Yarn storage type yarn feeder

Abstract

This application relates to a yarn feeder of the storage type. A motorized winding device (16) winds a yarn coil onto a spool (12). A spacer (20) is provided with a series of fingers (26) that have an oscillating motion, causing the yarn coil to advance. The fingers (26) are connected to the spool (12) via a partially flexible joint (33) that prevents the fingers (26) from rotating and allows the oscillating motion. The hollow body (34) of the joint (33) is provided as a single piece, having an inner annular portion (36), an outer annular portion (40), and a middle portion (48). The inner annular portion engages the spool (12) in a manner that is axially free and integrally rotatable, the outer annular portion engages the fingers (26) in a manner that is axially free and integrally rotatable, and the middle portion is flexible in the longitudinal direction and substantially rigid when twisted.

Description

TECHNICAL FIELD

[0001] The present invention relates to an accumulation yarn feeder provided with spacing means for separating the loops of yarn wound on a drum. BACKGROUND

[0002] As is known, yarn feeders of the so-called "accumulation" type can comprise a drum on which a plurality of loops of yarn forming a reserve are wound. By traction of the ordinary downstream textile machine, the loops of yarn are unwound from the drum.

[0003] When the drum is empty, a motorized flywheel coaxial to the drum winds new yarn taken from an upstream supply bobbin onto said drum.

[0004] As is known, the yarn feeder can be provided with spacing means, the purpose of which is to keep the loops of yarn wound on the drum mutually and uniformly spaced, thus ensuring a smooth and regular unwinding of the yarn from the drum, also acting as control of the tension to which the yarn exiting said drum is subjected.

[0005] In a manner known per se, for example from EP 0829442 B1, the spacing means can comprise a hub freely fitted on a drive shaft which makes the flywheel rotate and supports a series of fingers which extend in a substantially longitudinal direction with respect to the axis of the hub and are inserted in corresponding longitudinal slits provided on the drum.

[0006] At least one rolling bearing and a bushing combined with the drive shaft are interposed between the hub and the drive shaft. The bushing has an external cylindrical surface having an axis inclined with respect to the axis of the drive shaft and engages with the inner ring of the bearing.

[0007] Thanks to the engagement of the hub with the bushing, the fingers perform an oscillating motion having a longitudinal component which causes a progressive advancement of the loops of yarn as they are wound onto the drum.

[0008] In order to prevent the rotation of the hub with respect to the drum and, at the same time, allow said oscillating motion of the fingers, said fingers are connected to the drum by a partially yielding joint.

[0009] In a known embodiment, the joint has a central tubular portion with a corrugated wall made of rubber, and two annular elements made of rigid plastic material, which are associated with opposite axial ends of the central tubular portion. Through the two annular elements, the joint is fixed respectively to the end of the finger and to the end of the drum.

[0010] In the known solution, the two annular elements are vulcanized on the central tubular portion.

[0011] As is known, this solution is praiseworthy because it greatly facilitates the assembly of the spacing device inside the drum, but it has the drawback that the processing to which the annular elements must be subjected and the subsequent vulcanization process are relatively expensive. SUMMARY

[0012] It is therefore the object of the present application to provide a yarn feeder of the cheese type, provided with a spacing device suitable for separating the coils of yarn wound on a drum, which is less expensive to manufacture than the known systems described above, but which is equally easy to assemble in the feeder drum.

[0013] This object and other objects that will become more apparent from the following description are achieved by the following aspects.

[0014] 1) A yarn feeder of the cheese type comprising a hollow drum and a spacing device, motorized winding means winding coils of yarn on said drum, said spacing device being provided with a series of fingers inserted in respective longitudinal slits of said drum and driven in an oscillating motion having a longitudinal component so as to cause a progressive advancement of said coils of yarn as they are wound on said drum, said fingers being connected to said drum by means of a joint that is partially soft, said joint being configured to prevent the rotation of said fingers with respect to said drum about the axis of said drum and to allow said oscillating motion, characterized in that said joint comprises a hollow body formed in a single piece and having:

[0015] - an internal annular portion provided with first rotational coupling surfaces that engage in an axially free per se manner with corresponding first rotational coupling counter-surfaces associated with said drum, so that said internal annular portion rotates integrally with said drum,

[0016] - an outer annular portion provided with a second rotary coupling surface which engages in an axially free manner per se with a corresponding second rotary coupling counter-surface associated with the finger, thus making the outer annular portion rotate integrally with the finger, and

[0017] - an intermediate portion which is soft in the longitudinal direction and substantially rigid when twisted.

