RU2744697C2 - Screw for engagement with wood or other composites - Google Patents

Abstract

FIELD: metal-working.

SUBSTANCE: invention relates to a screw for engagement with wood or a similar composite. A screw (10), going axially (A) for engagement with wood or a similar composite with the screw rotating in the direction (W) of rotation on the axis (AC) of rotation, comprising of: a body (14) with the thread section (15); hidden head (12) wherein the top side (19) has a socket (43) for a driving tool and the bottom part (18) is substantially frusto-conical and has a cutting socket area (20) with a back area (22) looking in the direction (W) of rotation, wherein said back area has a cutting edge (23) with a first axis end point (41) and a second first axis end point (42) wherein the end points form an imaginary line (AI) determining a positive angle (α) of the cutting edge with respect to the plane (AP) going in the radial direction (R) from the axis (AC) of rotation to the first axis end point (41) and axially (A); wherein the extent of the maximum depth of the cutting socket area (20) in the radial direction (R) is substantially evened out with the innermost point (46) of the socket (43) for a driving tool and the cutting socket area (20) is additionally determined by the frontal area (28) wherein the frontal area (30) is shaped substantially as an upside-down letter D.

EFFECT: improved cutting effect of a screw for engagement with wood or a similar composite.

12 cl, 11 dwg

Description

Scope of invention

The present invention relates to a screw for engaging with wood or a similar composite material, such as a composite deck material. The screw contains a countersunk head having an upper side for receiving a power tool for rotating the screw, and a substantially frusto-conical lower portion

Prior art

Screws are essentially needed to screw directly into a work piece or into a pilot hole in a work piece. One common type of screw that is configured to cut its own hole as it is screwed into a part is a self-tapping screw (self-tapping screw). Self-tapping screws are fasteners designed to drill their own hole as they are screwed into a part. In particular, self-tapping screws are suitable for softer parts made of, for example, wood or composite materials, such as deck materials. The use of a powered tool such as a screwdriver and a self-tapping screw can be used to produce precisely tailored holes.

Screws of this type are available in different shapes and sizes, and also come with different types of heads. In the field of wood screws and screws for decking materials, it is customary to use the so-called countersunk head, which allows the head of such a screw, when it engages with a work part, to be flush with the surface of the work part or under it. In addition, wood screws and deck screws usually have a portion of the shank under the head that is partially non-threaded. The unthreaded section of the rod is designed to slide through the top board (closest to the screw head) so as to press this board tightly against the board to which it is attached.

While these types of screws are effective at creating a strong engagement with a work piece, one common problem is that the head portion can create unwanted deformation of the work piece or the surface of the work piece, leading to cracking or denting in the work piece material. In order to partially eliminate such problems, some portions of the head of the screw are provided with ribs protruding outward from the lower part of the head portion or with recesses having a cutting edge for cutting the fibers when the lower part contacts the part as the screw rotates.

For example, US Pat. No. 5,863,217 A1 discloses a self-centered screw comprising an inverted cone head portion, on the bottom of which a plurality of substantially triangular recesses are formed. Each of the plurality of substantially triangular recesses comprises a flat back wall defining a linear cutting edge at the confluence of the back wall with the surface of the underside.

However, creating screws that will firmly engage with the work piece while avoiding noticeable damage to the surface finish of the work piece remains a challenge.

Therefore, it would be desirable to further improve screw performance for wood and composite materials such as deck deck materials.

Despite the activity in this area, as exemplified by the above source, there remains a need for a screw that creates improved engagement with the part, while minimizing the level of deformation of the material (s) that make up the work part, such as a wooden part or deck deck. ... In addition, it would be desirable to minimize manufacturing costs when mass-producing such screws.

Brief description of the invention

It is an object of the present invention to improve the cutting performance of a screw for engaging with wood or a similar composite material, for example a deck deck composite material. This objective is at least partially achieved by the features set forth in claim 1.

The invention relates to a screw for engaging with wood or a similar composite material, for example a composite deck material, by rotating the screw in the direction of rotation about the axis of rotation of the screw. The screw runs axially and contains:

- a countersunk head having an upper side for interaction with a driving tool for rotating a screw, and a substantially frusto-conical lower part;

- a rod extending from the countersunk head to the sharp end and having a threaded section,

- in which the frusto-conical lower part comprises a cutting recess region having a rear region as viewed in the direction of rotation; and

- in which the trailing region comprises a cutting edge having a first axial end point and a second axial end point defining an imaginary line. In addition, the imaginary line defines a positive angle α with respect to the plane AP. Plane AP extends in the radial direction, at least from the axis of rotation to the first axial end point, and in the axial direction A.

Thus, a screw is offered with an improved cutting function for fibers such as wood fibers or deck materials. In particular, there is a countersunk head screw with an improved head cutting function. The countersunk screw is designed to be recessed into the material. In addition to its improved fiber cutting function, the screw is able to remove fibers from the material efficiently and smoothly, i. E. without the risk of cracking wood material, composite material, etc., and also reduce the amount of fibers when engaging and assembling with a working part (for example, with a deck deck).

