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JP-7855193-B2 - Spherical stamp

JP7855193B2JP 7855193 B2JP7855193 B2JP 7855193B2JP-7855193-B2

Inventors

  • 大▲崎▼ 友也

Assignees

  • シヤチハタ株式会社

Dates

Publication Date
20260508
Application Date
20220309

Claims (3)

  1. A spherical stamp capable of imprinting on a stamping target having a convex spherical surface, The head of the seal is, A holder having a concave spherical portion that receives the convex spherical surface, A flexible printing element is provided at the end of the holder so as to face the concave spherical portion , The system comprises a cushioning foam provided between the printing body and the concave spherical portion , The aforementioned printing element is a porous film printing element stretched over a frame, When not stamped, at least the central part of the foam is separated from the concave spherical part , and a stress relaxation space is formed between the foam and the concave spherical part. A spherical stamp in which substantially the entire back surface of the foam can come into contact with the concave spherical surface when stamping .
  2. The spherical stamp according to claim 1, wherein the frame has an opening that is substantially circular in plan view, and the printing element is stretched outward around its entire circumference so as to cover the opening.
  3. The spherical stamp according to claim 1 or 2, wherein the foam is an ink absorber.

Description

This invention relates to a spherical stamp that can be used to stamp on a stamping surface having a convex spherical shape. Conventionally, stamps capable of imprinting on convex spherical surfaces are known. Patent Document 1 describes a stamp specifically for watermelons, in which a spring body is positioned between a stamp base having a concave spherical portion and the stamp surface. This stamp can imprint on either a flat or convex spherical surface, as the stamp surface deforms to conform to the surface shape. Furthermore, Patent Document 2 describes a stamping device comprising a main body with a metal plate curved in a concave shape, and a cushioning material and a printing element provided so as to conform seamlessly to the metal plate. This stamping device is configured to allow the metal plate to be pressed from the inside to the outside of the main body, thereby pushing the curved metal plate and printing element downwards to flatten them. This allows for the application of ink to the stamp surface using a flat stamp pad, followed by the return of the printing element to its curved shape for stamping on a curved surface. When using the stamp described in Patent Document 1, the flat stamp surface, approximately in the center, first contacts the spherical object being stamped. Therefore, the load is strongest near the center of the stamp surface. Furthermore, the force resisting the compression of the spring body located directly beneath the center of the stamp body is also applied, making it difficult to relieve stress in the center of the stamp body. In fact, the area where this spring body contacts the back of the stamp body is smaller than the entire stamp surface, resulting in greater stress. Consequently, the load acting on the center and periphery of the stamp surface is not uniform, potentially causing unevenness or misalignment in the imprint. Furthermore, in the stamping device described in Patent Document 2, because the printing element and cushioning material are arranged to conform seamlessly to the concave curved surface of the main body, the pressing force applied to the center of the stamp surface during stamping is not sufficiently relieved, potentially resulting in uneven load distribution between the center and both ends of the stamp surface. This can lead to excessive pressure being applied to the center, causing excessive ink discharge and blurring of the stamp impression, for example, when the stamping device or the object being stamped is moved to ensure the stamp surface follows the surface of the object being stamped. Japanese Public Gazette No. 03-12386Japanese Utility Model Publication No. 07-11349 This is a perspective view showing a spherical stamp according to an embodiment.This is a perspective view of the stamp head of the embodiment.This is an exploded perspective view of the stamp head of the embodiment.This is a cross-sectional view of the stamp head of the embodiment. It shows the state in which the object to be stamped and the stamp surface are in contact at the start of the stamping operation.This is a cross-sectional view showing a state in which the stamped member presses further against the printing body, resulting in a smaller stress relaxation space, compared to the state shown in Figure 4.This cross-sectional view shows the state in which the object to be stamped presses further against the printing body from the state shown in Figure 5, and substantially the entire back surface of the ink absorber is in contact with the concave spherical surface of the holder. The following describes embodiments for carrying out the invention. The spherical stamp 1 of the present invention is a stamp that can be used to stamp on the surface of a stamped member having a convex spherical surface, such as a ball. As shown in Figure 1, the spherical stamp 1 of the embodiment comprises a stamp head 11 having a printing body 3 and a cover frame 4, a handle 7 into which the stamp head 11 is fitted, and a cap 71 capable of covering the printing body 3 and the cover frame 4. The means for gripping the stamp head 11 is not limited to the handle 7, but may be of other shapes. Furthermore, the method of stamping is not limited to holding it in the hand, and the spherical stamp 1 may be mounted on a machine or the like. The stamp head 11 will now be described. As shown in Figure 2, the stamp head 11 of this embodiment comprises a holder 2 and a flexible printing body 3. The printing body 3 of this embodiment is a porous film printing body with a printing surface 31 formed on its outer surface, and is positioned at the end of the holder 2. Furthermore, the stamp head 11 of this embodiment includes a frame-shaped lid portion 4 that can be fitted into the holder 2, and a substantially circular opening 41 is formed on the upper surface of the lid frame portion 4 in plan view. The printing body 3 is stretched over the lid frame portion 4 so as to cover this opening 41. While the holder