CA2074406C - Clamp connection for connecting two construction components for a setting device, particularly an osteosynthetic setting device - Google Patents
Clamp connection for connecting two construction components for a setting device, particularly an osteosynthetic setting deviceInfo
- Publication number
- CA2074406C CA2074406C CA002074406A CA2074406A CA2074406C CA 2074406 C CA2074406 C CA 2074406C CA 002074406 A CA002074406 A CA 002074406A CA 2074406 A CA2074406 A CA 2074406A CA 2074406 C CA2074406 C CA 2074406C
- Authority
- CA
- Canada
- Prior art keywords
- component
- clamp
- clamping component
- clamping
- rod
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000002093 peripheral effect Effects 0.000 claims 3
- 238000010276 construction Methods 0.000 abstract description 41
- 230000001097 osteosynthetic effect Effects 0.000 abstract description 3
- 210000000988 bone and bone Anatomy 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 101100445364 Mus musculus Eomes gene Proteins 0.000 description 1
- 101100445365 Xenopus laevis eomes gene Proteins 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005923 long-lasting effect Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 230000000284 resting effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods
- A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
- A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws or setting implements
- A61B17/60—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws or setting implements for external osteosynthesis, e.g. distractors, contractors
- A61B17/64—Devices extending alongside the bones to be positioned
- A61B17/6466—Devices extending alongside the bones to be positioned with pin-clamps movable along a solid connecting rod
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B2/00—Friction-grip releasable fastenings
- F16B2/02—Clamps, i.e. with gripping action effected by positive means other than the inherent resistance to deformation of the material of the fastening
- F16B2/06—Clamps, i.e. with gripping action effected by positive means other than the inherent resistance to deformation of the material of the fastening external, i.e. with contracting action
- F16B2/065—Clamps, i.e. with gripping action effected by positive means other than the inherent resistance to deformation of the material of the fastening external, i.e. with contracting action using screw-thread elements
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B7/00—Connections of rods or tubes, e.g. of non-circular section, mutually, including resilient connections
- F16B7/04—Clamping or clipping connections
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods
- A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
- A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws or setting implements
- A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
- A61B17/70—Spinal positioners or stabilisers, e.g. stabilisers comprising fluid filler in an implant
- A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods
- A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
- A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws or setting implements
- A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
- A61B17/70—Spinal positioners or stabilisers, e.g. stabilisers comprising fluid filler in an implant
- A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
- A61B17/7041—Screws or hooks combined with longitudinal elements which do not contact vertebrae with single longitudinal rod offset laterally from single row of screws or hooks
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods
- A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
- A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws or setting implements
- A61B17/60—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws or setting implements for external osteosynthesis, e.g. distractors, contractors
- A61B2017/606—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws or setting implements for external osteosynthesis, e.g. distractors, contractors with resilient spring element
Landscapes
- Health & Medical Sciences (AREA)
- Engineering & Computer Science (AREA)
- Orthopedic Medicine & Surgery (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Surgery (AREA)
- Medical Informatics (AREA)
- Heart & Thoracic Surgery (AREA)
- Molecular Biology (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Biomedical Technology (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Surgical Instruments (AREA)
- Mutual Connection Of Rods And Tubes (AREA)
- Coupling Device And Connection With Printed Circuit (AREA)
- Joining Of Building Structures In Genera (AREA)
Abstract
A clamp connection serves to connect two construction components, in particular for an osteo-synthetic fixation device in a structure in which the construction components are off-set from the force axis of the loading force that retains them.
Description
11316.A29 20~
CLAMP CONNECTION FO~ CONNECTING TWO CONSTRUCTION COMPONENTS
FOR A SETTING DEVICE PARTICULA~LY AN OSTEOSYN-THETIC SETTING DEVICE
Field Of The Invention This invention relates to a clamp for joining two longitudinal components to one another, particularly for use in osteosynthesis.
Backqround ~ The Invention In a prior clamp according to DE-GM 91 01 321, there are two approximately equal clamp components and a pressure disc positioned between them, the whole assembly being penetrated by a centrally positioned threaded screw of a loading device. The loading device rests on the top clamp component, and is screwed into the bottom clamp component. The clamp components have two semi-cylindrical recesses that serve to hold rod shaped construction components. With this clamp two constr~ction components can be permanently connected~ Thus, for example, a carbon filament rod and a Schanz screw, are each inserted between a clamp component and the pressure disc, and clamped by the threaded screw, which has a rotary head. The actual gripping power brought to bear on the rod depends on the ratio of the distance between the axis of the loading device and the axis of the rod to the distance between the axis of the loading device and the support of the clamping component of the pressure disc.
