INTEGRATED INSTALLATION SPINDLE, AN INSTALLATION TOOL FOR INSTALLING A WIRE THREAD INSERT AND AN INSTALLATION METHOD

Description

1. Field of the invention

[0001] The present invention relates to an integrally designed installation spindle adapted to a wire thread insert, a retrofit kit for an installation tool with a plurality of such installation spindles, an installation tool consisting of a drive module and an integrally designed installation spindle, and an installation method for a wire thread insert with a retractable, non-removable drive pin using the aforementioned installation tool. 2. Background of the invention

[0002] Various technical solutions for installing a wire thread insert in a threaded bore are known in the prior art. The installation spindle used for installing the wire thread insert in the threaded bore depends on the design of the wire thread insert itself. For example, different wire thread insert designs feature a radially inward-projecting, straight installation pin that is broken out of the insert after installation. Another design provides the wire thread insert with a radially inward-positioned notch. A corresponding driver engages in this notch to screw the wire thread insert into the internal thread. This design eliminates the need to remove an installation pin after the wire thread insert is installed.Another design alternative for a wire thread insert features a radially inwardly bent mounting pin, with or without a notch. After installation, this mounting pin is bent radially outward back into the internal thread of the threaded bore.

[0003] Due to the different technical solutions for wire thread inserts, the number of known designs of mounting spindles for installing the respective wire thread insert in the threaded bore of a component also varies.

[0004] DE 699 03 965 T2 describes an installation spindle with a slot running parallel to the diameter of the installation spindle for receiving an installation pin of the wire thread insert. Due to the arrangement of the slot at the functional end of the installation spindle, the axial end face of the installation spindle at the functional end is divided into two axial extensions. These two opposing axial extensions each have chamfered sections. The chamfered section of one axial extension is inclined radially outwards. It facilitates the snap-in engagement of the radially inwardly bent installation pin of the wire thread insert. The second axial extension of the installation spindle has an inclined plane that is inclined radially inwards from the second axial extension towards the slot for the pin receptacle.This inclined plane serves to facilitate the removal of the mounting pin from the central gap at the functional end of the mounting spindle once the mounting spindle is to be removed from the wire thread insert after installation is complete. Thus, this design of the mounting spindle, due to its central gap at the functional end, allows for the use of a radially inwardly projecting mounting pin for installation, but does not allow for its modification after installation.

[0005] According to JP 2008 0 38937 A, the wire thread insert to be installed also has a straight, radially inward-projecting mounting pin. The spindle or threaded bolt has a radially oriented axial undercut on the axial end face of the spindle's functional end. As soon as the spindle is screwed into the wire thread insert, the mounting pin engages with this axial undercut. This creates a rotationally fixed connection between the mounting spindle and the wire thread insert, allowing the wire thread insert to be screwed into the threaded bore. Even if the threaded spindle or bolt is rotated backward, the mounting pin remains unchanged. The reverse rotation simply disengages the axial undercut and the mounting pin.

[0006] US 3,348,293 discloses an installation spindle for a wire thread insert, which has a radially inwardly bent, arcuate mounting pin. The mounting pin has a predetermined breaking point so that, after the wire thread insert has been installed in an internal thread, the mounting pin can be broken out of the wire thread insert. The installation spindle, in turn, has a drive shoulder at its functional end that engages in the bend of the wire thread insert opposite the apex between the mounting pin and the rest of the wire thread insert. In this way, a rotationally fixed connection is created between the installation spindle and the wire thread insert, so that the wire thread insert can be screwed into the internal thread. If the installation spindle is turned in the opposite direction of insertion, the installation spindle is unscrewed from the installed wire thread insert.Once this has been done, the mounting pin connected via the predetermined breaking point can be separated.

[0007] The technical solutions described above for installing a wire thread insert with a removable mounting pin have the disadvantage that the removed mounting pin either has to be collected after installation and removal or remains in the component. The removed mounting pin remaining in the component can lead to malfunctions, noise, or blockages during further assembly of the component.

[0008] EP 3 212 361 B1 discloses an installation spindle for a wire thread insert with a retractable installation pin. This retractable installation pin has an installation notch on its radial inner side, into which the installation spindle engages to screw the wire thread insert into the internal thread of the threaded bore. The installation spindle has an axial extension at the axial end face of the installation end. This axial extension utilizes a reduced-length thread along its circumference to guide the wire thread insert. In the installation direction, at the beginning of the reduced-length thread, a drive edge is provided that engages in the radially inner notch of the wire thread insert. The drive edge extends parallel to the longitudinal axis of the installation spindle to ensure reliable engagement with the drive notch of the wire thread insert.At the opposite end of the reduced-length thread of the axial extension, a circular arc-shaped bending shoulder is provided. When the installation spindle is rotated against the installation direction, the bending shoulder engages the mounting pin and presses it radially outward into the internal thread of the threaded opening. This design of the installation spindle has the disadvantage that it can only be used in combination with a wire thread insert with a radially internal drive notch. Otherwise, the drive edge of the installation spindle would have no way to engage the wire thread insert and screw it into the threaded opening.