[0018] 2) The yarn supply with creel according to 1), characterized in that the inner annular portion is clamped between a seat, which is associated with the drum, and a flange by means of clamping means.

[0019] 3) The yarn supply with creel according to 2), characterized in that the seat has a substantially tubular profile and is provided with a third rotary coupling surface aligned with the first rotary coupling surface; the first rotary coupling counter-surface is provided on a tubular extension of the flange and engages both the first and the third rotary coupling surfaces.

[0020] 4) The yarn supply with creel according to 3), characterized in that the first rotary coupling surface comprises a series of first internal longitudinal slots provided on the inner annular portion, the third rotary coupling surface comprises a series of second internal longitudinal slots provided on the seat, and the first rotary coupling counter-surface comprises a series of longitudinal protrusions which are inserted into the first and second internal longitudinal slots.

[0021] 5) The yarn supply with creel according to 4), characterized in that the second rotary coupling surface comprises a series of external longitudinal slots and the second rotary coupling counter-surface comprises a series of corresponding longitudinal ribs provided on the finger.

[0022] 6) The yarn supply with creel according to 5), characterized in that the external longitudinal slots are provided at the end of respective radial protrusions which extend integrally outward from the outer annular portion.

[0023] 7) The yarn supply with creel according to 3), characterized in that the clamping means comprise a bushing, which is internally threaded and is inserted into the seat, and a first screw, which is inserted into the flange and is screwed to one end of the bushing.

[0024] 8) The yarn-in-housing yarn feeder according to 7), characterized in that said support is fixed to the front wall of the bobbin by means of a second screw inserted in said front wall and screwed to the opposite end of said bushing.

[0025] 9) The yarn-in-housing yarn feeder according to 8), characterized in that said second screw is provided with a knob for manual tightening.

[0026] 10) The yarn-in-housing yarn feeder according to 1), wherein said finger is combined with a hub coaxial to said bobbin, characterized in that said outer annular portion is axially delimited by a flat surface facing said hub and provided with an annular groove engaging, for centering purposes, a corresponding annular lip axially extending from said hub.

[0027] 11) The yarn-in-housing yarn feeder according to 1), characterized in that said hollow body is made of a resiliently soft material.

[0028] 12) The yarn-in-housing yarn feeder according to 1), characterized in that said intermediate portion has a thin-walled profile extending in a radial direction.

[0029] 13) The yarn-in-housing yarn feeder according to 1), characterized in that said intermediate portion has at least one corrugation.

[0030] 14) The yarn-in-housing yarn feeder according to 2), characterized in that said support has a substantially tubular profile and said first rotary coupling counter surface is provided on said support.

[0031] 15) The yarn-in-housing yarn feeder according to 14), characterized in that said first rotary coupling surface comprises a series of first internal longitudinal notches provided on said inner annular portion and said first rotary coupling counter surface comprises a series of longitudinal protrusions provided on the tubular extension of said support and inserted in said first internal longitudinal notches. BRIEF DESCRIPTION OF DRAWINGS

[0032] The application will now be described in greater detail, with reference to some preferred but not exclusive embodiments thereof, shown by way of non-limiting example in the accompanying drawings, wherein:

[0033] Figure 1 is a perspective view of a yarn-in-housing yarn feeder of the type to which the present application relates;

[0034] Figure 2 is an exploded perspective view of an end portion of the yarn-in-housing yarn feeder of Figure 1 , in which the spacing device according to the present application is incorporated;

[0035] Figure 3 It is displayed separately. Figure 2 Exploded perspective view of the spacer device;

[0036] Figure 4 yes Figure 2 An axial sectional view of the end portion;

[0037] Figure 5 This is similar to another embodiment of the present invention. Figure 3 The view. Detailed Implementation

[0038] First refer to Figure 1 A typical yarn feeder 10 includes a hollow drum 12 adapted to carry multiple yarn loops (not shown) wound on the drum to form a yarn reservoir. When pulled by a typical downstream textile machine (not shown), the yarn is adapted to unwind from the drum 12. In a manner known per se, before being conveyed to the textile machine, the unwound yarn from the drum 12 passes through a weft brake 14, which controls the mechanical tension of the yarn. The weft brake 14 is not part of the purpose and objective of this invention; it can be of conventional type and therefore will not be described in detail herein.

