Making closed end tubes for surgical instruments

Abstract

Techniques are described for making one-piece tubes for surgical instruments in which an inner tube that carries a cutting implement is disposed for movement within an outer tube having a cutting window that exposes the cutting implement to tissue. Swaging is performed to close an end of a tubular member that is to serve as either the inner tube or the outer tube. Other processing steps are also performed. For example, a selected amount of a protrusion formed by the swaging is cut away, the tube material is fused together at a seam formed by the swaging, and the closed distal end of the tubular member is formed into a selected shape. For example, the selected shape is rounded so that the distal end defines convex (e.g., substantially hemispherical) interior and exterior distal surfaces. This renders the tube suitable for use in full-radius surgical instruments. Alternatively, the selected shape is flattened so that the distal end defines flattened interior and exterior distal surfaces. In this case, the tube can be used in end cutting surgical instruments.

What is claimed is:  
     
         1 . A method of making a surgical instrument of the kind that includes an inner tube disposed for movement within an outer tube, comprising 
 providing a tubular member to serve as either the inner tube or the outer tube, the tubular member having an open distal end, and    swaging the distal end of the tubular member closed.    
     
     
         2 . The method of  claim 1  further comprising performing the swaging by rotary swaging.  
     
     
         3 . The method of  claim 1  wherein the tubular member includes a distal edge that defines an opening at the distal end, the swaging comprising driving regions of the tubular member disposed adjacent to the distal edge together to close the opening.  
     
     
         4 . The method of  claim 3  wherein, prior to the swaging, the distal edge is disposed symmetrically about an axis of the tubular member, the swaging comprising driving the adjacent regions of the tubular member together symmetrically with respect to the axis.  
     
     
         5 . The method of  claim 3  wherein, prior to the swaging, the distal edge is disposed perpendicularly to the axis of the tubular member.  
     
     
         6 . The method of  claim 1  wherein the swaging produces a seam in material of the tubular member at the distal end, and further comprising fusing the material together at the seam.  
     
     
         7 . The method of  claim 6  further comprising performing the fusing by welding the distal end.  
     
     
         8 . The method of  claim 6  wherein the swaging produces a protrusion of the tubular member material at the seam, and further comprising cutting away a selected amount of the protrusion prior to performing the fusing.  
     
     
         9 . The method of  claim 1  further comprising forming the closed distal end of the tubular member into a selected shape.  
     
     
         10 . The method of  claim 9  wherein the selected shape is rounded so that the distal end defines convex interior and exterior distal surfaces.  
     
     
         11 . The method of  claim 10  wherein the convex distal surfaces are substantially hemispherical.  
     
     
         12 . The method of  claim 9  wherein the selected shape is flattened so that the distal end defines flattened interior and exterior distal surfaces.  
     
     
         13 . The method of  claim 9  further comprising performing said forming by pressing the distal end between a pair of dies that define the selected shape.  
     
     
         14 . The method of  claim 1  further comprising 
 providing the tubular member as the inner tube of the surgical instrument, and  
 after the swaging, disposing a cutting implement at the distal end of the tubular member.  
 
     
     
         15 . The method of  claim 14  further comprising disposing the tubular member for rotation within the outer tube of the surgical instrument.  
     
     
         16 . The method of  claim 1  further comprising 
 providing the tubular member as the outer tube of the surgical instrument, and  
 after the swaging, defining a window at the distal end for exposing a cutting implement carried by the inner tube.  
 
     
     
         17 . The method of  claim 1  further comprising 
 providing a second tubular member to serve as the other one of the inner tube or the outer tube, the second tubular member having an open distal end, and  
 swaging the distal end of the second tubular member closed.  
 
     
     
         18 . A method of making a surgical instrument of the kind that includes an inner tube having a closed distal end disposed for movement within an outer tube having a closed distal end, comprising 
 providing a tubular member to serve as either the inner tube or the outer tube, the tubular member having an open distal end,    swaging the distal end of the tubular member closed, the swaging producing a seam in material of the tubular member at the distal end and a protrusion of the tubular member material at the seam,    cutting away a selected amount of the protrusion,    fusing the material together at the seam after the cutting, and    after the fusing, forming the closed distal end of the tubular member into a selected shape.    
     
     
         19 . The method of  claim 18  further comprising performing the swaging by rotary swaging.  
     
     
         20 . The method of  claim 18  further comprising performing the fusing by welding the distal end.  
     
