Drive element, especially in the form of a screw

Abstract

Drive element, in particular in the form of a screw, which has an inner drive profile (2) that defines a profile axis (Pl) and has several drive surfaces (3) arranged evenly distributed around the profile axis (Pl) on its inner side, wherein the inner drive profile (2) forms an insertion opening (2a) at one upper end, through which the inner drive profile (2) can be connected to an outer drive profile (5) of a corresponding drive element, characterized in that clamping lugs (7) are provided on the drive surfaces (3), which extend upwards from the lower end of the drive surfaces (3) in the direction of the insertion opening (2a),and that the clamping lugs (7), viewed from the profile axis (Pl) in the direction of the respective drive surface (3), have an inverted paraboloid outer contour with a vertex pointing towards the insertion opening (2a) and, in cross-section perpendicular to the profile axis (Pl), a paraboloid cross-sectional contour with a vertex pointing towards the interior of the inner drive profile (2), wherein the cross-sectional area of ​​the clamping lugs (7) decreases continuously from the lower to the upper end of the clamping lugs (7).

Description

The present invention relates to a drive element, in particular in the form of a screw, which has an inner entrainment profile which defines a profile axis and has on its inner side a plurality of drive surfaces which are arranged distributed uniformly around the profile axis, wherein the entrainment profile forms at its one upper end an insertion opening via which the inner entrainment profile can be plugged together with an outer entrainment profile of a corresponding drive element.Furthermore, the present invention relates to a drive element, in particular in the form of a screw, which has an inner entrainment profile which is designed as an inner multiple-round profile, in particular as an inner multiple-round profile, wherein the inner entrainment profile defines a profile axis and has on its inner side a plurality of drive surfaces which are arranged distributed uniformly around the profile axis and are formed by the regions of the inner multiple-round profile which are directed concavely inward, and has transition regions which lie between the drive surfaces and are curved convexly outward away from the profile axis, wherein the inner entrainment profile forms at its one upper end an insertion opening via which the inner entrainment profile can be plugged together with an outer entrainment profile of a corresponding drive element.Screws and turning tools are known from the prior art in different embodiments. The screws comprise a screw shank with an external thread, on the upper end region of which a screw head with a driver profile is provided for coupling to a turning tool. The turning tools are designed, for example, in the form of ring or jaw keys and comprise replaceable bits which are connected via a bit holder to a drive, for example in the form of a handle or an cordless screwdriver. Alternatively, the bit holder can be connected via an adapter for alternating use to a screwdriver handle or an angled handle, to a ratchet, a torque wrench, an cordless screwdriver or a ratchet screwdriver.The screw and the turning tool are offered with driving profiles formed in a complementary manner to one another for transmitting a torque from the torque to the screw. For this purpose, one of the components has an outer entrainment profile with external drive surfaces and the other component has an inner entrainment profile, which is complementary to the outer entrainment profile and has internal drive surfaces. The entrainment profiles are designed, for example, in the form of an internal hexagon, an external hexagon, a Torx profile or the like. In the present application, the screws used are primarily screws which are provided with an inner entrainment profile, for example in the form of an internal hexagon or a torx profile.When a turning tool is inserted into such an inner entrainment profile of the screw, this results in the inner entrainment profile of the screw and the outer entrainment profile of the turning tool resting against one another with play. This has the result that the entrainment profiles can unintentionally become detached from one another and it is also not possible to align the entrainment profiles axially cleanly with respect to one another. In order to simplify handling when screwing in and releasing the screw with the turning tool, two turning mechanisms are available which are provided with a magnet, or ferromagnetic turning tools which are magnetizable with a magnet. However, this is associated with additional outlay.To overcome this problem, it is known from DE 10 2005 011 734 A1 to form the drive surfaces inclined at an acute angle to the profile axis in a turning tool for screwing in and releasing so-called trix screws, so that a clamping fit is created when the entrainment profiles of the turning tool and the screw are pushed