US 12,172,352 B2
Screw for injection molding machine, injection device, and injection molding machine
Yugo Kashiwabara, Tokyo (JP); Takuya Yufu, Tokyo (JP); and Kazuma Nakagawa, Tokyo (JP)
Assigned to THE JAPAN STEEL WORKS, LTD., Tokyo (JP)
Filed by THE JAPAN STEEL WORKS, LTD., Tokyo (JP)
Filed on Oct. 12, 2021, as Appl. No. 17/498,889.
Claims priority of application No. 2020-172371 (JP), filed on Oct. 13, 2020.
Prior Publication US 2022/0111571 A1, Apr. 14, 2022
Int. Cl. B29C 45/47 (2006.01); B29C 45/60 (2006.01); B29C 45/62 (2006.01); B29C 45/74 (2006.01); B29C 45/76 (2006.01)
CPC B29C 45/47 (2013.01) [B29C 45/60 (2013.01); B29C 45/62 (2013.01); B29C 45/74 (2013.01); B29C 45/76 (2013.01); B29C 2945/7613 (2013.01)] 12 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a cylinder having a bore; and
a screw that is insertable into the bore of the cylinder, the screw comprising:
a flight,
wherein a step-shaped step portion is formed on a top portion of the flight of a part of the screw, and the flight on which the step-shaped step portion is formed is a stepped flight;
wherein the stepped flight includes a large diameter portion on an upstream side and a land portion on a downstream side, and
wherein a gap ratio m=H1/H2 is 2.3 or more and 4.33 or less,
wherein gap H1 is the distance between the land portion and the bore,
wherein gap H2 is the distance between the large diameter portion and the bore,
wherein for a flight width B1 in a direction perpendicular to a lead angle and a width B2 of the land portion in the stepped flight, the width B2 is 0.5 times or more and 0.95 times or less of the width B1, and
wherein the flight width B1 and the width B2 of the land portion in the stepped flight are directed from downstream to upstream of the screw.