position the lid apparatus includes at least one pair of contact surfaces which are perpendicular to the axis of rotation and resiliently biased against each other wherein at least one of the contact surfaces includes a rolling and latching geometry which is configured such that the lid latches in the second position and the pivoting moveability of the pivot joint is only released when the resilient biasing force is overcome a medical device for extracorporeal blood treatment including a peristaltic pump and such a lid apparatus is also disclosed application_number US 201313927773 A description fig1 shows a schematic illustration of the essential basic components of a medical device 19 for extracorporeal blood treatment comprising a blood pump wherein in particular the blood pump concerns a peristaltic pump the peristaltic pump thus comprises a pump housing 10 which typically is attached to the front side of the dialysis machine 19 arterial blood 21 of a patient is fed to this peristaltic pump and conducted through the extracorporeal blood circuit subsequently the blood is returned to the patient as venous blood 22 in this way the blood is supplied by means of the pump through a transfer system which is connected to a plurality of components of the dialysis device wherein a tube segment 20 of the transfer system is placed in the peristaltic pump and a rotor 30 supplies the blood peristaltically through said tube segment 20 as is to be understood by the enlarged view of fig2 after passing through the blood pump and after it may have passed though an arterial air trap 13 the blood reaches the dialyzer 15 in the dialyzer 15.