Abstract: A magneto-rheological (“MR”) damper having a gas cup that slidably moves within a damper body tube and isolates an MR fluid from a gas in one end of the damper body tube. The gas cup has a dynamic seal that comprises an MR fluid compatible O-ring located in a narrow O-ring groove disposed in an outer surface of the gas cup. The narrow O-ring groove is sized to reduce entrapment of abrasive magnetic particles in the MR fluid between the O-ring and an inner surface of the damper body tube. The O-ring groove has a free roll room of about less than 12%.

Abstract: A piston assembly for magneto rheological (MR) fluid vibration damper affixed to a suspension system includes a piston that strokes inside a housing to dampen vibrations. The piston includes a core affixed to a piston shaft. An electric coil is affixed to the core and is coaxially aligned with the piston shaft. A sleeve circumscribes the piston core having a wall with a first inner diameter. An annular fluid passage is formed between the sleeve and the core. Fluid passes through the annular passage when the piston strokes inside the damper. The wall includes a channel having a second inner diameter greater than the first inner diameter. The channel reduces resistance to the piston from the MR fluid derived from temperature induced viscosity variations.

Abstract: A novel and improved magnetorheological fluid damper is provided which effectively secures a flux ring to a piston core in a manner which prevents relative axial and radial movement between the flux ring and the core throughout operation while minimizing the size of the piston assembly yet providing effective damping. Several connector devices are disclosed for both axially and radially securing the flux ring relative to the piston core at one end of the piston assembly in a simple manner without increasing the length of the piston assembly. The connector device may include an outer portion brazed to the flux ring, an inner portion connected to the piston core, bridge portions extending between the outer and inner portions, flow passages formed between the bridge portions and an inlet cavity formed adjacent an annular flow gap to permit unimpeded, enhanced laminar flow through the flow gap by improving the damping effect.

Abstract: A damper and electrical connector system wherein the damper includes a ring mounting element having a base portion attached to a housing of the damper and a hole extending through the base portion and communicating with an interior chamber of the housing. A slot is formed through a side of the ring mounting element and communicates with the hole in the base. The electrical connector includes an end inserted through the slot and a power terminal extends through the hole formed in the base and makes electrical connection with an element requiring electrical power that is carried in the housing. Preferably the electrical connector also includes a ground terminal which makes electrical contact with the ring mounting element. A vehicle mounting rod is inserted through the ring mount to hold the connector in place.

Abstract: The invention relates to a method of removing a slewing ring (3) from a pedestal-mounted crane (2). A carriage (14) is positioned on a pair of elongate guide members (9) which lie substantially parallel, both to one another and to the plane of the slewing ring (3), and which extend alongside the pedestal (14). The crane (2) is raised relative to the pedestal (4) by means of jacks (7) and the carriage (14) is moved to a position beneath the crane (2). The slewing ring (3) is then positioned on the carriage and withdrawn on the carriage from beneath the crane.

Abstract: A crane has a hoist rope which passes over a boom to a drum driven by a hudraulic motor and including a brake. The crane includes means for releasing the brake when the free end of the rope is a given distance below the crane, and has means for relieving hydraulic pressure from the motor in response to the horizontal radius of the free end of the rope so that at a given radius the motor can lift only a given maximum load.