Wrench for removing damaged fasteners

Abstract

Wrench for dismantling damaged fastening elements (100), characterized in that it comprises: a key body (1) provided with a receiving opening (10) along a rotation axis (X), the receiving opening (10) being designed to receive a fastening element (3, 5); and a locking unit (2) arranged around the axis of rotation (X) on the inner edge of the receiving opening (10), wherein the locking unit (2) has six first recesses (20) and six second recesses (30) arranged at equal angular distances from one another, wherein a second recess (30) is arranged between each two first recesses (20), and wherein each second recess (30) has a first inclined force transmission surface (31) and a second inclined force transmission surface (32) on both sides, wherein a contact surface (33) is formed at one end of the first inclined force transmission surface (31) and the second inclined force transmission surface (32) and is aligned in the direction of the axis of rotation (X).

Description

The present invention relates to a wrench, in particular a wrench for dismantling damaged fastening elements.Screws, nuts and other fasteners are essential basic components of the modern industry. In various assembly and disassembly processes, ring keys or socket keys are used due to their receiving openings in order to ensure a precise adaptation to the fastening elements. They are widely used in the tightening and loosening of screw connections.However, conventional ring keys or socket keys have the following problems in practical application:Problem of fastener damage: Due to long term use or adverse environmental conditions, fasteners are subject to corrosion, wear and can break out at the edges by the application of excessive force. If there is insufficient fit between the receiving opening of the key and a damaged screw member, slipping off easily occurs, which makes the loosening difficult and possibly causes further damage to the fastening member.Limited tool applicability: tools which are designed specifically for certain damaged fastening elements have a limited field of application and are suitable only for specific types of damage to screw connections. If such tools are used on undamaged fastening elements, this can cause new damage due to the application of an excessive force.The object of the invention is to provide a wrench for dismantling damaged fastening elements, which wrench can be used both for damaged and for undamaged fastening elements and avoids damage to the fastening elements.This object is achieved according to the invention by a wrench for dismantling damaged fastening elements, which wrench has the features specified in claim 1. Further advantageous developments of the invention emerge from the features of the dependent claims.According to the invention, the wrench for dismantling damaged fastening elements has a wrench body and a locking unit. The key body is provided along an axis of rotation with a receiving opening which is designed to receive a fastening element. The locking unit is arranged around the axis of rotation on the inner edge of the receiving opening and comprises six first recesses and six second recesses which are arranged at equal angular distances from one another. A second recess is provided between each of two first recesses. Each second recess has a first inclined force transmission surface and a second inclined force transmission surface on both sides, wherein an abutment surface at one end of the first inclined force transmission surface and the second inclined force transmission surface is oriented in the direction of the rotational axis.If the fastening element is a dodecagonal screw element, the first and second recesses are each adapted to the corner regions of the screw element, whereby damage to the corner regions is avoided. In addition, the contact surfaces bear closely against the lateral base edges of the corner regions, so that they engage with an exact fit at the tooth root position of the corner regions. This prevents slipping off and reliable toothing is achieved, which enables a stable rotational movement of the wrench.Therefore, the wrench according to the invention is suitable for fastening or loosening both damaged and undamaged fastening elements. The low working angle required minimizes the physical burden on the user.In a further exemplary embodiment, the angle between the first inclined force transmission surface and the second inclined force transmission surface is at most 120°. This reduces the wear of the second recesses during the rotational movement, thereby increasing the service life of the wrench.The invention and its embodiments are explained in more detail below with reference to the drawings. The drawing shows: FIG. 1 is a plan view of the wrench for disassembling damaged fasteners according to the present invention; FIG. 2 shows a schematic illustration of the wrench according to the invention for dismantling damaged fastening elements in conjunction with a twelve-sided fastening element; FIG. 3 is an enlarged fragmentary view of FIG. 2; FIG. 4 shows a schematic illustration of the wrench according to the invention for dismantling damaged fastening elements in conjunction with a damaged twelve-sided fastening element; FIG. 5 shows a schematic illustration of the wrench according to the invention for dismantling damaged fastening elements in conjunction with a Torx-shaped fastening element; and FIG. 6 shows a schematic illustration of the wrench according to the invention for dismantling damaged fastening elements in conjunction with a damaged Torx-shaped fastening element.As illustrated in FIGS. 1 to 6, the present disclosure relates to a wrench 100 for disassembling damaged fasteners, including a wrench body 1 and a locking unit 2.The key body 1 is provided along an axis of rotation X with a receiving opening 10 which is designed to receive a fastening element 