[0009] European patent 2 637 825 B1 discloses a wire thread insert for installation in a receiving thread of a component. This wire thread insert has a drive pin that projects into the interior of the wire thread insert's walls via a bending section. The drive pin is permanently connected to the helix of the wire thread insert. The radially inwardly bent drive pin is characterized by the fact that it can be bent back into a receiving thread of a threaded bore using a suitable tool. For the reliable installation of this wire thread insert with a bendable drive pin, the aforementioned European patent describes an installation tool that is specially designed at one functional end of the installation spindle. On an axial end face of the installation spindle pointing in the installation direction, two separately arranged axial extensions project from the axial end face.A receiving slot is formed between these axial extensions, in which a radially movable upsetting blade is arranged. Together, the two axial extensions and the intermediate movable upsetting blade form a reduced-length thread through their radial outer surfaces to guide a portion of the wire thread insert. While the axial extension located at the front in the direction of rotation forms a drive shoulder engaging the drive pin of the wire thread insert, the second axial extension, located at the end of the reduced-length thread in the direction of rotation, serves as a re-bending shoulder for bending the drive pin back into the receiving thread of the threaded bore. The upsetting blade arranged between the two axial extensions is moved radially such that, in a radially outer position, it blocks the reduced-length thread to allow the drive pin to be upset during the re-bending process.

[0010] The structurally complex installation spindle for installing the wire thread insert with retractable mounting pin must be controlled appropriately in order to be able to utilize all design features during the installation of the wire thread insert.

[0011] A locking bolt with a wire thread is known from US 2,745,457 A. This bolt comprises, in combination, a bolt and a wire coil insert for a threaded hole, forming an inner and an outer screw thread. The bolt has a head designed to exert a torque and a shank section with a free end opposite the head. The shank section is provided with an outer screw thread that engages with the inner screw thread formed by the insert. The free end is provided with an axial slot having flanking walls parallel to each other and to the axis of the bolt. The slot forms two end projections of the shank, each having an end face inclined substantially from the bottom of the slot at its opposite ends and upward to the outermost end of the projections in the same direction as the thread of the bolt.The wire coil has a diametrically opposed pin at one end, which is positioned in the slot, the end faces being inclined so that the pin can run on them but is thereby deformed before the wire coil leaves the slot if a torque which tends to reverse the bolt in the insert exceeds a predetermined value.

[0012] With regard to the known design of an installation spindle for a wire thread insert with a bendable mounting pin according to EP 2 637 825 B1, the object of the present invention is to provide an alternative design of an installation spindle for a wire thread insert with a bendable mounting pin with a long service life. 3. Summary of the invention

[0013] The above problem is solved by an integrally formed installation spindle according to independent claim 1, a retrofit kit for an installation tool with drive module and detachable installation spindle with at least two integrally formed installation spindles according to independent claim 9, an installation tool with the integrally formed installation spindle according to independent claim 10, and by an installation method for a wire thread insert using the installation tool according to the invention according to independent claim 11. Advantageous embodiments and further developments of the present invention will become apparent from the following description, the accompanying drawings, and the appended claims.

[0014] The present invention discloses an integrally formed installation spindle adapted to a wire thread insert, which has a cylindrical helix with a plurality of helically wound turns of wire, in which a first turn comprises a preferably arc-shaped drive pin without a drive notch, projecting over a bending region into an interior of the helix, with which the wire thread insert can be screwed into a threaded bore of a component in an insertion direction. The installation spindle according to the invention has the following features: a drive and holding end for rotating and holding the installation spindle in an installation tool and a functional end for installing the wire thread insert in a threaded bore of a component; an axial extension projects from an axial end face of the installation spindle at the functional end in the direction of a longitudinal axis of the installation spindle.which is limited along a circumferential extension of the installation spindle by an arc-shaped radial outer surface at a rotation angle α from a range of 30° ≤ α ≤ 180°, with respect to the direction of rotation, the axial extension has a ramp starting at a front end of the arc-shaped radial outer surface, which extends upwards in the axial direction of the installation spindle, and with respect to the direction of rotation, the axial extension drops axially at a rear end of the arc-shaped radial outer surface in an axial re-bend surface, which is arranged radially similarly.

[0015] The integrally designed installation spindle according to the invention is constructed as a robust, one-piece installation spindle that can be used interchangeably in an installation tool for wire thread inserts. Compared to known installation spindles for wire thread inserts with a retractable installation pin, the present installation spindle is more robust in use due to its one-piece construction and is therefore characterized by greater durability and service life compared to multi-piece installation spindles.

[0016] The central element of the installation spindle is an axial extension located at one functional end of the spindle—that is, the end onto which the wire thread insert with its retractable mounting pin is threaded or attached. This extension is arranged on the axial face of the spindle at its functional end. This preferably single axial extension is shaped such that, after the wire thread insert with its retractable mounting pin is threaded onto the spindle, it forms a rotationally fixed connection with the insert. To achieve this, as the wire thread insert is threaded onto the spindle, the retractable mounting pin snaps over the axial extension until, after further rotation of the installation spindle, it locks securely into place. This rotationally fixed, positive-locking connection ensures that the wire thread insert can be easily screwed or turned into the internal thread of the threaded bore of a component.

[0017] To allow the radially inwardly bent mounting pin to easily engage or anchor itself to the axial extension, it slides up the ramp in the axial direction of the mounting spindle until it slides off the axial extension at the end of the ramp. In this way, the strip-shaped ramp prepares the surface for a spring-loaded snap connection between the radially inwardly bent, retractable mounting pin and the axial extension on the axial base surface of the mounting spindle.

[0018] After the wire thread insert has been installed, the mounting spindle can be removed from the insert by turning it in the opposite direction to the installation rotation. In addition to removing the mounting spindle from the insert, this reverse rotation simultaneously bends the retractable mounting pin back into the internal thread of the threaded bore. Since the axial extension preferably terminates in a retractable surface at the end opposite the ramp, this surface presses the mounting pin radially outward toward the internal thread of the threaded bore when the mounting spindle is reversed. Thus, the preferably single axial extension on the axial end face of the mounting spindle represents a multifunctional axial extension.This multifunctional extension supports the installation process of the wire thread insert into the threaded bore through its strip-like ramp and also completes the installation process by bending the installation pin back into the internal thread of the threaded bore using the bending surface.

