A control mechanism of a volumetric dispenser forming part of a gunpowder dosing device, enabling adequate volume control of the gunpowder compartment for easy and accurate dosing of gunpowder. The control mechanism includes a holder with a fastening element attached to the gunpowder compartment and a recess for receiving limiting means, an outer and an inner member, each with a gear section and a synchronising pinion connecting the gear sections. The outer member is coaxially fixed to the head of an adjusting screw. The slide is connected to the adjusting screw. The outer member has a scale and a window for displaying units on a measuring scale. The surface of the outer circumference has shallow grooves which the limiting element engages when the outer member is displaced a fraction of a turn. The inner member has the measuring scale displaying the displacement of the outer member by one complete turn.

A metering distribution assembly and a coating system. The metering distribution assembly includes a volumetric cavity pump that comprises a flow passage plate having flow passages, a nozzle plate with a flow passage, a gear fixing plate attached between the flow passage plate and the nozzle plate, and a gear set located in an aperture of the fixing plate. The gear set has a fluid inlet and a fluid outlet on a side of the gear set opposite to the fluid inlet. The fluid inlet is in fluid communication with the flow passages of the flow passage plate, and the fluid outlet is in fluid communication with the flow passage of the nozzle plate. A part of the flow passages of the flow passage plate, which is in direct fluid communication with the fluid inlet, extends in a direction parallel to a rotation axis of the gear set.