Spring safety device

摘要

A self-contained spring biasing device, particularly useful for providing a movement-resisting force on the power shaft of a valve actuator, comprises spring cartridge means and safety means. The spring cartridge means has therein a compression spring and a bearing plate that is pushed by the power shaft to compress the spring and resist movement of the shaft. The safety means is accessible from the exterior of the spring cartridge means and removably secures the power shaft to the bearing plate, thus preventing the spring from launching the spring cartridge means from the actuator.