EP0484997A1

EP0484997A1 - Improvement in spinning machines with a pneumatic suction system for removing dust, fibre web and broken yarns

Info

Publication number: EP0484997A1
Application number: EP91202689A
Authority: EP
Inventors: Sandro Sartoni; Alessandro Mirri
Original assignee: Savio SpA; Savio Macchine Tessili SpA
Current assignee: Savio SpA; Savio Macchine Tessili SpA
Priority date: 1990-10-23
Filing date: 1991-10-16
Publication date: 1992-05-13
Also published as: IT9021825A0; IT9021825A1; IT1246306B

Abstract

The invention provides improvements in spinning machines (1) producing textile yarns and comprising a pneumatic system for removing dust, fibre web, broken yarn ends and the like, said improvements including a pneumatic system composed of two suction centres (3,6), one at each end of the spinning machine, each suction centre maintaining under vacuum a duct (2,4) which extends along one half of the entire spinning face and is arranged to remove dust, fibre web and yarn pieces from one half of the total number of spinning spindles (18).

Description

This invention relates to improvements in the pneumatic system provided for removing dust, fibre web and broken yarns in spinning machines, in particular ring spinning machines, which produce yarn for depositing on rod-shaped tubes in order to form wound yarn packages.
Said ring spinning machines comprise a plurality of working positions, normally on two opposing faces, and are therefore of considerable length.
Textile machines comprise suction ducts used for the most varying purposes, such as to clean determined parts of the machine, to remove fibre dust and to draw in excess yarn ends, cut-off yarn pieces and the like. It is well known that in drafting systems on spinning machines, a fibre sliver consisting of an assembly of fibres of a certain length is subjected to considerable traction with the result that a certain quantity of fibres, particularly the short fibres, separate to form dust. It is therefore necessary to clean the drafting components and to remove the spinning fly and dust from the various machine parts and from the yarn under formation. Any pieces of broken yarn also have to be drawn off. To achieve this, the suction action must be efficient and uniform along the entire spinning face. In addition, the spinning faces of ring spinning machines are known to extend horizontally for a considerable length, namely for several tens of metres, given that the number of spinning spindles can be of the order of one thousand, one following another.
The cross-section of the suction air duct and the power of the pneumatic system must therefore be relatively large, with a consequently high system and operating cost for this service. In addition, given the considerable length of ring spinning machines, the draw-off of dust, fibres. broken yarns etc. in known systems is insufficiently continuous in those regions furthest from the suction fan or other motorized device which provides the suction action. The air throughput in a centralized suction system in which a suction duct extending along the entire spinning face serves all the spinning spindles via suction nozzles or slots is equal to the total air quantity required to provide energetic suction action at all the spinning spindles.
To achieve proper pick-up of broken yarn and filament particles together with their effective conveying into the collection housing at the machine headstock where the suction fan and filters are located, the air velocity in the ducts and through the suction slots must be sufficiently high, and the vacuum produced must take account of the overall and localized pressure drops.
Known constructions suffer from problems such as the retention of a certain number of fibre and yarn pieces in the suction tubes acting on the spinning spindles located in the regions furthest from the fan in the machine headstock.
Fibres, dust and broken yarns which have not been properly drawn in by the suction tubes often trigger a build-up which obstructs the suction action required for continuous cleaning of the spindles, which then suffer from a progressive deposition of fibre dust on their various parts and on the yarn under formation. The result is that irregularities and defects appear in the yarn to the detriment of quality, such irregularities leading in the limit to yarn breakage either during its formation or during the subsequent yarn working stages. The reasons for all this are the provision of only one suction duct from which all the suction tubes extend, there being more than one for each spinning spindle, and the provision of only one suction fan, located only at the headstock end of the spinning machine. The provision of only one suction duct and suction fan do not sufficiently guarantee a substantially uniform suction along the entire spinning face, with the consequence that the fibrils and dust which deposit on the various spinning machine members are not effectively removed, so compromising proper spinning.
Secondly, the slots in the suction tubes, which are of narrow cross-section, easily and frequently clog due to the fact that the suction action is weak, so that the suction efficiency is considerably reduced after a few hours of operation, making frequent maintenance and cleaning of the suction slots necessary.
In addition, the said maintenance and cleaning of the suction slots requires considerable care by the service personnel, who are required to operate without any preprogrammed timing. It is a known fact that such random unprogrammed work results in low labour efficiency.
An object of the present invention is to provide a pneumatic system for removing fibre dust and broken yarn pieces in spinning machines which is free of the aforesaid drawbacks and is able to function with greater effectiveness and for a longer time, without requiring frequent maintenance.
A further object of the present invention is to rationalize the construction of the pneumatic system of a ring spinning machine, both in terms of its capacity and in terms of its suction efficiency in effectively removing the fibrils and flying yarn pieces from the spinning spindles. A further object of the present invention is to provide a pneumatic suction system which is of new conception while at the same time being simple, and offering the facility for applying suction to further additional regions which complete the entire suction requirement in terms of any further functions required by the particular application under way.
