Disc for receiving a counter-torque from a tool

Abstract

A disc (100, 200, 300, 400) for receiving a counter-torque generated when tightening or loosening a threaded fastener, comprising: a body part (110) extending radially about a central axis (102) of the disc (100, 200, 300, 400); a central bore (105) in the body part (110) configured to enclose the threaded fastener and aligned with the central axis (102); and an outer circumferential part (120) of the disc (100, 200, 300, 400) configured to be mechanically coupled to a tool for receiving the counter-torque; wherein the outer circumferential part (120) of the disk (100, 200, 300, 400) comprises circumferentially spaced projections (130) which extend outwards from the disk (100, 200, 300, 400) in order to be mechanically coupled to the tool for receiving the counter-torque;characterized in that a bottom side of the outer circumferential part (125) of the disk (100, 200, 300, 400) is configured by means of a first type of means for increasing the coefficient of friction to interact with a bearing surface for receiving the counter-torque.

Description

The present invention relates to a disc for receiving a counter-torque that arises when tightening or loosening a threaded fastening arrangement. To tighten threaded fasteners, a tool is used to apply a specific torque to the screw head or nut of the threaded fastener, which should result in a well-defined tension on the fastener. However, during tightening or loosening of a threaded fastener, a counter-torque may be exerted on the operator via the tool. This can occur due to friction between a washer or bearing and the screw head and / or nut of the threaded fastener, or between the washer and bearing, or between the screw thread and the nut thread. Particularly when tightening larger threaded fasteners, a counter-torque acting on an operator can pose a significant health hazard, making it necessary to compensate for this counter-torque. Such compensation can be implemented, for example, by a tool that serves to apply a tightening torque to the arrangement, which includes an extension arm that is coupled to a surface of one of the workpieces, which are intended to be held together by the threaded fastening arrangement, so that the counter-torque is transmitted and compensated by the workpiece. Alternatively, a washer can be used in the threaded fastening arrangement, which on the one hand securely holds the surface (the bearing) on ​​one side of one of the workpieces, such as a flange, through which the threaded fastening element extends, and on the other hand is shaped so that the tool for applying the torque to the nut or screw head of the threaded fastening arrangement can engage with the washer, so that the counter-torque can be further absorbed and compensated by the workpiece. Such a disc, referred to as a "reaction disc" or "intervention disc", is described, for example, in EP 3 083 146 A1 or US 11,396,902 B2. US 2009 / 142155 A1 relates to a captive device comprising at least one ring plate, wherein the ring plate comprises an opening formed in the central section of the ring plate; a plurality of slots formed radially on a first surface of the ring plate and around the opening, the slots extending from the opening to the outer edge of the ring plate; a plurality of wedge-shaped structures formed between the slots, each wedge-shaped structure having a contact surface, the contact surface being an inclined surface between two adjacent slots; and a plurality of projections formed on a second surface of the ring plate corresponding to the first surface, the projections being formed radially on the second surface. The present invention aims to develop further such discs, and in particular to improve the retention of the disc on the surface of the workpiece, i.e. to increase the torque with which the disc can be subjected before it rotates freely on its bearing. Accordingly, the present invention relates to a disc for receiving a counter-torque generated when tightening or loosening a threaded fastening arrangement, comprising: a body part extending radially about a central axis of the disc; a central bore in the body part configured to enclose the threaded fastening element and aligned with the central axis; and an outer circumferential part of the disc configured to be mechanically coupled to a tool for receiving the counter-torque; wherein the outer circumferential part of the disc consists of circumferentially spaced projections extending outwards from the disc to be mechanically coupled to the tool for receiving the counter-torque;wherein a bottom surface of the outer circumferential part of the disc is configured by means of a first type of means for increasing the coefficient of friction to interact with a bearing surface to receive the counter-torque. Advantageous modifications of the invention are listed in the dependent claims. All combinations of at least two of the features disclosed in the description, the claims, and the figures fall within the scope of this invention. The "underside" of the disc is to be understood as the surface of the disc which is intended to engage with the workpiece surface during operation, which is referred to as the bearing surface. The "top" of the disc is to be understood as the opposite surface of the disc which is intended to engage with the nut or screw head on the underside of the threaded fastening assembly during operation. The "disk central axis" is an axis that is perpendicular to the plane of the disk and encompasses the center of the disk. Typically, the outer circumferential part of the disc, which is configured to be mechanically coupled to a tool to receive the counter-torque, is not cylindrically symmetrical with respect to the disc's central axis. Furthermore, the body part of the disk is usually the part of the disk that is completely cylindrically symmetrical with respect to the disk's central axis, i.e., it maps onto itself when rotated about the axis at any angle. The disc according to the present invention comprises means for increasing the coefficient of friction on the underside of said outer circumferential part of the disc. The outer circumferential part of the disc is spaced as far away as possible from the disc's central axis in the radial direction, and in this way the means for increasing the coefficient of friction are most effective on this part of the underside of the disc in increasing the friction between the disc and the bearing surface and thus improving the retention of the disc on the bearing surface. Means for increasing the coefficient of friction on the surfaces of discs are well known as such, since the resistance when loosening the threaded fastening arrangement is determined by the friction between a top of the disc and the screw and / or nut or the friction between the disc and the bearing on a workpiece, so that higher friction resulting from the use of such means to increase the coefficient of friction increases the resistance when loosening the threaded fastening arrangement. In practice, when tightening a threaded fastener, the screw head and / or nut are subjected to a certain torque, which should result in a well-defined tension. However, this only applies if the friction between the underside of the washer and the bearing surface and / or the flange surface and / or mounting surface with which it is intended to engage and / or interact is also well-defined and sufficient. In a preferred embodiment of the disc according to the invention, the underside of the body part of the disc according to the invention is further configured to interact with the bearing surface by means of a second type of means for increasing the coefficient of friction. In this embodiment, the retention of the disc on the bearing is further improved. The first type of means for increasing the coefficient of friction and / or the second type of means for increasing the coefficient of friction of the underside of the disc can be any means, in particular they can have any form that improves the friction between the disc and the bearing surface. In a preferred embodiment, the first type of means for increasing the coefficient of friction and / or the second type of means for increasing the coefficient of friction of the underside of the disc are structured and / or knurled and / or textured and / or toothed by means of a plurality of elongated protrusions; and / or structured by means of a plurality of elongated depressions. The respective means for increasing the coefficient of friction can thus include a corresponding type of structure and / or texture and / or pattern and / or topography of the underside of the body part and / or the outer circumferential part of the disc in order to increase the coefficient of friction between the underside of the respective part of the disc and the bearing surface. Furthermore, the first type of means for increasing the coefficient of friction can advantageously be present on the entire area of ​​the underside of the outer circumferential part of the disk, and / or the second type of means for increasing the coefficient of friction can advantageously be present on the entire area of ​​the underside of the body part of the disk. Accordingly, from one perspective, the underside of the outer circumferential part of the disc may include or consist of the first type of means for increasing the coefficient of friction and / or a first type of structure and / or a first type of texture and / or a first type of topography configured to interact with the bearing surface to receive the counter-torque. From another perspective, the first type of means for increasing the coefficient of friction and the second type of means for increasing the coefficient of friction on the underside of the disc can be identical. They can be applied uniformly to both parts of the underside, e.g., to the entire underside of the disc. By using identical means to increase the coefficient of friction, the means to increase the coefficient of friction can be optimized to absorb a high amount of counter-torque. The disc may or may not have a beveled section on the inner circumference of its underside. It is further preferred that each respective elevation of the first and / or second means for increasing the coefficient of friction on the underside of the disk comprises or consists of a wedge and / or a tooth and / or a burr and / or a toothing. From one perspective, individual wedges and / or individual teeth and / or individual ridges and / or individual elongated elevations encompass an edge distal to the underside. One aspect that is proposed is that the elongated elevations have a symmetrical cross-section and / or the elongated depressions have a symmetrical cross-section. This can protect the bearing surface regardless of the direction of any torque acting on the disc. Accordingly, the