In order to achieve the most effective possible grip on the rod for a given loading device, according to the law of leverage, the aforementioned ratio must be as small as possible. ~he 2~7~d~
consequence is that the gripping oomponents are inevitably larger in size. These gripping connections, ~sed particularly for external fixation in osteosynthesis, are used.chiefly for setting small parts of the body, a use in which the gripping components must not be too large. In practice, it has been found that for the reasons indicated the gripping power achieved with clamps of the type described is not firm enough, and thus a secure bracing between the construction components or the setting device as a whole is not achieved. In addition, it often happens that the gripping power weakens after a certain time and thus fixation no longer exists at all.
Another gripping device, described in WO-Al 88/01152, provides for gripping discs similar to that described above. A
pair of these gripping discs position a screw or similar device in semi-circular recesses and grip it ~y means of a screw positioned axially to them. To hold two construction components, two pairs of such gripping discs are provided for one loading screw. Theoretically, this gripping device has the same disadvantages as the device described above, because the gripping power actually exerted on a rod similarly assumes an unfavorable ratio of distance between the axis of the bracing screw and the support of the gripping discs. This is not altered by the construction of the gripping discs on the support with toothed gearing provided on each side. In this known, open system, the oblique plane present is used not to improve the grip but merely to improve the centering between the connection and the gripping component.
2 ~
Summary Of The Invention To eliminate the disadvantages of the deyice described above, the present invention provides a clamp which, by a simple manual operation,.creates a strong, long-lasting, and more or less continuous gripping force connecting two construction components.
Specifically, the invention comprises a clamp for connecting two construction components comprising a connection component, a clamping component, clamping means associated with said clamping component, means in said connection component and in said clamping component for receiving a construction component, and loading means for applying a loading force along a force axis, said clamping component resting on said connection component and being positioned to be pressed by a moment created by said loading force against the connection component, thereby to develop a frictional force between the clamping and connection components which acts to reduce the force applied to the construction component.
'~ A clamp according to the invention has the particular advantage of facilitating a significantly greater resulting gripping power with the same size and the same applied loading force as in the state-of-the-art technology. In addition, the design of the clamp is vary flexible, so that vibrations and similar events will not dissolve the connection, enabling the long-term clamping effect to continue to exist.
2 ~
To achieve a maximum gripping power exerted on the construction component, the ratio of the distance between the axis of the construction component and the aXis of the loading force to the distance between the construction component axis and the line of action of the support force should be less than 1.0, and preferably should be between 0.6 and 0.1~
The loading surfaces of the connection and construction components, or the support surfaces of the gripping and connection components, are as smooth as possible, for their mutual, more or less frictionless, support.
The connection component can be cylindrical or rectangular, or have any other shape, and on each end it has a threaded screw, both screws having the same axis, with a cup-shaped clamping component being positioned on the screws, which cup-shaped component exerts a compressive force on the construction element gripped in between, and, with its support surface parallel to the loading axis, engages the support surface of the connection component. Depending on the individual case, these corresponding support surfaces are cylindrical or flat.
Brief Descri~tion Of 'rhe Drawings The invention will be further described with reference to the accompanying drawings, in which:
Fig. 1 is a view in side elevation and partly in vertical section of a clamp connection according to the invention;
Fig. 2 is a plan view, partly in horizontal section at cross-section II-II of Fig. li Fig. 3 is a view in elevation and partly in vertical section of another embodiment of the invention with a pedicle screw;
Fig. 4 is a view in vertical section of ~nother variant of a clamp according to the invention;
Fig. 5 and Fig. 6 are perspective views of a further variant of a clamp according to the invention; and Fig. 7a and 7b are vertical sections through another variant of a clamp according to the invention.
Detailed Descri~tion Of Embodiments of the Invention Fig. 1 shows a clamp 10 as a component of an osteosynthetic fixation device not illustrated in detail, which fixation device comprises two construction components 12 and 14 connected to one another through clamp 10. Said construction components may consist, for example, of a connection rod and a Schanz screw, which screw may be driven into, for example, a portion of a broken finger bone. A second clamp can then appropriately connect another screw in the other bone part with the connection rod.
