Combination seat pad

Abstract

A seat pad has a circular central pad element and at least one annular pad element. The circular central pad element is inflatable. The at least one annular pad element is inflatable and is mounted concentrically around the central pad element. At least one set of an annular combination recess and an annular combination protrusion is formed between the central pad element and the at least one annular pad element to connect the central pad element and the at least one annular pad element with each other. The combination recess has at least one engaging rib formed on an inner surface of the combination recess. The combination protrusion has at least one engaging recess formed in an outer surface of the combination protrusion and engaged respectively with the at least one engaging rib of the combination recess.

What is claimed is: 
     
         1 . A seat pad comprising:
 a circular central pad element being inflatable;   at least one annular pad element being inflatable and mounted concentrically around the central pad element; and   at least one set of an annular combination recess and an annular combination protrusion formed between the central pad element and the at least one annular pad element to connect the central pad element and the at least one annular pad element with each other, wherein   the combination recess of each one of the at least one set has at least one engaging rib formed on an inner surface of the combination recess; and   the combination protrusion of each one of the at least one set has at least one engaging recess formed in an outer surface of the combination protrusion and engaged respectively with the at least one engaging rib of a corresponding combination recess.   
     
     
         2 . The seat pad as claimed in  claim 1 , wherein the at least one annular pad element is implemented as one in amount; and
 one set of an annular combination recess and an annular combination protrusion is formed between the central pad element and the annular pad element.   
     
     
         3 . The seat pad as claimed in  claim 2 , wherein the combination recess is concave in cross sectional shape; and
 the combination protrusion is convex in cross sectional shape.   
     
     
         4 . The seat pad as claimed in  claim 3 , wherein each one of the central pad element and the annular pad element has multiple protuberances formed on and protruding from a top surface of the pad element. 
     
     
         5 . The seat pad as claimed in  claim 4 , wherein the annular pad element has a grip hole defined through the alar pad element. 
     
     
         6 . The seat pad as claimed in  claim 5 , wherein the central pad element further has a rod hole defined through the central pad element. 
     
     
         7 . The seat pad as claimed in  claim 1 , wherein the at least one annular pad element is implemented as multiple in amount; and
 multiple sets of an annular combination recess and an annular combination protrusion are formed between the central pad element and the multiple annular pad elements.   
     
     
         8 . The seat pad as claimed in  claim 7 , wherein each combination recess is concave in cross sectional shape; and
 each combination protrusion is convex in cross sectional shape.   
     
     
         9 . The seat pad as claimed in  claim 8 , wherein each one of the central pad element and the multiple annular pad elements has multiple protuberances formed on and protruding from a top surface of the pad element. 
     
     
         10 . The seat pad as claimed in  claim 9 , wherein the multiple annular pad elements include an outermost annular pad element; and
 the outermost annular pad element has a grip hole defined through the outermost annular pad element.   
     
     
         11 . The seat pad as claimed in  claim 10 , wherein the central pad element further has a rod hole defined through the central pad element. 
     
     
         12 . The seat pad as claimed in  claim 1 , wherein the combination recess of each one of the at least one set is concave in cross sectional shape; and
 the combination protrusion of each one of the at least one set is convex in cross sectional shape.   
     
     
         13 . The seat pad as claimed in  claim 1 , wherein each one of the central pad element and the at least one annular pad element has multiple protuberances formed on and protruding from a top surface of the pad element. 
     
     
         14 . The seat pad as claimed in  claim 1 , wherein the at least one annular pad element includes an outermost annular pad element; and
 the outermost annular pad element has a grip hole defined through the outermost annular pad element.   
     
     
         15 . The seat pad as claimed in  claim 1 , wherein the central pad element further has a rod hole defined through the central pad element.