A method of fastening hinged doors and windows in wall openings, a combination of a hinge and screw for such method, and a screw for such combination

Abstract

A method of fastening hinged doors and windows in wall openings, a combination of a hinge and screw for such method, and a screw for such combination. A combination of a hinge (1) and a screw (14) is used for mounting a door or window in a wall opening. A first leaf (1A) of the hinge (1) is fastened to the frame (23) of the door or window and comprises only identical conical screw holes (3A), distributed at different positions over the first leaf (1A). In addition to smaller screws that are used to fix the hinge (1) to the frame (23), a larger screw (14) is provided having a head (15) with a conical underside (32) matching the screw holes (3A). The screw (15) has a length L long enough to extend from the hinge (1) through the frame (23) and into the wall (20) and a thread (16) around and along a stem (19) of the screw (14) with a pitch P of 4-6 mm, and each screw hole (3A) has a thickness T of the material at a rim of the screw hole (3A) of no more than 50% of the pitch P.

Description

[0001] A method of fastening hinged doors and windows in wall openings, a combination of a hinge and screw for such method, and a screw for such combination

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a method of fastening hinged doors and windows in wall openings and a combination of a hinge and screw for such method, as well as a screw in relation to such combination.

[0004] BACKGROUND OF THE INVENTION

[0005] When mounting doors and windows in wall openings, the frames of the doors and windows are fastened in the wall that surrounds the corresponding frame. Often, pilot holes are drilled through the frame and into the wall, and screws are screwed through the frame and into the pilot hole for fixation of the frame in the wall. For doors and hinged windows, it is also common practice to drive a screw through one of the screw holes of the hinge and through the frame and into pilot holes in the wall. Additional screws of smaller dimensions are used to fix one of the hinge leaves of the hinge to the frame and the other of the hinge leaves to the pivotal door panel or window sash. The screws for fixing the leaves to the door or window are relatively small, as the wood material of the door or window should not crack by oversized screws. In contrast thereto, the screw for fixing the hinge in the pilot hole in the wall has to be larger and solid for not breaking when screwed into solid concrete walls and also for providing sufficient stability of the screw in the wall. This implies that the hinge has two types of screw holes, one set of smaller holes for the smaller woodscrews and, typically, a single larger screw hole for the larger and longer screw that is driven through the frame into the pilot hole in the wall. However, the production of hinges with different sized screw holes, although necessary, is disadvantageous in that the extra screw hole requires an additional production step and also requires larger hinge leaves and, thus, excessive material as compared to a hinge that would only have one type of screw holes. Additionally, once, the hinge is mounted in the frame, the location of the larger screw hole is fixed in relation to the frame and, thus, also in relation to the wall opening. For brick walls, this implies a risk that the location, unfortunately, is at level with a mortar joint instead of a brick, which results in inferior stability of the mounting.

[0006] It would be desirable to avoid such disadvantages of the prior art and provide an improved system.

[0007] DESCRIPTION / SUMMARY OF THE INVENTION

[0008] It is therefore an objective of the invention to provide an improvement in the art. In particular, it is an objective to provide an improved method of fastening hinged doors and windows in wall openings and providing a combination of a hinge and screw for such method, as well as a screw that has advantages in relation to such combination. This objective and further advantages are achieved with a method, a combination of a hinge and screw, as well as a screw as described below and in the claims.

[0009] In short a combination of a hinge and a screw is used for mounting a door or window in a wall opening. A first leaf of the hinge is fastened to the frame of the door or window and comprises only identical conical screw holes, distributed at different positions over the first leaf. In addition to smaller screws that are used to fix the hinge to the frame, a larger screw is provided having a head with a conical underside matching the screw holes. The screw has a length L long enough to extend from the hinge through the frame and into the wall, for example in the range of 40-300 mm. It has a thread around and along a stem of the screw with a pitch P in the range of 4-6 mm, and each screw hole has a thickness T of the material at a rim of the screw hole of no more than 50% of the pitch P.

[0010] Details are given in the following.

[0011] A method is presented herein of mounting a window or door in a wall-opening of a wall. The window is a combination of a frame and a hinged sash and the door is a combination of a frame and a hinged panel. Additionally, a hinge is provided for hinging the sash or panel inside the frame. The hinge comprises a first leaf to be fastened to the frame and a second leaf to be fastened to the sash or panel. The first leaf has a plurality of identical conical screw holes for screws, the identical conical screw holes being distributed at different positions over the first leaf. Additionally, a plurality of screws of a first type of screw are provided as well as a further screw of a second type of screw. The second type of screw is longer than the first type of screw, typically, in the range of 40-300 mm, optionally, 80-200 mm in order to fit through the frame and into the wall, and it is also typically thicker.

