The example shows the externally visible components of a door closing system and the associated forces when the door is operated manually.
We consider the opening and closing of the door by using the door handle or (at least for the opening process) by pushing the door directly (such that the lever arm is shorter).
The friction that occurs at the visible joints of this mechanism is taken into account in a simplified way. These are friction moments that are essentially not force-dependent. Friction coefficients and pin diameters are also available for joint friction in the kinematics software ASOM v7, but are not required here.
The kinematic inner workings of the door closer (here only as Black Box) are also taken into account in a simplified manner by applying a programmable torque.