Patent ID: 7750788
Filing Date: 2010-07-06
Classification: H01H

Abstract:
1. A dual protection device for a circuit, comprising: a cover made of a conductive material and having a first terminal connected thereto; a first protection unit comprising an elastic contact piece and a first conductive member, the elastic contact piece including a first end fixed to the cover and a second end having a first contact point disposed on a bottom thereof, the elastic contact piece being made of metal, slightly curved, and capable of bending toward two opposite directions due to temperature change, the first conductive member having a second contact point disposed on a top thereof, the first contact point located corresponding to the second contact point, the first contact point contacted with the second contact point; a second protection unit comprising a flexible second conductive member, a fuse member and a second terminal, a first end of the second conductive member fixed to and electrically connected with the first conductive member, a second end of the second conductive member being a free end that is not connected with the second terminal under an un-forced state, the free end of the second conductive member forced to contact and electrically connect with the second terminal by the fuse member; and a base having a recess defined therein so as to receive the first conductive member, the second conductive member and the fuse member, the second terminal fixed on the base; wherein the elastic contact piece of the first protection unit is deformed and bent toward another direction to separate the first contact point from the second contact point when the elastic contact piece reaches a first predetermined temperature; when the circuit is raised to a second predetermined temperature, the fuse member melts and the free end of the second conductive member is separated from the second terminal due to elasticity of the second conductive member.