Abstract: A method and apparatus to control delivery of pressurized hydraulic fluid at a controlled pressure to open and close blowout preventers. A source of pressurized hydraulic fluid is connected through a pair of supply lines and through a control shifter valve for charging a closed system to a set-point pressure. A velocity fuse in each supply line diverts flow to one line if the other line breaks. Fluid from the source of pressurized hydraulic fluid is also delivered through a regulator valve to a regulated pressure line which is connected to one or more control valves. Each of the control valves is adapted to direct pressurized fluid selectively to either end of a blowout preventer actuator chamber.

Abstract: In the preferred and illustrated embodiment of an exercise device, a free standing frame with adjustable resistance assemblies mounted to the frame is disclosed. Resistance in all directions is provided by a linear drag brake and a rotary drag brake. The linear drag brake comprises a slide bar reciprocably movable between two friction pads. The rotary drag brake comprises an arm member pivotally mounted between two friction pads. The exercise device provides active resistance through a full range of motion both in flexion and extension.

Abstract: In the preferred and illustrated embodiments, an interactive exercise device is disclosed. One embodiment utilizes an exercise bicycle wherein wheel speed and force are monitored. An electromagnetic brake is adjusted by a control apparatus to relate the measured force to the required force. The electromagnetic brake controls the drag to implement a selected exercise program. The program paces the user through a specified load for a specified interval. The work load can be varied in any manner to achieve a desired exercise program. The interactive apparatus utilizes a video monitor to display an exercise program or race for the user. The race or exercise program is recorded on a video cassette. On playback, the cassette provides video for the monitor to be viewed by the user. The audio track is conveniently used to record instructions which are converted into a drive current for the brake, thereby modifying the drag and required velocity of the user.