order to secure the lateral displacement of the balls, the axial guide tube can have its upper end obliquely cut.

In the reverse step, the relative moving away of the cylindrical housing body and of the yarn guide tube automatically causes the balls to fall back to their position of closure of the openings on the bottom of the relevant funnel-shaped portions of the yarn-guide elements, in which position they act on the inserted yarn.

Further details and advantages of the present invention will be better understood from the following disclosure in detail of a form of practical embodiment of the same invention, illustrated by referring to the hereto attached drawings, in which: Figure 1 shows an elevation view of a double-twist spindle provided with a yarn tensioner device according to the present invention; Figure 2 shows an axial sectional view of a yarn tensioner device according to the present invention, in its work position; Figure 3 shows an axial sectional view of a yarn tensioner device according to the present invention in its suitable position for yarn threading.

In the drawing (Figure 1), by the reference numeral 10 a stationary support structure for a double-twist spindle 11 is indicated, which rotatably supports a shaft portion 12 of a rotary disk 13, provided with an axial and radial passage, not illustrated in greater detail, for the yarn 14 to which the double twist has to be supplied in a p~r~~~ known way. The disk 13 is driven to revolve by means of a belt 15 acting on the shaft 12.

The disk 13 drives to revolve a yarn tensioner device 16 which comprises a substantially cylindrical support 17, suitable for receiving a yarn bobbin 18, from which the yarn 14 to be twisted is unwound. The path of the yarn 14 is depicted in the drawing.

The support 17 is provided in its interior, in a es,s known way, with a plurality of yarn-guide elements 19 (Figure 2), which are positioned lined-up along the axis of the support 17, and have an inner configuration to which a substantial funnel shape 20 is given, and house respective yarn tensioning balls 21. The end yarnguide elements 19 are respectively in communication with a yarn inlet and a yarn outlet, generally indicated by the reference numerals 22 and 23.

In their work position, the balls 21 rest by gravity on the bottom of the respective funnel-shaped portions 20 in correspondence of openings 24 of the yarn-guide elements 19, through which the yarn 14 is made run. In this position, the balls 21 cause the yarn 14 to run along a tortuous path, and tension it, as it can be seen in Figure 2, simultaneously stopping the transfer upwards of the yarn twists which are generated downstream the device.

The yarn-guide elements 19, preferably of a ceramic material, are arranged inside a substantially cylindrical housing body 25, which can be axially shifted inside the support 17. For this purpose, the body 25 has an upper portion provided with an axial seat 26 for housing the yarn-guide 19 elements, and a bottom guide portion.

On the upper end of the housing body 25, an outwards-tapered head 27 is installed, through which the yarn 14 inlet opening 22 is provided, and which constitutes an engagement element for the axial displacement of the body 25. Is also performs the task of keeping in the right position the stack of yarn-guide elements 19, which are preferably spaced apart from each other by means of ring spacers 28, and are installed inside the seat provided in the body 25, with possibility of removal.

Inside the support 17, near the base thereof, a fastening body 29 is made integral with the same support, and rigidly supports in the axial position an axial guide tube 30 acting as the axial guide for the yarn 14. The tube 30 extends substantially throughout the whole height of the support 17 and enters an axial channel 31 provided in the lower portion of the housing body 25. The upper end of the tube 30, suitable for engaging and laterally displacing the balls 21, is advantageously obliquely cut.

The tube 30 has an outer diameter slightly smaller that the diameter of the openings 24 of the yarn-guide elements 19, so that it can penetrate them.

The balls 21 advantageously have such a diameter, as to find place laterally to the tube 30 once that this has penetrated the yarn-guide elements 19.

According to a particular aspect of the present invention, the device has as a number of work positions equal to the number of yarn-guides 19. Each one of these work position is made stable thanks to cooperating stop means provided between the support 17 and the housing body 25, these means can be advantageously constituted by seats 32 provided at various heights along the support 17, and suitable for receiving, in snap-engagement, a stop element 33, e.g., a ball, elastically installed inside a radial seat 34 provided in the housing body 25. The seats 32 are spaced apart in height from each other by a distance corresponding to the distance between the yarnguide elements 19. Suitably, also a seat 32a for the yarn threading position can be provided.

For greater convenience, inside the support 17 a Longitudinal slot 35 can be provided, which defines at its ends stroke-end positions for a grub screw 36 which can be screwed down inside a screw-threaded bore 37 from a plurality of screw-threaded bores positioned at various heights along the housing body 25, corresponding to as many work positions.

