A damping force change mechanism includes an on-off valve located in a through hole of a piston rod. The on-off valve opens/closes a third hydraulic oil passage that allows a first oil chamber on a free piston side and a second oil chamber between a first piston and a second piston to communicate with each other. The on-off valve includes an expanded diameter portion in the first oil chamber extending outward in the radial direction. The expanded diameter portion faces the entire opening edge of the through hole and tightly contacts an end surface of the piston rod. The magnitude of a damping force is easily changed, and a damping force characteristic in a case in which the damping force is large is stabilized.

A gas cup for a damper assembly comprises a body including an upper surface, a lower surface, an exterior surface and an interior surface. The body defines an aperture extending through the upper surface and the lower surface. A decoupler is located in the aperture and secured to the body. A bridging member is located between the decoupler and the body and coupled to the decoupler and the body. The decoupler and the bridging member is made from materials having different elasticity to allow the decoupler to move in the aperture in response to a volumetric change in the damper assembly and to provide variable tuning of the damper assembly. A damper assembly including the gas cup is also disclosed herein.

A metal stamping tool includes a hybrid magnetorheological-nitrogen spring including a housing having an interior wall defining an interior volume. A fixed divider separates the interior volume into a nitrogen gas chamber and a magnetorheological fluid chamber. A piston extends into both the nitrogen gas chamber and the magnetorheological fluid chamber. The piston defines a magnetorheological fluid gap within the magnetorheological fluid chamber. An electric coil positioned adjacent the fluid gap to apply a magnetic field to magnetorheological fluid within the fluid gap when the electric coil is energized.

A shock absorber according to the present invention includes: a cylinder; a rod movably inserted into the cylinder; an extension side chamber (operation chamber) and a compression side chamber (operation chamber) provided in the cylinder; a valve disc that is provided to be movable in the axial direction on the outer circumference of the rod and has an annular valve seat and a port which is opened on the inner circumference of the annular valve seat and causes the extension side chamber (operation chamber) and the compression side chamber (operation chamber) to communicate with each other; and an annular leaf valve that opens and closes the port.

A heave compensator with adjustable dampening properties includes a length extension device having an inner space divided by a slide-able piston into a vacuum chamber and a liquid filled chamber, a gas accumulator divided by a slide-able piston into a gas filled chamber and a liquid filled chamber, and a gas tank having an expansion chamber. The liquid and gas chamber are fluidly connected to each other with valve controlled conduits. Further, the device includes pressure and temperature sensors that register pressure and temperature in the gas and liquid phases. The device further includes a control unit having a signal receiving unit, a writeable computer memory, a data processing unit, and a signal transmitting unit. The data processing unit contains computer software that calculates suited amounts of gas and gas pressure in the gas accumulator and/or gas tank based on the information of which lifting operation is going to be performed. The data processing unit further engages activation means such that the suited amount of gas and gas pressure are achieved and maintained during the different phases of the lifting operation.

A mono-tube type hydraulic shock absorber includes a cylinder, a free piston that partitions the inside of the cylinder into a liquid chamber in which a hydraulic fluid is filled and a gas chamber in which a gas is filled, a piston slidably inserted into the cylinder, the piston partitioning the liquid chamber into two working chambers, a sealing ring provided on an outer periphery of the free piston, the sealing ring being configured to seal between the cylinder and the free piston, and a lubricating oil enclosed within the gas chamber to lubricate between the sealing ring and the cylinder.

A method for monitoring a dual-stage, stroke activated, mixed fluid gas shock strut includes receiving, by a controller, primary chamber temperature and pressure sensor readings, secondary chamber pressure and temperature sensor readings, and a shock strut stroke sensor reading, calculating, by the controller, a compression factor, determining, by the controller, a plurality of compression factors for known oil volumes based on the primary chamber temperature sensor reading and/or the shock strut stroke sensor reading, and calculating, by the controller, an oil volume in a primary chamber of the shock strut, a number of moles of gas in the primary chamber of the shock strut, a volume of gas in a secondary chamber of the shock strut, and a number of moles of gas in the secondary chamber.

A method of manufacturing a shock absorber includes inserting a floating piston into a tube, disposing oil into the tube, and inserting a piston-rod assembly into the tube. The piston-rod assembly has a piston coupled to a rod. The method includes inserting a rod guide assembly into the tube. The rod guide assembly includes a sintered metal rod guide having a seat and a seal disposed in the seat. The rod extends through the seal. The method also includes deforming a wall of the tube into engagement with the sintered metal rod guide to provide a piston-cylinder assembly and inhibit axial movement of the rod guide assembly relative to the tube. The method further includes pressurizing the piston-cylinder assembly and forming a flange portion of the tube over an upper surface of the sintered metal rod guide.

A gas cup for a damper assembly comprises a body including an upper surface, a lower surface, an exterior surface and an interior surface. The body defines an aperture extending through the upper surface and the lower surface. A decoupler is located in the aperture and secured to the body. A bridging member is located between the decoupler and the body and coupled to the decoupler and the body. The decoupler and the bridging member is made from materials having different elasticity to allow the decoupler to move in the aperture in response to a volumetric change in the damper assembly and to provide variable tuning of the damper assembly. A damper assembly including the gas cup is also disclosed herein.

A shock absorber assembly with a coil spring and a shock absorber. The shock absorber includes a cylinder; a piston rod; a cylinder piston connected to the piston rod; a reservoir fluidly connected to the cylinder, the reservoir and the cylinder defining a fluid chamber for receiving a hydraulic fluid; a reservoir base valve separating the fluid chamber into a first portion and a second portion, the reservoir base valve defining passages fluidly connecting the first and second portions; a bypass channel fluidly connecting the first portion to the second portion; a bypass valve configured to selectively control fluid flow through the bypass channel; and a check valve disposed in the bypass passage and being configured to: permit fluid flow through the bypass channel from the first portion to the second portion, and impede fluid flow through the bypass channel from the second portion to the first portion.