This creation is a kind of skylight opening and closing unit in greenhouse,System is made of dynamical element and plural headstock gear,And headstock gear include a box,Chain elements,Elevating lever,First connecting rod and second connecting rod,The inside setting chain elements of a box are referred mainly to,And the bottom end of elevating lever positions pivot knot what chain elements,And a box is pierced by elevating lever,And it is pivotally connected the second connecting rod that constitutes skylight switching motion,And one end of first connecting rod consolidates what seat box top,Its other end consolidates the base shaft that constitutes skylight pivotal point,And one end of second connecting rod is also pivotally connected what base shaft,The affixed what of its other end constitutes the outer bar of skylight outer rim again； Accordingly,Chain elements are activated by the transmission shaft of dynamical element,According to make go up and down lever linkage second connecting rod and make skylight can closure or openness,And reach the greenhouse skylight of unidirectional open-type,And its interlinked mechanism more shape person of simplifying.本創作係一種溫室之天窗啟閉單元，係由動力元件及複數啟閉裝置所組成，而啟閉裝置包含有座盒、鏈條元件、升降桿、第一連桿及第二連桿，主要指座盒之內部設置鏈條元件，而升降桿之底端定位樞結於鏈條元件，且升降桿之上方穿出座盒，並樞接於構成天窗啟閉動作的第二連桿，而第一連桿之一端固結於座盒頂端，其另一端固結於構成天窗樞轉點的基桿，且第二連桿之一端亦樞接於基桿，又其另一端固接於構成天窗外緣之外桿；據此，藉由動力元件之傳動軸致動鏈條元件，據使升降桿連動第二連桿而使天窗可開啟或閉合，而達到單向開啟式之溫室天窗，且其連動機構更形精簡者。
