| 摘要 |
<p>The front plate of an emergency telephone which bears operating instructions or other information which is liable to become obscured by a deposit of snow or ice is fitted with a flexible, water- and ice-repellant (pref. chloroprene polymer) cover. The cover is fastened to the plate, pref. along its top edge, and has (magnetic) catch at the bottom. Lead weights hold it down, and it may be reinforced with steel wire. When the cover is raised, a magnetic force switch activates the electrical appts. in the box.</p> |