The clamp 10 comprises a connection component 15 and on both o~ its ends loading devices each comprising threads on a central rod 16 which receive nuts 16'. Two clamp components 18 are provided. These are cup-like elements having asymmetrical holes and a side wall which on one side is longer than on the other side. On the shorter side, as at 18', an arcuate recess is provided to receive construction component 12. As shown in ~ig.
1, central rod 16 is placed through the asymmetrical hole in 2 ~
clamp component 18 and component 18 slides over connection element 15 so that its longer side wall engages the side of element 15.
As shown in Fig. 1, the lower clamp component 18, which is the same as the upper component shown in cross-section, is rotated 90~ and receives a second construction component 14 in the same way the construction component 12 is received in the ~pper part of the device.
According to the invention, the clamp component 18 engages the connection component 15, parallel to the direction of loading force Fv, and through the moment created by force Fv is pressed on connection element 15 with a bearing force Fa acting perpendicular to loading force Fv, which bearing force Fa creates a frictional force Fr between the clamp and connection component, which is the only force reducing the loading effect of the force Fv acting on the relevant construction component 12. In contrast to the direct bearing characteristic of conventional devices, in this invention the friction Fr is on the one hand smaller by the factor of the friction coefficient; on the other hand, the ratio of the distance a between the axis of construction component 12 and the axis of loading force Fv to the distance b between the axis of construction component 12 and the line of action of bearing force Fa is less than 1.0, and is preferably between 0.6 and 0.1. This can be achieved without any need to enlarge the diameter of the clamp component 18 and hence the clamp 10 as a whole.
2~7~ AI~;s As shown in Fig. 2, the cylindrical clamp component 18 encompasses construction component 12 and connection component 15. Threaded screw 16 in the center of conne~tion component 15 has a pressure channel 19 into which the construction component 12 fits. This leads to a reduction in the size of the clamp.
The clamp and connection component could also be rectangular, or have any other shape.
Fig. 3 shows a clamp connection 20, which comprises a cylindrical connection component 2S formed at the head of a pedicle screw 23, and ~wo annular clamp components 28, 29 positioned to slide axially on the pedicle screw 23. Connection component 25 has a threaded end 26 and a nut 26' is screwed onto this threaded end 26, which nut 26' comes into contact with top clamp component 28. When nut 26' is turned down, clamp component 2~ presses on a construction component 22, shown as a transverse rod, which construction component 22 in turn presses on the second clamp component 29 and presses it on another construction component 24, which, like the construction component 22, is supported by connection component 25, being positioned in a groove-shaped recess 24', in ~onnection component 25. The two recesses 24', 25' are one above the other and are offset in relation to each other at an angle of 90~, and at least one of them is designed in such manner that the transverse rod positioned in it can be adjusted by a few degrees, e.g. 40~, to the connection component 25. The pedicle screw 23, positioned coaxially to the connection component 25, is thereupon screwed into a bone or similar substance, while the construction ~ ~7 component 22 and the cons-truction component 24 are connected as part of a fixation device with additional clamp connections.
Surfaces 28', 25", of clamp component 28 and connection component 25 are rotationally symmetrical, and in the contact area they preferably have toothing, so that they can be slid, but not turn~d, against each other practically without friction along the loading axis. The position of construction component 22 in relation to element 26, is maintained by a non-rotatable design of the interior surface of clamp component 28 and external surface of element 26, preferably by longitudinal toothing or by a non-cylindrical geometry of element 26 and clamp component 28, preferably by a polygonal (e.g. hexagonal) shape.
A clamp 30 according to Fig. 4 has two clamp components 38, 39 and an essentially cylindrical connection component 35 with threaded extensions 36, at either end. Components 38, 39 are coaxial with the connection component 35. Connection component 35 has recesses 35', 35", which serve to receive construction components 12, 14. Lateral recess 35" is designed in such manner that through its roughly semi-circular design it creates a three-point bearing when a construction component 12 is seated in it.
Advantageously, construction component 12 is tubular, so that for purposes of increasing the clamping effect, it undergoes a certain deformation, in adapting to recess 35~. The other construction component 14 is pressed by clamp component 39, which forms a longitudinal groove, into the practically rectangular recess 35' of the connection component. The clamping component 39, and connection component 35, are positioned facing each other 2 ~
and in suGh manner that they cannot ~urn against each other by means of cylindrical toothed element 32; in the direction of loading, in contrast, they are positioned to be in contact with each other as frictionlessly as possible.
