Arrangement with a tool and with a fastening means, and method for fastening a fastening means

Abstract

An arrangement with a tool and with a fastening means having a longitudinal direction is provided. The tool is designed to screw the fastening means into a body in the longitudinal direction; the tool has a blade with a first holding element and a second holding element; the fastening means has a first holding section with a complementary first holding element and a second holding section with a complementary second holding element. In the first holding section, the first holding element and the complementary first holding element interact in such a way that a translatory movement of the blade in the longitudinal direction is blocked. In the second holding section, the second holding element and the complementary second holding element interact in such a way that a rotary movement of the blade can be transferred to the fastening means and the fastening means can be screwed into the body.

Claims

1. An arrangement with a tool (7) and with a fastening means (4) having a longitudinal direction (L), wherein the tool (7) is designed to screw the fastening means (4) into a body in the longitudinal direction (L); the tool (7) has a blade (12) with a first holding element (5) and a second holding element (6), and the fastening means (4) has a first holding section (8) with a complementary first holding element (3) and a second holding section (9) with a complementary second holding element (2), and the blade (12) can be inserted into the fastening means (4), and in the first holding section (8) the first holding element (5) and the complementary first holding element (3) interact in such a way that a translatory movement of the blade (12) in the longitudinal direction (L) is blocked and thus it is difficult for the fastening means (4) to fall from the tool (7) by means of a backwards movement, and in the second holding section (9) the second holding element (6) and the complementary second holding element (2) interact in such a way that a rotary movement of the blade (12) can be transferred to the fastening means (4) and the fastening means (4) can be screwed into the body.

2. The arrangement according to claim 1, characterised in that the blade (12) can be introduced into the fastening means (4) only if the first holding element (5) and the complementary first holding element (3) interact.

3. The arrangement according to claim 1, characterised in that an outer periphery of the second holding element (6) is formed as a polygon in a cross-section perpendicular to the longitudinal direction (L), and an internal periphery of the complementary second holding element (2) forms a complementary shape.

4. The arrangement according to claim 1, characterised in that the first holding element has a mandrel (5) and the first complementary holding element has a channel (3) running along an inner wall of the first holding section, along which the mandrel (5) can be guided during the insertion operation.

5. The arrangement according to claim 1, characterised in that a curve of the channel (3) is S-shaped.

6. The arrangement according to claim 1, characterised in that the channel (3) in the second holding section (9) runs in the longitudinal direction (L).

7. The arrangement according to claim 1, characterised in that the mandrel (5) is arranged at one end of the blade (12).

8. The arrangement according to claim 1, characterised in that the fastening means is formed as a screw (4).

9. A method for fastening a fastening means (4) with a longitudinal direction (L) with a tool (7) in a body, wherein the tool (7) has a blade (12) with a first holding element (5) and a second holding element (6), and the fastening means (4) has a first holding section (8) with a complementary first holding element (3) and a second holding section (9) with a complementary second holding element (2), wherein the blade (12) is introduced into the first holding section (8) in a non-translatory movement, and in the first holding section (8) the first holding element (5) and the complementary first holding element (3) interact, and wherein the blade (12) is introduced into the second holding section (9) and there the second holding element (6) and the complementary second holding element (2) interact, and the tool (7) is rotated and a rotary movement of the tool (7) can be transferred to the fastening means (4) and the fastening means (4) can be screwed into a body.

10. The method according to claim 9, characterised in that when the second holding element (6) becomes loose from the complementary second holding element (2), the first holding element (5) interacts with the complementary first holding element (3) in the first holding section (8) and it is made difficult for the fastening means (4) to fall from the tool (7).

11. The method according to claim 9, characterised in that the tool (7) is guided in an S-shaped movement through the first holding section (8).

12. The method according to claim 9, characterised in that the tool (7) is introduced into the first holding section (8) in an S-shaped movement which also comprises a translatory movement counter to the longitudinal direction (L).

13. The method according to claim 9, characterised in that the blade (12) is introduced initially into the first holding section (8) and then into the second holding section (9).

14. The method according to claim 9, characterised in that a screw (4) is selected as the fastening means and the screw (4) is firmly screwed into the body.

Description

[0039] The invention is described with reference to an embodiment with five drawings. In the drawings:

[0040] FIG. 1 shows an oblique view of a prosthetic screw head with an internal hexagon and a channel formed in an inner wall,

[0041] FIG. 2 shows a sectional view along the line II-II in FIG. 1,

[0042] FIG. 3a shows a screwdriver with an external hexagon and two mandrels,

[0043] FIG. 3b shows a view of the screwdriver rotated by 90° relative to FIG. 3a,

[0044] FIG. 4 shows a side view, partially as a sectional view of a blade of the screwdriver introduced into the screw.

[0045] FIG. 1 shows a screw head 1 of a screw 4 according to the invention with an inner wall and an outer wall which transitions into a thread in the section remote from the head.

[0046] Two opposing, preferably concave channels 3 are formed in the inner wall of the screw head 1. The channels 3 have an S-shaped curvature in an upper first holding section 8 at the head end. The two channels can be identically mapped to one another rotatably by 180° about a centre axis of the screw head 1. The S-shaped channel 3 is designed in such a way that at the start of the first holding section 8 it runs substantially in a longitudinal direction L of the screw 4 and then forms a curve running towards the left, wherein the channel 3 is then turned back some way in the direction of the upper end of the screw head 1, in order then to run through again in a curve towards the right again strictly in the longitudinal direction L until the end of a second holding section 9. The opposing channel is not illustrated in FIG. 1 apart from a channel inlet.

