The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 25, 2000
Filed:
Oct. 02, 1998
Young Jo Kim, Bokhyun-2dong, Buk-gu, Taegu Ci, KR;
Other;
Abstract
A door locking device for locking a door in predetermined, opened positions and automatically unlocking the door from the open positions in the event of a fire. The door locking device comprises a rotating body which includes channels and a support body which includes guide grooves separated by locking grooves. The rotating body and support body are operatively connected together. A locking device which includes locking balls mounted on springs extends through the channels for selective spring biased engagement of the locking balls with the locking grooves or guide grooves of the support body. A heat detection device is operatively connected to the locking device, the heat detection device including a heat-sensitive material. If the door locking device is exposed to a predetermined amount of heat, the heat-sensitive material loses its shape, causing the locking device to permit the locking balls to move from the locking grooves to the guide grooves for releasing the locking device.