Fig. S shows yet another clamp connection 40 for joining in partieular a Sehanz screw 12 with a transverse rod 14 in an external fixation device. In eontrast to the clamp eonneetion illustrated in Fig. 1, only one loading means 46, 46' is provided for the two rods to be elamped. A nut 46' eomes into contact with a top elamp eomponent 47, whieh has a longitudinal recess for Sehanz serew 12. Serew 12 in turn rests on a spaeing eollar 48 that rests on bottom elamp eomponent 49. Spaeing eollar 48 exerts a loading force on elamp component 49, whieh clamps transverse rod 14 to a conneetion component 45. The two clamp components 47 and 49 rest on connection component 45, unitary with component 46 opposite the rods, parallel to the direction of eompression, so that the aforementioned friction is created as a reduced counter-foree in the clamping operation.
Clamp 50 according to Fig. 6 differs from the clamp eonneetion aceording to Fig. 3 only by the faet that eonnection eomponent 55 has a single transverse recess 55~ for a eonstruetion component 12. Otherwise, here again, a loading foree can be exerted, via clamp eomponent 58, on construction eomponent 12, by the screw and nut 56, 56', and said construction component 12 is clamped. Moreover, the cylindrical connection eomponent 55 has a coaxial pedicle screw 24.
2 ~ 7 A, ~ J~
The clamp connection 60 according to Fig. 7a and 7b has an essentially cylindrical connection component 65 on a pedicle serew 63 with a cylindrical recess 65', in which a coaxial threaded screw 66 is positioned. On the screw 66 an external cylindrical clamping eomponent 68 is positioned. It fits into the reeess 65' and ean be slid therein by a nut 66'. A
eonstruetion eomponent 12 that is lateral and transverse to the axis of the threaded serew 66, and whieh is positioned in an off-eenter slot o~ the eonneetion eomponent 6S, is elamped by the loading foree ereated by serew and nut 66, 66' on elamping eomponent 68 to an internal bearing surfaee 65" of eonneetion eomponent 65. Opposite it, elamp eomponent 68 aceording to the invention bears, parallel to the loading direction, on connection component 65, whereby the desired most effective possible gripping power on construction eomponent 12 is achieved.
In this embodiment, reeess 65' and internal bearing surface 65" can be designed in two different ways. In Fig. 7a, eomponents 65' and 65N eorrespond to the shape of construction eomponent 12; in Fig. 7b, they are designed in such manner that in eombination with elamping eomponent 68 they ereate a three-point bearing.
Needless to say, the invention ean also be embodied in other variants. It should be noted, in this conneetion, that ~;~ theoretically instead of a serew/nut connection, another known prineiple could be used to develop a loading force.
::
CLAMP CONNECTION FO~ CONNECTING TWO CONSTRUCTION COMPONENTS
FOR A SETTING DEVICE PARTICULA~LY AN OSTEOSYN-THETIC SETTING DEVICE
Field Of The Invention This invention relates to a clamp for joining two longitudinal components to one another, particularly for use in osteosynthesis.
Backqround ~ The Invention In a prior clamp according to DE-GM 91 01 321, there are two approximately equal clamp components and a pressure disc positioned between them, the whole assembly being penetrated by a centrally positioned threaded screw of a loading device. The loading device rests on the top clamp component, and is screwed into the bottom clamp component. The clamp components have two semi-cylindrical recesses that serve to hold rod shaped construction components. With this clamp two constr~ction components can be permanently connected~ Thus, for example, a carbon filament rod and a Schanz screw, are each inserted between a clamp component and the pressure disc, and clamped by the threaded screw, which has a rotary head. The actual gripping power brought to bear on the rod depends on the ratio of the distance between the axis of the loading device and the axis of the rod to the distance between the axis of the loading device and the support of the clamping component of the pressure disc.
In order to achieve the most effective possible grip on the rod for a given loading device, according to the law of leverage, the aforementioned ratio must be as small as possible. ~he 2~7~d~
consequence is that the gripping oomponents are inevitably larger in size. These gripping connections, ~sed particularly for external fixation in osteosynthesis, are used.chiefly for setting small parts of the body, a use in which the gripping components must not be too large. In practice, it has been found that for the reasons indicated the gripping power achieved with clamps of the type described is not firm enough, and thus a secure bracing between the construction components or the setting device as a whole is not achieved. In addition, it often happens that the gripping power weakens after a certain time and thus fixation no longer exists at all.
