| 摘要 |
The present invention provides for an improved diaphragm pump having two material pumping chambers. The material pumping chambers are operated by two working fluid chambers which are separated from the material pumping chambers by two diaphragms. The diaphragms are interconnected to provide that the two material pumping chambers alternatively receive and discharge the material to be pumped. A control valve controls the stroke reversal of the improved diaphragm pump. The control valve is actuated by the pressurized working fluid which is being discharged from a pressurized fluid chamber. Further valving provides for a portion of the pressurized working fluid being discharged from a pressurized fluid chamber to be reused and introduced into the exhausted fluid chamber to initiate expansion of the exhausted fluid chamber. The pre-pressurization of the exhausted fluid chamber reduces the amount of source air required at the beginning of the stroke. |