[0047] A diameter of the first holding section 8 is greater than a diameter of the second holding section 9. Advantageously, each diameter of the first holding section 8 is greater than a diameter of the second holding section 9. The second holding section 9 is designed as an internal hexagon 2, the first holding section 8 is designed as an internal cylinder with two channels 3 running in the cylinder wall.

[0048] FIG. 2 shows the screw 4 in a sectional view. The screw head 1 has the first holding section 8 in the upper region and has the second holding section 9 in the lower region. One of the two opposing channels 3 is illustrated in FIG. 2. The region to be screwed into the body is designed as an external thread.

[0049] FIG. 3a and FIG. 3b show the tool in the form of a screwdriver 7 with a screwdriver head 11 and a blade 12. The representation of FIG. 3a is rotated by 90° relative to the representation in FIG. 3b. The blade 12 has a first holding element in the form of two preferably hemispherical mandrels 5 as well as a second holding element in the form of an external hexagon 6. The mandrels 5 naturally can also be shaped differently. Cylindrical or tetrahedral shapes or other shapes can also be used for the mandrel 5. The second holding element does not necessarily have to be designed as an external hexagon, it can also be designed as an external square or pentagon or can also have another shape. However, the shape should not be rotationally symmetrical, but in the embodiment with two mandrels 5 it should preferably be rotationally symmetrical about 180°.

[0050] The screw 4 illustrated in FIGS. 1 and 2 is preferably a prosthetic screw. The screwdriver 7 according to the invention, which is illustrated here as an external hexagon 6 having two mandrels 5, can engage in the screw head 1 and can be inserted therein in two spatial positions. The two positions are rotationally symmetrical about 180°.

[0051] In both engaged positions the two mandrels 5 engage simultaneously in the two concave channels 3 which are formed in the screw head inner wall. The two channels 3 are situated opposite one another and are rotated by 180° with respect to one another and have the S-shaped curve illustrated in FIG. 1.

[0052] In FIG. 4 it is shown how the blade 12 of the screwdriver 7 is introduced into the screw head 1. In this case first the blade 12 of the screwdriver 7 with the two mandrels 5 is positioned above the associated channels 3 and is introduced into the first holding section 8 in a non-translatory movement. In this case the screwdriver 7 is guided in the path predetermined by the S-shaped configuration of the channel 3. First of all the screwdriver 7 is moved towards the screw and then in a rotation in a clockwise direction is again rotated some way out of the screw head 1, in order then to be introduced into the second holding section 9 in a translatory movement in a longitudinal direction L. The start and the end of the channel 3 optimally span the greatest possible angle in relation to the circular cross-section of the screw head 1. In the exemplary embodiment described here, for better representation in the drawings this angle is chosen to be somewhat smaller than it really is. The greater this angle is, i.e. the longer the path of the channel 3 extends over the screw head, the smaller is the risk of an accidental or unintentional reversal of this introduction movement and thus of the separation of the connection between the blade 12 and the screw head 1. After the engagement of the mandrel 5 in the channel 3, during the rotation in a clockwise direction relative to the prosthetic screw 4 and around the common longitudinal axis, the hexagonal screwdriver 7 follows the curvature of the channel 3, and a form-fitting connection is produced. For completion of the movement in the first holding section 8, the hexagonal screwdriver 7 and the prosthetic screw 4 approach a position in which the external hexagon 6 is inserted perpendicularly, i.e. in the longitudinal direction L, into the internal hexagon 2 of the screw head 1, producing a force-fitting connection in the longitudinal direction and a form-fitting connection in the direction of rotation. The channels 3 of the first holding part 8 are continued in the walls of the second holding sections 9, so that the mandrels 5 of the force-fitting hexagonal connection do not stand in the way. If the external hexagon 6 of the screwdriver should come loose from the internal hexagon 2 the screw 4 due to sudden shear or pull-off forces which could act on the screw 4, for example by sudden tongue movements of the patient, the screw 4 is prevented from suddenly falling from the screwdriver 7 by the interengagement of the mandrel 5 and the channel 3. The screw 4 remains loosely fastened to the screwdriver 7, and as a result time remains for the dentist or the user to in order to reintroduce the screwdriver completely into the screw and to restore the connection in the second holding section 9. Thus, furthermore, the user must carefully monitor the procedures with regard to any action of such forces in order to react quickly if necessary. Overall, due to the succession of a first holding section 8 and a second holding section 9 the reliability of the screwing in of screws into an external thread is significantly increased, since the probability of the screw 4 falling by chance from the screwdriver 7 is significantly reduced. Even if the connection of the external and internal hexagons 6, 2 is lost, the screw 4 is initially still arranged on the screwdriver 7 by means of the interaction of the channel 3 and the mandrel 5 and for example in the event of dental treatment it does not immediately fall into the patient's oral cavity or throat.

LIST OF REFERENCES

[0053] 1 screw head [0054] 2 internal hexagon [0055] 3 channel [0056] 4 screw [0057] 5 mandrel [0058] 6 external hexagon [0059] 7 screwdriver [0060] 8 first holding section [0061] 9 second holding section [0062] 11 screwdriver head [0063] 12 blade [0064] L longitudinal direction