1. A spinal osteosynthesis system for anterior fixation, comprising:
an elongate connection element;
a first vertebral screw having a threaded shank and a head having a threaded portion;
a connector including a first and second branch, said first branch having a bone contacting surface with a first opening surrounded by a concave recess which can be fitted on the screw and an opening between said first and second branches for securing the connection element between them, said first branch having a second opening for receiving a second vertebral screw; and
a threaded clamping member which can cooperate with the threaded head in order to clamp the branches onto the connection element, the clamping member comprising a threaded element which can engage the threads of the first vertebral screw head, wherein the clamping member comprises a head having a spherical and convex lower face, a second of said branches of the connector having a concave recess around an opening in the upper face which can be in contact with the convex lower face of the clamping member at one of a plurality of different angular orientations upon clamping of the branches.
2. The system according to claim 1, wherein the clamping member has a recess of polygonal profile along a longitudinal axis of the member.
3. The system according to claim 1, wherein the recess of the first opening of the first branch of the connector has a spherical and concave upper face which contacts a spherical and convex face of the vertebral screw upon clamping of the branches.
4. The system according to claim 1, wherein the threaded portion of the head of the first vertebral screw has a recess of polygonal profile extending along a longitudinal axis of the screw.
5. The system according to claim 4, wherein the recess extends in the thread of the threaded portion.
6. A system according to claim 4, wherein the profile of the polygonal recess of the first vertebral screw and the profile of the recess of the clamping member have the same shape and the same dimensions.
7. The system according to claim 1, wherein the head of the first vertebral screw has a lateral face with a smooth outer end.
8. The system according to claim 1 further comprising a second elongate connection element, the connector being able to be fixed to the two connection elements.
9. A spinal system comprising:
a first generally U-shaped connector, a base of said U-shaped connector for receiving a rod extending along an axis, said connector having a first bone contacting branch and a second branch extending from said rod receiving base forming the legs of the U, said branches each having first openings therein having a concave surface formed there around;
a first vertebral screw having a threaded shank and a head with a threaded portion, said head engaging said first branch in the area of said first opening therein, said screw having a convex surface for engaging a bone facing concave surface on said first branch; and
a first threaded clamping member engaging said second branch in the area of said first opening therein, said clamping member threadably engaging said threaded head of said vertebral screw within said openings in said first and second branches, said clamping member having a convex surface formed thereon for engaging the concave surface on said second branch at one of a plurality of different angular orientations.
10. The spinal system as set forth in claim 9, wherein said vertebral screw and said threaded clamping member include polygonal drive surfaces.
11. The spinal system as set forth in claim 9, wherein said first branch includes a second opening located at a greater distance from said base than said first opening for receiving a second bone screw.
12. The spinal system as set forth in claim 11, wherein said first branch has a rod receiving recess between said first and second openings.
13. The spinal system as set forth in claim 12, wherein said second branch has a portion for engaging a rod located in said rod receiving recess in said first branch.
14. The spinal system as set forth in claim 9, wherein said system further comprises:
a second generally U-shaped connector, a base of said U-shaped connector for receiving a rod extending along an axis, said second connector having a first and a second branch extending from said rod receiving base forming the legs of the U, said branches each having first openings therein;
a second vertebral screw having a threaded shank and a head with a threaded portion, said head engaging said first branch of said second connector in the area of said first opening therein;
a second threaded clamping member engaging said second branch of said second connector in the area of said first opening therein, said clamping member threadably engaging said threaded head of said vertical screw within said openings in said first and second branches of said second connector; and
a rod extending between said first and second U-shaped connectors.