elongated projections, such as wedges, teeth, ridges or serrations, preferably have a symmetrical cross-section and / or the elongated depressions have a symmetrical cross-section, i.e. preferably the teeth and / or elongated projections and / or elongated depressions are designed such that they have a symmetrical shape with respect to a direction perpendicular to a disk plane in the sectional view of the respective structure. Accordingly, one aspect proposes that the teeth and / or the elongated elevations and / or elongated depressions of the underside of the outer circumferential part and / or the body part of the disc, in the sectional view of their longitudinal direction, have a shape that is symmetrical to the perpendicular angle bisector passing through a tip of the tooth and / or through a tip of the edge. The teeth and / or elongated protrusions in the cross-sectional view of their longitudinal direction can thus have a triangular shape and / or a rectangular shape. In a sectional view, the elongated elevation can have an approximately triangular shape, with an angle of the triangle-forming flanks of the elevation of a disk plane being 35 to 65°, more preferably 40 to 60° and most preferably 45 to 55°, such as 50°. Preferably, the upper sections of the teeth and / or elongated elevations of the underside of the outer circumferential part and / or the body part of the disc are rounded in the sectional view of their longitudinal direction. The radius of a rounded upper section of the teeth and / or the elongated elevations of the underside can range from 0.05 mm to 0.20 mm, or from 0.07 mm to 0.18 mm, or from 0.08 mm to 0.16 mm, or from 0.08 mm to 0.12 mm. Preferably, the rounded section occupies 30 to 70% of the total height of the tooth, more preferably 40 to 60%, and most preferably 45 to 45%, e.g. 50%. In this way, no sharp edges of the means for increasing the coefficient of friction of the disc protrude towards the bearing and grab it when tightening. For example, the upper part of the elevation, which has a triangular or rectangular shape in a sectional view, can start at 50% of the elevation height and be rounded, for example, with a radius of 0.05 mm to 0.08 mm. Preferably, the first and / or second type of means for increasing the coefficient of friction of the underside of the outer circumferential part of the disc and / or the body part of the disc are configured as teeth and / or comprise a plurality of teeth or consist thereof. Preferably, the height of the teeth and / or the elongated projections and / or the elongated depressions, i.e., the highest dimension of the respective structure in a direction perpendicular to the plane of the disk, is from 0.125 mm to 0.25 mm, more preferably from 0.13 mm to 0.24 mm and most preferably from 0.14 mm to 0.23 mm, such as from 0.15 mm to 0.20 mm. Furthermore, the teeth and / or elongated elevations and / or the respective structures are preferably not located directly next to each other, but rather flat sections are arranged between the respective structures. The number of teeth and / or elongated protrusions and / or elongated depressions arranged on the underside is preferably between 1.0 and 2.0 per mm, more preferably between 1.1 and 1.9 per mm of the circumference of the disc's central bore. For example, a 1-inch disc typically has a central bore circumference of approximately 89.5 mm and 98 teeth, resulting in 1.1 teeth per mm of the circumference. Preferably, the elongated projections and / or the elongated depressions and / or the teeth of the underside of the outer circumferential part and / or the body part of the disc, in a top view of the underside of the disc, extend longitudinally in a direction from an inner edge to an outer edge of the underside of the disc and / or from an inner to an outer circumference of the underside of the disc, and more preferably extend completely from the inner edge to the outer edge of the underside of the disc and / or extend completely from an inner to an outer circumference of the underside of the disc. From one perspective, the longitudinal direction of the teeth and / or the elongated elevations and / or the elongated depressions of the underside of the outer circumferential part and / or the body part of the disc corresponds to the straight lines. In one aspect, the longitudinal direction of the teeth and / or the elongated projections and / or the elongated depressions on the underside of the outer circumferential part and / or the body part of the disc extends outwards with respect to the central axis of the disc and is inclined counterclockwise with respect to a radial direction on the underside of the disc. For example, the longitudinal direction of the teeth and / or the elongated projections and / or the elongated depressions on the underside of the outer circumferential part and / or the body part of the disc extends straight outwards with respect to the central axis of the disc and is inclined counterclockwise with respect to a radial direction on the underside of the disc. A counterclockwise inclination of the, preferably straight, longitudinal direction of the teeth and / or the elongated projections and / or the elongated depressions on the underside of the outer circumferential part and / or the body part of the disc is preferred for discs intended for use with fastening assemblies that include a right-hand thread, so that the nut rotates clockwise when the