WO2011042298A1

WO2011042298A1 - Winding device for winding a strip of fabric or knitted material or the like on a roller, particularly for circular knitting machines

Info

Publication number: WO2011042298A1
Application number: PCT/EP2010/063919
Authority: WO
Inventors: Ettore Lonati; Tiberio Lonati; Fausto Lonati
Original assignee: Santoni S.P.A.
Priority date: 2009-10-07
Filing date: 2010-09-21
Publication date: 2011-04-14
Also published as: ITMI20091711A1; CN102548878B; IT1396191B1; CN102548878A

Abstract

A winding device for winding a strip of fabric or knitted material or the like on a roller, particularly for circular knitting machines, comprising a frame (2) which supports, so that it can rotate about its own horizontally arranged axis (3 a), a takeup roller (3) onto which the strip (4) of fabric or knitted material or the like is designed to be wound, and at least one winding roller (5), which is supported so that it can rotate about its own axis (5a), which is arranged parallel to the axis (3a) of the takeup roller (3), by the frame (2) and can be actuated with a rotary motion about its own axis (5a) with respect to the frame (2), the takeup roller (3) resting, with the interposition of the strip (4) wound onto it, on the winding roller (5) for transmission of the rotation of the winding roller (5) to the takeup roller (3) and being movable with respect to the winding roller (5) along a vertical direction as the winding diameter of the strip (4), varies, the device comprising means for limiting the winding torque transmitted by the winding roller (5) to the takeup roller (3) so as to obtain a uniform winding and avoid stressing the fabric or knitted material or the like during its winding.

Description

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WINDING DEVICE FOR WINDING A STRIP OF FABRIC OR KNITTED MATERIAL OR THE LIKE ON A ROLLER, PARTICULARLY FOR CIRCULAR KNITTING MACHINES

Technical field

The present invention relates to a winding device for winding a strip of fabric or knitted material or the like on a roller, particularly for circular knitting machines.

Background art

As is known, circular knitting machines are usually provided with a knitting takedown device, which is arranged below the needle cylinder of the machine and applies to the knitted item being formation a downward traction which is necessary in order to ensure correct formation of the item.

Usually, these takedown devices comprise a pair of rollers, with mutually parallel horizontal axes, between which the knitted item, constituted by a flattened tubular body, is made to pass, and one of these two rollers is motorized so as to apply, in cooperation with the other roller, traction to the item.

Laterally to the motorized roller, on the opposite side with respect to the roller that cooperates with it in the traction of the knitted item, another roller is generally arranged which has the function of increasing the winding angle of the knitted item on the motorized roller and to guide the knitted item toward a takeup roller arranged below the takedown device.

The takeup roller is part of a winding device that is located below the takedown device and generally comprises a frame which supports, so that it can rotate about its own horizontally arranged axis, the takeup roller onto which the knitted item must be wound and at least one winding roller that is also supported so that it can rotate about its own axis, which is arranged parallel to the axis of the takeup roller, by the frame itself. The winding roller can be actuated with a rotary motion about its own axis with respect to the frame and the takeup roller rests, with the interposition of the item that winds onto it, on the winding roller, so that the rotary motion of the winding roller is transmitted, by contact, to the takeup roller, causing the progressive winding of the knitted item onto it. The takeup roller is movable with respect to the winding roller along a vertical direction as the winding diameter of the knitted item varies, so as to allow the progressive winding of the knitted item onto it while maintaining contact with the winding roller in a downward region.

The use of these devices has highlighted a variability in the tensioning of the item during its winding, which causes an uneven winding of the item on the takeup roller.

Moreover, because of this tensioning variability, an excessive stretching of the knitted item may occur during its winding onto the takeup roller. This excessive stretching may result, for example, from an excessive rotation rate of the takeup roller with respect to the rate at which the machine forms the item and from an excessive torque transmitted by the winding roller to the takeup roller.

This excessive stretching, in the case of particularly delicate items, can damage the item or permanently deform it.

Disclosure of the invention

The aim of the present invention is to solve the problem mentioned above, by providing a winding device for winding a strip of fabric or knitted material or the like on a roller, particularly for circular knitting machines, which avoids effectively an excessive tensioning of the strip of fabric or knitted material or the like during winding.

Within this aim, an object of the invention is to provide a device that ensures extremely uniform winding of a strip of fabric or knitted material or the like on a takeup roller.

Another object of the invention is to provide a device capable of winding a strip of fabric or knitted material or the like on a takeup roller with almost no traction applied to the strip. Another object of the invention is to provide a device that is structurally simple and can be manufactured with competitive costs.

Another object of the invention is to provide a device that is highly precise and reliable in use.

