JPS62142547A - Apparatus for positioning and fixing parts equipped with circular region - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fixation device allowing the positioning of a retaining part, which device is used inter alia in the field of external bone fixation devices.

To reduce bone fracture, techniques have been developed previously, for example, to fixate pins in the bone, where the pins extend into adjacent bone or are fixed within an external fixation device that includes a frame. to hold the broken part in place.

Frame devices constituting arcuate cradles are known today, for example as described in Swiss Patent No. 630,798.

Similarly, the cross-sectional shapes of such arcs have been analyzed to date, and most consideration has been given to the shape described in Swiss Patent Application No. 309/85; This makes it possible to realize a large number of wide-ranging possibilities for attaching the frame rod 9 and other connecting parts or parts.

The elements comprising such external fixation means must be designed with two purposes. Firstly, they must be as simple as possible so as to facilitate the surgeon's work during the operation while allowing a wide range of possible positioning. Secondly, they must ensure that the need to reduce bone damage during post-treatment by providing a thoroughly rigid and firm fixation effect is not neglected.

Positioning and fixing devices are known which consist of jaws for clamping a part, in which the contact surfaces of the jaws and the part to be clamped with the jaws are realized somewhat roughly so that they can be obtained, for example, by sand-plasty ink. Although these devices are generally satisfactory, over time the rough surfaces wear smooth and the roughness is lost. As the contact surfaces become smoother, the clamping effect becomes less and less effective. .

Similarly, conventional devices generally consist of grooved flat surfaces for clamping cylinders or balls of plastic material. As an alternative, it can also be provided on a component with rounded parts that can be tightened with the groove. Such devices are described, for example, in PCT Application No. 83
This is as described in No./02554. Although this device gives good results, it has the disadvantage of a relatively short lifespan due to the rapid deterioration of the plastic parts.

It is an object of the present invention to eliminate the above-mentioned drawbacks and to provide an effective positioning and fixing device with a relatively long service life.

The positioning and fixing device according to the invention consists of two jaws arranged to press against each other and clamp the part. The device is characterized by a circular area on which the parts and/or jaws present a series of regularly arranged planar or curved facades;
A point where adjacent surfaces form an obtuse angle with the apex forming a sharp edge or point.

The part also has a central hole intended to accommodate the rod 8 or pin. It may be divided into two parts along the axis of the central hole, or it may be a one-piece piece with a tube extending from the sphere on either of its sides.

Furthermore, the parts to be clamped are at least partially
The area can take the form of a cylinder or a truncated cone with several front faces. The cylinder to be clamped is likewise provided with a central hole perpendicular to its axis to accommodate the pin or rod, and is adapted to be divided into two parts along the central hole axis.

The continuous surface is provided on a material that is harder than the material of the jaws clamping the surface area. These materials may be tempered steel and untempered steel, steel and light metal, light metal alloys with different hardnesses, alloys and plastic materials, respectively.

According to one aspect of the invention, the jaws for clamping parts having rounded portions are clamped by clamping at least one of the elements by tightening the jaws by means of two screws whose center lines form an angle with each other. The edges are bent to better grip rounded parts of the part.

The accompanying drawings illustrate some embodiments and variants of the device for positioning and fixing parts according to the invention.

The positioning and fixing device shown in FIGS. 1 to 4 mainly consists of two fixing screws 10 and 20, which cooperate with a shackle 50 after passing through an upper member 30 and a lower member 40. All serve to position and secure the sleeve 60 and to clamp the assembly to the arc 70.

It should first be noted that the center lines 11, 21 of the fixing screws 10, 20 are not parallel but form an angle of approximately 10° for reasons explained below.

The screws 10.20 are provided with large heads 12.22 to facilitate their positioning and mutual tightening before being tightened with a suitable tool when the device is in place. Although the screw depicted in the drawings has square shaped spatulas #12, 22, it is clear that other shaped heads may be employed without departing from the scope of the invention.

Furthermore, the screws 10, 20 each have a washer 13.23 which presents a plane 14.24 and is supported not only against the corresponding screw head 12.22 but also against a spherical portion 15.25 on the opposite surface. It is equipped with (The operation of which will be described below.) The point is that the washers 13, 23, after their final engagement with the screws 10, 20, rotate into the recesses 16, 26 in the screws 10, 20 at their bases. I want to be noticed. The washers 13, 23 thus remain integral with the screws 10, 20 during operations such as assembly and disinfection. In FIG. 2, a washer 13 is depicted for the screw head ''12, representing the recess 16, which is substantially in the lower part of the recess 26.

