TWO-PART NUT WITH HIGH PRESSING FORCE

Abstract

The invention relates to a nut having an internal thread and two nut parts (1, 2), each of the nut parts (1, 2) having a section of the internal thread which is radially slidable onto an external thread (25), the nut parts (1, 2) having cooperating connecting elements which permit relative displacement of the nut parts (1, 2) in a direction extending radially with respect to the axis of the internal thread until reaching a use position in which the internal thread of the nut engages around the external thread (25) with a small clearance. The connecting elements have guide surfaces (9-20) which guide the nut parts (1, 2) of the nut in a rotational movement about an axis of rotation extending transversely to the axis of the internal thread when displaced into the use position,

wherein each nut part (1, 2) has at least one first locking arm (5, 7) which has on one side a guide surface (9, 11) which induces the rotational movement when the nut parts (1, 2) are displaced and bears against a complementary guide surface (10, 12) on a second locking arm (6, 8) of the other nut part (1, 2).

The nut has a plurality of pressure threads (36-41) which are arranged around the internal thread and receive the pressure screws (26-31) that can be screwed out in the axial direction from a first axial end face (21) of the nut and have a receiving means (35) for a screwing tool in the region of a second axial end face (22) of the nut, wherein at least one pressure thread (36, 39) is arranged in the first locking arm (5, 7), which has the first axial end face (21), and wherein the second locking arm (6, 8) with the second axial end face (22), which cooperates with the first locking arm (5, 7), has a recess (42, 43) through which the pressure screw (29, 26) projects.

Claims

1. A nut, comprising: an internal thread; and two nut parts, each of the nut parts having a section of the internal thread which is radially slidable onto an external thread, the nut parts having co-operating connecting elements which permit relative displacement of the nut parts in a direction running radially to the axis of the internal thread until reaching a use position in which the internal thread of the nut engages around the external thread with a small clearance, wherein the connecting elements have guide surfaces which guide the nut parts of the screw nut in a rotational movement about an axis of rotation extending transversely to the axis of the internal thread when displaced into the use position, wherein each nut part has at least one first locking arm which has on one side a guide surface which induces the rotational movement when the nut parts are displaced and bears against a complementary guide surface on a second locking arm of the other nut part wherein the nut has a plurality of pressure threads which are arranged around the internal thread and which receive pressure screws that can be screwed out in the axial direction from a first axial end face of the nut and have a receiving means for a screwing tool in the region of a second axial end face of the nut, wherein at least one pressure thread is arranged in the first locking arm, which has the first axial end face, and wherein the second locking arm with the second axial end face, which cooperates with the first locking arm, has a recess, through which the pressure screw projects.

2. The nut according to claim 1, wherein the recess is an elongated hole which guides the pressure screw when the second nut part is displaced with respect to the first nut part out of the use position.

3. The nut according to claim 1, wherein the internal thread sections of the two nut parts are separated along a parting plane extending in the direction of the thread axis, and each nut part of the nut has two locking arms arranged on either side of a central plane extending perpendicular to the parting plane.

4. The nut according to claim 1, wherein the guide surfaces are inclined or curved.

5. The nut according to claim 1, wherein each nut part has at least one pressure thread in a region in which the nut part extends from the first axial end face to the second axial end face.

6. The nut according to claim 2, wherein the pressure screw which projects through the elongated hole of the second locking arm and is screwed into the pressure thread of the first locking arm, connects the two nut parts displaceably but inseparably to one another.

7. The nut according to claim 2, wherein the internal thread sections of the two nut parts are separated along a parting plane extending in the direction of the thread axis, and each nut part of the nut has two locking arms arranged on either side of a central plane extending perpendicular to the parting plane.

8. The nut according to claim 4, wherein the internal thread sections of the two nut parts are separated along a parting plane extending in the direction of the thread axis, and each nut part of the nut has two locking arms arranged on either side of a central plane extending perpendicular to the parting plane.