[0039] When the drum 12 is emptied, a known winding device (which in this embodiment includes a motorized flywheel 16) winds new yarn taken from an upstream supply spool (not shown) onto the drum 12. The flywheel 16 rotates coaxially with the drum 12 under the drive of the motor 18.

[0040] The yarn feeder 10 is provided with a spacing device 20, which is used to keep the yarn loops wound on the drum 12 regularly spaced apart from each other, thereby ensuring that the yarn is smoothly and regularly unwound from the drum 12, and also to control the tension of the yarn through the weft braking device 14.

[0041] In a manner known per se, the spacer 20 may include a hub 22 from which a series of spokes 24 project radially, for example, five spokes 24 equidistant from each other at an angle. Each spoke 24 supports a corresponding finger 26 at its outer end, the finger 26 extending in a generally longitudinal direction relative to the axis of the hub.

[0042] The hub 22 is freely mounted on the drive shaft 30 that rotates the flywheel 16, wherein fingers 26 are inserted into corresponding longitudinal slits 28 provided on the drum 12. The fingers 26 are depicted as rotating integrally with the drum 12 in a manner that will be described in detail below. At least one rolling bearing (in this embodiment) Figure 4 The structure consists of two bearings 31 and a bushing 32 keyed to the drive shaft 30. Figure 3) placed between the hub 22 and the drive shaft 30.

[0043] In a manner that is per se conventional, the bushing 32 has an external cylindrical surface that engages the inner ring of the rolling bearing 31, which has an axis that is inclined with respect to the axis of the drive shaft 30.

[0044] The rotation of the bushing 32 imparts to the hub 22 and to the fingers 26, which are coupled thereto, an oscillating movement that has a longitudinal component. In a manner that is per se conventional, this oscillating movement causes a progressive advancement of the yarn loops as they are wound on the drum 12, by means of which the yarn loops remain regularly equidistant from one another.

[0045] The fingers 26 are connected to the drum 12 by means of a joint 33, which is configured to prevent the rotation of the fingers 26 about the axis of the drum 12 and at the same time to allow said oscillating movement.

[0046] The joint 33 according to the present application comprises a hollow body 34, which is formed as a single piece and has an internal annular portion 36, which is provided with a series of first internal longitudinal notches 38 that engage, in a manner that is per se axially free, with corresponding longitudinal protrusions 58 that are coupled to the drum 12, so that the internal annular portion 36 rotates integrally with the drum 12, an external annular portion 40, which is provided with a series of external longitudinal notches 42 that engage, in a manner that is per se axially free, with corresponding longitudinal ribs 46 that are provided on the fingers 26, so that the external annular portion rotates integrally with the fingers 26, and an intermediate portion 48, which is flexible in the longitudinal direction and substantially rigid when twisted.

[0047] Preferably, the internal annular portion 36 is axially blocked with respect to the drum 12 and, for this purpose, it is clamped between a seat 50, which is coupled to the drum 12, and a flange 54 by means of clamping means, which will be described in greater detail below.

[0048] In this embodiment, the seat 50 has a substantially tubular profile, is housed coaxially inside the drum 12, and has a series of second internal longitudinal notches 52 that are aligned with the first internal longitudinal notches Figure 3 ); the longitudinal protrusions 58 are provided on a tubular extension 56 of the flange 54 and engage both the first internal longitudinal notches 38 and the second internal longitudinal notches 52.

[0049] Preferably, the hollow body 34 is made of a material that can be elastically bent, advantageously neoprene or chlorobutadiene. Moreover, the intermediate portion 48 preferably has a thin-walled profile extending in the radial direction and at least one corrugation to ensure proper flexibility in the longitudinal direction.

[0050] Advantageously, for the purpose of lightening, the external longitudinal notch 42 is provided on the respective radial projection 57 that extends integrally outward from the external annular portion 40.

[0051] With reference to Figure 4 , the flange 54 has an external flat portion 54a and an internal tapered portion 54b that externally engages a corresponding bevel 59 provided on the internal tubular portion 36.

