Locating frame for units for drawing and compacting bundles of textile fibers

Information

  • Patent Grant
  • 6332246
  • Patent Number
    6,332,246
  • Date Filed
    Thursday, June 7, 2001
    23 years ago
  • Date Issued
    Tuesday, December 25, 2001
    22 years ago
Abstract
A locating frame for drawing and compacting units of a pair of adjacent spinning stations in a spinning machine where each drawing unit has a pressure roller which supplies the bundle of fibers to the compacting unit and which rotates a pressure roller of the compacting unit, by means of a belt transmission. The frame comprises: two pairs of seats for housing and keeping parallel and spaced apart two axles on which the pressure rollers of the drawing units and the pressure rollers of the compacting units of the two adjacent stations are mounted rotatably, longitudinal arms acting on the axles in order to keep the pressure rollers of the same spinning station aligned longitudinally, and transverse arms for keeping the transmission belts of the two adjacent stations, respectively, aligned with ring gears fixed for rotation with the pressure rollers.
Description




BACKGROUND OF THE INVENTION




The present invention relates to a locating frame for units for drawing and compacting bundles of textile fibres.




The field of application of the present invention is that of spinning machines provided with a plurality of adjacent spinning stations, in each of which there is a drawing unit associated with a compacting unit, for transforming a roving or bundle of textile fibres into a twisted yarn.





FIG. 1

is a partially-sectioned side view of a drawing and compacting unit of a spinning station in a spinning machine including a plurality of stations (not shown) disposed side by side in a direction defined herein as a transverse direction.




With reference to

FIG. 1

, a bundle of fibres or roving


1


is supplied to a drawing unit, generally indicated


2


, which usually comprises three pairs of members that draw the roving along at increasing linear velocities in order to attenuate it gradually.




In the drawing unit


2


, a first pair of rollers


3


,


4


takes up the roving at a controlled linear velocity. The roller


4


is rotated in accordance with the arrow A and the upper counter-roller


3


is freely rotatable on an upper support


5


in order to be pressed against the roller


4


with the crude roving interposed between them A second pair of members of the drawing unit comprises belts


6


,


7


, of which the lower belt


6


is circulated by a motor-driven roller


8


at a linear velocity greater than the output velocity of the first pair of rollers


3


,


4


, and the upper belt


7


is circulated about an idle roller


9


and a bar


10


, both mounted on the upper support


5


. A third pair of drawing members comprises an idle upper roller


12


, pressed against a lower roller


11


which is driven with a linear velocity greater than that of the second pair of drawing members.




The roving output by the drawing unit


2


then goes to a compacting unit


13


disposed downstream of the drawing unit, before being sent for twisting.




The compacting unit


13


comprises a lower, fixed tube


14


connected to a suction source; the tube


14


, which is common to several spinning stations disposed side by side, has a narrow suction slot


15


arranged on the path of the roving and along its direction of advance, in each station. A filter element


16


which preferably consists of a movable loop of flexible textile material that covers the corresponding slot


15


with a wide margin, is circulated about the fixed tube


14


by an upper pressure roller


19


of elastomeric material which presses the roving against the filter loop


16


.




The path of each filter loop


16


is defined by the upper surface of the tube


14


and by a guide bar


17


provided with a resilient element


18


for keeping the filter loop


16


taut.




As a result of the suction, the fibres of which the roving


1


is composed are drawn towards the slot


15


and are squeezed together and compacted transversely on the filter surface


16


.




The thread output from the compacting unit


13


is distributed and wound, in known manner, on a spindle (disposed downstream and not shown), rotated at high speed. The rotation of the spindle, drawing in the thread supplied by the drawing unit, drives a traveller which runs on a circular track of the spinning ring and produces a twist in the fibres, about the axis of the thread; the pressure exerted by the roller


19


prevents the twist which rises from the spindle from being propagated upstream of the point at which the thread is released by the roller


19


.




The pressure roller


19


is rotated by the last pressure roller


12


of the drawing unit, by means of a belt transmission


20


. The peripheral velocity of the pressure roller


19


is slightly greater than that of the rollers


11


,


12


to ensure that the roving is not too slack in the section in which it passes over the suction slot.




SUMMARY OF THE INVENTION




The object of the present invention is to ensure the correct location of the axles on which the pressure rollers of the last pair of members of the drawing unit and of the compacting unit are rotatable. In particular, it is desired to keep the axles of the above-mentioned pressure rollers correctly spaced and parallel.




Another object of the invention is to keep the belts which transmit the rotation from the last pressure roller of the drawing unit to the pressure roller of the compacting unit correctly aligned.




These objects are achieved, according to the present invention, by a device having the characteristics defined in claim


1


.




Further important characteristics of the invention are defined in the dependent claims.











