Journal for a film roll and film roll assembly having a journal

Abstract

The bearing pin (3) comprises a fastening section (I) with an insertion sleeve (5) and a bearing section (II). In the area of ​​the insertion sleeve (5), several barbs (13) are arranged distributed over the circumference of a wall of the insertion sleeve (3), these barbs (13) projecting radially outwards from the wall of the insertion sleeve (5), and at least a part of the barbs (13) are connected to the wall (7) of the insertion sleeve (5) via elastically deformable connecting sections (15).

Description

[0001] The invention relates to a bearing journal for a film roll and a film roll arrangement with a bearing journal.

[0002] Foil rolls typically comprise a cardboard core onto which, for example, a strip of cling film, aluminum foil, baking paper, or generally a strip of a sheet material is wound.

[0003] These rolls of film are typically mounted in dispenser housings or dispenser units so they can rotate freely. Through a dispensing opening in these housings, end sections of film can be pulled off the wound-up film supply and separated for further use.

[0004] It is known to arrange bearing pins on the end sections of the core sleeve of the film rolls for easy rotatable storage of film rolls in dispenser housings.

[0005] From DE202005021166U1, an end plug for a material roll is known. This plug comprises a bearing journal for rotatably mounting the material roll in a dispenser housing and, opposite this, a cylindrical section that can be inserted into an end section of a core sleeve of the material roll. Several longitudinal ribs project radially from the outside of the cylindrical section, distributed around its circumference. Towards the axially inner end, the projection height of the longitudinal ribs decreases in a ramp-like manner. Adjacent to this end, the height of the longitudinal ribs essentially corresponds to the inner diameter of the core sleeve. At the front end of the cylindrical section, a flange or shoulders formed on the longitudinal ribs project, which limit the insertion depth when the end plug is inserted into the core sleeve. Several wedge-shaped anchor sections also project radially from the cylindrical section and slightly above the level of the longitudinal ribs.They penetrate the material of the core sleeve and secure the end plug in the core sleeve.

[0006] DE1461745A1 discloses a film dispensing device with a container for receiving a film roll. The container has the shape of a cylindrical segment. End pieces are connected to a cardboard core at the ends of the film roll. The end pieces include grooved gripping elements that project beyond the container ends and facilitate grasping the film end for pulling film sections from the container by manual rotation. To connect the end pieces to the core, the end pieces internally include a hollow pin whose outer diameter essentially corresponds to the inner diameter of the core. The hollow pin includes ribs or teeth for creating a rigid connection with the core. Between the gripping elements and the hollow pin, the end pieces each include a section with an annular groove for receiving the end sections of the container. The annular grooves define a sliding guide for rotatably supporting the film roll with the attached end pieces.

[0007] One problem with these known end pieces is that, due to tolerances in the inner diameters of the core sleeves, they do not provide a reliable fastening or securing mechanism. Torque and axial forces acting between the end pieces and the core sleeve can cause the core sleeve to be damaged by the locking elements of the end pieces, leading to the loosening of the connections between the parts.

[0008] One object of the present invention is therefore to create a bearing journal that can be easily and securely connected to the core sleeve of a film roll and a film roll arrangement with such a bearing journal.

[0009] These problems are solved by a bearing journal for a film roll according to the features of claim 1 and by a film roll arrangement with such a bearing journal according to the features of claim 11.

[0010] The bearing journal comprises a mounting section with a cylindrical insertion sleeve and a bearing section axially adjacent to the mounting section. The outer diameter of the insertion sleeve essentially corresponds to the inner diameter of the core tubes of film rolls in which the bearing journal can be used. Such core tubes are made of cardboard. Their inner diameters may deviate from the specified value due to manufacturing tolerances. For a core tube with a specified inner diameter of, for example, 40 mm, the tolerance can be approximately + / - 1 mm. The actual value can therefore lie between the minimum value of 39 mm and the maximum value of 41 mm. The outer diameter of the insertion sleeve is at least approximately equal to, or slightly smaller than, the minimum inner diameter of the core tubes in which the insertion sleeve can be used.For a bearing journal intended for use with a core sleeve with an inner diameter of 40 mm + / - 1 mm, the outer diameter of the insertion sleeve can be, for example, on the order of 38.6 mm + / - 0.1 mm. This ensures that insertion sleeves can be fitted into the end sections of the bearing journals of each of the intended core sleeves.

