Band clamp with a metal band with an ear-shaped tensioning device with a concave profile

Abstract

The invention relates to a band clamp (10) with a metal band and an ear-shaped tensioning device (12), wherein the ear-shaped tensioning device (12) has two lateral leg sections (12a, 12b) and a connecting section (12c) connecting the lateral leg sections (12a, 12b), wherein the connecting section (12c) comprises a projection (14) which projects radially inwardly, wherein the projection (14) is configured such that it prevents buckling of material arranged under the ear-shaped tensioning device (12) when the ear-shaped tensioning device (12) is tensioned by bringing the leg sections (12a, 12b) closer together. It is proposed that in a non-tightened configuration of the band clamp (10), a radially inner side (14a) of the projection (14) has a concave profile when viewed in the axial direction of the band clamp (10).

Description

[0001] The invention relates to a band clamp according to the preamble of claim 1.

[0002] Documents DE2920983A1 and DE2255110A disclose band clamps comprising a metal band with an ear-shaped tensioning device, wherein the ear-shaped tensioning device comprises two lateral leg portions and a connecting portion connecting the lateral leg portions, wherein the connecting portion comprises a projection projecting radially inwardly, wherein the projection is configured to prevent buckling of the material arranged under the ear-shaped tensioning device when the ear-shaped tensioning device is tensioned by bringing its leg portions closer together.

[0003] For ease of manufacture, prior art anti-buckling protrusions generally have convex or flat profiles in the untightened state. This flat or convex shape results in a certain distance from the radially inner side of the protrusion, at least in portions outside the center of the protrusion in the circumferential direction. This means that buckling of the material cannot be completely prevented.

[0004] The problem is solved by a device having the features of claim 1. Advantageous embodiments of the invention are defined in the dependent claims.

[0005] The invention relates to a band clamp comprising a metal band with an ear-shaped clamping device, the ear-shaped clamping device comprising two lateral leg portions and a connecting portion connecting the lateral leg portions, the connecting portion comprising a projection projecting radially inward, the projection being configured to prevent buckling of the material arranged under the ear-shaped clamping device when the ear-shaped clamping device is tightened by bringing its leg portions closer together.

[0006] The lateral leg portions generally project radially or approximately radially outwardly from a main portion of the band clamp. Those skilled in the art will understand that the aforementioned projection projects radially inwardly in the sheet material of the band and, viewed from the radially outer side, corresponds to a depression or dimple. In the context of this document, and unless otherwise stated, the terms "radial," "axial," or "circumferential" refer to the circular shape of the band clamp as a whole in a pre-assembled and untightened or tightened configuration.

[0007] The invention is applicable to various types of band clamps. Depending on the type of band clamp, the material arranged under the ear-shaped tensioning device can be a hose or bellows, a band clamp insert, or an inner band section of the band clamp, depending on the circumstances.

[0008] It is proposed that the radially inner side of the protrusion have a concave profile when viewed in the axial direction of the band clamp. The concave profile allows the protrusion profile to follow the convex profile of the material located under the ear-shaped clamping device, improving buckling prevention.

[0009] According to a preferred embodiment of the invention, the inventors propose that, in the untightened configuration of the band clamp, the radially inner side of the projection be arranged flush with the radially inner side of the metal band adjacent to the leg portions of the ear-shaped clamping device. Accordingly, the radially inner side of the projection can be brought into contact with the material disposed beneath the ear-shaped clamping device upon initiation of tightening, further improving buckling prevention.

[0010] It is also proposed that the radius of curvature of the concave profile be equal to the radius of curvature of a main section of the metal strip. This ensures that the profile of the projection follows the convex profile of the material located under the ear-shaped clamping device.

[0011] In a preferred embodiment of the invention, a lower portion of the projection is provided with at least one embossed reinforcing structure. The embossed structure strengthens the material through work hardening and by increasing rigidity, so that contact to prevent buckling during the clamping process is maintained over a long period of time and the projection is not easily deformed.

[0012] Preferably, the at least one reinforcing structure comprises a step extending in the circumferential direction. The circumferential direction is the direction in which stiffening is most needed, and the step can further improve the alignment of the clamp during tightening.

[0013] It is further proposed that the band clamp further comprise an inner band portion disposed beneath the ear-like tensioning device. The inner band portion comprises at least one rib extending circumferentially, the rib being configured to engage the radially inner side of the projection and align the inner band portion with the projection. This improves the alignment of the inner band portion and the outer band portion with the tensioning device. Since inaccurate alignment can be a cause of buckling, the improved alignment further reduces the risk of buckling.