The screws 10 and 20 each further have a threaded length 17.
．． 27 and adapted to mate with corresponding threaded holes as will be seen below.

The screws 10, 20 and their washers 13, 23 are typically made from stainless steel, thus providing a durable and suitable part for disinfection.

The upper member 30 has a center line 11°2 for the screws 10, 20.
1 are provided with two passages 31, 32, the upper part of which is counterbored at part 33, 34 so as to cooperate with the spherical surface 15 or 25 of the washer 13, 230. recess 3
3 and 34 can be either spherical or conical. The spherical part of the washer 15. to avoid the risk of cracking.
Not only the surface of 25 but also that of recess 33.34 should be highly polished.

The bottom surface of member 30 further includes a socket centered between passages 31, 32 as depicted in FIG. The socket 35 has a central recess 36. (The purpose of which is explained below.) The fastening member 30 has a recessed lateral region 37,38 on one side of the socket and a third recessed lateral region 37,38.
This makes it possible to position the tubular extensions 61,62 of the sleeve 60 shown in the figures at an angle.

The lower member 40 likewise faces the previously mentioned upper member 3°. It consists of two passages/l on the center line 11°21 of the screws 10, 20.1. , 4.2, a socket 43 with a central recess 44, and two lateral regions 45, 46 with a central recess 44, all of these features being present in the second
It can be seen either in perspective view in the figure or in side view in figure 3.

In its lower part, the member 4o furthermore consists of a support extension 47 and a jaw 48 presenting an inclined surface 8, which can be seen in particular in FIG.

The extension part 47 has threaded holes 52, 53 with center line 11°21
The shackle 500 serves as a support surface for the surface 51 of the shackle 500, which is provided thereon and accommodates the threaded portions 17, 27 of the screws 10, 20.

Describing an embodiment in which the device is mounted on an arcuate member of cross-section 71 formed by two triangles connected by a web (see FIG. 1), the shackle 50 connects the jaws 48 of the lower clamping member 40 with the jaws 54 of the lower clamping member 40. A sloping jaw 54 is provided with an arcuate member 70 for being held between.

As mentioned earlier, this embodiment relates to a device for mounting on an arc-shaped member. For this purpose, clamp material 30
, 40.50 have a slight curvature, especially as depicted in FIG. 4, which curvature is matched to the curvature of the arc on which the device is mounted. Of course, in other embodiments the clamping material 30, 40 together with the shackle 50 (if present) are flat and uncurved.

Furthermore, although the positioning fixtures presented herein are to be flanged on the outside of the arc, devices intended to be placed inside the arc may be used without departing from the scope of the invention. Needless to say, it can be manufactured.

The shackle 50, together with the clamping members 30, 40, are typically made from a light weight alloy, but could alternatively be made from a synthetic material suitable for disinfection.

For a spherical sleeve 60 intended to be clamped between a clamping member 30, 40, two tubular extensions 6 are placed on either side of the sphere 63 as shown in FIG.
1. , 62.

In the variant of FIGS. 1 and 2, only one lateral extension 64 is provided, the central hole 65 of which serves to guide frame rods or other connecting pieces or elements.

In the variant illustrated in FIG. 5, the sleeve also has a generally spherical section 63. Please note the small plane in this figure. Although they exist, they are not shown in Figures 1 and 2 for clarity.

The sleeve of FIGS. 5 and 6 consists of two shells 66 and 67, each of which is provided with a tiger 768 or 69. These troughs are dimensioned to accommodate the fixing rods disposed in the central passageway 65 and to secure them against the rotational direction as well as their longitudinal direction.

In the variant of FIG. 6A, the tiger 768 formed in each half-shell 66 or 67 has a semicircular cross-section.

Instead, the trough 69 is equilaterally triangular in cross section with the sloping side forming an angle greater than or equal to 7° with the perpendicular to the other two sides as depicted in FIG. 6B. The outside of the spherical sleeve 63 depicted in FIG. 7 consists of hexagonal surfaces. It goes without saying that it is possible to consider using other polygons.

FIG. 8 shows a tubular extension 61. located on one side of the ball 63.
3 depicts the central portion of the sleeve 60 shown in FIG. 3 with 62, but with the central portion much enlarged. Note the series of small surfaces 81 placed at regular intervals on the sleeve surface.

FIG. 9 shows an enlarged detail of surface 81, which
According to the figure, 81 is stamped in adjacent circles 82, and each set of circles has another circle of the same diameter at its center intersecting the other four circles, with a sharp edge 83 and a corner 84 of surface 81. is configured. Corner 82 is preferably sized so that a single-sided corner is imprinted at an angle of about 10° from the center of sphere 63.

