Abstract: A vacuum cleaner is used with a detachable built-in filter bag, and includes a shell, a mounting piece, an intake tube, a cover plate, a bag holder, a blocking member, a prop member, a biasing spring, and a vacuum air stream generating member. The cover plate is configured to be brought into mating engagement with the shell so as to enclose a chamber in the shell. When no filter bag is installed inside a chamber of the shell, the cover plate is prevented from being brought into mating engagement with the shell. Once the cover plate is brought into mating engagement with the shell, the prop member is brought into pressing engagement with the blocking member to lift the blocking member.

Abstract: A bypass-type motor protecting device includes: a casing fitted into a bypass opening in a body housing of a vacuum cleaner and having an inner abutment wall; a seat body having a bypass entry port; a valve body unit movable within the casing relative to the bypass entry port and including a valve disc to be engaged with and disengaged from the seat body, a plunger body having an externally accessible operated head and an axially extending threaded shank, and an abutment member threadedly engaged with the shank such that rotation of the operated head results in a change of an axial distance between the abutment member and the inner abutment wall; and a biasing member disposed to bias the abutment member and the inner abutment wall such that a biasing force thereof is varied in strength by the change of the axial distance.

Abstract: A bypass-type motor protecting device includes: a casing fitted into a bypass opening in a body housing of a vacuum cleaner and having an inner abutment wall; a seat body having a bypass entry port; a valve body unit movable within the casing relative to the bypass entry port and including a valve disc to be engaged with and disengaged from the seat body, a plunger body having an externally accessible operated head and an axially extending threaded shank, and an abutment member threadedly engaged with the shank such that rotation of the operated head results in a change of an axial distance between the abutment member and the inner abutment wall; and a biasing member disposed to bias the abutment member and the inner abutment wall such that a biasing force thereof is varied in strength by the change of the axial distance.