Mounting structure for staple guns

A mounting structure for a staple gun, comprising:

• a gun body having an air chamber defined therein;
• a cylinder disposed in said air chamber, said cylinder being fitted with an O-ring and having two spaced flanged rings extending from an outer periphery thereof;
• a buffer disposed at an end of said air chamber defined in said gun body, said cylinder accommodating a piston rod and said cylinder engaging said buffer so that a strike pin of said piston rod passes through a central hole defined in said buffer and a bottom side of said cylinder rests upon a plurality of ribs on an upper side of said buffer, said upper side of said buffer and said bottom side of said cylinder defining a clearance for passage of air inside said air chamber into said cylinder;
• a sleeve engaged with said cylinder, said sleeve being disposed between said two spaced flanged rings and secured from axial movement thereby, said sleeve pressing against a plurality of ribs extending along an inner wall of said gun body such that said sleeve engages said inner wall of said gun body and firmly positions said cylinder inside said air chamber, said sleeve dividing said air chamber into an upper air chamber and a lower air chamber;
• a press element being engaged with a top end of said cylinder, said press element being provided with an opening which communicates with an interior of said cylinder;
• and
• a guide means disposed in a top cover of said gun body,
• wherein said cylinder is provided with two raised rings spaced apart from each other and disposed below said flanged rings, at least one of said raised rings being provided with a plurality of air vents, said O-ring being fitted between said raised rings for covering said air vents for providing an unidirectional supply of air to said lower air chamber during return strokes of said piston rod.