| 摘要 |
A device is provided for aiding in the removal and replacement of a spa cover atop a spa tub. A pair of lifting assemblies are located on opposite sides of the spa tub. Each of the lifting assemblies includes a spring having an anchored end secured relative to the spa tub and a moveable end. Each lifting assembly employs a lifting arm mounted for rotation relative to the spa tub and including a cover-engaging end attached to the spa cover, a spring-engaging end attached to the moveable end of the spring, and a fulcrum located between the lifting arm ends. The lifting arm is rotatable between extreme covering and uncovering positions in which the spring-engaging end of the lifting arm lies on opposite sides of a straight line extending between the lifting arm axis of rotation and the anchored end of the spring. The lifting arm is rotatable through an intermediate position in which the spring-engaging end of the lifting arm passes between the fulcrum and the anchored end of the spring. At this intermediate position the spring force is at a minimum. The lifting device thereby tends to balance the gravitational moment exerted by the cover on the lifting arms more closely than is achieved with conventional devices. In an alternative arrangement the fulcrum of the lifting arm is located at one end thereof and the moveable end of the spring is joined to the lifting arm at an intermediate spring coupling. A clamping mechanism is employed to lock the lifting arm to prevent accidental closure of the cover.
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