| 摘要 |
Punching apparatus for punching a series of longitudinally aligned ports in cylindrical tubing of the type used in gas burners includes a vertically reciprocable punch 26 which is reciprocated in synchronism with longitudinal advancement of a chain 20 secured to a tube holder assembly 12 so that a tube is advanced through a collar 28 in a punch arbor 27 by a predetermined amount for each punching stroke. <IMAGE> |
