DEVICE FOR COVERING FLOOR OPENING Russian patent published in 2003 - IPC

FIELD: theater equipment. SUBSTANCE: device has cover 1 closing the opening, drive 2 for opening the cover, power springs 3, cover hand lifting lever 4, stop 5 and, additionally, chute 6 installed over perimeter of opening. Chute is filled up with hissing material - sand 7. Cover has ring projection 8 located from below diametrically relative to chute, and load reducer 9. Four springs 3 and two screw pairs 11, 12 with lever 4 are built into cover body. Drive 2 is made in form of draw truck. Horizontal rollers 15 and stop 5 for engagement, respectively, with side and front walls of chute are installed on base 14. Cover also installed on base is mounted on base of truck by means of power springs for resting onto chute outlines under action of load reducer 9 and displacement in height to stop against bead 13 by means of lever 4 and dipping of ring projection into chute loose material. To open cover it is lifted first until ring projection gets out of chute completely and then truck with cover is rolled off beyond the limits of opening. EFFECT: improved operating characteristics of device. 1 dwg