EP1737774B1

EP1737774B1 - Yarn feeder

Info

Publication number: EP1737774B1
Application number: EP05733429A
Authority: EP
Inventors: Gerardo Salton
Original assignee: Iro AB
Current assignee: Iro AB
Priority date: 2004-04-21
Filing date: 2005-04-14
Publication date: 2009-09-02
Anticipated expiration: 2025-04-14
Also published as: CN1942382A; EP1737774A1; WO2005102892A1; CN1942382B; SE0401064D0

Description

The invention relates a yarn feeder according to the preamble of claim 1.
Depending on the yarn quality processed in the yarn feeder and/or depending on a yarn treatment with wax, oil or another substance, it is desirable to adjust the height position of the top surface of the reflector body accordingly and such that the top surface either protrudes beyond the adjacent storage surface, is essentially flush with the storage surface, or is set back in relation to the storage surface.
The yarn feeder according to the preamble of claim 1 known from US-A-4,936,356 has the reflector body mounted in the storage body reception by two bolts, metal washers and two counter nuts engaging at the lower side of the storage body reception on the bolts. Two operative positions of the top side of the reflector body in relation to an adjacent storage surface of the storage body are achieved by either placing the washers inside the reception or under the counter nuts. Adjusting the reflector body operative position is a tedious and time consuming procedure.
In the yarn feeder known from EP-A-0 811 573 , Figs. 3 and 6, the reflector body is mounted for radial continuous adjustments at both ends by two adjustment screws threaded into opposed end walls of the reception. At least one spring is compressed between the bottom of the reception and the lower side of the reflector body. Adjustments have to be carried out at both adjustment screws. In the embodiment of Fig. 7 adjustments can be carried out with a single adjusting screw against spring load.
EP-A-0,171,516 discloses a yarn feeder having several reflector bodies which are moveably provided in the storage body reception. Each reflector body is displaced in operation of the yarn feeder by the yarn windings, while the yarn windings are conveyed forward along the storage surface of the storage body. Detector elements located outside of the storage body scan the respective position of each reflector body and generate a signal when the reflector body changes position. Each reflector body is arranged such that it changes the position between two predetermined locations when the yarn windings are wiping over the protruding surface of the reflector body. A return spring urges the reflector body in a direction to a location where the surface of the reflector body protrudes beyond the adjacent storage body surface.
WO-A-02/052081 discloses to glue the reflector body into the storage body reception. The bolt is inserted into a through hole at the bottom of the storage body reception. The top side of the reflector body is adjusted flush with the adjacent storage surface. The gluing procedure is tedious and time consuming. Furthermore, it is difficult to precisely bring the top surface of the reflector body into a flush relation to the adjacent storage surface. The main drawback is, furthermore, that no subsequent height adjustment of the top surface in relation to the storage surface will be possible.
It is an object of the invention to improve a yarn feeder such that even minute height adjustments of the reflector body can be carried out simply and reliably.
Said object can be achieved by the features of claim 1.
Contrary to the know principle to carry out height adjustments of the reflector body by removing or inserting a rigid spacer element and contrary to the principle to permanently install the reflector body in one fixed operation position, the pre-loaded and resiliently compressible O-ring penetrated by the bolt allows to carry out height adjustments in a simple and reliable way. O-rings are available for fair costs in practically any suitable sizes and have good spring properties. O-ring deformation projections are provided at a bottom of the storage body reception and/or at the rear side of the reflector body. These deformation projections may be ribs of triangular or rounded cross-sections and extend essentially radially to the bolt. The projections are useful to achieve a relatively uniform spring constant for the pre-load of the O-ring and provide an anti-rotation function for the reflector body. When the reflector body has to be adjusted deeper in relation to the adjacent storage surface, the counter element forces the O-ring to yield and pulls the reflector body deeper inside. When the reflector element has to be adjusted higher, only the counter element has to be untightened such