公开(公告)号：US3887252A

公开(公告)日：1975-06-03

申请号：US42171973

申请日：1973-12-04

Applicant: RONEO VICKERS LTD

Inventor： FULLER PAUL

IPC: A47B63/06 ,  A47B77/08

CPC classification number: A47B63/067

Abstract: A light operated guard for a path which may be followed by a person or part of a person with a purpose of raising an alarm, of closing the path or stopping dangerous machinery, which utilises a modulated beam of light which traverses the said path and falls upon a photocell associated with a frequency sensitive device which acts to inhibit the raising of an alarm or the closing of the path or the stopping of the dangerous machinery or the like while the beam is uninterrupted the one to maintain a constant loop gain and the other to nullify spurious signals due to vibration and other mechanical effects due to motion of the parts of the apparatus during operation of the same.

Abstract translation: 用于路径的轻型操纵的防护装置，其可以由人或其部分人员跟随，目的是提高警报，关闭路径或停止危险的机械，利用经过所述路径并下降的调制光束 在与频率敏感装置相关联的光电管上，其作用是阻止报警的增加或关闭路径或停止危险机器等，同时波束不间断地保持恒定的环路增益，而另一个 以消除由于在其操作期间由于装置的部件的运动而引起的振动和其它机械效应引起的杂散信号。