The cross-sectional view of FIG. 10 is taken along line X--X of FIG. 9 and shows a series of planes 81 that all intersect a common corner 84 of the continuous planes. Thus each corner 84 has a clamping material 3
This is the point of contact with sockets 35 and 4.3 of 0 and 4.0.

The cross-sectional view of FIG. 11 is taken along line XI--XI of FIG. 9 and perpendicularly intersects sharp edge 83.

Although the surface is flat in FIGS. 9 to 11, which correspond to the first embodiment, in the female example of FIG. 12 (corresponding to FIG. 11), the surface 81 is curved. The result is a sharper apex, so they are
．． 40 sockets 35.43.

Additionally, it will be apparent to those skilled in the art that the surfaces may have other polygonal shapes. The purpose of the presence of surfaces, whether flat or curved, can be expressed as creating sharp edges or points between the surfaces to enable the gripping effect of the jaws.

This is because the sleeve component 60 as a whole is traversed by a pin or iron having a diameter of 2 to 8 rrrM and is held therein. Therefore, the diameter of the spherical part is typically 15-20
It will be mm.

In principle, the jaws 30, 40 would be made of a material with a lower hardness than the material of the sleeve 60. The enclosure formed by the jaws will therefore be more resilient than the sleeve portion 63.

Based on the above, many materials can be selected. For example, the sleeve 60 can be made of tempered steel and the jaws can be made of untempered steel. Alternatively, the steel sleeve can also be associated with a light alloy sleeve with jaws of light alloy or with lower hardness jaws, for example of plastic material.

The use of the positioning and fixing device shown in FIGS. 1 to 4 will now be described in detail.

In each case, the type of sleeve 60 required for assembly,
Sleeve with two lateral extensions 61, 62 (see FIG. 3) or one extension 64 (see FIG. 2)
It is first decided whether the sleeve should be a simple spherical sleeve consisting of two hemispherical shells 66, 67 (FIG. 5).

The diameter of the center hole 65 is selected depending on the parts to be assembled.

The assembly will then be mounted directly onto the arc, but the screws 10 in the corresponding threaded holes 52, 53 of the part 50
, 20, of course. Arrange the arc profile 70 with the spherical portion 60 as required.

Now the lateral gaps 37, 38 of member 30 and 45 of member 40
.
．． 62 can be coordinated.

Once proper positioning is achieved, the screws 10, 20 can be tightened to lock the assembly, but it will be appreciated that they can then be unlocked at any time to make any adjustments.

Center lines 11.21 are not exactly parallel (approximately 10' from each other)
It will be appreciated how this improves the safety of both the sleeve and the arc, taking into account that the tightening of the screws bends the clamping members 30, 40.

Deformations due to deflection of the parts 30 and/or 40 are compensated by the play of the washers 13, 23, whose spherical parts 15 or 25 rest in spherical or conical sockets 33, 24. These washers serve to reduce friction while increasing the retention effect. In practice, the spherical portion 15.25 of the washer should be dimensioned such that contact with the corresponding socket takes place approximately in the center of the rounded portion.

The recesses 36, 44 of the clamp members 30, 40 serve to increase the resiliency and clamping force of the members 30, 400, respectively, as they double the fulcrum on the spherical portion of the sleeve.

Figures 13-15 depict a second embodiment of a positioning fixation device, also used in an external fixation device.

The fixing body 100 is intended for clamping onto several piercing pins by means of screws 101, 102; for this purpose the jaws 103, 104 have channels 105 for clamping piercing pins (not shown in the drawings). is formed.

This fixing body 100 for a piercing bottle further includes a clamp member 1.
It consists of a cylindrical portion 106 with an inner circular groove (not shown) for cooperating with 10.

For this purpose, member 110 is constructed such that its lower portion is cylindrical 10.
leg 113, 1 with 5 to engage in the inner circular groove of 6;
Two clamp members 111 and 112 having 14 are provided. A threaded set 8115, which is engaged with the wing nut 116 at its upper end, crosses between the clamp members 111 and 112. The clamp parts 111 and 112 are made of two circular pieces 12.
1,122 (FIG. 14), the pieces 121,122 themselves holding a rod 123 in a hole common to the duplexes 121,122. As with the previous types, the cross section of this hole can be polygonal.

