Apparatus for feeding strip materials to a winding machine

Abstract

The apparatus for feeding strip materials to a winding machine comprises a first group of unwinding rollers (11) of at least one flexible strip (2) and a second group of unwinding rollers (12) of said at least one flexible strip (2). Said first and second unwinding rollers (11, 12) are alternately associated with a folding bellows frame (10) extendable along a feeding direction of the strip material. Said folding bellows frame (10) is extendable between a first folded operating position, in which said unwinding rollers (11, 12) are arranged mutually approached, and a second stretched operating position along said feeding direction of the strip material. The folding bellows frame (10) is constrained at one end to said winding machine (20) so as to follow the alternating movement of the winding machine (20) itself between said first operating position and said second operating position.

Description

DescriptionAPPARATUS FOR FEEDING STRIP MATERIALS TO A WINDING MACHINETechnical field

[0001] The present invention relates to an apparatus for feeding strip materials to a winding machine.Prior art

[0002] It is currently known, in various technical fields, the need to wind one or more strip materials in order to obtain a cylindrical or similar winding. For example, in the field of electrical energy storage devices, it is known to use electric batteries consisting of a plurality of superimposed strip elements, forming at least an anode, a cathode and a separator element interposed between said anode and cathode. According to a widespread embodiment, said superimposed strip elements are wound so as to form a cylindrical or similar shaped cell, for example oval or prismatic. The strip elements are provided in the form of flexible strips that are unwound from respective reels.

[0003] A known process for making the aforementioned cylindrical windings involves feeding the strip elements to an area of a winding machine in which the same strip elements are superimposed on each other and associated, at the free end, with a spindle that is adapted to be set in rotation according to its longitudinal axis. The rotation of the spindle causes superimposed strips to be wound on it. When a portion with predefined length of the strips has been wound on the winding spindle, suitable cutting means intervene to cut the strips themselves.

[0004] According to a known embodiment, the winding spindle is formed by two halves, for example of semi-cylindrical or prismatic shape, adapted to be alternately approached and moved away from each other between a spaced position and an approached position. In the spaced position, it is possible to insert the free end of the strip elements between the two halves of the winding spindle; in the approached position, the strip elements are tightened, allowing the winding spindle to be rotatably driven to operate the winding of the strip elements themselves so as to form the cylindrical winding.

[0005] According to a known embodiment, the winding spindle is carried by a group of the winding machine which is movable with reciprocating translational motion along a direction substantially coinciding with the feeding direction of the strip materials, for example horizontal. In this way it is possible to lengthen or alternatively shorten, depending on the operating steps, the path of the strip materials in proximity to the aforementioned winding spindle. In this way, of course, by keeping the advancement speed of the strip materials constant, the time taken to complete the feeding of the same strip materials increases or decreases proportionally.

[0006] Figures 3 and 4 schematically illustrate an embodiment of the aforementioned solution, in which the group 20 of the winding machine bearing the winding head 21 is movable with reciprocating motion along a guide track 22 between two extreme positions. In the first position, the path of the strip materials 2 fed to the winding spindle associated with the head 21 is minimal; in the second position, the length of this path is the maximum expected.

[0007] A problem complained of in the use of the mentioned solution consists in the fact that the translation of the winding head and the corresponding lengthening of the path of the strip materials negatively affect the transverse stability of the advancing strip materials. During the translation step, in fact, the tension of the material is not kept constant and therefore relative slippage can occur between the strip materials and the rollers that guide the unwinding, due to the creation of an air gap between the same strip materials and the unwinding rollers. Obviously, this phenomenon can easily compromise the correct alignment of the strip materials during the winding, in particular in the case where said winding is composed of a plurality of strips superimposed on each other.Disclosure

[0008] The task of the present invention is to solve the aforementioned problems, by devising an apparatus that allows to optimally feed strip materials to a winding machine.

[0009] Within this task, a further object of the invention is to provide an apparatus for feeding strip materials to a winding machine that allows to obtain a perfect alignment of the superimposed strip materials.

[0010] Another object of the invention is to provide an apparatus that ensures the achievement of a high production speed.

[0011] A further object of the invention is to provide an apparatus for feeding strip materials to a winding machine that is of simple constructive and functional design, provided with reliable operation, versatile use, as well as relatively economical cost.

[0012] The aforementioned objects are achieved, according to the present invention, by the apparatus for feeding strip materials to a winding machine according to claim 1.