[0019] According to a preferred embodiment of the present invention, the axial extension has at least one thread turn with reduced length in the circumferential direction.

[0020] As mentioned above, the axial extension projects from the axial end face at the functional end of the mounting spindle. The radial outer surface of the axial extension extends circumferentially around the mounting spindle. Furthermore, the thread at the functional end of the mounting spindle preferably continues along the radial outer surface in the form of a preferably shortened thread in the circumferential direction of the axial extension. Preferably, depending on its axial height, i.e., its projection above the axial end face of the mounting spindle, the axial extension has one or two threads on its arcuate radial outer surface. It is also preferred to provide more than two shortened threads if these facilitate the installation and / or removal of the mounting spindle from an installed wire thread insert with a retractable mounting pin.

[0021] Preferably, the axial extension at the functional end of the installation spindle protrudes axially on the axial end face.

[0022] Furthermore, according to the invention, it is preferred that the axial extension occupies less than 40% of the axial end face at the functional end.

[0023] To ensure the multifunctional function of the axial extension, it preferably occupies an area of ​​less than 50% of the axial end face at the functional end of the mounting spindle. This area, which can also be reduced to 25-35%, is sufficient to create a rotationally fixed mounting position for the wire thread insert on the axial extension and to effectively and sufficiently bend the retractable mounting pin back into the internal thread of the threaded bore when the mounting spindle is removed.

[0024] According to a preferred embodiment of the present invention, the axial extension on the radial outer side has two length-reduced threads which differ in at least one of the following dimensions: circumferential length, core diameter and pitch.

[0025] To ensure effective threading of the wire thread insert with its retractable mounting pin, and thus effective anchoring of the mounting pin for insertion of the wire thread insert into the threaded bore, two reduced-length threads are preferably provided on the circumferential radial outer surface. During threading of the wire thread insert onto the functional end of the mounting spindle, the reduced-length threads guide the wire helix of the wire thread insert. Once the retractable mounting pin is securely held against rotation on the axial extension, this hold is further supported by the course of the wire helix of the wire thread insert in at least one of the reduced-length threads.

[0026] While this support stabilizes the insertion process, a specific design of the reduced-length threads ensures effective re-bending of the retractable insertion pin into the internal thread of the threaded hole. For this purpose, the core diameter and / or pitch of the two reduced-length threads are designed differently compared to the rest of the thread on the insertion spindle. Alternatively, the core diameter and / or pitch of only one reduced-length thread is designed differently compared to the rest of the thread on the insertion spindle. Preferably, a larger core diameter of only the axially outer reduced-length thread, or of both reduced-length threads, facilitates re-bending of the retractable insertion pin into the internal thread of the threaded hole.

[0027] Furthermore, it is preferred to use a larger pitch of one or both of the reduced-length threads compared to the rest of the thread of the mounting spindle in order to support the bending back of the bendable mounting pin into the internal thread of the threaded bore.

[0028] By varying the circumferential length, preferably by increasing the circumferential length, at least one reduced-length thread turn, additional guidance of the helix of the wire thread insert by the axial extension is also preferably ensured.

[0029] Preferably, the axially outer, length-reduced thread has a larger core diameter and / or a larger pitch compared to the adjacent length-reduced thread.

[0030] According to a further preferred embodiment of the present invention, the axial extension in the axial direction between the axial end face of the functional end and the front end of the ramp has an axial web as a driving shoulder which is adapted to hold a wire thread insert rotationally fixed when screwing it into a threaded bore.

[0031] During the threading of the wire thread insert onto the functional end of the mounting spindle, the axial extension is preferably unscrewed axially from the interior of the wire thread insert. If the axial extension protrudes only slightly beyond the interior of the wire thread insert, the retractable mounting pin slides along the ramp on the axial extension, and the screwing of the mounting spindle into the wire thread insert or the threading of the wire thread insert onto the functional end of the mounting spindle continues. As soon as the axial extension preferably protrudes sufficiently far from the interior of the wire thread insert, the mounting pin can no longer run onto the ramp and slide over the axial extension. Instead, the retractable mounting pin remains at the preferred drive shoulder or...The drive shoulder, or axial rib, which is located between the start of the ramp and the adjacent axial end face of the drive spindle, thus forms a rotationally fixed connection between the functional end of the installation spindle and the threaded wire insert. This creates a positive-locking connection with the installation pin, preventing further threading of the wire insert onto the functional end of the installation spindle.

[0032] Also preferably according to the invention, the axial bending surface encloses an angle β with the adjacent axial end face of the functional end in the range of 65° ≤ β ≤ 90°.

[0033] At the circumferentially opposite end of the axial extension, an axial bending surface is provided for preferably bending the mounting pin back into the internal thread of the threaded bore. To support the retention or support of the mounting pin against the bending surface and to prevent the retractable mounting pin from snapping over the bending surface towards the ramp, the axial bending surface forms an angle of less than 90° with respect to the axial end face of the mounting spindle. In this way, the retractable mounting pin is preferably held at an acute angle between the bending surface and the axial end face of the mounting spindle while it is bent in the opposite direction to the insertion of the wire thread insert into the internal thread of the threaded bore.

[0034] The present invention also comprises a retrofit kit for an installation tool of a wire thread insert with a detachably connectable drive module and a mounting spindle, which has at least two integrally designed mounting spindles as interchangeable mounting spindles according to one of the embodiments described above, which differ in a design and / or dimension of the mounting spindle.

[0035] Furthermore, the present invention comprises an installation tool, in particular a manual installation tool or an installation machine, of a wire thread insert with a detachably connectable drive module and an integrally designed installation spindle according to one of the embodiments described above.