9. The nut according to claim 5, wherein the internal thread sections of the two nut parts are separated along a parting plane extending in the direction of the thread axis, and each nut part of the nut has two locking arms arranged on either side of a central plane extending perpendicular to the parting plane.

10. The nut according to claim 6, wherein the internal thread sections of the two nut parts are separated along a parting plane extending in the direction of the thread axis, and each nut part of the nut has two locking arms arranged on either side of a central plane extending perpendicular to the parting plane.

11. The nut according to claim 2, wherein the guide surfaces are inclined or curved.

12. The nut according to claim 3, wherein the guide surfaces are inclined or curved.

13. The nut according to claim 5, wherein the guide surfaces are inclined or curved.

14. The nut according to claim 6, wherein the guide surfaces are inclined or curved.

15. The nut according to claim 2, wherein each nut part has at least one pressure thread in a region in which the nut part extends from the first axial end face to the second axial end face.

16. The nut according to claim 3, wherein each nut part has at least one pressure thread in a region in which the nut part extends from the first axial end face to the second axial end face.

17. The nut according to claim 4, wherein each nut part has at least one pressure thread in a region in which the nut part extends from the first axial end face to the second axial end face.

18. The nut according to claim 6, wherein each nut part has at least one pressure thread in a region in which the nut part extends from the first axial end face to the second axial end face.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0050] A practical embodiment and further advantages of the system described herein are described below in connection with the drawings.

[0051] FIG. 1 shows a three-dimensional oblique side view of a fastening and tensioning arrangement with a two-part nut with pressure screws in the closed use position.

[0052] FIG. 2 shows a representation of the fastening and tensioning arrangement corresponding to FIG. 1 in the half-open position.

[0053] FIG. 3 shows a representation of the fastening and tensioning arrangement corresponding to FIGS. 1 and 2 in the fully open position.

[0054] FIG. 4 shows an illustration corresponding to FIG. 3 with the nut lifted from the supporting surface.

[0055] FIG. 5 shows an enlarged and isolated three-dimensional representation of the nut from FIG. 4 in the open position.

[0056] FIG. 6 shows a lateral three-dimensional representation of the nut parts of the nut of FIG. 5, which are further displaced relative to each other along the cylindrically curved guide surfaces.

[0057] FIG. 7 shows a three-dimensional oblique plan view of the nut from FIG. 6.

[0058] FIG. 8 shows an isolated representation of the first nut part of the nut from FIGS. 5-7.

[0059] FIG. 9 shows an isolated representation of the second nut part of the nut from FIGS. 5-7.

DESCRIPTION OF VARIOUS EMBODIMENTS

[0060] FIGS. 1-4 show a fastening and tensioning arrangement with an embodiment of the nut according to the system described herein. The nut consists of two nut parts 1, 2 and corresponds in its mode of operation to the embodiment of FIGS. 9-13 of EP 1 982 082 B1. The nut is shown isolated and enlarged in FIGS. 5 to 7 and the individual nut parts can be seen in FIGS. 8 and 9.

[0061] The nut part 1 has a first, internally threaded section 3 extending over 180°. The second nut part 2 has the second, opposite internal thread section 4, which also extends over 180°. The two internal thread sections 3, 4 are divided in a parting plane containing the axis of the internal thread. Each of the nut parts 1, 2 has two locking arms 5,6 and 7,8, respectively. In this case, the two locking arms 5,6 and 7,8 of each nut part 1 and 2, respectively, extend on both sides of a center plane that is perpendicular to the parting plane of the internal thread.

