Step keys, a step key assembly, and a terminal having the step key assembly are disclosed. An individual step key includes a first slope portion inclined at a first predetermined angle, a second slope portion inclined at a second predetermined angle in the opposite direction to the first slope portion, a recess having a first height and opened under the first slope portion in the forward direction of the step key, a protrusion having a second height lower than the first height and extended from under the second slope portion in the rear direction of the step key, and an extension extended from under the first and second slope portions.

A system for detecting the pressure and passage of a vehicle wheel on a surface includes an element made of a deformable conductive rubber component which is urged into contact with an opposing conductive metal component by the passage of a wheel over the element. The rubber component is maintained in a bracket having a generally square profile, and the element is connected to a two-conductor cable through a connection made of an insulating material.

A safety strip for use on moving devices with the danger of pinching has a plurality of contact elements assembled into a row under an axial prestress along the safety strip. Extending in these contact elements are electrically conductive contact pins that, in the off, i.e. non-operate state maintain a circuit through the adjacent contact elements by contact and in the event that the safety strip is deformed through some external force open the circuit through the spatial distance from each other. The axial prestress and control of the individual contact elements is effected by means of an elastic tubing. However, in the present state-of-the-art, such safety strips result in a high material load in the area of the contact zones between the individual contact elements and, in addition, have only a limited maintainability. This problem is overcome by generating the prestress through individual tubing pieces that, in alternating sequence, overlay two contact elements and press the overlapping contact elements against each other.

A hearing aid is used to be inserted into and removed from an ear hole. A cam attached to a taking-out knob pushes up a battery holder by lifting up the taking-out knob when the hearing aid is taken out from an ear hole, whereby the electrode of the battery in the battery holder is left from the battery connecting tongues attached to a panel portion to thereby turn OFF a power supply. A howling prevention fixture is fixed to a hearing aid case at the head portion thereof to prevent howling.

A switching pad or plate having electroinsulating flat bodies arranged essentially in parallel to one another, to which at least one current-conducting contact path is assigned which has disconnecting switches disposed in series and are actuated by pressure on one of the flat bodies. Contact pins are assigned to the disconnecting switches which contact pins subjected to spring force, rest against the contact path by a contact head. The contact pins are firmly connected at the end facing away from the contact head with one of the flat bodies and each contact pin is movably held in a guide which is formed by an insulating flat body.