[0036] The integrally designed installation spindle described above, with its various configurations, is used within an installation tool for installing wire thread inserts. These installation tools include, on the one hand, manually operated tools. With these tools, an operator manually positions the insert, orients it towards the threaded opening, and then triggers the insertion of the wire thread insert into the threaded bore by actuating corresponding switches. In another configuration, the integrally designed installation spindle is used in an automated wire thread insert installation machine. These machines operate automatically, meaning that the wire thread insert is positioned on the installation spindle via a mechanical feed.A further machine feeder positions the component with the threaded opening correctly in the installation direction below the installation tool. After these steps are completed and signaled to a central control system, the integrally designed installation spindle with the threaded wire insert is positioned towards the threaded opening and screws the wire insert into the opening.

[0037] The present invention further discloses an installation method for a wire thread insert with a retractable, non-removable drive pin without a drive notch, using an installation tool preferred according to the invention, in a receiving thread of a component, comprising the following steps: threading or fitting the wire thread insert onto the functional end of the integrally formed installation spindle of the installation tool such that the drive pin engages positively with the axial extension of the installation spindle and connects the wire thread insert to the installation spindle in a rotationally fixed manner; screwing the wire thread insert into the receiving thread by rotating the installation spindle in a first direction of rotation; retracting the drive pin into the receiving thread by rotating the installation spindle in a second direction of rotation opposite to the first, wherein the axial retraction surface of the axial extension deforms the drive pin.and unscrewing or removing the mounting spindle from the wire thread insert with the drive pin bent back.

[0038] The installation method according to the invention for the wire thread insert with a retractable mounting pin, using the integrally formed mounting spindle, is based on the installation method according to European Patent 3 212 361 B1. In contrast to the prior art, the integrally formed mounting spindle alone serves to screw in the wire thread insert and to retract the mounting pin into the internal thread of the threaded bore. Thus, the entire functionality of the integrally formed mounting spindle is reduced to the interaction between the preferably single axial extension on the axial end face of the functional end of the mounting spindle. This axial extension serves, on the one hand, to create a rotationally fixed, positive-locking connection between the wire thread insert and the mounting spindle. This positive-locking connection ensures that the wire thread insert can be screwed into the desired depth of the threaded bore.Once this depth is reached, the shape of the axial extension is sufficient to permanently bend the retractable mounting pin back into the internal thread of the threaded hole. In this process, only the retractable surface of the axial extension is relevant to completing the installation of the wire thread insert in the threaded hole. Therefore, it is not necessary to move an additional upsetting blade radially outward into the thread of the mounting spindle to bend the retractable mounting pin back into the internal thread.

[0039] According to a preferred embodiment of the installation method, the drive pin is radially bent back by means of a bending shoulder or a second threaded area with an enlarged core diameter compared to a first threaded area at the functional end of the installation spindle. 4. Brief description of the accompanying drawings

[0040] The preferred embodiments of the present invention are explained in more detail with reference to the accompanying drawings. These show: Figure 1 a perspective view of the integrally designed installation spindle preferred according to the invention, Figure 2 a a side sectional view of the integrally designed installation spindle preferred according to the invention, Figure 3 a perspective view of a wire thread insert with a retractable installation pin, Figure 4 an axial top view of a preferred embodiment of the end face of the installation spindle at its functional end, Figure 5 a further perspective top view of the axial end face of the Figure 3In a further preferred embodiment, Figure 4 shows a side view of the functional end of the integrally formed installation spindle in a preferred embodiment, Figure 5 shows a perspective top view of the functional end 20 of the installation spindle according to the present invention, Figure 6 shows an enlarged side view of the preferred functional end of the installation spindle according to the invention, Figure 7 shows another side view of the preferred functional end of the installation spindle, Figure 8 a, b, c shows various preferred embodiments of the re-bending shoulder at the functional end of the installation spindle, Figure 9 shows a preferred re-bending process of the installation pin of the installed wire thread insert in a torque-time diagram, Figure 10 shows a flowchart of a preferred embodiment of the installation method according to the present invention, and Figure 11 shows an example of an installation tool for a wire thread insert in which the installation spindle can be installed interchangeably. 5. Detailed description of preferred embodiments

[0041] Figure 1 Figure 1 shows a preferred embodiment of an integrally formed installation spindle 1. Such installation spindles 1 are used in an installation tool W with which a wire thread insert D is installed in a threaded bore of a component. A preferred installation tool W in the form of a handheld device is shown. Figure 11It comprises a drive unit 3 for rotating the preferred installation spindle 1. For this purpose, the drive unit 3 is preferably non-rotatably connected to the drive and holding end 10 of the installation spindle 1. According to a preferred embodiment of the installation tool W, the drive unit 3 is started or stopped via an actuating switch 5. A depth stop 7 preferably determines, in a known manner, the maximum depth to which a wire thread insert D with a retractable mounting pin Z can be screwed or inserted into a threaded bore of a component by rotating the installation spindle 1.

[0042] It is also preferred to use the integrally designed installation spindle 1 in an installation machine. This machine installs a wire thread insert D into a threaded bore of a component via automated work processes.

[0043] The integrally designed installation spindle 1 preferred according to the invention consists of a single piece. This means that no moving or stationary parts are attached to the installation spindle 1, such as a pivotable or rotatable installation or upsetting blade.

