Inertia switch

An inertia switch comprising:

• a casing that is divided into two chambers by an axially movable diaphragm;
• an electrical contact carried by said diaphragm on a face thereof that bounds one of said chambers, said electrical contact being disposed centrally on said face;
• a pair of spaced apart terminals disposed in said one chamber in the path of said electrical contact as said diaphragm moves toward said one chamber, a circuit being completed between said pair of terminals when said pair of terminals is contacted by said electrical contact;
• orifice means passing through said electrical contact and said diaphragm to communicate said two chambers with each other, said orifice means comprising a control orifice;
• said inertia switch occupying an off state, when subjected to axial force below a predetermined magnitude and duration characteristic in a sense urging said electrical contact and said diaphragm toward said pair of terminals, said off state being defined by said electrical contact being spaced from said pair of terminals;
• and
• said inertia switch assuming an on state, when subjected to axial force in said sense equaling or exceeding said predetermined magnitude and duration characteristic, said on state being defined by said electrical contact being placed in contact with said pair of terminals;
• in which said diaphragm is constructed and arranged so as to be inherently biased in the axial direction away from said pair of terminals;
• in which said diaphragm includes a mass that is carried central by said diaphragm on the face thereof that is toward the other of said chambers, said orifice means also passing through said mass;
• and
• including a stop for engaging said mass to set a limit for the extent to which said diaphragm is biased away from said pair of terminals.

Inertia switch structure comprising:

• a casing;
• a diaphragm that divides said casing into two chambers and is axially displaceable within said casing;
• orifice means in said structure through which a gas in one of said two chambers can be driven from said one chamber;
• electrical terminal means disposed in said one chamber in the path of axial displacement of said diaphragm;
• said two chambers, said diaphragm, and said terminal means being constructed and arranged such that in response to an axial force of predetermined magnitude and duration applied to said inertia switch structure, said diaphragm is displaced axially within said casing toward said one chamber to cause a switch signal representative of the occurrence of said axial force to be given at said terminal means;
• and
• said orifice means comprising control orifice means through which gas is driven from said one chamber as said diaphragm is being displace toward said one chamber, said control orifice means serving to impart dampening to the motion of said diaphragm toward said terminal means.