Screw

Abstract

The invention relates to a screw (1) comprising a screw head (2), a screw shaft (3), and a substantially conical screw tip (4), wherein the screw (1) has a screw thread (5) which extends from the screw tip (4) along the screw shaft (3) toward the screw head (2), wherein the screw (1) has at least one raised portion (6) which extends toward the screw shaft (3) from at least one point of the raised portion (6) lying frontmost in a screw-in direction (E) of the screw (1) and which has a course which corresponds to at least one portion of an ellipse, wherein the ellipse is located in a plane which intersects with the screw shaft (3) at an angle of between 15 degrees and 75 degrees and the height of the raised portion (6) is less than the height of the screw thread (5).

Description

[0001] screw

[0002] The invention relates to a screw having the features of the preamble of claim 1, as well as a rolling die according to claim 16.

[0003] Screws are widely used in fastening technology and are used to firmly connect multiple objects together. For example, screws are used in the construction of buildings or furniture. State-of-the-art screws comprise a screw head, a screw shaft, and a generally conical screw tip. They also have a thread that extends from the screw tip along the screw shaft toward the screw head.

[0004] Screws are used to connect elements that may be made of the same or different materials. For example, screws used to connect wooden elements are called wood screws. Wood screws are generally used to fasten or connect components made of wood or a wood-like material. For this purpose, they automatically cut a corresponding counter-thread into the material, which serves to absorb the forces acting on the screw. Such wood screws are screwed into a component with their point first, whereby the component's material is displaced and cut by the wood screw.

[0005] A key characteristic for screws is their thread pullout force, or pull-out capacity. This is the holding force provided by the screw thread screwed into the component to connect the components being screwed together. It is obvious that a screw should have a design that provides a high thread pullout force.

[0006] When a screw is screwed in, the displaced material creates pressure that acts both on the screwed-in screw and within the component material. This pressure can have the disadvantage of bursting or destroying the component due to the splitting effect of the screwed-in screw when screwing in. Furthermore, the pressure created when screwing in leads to increased force and / or an increased screwing-in torque that must be applied when screwing in the screw. This creates the disadvantage that excessive screwing-in torque can lead to the screw being unscrewed when screwing in, thus damaging the component. Furthermore, it is desirable for the screw to have an unscrewing torque that exceeds the screwing-in torque.State-of-the-art screws typically cut the fibers of the component material they are screwed into during screwing, producing chips. These chips remain in the mating thread cut by the screw in the component material. This has the disadvantage of increasing the screwing-in torque while simultaneously reducing the thread pull-out force and unscrewing torque.

[0007] It is the object of the present invention to provide a screw and a rolling die for producing such a screw, which further improves the aforementioned properties and avoids the disadvantages of the prior art.

[0008] According to the invention, this object is achieved by providing a screw which has a screw head, a screw shaft and a substantially conical screw tip. The screw further comprises a thread which extends from the screw tip along the screw shaft in the direction of the screw head. According to the invention, the screw has at least one elevation which extends from at least one foremost point of the elevation in a screwing direction of the screw in the direction of the screw, and has a profile which corresponds to at least a section of an ellipse. This ellipse is arranged in a plane which intersects the screw shaft at an angle between 15 degrees and 75 degrees, wherein a height of the elevation is less than a height of the thread.

[0009] The elevation, which has an elliptical shape at least in sections, and its inclination relative to the screw shaft at an angle of between 15 degrees and 75 degrees, achieves the advantage of creating a punching effect when the screw is screwed into a component material such as wood, preventing excessive splitting from occurring when the screw is driven in. This punches out a portion of the component material's fibers along the screwing direction of the screw, effectively preventing the component from splitting when the screw is screwed in.

[0010] Preferably, the profile of the raised portion forms an ellipse that is open against the screw-in direction. Alternatively, the profile of the raised portion forms an ellipse that is open in the screw-in direction. These designs prevent dust-like component material, such as wood flour, from accumulating within the ellipses, which could lead to an increased splitting effect and a higher screw-in torque.

[0011] According to an alternative embodiment of the screw according to the invention, the raised portion has a profile corresponding to a complete ellipse. This improves the punching effect of the screw according to the invention and further reduces the splitting effect.