[0044] Furthermore, the installation spindle 1 according to the invention is adapted to install a wire thread insert D with a retractable mounting pin Z in a threaded bore of a component. The wire thread insert D is exemplified in Figure 2bIt comprises a cylindrical helix with a plurality of helically wound turns of wire, in which a first turn has a preferably arcuate drive pin Z projecting over a bending region into the interior of the helix without a drive notch. Such wire thread inserts are described and illustrated in EP 2 637 825 B1 according to various preferred embodiments, which is incorporated herein by reference for the technical understanding of the wire thread insert.

[0045] The installation spindle 1 has a drive and holding end 10 to connect the installation spindle 1 to a drive module of an installation tool (see Fig. 11) to connect. Preferably, the drive and holding end 10 is detachably held in the drive module via a poly-edged end and / or other known coupling structures. Such drive and holding ends 10 for holding and transmitting a torque to the installed spindle 1 are known in the prior art.

[0046] A functional end 20 of the mounting spindle 1 is provided axially opposite the drive and holding end 10. The functional end 20 of the mounting spindle 1 preferably has a spindle section 22, i.e., a right- or left-hand external thread 26. The spindle section 22 serves to thread the wire thread insert D onto the spindle in the direction of the drive end 10. The wire thread insert D is threaded onto the functional end 20 until the retractable mounting pin Z is rotationally fixed to an axial extension 30 of an axial end face 24 of the mounting spindle 1. Rotationally fixed in this context means that the mounting pin Z and the axial extension 30 form a positive-locking connection, so that the mounting spindle 10 rotates the wire thread insert D.

[0047] While Figure 1 A perspective view of the installation spindle 1 shows, is in Figure 2AA lateral sectional view of the installation spindle 1 is shown. It can be seen that the axial extension 30 projects from the axial end face 24 of the installation spindle 1 in the direction of the longitudinal axis of the installation spindle 1 and thus axially.

[0048] According to various preferred embodiments of the mounting spindle 1, the mounting spindle 1 is integral, i.e., provided as a single, solid unit. Accordingly, in one preferred embodiment, the mounting spindle 1 and the axial extension 30 are manufactured from a single piece.

[0049] The axial extension 30 (see below) is subject to wear due to the installation processes of wire thread inserts D, while the rest of the mounting spindle 1 experiences less wear. Therefore, it is also preferred to manufacture the axial extension 30 separately and then firmly and integrally connect it to the rest of the mounting spindle 1. For this purpose, metallurgical joining methods such as welding and bonding are preferred.

[0050] In an alternative embodiment to the spindle area 22, it is also preferred to provide a threadless outer surface (not shown) at the functional end 20 instead of an external thread 26. Accordingly, the wire thread insert D would be pushed onto the unthreaded functional end 20 in the axial direction until the retractable mounting pin Z is rotationally fixed to the axial extension 30. The wire thread insert D, held rotationally fixed to the functional end 20, is then screwed into the threaded bore of the component, preferably in the same manner as described below.

[0051] How to use the following Figure 2a as well as in the enlarged view of the Figure 4bAs can be seen, the external thread 26 extends on the spindle area 22 of the functional end 20 as well as on a radial outer surface 32 of the axial extension 30. Since the axial extension 30 covers only a fraction of the axial end face 24 of the installation spindle, preferably a proportion of less than 50% of the axial end face 24, the external thread 26 continues as at least one reduced-length thread turn 34 on the radial outer surface of the axial extension 30 - i.e., along the circumference of the installation spindle.

[0052] According to a preferred embodiment of the present invention, the axial extension 30 has a height relative to the axial end face 24 of the mounting spindle 1 such that two or more reduced-length threads 34 are arranged on the radial and circumferential outer surface 32 of the axial extension 30. The geometric design of the preferably at least two reduced-length threads 34 will be discussed in more detail below.

[0053] The Figures 3, 4a and 5 Figure 1 shows views of preferred embodiments of the axial end face 24 of the mounting spindle 1. On the axial end face 24, the axial extension 30 is preferably arranged off-center with respect to the end face 24 and projects from it. Furthermore, preferably only one axial extension 30 is provided on the axial end face 24 in order to screw the wire thread insert D into the threaded bore and to bend the mounting pin back into the internal thread.

[0054] The preferred axial extension 30 occupies a surface area of ​​less than 50%, preferably in the range of 30 to 40%, of the axial end face 24.

[0055] For this purpose, the axial end face 24 is considered as a circular area determined by the radius of the mounting spindle 1 on the end face 24.

[0056] Preferably, the axial extension 30 consists at least of the radial outer surface 32 in the form of a wall viewed in the circumferential direction of the functional end 20, with a profile and extent in the form of a circular arc. In this context, it is also preferred that, instead of a circular arc, an approximation by a curvilinear profile is used.

[0057] Extending radially inwards from the radial outer surface 32, the axial extension 30 has a preferred circumferentially variable radial width B of 0.1R ≤ B ≤ 0.8R, where R describes the radius of the functional end 20. B is not necessarily constant along the radial outer surface 32, so that the axial extension 30 may have an irregular shape with an arcuate radial side in axial plan view.

[0058] In the axial top view of the Figure 3 According to a preferred embodiment of the present invention, the axial extension 30 has a ramp 36 on a side facing away from the drive and holding end 10.

[0059] Contrary to the direction of insertion RE for a wire thread insert D into the threaded bore, the ramp 36 preferably rises continuously in an angular range of 5° ≤ α ≤ 40° to the axially highest or axially furthest point of the axial extension 30 from the holding end 10.

