| 摘要 |
A self-balancing boom apparatus includes a vertical support post, a boom pivotally mounted to the support post, and a spring which produces a force along a force axis to counteract gravitational forces on the boom. A spring force coupling mechanism couples the spring force to the boom at a point between the pivot axis and the distal end of the boom. The spring force coupling mechanism is constructed and arranged for vertical movement on the support post, causing the spring force to vary as the boom is pivoted. The force coupling mechanism includes a pair of horizontally extending cam members engaged by a pair of rollers which are attached to the boom and moved to vary the distance between the force axis and the point of application of the force inversely with variation in the spring force as the boom is pivoted.
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