Abstract: A horn actuating device for a motor-vehicle steering-wheel comprises a plurality of spring which resiliently support an actuating element constituted by the housing of the air-bag associated with the steering-wheel or a covering element for the steering-wheel hub. The springs define movable electric contacts adapted for co-operation with fixed electric contacts for actuation of the horn. All these contacts are connected to electric conductive strips embedded in a flexible strip of plastic material which is connected to supports also made of plastic material, on which the above mentioned springs rest. The actuating element is provided with studs guided within bushes forming part of said supports of plastic material. The studs are held at the lower end by elastically deformable stop means which enable a rapid installation of the air-bag unit or the hub covering element on the steering-wheel frame.

Abstract: The hydraulic tappet comprises a cup-shaped body having a cylindrical side wall and a flat bottom wall, a piston element moving axially inside a cavity, formed in the said bottom wall and defining a first pressure chamber, an annular element of deformable material located on the outside of the said piston element and inside the said cylindrical wall, ducts for hydraulically connecting the said second chamber to the said first chamber and on which is fitted an on-off member, and a guide element moving axially inside the said cylindrical wall on the said cup-shaped body and having a side surface and a bottom wall.