External fixation device
AssigneeHowmedica International Inc.
InventorsJacques Mata, Marcel Nyfeler, Denis Worek
Life of this patent
Estimating the term…
Abstract
An articulation element for the relative positioning of fixation bars or bone pins of an external fixator includes a plurality of pairs of jaws. The jaws have on their adjacent faces grooves which form a passage intended to receive a bar or a pin. A spring is interposed between the pairs of jaws. The grooves which form the passage are positioned and arranged so as to have an external opening allowing the bar or bone pin to be snapped in by pressure on it, from the opening of the jaw into the passage, against the spring force which presses the adjacent faces of the haws against one another. This force holds the articulation element on the bars or pins before locking of the articulation by means of a clamping shaft.
Claims15
An articulation element for the relative positioning of fixation bars, rods or pins of an external fixator, comprising as 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 direction transverse to said axis which groove forms a passage intended to receive said rod, bar or a pin wherein said groove is positioned on said jaw radially outwardly from said internal shaft;
- an elastic element acting on at least one of said jaws tending to press said adjacent faces together;
- 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 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 the force of said elastic element which presses the adjacent faces against one another to hold the articulation element on the bars, rods or pins before the clamping element locks the pairs of jaws, said passage formed by said groove having a cross-section smaller than a cross-section of said pins rod or bars prior to the rod, bar or pin being placed therein.
An articulation element for clamping rods or bars of an external fixator comprising:
- a shaft;
- at least one pair of jaw members mounted on and surrounding said shaft, said jaw members having adjacent faces, at least one jaw member movable with respect to said shaft, at least one of said jaw members having a partial groove formed in the face thereof, said groove partially circumferentially open to an outer surface of said jaw member in a direction transverse to said shaft;
- an elastic element engaging said at least one moveable jaw member, forcing the partial circumferential opening of said groove toward the face of said other jaw member, an initial width of said partial circumferential opening of said groove being less than a cross-section of said rod or bar so that the rod or bar may be inserted therein in radial direction with respect to said groove and said shaft against said force of said elastic element;
- and
- a locking element engaging said shaft and at least one of said jaw members to lock said jaw members against the bar or rod captured in said groove.
An external fixator for locating at least two bone pins for insertion on either side of a fracture and connected by rods comprising:
- at least one articulation element arranged between one of said pins and a rod or between two rods for their relative positioning, said articulation element comprising at least one pair of jaw members mounted on and surrounding a shaft extending along a central axis of said articulation element, at least one jaw member of said pair having an internal transverse recess forming a passageway therethrough for receiving said pins or rod, said passage having an outwardly facing opening for receiving said pin or rod along an axis transverse to said central axis, said opening intersecting with the passageway allowing insertion of said pin or rods in a radial direction with respect to said passageway;
- a spring element acting against at least one of said jaw members of said pair of jaw members;
- and
- a stop surface formed on said adjacent members to define a minimum cross-section of said recess and a width of said opening, said spring element resisting forces tending to increase with width of said opening generated by the insertion of said pin or rods into said passageway.
Dependencies are inferred from the claim text.