Hot-rolled steel bar with helically extending ribs, method of and apparatus for producing the steel bar
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Sep 4, 1990
Grant Date -
N/A
app pub date -
Oct 25, 1988
filing date -
Oct 31, 1987
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
In the production of a hot-rolled steel bar, such as a concrete reinforcing bar, a continuous thread is formed on the bar. The thread is arranged so that an anchoring or connecting member with a female thread can be screwed onto the male thread formed on the bar. Initially, first ribs are hot rolled on the bar surface with the ribs located on opposite sides of the bar and extending only for a portion of the circumference of the bar. Immediately following the formation of the first ribs, second ribs are hot rolled extending between and interconnecting the first ribs whereby the first and second ribs form a continuous thread. The ribs are formed in a unit made up of adjacent roll stands, each containing two rolls, the axes of the rolls in one stand are offset by 90.degree. to the axes of the rolls in the other stand. The rolls are interconnected so as to move together. The rolls in each roll stand form a roll gap with shaped surfaces on the rolls for defining the partial ribs forming the continuous thread.
First Claim
Other Claims data not available