Determination of the air play in a brake with two directions application devices

The method according to claim 15, wherein,

• the air gap is calculated according to the following relationship:
• L=C*(a1*x1−b1*x2)/2.

The method according to claim 15, wherein

• the air gap has a specified maximum value and when the maximum value is exceeded an adjusting device of the brake is actuated to reduce the air gap.

The method according to claim 15, wherein

• the air gap is compared to a minimum value and when the value falls below the minimum value the air gap is increased by means of an adjusting device.

A control device for determining an operating variable of a brake

• having a friction element, which can be moved in at least two application directions against the friction surface of an element to be braked, wherein the control device is operable to place the friction element into a first and a second point of contact with the element to be braked, and comprises sensors to detect the position of the contact points and is further operable to determine the operating variable from said detected positions.