[0060] According to a preferred embodiment of the present invention, the ramp 36 consists of a strip surface that runs onto the axial extension 30 in an inclined axial direction. It is also preferred to provide the ramp 36 as a rib or bead-like thickening that runs onto the axial extension 30. The various preferred configurations of the ramp 36 allow the radially inwardly bent mounting pin Z of the wire thread insert D to run onto the axial extension 30 during the threading of the wire thread insert D onto the functional end 20. As long as the wire thread insert D is not rotationally fixed to the axial extension 30 by the mounting pin Z when screwed or threaded onto the functional end 20, or when the functional end 20 is screwed into the wire thread insert D, the mounting pin Z slides onto and over the axial extension 30, supported by the ramp 36.

[0061] If the functional end 20 is screwed sufficiently far into the wire thread insert D in the direction of rotation RE, the wire thread insert D is preferably held by a drive shoulder 38 and rotated with the installation spindle 1. The drive shoulder 38 consists of an approximately axially extending web or stop. This is arranged between the axial end face 24 and a beginning of the ramp 36, viewed in the circumferential direction of the installation spindle 1, as shown in the Figures 4b and 5 This can be seen. Since the functional end 20 of the mounting spindle 1 is already screwed sufficiently far into the wire thread insert D, the mounting pin Z encounters the drive shoulder 38 during further rotation of the mounting spindle 1 in the screw-in direction RE. This prevents the mounting pin Z from running onto the ramp 36 and from snapping over the axial extension 30.

[0062] According to the invention, at least one reduced-length thread 34 is preferably provided on the radial outer surface 32 of the axial extension 30, continuing the external thread 26 at the functional end 20. Since the axial extension 30 only extends along a portion of the circumference of the functional end 20, the at least one thread 34 is reduced in length.

[0063] The at least one reduced-length thread 34 preferably extends, like the axial extension 30, over an angle of rotation α in the range of 30° ≤ 180°. Preferably, the axial extension 30 extends over an angle of rotation α ≤ 90°. In this context, the angle of rotation α is determined between the drive shoulder 38 at the leading end RE of the axial extension 30 (in the direction of rotation) and an axial bending surface 40 at the trailing end RE of the axial extension 30 (in the direction of rotation).

[0064] In the axial direction, the axial extension 30 projects approximately a height H beyond the axial end face 24. The axial height H (see Figure 2a ) lies in a range of 0.5 x P ≤ H ≤ 2.5 P, in particular 0.7 P ≤ H ≤ 1.5 P, where P describes a pitch of the thread 26 at the functional end 20 of the installation spindle 1.

[0065] To facilitate the reliable insertion or screwing of the wire thread insert D into the threaded bore of a component with the functional end 20 of the mounting spindle 1, the axial extension 30 preferably has at least one reduced-length thread 34 on its radial arcuate outer surface 32. According to the invention, preferably two reduced-length threads 34a, 34b are arranged side by side in the axial direction. These are located in the Figures 4b , 6 and 7 to recognize.

[0066] Preferably, the threads 34a and 34b are geometrically designed in the same way as the external thread 26 at the functional end 20.

[0067] According to a further preferred embodiment of the present invention, only the thread 34a, which faces the holding end 10, is geometrically designed in the same way as the external thread 26.

[0068] Furthermore, the axially outer, length-reduced thread 34b preferably has a larger core diameter than the external thread 26. Due to this preferred increase in core diameter and thus also core radius in thread 34b, the mounting pin Z is pressed more firmly into the internal thread of the component's threaded bore when the installation spindle 1 is preferably turned back than with the external thread 26. Thread 34b therefore preferably interacts with the axial bending surface 40 described in more detail below and ensures that the mounting pin Z is permanently bent back into the internal thread of the component's threaded bore.

[0069] In comparison to the external thread 26, the core diameter of the thread pitch 34b is preferably 3% to 20%, preferably 5-17%, larger than the core diameter of the external thread 26.

[0070] According to a further preferred embodiment of the axially outer, length-reduced thread 34b, the outermost thread flank 35 in the direction of rotation RE is radially shortened compared to the adjacent thread flank of the thread 34a. Preferably, the radius of the outermost thread flank 35 is 2 to 15% smaller than the radius of the directly adjacent, non-shortened thread flank. This geometric design facilitates the sliding or dragging of the mounting pin Z over the ramp 36 and thus the axial extension 30. This is because the radially reduced thread flank 35 reduces the friction between the axial extension 30 on the thread flank 35 and the wire thread insert D.

[0071] Looking at the axial extension 30 in the radial plane, the axial bending surface 40 is located at the end of the axial extension 30, relative to the insertion direction RE of a wire thread insert D into a threaded bore. After the wire thread insert Z has been driven sufficiently deep into the threaded bore by rotating the installation spindle 1 in the insertion direction RE, the direction of rotation of the installation spindle 1 is reversed in the extraction direction RA. By rotating the installation spindle 1 in the extraction direction RA, the installation spindle 1 is unscrewed from the wire thread insert D installed in the threaded bore. Furthermore, the installation pin Z is supported against the axial bending surface 40 during the extraction of the functional end 20 from the wire thread insert D and is bent radially outwards into the internal thread of the threaded bore during the extraction process.

[0072] During the bending back of the mounting pin Z into the internal thread of the threaded bore, the axial bending surface 40 and a bending shoulder 42 preferably act alternately, individually or in combination, on the mounting pin Z. The bending shoulder 42 (see Figures 3, 4a , 5 , 7 ) is preferably formed by the transition surface or the transition edge between the re-bending surface 40 and the axially outer length-reduced thread 34b or the at least two axially outer length-reduced threads 34a, 34b.

