Optical force sensor, especially for measuring the load in elevator cabins

摘要

The rigid cylindrical steel housing (7) has an elastic deformation characteristic such that the distance between its upper and lower faces (13,9) varies with the applied load. An L-shaped blade (19) fixed to the upper face and contacted by a set screw (31) has an aperture (27) through which light emitted by a diode (21) falls on a detector (23) fixed to the lower face. A signal-processing circuit determines the force applied to the upper face from the floor (1) of the cage. This circuit together with the diode and detector may be mounted on the lower face of the housing or on a circuit board (25) close to it.