By creating a cutting groove section on the frusto-tapered bottom of the head and the adjacent cutting edge, it allows the removed fibers to accumulate in the groove, thereby further reducing the risk of material cracking.

Having a depression with a positive cutting edge angle, as defined above, allows the head to be configured to cut through the fibers and then push the fibers downward rather than upward, which typically occurs with a negative cutting edge angle. Thus, the improved cutting function of the screw due to the positive cutting edge angle contributes to a reduction in the amount of fiber when the screw head meets the part when engaging and assembling the screw with the work part, which increases the chances of obtaining an improved end result while maintaining the finish or surface of the wood material.

The positive cutting edge angle also tends to deflect the fibers of the material downward so that the fibers are pressed against the part and then consolidate between the part and the bottom of the screw head. Thus, it becomes possible to prevent the accumulation and penetration of water under the screw head, which appears from the outside, for example, during rain.

Having a head having a substantially frusto-conical bottom helps to hide the screw in the wood material. For example, a screw can be inserted into the material to a depth of 4-7 mm as defined between the top of the screw and the deck deck surface.

The area of the cutting recess is able to accommodate the fibers generated by the sinking of the screw. It should be noted that the region of the cutting recess can typically be further defined by an internal volume defined by the surfaces of the region of the cutting recess and the nominal surface of the frusto-conical lower portion in line with the peripheral surface of the frusto-conical lower portion.

Other advantages arise from the implementation of one or more of the features listed in the dependent claims.

Typically, the positive cutting edge angle α is 0 ° <α <90 °. In particular, the positive cutting edge angle α is 2 ° to 45 °. More specifically, the positive cutting edge angle is 3 ° -25 °. More specifically, the positive cutting edge angle is 5 ° -15 °.

In some illustrative embodiments, the region of the cutting recess is located on the peripheral surface of the frusto-conical lower portion.

Typically, the cutting edge forms an intersection between the peripheral surface of the frusto-conical bottom and the rear region of this region of the cutting recess.

The region of the cutting recess is typically defined as a closed recess located on the peripheral surface of the frusto-conical bottom. That is, the extent of the surface of the cutting recess on the peripheral surface of the frusto-conical lower part is defined by a closed contour including the cutting edge. A closed loop can be created in several different ways.

For example, the axial extent of the cutting recess region is defined by opposing axial end points. In other words, the region of the cutting recess is defined by a first axial end point and a second axial end point. Accordingly, the region of the cutting recess is different from the groove or channel extending completely from the top surface of the head to the screw shank.

In some illustrative embodiments, the top side of the head does not have a cutting recess region.

Typically, although not necessarily, the top of the head defines a peripheral circular, continuous outer edge.

In some embodiments, the top of the head includes a recess for receiving a power tool for engaging with the power tool. For example, a powered tool is a six-arm type (torx). However, other types of tools can be used to insert the screw into engagement with the material.

In some embodiments, the frusto-conical bottom includes a plurality of cutting recess regions. In addition, each of the plurality of cutting recess regions has a corresponding rear region as viewed in the rotational direction. Further, each of the trailing regions comprises a corresponding cutting edge having a corresponding first axial end point and a second cutting end edge defining a corresponding imaginary line. This imaginary line defines the corresponding positive angle of the cutting edge with respect to the corresponding plane, which extends radially from the axis of rotation to the corresponding first end point and second end point and in the axial direction.

Typically, a plurality of cutting recess regions are distributed in an amount of 2 B 16 around the circumference of the frusto-conical bottom. However, the number of the distributed cutting recess regions may be more than 16, for example, 2 B 20, or even more than 20 cutting recess regions.

In one illustrative embodiment, a plurality of cutting recess regions are uniformly distributed around the circumference of the frusto-tapered lower portion.

In one illustrative embodiment, the length of the cutting edge is a function of the thread pitch in the threaded portion. Additionally or alternatively, the length of the cutting edge is a function of the thread run in the threaded portion. In one example, this function is such that the total length of all cutting edges, i.e. the sum of the lengths of all cutting edges, is chosen such that the entire part of the workpiece exposed to the peripheral surface of the head meets the cutting edge. For example, a very short pitch will result in more screw revolutions during the cutting phase, and such a screw will require fewer or shorter cutting edges than a large pitch screw that makes fewer revolutions during the cutting phase before the screw head is fully embedded in part material. For screws with two-start threads or congruent spirals, the cutting edge must be adapted to the thread run in the same way as described above. The thread angle also adapts to both the diameter and the pitch of the thread.

Typically, although not necessarily, the area of the cutting recess is further defined by the front area. For example, the front region is curved and gives the cut region a substantially inverted D shape. The presence of an inverted D cut region further promotes efficient downward movement of the material fibers so that the fibers are pressed against the work piece and consolidated between the work piece. and the bottom of the screw head. The inverted D-shape of the cutting recess area further gives the largest possible volume of such a cutting recess area to create space for as many fibers as possible. Therefore, the curved shape of the front region, in combination with the above-described rear region, further improves the ability to transport the fibers of the material down into the work piece. The final shape and maximum depth of the anterior region are determined by modeling, where the clamping force between the head and the material determines the maximum size of the anterior region. Depending on the size of the screw, the front area may have a slightly different shape. However, regardless of the size of the screw, the anterior region remains curved, creating an essentially inverted D-shaped cutting recess region.