[0012] The smaller screws of the first type of screw are only used to fix the hinge to the frame and the door panel or sash, respectively. Accordingly, they do only extend into the frame but not through the frame. They have a head with a conical underside matching the identical conical screw holes in order for the head being flush with the leaf when the further screws extend through the identical conical screw holes and into the frame, typically wooden frame. These smaller screws of the first type of screws are screwed through a subgroup of the identical conical screw holes into the frame for fastening the first leaf to the frame. However, at least one remaining screw hole of the identical conical screw holes is left open into which the longer screw of the second type of screw is inserted. For proper fit, this longer screw has a head with a conical underside matching the identical conical screw holes in order for the head being flush with the leaf when the longer screw extends through the remaining of the identical conical screw holes in the leaf. Once, the frame is positioned in the wall-opening, the longer screw of the second type of screw is driven through the remaining of the identical conical screw holes and through the frame and into the wall for fixing the hinge and the frame relatively to the wall inside the wall-opening.

[0013] Typically, a pilot hole is pre-drilled through the frame and into the wall, the diameter of the pilot hole being at least of the diameter of the stem of the screw, for example 5 mm, but less than the diameter of the thread, for example the thread diameter being in the range of 6-8 mm, optionally 7-8 mm, for example nominally 7.5 mm, in order for the thread to fasten inside the pre-drilled pilot hole in the wall.

[0014] In contrast to the prior art, the hinge only needs a single type of conical screw holes and not additional conical screw holes of larger diameters, which is a great advantage for the producers of hinges. Additionally, there is a great advantage for the craftsmen who are mounting the frame in a wall opening of a brick wall. Such a wall has bricks with mortar joints between the bricks, and there is always a risk of the longer screws extending into the mortar joint, which is unfortunate with respect to mechanical stability. To improve the situation, the method comprises, in a further embodiment, checking for mortar joint positions between the bricks relatively to positions of the identical conical screw holes in the first leaf and selecting a remaining of the identical conical openings in the hinge such that it is at level with one of the bricks and not at the level with the mortar joint and, then, driving the screw of the second type of screw through this remaining of the identical conical openings and through the frame into the brick or bricks.

[0015] For such method, the following combination of a hinge and a screw is useful. The hinge has a first leaf for fastening to a frame of a door or window and a second leaf for fastening to a pivotal door panel or window sash as well as a pivot axle between the first leaf and the second leaf, wherein the first leaf comprises only identical conical screw holes for screws, the conical screw holes being distributed at different positions over the first leaf. The screw of the second type of screw has a head with a conical underside matching the identical conical screw holes in order for the screw head being flush with the first leaf when the screw extends through one of the identical conical screw holes in the leaf and through the frame and into the wall.

[0016] Advantageously, in order to fit through the frame and into the wall, the screw of the second type of screw has a length L of 40-300 mm and a thread around and along a stem.

[0017] In useful embodiments, in order to fit snugly through the screw hole, the screw has a pitch P of 4-6 mm, which is substantially larger than the thickness T of the material at a rim of the screw hole. For example, the thickness T is no more than 75%, or even no more than 50%, of the pitch P. This implies that the longer screw can be screwed through the screw hole, even if the nominal outer diameter D-thread is only slightly smaller than the nominal screw hole diameter or equal to the nominal screw hole diameter. For example, the identical conical screw holes have a nominal screw hole diameter which is no more than 5% larger than D-thread. The term nominal is used herein for the average screw hole diameter or thread diameter, well knowing that there are minor production tolerances. For example, if the nominal screw hole diameter is identical to the nominal thread diameter, there will be some hinges that have screw holes that have diameters smaller than the diameters of the thread of at least some of the screws. Due to the coarse pitch of the thread, however, this is not a problem because the material at the rim of the screw hole fits into the thread between adjacent thread turns so that not the thread is determining as to whether the screw fits through the screw hole but rather the diameter of the stem. This is a pronounced advantage of the screw in relation to the hinge.

[0018] For example, the stem has a nominal diameter D-stem and the thread has a nominal outer diameter D-thread, and the identical conical screw holes have a nominal screw hole diameter which is between D-stem and D-thread. For example, it suffices if the nominal screw hole diameter is only 1-2 mm larger than D-stem but smaller than D- thread. A good relationship between the nominal screw hole diameter and the nominal thread diameter have been found if the nominal screw hole diameter D-hole is at least the stem diameter D-stem and half the difference between the thread diameter D-thread and D-stem. In mathematical terms: D-hole > (D-stem + D-thread) / 2

[0019] In order for the screw of the second type of screw to easily enter the wall material, it has been found advantageous if the thread has a thread angle A-thread of 25-35 degrees when measured in a plane containing a central axis of the screw. This thread angle is about half of the thread angle of 60 degrees in prior art screws that are typically used for fastening door frames and window frames in wall openings.