threaded fastening assembly is tightened. The vast majority of threaded fasteners include right-hand threads. As is immediately apparent to those skilled in the art, in the case of discs intended for use with fastening arrangements comprising a left-hand thread, such that the nut rotates counterclockwise when the threaded fastening arrangement is tightened, the longitudinal direction of the teeth and / or the elongated projections and / or the elongated depressions of the underside of the outer circumferential part and / or the body part of the disc extends outwards, preferably straight, with respect to the central axis of the disc, and is inclined counterclockwise with respect to a radial direction on the underside of the disc. In general, if elements of the disc according to the invention are described here that are adapted for use with fastening arrangements comprising a right-hand thread, these elements can be suitable to have the same effect in discs according to the invention that are adapted for use with fastening arrangements comprising a left-hand thread, as is readily apparent to those skilled in the art. An angle of inclination in plan view, defined as the angle between radially extending straight lines originating in the center of the disk and the teeth and / or the elongated projections and / or the elongated depressions, may range from 40 to 80°, preferably from 50 to 70° and more preferably from 55 to 65°, such as 60°. According to a preferred aspect, the longitudinal direction of the teeth and / or the elongated elevations and / or the elongated depressions of the underside of the outer circumferential part and / or the body part of the disc coincides with the radially extending straight lines whose origin lies in the central axis of the disc. According to one aspect, the teeth and / or the elongated elevations of the underside of the outer circumferential part and / or the body part of the disc, which in particular form the structured and / or knurled and / or textured and / or toothed underside of the disc, are arranged separately from one another, in particular by means of a flat section on the underside of the disc which is arranged between each tooth and / or each elongated elevation. This can mean that the teeth and / or the elongated elevations of the underside of the outer circumferential part and / or the body part of the disc are arranged adjacent to a flat intermediate section, the flat intermediate section being a flat section of a surface of the disc. Preferably, the underside of the outer circumferential part and the underside of the body part of the disc are configured as serrations comprising a plurality of teeth. Preferably, the teeth of the underside of the outer circumferential part and those of the body part interlock seamlessly. For example, the second type of friction-enhancing means, such as teeth, on the underside of the body part of the disk can correspond to the first type of friction-enhancing means on the underside of the outer circumferential part of the disk and can be configured to extend seamlessly and / or flatly with respect to the central axis of the disk from the underside of the body part of the disk to the underside of the outer circumferential part of the disk, preferably from the inner circumference of the underside of the underside of the body part of the disk to the outer edge of the underside of the outer circumferential part of the disk. This could mean that the entire underside of the disc is covered by some kind of means to increase the coefficient of friction. According to one aspect, a circumferential surface of an outer edge of the outer circumferential part of the disk is formed perpendicular to the underside of the disk, and in particular is not conical with respect to the underside of the disk. In this way, the circumferential surface of the outer edge of the outer circumferential part of the underside of the disc engages in the bearing during operation when the threaded fastening arrangement is tightened or jammed. In this embodiment, the first type of means for increasing the coefficient of friction of the underside of the outer circumferential part of the disc can extend to the maximum distance from the center of the disc and thus increase the holding of the disc on the workpiece. Typically, the outer circumferential part of the disc, which is configured to be mechanically coupled to a tool to receive the counter-torque, is not cylindrically symmetrical with respect to the disc's central axis, i.e., it does not map onto itself when rotated about the axis at any angle. The outer circumferential part of the disc can thus be configured by a shape such as a contour of the outer circumferential part of the disc and / or a structure of the outer circumferential part of the disc and / or cutouts of the outer circumferential part of the disc in order to be mechanically coupled to the tool to receive the counter-torque. The configuration of the outer circumferential part consists of circumferentially spaced projections that extend axially outwards from the disc in order to be mechanically coupled to the tool in order to absorb the counter-torque. Such projections are also called crenellations or turrets. The outer circumferential part of the disk can be axially (strictly defined, i.e., not cylindrical) symmetrical to the central axis of the disk, so that it maps onto itself when rotated about the axis at a specific