[0011] In the area of ​​the insertion sleeves, each bearing journal comprises several barbs. These protrude radially outwards from the insertion sleeve. The barbs are distributed around the circumference of the insertion sleeve in such a way as to support coaxial alignment and securing of the bearing journal to the core sleeve. A forward portion of the bearing journal, or the insertion sleeve itself, is inserted axially into an end region of the core sleeve. At the rear end, relative to the insertion direction, the insertion sleeve includes at least one radially projecting shoulder. When the insertion sleeve is inserted into the core sleeve, this shoulder, through its positive engagement with the end face of the core sleeve, defines the final position of the bearing journal and prevents the bearing journal from being inserted too far into the core sleeve. The shoulder can, for example, be the outer edge of a reinforcing ring or plate at the rear end of the insertion sleeve.Alternatively, one or more radially projecting steps could be arranged distributed around the circumference of the insertion sleeve at its rear end.

[0012] Preferably, at least three, e.g., four or six, preferably evenly distributed around the circumference, toothed areas are defined on the insertion sleeve, in which barbs are formed. Such toothed areas can be defined on the insertion sleeve, for example, by a mean angular position relative to a predefinable reference angular position along the circumference. Optionally, toothed areas can also be defined by angular ranges around such mean angular positions. Toothed areas extend in the axial direction over at least a portion of the total length of the insertion sleeve.

[0013] The maximum radial projection of the barbs beyond the wall of the insertion sleeves is dimensioned such that the corresponding maximum outer diameter of the bearing journals in the area of ​​the barbs themselves, taking into account all manufacturing tolerances, is always larger than the maximum possible inner diameter of the core sleeve.

[0014] The barbs are connected to the wall of the insertion sleeve in all or at least some of the toothed areas via elastically deformable connecting sections. These connecting sections can include self-supporting supports exposed by recesses in the wall of the insertion sleeve. The supports can, in particular, be exposed sections of the wall of the insertion sleeve or comprise such sections.

[0015] The insertion sleeve includes reinforcing elements axially in front of and behind the recesses, such as annular end sections of the wall and / or reinforcing plates, for example, in the shape of a circle or annulus. These reinforcing elements ensure high dimensional stability of the insertion sleeve. Under radial pressure in the area of ​​the supports with the barbs, the supports are primarily deformed elastically. Outside the supports, the deformation of the insertion sleeve due to force applied to the supports is significantly less.

[0016] The barbs are preferably teeth or rows of teeth arranged opposite each other in the area of ​​the exposed end edges of the supports for anchoring the supports to the wall of the insertion sleeve.

[0017] The teeth are preferably sawtooth-shaped, particularly with cross-sections in the form of right-angled triangles. The longest sides of these triangles are ramps arranged at the front of the insertion sleeve in the insertion direction, inclined at an acute angle to the wall of the insertion sleeve. When inserted into a core sleeve, the compressive forces exerted by the core sleeve on the ramps cause the teeth to deform elastically slightly radially inwards. This enables and facilitates the insertion of the insertion sleeves until the shoulder at the rear end of the insertion sleeve abuts the core sleeve face-up.

[0018] The elastic restoring force of the carriers is sufficiently large that the comparatively hard teeth, at least in the area of ​​their tips on the inside, can dig into the wall of the less rigid cardboard core sleeve. This interlocking creates a positive connection between the insertion sleeve and the core sleeve. Pull-out forces acting on the insertion sleeve axially opposite to the insertion direction reinforce the interlocking and secure the insertion sleeve in its final position against the core sleeve.

