membrane 70 is completely inserted into each pair of corresponding first inner indented ring 605 and second outer indented ring 606 at the upper side of the pump head body 60 upon assembly of the pump head body 60 and the diaphragm membrane 70 as shown in fig8 with the result that a short length of moment arm l 2 from the first inner protruding ring 705 to the peripheral of the annular positioning protrusion 76 in the diaphragm membrane 70 is obtained in the operation of the present invention as shown in fig8 the newly devised contrivances of pump head body 60 and diaphragm membrane 70 not only have significant effect in reducing vibration but also enhance steadiness by preventing relative displacement and maintaining the length of moment arm l 2 for resisting against the acting force f on the eccentric roundel 52 as shown in fig8 and 88 in the seventh exemplary embodiment each pair of concentric first inner indented ring 605 and second outer indented ring 606 in the pump head body 60 can be replaced by a pair of concentric first inner perforated ring 614 and second outer perforated ring 615 as shown in fig8 and 90 in the seventh exemplary embodiment each pair of concentric first inner indented ring 605 and second outer indented ring 606 in the pump head body 60 as shown in fig8 and each corresponding pair of concentric first inner protruding ring 705 and second outer protruding ring 706 in the diaphragm.