Another gripping device, described in WO-Al 88/01152, provides for gripping discs similar to that described above. A
pair of these gripping discs position a screw or similar device in semi-circular recesses and grip it ~y means of a screw positioned axially to them. To hold two construction components, two pairs of such gripping discs are provided for one loading screw. Theoretically, this gripping device has the same disadvantages as the device described above, because the gripping power actually exerted on a rod similarly assumes an unfavorable ratio of distance between the axis of the bracing screw and the support of the gripping discs. This is not altered by the construction of the gripping discs on the support with toothed gearing provided on each side. In this known, open system, the oblique plane present is used not to improve the grip but merely to improve the centering between the connection and the gripping component.
2 ~
Summary Of The Invention To eliminate the disadvantages of the deyice described above, the present invention provides a clamp which, by a simple manual operation,.creates a strong, long-lasting, and more or less continuous gripping force connecting two construction components.
Specifically, the invention comprises a clamp for connecting two construction components comprising a connection component, a clamping component, clamping means associated with said clamping component, means in said connection component and in said clamping component for receiving a construction component, and loading means for applying a loading force along a force axis, said clamping component resting on said connection component and being positioned to be pressed by a moment created by said loading force against the connection component, thereby to develop a frictional force between the clamping and connection components which acts to reduce the force applied to the construction component.
'~ A clamp according to the invention has the particular advantage of facilitating a significantly greater resulting gripping power with the same size and the same applied loading force as in the state-of-the-art technology. In addition, the design of the clamp is vary flexible, so that vibrations and similar events will not dissolve the connection, enabling the long-term clamping effect to continue to exist.
2 ~
To achieve a maximum gripping power exerted on the construction component, the ratio of the distance between the axis of the construction component and the aXis of the loading force to the distance between the construction component axis and the line of action of the support force should be less than 1.0, and preferably should be between 0.6 and 0.1~
The loading surfaces of the connection and construction components, or the support surfaces of the gripping and connection components, are as smooth as possible, for their mutual, more or less frictionless, support.
The connection component can be cylindrical or rectangular, or have any other shape, and on each end it has a threaded screw, both screws having the same axis, with a cup-shaped clamping component being positioned on the screws, which cup-shaped component exerts a compressive force on the construction element gripped in between, and, with its support surface parallel to the loading axis, engages the support surface of the connection component. Depending on the individual case, these corresponding support surfaces are cylindrical or flat.
Brief Descri~tion Of 'rhe Drawings The invention will be further described with reference to the accompanying drawings, in which:
Fig. 1 is a view in side elevation and partly in vertical section of a clamp connection according to the invention;
Fig. 2 is a plan view, partly in horizontal section at cross-section II-II of Fig. li Fig. 3 is a view in elevation and partly in vertical section of another embodiment of the invention with a pedicle screw;
Fig. 4 is a view in vertical section of ~nother variant of a clamp according to the invention;
Fig. 5 and Fig. 6 are perspective views of a further variant of a clamp according to the invention; and Fig. 7a and 7b are vertical sections through another variant of a clamp according to the invention.
Detailed Descri~tion Of Embodiments of the Invention Fig. 1 shows a clamp 10 as a component of an osteosynthetic fixation device not illustrated in detail, which fixation device comprises two construction components 12 and 14 connected to one another through clamp 10. Said construction components may consist, for example, of a connection rod and a Schanz screw, which screw may be driven into, for example, a portion of a broken finger bone. A second clamp can then appropriately connect another screw in the other bone part with the connection rod.
The clamp 10 comprises a connection component 15 and on both o~ its ends loading devices each comprising threads on a central rod 16 which receive nuts 16'. Two clamp components 18 are provided. These are cup-like elements having asymmetrical holes and a side wall which on one side is longer than on the other side. On the shorter side, as at 18', an arcuate recess is provided to receive construction component 12. As shown in ~ig.
1, central rod 16 is placed through the asymmetrical hole in 2 ~
clamp component 18 and component 18 slides over connection element 15 so that its longer side wall engages the side of element 15.
As shown in Fig. 1, the lower clamp component 18, which is the same as the upper component shown in cross-section, is rotated 90~ and receives a second construction component 14 in the same way the construction component 12 is received in the ~pper part of the device.