A screw according to any of the illustrative embodiments mentioned above typically has a self-tapping screw configuration.

Essentially, a self-tapping screw is a screw that can cut its own hole as it is screwed into the deck material, wood and / or composite material. The self-tapping ability can, in essence, be provided by a sharp end that merges into a gimbal (in which a groove is not required). In some embodiments, the screw may be self-drilling, as is well known in the art.

It should be noted that the region of the cutting recess typically defines an internal volume. The interior volume of the recess is typically, although not necessarily, defined by the surfaces of the cutting recess regions and the nominal surface of the frusto-conical bottom.

In some illustrative embodiments, the cutting edge is a straight cutting edge extending between the first axial end point and the second axial end point. In other illustrative embodiments, the cutting edge is a curved cutting edge extending between the first axial end point and the second axial end point.

The term "thread" typically refers to a ridge or groove that is wound around the shank of a screw. In addition, the thread can be defined by the profile of the thread, i. E. the thread and / or thread area is determined by the thread profile. The term "thread profile" refers to the cross-sectional shape, angle and pitch of the thread (s). Different exemplary embodiments of the screw can use different profiles of the thread (threads) of the screw. The thread shape for a given thread and / or thread area is typically selected depending on the type of installation and the type of application of the screw. In some examples, the thread is a helical ridge with some pitch. The pitch of the spiral is the width of one complete turn of the spiral, measured parallel to the axis of the spiral. Additionally, the pitch of the helix can be constant in the axial direction of the component. The screw may have a plurality of threads, for example, two, three or four congruent spirals with the same axis, differing from each other by a linear displacement along the axis. Typically, two, three, or four congruent spirals can have the same pitch.

Other features and advantages of illustrative embodiments of the present invention will be apparent from the following detailed description and the appended claims. Those of skill in the art will understand that different features of the illustrative embodiments may be combined to create variations that differ from those described, but do not depart from the scope of the present invention.

Brief Description of Drawings

The following is a more detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings, where:

FIG. 1a is a side view of a screw of an illustrative embodiment of the present invention comprising a countersunk head having an upper portion for engaging a driving tool for rotating the screw and a substantially frusto-tapered lower portion.

FIG. 1b is another side view of an illustrative embodiment of the present invention comprising a countersunk head having an upper portion for engaging a driving tool for rotating the screw and a substantially frusto-tapered lower portion.

Figs-1e illustrate additional details of the countersunk head of the ball according to the embodiment shown in Figs. 1a and 1b.

FIG. 2 is a schematic section through the screw of FIG. 1a along the line B-B.

FIG. 3 is a schematic section through the screw of FIG. 1a along line AA.

FIG. 4 is a side view of another illustrative embodiment of portions of a screw of the present invention.

FIG. 5 is a cross-section of the screw of FIG. 4 corresponding to the section along the line A-A shown in FIG. 3.

FIG. 6a is a schematic side view of a screw according to the present invention.

FIG. 6b is a schematic section through the screw of FIG. 6a along the C-C line.

Detailed description of illustrative options

The following is a more complete description of various aspects of the present invention with reference to the accompanying drawings, which show illustrative embodiments of the invention. These illustrative variations, however, can be implemented in many different forms and should not be construed as limiting the scope of the present invention as they are provided for completeness and completeness of the description. The same reference numbers throughout the description indicate the same elements.

For purposes of description, the terms "top", "under", "top", "bottom", "bottom", "up", "down", "longitudinal", "inward", "outward", "radial", "axial "," peripheral = th "and their derivatives refer to an illustrative embodiment of the invention in the orientation shown in FIG. 1a and 1b.

However, it should be understood that these illustrative embodiments can take on various alternative orientations, unless expressly indicated otherwise. It should also be understood that the examples illustrated in the attached charts and described in the following description are merely illustrative. Therefore, dimensions and other physical characteristics related to the described illustrative options are not to be construed as limiting, unless expressly indicated otherwise in the appended claims.

The description refers mainly to screws for engaging with wood or similar composite material. One type of composite material is a composite deck deck material. For simplicity, the exemplary screw embodiments described with reference to FIGS. 1a-5 are wood screws. However, this does not mean that illustrative embodiments of the invention are limited to screwing a screw into the wood material. Conversely, such a screw may be a so-called deck screw or the like. Thus, although not shown, exemplary screw designs can be screwed into a composite material such as a deck deck material. Further, it should be noted that the general construction of the above screw is known, and a wide variety of types of such screws and their various optional components are not described.

In the drawings, and in particular FIG. 1a, a screw 10 of the present invention is shown. In this illustrative embodiment, the screw is for wood to engage with wood material. In addition, in this illustrative embodiment, the screw has a self-tapping screw configuration. FIG. 1a is a side view of an exemplary screw where the screw has partially penetrated the wood material, and FIG. 1b shows a screw in a position where the screw has penetrated further into the wood material of the work piece 25 to engage with it. Typically the work piece is the deck flooring material. The deck material can be either wood material or any suitable composite material. Other details of the screw of FIG. 1a and 1b are described with reference to FIGS. 1c-1e and FIG. 2-5.

