| 摘要 |
A device for product promotion comprises an upright tank 2 of transparent material to support a column of water, a means 10 at the lower end 3 of the tank 2 for generating a stream of air bubbles 29 which will rise upwardly, a plurality of individual vessels 5 immersed within the fluid, means 18, 19 to maintain the vessels 5 in an upright disposition, and each vessel 5 having a hole 15 for the entry of the water and air to a cavity 45 within the vessel 5. Each vessel also incorporates a float valve 24, movable between open and closed positions in accordance with the level of fluid within the cavity 45 of the vessel 5 to change the buoyancy of the vessel 5, such that, with a negative buoyancy vessel 5 is located at the lower end of the tank and with the valve 24 in a closed position, a number of bubbles enter and are trapped within the cavity 45 creating a positive buoyancy vessel which rises until at the upper end 30 of the tank. The progressively decreasing level of fluid within the cavity 45 eventually causes the float valve 24 to open to release at least some of the air bubbles 29 trapped in the cavity 45, thereby destroying the positive buoyancy such that the vessel sinks and the float valve is closed. |
