# US 2014/0360349 A1 · Hydraulic cylinder for use for example in a hydraulic tool > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0360349 A1 - Document ID: US20140360349A1 - Status: Published application - Kind: A1 - Application number: 14/301,267 - Filed: 2014-06-10 - Published: 2014-12-11 - Earliest claimed: 2013-06-11 - Assignees: Demolition and Recycling Equipment B.V. - Applicants: Demolition and Recycling Equipment B.V. - Inventors: Gertrudis Maria Gerardus De Gier - Web page: https://patentgrep.com/patent/US20140360349A1 ## CPC - F15B 15/149: {Fluid interconnections, e.g. fluid connectors, passages} - E02F 3/965: {of metal-cutting or concrete-crushing implements (shearing devices B23D17/00; wrecking of buildings, e.g. tools therefor, E04G23/08)} - E02F 9/2267: {Valves or distributors (position of valves arrangements on upper-structures E02F9/0875)} - E02F 9/2271: {Actuators and supports therefor and protection therefor} - F15B 11/024: by means of differential connection of the servomotor lines, e.g. regenerative circuits - F15B 13/0401: {Valve members; Fluid interconnections therefor} - F15B 20/007: {Overload} - F15B 11/022: {in which a rapid approach stroke is followed by a slower, high-force working stroke (F15B11/0325 takes precedence)} - F15B 2011/0243: {the regenerative circuit being activated or deactivated automatically} - F15B 2211/30505: Non-return valves, i.e. check valves - F15B 2211/3058: having additional valves for interconnecting the fluid chambers of a double-acting actuator, e.g. for regeneration mode or for floating mode - F15B 2211/329: actuated by fluid pressure - F15B 2211/355: Pilot pressure control - F15B 2211/50518: using pressure relief valves - F15B 2211/5153: being connected to an output member and a directional control valve - F15B 2211/55: for limiting a pressure up to a maximum pressure, e.g. by using a pressure relief valve - F15B 2211/775: Combined control, e.g. control of speed and force for providing a high speed approach stroke with low force followed by a low speed working stroke with high force, e.g. for a hydraulic press - F15B 2211/8636: Circuit failure, e.g. valve or hose failure - F15B 2211/8752: Emergency operation mode, e.g. fail-safe operation mode - F15B: SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR - E02F: DREDGING; SOIL-SHIFTING (winning peat E21C49/00) ## Abstract The invention relates to a hydraulic cylinder, for example for use in a hydraulic tool, comprising at least one piston/cylinder combination composed of a cylinder body and a piston accommodated in said cylinder body and provided with a piston rod that projects from said cylinder body, wherein the cylinder body and the piston body define a first cylinder chamber while the cylinder body, the piston body and the piston rod define a second cylinder chamber, and wherein during operation the piston performs alternating forward and return operational cycles under the influence of a fluidum under pressure that is conducted to the first and the second cylinder chamber through a first and a second line, respectively, and a control valve which regulates the supply of a fluid under pressure through the first or the second line to the piston/cylinder combination. ## Claims ### Claim 1 A hydraulic cylinder, for example for use in a hydraulic tool, comprising at least one piston/cylinder combination composed of a cylinder body and a piston accommodated in said cylinder body and provided with a piston rod that projects from said cylinder body, wherein the cylinder body and the piston body define a first cylinder chamber while the cylinder body, the piston body and the piston rod define a second cylinder chamber, and wherein during operation the piston performs alternating forward and return operational cycles under the influence of a fluid under pressure that is conducted to the first and the second cylinder chamber through a first and a second line, respectively, a control valve which regulates the supply of a fluid under pressure through the first or the second line to the piston/cylinder combination, and a separation valve which regulates the discharge of fluid under pressure from the second cylinder chamber in dependence on the pressure difference between the first and the second cylinder chamber, and a safety valve which is passive in a first position and which in a second position, if the pressure in the second cylinder chamber is higher than a preset load pressure, connects the second cylinder chamber to the first cylinder chamber via the separation valve. ### Claim 2 (depends on 1) The hydraulic cylinder according to claim 1, wherein the separation valve is constructed as a non-return valve arranged between the first and the second line. ### Claim 3 (depends on 1) The hydraulic cylinder according to claim 1, wherein the separation valve is constructed as a differential valve. ### Claim 4 (depends on 3) The hydraulic cylinder according to claim 3, characterised in that the differential valve comprises a non-return valve arranged between the first and the second line. ### Claim 5 (depends on 4) The hydraulic cylinder according to claim 4, wherein the differential valve further comprises a valve included in the second line, which valve connects the second cylinder chamber to the second line if the pressure in the first cylinder chamber is higher than a preset value. ### Claim 6 (depends on 1) The hydraulic cylinder according to claim 1 wherein the safety valve comprises a valve which in its first position maintains the pressure in a control line of the separation valve and which in its second position releases the pressure in the control line of the separation valve. ### Claim 7 (depends on 6) The hydraulic cylinder according to claim 6, wherein the safety valve comprises a first non-return valve which connects the second line to a control line of the valve. ### Claim 8 (depends on 7) The hydraulic cylinder according to claim 7, wherein the control surface of the valve is of a stepped design. ### Claim 9 (depends on 8) The hydraulic cylinder according to claim 8, wherein the safety valve comprises a further non-return valve which connects the second line to the control line of the separation valve. ### Claim 10 (depends on 2) The hydraulic cylinder according to claim 2 wherein the safety valve comprises a valve which in its first position maintains the pressure in a control line of the separation valve and which in its second position releases the pressure in the control line of the separation valve. ### Claim 11 (depends on 3) The hydraulic cylinder according to claim 3 wherein the safety valve comprises a valve which in its first position maintains the pressure in a control line of the separation valve and which in its second position releases the pressure in the control line of the separation valve. ### Claim 12 (depends on 4) The hydraulic cylinder according to claim 4 wherein the safety valve comprises a valve which in its first position maintains the pressure in a control line of the separation valve and which in its second position releases the pressure in the control line of the separation valve. ### Claim 13 (depends on 5) The hydraulic cylinder according to claim 5 wherein the safety valve comprises a valve which in its first position maintains the pressure in a control line of the separation valve and which in its second position releases the pressure in the control line of the separation valve. ### Claim 14 (depends on 10) The hydraulic cylinder according to claim 10, wherein the safety valve comprises a first non-return valve which connects the second line to a control line of the valve. ### Claim 15 (depends on 11) The hydraulic cylinder according to claim 11, wherein the safety valve comprises a first non-return valve which connects the second line to a control line of the valve. ### Claim 16 (depends on 12) The hydraulic cylinder according to claim 12, wherein the safety valve comprises a first non-return valve which connects the second line to a control line of the valve. ### Claim 17 (depends on 13) The hydraulic cylinder according to claim 13, wherein the safety valve comprises a first non-return valve which connects the second line to a control line of the valve. ### Claim 18 (depends on 7) The hydraulic cylinder according to claim 7, wherein the control surface of the valve is of a stepped design. ### Claim 19 (depends on 14) The hydraulic cylinder according to claim 14, wherein the control surface of the valve is of a stepped design. ### Claim 20 (depends on 15) The hydraulic cylinder according to claim 15, wherein the control surface of the valve is of a stepped design.