[0073] During the reverse rotation of the installation spindle 1, the installation pin Z initially bears against the re-bending surface 40, and its free end is pressed towards the reduced thread 34b. This process is supported by the radially similar arrangement of the re-bending surface 40. In this context, "radially similar" means that the re-bending surface 40 extends essentially radially along the end face of the installation spindle. Since the re-bending surface 40 does not necessarily begin at the center of the end face but can also start off-center, it is oriented similarly to the radius of the installation spindle. Furthermore, the re-bending surface 40 preferably bends the installation pin Z into the internal thread of the threaded bore. During this time, the free end of the installation pin Z preferably does not yet engage in the reduced thread 34b. This process can be demonstrated by a torque measurement on a preferred embodiment of the invention in [reference to be added]. Figure 9The data is shown at points 0 to 2. The torque τ applied by the spindle 1 is plotted on the y-axis. It takes on negative values ​​because the spindle 1 is rotated backwards. Time is plotted on the x-axis.

[0074] During the reversal of the installation spindle 1 between points 2 and 3, the installation pin Z is pushed radially outwards or bent so far and the free end of the installation pin Z is aligned at the bending shoulder 42 at the transition into the length-reduced thread 34b, so that the bent-back installation pin Z can then enter the thread 34b.

[0075] The insertion of the mounting pin Z into the thread 34b is preferably visible between points 3 and 4. Due to the curvature already achieved by the mounting pin Z during the bending back, the mounting pin Z preferably enters the thread 34b under the influence of a reduced or decreasing torque compared to the previous steps.

[0076] Preferably, the torque is increased again during the further reversal of the installation spindle 1 between points 4 and 5. In this phase, the larger core radius of the thread 34b, compared to the other threads of the external thread 26, preferably acts by pushing or bending the installation pin Z further radially outwards into the internal thread of the threaded bore.

[0077] After the mounting pin Z has preferably been sufficiently bent back into the internal thread of the threaded bore at point 5, the mounting spindle 1 is unscrewed from the wire thread insert D with reduced torque.

[0078] To assist the insertion of the mounting pin Z into the thread 34b and preferably to hold or catch it on the bending shoulder 42, the return bending surface 40 is arranged at a preferred angle β to the axial end face 24 (see Figure 6 The angle β is preferably in the range of 65° ≤ β ≤ 90°, in particular 70° ≤ β ≤ 85°.

[0079] It is preferred to provide the axial end face 24 as a flat surface. Accordingly, the angle β above is enclosed by the end face 24 and the back-bend surface 40.

[0080] According to a further preferred embodiment of the present invention, at least the axial extension 30 of the installed spindle 1, with its preferred geometric features, is manufactured by a machining process, such as milling. When preferably using a milling process to produce the axial extension 30 on the axial end face 24, a recess 44 is formed in the axial direction in the end face 24. The recess 44 preferably borders the bending surface 40. Furthermore, it preferably has an elongated shape extending along the end face edge of the bending surface 40.

[0081] The recess 44 at the end face of the bending surface 40 has proven advantageous when bending back a mounting pin Z of the wire thread insert D into an internal thread of the threaded bore of a component. This is because the recess 44 preferably assists in capturing and holding the mounting pin Z on the bending surface 40, thus ensuring the transfer of the bending forces from the bending surface 40 to the mounting pin Z.

[0082] Preferably, the recess 44 also results in the angle β being increased by an angle range of 0.5 to 5° adjacent to the end face of the bending surface 40. This preferably leads to an increased overhang of the bending surface 40 over a mounting pin Z that is caught at the angle β and bent back.

[0083] According to a further preferred embodiment of the present invention, the thread 34b is cut by the return bending surface 40. As a result, the thread flank 35 projects beyond the bending shoulder 42 in the reverse direction RR. Furthermore, the bending shoulder 42, which springs back in the opposite direction of reverse RR, is preferably concave (see figure). Figure 8a, b ) or straight (see Figure 8c ) shaped.

[0084] Preferably, the concavely shaped backbend shoulder 42 supports the retention of the mounting pin Z on the upbend shoulder 42 with increasing curvature.

[0085] Referring to the flowchart of the Figure 10The installation procedure for the wire thread insert with a retractable, non-removable drive pin Z without a drive notch can be summarized in the following steps. First, in step S1, the wire thread insert D is screwed or pushed onto the installation spindle 1 according to one of the embodiments described above. This step is complete when the wire thread insert D is positively engaged at the functional end 20 of the installation spindle 1. For this purpose, the drive pin Z preferably engages positively with the axial extension 30 of the installation spindle 1. In the subsequent step S2, the wire thread insert D is screwed into the internal thread or receiving thread of the threaded bore of the component using the installation spindle 1. As soon as the desired installation depth of the wire thread insert D in the threaded bore is reached, the direction of rotation of the installation spindle 1 is reversed.Now the installation spindle 1 is rotated in the reverse direction, opposite to the direction of rotation when turning it in.

[0086] During the retraction of the installation spindle 1, the drive pin Z is bent back into the receiving thread of the component's threaded bore, as described in detail above. As the installation spindle 1 is turned back, the axial extension 30 engages the drive pin Z via the retraction surface 40 and the bending shoulder 42, bending it into the receiving thread of the threaded bore. Preferably, this retraction is supplemented or supported by the action of the threaded section 34b with its enlarged core diameter, as this also pushes or bends the drive pin Z radially outwards.

[0087] Based on the effect of the mounting spindle 1 during the reversing process on the mounting pin or drive pin Z, the latter is bent back into the internal thread of the threaded bore to such an extent that the subsequent screwing in of a threaded bolt into the threaded bore of the component with reinforcing wire thread insert D is not hindered by the bent-back mounting pin Z.

