Anti-turn mechanism

Abstract

The invention relates to an anti-turn mechanism for bolted connections. The anti-turn mechanism comprises two half shells which each extend along a longitudinal axis. The first lateral end of each half shell is formed by a groove extending in parallel with the longitudinal axis, and the second lateral end of each half shell is formed by a latching rib which extends in parallel with the longitudinal axis and is suitable for engaging with the groove of the other half shell in a clamping connection.

Description

[0001] Anti-twist device

[0002] The invention relates to the art of pipe couplings and in particular to a device designed to prevent unwanted loosening of a threaded pipe coupling.

[0003] The device of the invention is particularly suitable for use in connection with connections between a pressure gauge and a system whose pressure is to be measured, and will be described in this context. However, the invention can also be used with other types of couplings, including couplings formed as an integral part of a flow device, such as a valve.

[0004] A pressure gauge typically has a hollow screw with an external thread / connector thread as its connection, which is used to connect the gauge to the system whose pressure is to be measured. The thread can be of different sizes and standards depending on the requirements of the application.

[0005] The connection fitting on the system is the counterpart to the connection thread on the pressure gauge. It has a union nut that fits onto the connection thread of the pressure gauge. The connection fitting creates a mechanical, tight connection between the pressure gauge and the system, preventing any gas or fluid from escaping. The connection thread of the pressure gauge and the connection fitting on the system must be compatible to ensure a proper and secure connection. A gasket is often used between the connection fitting and the system to improve the seal and prevent leaks.

[0006] When installing pressure gauges, an anti-twist device is often installed to ensure that the union nut does not loosen and subsequently leak. Common anti-twist devices consist of retaining clamps, as disclosed, for example, in EP 0786617 A2. The anti-twist devices are usually made of metal and may also have an internal retaining ring made of a flexible material. The retaining clamps are screwed on at their lateral ends (see Fig. 3 or EP 0786617 A2).

[0007] The anti-twist device using a clamp has proven impractical in everyday use. For regular maintenance, the clamp must be removed and reattached. However, it is very cumbersome to remove. Tools are required to loosen the locking nut on the retaining screw. Depending on the location of the pressure gauge in a system, the clamp may also be difficult to access. Vibrations in the lines of a system pose the risk of the retaining screws becoming loose. The invention is therefore based on the object of providing an anti-twist device that is user-friendly and does not easily shake loose.

[0008] This object is achieved according to the invention by an anti-twist device having the features specified in independent claim 1. The concept of the anti-twist device according to the invention is based on a toothing of the anti-twist device with the union nut and a clamping connection that can be released without additional tools.

[0009] The anti-twist device comprises two half-shells, each extending along a longitudinal axis. The first lateral end of each half-shell is formed by a groove extending parallel to the longitudinal axis, and the second lateral end of each half-shell is formed by a locking rib extending parallel to the longitudinal axis, which is suitable for forming a clamping connection with the groove of the other half-shell.

[0010] Preferably, the inside of each half-shell has two sections along the longitudinal axis, each with a different profile, so that they are each adapted to the screws and counterparts to be secured against each other. In the case of securing a pressure gauge connection, one section is adapted to a connection piece on the pressure gauge, and the other section is adapted to the outside of the union nut. This prevents the union nut from twisting against the connection piece of the pressure gauge.

[0011] There are pressure gauges in which the pressure gauge connection piece has a square profile. Accordingly, the inside of each half-shell in the first section has two smooth surfaces arranged at right angles to each other. The inside in the second section preferably corresponds to a section of a cylinder jacket and is structured by ribs running parallel to the longitudinal axis. Since the rotational position of the union nut is not fixed, the polygonal union nut can be fixed in any position by the ribs. In a preferred embodiment, the vertices of the ribs have an angular distance from each other in the range of 6° to 9°, preferably 7.5°.

[0012] The anti-twist device may have a handle at its first lateral end beyond the groove, which facilitates the fastening and release of the clamping connection between the two half-shells. Preferably, the handle extends over the entire length of the first lateral end.

[0013] In an embodiment in which the half-shells are substantially semi-cylindrical, the handles protrude tangentially from the first lateral end.

[0014] A preferred material for the anti-twist device is plastic. A plastic anti-twist device could be produced, for example, using 3D printing. The thermoplastic PETG (polyethylene terephthalate modified with glycol) is preferred for this purpose.

