Light-weighed diaphragm pump

Abstract

To reduce number of parts, reduce the weight, make easy and quick to start, and reduce consuming quantity of electric power of a diaphragm pump, a con rod is made of a synthetic resin material, and the con rod has an annular groove made next to its enlarged end. A diaphragm is of rubber, and is integrally connected to the enlarged end of the con rod by fitting into the annular groove, wrapping the enlarged end of the con rod.

What is claimed is:  
     
         1 . A diaphragm pump comprising at least a drive motor, an eccentric member connected to a shaft of the drive motor, a con rod operatively connected to the eccentric member, and a diaphragm connected to the con rod to be operated via the con rod when the drive motor rotates, wherein the con rod is made of a synthetic resin material, and the con rod has an annular groove made next to its enlarged end, the diaphragm being of rubber, and being integrally connected to the enlarged end of the con rod by fitting into the annular groove, wrapping the enlarged end of the con rod.  
     
     
         2 . A diaphragm pump according to  claim 1 , wherein the synthetic resin material is a polyamide resin.  
     
     
         3 . A diaphragm pump according to  claim 1 , wherein the con rod has an adhesive or bond interface between the enlarged end and the diaphragm.  
     
     
         4 . A diaphragm pump according to  claim 1 , wherein it further comprises umbrella-like valves on its suction and ejection sides.