together axially, and therefore no additional holding means are required in order to screw the screw into a thread. It is the object of the invention to configure a drive element of this type mentioned at the beginning, which has an inner entrainment profile, in such a way that a reliable connection can be produced with an outer entrainment profile of a corresponding drive element, for example a turning tool.This object is achieved according to the invention in a drive element of the type mentioned at the beginning in that clamping lugs are provided on the drive surfaces, which clamping lugs extend upwards in the direction of the insertion opening starting from the lower end of the drive surfaces, and in that the clamping lugs have, as viewed from the profile axis in the direction of the respective drive surface, an inversely paraboloid outer contour with an apex pointing towards the insertion opening and, in the cross section perpendicular to the profile axis, a paraboloid cross-sectional contour with an apex pointing towards the interior of the entrainment profile, wherein the cross-sectional area of the clamping lugs continuously decreases from the lower end to the upper end of the clamping lugs.The transition from the clamping lugs to the drive surfaces at the upper end of the clamping lugs is expediently effected without any discontinuity and can be continuous, i.e. rounded.In a preferred manner, the clamping lugs are each formed symmetrically with respect to a longitudinal central plane of the respective drive surface intersecting the profile axis.According to one embodiment of the invention, it is provided that, viewed in the longitudinal central plane of the respective drive surface, the sides of the clamping lugs pointing towards the profile axis are formed in a straight line at least over a subsection of their axial length, preferably over their entire axial length, and include with the profile axis an angle of inclination α of at least 1°, in particular at least 1.5°, preferably at least 2.5° and particularly preferably at least 4.5° and / or at most 10°, in particular at most 9°, preferably at most 8° and particularly preferably at most 7°. The angle of inclination is preferably in a range from 2 to 5°, in particular 3 to 4°.The invention is based on the consideration of providing clamping lugs on the drive surfaces, which clamping lugs project from the drive surfaces in the direction of the profile axis and become thicker towards the lower end of the drive surfaces, so that their distance from the profile axis becomes smaller. The clamping lugs are configured such that the leading edge of an outer entrainment profile corresponding to the inner entrainment profile comes into contact with the clamping lugs when the outer entrainment profile is inserted axially into the inner entrainment profile, with the result that the outer entrainment profile is fixed in a clamping manner in the inner entrainment profile and optionally also aligned axially. This significantly simplifies handling.In one embodiment of the invention, it is provided that the clamping lugs extend, starting from the lower end of the drive surfaces, over at least 10%, in particular at least 20%, preferably at least 30% and particularly preferably over at least 40% and / or over a maximum of 100%, in particular a maximum of 80%, preferably a maximum of 70%, preferably a maximum of 60% and particularly preferably a maximum of 50% of the axial height of the drive surfaces. In particular, the clamping lugs can extend over 30 to 40% of the height of the drive surfaces. It has been found that it can be sufficient if the clamping lugs are formed only in the lower end region of the drive surfaces if the entrainment profiles have a certain axial length / height. If the entrainment profiles are flat, i.e. have a small height, the clamping lugs will, however, already extend into the upper end region of the drive surfaces for production reasons.Clamping lugs can expediently be formed on all the drive surfaces. It is likewise expedient if all clamping lugs are of identical design.In conventional screws and helical bits, the entrainment profiles are of regular design. In this case, the drive surfaces each extend over a predetermined circumferential angle β about the profile axis of the entrainment profile. In the case of hexagonal profiles or Torx profiles, this circumferential angle is 60°. According to one embodiment of the invention, the clamping lugs extend at their lower end over the entire circumferential angle β. However, it is preferably provided that the clamping lugs extend over a circumferential angle γ which is at least 10%, in particular at least 20%, preferably at least 30% and / or at most 70%, in particular at most 60% and preferably at most 50% of the circumferential angle β. In other words, the clamping lugs extend only over a part of the circumferential angle β.As already mentioned, the inner entrainment profile can be designed as an internal hexagonal profile with six planar drive surfaces arranged