US 5,488,959 AGranted

Medical guidewire and welding process

AssigneeCordis Corporation

InventorFrancisco Ales

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Abstract

A process is provided which is particularly suitable for manufacturing medical guidewires. The resulting products have a weld that has good pull strength and is of minimum brittleness even when one of the components being welded together is a fine wire of material that is susceptible to damage and severe deterioration when subjected to harsh heating conditions. The invention is particularly suitable when that material is a Nitinol alloy. The process supports the other component to be welded such as a coil within a collet such that a substantial portion of it projects beyond the collet and is not supported thereby. A heat source renders this projecting portion molten, after which the other component made of Nitinol, for example, is embedded into the molten mass, usually still under the influence of the heat source, to thereby effect a joining which, after cooling, provides the improved weld without imparting brittleness to either component.

Claims21

Dependent claims

A process for manufacturing a medical guidewire, the process including a procedure for providing an assembly of a core wire and a coil generally coaxial with each other, the procedure comprising the steps of:

inserting a guidewire coil into a collet to thereby support the guidewire, said inserting step including projecting a distal end portion of the coil beyond a face of the collet such that the distal end portion of the coil is not in engagement with the collet and extends therebeyond;
locating an elongated core wire at a staged position remote from and at a location behind the face of the collet, the core wire having a leading end;
heating the distal end portion of the coil in order to form a heated tip mass, and continuing the heating until the heated tip mass engages the face of the collet;
effecting relative movement between the coil and the core wire at its staged position until the core wire is at a location within the coil supported by the collet, said effecting step including engaging the leading end of the core wire with the heated tip mass;
said effecting step further including joining the core wire leading end and the coil tip mass into a welded assembly of respective distal ends of the coil and core wire;
and
removing the welded assembly from the collet to define a distal tip of the medical guidewire.

4 more elements

A process for manufacturing, including a procedure for welding an elongated component made of an alloy of nickel and titanium as its primary components together with an assembly component having an elongated passageway, the process comprising the steps of:

inserting an assembly component having an elongated passageway into a collet to thereby support the assembly component, said inserting step including projecting a portion of the assembly component beyond a face of the collet such that said portion of the assembly is a projecting end portion which is not in engagement with the collet;
locating an elongated component made of an alloy that is primarily nickel and titanium at a staged position remote from and at a location behind the face of the collet, said elongated component having a leading end;
heating the projecting end portion of the assembly component in order to form a heated mass and continuing the heating until the heated mass engages the face of the collet;
effecting relative movement between the assembly component and the elongated component at its staged position so that the elongated component is at a location within the elongated passageway of the assembly component, said effecting step including engaging the leading end of the elongated component with the heated mass, said effecting step further including joining the elongated component leading end and the heated mass into a welded assembly;
and
removing the welded assembly from the collet.

3 more elements

Dependencies are inferred from the claim text.