Abstract: There is provided a method of measuring liquid volume in a sealed container of a breast pump of known volume comprising liquid and gas. The method includes a measurement phase, measuring the volume of gas in the container by changing a first parameter of the gas by a known amount. The method also includes measuring a change in a second parameter of the gas; calculating the volume of gas in the container using the measured change and a predetermined operation equation; and determining the volume of liquid in the container based on the calculation.

Abstract: A throwing arm for a target throwing device the arm including upper and lower plates which receive respective targets so that in operation two targets are thrown simultaneously. The arm is formed as an extrusion for strength lightness and ease of fabrication. A novel magazine is also disclosed which utilizes extruded elements which are shaped and disposed so as to hold targets in columns in the magazine.

Abstract: A magazine for targets to be thrown from a throwing device having a rotatable throwing arm mounted for rotation with a shaft is disclosed. The magazine comprises a stationary plate having a transfer opening therein and a holding member for holding a plurality of columns of targets. The columns are supported by this stationary plate except at the transfer opening. An indexing mechanism selectively rotates the holding member about the shaft in synchronism with the throwing arm so that when one of the columns passes over the transfer opening, the lowermost target in the column passes through the opening and onto the throwing arm. The indexing mechanism is arranged to arrest movement of the holding member relative to the shaft in a position where the targets cannot pass through the opening. A restraining mechanism prevents all but the lowermost target in each column from passing through the transfer opening, as the columns pass above the transfer opening.