uniformly distributed about the profile axis.Alternatively, it is possible that the inner entrainment profile is designed as an inner multiple-round profile, in particular as an inner multiple-round profile, wherein the drive surfaces are formed by the regions of the inner multiple-round profile that run concavely inward in the direction of the profile axis. The inner multi-round profile further has transition surfaces lying between the drive surfaces, which transition surfaces are curved convexly outwards away from the profile axis.In the case of multi-round profiles, the clamping lugs can also be provided according to a further aspect on the transition surfaces or in the regions in which the drive surfaces merge into the transition surfaces.Specifically, according to the further aspect of the invention, it is provided that clamping lugs are provided on the transition surfaces, which clamping lugs extend upwards in the direction of the insertion opening starting from the lower end of the transition surfaces, and that the clamping lugs have an inversely paraboloid outer contour with an apex pointing towards the insertion opening, as viewed from the profile axis in the direction of the respective transition surface, and in particular have a paraboloid cross-sectional contour with an apex pointing towards the interior of the inner entrainment profile in the cross section perpendicular to the profile axis of the transition surface, wherein the cross-sectional area of the clamping lugs continuously decreases from the lower end to the upper end of the clamping lugs.In this case, the clamping lugs can each be formed symmetrically with respect to a longitudinal central plane of the respective transition surface intersecting the profile axis.According to one embodiment of the invention, it is provided that, viewed in the longitudinal central plane of the respective transition surface, the sides pointing towards the profile axis run in a straight line at least over a subsection of their axial length, preferably over their entire axial length, and include with the profile axis an angle of inclination α of at least 1°, in particular at least 1.5°, preferably at least 2.5° and especially preferably at least 4.5° and / or at most 10°, in particular at most 9°, preferably at most 8° and especially preferably at most 7°.The angle of inclination is preferably in a range from 2° to 5°, in particular 3° to 4°.According to one embodiment, it is provided that the clamping lugs extend, starting from the lower end of the transition surfaces, over at least 10%, in particular at least 20%, preferably at least 30% and particularly preferably over at least 40% and / or over a maximum of 100%, in particular a maximum of 80%, preferably a maximum of 70%, preferably a maximum of 60% and particularly preferably a maximum of 50% of the axial height of the transition surfaces.Expediently, clamping lugs can be formed on all the drive surfaces. It is likewise expedient if all clamping lugs are of identical design.The transition surfaces regularly extend over a predetermined circumferential angle about the profile axis. It is preferably provided that the clamping lugs extend over a circumferential angle which amounts to at least 10%, in particular at least 20%, preferably at least 30% and / or at most 70%, in particular at most 60% and preferably at most 50% of this circumferential angle.The above explanations with respect to the angle of inclination of the other configuration of the clamping lugs also apply if the clamping lugs are not formed symmetrically with respect to a respective drive surface or transition surface intersecting the longitudinal central plane of the profile axis.Further features and advantages of the invention will be described with reference to the accompanying drawings. The drawing shows: FIG. 1 shows a perspective view of the screw head of a drive element designed as a screw according to the present invention with an inner entrainment profile designed as an internal hexagonal profile, FIG. 2 shows a plan view of the screw head of the screw from FIG. 1, FIG. 3 shows the screw head in section along the longitudinal central plane A-A from FIG. 2 through two drive surfaces of the screw head lying opposite one another, FIG. 4 shows a perspective view of the screw which is engaged with a corresponding drive element, which is designed as a screw bit and has an outer entrainment profile, FIG. 5 shows the arrangement from FIG. 4 in plan view, FIG. 6 shows the arrangement in section along a longitudinal central plane A-A through two mutually opposite drive surfaces of the screw head, FIG. 7 shows a perspective view of the screw head of a further drive element according to the invention, which is designed as a screw and the inner entrainment profile of which is designed as an internal hexagonal profile, FIG. 8 shows the screw head from FIG. 7 in plan view, FIG. 9 shows the screw head in section along the longitudinal central plane A-A from FIG. 8 through two drive surfaces of the screw head lying opposite