[0088] After the drive pin Z has been sufficiently bent back into the internal thread of the threaded bore in steps S3 and / or S4, the mounting spindle 1 is completely unscrewed or removed from the wire thread insert D (step S5). Reference symbol list

[0089] 1 Installation spindle 3 Drive unit of the installation tool 5 Actuating switch of the drive unit 7 Depth stop 10 Drive and holding end 20 Functional end 22 Spindle area 24 Axial face 26 External thread 30 Axial extension 32 Radial outer surface of the axial extension 34 Length-reduced thread on the axial extension 35 Radially reduced thread flanks of the length-reduced thread 34 36 Lead-in chamfer 38 Driver shoulder 40 Axial rebending surface 42 Bending shoulder 44 Axial recess on the face 24 D Wire thread insert Z Rebating mounting pin of the wire thread insert RE Direction of insertion of the functional end into the wire thread insert D and direction of insertion of the wire thread insert into the threaded bore of the component α Angle of rotation of the axial extension 30 H Axial height of the axial extension 30 Thread pitch 26 at the functional end 20 RA Direction of extraction WInstallation tool

Claims

1. An integrally formed mounting spindle (1) adapted to a wire thread insert (D) having a cylindrical coil with a plurality of screw like wound windings of a wire, in which a first winding comprises a dragging tang without dragging notch, wherein the dragging tang reaches via a bending portion into an interior of the coil and is preferably formed like an arch, with which first winding the wire thread insert (D) is screwable in a screw-in direction into a thread bore of a component, wherein the mounting spindle (1) comprises the following features: a. a drive and retention end (10) for rotating and retaining the mounting spindle (1) in a mounting tool and a functional end (20) for installing the wire thread insert (D) in a thread bore of a component, b. an axial extension (30) projects from an axial face side (24) of the mounting spindle (1) at the functional end (20) in the direction of a longitudinal axis of the mounting spindle (1) which along a circumferential extension of the mounting spindle (1) is limited by an arcuate radial outside in a rotation angle α from a range from 30° ≤ α ≤ 180°, characterized in that c. with respect to the screw-in direction, the axial extension (30) comprises a ramp slope (36) starting at a front end of the arcuate radial outside (32) which extends increasingly in the axial direction of the mounting spindle (1) as a striped surface on the axial extension (30), and d. with respect to the screw-in direction, the axial extension (30) drops axially at a rear end of the arcuate radial outside (32) in an axial return-bending surface (40), which is arranged radial-like.

2. The integrally formed mounting spindle (1) according to claim 1, having at the axial extension (30) at least one thread (34a; 34b) which is reduced in length in circumferential direction.

3. The integrally formed mounting spindle (1) according to one of the preceding claims, in which the axial extension (30) projects axially at the functional end of the mounting spindle (1) individually at the axial face side (24) or in which an axially projecting bulge-like counter bearing is provided radially opposite the axial extension (30) at the axial face side (24).

4. The integrally formed mounting spindle (1) according to one of the preceding claims in which the axial extension (30) occupies an area of less than 40 % of the axial face side (24) at the functional end (20).

5. The integrally formed mounting spindle (1) according to claim 2, the axial extension (30) of which comprises at the radial outside (32) two length-reduced threads (34a, 34b), which are configured differently with regard to at least one of the following sizes: circumferential length, core diameter and pitch.

6. The integrally formed mounting spindle (1) according to claim 5, in which the axially outer length-reduced thread (34b) has a larger core diameter and / or a larger pitch (P) in comparison with the adjacent, length-reduced thread (34a).

7. The integrally formed mounting spindle (1) according to one of the preceding claims, in which the axial extension (30) comprises in axial direction between the axial face side (24) of the functional end (20) and the front end of the ramp slope (36) an axial web (38) as a dragging shoulder, which is adapted so as to retain a wire thread insert (D) torque-proof when being screwed into a thread bore.

8. The integrally formed mounting spindle (1) according to one of the preceding claims, in which the axial return-bending surface (40) encloses an angle β in the range from 65 ° ≤ β ≤ 90° with the adjacent axial front side (24) of the functional end (20).

9. A retrofit kit for an installation tool of a wire thread insert (D) with a releasably connectable drive module and a mounting spindle (1) which as the exchangeable mounting spindle (1) comprises at least two integrally formed mounting spindles (1) according to one of the preceding claims 1 to 8 which differ in a construction and / or dimension of the mounting spindle (1).

10. An installation tool, in particular a manual installation tool or a mounting automat of a wire thread insert (D) with a drive module and an integrally formed mounting spindle (1) according to one of the preceding claims 1 to 8 which are releasably connectable with one another.

11. Installation method of a wire thread insert (D) with dragging tang (Z) that is bendable back and cannot be removed without dragging notch with the help of an installation tool according to claim 10 in a receiving thread of a component, comprising the following steps: a. threading on or plugging the wire thread insert (D) onto the functional end (20) of the integrally formed mounting spindle (1) of the installation tool in a way that the dragging tang (Z) couples to the axial extension (30) of the mounting spindle (1) in a form fit manner and connects the wire thread insert (D) with the mounting spindle (1) in a torque proof manner, (S1) b. screwing the wire thread insert (D) into the receiving thread by rotating the mounting spindle (1) in a first rotation direction, (S2) c. bending back (S3; S4) the dragging tang (Z) into the receiving thread by rotating the mounting spindle (1) in a second rotation direction contrary to the first rotation direction, wherein the axial return-bending surface (40) of the axial extension (30) deforms the dragging tang (Z), and d. threading out or removing the mounting spindle (1) from the wire thread insert (D) with bent-back dragging tang (Z) (S5).

12. Installation method according to claim 11, which furthermore comprises: bending back the dragging tang (Z) radially by a bend open shoulder (42) (S3) and / or a second thread portion (34b) with enlarged core diameter in comparison with a first thread portion at the functional end (20) of the mounting spindle (1) (S4).