| 摘要 |
The disclosure relates to an arrangement in a drive unit (2) for an ultrasound sealing unit (1). The drive unit is of the type which consists of a number of piezoelectric ceramic plates (3) with interjacent, conductive metal sheets (4), connected to an a.c. source. The drive unit (2) further consists of a counterweight (5) and a clamping screw (6). The clamping screw (6) holds together under a certain pretensioning the ceramic plates (3), the metal sheets (4), and the counterweight (5). Moreover, the clamping screw fixedly secures the drive unit (2) in the sealing unit (1). The sealing unit (1) comprises a homogeneous body (13), consisting of reaction bodies (7) which surround the drive unit, a nodal plane (10) with an anchorage edge (11), and a horn (8) with an elongate, narrow sealing surface (9). The arrangement according to the present invention consists of a gasket (12) so disposed that it constitutes a spacer (H) between the body (13) of the sealing unit (1) and the ceramic plates (3). The gasket (12) permits the oscillation of the ultrasound sealing unit (1), but prevents residual flexural stresses from reaching the drive unit (2). The spacing dimension (H) of the gasket (12) may be selected so as to govern the amplitude of the sealing unit (1) to a predetermined, preselected amplitude. <IMAGE> |