[0062] The two locking arms 5, 6 and 7, 8 of the two nut parts 1 and 2 respectively each have a curved guide surface 9-12 which runs essentially radially to the axis of the internal thread. The two guide surfaces 9, 10 or 11, 12 of each nut part 1 or 2 face essentially in opposite directions. Thus, in the case of the first nut part 1, the guide surface 9 lying at the front for the observer in FIG. 7 faces upwards and the guide surface 10 lying further back faces downwards. Correspondingly and additionally, on the second nut part 2, the guide surface 11 of the second nut part 2 lying at the rear in FIG. 7 faces upward and the guide surface 12 of the nut part 2 lying further forward faces downward. On the first nut part 1, the upward-facing guide surface 9 forms the upper side of the first locking arm 5, which rests with its underside on the supporting surface 23 (see FIG. 1). In the use position, the downward-facing guide surface 12 of the second nut part 2 rests against the upward-facing guide surface 9 of the first locking arm 5 of the first nut part 1. The guide surface 12 is associated with the second locking arm 8 of the second nut part 2, which rests on the locking arm 5 of the first nut part 1 away from the supporting surface 23.

[0063] Accordingly, the downward-facing guide surface 10 on the second locking arm 6 of the first nut part 1 rests against the upward-facing guide surface 11 of the first locking arm 7 of the second nut part 2. The use position is shown in FIG. 1.

[0064] The type of pivoting movement which the two nut parts 1, 2 perform relative to each other when opening results from the observation of FIGS. 1 to 3. In FIG. 3, the guide surfaces 9 and 12 rest against each other, but the nut parts 1, 2 are pivoted open to such an extent that they can be pushed without problems onto an external thread 25 which is complementary to the internal thread. In FIG. 1, the nut parts 1, 2 are pivoted into the use position in which the internal thread is closed and positively surrounds the external thread 25 with a small clearance. All curved guide surfaces 9-12 extend along a common cylindrical surface, which is curved about a cylindrical axis at right angles to the thread axis, which lies in the parting plane of the internal thread. In this way, the two nut parts 1, 2 are joined together or released from each other by pivoting about the said cylinder axis along this cylindrical surface.

[0065] Tilting of the nut parts 1, 2 about an axis running parallel to the locking arms 5-8 during pivoting along the cylinder jacket-shaped guide surfaces 9-12 is prevented by additional flat guide surfaces 13-20 lying against each other, which extend parallel to the axis of the internal thread and in the direction of displacement of the nut parts, i.e. perpendicular to the parting plane of the internal thread. The flat guide surfaces 13-20 are in contact with each other in pairs.

[0066] The pivoting along the cylindrically curved guide surfaces 9-12 causes the axial end surfaces in the direction of the axis of the internal thread, i.e. the upper side 22 and the lower side 21 of the nut, to deviate from their flat configuration in the use position (see FIGS. 4-6). Consequently, pivoting and loosening of the nut from an external thread 25 onto which the internal thread of the closed nut is screwed is blocked when first axial end surface, in the drawings the lower surface 21, is supported against a supporting surface 23 by screwing tightly onto the external thread 25 via pressure screws 26-31 described further below.

[0067] The movement sequence when connecting the nut parts 1, 2 of the nut is as follows. The nut parts 1, 2 are displaced relative to each other at right angles to the parting plane of the closed internal thread and are pivoted about an axis of rotation running in the parting plane 25 of the internal thread and extending at right angles to the thread axis.

[0068] The nut further has pressure screws 26-31, which can be used to set a predefined pressure force with which the nut is supported against the supporting surface 23. FIGS. 1 to 4 schematically show a rectangular section 32 of a housing wall to which the external thread 25 is attached. An annular washer 33 surrounds the external thread 25 and forms the supporting surface 23 on which the pressure screws 26-31 are supported. At an end of each pressure screw 26-31 near the supporting surface 23, each pressure screw 26-31 has a pressure section 34 which is free of threads. At an opposite end of each pressure screw 26-31, each pressure screw 31-36 has a receiving means 35 for a screwing tool. In the drawings, each pressure screw 26-31 is provided with a hexagonal receiving means 35 for a wrench. Other known receiving means for screwdriving tools (Allen, Torx) can be selected. The pressure sections 34 and receiving means 35 are only occasionally provided with reference signs in the drawings.