that the pre-loaded O-ring is set free to then lift the reflector body. The permanent co-action between the axial pre-load of the O-ring and the counter element ensures a stable operation position of the reflector body. Since the pre-loaded and axially compressible O-ring remains in the storage body reception for all operation positions of the reflector body, the adjustment procedure is considerably simplified, because the O-ring does not need to be removed for any height adjustment procedures. Furthermore, the pre-loaded and axially compressible O-ring allows to carry out extremely fine adjustments and hence allows to compensate for manufacturing tolerances of the storage body and/or the reflector body such that in a series of identical yarn feeders exactly the same operation positions of the reflector body can be set already at the manufacturing site. The shut-down time needed for a height adjustment or a height correction at the textile machine, respectively, which also means shut-down time for the textile machine, can be kept advantageously short. The fixation principle of the reflector body is equally suitable for weaving machine feeders and knitting machine feeders, or the like. The fixation principle, moreover, is of particular usefulness for storage bodies the storage surface of which is plasma coated, because the axially compressible O-ring permanently remaining below the reflector body allows to carry out even minute height adjustments to bring the top surface of the reflector body into the desired height position in relation to the surrounding plasma coated surface. Compared to the prior art solutions, the new fixation principle is very comfortable for the weaving operator or the knitting operator, respectively.
In order to improve the convenience for the manipulation of the fixation system, the reflector body is adjustable in predetermined steps. In this, the self-locking property of the fixation system is of advantage. A comfortable handling can be achieved by a snap-detent system provided, e.g. between the counter element and the lower side of the storage body reception.
In a preferred embodiment the bolt is provided with an exterior thread for a counter nut. The threaded connection is self-locking under the pre-load of the compressible O-ring. The thread allows a gradual fine adjustment, preferably assisted by the snap-detent system. The counter nut can be made of plastic material or may have a plastic material coat and an inserted threaded metal sleeve in order to save weight and to ensure long service life. A simple snap-detent system is achieved by circumferentially distributed depressions in the abutting surface of the counter nut and at least one projection at the lower side of the storage body reception. Each step can be felt when carrying out an adjustment. The detent system, additionally, improves the self-locking function.
As a precautionary measure hindering unauthorised personnel to unintentionally or intentionally carry out false adjustments, the counter nut may be provided in its outer coat with circumferentially distributed, axial engagement recesses. A special tool belongs to the yarn feeder allowing to properly adjust the reflector body by turning the special counter nut. The special tool engagement jaws fit into the engagement recesses of the counter nut. Preferably, inbuilt insertion stops define the proper position of the tool for adjustments.
Since a gap gauge belongs to the standard equipment of a measuring yarn feeder having a variable diameter drum and a radially adjustable stopper housing or stopping device, the special tool for rotating the counter nut of the fixation of the reflector body may be integrated into the gap gauge.
In another preferred embodiment the counter element is constituted by an eccentric body supported at anchors laterally protruding from the free end portion of the bolt. The eccentric body abuts at the lower side of the storage body reception and either has different flat abutment surfaces each with a different distance from the rotational axis of the eccentric body in order to pull the bolt further into the storage body reception or to further lift the reflector body with the help of the pre-load of the spacer element, or a cam surface which runs spirally and eccentrically with respect to the rotational axis of the eccentric body.
Expediently, the cam surface and/or the lower side of the storage body reception is provided with a structure in order to achieve a form-fit between the eccentric cam surface and the lower surface, and, preferably, in order to define different self-locked adjustment positions of the eccentric body and in turn of the reflector body.
Embodiments of the invention will be explained with the help of the drawings. In the drawings is:

