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1. (WO2017039366) PIPE EXPANDING PUNCH

Pub. No.:    WO/2017/039366    International Application No.:    PCT/KR2016/009817
Publication Date: Fri Mar 10 00:59:59 CET 2017 International Filing Date: Sat Sep 03 01:59:59 CEST 2016
IPC: B21D 39/08
B21D 39/14
B21D 39/20
B21D 41/02
Applicants: JUNG, Gu Wang
정구왕
Inventors: JUNG, Gu Wang
정구왕
Title: PIPE EXPANDING PUNCH
Abstract:
The present invention relates to a pipe expanding punch and, more particularly, to a pipe expanding punch for a drill which can expand a pipe by hitting the pipe by means of an anchor drill or a rechargeable drill. The pipe expanding punch according to an embodiment of the present invention comprises: an expanding ball in which one or more portions (hereinafter referred to as "an expanding part") having an outer diameter larger than an inner diameter of a pipe to be expanded are formed; and a holder which is formed integrally with the expanding ball and fixedly coupled to a drill so that the pipe can be expanded by means of the drill, wherein the outer diameter of an introduction part of an end portion of the expanding ball is formed to be smaller than the inner diameter of the pipe, a tapered first step is formed between the introduction part and the expanding part, and the tapered first step is polished, thereby having one or more polished surfaces formed thereon.