Abstract: The invention concerns an injection device for apportioning set doses of a drug from a reservoir to a subject. The injection device comprises a housing having an interior thread formed as an outwardly pointing thread carried on an upstanding tower centrally located in the injection device. The outwardly pointing thread forms a first thread connection with an interior thread of a rotatable scale drum. The injection device further comprises a driver for moving a piston rod forward when moved axially. The driver operates the piston rod through a second thread connection having a pitch different than the first thread connection.

Abstract: A push button connection for an injection device comprising a push button (10) and a driving part (20). The two parts of the push button connection are mounted to each other and is relatively rotatable to each other. In order to minimize the friction occurring between the push button and the driving part when relatively rotated forces are transmitted via a pivot bearing (18, 22). In order also to minimize the effect of forces appearing dislocated from the center line a number of radial bearings (13, 23; 14, 25) having a little friction diameter is provided.

Abstract: A push button connection for an injection device comprising a push button (10) and a driving part (20). The two parts of the push button connection are mounted to each other and is relatively rotatable to each other. In order to minimize the friction occurring between the push button and the driving part when relatively rotated forces are transmitted via a pivot bearing (18, 22). In order also to minimize the effect of forces appearing dislocated from the centre line a number of radial bearings (13, 23; 14, 25) having a little friction diameter is provided.