Patent ID: 6039072
Filing Date: 2000-03-21
Classification: F16K,Y10T

Abstract:
A safety valve arrangement for an installation operating with a pressure medium, comprising:a pressure medium input and a pressure medium output;a valve located between said pressure medium input and said pressure medium output, said valve comprising a valve seat and a valve closing element, said valve closing element being moveable between an open position and a closed position, said valve closing element having an active surface subject to said pressure-medium in the opening direction of said valve, said active surface constituting an area of said valve closing element which is delimited by said valve seat;said valve closing element further having an auxiliary surface located on an area of said valve closing element outside said area of said valve closing element which is delimited by said valve seat, said auxiliary surface being subject to said pressure medium in the opening direction of said valve only when said valve closing element is lifted from said valve seat;a spring arrangement holding said valve closing element in a first end position wherein said valve is closed, said valve closing element moving from said first end position to a second end position wherein said valve is open when the force of said pressure medium acting upon said valve closing element is greater than the opposing force of said spring arrangement acting upon said valve closing element;an auxiliary valve connecting said pressure medium input to said pressure medium output and being moveable from an open position to a closed position, said auxiliary valve having a bore for receiving said pressure medium and a valve closing element positioned so as to control said pressure medium through said bore, said auxiliary valve being located between said valve and said medium output;said spring arrangement holding said valve closing element of said auxiliary valve in a first end position wherein said auxiliary valve is closed, said auxiliary valve closing element moving from said first end position to a second end position wherein said valve is open when the force of said pressure medium acting upon said valve closing element of said valve is greater than the opposing force of said spring arrangement acting upon said auxiliary valve closing element; andsaid valve closing element of said valve and said valve closing element of said auxiliary valve being configured so that said auxiliary valve opens later than said valve and said auxiliary valve closes before said valve,wherein said spring arrangement has a force as a function of a distance characteristic curve, a portion of which has a negative slope, and wherein the actuating pressure of said valve occurs along the negatively sloped portion of said curve.