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:
Aug. 21, 1984
Filed:
May. 21, 1982
Klaus Rathmann, Frankfurt am Main, DE;
VDO Adolf Schindling AG, Frankfurt am Main, DE;
Abstract
A device for the unlocking and locking of doors having pneumatic setting members in the individual door-locking mechanisms is provided centrally with a pneumatic pump (19) having a motor (18) of controlled direction of rotation. This motor can be controlled by means of a DC door switch (2). Immediately after a pressure build-up or vacuum build-up a holding-circuit switch (23) closes a holding circuit so that the DC motor (18) which drives the pneumatic pump (19) continues to operate even if it is immediately switched back directly after the making of contact by the door switch (2). Upon an increase in vacuum or pressure, a contact finger (26) of the holding-circuit switch (23) displaces a contact bridge in such a way that it actuates a bistable change-over switch (10) via mechanical transmission members. This change-over switch (10) disconnects the DC motor (18) from the source of voltage and makes it possible for the DC motor (18) to start up in the opposite direction of rotation upon the next following actuation of the door switch.