SPINDLE FOR SPINNING MACHINE OR TWISTING FRAME WITH ANTI-BALLOON CONTAINER

Abstract: Spindle for a spinning machine or twisting frame with anti-balloon container, advantageously for twisting frames for elastic yarns and in coating and covering machines, the spindle being assembled on a spindle-bearing block (10) and associated with rotation shaft means, a cop (13) to wind the yarn (14) being keyed onto the spindle, the spindle being mounted on a support (15) laterally movable with respect to the block (10), a tubular container (18) being solidly attached to the movable support (15), arranged coaxial and outside the spindle (11), with the function of limiting the balloon, the container (18) being laterally movable in a single piece with the support (15) and with the spindle (11).

Description: "SPINDLE FOR SPINNING MACHINE OR TWISTING FRAME WITH ANTI- BALLOON CONTAINER" • k k k k -k FIELD OF THE INVENTION This invention concerns a spindle for a spinning machine or twisting frame with an anti-balloon container as set forth in the main claim. The invention is applied generally in the textile field in spinning machines and twisting frames and, more particularly in twisting frames for elastic yarn and in coating and covering machines . BACKGROUND OF THE INVENTION The general structure of a spinning machine or twisting frame, wherein a plurality of spindles arranged in rows is made to rotate by tangential belts driven by one or more motors, is well-known in the state of the art. One known problem which affects productivity and the speeds of rotation which can be obtained with traditional spindles concerns the formation of a balloon outside the spindle, as the thread is being unwound. If a large balloon is formed, it creates differences in tension between one point and another of the thread, and causes differences in the unwinding which have a negative effect on the final product . Moreover, a balloon which is too large creates a limit to the height of the cops which can be used, so that the productivity of the spinning machine is also reduced. It should be noted that the energy consumed to drive the spindles increases in a linear manner with height, which is not therefore a particularly critical factor; on the contrary, it is cubed as the diameter increases, which means that the diameter of the spindle needs to be limited so as not to increase consumption excessively. - 2 - To overcome these problems, devices have been proposed which use fixed, tubular containers arranged around the rotating spindle, which limit to a reduced value the expansion of the balloon. Devices of this type are described in DE-B-1285368, DE-A-3033046, and WO-A-93/24688. Although this type of container on the one hand resolves the problem of not having a balloon which is too large, on the other hand it creates a plurality of operative problems in manipulating the cops of yarn, particularly at the beginning and end of winding. In fact, the inclusion of yarn-guiding devices, tensioners and/or unwinding devices above the spindle makes it difficult if not impossible to remove the cop axially without inclining the cop with respect to the axis of the spindle. However, the presence of the anti-balloon container is an obstacle to inclining the cop and, even when it allows the cop to be removed, creates the serious danger of the wound yarn rubbing against the upper edge, consequently damaging the yarn and possibly even leading to the yarn being discarded. Another problem derives from the continuous rubbing of the yarn against the inner walls of the tubular container which, in the case of thin, elastic yarn such as that used for women's stockings, may even lead to the yarn itself breaking. The state of the art also includes spindles which can pivot from a position wherein the yarn is wound to a position wherein the cop is removed/inserted; such spindles are taken to a position of non-interference with the guiding and tensioning devices thereabove. The lateral displacement of the spindles also makes possible to distance the drive shaft of the spindle from the tangential belt, thus facilitating the braking operation. - 3 - However, these movable spindles do not solve the problem of limiting the balloon and therefore they are very limited in use and application, particularly in the case of thin and ultra-thin yarn such as that used for women's stockings or similar. The present applicant has devised and embodied this invention to overcome these shortcomings. SUMMARY OF THE INVENTION The invention is set forth and characterised in the main claim, while the dependent claims describe other characteristics of the idea of the main embodiment. The purpose of the invention is to achieve a spindle for spinning machines or twisting frames, particularly for elasticised and thin yarns, such as for example yarns for women's stockings or similar, which will solve the problem of limiting the balloon and, at the same time, will not involve risks of damaging or breaking the yarn, either when the full cop is removed from the spindle, or during winding. The invention also facilitates braking operations of the spindle during the end-of-winding steps. According to the invention, a movable spindle is provided which can pivot from a first position, maintained during the winding operations of the yarn onto the cop or reel, to a second, laterally displaced position which is assumed for the operations to remove/insert the cop from/onto the spindle . This facilitates and simplifies these operations since it eliminates interference with the guide, tensioning and unwinding elements arranged above the spindle, also distancing the drive shaft of the spindle from the tangential belts which make it rotate. According to a variant, the spindle can be removed like a drawer, or in some other desired manner. According to the invention, a tubular container is arranged around and coaxial to the spindle and is mounted on the movable structure supporting the spindle and is therefore pivotable, movable laterally, like