| 摘要 |
<p>PURPOSE: To prevent air from going in and out of a housing caused by pressure difference acompanying expansion and contraction of a pole. CONSTITUTION: A drive cord 8 is passed inside a telescopic pole 1 provided with an indicating lamp 19 on the extreme end, and a winding drum 5 for winding or unwinding the drive cord 8 and a motor 14 for driving the winding drum 5 to rotate normally or reversely in both directions are received in a housing 3 connected to the lower end of the telescopic pole 1. The detachably fitting port 3b of the motor 14 in the housing 3 is covered with a cap 34 made of synthetic rubber having a flexible thin wall part 34a capable of being bent in the inner and outer directions. When the telescopic pole 1 is expanded or contracted, the pressure in the housing 3 is intended to vary, but the flexible thin wall part 34a of the cap 34 is bent so as to keep pressure balance between the inside and the outside. Consequently, the inner pressure of the housing 3 is not lower than the outside, and hence water content does not remain in the housing because air does not go in and out against the housing 3.</p> |