Clamp pieces 111°112 due to the action of the nut 1160
When tightened, legs 113, 114 are held firmly against the grooves in portion 106 and prevent upper assembly 1100 from rotating. The clamping parts 111, 112 are provided with circular surfaces 117, 118 arranged facing each other, against which the circular surfaces 123, 124 of the cylindrical pieces 121, 122 are to rest. These surfaces 123, 124 present a series of rectangular surfaces forming sharp edges between them. In the case of the embodiment shown in FIG. 14, the rotation is made by the clamp piece 121.
. In this case, the surface is a flat surface made of a harder material than the material constituting the clamp portions 111 and 112.

In the variant of FIG. 15, clamping parts 111, 112 are again provided which have the same shape as the clamping part of FIG. 14, except that the inner surfaces 117, 118 are in the form of frustoconical holes. The circular pieces 121, 122 for clamping the lock F″123 are likewise frustoconical transverse portions 12.
5,126, which presents a series of rectangular surfaces arranged along the generatrices of a truncated cone section. The surfaces form sharp edges between them that rest against the corresponding smooth parts and are in the form of truncated cones of the clamping parts 111,112. As in the case of the above-mentioned embodiment and modification, the clamp pieces 121, 122 are connected to the clamp portion 111°11.
It will be made from a harder material than 2.

The embodiments and variants described herein present a means of positioning and fixing parts by means of jaws which provides a much better ramping effect than what was previously known in the prior art. This clamping effect is obtained by providing a series of flat or curved surfaces on the clamped part arranged over the area of the clamped part such that adjacent surfaces form sharp edges or points between them. The parts to be clamped consisting of surfaces are made of a harder material than that of the jaws. This makes it possible for the sharp edges formed by the surfaces to create elastic deformations in the jaws, thereby providing a particularly effective ramp effect. It will be clear to those skilled in the art that a surface could alternatively be provided on the top of the jaw.

In that case, the jaws would be made of a harder material than the material of the parts to be clamped.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a positioning and fixing device for holding a guide sleeve (also shown in dotted lines) which is placed on an arcuate crate member (indicated by dotted lines) and includes a tubular portion extending from a central sphere; FIG. 1 is an exploded perspective view of the elements shown in FIG. 1, and FIG. 3 is a side view of the device previously shown except that in this case a sleeve is shown having a tubular portion extending to one side of the central sphere. , FIG. 4 is a sectional view taken along line It/-IV in FIG. 3, FIG. 5 is a side view of the spherical sleeve, and FIGS. 6A and 6B are views of the sleeve of FIG. 5 in different embodiments. 7 is a side view of the deformation of the sleeve; FIG. 8 is an enlarged view of the central part of the sleeve of FIG. 3 showing the regularly arranged surfaces on the surface of the spherical portion; and FIG. 9 is a plan view. FIG. 8 is an enlarged view of a small part of the surface of the sleeve shown in FIG. includes a part of the jaw, Figure 11 is X in Figure 9.
12 is a sectional view taken along the line I-XI, also including part of the jaw; FIG. 12 is a sectional view of the second embodiment similar to FIG. 10, but with a concave surface; FIG. 13; 14 is a side view of the device of FIG. 13 for positioning and fixing the connecting bar, partially showing the upper section of the jaw; FIG. 15 is a side view of a modification of the part of FIG. 14; 10.20...Fixing screw 50...Shackle 6
0... Sleeve 70... Arc shaped member 11...
Center line 12, 22...Head 13.23.
...Washers 15, 25...Spherical part 33.3
4... Concavity 61, 62... Tubular extension (5 people outside)

Claims (1)