The screw 10 in these examples is suitable for engaging wood or similar composite material. One type of composite material is a composite deck deck material. In the drawings, the wood material is designated 25. The screw 10 engages with the wood material 25 by rotating the screw in the W direction about the screw rotation axis AC. As shown in the drawings, the screw is extended in the axial direction A. In addition, the screw extends in the radial direction R. The screw also has a circumference in the direction of the circumference of the screw.

The screw comprises a countersunk head 12 having an upper side 19 for receiving a power tool for rotating the screw and a substantially frusto-conical lower part 18. The upper side is thus adapted to interact with a power tool. In this illustrative embodiment, the top side 19 of the head 12 includes a power tool receiving recess 43 adapted to cooperate with a power tool, such as a six-pointed screwdriver. One example of a recess 43 for receiving a power tool is shown in FIG. 2, which is a cross-sectional view taken along the line BB in FIG. 1a. However, it should be noted that the screw can be rotated by the driven tool in other possible ways to insert the screw into the work piece 25. In addition, the six-pointed screwdriver is only one of many possible examples of driven tools.

Returning to FIG. 1a, the screw axis AC of rotation in this example corresponds substantially to the center line of the screw along axis A.

In addition, as shown in the drawings, for example in FIG. 1a and 1b, the substantially frusto-conical lower part of the head faces the shaft.

In other words, the peripheral surface 18a of the frustoconical lower portion 18 forms a transition between the upper side 19 of the head 12 and the shaft 14. Accordingly, the transition from the upper side 19 of the head to the shaft 12 is formed by the inclined peripheral surface of the frustoconical portion 18. The slope of this oblique peripheral surface can be defined by the angle β. Angle β is shown for the illustrative embodiment illustrated in FIG. 4. However, this feature can also be implemented in the exemplary embodiment shown in FIG. 1a-1e. For example, β is in the range 160 ° -40 °. In this example, as shown in FIG. 1a-1e, angle β is approx. 80 °. The angle β can vary depending on the type of screw and the type of material of the part.

In addition, as shown in FIG. 1a, the screw comprises a shank 14 extending from the head to the sharp end 11. The shank has a threaded portion 15. The threaded portion 15 extends at least partially over the shank. The length of the threaded portion on the rod is determined based on the type of screw, the application and installation of the screw, and the material of the part. Typically, but not necessarily, shank 14 further comprises a non-threaded portion located between the head and the threaded portion, as shown in FIG. 1a.

Regarding the threaded portion 15, it should be noted that the threaded portion typically extends from the start point of the threads at the end 11 to the head 12 of the screw. The threaded portion contains threads 15a. The thread 15a runs in a spiral along the screw 10, allowing the screw 10 to be screwed into the part 25, rotating it clockwise, when viewed from the side of the head 12 towards the end 11, around the axis of rotation AC. The thread has a thread lead. In addition, the thread has a thread pitch. The possible options for the dimensions of the threaded portion and the threads are well known and, therefore, their description is omitted. It should be noted, however, that the dimensions of the threaded portion and the threads are typically selected based on the type of screw and the type of part. In addition, it should be understood that the threaded portion does not necessarily have to extend continuously from the end of the screw to its head, and the thread may be completely or partially absent at one or more positions from the start point of the thread at the end to the end of the thread. Additionally, the threaded portion can extend completely from the head to the end of the screw.

In addition, the frusto-conical bottom portion 18 comprises a cutting recess region 20 as viewed in the direction of rotation W. The region 20 of the cutting recess can accommodate fibers resulting from the sinking of the screw. The cutting recess region 20 is configured to receive fibers or compressed materials of the part when the head 12 of the screw 10 penetrates the part 25. In this example, the cutting recess region 20 is defined by an internal volume 21. In other words, the internal volume is defined by the surfaces of the cutting recess region 20 and the nominal surface 18b a frusto-conical lower portion in line with the peripheral surface 18a of this frusto-conical lower portion 18, as will be further described with reference to FIGS. 2.

As indicated above, the cutting recess region 20 is located on the peripheral surface 18a of the frusto-conical lower portion 18.

As shown in FIG. 1a, the back region 22 comprises a cutting edge 23. The cutting edge 23 has a first axial end point 41 and a second axial end point 42. In this example, the cutting edge is a substantially straight edge passing between the first axial end point and the second axial end point. The cutting edge 23 and the axial end points are further shown in FIG. 1c-1t. FIG. 1c is a side view of the screw 10 corresponding to the side view of the screw 10 in FIG. 1a, and in FIG. 1d shows another side view of a screw 10 in which the screw 10 is rotated approximately 90 ° in the direction of rotation. In other words, the view of the screw 10 in FIG. 1d is orthogonal to the view in FIG. 1c. FIG. 1t additionally shows the projection of the cutting edge 23 onto the tangent plane TP, which coincides with the first axial end point 41. This tangent plane and FIG. 1e will be further described below.