[0012] Preferably, the foremost point of the raised portion is located at the screw tip. This creates the punching effect immediately upon screwing in the screw, effectively preventing splitting of highly unstable or easily splittable material.

[0013] Preferably, the screw has two protrusions, each extending from at least one foremost point of the respective protrusion in a screwing direction of the screw on substantially opposite sides of the screw in the direction of the screw shaft. The protrusions each have a profile corresponding to at least part of an ellipse, and each ellipse is arranged in a plane that intersects the screw shaft at an angle between 15 degrees and 75 degrees. This further improves the punching effect of the screw according to the invention.

[0014] According to the preferred embodiment of the screw according to the invention, the foremost points of each of the protrusions are offset from one another in the screwing direction of the screw. This achieves a gradual increase in the punching effect through the protrusions. Furthermore, this prevents the need to overcome an increased screwing torque when inserting the screw.

[0015] The contours of the raised portions can each form an ellipse open against the screw-in direction, or an ellipse open in the screw-in direction. These designs prevent dust-like component material, such as wood flour, from accumulating within the ellipses, which could lead to an increased splitting effect and a higher screw-in torque. Alternatively, the raised portions can have contours that correspond to complete ellipses.

[0016] The at least one foremost point of at least one of the elevations is preferably located on the screw tip. This creates the punching effect immediately upon screwing in the screw, effectively preventing splitting of highly unstable or easily splittable material. Preferably, the foremost points of both elevations are located on the screw tip.

[0017] According to the preferred embodiment of the screw according to the invention, the profiles of the raised portions intersect at intersection points that are arranged in a plane with a central screw axis running through the screw tip. This prevents the screw from wobbling during the screwing-in process. Alternatively, the profiles of the raised portions intersect at intersection points, with a connecting line through the intersection points being spaced from a central screw axis running through the screw tip. This induces the screw to wobble during the screwing-in process, thereby reducing the screwing-in torque. According to another alternative embodiment of the screw according to the invention, the raised portions do not intersect.

[0018] The object of the invention is further achieved by providing a rolling die which is designed for rolling out the screw according to the invention.

[0019] Advantageous embodiments of the screw according to the invention as well as alternative embodiments are explained in more detail below with reference to the figures.

[0020] Figures 1a to 1c show a screw according to the invention with a protrusion in the shape of a half-ellipse, which is arranged in a plane that intersects a screw shank of the screw at a slight angle. Figure 1d shows a cross-section through the screw according to Figure 1a.

[0021] Figures 2a to 2c show a screw according to the invention with a raised portion in the shape of a half-ellipse, which is arranged in a plane that intersects the screw shaft at a larger angle. Figure 2d shows a cross-section through the screw according to Figure 2a.

[0022] Figures 3a to 3c show a screw according to the invention with a raised portion in the shape of a complete ellipse, which is arranged in a plane that intersects the screw shaft at a slight angle. Figure 3d shows a cross-section through the screw according to Figure 3a.

[0023] Figures 4a to 4c show a screw according to the invention with a raised portion in the shape of a complete ellipse, which is arranged in a plane that intersects the screw shaft at a larger angle. Figure 4d shows a cross-section through the screw according to Figure 4a.

[0024] Figures 5a to 5c show a screw according to the invention with an elevation having a profile in the shape of a complete ellipse which is arranged in a plane that intersects the screw shaft of the screw at a small angle, wherein the elevation is offset along the screw shaft compared to the screw according to Figures 3a to 3d. Figure 5d shows a cross section through the screw according to Figure 5a. Figures 6a to 6c show a screw according to the invention with an elevation having a profile in the shape of a complete ellipse which is arranged in a plane that intersects the screw shaft of the screw at a larger angle and is offset along the screw shaft compared to Figures 3a to 3d. Figure 5d shows a cross section through the screw according to Figure 5a.

[0025] Figures 7a to 7c show a screw according to the invention with two elevations, each with a profile in the shape of a complete ellipse arranged in a plane that intersects the screw shaft at a slight angle. Figure 7d shows a cross-section through the screw according to Figure 7a.

[0026] Figures 8a to 8c show a screw according to the invention with two elevations, each with a profile in the shape of a complete ellipse arranged in a plane that intersects the screw shaft at a larger angle. Figure 8d shows a cross-section through the screw according to Figure 8a.

