Patent ID: 7357615

Claim:
A seaming machine for seaming metal ends onto composite cans, the seaming machine comprising: a rotary turntable supporting a plurality of chambers spaced about a circumference of the turntable, each chamber being structured and arranged to enclose an upright composite can with a metal end loosely placed on a top edge of the composite can, each chamber having a bottom comprising a lifting plate that supports the composite can and that is structured and arranged to be raised and lowered; a seaming chuck disposed above each of the chambers for engaging a metal end placed atop a composite can in the chamber; a pair of seaming rollers disposed above each of the chambers for seaming a metal end onto a composite can in the chamber; a cam mounted beneath the turntable and engaging lifters respectively connected to the lifting plates, the cam defining a cam profile such that as the turntable is rotated about an axis thereof, the lifter for a given chamber is moved vertically according to the cam profile to cause the lifting plate to rise and fall, thereby lifting and lowering the composite can relative to the seaming chuck for the chamber; wherein each seaming chuck comprises a magnet for magnetically attracting and holding onto a metal end atop a composite can in the respective chamber such that the metal end is prevented from falling when the composite can is lowered; and wherein the cam profile is configured to cause each lifting plate to be raised to bring a metal end atop a composite can supported on the lifting plate into engagement with the seaming chuck so that the metal end is held by the magnet, and then to be lowered so as to lower the composite can and thereby create a gap between the composite can and the metal end held on the magnetic seaming chuck, so that gas transfer can take place into and out of the composite can through the gap, and wherein each lifting plate further comprises a magnet for attracting and holding onto a metal end affixed to a bottom end of a composite can supported on the lifting plate.