Abstract: A stair assembly suited for a vehicle entrance includes a plurality of step treads, each of the step treads having a tread width, and a stringer to which the plurality of step treads are secured. The stringer is positioned within the tread width.

Abstract: A boat lift includes posts and linear actuators, each attached to one of the posts. Each linear actuator includes an extendable and retractable member oriented for extension and retraction substantially parallel to the post. Ends of a first pair of the extendable and retractable members are connected to a first carrier, and ends of a second pair of the extendable and retractable members are connected to a second carrier. A cradle or platform is supported by the first and second carriers. The boat lift may be supported by the ground, by a structure, for example, a dock, a sea wall or a wall of a boat house, or by pontoons.

Abstract: A stabilizing system includes a plurality of jacks, each operated by a corresponding hydraulic actuator. A hydraulic fluid transfer pump supplies hydraulic fluid to and receives hydraulic fluid from one or more pressure chambers of the actuator. A pilot-operated check or directional valve may be provided in fluid communication with one or more of the pressure chambers and configured to regulate the flow of hydraulic fluid to and from the pressure chamber. A directional control valve may connect the pump output with the jacks via respective pilot-operated directional valves. The directional control valve may include a plurality of switch positions respectively connecting the pump output with pairs of the jacks.

Abstract: A stabilizing system includes a plurality of jacks, each operated by a corresponding hydraulic actuator. A hydraulic fluid transfer pump supplies hydraulic fluid to and receives hydraulic fluid from one or more pressure chambers of the actuator. A pilot-operated check or directional valve may be provided in fluid communication with one or more of the pressure chambers and configured to regulate the flow of hydraulic fluid to and from the pressure chamber. A directional control valve may connect the pump output with the jacks via respective pilot-operated directional valves. The directional control valve may include a plurality of switch positions respectively connecting the pump output with pairs of the jacks.

Abstract: A boat lift includes posts and linear actuators, each attached to one of the posts. Each linear actuator includes an extendable and retractable member oriented for extension and retraction substantially parallel to the post. Ends of a first pair of the extendable and retractable members are connected to a first carrier, and ends of a second pair of the extendable and retractable members are connected to a second carrier. A cradle or platform is supported by the first and second carriers. The boat lift may be supported by the ground, by a structure, for example, a dock, a sea wall or a wall of a boat house, or by pontoons.

Abstract: A stabilizing system includes a plurality of jacks, each operated by a corresponding hydraulic actuator. A hydraulic fluid transfer pump provides supplies hydraulic fluid to and receives hydraulic fluid from one or more pressure chambers of the actuator. A pilot-operated check or directional valve may be provided in fluid communication with one or more of the pressure chambers and configured to regulate the flow of hydraulic fluid to and from the pressure chamber.

Abstract: A boat lift includes four posts and four linear actuators, each attached to one of the posts. Each linear actuator includes an extendable and retractable member oriented for extension and retraction substantially parallel to the post. Ends of a first pair of the extendable and retractable members are connected to a first carrier and ends of a second pair of the extendable and retractable members are connected to a second carrier. A cradle or platform is supported by the first and second carriers. The boat lift may be supported by the ground, by a structure, for example, a dock, a sea wall or a wall of a boat house, or by pontoons.

Abstract: A stabilizing system includes a plurality of jacks, each operated by a corresponding hydraulic actuator. A hydraulic fluid transfer pump supplies hydraulic fluid to and receives hydraulic fluid from one or more pressure chambers of the actuator. A pilot-operated check or directional valve may be provided in fluid communication with one or more of the pressure chambers and configured to regulate the flow of hydraulic fluid to and from the pressure chamber. A directional control valve may connect the pump output with the jacks via respective pilot-operated directional valves. The directional control valve may include a plurality of switch positions respectively connecting the pump output with pairs of the jacks.

Abstract: A stabilizing system includes a plurality of jacks, each operated by a corresponding hydraulic actuator. A hydraulic fluid transfer pump provides supplies hydraulic fluid to and receives hydraulic fluid from one or more pressure chambers of the actuator. A pilot-operated check or directional valve may be provided in fluid communication with one or more of the pressure chambers and configured to regulate the flow of hydraulic fluid to and from the pressure chamber.

Abstract: A stabilizing system includes a plurality of jacks, each operated by a corresponding hydraulic actuator. A hydraulic fluid transfer pump provides supplies hydraulic fluid to and receives hydraulic fluid from one or more pressure chambers of the actuator. A pilot-operated check or directional valve may be provided in fluid communication with one or more of the pressure chambers and configured to regulate the flow of hydraulic fluid to and from the pressure chamber.

Abstract: A boat lift includes four posts and four linear actuators, each attached to one of the posts. Each linear actuator includes an extendable and retractable member oriented for extension and retraction substantially parallel to the post. Ends of a first pair of the extendable and retractable members are connected to a first carrier and ends of a second pair of the extendable and retractable members are connected to a second carrier. A cradle or platform is supported by the first and second carriers. The boat lift may be supported by the ground, by a structure, for example, a dock, a sea wall or a wall of a boat house, or by pontoons.

Abstract: A hydraulic stabilizing system includes a pump having first and second flow ports, and first and second actuators, each having an extend chamber and a retract chamber. A first pilot-operated check valve is installed between the pump first flow port and the extend chamber of the first actuator. A second pilot-operated check valve is installed between the pump first flow port and the extend chamber of the second actuator. A third pilot-operated check valve is installed between the pump second flow port and the retract chambers of the first and second actuators. The pilot ports of the first and second pilot-operated check valves are coupled to the second pump flow port, and the pilot port of the third pilot-operated check valve is coupled to the first pump flow port.

Abstract: An operating mechanism for reciprocating a movable compartment through an opening in a wall of structure includes a shell, a slide received within the shell, and a linear actuator connected between the slide and the shell.

Abstract: A piston and piston rod assembly includes a piston rod having a first portion and a smaller second portion extending from the first portion. The second portion has a circumferential groove that receives at least one sealing ring or O-ring located between the first portion and the free end of the second portion. A piston has an aperture extending between two ends, with the top open end having a larger diameter than the bottom open end. The second portion of the piston rod is inserted through the aperture of the piston so that the free end of the second portion emerges through the top open end of the piston and compresses the at least one sealing ring or O-ring with the inner surface of the piston. The free end of the second portion of the piston rod is cold-worked to overlie at least a portion of the top open end of the piston.