A spring device includes a top plate, a certain force spring, a bottom plate and a tension spring.One end of the force fixing spring is connected with the top plate； the bottom plate is connected with the other end of the force fixing spring； one end of the tension spring is connected with the top plate, the other end is connected with the bottom plate, and is connected in parallel with the force fixing spring.The invention also discloses a large span zero free length spring device.The invention has the advantages of simple structure, complete gravity balance, large span and zero free length spring device, sufficient spring force and long tensile length.一種彈簧裝置，包括一頂板、一定力彈簧、一底板以及一拉伸彈簧。該定力彈簧之一端係與該頂板連接；該底板係與該定力彈簧之另一端連接；該拉伸彈簧之一端係與該頂板連接，另一端係與該底板連接，而與該定力彈簧並聯。本發明亦揭露一種大跨距零自由長度彈簧裝置。本發明構造簡單，且可達到完全重力平衡之大跨距零自由長度彈簧裝置，並可提供足夠之彈簧力量，有效解決拉伸彈簧之拉伸長度過長的問題。