angle (not an arbitrary angle). For example, the outer circumferential part of the disk can be axially symmetrical to the central axis of the disk if it is rotated around the axis at an angle of 10 to 50°, or of 15 to 40°. According to the embodiment of the disc with a circumferential surface of an outer edge of the outer circumferential part of the disc, which is formed perpendicular to the underside of the disc, in particular not conical, with respect to the underside of the disc, the surfaces of the outer edges of the circumferentially spaced projections, which extend axially outwards from the disc, which represent the circumferential surface of an outer edge of the outer circumferential part of the disc in this embodiment, are not conical with respect to the underside of the disc. Part of an actuated tool used to tighten the threaded fastener can engage with the outer circumferential portion of the washer to absorb the counter-torque generated when the threaded fastener is tightened or loosened. This prevents torque exerted on the user through the part of the tool held by the user when tightening or loosening the threaded fastener. Preferably the disc comprises a top surface that faces the underside of the nut or screw head of the threaded fastening arrangement; and wherein a top surface of the outer circumferential part and / or a top surface of the body part of the disc comprises a third type of means for increasing the coefficient of friction, in particular to prevent vibrational rotation of the tightened threaded fastening element. The top side of the disc can be located on the side opposite the bottom side of the disc. The third type of means for increasing the coefficient of friction can be configured independently of any of the embodiments described here for the first and / or the second type of means for increasing the coefficient of friction. According to one aspect, the third type of means for increasing the coefficient of friction is a third type of tooth structure and / or a third type of elongated protrusions projecting from the top of the disk in a direction aligned with the central axis; and wherein each tooth and / or elongated protrusion is structured as a wedge with an edge arranged distal to the top, the distal edge extending in a radial direction of the disk. According to another aspect, the distal edge of the third type of tooth structure and / or the distal edge of the wedge extends straight outwards with respect to the central axis of the disc and is inclined clockwise with respect to the radial direction at the top of the disc. This applies to discs intended for use with fastening assemblies that include a right-hand thread. In the case of discs intended for use with fastening arrangements that include a left-hand thread, the distal edge of the third type of tooth structure and / or the distal edge of the wedge extends straight outwards with respect to the central axis of the disc and is inclined counterclockwise with respect to the radial direction on the top of the disc. According to one aspect, it is proposed that each wedge comprises two flat sides inclined with respect to the top of the disc, forming the distal edge; and wherein the flat sides comprise different inclinations such that they tend more to inhibit the rotation of a nut and / or screw head of the threaded fastener relative to the disc in the direction of loosening than in a direction of tightening. For example, the top surface of the disc may have teeth comprising between 0.8 and 1.2, preferably 0.85 and 1.15, saw teeth per mm of the disc's inner circumference. For example, a 1-inch disc typically has an inner circumference of approximately 89.5 mm and a saw tooth count of 98, resulting in 1.08 saw teeth per mm of inner circumference. The saw teeth are preferably evenly spaced. Preferably, the dimension of each of the saw teeth along an inner circumference of the disc (when extending over a chamfer to the inner circumference) is 0.8 mm to 1.2 mm, more preferably 0.85 mm to 1.15 mm. Since threaded fastening devices usually have right-hand threads and must be turned clockwise to tighten, the tightening direction of the washer in this case is counterclockwise, and the direction to loosen the washer is clockwise. The disk according to the invention preferably comprises a chamfered section (bevel) on the inner circumference of the top side of the disk. The chamfered section prevents the inner part of the washer's top surface from interfering with a thickened portion of the screw head, which may be present where the screw connects to the shank. Furthermore, it makes it easier for the user to determine which surface of the washer should contact the screw head or nut, and which should contact the bearing. The disc may or may not have a chamfered section (bevel) on an outer circumference of the top surface. Preferably, the beveled section represents at most 30% of the width of the disk's surface, preferably at most 20% of the disk's surface width. The chamfer preferably has a flat surface. Furthermore, the chamfered section forms an angle with the top of the disk of 20 to 70°, more preferably 30 to 60° and most preferably 35 to 49°, such as 45°. The chamfer preferably extends into the disk to a depth of up to 50% of the disk's thickness, more preferably up to 40%, and most preferably up to 30%. The radius of the rounded upper section of the saw teeth on the top side is preferably 0.10 mm to 0.40 