Patent ID: 8857571

Claim:
An elevator installation having an elevator car and a counterweight, which car and counterweight are movable in opposite sense along guide rails in an elevator shaft by a support apparatus guided over a drive pulley of a drive, and a monitoring device for detection of slackening of the support apparatus, wherein the drive pulley is arranged between two stationary support apparatus fastening points in the shaft and the support apparatus is guided over the drive pulley to form two loops, and wherein the car is supported in one of the two loops and the counterweight is supported in another of the two loops, comprising: the monitoring device being arranged at a roller, the roller being arranged at the car or the counterweight; the monitoring device including a sensor which is switched on in a normal operating state of the elevator installation for monitoring a load on the support apparatus; and the roller being displaceably mounted by a force store element, which element is subject to a defined prestress force, whereby in response to relief of the load on the support apparatus, the force store element displaces the roller to actuate the switched on sensor to issue a load relief detection signal.