15. A method for linking a first and a second vertebrae comprising:
inserting first and second vertebral screws, each having a threaded shank and a part spherical head with a threaded portion into respective first and second vertebrae;
placing a generally U-shaped connector having an opening therein for receiving said screw head on each of said first and second vertebral screws, a base of each of said U-shaped connectors for receiving a rod, a first and second branch of each said connectors extending from said rod receiving base, said first branch of each of said connectors having a bone contacting surface with a recess around said opening for respectively engaging the head of said first and second vertebral screws;
controlling the angular orientation of the vertebral screw by the engagement of said part spherical surface on each of said vertebral screw heads with said recess in said first branch of said connector by moving said part-spherical screw head surface with respect to said recess;
inserting a rod in said rod receiving bases of each of said U-shaped connectors to link said connectors; and
clamping said first and second branches of each of said U-shaped connectors together by inserting a threaded clamping member engageable with said second branch of each of said connectors into said threaded portion of said heads of said first and second vertebral screws.
16. The method as set forth in claim 15 further comprising inserting a second vertebral screw into said first and second vertebrae through an opening in said first branch of each U-shaped connector.
17. The method as set forth in claim 16 further comprising clamping a second rod between said U-shaped connectors at a position on each connector between said first and second screws.
18. The method as set forth in claim 15 further comprising the removal of a diseased vertebrae intermediate said first and second vertebrae.
19. The method as set forth in claim 15 wherein each of said second branches of said connector has an opening therethroiigh and an outwardly facing surface having a recess surrounding said opening, said recess engaging a head on said threaded clamping member.
20. The method as set forth in claim 19 wherein said recesses have a concave shape and said heads of said first and second screws and a head of said clamping members have a convex shape.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A sensor for force measurement, comprising: a magnetizable orand conductive body moveable relative to a stator having at least one pole winding and moveable against an elastic restoring force generated by a spring or an elastically deformable member; a device determines a measuring signal which is dependent upon inductivity of the pole winding which is influenced by the position of the body relative to the pole winding; and the device determines a force applied to the body which utilize known relationships between the measuring signal, the position of the body and the restoring force.
2. The sensor according to claim 1, wherein the stator has several pole windings with windings with winding axes that extend in a star pattern from the stator, and the body surrounds the stator.
3. The sensor according to claim 2, wherein the body surrounds the stator in a ring shape or a spherical shape.
4. The sensor according to claim 2, wherein the body, by changing the position, is movable in a plane defined by the pole winding axes of the several pole windings of the stator.
5. The sensor according to claim 1, wherein the body is formed by a pipe surrounding the stator, and the stator has several pole windings with pole winding axes that extend perpendicular to an axis of the pipe.
6. The sensor according to claim 1, wherein the stator has three pole windings whose pole winding axes enclose with each other respectively an angle of 120\xb0.
7. The sensor according to claim 1, wherein the stator has several pole windings which are switched in a star connection.
8. The sensor according to claim 7, wherein the devices for determining the measurement signal are provided at a star point for evaluating a potential that changes with alternating voltage application of the pole windings.
9. The sensor according to claim 8, wherein the pole windings are provided for receiving voltage pulses in a manner of operation of an electrical synchronous motor by pulse width modulation.
10. The sensor according to claim 5, wherein the stator is arranged in a longitudinal center of the pipe, and the pipe is elastically mounted at its ends for producing radial restoring forces.
11. The sensor according to claim 2, wherein the body has a ring shaped or spherically shaped inner surface located opposite end faces of several pole windings, the body further having a structuring comprised of projections orand recesses on the inner surface.
12. The sensor according to claim 11, wherein the structuring is constructed periodically.
13. The sensor according to claim 12, wherein the structuring extends circumferentially around the inner surface.
14. The sensor according to claim 11, wherein the structuring is constructed so as to result in the measurement signal depending upon the position of rotation of the body about the ring or sphere axis.
15. The sensor according to claim 1, wherein current supply of the at least one pole winding is controllable with aid of the measuring signal by producing a desired magnetic force acting from the stator on the body.
16. The sensor according to claim 15, wherein the sensor forms a contactless rotary bearing for a ring shaped or spherically shaped body.