mm, more preferably 0.12 mm to 0.35 mm and most preferably 0.17 mm to 0.32 mm. Furthermore, it is preferred that the section between the steep flanks of the saw teeth and the surface of the disc is also rounded. Preferably, the radius is less than 0.15 mm, more preferably less than 0.12 mm. In the disc according to the invention, the upper sections of the edges of both the saw teeth on the top and the teeth on the bottom are rounded in the cross-sectional view of the teeth. The disc according to the invention can have a surface and core hardness of 38 to 50 HRC, e.g. 39 to 48 HRC or 40 to 45 HRC. All Rockwell hardness values ​​(HRC) mentioned here are measured according to ISO 6508-1, 2016 edition. Various surface coatings can be applied to the disc, such as mechanical galvanizing or zinc flake coating. The disc can have a flat shape, i.e., the surfaces of the disc are parallel to a plane that encompasses the disc and its center. The disk can also have a conical shape, i.e., the surfaces of the disk are parallel to a cone whose axis passes through the center of the disk. A “plane of the disk”, as mentioned above, is then a tangent plane to the surface of the disk. Reference sign 100, 200, 300, 400 Disc 102 Centerline 105 Center bore 110 Body part 115, 215, 315, 415 First type of means to increase the coefficient of friction 120 Outer circumferential part 125, 225, 325, 425 Means to increase the coefficient of friction 130 Projection 135 Outer surface 140, 240 Raise 150, 250 Flat section 310 Inner diameter 320 Outer diameter 330, 430 Third type of means to increase the coefficient of friction 350 Chamfer Brief description of the drawings The accompanying drawings, which are included here to further enhance understanding of the invention and which are incorporated into and form part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the principle of the invention. The figures show: Fig. 1a, b an isometric top view of a bottom surface of a disk with means for increasing the coefficient of friction; Fig. 2 an isometric top view of a bottom surface of a disk with further means for increasing the coefficient of friction; Fig. 3 an isometric top view of a top surface of a disk with means for increasing the coefficient of friction; and Fig. 4 an isometric top view of a bottom surface of a disk with further means for increasing the coefficient of friction. Fig. 1a schematically shows an isometric top view of a bottom surface 115, 125 of a disk 100 for receiving a counter-torque generated when tightening or loosening a threaded fastener. The disk 100 comprises a body part 110 and an outer circumferential part 120. The body part 110 extends radially about a central axis 102 of the disk 100. A central bore 105 in the body part 110 is configured to enclose the threaded fastener, and the central bore 105 is aligned with the central axis 102. The outer circumferential part 120 of the disk 100 is configured to be mechanically coupled to a tool for receiving the counter-torque. A bottom surface of the outer circumferential part 125 of the disk 100 is configured, by means of a first type of friction-enhancing device, to interact with a bearing surface for receiving the counter-torque. An underside of the body part 115 of the disc 100 is configured to interact with the bearing surface by means of a second type of friction-enhancing means, wherein in Fig. 1a the first type of friction-enhancing means is identical to the second type of friction-enhancing means, and a structure or texture or toothing or knurling of the friction-enhancing means on the underside of the body part 115 and on the underside of the outer circumferential part 125 of the disc 100 seamlessly integrate. The first type of means for increasing the coefficient of friction and / or the second type of means for increasing the coefficient of friction of the underside 115, 125 of the disc 100 are structured and / or knurled and / or textured and / or toothed by means of a multitude of elongated elevations 140. The upper sections of the elongated projections 140 on the underside of the outer circumferential part 125 and the body part 115 of the disc 100 are rounded in their longitudinal direction in the sectional view. The elongated projections 140 on the underside of the outer circumferential part 125 and the body part 115 of the disc 100 form the structured, knurled, textured, or toothed underside 115, 125 of the disc 100 and are separated from each other by a flat section 150 located on the underside 115, 125 of the disc 100 between each pair of elongated projections 140. A circumferential surface 135 of an outer edge of the outer circumferential part 120 of the disk 100, in order to mechanically couple a tool to it for receiving the counter-torque, is formed perpendicular to the underside 115, 125 of the disk 100, which is not to be conical with respect to the underside of the outer circumferential part 125 of the disk 100. The configuration of the outer circumferential part comprises circumferentially spaced projections 130 extending outwards from the disc 100 to be mechanically coupled to the tool for receiving the counter-torque, and the projections 130 are configured to engage with fingers of the tool for receiving the counter-torque in order to restrain rotation of the disc 100 relative to the tool for tightening the threaded fastener. Fig. 1b schematically shows an isometric top view of the underside of the disc 100 as an