     
         21 . The method of  claim 18  wherein the selected shape is rounded so that the distal end defines convex interior and exterior distal surfaces.  
     
     
         22 . The method of  claim 21  wherein the convex distal surfaces are substantially hemispherical.  
     
     
         23 . The method of  claim 18  wherein the selected shape is flattened so that the distal end defines flattened interior and exterior distal surfaces.  
     
     
         24 . The method of  claim 18  further comprising 
 providing the tubular member as the inner tube of the surgical instrument, and  
 after the swaging, disposing a cutting implement at the distal end of the tubular member.  
 
     
     
         25 . The method of  claim 24  further comprising disposing the tubular member for rotation within the outer tube of the surgical instrument.  
     
     
         26 . The method of  claim 18  further comprising 
 providing the tubular member as the outer tube of the surgical instrument, and  
 after the swaging, defining a window at the distal end for exposing a cutting implement carried by the inner tube.  
 
     
     
         27 . The method of  claim 18  further comprising 
 providing a second tubular member to serve as the other one of the inner tube or the outer tube, the second tubular member having an open distal end, and  
 swaging the distal end of the second tubular member closed.  
 
     
     
         28 . The method of  claim 18  further comprising 
 conveying the tubular member between stations for performing the swaging, cutting, fusing, and forming, and  
 controlling the conveying and coordinating operation of the stations.  
 
     
     
         29 . Apparatus for making a surgical instrument of the kind that includes an inner tube disposed for movement within an outer tube, comprising 
 a swaging station for receiving a tubular member having an open distal end and for swaging the distal end of the tubular member closed, whereby the tubular member can serve as either the inner tube or the outer tube.    
     
     
         30 . The apparatus of  claim 29  wherein the swaging station includes a rotary swager.  
     
     
         31 . The apparatus of  claim 29  wherein the swaging produces a seam in material of the tubular member at the distal end, the apparatus further comprising a fusing station for fusing the material together at the seam.  
     
     
         32 . The apparatus of  claim 31  wherein the fusion station comprises a welding device.  
     
     
         33 . The apparatus of  claim 32  wherein the swaging produces a protrusion of the tubular member material at the seam, the apparatus further comprising a cutting station disposed between the swager and the fusion station, for cutting away a selected amount of the protrusion.  
     
     
         34 . The apparatus of  claim 29  further comprising a forming station for forming the closed distal end of the tubular member into a selected shape.  
     
     
         35 . The apparatus of  claim 34  wherein the selected shape is rounded so that the distal end defines convex interior and exterior distal surfaces.  
     
     
         36 . The apparatus of  claim 35  wherein the convex distal surfaces are substantially hemispherical.  
     
     
         37 . The apparatus of  claim 35  wherein the selected shape is flattened so that th e distal end defines flattened interior and exterior distal surfaces.  
     
     
         38 . The apparatus of  claim 34  wherein the forming station comprises a pair of dies that define the selected shape for pressing the distal end therebetween.  
     
     
         39 . Apparatus of making a surgical instrument of the kind that includes an inner tube having a closed distal end disposed for movement within an outer tube having a closed distal end, comprising 
 a swager for receiving a tubular member having an open distal end and for swaging the distal end of the tubular member closed, whereby the tubular member can serve as either the inner tube or the outer tube, the swaging producing a seam in material of the tubular member at the distal end and a protrusion of the tubular member material at the seam,    a cutting station for cutting away a selected amount of the protrusion,    a fusion station for fusing the material together at the seam after the cutting, and    a forming station for forming the closed distal end of the tubular member into a selected shape.    
     
     
         40 . The apparatus of  claim 39  wherein the swaging station includes a rotary swager.  
     
     
         41 . The apparatus of  claim 39  wherein the fusion station comprises a welding device.  
     
     
         42 . The apparatus of  claim 39  wherein the selected shape is rounded so that the distal end defines convex interior and exterior distal surfaces.  
     
     
         43 . The apparatus of  claim 42  wherein the convex distal surfaces are substantially hemispherical.  
     
     
         44 . The apparatus of  claim 39  wherein the selected shape is flattened so that the distal end defines flattened interior and exterior distal surfaces.  
     
     
         45 . The apparatus of  claim 39  further comprising 
 devices for conveying the tubular member between the stations, and  
 a controller for controlling the devices and coordinating operation of the stations.