A cam type door closer includes a housing, a first piston set mounted in one side of the housing, a second piston set mounted in the other side of the housing, which includes a second piston movably mounted in a shaft hole of a first piston of the first piston set, a gap compensation device mounted in the second piston, a second spring having one end thereof stopped against the second piston and a security and sealing cap mounted in the housing to stop the other end of the second spring, and a drive shaft assembly rotatably mounted in a longitudinal passage of housing, which includes a shaft and an eccentric cam mounted on the shaft with one side thereof stopped against a roller of the first piston set and an opposite side thereof stopped against the second piston.

A hydraulic lock for a hydraulic system includes a flow control valve and a second check valve. The flow control valve having a first inlet, a first outlet, a first check valve and a flow restrictor, each of the first check valve and the flow restrictor being communicably coupled to the first inlet and the first outlet and being arranged in parallel between the first inlet and the first outlet. The second check valve having a second inlet and a second outlet, the second inlet being communicably coupled to the first outlet, the second check valve further having a ball seating surface having an aperture there through, a ball, and a resilient member biasing the ball towards the ball seating surface to seal the aperture, the aperture being communicably coupled to the second inlet and the second outlet.

A regulating valve for activating a strike function of a hydraulic door, gate, or window drive, in particular a hydraulic door closer, which is arranged in a hydraulic channel via which hydraulic fluid can flow, comprises a valve member which is axially displaceable in a valve bore between a closed position and an open position, is acted on in an opening direction by a spring unit, is acted on by the pressure in a pressure chamber in the closing direction and can be transferred into the open position thereof by the spring force of the spring unit when there is a drop in pressure in the pressure chamber below a predeterminable limit pressure.

A hydraulic drive for a sash of a door, a gate, a window or the like comprises a housing and a piston which is displaceably guided in the housing and which divides the interior of the housing into a pressure chamber and a non-pressurized chamber. In this case, the drive, which can in particular be a hydraulic door closer, comprises a regulating valve which is arranged on the end face of the housing delimiting the pressure chamber on the side facing away from the piston and which is integrated in particular in a housing cover for activating an impact function. The regulating valve has a valve member which is displaceable between a closed position and an open position in a valve bore of a valve housing formed in particular by the housing cover, is impinged on in the closing direction by the pressure in the pressure chamber and can be transferred into the open position thereof by the spring force of a spring unit when the pressure in the pressure chamber falls below a predeterminable limit pressure.

A power-assist device (1) with a piston rod (8), which is mounted movably in a housing (7) and has a first position and a second position, and with a preferably elastic return element (12), which can be arrested by a positionally variable arresting part (10) and which, in the unlocked state, can transmit an assisting force to the piston rod (8) and, in the arrested state, is decoupled in terms of force from the piston rod (8), such that, in the unlocked state, as a result of the piston rod (8) being moved into the first position, the arresting part (10) is moved out of an unlocking position into an arresting position, which enables arresting of the restoring return (12) only within a limited time period.

A hydraulic lock for a hydraulic system includes a flow control valve and a second check valve. The flow control valve having a first inlet, a first outlet, a first check valve and a flow restrictor, each of the first check valve and the flow restrictor being communicably coupled to the first inlet and the first outlet and being arranged in parallel between the first inlet and the first outlet. The second check valve having a second inlet and a second outlet, the second inlet being communicably coupled to the first outlet, the second check valve further having a ball seating surface having an aperture there through, a ball, and a resilient member biasing the ball towards the ball seating surface to seal the aperture, the aperture being communicably coupled to the second inlet and the second outlet.

A door closer pivoted on a door at least includes a case and a piston. When the door is open, the door closer blocks a communicating hole of the case by an oil sealing ring of the piston to allow an oil filled in the door closer cannot flow through the communicating hole. As a result, the open door can be held in a predetermined position.

A door closer including: a body defining a chamber therein; a piston slidably supported within the chamber, and dividing the chamber into first and second cavities either side of the piston, which in use receive liquid; a biasing device for biasing the piston towards the first cavity; a passageway connecting the first cavity to the second cavity for permitting the flow of fluid therebetween; a blocking member for controlling the flow of liquid through the passageway between the cavities; a moveable member moveable between first and second positions, wherein when the moveable member is in its first position the moveable member causes or permits the blocking member to assume a blocking position, thus preventing or at least inhibiting the flow of liquid from the first to the second cavity, and wherein when the moveable member is in its second position the moveable member causes or permits the blocking member to assume a non-blocking position, thus permitting the flow of liquid from the first to the second cavity; and a permanent magnet positioned adjacent or close to the moveable member for holding the moveable member in its first position; wherein the door closer includes a pole switching device that can produce a magnetic field that is in opposition to the magnetic field of the permanent magnet to effectively cancel out or overcome the magnetic field of the permanent magnet and produce a net magnetic field that is either zero or in the opposite direction to the magnetic field of the permanent magnet so as to effect movement of the moveable member between its first and second positions.

The present invention relates to novel lignin-derived compounds and compositions comprising the same and their use as redox flow battery electrolytes. The invention further provides a method for preparing said compounds and compositions as well as a redox flow battery comprising said compounds and compositions. Additionally, an assembly for carrying out the inventive method is provided.

The present invention relates to a method for producing one or more low molecular weight aromatic lignin-derived compounds. The method preferably comprises providing lignocellulosic material, subjecting the lignocellulosic material to a pulping process, separating pulp to provide a substantially pulp-free process stream comprising a modified lignin-derived component, isolating the modified lignin-derived component, subjecting the isolated modified lignin-derived component to a decomposition step comprising oxidative cracking (cracking and oxidizing) or reducing under the influence of a catalyst or electro-oxidation, and subjecting the resulting products to an isolation step, to provide a low molecular weight aromatic lignin-derived compound. Said compound may be further modified, e.g. by annulation. The inventive method preferably comprises further oxidizing said compound to a redox active compound. Additionally, the present invention relates to compounds obtainable by the inventive method and to an assembly for carrying out the inventive method. Furthermore, the present invention refers to a method for providing an existing pulp and/or paper manufacturing plant with said assembly.