Abstract: An apparatus for the dosed dispensing of a liquid by means of an injection device equipped with a motor-driven spindle mechanism, a cylinder and a piston, one end of the piston being axially displaceable in the cylinder and the other end being operatively connected with one end of a spindle shaft of the spindle mechanism. At the opposite end of the spindle shaft there is provided a first scale ring connected with the spindleshaft and a second scale ring which engages with the first scale ring. A coupling element connects the second scale ring with an adjustment device, the second scale ring being rotatable and thus adjustable with respect to the first scale ring by axially disengaging or declutching the same. Both of the scale rings are equipped with at least one stop means for limiting the adjustment path of the second scale ring for setting the volume of the liquid to be dispensed or dosed.