# US 8,739,681 B2 · Valve apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,739,681 B2 - Document ID: US8739681B2 - Status: Granted - Kind: B2 - Application number: 12/734,563 - Filed: 2008-08-26 - Published: 2010-09-16 - Granted: 2014-06-03 - Earliest claimed: 2007-11-13 - Assignees: Hydac Fluidtechnik GmbH - Applicants: Axel Grigoleit; Bernhard Steinmann - Inventors: Axel Grigoleit; Bernhard Steinmann - Web page: https://patentgrep.com/patent/US8739681B2 ## CPC - F15B 11/028: for controlling the actuating force (F15B11/024 takes precedence) - B23B 31/302: {Hydraulic equipment, e.g. pistons, valves, rotary joints} - B23Q 17/005: {by measuring a force, a pressure or a deformation} - F15B 21/08: Servomotor systems incorporating electrically operated control means (F15B21/02, {F15B21/065} take precedence) - F15B 2211/20538: constant capacity - F15B 2211/212: the pressure sources being accumulators - F15B 2211/30505: Non-return valves, i.e. check valves - F15B 2211/3051: Cross-check valves - F15B 2211/30525: Directional control valves, e.g. 4/3-directional control valve - F15B 2211/3057: having two valves, one for each port of a double-acting output member - F15B 2211/3111: the pump port being closed in the centre position, e.g. so-called closed centre - F15B 2211/3138: the positions being discrete - F15B 2211/327: electrically or electronically - F15B 2211/40507: with constant throttles or orifices - F15B 2211/41509: being connected to a pressure source and a directional control valve - F15B 2211/50554: the pressure control means controlling a pressure downstream of the pressure control means, e.g. pressure reducing valve - F15B 2211/526: electrically or electronically - F15B 2211/565: Control of a downstream pressure - F15B 2211/625: Accumulators - F15B 2211/6313: the pressure being a load pressure - F15B 2211/6653: Pressure control - F15B 2211/7054: Having equal piston areas - Y10T 137/7837: Direct response valves [i.e., check valve type] - Y10T 137/7846: Mechanically interconnected - F15B: SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR - B23B: TURNING; BORING (arrangements for copying or controlling B23Q) - B23Q: DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING (tools of the kind used in lathes or boring machines B23B27/00); MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A valve apparatus for setting and monitoring the clamping pressure of a clamping device (9) for workpieces to be clamped, in particular in lathes, has at least one pressure control valve (1A, 1B) for setting the clamping pressure, and has at least one pressure sensor (6A, 6B) detecting the clamping pressure. The clamping pressure is adjusted in relation to a predefinable setpoint clamping pressure. The valve apparatus can set the clamping pressure for safety and monitor it to maintain or reduce it during the machining. ## Claims ### Claim 1 A valve apparatus for setting and monitoring a clamping pressure of a clamping device for workpieces being clamped in the clamping device, comprising: a clamping device connection; a first pressure reducing valve for adjusting fluid pressure conveyed to said clamping device connection and having a mechanical self-locking device including self-locking gearing of a positioning motor triggered by a control; a first pressure sensor detecting pressure of the fluid pressure conveyed to said clamping device connection for adjustment to a definable setpoint clamping pressure; and first and second directional control valves switchable independently of one another, said first directional control valve being connected in a hydraulic supply circuit between said first pressure reducing valve and said clamping device connection. ### Claim 2 (depends on 1) A valve apparatus according to claim 1 wherein said pressure reducing valve comprises a proportional pressure reduction valve. ### Claim 3 (depends on 1) A valve apparatus according to claim 1 wherein said pressure sensor is connected to an electronic control. ### Claim 4 (depends on 1) A valve apparatus according to claim 1 wherein said pressure sensor is part of a programmable electronic control. ### Claim 5 (depends on 1) A valve apparatus according to claim 1 wherein each of said first and second directional control valves is at least a 3/2 directional control valve and supplies fluid pressure to said clamping device connection. ### Claim 6 (depends on 1) A valve apparatus according to claim 1 wherein an orifice is on an output side of said pressure reducing valve and has a volumetric size adjusted to the clamping device. ### Claim 7 A valve apparatus for setting and monitoring a clamping pressure of a clamping device for workpieces being clamped in the clamping device, comprising: a clamping device connection; a first pressure reducing valve for adjusting fluid pressure conveyed to said clamping device connection and having a mechanical self-locking device; a first pressure sensor detecting pressure of the fluid pressure conveyed to said clamping device connection for adjustment to a definable setpoint clamping pressure; and first and second directional control valves switchable independently of one another, said first directional control valve being connected in a hydraulic supply circuit between said first pressure reducing valve and said clamping device connection, each of said first and second directional control valves being at least a 4/2 directional control valve and supplying fluid pressure to said clamping device connection. ### Claim 8 (depends on 7) A valve apparatus according to claim 7 wherein said mechanical self-locking device comprises self-locking gearing of a positioning motor triggered by a control. ### Claim 