| 摘要 |
<p>The pneumatic piston device is controlled by a hand pump, being for driving a plastic ball in a table game. The pump is of flexible plastics drawing in and compressing the air. The air is delivered via a plastic tube to a plastic unit with a hole in which a plastic piston slides (5), acting as a striker for ball propulsion (9). The pump can be so designed as to effect both outward and return piston strokes, no return spring or other metal component being necessary.</p> |
