DD203104A1 - SELF-CUTTING AND BACK-SECURITY THREADED INSERT - Google Patents

Abstract

In a self-tapping and reset secured threaded insert with central threaded hole u. aeuszerem threaded jacket whose thread amount are arranged on Laengsrippen separated by Laengskehlen the trailing edge of a Laengsrippe has a cutting angle alpha v 90 degrees and this Laengsrippe is axially resilient as a result of an open at the rear edge and extending in the screwing slot.

Description

1 3BU64 3

^ EB PENTACOf-I DHSSDGM Dresden, 18.12.1981

Camera and cinema works

Title of the invention

Self-tapping and recoil-proof threaded insert

A field of application of the invention

The invention relates to a self-tapping and reset-secured threaded insert with central threaded bore and outer thread sheath whose threads are arranged on longitudinal ribs separated by longitudinal ribs.

Characteristic of the known technical solutions

In a known threaded insert (DE-AS 2- 4-15 9 ^ 1) front cutting edges were created by longitudinal grooves, which cut when screwing an external thread corresponding .Innengewinde in the workpiece, with bulges on the external thread of the threaded insert is this when screwing through material displacement in Workpiece clamped and thus secured against turning back. The essentially frictional locking holds, but larger Rückdrehmomenten by the obliquely rising in Rückarehsinn Ausbuch-

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not stand up. According to another known embodiment (DE-OS 28 28 4-38), a reverse rotation is created in that the threaded insert is screwed in the opposite direction as in the first-described known arrangement in the workpiece. However, there is no cutting of the external thread of the threaded insert into the workpiece, but rather in the form of a. -, Ausbuchtung.xaBch ^ aUÄ-Asi.-L ^ SSkhle., On his; Outside diameter rising external thread must be screwed only under material displacement in the workpiece, which requires both relatively large torques and sufficiently strong forming the workpiece to accommodate these large torques can.

Object of the invention

In order to achieve an effective reverse rotation and low input, torques, it is an object of the invention to change the external thread bearing longitudinal ribs of the threaded insert e.

Essence of the invention

According to the invention, this is achieved in that the front edges and the trailing edges of the interrupted threads are cut- shaped , the trailing edges of at least some longitudinal ribs having a cutting angle . Have 90 °, and that each of these longitudinal ribs is formed as a result of a radially open at the trailing edge and extending in the direction of insertion slot. As a result, when the threaded insert is unintentionally reversed, a certain spreading of the slotted part takes place. Longitudinal ribs, wherein the trailing edges of the threads penetrate deeper and deeper into the workpiece _a of an appropriate training

According to the slot runs parallel to the central threaded hole. According to a further advantageous embodiment, the thread profile is continuously inclined from the trailing edges to the leading edges in the sense of reducing the thread profile of the leading edges, whereby additional reinforcement of the reverse rotation fuse is achieved.

Embodiments of the invention

The invention is illustrated on hand illustrated and described embodiments: It show

Fig. 1 is a side view A-B of a threaded insert.

5 "2 the front view of the threaded insert,

3 a longitudinal rib in section,

FIG. 4 shows another embodiment of a longitudinal rib in FIG

Cut and

5 shows the front edge and the trailing edge of a thread in front view,

In the illustrated threaded insert; 1 and 2), the threads 1 of the outer thread jacket are arranged on longitudinal ribs 7 which are separated from each other by longitudinal grooves 2, so that cutting-front edges 3 and cutting-edge trailing edges 4 are formed in the clockwise direction of rotation. The central threaded hole 5 serves to receive a screw or a threaded bolt.

Slits 8, which are open at the trailing edges 4 and extend in the direction of the direction of rotation (see FIG. 3), are incorporated in the trailing edges 4 of opposing thread ribs 7. As a result, the relevant thread 1 is resiliently formed in its trailing edge 4 , In addition, the trailing edge 4- has an acute cutting angle <L < 90 °.

The mode of action is the following:

When screwing the threaded insert into a workpiece 6, the leading edges 3 penetrate cutting into the workpiece. The cutting leading edges 3 are followed by the trailing edges 4, which are provided with the cutting angle 6 6, and which have slots 8, at least for the sake of filing. When unintentionally turning back the threaded insert penetrate the trailing edges 4 due to their acute cutting angle. oC in the workpiece 6, wherein the slots 8 aufspredern. This Ί0 increases the penetration depth of the trailing edges 4 in the workpiece, so that a good reverse rotation is given.

According to a further embodiment (see Fig. 4 and 5), the thread diameter is reduced in total from the trailing edges 14 to the leading edges 13, so that the radius rg of the trailing edge 4 is greater than the radius ry of the leading edge 3 · When screwing this Threaded insert in a workpiece 6 penetrate the leading edges 13 cutting into the workpiece 6 a. The cutting leading edges 13 are followed by the profile-increasing threads 11, which penetrate under material displacement up to the trailing edges 14 in the workpiece 6, wherein the trailing edges 14 radially resiliently recede by the slots 8 are slightly compressed. In this way, the unintentional turning back of the threaded insert increases the Sindringtiefe the trailing edge 14 in the workpiece δ, which has an even more effective reverse rotation assurance result.

The invention is not limited to the embodiments shown, for example, the slots 8 and inclined obliquely against the threaded bore 5 of the Gewindeinsätζes se:

Claims (3)

invention claim 1. Self-tapping and resetting threaded insert with central thread tapping and outer. Gewina emant'el, whose threads are arranged on longitudinal ribs separated by longitudinal grooves, characterized in that the leading edges (3, 13) and the trailing edges (4 ·, 14) of the interrupted threads (1, 11) formed cutförinig. are, wherein the trailing edge of at least some longitudinal ribs (7) a 3chnittwinkelc £. Have 90 °, and that each of these longitudinal ribs (7) is formed as a result of a radially at the rear edges (4-, 14) open and in Eindreh direction extending contactor (8). 2 «thread insert according to item 1, characterized in that the slot (8) parallel to the central threaded bore (5). Thread insert according to item 1 or 2, characterized in that the thread profile is continuously inclined from the trailing edges (4, 14) to the leading edges (3j13) in the sense of reducing the thread profile of the leading edges (3 »13). (See 1 page drawing)