Electrical code element reader for use in hazardous locations

Claim 1

IN A CODE CARD READER UNIT, A CODE READER HAVING A PLURAITY OF ELECTRICAL CIRCUITS INTERCONNECTED TO PROVIDE A PLURALITY OF DIFFERENT OPERABLE PERMUTATIONS, EACH CIRCUIT INCLUDING CONTACTS MOVABLE RELATIVE TO EACH OTHER AND HAVING A STANDBY POSITION AND A STATIC READING POSITION, EACH OF SAID PERMUTATIONS BEING RELATED TO A CORRESPONDING CODE INPUT MEMBER ENGAGING SAID CONTACTS AND PERMITTING MOVEMENT OF ONLY SELECTED RELATED ELECTRICAL CONTACTS RELATIVE TO EACH OTHER FROM THE STANDBY POSITION TO THE STATIC READING POSITION, POWER CONTROL SWITCH MEANS CONNECTED TO CONTROL THE APPLICATION AND THE REMOVAL OF POWER TO THE CONTACTS, SAID SWITCH MEANS BEING WITHIN AN EXPLOSION PROOF ENCLOSURE MEANS, AND MEANS COUPLED TO THE CODE READER AND TO THE POWER CONTROL SWITCH MEANS AND SEQUENTIALLY MOVING THE CONTACTS AND THE POWER CONTROL SWITCH MEANS BETWEEN SAID POSITIONS AND MOVING THE CONTACTS TO A STATIC READING POSITION BEFORE ACTUATION OF THE POWER CONTROL MEANS FOR THE APPLICATION OF POWER TO THE CONTACTS AND ACTUATING THE POWER CONTROL SWITCH MEANS AND REMOVING POWER FROM THE CONTACTS BEFORE THE MOVEMENT OF THE CONTACTS TO THE STANDBY POSITION WHEREBY SAID READER UNIT IS ADAPTED FOR INSTALLATION WITHIN AN EXPLOSIVE ENVIRONMENT.