Abstract: The invention provides a pump assembly comprising an actuator lever, an actuator for moving the actuator lever, a supporting structure, a pump comprising a pump member moveable by actuation of the actuator lever, a first pivoting joint formed between the actuator lever and the supporting structure, and a second pivoting joint formed between the actuator and the supporting structure. The actuator lever and the actuator are coupled to each other by a coupling joint arranged between the first and the second pivoting joint in such a way that rotation of the actuator in a first direction causes the actuator lever to rotate in an opposite second direction. By providing an actuator system comprising two actuator elements linked to each other by a coupling joint ensuring counter rotation of the two members, a system is provided which can be made less susceptible to the influence of acceleration.