Hand pump for pumping air of lower pressure and high pressure

Abstract

A hand pump includes a receptacle having a compartment and a chamber, a tubular member engaged into the chamber and secured to the receptacle, a cylinder engaged onto the tubular member, a piston is engaged between the tubular member and the cylinder for forcing an air from a front space of the cylinder into the tubular member with a lower pressure, a lid is attached to the cylinder and a check valve controls the air to flow only from the outer environment into the cylinder, a control valve member is engaged in the lid for controlling the air to flow through the lid, and an actuator is attached to the lid and engaged with the control valve member for opening the hole of the lid and for releasing the air selectively.

I claim: 
     
         1 . A hand pump comprising:
 a receptacle including a partition provided therein to form a compartment and a chamber in said receptacle, said partition being located between said chamber and said compartment and including an opening formed in said partition and communicating with said chamber and said compartment of said receptacle,   a tubular member including a first end portion engaged into said chamber and secured to said receptacle, and a second end portion extended out of said receptacle, and said tubular member including a bore formed therein and communicating with said opening of said partition and said compartment of said receptacle,   a cylinder slidably engaged onto said tubular member, said cylinder including a first end portion engageable into said chamber of said receptacle and a second end portion extended out of said receptacle, said cylinder including a space having an inner diameter greater than an outer diameter of said tubular member,   a piston attached to said second end portion of said tubular member and slidably engaged between said tubular member and said cylinder for separating said space of said cylinder into a front space and a rear space, said piston including a passage formed therein,   a control valve device attached to said piston for controlling the air to flow through said passage of said piston selectively,   a first check valve disposed between said piston and said control valve device for controlling the air to flow only from said control valve device through said passage of said piston and into said bore of said tubular member, and to prevent the air from flowing backwardly from said bore of said tubular member into said control valve device,   a cover attached to said first end portion of said cylinder,   a second check valve attached to said first end portion of said cylinder for controlling the air to flow from an outer environment into said front space of said cylinder when said cylinder is moved toward said receptacle, and to prevent the air from flowing out of said front space of said cylinder when said cylinder is moved away from said receptacle,   a lid attached to said second end portion of said cylinder, said lid including a hole formed therein,   a third check valve attached to said second end portion of said cylinder for controlling the air to flow only from said outer environment through said hole of said lid and into said rear space of said cylinder when said cylinder is moved away from said receptacle, and to prevent the air from flowing out of said rear space of said cylinder when said cylinder is moved toward said receptacle,   a control valve member engaged in said lid for controlling the air to flow through said hole of said lid, and   an actuator attached to said lid and engaged with said control valve member for selectively opening said hole of said lid.   
     
     
         2 . The hand pump as claimed in  claim 1 , wherein said control valve member includes a sliding member slidably engaged in said cylinder, said sliding member includes a stem extendible out of said hole of said lid, and a spring biasing member is engaged with said sliding member for biasing said sliding member to block said hole of said lid selectively. 
     
     
         3 . The hand pump as claimed in  claim 2 , wherein said control valve member includes a barrel attached onto said second end portion of said cylinder, said barrel includes a compartment formed therein and includes a slot communicating with said compartment of said barrel, and said actuator is engaged in said compartment of said barrel and includes a shank extendible out of said slot of said barrel. 
     
     
         4 . The hand pump as claimed in  claim 1 , wherein said control valve device includes an outer peripheral groove formed therein, and a manifold formed in said control valve device and communicating with said passage of said piston and said outer peripheral groove of said control valve device, and a valve piece engaged into said outer peripheral groove of said control valve device and arranged to control the air to flow only from said front space of said cylinder into said manifold of said control valve device and into said bore of said tubular member when said cylinder is moved away from said receptacle, and to prevent the air from flowing from said rear space of said cylinder into said manifold of said control valve device and into said bore of said tubular member when said cylinder is moved toward said receptacle. 
     
     
         5 . The hand pump as claimed in  claim 4 , wherein said valve piece is selected from a sealing ring engaged into said outer peripheral groove of said control valve device. 
     
     
         6 . The hand pump as claimed in  claim 1 , wherein said receptacle includes a valve piece and a gasket engaged into said compartment of said receptacle, and a cap secured to said receptacle for retaining said valve piece and said gasket within said compartment of said receptacle.