This aim and these and other objects that will become better apparent hereinafter are achieved by a winding device for winding a strip of fabric or knitted material or the like on a roller, particularly for circular knitting machines, which comprises a frame which supports, so that it can rotate about its own horizontally arranged axis, a takeup roller onto which the strip of fabric or knitted material or the like is designed to be wound and at least one winding roller, which is supported so that it can rotate about its own axis, which is arranged parallel to the axis of said takeup roller, by said frame and can be actuated with a rotary motion about its own axis with respect to said frame, said takeup roller resting, with the interposition of said strip wound onto it, on said winding roller for transmission of the rotation of said winding roller to said takeup roller and being movable with respect to said winding roller along a vertical direction as the winding diameter of said strip varies, characterized in that it comprises means for limiting the winding torque transmitted by said winding roller to said takeup roller.

Brief description of the drawings

Further characteristics and advantages of the invention will become better apparent from the description of a preferred but not exclusive embodiment of the device according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a partially exploded perspective view of the device according to the invention;

Figure 2 is a side elevation view of the device according to the invention;

Figure 3 is a sectional view of Figure 2, taken along the line ΙΙΙ-ΙΠ; Figure 4 is a sectional view of Figure 2, taken along the line IV-IV; Figure 5 is a front elevation view of the device according to the invention;

Figures 6 and 7 are schematic views of the device according to the invention and of a takedown device, illustrating the operation of the device according to the invention.

Ways of carrying out the invention

With reference to the figures, the device according to the invention, generally designated by the reference numeral 1 , comprises a frame 2 which supports, so that it can rotate about its own horizontally arranged axis 3 a, a takeup roller 3 onto which the strip 4 of fabric or knitted material or the like is designed to be wound. The device also comprises a winding roller 5, which is supported so that it can rotate about its own axis 5a, which is arranged parallel to the axis 3a of the takeup roller 3, by the frame 2 itself and can be actuated with a rotary motion about its own axis 5a with respect to the frame 2. The takeup roller 3 rests, with the interposition of the strip 4 wound onto it, on the winding roller 5 so that the rotation of the winding roller 5 is transmitted, by contact, to the takeup roller 3. The takeup roller 3 is movable with respect to the winding roller 5 along a vertical direction as the winding diameter of the strip 4 varies.

According to the invention, the device comprises means for limiting the winding torque that is transmitted by the winding roller 5 to the takeup roller 3.

More particularly, the frame 2 is composed of a lower profile 6, which is arranged substantially horizontally and from which two vertical shoulders 7, 8 rise which are mutually connected, at their upper end, by horizontal bars 9, 10. The shoulders 7 and 8, if the device according to the invention is designed to be mounted on a circular knitting machine, can have, in an upward region, arms 1 1, 12 for connecting the frame 2 to the needle cylinder of the machine. The frame 2 supports, proximate to the upper end of the shoulders 7, 8, a takedown device 40, of a known type, for example a takedown device of the type disclosed in PCT/EP2010/054796 by the same Applicant, which is composed of three adjacent rollers, respectively: a motorized central roller 13, a contact roller 14 arranged on one side of the central roller 13 and a guiding roller 15 arranged on the other side of the central roller 13. The rollers 13, 14 and 15 are arranged so that their axes are mutually parallel and horizontal and the strip 4 to be wound onto the takeup roller 3 passes between the contact roller 14 and the central roller 13 and then passes between the central roller and the guiding roller 15 to reach finally the takeup roller 3, which is supported by the frame 2 so that its axis 3 a is parallel to the axes 13a, 14a, 15a of the rollers 13, 14, 15 of the takedown device 40.

The takeup roller 3 is composed of a cylindrical jacket 20, onto which the strip 4 is designed to be wound and which is closed, at its axial ends, by portions of shaft or coaxial pivots that constitute the axial ends 21 , 22 of the takeup roller 3. These axial ends 21, 22 of the takeup roller 3 are each coupled, so that they can slide, to a corresponding vertical guide 23, 24, which is fixed to the corresponding shoulder 7, 8.

The means for limiting the winding torque comprise at least one pinion 25, 26, which is connected to the takeup roller 3 and meshes with a rack 27, 28 that is fixed to the frame 2 and is extended vertically. The pinion 25, 26 is connected to the takeup roller 3 by means of a unidirectional motion transmission device 29, 30, which is adapted to jointly connect the pinion 25, 26 to the takeup roller 3 in the rotation about its axis 3a in the direction of rotation that produces an unwinding of the strip 4 from the takeup roller 3 and to disengage the pinion 25, 26 from the takeup roller 3 in the rotation about its axis 3a in the opposite direction of rotation. The rack 27, 28 is coupled to the pinion 25, 26 and is arranged with respect to it so as to obtain a rise of the pinion 25, 26 along said rack 27, 28 when the pinion 25, 26 rotates jointly with the takeup roller 3 by way of the action of the unidirectional motion transmission device 29, 30.