[0013] The winding machine comprises an operating group bearing a winding head of said strip materials and movable with reciprocating motion, variable as a function of the operating steps, along the feeding direction of said strip materials.

[0014] Said strip materials comprise at least one flexible strip.

[0015] Advantageously, said strip materials comprise a plurality of flexible strips adapted to be fed superimposed on each other to said winding machine.

[0016] The apparatus for feeding strip materials to a winding machine comprises a plurality of unwinding rollers of said at least one flexible strip to be fed to said winding machine.

[0017] According to the present invention, said plurality of unwinding rollers comprises a firstgroup of unwinding rollers of said at least one flexible strip and a second group of unwinding rollers of said at least one flexible strip.

[0018] Advantageously, said first group of unwinding rollers comprises a distal roller having a fixed position; a proximal roller constrained to said winding machine and movable integrally to the same winding machine; and a plurality of central rollers arranged between said distal roller and said proximal roller.

[0019] Preferably said central rollers are slidable along a longitudinal guide arranged according to said feeding direction of the strip material.

[0020] Said first and second unwinding rollers are alternately associated with a folding bellows frame extendable along a feeding direction of said at least one flexible strip.

[0021] According to one aspect of the present invention, said folding bellows frame is extendible between a first folded operating position, in which said unwinding rollers are arranged mutually approached, and a second stretched operating position along said feeding direction of said at least one flexible strip.

[0022] According to a prerogative of the invention, said unwinding rollers are arranged on said folding bellows frame in positions such as to keep the mutual distance with the adjacent unwinding rollers constant.

[0023] Said folding bellows frame is constrained at one end to said winding machine so as to follow the alternating movement of the winding machine itself between said first operating position and said second operating position along said feeding direction of said at least one flexible strip.

[0024] Advantageously, said folding bellows frame comprises a group of rods hinged in sequence to each other and bearing said unwinding rollers of said at least one flexible strip freely rotatable.

[0025] Preferably said group of rods hinged in sequence to each other comprises a plurality of rods carried slidable at a respective end on linear guide means along said feeding direction of the strip material.

[0026] Preferably said group of rods comprises first rods and second rods which at one end are alternately hinged to each other and at the opposite end bear respective first unwinding rollers freely rotatable.

[0027] Preferably, said rods that are carried slidable on said linear guide means bear at said end respective first unwinding roller freely rotatable.

[0028] Preferably said first rods and second rods are also alternatively hinged to each other in a substantially central position.

[0029] Preferably, at said substantially central hinging position, said first rods and second rods bear respective second unwinding rollers freely rotatable.

[0030] The present invention also relates to a method for feeding strip material to a windingmachine comprising the steps of a. arranging a first group of unwinding rollers and a second group of unwinding rollers of at least one flexible strip, said first and second unwinding rollers being alternately associated with a folding bellows frame extendable along a feeding direction of the strip material; b. constraining an end of said folding bellows frame to said winding machine; c. commanding in an operating step the alternating movement of said winding machine between a first operating position, in which said unwinding rollers are arranged mutually approached, and a second operating position, in which the unwinding rollers themselves are stretched along said feeding direction of the strip material.

[0031] Advantageously said step of c. commanding the alternating movement of said winding machine between said first operating position and said second operating position provides for c1. simultaneously operating the sliding of said folding bellows frame on linear guide means so as to operate its extension along said feeding direction of the strip material.Description of the drawings

[0032] The details of the invention will become more apparent from the detailed description of a preferred embodiment of the apparatus for feeding strip materials to a winding machine, illustrated by way of example in the accompanying drawings, in which: figures 1 and 2 respectively show a schematic side view of the apparatus for feeding strip materials to a winding machine according to the present invention, in different operating positions; figures 3 and 4 show a schematic side view of an apparatus for feeding strip materials of known type, in the mentioned different operating positions.Description of embodiment of the invention

[0033] With particular reference to these figures, the apparatus for feeding strip material 2 to an operating group 20 of the winding machine bearing the winding head 21 is indicated as a whole with 1. In the following, for simplicity’s sake, the operating group of the winding machine bearing the winding head is also referred to as the operating head.

[0034] In the illustrated case, two flexible strips 2 are simultaneously fed to the winding head 21 of the winding machine, according to parallel feeding directions. The two flexible strips 2 are fed, one superimposed on the other, to the winding head 21 of the winding machine which winds the superimposed strips, for example into a cylindrical shape.

[0035] However, it is possible to provide for a different number of flexible strips to be fed to the machine. For example, in the case of making windings for electrical energy storage devices, four flexible strips intended to be superimposed on each other are typically fed simultaneously to the machine.