[0015] Each half-shell has an inner diameter that is adapted to the connection to be secured, for example in the range of 10 to 100 mm, preferably in the range of 20 to 80 mm, particularly preferably in the

[0016] Range from 25 to 35 mm. The length of each half-shell is in the range from 20 mm to 60 mm, preferably in the range from 30 mm to 50 mm, particularly preferably 40 mm.

[0017] The invention also relates to a single one of the half-shells described above, which can then be joined together with another identical half-shell to form an anti-twist device.

[0018] Figures and examples

[0019] Embodiments of the invention are illustrated in the figures and are explained in more detail below.

[0020] Shown: Fig. 1 Connection between pressure gauge and system not screwed

[0021] Fig. 2 Connection between pressure gauge and system screwed

[0022] Fig. 3 Safety clamp with retaining ring

[0023] Fig. 4 Perspective view of the anti-twist device

[0024] Fig. 4 Perspective view of the anti-twist device in a variant Fig. 5 Top view of the anti-twist device

[0025] Fig. 5 Top view of anti-twist device in a variant

[0026] Fig. 6 Connection between pressure gauge and system screwed and with a half shell of the anti-twist device

[0027] Fig. 7 Connection between pressure gauge and system screwed and with anti-twist device first perspective view

[0028] Fig. 8 Connection between pressure gauge and system screwed and with anti-twist device second perspective view

[0029] Reference symbol

[0030] A - Longitudinal axis

[0031] 10 - Half shell

[0032] 12 - Groove

[0033] 14 - Locking rib

[0034] 16 - upper end

[0035] 18 - lower end

[0036] 20 - Handle

[0037] 22 - first section of the inside

[0038] 24 - second section of the inside

[0039] 26a, 26b - smooth surface

[0040] 28 - Rib

[0041] 29 - Chamfer

[0042] 100 - Pressure gauge

[0043] 110 - Connection piece

[0044] 115 - Connection thread

[0045] 120 - Connection piece

[0046] 122 - Union nut

[0047] 200 - Safety clamp

[0048] 205 - Tab

[0049] 207 - Retaining screw

[0050] 209 - Lock nut 220 - Retaining ring

[0051] Fig. 1 shows the part of a pressure gauge 100 from which the connection to another system originates. In the connection area, there is a connector 110 that is permanently connected to the pressure gauge 100. From the connector 110, there is a hollow screw with a connecting thread 115, via which the pressure gauge is connected to the system whose pressure is to be measured. On the opposite side, there is the connecting piece 120 with the union nut 122. In Fig. 1, the union nut 122 is not screwed to the connecting thread 115. In Fig. 2, the union nut 122 is screwed to the connecting thread 115.

[0052] According to the prior art, the screw connection between pressure gauge 100 and connection piece 120 is typically secured by a retaining clamp 200 with an internal retaining ring 220. An exemplary retaining clamp 200 is shown in Fig. 3. The illustrated retaining clamp 200 consists of two parallel metal rings with radially projecting tabs 205 at the open lateral ends of the metal rings. The metal rings are pushed over the connection before mounting the pressure gauge. The opposing tabs 205 of each metal ring have an opening through which a retaining screw 207 is inserted, which is loaded with a lock nut 209 at the inserted end.In use, the retaining ring 220 is placed over the connecting piece 110, and the retaining clamp 200 is tightened using the retaining screw 207 and lock nut 209 and secured to the union nut 122 so that the union nut 122 can no longer rotate relative to the connecting piece 110 and thus to the external thread 115. Tools (screwdriver, wrench, etc.) are required to attach and remove the retaining clamp 200 in order to tighten or loosen the lock nuts 209 on the retaining screws 207.

[0053] The anti-twist device according to the invention consists of two half-shells 10 (Fig. 4, Fig. 4a, Fig. 5, Fig. 5a). As shown in Fig. 4, Fig. 4a, each half-shell 10 extends along a longitudinal axis A. The first lateral end of each half-shell 10 is formed by a groove 12 extending parallel to the longitudinal axis A. The second lateral end of each half-shell is formed by a locking rib 14 extending parallel to the longitudinal axis. Two half-shells 10 are connected to one another by inserting the locking rib 14 of the first half-shell 10 into the groove 12 of the second half-shell 10 and then clamping the locking rib 14 of the second half-shell 10 to the groove 12 of the first half-shell 10 against a slight counterpressure of the flexible material. Once connected, both half shells 10 form a casing for a screw connection which acts as an anti-twist device, for example for the connection between pressure gauge 100 and connection piece 120.

