Control valve

Abstract

The control valve for keeping constant viscosity and temperature of a pressure medium in a hydraulic circuit includes a preliminary control valve which supports a temperature sensitive control element and adjustable throttling means including a throttling plunger controlled by the control element; a control slider arranged in the valve upstream of the preliminary control valve is provided with first throttling means for admitting pressure medium against the preliminary control valve to establish a bypass connection in addition to the main connection controlled by the slider; to avoid excessive temperature increase of the medium in the case of a damage of the control element, a temperature sensitive shearing pin is provided between the control element and the throttling plunger to cause an override of the plunger to a position in which an additional bypass connection is established which prevents throttling and thus temperature increase of the pressure medium.

Dependencies are inferred from the claim text.