[0020] Summarizing for specific embodiments, the following specifications for a screw are useful

[0021] - a stem having a diameter D-stem of 4-6 mm,

[0022] - a head at one end of the stem and a pointed tip at an opposite end,

[0023] - the head having a largely conical underside,

[0024] - a tool receiver in a central recess in the upper side,

[0025] - a length L of the screw of 40-300 mm,

[0026] - a thread around the stem having an outer diameter 1.5-3 mm larger than the stem diameter and a pitch P of 4-6 mm. The upper side of the head is substantially flat, which means flat or only slightly convex. The term slightly convex means rounded by a radius of at least 8 mm, for example in the range of 9-11 mm. Typically, with the common diameters of the head, the convex head results in the screw at the centre being only 0.1 -0.3 mm longer than at the rim of the head.

[0027] Additionally, it is useful if the thread has a thread angle A-thread of 25-35 degrees when measured in a plane containing a central axis of the screw.

[0028] One or more of the following parameters can be added for further advantages.

[0029] - a drilling point at the opposite end, for example extending 9-13 mm towards the head from the opposite end,

[0030] - milling ribs on the conical underside of the head, for example each milling rib having a flat planar front side in a milling direction and a milling edge for milling wood material during countersinking of the head in wood, optionally, the milling edges of the milling ribs following a conus having an angular span of 80-100 degrees, and optionally, each milling rib being inclined for inward pressing of milled wood material towards the stem during countersinking,

[0031] - the conical underside of the head a is formed as a conus that has an angular span that is 10-20 degrees less than the conus that is followed by the milling edges.

[0032] - a cylindrical portion between the conical underside of the head and the thread, the conical portion having a length of 1-8 mm when measured along the central axis of the screw.

[0033] SHORT DESCRIPTION OF THE DRAWINGS

[0034] The invention will be explained in more detail with reference to the drawing, where FIG. 1 illustrates a prior art type of hinge for a door;

[0035] FIG. 2 illustrates a prior art type of screw;

[0036] FIG. 3 illustrates an embodiment of an alternative hinge for a door or window;

[0037] FIG. 4 illustrates an embodiment of a screw of the invention;

[0038] FIG. 5 illustrates an embodiment of a screw of the invention in comparison with two prior art screws; FIG. 6 is a principle sketch for a mount of a frame in a brick wall with a hinge, using a prior art screw;

[0039] FIG. 7 is a principle sketch for a mount of a frame in a brick wall with a hinge, using a screw of the invention;

[0040] FIG. 8 is a drawing of an alternative embodiment with the screw at the level of a mortarjoint;

[0041] FIG. 9 is a drawing of the alternative embodiment of FIG. 8 with the screw placed in a different screw hole at the level of a brick;

[0042] FIG. 10 is a close up view of the thread of a screw according to the prior art inside a brick;

[0043] FIG. 11 is a close up view of a thread of an embodiment of a screw inside a brick.

[0044] FIG. 12 is a side view of an embodiment of a screw;

[0045] FIG. 13 is a cross sectional side view of the screw of FIG. 12;

[0046] FIG. 14 illustrates an embodiment of a drill point;

[0047] FIG. 15 illustrates an embodiment of a screw head;

[0048] FIG. 16 is a cross sectional view of the embodiment of FIG. 15;

[0049] FIG. 17 illustrates an upper side of a screw head of an embodiment;

[0050] FIG. 18 illustrates an underside of a screw head of an embodiment in a cross section of the screw of FIG. 15;

[0051] FIG. 19 illustrates the drill point of FIG. 12 in greater detail.

[0052] DETAILED DESCRIPTION / PREFERRED EMBODIMENT

[0053] FIG. 1 Illustrates a hinge 1 according to the prior art. The hinge 1 comprises a first leaf 1 A and a second leaf IB which are connected by a pivotal axle 2. In use, the first leaf 1 A is fastened to a frame of a window or a door, and the second leaf is fastened to a pivotal window sash or door panel. The first leaf 1 A as well as the second leaf IB are provided with multiple identical conical screw holes 3A for corresponding screws of a first type, typically woodscrews, which are screwed into the frame of the sash or panel. Additionally, the first leaf 1 A has a single different conical screw hole 3B for another, prior art screw of another type of screw, which is longer. This single different conical screw hole 3B for this longer prior art screw has a larger diameter than the screw holes 3 A for the first type of screw and is, typically, arranged centrally between two of the screw holes 3 A for the first type of screw. Whereas, relatively short woodscrews are used as the first type of screw, the prior art screw 4 of the other type of screw, for example of the type as illustrated in FIG. 2, is much longer in order to extend through the frame and into the wall in which the frame is fastened. Because this prior art screw 4 has to be stable enough for being screwed into hard materials such as concrete with its thread 6 and pointed tip 7, it has a larger diameter and a correspondingly larger head 5 than the screws of the first type of screw. The first type of screw (not shown) is thinner in order to minimise the risk for breaking of the wood, plastic, or wood / plastic composite of the frame and the sash or panel.