[0052] The clamping device comprises a bushing 60 with internal threading Figure 4 , housed in the seat 50 and coupled thereto, and a first screw 62 inserted in the flange 54 and screwed to one end of the bushing 60. Advantageously, as shown, a screw provided with a tapered head is used in order to engage the tapered portion 54b of the flange 54, thus ensuring correct centering.

[0053] The seat 50 is fixed to the front wall 12a of the drum 12 by means of a second screw 64 provided with a knob 66 for manual tightening. The second screw 64 is inserted in the front wall 12a and is screwed to the opposite end of the bushing 60 with respect to the first screw 62.

[0054] With particular reference to Figure 3 and Figure 4 , the external annular portion 40 of the hollow body 34 is axially delimited between a first flat end surface 40a facing the hub 22 and a second flat end surface 40b facing the front wall 12a of the drum 12. The first flat end surface 40a has an annular groove 68 that engages for centering purposes with a corresponding annular lip 22a extending axially from the end of the hub 22.

[0055] In the embodiment described herein, the seat 50 has an appendix 70 for supporting a sensor and any other accessory device outside the purposes and objects of the present application.

[0056] In operation, in a manner that is per se conventional, when the drive shaft 30 is turned in order to wind a new coil of yarn onto the drum 12 by means of the flywheel 16, the hub 22 and the fingers 26 that accompany it, the oscillating movement imparted by the bushing is performed, the hub 22 being fitted on the bushing by means of the rolling bearing 31.

[0057] The hollow body 34 prevents the rotation of the hub 22 and of the fingers 26 with respect to the reel 12, but allows the above-mentioned oscillating movement by deforming in the region of the intermediate portion 48.

[0058] In practice, it has been shown that the system according to the present application allows to fully achieve the intended purposes and objectives.

[0059] In particular, the spacing device 20, and in particular the joint 33, is very easy to assemble in the reel 12. For example, first the hollow body 34 can be fixed to the seat 50 by means of the flange 54 and the first screw 62. The thus assembled unit can then be fixed to the reel 12 by means of the second screw 64. Finally, the reel can be fixed to the body of the feeder 10. By placing the reel 12 axially adjacent to the body of the feeder 10, the external longitudinal notch 42 of the external annular portion 40 engages the longitudinal rib 46 of the finger 26, while the annular groove 68 engages the annular lip 22a of the hub 22, thus ensuring perfect centring.

[0060] The manufacture of the joint according to the present application does not require special treatments and is therefore much cheaper than the known solutions based on vulcanization treatments.

[0061] Figure 5 Another embodiment of the present application is shown, in which elements similar or identical to the previous embodiment are indicated by the same reference numerals increased by 100.

[0062] In particular, this embodiment differs from the previous one in that the longitudinal projection 158 engaging the first internal longitudinal notch 138 of the internal annular portion 136 of the hollow body 134 is provided on a tubular extension 156 which is combined with the seat 150 and in that the internal annular portion 136 is clamped between the seat 150 and the washer 154, the washer 154 replacing the flange in the previous embodiment by means of a screw 162 screwed on the tubular extension 156.

[0063] Some preferred embodiments of the present application have been described, but of course the skilled person in the art is able to make various modifications and variants within the scope of the claims.

[0064] For example, the longitudinal notches used as rotating coupling surfaces and the longitudinal projections and longitudinal ribs used as rotating coupling counter-surface can be interchanged. Moreover, the rotating coupling can be provided in different ways, for example by means of the engagement between polygonal surfaces.

[0065] Naturally, the mechanism generating the oscillation of the fingers is completely outside the purposes and objectives of the present application and can be provided in different ways from those described and illustrated by way of example, for example by means of a system based on cams or articulated levers.

[0066] The shape of the hollow body 34 can also be modified within the limits set by the claims. For example, depending on the available space, the intermediate portion can extend in the axial direction instead of radially as in the example described herein, and / or it can have a greater number of corrugations.

