Method and apparatus for punching openings in tubes

An apparatus for punching an opening through tubing comprising:

• a stationary mandrel having a guide aperture through the wall thereof and being insertable within the tubing,
• a moving actuator having an inclined ramp on one end thereof and receivable within the stationary mandrel,
• a punch having an inclined end for engagement on the inclined ramp of said actuator and an opposite end for engagement through the guide aperture in the wall of said stationary mandrel,
• interlocking structure on the inclined end of said punch and the inclined ramp of the moving actuator for slidable engagement of the punch on the actuator,
• power means for moving said moving actuator relative to said stationary mandrel whereby said punch is caused to move on the inclined ramp of said moving actuator and forced radially outward through the guide aperture of said stationary mandrel to punch an opening through the side wall of the tubing,
• a stop bar extending parallel to said stationary mandrel, and
• a plurality of stop arms hingedly secured to said stop bar for selective engagement against said stationary mandrel, said stop arms being selectively positionable along the longitudinal axis of said stop bar to permit varying the position of engagement of said stop arms on said stationary mandrel.

An apparatus for punching an opening through tubing comprising:

• a stationary mandrel having a guide aperture through the wall thereof and being insertable within the tubing,
• a moving actuator having an inclined ramp on one end thereof and receivable within the stationary mandrel,
• a punch having an inclined end for engagement on the inclined ramp of said actuator and an opposite end for engagement through the guide aperture in the wall of said stationary mandrel,
• interlocking structure on the inclined end of said punch and the inclined ramp of the moving actuator for slidable engagement of the punch on the actuator,
• power means for moving said moving actuator relative to said stationary mandrel whereby said punch is caused to move on the inclined ramp of said moving actuator and forced radially outward through the guide aperture of said stationary mandrel to punch an opening through the side wall of the tubing,
• a stop bar extending adjacent said stationary mandrel, and
• clamp structure supported from said stop bar and selectively movable from a first position circumferentially engaging said tube and a second position wherein said claim structure is removed from circumferential engagement of the tubing.

A method for punching a plurality of openings through tubing comprising:

• engaging the tubing over a tubular stationary mandrel having a guide aperture through the wall thereof,
• butting the end of the tube against a swing stop engaged against said stationary mandrel,
• forcing a moving actuator in a first direction longitudinally through the stationary mandrel to force a punch engaged on the inclined end of the moving actuator through the guide aperture of the mandrel whereby the punch is forced radially outwardly to form an opening in the side wall of the tubing from the interior of the tubing,
• moving the actuator in a second direction opposite the first direction to withdraw the punch into the stationary mandrel,
• pivoting said swing stop arm from a stop bar supported to one side of said stationary mandrel,
• advancing the tubing onto said stationary mandrel to engagement with a second swing stop arm engaged against said stationary mandrel, and
• moving said actuator longitudinally within the stationary mandrel to force the punch radially outwardly through the guide aperture in the stationary mandrel to form a second opening in the side wall of the tubing.