A sprinkler includes a hollow shaft to which a positioning part, a gear casing, a pipe are respectively connected to the hollow shaft. The positioning part and the pipe are respectively connected to a first end support and a second end support of a base. The positioning part has multiple grooves defined in a tubular portion thereof. A hollow positioning rod has a ratchet portion which is resiliently formed thereto. The hollow positioning rod is rotatably mounted to the hollow shaft and the ratchet portion is engaged with the grooves of the positioning part. The hollow positioning rod has a toothed portion which is engaged with an output gear of the gear casing. The gear casing is driven by a hydraulic power so as to swing the pipe periodically. The resilient ratchet portion allows the gear casing and the pipe to swing easily, and no metal spring is required.本創作係關於一種灑水器結構，係由一中空結合桿依序分別串接一定位套、一傳動齒輪箱及一噴水管後，將其安裝一基座上，進而構成一灑水器結構，又該定位套更包含有一中空的定位軸桿得套樞於該中空結合桿上，而該定位軸桿的桿體上設有一齒輪部及至少一區段的棘齒部，且該棘齒部得與該定位套具軸向凹槽的栓槽孔相嚙合，而該齒輪部係與該傳動齒輪箱的動力輸出齒輪相嚙合，俾使該傳動齒輪箱連同噴水管在外力的旋掣下，該定位軸桿可相對該定位套的栓槽孔產生彈性卡掣的功能，據使該噴水管能快速達成偏擺旋轉噴水位置的改變，進而達到簡化構件、降低製造成本功能的灑水器結構。