3 [see FIG. 2 ]. In an embodiment, the key body 1 also has a handle 11, wherein the receiving opening 10 is arranged at one end of the handle 11 and can be used for rotational movements both in the front and in the rear side for connection to the fastening element 3. The key body 1 is designed as a ring key.The locking unit 2 is arranged around the axis of rotation X on the inner edge of the receiving opening 10. The locking unit 2 comprises six first recesses 20 and six second recesses 30, which are arranged at equal angular distances from one another. A second recess 30 is located between each two first recesses 20, wherein the angle of separation between an adjacent first recess 20 and a second recess 30 is 30°. Each first recess 20 has two side edges 21 and a groove base 22 arranged between the two side edges 21.Each second recess 30 has a first inclined force transmission surface 31 and a second inclined force transmission surface 32 on both sides, respectively. At one end of each of the first inclined force transmission surface 31 and the second inclined force transmission surface 32, an abutment surface 33 is arranged which is oriented in the direction of the axis of rotation X. In one exemplary embodiment, the width of the contact surfaces 33 is between 0.1 mm and 0.5 mm. The angle A between the first inclined force transmission surface 31 and the second inclined force transmission surface 32 is at most 120°. In a further exemplary embodiment, the angle A is between 116° and 120°.Moreover, each first inclined force transmitting surface 31 and each second inclined force transmitting surface 32 are connected to a curved groove 34 on the side opposite to the rotation axis X.In one embodiment, the side edges 21 are connected to the first inclined force transmitting surface 31 and the second inclined force transmitting surface 32, respectively. The side lengths of the side edges 21 are respectively smaller than the side lengths of the first inclined force transmission surface 31 and the second inclined force transmission surface 32.FIGS. 2 and 3 show a schematic illustration and an enlarged view of the wrench in conjunction with a fastening element 3. The fastening element 3 is designed as a dodecagon screw element and has twelve corner regions 3 a. The six first recesses 20 and the six second recesses 30 of the locking unit 2 are each adapted to the twelve corner regions 3 aof the fastening element 3 in such a way that a complete form-fit connection is produced. As a result, during the rotational movement, the wear at the corner regions 3 ais reduced, which brings about a protective function for these corner regions 3 a. In addition, the required working angle is only 30°, thereby reducing the load on the user. Due to the configuration of the angle A between the first inclined force transmission surface 31 and the second inclined force transmission surface 32 in the range of 116° to 120°, these surfaces can effectively contact the corner portions 3 aduring the turning operation. This ensures stable meshing of the key with the fastening element 3, which reduces the risk of sliding friction. At the same time, the wear on the first inclined force transmitting surface 31 and the second inclined force transmitting surface 32 is minimized, thereby reducing the amount of wear of the second recesses 30 and avoiding excessive increase in the angle A. This contributes to the increase of the life of the wrench.In an exemplary embodiment of the present invention, the contact surfaces 33 each bear closely against the base edges of the corner regions 3 aon both sides. As a result, the contact surfaces 33 engage positively at the tooth root position of the corner regions 3 a, as a result of which slipping off is prevented and reliable toothing is achieved. This enables stable power transmission and facilitates the rotational movement of the wrench. As shown in FIG. 4, the wrench can still ensure a secure toothing with the fastening element 4 even if it is a damaged dodecagonal screw element. The contact surfaces 33 furthermore engage the tooth root position of the corner regions 3 a, whereby a firm locking of the fastening element 4 is ensured. As a result, the wrench can execute a reliable rotational movement even when the outer profile of the fastening element 4 is worn away.As shown in FIG. 5, the fastening element 5 is designed as a Torx-shaped screw element and has six rounded corner regions 5 a. The six first recesses 20 of the present invention are precisely adapted to the six rounded corner regions 5 a, so that a precisely fitting connection is produced. The contact surfaces 33 are in close contact with the two-sided surfaces of each rounded corner region 5a, whereby a stable rotary movement is ensured. As shown in FIG. 6, the wrench can allow a reliable rotational movement even when the fastening element 6 is a worn torx-shaped screw element. The contact surfaces 33 continue to engage securely on the rounded corner regions 5 a, so that the fastening element 6 can be actuated without problems despite the wear.The wrench according to the invention can likewise be used for undamaged as well as damaged hexagonal fastening elements and, due to the structures described above, enables an easy rotational movement.In summary, the configuration of the locking unit 2 with the six first recesses 20 and the six second recesses 30 is suitable for both hexagonal and for dodecagonal and Torx-shaped fastening elements. Even if these fastening elements have burrs or are deformed, the recesses according to the invention can effectively engage the damaged or deformed portions, thus enabling secure tightening or loosening.Due to the above-described structure, the wrench according to the invention enables a both-sided application for fastening and loosening fastening elements. In addition, the required working angle is small, thereby minimizing the physical burden on the user.

