2004: Birth of Modern Proximity Safety Systems using Magnetic Fields
During the middle of the 1970’s, the Bureau of Mines performed numerous studies and investigations into the possible use of magnetic fields to accomplish communications in underground mines. Many analytical studies and tests were performed by major engineering firms, such as Arthur D. Little and detailed reports were prepared. Mr. William Schiffbauer was an employee of the Bureau of Mines during that time and participated in the investigation and testing. Much was learned and extensively documented about the characteristics and operational parameters of magnetic fields, especially for mining environments.
After the Bureau of Mines was abolished, many of the personnel were transferred into the National Institute of Safety and Health (NIOSH), as part of the Centers for Disease Control. Mr. Schiffbauer retained copies of most of those outstanding technical reports and continued his interest into magnetic fields. He and others pursued the idea of providing safety for personnel working close to mining equipment and he assembled magnetic devices and performed various tests at NIOSH to confirm and better develop his ideas.
Mr. Schiffbauer was awarded two patents; the second one presenting the basic concept of magnetic fields being used for Proximity Detection by companies like FEP and Strata for use on vehicles and mobile equipment in a wide range of environments.
This second Schiffbauer patent ( Patent # 6,810,353) was issued by the USPTO on October 26, 2004. This patent disclosed to the mining industry the use of magnetic fields, produced by generators mounted on continuous miners, and detected by a Personal Alarm Device carried by pedestrians. The concept is closed loop so that the pedestrian is warned but a UHF signal is returned to the machine to be used to warn the operator as well.