[0054] With reference to FIG. 1, the hinge 1 is designed with the two sizes of conical screw holes 3A, 3B according to the need for fastening the leaves 1A, IB in the wood with the first type of screw, on the one hand, and in concrete with a single longer screw, on the other hand. This explains the inherent need for different sizes of screw holes 3 A, 3B in the prior art hinges 1. However, screw holes 3 A, 3B of different sizes in hinges 1 add to complexity in production, which is unwanted, as it increases pricing and production time.

[0055] For example, FIG. 3 illustrates an alternative hinge 1 in which all screw holes 3 A have the same size, which is highly advantageous because production is simplified and faster. A further important advantage of the avoidance of the additional single larger screw hole 3B is the possibility of the hinge 1 being be made smaller and, thus, can be produced at lower cost as well as transported at lower cost due to the reduced weight. Also, in this way, smaller hinges 1 are environmentally advantageous.

[0056] However, in such case, it is necessary to solve the problem of providing a second type of screw that is stable enough for being screwed into concrete and which fits through the identical conical screw holes 3A. This problem is solved with a screw presented herein.

[0057] FIG. 4 illustrates an embodiment of a screw 14 of such second type of screw that is useful for such purpose. It has a head 15 that is smaller in diameter than the corresponding prior art screws 4 in order to fit into the one-sized conical screw holes 3A. More importantly, though, is the fact that the thread 16 of the screw 14 of the invention has a pitch much larger than the prior art screws 4 used for screwing through the frame into the wall, such as brick wall or concrete wall.

[0058] FIG. 5 illustrates the difference in the thread pitch between two typical prior art screws 4 and an embodiment of a screw 14 according to the invention. Whereas the pitch in the prior art screws is around 2.8 mm, the pitch in a screw 14 according to the invention is much coarser, advantageously in the range of 4.5 to 6 mm, the upper end of the interval being almost twice as large as the prior art pitch.

[0059] The coarser thread 16 of the screw 14 according to the invention has multiple functions in the specific use of fastening frames in wall openings. These functions and advantages will be explained in comparison with the prior art screw 4.

[0060] Due to the relatively fine thread of the prior art screw 4, the nominal outer diameter of the thread 6 has to be substantially smaller than the nominal diameter of the corresponding screw hole 3B. Otherwise, the prior art screw 4 may get stuck in the screw hole 3B, which is highly undesirable. The problem appears, especially, because there are production tolerances resulting in the diameter of the threads for some of the screws being larger than a nominal thread diameter and the conical holes of some of the hinges being smaller than a nominal hole diameter. As the specific screw hole 3B for the prior art screw 4 must be larger than the nominal thread diameter of the prior art screw 4 plus the maximum production tolerance of the screw thread 6 and the screw hole 3B, the screw hole 3B for the prior art screw is produced with a substantially larger diameter than the screw holes 3A for the first type of screw and substantially larger than the nominal thread diameter of the prior art screw 4.

[0061] The conditions are different for a screw 14 according to the invention. Although, also having a larger diameter than the first type of screw, this second type of screw fits through the same screw hole 3A as the first type of screw. This is mainly due to the coarser thread 16. For example, the pitch P of the screw 14 is in the range of 4 to 6 mm, and thus in the range of 60% - 100% larger than the pitch of 2.8 mm of the standard used prior art screws 4 that were illustrated in FIG. 2 and 3. Due to the coarser thread 16, it can pass through the smaller screw hole 3A of the hinge 1, even if the screw 14 of the invention has an outer thread diameter slightly larger than the screw hole 3 A, be it by design or due to dimensional production tolerances. This is so because the material of the conical screw hole 3 A, which is relatively thin at its rim, fits around the stem 19 freely in the space 18 between two successive thread turns of the coarse thread 16 with the large pitch. With reference to FIG. 7, a good criteria is that the thickness T of the material at the rim of the screw hole 3A is no more than 75% of the pitch of the screw 14, advantageously no more than 50% of the pitch. In other words, the screw 14 according to the invention can be screwed through the screw hole 3A of the hinge 1 without damaging the rim of the screw hole 3 A with its thread 16. This is not possible with a screw 4 according to the prior art because the pitch is too small and the thread 6 correspondingly too narrow for the rim of the screw hole 3A to fit freely in between two consecutive turns of the thread 6. Whereas, for the prior art screws 4, the outer diameter of the thread 6 plus production tolerances for the thread 6 and for the screw hole 3B are decisive for the size of the corresponding screw hole 3B, this is different for the screw 14 according to the invention, as it is rather the diameter of the stem 19 that determines the minimum size of the screw hole 3 A. in order for the rim of the screw hole 3A fitting in between consecutive turns of the thread 16 the thread 16 needs to be single-threaded, which is in contrast to screws with are double-threaded with two thread intertwined. Normally, the screw 14 only has only one thread 16, and this single thread is single-threaded and not double-threaded. Although, the screw 14, in principle, may comprise more than one thread, each of such threads would be single-threaded and, thus, in extension to each other and not intertwined. This is an important aspect in that it provides the necessary spacing 18 between subsequent turns of the single-threaded thread 16, the spacing 18 being identical to the pitch P. In comparison and contrast thereto, double threaded screws have a spacing between thread turns that is only half the pitch.