According to the invention, the clamp component 18 engages the connection component 15, parallel to the direction of loading force Fv, and through the moment created by force Fv is pressed on connection element 15 with a bearing force Fa acting perpendicular to loading force Fv, which bearing force Fa creates a frictional force Fr between the clamp and connection component, which is the only force reducing the loading effect of the force Fv acting on the relevant construction component 12. In contrast to the direct bearing characteristic of conventional devices, in this invention the friction Fr is on the one hand smaller by the factor of the friction coefficient; on the other hand, the ratio of the distance a between the axis of construction component 12 and the axis of loading force Fv to the distance b between the axis of construction component 12 and the line of action of bearing force Fa is less than 1.0, and is preferably between 0.6 and 0.1. This can be achieved without any need to enlarge the diameter of the clamp component 18 and hence the clamp 10 as a whole.
2~7~ AI~;s As shown in Fig. 2, the cylindrical clamp component 18 encompasses construction component 12 and connection component 15. Threaded screw 16 in the center of conne~tion component 15 has a pressure channel 19 into which the construction component 12 fits. This leads to a reduction in the size of the clamp.
The clamp and connection component could also be rectangular, or have any other shape.
Fig. 3 shows a clamp connection 20, which comprises a cylindrical connection component 2S formed at the head of a pedicle screw 23, and ~wo annular clamp components 28, 29 positioned to slide axially on the pedicle screw 23. Connection component 25 has a threaded end 26 and a nut 26' is screwed onto this threaded end 26, which nut 26' comes into contact with top clamp component 28. When nut 26' is turned down, clamp component 2~ presses on a construction component 22, shown as a transverse rod, which construction component 22 in turn presses on the second clamp component 29 and presses it on another construction component 24, which, like the construction component 22, is supported by connection component 25, being positioned in a groove-shaped recess 24', in ~onnection component 25. The two recesses 24', 25' are one above the other and are offset in relation to each other at an angle of 90~, and at least one of them is designed in such manner that the transverse rod positioned in it can be adjusted by a few degrees, e.g. 40~, to the connection component 25. The pedicle screw 23, positioned coaxially to the connection component 25, is thereupon screwed into a bone or similar substance, while the construction ~ ~7 component 22 and the cons-truction component 24 are connected as part of a fixation device with additional clamp connections.
Surfaces 28', 25", of clamp component 28 and connection component 25 are rotationally symmetrical, and in the contact area they preferably have toothing, so that they can be slid, but not turn~d, against each other practically without friction along the loading axis. The position of construction component 22 in relation to element 26, is maintained by a non-rotatable design of the interior surface of clamp component 28 and external surface of element 26, preferably by longitudinal toothing or by a non-cylindrical geometry of element 26 and clamp component 28, preferably by a polygonal (e.g. hexagonal) shape.
A clamp 30 according to Fig. 4 has two clamp components 38, 39 and an essentially cylindrical connection component 35 with threaded extensions 36, at either end. Components 38, 39 are coaxial with the connection component 35. Connection component 35 has recesses 35', 35", which serve to receive construction components 12, 14. Lateral recess 35" is designed in such manner that through its roughly semi-circular design it creates a three-point bearing when a construction component 12 is seated in it.
Advantageously, construction component 12 is tubular, so that for purposes of increasing the clamping effect, it undergoes a certain deformation, in adapting to recess 35~. The other construction component 14 is pressed by clamp component 39, which forms a longitudinal groove, into the practically rectangular recess 35' of the connection component. The clamping component 39, and connection component 35, are positioned facing each other 2 ~
and in suGh manner that they cannot ~urn against each other by means of cylindrical toothed element 32; in the direction of loading, in contrast, they are positioned to be in contact with each other as frictionlessly as possible.
Fig. S shows yet another clamp connection 40 for joining in partieular a Sehanz screw 12 with a transverse rod 14 in an external fixation device. In eontrast to the clamp eonneetion illustrated in Fig. 1, only one loading means 46, 46' is provided for the two rods to be elamped. A nut 46' eomes into contact with a top elamp eomponent 47, whieh has a longitudinal recess for Sehanz serew 12. Serew 12 in turn rests on a spaeing eollar 48 that rests on bottom elamp eomponent 49. Spaeing eollar 48 exerts a loading force on elamp component 49, whieh clamps transverse rod 14 to a conneetion component 45. The two clamp components 47 and 49 rest on connection component 45, unitary with component 46 opposite the rods, parallel to the direction of eompression, so that the aforementioned friction is created as a reduced counter-foree in the clamping operation.