BRIEF DESCRIPTION OF THE DRAWINGS




The characteristics and the advantages of the invention will become clear from the detailed description of an embodiment thereof, given with reference to the appended drawings provided by way of non-limiting example, in which:





FIG. 1

is a partially-sectioned side elevational view of drawing and compacting units of a known spinning station,





FIG. 2

is a partially-sectioned side elevational view of drawing and compacting units of a spinning station provided with a locating frame according to the invention,





FIG. 3

is an exploded perspective view showing the locating frame according to the invention, from below,





FIG. 4

is a perspective view showing the frame of the invention from below, in the assembled condition,





FIG. 5

is a side elevational view of the frame, assembled with a protective cover,





FIG. 6

is a view from above, taken on the arrow VI of

FIG. 5

,





FIG. 7

is a side elevational view of the frame, assembled with a cleaning roller, and





FIG. 8

is a view from above, taken on the arrow VIII of FIG.


7


.











DETAILED DESCRIPTION OF THE INVENTION




The general layout of the drawing and compacting units shown in

FIG. 2

can be considered generally known. Only elements of specific importance and interest for the purposes of the implementation of the present invention will therefore be described in detail below. For the construction of the parts and of the elements not described in detail, reference may therefore be made to a solution of the type described in the introductory portion of the description, or to any known spinning station.




With reference to

FIGS. 2

,


5


and


6


, in two adjacent spinning stations, the pressure rollers


12


and


19


are mounted rotatably by means of rolling-contact bearings (not shown for simplicity) on one end of respective axles


21


,


22


which carry, at their opposite ends, identical pressure rollers


12


,


19


of an adjacent spinning station. In greater detail, the rollers


12


,


19


are fitted tightly on cylindrical elements


23


,


24


fixed for rotation with the outer rolling rings of the above-mentioned bearings.




Each of the last pressure rollers


12


of the drawing unit of a spinning station rotates the next pressure roller


19


of the compacting unit by means of a toothed belt


20


wound around ring gears


25


,


26


fixed to or integral with the cylindrical elements


23


,


24


.




The axles


21


,


22


are mounted in a locating frame, generally indicated


27


(FIG.


3


).




In the preferred embodiment, the frame


27


comprises a body


28


of moulded plastics material which has a symmetrical structure with respect to a vertical and longitudinal median plane. The body


28


, which is shown separately in

FIG. 3

, is shaped in various ways so as to form two pairs of opposed lateral seats


29


,


30


for housing the axles


21


,


22


, an upper surface


31


arranged for the mounting of a protective cover or of a cleaning roller (as will be explained further below), and a lower surface


32


arranged for the mounting of a multifunctional locating element


40


.




The lateral seats


29


,


30


are in the form of inverted U-shaped recesses aligned in pairs parallel to a horizontal transverse axis (perpendicular to the direction of advance of the thread). In the preferred embodiment, the seats


29


,


30


are shaped so as to have a width corresponding to that of the axles


21


,


22


so as to house them with slight clearance or with minimal interference.




In the upper surface


31


of the body


28


there is a pair of holes


33


(

FIGS. 5 and 6

) for housing corresponding pins


35


projecting from the bottom of a substantially rectangular cover


34


. The cover


34


is of a size such as to cover the region between the two rollers


12


and


19


above the respective slots


14


in both adjacent spinning stations, to reduce the amount of dust drawn into the slot when the spinning machine is in operation.




Alternatively, as shown in

FIGS. 7 and 8

, the holes


33


may serve for the releasable mounting, on the locating frame


27


, of a bracket-like device


36


which extends vertically from the upper surface


31


of the body


28


in order to hold a cleaning roller


37


engaged on top of and straddling the two pressure rollers


12


and


19


of the same spinning station. The cleaning roller


37


, which is made of spongy material or the like, is freely rotatable and is forced to roll on the upper portions of the pressure rollers


12


,


19


, keeping them clean.




The upper surface


31


of the plastics body


28


is extended at the front to form an arcuate appendage


31




a


for covering and protecting the pressure rollers


19


of the compacting units of the two adjacent spinning stations and for preventing the formation of windings of fibres on the rubber rollers


19


.




In the embodiment shown, the pins


35


and the holes


33


constitute quick snap-engagement elements, but it is intended that they may be replaced by different releasable connection means, for example, of the threaded type.




A threaded hole


38


is formed centrally in the lower surface


32


of the body


28


, which is that facing the bundle of fibres, for the fixing of a cross-shaped, rigid, multifunctional element, generally indicated


40


, to the frame


27


, by means of a conical-headed fixing screw


39


; the cross-shaped element


40


has an upwardly-tapered frustoconical seat


41


in a baricentric position, for housing the head of the screw


39


.




As can best be seen in

FIG. 3

, the cross-shaped element


40


has a first, longitudinal pair of opposed and aligned arms


42


the ends


42




a


of which are shaped for engaging smaller-diameter central portions


21




a


,


22




a


of the axles


21


,


22


(

FIG. 4

) so as to keep these axles in correct transverse positions with the rollers


12


,


19


of both of the spinning stations arranged centrally on the path of the thread being compacted. The ends


42




a


of the longitudinal arms


42


are preferably chamfered at the bottom in directions substantially tangential to the surfaces of the central portions


21




a


,


22




a


of the axles


21


and


22


.