Conveniently, the means for limiting the winding torque comprise a pinion 25, 26 which meshes with a corresponding rack 27, 28 and a corresponding unidirectional motion transmission device 29, 30 arranged between the pinion 25, 26 and the takeup roller 3 for each one of the axial ends 21 , 22 of the takeup roller 3.

The unidirectional motion transmission device 29, 30 is preferably constituted by a device of the freewheel type.

Conveniently, each pinion 25, 26 is fitted coaxially on the corresponding axial end 21 , 22 of the takeup roller 3 and the unidirectional motion transmission device 29, 30 is interposed between the takeup roller 3 and the pinion 25, 26.

A portion of the pinions 25, 26, at each axial end 21, 22 of the takeup roller 3 is also coupled slidingly with the guide 23, 24 in order to guide the vertical translation of the takeup roller 3 following its progressive increase in diameter caused by the winding of the strip 4 onto it.

The winding roller 5 may be actuated in a manner similar to what is disclosed in PCT/EP2010/054796 with reference to the takedown device 40, i.e., by means of a spring 51 which is connected, with one of its ends, to an annular body 52 fixed coaxially to an axial end of the winding roller 5. The spring 51 is engaged with the annular body 52 in a region that is spaced from the axis 5a of the winding roller 5 and the other end of the spring 51 is connected to the frame 2, optionally with the possibility to adjust the tension of the spring 51 in order to vary the force with which said spring acts on the winding roller 5. The spring 51 is reloaded cyclically by way of the actuation of a fluid-operated cylinder 53, which is connected, by means of its body, to the frame 2 and acts, by means of the stem 54 of its piston, on a region of the annular body 52 that is spaced from the axis 5 a of the winding roller 5 in contrast with the action of the spring 51 in a manner similar to the actuation of the takedown device disclosed in PCT/EP2010/054796, assumed included herein by reference and to which reference is made for the sake of completeness.

As an alternative, the actuation of the winding roller 5 can be obtained by way of other actuation means of a known type, such as for example an electric motor connected with its output off shaft to the winding roller 5.

For the sake of descriptive completeness, it should be noted that the frame 2 can be supported also by means of a lower supporting element 60, which supports the frame 2 so that it can rotate about a vertical central axis which, in the installation of the device on the knitting machine, will be arranged at the axis of the needle cylinder in order to allow the frame 2 to rotate together with the needle cylinder of the knitting machine.

Operation of the device according to the invention is as follow.

At the beginning of the winding of the strip 4 on the takeup roller 3, said roller is arranged so that its axial ends 21, 22, and therefore the pinions 25, 26, are proximate to the lower end of the racks 27, 28. The strip 4 of fabric or knitted material or the like that arrives from the takedown device 40 is wound for an initial portion onto the takeup roller 3, which due to its own weight rests on the winding roller 5. The rotary actuation about its own axis 5a of the winding roller 5 causes, by contact, the rotation of the takeup roller 3 about its own axis 3a and therefore the progressive winding onto it of the strip 4 that comes from the takedown device 40. As a consequence of the progressive winding of the strip 4 onto the takeup roller 3, there is a progressive increase in the diameter of the assembly constituted by the takeup roller 3 and the strip 4 wound onto it, with the consequent rise of the takeup roller 3 with its axial ends 21, 22 along the guides 23, 24 and of the pinions 25, 26 along the racks 27, 28. It should be noted that during the winding of the strip 4 onto the takeup roller 3, the takeup roller 3 rotates with respect to the pinions 25, 26 in the winding direction that achieves its disengagement, by the unidirectional motion transmission devices 29, 30, in the rotation about the axis 3a of the takeup roller 3, from the pinions 25, 26 that mesh with the racks 27, 28.

If, during the winding of the strip 4 onto the takeup roller 3, an excessive tension T of the strip 4 occurs upstream of the takeup roller 3, i.e., between the takeup roller 3 and the takedown device 40, and if said tension T develops a lifting force F greater than the weight P of the assembly constituted by the takeup roller 3 and the strip 4 wound onto it, this tension would tend to turn the takeup roller 3 in the opposite direction with respect to the direction of winding. In this situation, the unidirectional motion transmission devices 29, 30 intervene by jointly connecting the takeup roller 3 for rotation about its axis 3a (clockwise in Figures 6 and 7) to the pinions 25, 26, which by being coupled to the racks 27, 28 cause the temporary rise of the takeup roller 3 with respect to the winding roller 5, thus limiting the torque that is transmitted by the winding roller 5 to the takeup roller 3.

More particularly, with reference to Figures 6 and 7, the unidirectional motion transmission devices 29, 30 intervene, rigidly coupling the pinions 25, 26 to the takeup roller 3 in the rotation about its own axis 3 a, when the tension T of the strip 4 is such that F > P.

where:

C_R = T · R

T = C_r / r

F = T · R / b

F = C_R - R / r - b

If the winding roller 5 is actuated by using a spring 51 as shown, C_r is the torque generated by the spring 51, i.e., the force developed by the spring 51 for its arm with respect to the axis 3a.

