Abstract: The invention relates to a coating mask (1) for electrolytically coating the piston ring groove (39) of a piston (38), which is made of an elastically deformable material and has openings (3 to 10) that are arranged axially and are distributed in a uniform manner over the periphery, into which rods (11 to 18) of an expansion device (19) can be introduced, the rods being arranged in a displaceable manner such that the expansion device (19) can increase the radial diameter of the coating mask (1) and also the inner opening (2) so that the piston (38) can be introduced into the inner opening (2). The radial diameter of the coating mask (1) is selected in such a manner that after the reduction of radial diameter of the coating mask (1) and the inner opening, the elastically tensed coating mask (1) presses sealing lips (44, 45) of the coating groove (37) against the piston (38), on both sides of the piston ring groove (39).

Abstract: The invention relates to a coating mask (1) for electrolytically coating the piston ring groove (39) of a piston (38), which is made of an elastically deformable material and has openings (3 to 10) that are arranged axially and are distributed in a uniform manner over the periphery, into which rods (11 to 18) of an expansion device (19) can be introduced, the rods being arranged in a displaceable manner such that the expansion device (19) can increase the radial diameter of the coating mask (1) and also the inner opening (2) so that the piston (38) can be introduced into the inner opening (2). The radial diameter of the coating mask (1) is selected in such a manner that after the reduction of radial diameter of the coating mask (1) and the inner opening, the elastically tensed coating mask (1) presses sealing lips (44, 45) of the coating groove (37) against the piston (38), on both sides of the piston ring groove (39).

Abstract: An emergency off switching device for disconnecting an electrically operated machine from a circuit including a plurality of operated machines, includes a housing attached to the machine against which an externally accessible actuator cap is held in an axially movable arrangement, a contact switch accommodated in the housing which is closed when the switching device is in the non-actuated condition and by means of which the machine is electrically connected to the circuit, and a driver sleeve supported against the inside of the housing that is connected to the actuator cap with the free end of the driver sleeve opposite to the actuator cap facing the contact switch and disconnecting it from the circuit in the actuated condition, wherein a monitoring signal is generated when the switching device is in the actuated condition, to ascertain which of a plurality of the switching devices has been actuated.

Abstract: In an emergency off switching device (1) for disconnecting an electrically operated machine (2) from a circuit (3), with a housing (4) firmly attached to the machine (2) against which an externally accessible actuator cap (5) is held in an axially movable arrangement, with a contact switch (11) accommodated in the housing (4) which is closed when the switching device (1) is in the non-actuated condition and by means of which the machine (2) is electrically connected to the circuit (3), and with a driver sleeve (7) supported against the inside (6) of the housing (4) that is firmly connected to the actuator cap (5) with the free end (10) of the driver sleeve (7) opposite to the actuator cap (5) facing the contact switch (11) and disconnecting it from the circuit (3) in the actuated condition, functional reliability should firstly be guaranteed and, secondly, a monitoring signal should be generated when the switching device (1) is in the actuated condition, by means of which it is possible without any time delay