Railroad accident prevention system with ground-retractable vehicle barrier

A railroad accident prevention system in combination with a railroad crossing having railroad tracks passing through said railroad crossing and with at least one gate arm which is lowered from an upright gate open position to a horizontal gate closed position under control of a remote controller activated when a train approaches the railroad crossing, comprising:

• at least one ground-retractable vehicle barrier means for preventing penetration of a vehicle to the railroad tracks when said gate arm is in a closed position;
• and
• drive means for switching said gate arm between said upright gate open position and said horizontal gate closed position, said drive means being activated by a signal from said remote controller;
• said drive means being an electric motor having a drive shaft, said at least one ground-retractable vehicle barrier means comprising a plurality of cogs rigidly attached to said drive shaft, each said cog being made in the form of a double-arm lever with the pivot point on said drive shaft, said double arm lever having a first arm capable of projecting above the ground and functioning as an obstacle for a vehicle, and a second arm functioning as a stopper against a stationary object that prevents further rotation of said cog;
• at least one recess below the ground level on said railroad crossing, said drive motor, said drive shaft and said plurality of cogs on said drive shaft being located in said recess, said drive shaft being substantially parallel to railroad tracks passing through said railroad crossing, said first arm being formed as a sharp tooth, in said projecting position said sharp tooth being inclined under an acute angle toward oncoming vehicles;
• said drive motor being kinematically connected to said at least one gate arm through a transmission mechanism;
• said transmission mechanism comprising a gear reducer for transmitting rotation in mutually perpendicular directions and flexible elements connected to said reducer for lowering said gate arm when said drive motor rotates in one direction and for raising said gate arm when said drive motor rotates in a direction opposite to said one direction;
• a first sensor means capable of sensing the presence of an obstacle on the path of said train through said highway-railroad crossing when said at least one gate arm is turned into said closed position;
• an alarm means capable of generating a signal selected from an audible signal and a visible signal;
• first interlock means connected to said drive means and interlocking said at least one sensor means with said alarm means for activating said alarm means when said sensor senses said obstacle with said at least one gate arm in said closed position;
• and
• a second sensor means located at a point ahead of said railroad crossing on the way of said train, said second sensor means being responsive to the presence of said train;
• and second interlock means between said second sensor means and said alarm means for preventing activation of said alarm means in response to the train when no obstacle is sensed by said first sensor means on the railroad crossing;
• said first interlock means and said second interlock being a pair of switching means selected from electromechanical relays and solid-state relays, said first interlock means and said second interlock means being connected to said alarm means through a respective controller and said relays;
• said first and second sensor means comprising a resonance-type oscillating circuit consisting of an oscillating voltage generator, a capacitance, and a sensitive element capable of violating resonance conditions of said oscillating circuit in response to a mass of an object having ferromagnetic parts.