| 摘要 |
The device has a pair of paddle-like handles with each handle having a groove disposed therein for connection to opposite ends of a helical spring. A small car having a series of rollers disposed therein is mounted upon the spring for movement along the helical coils thereof. When the paddles are held in a position vertically spaced from each other, the coils of the spring are separated and the car is allowed to traverse the length of the spring following a helical path as defined by these coils.
|