enlargement of a section of Fig. 1a, in order to depict in more detail the elongated elevations 140 and the flat sections 150 on the underside of the body part 110 and the outer circumferential part 120 of the disc 100. Fig. 2 schematically shows an isometric top view of the underside of a disk 200 and corresponds to the schematically drawn disk 100 of Fig. 1a, with the difference that the longitudinal direction of the elongated projections 240 of the underside of the outer circumferential part 225 and / or the body part 215 of the disk 200 extends straight outwards with respect to the central axis 102 of the disk 200 and is inclined counterclockwise with respect to a radial direction on the underside 215, 225 of the disk 200. The disk described is intended to be used with threaded fastening devices that include right-hand threads; for disks intended to be used with threaded fastening devices that include left-hand threads, the inclination would be clockwise. Fig. 3 schematically shows an isometric top view of the upper surface of a disk 300 with a body part 110 and an outer circumferential part 120, wherein the disk 300 comprises an upper surface facing a lower surface. The upper surface of the body part 315 of the disk 300 comprises a third type of means for increasing the coefficient of friction 330, which partially covers the upper surface, in particular to prevent vibrational rotation of the tightened threaded fastener. The third type of means for increasing the coefficient of friction comprises a third type of elongated projections 330, which project from the upper surface of the disk in a direction aligned with the central axis 102. Each elongated projection is structured as a wedge with an edge arranged distal to the upper surface, the distal edge extending in a radial direction of the disk that is inclined clockwise with respect to a radial direction of the disk 300. The elongated protrusions 330 can form a toothing on the upper surface of the disk 300, comprising a sawtooth structure. The saw wedges or saw teeth can be characterized by the fact that, in a sectional view of the toothing, the teeth or wedges are asymmetrical with respect to a plane perpendicular to the surface of the disk passing through the highest point of the sawtooth or wedge; that is, there is one flank with a smaller angle (shallower flank) and one flank with a larger angle (steeper flank) with respect to a plane of the disk. The plane of the disk is a plane parallel to the surfaces of the disk 300. The saw teeth or saw wedges are arranged to allow easier rotation in the tightening direction (also known as the tightening direction) than in the loosening direction (also known as the loosening direction). This means that any ridge under the head of a screw, whether present or not, can slide along the flatter flanks of the saw teeth when the threaded fastener is tightened. Thus, the friction in the tightening direction is lower than the friction in the loosening direction. The saw teeth of the 330 saw tooth structure are directly adjacent to one another, so there is no flat section between the saw teeth on the washer surface. It is preferred that the angle between the flatter flank of the saw teeth and the plane perpendicular to the surface of the disk passing through the highest part of the saw tooth be between 2 and 20°, more preferably between 4 and 15°, and most preferably between 6 and 12°. Furthermore, it is preferred that the angle between the steep flank of the saw teeth and the plane perpendicular to the surface of the disk passing through the highest part of the saw tooth be between 55 and 75°, more preferably between 58 and 72°, and most preferably between 60 and 70°. Preferably, the height of the saw teeth, i.e., a maximum dimension of the saw teeth in a direction perpendicular to the disk plane, is from 0.12 mm to 0.25 mm, more preferably from 0.13 mm to 0.24 mm and most preferably from 0.13 mm to 0.23 mm, such as from 0.15 mm to 0.20 mm. The disc 300 has a chamfered section (bevel) 350 on an inner circumference of the top surface. Fig. 4 schematically shows an isometric top view of the upper surface of a disk 400 according to the disk 300 in Fig. 3. It differs from the disk 300 in Fig. 3 in that the distal edge of the wedge of the elongated projections 430 extends in a radial direction of the disk. QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature EP 3 083 146 A1

[0005] US 11,396,902 B2

[0005] US 2009 / 142155 A1

[0006] Cited non-patent literature ISO 6508-1

[0090]

Claims

A disc (100, 200, 300, 400) for receiving a counter-torque generated when tightening or loosening a threaded fastener, comprising: a body part (110) extending radially about a central axis (102) of the disc (100, 200, 300, 400); a central bore (105) in the body part (110) configured to enclose the threaded fastener and aligned with the central axis (102); and an outer circumferential part (120) of the disc (100, 200, 300, 400) configured to be mechanically coupled to a tool for receiving the counter-torque; wherein the outer circumferential part (120) of the disk (100, 200, 300, 400) comprises circumferentially spaced projections (130) which extend outwards from the disk (100, 200, 300, 400) in order to be mechanically coupled to the tool for receiving the counter-torque;characterized in that a bottom side of the outer circumferential part (125) of the disk (100, 200, 300, 400) is configured by means of a first