Screw drive

Abstract

A screw head bush (2) for a screw (1), wherein the screw head bush (2) has an external portion (3) and an internal portion (4) following the external portion (3), wherein the external portion (3) has a larger diameter (D) than the internal portion (4) and the external portion (3) is configured essentially as a truncated cone tapering towards the internal portion (4) and the internal portion (4) is configured as engagement geometry for the rotationally fixed accommodation of a screw head drive (6).

Description

[0001] Screw drive

[0002] The invention relates to a screw head bushing for a screw according to the preamble of claim 1, a screw head drive according to the preamble of claim 6, a forming tool for forming a screw head bushing according to the preamble of claim 11, a screw according to the preamble of claim 16, and a kit comprising a screw and a screw head drive.

[0003] Screw head bushings are geometric structures formed within screw heads that serve to provide a rotationally fixed mounting for a screw head drive. The screw head drive allows torque to be transmitted to the screw, enabling it to be driven into or unscrewed from a material. A number of geometries for screw head drives and screw head bushings are known in the art, such as Phillips, slotted, or Torx geometries. These geometries are often referred to as screw drives. Geometries such as the Torx geometry are optimized to transmit high torques from the screw head drive to the screw head bushing.

[0004] A disadvantage of many screw drives is that if the screw head drive is not properly centered or is misaligned with the screw head bushing, a positive connection between the screw head drive and the bushing is insufficiently established, causing the screw head drive to slip within the bushing. This can damage the bushing and / or the screw head drive, preventing the necessary torque for driving or removing a screw with that drive from being transmitted. As a result, the screw can no longer be driven in or easily removed from the material, potentially damaging the workpiece or impairing its function.

[0005] A geometry for improved alignment of a screw head drive in a screw head bushing is known in the art as the TTAP screw drive and is published under US Patent 6,951,158 B1. The screw head bushing of the TTAP screw drive comprises an outer and an inner section, the inner section including a centering cone. This ensures that the screw head drive is centered within the screw head bushing.

[0006] The present invention is based on the objective of providing an alternative geometry for screw drives which ensures high torque transmission and additionally provides centering of the screw head drive in the screw head bushing.

[0007] According to the invention, this problem is solved by a screw head bushing with the features of claim 1, a screw head drive with the features of claim 6, a forming tool for forming a screw head bushing with the features of claim 11, a screw with the features of claim 16 and a kit comprising a screw and a screw head drive with the features of claim 17.

[0008] The inventive embodiment of the screw head bushing for a screw comprises an outer section and an inner section following the outer section. The outer section has a larger diameter than the inner section in at least one first axis oriented perpendicular to a depth of the screw head bushing and is essentially designed as a truncated cone tapering towards the inner section. The inner section is designed as an engagement geometry for the rotationally fixed reception of a screw head drive. The tapered outer section provides a guide for the screw head drive, thereby preventing the screw head drive from being inserted obliquely into the screw head bushing.Furthermore, the inner section, designed as the engagement geometry, is located behind, or at a greater depth than, the outer section. This ensures that the screw head drive is centered and aligned by the outer section before engaging the engagement geometry. This prevents wear of the engagement geometry caused by improperly used screw head drives.

[0009] Preferably, the outer section comprises a conical truncated shell inclined at an angle of 2.5° to 10° relative to a cylindrical surface. This offers the advantage that an obliquely mounted screw head drive can be centered without requiring significant force.

[0010] Furthermore, according to the preferred embodiment, the screw head bushing according to the invention comprises an insertion area arranged between the outer section and the inner section, with insertion surfaces having an inclination of essentially 10° relative to a base surface of the truncated cone of the outer section. This facilitates the sliding of an engagement geometry of the screw head drive into the engagement geometry of the screw head bushing.

[0011] The engagement geometry of the screw head bushing according to the invention is preferably a Phillips geometry, a Torx geometry, or a slotted geometry. A particularly preferred engagement geometry is a slotted geometry running through the screw head bushing in a second axis oriented perpendicular to the depth of the screw head bushing and different from the first axis. This achieves the advantage that a large number of different screw drive geometries can be used within the scope of the invention.

