| 摘要 |
An umbrella has an intermediate point of equilibrium between its fully open and closed positions, which reduces the peak force required to move the umbrella in either direction. To actuate the umbrella, a resiliently flexible steel band is able to not only carry tension to pull the umbrella open, but the band also has sufficient rigidity to operate in compression to push the umbrella closed. The band's flexibility allows it to feed through a small sidewall hole in the mast as well as snake through a hinge on an umbrella mast that can tilt. Manually sliding an actuator sleeve upward closes the umbrella. Sliding the sleeve down opens the umbrella. Although lifting to close and lowering to open may seem counterintuitive at first, such action greatly reduces the maximum force required to operate the umbrella.
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