[0027] Figures 9a to 9c show a screw according to the invention with two elevations, each with a profile in the shape of a half ellipse, which is open opposite to the screwing direction and which is arranged in a plane that intersects the screw shaft at a slight angle. Figure 9d shows a cross-section through the screw according to Figure 9a.

[0028] Figures 10a to 10c show a screw according to the invention with two elevations, each with a profile in the shape of a half ellipse, which is open opposite to the screwing direction and which is arranged in a plane that intersects the screw shaft at a larger angle. Figure 10d shows a cross-section through the screw according to Figure 10a.

[0029] Figures 11a to 11c show a screw according to the invention with two elevations, each with a profile in the shape of a half ellipse, which is open in the screwing direction and which is arranged in a plane that intersects the screw shaft at a slight angle. Figure 11d shows a cross-section through the screw according to Figure 11a.

[0030] Figures 12a to 12c show a screw according to the invention with two elevations, each with a profile in the shape of a half ellipse, which is open in the screwing direction and which is arranged in a plane that intersects the screw shaft at a larger angle. Figure 12d shows a cross-section through the screw according to Figure 12a. Figures 13a to 13c show a screw according to the invention with two elevations, each with a profile in the shape of a complete ellipse, which is open in the screwing direction and which is arranged in a plane that intersects the screw shaft at a small angle. Figure 13d shows a cross-section through the screw according to Figure 13a.

[0031] Figures 14a to 14c show a screw according to the invention with two elevations offset along the screwing direction, each with a profile in the shape of a half ellipse, which is open opposite to the screwing direction. Figure 14d shows a cross-section through the screw according to Figure 14a.

[0032] Figure 15a shows a rolling die for rolling out the screw according to the invention in a perspective view, and Figure 15b shows the rolling die according to Figure 15a in a plan view.

[0033] The screw 1 according to the invention is shown in Figures 1a to 14d in various embodiments and comprises a screw head 2, a screw shaft 3 and a substantially conical screw tip 4. As is generally known to those skilled in the art in the field of screws, the screw head 2 has a screw head drive not shown in the figures, such as a Phillips screw, slotted screw, or Torx screw geometry. This serves to apply a torque to the screw head 2 by means of a corresponding screw drive tool in order to screw the screw 1 according to the invention into a workpiece or component not visible in the figures. The screw 1 according to the invention also has a thread 5 which extends from the screw tip 4 along the screw shaft 3 in the direction of the screw head 2.The thread 5 can run along the entire screw shaft 3, or, as can be seen, for example, in Figure 1a and Figure 1b, only run in sections along the screw shaft 3, starting from the screw tip 4. The screw 1 according to the invention is preferably a wood screw.

[0034] According to the invention, the screw 1 has at least one elevation 6 which extends from at least one foremost point of the elevation 6 in a screwing direction E of the screw 1, indicated by an arrow in Figure 1a, in the direction of the screw shaft 3. This elevation 6 is shown in detail in Figure 1e, for example. Figure 1d shows a cross-section through the screw 1 in the region of the elevation 6. The elevation 6 has a profile which corresponds to at least a section of an ellipse. The ellipse is arranged in a plane which intersects the screw shaft 3 at an angle of between 15 degrees and 75 degrees. In addition, a height of the elevation 6 is smaller than a height of the thread 5, as can be seen in Figure 1d. The height of the thread is also referred to as thread height or thread depth.This is the height at which the threads of the thread 5 are raised from the screw shaft 3 or from the screw tip 4 at a right angle to the screwing direction E. The height of the elevation 6 refers to the height at which the elevation 6 is raised from the screw shaft 3 or the screw tip 4 at a right angle to the screwing direction E. According to an alternative embodiment, the ellipse can also be arranged in a plane that intersects the screw shaft 3 at an angle between 30 degrees and 60 degrees.

[0035] Due to the elliptical shape of the elevation 6, at least in sections, and its inclination relative to the screw shaft 3 at an angle of between 15 degrees and 75 degrees, a punching effect is achieved when the screw 1 is screwed into a component material such as wood, and at the same time the necessary screwing-in torque is reduced. This punching effect prevents an excessive splitting effect on the component material when the screw 1 is driven in. This effectively prevents the component from splitting when the screw 1 is screwed in. The lower height of the elevation 6 compared to the height of the thread 5 has the advantage that the thread 5 reaches a sufficient engagement depth for effective propulsion in the component material.