[0012] The screw head drive according to the invention comprises an outer section and an inner section following the outer section, wherein the inner section has a larger diameter than the outer section in at least one first axis oriented normal to a height of the screw head drive. The inner section is essentially designed as a truncated cone tapering towards the outer section, and the outer section comprises an engagement geometry configured to engage in a rotationally fixed manner with the engagement geometry of a screw head bushing. The tapered inner section of the screw head drive provides guidance, preventing the engagement geometry of the screw head drive from being inserted obliquely into the engagement geometry of a screw head bushing.

[0013] Preferably, the inner section of the screw head drive according to the invention comprises a conical truncated shell inclined at an angle of 2.5° to 10° relative to a cylindrical surface. This achieves the advantage that an obliquely mounted screw head drive can be centered without requiring significant force.

[0014] Furthermore, the screw head drive according to the invention comprises an insertion area arranged between the outer section and the inner section, with insertion surfaces having an inclination of essentially 10° relative to a base surface of the truncated cone of the inner section. This facilitates the sliding of the engagement geometry of the screw head drive into the engagement geometry of the screw head bushing.

[0015] The drive geometry of the screw head drive according to the invention is preferably a Phillips geometry, a Torx geometry, or a slotted geometry. A slotted geometry is particularly preferred, extending through the screw head drive in a second axis oriented perpendicular to the height of the screw head drive and distinct from the first axis. This offers the advantage that a variety of different screw drive geometries can be used within the scope of the invention.

[0016] The forming tool according to the invention for forming a screw head bushing in a screw head comprises an outer section and an inner section following the outer section, wherein the inner section has a larger diameter than the outer section in at least one first axis oriented normal to a height of the forming tool. The inner section is essentially designed as a truncated cone tapering towards the outer section, and the outer section comprises an engagement geometry designed to form an engagement geometry in the screw head for the rotationally fixed reception of a screw head drive. This achieves the advantage that a screw head bushing according to the invention can be formed in a screw blank.

[0017] The inner section of the forming tool according to the invention preferably comprises a truncated cone inclined at an angle of 2.5° to 10° relative to a cylindrical surface. According to a preferred embodiment of the forming tool according to the invention, it further comprises an insertion area arranged between the outer and inner sections, with insertion surfaces having an inclination of essentially 10° relative to the base of the truncated cone of the inner section. This facilitates the simple insertion and centering of a screw head drive in a screw head bushing.

[0018] Preferably, the attack geometry of the forming tool according to the invention is a Phillips geometry, a Torx geometry, or a slotted geometry. Particularly preferred is a slotted geometry through the forming tool in a second axis oriented perpendicular to the height of the forming tool and different from the first axis. This achieves the advantage that a large number of different screw drive geometries can be used within the scope of the invention.

[0019] The screw according to the invention comprises a screw head bushing according to the invention, which was preferably formed using a forming tool according to the invention.

[0020] The kit according to the invention comprises a screw and a screw head drive according to the invention. The inner section of the screw head drive of the kit according to the invention has a truncated cone with a greater angle of inclination than a cylindrical surface, compared to the truncated cone of the outer section of the screw head bushing of the screw according to the kit. This creates a frictional connection between the screw head bushing of the screw and the screw head drive, thereby providing a holding force. Due to this holding force, the screw remains firmly in place on the screw head drive and can be easily inserted into a workpiece. This holding force is easily overcome when the screw head drive is withdrawn from the screw head bushing.The inventive design of the kit achieves the advantage that a holding force acting on the screw can be provided without additional magnetic elements known from the prior art.

[0021] Figure 1a shows a cross-section through a screw head of a screw according to the invention with a screw head bushing according to the invention.

[0022] Figure lb shows the screw head bushing according to Figure 1a in a further cross-sectional view.

[0023] Figure lc shows the screw head bushing according to Figure 1a and Figure 1lb in a top view.

