Screw set and method for fastening such screw set to at least one component

Abstract

The invention relates to a screw set (1) comprising a screw (2) with a screw head (6) and a screw shank (7) extending in a longitudinal direction (L), which is provided with an external thread (12) in the region of its free end, a tensioning means (3) designed to be slid on the screw shank (7) in the longitudinal direction (L), a hexagon nut (5) which has an internal thread (16) matching the external thread (12) of the screw (2), and a washer (4) having a central opening (15) and dimensions chosen in such a way that the washer (4) projects in a radial direction beyond the outer circumference of the hexagon nut (5) when the washer (4) and the nut (5) are arranged on the screw shank (7), wherein the contour of the central opening (15) of the washer (14) and the cross-section of a distal screw shank section (10) forming the free end of the screw shank (7) are selected such that the washer (4) can be slid in the longitudinal direction (L) onto the distal screw shank section (10) in a form-fitting manner.

Description

[0001] Description

[0002] Screw set and method for fastening such screw set to at least one component

[0003] The invention relates to a screw set comprising a screw with a screw head and a screw shank extending in a longitudinal direction, which is provided with an external thread in the region of its free end, tensioning means designed to be slid on the screw shank in the longitudinal direction, a hexagon nut which has an internal thread matching the external thread of the screw, and a washer having a central opening which is dimensioned in such a way that it projects in the radial direction beyond the outer circumference of the hexagon nut when the washer and the nut are arranged on the screw shank. Moreover, the present invention relates to a method for fastening such a screw set to at least one component which is provided with at least one screw passage opening.

[0004] Screw sets of the above-mentioned type comprising a screw, a hexagon nut, a washer and tensioning means, e.g. in the form of disc springs, are well known in prior art. Moreover, different types of screw locking methods are known, such as methods using a cotter pin, a slotted nut and a screw having a hole for receiving the cotter pin. Alternatively, so called self-locking nuts can be used or safety wires, double nuts, spring washers, hot melt adhesive, etc. Against thi s background it is an obj ect of the present invention to provide an alternative screw set and an alternative method of the above-mentioned type .

[0005] In order to solve this obj ect the present invention provides a screw set comprising a screw with a s crew head and a screw shank extending in a longitudinal direction , which is provided with an external thread in the region of its free end , a tensioning means des igned to be s lid on the screw shank in the longitudinal direction , a hexagon nut which ha s an internal thread matching the external thread of the s crew, and a washer having a central opening and dimensions chosen in such a way that the wa sher proj ects in a radial direction beyond the outer circumference of the hexagon nut when the washer and the nut are arranged on the screw shank , characterized in that the contour of the central opening of the washer and the cros s-section of a di stal screw shank section forming the free end of the s crew shank are selected such that the washer can be slid in the longitudinal direction onto the di stal screw shank section in a form-fitting manner . In use , at lea st the wa sher and the hexagon nut are arranged on the lateral surface of the distal screw shank portion of the screw .

[0006] In thi s pos ition the washer cannot be rotated relative to the screw . After having screwed the hexagon nut onto the di stal screw shank section with a predetermined torque , a loosening of the nut can be prevented by deforming regions of the washer , which proj ect beyond the outer circumference of the hexagon nut in a radial direction , such that the deformed regions abut against external perimeter surfaces of the hexagon nut .

[0007] According to one aspect of the pre sent invention the di stal screw shank section ha s a cylindrical lateral surface portion provided with the external thread and a planar lateral surface portion extending in the longitudinal direction. The central opening of the washer has a corresponding contour.

[0008] When viewing the cross section of the distal screw shank section, the generally cylindrical lateral surface preferably extends over an angle of at least 210°. On the one hand, this leads to a safe lock against a rotation movement of the washer relative the distal screw shank section. On the other hand, sufficient surface area is provided for the outer thread.

[0009] The screw and / or the hexagon nut and / or the washer and / or the tensioning means is / are advantageously made of steel. In principle, all steels known from conventional screw fittings are suitable.

[0010] According to one aspect of the present invention, the tensioning means comprise several disc springs made of spring steel, in particular four disc springs.

