JPH038689Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention relates to a core for winding plastic films for magnetic tapes, metal foils such as aluminum foil, paper, sheet filters, etc.

In this specification, the term "sheet material" includes anything made of metal, paper, synthetic resin, composite materials thereof, etc., and which can be handled as a rolled product.

Prior Art and its Problems Conventionally, this type of winding core 21 has been used in a cylindrical shape, as shown in FIG. However, in this method of winding the sheet material S onto the winding core 21, the winding start end of the sheet material S is placed on the winding core 21.
This method involves winding the sheet material S without fixing it to the outer peripheral surface of the sheet material S. As can be seen from FIG. A stepped portion is formed in the material S, and as the number of turns increases, wrinkles are generated at this stepped portion, and as a result, the sheet material S is deformed. Even if the sheet material S is unwound from the winding core 21, this deformation and wrinkles remain, and the unwound sheet material S
When performing surface treatments such as coating or printing on the sheet material or laminating it with other sheet materials, there is a problem in that uniform processing and finishing cannot be achieved. Further, during winding, both ends of the sheet material S in the width direction at the winding start end may be bent into a triangular shape, and there is a problem in that the deformation and wrinkles become particularly large in these parts.

Therefore, in order to solve the above-mentioned problem, a step part for receiving the sheet material end, which is parallel to the axial direction and has a height approximately equal to the thickness of the sheet material to be wound up, is provided on the outer peripheral surface of the peripheral wall over the entire length. A winding core has been proposed (see Utility Model Application Publication No. 57-91744). However, with this winding core, the force when winding up the sheet material causes the end of the sheet material to move away from the step, creating a gap between the step and the end of the sheet material. Therefore, the sheet material is deformed at this portion. In particular, creases are formed in the sheet material at corners between the step and the outer circumferential surface of the cylindrical body. Even if the sheet material is rewound from the core, the curls remain, and when surface treatments such as coating or printing are applied to the rewound sheet material, or lamination processing with other sheet materials, the resulting product may be affected. There is also the problem that the above-mentioned habit appears.

The purpose of this invention is to provide a winding core that solves the above problems.

Means for Solving the Problems The sheet material winding core according to this invention is a winding core for winding a sheet material, which is provided with an inward folded portion at the winding start end, and has a winding core on the outer circumferential surface of the peripheral wall. A sheet material end receiving stepped portion having a height approximately equal to the thickness of the sheet material to be wound up is provided over the entire length, and a folded portion of the sheet material is provided at a portion of the outer peripheral surface of the peripheral wall that is continuous with the lower end of the stepped portion. A recess into which it is fitted is formed over the entire length.

In the above, the sheet material end receiving stepped portion is provided by providing at least one of a recess and a convex portion on the outer peripheral surface of the peripheral wall.
The bottom surface of the recess should be smoothly connected to the outer peripheral surface of the peripheral wall. Further, the outer surface of the convex portion is arranged to be smoothly continuous with the outer circumferential surface of the peripheral wall.

Further, the winding core is made of metal, synthetic resin, paper, or composite materials thereof.

Effect If a recess into which the folded part of the sheet material is inserted is formed over the entire length in the part of the outer peripheral surface of the peripheral wall that is connected to the lower end of the stepped part, the inner folded part will be placed at the winding start end. If the provided sheet material is rolled up with the inner folded part inserted into the recess,
The tip of the inwardly folded portion catches on the edge of the recess, preventing the end of the sheet material from moving away from the stepped portion. Therefore, the formation of a gap between the end of the sheet material and the stepped portion is prevented.

Embodiments Hereinafter, embodiments of this invention will be described with reference to the drawings.

In FIGS. 1 and 2, a winding core 1 for sheet material is made of a cylindrical body, and a peripheral wall 2 of the core 1 has a height parallel to the axial direction and approximately equal to the thickness of the sheet material S to be wound. Stepped part 3 for sheet material end receiving
It is equipped with this over its entire length.

The sheet material end receiving step portion 3 is provided on the outer peripheral surface of the peripheral wall 2,
A recess 4 having a substantially triangular cross section whose shortest side corresponds to the step portion 3 is formed by embossing, cutting, or the like. The outer shape of the peripheral wall 2 before forming the recess 4 is shown in chain lines in FIG. In the bottom of the recess 4, the part connected to the lower end of the step 3 has a
A groove 12 into which the folded portion S1 at the winding start end of the sheet material S is inserted is formed over the entire length.

In such a configuration, when winding the sheet material S having the inner folded part S1 at the winding start end onto the winding core 1, first the inner folded part S1 of the sheet material S is placed in the groove 12. In the fitted state, the winding start end is brought into contact with the sheet material end receiving stepped portion 3, and in this state, winding is started while pulling the sheet material S with a predetermined force. The outer surface of the winding start end of the sheet material S is connected to the upper end of the stepped portion 3 on the outer circumferential surface of the peripheral wall 2 so as to form a substantially smooth arc, and there is a stepped portion between the two. Can not. Therefore, the outer surface of the terminal end of the n-th roll of the sheet material S and (n+
1) The outer surfaces of the starting ends of the windings (n is a natural number) are also continuous to form a substantially smooth arc shape, and no step portion is formed on the outer peripheral surface of the wound product.
Furthermore, the tip of the inwardly folded portion S1 is caught on the edge of the groove 12, and the end of the sheet material S is prevented from moving away from the stepped portion 3. Therefore,
This prevents a gap from forming between the end of the sheet material S and the stepped portion 3.

Effects of the invention According to the winding core for sheet material of this invention, as described above, if a sheet material having an inward folded portion at the winding start end is wound up, the end of the n-th winding and (n+
1) The sheet material can be wound up so that the outer circumferential surface with the winding start end (n is a natural number) is continuous in a substantially smooth arc shape. Therefore, the rolled-up sheet material does not become deformed due to the formation of stepped portions, and the above-mentioned conventional problems caused by deformation of the sheet material can be solved. Moreover, since a gap is prevented from forming between the edge of the sheet material and the stepped portion, deformation of the sheet material at this portion, especially at the corner between the stepped portion and the outer peripheral surface of the cylindrical body, is prevented. Creases are prevented from forming in the sheet material. Therefore, even when the sheet material rewound from the core is processed, there is no problem with the processed product.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted perspective view showing an embodiment of this invention, FIG. 2 is an enlarged sectional view of the main part, and FIG. 3 is a view corresponding to FIG. 1 showing the drawbacks of the conventional product. DESCRIPTION OF SYMBOLS 1... Winding core for sheet material, 2... Peripheral wall, 3... Step part for sheet material end receiving, 12... Concave groove, S... Sheet material, S1... Inward folded part.

Claims (1)

[Scope of utility model registration request] A winding core for winding a sheet material having an inward folded portion at the winding start end, and a sheet material end holder having a height approximately equal to the thickness of the sheet material to be wound on the outer peripheral surface of the peripheral wall. A winding core for sheet material, in which a stepped portion is provided over the entire length, and a recess into which a folded portion of the sheet material is fitted is formed over the entire length in a portion of the outer peripheral surface of the peripheral wall that is continuous with the lower end of the stepped portion. .