[0069] In FIG. 8, it can be seen that the nut part 1 has two pressure screws 27, 28 which extend in a material section which extends from the upper side 22 to the lower side 21 of the nut. Pressure threads 37, 38 are provided for these pressure screws 27, 28, which can extend from the upper side 22 of the nut to its lower side 21. However, the length of the pressure threads 37, 38 may be less than the length of the bore through the nut. The bore may also have sections without threads.

[0070] In contrast, the pressure screw 26 is screwed into a pressure thread 36, which extends only from the underside 21 of the nut to the curved guide surface 9 of the locking arm 5. Similarly, it can be seen in FIG. 9 that the two pressure screws 30, 31 are received in pressure threads 40, 41 which extend from the upper surface 22 to the lower surface 21 of the nut. In contrast, the pressure screw 29 is screwed into a pressure thread 39 which extends through the locking arm 7 of the second nut part 2 from the underside 21 to the curved guide surface 11 (see also FIG. 7).

[0071] To enable the arrangement of the pressure screws 26-31 in the area of the locking arms 5-9, the second locking arms 6, 8 located on the upper side 22 of the nut each have a recess 42,43 through which project the corresponding pressure screws 29, 26 in the pressure threads 39, 36 of the locking arms 7, 5. The recesses 42, 43 are formed as elongate holes, the width of which is slightly larger than the diameter of the pressure screw 29, 26 projecting through them. The center line of each of the elongate holes 42, 43 extends straight and parallel to the displacement direction in which the nut parts 1, 2 are displaced relative to each other. In particular, it can be seen in FIG. 7 that the nut parts 1, 2 cannot be joined together with pressure screws 26, 29 screwed into the first locking arms 5, 7. To join the nut parts 1, 2 together, it is necessary to remove the pressure screws 26, 29 from the pressure threads 36, 39 of the locking arms 5, 7. Only when the nut parts 1, 2 have been joined together in the open position shown in FIG. 5, in which the elongate holes 42, 43 in the second locking arms 6, 8 are aligned with the pressure threads 39, 36 in the first locking arms 7, 5, can the pressure screws 29, 26 be inserted through the elongate holes 42, 43 and screwed into the pressure threads 39, 36. The pressure screws 26, 29 screwed into the first locking arms 5, 7 on the underside 21 of the nut fix the nut part 2 to the nut part 1, so that only a displacement from the open position shown in FIG. 5 to the use position shown in FIG. 1 is possible.

[0072] In the closed use position shown in FIG. 1, the nut can be tightened along the external thread 25 toward the supporting surface 23 until the pressure sections 34 of the pressure screws 26-31 rest against the supporting surface 23. No particularly large force is required for this. The simple contact of the pressure sections 34 of the pressure screws 26-31 against the supporting surface 23 is sufficient to prevent the nut parts 1, 2 from pivoting and opening. Now, a screwdriving tool (wrench, not shown) can be used to apply torque to the pressure screws 26-31 by means of the hexagonal sockets 35 of the pressure screws 36-31, so that the pressure force on the supporting surface 23 increases. The torque for tightening the pressure screws 26-31 to produce a certain compressive force is much less than a corresponding torque for producing the same compressive force by turning the nut itself on the external thread 25. It should be noted that the pressure portions 34 of the pressure screws 26-31 do not necessarily have to bear on an annular washer 33. If the housing wall section 32 to which the external thread 25 is attached has sufficient stability, the pressure sections 34 of the pressure screws 26-31 can also bear directly on the housing wall section 32.

[0073] The features of the invention disclosed in the present description, in the drawings as well as in the claims may be essential, both individually and in any combination, for the realization of the invention in its various embodiments. The invention is not limited to the embodiments described. It may be varied within the scope of the claims and with due regard to the knowledge of the person skilled in the art.