V-clamp with band lock

Abstract

The present invention provides a clamp, preferably a screw-type V-clamp, for fastening around an object. The clamp comprises a clamp band 10 having first and second band portions 11,12, a connection means 30 attached to first end regions of the first and second band portions 11,12 and suitable for fastening the clamp band 10 around a fastening object, and a band lock 20 formed in the second end regions of the first and second band portions 11,12 and suitable for releasably fastening the first band portion 11 to the second band portion 12. The band lock 20 comprises a hook member 22 formed in the second band portion 12 and an opening 21 formed in the first band portion 11, the opening 21 being adapted to receive the hook member 22 when the second end regions of the first and second band portions 11,12 circumferentially overlap one another in a locked configuration of the band lock 20. The tip portion 22b of the hook member 22 protrudes radially inward so as to overlap with the second end region of the first band portion 11 in the circumferential direction. This prevents the band lock 20 from coming undone even when a high tensile force is applied to the clamp band 10 in the circumferential direction.

Description

Technical Field

[0001] The present invention relates to a clamp fixed around an object having a substantially circular cross section, and more specifically, to a threaded clamp having a V-shaped cross section, which is used to connect circular flanges formed at mutually opposing ends of two pipes to be interconnected.

Background Art

[0002] An example of such a V-clamp is described in International Publication No. 2018 / 010821. This type of clamp comprises at least one inner segment with a substantially V-shaped cross section adapted to surround a pipe flange, a clamp band surrounding the at least one segment, loops provided at both ends of the clamp band, a pair of trunnions surrounded by the loops, and a threaded bolt extending through the trunnions. The at least one segment with a substantially V-shaped cross section includes two inclined surfaces configured to interact with the flanges, such that the radial force exerted by the clamp band is at least partially converted into an axial force that presses the flanges against each other.

[0003] By screwing the threaded bolt, the two ends of the clamp band can be drawn toward each other when tightening the clamp around a fixed object such as a hose or a pipe. In practice, hoses or pipes are often installed in automobiles (or other types of machinery) that have only a small assembly space, in a manner that generally makes it difficult or impossible to slide the clamp as a closed (but not yet tightened) ring onto the pipe or hose. Therefore, it is necessary to open the clamp and insert the pipe or hose through the clamp opening between the two free band ends.

[0004] Screw-type V-clamps, such as those described in International Publication No. 2018 / 010821 or German Patent Application Publication No. 102016111117, can be opened by loosening a threaded bolt from one side of the trunnion, but opening this type of clamp is cumbersome and time-consuming. The screwdriver must reach the bolt head, and loosening the bolt from the threaded trunnion requires a relatively large number of rotations. Therefore, there is a need to provide a way to open the clamp more quickly during the assembly stage.

[0005] A known solution to this problem is the so-called band lock or quick lock. For example, as disclosed in U.S. Patent No. 4,521,940 or U.S. Patent No. 5,299,344, a screw clamp may be provided with a clamp band that is separable into two band sections. The first end of each band section is provided with a loop surrounding a pair of trunnions for engagement with a threaded bolt, while the second end region of each band section is provided with a band lock for quickly joining the second ends of the two band sections together when assembling the clamp around an object to be fixed. The band lock comprises a hook member provided on the first band section for engaging with a hole provided on the second band section. The hook member has a tongue-shaped portion that projects radially outward so as to be received in a window-shaped hole formed in the second band section. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2018 / 010821 [Patent Document 2] German Patent Application Publication No. 102016111117 [Patent Document 3] U.S. Patent No. 4521940 [Patent Document 4] U.S. Patent No. 5,299,344 [Patent Document 5] German Patent Application Publication No. 2619179 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, the screw-type clamps described in U.S. Patent No. 4,521,940 or U.S. Patent No. 5,299,344 are not V-clamps, and a quick-lock solution for V-clamps does not yet exist. Furthermore, the band-lock engagement of prior art quick-locks has shown insufficient reliability in overtightening stress tests. Ultimately, it was found that if the circumferential tensile force from the second band portion becomes too large, the tongue-shaped portion may deform. This could then cause the hook member to slip out of the hole, potentially leading to clamp failure.