[0054] To facilitate the clamping of the locking rib 14 of the second half-shell 10 with the groove 12 of the first half-shell 10, a handle 20 is located at the first lateral end beyond the groove 12. With the handle 20, the groove 12 of the first half-shell 10 can be pulled over the locking rib 14 of the second half-shell 10. When opening the clamping connection between the groove 12 and the locking rib 14, the groove 12 can also be lifted off the locking rib 14 using the handle 20. The handle 20 is easy to grip because it extends over the entire length of the first lateral end of the half-shell 10. In addition, the handle 20 protrudes tangentially from the first lateral end of the essentially semi-cylindrical half-shell 10.

[0055] To ensure that the inner sides of the half-shells 10 fit even better against the connecting piece 110 and the union nut 122 when connecting the pressure gauge 100 to the connecting piece 120, the inner side of each half-shell 10 has two sections 22, 24 along the longitudinal axis A, each with a different profile. The inner side in the first section 22 has two smooth surfaces 26a, 26b arranged at right angles to one another. The two smooth surfaces 26a, 26b arranged at right angles to one another either meet directly at right angles (Fig. 4a, Fig. 5a) or the edge at which the smooth surfaces 26a, 26b arranged at right angles to one another meet is chamfered (Fig. 4, Fig. 5, chamfer 29). The inner side in the second section 24 corresponds to a section of a cylinder jacket and is structured by ribs 28 running parallel to the longitudinal axis A. In the embodiment shown, the vertices of the ribs have an angular distance of 7.5° from each other.

[0056] In a preferred embodiment, the inner diameter of each half-shell 10 is 31 mm and the outer diameter is 19.8 mm. The width of the smooth surfaces 26a, 26b is 19.8 mm in the embodiment with the bevel 29 (Fig. 4, Fig. 5) and 22 mm in the variant without a bevel. The handle has a width of 16.6 mm. The length of each half-shell is in the range of 20 mm to 60 mm, preferably in the range of 30 mm to 50 mm, and particularly preferably 40 mm.

[0057] Fig. 6 shows how a half-shell 10 is attached to the connection piece 110 on the one hand and the union nut 122 on the other hand in the area of ​​the connection between the pressure gauge 100 and the connecting piece 120. In Figs. 7 and 8, the second half-shell has been added, so that the connection between the pressure gauge 100 and the connecting piece 120 is secured by the anti-twist device.

Claims

Patent claims 1. Anti-twist device - two half-shells, each extending along a longitudinal axis, - wherein the first lateral end of each half-shell is formed by a groove extending parallel to the longitudinal axis, and - the second lateral end of each half-shell is formed by a locking rib extending parallel to the longitudinal axis, which is suitable for forming a clamping connection with the groove of the other half-shell.

2. Anti-twist device according to claim 1, characterized in that the inner side of each half-shell has two sections along the longitudinal axis, each of which has a different profile.

3. Anti-twist device according to claim 1 or 2, characterized in that the inner side in the first section has two smooth surfaces arranged at right angles to one another.

4. Anti-rotation device according to one of claims 1 to 3, characterized in that the inner side in the second section corresponds to a section of a cylinder jacket and is structured by ribs running parallel to the longitudinal axis.

5. Anti-twist device according to claim 4, characterized in that the vertices of the ribs have an angular distance in the range of 6° to 9°, preferably of 7.5° to one another.

6. Anti-rotation device according to one of claims 1 to 5, characterized in that a handle is located at the first lateral end beyond the groove.

7. Anti-twist device according to claim 6, characterized in that the handle extends over the entire length of the first lateral end.

8. Anti-twist device according to claim 6 or 7, characterized in that the handle protrudes tangentially from the first lateral end.

9. Anti-rotation device according to one of claims 1 to 8, characterized in that the half-shells are substantially semi-cylindrical.

10. Anti-twist device according to one of claims 1 to 9, characterized in that the anti-twist device consists of plastic, preferably of polyethylene terephthalate modified with glycol.

11. Anti-twist device according to one of claims 1 to 10, characterized in that it is designed as a 3-D pressure is produced.

12. Half-shell for use with a second identical half-shell as an anti-twist device, having - an extension along a longitudinal axis, - wherein the first lateral end of the half-shell is formed by a groove extending parallel to the longitudinal axis, and - the second lateral end of the half-shell is formed by a locking rib extending parallel to the longitudinal axis, which is suitable for forming a clamping connection with the groove of a second identical half-shell.

13. Half-shell according to claim 12 and one or more of the features of claims 2 to

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