When there is a breakdown in either one of first and second power converters supplying electrical power to a multi-winding motor comprising a wind-up mechanism, a rescue operation can be safely and reliably carried out by using the remaining power converter. The invention further relates to pharmaceutical compositions comprising compounds of formula, and the use of such compounds in the treatment of various diseases. The pull down bed includes a device for locking said mattress frame in the closed or horizontal position, which is actuated by an actuation device, which includes the feet. The invention can be used for the production of inserts.