The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 13, 2004
Filed:
Sep. 12, 2001
Applicant:
Inventors:
Assignee:
Denso Corporation, Kariya, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B26D 9/00 ;
U.S. Cl.
CPC ...
B26D 9/00 ;
Abstract
A method for forming a plurality of slits in a tube includes first, forming a plurality of grooves in the pipe by operating a grooving punch along the length of each of the slits to be made. Then, each slit is formed in the pipe by operating a hole-making punch. The punch has ends at an acute angle and the punch is recessed from the ends toward the center thereof. In view of the fact that each groove is formed beforehand in the surface of the pipe and that the corresponding slit is made while moving the hole-making punch slowly from the ends, a large load is not exerted on the pipe and therefore the pipe is not crushed, burrs are not generated and the cutting chip is removed.