[0014] Preferably, the rib of the inner band portion is configured to engage the step in the lower portion of the projection. The engagement between the step and rib forms guide rails that guide the relative movement of the inner band portion during tightening. Preferably, the ribs and steps described above are provided on both axial sides of the projection.

[0015] Further features and advantages will become apparent from the following description of the embodiments and figures. The entire description, claims, and figures disclose features of the invention in specific embodiments and combinations. Those skilled in the art will also consider the features individually and combine them into further combinations or subcombinations to adapt the invention, as defined in the claims, to their needs or specific fields of application.

[0016] The figures illustrate the following: Fig. 1 shows a band clamp according to a first embodiment of the invention; Fig. 2 is a detail of an ear-shaped tensioning device of the band clamp of Fig. 1; Fig. 3 is a radial section of the band clamp of Fig. 1 with an inner band section; Fig. 4 is a radial section of a projection of the band clamp of the ear-like tensioning device of the band clamp of Fig. 1; Fig. 5 is a view of the ear-shaped clamping device from a radially inner side; Fig. 6 is a view of the ear-shaped clamping device from a radially outer side; and Fig. 7 is a perspective view of the ear-shaped clamping device from a radially outer side.

[0017] Fig. Figure 1 shows a band clamp according to a first embodiment of the invention in an untightened configuration. The invention relates to a band clamp 10 comprising a metal band with an ear-shaped tensioning device 12, wherein the ear-shaped tensioning device 12 comprises two lateral leg portions 12a, 12b and a connecting portion 12c connecting the lateral leg portions 12a, 12b, wherein the connecting portion 12c comprises a projection 14 projecting radially inwardly, wherein the projection 14 is configured to prevent buckling of material disposed beneath the ear-shaped tensioning device 12 when the ear-shaped tensioning device 12 is tensioned by bringing its leg portions 12a, 12b closer together.

[0018] The band clamp 10 consists of a stamped metal band that is closed to form a loop. The band clamp 10 has an outer band portion 10a that encompasses the ear-shaped tensioning device 12, wherein the outer band portion 10a partially overlaps an inner band portion 10b provided with a tongue 10c at its end. The tongue 10c engages a tongue channel 10d, and the band is closed by the engagement of hooks 10e on the inner band portion 10b with openings 10f on the outer band portion 10a as a mechanical lock on a side of the ear-shaped tensioning device 12 that is circumferentially opposite the side of the tongue 10c and the tongue channel 10d.

[0019] In the embodiment of Fig. 1, the material disposed beneath the ear-shaped clamping device 12 is the inner band portion 10b. However, the invention is not limited to clamps with a mechanical locking mechanism and an inner band portion 10b and is applicable to clamps without an inner band portion 10b disposed beneath the ear-shaped clamping device 12, i.e., where a hose or other element to be clamped is disposed beneath the ear-shaped clamping device 12.

[0020] During tightening of the band clamp 10, the ear-shaped tensioning device 12 is circumferentially compressed by a crimping tool acting on the radially inner ends of the leg portions 12a, 12b and by pressing the connecting portion 12c radially inward to form a flattened loop (not shown). During this tightening process, the inner band portion 10b moves relative to the center of the ear-shaped tensioning device 12, and the tongue 10c slides into the tongue channel 10d.

[0021] According to the invention, the radially inner side 14a of the projection 14 in a non-tightened configuration of the band clamp 10, as shown in Fig. 1, has a concave profile when viewed in the axial direction of the band clamp 10. In the embodiment of Fig. 1, the radially inner side 14a of the projection 14 is arranged on a plane with the radially inner side of the outer band portion 10a of the metal band, which is adjacent to the leg portions 12a, 12b of the ear-shaped clamping device 12. Accordingly, not only the center of the projection 14, but rather an entire portion covering part of the radially inner side 14a of the projection 14, comes into direct contact with the inner band portion 10b, preventing the inner band portion 10b from bending when the band clamp 10 is tightened.

[0022] Fig. 2 is a detail of an ear-like tensioning device 12 of the band clamp 10 of Fig. 1, Fig. 3 is a radial section of the band clamp 10 of Fig. 1 with an inner band section 10b along the line III -III in Fig. 1 and Fig. 4 is a radial section of a projection 14 of the band clamp 10 of the ear-like tensioning device 12 of the band clamp 10 of Fig. 1 along the line III-III in Fig. 1.