Clamp 50 according to Fig. 6 differs from the clamp eonneetion aceording to Fig. 3 only by the faet that eonnection eomponent 55 has a single transverse recess 55~ for a eonstruetion component 12. Otherwise, here again, a loading foree can be exerted, via clamp eomponent 58, on construction eomponent 12, by the screw and nut 56, 56', and said construction component 12 is clamped. Moreover, the cylindrical connection eomponent 55 has a coaxial pedicle screw 24.
2 ~ 7 A, ~ J~
The clamp connection 60 according to Fig. 7a and 7b has an essentially cylindrical connection component 65 on a pedicle serew 63 with a cylindrical recess 65', in which a coaxial threaded screw 66 is positioned. On the screw 66 an external cylindrical clamping eomponent 68 is positioned. It fits into the reeess 65' and ean be slid therein by a nut 66'. A
eonstruetion eomponent 12 that is lateral and transverse to the axis of the threaded serew 66, and whieh is positioned in an off-eenter slot o~ the eonneetion eomponent 6S, is elamped by the loading foree ereated by serew and nut 66, 66' on elamping eomponent 68 to an internal bearing surfaee 65" of eonneetion eomponent 65. Opposite it, elamp eomponent 68 aceording to the invention bears, parallel to the loading direction, on connection component 65, whereby the desired most effective possible gripping power on construction eomponent 12 is achieved.
In this embodiment, reeess 65' and internal bearing surface 65" can be designed in two different ways. In Fig. 7a, eomponents 65' and 65N eorrespond to the shape of construction eomponent 12; in Fig. 7b, they are designed in such manner that in eombination with elamping eomponent 68 they ereate a three-point bearing.
Needless to say, the invention ean also be embodied in other variants. It should be noted, in this conneetion, that ~;~ theoretically instead of a serew/nut connection, another known prineiple could be used to develop a loading force.
::
Claims (13)
1. A clamp for securing a support rod comprising a clamping component having a cylindrical through hole and a socket adapted to receive a support rod, a connecting component having a base section and a cylindrical leg integrally formed with said base section and having a central axis extending from said base section into said through hole, and loading means mounted in said leg, said connecting component and said clamping component having curved surfaces in contact with each other, said curved surfaces being cylindrical about a central axis coinciding with the central axis of said leg, said loading means being positioned to bear against said clamping component to cause said clamping component to press a rod inserted in the socket of said clamping component against the base section of said connecting component and to press the curved surface of said clamping component against the curved surface of said connecting component.
2. A clamp for securing a rod comprising a clamping component having a through hole and a socket adapted to receive a rod, a connecting component having a cylindrical base section with a central axis, and a leg extending from said base section along said central axis through the through hole of said clamping component, said connecting component having a surface in lateral contact with a surface of said clamping component, in combination with loading means mounted in said leg and positioned to bear against said clamping component thereby to cause said clamping component to press a rod inserted in said socket against the base section of said contacting component and to press said laterally connecting surfaces of said clamping and connecting components against one another.
3. The clamp claimed in claim 1 wherein the clamping component is cup shaped.
4. The clamp claimed in claim 3 wherein the clamping component has an upper surface and a skirt having a long section and a short section.
5. The clamp claimed in claim 4 wherein the long section of said skirt has a surface in contact with said connecting component.
6. The clamp claimed in claim 1 wherein the connecting component has a lateral socket for receiving a rod.
7. The clamp claimed in claim 6 wherein the socket of the connecting component is shaped to permit swinging movement of a rod seated therein.
8. The clamp claimed in claim 1 wherein the connecting component base section has a roughened surface in lateral contact with a surface of said clamping component.
9. The clamp claimed in claim 1 wherein the clamping component has a roughened inner surface in lateral contact with a surface of said connecting component.
10. The clamp claimed in claim 7 wherein the connecting component base section has a roughened surface in lateral contact with a surface of said clamping component.
