摘要 |
A diaphragm for use in a fluid flow chamber comprising a generally flat flexible sheet that is engageable at its periphery and has a central portion that is reciprocally movable along an axis perpendicular to a plane through the periphery, the flexible sheet having annular corrugations around the center portion, and a magnet secured to the center of the sheet, the magnet having a front and a rear, the corrugations causing the front and rear to maintain their orientation with respect to the axis as the central portion travels along the axis. |