Flexible intravenous catheter provided with cutting tip means

Claim 1

In a catheter for intravenous injections: elongate conduit means comprising a flexible hollow tube having a smooth continuous outer surface, elongate force-transmitting means comprising a relatively rigid member axially aligned within said tube and longitudinally slidable relative thereto, cutting means comprising a hardened end portion on said hollow tube and of uniform continuous external diameter with said outer surface thereof, said end portion having a cutting edge thereon, ridge means comprising a radially inward projecting ridge on the inner surface of said end portion, blunt distal edge means formed on said rigid member, said edge means having a bearing surface adapted to bear against said ridge on said end portion in force transmitting relationship, and with substantially uniform circumferential distribution of said force over said bearing surfaces and said ridge, whereby force applied to said relatively rigid member in a direction toward said end portion is transmitted to said end portion through said bearing surface and said ridge means, said hardened end portion consisting of a relatively rigid cylindrical ferrule secured to said flexible hollow tube, an inner dividing partition situated within said ferrule, and a forward cutting edge on said inner dividing partition for fragmenting particles cut by said cutting edge on said hardened end portion.