Fig. 1: a side view of a front part of a yarn feeder,
Fig. 2: a cross-section of a storage body of the yarn feeder of Fig. 1,
Fig. 3: an explosive perspective view of the component group shown in Fig. 2,

Fig. 4: a perspective view of the embodiments of Figs 2 and 3 during a manipulating process,
Figs 5 & 6: a further embodiment in perspective view, and
Fig. 7: a side view of a further embodiment.

The invention will be explained for a so-called measuring yarn feeder for a jet weaving machine. However, the measuring yarn feeder is selected as an example only. The reflector body fixation principle instead can be employed in other types of yarn feeders, e.g. for other weaving machines or for knitting machines or the like.
A measuring yarn feeder F in Fig. 1 comprises a housing 1, a stationary storage body 2 and a stopper housing 3. The storage body 2 is of variable diameter. The stopper housing 3 is adjustable in radial direction in relation to the axis of the storage body 2 in order to adjust, as soon as a predetermined diameter of the storage body 2 has been adjusted, the radial position of the stopper housing 3 such that a yarn passing gap X between a storage surface 8 of the storage drum 2 and the stopper housing 3 always has a certain width. This measure conventionally is carried out with a gap gauge G (Fig. 4).
The stopper housing 3 contains a pin-shaped stop element 4 for co-operation with the storage body 2. The stop element 4 either is extended (as shown) and blocks the gap X, or is retracted and clears the gap.
In the embodiment shown the storage body 2 consists of several segments 6, 6'. The segment 6' is prepared for co-operation with the stopping device or stop element 4 and also for a co-operation with an optoelectronic reflection type sensor S, the emitting and receiving components of which are contained in the stopper housing 3. The segment 6' contains a reflector body R for the sensor S. Instead the storage body 2 could be a rod cage-like drum or a completely continuous drum. The reflector body R is mounted in a storage body reception 7, typically in a shallow depression corresponding in shape with the shape of the reflector body R. Depending on the yarn quality processed in the yarn feeder F and/or on the performance of the yarn feeder the top surface of the reflector body R has to be adjusted such that the top surface either is set back in relation to the adjacent storage surface 8, or is essentially flush with the storage surface 8, or is slightly protruding beyond the adjacent storage surface 8.
In order to allow the above-mentioned adjustments of the height position of the top surface of the reflector body R, an adjustable reflector body fixation system is provided, as shown in Figs 2-7.
In the sectional view of the segment 6' the top surface of the reflector body R is set back relative to the adjacent storage surface 8 by an amount -Y. The reflector body R has a foot part formed like a bolt 9 which penetrates a through hole in the bottom of the storage surface reception 7, which is a blind hole with an inner diameter slightly larger than the outer diameter of the reflector body R. The bolt 9 has a shaft 10 with an exterior thread for a counter element K abutting at a lower surface 14 of the storage body reception 7. The counter element K in the embodiment shown is a counter nut 11 having a special design. However, a regular counter nut as well could be used.
At the bottom of the storage body reception 7, preferably in a circumferential rounded groove, a spacer element D is provided between the rear side of the reflector body R and the bottom of the storage body reception 7. In the embodiment shown, the spacer element D is constituted by an O-ring 12 which is penetrated by the bolt 9. Instead several O-rings could be provided. It is important the spacer element D is resiliently compressible in axial direction and that the spacer element D always is kept under pre-load by the counter element K The spacer element D does not necessarily need that the bolt 9 penetrates it. Instead at least one spacer element D could be provided just beside the bolt 9.
At the rear surface of the reflector body R several deformation projections 13 are provided, e.g. ribs which extend essentially radially to the bolt 9 and which are of triangular or rounded cross-section. The projections 13 have dual function, because they influence the spring characteristic of the compressible spacer element D, and hinder an unintended rotation of the reflector body R during adjustments.
Furthermore, the counter nut 11 may have, as shown, circumferentially distributed, e.g. rounded, depressions 15 for a positive co-action with at least one projection 16 (Fig. 3) provided at the lower surface 14 of the storage body reception 7. The depressions 15 and the co-acting projection 16 constitute a snap detent system when rotating the counter nut 11 in discrete predetermined steps.
In the embodiment shown, the counter nut 11 may be made from plastic (injection mould part), preferably with an inserted threaded metallic sleeve for the co-operation with the exterior thread of the shaft 10. The coat portion of the counter nut 11 has circumferentially distributed, preferably regularly, axial recesses 17 each bounded by an insertion stop 18. The purpose of this design is to force an operator to use a special tool for adjustments and to prevent unauthorised personnel from carrying out false adjustments.
As already mentioned the gap X between the stopper housing 3 and the storage surface 8 needs to be adjusted whenever the diameter of the storage body 2 is changed. For this purpose, conventionally, a gap gauge G (Fig. 4) belongs to the equipment of the measuring yarn feeder F. In the embodiment shown, a special rotating tool T for rotating the specially designed counter nut 11 is integrated into the gap gauge G. The special tool T has a cut-out 20 and e.g. two engagement jaws 21 which fit into the axial recesses 17 of the counter nut 11 and can be seated on the engagement stops 18. The cut-out 20 and the engagement jaws 21 are formed in a free end 19 of the special tool T opposite to the gap gauge G.
In case of another type of a yarn feeder having no adjustable stopper housing, instead a special tool T without a gap gauge G could be provided as an equipment part of the yarn feeder.
In the embodiment of Figs 5 and 6 the counter element K is an eccentric body 23 designed for co-operation with the bolt 9 of the reflector body R. The bolt 9 is provided with e.g. two laterally protruding anchors 22 (fulcrum pins) at a free end portion of the bolt 9. The eccentric body 23 has a fork-like design with cut-outs 25 which fit on the anchors 22. Furthermore, the eccentric body 23 has a manipulating lever 24 and a plurality of flat cam surfaces or abutment surfaces 26 each of which has another radial distance from the fulcrum constituted by the cut-outs 25.
After the reflector body R is inserted into the storage body reception 7 (the through hole at the bottom allows to pass the anchors 22), the reflector body R is pressed in manually until the eccentric body 23 can be hooked over the anchors 22. Then one pair of the cam surfaces 26 abuts at the lower surface 14 of the storage body reception 7 in order to hold the reflector body R in a predetermined adjustment position. By tilting the eccentric body 23 until another cam surface 26 comes into engagement, different predetermined adjustment positions can be selected. The respective selected adjustment position is stabilised by the co-action between the cam surface 26 and the lower surface 14 and the pre-load of the spacer element D.
In the embodiment of Fig. 7 the eccentric body 23 is provided with a relatively continuous cam surface 27. The cam surface 27 may have a structure 28 with ribs or other form-fit components for co-action with the lower surface 14, which, preferably, also has a mating structure in order to achieve a self-locking function of the eccentric body 23 in each selected adjustment position of the reflector body R.
In another not shown embodiment the counter element K could be constituted by a sort of a counter nut co-operating with the bolt like a bayonet closure. In another embodiment, a wedge-shaped element could be used in order to change the operation position of the reflector body. The wedge-shaped element may be displaced e.g. laterally through the bolt 9 by an adjustment spindle.

