| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a fire door closing device which is excellent in operability and durability. <P>SOLUTION: This fire door closing device 10 comprises a guide case 11, a holding mechanism 21 for electrical unlocking, an arm joint 41, and a connecting section 51. The holding mechanism 21 for electrical unlocking includes a solenoid 22 through which a movable iron core 22a is pushed in or pulled out, and a plurality of rolling elements 23 at least one of which is to be disposed in a certain position in the course of pushing-pulling movement by the movable iron core 22a. The connecting section 51 has a storing groove 51c in which at least one of the rolling elements 23 can be placed. When the plurality of rolling elements 23 are arranged in tandem in the storing groove 51c, the connecting section 51 is engaged with the holding mechanism 21 for electrical unlocking, whereas when the solenoid 22 has been activated to force the movable iron core 22a to push the rolling elements 23, which releases rolling elements 23 from the storing groove 51c, the connecting section 51 gets disengaged from the holding mechanism 21 for electrical unlocking. <P>COPYRIGHT: (C)2013,JPO&INPIT |
