Abstract: The present invention relates generally to a device for locating ear-muffs arranged on a helmet or the like by means of bearing members arranged in the helmet to pivotally receive attachment members, each of said members cooperating with an ear-muff cover by a clamp-shaped arm. The attachment members being with their upper ends of said arms located inside the helmet and displaceable arranged in a longitudinal direction. In this way any desired location of said ear-muffs -- parking position within the helmet or working position covering the ears -- could easily be established.

Abstract: The present invention relates generally to a receiver antenna construction for a mobil communication unit adapted to be worn by the operator on the head. The antenna of the receiver is initially orientated in an inclined position in relation to the geometrical vertical line of the head in order to be able to receive the optimal value of the field strength deriving normal work positions of the head of the operator.

Abstract: A switch member for portable, battery operated apparatus, such as staff location systems, which is provided with hearing sets worn on the head, ear-phones, speech amplifiers, radio receivers and the like including at least one attachement or suspension member. The switch member is arranged to be automatically moved to and forcibly retained in a circuit-closing contact position under pressure from the attachment or suspension member of the apparatus.