the adapter 34 is initially separated from the housing on the round contact side the corresponding pin 54 can be moved out in a controlled manner not shown in any more detail here by the pump side housing so that the round side 42 of the adapter 32 snaps out of the clip receiver a type of key lock principle results by the design of the round recess 42 on the one hand in connection with the round projection 53 of the housing and the angled recess 40 in connection with the angled projection 51 of the housing for which protection is claimed separately the tilt movement generated by the arrangement of the pin 54 on the ejection of the adapter has yet another advantage the roller pump 10 is equipped with two radial pins such as is also described in u s pat no 4 545 744 the two pins are attached on mutually oppositely disposed sides when the left hand side of the adapter 32 is raised and the right hand side of the adapter 32 is not raised the lower pin can move easily beneath the hose in the clockwise direction in order to raise this whereas the upper pin can first extend without problem over the still inserted hose with a simultaneous raising of both pins a pin can catch in the pump hose system this is prevented by the tilt movement on the ejection of the adapter 32 the adapter 32 is made such that it permits a cant free connection between the pump hose.