[0011] Moreover, the present invention provides a method for fastening a screw set according to one of the preceding claims to at least one component which is provided with at least one screw passage opening, comprising the steps of a) inserting the screw shank into the at least one screw passage opening of the at least one component such that the distal screw shank section protrudes from the component , b) sliding the tensioning means onto the distal screw shank section, c) sliding the washer onto the distal screw shank section, d) screwing the hexagon nut onto the distal screw shank section until a predetermined torque is reached and e) deforming regions of the washer projecting beyond the outer circumference of the hexagon nut in a radial direction such that the deformed regions abut against external perimeter surfaces of the hexagon nut.

[0012] Preferably, the tensioning means comprises four disc springs, wherein the disc springs are arranged next to each other in two groups, wherein the tapered ends of the disc springs of each group are pointing towards each other .

[0013] Advantageously, two opposite regions of the washer are deformed in step e) .

[0014] According to one aspect of the present invention, the deformation in step e) is achieved manually using pliers.

[0015] Further features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawing. In the drawing

[0016] Figure 1 is a perspective view of a screw of a screw set according to an embodiment of the present invention,

[0017] Figure 2 is a cross-sectional view of the screw shown in figure 1,

[0018] Figure 3 is a cross sectional view of a disc spring forming a part of a tensioning means of said screw set,

[0019] Figure 4 is a top view of a washer of said screw set,

[0020] Figure 5 is a side view of the washer shown in Figure 4,

[0021] Figure 6 is a top view of a hexagon nut of said screw set , Figure 7 is a side view of the hexagon nut shown in figure 6,

[0022] Figure 8 is a perspective exploded view of said screw set when fastened to a component, wherein the washer is in an non-deformed state, and

[0023] Figure 9 is a perspective non-exploded view of the arrangement shown in figure 8, wherein the washer is in a deformed state.

[0024] Figures 1 to 9 show a screw set 1 according to an embodiment of the present invention or components of said screw set 1. The screw set 1 comprises a screw 2, a tensioning means 3, a washer 4 and a hexagon nut 5.

[0025] The screw 2, as it is shown in figures 1 and 2, has a screw head 6 and a screw shank 7 extending in a longitudinal direction L. The screw head 6 is provided with a rotary drive 8 presently formed as a slit for receiving a slotted screwdriver. However, it should be noted that other types of rotary drives are possible, such as a hexagon screw head or the like. The screw shank 7 presently comprises a proximal screw shank section 9 and a distal screw shank section 10. The proximal screw shank section 9 has a cylindrical form. The distal screw shank section 10 has a cylindrical lateral surface portion 11 provided with an external thread 12 and a planar lateral surface portion 13 extending in the longitudinal direction L. When viewing the cross section of the distal screw shank section 10, the generally cylindrical lateral surface preferably extends over an angle a of at least 210° .

[0026] The tensioning means 3 is designed to be slid on the screw shank 7 in the longitudinal direction L. In the present embodiment the tensioning means 3 comprises four common disc springs 14 as shown in figure 3.

[0027] The washer 4, which is shown in figures 4 and 5, comprises a central opening 15 having a contour corresponding to the cross-section of the distal screw shank section 10, such that the washer 4 can be slid in the longitudinal direction L onto the distal screw shank section 10 in a form-fitting manner. The diameter d of the washer 4 is chosen in such a way that the washer 4 projects in the radial direction beyond the outer circumference of the hexagon nut 5 when the washer 4 and the nut 5 are arranged on the screw shank 7 as shown in figure 8.

[0028] The hexagon nut 5 shown in figure 6 and 7 has an internal thread 16 matching the external thread 12 of the screw 2.

[0029] The screw 2, the hexagon nut 5 and the washer 4 are made of steel, the disc springs 14 are made of spring steel. The steels chosen for the screw 2, the hexagon nut 5 and the washer 4 may be different steels.

