| 摘要 |
An injector of the invention has a generally cylindrical body which is arranged vertically. The body is closed at its upper end with an end wall and opened at its lower end. The upper end wall has an inlet and an outlet in spaced relation to each other. A piston is accommodated within the body with its periphery slidably and sealingly engaged with an inner peripheral surface of the cylindrical body. Also, a rod is inserted into the body through the lower end and is coupled to the piston for movement together therewith. Particularly, one of the respective surfaces of the end wall and the piston which confront each other includes a groove for defining a passage communicating between the inlet and the outlet. |
