Application of an improved damper to an intervertebral stabilization device
First Claim
1. An intervertebral stabilization device for attachment into two vertebrae comprising, a housing having opposite ends and defining an internal chamber, one of said ends of said housing being closed, a piston means slidably deposed within said internal chamber, a first rod element extending outwardly relative to said chamber from said one end of said housing and a second rod element extending outwardly relative to said chamber from said piston means, each of said first and second rod elements having outer ends, a first ball joint on said outer end of said first rod element and a second ball joint on said outer end of said second rod element for attachment into two vertebrae, a first elastic body damper means disposed within said chamber, said first elastic body damper means being engagable by said piston means so as to resist compression of said first elastic body damper means by said piston means under the effect of a force urging said piston means in axial compression relative to said elastic body dampen means, and said first elastic body damper means functioning as a stop to prevent further displacement of said piston means under the force of axial compression after a predetermined displacement of said piston means.
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Accused Products
Abstract
An improved damper, of the type comprising elements for progressively resisting, in exponential manner, the advance of a piston under the effect of a force of axial compression, which functions as a stop opposing any displacement of the piston beyond a predetermined value, in an intervertebral stabilization device.
859 Citations
12 Claims
- 1. An intervertebral stabilization device for attachment into two vertebrae comprising, a housing having opposite ends and defining an internal chamber, one of said ends of said housing being closed, a piston means slidably deposed within said internal chamber, a first rod element extending outwardly relative to said chamber from said one end of said housing and a second rod element extending outwardly relative to said chamber from said piston means, each of said first and second rod elements having outer ends, a first ball joint on said outer end of said first rod element and a second ball joint on said outer end of said second rod element for attachment into two vertebrae, a first elastic body damper means disposed within said chamber, said first elastic body damper means being engagable by said piston means so as to resist compression of said first elastic body damper means by said piston means under the effect of a force urging said piston means in axial compression relative to said elastic body dampen means, and said first elastic body damper means functioning as a stop to prevent further displacement of said piston means under the force of axial compression after a predetermined displacement of said piston means.
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12. An intervertebral stabilization device for attachment into two vertebrae comprising, a housing having opposite ends and defining an internal chamber, one of said ends of said housing being closed, a piston means slidably deposed within said internal chamber, a first rod element extending outwardly relative to said chamber from said one end of said housing and a second rod element extending outwardly relative to said chamber from said piston means, each of said first and second rod elements having outer ends for attachment into two vertebrae, a first elastic body damper means disposed within said chamber, said first elastic body damper means being engagable by said piston means so as to resist compression of said first elastic body damper means by said piston means under the effect of a force urging said piston means in axial compression relative to said elastic body dampen means, and said first elastic body damper means functioning as a stop to prevent further displacement of said piston means under the force of axial compression after a predetermined displacement of said piston means, a cover means mounted to said other end of said housing, an opening through said cover means, and said second rod element extending through said opening in said cover means, and a bellows means mounted in surrounding relationship with respect to said second rod element and having a first portion engaging said cover means and a second portion adjacent said outer end of said second rod element whereby said bellow means substantially seals said opening in said cover means.
Specification