In Figure 2, a work position of the device according to the present invention is depicted, wherein the housing body 25 protrudes from the support 17 from the yarn 14 inlet side, and the balls 21 are resting in correspondence of the openings 24 and provide, by gravity, for the yarn 14 to be properly tensioned.

In order to perform the threading of the yarn 14, it will be enough to cause the housing body 25 to enter back into the support 17, by means of an axial downwards shift. This shift cause the axial guide tube 30 to penetrate the openings 24 of the yarn-guide elements 19, while the cut end of the tube 30 causes the balls 21 to move away from the respective openings 24, by sideways moving them away from the axis of the yarn guide. When all of the balls 21 are displaced, as shown in Figure 3, the yarn 14 can be threaded through the axial guide tube 30, which in this situation connects the device inlet to the device outlet.

The threading can be advantageously carried out by suction through the axial tube 30, by associating an intake duct to the support 17 outlet.

Once that the yarn 14 is inserted, in order to restore the working conditions of the ball 21, it will be enough to cause the housing body 25 to perform the reverse movement, by which the tube 30 leaves free the balls 21, which fall back to the bottom of the respective yarn-guide elements 19.

It should be observed that the herein disclosed device is well suited for varying the tension applied to the yarn 14, by varying the number of operating yarnguides. For this purpose, it is enough to place the housing body 25 in a different work position, e.g., the position schematically shown in chain in Figure 2, in which the tube 30 disables a certain number of balls 21, by sideways displacing them, and only those balls which are situated above the upper end of the tube 30 will remain operating.

Therefore, differently from other ball yarn-guide devices known from the prior art, in order to vary the tension of the yarn, it is not necessary to remove the not used yarn-guide elements; the waste of time necessary in order to achieve an adjustment of the yarn tension value is therefore considerebly reduced.

From the above disclosure, one can easily understand how with a yarn tensioner device according to the present invention, the operation of yarn threading can be carried out rapidly and automatically, as well as the yarn tension level can be easily modified by means of simple axial movements of the device.

Instead of making axially shiftable the housing body 25, one could also provide for this body to be stationary, and make axially shiftable the axial guide tube 30 for the yarn. This shift could be accomplished1 e.g., by pneumatic means, by providing an element, integral with the tube 30, which element acts as a piston sliding inside the support 17.

Claims

Claims C l a i m s

1. Ball yarn tensioner device, in particular for double-twist spindles, comprising a substantially cylindrical support capable of receiving a yarn bobbin, and provided, in its interior, with a plurality of yarnguide elements having respective funnel-shaped portions and Lined-up along the axis of the support, with said portions respectively housing balls for yarn tensioning and the end yarn-guide elements respectively being in communication with a yarn inlet and a yarn outlet, characterized in that the yarn-guide elements are positioned inside a housing body borne by the support, and that inside the support an axial yarn-guide tube is positioned, which has an end capable of laterally displacing the balls, with the housing body or the axial tube being substantially shiftable relatively to each other between a yarn threading position, in which the tube runs through the yarn-guide elements and keeps the balls moved away from the axis of the yarn-guide elements, placing the yarn inlet in communication with the yarn outlet, and at least one work position, in which the tube leaves free at least a portion of the balls.

2. Device according to claim 1, characterized in that the housing body is axially shiftable inside the support, and in said at least one work position, it protrudes from the support from the yarn entry side.

3. Device according to claim 1 or 2, characterized in that the upper end of the guide tube, designed to come into contact with the balls, is obliquely cut.

4. Device according to one or more of the preceding claims, characterized in that said cylindrical housing body has an upper portion having an axial seat for housing said plurality of yarn-guide elements, and a lower portion provided with an axial channel for enabling said axial yarn guide tube to pass through.

5. Device according to claim 4, characterized in that the yarn-guide elements are housed with possibility of removal inside said housing seat.

6. Device according to claim 1, characterized in that the number of its work positions equals the number of the yarn-guide elements.

7. Device according to one or more of the preceding claims, characterized in that said housing body is provided at its top with an engagement head for the axial shift of said body between said positions.

8. Device according to one or more of the preceding claims, characterized in that said housing body and said support are provided with cooperating means for locking said housing body in said positions.

9. Device according to one or more of the preceding claims, characterized in that with the outlet of said support a suction duct for the automatic threading of the yarn is associated.

10. Device according to one or more of the preceding claims, characterized in that said axial guide tube extends substantially over the whole height of the support.

11. Device according to one or more of the preceding claims, characterized in that the guide tube has an outer diameter slightly smaller than the diameter of the openings of the yarn-guide elements.

12. Ball yarn tensioner device substantially as hereinbefore described with reference to the accompanying drawings.