[0036] According to one embodiment of the screw 1 according to the invention, the profile of the elevation 6 can form an ellipse open opposite to the screwing direction E. Alternatively, the profile of the elevation 6 can also form an ellipse open in the screwing direction E. In the screw 1 shown in Figures 1a to 1d, the profile corresponds to a half ellipse open opposite to the screwing direction E. This achieves the advantage that dust-like or ground component material accumulated within the profile of the elevation 6 is removed.

[0037] Figures 2a to 2d also show an embodiment of the screw 1 according to the invention, in which the profile of the elevation 6 corresponds to a half-ellipse open opposite to the screwing direction E. However, in the embodiment of the screw 1 according to the invention shown in Figures 2a to 2d, the ellipse of the profile intersects the screw shaft 3 in a plane arranged at a greater angle than in the embodiment shown in Figures 1a to 2d. According to the invention, this angle is between 15 and 75 degrees.

[0038] According to alternative embodiments shown in Figures 3a to 5d, the elevation 6 can also have a profile corresponding to a complete ellipse. This achieves the advantage that the punching effect occurs more quickly and uniformly along the entire circumference of the screw shaft 3 when screwing in the screw 1. Furthermore, the foremost point of the elevation 6 is preferably located on the screw tip 4. This can be seen, for example, in Figures 3b and 3c. This further increases the punching effect.

[0039] According to an alternative embodiment of the screw 1 according to the invention, the screw 1 has two elevations 6, which extend from at least one foremost point of the respective elevation 6 in a screwing direction E of the screw 1 on substantially opposite sides of the screw 1 in the direction of the screw shaft 3, wherein the elevations 6 each have a profile which corresponds to at least part of an ellipse, and each ellipse is arranged in a plane which intersects the screw shaft 3 at an angle between 15 degrees and 75 degrees. A variant of a screw 1 according to the invention configured in this way can be seen, for example, in Figures 7a to 7d. The two elevations 6 achieve greater displacement of the workpiece material when the screw 1 is screwed into a workpiece, thereby further improving the punching effect.According to an alternative embodiment, the ellipses can also be arranged in a plane which intersects the screw shaft 3 at an angle between 30 degrees and 60 degrees. In general, for example, angles between the plane and the screw shaft 3 are 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74 and 75 degrees possible.

[0040] As can be seen from the embodiment of the screw 1 according to the invention shown in Figures 7a to 7d, the foremost points of each of the elevations 6 can be arranged offset from one another in the screwing direction E of the screw 1. This prevents the screwing torque from increasing too much at one point along the screwing direction E of the screw 1. Such a configuration can also be seen from the embodiment of the screw 1 according to the invention shown in Figures 8a to 8d, wherein the angle of the planes in which the ellipses of the elevations are arranged is higher than in the embodiment shown in Figures 7a to 7d.

[0041] The courses of the elevations 6 can each form complete ellipses, as can be seen in Figures 7a to 8d. Alternatively, the courses of the elevations 6 can each form an ellipse that is open in the screw-in direction E or counter to the screw-in direction E. Screws 1 configured in this way can be seen in Figures 9a to 12d, as well as 14a to 14d. This prevents material removed from the material during screwing from accumulating within the ellipses, which could make screwing more difficult. Preferably, the foremost point of at least one or both of the elevations 6 is arranged on the screw tip 4. This can be seen, for example, in Figures 14a to 14d. This ensures that the punching effect occurs even at a shallow screw-in depth, effectively suppressing splitting of the material during the first few revolutions of the screw 1 in the material.In Figures 14a to 14d, both frontmost points of the elevations 6 are arranged on the screw tip 4.