The disengagement of the takeup roller 3 from the winding roller 5 during the operation of the knitting machine is only temporary, because the progress in the production of the strip 4 reduces the tension T and thus the force F, restoring the resting of the takeup roller 3 on the winding roller and disengaging, in the rotation about the axis 3a, the pinions 25, 26 from the takeup roller 3.

With the device according to the invention, by selecting adequately he value of the torque C_r applied to the winding roller 5 it is possible to wind a strip 4 onto the takeup roller 3 uniformly and with almost no tension T.

In practice it has been found that the device according to the invention fully achieves the intended aim, since it allows to wind a strip of fabric or knitted material or the like onto a takeup roller in a uniform manner and by limiting the tension of the strip during its winding and thus preventing the strip from being subjected to unwanted deformations or damage.

The device thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims; thus, for example, the winding roller 5 can also be replaced with two winding rollers with parallel axes, on which the takeup roller 3 is rested. All the details may further be replaced with other technically equivalent elements.

In practice, the materials used, as well as the dimensions, may be any according to requirements and to the state of the art.

The disclosures in Italian Patent Application No. MI2009A00171 1 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A winding device for winding a strip of fabric or knitted material or the like on a roller, particularly for circular knitting machines, comprising a frame (2) which supports, so that it can rotate about its own horizontally arranged axis (3a), a takeup roller (3) onto which the strip (4) of fabric or knitted material or the like is designed to be wound and at least one winding roller (5), which is supported so that it can rotate about its own axis (5a), which is arranged parallel to the axis (3a) of said takeup roller (3), by said frame (2) and can be actuated with a rotary motion about its own axis (5a) with respect to said frame (2), said takeup roller (3) resting, with the interposition of said strip (4) wound onto it, on said winding roller (5) for transmission of the rotation of said winding roller (5) to said takeup roller (3) and being movable with respect to said winding roller (5) along a vertical direction as the winding diameter of said strip (4) varies, characterized in that it comprises means for limiting the winding torque transmitted by said winding roller (5) to said takeup roller (3).

2. The device according to claim 1, characterized in that said means for limiting the winding torque comprise at least one pinion (25, 26), which is connected to said takeup roller (3) and meshes with a rack (27, 28) which is fixed to said frame (2) and is extended vertically, said at least one pinion (25, 26) being connected to said takeup roller (3) through a unidirectional motion transmission device (29, 30), which is adapted to jointly connect said at least one pinion (25, 26) to said takeup roller (3) in rotation about its axis (3a) in the direction of rotation that produces an unwinding of said strip (4) from said takeup roller (3) and to disengage said at least one pinion (25, 26) from said takeup roller (3) in rotation about its own axis (3 a) in the opposite direction of rotation, said rack (27, 28) being coupled to said at least one pinion (25, 26) for a rise of said at least one pinion (25, 26) along said rack (27, 28) in its rotation jointly with the rotation of said takeup roller (3) by way of the action of said unidirectional motion transmission device (29, 30).

3. The device according to claims 1 and 2, characterized in that said means for limiting the winding torque comprise a pinion (25, 26) which meshes with a rack (27, 28) and a corresponding device (29, 30) for unidirectional motion transmission between the pinion (25, 26) and the takeup roller (3) for each one of the axial ends (21 , 22) of said takeup roller (3).

4. The device according to one or more of the preceding claims, characterized in that said unidirectional motion transmission device (29, 30) is a device of the freewheel type.

5. The device according to one or more of the preceding claims, characterized in that said pinion (25, 26) is fitted coaxially on an axial end (21, 22) of said takeup roller (3), said unidirectional motion transmission device (29, 30) being interposed between said takeup roller (3) and said pinion (25, 26).

6. The device according to one or more of the preceding claims, characterized in that the axial ends (21, 22) of said takeup roller (3) are accommodated so that they can slide in vertical guides (23, 24) which are jointly connected to said frame (2).

7. The device according to one or more of the preceding claims, characterized in that said winding roller (5) is actuated with a rotary motion about its own axis (5a) by means of a spring (51), which is reloaded cyclically by a fluid-operated cylinder (53).

8. The device according to one or more of the preceding claims, characterized in that said spring (51) is connected with one of its ends to an annular body (52) fixed coaxially to said winding roller (5); said spring (51) being connected with one of its ends to a region of said annular body (52) that is spaced from the axis (5a) of said winding roller (5) and with its other end to said frame (2); said fluid-operated cylinder (53) being connected with its body to said frame (2) and acting with the stem (54) of its piston on a region of said annular body (52) that is spaced from the axis (5a) of said winding roller (5) in contrast with the action of said spring (51).