one another, FIG. 10 shows a perspective view of the screw which is engaged with a corresponding drive element, which is designed as a screw bit and has an outer entrainment profile, FIG. 11 shows the arrangement from FIG. 10 in plan view, FIG. 12 shows the arrangement in section along the longitudinal central plane A-A from FIG. 11 through two mutually opposite drive surfaces of the screw head, FIG. 13 shows a perspective view of a screw head of a further drive element designed as a screw according to the present invention, the inner entrainment profile of which is designed as an internal hexagonal profile, FIG. 14 shows the screw head from FIG. 13 in plan view, FIG. 15 shows the screw head in section along the longitudinal central plane A-A from FIG. 14 through two mutually opposite transition surfaces of the screw head, FIG. 16 shows a perspective view of a screw head of a further drive element designed as a screw according to the present invention, the inner entrainment profile of which is designed as an internal hexagonal profile, FIG. 17 shows the screw head from FIG. 16 in plan view, and FIG. 18 shows the screw head in section along the longitudinal central plane A-A from FIG. 17 through two mutually opposite transition surfaces of the screw head.FIG. 1 shows, by way of example, a drive element according to the present invention in the form of a screw, of which only the screw head 1 is shown. The screw includes a shank, not shown, that carries an external thread and defines a longitudinal axis of the screw. At the upper end of the shank, the screw head 1 is provided. On its inner side, it has an inner entrainment profile 2 open toward the upper side of the screw head 1 and having inner drive surfaces 3, which inner entrainment profile defines a profile axis Pl which is coaxial with the longitudinal axis of the screw. The open upper side of the screw head 1 forms an insertion opening 2 aof the inner entrainment profile 2 for a drive element designed as a screw bit 4.The inner entrainment profile 2 of the screw is designed as an internal six-tooth profile or an internal six-tooth profile, also known under the trade name Torx profile. It has six drive surfaces 3, which each extend over a circumferential angle β with respect to the profile axis Pl of 60° and have the shape of a region which is concavely curved inward in the direction of the profile axis Pl, that is to say an inwardly projecting arc tooth. The drive surfaces 3 run parallel to the profile axis Pl or the longitudinal axis of the screw 1, respectively. The drive surfaces 3 are connected to one another by transition surfaces 8, which here are curved away from the profile axis Pl, i.e. convexly outwards.The drive element, which is designed as a bolt bit 4, has an outer entrainment profile 5, which is designed to correspond to the inner entrainment profile 2 of the bolt. Correspondingly, the outer entrainment profile 5, which is designed as an external six-round profile, has six drive surfaces 6, which extend over a circumferential angle β of in each case 60° with respect to the profile axis PA of the outer entrainment profile 5 and run parallel to the profile axis PA.According to the invention, clamping lugs 7 are formed on the drive surfaces 3 of the inner entrainment profile 2 of the screw, which clamping lugs are formed symmetrically with respect to a longitudinal central plane A-A containing the profile axis Pl by the respective drive surface 3 and extend upwards in the direction of the insertion opening 2 a, starting from the lower end of the drive surfaces 3. Viewed from the profile axis Pl in the direction of the drive surfaces 3, i.e. in a front view of the drive surfaces 3, the clamping noses 7 have an inverted paraboloid outer contour with an apex pointing towards the insertion opening 2a. Similarly, in cross section perpendicular to the profile axis Pl, they have a paraboloid cross-sectional contour with an apex pointing toward the inside, here toward the profile axis Pl of the entrainment profile 2.As can be seen in particular from FIG. 2, the cross-sectional area of the clamping lugs 7 decreases continuously from the lower end to the upper end of the clamping lugs 7. The arrangement is made such that the sides of the clamping lugs 7 facing the profile axis Pl, when viewed in the longitudinal central plane A-A of the respective drive surface 3, enclose an angle of inclination α of preferably 3 to 4° with the profile axis Pl; thus, when viewed in the longitudinal central plane, the inwardly facing contour of the clamping lugs 7 tapers conically in the direction of the profile axis Pl. The clamping lugs 7 pass at their upper end without any jump into the drive surfaces 3.In the exemplary embodiment shown, the clamping lugs 7 extend approximately over 30% of the height of the drive surfaces 3. Viewed in the circumferential direction, the clamping lugs 7 extend at their lower end over a circumferential angle γ with respect to the profile axis Pl of approximately more than 20°, i.e. approximately more than 