Claims

Yarn feeder (F), comprising a storage body (2), at least one optoelectronic reflection sensor (S), and a reflector body (R) mounted in a storage body reception (7) such that the reflector body height is adjustable between different operation positions of the reflector body (R) in relation to an adjacent storage surface (8), the reflector body (R) being provided at a bolt (9) passing a spacer element (D) provided in the storage body reception, the bolt (9) being fixed by a counter element (K) provided on the bolt behind the storage body reception, characterised in that the spacer element (D) is a pre-loaded and resiliently compressible O-ring (12) which is penetrated by the bolt (9), and which remains in the storage body reception (7) for all operation positions of the reflector body (R), and that O-ring deforming projections (13) are provided at a bottom of the storage body reception (7) and/or at a rear side of the reflector body (R).
Yarn feeder as in claim 1, characterised in that the O-ring (12) deforming projections (13) are several ribs (13) of triangular or rounded cross-sections extending essentially radially to the axis of the bolt (9).
Yarn feeder as in claim 1, characterised in that the height position of the reflector body is adjustable in predetermined steps, predetermined by positively co-operating engagement elements (15,16; 28) provided at the counter element (K) and at the lower side (14) of the storage body reception (7), the elements jointly forming a snap-detent system (A) kept in engagement by the pre-load of the O-ring (12).
Yarn feeder as in claim 3, characterised in that the bolt (9) has a threaded shaft (10), and that the counter element (K) is a counter nut (11), preferably made from plastic material or equipped with a plastic material coat portion, and that the counter nut (11) is provided at an abutting counter nut surface with circumferentially distributed depressions, and that at least one protrusion at the lower side (14) of the storage body reception (7) is aligned with the moving path of the depressions, the depressions and the protrusion defining elements (15,16) of the snap-detent system (A).
Yarn feeder as in claim 4, characterised in that the coat portion of the counter nut (11) has circumferentially distributed, axial engagement recesses (17), preferably with inbuilt engagement stops (18), and that a special rotation tool (T) is provided for the counter nut (11), the tool (T) having at least two engaging jaws (21) for simultaneously engaging into engagement recesses (17) of the counter nut (11).
Yarn feeder as in claim 5, characterised in that the special rotation tool (T) is integrated into an end section of a gap gauge (G), preferably into a gap gauge (G) provided for an adjustment of a radial gap (X) between an adjustable stopper housing (3) and the storage body (2) of the yarn feeder (F).
Yarn feeder as in claim 1, characterised in that at least one laterally protruding anchor (22) is provided at a free end portion of the bolt (9), that an eccentric body (23) defining the counter element (K) is movably secured to the anchor (22), and that, preferably, the eccentric body (23) either has several abutment surfaces (26) at different radial distances from the rotational axis of the eccentric body, or a cam surface (27), respectively, and that the cam surface (27) and/or the lower side (14) of the storage body reception (7) is formed with a structure (28).