Patent ID: 7779738

Claim:
A pivot punch apparatus for punching holes in a web of film material that is continuously moving in a film transport direction, the apparatus comprising: an apertured backing plate on which the moving web of film is supported; and a punch mechanism disposed over said backing plate and including a bracket adapted to be mounted onto a support member; a pivoting yoke member having a horizontal pivot member at one end thereof, the pivot member being journalled onto said bracket at a horizontal pivot axis transverse to said film transport direction; a spring disposed on the yoke member above said horizontal pivot axis between said yoke member and said bracket for biasing said yoke member to a vertical home position but allowing the yoke member to tilt on said pivot axis; and an air cylinder actuator mounted on said yoke member above said horizontal pivot axis and having a punch head mounted on a rod thereof and below said horizontal pivot axis, the actuator having a reciprocation axis that is offset from the pivot axis in the film transport direction and holding said punch head in registered alignment with an aperture in said backing plate when said yoke member is in its home position, and said actuator including means for reciprocating said punch head in a direction substantially normal to said backing plate; so that in a punch cycle the punch head descends vertically to contact and to cut said film and then moves in the direction of film transport until the head rises out of contact with the film, after which the spring urges the yoke member, the actuator, and the cutting head back to the home position.