[0024] Figures 2a, 2b, and 2c show a further embodiment of the screw head bushing according to the invention with a Phillips-type engagement geometry. Figures 3a, 3b, and 3c show a further embodiment of the screw head bushing according to the invention with a slot-type engagement geometry.

[0025] Figure 4a shows a screw head drive according to the invention in a side view.

[0026] Figure 4b shows the screw head drive according to Figure 4a in a perspective view.

[0027] Figure 4c shows the screw head drive according to Figure 4a and Figure 4b in a top view.

[0028] Figure 5a, Figure 5b and Figure 5c show a further embodiment of the screw head drive according to the invention with an attack geometry in the form of a Phillips geometry.

[0029] Figures 6a, 6b, and 6c show a further embodiment of the screw head drive according to the invention with an attack geometry in the form of a slot geometry.

[0030] Figures 7a and 7b show a forming tool according to the invention with an attack geometry in the form of a Torx geometry.

[0031] Figures 8a and 8b show the forming tool according to the invention with an attack geometry in the form of a Phillips geometry.

[0032] Figures 9a and 9b show the forming tool according to the invention with an attack geometry in the form of a slot geometry.

[0033] Figure 10a and Figure 10b show a first embodiment of the screw according to the invention.

[0034] Figure 11a and Figure 1b show a second embodiment of the screw 1 according to the invention. Figure 12a and Figure 12b show a third embodiment of the screw 1 according to the invention.

[0035] Figure 1a shows a cross-section of the screw head of a screw 1 according to the invention, illustrating a screw head bushing 2 provided in the screw 1 according to the invention. The screw head bushing 2 according to the invention has an outer section 3 and an inner section 4, which follows the outer section 3. The outer section 3 begins at a cover surface 5 of the screw head, and to screw in the screw 1, a screw head drive 6 according to the invention, which is shown in Figures 4a to 4c, is inserted through the outer section 3 into the inner section 4. The outer section 3 has a larger diameter D than the inner section 4 in at least one first axis A1, which is oriented normal to a depth T of the screw head bushing 2 and is visible in Figure 1c. This facilitates the insertion of the screw head drive 6 into the screw head bushing 2.The outer section 3 essentially has the shape of a truncated cone tapering towards the inner section 4. This provides a guide for the screw head drive 6. The inner section 4 is designed as an engagement geometry for the rotationally fixed reception of the screw head drive 6. Within the scope of the invention, any geometry known from the prior art for screw drives can be provided as the engagement geometry. In particular, a Phillips geometry, a Torx geometry, or a slotted geometry is preferred as the engagement geometry. Figures 1 to 1c show a Torx geometry. The inventive configuration of the outer section 3 and the inner section 4 provides improved guidance of the screw head drive 6 during insertion into the screw head bushing 2 and centering of the screw head drive 6 in the screw head bushing 2 before it fully engages with the engagement geometry.This prevents wear of the engagement geometry caused by improperly used screw head drives 6. Figure 1b shows the screw head of the screw 1 with the screw head bushing 2 according to Figure 1a in a further cross-sectional view, which is rotated relative to Figure 1a about a longitudinal axis L of the screw head drive 2. The engagement geometry shown in Figures 1a to 1c is a Torx geometry, with a maximum diameter of the Torx geometry visible in Figure 1a. Figure 1c shows the screw head according to Figures 1a and 1b from above, with the engagement geometry visible in plan view.

[0036] The outer section 3 of the screw head bushing according to the invention preferably has a truncated cone inclined at an angle of 2.5° to 10° relative to a cylindrical surface. The inclination of the truncated cone is indicated by the angle α in Figures 1a and 1b. This angular range has proven particularly advantageous with regard to the easy insertion of the screw head drive 6. Preferably, the screw head bushing 2 also comprises an insertion area 7 arranged between the outer section 3 and the inner section 4, with insertion surfaces 8. These are shown in Figures 1a, 1b, and 1c. According to the preferred embodiment of the screw head bushing 2 according to the invention, the insertion surfaces 8 have an inclination β of essentially 10° relative to a base surface of the truncated cone of the outer section 3, as shown in Figure 1a.This facilitates the sliding of an attack geometry of the screw head drive 6 into the engagement geometry of the screw head bushing 2.