These and further objects of the invention, which will be apparent from the description, are attained by improvements in a pneumatic system in a spinning machine of considerable length, in particular a ring spinning machine, wherein said pneumatic suction system is composed of two suction centres, one at each end of the spinning machine, each suction centre maintaining under vacuum a duct which extends along one half of the entire spinning face and is arranged to operate on and serve substantially one half of the total number of spinning spindles of a ring spinning machine. Said ducts, one for each suction centre, are aligned and parallel to the machine axis, and are arranged one following the other along the entire spinning face. According to an advantageous embodiment the two suction ducts abut frontally in perfect collimation at the middle of the spinning face, they being separated hermetically at said middle by a plate inclined to the plane perpendicular to the axis of the ducts. According to a further embodiment, each suction duct comprises in proximity to said hermetic separator plate a gate for closing or opening the entry of external air so as to regulate the suction along the duct.
The invention is described in greater detail hereinafter with reference to the accompanying drawings, which show one embodiment thereof given by way of non-limiting example only.
Figure 1 is a schematic frontal view of the improved pneumatic suction system of a ring spinning machine according to the present invention, showing in particular the two motor-driven suction fans, one for each end of the spinning machine, each fan maintaining vacuum in one duct extending along one half of the entire spinning face.
Figure 2 is a schematic frontal section of Figure 1 taken on the line A-A, said section being taken in proximity to the middle of the spinning face at which both the inclined plate for hermetically separating the two suction ducts and the gates for closing and opening the entry of external air are located, the figure schematically illustrating a known spindle of a ring spinning machine with the overlying drafting unit.
In the figures, corresponding parts or parts with identical functions are indicated for simplicity by the same reference numerals.
The various units and equipment which in combination form the yarn in the ring spinning machine, in which the improved pneumatic suction system of the present invention is incorporated, are neither illustrated nor operationally described as they are already known, and are not involved in the improvement of the present invention.
In the accompanying figures:
1 schematically indicates the ring spinning machine which operates on two opposing faces comprising a large plurality of working positions and is hence of considerable length; 2 is the suction duct in which vacuum is created by the motor-driven fan 3, this latter being located and fixed at the end 5 of the spinning machine 1; 4 is the suction duct in which vacuum is created by the motor-driven fan 6, this latter being located and fixed at the end 7; 8 is the end gate of the duct 4, said gate 8 being movable horizontally by the service operator to open or close the entry of external air to regulate the suction along the duct; 9 is the sufficiently inclined plate located to substantially correspond with the middle of the entire spinning face of the spinning machine 1, said plate 9 hermetically separating the two suction ducts 2 and 4; 12 is the end gate of the duct 2, said gate 12 being movable horizontally by the service operator to open or close the entry of external air to regulate the suction along the duct; 14 and 16 are suction tubes extending from one of the two suction ducts 2 and 4, said tubes 14 and 16 each operating on one spinning face opposite the other. Said suction tubes 14 and 16 enter the suction duct advantageously inclined thereto both to a plane perpendicular to the axis of the spinning machine and to a plane parallel to said axis. The angles of inclination of the suction tubes 14 and 16 to said planes are such that the air in flowing from the tube slots and into the suction duct 2 or 4 does not undergo a sharp direction change, hence considerably reducing localized pressure drops. The entry slots in the suction tubes 14 and 16 lie in a position corresponding with and in proximity to the known ring of the spinning spindle 18, where a certain quantity of especially short fibres is present, together with the formation of dust and broken yarn pieces and the like. The entry slots in said suction tubes 14 and 16 can take varied geometrical forms, for instance a substantially circular or oval geometrical form, or an actual thin rectangular slit, or other forms; 11 and 15 are suction tubes flowing into one of the two suction ducts 2 and 4, said tubes 11 and 15 each operating on one spinning face opposite the other, they lying with their entry slots in a position corresponding with the region immediately below the exit rollers of the drafting unit 19 to effectively remove those fibres which separate from the fibre web in this region, as is well known to the expert of the art.
Said suction tubes 11 and 15 enter the suction duct advantageously inclined thereto in the same manner as described for the suction tubes 14 and 16. The entry slots in said suction tubes 11 and 15 can take varied geometrical forms, for instance a substantially circular geometrical form, or a horizontal or vertical thin rectangular slit, or other thin forms.
The operation of the improved pneumatic suction system of the present invention shown in the figures of the accompanying drawings is immediately apparent.
The fan housings 3 and 6 house the suction fans and the filter elements. The fibre dust and broken yarn pieces are drawn through the slots in the tubes 11, 15 and 14, 16 and pass from the suction ducts 2 or 4 to the respective housings 3 or 6 for collection, where they are retained by the filter surface. It is apparent that modifications can be made to the improvement in the pneumatic suction system proposed in the present invention, but without leaving the scope of the inventive idea.

Claims

Improvements in spinning machines producing textile yarns to be deposited on tubes in order to form wound yarn packages and which comprise a pneumatic system for removing dust, fibre web, broken yarn ends and the like, characterised in that said pneumatic system is composed of two suction centres, one at each end of the spinning machine, each suction centre maintaining under vacuum a duct which extends substantially along one half of the entire spinning face and is arranged to operate on and serve substantially one half of the total number of spinning spindles of a ring spinning machine.
Improvements in spinning machines producing textile yarns as claimed in claim 1, characterised in that the two ducts, one for each suction centre, are aligned and parallel to the machine axis, and are arranged one following the other along the entire spinning face.
Improvements in spinning machines producing textile yarns as claimed in claims 1 and 2, characterised in that the two ducts abut frontally in perfect collimation substantially at the middle of the spinning face, they being separated hermetically at said middle by a plate inclined to the plane perpendicular to the axis of the ducts.
Improvements in spinning machines producing textile yarns as claimed in claim 1, characterised in that each duct comprises in proximity to the hermetic separator plate a gate for closing or opening the entry of external air so as to regulate the suction along the duct.