公开(公告)号：US20220128082A1

公开(公告)日：2022-04-28

申请号：US17430625

申请日：2020-02-03

Applicant: TOPURA CO., LTD.

Inventor： Shigeto MORI ,  Mayumi MATSUNO ,  Naoki HORIUCHI

IPC: F16B33/02

Abstract: To provide a screw thread which achieves a further reduction in screwing torque while securing removability of a coating film or the like and which is capable of stabilizing conductivity. In a screw thread in which a recessed portion (7) is partially provided on a flank surface (131) of a screw thread ridge provided on a screw thread shaft main body (5), a screw thread ridge (13) in a section where the recessed portion (7) is formed is smaller than a regular screw thread ridge (3), and a ridge height (H12) in a distal end portion in a screwing direction is lower than a ridge height (H11) in a rear end portion in the screwing direction W.

公开(公告)号：US20210231157A1

公开(公告)日：2021-07-29

申请号：US17160151

申请日：2021-01-27

Applicant: TOPURA CO., LTD.

Inventor： Minoru SUGIYAMA ,  Shigeto MORI ,  Mayumi MATSUNO ,  Naoki HORIUCHI

IPC: F16B25/00

Abstract: An external screw member includes a parallel screw portion and a tapered screw portion provided on a side further toward a tip end than the parallel screw portion, and a plurality of sets of step portion and a transition screw thread portion are provided on at least one of the parallel screw portion and the tapered screw portion, the step portion having a reduced thread height in a radial direction and the transition screw thread portion gradually increasing in diameter from the step portion in an anti-driving rotation direction so as to reach a thread height of a normal screw thread portion. A top portion of the transition screw thread portion is positioned at an offset toward a pressure side relative to a position of a regular screw pitch in a minimum diameter portion of the step portion, and transitions to the regular screw pitch in the anti-driving rotation direction.

公开(公告)号：US20200370587A1

公开(公告)日：2020-11-26

申请号：US16879344

申请日：2020-05-20

Applicant: TOPURA CO., LTD.

Inventor： Takehiro OKUWAKI ,  Kenju SAWANISHI ,  Shigeto MORI ,  Mayumi MATSUNO ,  Yoshie SATO

IPC: F16B25/00 ,  F16B33/02 ,  F16B25/10 ,  F16B35/04

Abstract: An external screw member includes a head, a shank, a parallel threaded portion, a tapered threaded portion, a screw thread, a convex portion and a screw driving side end face of the convex portion. The convex portion protruding more radially outward than the crest of the screw thread is formed in at least one of the parallel threaded portion and the tapered threaded portion over the tapered threaded portion and the parallel threaded portion. The screw driving side end face of the convex portion is configured to form an inclined plane which gradually rises from a root position of the end face at the side of the crest of the screw thread toward a crest of the convex portion in a direction opposite to a screw driving direction of the screw thread to reach the crest of the convex portion.