[0037] Figures 2a, 2b and 2c show an alternative embodiment of the screw head bushing 2 according to the invention with an engagement geometry in the form of a Phillips geometry, and figures 3a, 3b, and 3c show a further embodiment of the screw head bushing 2 according to the invention with an engagement geometry in the form of a slot geometry.

[0038] As can be seen from Figure 3c, the engagement geometry can be a slot geometry running through the screw head bushing 2 in a second axis A2, oriented normal to the depth T of the screw head bushing 2 and different from the first axis Ai. This achieves the advantage that slotted screwdrivers known in the prior art can be used to drive a screw 1 equipped with the screw head bushing 2 according to the invention.

[0039] The screw head drive 6 according to the invention is shown in Figures 4a, 4b, and 4c. The screw head drive 6 according to the invention has an outer section 9 and an inner section 10 following the outer section 9, wherein the inner section 10 has a larger diameter D than the outer section 9 in at least one first axis Ai, visible in Figure 4c and oriented perpendicular to a height H of the screw head drive 6. The inner section 10 is essentially designed as a truncated cone tapering towards the outer section 9. The outer section 9 comprises an engagement geometry designed to engage in a rotationally fixed manner with the engagement geometry of the screw head bushing 2 according to the invention. Within the scope of the invention, any geometry known from the prior art for screw drives can be provided as the engagement geometry. This is shown in detail in Figures 4b and 4c.

[0040] Figures 4a to 4c show a Torx geometry. In particular, a Phillips geometry, a Torx geometry, or a slotted geometry is preferred as the engagement geometry. The screw head drive 6 and the screw head bushing 2 essentially represent complementary geometric shapes. The tapered inner section 10 of the screw head drive 6, in conjunction with the tapered shape of the outer section 3 of the screw head bushing 2, provides a guide, preventing the engagement geometry of the screw head drive 6 from being inserted obliquely into the engagement geometry of the screw head bushing 2. This prevents improper insertion of the screw head drive 6 into the screw head bushing 2 and avoids the screw head drive 6 spinning freely in the screw head bushing 2.

[0041] The inner section 10 of the screw head drive 6 according to the invention comprises a conical truncated shell inclined relative to a cylindrical surface in the range of 2.5° to 10°. This inclination is indicated by the angle of inclination g in Figure 4a. This angular range has proven to be particularly advantageous with regard to the ease of insertion of the screw head drive 6.

[0042] Preferably, the screw head drive 6 comprises an insertion area 11 arranged between the outer section 9 and the inner section 10, with insertion surfaces 12. These insertion surfaces 12 are shown in Figures 4b and 4c. The insertion surfaces 12 preferably have an inclination d of substantially 10° relative to a base surface of the truncated cone of the inner section 10, as shown in Figure 4b. This facilitates the sliding of the engagement geometry of the screw head drive 6 into the engagement geometry of the screw head bushing 2.

[0043] Figures 5a, 5b and 5c show an alternative embodiment of the screw head drive 6 according to the invention with an attack geometry in the form of a Phillips geometry, and figures 6a, 6b and 6c show a further embodiment of the screw head drive 6 according to the invention with an attack geometry in the form of a slot geometry.

[0044] As can be seen from Figure 6c, the attack geometry can be a slot geometry through the screw head drive 6 in a second axis A2 oriented normal to the height H of the screw head drive 6 and different from the first axis Ai.

[0045] A forming tool 13 according to the invention for forming a screw head bushing 2 in a screw head is used in screw production to form the screw head bushing 2 according to the invention in the screw head of a screw blank. This forming tool 13 has essentially the same geometry as the screw head drive 6 according to the invention. The forming tool 13 and the screw head bushing 2 thus represent essentially complementary geometric shapes. Figures 4a, 4b and 4c, 5a, 5b and 5c, as well as 6a, 6b and 6c also show, by way of example, an upper section of the forming tool 13 according to the invention.

