# US 10,871,177 B2 · Discharge pressure scale and lifting-lowering device having a discharge pressure scale of this type > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,871,177 B2 - Document ID: US10871177B2 - Status: Granted - Kind: B2 - Application number: 16/340,799 - Filed: 2017-08-31 - Published: 2019-08-15 - Granted: 2020-12-22 - Earliest claimed: 2016-10-13 - Assignees: Hydac Fluidtechnik GmbH - Applicants: Hydac Fluidtechnik GmbH - Inventors: Philipp Hilzendegen; Markus Bill; Maximilian Felix Hess - Web page: https://patentgrep.com/patent/US10871177B2 ## CPC - F15B 13/0417: {Load sensing elements; Internal fluid connections therefor; Anti-saturation or pressure-compensation valves} - F15B 11/05: specially adapted to maintain constant speed, e.g. pressure-compensated, load-responsive {(F15B11/161 takes precedence)} - F15B 13/01: Locking-valves or other detent {i.e. load-holding} devices - F15B 13/026: {Pressure compensating valves} - F15B 13/0405: {for seat valves, i.e. poppet valves} - G05D 16/2024: {the throttling means being a multiple-way valve} - F15B 2013/004: {Cartridge valves} - F15B 2211/3055: the pressure compensating valve is arranged between directional control valve and return line - F15B 2211/40515: with variable throttles or orifices - F15B 2211/40569: the pressure compensating valve arranged downstream of the flow control means - F15B 2211/41554: being connected to a return line and a directional control valve - F15B 2211/41563: being connected to a pressure source and a return line - F15B 2211/41581: being connected to an output member and a return line - F15B 2211/426: electrically or electronically - F15B 2211/46: Control of flow in the return line, i.e. meter-out control - F15B 2211/465: Flow control with pressure compensation - F15B 2211/8606: the abnormal condition being a shock - F15B 2211/8613: the abnormal condition being oscillations - F15B: SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES ## Abstract A discharge pressure scale (30) includes a valve housing (41) having a functional connector (A), a return flow connector (T) and a user connector (28). A valve piston (52) is guided such that it moves longitudinally against the effect of an energy accumulator (42), moving from a respective opening or regulating position, against a valve seat (94), into a closed position. The user connector (28) and return flow connectors (T) are separated from one another. The fluid pressure present at the user connector (28) can be guided onto a pressure-active surface (A1*) of the valve piston (52) by a pressure compensation device (70) in such a way that it moves into its respective opening or regulating position in a pressure-compensated manner due to the force of the energy accumulator (42). ## Claims ### Claim 1 A discharge pressure maintenance type component, comprising: a valve housing having a user port, a return port and a control port; a valve piston guided for longitudinal movement in said valve housing against a force of an energy store from an open position providing fluid communication between said user port and said return port to a closed position blocking fluid communication between said user port and said return port; a pressure compensator conveying fluid pressure at said user port to a pressure-effective surface of said valve piston such that said valve piston reaches the open position in a pressure-balanced manner due to the force of said energy store, said pressure compensator having a pressure compensation channel extending through said valve piston, said pressure compensation channel having a first free end opening in said valve housing in a direction of said user port and a second free end opening in an annular channel in said valve piston, said annular channel having said pressure-effective surface; and a valve seat in said valve housing with an inclined seat forming a tightly sealed leak-free stop for said valve piston with an included contact surface on said valve piston, said pressure-effective surface having a size equal to said inclined contact surface of said valve piston in an area of said valve seat, and being larger than a control surface at a free end face of said valve piston facing said user port due to an embossing process caused by movement of said valve piston and a geometric configuration of said valve seat. ### Claim 2 (depends on 1) A discharge pressure maintenance component according to claim 1 wherein said pressure compensation channel extends centrally through said valve piston. ### Claim 3 (depends on 1) A discharge pressure maintenance component according to claim 1 wherein said annular channel is arranged between said valve seat and said return port in the closed position of said valve piston in said valve housing. ### Claim 4 (depends on 1) A discharge pressure maintenance component according to claim 1 wherein said pressure compensation channel comprises a drilled longitudinal hole at least one of centrally or eccentrically extending in said valve piston relative to a longitudinal axis of said valve piston and comprises a transverse drilled hole extending transverse to said longitudinal axis between said drilled longitudinal hole and said annular channel; and a check valve opening in the direction of said annular channel in said transverse drilled hole. ### Claim 5 (depends on 4) A discharge pressure maintenance component according to claim 4 wherein said annular channel in cross section comprises a rectilinear groove bottom, said transverse drilled hole opens into said rectilinear groove bottom; and said annular channel has a convex course in a direction of said valve seat at a first axial end thereof and has a bevel at a second axial end with a constant