a drawer or in some other manner together therewith. The function of the tubular container is to limit the amplitude of the balloon which is formed while the yarn is winding onto the cop, eliminating all the problems which too large a balloon entails during the winding of the yarn. According to another characteristic of the invention, the inner wall of the tubular container is at least partly corrugated, or is equipped with helical, concentric or similar protrusions, in order to reduce the contact surface with the yarn during winding and therefore to reduce friction caused by the yarn sliding over the wall, thus considerably limiting the risk of damaging or breaking the yarn due to friction. According to a further characteristic of the invention, the spindle is axially covered with a sheath of the desired thickness; this sheath constitutes a contrast which limits the maximum angle of the cop when it is removed, and means that the cop has to be removed in a substantially axial, or almost axial , manner . This reduces the danger of an excessive angle causing the yarn to rub against the upper edge of the container, when the full cop is removed from the spindle, with the consequent risk of damaging the yarn, given the delicate nature of this type of yarn. According to a further characteristic of the invention, the tubular container is at least partly movable in an axial direction with respect to the spindle, so that the upper part of the spindle can be left uncovered during the step to remove and replace the cop of yarn. BRIEF DESCRIPTION OF THE DRAWINGS - The attached Figures are given as a non-restrictive example and show some preferred embodiments of the invention as follows: 5 Fig. 1 shows a segment of a spindle-bearing block of a spinning machine or twisting frame adopting the spindle according to the invention; Fig. 2 shows a longitudinal section of the spindle with an anti-balloon container according to the invention; L0 Fig. 3 is a plane view of Fig. 2; Fig. 4 shows a first variant of the anti-balloon container according to the invention, both in the working position and in the inactive position; Fig. 5 shows an enlarged, sectioned detail of Fig. 4; .5 Fig. 6 shows a second variant of the anti-balloon container according to the invention, both in the working position and in the inactive position. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Fig. 1 is a part view of a spindle-bearing block 10 on 0 which a plurality of spindles 11 are mounted in a row, only three of which are illustrated in this case. The spindles 11 extend axially in a shaft 12 with which tangential belts (not shown here) cooperate and make them rotate at speeds which, in modern spinning machines and for 5 thin yarns of the type used for women' s stockings, reach up to 32000 rpm. The drive and braking mechanisms of the spindles 11, the mechanisms to feed and guide the reels and every other element which is conventionally included in spinning 3 machines and twisting frames are taken as known and are not described in any detail herein. A cop 13, which includes a central body 13a (Fig. 2) to position the yarn 14 and retaining flanges 13b, is axially RECTIFIED SHEET (RULE 91) ISA/EP threaded onto the spindle 11. The spindle 11 is positioned on a support 15 which is mounted pivotable around a rotation shaft 16 solid with the bench 10. The axis of the shaft 16 is substantially parallel to the axis of the spindle 11, and therefore the support 15 is able to move laterally with respect to the block 10, remaining substantially on the same plane, without any inclinations of the axis of the spindle 11. According to a variant, which is not shown in the drawings, the support 15 of the spindle 11 can be laterally removed, like a drawer, from the block 10. According to a first embodiment of the invention (Figs. 1- 3) , on a supporting plate 17 of the support 15 a tubular container 18 is solidly attached, coaxial with the spindle 11, with the function of limiting the balloon which forms around the cop 13 while the yarn 14 is being wound. Limiting the balloon reduces the lack of uniformity in the tension of the yarn, reduces overall energy consumption and makes possible to use taller cops 13, thus increasing productivity. The association between the supporting plate 17 and the container 18 is achieved for example by means of screws 19. During the end-of-winding, or inactive step, the entire spindle 11-container 18 assembly is laterally pivoted around the rotation shaft 16, thus allowing to freely withdraw the cop 13 in an axial direction, without any interference from the yarn-guide and any possible overlying devices, which are not shown in the Figures . The removal of the cop 13, in this case, is facilitated by using an upper grip 21 associated therewith. The inner wall of the container 18 includes corrugations 22 (see the enlarged detail in Fig. 2) in order to reduce friction, limiting the area of contact between the wall and - 7 - the thread, which runs over the wall during - the winding steps . It comes within the scope of the invention to include, instead of the corrugations 22, any type whatsoever of surface protrusion, threading or similar, which is suitable to reduce the overall area of contact between the thread and the inner wall of the container 18. According to another particularity of the invention, the spindle 11 is covered by a sheath or sleeve 23, which has the function of preventing an excessive angling of the cop 13 during the removal step, thus preventing the yarn 14 from rubbing against the upper edge of the container 18, and from becoming damaged in a sometimes irreparable manner, especially in the case of thin and ultra-thin yarn. The thickness of the sheath 23 is therefore functionally correlated to the free space defined between the yarn 14 at the end of winding and the container 18, in such a way that the cop 13 is removed from the spindle 11 in a substantially coaxial manner, which will not take the yarn 14 against the upper edge of the container 