[0046] The forming tool 13 for forming the screw head bushing 2 in a screw head comprises, like the screw head drive 6, an outer section 9 and an inner section 10 following the outer section 9, wherein the inner section 10 has a larger diameter D than the outer section 9 in at least one first axis Ai oriented normal to a height H of the forming tool 13. The inner section 10 is essentially designed as a truncated cone tapering towards the outer section 9, and the outer section 9 comprises an engagement geometry configured to form a meshing geometry in the screw head for the rotationally fixed reception of the screw head drive 6. Within the scope of the invention, any geometry known from the prior art for screw drives can be provided as the engagement geometry or meshing geometry.

[0047] The inner section 10 of the forming tool 13 preferably comprises a conical truncated shell inclined at an angle of 2.5° to 10° relative to a cylindrical surface. This inclination is indicated by the angle of inclination g in Figure 4a. This angular range has proven particularly advantageous with regard to the easy insertion of the screw head drive 6.

[0048] According to the preferred embodiment of the forming tool 13 according to the invention, it comprises an insertion area 11 arranged between the outer section 9 and the inner section 10, with insertion surfaces 12. The insertion surfaces 12 preferably have an inclination d of substantially 10° relative to a base surface of the truncated cone of the inner section 10, as can be seen in Figure 4b. This facilitates the sliding of the engagement geometry of the screw head drive 6 into the engagement geometry of the screw head bushing 2.

[0049] Figures 5a, 5b and 5c show an alternative embodiment of the forming tool 13 according to the invention with an attack geometry in the form of a Phillips geometry, and figures 6a, 6b and 6c show a further embodiment of the forming tool 13 according to the invention with an attack geometry in the form of a slot geometry.

[0050] As can be seen from Figure 6c, the attack geometry can be a slot geometry through the forming tool 13 in a second axis A2, oriented normal to the height H of the screw head drive 6 and different from the first axis A1. Figures 7a to 9b show the forming tool 13 according to the invention in substantially complete views, wherein the forming tool 13 comprises a section 14 for fastening the forming tool 13 in a screw production device. Figures 7a and 7b show the forming tool 13 according to the invention with an attack geometry in the form of a Torx geometry, in two different sizes.Figures 8a and 8b show the inventive forming tool 13 with an attack geometry in the form of a Phillips geometry, in two different sizes, and figures 9a and 9b show the inventive forming tool 13 with an attack geometry in the form of a slot geometry in two different sizes.

[0051] A kit according to the invention comprises a screw 1 according to the invention and a screw head drive 6 according to the invention. The inner section 10 of the screw head drive 6 of the kit according to the invention has a conical truncated shell with a larger angle of inclination g than a cylindrical shell compared to a conical truncated shell of the outer section 3 of the screw head bushing 2 of the screw 1 according to the invention. This results in a positive fit between the conical truncated shells of the screw head bushing 2 and the screw head drive 6 when the screw head drive 6 is inserted into the screw head bushing 2 of the screw 1, and the screw 1 is held securely on the screw head drive 6. This offers the advantage that the screw 1 can be easily positioned and screwed into a workpiece without having to hold it. Furthermore, this eliminates the need for magnetic elements in the screw head drive 6.Tests have shown that the screw head drives currently available on the market are generally over-dimensioned. For example, a TX25 drive known from the prior art can transmit several times the breaking torque of a 4 mm diameter wood screw because the drive has a relatively large depth. This finding is utilized in the invention, as it follows that the entire depth of the drive is not required to drive in a screw. Thus, according to the invention, part of the depth is used for a self-adhering positive fit to hold the screw 1 on the screw head drive 6. The different angles a and g of the two conical blunt surfaces of the screw head drive 6 and the screw head bushing 2, such as 5° at the screw head bushing 2 and 10° at the screw head drive 6, result in a very effective positive fit that holds the screw 1 on the screw head drive 6.This inventive effect can be used with any type of screw drive geometry. A further advantage lies in the precise axial guidance of the screw head drive 6. This prevents the screw head drive 6 from being engaged at an angle or at an oblique angle on the screw 1, thereby minimizing or even completely preventing unwanted rubbing of the screw head bushing 2 and / or excessive wear of the screw head drive 6.

