Alarm system for passageways

摘要

An improved alarm system for monitoring movement through a passageway defined by opposing sidewalls comprises a lower passage indicator disposed toward the lower ends of the sidewalls, an upper passage indicator disposed toward the upper ends of the sidewalls and a control mechanism configured to sound an alarm if one of the passage indicators indicates passage through the passageway and the other passage indicator does not. In a preferred embodiment, the alarm system is configured as a pool alarm and each passage indicator comprises an emitter/receiver that emits an infrared beam toward an opposing reflector to provide a lower beam and an upper beam. If only the lower beam is interrupted, indicating a child passing through the passageway, the control mechanism will generate an alarm signal. If both beams are interrupted, indicating an adult passing through the passageway, the control mechanism will not generate the alarm signal.

主权项

1. An alarm system for a passageway defined by a first sidewall and a second sidewall, said alarm system comprising:
lower passage indicator means disposed generally toward a lower end of said first sidewall and generally toward a lower end of said second sidewall for indicating passage through said passageway by a child or an adult; upper passage indicator means disposed generally toward an upper end of said first sidewall and generally toward an upper end of said second sidewall for indicating passage through said passageway by the adult, said upper passage indicator means sufficiently spaced above said lower passage indicator means so as to not indicate passage through said passageway by the child; and control means operatively connected to each of said lower passage indicator means and said upper passage indicator means for determining whether passage through said passageway is by the child or by the adult, said control means configured to generate a signal when passage through said passageway is by the child and to not generate said signal when passage through said passageway is by the adult.