gradient on an outer peripheral side of said valve piston. ### Claim 6 (depends on 1) A discharge pressure maintenance component according to claim 1 wherein said valve piston comprises a damping device opposite said pressure compensation channel, said damping device including an antechamber closed by an orifice disk or throttle and opening into a spring chamber having a compression spring therein forming said energy storage, said control port opening into said spring chamber in said valve housing. ### Claim 7 (depends on 6) A discharge pressure maintenance component according to claim 6 wherein said antechamber in said valve piston opens into a damping chamber in said valve housing via said orifice disk or throttle of said damping device. ### Claim 8 A lifting-lowering device, comprising: a hydraulic power cylinder; a proportional throttle valve performing a proportional flow regulating function connected to said hydraulic power cylinder; and a discharge pressure maintenance component connected at an output side of said proportional throttle valve, said discharge pressure maintenance component including a valve housing having a user port, a return port and a control port, a valve piston guided for longitudinal movement in said valve housing against a force of an energy store from an open position providing fluid communication between said user port and said return port to a closed position blocking fluid communication between said user port and said return port, a pressure compensator conveying fluid pressure at said user port to a pressure-effective surface of said valve piston such that said valve piston reaches the open position in a pressure-balanced manner due to the force of said energy store, said pressure compensator having a pressure compensation channel extending through said valve piston, said pressure compensation channel having a first free end opening in said valve housing in a direction of said user port and a second free end opening in an annular channel in said valve piston, said annular channel having said pressure-effective surface, and a valve seat in said valve housing with an inclined seat forming a tightly sealed leak-free stop for said valve piston with an included contact surface on said valve piston, said pressure-effective surface having a size equal to said inclined contact surface of said valve piston in an area of said valve seat, and being larger than a control surface at a free end face of said valve piston facing said user port due to an embossing process caused by movement of said valve piston and a geometric configuration of said valve seat. ### Claim 9 (depends on 8) A lifting-lowering device according to claim 8 wherein said pressure compensation channel extends centrally through said valve piston. ### Claim 10 (depends on 8) A lifting-lowering device according to claim 8 wherein said annular channel is arranged between said valve seat and said return port in the closed position of said valve piston in said valve housing. ### Claim 11 (depends on 8) A lifting-lowering device according to claim 8 wherein said pressure compensation channel comprises a drilled longitudinal hole at least one of centrally or eccentrically extending in said valve piston relative to a longitudinal axis of said valve piston and comprises a transverse drilled hole extending transverse to said longitudinal axis between said drilled longitudinal hole and said annular channel; and a check valve opening in the direction of said annular channel in said transverse drilled hole. ### Claim 12 (depends on 11) A lifting-lowering device according to claim 11 wherein said annular channel in cross section comprises a rectilinear groove bottom, said transverse drilled hole opens into said rectilinear groove bottom; and said annular channel has a convex course in a direction of said valve seat at a first axial end thereof and has a bevel at a second axial end with a constant gradient on an outer peripheral side of said valve piston. ### Claim 13 (depends on 8) A lifting-lowering device according to claim 8 wherein said valve piston comprises a damping device opposite said pressure compensation channel, said damping device including an antechamber closed by an orifice disk or throttle and opening into a spring chamber having a compression spring therein forming said energy storage, said control port opening into said spring chamber in said valve housing. ### Claim 14 (depends on 13) A lifting-lowering device according to claim 13 wherein said antechamber in said valve piston opens into a damping chamber in said valve housing via said orifice disk or throttle of said damping device. ### Claim 15 A discharge pressure maintenance component, comprising: a valve housing having a user port, a return port and a control port; a valve piston guided for longitudinal movement in said valve housing against a force of a compression spring from an open position providing fluid communication between said user port and said return port to a closed position blocking fluid communication between said user port and said return port; a pressure compensator conveying fluid pressure at said user port to a pressure-effective surface of said valve piston such that said valve piston reaches the open position in a pressure-balanced manner due to the force of said compression spring; and a damping device being opposite said pressure compensator and including an antechamber closed by an orifice disk or throttle and opening into a spring chamber having said compression spring therein, said control port opening in said spring chamber in said valve housing, said antechamber opening into a damping chamber in said valve housing via said orifice or throttle of said damping device.