[0062] In conclusion, due to the coarser thread 16, the diameter of the screw hole 3 A can be held smaller for a screw 14 according to the invention, as compared to the necessary diameter of the screw hole 3B for prior art screws 4. Accordingly, no specific screw hole 3B needs to be made in the hinge for a screw 14 according to the invention. Single sized screw holes 3 A can be used for the woodscrews that are used to fasten the hinge 1 to the frame 23 and the longer screws 14 that extends through the frame and into the wall around the wall opening, such as a concrete wall. This implies some further advantages, as explained in the following with reference to FIG. 6, FIG. 7, FIG. 8, and FIG. 9. In these examples, the wall is a brick wall 20 with bricks 21 having mortar joints 22 between the bricks 21.

[0063] First of all, it is pointed out that the hinge 1, once mounted to the frame 23, is fixed at a level relatively to the wall 20 in the wall opening in which the frame 23 is going to be mounted. Notice, additionally, that the prior art screw 4 has only a single possible position in the first leaf 1A of the hinge 1 due to the single screw hole 3B of larger diameter. Now, with reference to the example of the prior art hinge of FIG. 1, it may accidentally happen that the larger screw hole 3B for the prior art screw 4 of the second type of screw is at the level of such mortar joint 22, as illustrated in FIG. 6. If the prior art screw 4 is fastened in such mortar joint 22, the stability is less than if the prior art screw 4 would have been fastened in a brick 21. However, at this stage of mounting the frame 23, it is too late for changing the level of the hinge 1, as that would leave visually open the already established marks in the frame 23 made by the woodscrews 24 of the first type of screw. Also, the second leaf IB may already have been mounted on the door panel or window sash, so that the first leaf 1 A cannot be moved to another level on the frame 23. Accordingly, the craftsman mounting the frame 23 in the brick wall 20, typically, accepts this undesired lower stability of the frame 23 if a screw 4 according to prior art hits such mortar joint 22.

[0064] For a screw 14 of the invention, the conditions are entirely different. Due to the fact that it fits into any of the available identical screw holes 3A, the craftsman may select one of the screw holes 3 A that fits the level of one of the bricks 21, as illustrated in FIG. 7. As the first leaf 1 A has multiple identical screw holes 3A, the craftsman may select the most advantageous screw hole for the longer second type of screw and fasten the screw 4 in the brick 21, as illustrated in FIG. 7.

[0065] As illustrated in FIG. 8 and FIG. 9, after having mounted the screw 14 accidentally in a mortar joint 22, the craftsman may, after a further pre-drilling through the frame 23 and into the wall 22, place the screw 14 in another screw hole 3A, which is aligned with a brick 21 and which in FIG. 9 is illustrated as the uppermost of the three screw holes 3 A. Accordingly, the screw 14 of the invention yields great flexibility with regard to mounting the frame 23 in the wall.

[0066] Even in the event that the craftsman would drill two pilot holes through the frame 23, a first one into a mortar joint 22 by mistake and one subsequently into a brick 21 on purpose, the total number of screws 14, 24 into or through the frame 23 at the end of the mounting procedure would remain the same and create good stability for the frame 23.

[0067] Especially for brick walls 20, it has surprisingly turned out that the coarse thread 16 of the screw 14 according to the invention results in the screw resisting a larger pull-out force than the prior art screws 4. This is reasoned in that the coarser thread 16 accommodates more dust material from the brick 21 and damages less of the brick 21 when the screw 14 is screwed into the pilot hole of the pre-drilled brick 21.