As shown in FIG. 1c, a cutting edge having a first axial end point 41 and a second axial end point 42 can also be defined by an imaginary line AI. That is, the imaginary line AI extends between the first axial end point 41 and the second axial end point 42 of the cutting edge 23. This imaginary line AI is further shown in FIG. 1e, which shows a slightly curved cutting edge 23. In this figure, the cutting edge 23 is curved although it passes between the first axial end point 41 and the second axial end point 42, while the imaginary line AI corresponds to a straight line defining the distance between the first axial end point 41 and the second axial end point 42 of the cutting edge. The curved cutting edge can be convex or concave with respect to the imaginary line AI, or an unevenly curved cutting edge. However, it should be understood that the cutting edge 23, in some illustrative embodiments, as shown in FIG. 1a-1d, corresponds to the imaginary line AI. In other words, the cutting edge 23 in this illustrative embodiment corresponds to a straight edge extending between the first and second axial end points 41 and 42.

Returning to FIG. 1c, the first axial end point 41a and the second axial end point 42 define an imaginary line AI. That is, this imaginary line AI extends between the first and second axial end points 41 and 42. The imaginary line AI defines a positive cutting edge angle α with respect to plane AP. The positive cutting edge angle α refers to the angle measured in the counterclockwise direction from AP to AI. As can be understood from FIG. 1c and 1d, the plane AP extends in the radial direction R from the axis of rotation AC to the first axial end point 41. In addition, the plane AP extends in the axial direction A.

Returning to FIG. 1c-1e, a positive cutting edge angle α is achieved by projecting the cutting edge 23 onto the tangent plane TP coinciding with the first axial end point 41 (see, for example, FIG. 1d). The tangent plane TP is also perpendicular to the plane FP and extends in the axial direction A and the tangent direction T, as shown in FIG. 1c in combination with FIG. 1d. Thus, the projection of the imaginary line AI onto the tangent plane TP determines the positive angle α of the cutting edge relative to the plane AP.

Accordingly, in some examples, when the cutting edge 23 is straight between the axial end points 41, 42, the cutting edge 23 corresponds to an imaginary line AI that defines a positive cutting edge angle α with respect to plane AP, as described above. However, in other examples, when the cutting edge is curved or slightly curved, the imaginary line AP defines a positive angle α of the cutting edge relative to the plane AP, as indicated above and shown in FIG. 1e. It should be understood that the cutting edge 23 is angled radially inward due to the shape of the frusto-conical lower portion 18. In other words, as shown, for example, in FIG. 1d, the cutting edge 23 is inclined inwardly from the upper first axial end point 41 towards the center line (axis of rotation) to the lower axial end point 42 when viewed in the radial direction R. The cutting edge 23 is designed to cut fibers when the frusto-tapered bottom portion 18 comes into contact with the surface of the work piece 25. In this example, the cutting edge 23 forms an intersection between the peripheral surface 18a of the frusto-conical lower portion 18 and the rear region 22 of the cutting recess region 20.

A cutting edge 23 with a positive angle α, as defined in this illustrative embodiment, allows the fibers of the work piece to be cut and directed downward so that these fibers are pressed against the work piece and further consolidated between the piece and the lowermost part of the screw head.

Accordingly, it will be understood from the description and drawings of various illustrative embodiments that one example of the advantages of the present invention is improved fiber cutting, pushing the fibers downward as opposed to upward (typically referred to as opposite directions along axial direction A in FIG. 1a). which is typical for recesses with a negative cutting edge angle. Thus, the improved cutting of the screw helps to reduce the amount of fiber when the screw head meets the part while engaging and driving the screw into the part, which increases the chances of obtaining an improved end result while maintaining the finish or surface of the wood material.

Typically, the positive cutting edge angle α may be greater than 0 ° but less than 90 °. That is, the positive cutting edge angle α may be in the range of 0 ° <α <90 °. This creates a cutting edge configured for optimal cutting as described above. However, it should be understood that the value of the positive angle α of the cutting edge may be different, depending on the type of screw and / or type of part. Therefore, it is acceptable that the value of the positive angle α of the cutting edge is different for different screws and applications. In particular, the positive cutting edge angle α can be in the range of 2 ° to 45 °. More specifically, the positive cutting edge angle α may be in the range of 3 ° to 25 °, even more specifically, the positive cutting edge angle α may be in the range of 5 ° to 15 °. In some examples, the positive cutting edge angle α may be in the range of 4 ° -10 °. In this example, as shown in FIG. 1a, the positive cutting edge angle α is approximately 6 °.

In addition, as indicated above, the cutting edge 23 may be a straight edge if the imaginary line AI defines a positive cutting angle with respect to plane AP. However, in some illustrative embodiments, the cutting edge 23 may be curved if the imaginary line AI between the axial end points defines a positive cutting angle with respect to plane AP.

Returning again to FIG. 1a, the cutting recess region 20 is a so-called closed recess located on the peripheral surface 18a of the frusto-conical lower portion 18. That is, the extent of the surface of the cutting recess region 20 on the peripheral surface of the frusto-conical portion is defined by a closed contour including the cutting edge 23. Others in other words, the term "closed contour" can refer to a continuous peripheral edge. This type of contour can be created in several ways. In this illustrative embodiment and in other possible embodiments, for example, as shown in FIG. 4 and 5, the cutting recess region 23 is further defined by the leading region 28. The leading region is curved here, creating an inverted D-shaped cutting region. As shown in the drawings, for example, FIG. 1a and 3, an inverted D-shape is defined by a curved leading edge 30. It is also clear from this figure that the leading edge 30 together with the cutting edge 23 define the contour of the cutting recess region 20. In other words, the cutting recess region 20 is typically formed by a leading region having a leading edge and a trailing region having a trailing edge (corresponding to the cutting edge).