11. The clamp claimed in claim 1 wherein the connecting component is cup shaped and has a peripheral wall.
12. The clamp claimed in claim 11 wherein the peripheral wall has a recess for receiving a rod.
13. The clamp claimed in claim 11 wherein the peripheral wall has an inner surface which is in lateral contact with a surface of the clamping component.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH02195/91A CH686902A5 (en) | 1991-07-23 | 1991-07-23 | clamp connection |
| CH02195/91-0 | 1991-07-23 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2074406A1 CA2074406A1 (en) | 1993-01-24 |
| CA2074406C true CA2074406C (en) | 1999-01-19 |
Family
ID=4228112
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002074406A Expired - Lifetime CA2074406C (en) | 1991-07-23 | 1992-07-22 | Clamp connection for connecting two construction components for a setting device, particularly an osteosynthetic setting device |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0524441B1 (en) |
| JP (1) | JP3258712B2 (en) |
| AT (1) | ATE130913T1 (en) |
| CA (1) | CA2074406C (en) |
| CH (1) | CH686902A5 (en) |
| DE (1) | DE59204475D1 (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH690293A5 (en) * | 1994-09-06 | 2000-07-14 | Jaquet Orthopedie | Joint for components of an external fixator. |
| CH689247A5 (en) * | 1994-09-07 | 1999-01-15 | Hans Weigum | Apparatus for external fixation of fractures. |
| US5683389A (en) | 1994-12-05 | 1997-11-04 | Smith & Nephew, Inc. | External fixator for distal radius fractures |
| US5562661A (en) * | 1995-03-16 | 1996-10-08 | Alphatec Manufacturing Incorporated | Top tightening bone fixation apparatus |
| DE59811438D1 (en) * | 1998-09-29 | 2004-06-24 | Synthes Ag | DEVICE FOR CONNECTING A LONGITUDE TO A BONE FIXING AGENT |
| US6613049B2 (en) | 2000-02-02 | 2003-09-02 | Robert A. Winquist | Adjustable bone stabilizing frame system |
| US7048735B2 (en) | 2002-02-04 | 2006-05-23 | Smith & Nephew | External fixation system |
| US7004943B2 (en) | 2002-02-04 | 2006-02-28 | Smith & Nephew, Inc. | Devices, systems, and methods for placing and positioning fixation elements in external fixation systems |
| US7758582B2 (en) | 2002-06-14 | 2010-07-20 | Smith & Nephew, Inc. | Device and methods for placing external fixation elements |
| US7608074B2 (en) | 2003-01-10 | 2009-10-27 | Smith & Nephew, Inc. | External fixation apparatus and method |
| DE102004006210B4 (en) * | 2004-02-09 | 2005-12-15 | Hilti Ag | A joint connector |
| DE102004056091B8 (en) | 2004-11-12 | 2007-04-26 | Aesculap Ag & Co. Kg | Orthopedic fixation device and orthopedic fixation system |
| US8523858B2 (en) | 2005-06-21 | 2013-09-03 | DePuy Synthes Products, LLC | Adjustable fixation clamp and method |
| US9770272B2 (en) | 2012-12-12 | 2017-09-26 | Wright Medical Technology, Inc. | Orthopedic compression/distraction device |
| CN116066703A (en) * | 2023-01-30 | 2023-05-05 | 北京玛格纳科技有限公司 | Locking device of tracer and tracer |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2831717A (en) * | 1954-12-20 | 1958-04-22 | Simplicity Tool Company | Sliding fit fastener |
| DE1045181B (en) * | 1955-04-05 | 1958-11-27 | Rhema Glas Rheinmainische Glas | Device for detachable fastening of rods, ropes and the like. like |
| US3677584A (en) * | 1971-03-24 | 1972-07-18 | Simplimatic Eng Co | Two direction quick adjusting bar clamp |
| GB8620504D0 (en) * | 1986-08-22 | 1986-10-01 | Central Orthopaedics Ltd | Fixator |
| DE9101321U1 (en) * | 1991-02-06 | 1991-04-25 | Aesculap AG, 7200 Tuttlingen | External fixator |
-
1991
- 1991-07-23 CH CH02195/91A patent/CH686902A5/en not_active IP Right Cessation
-
1992
- 1992-06-23 EP EP92110526A patent/EP0524441B1/en not_active Expired - Lifetime
- 1992-06-23 AT AT92110526T patent/ATE130913T1/en not_active IP Right Cessation
- 1992-06-23 DE DE59204475T patent/DE59204475D1/en not_active Expired - Lifetime
- 1992-07-22 JP JP21571092A patent/JP3258712B2/en not_active Expired - Lifetime
- 1992-07-22 CA CA002074406A patent/CA2074406C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| CA2074406A1 (en) | 1993-01-24 |
| JPH05245160A (en) | 1993-09-24 |
| CH686902A5 (en) | 1996-07-31 |
| JP3258712B2 (en) | 2002-02-18 |
| DE59204475D1 (en) | 1996-01-11 |
| EP0524441A1 (en) | 1993-01-27 |
| ATE130913T1 (en) | 1995-12-15 |
| EP0524441B1 (en) | 1995-11-29 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKEX | Expiry |