Patent · US Expired

Automatic door safety system

US4914859A · kind A · utility

50Cited by
3References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 23, 1988
Grant dateApr 10, 1990
Priority date
Expiry dateSep 23, 2008

Classification

  • Technology area (CPC E)Fixed Constructions
  • CPC primaryE05Y2900/104
  • WIPO fieldHandling
  • WIPO sectorMechanical engineering

Abstract

Mechanism primarily suited to automatic sliding door applications wherein at least a pair of object presence sensing detectors, preferably of the ultra-sonic transducer type are arranged to be placed in linear spaced relation to one another effective to cast sonic beams produced thereby spanning the doorway to which applied. So as to assure satisfactorily a beam path to be intercepted by an object stationary or moving in the beams, they are purposely overlapped. The door upon being operatively moved by motion sensing detectors or manual means acts at different opening positions to switch the object sensing detectors on and upon reverse closing positions switches the object sensing detectors off.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.