Bicycle Pump with Universal Head

Abstract

A bicycle pump comprises a head, a socket, a ball, a retaining collar, a cylinder, and a piston unit. The head is provided with a connection portion and defines an air inlet and an air outlet. The socket is provided in the head and defines a round recess and a through hole. The ball can be retained between the socket and the retaining collar and rotated about its center in all directions. The cylinder defines a chamber therein. Also, the cylinder has a first connection portion at one end thereof and defines an air outlet at a center of the first connection portion. The piston unit is provided for conducting reciprocating motion along the chamber of the cylinder, so that air in the chamber can be forced out of the air outlet of the cylinder and finally forced out of the air outlet of the head to inflate a tire.

I claim: 
     
         1 . A bicycle pump, comprising
 a head including a housing that is provided with a connection portion, and defines an air inlet and an air outlet communicating with said air inlet;   a socket provided in said head, said socket defining a round recess and a through hole communicating with said round recess and said air inlet of said head;   a ball partially disposed in said round recess of said socket, said ball defining a through hole communicating with said through hole of said socket, said ball having a connection portion;   a retaining collar having an inner curved surface to be mated with an outer surface of a part of said ball located outside of said socket, and having a connection portion attached with said connection portion of said head, so that said ball can be retained between said socket and said retaining collar and rotated about its center in all directions;   a cylinder defining a chamber therein, said cylinder having a first connection portion at one end thereof, said cylinder defining an air outlet at a center of said first connection portion, said air outlet of said cylinder communicating with said chamber, said first connection portion being attached with said connection portion of said ball, to allow said air outlet of said cylinder to communicate with said through hole of said ball; and   a piston unit for conducting reciprocating motion along said chamber of said cylinder, so that air in said chamber can be forced out of said air outlet of said cylinder and finally forced out of said air outlet of said head to inflate a tire.   
     
     
         2 . The bicycle pump of  claim 1 , wherein said head further includes a nozzle, a pressing unit, and a lever, said nozzle being mounted in said housing and located at a bottom portion of said housing, said nozzle defining an air passage communicating with said air outlet and said air inlet of said head and capable of accommodating a valve of a tire of a bike, said pressing unit being hermetically and movably mounted in said housing and placed above said nozzle, said connection portion of said housing being formed on an annular member at a side of said housing, said air inlet of said head being defined at a center of said annular member of said housing, said lever being pivotally mounted to said housing in cooperation with said pressing unit, whereby when said lever is pivotally moved from a first position to a second position, said pressing unit can be urged by said lever to move downward to secure a valve on a tire of a bike. 
     
     
         3 . The bicycle pump of  claim 2 , wherein said pressing unit includes a pressing cup and a plunger fixed to said pressing cup, said plunger being inserted into said nozzle, said pressing cup being engaged with said lever, whereby when said lever is pivotally moved from a first position to a second position, said lever can urge said pressing cup, which in turn drive down the plunger to urge the valve, thereby securing the valve in said nozzle. 
     
     
         4 . The bicycle pump of  claim 2 , wherein when said lever is at the first position, said pressing unit is not urged by said lever; when said lever is at the second position, said pressing unit is urged by said lever. 
     
     
         5 . The bicycle pump of  claim 1 , wherein said cylinder defines an opening at the other end thereof and communicates with said chamber of said cylinder; said piston unit includes a piston and a connecting rod, said piston being mounted in said chamber of said cylinder, said connecting rod having a first end connected to said piston and a second end extending through said opening of said cylinder. 
     
     
         6 . The bicycle pump of  claim 5 , wherein said cylinder has a second connection portion provided at an outer surface of the end that defines said opening, and which further comprises an end cap defining a through hole at a center thereof and having a connection portion attached with said second connection portion of said cylinder, wherein the second end of said connecting rod extends through said through hole of said end cup; said through hole of said end cap having a dimension less than said piston. 
     
     
         7 . The bicycle pump of  claim 6 , wherein said second connection portion of said cylinder is formed as external threads, whereas said connection portion of said end cap is formed as internal threads, which can be threadedly engaged with said external threads of said cylinder. 
     
     
         8 . The bicycle pump of  claim 6 , further comprising a handle connected to the second end of the connecting rod that extends through said through hole of said end cap. 
     
     
         9 . The bicycle pump of  claim 1 , wherein an airtight ring is provided between said through hole of said ball and said air outlet of said cylinder. 
     
     
         10 . The bicycle pump of  claim 1 , wherein said connection portion of said head is formed as external threads, whereas said connection portion of said retaining collar is formed as internal threads, which can be threadedly engaged with said external threads of said head; said connection portion of said ball is formed as internal threads, whereas said first connection portion of said cylinder is formed as external threads, which can be threadedly engaged with said internal threads of said ball.