Positioning and locking device

Abstract

A device for positioning and locking rods, pins or wires, particularly for an external fixator in the field of orthopaedics is provided. The device comprises two jaw faces and a tightening assembly exhibiting a connecting element secured to a tightening member, the assembly allowing the jaws to form at least one opening exhibiting at least one cavity in the form of a gripping jaw allowing a hoop, a rod, a pin or a wire to be clipped by pressure against the action of an elastic member keeping the device in position prior to the locking action which is performed using the tightening member.

1 . A clamp having first and second surfaces with an external surface extending therebetween for use in an external fixation system, comprising: 
 at least one pair of jaws having adjacent faces separated by a slit, said slit intersecting said external surface and extending intermediate said first and second surfaces and terminating in an internal widened area adjacent a first part of said of the external surface of said clamp;    a groove formed in at least one of said jaws open to a second part of said external surface of said clamp, said groove intersecting said slit;    a clamping element for closing the slit and preventing the faces of said jaws from moving away from one another.    
     
     
         2 . The clamp as said forth in  claim 1 , wherein said groove and said widened area extend in parallel directions.  
     
     
         3 . The clamp as set forth in  claim 2 , wherein said first and second parts of said external surface are opposite one another.  
     
     
         4 . The clamp set forth in  claim 1 , wherein said widened area is spaced internally from said first part of said external surface by a thin piece of material acting as a spring.  
     
     
         5 . The clamp as set forth in  claim 1 , wherein said groove is sized to accept a rod, wire or pin.  
     
     
         6 . The clamp as set forth in  claim 5 , wherein the groove has a cross-section smaller than the rod, wire or pin to be placed therein so that upon insertion of said rod, wire or pin from a direction perpendicular to a longitudinal extent of said groove, said jaw faces are moved apart along said slit by deflecting said thin piece of material.  
     
     
         7 . The clamp as set forth in  claim 1 , wherein the clamping element is a bolt extending between said first and second surfaces.  
     
     
         8 . The clamp as set forth in  claim 7 , wherein said bolt extends through a bore located intermediate said internal widened area and said groove.  
     
     
         9 . The clamp as set forth in  claim 8  having two pairs of jaws mounted on said bolt with each pair of jaws having faces separated by a slit intersecting a groove and an internal widened area.  
     
     
         10 . The clamp as set forth in  claim 1  wherein said widened area is a through bore.  
     
     
         11 . An articulation element for the relative positioning of fixation bars, rods or pins of an external fixator, comprising a clamp having at least one pair of jaws mounted around an internal shaft and arranged along an axis of said shaft and having adjacent faces with at least one face having a groove extending in a direction transverse to said axis which groove forms a passage intended to receive said rod, pin or bar radially outwardly from said internal shaft; 
 said pair of jaws having adjacent faces separated by a slit extending from said groove, around said shaft and terminating in an internal through bore adjacent a first external surface of said clamp, said bore spaced internally from said external surface by a thin piece of material of the clamp acting as a spring;    a clamping element for clamping said pair of jaws together and locking said rods, bars or pins held between said jaws in a relative position;    said groove forming said passage is positioned and arranged so as to have an external opening on a second external surface of said clamp opposite said first external surface and extending along said transverse direction allowing the bar, rod or pin to be placed in said passage by pressure in a direction perpendicular to both said axis of said shaft and said direction transverse to said axis against an elastic force developed by the movement of said faces away from one another deflecting the thin piece of material acting as a spring to hold the articulation element on the bars, rods or pins before the clamping element locks the pair of jaws, said passage formed by said groove having an initial cross-section smaller than a cross-section of said pins, rods or bars prior to the rod, bar or pin being placed therein.    
     
     
         12 . The articulation element as set forth in  claim 11 , wherein said elastic force acts in a radial direction of said groove.  
     
     
         13 . The articulation element according to  claim 11 , wherein the grooves are of a rounded cross-section.  
     
     
         14 . The clamp as set forth in  claim 11 , wherein said groove and said bore extend in parallel directions.  
     
     
         15 . The clamp as set forth in  claim 11 , wherein said groove is sized to accept a rod, wire or pin.  
     
     
         16 . The articulation element as set forth in  claim 11 , wherein said shaft is a bolt and said clamping element is a nut threaded onto said bolt for engaging one of said jaws.  
     
     
         17 . A clamp for an external fixation system comprising: 
 a body having a first and second end separated by an external circumferential surface with a slit intermediate said ends; said slit open to said external surface of said body over less than the entire circumference thereof and a rod receiving opening extending into said slit and in communication with said external surface and a clamping element extending between said first and second ends internally of said rod receiving opening with respect to said external circumferential surface.    
     
     
         18 . The clamp as set forth in  claim 17 , wherein said rod receiving opening is a groove open to said external surface.  
     
     
         19 . The clamp as set forth in  claim 18 , wherein said slit terminates in an internal bore of said body.  
     
     
         20 . The clamp as set forth in  claim 19 , wherein said groove and said bore extend in parallel directions.  
     
     
         21 . The clamp as set forth in  claim 20 , wherein said internal bore is spaced internally from said external surface by a thin piece of material acting as a spring.  
     
     
         22 . The clamp as set forth in  claim 21 , wherein the clamping element extending through said body intermediate said internal bore and said groove.  
     
     
         23 . The clamp as set forth in  claim 22  wherein said clamping element is a bolt.  
     
     
         24 . The clamp as set forth in  claim 21 , wherein the groove has a cross-section smaller than the rod, wire or pin to be placed therein so that upon insertion of said rod, wire or pin from a direction perpendicular to a longitudinal extent of said groove, said jaw faces are moved apart along said slit by deflecting said thin piece of material.  
     
     
         25 . The clamp as set forth in  claim 18 , wherein said groove is sized to accept a rod, wire or pin.