Apparatus for reducing the diameter of a stent

Abstract

The apparatus ( 1 a ) for reducing the diameter of a stent ( 2 ) includes compressors ( 9 a ) which are supported on a circumferential abutment ( 3 a ) and act, at least indirectly, radially on the outer surface of the stent ( 2 ). Resiliently elastic tensioning members ( 15 ) are provided between the radially inwardly displaceable segmental compressors ( 9 a ) and the abutment ( 3 a ) and can be acted upon by a pressure fluid in opposition to a resiliently elastic rebound force ( 21 ).

1 . Apparatus for reducing the diameter of a stent, comprising radially inwardly moving segmental compressors which act, at least indirectly, radially on an outer surface of the stent and are supported on a circumferential abutment, flexible tensioning members provided between the compressors and the abutment and actuatable by a pressure fluid in opposition to a resiliently elastic rebound force.  
   
   
       2 . Apparatus according to  claim 1 , wherein the tensioning members are formed by balloons or expandable tubes.  
   
   
       3 . Apparatus according to  claim 1 , wherein the compressors have concave contact surfaces in a direction towards the circumferential abutment, and wherein the abutment has concavely curved resistance surfaces, which are open towards a center axis of the abutment for the tensioning members.  
   
   
       4 . Apparatus according to  claim 1 , wherein the compressors are disposed in at least two parallel planes and radially movable in each plane independently of compressors of a neighboring plane.  
   
   
       5 . Apparatus according to  claim 4 , wherein the abutment extends across all planes.  
   
   
       6 . Apparatus according to  claim 1 , wherein each of the compressors embraces a radially inwardly extending strut of the abutment and is supported resiliently elastically upon the strut.  
   
   
       7 . Apparatus according to  claim 6 , wherein the compressors are constructed as hollow circular segments, supported directly on the struts with their radially directed diverging-legs as well as projections, which extend toward one another adjacent to the abutment, and supported with inwardly directed resilient tongues on crossbars of the struts.  
   
   
       8 . Apparatus according to  claim 1 , wherein the compressors are made of plastic and the abutment is made of a metal.  
   
   
       9 . Apparatus according to  claim 1 , wherein the compressors are part of a metallic spring band which extends in the form of a meander in circumferential direction and is respectively supported with trapezoidal zones on two neighboring struts of the abutment made of a metal.  
   
   
       10 . Apparatus for reducing the diameter of a stent, comprising: 
 a compressor constructed to move radially inwardly to act, at least indirectly, radially upon an outer surface of a stent;    an abutment for support of the compressor;    a resiliently elastic rebound mechanism; and    a flexible tensioning member arranged between the abutment and the compressor and rendered operative by pressure fluid in opposition to a force applied by the rebound mechanism.    
   
   
       11 . The apparatus of  claim 10 , wherein the tensioning member is a balloon.  
   
   
       12 . The apparatus of  claim 10 , wherein the tensioning member is an expandable tube.  
   
   
       13 . The apparatus of  claim 10 , wherein the abutment is defined by a center axis, the compressor having a concave contact surface in a direction towards the abutment and the abutment having a complementary concavely curved resistance surface, which is open towards the center axis, to define a space for receiving the tensioning member.  
   
   
       14 . The apparatus of  claim 10 , further comprising a plurality of said compressor disposed in parallel planes, wherein compressors in one plane are movable in radial direction independently of compressors in a neighboring plane.  
   
   
       15 . The apparatus of  claim 14 , wherein the compressors are positioned about a circle, with the abutment disposed in surrounding relationship to the compressors.  
   
   
       16 . The apparatus of  claim 14 , wherein the abutment is sized to extend across all the planes.  
   
   
       17 . The apparatus of  claim 14 , wherein the abutment has a cylindrical configuration.  
   
   
       18 . The apparatus of  claim 10 , wherein the abutment has a radially inwardly extending strut, the compressor being constructed to embrace the strut and supported resiliently on the strut to provide the rebound mechanism.  
   
   
       19 . The apparatus of  claim 18 , wherein the compressor is constructed as hollow circular segment having diverging radial legs, projections extending toward one another in an area adjacent to the abutment for direct support on the strut, and inwardly directed resilient tongues defining the rebound mechanism and supported on crossbars of the strut.  
   
   
       20 . The apparatus of  claim 10 , wherein the compressor is made of plastic, and the abutment is made of metal.  
   
   
       21 . The apparatus of  claim 10 , wherein the compressor is part of a metallic spring band which extends in the form of a meander in circumferential direction and is configured with trapezoidal areas for support on two neighboring struts of the abutment.  
   
   
       22 . The apparatus of  claim 21 , wherein the abutment is made of a metal.