[0019] The teeth typically have a thickness of approximately 0.75 mm to approximately 2 mm, preferably approximately 0.8 mm to approximately 1.2 mm, and particularly approximately 1 mm. This ensures that commercially available cardboard core sleeves are not permanently damaged by the teeth when the insertion sleeve is inserted, and that the teeth allow for a secure anchoring of the bearing pin to the core sleeve in its final position.

[0020] Preferably, the bearing pins or at least the insertion sleeves, the supports and the barbs are manufactured as one-piece injection-molded parts from a polymer, in particular from polyethylene (PE) or polypropylene (PP).

[0021] In some embodiments of the bearing pin, the barbs or teeth on the supports can protrude radially in different directions, e.g. orthogonally to the wall of the insertion sleeve.

[0022] Preferably, at least some of the barbs or teeth are arranged in one or more parallel planes. This significantly simplifies the molds for manufacturing the bearing journals as injection-molded parts and keeps manufacturing costs low. Furthermore, teeth that protrude from the wall of the insertion sleeve at an angle between the orthogonal and tangential planes have the property of providing improved engagement and securing of the insertion sleeve against rotation in the respective direction of rotation.

[0023] In some embodiments of the bearing journal, the barbs or teeth in one or more toothed sections can project rigidly, without elastically deformable connecting sections, directly from the wall of the insertion sleeve. The wall of the insertion sleeve can, for example, comprise two, three, or four such rigid toothed sections. Preferably, these rigid toothed sections are arranged alternately between each pair of toothed sections with elastically deformable connecting sections. The radial projection of the barbs beyond the wall of the insertion sleeve is preferably, for example, by a factor of 0.2 to 0.5 smaller in the rigid toothed sections than in the elastically deformable connecting sections.This ensures that the insertion sleeve can be easily inserted into a cardboard core sleeve despite the lower elasticity of the rigid toothed areas, and that the barbs of rigid toothed areas still allow for good securing of the bearing journals to such core sleeves.

[0024] Exemplary embodiments of the invention are described in more detail with reference to several figures. Figure 1: A perspective view of an arrangement with a bearing journal and the end of a core sleeve of a film roll; Figure 2: The perspective view of the arrangement. Figure 1 , wherein the bearing journal is attached to the core sleeve, Figure 3 shows the arrangement cut in longitudinal direction from Figure 2 Figure 4 shows a front view of the cutaway arrangement made of Figure 3 Figure 5 shows another perspective view of the bearing journal. Figure 1 Figure 6 shows a top view of the bearing journal. Figure 5Figure 7 shows a side view from the left of the bearing journal. Figure 6 Figure 8 shows a front view of the bearing journal. Figure 6 Figure 9 shows another bearing journal in perspective view, Figure 10 shows another perspective view of the bearing journal from Figure 9 .

[0025] Figure 1 Figure 1 shows an end section of a core sleeve 1 and a bearing journal 3 in perspective. The bearing journal 3 includes an insertion sleeve 5, which can be inserted into the end section of the core sleeve 1 in an insertion direction shown by arrow P1 in order to connect the bearing journal 3 to the core sleeve 1.

[0026] The insertion sleeve 5 comprises a cylindrical wall 7, the outer diameter D1 of which essentially corresponds to the inner diameter D2 of the core sleeve 1 or, taking into account all manufacturing tolerances, is at most equal to or slightly smaller than the inner diameter D2 of the core sleeve 1 ( Figure 4Typical inner diameters D2 of core sleeves 1 are, for example, approximately 40 mm or approximately 25 mm. Examples of tolerance ranges for such core sleeves are D2 = 40 mm + / - 1 mm or D2 = 25.4 mm + / - 0.1 mm. The tolerances are usually in the range of approximately + / - 0.5% to approximately 3% of the respective nominal value.