[0052] Figures 10a and 10b show a first embodiment of the screw 1 according to the invention. Figure 10a shows a top view of the screw 1, and Figure 10b shows a sectional view of the screw from Figure 10a along line AA. In this embodiment, the screw 1 has a projection 15 that essentially surrounds the outer section 3 of the screw head bushing 2 in a ring-like fashion and extends essentially in the longitudinal direction of the screw 1. The projection 15 preferably has a height of 0.75 mm. The projection 15 offers the advantage of providing an additional depth T of the screw head bushing 2, allowing the outer section 3 to extend at least partially within the projection 15. This increases the depth of the inner section 4, resulting in a larger force-transmitting contact area between the engagement geometry of the screw head bushing 2 and the engagement geometry of the screw head drive 6.

[0053] Figure 11a and Figure 1lb show a second embodiment of the screw 1 according to the invention, in which the screw 1 has a cover surface 16 that essentially surrounds the outer section 3 of the screw head bushing 2 in a ring-like fashion and slopes outwards in the radial direction of the screw 2. The cover surface 16 preferably slopes down over a height of 0.75 mm. Figure 11a shows the screw 1 in a top view and Figure 1lb shows a sectional view of the screw from Figure 11a along line AA. As in the first embodiment of the screw 1 according to the invention, the shape of the cover surface 16 achieves the technical effect of providing an additional depth T of the screw head bushing 2.

[0054] Figures 12a and 12b show a third embodiment of the screw 1 according to the invention. Figure 12a shows a top view of the screw 1, and Figure 12b shows a sectional view of the screw from Figure 12a along line AA. According to this embodiment, the screw 1 has an outer surface 17 extending in the longitudinal direction of the screw 1 and substantially completely circumferentially surrounding the outer section 3 of the screw head bushing 2. The outer surface 17 preferably has a height of 1.31 mm. The outer surface 17 also provides an additional depth T of the screw head bushing 2, as well as additional mechanical stability to the outer section 3.

[0055] A known TX25 drive has a screw head bushing depth (T) of 1.9 mm to 2.3 mm. This depth is typically achieved with a screw head bushing diameter of 5 mm and a head diameter of 9.5 mm to 10 mm. The screw head height is 4.8 mm to 5.2 mm.

[0056] The screw 1 according to the invention has, according to a defined screw size, a screw head height of approximately 5.75 mm, wherein the depth of the engagement geometry of the inner section 4 is preferably approximately 1.95 mm. The head diameter of the screw 1 is approximately 10 mm. For other screw sizes, these values ​​are scaled accordingly.

Claims

Claims:

1. Screw head bushing (2) for a screw (1), wherein the screw head bushing (2) has an outer section (3) and an inner section (4) following the outer section (3), wherein the outer section (3) has a larger diameter (D) than the inner section (4) in at least one first axis (Ai) oriented normal to a depth (T) of the screw head bushing (2), characterized in that the outer section (3) is essentially designed as a truncated cone tapering towards the inner section (4) and the inner section (4) as an engagement geometry for the rotationally fixed reception of a screw head drive (6).

2. Screw head bushing (2) according to claim 1, characterized in that the outer section (3) comprises a conical blunt shell inclined relative to a cylindrical shell in the angular range of 2.5° to 10°.

3. Screw head bushing (2) according to one of claims 1 or 2, characterized in that the screw head bushing (2) comprises an insertion area (11) arranged between the outer section (3) and the inner section (4) with insertion surfaces (12), wherein the insertion surfaces (12) have an inclination of substantially 10° relative to a base surface of the truncated cone of the outer section (3).

4. Screw head bushing (2) according to one of claims 1 to 3, characterized in that the engagement geometry is a Phillips geometry, a Torx geometry or a slotted geometry.

