| 摘要 |
A vacuum device (10) for attaching an object to a surface (12), comprising a body (14) fixable to the object and a piston (16) connected to the body along a first sealing contour, thereby defining with the body a first chamber (20). The piston has a protruding sealing lip (22) adapted to contact the surface along a second sealing contour, thereby defining with the surface a second chamber (24). The two chambers are connected to a source of vacuum, and are preferably in fluid communication with each other. The piston is movable with respect to the body by the action of the vacuum in the first chamber and/or by an external force due to the contact of the sealing lip with the surface. The sealing lip is urged to the surface by a first sealing force due to the action of the vacuum in the second chamber. The vacuum device further comprises a spring (28) connected to the piston and the body so as to deform when the piston moves with respect to the body. Thus the spring creates a second sealing force urging the sealing lip towards the surface, and this force is independent of the vacuum in the second chamber.
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