Title:
STRUCTURE FOR PREVENTING STRAIN OF SHELL SKIN IN SKYROCKET AND MANUFACTURE THEREOF
Document Type and Number:
Japanese Patent JP2597281
Kind Code:
B2
Abstract:
PURPOSE: To prevent occurrence of a strain with drying by a method wherein the peripheral edge part of a shell skin formed,like a semispheric surface is formed of a spiral paper tube material being excellent in rigidity.
CONSTITUTION: An adhesive is applied on the whole of the inside of a round shell 2 of a prescribed diameter formed by cutting from a cardboard, then a round shell 3 having a smaller diameter than the round shell 2 and formed of the same material is joined integrally on the concentric circle and thereby a disk-shaped cardboard material 1 having a cut-shaped stepped part 4 at the peripheral edge is obtained. The disk-shaped cardboard material 1 is set on a press bottom tool having a semispheric recessed surface, with the central position thereof aligned therewith. Besides, a short- tube-shaped spiral paper tube material 5 is obtained by cutting a spiral paper tube of a prescribed diameter in a prescribed width dimension, and a stepped part 8 is formed by cutting at the outer peripheral edge thereof. The short-tube-shaped spiral paper tube material 5 provided with this stepped part 8 is put on and made to engage with the upper-edge expanded-diameter part of a press top force 9 having a semispheric projecting surface corresponding to the surface of the press bottom tool 7. In this state, pressing is executed. According to this constitution, occurrence of a strain with drying can be prevented.
Inventors:
Shizuo Ota
Application Number:
JP34971592A
Publication Date:
April 02, 1997
Filing Date:
December 01, 1992
Export Citation:
Assignee:
Shizuo Ota
International Classes:
F42B4/00; F42B4/30; (IPC1-7): F42B4/30; F42B4/00
Domestic Patent References:
| JP198900A | ||||
| JP482592U | ||||
| JP2115693U | ||||
| JP54140090U |
Attorney, Agent or Firm:
Hideki Matsunami