lever 19 the abutment 30 and the end disk 23 are displaced to the position shown in broken lines the abutment 30 actuates a microswitch 31 which releases via control conduit 32 the check valve 11 and moreover informs the tractor driver for example by an known acoustic or optical signal that the rear housing part 5 can be turned without danger toward the front housing part 3 after this both housing parts resume the position shown in fig1 since during turning of the rear housing part 5 to the front housing part 3 the pin 23 of the lever 24 is turned in direction of the housing part 3 and since the pin 28 of the lever 19 is also turned about the pin 17 the spring 22 is again somewhat prestressed so that the rod 16 resumes a substantially horizontal position shown in fig1 during this movement the abutment 30 is moved back from the switch 31 the winding of further bales is performed in an analogous manner it will be understood that each of the elements described above or two or more together may also find a useful aplication in other types of construction differing from the types described above while the invention has been illustrated and described as embodied in a round baling press it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention without further analysis the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that from the standpoint of prior art fairly constitute essential.