Patent ID: 6170507
Filing Date: 2001-01-09
Classification: G05D,Y10T

Abstract:
In a flow control device of the type which varies fluid flow as a function of force exerted on a control element by a regulator spring extending between the control element and a seat, improved apparatus for providing a plurality of independently adjustable seat positions comprising:a first stop element whose position is adjustable relative to the control element along an axis, said first stop element having first and second opposing stop surfaces of which the first stop surface establishes a limiting position of the seat in a first direction;a second stop element whose position is adjustable relative to the control element along the axis, said second stop element establishing stop positions of the seat away from said first stop element, the stop positions being determined in part by the second stop surface of said first stop element;a carriage mounted for variable positioning relative to the control element along the axis, and carrying said second stop element for sliding movement in said carriage between a first stop structure in a direction away from the seat and a second stop structure in a direction toward the seat, positioning of said second stop element against the first and second stop structures respectively permitting positioning of the seat in its limiting position in the first direction, and, in part, establishing a limiting position of the seat in a second direction opposite the first direction;a first biasing means biasing said second stop element toward the first stop structure of said carriage;a second biasing means for selectively biasing said second stop element toward the second stop structure of said carriage, said second biasing means being operable when selected, to overcome the bias imparted by said first biasing means, anda selector device for selecting operation of said second biasing means.