As can be seen in

FIG. 4

, the longitudinal arms


42


extend in a longitudinal direction in a manner such that their ends prevent the axles


21


and


22


from accidentally slipping out of the seats


29


and


30


during assembly or maintenance when the frame


27


is removed from the spinning machine.




The cross-shaped element


40


has a second, transverse pair of arms


43


which extend transversely beyond the toothed belts


20


so that the lower lengths


20




a


of the belts extend in respective arm portions


43




a


of reduced thickness which form lateral shoulder surfaces for keeping each belt correctly aligned in engagement with the ring gears


25


and


26


. The portions


43




a


of reduced thickness preferably have smooth and rounded surfaces to reduce the friction produced by the belts.




As shown in

FIG. 3

, a recessed region


44


is formed in the lower surface


32


of the body


28


for engaging the longitudinal arms


42


and/or the transverse arms


43


so as to keep the cross-shaped element


40


oriented in the longitudinal and transverse directions. To ensure and to regulate the tension of the transmission belts


20


, the recessed region


44


may have a depth such that the cross-shaped element


40


can be locked selectively at different levels according to the extent to which the screw


39


is screwed into the hole


38


. Tightening of the screw


39


thus determines the degree of tension in the belts


20


(FIG.


5


).




In order to mount the frame


27


on the spinning machine, a rear and central portion of the plastics body


28


(see

FIGS. 3

,


6


and


8


) has a recess


45


in which the front end of an arm-like portion


5




a


, which projects forwards from the upper support


5


(FIG.


2


), is fitted; the arm-like portion


5




a


forms a seat (not shown) which houses the axle


21


of the pressure rollers


12


of the drawing unit.



Claims
  • 1. A locating frame for drawing and compacting units of a pair of adjacent spinning stations in a spinning machine, in which a drawing unit associated with a compacting unit is provided in each station for drawing and compacting a bundle of textile fibres, and in which each drawing unit has a pressure roller from which the bundle of fibres is passed to the compacting unit and which rotates a pressure roller of the compacting unit, by means of a transmission belt, the frame comprising:two pairs of seats for housing and keeping parallel and spaced apart two axles on which the pressure rollers of the drawing units and the pressure rollers of the compacting units of the two adjacent stations are mounted rotatably, first transverse locating means spaced apart longitudinally and acting on the axles in order to keep the pressure rollers of the same spinning station aligned longitudinally, and second transverse locating means spaced apart transversely for keeping the two transmission belts of the two adjacent stations, respectively, aligned with engagement surfaces fixed for rotation with the pressure rollers.
  • 2. The locating frame of claim 1, wherein the two pairs of seats are formed in a body made of plastics material.
  • 3. The locating frame of claim 1, wherein the first transverse locating means comprise a pair of opposed and aligned longitudinal arms the ends of which can engage portions of differentiated diameter of the axles.
  • 4. The locating frame of claim 3, wherein the ends of the longitudinal arms are chamfered in directions substantially tangential to the surfaces of the engagement portions of the axles.
  • 5. The locating frame of claim 1, wherein the second transverse locating means comprise a pair of transverse arms having lateral shoulder surfaces for keeping each belt aligned and engaged with the engagement surfaces.
  • 6. The locating frame of claim 5, wherein the transverse arms have end portions of differentiated thickness which define the lateral shoulder surfaces.
  • 7. The locating frame of claim 6, wherein the end portions of the transverse arms have smooth and rounded surfaces for reducing friction against the belts.
  • 8. The locating frame of claim 1, wherein the first and second locating means comprise a pair of transverse arms and a pair of longitudinal arms formed by a substantially cross-shaped element which can be fixed to a lower surface of the body made of plastics material.
  • 9. The locating frame of claim 8, wherein at least one recessed region is formed in the lower surface of said body, for keeping the cross-shaped element oriented in the longitudinal and transverse directions.
  • 10. The locating frame of claim 2, wherein said body has an upper surface arranged for the releasable mounting of a cover of a size such as to cover the region between the two pressure rollers in the two adjacent spinning stations.
  • 11. The locating frame of claim 2, wherein said body has an upper surface arranged for the releasable mounting of a support device for holding a cleaning roller engaged on top of and straddling the two pressure rollers of the same spinning station.
  • 12. The locating frame of claim 2, wherein the upper surface of the plastics body is extended at the front to form an arcuate appendage for protecting the pressure rollers of the compacting units of the two adjacent spinning stations.
  • 13. The locating frame of claim 5, further comprising means for selectively adjusting the height of the transverse arms in order consequently to adjust the degree of tension in the belts.
Priority Claims (1)
Number Date Country Kind
T020A0548 Jun 2000 IT
US Referenced Citations (6)
Number Name Date Kind
2696643 Dolling et al. Dec 1954
4391021 Kamel Jul 1983
4551887 Uematsu Nov 1985
4768262 Gunter Sep 1988
5303454 Stahlecker et al. Apr 1994
5915510 Dinkelmann et al. Jun 1999