[0027] The bearing journal 3 comprises at least one stop 9 adjacent to the wall 7 of the insertion sleeve 5 at its rear, the stop projecting radially beyond the cylindrical wall 7. When the insertion sleeve 5 is pressed into the core sleeve 1 along a sleeve axis A, provided that this sleeve axis A and the axis of symmetry of the core sleeve 1 are coaxially aligned, this stop 9 defines the final position of the insertion sleeve 5 by bearing against the end face of the core sleeve 1, thereby preventing further penetration into the core sleeve 1. As in the illustrated embodiment of the bearing journal 3, the stop 9 can, for example, comprise an annular disc whose projection beyond the cylindrical wall 7 is typically about 5% to about 15% of the outer radius R1 or half the outer diameter D1, and in particular about 10%.

[0028] The ring disc or the area with the stop 9 divides the bearing pin 3 axially into a front mounting section I with the insertion sleeve 5 and a rear bearing section II.

[0029] Figure 2 shows the arrangement with the bearing pin 3 and the core sleeve 1. Figure 1 , wherein the insertion sleeve 5 of the bearing pin 3 is fully pressed into the core sleeve 1 up to the stop 9 in insertion direction P1. Figure 3 shows the perspective arrangement cut along the sleeve axis A. Figure 2, Figure 4 a longitudinal section.

[0030] In the area of ​​the insertion sleeve 5, the bearing pin comprises 3 anchoring elements in the form of barbs 13, which are connected to the wall 7 of the insertion sleeve 5 via elastically deformable connecting sections 15. In the Figures 1 to 8In the illustrated embodiment of the bearing journal 3, the cylindrical wall 7 of the insertion sleeve 5 comprises six approximately rectangular plates as connecting sections 15, each separated on three sides from adjacent areas of the wall 7 by recesses 17 and connected to the wall 7 on one side. The connecting sections 15 are therefore self-supporting beams, with one or more barbs 13 or teeth arranged at the free ends of these beams.

[0031] In the illustrated embodiment of the bearing pin 3, the insertion sleeve 5 comprises six areas with barbs 13 arranged evenly around its circumference. The barbs 13 are arranged in three parallel planes E1, E2, E3 ( Fig. 7 ) arranged.

[0032] In two connecting sections 15, which are diametrically opposed to each other in the central plane E1, in which the sleeve axis A also lies, a row of barbs 13 projects radially from the insertion sleeve 5, essentially orthogonal to the plane of the associated connecting section 15 and to the wall 7. The barbs 13 are designed as teeth in the form of right-angled triangles, with the rear edge of each triangle projecting orthogonally to the sleeve axis A from the insertion sleeve 5 in the insertion direction P1. The longest side of each triangle forms a ramp that is inclined at this point at an angle α of preferably about 15° to about 45° relative to a tangent plane of the insertion sleeve 5. The radial projection H1 of the barbs 13 beyond the wall 7 of the insertion sleeve 5 is preferably on the order of about 1.5 mm to about 2.5 mm and is, for example, about 2 mm.

[0033] When the insertion sleeve 5 is inserted or pressed into the end section of a core sleeve 1 in the insertion direction P1, the ramps of the barbs 13 successively contact the end face of the core sleeve 1. This causes a radially inward force component at each connection section 15. As a result, the connection sections 15 are elastically deformed, and the barbs 13 are displaced radially inward, allowing the insertion sleeve 5 to be inserted into the core sleeve 1 until it reaches the stop 9. The barbs 13 are pressed radially outward against the inner surface of the core sleeve 1 by the elastic restoring force of the connection sections 15. The restoring force depends on parameters such as the material and wall thickness of the insertion sleeve 5, as well as the lengths and widths B1, B2 of the connection sections 15, and can be predetermined by appropriately selecting the values ​​of these parameters.During movements in the insertion direction P1, the comparatively small angles of attack α of the ramps mean that the barbs 13 offer little resistance, and that the insertion sleeve 5 can be inserted into the core sleeve 1 with comparatively little effort.

[0034] If, on the other hand, a pull-out force acts on the bearing pin 3 in the opposite direction to the insertion direction P1, the tips of the barbs 13 dig into the core sleeve 1 on the inside and thereby reliably secure the bearing pin 3 in its final position.

