Wheel slip suppression system

Claim 1

IN A LOCOMOTIVE HAVING POWERED AXLES WITH WHEELS THEREON ADAPTED TO HAVE ROLLING CONTACT WITH RAIL, MEANS FOR DETECTING SLIPPAGE OF THE WHEELS ON THE RAIL, AN AIR BRAKE SYSTEM INCLUDING A BRAKE CYLINDER ARRANGED WHEN PNEUMATICALLY ACTUATED TO FORCE BRAKING ELEMENTS INTO CONTACT WITH THE LOCOMOTIVE WHEELS, A COMPRESSED AIR SOURCE, CONDUIT MEANS FOR PNEUMATICALLY CONNECTING THE AIR SOURCE TO THE BRAKE CYLINDER INCLUDING A PNEUMATICALLY CONTROLLED RELAY VALVE HAVING CONTROL MEANS ADAPTED TO ALLOW PASSAGE OF AIR FROM THE AIR SOURCE TO THE BRAKE CYLINDER UPON APPLICATION OF A PNEUMATIC CONTROL SIGNAL TO THE CONTROL MEANS: PNEUMATIC CONDUIT MEANS INCLUDING A MAGNET VALVE CONNECTING THE PRESSURE SOURCE TO SAID RELAY VALVE CONTROL MEANS; MEANS OPERABLE BY SIA DETECTING MEANS IN RESPONSE TO DETECTION OF WHEEL SLIPPAGE FOR ENERGIZING SAID MAGNET VALVE TO CAUSE APPLICATION OF A PNEUMATIC CONTROL SIGNAL TO SAID RELAY VALVE CONTROL MEANS TO BRAKE THE LOCOMOTIVE WHEELS TO SUPPRESS THE WHEEL SLIPPAGE; AN AIR RESERVOIR CONNECTED TO SAID PNEUMATIC CONDUIT MEANS WHEREBY THE AIR PRESSURE IN SAID RESERVOIR BUILDS UP AS A FUNCTION OF THE TIME SAID MAGNET VALVE IS ENERGIZED, AN EXHAUST VENT FOR ALLOWING BLEED-OFF OF THE PRESSURE IN SAID RESERVOIR; A LOCOMOTIVE SANDING SYSTEM INCLUDING A SAND TRAP AND CONDUIT MEANS CONNECTING SAID SAND TRAP TO AN AIR PRESSURE SOURCE THROUGH A SANDING RELAY VALVE HAVING PNEUMATIC CONTROL MEANS FOR OPENING SAID SANDING RELAY VALVE TO ALLOW SAND TO BE BLOWN FROM SAID SAND TRAP BETWEEN THE LOCOMOTIVE WHEELS AND RAIL, SAID SANDING RELAY VALVE CONTROL MEANS BEING PNEUMATICALLY CONNECTED TO SAID RESERVOIR WHEREBY SAID SANDING RELAY VALVE IS OPENED WHEN THE PRESSURE IN SAID RESERVOIR REACHES A PREDETERMINED VALVE AND REMAINS OPEN UNTIL THE PRESSURE IN SAID RESERVOIR FALLS BELOW A PREDETERMINED VALUE WHEREBY SAID SANDING SYSTEM IS ACTUATED AS A FUNCTION OF WHEEL SLIP ACTIVITY AND CONTINUES TO BE ACTUATED AFTER CESSATION OF DETECTION OF WHEEL SLIPPAGE FOR A PERIOD OF TIME DEPENDENT ON THE TIME DURATION OF DETECTED WHEEL SLIPPAGE IN A GIVEN INTERVAL OF TIME.