Patent Application
20250187867
The disclosure relates to a support plug for a tubular roller sleeve, especially for a tubular roller sleeve made of cardboard.
In many cases, paper or another sheet-like product is rolled around a tubular roller sleeve which can be made of e.g. cardboard. The tubular roller sleeve can be however unsuitable for being directly in a mechanical contact with a shaft of a roller machine or another device for handling the tubular roller sleeve, but there is a need for support plugs such that an outer rim surface of each support plug is against an inner surface of the tubular roller sleeve and each support plug has a through hole in the center of the support plug. The through hole is suitable for the shaft of the roller machine or the other device for handling the tubular roller sleeve. A support plug of the kind mentioned above must fulfill given mechanical durability requirements. For example, a support plug must be sufficiently strong against mechanical compression in a radial direction of the support plug so that the support plug does not buckle and/or break under radial compression.
Typically, support plugs of the kind mentioned above are made of plywood whose thickness ranges from 20 mm to 40 mm. An advantage of a support plug made of plywood is the ability to withstand mechanical compression in radial directions because plywood consists of veneer layers with crossing grain directions. On the other hand, an inconvenience related to support plugs made of plywood is their weight. Furthermore, plywood is virginal material, and this inherently increases costs of the support plugs made of plywood.
To reduce material costs and to reduce use of virginal materials, there is nowadays a desire to manufacture many elements such as support plugs of the kind mentioned above from recycled materials, such as recycled plastic, and/or from surplus materials, such as sawdust and wood chips, remaining during manufacture of other products.
The following presents a simplified summary to provide a basic understanding of some aspects of various invention embodiments. The summary is not an extensive overview of the invention. It is neither intended to identify key or critical elements of the invention nor to delineate the scope of the invention. The following summary merely presents some concepts of the invention in a simplified form as a prelude to a more detailed description of exemplifying embodiments of the invention.
In this document, the word “geometric” when used as a prefix means a geometric concept that is not necessarily a part of any physical object. The geometric concept can be for example a geometric point, a straight or curved geometric line, a planar or non-planar geometric surface, a geometric space, or any other geometric entity that is zero, one, two, or three dimensional.
In accordance with the invention, there is provided a support plug for a tubular roller sleeve, especially for a tubular roller sleeve made of cardboard. A support plug according to the invention is disk-shaped and comprises:
The above-mentioned first surface has recessions such that stiffener ridges are formed between the recessions. The stiffener ridges extend between different sectors of an outer rim area of the first surface so that the stiffener ridges bypass the through hole. Thus, the stiffener ridges conduct mechanical tensions to bypass a rim area of the through hole which is typically a fracture-prone area. Furthermore, as the stiffener ridges extend between different sectors of the outer rim area, the ridges provide mechanical strength against buckling under radial compression.
A support plug according to the invention can be made of for example recycled plastic or of composite material comprising recycled plastic and wood fibers.
Exemplifying and non-limiting embodiments are described in accompanied dependent claims.
Various exemplifying and non-limiting embodiments both as to constructions and to methods of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific exemplifying and non-limiting embodiments when read in conjunction with the accompanying drawings.
The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of unrecited features.
The features recited in dependent claims are mutually freely combinable unless otherwise explicitly stated.
Furthermore, it is to be understood that the use of “a” or “an”, i.e. a singular form, throughout this document does not exclude a plurality.
Exemplifying and non-limiting embodiments and their advantages are explained in greater detail below in the sense of examples and with reference to the accompanying drawings, in which:
The specific examples provided in the description below should not be construed as limiting the scope and/or the applicability of the accompanied claims. Lists and groups of examples provided in the description are not exhaustive unless otherwise explicitly stated.
In a support plug according to an exemplifying and non-limiting embodiment, the stiffener ridges cross each other as illustrated in
In a support plug according to an exemplifying and non-limiting embodiment, the first surface 101 has an annular recession 110 surrounding the through hole 103. In a support plug according to an exemplifying and non-limiting embodiment, the second surface has an annular ridge 111 surrounding the through hole 103. In a support plug according to an exemplifying and non-limiting embodiment, the first surface 101 has an annular recession 112 on the outer rim area of the first surface. In a support plug according to an exemplifying and non-limiting embodiment, the second surface 102 has an annular ridge 113 on an outer rim area of the second surface. In a support plug according to an exemplifying and non-limiting embodiment, a part 115 of the second surface 102 extending from an outer rim area of the second surface 102 to an inner rim area of the second surface 102 surrounding the through hole 103 is conical. A cone angle θ of the conical surface is at least 170 degrees, and the cone angle θ opens in a direction away from the first surface 101, i.e. in the negative z-direction of the coordinate system 199.
By design of the above-mentioned annular recessions 110 and 112, the annular ridges 111 and 114, and the conicity of the second surface 102 it is possible to adjust tension distribution within the material of the support plug 100 in the axial direction of the support plug 100, i.e. in the z-direction of the coordinate system 199. Thus, the above-mentioned annular recessions, the annular ridges, and the conicity of the second surface 102 can be optimized to maximize mechanical strength of the support plug 100 against buckling with respect to amount of the material of the support plug 100. The annular recessions, the annular ridges, and the conicity of the second surface 102 can be optimized with e.g. prototypes and tests and/or with strength-technical simulations.
In a support plug according to an exemplifying and non-limiting embodiment, the depths of the recessions of the first surface 101 are such that material thickness between bottoms of the recessions of the first surface 101 and the second surface 102 is substantially constant. In
In a support plug according to an exemplifying and non-limiting embodiment, a part of the outer rim surface 105 connected to the second surface 102 has a bevel 114. The bevel 114 makes it easier to install the support plug 100 in a tubular roller sleeve.
30 In a support plug according to an exemplifying and non-limiting embodiment, the outer rim surface 105 comprises lumps on the periphery of the support plug 100 to improve a grip between the support plug 100 and an inner surface of a tubular roller sleeve. In
A support plug according to an exemplifying and non-limiting embodiment is made of plastic that is advantageously recycled plastic.
A support plug according to an exemplifying and non-limiting embodiment is made of composite material comprising wood fibers and plastic. The wood fibers and/or the plastic is/are advantageously recycled material.
A support plug according to an exemplifying and non-limiting embodiment is manufactured with compression molding or some other suitable manufacturing method.
The specific examples provided in the description given above should not be construed as limiting the applicability and/or interpretation of the appended claims. It is to be noted that lists and groups of examples given in this document are non-exhaustive lists and groups unless otherwise explicitly stated.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20237204 | Dec 2023 | FI | national |