9 (depends on 7) A valve apparatus according to claim 7 wherein first and second check valves are connected in fluid communication to said clamping device connection and assumes a blocking position in a direction of said pressure reducing valve. ### Claim 10 (depends on 9) A valve apparatus according to claim 9 wherein said first and second check valves are connected to outputs of said first and second directional control valves, respectively, in fluid communication. ### Claim 11 A valve apparatus for setting and monitoring a clamping pressure of a clamping device for workpieces being clamped in the clamping device, comprising: a clamping device connection; a first pressure reducing valve for adjusting fluid pressure conveyed to said clamping device connection and having a mechanical self-locking device; a first pressure sensor detecting pressure of the fluid pressure conveyed to said clamping device connection for adjustment to a definable setpoint clamping pressure; first and second directional control valves switchable independently of one another, said first directional control valve being connected in a hydraulic supply circuit between said first pressure reducing valve and said clamping device connection; and a second pressure reducing valve for adjusting fluid pressure conveyed to said clamping device connection being connected in a hydraulic circuit such that said second directional control valve is between said second pressure reducing valve and said clamping device connection, said first and second pressure reducing valves being switchable independently. ### Claim 12 A clamping apparatus for setting and monitoring a clamping pressure on workpieces, comprising: a clamping device; a first pressure reducing valve for adjusting fluid pressure conveyed to said clamping device and having a mechanical self-locking device including self-locking gearing of a positioning motor triggered by a control; a first pressure sensor detecting pressure of the fluid pressure conveyed to said clamping device for adjustment to a definable setpoint clamping pressure; and first and second directional control valves switchable independently of one another, said first directional control valve being connected in a hydraulic supply circuit between said first pressure reducing valve and said clamping device. ### Claim 13 (depends on 12) A clamping apparatus according to claim 12 wherein said pressure reducing valve comprises a proportional pressure reduction valve. ### Claim 14 (depends on 12) A clamping apparatus according to claim 12 wherein said pressure sensor is connected to an electronic control. ### Claim 15 (depends on 12) A clamping apparatus according to claim 12 wherein said pressure sensor is part of a programmable electronic control. ### Claim 16 (depends on 12) A clamping apparatus according to claim 12 wherein each of said first and second directional control valves is at least a 3/2 directional control valve and supplies fluid pressure to said clamping device. ### Claim 17 (depends on 12) A clamping apparatus according to claim 12 wherein an orifice is on an output side of said pressure reducing valve and has a volumetric size adjusted to the clamping device. ### Claim 18 A clamping apparatus for setting and monitoring a clamping pressure on workpieces, comprising: a clamping device; a first pressure reducing valve for adjusting fluid pressure conveyed to said clamping device and having a mechanical self-locking device; a first pressure sensor detecting pressure of the fluid pressure conveyed to said clamping device for adjustment to a definable setpoint clamping pressure; and first and second directional control valves switchable independently of one another, said first directional control valve being connected in a hydraulic supply circuit between said first pressure reducing valve and said clamping device, each of said first and second directional control valves being at least a 4/2 directional control valve and supplying fluid pressure to said clamping device. ### Claim 19 (depends on 18) A clamping apparatus according to claim 18 wherein said mechanical self-locking device comprises self-locking gearing of a positioning motor triggered by a control. ### Claim 20 (depends on 18) A valve apparatus according to claim 18 wherein first and second check valves are connected in fluid communication to said clamping device and assumes a blocking position in a direction of said pressure reducing valve. ### Claim 21 (depends on 20) A clamping apparatus according to claim 20 wherein said first and second check valves are connected to outputs of said first and second directional control valves, respectively, in fluid communication. ### Claim 22 A clamping apparatus for setting and monitoring a clamping pressure on workpieces, comprising: a clamping device; a first pressure reducing valve for adjusting fluid pressure conveyed to said clamping device and having a mechanical self-locking device; a first pressure sensor detecting pressure of the fluid pressure conveyed to said clamping device for adjustment to a definable setpoint clamping pressure; first and second directional control valves switchable independently of one another, said first directional control valve being connected in a hydraulic supply circuit between said first pressure reducing valve and said clamping device; and a second pressure reducing valve for adjusting fluid pressure conveyed to said clamping device being connected in a hydraulic circuit such that said second directional control valve is between said second pressure reducing valve and said clamping device, said first and second pressure reducing valves being switchable independently.