18. According to a first variant, shown in Figs. 4 and 5, the tubular container 18 consists of two parts: an inner part 18a, attached to the supporting plate 17, and an outer part 18b mounted coaxial to the inner part 18a and sliding axially with respect thereto. In the working position, shown on the left of Fig. 4, that is to say, during the winding of the yarn 14 onto the cops 13, the outer part 18b is raised with respect to the inner part 18a and is attached thereto by means of at least two inner teeth 24, diametrically opposite, which cooperate with two corresponding upper notches 25. In the inactive position, shown on the right of Fig. 4, the outer part 18b is lowered to the same level of the inner - 8 - part 18a and the teeth 25 cooperate with lower notches 26 of the latter. In this way the upper part of the cop 13 remains uncovered and free to be easily manipulated by the workers responsible for the spindles in order to replace the cop 13. According to a second variant, shown in Fig. 6, the shafts 12 on which the spindles 11 are keyed are higher, for example by several centimetres, than the block 10, and the supporting plate 17 to which the container 18 is attached is mounted at the upper end of a rod 27. In turn the rod 27 is mounted on the support 15, axially sliding between a first raised or working position, shown on the left in Fig. 6, wherein the container 18 is arranged completely around the spindle 11 and the cop 13 associated therewith, and a lowered or inactive position; shown on the right in Fig. 6, wherein the container 18 leaves the upper part of the cop 13 uncovered, so that the latter can be easily removed from the spindle 11. A positioning mechanism 28, provided with a ball 29 thrust by a spring 33, is suitable to cooperate with two notches 30 and 31 to maintain the rod 27 and the container 18 stably in one position or the other, raised and respectively lowered. A gripper ring 32 is attached to the upper part of the rod 27 to make it easier for the worker to raise the container 18. It is evident that modifications or additions may be made to the spindle for a spinning machine or twisting frame with the associated anti-balloon container as described heretofore, yet will remain within the scope of the invention.

Claims: - 9 - CLAIMS 1 - Spindle for a spinning machine or twisting frame, with associated anti-balloon container (18), wherein the spindle is assembled rotary on a support (15) pivoted on a shaft (16) of a spindle-bearing block (10) and is associated with means suitable to make it rotate, and wherein a cop (13) to wind the yarn (14) is suitable to be removably assembled on the spindle (11), the spindle being characterised in that the axis of the shaft (16) is substantially parallel to the axis of the spindle (11), therefore the support (15) is laterally movable with respect to the block (10) yet remaining substantially on the same plane, without inclinations of the axis of the spindle (11) , and that the tubular container (18) is mounted on the movable support (15) to be laterally displaced, without inclinations, together with the support (15) and the spindle (11) . 2 - Spindle as in Claim 1, characterised in that the support (15) , together with the container (18) and the spindle (11) , is pivotable with respect to the axis of rotation (16) . 3 - Spindle as in Claim 1, characterised in that the support (15), together with the container (18) and the spindle (11), can be laterally removed like a drawer. 4 - Spindle as in any claim hereinbefore, characterised in that the container (18) is mounted on a supporting plate (17) solidly attached to the movable support (15). 5 - Spindle as in any claim hereinbefore, characterised in that the container (18) includes corrugations (22) or similar on its inner wall. 6 - Spindle as in any claim hereinbefore, characterised in that it is axially lined by a sheath (23) with a thickness functionally correlated to the free space defined between the container (18) and the yarn (14) wound onto the cop (13) . - 10 - 7 - Spindle as in any claim hereinbefore, characterised in that at least a part of the container (18) is axially movable with respect to the spindle (11) . 8 - Spindle as in Claim 7, characterised in that the container (18) comprises two tubular parts, an inner (18a) and an outer (18b) coaxial to each other and axially sliding with respect to each other. 9 - Spindle as in Claim 8, characterised in that the inner part (18a) is attached on the support (15) and the outer part (18b) is suitable to slide axially between a first, raised working position, wherein it is in correspondence with the upper part of the cop (13), and an inactive position wherein it is arranged on the same level as the inner part (18a) , so as to leave the upper part of the cop (13) uncovered. 10 - Spindle as in Claim 9, characterised in that positioning means (24, 25, 26) are included in said parts (18a, 18b) of the container (18) to keep the outer part (18b) stably in each of the two positions, working and inactive. 11 - Spindle as in Claim 7, characterised in that the container (18) is attached to a rod (27) mounted on the support (15) so as to slide axially between a first, raised working position, wherein the container (18) is completely around the cop (13), and an inactive position wherein the container (18) is lowered, so as to leave at least the upper part of the cop (13) uncovered. 12 - Spindle as in Claim 11, characterised in that positioning means (28) are associated with the rod (27) to maintain it stably in each of the two positions, working and inactive . 13 - Spindle as in Claim 12, characterised in that the positioning means (28) comprise a pair of notches (30 and - 1 1 - 31) made on the rod (27) with which a spherical element (29), when thrust constantly theretowards, is suitable to cooperate.

Inventors: PETRAZ DANIELE, PETRAZ, DANIELE
Applicants: DADA SRL, PETRAZ DANIELE, DADA S.R.L., PETRAZ, DANIELE
Application year: 1999
Main classification: D01H7
IPC codes: D01H1, D01H7