US Patent 7967351 Suction device

A suction device (10) is described. The suction device (10) includes a cylinder (11) having a semi-closed end (113), a suction tip (13) connected to the semi-closed end (113), a piston (12), an elastic member (16) and an electromagnetic member (17). The piston (12) is slidably received in the cylinder (11), the piston (12) and the semi-closed end (113) encloses a working chamber (122). One end of the elastic member (16) is connected to the cylinder (11), the other end is connected to the piston (12). The electromagnetic member (17) causes the piston (12) to slide back and forth in the cylinder (11) to vary the volume of the working chamber (122) by adjusting the magnetic field of the electromagnetic member (17).