type of means for increasing the coefficient of friction to interact with a bearing surface for receiving the counter-torque. Disc (100, 200, 300, 400) according to claim 1, wherein furthermore an underside of the body part (115) of the disc is configured to interact with the bearing surface by means of a second type of means for increasing the coefficient of friction. Disc (100, 200, 300, 400) according to claim 1 or 2, wherein the first type is a means for increasing the coefficient of friction and / or the second type is a means for increasing the coefficient of friction of the underside of the disc (115, 125) being structured and / or knurled and / or textured and / or toothed by means of a plurality of elongated protrusions (140); and / or by means of a plurality of elongated depressions. Disc (100, 200, 300, 400) according to claim 3, wherein each respective projection (140) comprises a wedge and / or a tooth and / or a ridge and / or a toothing. Disc (100, 200, 300, 400) according to claim 3 or 4, wherein the elongated protrusions (140) have a symmetrical cross-section and / or the elongated depressions have a symmetrical cross-section. Disc (100, 200, 300, 400) according to claims 3 to 5, wherein in a top view of the underside of the disc (115, 125) the elongated projections (140) and / or the elongated depressions and / or the teeth of the underside of the outer circumferential part (125) and / or the body part (115) of the disc extend longitudinally in a direction from an inner to an outer edge of the underside of the disc (115, 125) and / or from an inner to an outer circumference of the underside of the disc (115, 125), and preferably extend completely from the inner to the outer edge of the underside of the disc and / or extend completely from an inner to an outer circumference of the underside of the disc. Disc (100, 200, 300, 400) according to claim 6, wherein the longitudinal direction of the teeth and / or the elongate protrusions and / or the elongate depressions of the underside of the outer circumferential part and / or the body part of the disc coincides with straight lines. Disc (100, 200, 300, 400) according to claim 6 or 7, wherein the longitudinal direction of the teeth and / or the elongate projections and / or the elongate depressions of the underside of the outer circumferential part and / or the body part of the disc coincides with the radially extending straight lines whose origin lies in the central axis (102) of the disc (100, 200, 300, 400). Disc (100, 200, 300, 400) according to claims 3 to 8, wherein the teeth and / or the elongated projections (140) have a triangular shape and / or a rectangular shape in the sectional view of their longitudinal direction. Disc (100, 200, 300, 400) according to one of claims 3 to 9, wherein upper sections of the teeth and / or the elongated projections (140) of the underside of the outer circumferential part (125) and / or the body part (115) of the disc (100, 200, 300, 400) are rounded in the sectional view of their longitudinal direction. Disc (100, 200, 300, 400) according to any one of claims 3 to 10, wherein the teeth and / or the elongated projections (140) of the underside of the outer circumferential part (125) and / or the body part (115) of the disc, which in particular form the structured and / or knurled and / or textured and / or toothed underside of the disc, are arranged separately from one another, in particular by means of a flat section (150) on the underside (115, 125) of the disc, which is arranged between each tooth and / or each elongated projection (140). Disc (100, 200, 300, 400) according to any one of claims 3 to 11, wherein both the underside of the outer circumferential part (125) and the underside of the body part (115) of the disc are configured as teeth comprising a plurality of teeth; and wherein the teeth of the underside of the outer circumferential part (125) and those of the body part (125) fit seamlessly together. Disc (100, 200, 300, 400) according to one of the preceding claims, wherein a circumferential surface (135) of an outer edge of the outer circumferential part of the disc (100, 200, 300, 400) is formed perpendicular to the underside (115, 125) of the disc, which in particular should not be conical with respect to the underside (115, 125) of the disc. A disk (100, 200, 300, 400) according to one of the preceding claims, wherein the configuration of the outer circumferential part of the disk (120) comprises circumferentially spaced projections (130) extending outwards from the disk (100, 200, 300, 400) to be mechanically coupled to the tool for receiving the counter-torque, and the projections (130) are in particular configured to engage with fingers of the tool for receiving the counter-torque in order to inhibit rotation of the disk (100, 200, 300, 400) relative to the tool. A washer (100, 200, 300, 400) according to any of the preceding claims, wherein the washer (100, 200, 300, 400) comprises a top surface facing the underside of the nut or screw head of the threaded fastening arrangement; and wherein a top surface of the outer circumferential part (325) and / or a top surface of the body part (325) of the washer (100, 200, 300, 400) comprises a third type of means for increasing the coefficient of friction (330, 430), in particular to prevent vibrational rotation of the tightened threaded fastening element.

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