[0068] The prior art screws 4 are relatively easy to screw even into a hard material due to the fine thread 6, requiring less torque during screwing with a machine, which is user friendly due to less load on the hand and wrist when using screwing machines. In comparison, a comparable coarse thread, usually, requires higher force. However, this can be overcome by using screwing machines that have a slight hammering function during screwing. It can also be overcome by a thread angle, A-thread, that is smaller, for example half of the thread angle of the prior art screws 4. For example, the thread angle A-thread of a screw 14 of the invention, as illustrated in FIG. 11, is in the range of 25- 35 degrees as compared to, typically, 60 degrees in screws 4 according to the prior art, as illustrated in FIG. 10. Thus, by using smaller thread angles, the screw 14 of the invention is as easy to screw into a wall as the prior art screws 4 but yield a higher pullout resistance and thus, bring about an additional surprising effect.

[0069] With reference to the prior art screw 4 in FIG. 10 in comparison to the screw 14 according to the invention in FIG. 11, the smaller pitch and the larger thread angle A-thread of the prior art screw 4 result in damage of the bricks 21, especially, in results in cracks 37 the interspacing 8 between the thread 16 turns. In contrast thereto, the larger pitch and smaller thread angle, A-thread, of the screw 4 according to the invention, as illustrated in FIG. 11, cause less damage and, thus, higher holding force by the screw 4. The screw 14 of the invention will be explained in further detail with respect to useful shapes and dimensions.

[0070] FIG. 12 is a side view drawing and FIG. 13 a cross-sectional drawing of an embodiment of the screw 14 according to the invention, such as the one also illustrated in FIG. 4. The screw 14 has a head 15 at one end and a pointed tip 17 at an opposite end, connected by a stem 19 around which a single helical thread 16 is provided. As illustrated, the pointed tip 17 of the screw 14 is on the central axis 26 of the screw 14 and part of a drill point 27. In this particular embodiment, as illustrated in greater detail in FIG. 14, the drill point 27 has been provided with a length L-drill in the range of 2-3 times the pitch P.

[0071] With reference to FIG. 14 and the enhanced image in FIG. 19, the drill point 27 of this embodiment is a leftover portion 28 after removal of some of the screw material. This is peculiar because prior art screws 4 have a tip that is cold-formed under pressure, like the rest of the screw. For the embodiment that is illustrated in FIG. 14 and 19, however, the screw 4 is cold-formed first, after which the drill point 27 is made by removal of half of the tip 27, namely half of the screw on one side of a plane through the screw axis 26 from the tip 17 of the screw 14 and until a line 30 that is at an angle to the screw axis 26. In the exemplified embodiment of FIG. 14 and FIG. 19, the cut-out 29 at the tip 17 follows a skew line 30 with a corresponding skew edge 31.

[0072] The embodiment of FIG. 19 illustrates that the screw tip 17 has a conical portion 40, and the thread 16 is also provided on this conical portion 40.

[0073] The screw head 15 is illustrated in greater detail on FIG. 15 in a side view and in FIG. 16 in a cross sectional side view. The head 15 has a flat or substantially flat upper side 35. In this context, the term substantially flat means flat or only slightly convex. The term slightly convex means rounded by a radius R-head of at least 8 mm, for example in the range of 9-11 mm, such as 10 mm. Typically, with the common diameters of the head 15, such convex upper side 35 of the head results in the screw along the axis 26 being only 0.1-0.3 mm longer than at the rim of the head 15, the numbers being illustrated in FIG. 16. The underside 32 of the head 15, optionally, has a flat portion 38 at the rim of the screw head 15, for example with a width W-rim of 0.1-0.5 mm.

[0074] As illustrated in FIG. 16 and FIG. 17, a tool receiver 36 is provided in the upper side 35 of the screw head 15, extending from the upper surface 35 to a depth D-tool into the head 15, for example a hexalobular (Torx®) tool receiver. Typically, the depth D-tool is in the range of 2-4 mm. Useful as a tool received is a Torx® size 25. In this connection, it is pointed out that the first type of screw, which is used for holding the hinge on the frame, normally, has a Torx® size 20, and all longer prior art screws, such as illustrated in FIG. 2, used for fastening the frame 23 in the wall opening, have Torx® size 30. This implies that the screw 14 according to the invention can be easily identified in frames 23 when only the head 15 of the screw 14 is available for controlling the type and position of the screw 14 that extends through the frame 23 into the wall 22.

[0075] For this particular embodiment, the tapering underside 32 is provided with a plurality of milling-ribs 33, although, the underside 32 can also be provided smoothly tapering, for example conical, without ribs.

[0076] As an example, the tapering underside 32 is provided with six milling ribs 33, so that the angle between neighbouring ribs is 60 degrees. These milling ribs 33 are useful in case that the screw 14 is used for screwing directly through a pilot hole in the wooden frame 23, but is also advantageous when screwed through the hinge 1 because the milling ribs 33 secure the screw 14 safely against becoming lose in the conical screw hole 3 A.

