Patent ID: 6152179
Filing Date: 2000-11-28
Classification: F15B,Y10T

Abstract:
A manually operable hydraulic pilot-control device having a continuously adjustable pressure-reducing valve (9), which has a housing (10) and, in a continuous housing bore (11), a control piston (50), which is actable upon by a control spring (61) in an opening direction of a connection between a pressure inlet (P) and a control outlet (A) and is actable upon in the opposite direction by pressure in the control outlet (A), and the control spring (61) of which is restrained between a first fixed stop (59) of the control piston (50) and a spring retainer (56), which is placeable against a second fixed stop (54) of the control piston (50) and is driveable along by an axially guided plunger (14) located at a first open end of the housing bore (11) and is supportable at a distance from the second stop (54) of the control piston (50), wherein the control piston (50) is displaceable in a control sleeve (20) put into the housing bore (11), and wherein an axial position of the control sleeve (20) is adjustable from outside, wherein space (39) in front of one end face of the control sleeve (20) in which the control spring (61) is located is connected to a tank outlet (T), and wherein two annular spaces (27, 28) are formed between the control sleeve (20) and the wall of the housing bore (11), which annular spaces (27, 28) are sealed off from one another at the bore wall and from the space (39) in front of one end face of the control sleeve (20), and of which one annular space (27) is connected to the pressure inlet (P) and the other annular space (28) is connected to the control outlet (A), and from which in each case at least one radial bore (43, 44) leads through the control sleeve (20) into its interior.