portion 17 the axial movement of the attachment member 20 through the guide portion 27 is effected by means of drive member 28 which at one end is connected to the second frame portion 17 and at the other lower end to a lever 29 the lever 29 is connected at one end to the end of the attachment member 20 and at the other end to the end of a connection rod 30 connected to the second frame portion 17 when the drive member 28 is energized the axial position of the attachment member 20 can be set namely in such a manner that upon a lengthening or shortening of drive member 28 a much greater axial displacement of the attachment member 20 is effected as a result of the lever action of lever 29 the drive member 28 is for example of the type provided with a spindle an electric motor and a potentiometer by means of which the change in length can be set accurately since it may be of importance for the teat cup to be attached as quickly as possible after detection of the teat the rate at which drive member 28 acts is increased by means of lever 29 in fig3 and 4 the attachment member 20 is shown in the lowermost position while the teat cup 21 located at the top end of the attachment.