5. Screw head bushing (2) according to one of claims 1 to 3, characterized in that the engagement geometry is a slot geometry through the screw head bushing (2) in a second axis (A2) oriented normal to the depth (T) of the screw head bushing (2) and different from the first axis (Ai).

6. Screw head drive (6) with an outer section (9) and an inner section (10) following the outer section (9), wherein the inner section (10) has a larger diameter (D) than the outer section (9) in at least one first axis (Ai) oriented normal to a height (H) of the screw head drive (6), characterized in that the inner section (10) is essentially designed as a truncated cone tapering towards the outer section (9), and the outer section (9) has an attack geometry includes which is designed to engage in a rotationally fixed manner in a mesh geometry of a screw head bushing (2).

7. Screw head drive (6) according to claim 6, characterized in that the inner section (10) comprises a conical blunt shell inclined relative to a cylindrical shell in the angular range of 2.5° to 10°.

8. Screw head drive (6) according to one of claims 6 or 7, characterized in that the screw head drive (6) comprises an insertion area (11) arranged between the outer section (9) and the inner section (10) with insertion surfaces (12), wherein the insertion surfaces (11) have an inclination of substantially 10° relative to a base surface of the truncated cone of the inner section.

9. Screw head drive (6) according to one of claims 6 to 8, characterized in that the attack geometry is a Phillips geometry, a Torx geometry or a slotted geometry.

10. Screw head drive (6) according to one of claims 6 to 8, characterized in that the attack geometry is a slot geometry passing through the screw head drive (6) in a second axis (A2) oriented normal to the height (H) of the screw head drive (6) and different from the first axis (Ai).

11. Forming tool (13) for forming a screw head bushing (2) in a screw head with an outer section (9) and an inner section (10) following the outer section (9), wherein the inner section (10) has a larger diameter (D) than the outer section (9) in at least one first axis (Ai) oriented normal to a height (H) of the forming tool (13), characterized in that the inner section (10) is essentially designed as a truncated cone tapering towards the outer section (9) and the outer section (9) comprises an engagement geometry designed to form an engagement geometry in the screw head for the rotationally fixed reception of a screw head drive (6).

12. Forming tool (13) according to claim 11, characterized in that the inner section (10) comprises a conical blunt shell inclined relative to a cylindrical shell in the range of 2.5° to 10°.

13. Forming tool (13) according to one of claims 11 or 12, characterized in that the forming tool (13) has a section between the outer part (9) and the inner section (10) comprising an insertion area (11) with insertion surfaces (12), wherein the insertion surfaces (12) have an inclination of substantially 10° to a base surface of the truncated cone of the inner section (10).

14. Forming tool (13) according to one of claims 11 to 13, characterized in that the attack geometry is a Phillips geometry, a Torx geometry or a slot geometry.

15. Forming tool (13) according to one of claims 11 to 13, characterized in that the attack geometry is a slot geometry through the forming tool (13) in a second axis (A2) oriented normal to the height (H) of the forming tool (13) and different from the first axis (Ai).

16. Screw (1) characterized in that the screw (1) comprises a screw head bushing (2) according to one of claims 1 to 5.

17. Screw (1) according to claim 16, characterized in that the screw (1) has a projection (15) which substantially circumscribes the outer section (3) of the screw head bushing (2) in a ring-like manner and extends substantially in the longitudinal axis direction of the screw (1).

18. Screw (1) according to claim 16, characterized in that the screw (1) has a cover surface (16) that substantially circumscribes the outer section (3) of the screw head bushing (2) in a ring-shaped manner and slopes outwards in the radial direction of the screw (2).

19. Screw (1) according to claim 16, characterized in that the screw (1) has an outer surface (17) extending in the longitudinal axis direction of the screw (1) and substantially completely circumferencing the outer section (3) of the screw head bushing (2).

20. Kit comprising a screw (1) according to one of claims 16 to 19 and a screw head drive (6) according to one of claims 6 to 10, characterized in that the inner section (10) of the screw head drive (6) has a conical truncated shell with a greater angle of inclination (g) than a cylindrical shell. Conical blunt shell of the outer section (3) of the screw head bushing (2) of the screw (1)