Claims

Wrench for dismantling damaged fastening elements (100), characterized in that it comprises: a wrench body (1) provided with a receiving opening (10) along an axis of rotation (X), the receiving opening (10) being designed to receive a fastening element (3, 5); and a locking unit (2) arranged around the axis of rotation (X) at the inner edge of the receiving opening (10), wherein the locking unit (2) has six first recesses (20) and six second recesses (30) arranged at equal angular distances from one another, wherein a second recess (30) is arranged between each two first recesses (20), and wherein each second recess (30) has a first inclined force transmission surface (31) and a second inclined force transmission surface (32) on both sides, wherein an abutment surface (33) is formed at one end of the first inclined force transmission surface (31) and the second inclined force transmission surface (32) and is oriented in the direction of the axis of rotation (X).Wrench for dismantling damaged fastening elements according to claim 1, characterised in that the width of the contact surfaces (33) is in the range between 0.1 mm and 0.5 mm.Wrench for dismantling damaged fastening elements according to claim 1 or 2, characterised in that the angle between the first inclined force transmission surface (31) and the second inclined force transmission surface (32) is at most 120°.Wrench for dismantling damaged fastening elements according to claim 3, characterised in that the angle between the first inclined force transmission surface (31) and the second inclined force transmission surface (32) is between 116° and 120°.Wrench for dismantling damaged fastening elements according to any one of claims 2 to 4, characterised in that each first inclined force transmission surface (31) and each second inclined force transmission surface (32) is connected to a curved groove (34) on the side facing away from the axis of rotation (X).Wrench for dismantling damaged fastening elements according to claim 5, characterised in that the first recesses (20) each have two side edges (21) and a groove base (22) arranged between the side edges (21), wherein the side edges (21) are respectively connected to the first inclined force transmission surface (31) and the second inclined force transmission surface (32) and have a shorter side length than the first inclined force transmission surface (31) and the second inclined force transmission surface (32).Wrench for dismantling damaged fastening elements according to one of Claims 1 to 6, characterized in that the fastening element (3) has twelve corner regions (3a), wherein the first recesses (20) and the second recesses (30) are each matched to the corner regions (3a), and wherein the contact surfaces (33) bear against the lateral base edges of each corner region (3a).Wrench for dismantling damaged fastening elements according to one of claims 1 to 7, characterised in that the fastening element (5) has six rounded corner regions (5a), wherein the first recesses (20) are each adapted to the rounded corner regions (5a) and wherein the contact surfaces (33) bear against the lateral surfaces of each rounded corner region (5a).

Images