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:
Apr. 24, 1984
Filed:
May. 21, 1982
Bernhard Stier, Kelkheim-Fischbach, DE;
Klaus Rathmann, Frankfurt am Main, DE;
VDO Adolf Schindling AG, Frankfurt am Main, DE;
Abstract
A device for the unlocking and locking of doors has a pneumatic blocking device (41) by which, in a third switch position of a main lock (1), all secondary door locks (3) in addition to the main door lock (1) are blocked in such a manner that they cannot be opened either from the inside or from the outside and thus can now be opened only by a main key (8) for the main lock (1). A 3/2-way valve (30) for controlling the setting members (35) of the secondary door locks (3) and the blocking device (41) is so developed that it is movable into its one position by an electric setting device (29) and into the other by a pneumatic setting device (37). The pneumatic setting device (37) is controlled by the alternating pressure which is produced by the pump (21) which is so switched and controlled that each time that it starts up it definitely alternately supplies vacuum or pressure.