Abstract: A piston pump delivers precise and repeatable volumes of a fluid from a reservoir to a downstream component, and includes a piston that is rotatably and reciprocally mounted within a cylinder. The outer periphery of the piston forms an interference fit with the inner periphery of the cylinder. At least one groove is formed in the outer periphery of the piston, with the groove defining a precise volume between the piston and the cylinder, and extending in an axial direction of the piston. The cylinder includes an inlet port for providing fluid communication between a reservoir and the at least one groove when the piston is in a first position, and an exit port circumferentially spaced from the inlet port for providing fluid communication between the at least one groove and a downstream component when the first piston is rotated to a second position where the at least one groove is aligned with the exit port.

Abstract: A pump cleaning unit for a heater fixture of a smoking device includes a base member. The base member includes a cup having an open end and a closed end, and a pedestal including a top part disposed in the cup proximate the open end of the cup and a leg connecting the top part to the closed end of the cup. A peripheral edge of the top part and an interior wall of the cup define a circumferential gap. The unit further includes a cylinder having a lower chamber and an upper chamber separated by a wall, a port extending through the wall. The cylinder has a cylinder wall proximate the lower chamber that fits in the circumferential gap and permits axial movement of the cylinder relative to the cup. A holder is provided for holding the heater fixture in the upper chamber over the port such that a central opening of the heater fixture is in flow communication with the port.