[0077] For example, the underside 32 of the screw head 15, as illustrated in FIG 18, is provided according to principles disclosed in W02020 / 125890. In such case, each milling-rib 33 has a front-side that is oriented towards a milling direction and delimited by a millingedge for milling material during countersinking of the screw-head. The front-side of the milling rib 33 is inclined relatively to the taper-direction, the inclination of the frontside and the milling-edge are oriented for inward-pressing of milled material towards the stem 19 during countersinking of the screw-head 15 in the material. Optionally, smoothly bending cavities 34 are provided between the milling-ribs 33. The cavities 34 extend into the tapering underside 32 of the screw-head 15. For example, each of the cavities 34 is smoothly concavely curved from one milling-rib 33 to a neighbouring milling -rib.

[0078] Between the tapering underside 32 of the head 15 and the stem 19, there is provided a cylindrical transition piece 39, for example having a length in the range of 1-8 mm, optionally 2-5 mm.

[0079] Useful exemplary dimensions are as follows:

[0080] Total length L of the screw: 40-300 mm

[0081] Diameter D-head of the screw head: 8-12 mm

[0082] Conical angle A-tip at the tip 17 of the screw: 45-55 degrees

[0083] Diameter D-stem of the stem: 4-6 mm

[0084] Diameter D-thread of the thread: 1.5-3 mm larger than D-stem

[0085] Pitch P: 4-6 mm

[0086] Angle A-thread of the windings of the thread 25-35 degrees:

[0087] Length L-drill of drill tip: 8-15 mm

[0088] Width W-rib of the ribs 33: 0.4-0.6 mm

[0089] Number of ribs: 5-8

[0090] Angle A-head of tapering region at underside of head 60-90 degrees:

[0091] Angle A-rib of ribs on tapering underside of head: 10-20 degrees more than A-head Total length L-head of the screw head in the direction of the central axis: 1-8 mm

[0092] As it appears from the above, the screw 14 according to the invention has multiple advantages. The coarse thread 16 allows the screw 14 to be driven to screw holes 3 A that are smaller than the outer diameter D-thread of the thread 16, which brings about advantages of a solidly stable screw 14 for narrow screw holes 3 A in hinges 1 or brackets. Additionally, the coarse thread 16 has turned out to yield a higher pull out force when mounted in brick walls 20. The thin thread 16 with a thread angle A-thread substantially smaller than in prior art screws eases driving the screw 14 into hard materials, such as concrete and minimized damage to bricks 21 when the screw 14 is driven into brick walls 22. In case that the screw 14 is provided with a drill tip 27 and / or milling ribs 33 at the underside of the head 15, the versatility of the screw 14 increases, as it becomes suitable also for use directly in frames 23 made of wood, plastic, or composites. The latter makes the screw 14 universal for use with hinges 1 as well as for fastening frames

[0093] 23 in wall openings even without screwing through the hinge 1.

Claims

CLAIMS1. Method of mounting a window or door in a wall -opening of a wall (20), the method comprising- providing a window as a combination of a frame (23) and a hinged sash or providing a door as a combination of a frame (23) and a hinged panel,- providing a hinge (1) for hinging the sash or panel inside the frame (23), the hinge (1) comprising a first leaf (1 A) to be fastened to the frame (23) and a second leaf (IB) to be fastened to the sash or panel, wherein the first leaf (1 A) has a plurality of identical conical screw holes (3 A) for screws, the screw holes (3 A) being distributed at different positions over the first leaf (1 A),- providing a plurality of screws (24) of a first type of screw, wherein the first type of screw has a screw head (15) with a conical underside (32) matching the identical conical screw holes (3 A) in order for the screw heads (15) being flush with the first leaf (1A) when the screws (24) of a first type of screw extend through the identical conical screw holes (3 A) and into the frame (23),- screwing the screws (24) of the first type of screw through a subgroup of the identical conical screw holes (3 A) into the frame (23) for fastening the first leaf (1 A) to the frame (23) but leaving at least one remaining conical screw hole (3 A) of the identical conical screw holes (3 A) open,- providing a screw (14) of a second type of screw, wherein the second type of screw is longer than the first type of screw, characterized in that the method comprises providing the screw (14) of the second type of screw with a head (15) having a conical underside (32) matching the identical conical screw holes (3 A) in order for the head (15) being flush with the first leaf (1 A) when the screw (14) of the second type of screw extends through the remaining of the identical conical screw holes (3 A) in the first leaf (1 A), and that the method comprises positioning the frame (23) in the wall-opening, and screwing the screw (14) of the second type of screw through the remaining of the identical conical screw holes (3 A) and through the frame (23) and into the wall (20) for fixing the first leaf (1 A) and the frame (23) relatively to the wall (20) inside the wall-opening.

