Patent ID: 8410799

Claim:
A motion sensing device comprising: a housing defining a chamber, the chamber comprising a plurality of sidewalls; a plurality of movable members, each movably connected to one of the plurality of sidewalls and able to move toward or away from the one of the plurality of sidewalls, and comprising at least one conductive groove facing the one of the plurality of sidewalls and having a resistance layer; a plurality of conductive spring members respectively fixed to the plurality of sidewalls and each comprising a free end movably received in one of the at least one conductive groove; and an inertial weight movably received in a space defined by the movable members, wherein when the motion sensing device is jerked, the inertial weight moves and is able to apply a pushing force to one of the plurality of movable members, causing one of the plurality of movable members to move and causing at least two of the free ends of the plurality of conductive spring members in a same one of the at least one conductive groove to move toward each other, causing a resistance value change between the at least two of the free ends, which is able to be detected to determine a movement direction of the housing that is opposite to the movement direction of the one of the plurality of movable members.