SCREW NUT WITH SCREW CAGE

Description

[0001] According to the preamble of claim 1, the invention relates to a screw nut with a cage or screw cage made of sheet metal.

[0002] Screw cages made of sheet metal are known from the prior art. These cages are used, particularly in inaccessible locations, to hold a nut in place while tightening or loosening the engaging screw (or similar), preventing it from rotating. A unit consisting of a nut and a screw cage is also called a cage nut.

[0003] Patent DE 10 2005 059 523 A1 describes a so-called flange cage nut. This flange cage nut comprises a conventional flange nut with a drive element that is hexagonal in plan view. The flange cage nut further comprises a cage attached to the nut, which is stamped and bent from a sheet of sheet metal folded multiple times. The cage has a clamping element and a retaining element. The retaining element consists of a flat sheet metal plate with a circumferentially closed opening in which the hexagonal drive element of the nut fits precisely and is rotationally fixed.

[0004] The closest patent, US 2013 / 0004259 A1, describes a fastener with a hexagonal nut and a sheet metal retainer cage. The nut is positioned in an opening of the retainer cage such that the retainer cage and nut cannot rotate relative to each other. The opening has several tabs formed as sheet metal through-holes that abut the lateral torque-transmitting surfaces of the nut. Additionally, the opening between the tabs has cutouts that expose the edges of the nut.

[0005] For the prior art, reference is also made to patent specifications WO 2012 / 156271 A9, DE 10 2011 000 660 A1, DE 691 00 071 T2, FR 2 983 269 A1, CN 101839269 A, EP 0 266 668 A1 and US 4,667,916 A.

[0006] In the screw-nut with screw cage according to claim 1, the screw cage is designed such that high holding forces or high counter-torques can be applied to the screw-nut. Additional features of the invention will become apparent from the dependent claims, the following description of the invention (which expressly includes features described as "for example", "preferred", "in particular", etc.) and the drawing.

[0007] The invention provides for a screw nut, particularly a metallic one, with a screw cage made of sheet metal (referring to a unit or connection of screw nut and screw cage, which can also be called a cage nut). The screw cage has a retaining section (retaining part) that holds the screw nut and a clamping section (clamping part) that supports the retaining section (e.g., against a body panel). The retaining section has a circumferentially closed opening in which the screw nut is arranged in a rotationally fixed manner or which rotationally fixedly engages the screw nut. According to the invention, the opening in the retaining section of the screw cage has several tabs designed as sheet metal through-holes, in particular tongue-like tabs, which bear against the (outer) lateral torque transmission surfaces or tool contact surfaces of the screw nut.

[0008] The tabs, designed as sheet metal through-holes, are arranged at the inner edge of the opening and extend, in particular, at least partially, in the axial direction of the nut and can therefore also be described as raised tabs. Preferably, the tabs are arranged evenly distributed in the circumferential direction, with one tab provided for each torque transmission surface of the nut. The nut is a hexagonal nut, in particular a hexagonal flange nut, with one tab provided on the screw cage for each of the torque transmission surfaces on the nut, i.e., for all six torque transmission surfaces.

[0009] The tabs, through a clamping effect, generate very high holding forces for the axial fixation of the nut in the screw cage and also facilitate the application of counter-torques (for torque support) to the nut. The large contact area between the tabs and the nut reduces scratching and chip formation during pre-assembly (i.e., when inserting the nut into the screw cage opening), especially on coated nuts. This also further reduces the risk of corrosion.

[0010] According to the invention, the opening (in the holding section of the screw cage) is at least partially larger than the nut. This means the nut does not fit snugly in the opening, but rather a gap exists between them, at least in the relevant sections, allowing for a small degree of movement (play). This gap or play facilitates pre-assembly and reduces scratching and chip formation. The gap is preferably no more than a few tenths of a millimeter wide.

[0011] The nut may have a coating, in particular a corrosion protection coating (e.g., zinc plating). Scratching or abrasion of this coating can be largely prevented by the measures described above (full contact of the tabs and / or gap or clearance).

[0012] According to the invention, the opening (in the holding section of the screw cage) is designed with additional positive locking elements that bear against or engage the screw nut in the edge regions between the torque transmission surfaces, optionally with a gap or clearance (so). An additional positive locking element is provided for each edge of the screw nut. An equal number of tabs and additional positive locking elements, arranged between each of the tabs, are provided (i.e., six tabs and six additional positive locking elements). Preferably, the additional positive locking elements project from the edge of the opening towards the screw nut and extend, in particular, in the plane of the holding section. The additional positive locking elements enable the transmission of very high torques or counter-torques (for torque support).

[0013] This allows for a functional separation, such that the tabs are primarily intended for the axial fixation of the screw nut in the screw cage, and the additional positive locking elements are primarily intended for torque support. When tightening or loosening a screw engaging the screw nut, the tabs can deform elastically, so that torque support can essentially only be achieved via the additional positive locking elements.

[0014] According to the invention, the additional positive locking elements are fork-shaped at their ends facing the nut, in particular with two prongs or teeth each, which bear against or engage the edges (formed between the torque transmission surfaces) of the nut on both sides. Preferably, the inner areas of these fork-shaped ends, meaning in particular the areas between the two prongs or teeth, are rounded or formed with radii to reduce notch effects and, in particular, to avoid notch stresses.

