| 摘要 |
mechanism is described for controlling the movement of an insect repelling screen frame for doors or windows. In particular, a mechanism for the controlled movement of the frame of the screen that operates by the coupling of the rapidly contracting spring bearing conventional mechanism for the development of the screen to a shaft which is coupled at will and follows the rotation of the winding drum of the screen, so that the rotation of the drum when the above shaft is coupled to it is retarded. Such time retardation derives as a result of the fact that the shaft rotates inside a chamber filled with an malleable solid substance, so that its friction with the walls of the chamber is increased and the desired pre-determined time retardation during the development or contraction of the screen is achieved. With a suitable coupling means, the said arrangement is activated preferably only during the winding of the screen to the drum, in which case it results to the slow, controlled contraction movement of the screen. |