[0023] As in Fig. 2, the connecting portion 12c is substantially flat in side view and the projection 14 projects radially inward. In the axial profile of Fig. 2, the side surfaces 14b, 14c of the projection 14 are conically tapered, so that the width of the projection 14, which constitutes 70-90% of the circumferential length of the connecting portion 12c at the radially outermost level, is reduced in the radially inward direction, where it constitutes 40-70% of the circumferential length of the connecting portion 12c. The radially innermost side 14a of the projection 14 connects the side surfaces and has the concave profile described above. To ensure good alignment, the radially inner side 14a has a radius of curvature equal to the radius of curvature of a main portion of the metal strip, which essentially, i.e. apart from permissible tolerances, matches the radius of curvature of the outer surface of the material or object to be clamped or, if present, the radius of curvature of the inner strip portion 10b, i.e.is adapted to the radius of curvature of the outer surface of the object against which the radially inner side 14a of the projection 14 rests before tightening the band clamp 10 and / or in an initial phase of tightening.

[0024] As in Fig. 3, a lower portion of the projection 14 is provided with at least one embossed reinforcing structure comprising two lateral steps 14d, 14e, each extending in a circumferential direction of the band clamp 10, i.e., in a longitudinal direction of the metal band and the projection 14, over the entire length of the projection 14. The inner band portion 10b comprises two ribs 18a, 18b, which also extend in the circumferential direction, the ribs 18a, 18b being configured to engage the steps 14d, 14e on the radially inner side 14a of the projection 14 and align the inner band portion 10b with the projection 14. The ribs 18a, 18b and the steps 14d, 14e form a kind of rails which guide the relative movement of the radially inner band portion 10b and move the tongue 10c into the tongue channel 10d when the band clamp 10 is tightened.

[0025] As in the Fig.As shown in Figures 4 to 7, the projection 14 on the radially inner side 14a of the strip corresponds to a recess on the radially outer side of the metal strip. The recess 16 is surrounded by a substantially rectangular, frame-shaped section of the metal strip. The recess 16 is formed by deep drawing and stamping the steps 14d, 14e and the reinforcing structures, which cause work hardening of the projection 14. This increases the flexural rigidity of the connecting section 12c of the ear-like clamping device 12, so that the connecting section 12c retains its substantially flat shape during the clamping process. List of reference numbers 10 band clamp 10a outer band section 10b inner band section 10c Tongue 10d lingual canal 10e hook 10f openings 10d lingual canal 12 ear-shaped clamping device 12a, 12b leg sections 12c connecting section 14 lead 14a radial inner side 14b Side surface 14c side surface 14d, 14e steps 16 recess 18a, 18b ribs

Claims

[1] A band clamp (10) comprising a metal band with an ear-shaped tensioning device (12), wherein the ear-shaped tensioning device (12) has two lateral leg portions (12a, 12b) and a connecting portion (12c) connecting the lateral leg portions (12a, 12b), wherein the connecting portion (12c) comprises a projection (14) projecting radially inwardly, wherein the projection (14) is configured to prevent buckling of material arranged under the ear-shaped tensioning device (12) when the ear-shaped tensioning device (12) is tensioned by bringing its leg portions (12a, 12b) closer together, wherein in an untightened configuration of the band clamp (10), a radially inner side (14a) of the projection (14) has a concave profile when viewed in an axial direction of the band clamp (10), characterized bythat in the non-tightened configuration of the band clamp (10), the radially inner side (14a) of the projection (14) is arranged on a plane with a radially inner side of the metal band adjacent to the leg portions (12a, 12b) of the ear-shaped tensioning device (12). [2] Band clamp (10) according to claim 1, characterized by that a radius of curvature of the concave profile is equal to a radius of curvature of a main section of the metal strip. [3] Band clamp (10) according to one of the preceding claims, characterized by that a lower portion of the projection (14) is provided with at least one embossed reinforcing structure. [4] Band clamp (10) according to claim 3, characterized by that the at least one reinforcing structure comprises a step (14d, 14e) extending in a circumferential direction of the band clamp (10). [5] Band clamp (10) according to one of the preceding claims, characterized byin that it further comprises an inner band portion (10b) disposed beneath the ear-like tensioning device (12), the inner band portion (10b) comprising at least one rib (18a, 18b) extending in a circumferential direction, the rib (18a, 18b) being configured to engage the radially inner side (14a) of the projection (14) and align the inner band portion (10b) with the projection (14). [6] Band clamp (10) according to claims 4 and 5, characterized by that the rib (18a, 18b) of the inner band portion (10b) is configured to engage the step (14d, 14e) in the lower portion of the projection (14).

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