The invention relates to a robot carrier structure constituted by a portal wagon (10) movable on rails (12, 13) and supported at its flanks by two carriages (20, 20 min ) each comprising two wheels (21, 22) longitudinally coupled by motion transmission means (25, 28, 30; 26, 29, 31) actuated in synchronism by an electric motor (27). The two electric motors (27) of the two carriages (20, 20 min ) further are so connected as to constitute an electric axis. nEach wheel (21, 22) has a structure adapted to ensure a high adherence to the rail (12, 13), particularly due to the provision of a pair of rings (45, 46) of elastomeric material engaging the rolling surface (47) of the rail (12, 13).

The invention relates to a roller ( 21 ) from a refractory material, for example in vitreous silica, for transporting a flat article provided at its end with a new arrangement for rotationally driving it as well as to an assembly of such a roller and its driving device. This roller ( 21 ) comprises an external surface ( 2 ), an inner surface ( 5 ) and two side surfaces ( 12 ), at least one side surface having indentations ( 22 ) parallel to the roller axis ( 3 ) and spaced apart from the external ( 2 ) and inner surface ( 5 ) for receiving rotationally driving pins ( 8 ), it is characterized in that at least one of the indentations ( 22 ) of the roller is provided with a metal jacket ( 24 ). The invention permits to avoid the breakage of the roller around the driving indentations.

The device has an operating unit (11) with a rotary toggle (12) that is rotatable in an associated bearing (13), a signal arrangement for producing signals depending on a toggle position and/or change in position and controller for processing the signals to influence the electric equipment. The toggle can also be moved linearly in at least one direction and the signal arrangement can detect the linear movement (L).