Abstract: In order to produce a monitoring device for checking for a predefined position of a body or checking for the presence of a body, comprising a pivotal check element, a motor for driving the checking element and a housing for accommodating the motor, which will be universally employable especially in difficult working surroundings, it is proposed that a seal be arrangement between the checking element and the housing around a shaft by means of which the checking element is driven.

Abstract: In order to improve a monitoring device for checking for a predefined position of a body or for checking for the presence of a body, comprising a pivotal checking element, a motor for driving the checking element and a control device for controlling the pivotal movement of the checking element, in such a manner that it is universally employable and, in particular, the exertion of too high a force on a body is prevented, it is proposed that the checking element be adapted to be pivoted commencing from a starting position through a transition region into a monitoring region in which the predefined position of the body lies or in which the presence of a body should be monitored, and that the control device limit the torque of the checking element in such a manner that the maximum possible torque in the monitoring region is reduced relative to that in the transition region.

Abstract: In order to produce a monitoring device for checking for a predefined position of a body or for checking for the presence of a body, comprising a pivotal checking element, a motor for driving the checking element and a control device for controlling the pivotal movement of the checking element, wherein the pivotal movement is effected in a controlled manner, provision is made for the control device to specify the pivotal position of the checking element in dependence on the time.