Air pump with electric motor

Abstract

An electric pumping device includes motor powered by batteries and a eccentric crank is driven by the motor so as to operate a piston assembly. The piston assembly generates pressurized air into the object such as a tire via an outlet. A pressure gauge assembly is connected to a side of the body of the pumping device and includes a gauge member having marks which can be seen via a window so that the user can control precisely the pressure that the pumping device generated.

What is claimed is:  
     
         1 . An electric pumping device comprising: 
 a head having an outlet defined in an end of the head and a passage defined in the head, the passage being in communicating between the outlet and a chamber, a block located in the passage and an end of a spring connected to the sealing block, a cylinder received in the head and a hole defined through a close end of the cylinder, the passage communicating with the hole, a sealing pad connected to the other end of the spring and movably sealing the hole, a side path communicating with the passage and the outlet, a receiving area defined in a side of the head and a communication hole in communication between the outlet and the receiving area, a pressure gauge assembly received in the receiving area, a cam member connected to the other end of the head;    a body having a battery box received therein and an inflating assembly received in the chamber of the head, the inflating assembly including a motor which has one end connected to the battery box by a switch and the control unit, the other end of the motor has a shaft which is connected to a small bevel gear which is engaged with a large bevel gear, a driving crank eccentrically connected to the large bevel gear, and    a piston assembly connected to the driving crank and reciprocally received in the cylinder, a one-direction valve connected to the piston assembly so that the one-direction valve pushes air in the pressure chamber irreversibly toward the passage, a path defined through the piston assembly and being sealed by the one-direction valve.    
     
     
         2 . The device as claimed in  claim 1 , wherein the one-direction valve has one end connected to the piston assembly and the other end of the one-direction valve covers onto the piston assembly.  
     
     
         3 . The device as claimed in  claim 1 , wherein a sealing ring is mounted to the piston assembly.  
     
     
         4 . The device as claimed in  claim 1 , wherein the receiving area has a inner threaded section and a window is defined through a wall of the receiving area, the pressure gauge assembly having scale marks which are located corresponding to the window.  
     
     
         5 . The device as claimed in  claim 4 , wherein the pressure gauge assembly includes a sealing member, a gauge member, a spring having one end received in the gauge member, a fixing member and an end cap, the sealing member engaged the communication hole and the other end of the spring mounted to a protrusion on the fixing member, the fixing member having an outer threaded section which is engaged with the inner threaded section of the receiving area, the end cap having a threaded section which is engaged with the inner threaded section of the receiving area.