[0035] In the connecting sections 15, which are opposite each other in the two lateral planes E2 and E3, the connecting sections 15 and the barbs 13 project in the respective planes E2 and E3. Relative to the tangential planes of the insertion sleeve 5 at these points, the planes E2 and E3, in which the connecting sections 15 and barbs 13 project from the insertion sleeve 5, are inclined at an angle β, which, depending on the position of the respective plane E2 and E3, is, for example, on the order of approximately 10° to approximately 45°. The width B2 of the connecting sections 15 is dimensioned such that the radial projection H2 of the barbs 13 in the lateral planes E2 and E3 corresponds at least approximately to the radial projection H1 of the barbs 13 in the central plane E1.The barbs 13 on the connecting sections 15 in the lateral planes E2, E3 are preferably designed and aligned similarly or identically to the barbs 13 on the connecting sections 15 in the middle plane E1.

[0036] When the insertion sleeve 5 is inserted into the core sleeve 1, the connecting sections 15 with the barbs 13 in the lateral planes E2, E3 are elastically deformed inwards, analogous to those in the central plane E1. Due to the inclination angle β of the connecting sections 15, these sections, or rather the barbs 13 arranged at the ends of the connecting sections 15, also lie at an angle on the inside of the core sleeve 1. This facilitates insertion into the core sleeve 1. If, however, a pull-out force opposite to the insertion direction P1 acts on the bearing pin 3 in the final position of the insertion sleeve 5, the tips of the barbs 13 dig into the core sleeve 1 from the inside, thereby reliably securing the bearing pin 3 in its final position.

[0037] The connecting areas 15 arranged in each of the lateral planes E2, E3, with opposing barbs 13, additionally provide improved security against rotations of the bearing journal 3 about the sleeve axis A. Due to the applied torque, the tips of the barbs 13, arranged at the front according to the respective direction of rotation, penetrate the core sleeve 1 from the inside, thereby reliably securing the bearing journal 3 in its end position against rotations about the sleeve axis A.

[0038] At its leading end (P1 in the insertion direction), the insertion sleeve 5 comprises a continuous stabilizing ring 19 adjacent to the recesses 17. This stiffens the insertion sleeve 5 and improves its stability. When the insertion sleeve 5 is pressed into a core sleeve 1, a compressive force with a radially inward force component acts on the barbs 13. This causes the connecting sections 15 to deform elastically radially inward. Due to their higher stiffness and stability, the adjacent areas of the insertion sleeve 5 are not deformed, or only minimally so. They form a stable base to which the connecting sections are linked. This allows for better coordination and control of the forces exerted by the barbs 13 on the inside of the core sleeve 1 when an insertion sleeve 5 is inserted.

[0039] The elastic restoring forces of the connection areas 15 can be matched to the core sleeves 1 in such a way that the insertion sleeves 5 can be inserted into such core sleeves 1 relatively easily and can be reliably secured in the final position by interlocking the barbs 13 with the softer material of the core sleeve 1.

[0040] The bearing journals 3 are preferably manufactured in one piece as injection-molded parts, e.g. from polyethylene or another thermoplastic material that is harder than the material of the core sleeve 1.

[0041] The arrangement of the connection areas 15 with the barbs 13 in parallel planes E1, E2, E3 has the additional advantage that the injection molds can be manufactured more easily and cost-effectively.

[0042] Adjacent to the mounting section I, bearing pins 3 in the bearing section II can be configured as desired according to the requirements of different operating locations. In the embodiment of a bearing pin 3 shown in the figures, it comprises, in the insertion direction P1, a first cylindrical section 21 with a small outer diameter D3 and, axially adjacent to the stop 9, a second cylindrical section 23 with a larger outer diameter D4. This allows for the simple rotatable mounting of a film roll with a core sleeve 1, to whose ends the bearing pins 3 are attached, in dispenser housings with differently designed bearing elements. Between the cylindrical sections 21 and 23, the bearing pin 3 includes a closed circular plate 25 as a reinforcing element.Optionally, the circular plate 25 could have one or more centrally arranged recesses that connect the cylindrical sections 21, 23 (not shown). This has the advantage that pressure differences, which arise, for example, when pressing in the insertion sleeve 5 between the interior enclosed by the core sleeve 1 and the exterior space, can be better compensated.