[0015] The nut is preferably designed with an M10, M12, or M14 internal thread (or larger). This allows for comparatively high tightening and loosening torques, which can be supported by the screw cage.

[0016] The screw cage is preferably designed as a one-piece sheet metal part (stamped and formed part) and is particularly made of spring steel sheet. The sheet preferably has a thickness of 1.0 mm to 1.5 mm.

[0017] The invention is explained in more detail below in a non-limiting manner with reference to the drawing. The features shown and / or explained below can, even independently of specific combinations of features, be general features of the invention and further develop the invention accordingly. Fig. 1 shows two separate views of an embodiment of a screw nut with a screw cage according to the invention. Fig. 2 shows an embodiment of a screw nut with a screw cage that does not conform to the invention.

[0018] In Fig. 1 The nut 110 is designed as a hexagonal nut with a flange 111 (so-called hexagonal flange nut) and a plastic insert 112 serving as a locking device (so-called locking nut). The screw cage 120, designed as a one-piece sheet metal part, has a flat retaining section 122 that holds the nut 110 and a clamping section (clamping spring) 121 that supports the retaining section 122. The retaining section 122 has a circumferentially closed opening 123 in which the nut 110 is held in a rotationally fixed position. The pre-assembled unit (cage nut) consisting of the nut 110 and the screw cage 120 is designated 100.

[0019] The opening 123 in the retaining section 122 of the screw cage 120 is partially larger than the screw nut 110, so that a gap 130 exists between the two in the relevant sections, as shown in the top view of the Fig. 1b As indicated. The gap 130 allows for a small degree of movement between the screw nut 110 and the screw cage 120.

[0020] The opening 123 has several tabs 124, designed as sheet metal through-holes or axially oriented, quasi-collar-like tabs, which bear against the outer torque transmission surfaces 114 of the nut 110 and clamp the nut 110 between them. As can be seen from the top view in Fig. 1b As can be seen, the tabs 124 are cut free on both sides so that they can spring better in the radial direction.

[0021] The opening 123 is further formed with additional positive locking elements 125, which are arranged between the tabs 124 and bear against the edges 115 or in the edge regions 115' of the nut 110. The additional positive locking elements 125 are fork-shaped. The V-shaped inner areas at the fork-like ends have radii 126 to prevent notch stresses. In the unloaded or torque-free state, the additional positive locking elements 125 are spaced apart from the nut 110 by the gap 130 (so).

[0022] As explained above, the tabs 124 are primarily for the axial fixation of the screw nut 110, and the additional positive locking elements 125 are primarily for torque support. When tightening or loosening a screw engaging the screw nut 110, a torque M acts on the screw nut 110 (see Fig. 1b ), whereby the tabs 124 are initially elastically deformed until the gap-related play between the screw nut 110 and the screw cage 120 is overcome and then torque support can be provided via the additional positive locking elements 125.

[0023] The in Fig. 2 The non-inventive embodiment shown differs from the one in Fig. 1 The embodiment shown differs essentially in that the screw nut 110 and the retaining section 122 of the screw cage 120 have a different relative orientation and that only three tabs 124 are provided, which bear against every second torque transmission surface 114 of the screw nut 110. Nevertheless, analogous to the embodiment of the Fig. 1 A total of six additional positive locking elements 125 are provided, so that an essentially equal counter-torque can be applied to the screw nut 110.

Claims

1. Screw nut (110) having a screw cage (120) which is produced from sheet metal and which has a retention portion (122) which retains the screw nut (110) and a clamping portion (121) which supports the retention portion (122), wherein the retention portion (122) is constructed with a circumferentially closed opening (123) in which the screw nut (110) is arranged in a rotationally secure manner, wherein the opening (123) is constructed in portions to be larger than the screw nut (110) so that in the relevant portions a gap (130) is provided between the two, wherein the opening (123) has multiple flaps (124) which are constructed as rimmed holes in the sheet metal which bear on the lateral torque transmission faces (114) of the screw nut (110), wherein the screw nut (110) is constructed as a hexagon nut and for each torque transmission face (114) of the screw nut (110) such a flap (124) is provided, wherein the flaps (124) bring about an axial fixing of the screw nut (110) in the screw cage (120) by means of a clamping effect, characterized in that the opening (123) is constructed with additional positive-locking elements (125) which for torque support in the edge regions (115') between the torque transmission faces (114) bear on the screw nut (110) and at the ends thereof facing the screw nut (110) are constructed in a fork-like manner, wherein each flap (124) is cut free at both sides with respect to the adjacent positive-locking elements (125).

2. Screw nut (110) having a screw cage (120) according to claim 1, characterized in that the screw nut (110) has a coating.

3. Screw nut (110) having a screw cage (120) according to any one of the preceding claims, characterized in that the inner regions of the fork-like ends of the positive-locking elements (125) are constructed with rounded portions (126).

4. Screw nut (110) having a screw cage (120) according to any one of the preceding claims, characterized in that the screw nut (110) is constructed with an M10, M12 or M14 internal thread.

5. Screw nut (110) having a screw cage (120) according to any one of the preceding claims, characterized in that the screw cage (120) is produced as an integral sheet metal component.