Abstract: An ink jet printing head has a chamber for pressurized ink and a substantially linear array of outlet nozzles (5) leading from the chamber. A plurality of closure elements are selectively displaceable by respective actuators (13) to open and close respective ones of the nozzles. The closure elements are provided on respective flexible strips (7), each of which is fixed at one end and has the closure element at the other end and is displaceable by a respective actuator acting on the strip between its ends. At least some of the strips interdigitate with one another at their closure element-carrying ends from opposite sides of the substantially linear array of nozzles.

Abstract: A fluid jet marking apparatus comprises a housing (5) defining a chamber (6) for marking fluid. A plurality of outlet nozzles (8) allow ink to be ejected from the chamber and a corresponding plurality of closure elements (9) are selectively displaceable to open and close the nozzles. Springs (11) bias the elements to close the nozzles. A plurality of solenoids (14) are each connected to a respective closure element by means of a pulling element (12) slidable, under the action of the solenoid, in a respective tube (13,13') connecting the solenoid to the housing. A fluid supply (23) supplies fluid to the chamber and at least one liquid constituent part of the fluid is supplied to the chamber through the respective tubes (13') on which the solenoids are mounted.