[0042] According to an alternative embodiment, the profiles of the elevations 6 intersect at intersection points 7, which are arranged in a plane with a central screw axis Z running through the screw tip 4. For example, the screws 1 according to the invention shown in Figures 9a to 13d are designed in this way. According to a further alternative embodiment, the profiles of the elevations 6 intersect at intersection points 7, wherein a connecting line through the intersection points 7 is at a distance from a central screw axis Z running through the screw tip 4. Screws 1 according to the invention designed in this way can be seen, for example, in Figures 7a - 8d and 14a to 14d. If the profiles of the elevations 6 intersect at intersection points 7, which are arranged in a plane with a central screw axis Z running through the screw tip 4, fluctuations in the screwing-in torque are avoided during screwing.This ensures that a user of the screw 1 according to the invention applies a uniform amount of force when screwing in. If the profiles of the elevations 6 intersect at intersection points 7, with a connecting line through the intersection points 7 being at a distance from a central screw axis Z running through the screw tip 4, a variable screwing-in torque is achieved when screwing in. This leads to additional displacement of the work piece material, whereby the extraction torque is increased compared to the screwing-in torque. According to a further alternative embodiment of the screw 1 according to the invention, the elevations 6 do not intersect. This can be seen, for example, in Figures 14a to 14c. This has the advantage that the removal of workpiece material from the elevations 6 is facilitated.

[0043] Figures 15a and 15b show a rolling die 8 according to the invention for rolling out the screw 1 according to the invention.

Claims

Patent claims:

1. A screw (1) with a screw head (2), a screw shaft (3), and a substantially conical screw tip (4), the screw (1) having a thread (5) which extends from the screw tip (4) along the screw shaft (3) in the direction of the screw head (2), characterized in that the screw (1) has at least one elevation (6) which extends from at least one foremost point of the elevation (6) in a screwing direction (E) of the screw (1) in the direction of the screw shaft (3), and has a profile which corresponds to at least a section of an ellipse, the ellipse being arranged in a plane which intersects the screw shaft (3) at an angle of between 15 degrees and 75 degrees, and a height of the elevation (6) being smaller than a height of the thread (5).

2. Screw (1) according to claim 1, characterized in that the profile of the elevation (6) forms an ellipse open opposite to the screwing direction (E).

3. Screw (1) according to claim 1, characterized in that the profile of the elevation (6) forms an ellipse open in the screwing direction (E).

4. Screw (1) according to claim 1, characterized in that the elevation (6) has a profile which corresponds to a complete ellipse.

5. Screw (1) according to one of claims 1 to 4, characterized in that the foremost point of the elevation (6) is arranged on the screw tip (4).

6. Screw (1) according to one of claims 1 to 5, characterized in that the screw (1) has two elevations (6) which extend from at least one foremost point of the respective elevation (6) in a screwing direction (E) of the screw (1) on substantially opposite sides of the screw (1) in the direction of the screw shaft (3), wherein the elevations (6) each have a profile which corresponds to at least part of an ellipse, and each ellipse is arranged in a plane which intersects the screw shaft (3) at an angle of between 15 degrees and 75 degrees.

7. Screw (1) according to claim 6, characterized in that the foremost points of each of the elevations (6) are arranged offset from one another in the screwing direction (E) of the screw (1).

8. Screw (1) according to one of claims 6 or 7, characterized in that the profiles of the elevations (6) each form an ellipse open opposite to the screwing direction (E).

9. Screw (1) according to one of claims 6 or 7, characterized in that the profiles of the elevations (6) each form an ellipse open in the screwing direction (E).

10. Screw (1) according to one of claims 6 or 7, characterized in that the elevations (6) have profiles which correspond to complete ellipses.

11. Screw (1) according to one of claims 6 to 10, characterized in that the at least one foremost point of at least one of the elevations (6) is arranged on the screw tip (4).

12. Screw (1) according to one of claims 6 to 10, characterized in that the foremost points of both elevations (6) are arranged on the screw tip (4).

13. Screw (1) according to one of claims 6 to 12, characterized in that the profiles of the elevations (6) intersect at intersection points (7) which are arranged in a plane with a screw central axis (Z) extending through the screw tip (4).

14. Screw (1) according to one of claims 6 to 12, characterized in that the courses of the elevations (6) intersect at crossing points (7), wherein a connecting line through the crossing points (7) is at a distance from a screw central axis (Z) running through the screw tip (4).

15. Screw (1) according to one of claims 6 to 12, characterized in that the elevations (6) do not intersect.

16. Rolling jaw (8), characterized in that the rolling jaw (8) is designed for rolling out a screw (1) according to one of claims 1 to 15.

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