30% of the circumferential angle β of the drive surfaces 6.There is always a certain clearance S between the inner entrainment profile 2 of the screw 1 and the outer entrainment profile 5 of the helical bit 4 when the helical bit 4 is inserted into the inner entrainment profile 2 of the screw. During the insertion process, however, the leading edge of the helical bit 4 comes into contact with the clamping lugs 7 and is clamped by these in the screw head 1, as can be clearly seen in FIGS. 5 and 6 or 11 and 12. This ensures secure retention of the helical bit 4 in the screw head 1.As shown in FIGS. 13 to 18, the clamping lugs 7 can also be provided in the transition regions 8. In the embodiment shown in FIGS. 13 to 15, it is possible, for example, to provide the clamping noses 7 at the apex of the convexly curved transition surfaces 8, respectively. Likewise, the clamping lugs can be formed at the transition between the drive surfaces 3 and the transition surfaces 8, as is shown in FIGS. 16 to 18.In Figs. 7 to 9, a driving element according to the present invention is shown in the form of a screw, of which only the screw head 1 is shown. In contrast to the embodiment shown in FIGS. 1 to 6, the inner entrainment profile 2 of the screw head is here not designed as an internal hexagonal profile, but as an internal hexagonal profile with six drive surface 3 arranged uniformly distributed along the circumference around a profile axis Pl. As in the screw head shown in FIGS. 1 to 3, the clamping lugs 7 are positioned centrally of the drive surfaces 3 and extend upwards from the lower end of the drive surfaces 3. With regard to the concrete configuration of the clamping lugs, the above explanations apply accordingly.List of reference characters1 Screw head 2 inner entrainment profile 2 ainsertion opening 3 drive surfaces 4 drive bit 5 outer entrainment profile 6 drive surfaces 7 clamping lugs 8 transition surfaces Pl profile axis PA profile axis S gap α angle of inclination of the clamping lugs β angle of circumference of the drive surfaces γ angle of circumference of the clamping lugsReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 2005 011 734 A1

[0006]

Claims

Drive element, in particular in the form of a screw, which has an inner entrainment profile (2) which defines a profile axis (Pl) and has on its inner side a plurality of drive surfaces (3) which are arranged distributed uniformly about the profile axis (Pl), wherein the inner entrainment profile (2) forms on its one upper end an insertion opening (2a), via which the inner entrainment profile (2) can be plugged together with an outer entrainment profile (5) of a corresponding drive element, characterized in that clamping lugs (7) are provided on the drive surfaces (3), which clamping lugs extend upwards in the direction of the insertion opening (2a) starting from the lower end of the drive surfaces (3), and that the clamping noses (7) viewed from the profile axis (Pl) in the direction of the respective drive surface (3) have an inverted paraboloid outer contour with an apex pointing towards the insertion opening (2a) and, in cross section perpendicular to the profile axis (Pl), a paraboloid cross-sectional contour with an apex pointing towards the interior of the inner entrainment profile (2), wherein the cross-sectional area of the clamping noses (7) decreases continuously from the lower to the upper end of the clamping noses (7).Drive element according to Claim 1, characterized in that the clamping lugs (7) are each formed symmetrically with respect to a longitudinal centre plane (A-A) of the respective drive surface (3) intersecting the profile axis (Pl).Drive element according to Claim 2, characterized in that, viewed in the longitudinal central plane (A-A) of the respective drive surface (3), the sides pointing towards the profile axis (Pl) run in a straight line at least over a subsection of their axial length, preferably over their entire axial length, and include with the profile axis (Pl) an angle of inclination α of at least 1°, in particular at least 1.5°, preferably at least 2.5° and particularly preferably at least 4.5° and / or at most 10°, in particular at most 9°, preferably at most 8° and particularly preferably at most 7°.Drive element according to claim 3, characterised in that the angle of inclination α lies in a range of 2 to 5°, in particular 3 to 4°.Drive element according to one of the preceding claims, characterized in that the clamping lugs (7) extend, starting from the lower end of the drive surfaces (3), over at least 10%, in particular at least 20%, preferably at least 30% and particularly preferably over at least 40% and / or over a maximum of 100%, in particular a maximum of 80%, preferably a maximum of 70%, preferably a maximum of 60% and particularly preferably a maximum of 50% of the axial height of the drive surfaces (3) and / or in that clamping lugs (7) are formed on all the drive surfaces (3) and / or in that all the clamping lugs (7) are of identical design.Drive element according to one