[Claims] 1. A device for positioning and fixing a part, which is composed of two jaws pressed against each other and arranged to clamp the part, in which the part and/or the jaws are arranged regularly over the area. A device as described above, characterized in that it comprises a circular region having a series of flat or curved surfaces arranged in a circular pattern, the adjacent surfaces forming obtuse angles between them whose apexes form sharp edges or points. 2. Claim 1, characterized in that the part to be positioned and fixed has a circular shape, at least a part of the circular shape has the series of surfaces, and the surface of the jaw that comes into contact with the part is smooth. The device described in. 3. Device according to claim 1, characterized in that the part to be positioned comprises a ball or a sleeve with at least one surfaced part. 4. Device according to claim 3, characterized in that the sphere is provided with a central hole for storing the rod. 5. Device according to claim 4, characterized in that the sphere is divided into two parts along the axis of the central hole. 6. Device according to claim 4, characterized in that the ball is integral with a tube extending the hole on each side of the ball. 7. Device according to claim 1, characterized in that the part is in the form of a cylinder with at least one surfaced part. 8. Device according to claim 7, characterized in that the surfaced part is in the form of a truncated cone. 9. Device according to claim 8, characterized in that the cylinder is provided with a central bore perpendicular to its axis. 10. Device according to claim 9, characterized in that the cylinder is divided into two parts along the axis of the central bore. 11. The device of claim 1, wherein the continuous surface is disposed on a harder material than the material gripping the surfaced area. 12. The device of claim 11, wherein the materials are tempered and untempered steel, respectively. 13. Device according to claim 11, characterized in that the materials are respectively steel and light metal. 14. Device according to claim 11, characterized in that the material is a light metal alloy with varying hardness. 15. Device according to claim 11, characterized in that the materials are respectively light metals and plastic or synthetic materials. 16. Device according to claim 11, characterized in that the materials are synthetic materials of different hardness. 17. A device for positioning and fixing at least one part having a rounded part, consisting of members arranged facing each other and for firmly clamping the part between them, The members are pressed together by at least two screws whose center lines form an angle with each other such that when the screws are tightened, at least one of the members deflects and the rounded portion of the part is bent. The device is characterized in that it is more firmly fixed. 18. Device according to claim 17, characterized in that the clamping member is made of a light alloy. 19. Device according to claim 17, characterized in that the clamping member is made of synthetic material. 20. that the screws pass freely through the clamping member, that their heads rest at least indirectly on the upper clamping member, and that their head ends cooperate with matching threaded holes provided in the shackle; 18. The apparatus of claim 17, characterized in: 21. Claim 2, characterized in that the shackle is connected in use to one of the clamping members.
The device according to item 0. 22. Device according to claim 20, characterized in that each head of the screw cooperates with a washer making it possible to compensate for deflections of the member. 23. Device according to claim 22, characterized in that the washer comprises a spherical part. 24. Device according to claim 23, characterized in that the upper clamping member is provided with a recess cooperating with the spherical part of the washer. 25. Device according to claim 24, characterized in that the recess is spherical. 26. Device according to claim 24, characterized in that the recess is conical. 27. Device according to claim 22, characterized in that each of the washers is bent into a recess provided on the central part of the screw so as to remain integral with the screw. 28. Device according to claim 17, characterized in that the part containing the rounded part to be positioned and fixed is a sleeve consisting of a part forming a spherical envelope. 29. Device according to claim 28, characterized in that the part forming the spherical envelope has a central passage. 30. Device according to claim 28, characterized in that the sleeve is made of stainless steel. 31. Device according to claim 28, characterized in that the material of the sleeve has a greater hardness than that of the member surrounding it. 32. The device of claim 29, wherein at least one tubular portion extends through the spherical portion and surrounds the central passage. 33. Device according to claim 29, characterized in that the spherical part is constituted by two shells, each with transverse troughs forming one half of the central passage. 34. Device according to claim 29, characterized in that the central passage has a polygonal cross-section. 35. Device according to claim 29, characterized in that the central passage has a circular cross-section. 36. Device according to claim 29, characterized in that the central passage serves as a fixed guide. 37. Apparatus according to claim 29, characterized in that the central passage houses a frame bar. 38. Apparatus according to claim 17, characterized in that each of the members surrounding the part has a rounded part with a socket corresponding to the shape of the part. 39. Device according to claim 38, characterized in that the socket is centered in a plane passing through the fixing screw. 40. Device according to claim 38, characterized in that the socket comprises at least one recess to increase the elasticity of the member. 41. Claim 38, characterized in that the socket communicates with a pair of gaps arranged on one side of the plane passing through the fixing screw, the gaps allowing movement of the tubular part of the sleeve. The device described in. 42. Device according to claim 28 or 38, characterized in that the sleeve and/or the spherical part of each sleeve has a surface, at least in part thereof, which improves the clamping effect. 43. Device according to claim 42, characterized in that the rough surface is obtained by surface treatment. 44. Claim characterized in that the surface comprises a series of regularly arranged planes or curved surfaces, the adjacent surfaces forming an obtuse angle between them such that the apex forms a sharp edge or point. The device according to paragraph 42. 45. Claim 20, characterized in that the lower clamping member and the shackle are each shaped to form the jaws of a vice so as to be able to fix them on the frame of the skeletal fixation device. Equipment described in Section. 46. Apparatus according to claim 45, characterized in that the frame is constituted at least in part by an arcuate cradle section. 47. The device of claim 46, wherein said member has a curvature appropriate to that of said arcuate portion.