2. Method according to claim 1, wherein the method comprises predrilling a pilot hole through the frame (23) and into the wall (20).

3. Method according to any preceding claim, wherein the wall is a brick wall (20) with bricks (21) having mortar joints (22) between the bricks (20), wherein the method comprises checking for mortar joint positions between the bricks (20) relatively to positions of the identical conical screw holes (3 A) in the first leaf (1 A), and selecting the remaining of the identical conical openings (3A) in the first leaf (1A) such that it is at level with one of the bricks (21) and not at the level with the mortar joint (22) and driving the screw (14) of the second type of screw through this remaining of the identical conical openings (3 A) and through the frame (23) into the brick (21).

4. The method according to any preceding claim, wherein the screw (14) of the second type of screw has a length L of 40-300 mm and a single-threaded thread (16) around and along a stem (19) of the screw with a pitch P of 4-6 mm, wherein the method comprises providing the identical conical screw holes (3 A) of the first leaf (1 A) with a thickness T of the material at a rim of each of the identical conical screw holes, wherein the thickness T no more than 50% of the pitch P.

5. The method according to claim 4, wherein the method comprises providing the thread (16) with a thread angle A-thread of 25-35 degrees when measured in a plane containing a central axis (26) of the screw (14).

6. A combination of a hinge (1) and plurality of screws (24) of a first type as well as a screw (14) of a second type and for a method according to any preceding claim, wherein the hinge (1) has a first leaf (1 A) for fastening to a frame (23) of a door or window and a second leaf (IB) for fastening to a pivotal door panel or window sash as well as a pivot axle between the first leaf (1A) and the second leaf (IB), wherein the first leaf (1A) comprises only identical conical screw holes (3A) for screws, the conical screw holes (3 A) being distributed at different positions over the first leaf (1 A), wherein the screw (14) of the second type has a head with a conical underside (32) matching the identical conical screw holes (3 A) in order for its screw head (15) being flush with the first leaf (1A) when the screw (14) of the second type extends through one of theidentical conical screw holes (3 A) in the first leaf (1 A) and through the frame (23) and into the wall.

7. A combination according to claim 6, wherein the screw (14) of the second type of screw has a length L of 40-300 mm and a thread (16) around and along a stem (19) of the screw with a pitch P of 4-6 mm, wherein the identical conical screw holes (3 A) have a thickness T of the material at a rim of the screw hole, wherein the thickness T no more than 50% of the pitch P.

8. A combination according to claim 7, wherein the thread (16) of the second type of screw has a nominal outer diameter D-thread, and wherein the identical conical screw holes (3 A) have a nominal screw hole diameter which is no more than 5% larger than D-thread.

9. A combination according to claim 7, wherein the stem (19) of the second type of screw has a nominal diameter D-stem and the thread (16) has a nominal outer diameter D-thread, and wherein the identical conical screw holes (3 A) have a nominal screw hole diameter which is between D-stem and D-thread.

10. A combination according to anyone of the claims 7-9, wherein the thread (16) of the second type of screw has a thread angle A-thread of 25-35 degrees when measured in a plane containing a central axis (26) of the screw.

11. A screw for a method according to anyone of the claims 1-5 and for a combination according to anyone of the claims 6-10, the screw comprising:- a stem (19) having a diameter D-stem of 4-6 mm,- a screw head at one end of the stem (19) and a pointed tip (17) at an opposite end, the screw head (15) having a conical underside (32),- a tool receiver (36) in a central recess in the upper side (35),- a length L of the screw (14) of 40-300 mm,- a single-threaded thread (16) around the stem (19) having an outer diameter 1.5-3 mm larger than the stem diameter and a pitch P of 4-6 mm, wherein the thread (16) has a thread angle A-thread of 25-35 degrees when measured in a plane containing a central axis (26) of the screw.

12. A screw according to claim 11, further comprising:- a drill point (27) at the opposite end (17) extending 9-13 mm towards the screw head (15) from the opposite end (17),- milling ribs (33) on the conical underside (32) of the screw head (15), each milling rib (33) having a flat planar front side in a milling direction and a milling edge for milling wood material during countersinking of the screw head (15) in wood, each milling rib (33) being inclined for inward pressing of milled wood material towards the stem (19) during countersinking; wherein the conical underside (32) of the screw head (15) a is formed as a conus that has an angular span A-head that is 10-20 degrees less than an angular span A-rib of the conus that is followed by the edges of the ribs (33);- a cylindrical transition piece (39) between the conical underside (32) of the screw head (15) and the thread (16), the conical portion (32) having a length of 1-8 mm when measured along the central axis (26) of the screw (14).

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