In addition, in this example, the axial extension 31 of the cutting recess region 20 is defined by opposite axial end points 41 and 42. As shown in FIG. 1a (and also in FIG. 4), the axial extension 31 of the cutting recess region 20 is defined by an upper first axial end point 41 and a lower second axial end point 42. The upper part 19 of the head 12 does not have any cutting recess regions 20. Thus, the cutting recess region 20 defines a closed void when viewed from the top 19 of the screw 10. The cutting recess region 20 that does not reach the top of the head minimizes the risk of fibers being transported in the wrong direction, i.e. upward (above top when viewed axially). Fibers pushed upwards often result in chipping or cracking on the surface of the part (deck deck). In addition, fibers that are pushed upwards can often have a negative effect on the engagement of the screw with the part.

It should be understood that the axial extent of the inverted D-shaped cutting recess region 20 is here defined by an upper first axial end point 41 and a lower second axial end point 42.

In other words, as shown in the drawings, for example, FIG. 3, the top side of the head defines a peripheral circular continuous outer edge 12a. Other details of the cutting recess region 20 will be described below with reference to FIGS. 3 and 4.

FIG. 1b shows an example where the screw 10 engages a part, for example a deck deck made of wood material 25. For example, a screw can penetrate the material to a depth of approx. 7 mm as defined between the top side 19 of the screw and the deck deck surface. In this context, having a head with a substantially truncated-tapered bottom helps to hide the screw in the wood material. When installing the deck deck, it is sometimes desirable to hide the screws in the material.

As shown in FIG. 2 and 3, the screw of the exemplary embodiments shown in FIGS. 1a-1t is further illustrated by two cross-sections along lines B-B and A-A. As shown in these figures, the screw 10 includes a plurality of cutting recess regions 20. That is, the frusto-conical lower portion 18 includes a plurality of cutting recess regions 20. Each of the plurality of cutting recess regions 20 includes a corresponding rear region 22 as viewed from the direction of rotation W. Further, each rear region 22 comprises a corresponding cutting edge 23 having a first axial end point 41 and a second axial end point 42 defining an imaginary line AI. The imaginary line AI defines the corresponding positive cutting edge angle α with respect to the corresponding plane AP. The corresponding plane AP extends in the radial direction R and in the axial direction A. In other words, the corresponding plane AP extends in the radial direction R at least from the axis of rotation AC of the corresponding first the axial end point 41 and in the axial direction A (not shown in FIGS. 2 and 3). It should be understood that each of the respective recesses may have the features, examples, and effects mentioned with respect to the example of the screw and recesses described with reference to FIGS. 1a-1e.

Additionally, each of the plurality of cutting recess regions 20 is here defined by a corresponding internal volume 21. In this example, the plurality of cutting recess regions 20 in 6 regions are uniformly distributed around the circumference of the frusto-conical lower portion 18.

Returning to FIG. 2 and 3, it should be noted that each of the cutting recess regions 20 extends substantially in the axial direction A. Further, each of the cutting recess regions 20 is inclined inwardly toward the center line (axis of rotation) as viewed in the radial direction R. Similarly, each of the cutting edges 23 extends substantially in the axial direction A. Further, each of the cutting edges 23 is inclined inwardly toward the center line (axis of rotation) as viewed in the radial direction R.

As noted above, in the exemplary embodiment shown in FIG. 1a, 1b, 2 and 3, each of the cutting recess regions 20 has a rear region 22 defined by a rear surface 22A and a front region 28 defined by a front surface 28A. Additionally, each of the cutting recess regions 20 has a lower region 27 defined by a lower surface 27A. Typically, the lower region connects the anterior region and the posterior region. In other words, the bottom surface connects the front surface to the back surface. These features may also apply to the example described with reference to FIGS. five.

In addition, in this illustrative embodiment, each of the cutting recess regions 20 has a substantially triangular cross-section when viewed in the circumferential direction and in the radial direction. The substantially triangular section is here defined by the front surface, the bottom surface and the rear surface. The flank surface 22A (trailing region 22) substantially forms a right angle with the peripheral surface 18a of the frusto-conical bottom portion 18. The cutting edge is configured to generate a cutting effect when it is in contact with the part when the screw is rotated, as described above. However, it should be noted that the angle between the flank surface 22A and the peripheral surface 18a may be different depending on the desired cutting effect. In some examples, the angle between the flank surface 22A and the peripheral surface 18a may be sharp, or even slightly obtuse, if the cutting edge produces the desired cutting effect.

Additionally, as shown in FIG. 2, the depth of the cutting recess region 20 increases from the front region 82 to the rear region 22. That is, the depth of the cutting recess region 20 increases from the front surface 28A to the rear surface 22A.

In addition, it should be understood that each of the cutting recess regions 20 is typically configured to receive fibers of the part material.