[0043] Alternatively, for the same purpose, the ring disc at the rear end of the insertion sleeve 5 could be designed as a closed circular disc or as a circular disc with centrally arranged recesses (not shown).

[0044] The rearmost cylindrical section 23 is open at the back. It can be used as a holding element to easily hold a roll of film when inserting it into or removing it from a dispenser housing.

[0045] The Figures 9 and 10Figure 1 shows an alternative embodiment of a bearing journal 3 in which only a portion of the barbs 13 are connected to the wall 7 of the insertion sleeve 5 via exposed, elastically deformable connecting sections 15. Along its circumference, the insertion sleeve 5 comprises, alternating with these elastically deformable connecting sections 14, comparatively rigid toothed sections where the barbs 13 project directly from the wall 7 of the insertion sleeve 5. This increases the stiffness of the insertion sleeve 5. In these rigid toothed sections, the radial projection H1 of the barbs 13 beyond the wall 7 is preferably smaller by a factor of 0.2 to 0.5 than in the elastically deformable sections.

Claims

1. Bearing journal (3) for a film roll with a core sleeve (1), comprising a fastening section (I) with an insertion sleeve (5) for insertion and fastening to the core sleeve (1) and a bearing section (II), characterized in that in the region of the insertion sleeve (5) a plurality of barbs (13) are arranged distributed over the circumference of a wall of the insertion sleeve (5), that these barbs (13) protrude outwards on the wall of the insertion sleeve (5), and that at least some of the barbs (13) are connected to the wall of the insertion sleeve (5) via elastically deformable connecting sections (15).

2. Bearing journal (3) according to claim 1, characterized in that the elastically deformable connecting sections (15) are self-supporting supports which are exposed through recesses (17) in the wall of the insertion sleeve (5).

3. Bearing journal (3) according to claim 2, characterized in thatthe insertion sleeve (5) comprises reinforcing elements axially adjacent to the recesses (17), in particular a stabilizing ring (19) and / or a reinforcing plate.

4. Bearing journal (3) according to claim 1 to 3, characterized in that it comprises a one-piece injection-molded plastic part.

5. Bearing journal (3) according to one of claims 1 to 4, characterized in that the insertion sleeve (3) is cylindrical, and that the barbs (13) are arranged in at least three toothed areas distributed evenly over the circumference of the wall of the insertion sleeve (5).

6. Bearing journal (3) according to claim 5, characterized in that the barbs (13) are arranged in four or six toothing areas.

7. Bearing journal (3) according to one of claims 1 to 6, characterized in that the barbs (13) protrude from the wall of the insertion sleeve (5) in at least two parallel planes (E1, E2, E3).

8. Bearing journal (3) according to one of claims 1 to 7, characterized in that the barbs (13) are teeth arranged in several rows in the shape of right-angled triangles.

9. Bearing journal (3) according to one of claims 1 to 8, characterized in that a part of the barbs (13) protrudes directly from the wall (7) of the insertion sleeve (5).

10. Bearing journal (3) according to one of claims 1 to 9, characterized in that at a rear end of the insertion sleeve (5) at least one stop (9) for defining an end position when inserted into a core sleeve (1) protrudes radially.

11. Film roll arrangement comprising a core sleeve (1) made of cardboard and two bearing pins (3) according to one of claims 1 to 10, characterized in that the bearing pins (3) are fastened and secured to the ends of the core sleeve (1), wherein the end sleeves (5) of the bearing pins (3) are inserted into the core sleeve (1) and secured in an end position by toothing of the barbs (13) on the inside of the core sleeve (1).

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