Intravenous catheter assembly

Claim 1

An intravenous catheter assembly comprising (i) a hub having a central bore disposed therethrough, (ii) a flexible catheter tube of elastic material, one end of said tube being secured to the hub at one end of said bore, said catheter tube being aligned axially with said bore, (iii) sealing means mounted at the other end of said bore, (iv) a passage angularly disposed relative to said bore, said passage being disposed intermediate the ends of the bore and being in fluid communication therewith, (v) a catheter plunger tube of rigid or semi-rigid material having a blunt end, said sealing means slidingly engaging the outer surface of said plunger tube to prevent the flow of fluid, (vi) a resealable plug mounted at the other end of said plunger tube, (vii) means for supporting said plunger tube coaxially relative to said bore, said plunger tube being displaceable between a retracted position and an extended position, (viii) means for urging said plunger tube between said positions, (ix) a removable trocar consisting of a fluid collecting chamber and a hollow introducer needle for introducing said catheter tube into a blood vessel, said needle being in fluid communication with said chamber, and, wherein (a) said needle extends through said plunger tube, said bore and said catheter tube, the sharpened end of said needle projecting beyond the distal end of said catheter tube and said resealable plug slidingly engaging the outer surface of said needle to permit sealing of said plunger tube when said needle is withdrawn therefrom, (b) said plunger tube and said introducer needle are relatively dimensioned so that the plunger tube slidingly engages the outer wall surface of said needle, (c) said plunger tube and said catheter tube are relatively dimensioned so that the plunger tube slidingly engages the inner wall surface of the catheter tube, and (d) said plunger tube and said catheter are relatively dimensioned in length so that when in said extended position the blunt end of said plunger tube projects slightly beyond the distal end of said catheter tube and when in said retracted position the blunt end of said plunger is intermediate said passage and said sealing means.