It should be noted that the maximum depth of the cutting recess region (s) 20 can be defined as the depth in the radial direction R and further defined as the distance from the nominal peripheral surface 18b to the bottom surface 27A of the cutting recess region 20. As shown in FIG. 2, the section along line B-B of the head 12 may include a power tool receiving recess 43 adapted to cooperate with a power tool, such as a six-pointed screwdriver. The maximum depth of the cutting recess region 20 is substantially aligned radially with the maximum depth of the power tool receiving recess 43. This will be described below.

Additionally, the region (s) 20 of the cutting recess of the screw can typically be considered a slot rather than regions protruding from the nominal peripheral surface of the frusto-tapered bottom of the screw head.

Typically, although not required, the front surface 28A may have a slightly curved contour, as shown in FIG. 3. However, such a construction of the front surface 28A is optional. Therefore, in other illustrative screw embodiments, the front surface 28A may taper towards the bottom surface 27A (bottom region 27).

It should be noted that the dimensions of the cutting recess regions 20 are typically selected depending on the size and installation of the screw in accordance with the illustrative embodiments. Therefore, the dimensions of the cutting recess region 20 in the axial direction, in the radial direction and in the circumferential direction are typically selected in consideration of the size of the screw and the type of material of the intended part. However, the dimensions of the cutting recess regions 20 are typically the same for all the cutting recess regions 20 on the screw 10. In addition, the distribution of the cutting recess regions 20 over the peripheral surface 18a is typically uniform, i.e., the distance between adjacent cutting recess regions 20 on the peripheral surface 18a are the same. However, in some illustrative variations (not shown), other variations in the arrangement of the cutting recess regions 20 may be used.

In one illustrative embodiment, as shown in FIG. 4 and 5, there is shown a screw substantially corresponding to the embodiment shown in FIG. 1a-1e and FIG. 2 and 3, except that the frusto-conical lower head portion 18 contains only one cutting recess region 20. Thus, the screw comprises a countersunk head 12 having an upper side 19 for receiving a power tool for rotating the screw and a substantially frusto-conical lower part 18. The upper side is adapted to cooperate with the power tool. In addition, the top side 19 of the head 12 may include a power tool recess 43 configured to interact with a power tool such as a six-pointed screwdriver. Further, the screw contains a rod extending from the head to the sharp end. The rod has a threaded portion 15. The threaded portion 15 extends at least partially over the rod. In addition, the frusto-conical bottom portion 18 comprises one cutting recess region 20 having a rear region 22 when viewed in the direction of rotation W. As indicated above with respect to the examples described with reference to FIGS. 1-3, the cutting recess region 20 is located on the peripheral surface 18a of the frusto-conical lower portion 18. As shown in FIG. 4 and 5, the rear region 22 comprises a cutting edge 23 having a first axial end point 41 and a second axial end point 42 that define an imaginary line AI. The imaginary line AI defines a positive angle α relative to the plane AP, as described above. The screw shown in FIG. 4 and 5 may perform similar functions and have the same features as the illustrative embodiment shown in FIG. 1a-1c and in FIG. 2 and 3. The illustrative embodiment of FIG. 4 and 5 can be mounted in the same way as the illustrative embodiment of FIG. 1a-1c and FIG. 2 and 3.

It should be understood that the number of cutting recess regions 20 may vary depending on the type of material of the part, and the examples described above with reference to the drawings are just two of many possible examples. Thus, the number B of the cutting recess regions 20 may be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16.

FIG. 6a is a schematic side view of a screw 10 of the present invention. Screw 10 in FIG. 6a is similar to the screw 10 shown in FIG. 1a.

FIG. 6b is a schematic sectional view taken along the line C-C of the screw 10 of FIG. 6a. As shown in the drawing, the screw 10 has six cutting recess regions 20. The difference between the screw 10 of FIG. 6a and screw 10 of FIG. 1a is that the areas of the cutting recess in the screw 10 of FIG. 6a are optimized to receive the maximum amount of material.

A sectional view taken along line C-C shows that the deepest point 45 of the cutting recess region 20 and the innermost point 26 of the power tool receiving recess 43 are substantially aligned. In this particular embodiment, the power tool receiving recess 43 is designed to receive a six-beam tool. As mentioned above, the maximum depth of the cutting recess region (s) 20 can be defined as the maximum depth in the radial direction R, and is further defined as the distance from the nominal peripheral surface 18b to the bottom surface 27A of the cutting recess region 20.

The maximum depth of the region 20 of the cutting recess is substantially aligned or substantially coincident in the radial direction with the maximum depth of the recess 43 for receiving the power tool closest to the corresponding region of the cutting recess. The orientation of the cutting recess region (s) 20 with respect to the direction of rotation is thus determined by the position (s) of the cutting recess region (s) 20 with respect to the power tool receiving recess 43. By aligning the deepest points 45 of the cutting recess region 20 and the innermost point 46 of the power tool receiving recess 43, the maximum amount of part material can be cut and transported to the interior volume 21 of the cutting recess region 20 while maintaining the required strength of the head 12 material. Another determining factor in the size of the cutting recess region (s) 20 is that the smallest cross-sectional surface area along the CC line of the head 12 is greater than the surface area of the shank 14. This makes the shank 14 structurally the weakest part of the screw 10, reducing the risk cutting off the head 12 of the screw 10 from the shank 14. This relationship is also true for a screw with fewer cutting recess regions 20 than shown in FIG. 6a, for example the screw of FIG. 4 and 5.

