Car door lock blocking against unwanted opening

In normal conditions, i.e. without acceleration, the lever (9) is spaced from the shaft (4) until acceleration swings the lever onto the shaft by supplementary force (14) thus preventing the shaft from movement. The contact faces (15,16) of lever and shaft make up a forcible or positive connection between the shaft and lever, possibly using toothing on lever or shaft for this purpose. The positive connection can also be provided by a latching device (17) and the re-set spring (12) fitted to the lever is of the leg type. Lateral impact (18) on the door lock, e.g. in accidents, applies moment to the lever which thus swings against its spring towards the shaft, there to latch home to arrest any shaft movement (19) despite inertia, securely guarding against forcible opening. Otherwise the lever is retracted by its spring clear of the shaft so the outside door handle (3) can be turned as required.