[0036] The group 20 of the winding machine is movable along a guide track 22 with reciprocating motion, variable according to the operating steps.

[0037] The apparatus according to the present invention comprises, for each of said flexible strips 2 to be fed to the operating head 20, a plurality of unwinding rollers of the same flexible strip. In particular, the apparatus comprises a first group of unwinding rollers 11 and a second group of unwinding rollers 12 of said flexible strip 2. In the following, for simplicity's sake, said unwinding rollers of the first and second group will also be indicated as first unwinding rollers 11 and second unwinding rollers 12.

[0038] The first and second unwinding rollers 11 , 12 are alternately associated with a folding bellows frame 10, extendable along a feeding direction D of the strip material. The folding bellows frame 10 has a first end having a fixed end and a second end constrained to the group 20 of the winding machine, so as to follow the reciprocating motion imposed on the same group 20 of the winding machine. In particular, the first unwinding rollers 11 associated with the folding bellows frame 10 comprise a distal roller 11a having a fixed position; a proximal roller 11 b constrained to the group 20 of the winding machine and therefore movable integrally to said group 20 of the winding machine; and a plurality of central rollers 11c, slidable along a longitudinal guide 13 arranged according to said feeding direction of the strip material.

[0039] The distance X1 between the proximal roller 11 b and the operating head 20 is fixed.

[0040] In practice, the folding bellows frame 10 is extendable between a first folded operating position, in which said unwinding rollers 11 , 12 are arranged mutually approached (see fig. 1), and a second operating position, stretched along said feeding direction of the strip material (see fig. 2), in which the same unwinding rollers 11 , 12 are arranged in positions such as to keep the mutual distance RD with the adjacent rollers constant.

[0041] More particularly, the folding bellows frame 10 comprises a group of rods 14, 15 hinged in sequence to each other and bearing first and second unwinding rollers 11 , 12 freely rotatable. This group of rods comprises first and second rods 14, 15 which at one end are alternately hinged to each other and at the opposite end bear respective first unwinding rollers 11 freely rotatable; the first and second rods 14, 15 are also alternately hinged to each other in a substantially central position, at which they bear respective second unwinding rollers 12 freely rotatable.

[0042] The operation of the apparatus for feeding strip materials to a winding machine can be easily understood from the following description.

[0043] The flexible strips 2 are fed to the winding head 21 of the winding machine by unwinding on the rollers 11 , 12 according to the path defined by the rollers 11 , 12 themselves depending on the configuration assumed by the folding bellows frame 10. At the winding head 21 of the winding machine the flexible strips 2 are superimposed on each other andbrought into rotation, in a known manner, by the winding spindle of the machine. The winding spindle of the machine winds the superimposed flexible strips 2, for example into a cylindrical shape.

[0044] When the operation of the machine requires it, the movement of the operating group 20 of the winding machine along the guide track 22 is commanded, in particular starting from said first operating position, in which the unwinding rollers 11 , 12 are arranged mutually approached (see fig. 1). The movement of the operating group 20 of the winding machine causes the extension of the folding bellows frame 10, having a fixed end, at the distal roller 11a, and constrained at the opposite end to the same operating group 20 of the winding machine, at the proximal roller 11b. In this way the unwinding rollers 11 , 12 assume a stretched position along the feeding direction of the strip material (see fig. 2).

[0045] Of course, the movement in reverse direction of the operating head 20 causes the folding bellows frame 10 to return to the folded position.

[0046] In essence, the folding frame 10 with extendable bellows allows the unwinding rollers 11 , 12 of the flexible strips 2 to follow the movement of the operating head of the winding machine, according to the machine's requests.

[0047] The described apparatus achieves the purpose of optimally feeding the strip materials to a winding machine, in particular allowing to obtain a perfect alignment of superimposed strip materials.

[0048] This result is achieved thanks to the inventive idea of unwinding the strip materials by means of a series of rollers carried by a folding bellows frame in order to keep the mutual distance of each unwinding roller with the adjacent unwinding rollers constant. In this way, the production of relative slippage between the strip materials and the rollers that guide the unwinding, complained of in the prior art, is avoided.

[0049] The apparatus described by way of example is susceptible to numerous modifications and variations according to different needs.

[0050] In the practical implementation of the invention, the materials employed, as well as the shape and sizes, may be any according to requirements.