In all exemplary screw embodiments, the axial cutting edge length is a function of the thread pitch of the threaded portion 15. Additionally or alternatively, the axial cutting edge length is a function of the thread travel of the threaded portion 15. Thus, it becomes possible to create a screw with a cutting edge, the effective length (i.e. , the axial length of the region 20 of the cutting recess) of which corresponds to the entire outer periphery of the fibers cut off during rotation and penetration of the screw into the part 25.

The present invention also encompasses all possible combinations of desirable aspects, variations, alternatives, and illustrative embodiments of the invention. In addition, the invention is not limited to the above-described aspects or examples, but is naturally applicable to other aspects and illustrative variations within the scope of the appended claims. Reference numbers mentioned in the claims should not be construed as limiting the subject matter protected by the claims and their sole function is to facilitate understanding of the claims.

Claims (16)

1. A screw (10) for engaging with wood or a similar composite material, such as a deck deck composite (25), by rotating the screw in the direction (W) of rotation about the screw rotation axis (AC) while the screw is pulled out in the axial direction ( A) and contains: a countersunk head (12) having an upper side (19) for receiving a power tool for rotating a screw, containing a recess (43) for receiving a power tool, and a substantially frusto-conical lower part (18); a rod (14) extending from the head to the sharp end (11) and having a threaded section (15), moreover, the frusto-conical lower part (18) comprises a cutting recess region (20) having a rear region (22) when viewed in the direction (W) of rotation; and said rear region (22) comprises a cutting edge (23) having a first axial end point (41) and a second axial end point (42) defining an imaginary line (AI) corresponding to a straight line defining an extension between the first axial end point (41) and the second axial end point (42) of the cutting edge (23), while the imaginary line (AI) defines a positive angle (α) of the cutting edge with respect to a plane (AP) extending in the radial direction (R) at least from the axis (AC ) rotation to the first axial end point (41) and in the axial direction (A), characterized in that the extension of the maximum depth of the region (20) of the cutting recess in the radial direction is substantially aligned with the innermost point of the recess (43) for receiving the driven tool, and the cutting recess region (20) is additionally defined by the front region (28), while the front region (28) is shaped (30) essentially like an inverted letter D. 2. A screw according to claim 1, wherein the positive angle (α) of the cutting edge is obtained by projecting the cutting edge (23) onto a tangent plane (TP) coinciding with the first axial end point (41), wherein the tangent plane (TP), in addition, it is perpendicular to the plane (AP) and runs in the axial direction (A) and tangential direction (T), whereby the projection of the imaginary line (AI) onto the tangent plane (TP) defines the positive angle (α) of the cutting edge relative to the plane (AP ). 3. A screw according to any one of the preceding claims, in which the positive angle (α) of the cutting edge is in the range 0 ° <α <90 °, in particular in the range 2 ° -45 °, in particular in the range 3 ° -25 ° and more specifically in the range of 5 ° -15 °. 4. A screw according to any one of the preceding claims, wherein the cutting recess region (20) is located on the peripheral surface (18a) of the frusto-conical bottom. 5. A screw according to claim 4, wherein the cutting edge (23) forms an intersection between the peripheral surface (18a) of the frusto-conical lower part and said rear region of the cutting recess region (20). 6. A screw according to any one of the preceding claims, in which the axial extension (31) of the cutting recess region (20) is defined by opposite axial end points (41, 42). 7. A screw according to any one of the preceding claims, in which the upper side of the head does not have a cutting recess region (20). 8. A screw according to any one of the preceding claims, wherein the top side of the head defines a peripheral circular, continuous outer edge (12a). 9. A screw according to any one of the preceding claims, wherein the frusto-conical lower portion comprises a plurality of cutting recess regions (20), and each of the plurality of cutting recess regions (20) has a corresponding rear region (22) when viewed from the direction (W) rotation, each of the trailing regions contains a corresponding cutting edge (23) having a corresponding first axial end point (41) and a second axial end point (42) defining an imaginary line (AI), and an imaginary line (AI) defines a corresponding positive the angle (α) of the cutting edge relative to the corresponding plane (AP), which extends in the radial direction (R) from the axis of rotation (AC) to the corresponding first axial end point (41), and in the axial direction (A). 10. A screw according to claim 9, wherein the plurality of cutting recess regions (20) are distributed in an amount of 2 ≤ B ≤ 16 around the circumference of the frusto-conical lower part. 11. A screw according to any one of the preceding claims, in which the axial length of the cutting edge is a function of the thread pitch of the threaded portion (15) and / or in which the axial length of the cutting edge is a function of the threading of the threaded portion (15) such that the total length of all cutting edges is such that the entire part of the part exposed to the peripheral surface of the head meets the cutting edge. 12. A screw according to any one of the preceding claims, wherein the screw is a self-tapping screw.

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