초록 ▼

A crash sensor for automobiles of the type including a ball moving against viscous damping in a closed tube has a much smaller hall than known designs and a power transistor to switch power in the firing circuit. A resistance sensing circuit enables the crash sensor to monitor the firing circuit and

A crash sensor for automobiles of the type including a ball moving against viscous damping in a closed tube has a much smaller hall than known designs and a power transistor to switch power in the firing circuit. A resistance sensing circuit enables the crash sensor to monitor the firing circuit and indicate a change in the resistance of the fining circuit. In two embodiments simple message patterns allow communication of diagnostic information through existing wiring. A latching circuit maintains the switch in its closed state after initial closing. The small size of the ball enables use of a plastic or aluminum tube. The tube may have fluted walls that form air ducts that viscously conduct much of the air displaced when the ball moves. Routing most of the air through the ducts eliminates the uncertainty in the viscous resistance resulting when all of the air flows between the ball and the inner diameter of the tube. The movable element may be a sensing mass having a nonspherical shape. Compensation for the variation of air viscosity with temperature may be obtained by varying the normal resting position of the sensing mass as a function of temperature or by varying the size of the air ducts. The small sensing mass and electronic components allow simple contacts. The combination of these elements provides a crash sensing and diagnostic system costing much less than known systems.

대표청구항 ▼

[ What is claimed is:] [1.] In an occupant protection system of the type comprising a first crash sensor for sensing a vehicular crash and thereupon completing an electrical firing circuit; the improvement comprising,said first crash sensor incorporating resistance sensing means for determining if t

[ What is claimed is:] [1.] In an occupant protection system of the type comprising a first crash sensor for sensing a vehicular crash and thereupon completing an electrical firing circuit; the improvement comprising,said first crash sensor incorporating resistance sensing means for determining if the resistance of said electrical firing circuit is between predetermined limits.