Cargo transfer logic circuitry

In a cargo transfer shutoff system, dock selector and status circuit means comprising:

• first diode means including an anode and a cathode, said first diode cathode being connected to an output lead;
• first resistance means of a predetermined value connected on one end to said first diode anode;
• first lamp means having a very low resistance when unlit connecting the other end of said first resistance means to ground;
• first switch means connecting said other end of said first resistance means to a positive voltage of predetermined value;
• second diode means including an anode and a cathode, said first diode anode being connected to said second diode anode;
• second lamp means having a very low resistance when unlit connecting said second diode cathode to ground;
• and
• second switch means connecting said second diode cathode to said positive voltage,
• whereby when said first switch means is closed as a selector switch, said output lead is positive to indicate a closed status condition of said second switch means and is zero to indicate an open status condition thereof.

In a cargo transfer shutoff system, control means comprising:

• at least one vehicle selector and status circuit means including
• first vehicle diode means comprising an anode and a cathode,
• first vehicle resistance means of a predetermined value connecting a positive voltage of predetermined value to said first vehicle diode anode.
• first vehicle lamp means having a very low resistance value when unlit connecting said first vehicle diode cathode to ground,
• first vehicle switch means connecting said first vehicle diode cathode to said positive voltage,
• second vehicle diode means comprising an anode and a cathode, said first vehicle diode anode being connected to said second vehicle diode anode,
• second vehicle lamp means having a very low resistance value when unlit connecting said second vehicle diode cathode to ground,
• second vehicle switch means connecting said second vehicle diode cathode to said positive voltage, said first vehicle resistance means being of predetermined value to reduce current passing through it so that said first and second vehicle lamp means remain respectively unlit when said first and second vehicle switch means are open,
• third vehicle diode means comprising an anode and a cathode, said second vehicle diode anode being connected to said third vehicle diode anode and said third vehicle diode cathode being connected to a vehicle output lead,
• fourth vehicle diode means comprising an anode and a cathode, said second vehicle diode cathode being connected to said fourth vehicle diode anode, and
• second vehicle resistance means of a predetermined value connecting said fourth vehicle diode cathode to a vehicle bus lead so that when said second vehicle switch means is closed as a selector switch, said second vehicle resistance means connects said positive voltage to said vehicle bus lead;
• and
• at least one dock selector and status circuit means including
• first dock diode means comprising an anode and a cathode, said first dock diode cathode being connected to a dock output lead,
• first dock resistance means of a predetermined value connected on one end to said first dock diode anode,
• first dock lamp means having a very low resistance when unlit connecting the other end of said first dock resistance means to ground,
• first dock switch means connecting said other end of said first dock resistance means to said positive voltage,
• second dock diode means comprising an anode and a cathode, said first dock diode anode being connected to said second dock diode anode,
• second dock lamp means having a very low resistance when unlit connecting said second dock diode cathode to ground,
• second dock switch means connecting said second dock diode cathode to said positive voltage,
• transistor means comprising a base, collector and emitter, said transistor emitter being connected to ground,
• second dock resistance means connecting said transistor collector to a dock bus lead, and
• third dock resistance means connecting said other end of said first dock resistance means to said transistor base so that when said first dock switch means is closed as a selector switch, said transistor means conducts and said second dock resistance means connects said dock bus lead to ground, said vehicle bus lead and said dock bus lead being connected to a common bus line,
• whereby when said second vehicle switch means and said first dock switch means are closed, said bus line is placed at a voltage according to said predetermined values of said second vehicle resistance means and said second dock resistance means.