| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the durability and the visibility by mounting a display part formed by laminating a face light-emitting element emitting the light corresponding to the power supply, and a non-light emitting sheet, and making the display part emit the light when a telescopic axle is expanded and contracted. SOLUTION: A display board 30 comprising an opaque sheet 34 as a non-light emitting sheet and an EL board 35 composed of an electroluminescent element as a face light-emitting element, is mounted at a rear part of a tire fender. In an electric circuit for controlling the light emission of the EL board 35, a limit switch 44 mounted on an axle cylinder of a telescopic axle is connected between a relay 41 and a relay driving power source 42, and the relay 41 and the relay driving power source 42 are disconnected when a rod of the axle cylinder is contracted, and connected when the rod is expanded. whereby the luminous display of, for example, 'AT WORK' is available on a display part 30a of the display board 30.</p> |
