Dual action air pump

Abstract

A dual action air pump has a body and a piston assembly. The body has an air chamber, an air channel and an elongated hole, which are defined longitudinally in the body parallel to each other. The air chamber has two ends, one of the ends has an outlet with an outlet check valve disk and a secondary inlet with a secondary inlet check valve disk formed therein, the other end has an inlet with an inlet check valve disk formed therein. The air channel has two ends, one of the ends communicates with one end of the air chamber, and the other end has a secondary outlet with a secondary outlet check valve disk formed therewith. The piston assembly is slidably abutting airtightly an inner surface of the air chamber, and can be pull or push to draw air and discharge air simultaneously. Moreover, an air hose used with the dual action air pump can be put into the elongated hole to have a pleasing appearance.

1 . A dual action air pump comprising
 a body being elongated and having
 a rear end; 
 a front end; 
 an air chamber being defined longitudinally in the body and having
 an inner surface; 
 a rear end; and 
 a front end; 
 
 an air channel being defined longitudinally in the body parallel to the air chamber and having
 a first end being formed in the rear end of the body and communicating with the rear end of the air chamber; and 
 a second end; 
 
 a downstroke outlet being formed near the front end of the body and communicating with the air chamber; 
 a downstroke outlet check valve disk being resilient, being mounted securely on the downstroke outlet and covering the downstroke outlet to keep air from flowing into the air chamber during an upstroke and to allow air inside the air chamber to flow out from the downstroke outlet during a downstroke; 
 a downstroke inlet being formed near the rear end of the body; 
 a downstroke inlet check valve disk being resilient, being mounted securely on the downstroke inlet and covering the downstroke inlet to allow ambient air to enter the air chamber and the air channel during a downstroke and to keep air inside the air chamber and the air channel from flowing out from the downstroke inlet during an upstroke; 
 an upstroke inlet being formed near the front end of the body and communicating with the air chamber; 
 an upstroke inlet check valve disk being resilient, being mounted securely on the upstroke inlet and covering the upstroke inlet to allow ambient air to enter the air chamber during an upstroke and to keep air inside the air chamber from flowing out from the upstroke inlet during a downstroke; 
 an upstroke outlet being formed near the second end of the air channel and communicating with the air channel; and 
 an upstroke outlet check valve disk being resilient, being mounted securely on the upstroke outlet and covering the upstroke outlet to keep air from flowing into the air channel during a downstroke and to allow air inside the air channel to flow out from the upstroke outlet during an upstroke; and 
   a piston assembly comprising
 a piston rod being mounted slidably through the rear end of the body and having an inner end being inside the air chamber; 
 a piston being mounted slidably in the air chamber and being attached securely to the inner end of the piston rod. 
   
   
   
       2 . The dual action air pump as claimed in  claim 1 , wherein the body further has an elongated hole being formed longitudinally in the body parallel to the air chamber and the air channel and having
 an open outer end being formed in the rear end of the body.   
   
   
       3 . The dual action air pump as claimed in  claim 2  further comprising an air hose being stored in the elongated hole in the body and having a proximal end and a distal end. 
   
   
       4 . The dual action air pump as claimed in  claim 3  further comprising a multi-valve body being mounted in the front end of the body and having
 a base being formed on the front end of the multi-valve body and having
 a division wall; and 
 a discharge chamber; 
   a chamber sleeve being formed with and protruding from the division wall of the base, being connected with an airtight seal to the air chamber and having
 a front end being formed integrally with the division wall in the base; 
 a sidewall; 
   a channel sleeve being formed with and protruding from the division wall of the base parallel to the chamber sleeve, being connected with an airtight seal to the air channel and having
 a front end being formed integrally with the division wall in the base; 
   wherein   the downstroke outlet is formed through the front end of the chamber sleeve and the division wall of the base and communicates with the air chamber and the discharge chamber in the base;   the downstroke outlet check valve disk is mounted securely on the front end of the chamber sleeve inside the discharge chamber in the base;   the upstroke inlet is formed on the sidewall of the chamber sleeve;   the upstroke inlet check valve disk is mounted securely on the sidewall of the chamber sleeve;   the upstroke outlet is formed through the front end of the channel sleeve and the division wall of the base and communicates with the air channel and the discharge chamber in the base; and   the upstroke outlet check valve disk is mounted securely on the front end of the channel sleeve inside the discharge chamber in the base.   
   
   
       5 . The dual action air pump as claimed in  claim 4  further comprising a rear end cap being mounted on the rear end of the body and having
 a cavity covering the rear end of the air chamber and the first end of the air channel;   a through hole being formed through the rear end cap coaxially relative to the air chamber of the body; and   an air hose hole being formed through rear end cap and being aligned with and corresponding to the elongated hole in the body,   wherein   the downstroke inlet is formed through the rear end cap; and   the downstroke inlet check valve disk is mounted securely in the cavity.   
   
   
       6 . The dual action air pump as claimed in  claim 5  further comprising a front end cap being mounted on the front end of the body, holding the multi-valve body and having
 a front end;   a space being defined in the front end cap, holding the multi-valve body and having a sidewall being mounted around the multi-valve body and forming an airtight seal;   a discharge hole being formed through the front end of the front end cap and communicating with the downstroke outlet and the upstroke outlet; and   multiple air holes being formed through the sidewall and communicating with the upstroke inlet.   
   
   
       7 . The dual action air pump as claimed in  claim 6 , wherein the piston assembly further has a seal assembly being mounted around the piston rod inside the rear end cap and connecting to the rear end cap. 
   
   
       8 . The dual action air pump as claimed in  claim 7 , wherein the piston of the piston assembly further has
 an outer edge;   an annular groove being formed in the outer edge of the piston; and   a seal being an O-ring, being mounted in the annular groove and abutting the inner surface of the air chamber to form an airtight seal.   
   
   
       9 . The dual action air pump as claimed in  claim 8 , wherein
 the discharge hole of the front end cap has an inner thread; and   the proximal end of the air hose has an external thread to be screwed into the internal thread in the discharge hole.   
   
   
       10 . The dual action air pump as claimed in  claim 9 , wherein
 the piston rod has an outer end protruding from the rear end of the body; and   the piston assembly further has a handle being mounted securely on the outer end of the piston rod.   
   
   
       11 . The dual action air pump as claimed in  claim 10 , wherein the rear end cap further has a storage plug corresponding to and being mounted detachably in the air hose hole in the rear end cap. 
   
   
       12 . The dual action air pump as claimed in  claim 11 , wherein the air hose further has a needle nozzle being attached to the distal end of the air hose.