Patent ID: 6422519
Filing Date: 2002-07-23
Classification: B61L

Abstract:
In a pneumatic operator for a railroad track switch including a solenoid-operated spool valve for directing compressed air from a source to the piston of a double acting pneumatic cylinder, a cylinder head assembly providing a mounting surface for the spool valve, and air flow porting between the spool valve and the cylinder, said porting including a compressed air inlet passage, a first supply passage directing compressed air to one side of the piston to stroke the piston in a first direction and receiving exhaust air from said one side of the piston when the piston is stroked in the opposite second direction, a second supply passage directing compressed air to the other side of the piston to stroke the piston in said second direction and receiving exhaust air from said other side of the piston when the piston is stroked in said first direction, a first exhaust port receiving air from said first supply passage and a second exhaust port receiving air from said second supply passage, an improved cylinder head assembly comprising:an exhaust passage interconnecting said first and second exhaust ports to permit the flow of exhaust air from either of said supply passages to pass through both of said exhaust ports; recessed portions in the cylinder head for receipt of electric power connections for operating the spool valve; voltage control means for applying nominal 12 volt electric operating power to the spool valve from line voltage in excess of about 14 volts and for passing line voltage between about 14 volts and a minimum operating voltage directly to the spool valve; said voltage control means comprising a control module received in one of said recessed portions; and, interface means in another of said recessed portions defining the valve mounting surface for receipt of the spool valve and providing direct connection to said ports and plug-in electric power connection to said voltage control module.