[0051] Where technical features mentioned in each claim are followed by reference marks, such reference marks have been included for the sole purpose of increasing the understanding of the claims and consequently they do not have any limiting value on the scope of each element identified by way of example by such reference marks.

Claims

1. An apparatus for feeding strip material to a winding machine, said apparatus comprising a plurality of unwinding rollers (11 , 12) of at least one flexible strip (2), said plurality of unwinding rollers (11 , 12) comprising a first group of unwinding rollers (11 ) of said at least one flexible strip (2) and a second group of unwinding rollers (12) of said at least one flexible strip (2), characterized in that said first and second unwinding rollers (11 , 12) are alternately associated with a folding bellows frame (10) extendable along a feeding direction (D) of the strip material; and in that said folding bellows frame (10) is constrained at one end thereof to an operating head (20) of said winding machine, so as to follow an alternating movement of the operating head (20) between a first operating position in which said unwinding rollers (11 , 12) are arranged mutually approached, and a second stretched operating position along said feeding direction of the strip material, wherein each of said unwinding rollers (11 , 12) is arranged in such a position as to keep the mutual distance (RD) with the unwinding rollers (11 , 12) immediately adjacent to them constant.

2. The apparatus of claim 1 , wherein said first unwinding rollers (11) associated with said folding bellows frame (10) comprise a distal roller (11a) having a fixed position; a proximal roller (11b) constrained to said operating head (20) of the winding machine and movable integrally with said operating head (20) of the winding machine; and a plurality of central rollers (11c), slidable along linear guide means (13) along said feeding direction of the strip material (D).

3. The apparatus of claim 1 or 2, wherein said folding bellows frame (10) comprises a group of rods (14, 14a, 14b, 15, 15a, 15b) hinged in sequence to each other and bearing said unwinding rollers (11 , 12) of said at least one flexible strip freely rotatable.

4. The apparatus of claim 3 when dependent on claim 2, wherein said group of sequentially hinged rods (14, 15) comprises a plurality of rods (14a, 14b, 15a, 15b) carried slidable on said linear guide means (13) at a respective end (16) bearing said central rollers (11c) freely rotatable.

5. The apparatus of claim 4, wherein said group of rods (14a, 14b, 15a, 15b) carried slidable on said linear guide means (13) comprises a first group of end rods (14a, 15a) whose length is substantially half with respect to a second group of intermediate rods (14b, 15b).

6. The apparatus of claim 3 or 4, wherein said group of rods (14, 15) comprises first rods (14, 14a, 14b) and second rods (15, 15a, 15b) which at one end are alternately hinged to each other and at the opposite end bear respective said first unwinding rollers (11 ) freely rotatable.

7. The apparatus of claim 6, wherein said first rods (14, 14a, 14b) and second rods (15, 15a, 15b) are further alternatively hinged to each other in a substantially central position.

8. The apparatus of claim 6 or 7, wherein said first rods (14, 14a, 14b) are configured to rotate integrally in a first direction when they are driven and in that said second rods (15, 15a, 15b) are configured to rotate integrally in a second direction, opposite to the first direction.

9. The apparatus of claim 6, wherein at said substantially central hinging position said first rods (14, 14a, 14b) and second rods (15, 15a, 15b) bear said second unwinding rollers (12) freely rotatable.

10. The apparatus of any one of the preceding claims, wherein said operating head (20) of the winding machine is movable with reciprocating motion along a guide track (22) between two extreme positions.

11. The apparatus of claim 10, wherein said guide track (22) is substantially parallel to the feeding direction (D) of the strip material.

12. A method for feeding strip material to a winding machine, said method being characterized in that it comprises the steps of: a. arranging a first group of unwinding rollers (11 ) and a second group of unwinding rollers (12) of at least one flexible strip (2), said first and second unwinding rollers (11 , 12) being alternately associated with a folding bellows frame (10) extendable along a feeding direction of the strip material; b. constraining an end of said folding bellows frame (10) to an operating head (20) of said winding machine; c. commanding in an operating step the alternating movement of said operating head (20) of the winding machine between a first operating position, in which said unwinding rollers (11 , 12) are arranged mutually approached, and a second operating position, in which the unwinding rollers (11 , 12) themselves are stretched along said feeding direction of the strip material.

13. The method of claim 12, wherein said step of c. commanding the alternating movement of said operating head (20) of the winding machine between said first operating position and said second operating position provides for c1. simultaneously operating the sliding of said folding bellows frame (10) on linear guide means (13) so as to operate its extension along said feeding direction of the strip material.

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