Photoelectric system for detecting objects in a zone including vibrating light source

• US 3,335,285 A
• Filed: 03/24/1964
• Issued: 08/08/1967
• Est. Priority Date: 03/24/1964
• Status: Expired due to Term

• Current Assignee: Arrowhead Enterprises, Inc.
• Original Assignee: Gally J.R. John, William G. Kahl Jr
• Inventors: GALLY JR JOHN, Kahl, William G. Jr.
• Application Number:
  US04/354,342
• Time in Patent Office: 1,232 Days
• US Class Current: 250/221
• CPC Class Codes: G08B 13/183 by interruption of a radiation beam or barrier
• CPC Class Codes: G08B 13/184 using radiation reflectors

Claims

4. A SYSTEM FOR DETECTING THE PRESENCE OF LIGHT OPAQUE MATERIALS IN A PRESELECTED ZONE WHICH COMPRISES:

A LIGHT SOURCE MOUNTED TO VIBRATE IN RESPONSE TO LOCAL VIBRATIONS TO CAUSE A LIGHT BEAM THEREFROM TO OSCILLATE;

MEANS FOR DIRECTING THE LIGHT BEAM FROM SAID SOURCE IN A PATH THROUGH SAID PRESELECTED ZONE;

LIGHT SENSITIVE MEANS POSITIONED TO PERIODICALLY RECEIVE THE OSCILLATING BEAM TO PRODUCE A FIRST INTERMITTENT ELECTRICAL SIGNAL THEREFROM;

PEAK DETECTOR MEANS HAVING A TIME CONSTANT LONGER THAN THE OSCILLATION PERIOD OF SAID BEAM CONNECTED TO RECEIVE SAID FIRST ELECTRICAL SIGNAL AND PRODUCE A SUBSTANTIALLY STEADY SECOND ELECTRICAL SIGNAL THEREFROM;

AND INDICATING MEANS CONNECTED TO RECEIVE SAID SECOND ELECTRICAL SIGNAL AND INDICATE ATTENUATION OF SAID BEAM RESULTING FROM THE PRESENCE IN SAID PATH OF SAID LIGHT OPAQUE MATERIALS.