of the preceding claims, wherein the drive surfaces (3) each extend over a predetermined circumferential angle β about the profile axis (PI), characterized in that the clamping lugs (7) extend at their lower end over the entire circumferential angle β.Drive element according to one of Claims 1 to 5, wherein the drive surfaces (3) extend over a predetermined circumferential angle β about the profile axis (PI), characterized in that the clamping lugs (9) extend over a circumferential angle which is at least 10%, in particular at least 20%, preferably at least 30% and / or at most 70%, in particular at most 60% and preferably at most 50% of the circumferential angle β.Drive element according to one of the preceding claims, characterized in that the inner entrainment profile (2) is designed as an internal hexagonal profile with six planar drive surfaces (3) arranged uniformly distributed about the profile axis (PI).Drive element according to one of Claims 1 to 7, characterized in that the inner entrainment profile (2) is designed as an inner quadrilateral profile, in particular as an inner quadrilateral profile, the drive surfaces (3) being formed by the regions of the inner quadrilateral profile which run concavely inwards in the direction of the profile axis (Pl).Drive element, in particular in the form of a screw, which has an inner entrainment profile (2) which is designed as an inner quadrilateral profile, in particular as an inner quadrilateral profile, wherein the inner entrainment profile (2) defines a profile axis (PI) and has on its inner side a plurality of drive surfaces (3) which are arranged distributed uniformly about the profile axis (PI) and are formed by the regions of the inner quadrilateral profile which are directed concavely inwards, and has transition regions (8) which lie between the drive surfaces (3) and are curved convexly outwards away from the profile axis (PI), wherein the inner entrainment profile (2) forms on its one upper end an insertion opening (2a), via which the inner entrainment profile (2) can be plugged together with an outer entrainment profile (5) of a corresponding drive element, characterized in that, that clamping noses (7) are provided on the transition surfaces (8), which extend starting from the lower end of the transition surfaces (8) upwards in the direction of the insertion opening (2a), and that the clamping noses (7) viewed from the profile axis (PI) in the direction of the respective transition surface (8) have an inverted paraboloid outer contour with an apex pointing towards the insertion opening (2a) and - in particular - have a paraboloid cross-sectional contour with an apex pointing towards the interior of the inner entrainment profile (2) in cross-section perpendicular to the profile axis (PI) of the transition surface (8), wherein the cross-sectional area of the clamping noses (7) continuously decreases from the lower to the upper end of the clamping noses (7).Drive element according to claim 10, characterised in that the clamping lugs (7) are each formed symmetrically with respect to a longitudinal centre plane (A-A) of the respective transition surface (8) intersecting the profile axis (Pl).Drive element according to Claim 11, characterized in that, viewed in the longitudinal central plane (A-A) of the respective transition surface (8), the sides pointing towards the profile axis (Pl) run in a straight line at least over a subsection of their axial length, preferably over their entire axial length, and include with the profile axis (Pl) an angle of inclination α of at least 1°, in particular at least 1.5°, preferably at least 2.5° and particularly preferably at least 4.5° and / or at most 10°, in particular at most 9°, preferably at most 8° and particularly preferably at most 7°.Drive element according to claim 12, characterised in that the angle of inclination α lies in a range of 2 to 5°, in particular 3 to 4°.Drive element according to one of the preceding claims, characterized in that the clamping lugs (7) extend, starting from the lower end of the transition surfaces (8), over at least 10%, in particular at least 20%, preferably at least 30% and particularly preferably over at least 40% and / or over a maximum of 100%, in particular a maximum of 80%, preferably a maximum of 70%, preferably a maximum of 60% and particularly preferably a maximum of 50% of the axial height of the transition surfaces (8), and / or in that clamping lugs (7) are formed on all transition surfaces (8), and / or in that all clamping lugs (7) are formed identically.Drive element according to one of Claims 10 to 14, wherein the transition surfaces (8) extend over a predetermined circumferential angle about the profile axis (PI), characterized in that the clamping lugs (9) extend over a circumferential angle which amounts to at least 10%, in particular at least 20%, preferably at least 30% and / or at most 70%, in particular at most 60% and preferably at most 50% of the circumferential angle.

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