Safety bindings for skis

A safety binding for skis, comprising:

• retaining means;
• said retaining means being adapted to retain the boot on the ski;
• a member for locking said retaining means;
• an electrical circuit for releasing the locking member and an electrical control circuit for detecting the stress exerted during skiing, or values representative of this stress, and transforming the latter into electrical signals and processing these signals for controlling electrical release circuit when the value of the stress detected exceeds a predetermined threshold, the electrical control circuit comprising means for automatically altering the adjustment of the binding depending upon detection of the stress exerted during skiing, said means comprising a circuit for controlling the adjustment threshold in order to vary the value of this threshold automatically, as a function of the level of the signal V.sub.S representing the value of the stress detected or a predetermined representative value of the latter and including;
• an integrator stage receiving, at its input, the V.sub.S signal and re-set to zero periodically by a signal h.sub.2, h'.sub.2, emitted by a clock;
• a comparison circuit with two inputs, one receiving the output signal from the integrator stage depending on the value of the stress detected and the other receiving a voltage V.sub.R, V'.sub.R, depending on the value of the adjustment threshold in force, a threshold circuit receiving at its input, the output signal of the comparison circuit and defining two voltage thresholds V.sub.A and V.sub.B, between which the adjustment of the binding is considered to be correct, the threshold circuit comprising first and second outputs, at which control signals appear respectively when the differential signal emitted by the comparison circuit is too high or too low and the electrical control circuit additionally comprising a circuit having a comparison threshold receiving, at one input, a signal V.sub.s depending on the stress detected and creating an adjustable threshold voltage V.sub.x with which the signal V.sub.s depending on the stress is compared, in order to supply a signal for controlling the electrical release circuit, the circuit having a comparison threshold comprising means respectively connected to the first and second outputs of the threshold circuit to vary the threshold voltage V.sub.x when the value of the differential signal emitted by the comparison circuit is not in the range corresponding to correct adjustment and which is defined by the two voltages V.sub.A and V.sub.B.