[0030] Figures 8 and 9 show the screw set 1 fastened to a component 17. The component 17 presently comprises to projections 18 and 19 having aligned screw passage openings 20. However, it should be noted that this is only an example. Of course, the screw set 1 can also be used to connect two or more components with each other. In order to achieve the arrangement shown in figures 8 and 9 the screw shank 7 is inserted into the screw passage openings 20 of the component 17 such that the distal screw shank section 10 protrudes outwardly from the component 17. Thereafter, the disc springs 14 are slid onto the distal screw shank section 10 in such a manner that they are arranged next to each other in two groups, wherein the tapered ends of the disc springs 14 of each group are pointing towards each other . In a further step , the wa sher 4 is slid onto the distal s crew shank section 10 . Thereafter , the hexagon nut 5 is screwed onto the distal screw shank section 10 until a predetermined torque is reached . In a f inal step , regions of the washer 4 proj ecting beyond the outer circumference of the hexagon nut 5 in a radial direction are deformed manually us ing pliers such that the deformed regions 21 abut against external perimeter surface s of the hexagon nut 5 . Presently, two opposite regions of the wa sher 4 are deformed . The si ze of the washer 4 or its diameter d should be chosen in such a manner that the external perimeter sections of the nut 5 can be firmly encompas sed by the deformed regions 21 . Preferably, the maximal width bmaxof the deformed regions 21 approximately corresponds to the height h of the external perimeter sections of the nut 5 .

[0031] Although the present invention has been des cribed in detail with reference to the preferred embodiment , it is to be understood that the pre sent invention is not limited by the disclosed examples , and that numerous additional modifications and variations could be made thereto by a person s killed in the art without departing from the scope of the invention .

[0032] Regardles s of the grammatical gender of a particular term, persons with male , female , or other gender identity are included .

Claims

Patent claims1. Screw set (1) comprising- a screw (2) with a screw head (6) and a screw shank (7) extending in a longitudinal direction (L) , which is provided with an external thread (12) in the region of its free end,- a tensioning means (3) designed to be slid on the screw shank (7) in the longitudinal direction (L) ,- a hexagon nut (5) which has an internal thread (16) matching the external thread (12) of the screw (2) , and- a washer (4) having a central opening (15) and dimensions chosen in such a way that the washer (4) projects in a radial direction beyond the outer circumference of the hexagon nut (5) when the washer (4) and the nut (5) are arranged on the screw shank (7) , characterized in that the contour of the central opening (15) of the washer (14) and the cross-section of a distal screw shank section (10) forming the free end of the screw shank (7) are selected such that the washer (4) can be slid in the longitudinal direction (L) onto the distal screw shank section (10) in a form-fitting manner.

2. Screw set (1) according to claim 1, characterized in that the distal screw shank section (10) has a cylindrical lateral surface portion (11) provided with the external thread (12) and a planar lateral surface portion (13) extending in the longitudinal direction (L) , and in that the central opening (15) of the washer (4) has a corresponding contour.

3. Screw stet (1) according to claim 2, characterized in that, when viewing the cross section of the distal screw shank section (19) , the generally cylindrical lateral surface extends over an angle (a) of at least 210°.

4. Screw set (1) according to one of the foregoing claims, characterized in that the screw (2) and / or the hexagon nut (5) and / or the washer (4) and / or the tensioning means (3) is / are made of steel.

5. Screw set (1) according to one of the foregoing claims, characterized in that the tensioning means (3) comprises several disc springs (14) made of spring steel, in particular four disc springs (14) .

6. Method for fastening a screw set (1) according to one of the preceding claims to at least one component (17) which is provided with at least one screw passage opening (20) , comprising the steps of a) inserting the screw shank (7) into the at least one screw passage opening (20) of the at least one component (17) such that the distal screw shank section (10) protrudes from the component (17) , b) sliding the tensioning means (3) onto the distal screw shank section (10) , c) sliding the washer (4) onto the distal screw shank section ( 10 ) , d) screwing the hexagon nut (5) onto the distal screw shank section (10) until a predetermined torque is reached and e) deforming regions of the washer (4) projecting beyond the outer circumference of the hexagon nut (5) in a radial direction such that the deformed regions (21) abut against external perimeter surfaces of the hexagon nut (5) .

7. Method according to claim 6, characterized in that the tensioning means (3) comprises four disc springs (14) , and in that the disc springs (14) are arranged next to each other in two groups, wherein the tapered ends of thedisc springs (14) of each group are pointing towards each other .

8. Method according to claim 6 or 7, characterized in that two opposite regions of the washer (4) are deformed in step e) .

9. Method according to one of the claims 6 to 8, characterized in that the deformation in step e) is achieved manually using pliers.

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