Claims

1. A yarn storage type yarn supply comprising a hollow bobbin (12) and a spacing device (20), a motorized winding device (16) winding yarn coils on the bobbin, the spacing device (20) being provided with a series of fingers (26) which are inserted into corresponding longitudinal slits (28) of the bobbin (12) and are driven in an oscillating movement having a longitudinal component in order to induce a progressive advancement of the yarn coils while being wound onto the bobbin (12), the fingers (26) being connected to the bobbin (12) by a partially flexible joint (33) which is configured to prevent the fingers (26) from rotating about the axis of the bobbin (12) relative to the bobbin (12) and to allow the oscillating movement, characterized in that, The joint (33) comprises a hollow body (34) formed as a single piece and having: - an inner annular portion (36) provided with a first rotary coupling surface (38) which engages in an axially free manner per se with a corresponding first rotary coupling counter-surface (58) associated with the reel (12), so that the inner annular portion (36) rotates integrally with the reel (12), - an outer annular portion (40) provided with a second rotary coupling surface (42) which engages in an axially free manner per se with a corresponding second rotary coupling counter-surface (46) associated with the finger (26), so that the outer annular portion (40) rotates integrally with the finger (26), and - an intermediate portion (48) which is soft in the longitudinal direction and substantially rigid when twisted.

2. The yarn supply of claim 1, wherein The inner annular portion (36) is clamped between an abutment (50) associated with the reel (12) and a flange (54) having an outer flat portion (54a) and an inner tapered portion (54b) which engages externally a corresponding bevel (59) provided on the inner annular portion (36).

3. The yarn supply of claim 2, wherein, The abutment (50) has a substantially tubular profile and is provided with a third rotary coupling surface (52) aligned with the first rotary coupling surface (38); the first rotary coupling counter-surface (58) is provided on a tubular extension (56) of the flange (54) and engages both the first rotary coupling surface (38) and the third rotary coupling surface (52).

4. The yarn supply of claim 3, wherein The first rotary coupling surface comprises a series of first internal longitudinal notches provided on the inner annular portion (36), the third rotary coupling surface comprises a series of second internal longitudinal notches provided on the abutment (50), and the first rotary coupling counter-surface comprises a series of longitudinal protrusions which are inserted into the first and second internal longitudinal notches.

5. The yarn supply of claim 4, wherein, The second rotary coupling surface comprises a series of external longitudinal notches, and the second rotary coupling counter-surface comprises a corresponding series of longitudinal ribs provided on the finger (26).

6. The yarn supply of claim 5, wherein, The external longitudinal notches are provided at the end of respective radial protrusions (57) which extend integrally outward from the outer annular portion (40).

7. The yarn supply of claim 3, wherein, The clamping device comprises a bushing (60) with internal threading and inserted into the abutment (50), and a first screw (62) inserted into the flange (54) and screwed to one end of the bushing (60).

8. The yarn supply of claim 7, wherein, Said support (50) is fixed to the front wall (12a) of the reel (12) by means of a second screw (64) which is inserted in the front wall (12a) and screwed to the opposite end of the bushing (60).

9. The yarn supply of claim 8, wherein, Said second screw (64) is provided with a knob (66) for manual screwing.

10. The stored-torque yarn supply of claim 1 wherein, Said fingers are associated with a hub (22) which is coaxial to the reel (12), characterized in that said outer annular portion (40) is axially delimited by a flat surface (40a) which faces the hub (22) and is provided with an annular groove (68) which engages, for centring purposes, a corresponding annular lip (22a) which axially extends from the hub (22).

11. The yarn supply of claim 1, wherein, Said hollow body (34) is made of a material which is elastically soft.

12. The yarn-in storage yarn feeder according to claim 1, characterized in that Said intermediate portion (48) has a thin-walled profile which extends in a radial direction.

13. The yarn supply of claim 1, wherein, Said intermediate portion (48) has at least one corrugation.

14. The yarn-in storage yarn feeder according to claim 1, characterized in that Said inner annular portion is clamped between a support, which is associated with the reel and has a substantially tubular profile, and a washer, and said first rotary coupling counter surface is provided on said support.

15. The yarn supply of claim 14, wherein, Said first rotary coupling surface comprises a series of first internal longitudinal notches (138) provided on said inner annular portion, and said first rotary coupling counter surface comprises a series of longitudinal protrusions (158) provided on a tubular extension (156) of said support (150) and inserted in said first internal longitudinal notches (138). Said first rotary coupling surface comprises a series of first internal longitudinal notches (138) provided on said inner annular portion, and said first rotary coupling counter surface comprises a series of longitudinal protrusions (158) provided on a tubular extension (156) of said support (150) and inserted in said first internal longitudinal notches (138).

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