[0008] German Patent Application Publication No. 2619179 describes a flat clamp band, the first and second ends of which are provided with holes for inserting hook elements provided at both ends of the band portion of a band tightening means. After the clamp band is positioned to surround the object to be clamped, the hook elements of the band tightening means must be inserted into the corresponding holes at the first and second ends of the clamp band. The clamp can then be tightened using a tightening screw. The clamp band itself is completely flat and does not have a band lock. In actual use of this prior art clamp, it has turned out to be cumbersome to simultaneously engage the hooks of the band tightening means at both ends with the flat clamp band. [Means for solving the problem]

[0009] The present invention addresses the above-mentioned problems and provides a clamp with improved reliability for band locking, as defined in the appended claims.

[0010] Similar to the prior art, the band lock of the present invention comprises first and second band portions, and the second end regions of the first and second band portions are provided with a hook member and a hole, respectively. However, the tongue-shaped tip of the hook member protrudes radially inward, rather than radially outward as in the prior art.

[0011] This means that when the band lock is closed by assembling the two band sections, the second band section, which has the hook member, is positioned radially outward from the first band section, which has the hole, and the tongue-shaped tip of the hook member protrudes radially inward from the hole in the first band section. As a result, the second end region of the first band section is sandwiched between the hook section and the remaining portion of the second end region of the second band section. In other words, the hook member is radially locked by the first band section and cannot be deformed radially outward. The improved reliability of this band lock has been demonstrated in tests. Even under high clamping stress, the tension of the first band section acts circumferentially and therefore parallel to the tip of the hook member.

[0012] This improvement is particularly important when the band lock of the present invention is applied to a V-clamp. As described above, such a V-clamp typically has one or more inner segments with a substantially V-shaped cross-section positioned radially between the clamp band and the object to be fixed. In the locked configuration of the band lock, the hook member of the second band portion is clamped between at least one inner segment and the second end region of the first band portion. This restrains the hook member radially from both sides. During stress testing, the tongue-shaped tip is crushed between the V-shaped inner segment and the first band portion. This radial restraint prevents the tongue from bending and coming out of the window-shaped hole of the band lock. In addition to the V-shape, other cross-sectional shapes of the inner segment are possible, such as H-shapes or similar. The present invention is equally applicable to such other shapes, as the clamping advantages described above are equally applicable.

[0013] The hook member preferably comprises a curved base portion extending radially inward at an inclination angle less than 90° (preferably between 10° and 70°, most preferably between 20° and 40°) and a tip portion extending substantially circumferentially. The tip portion extends parallel to the second end region of the first band portion, while the amount by which the base portion protrudes radially corresponds to the band thickness of the first band portion in the second end region. All of this supports smooth and secure hook insertion into the hole of the first band portion when closing the band lock. Furthermore, the band lock can be opened again without becoming stuck.

[0014] Preferably, the hook member is formed as a substantially rectangular tan, for example, punched out from the band material of the second band portion on three sides and remaining connected to the second end region of the second band portion on its fourth side. Similarly, the hole may be formed as a substantially rectangular window punched out from the band material of the first band portion on all four sides. This allows the band lock to be manufactured quickly and at relatively low cost from flat band material.

[0015] Other hook shapes are possible without losing the advantages of the present invention. For example, the tongue does not have to be rectangular and / or may be offset from the center position in the width direction. Also, instead of a single tongue, two or more tongue-shaped members (and correspondingly two or more windows) may be provided.

[0016] The hook member may be deformed to have a curved base portion extending radially inward and a tip portion extending substantially circumferentially. After the clamp is fixed, the amount by which the base portion extends radially corresponds to the band thickness of the first band portion in the second end region.

[0017] The present invention may be applied to a screw-type clamp, in which a threaded bolt extends through first and second trunnions provided in first and second band loops formed in first end regions of the first and second band portions. Instead of having trunnions, flat supports for bolts and nuts are also known in some fields of the art, and the present invention can likewise be fully used for those connection means. Furthermore, still other means for tightening the clamp around an object to be fastened, such as a deformable ear or a toothlock, are conceivable, and the present invention is likewise fully applicable to such tightening means. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. In the drawings, Fig. 1 is a perspective view of a V-clamp according to an embodiment of the present invention, Fig. 2 is a perspective view of the second end portion of the first band portion in a disconnected state, Fig. 3a is a top perspective view of the second end portion of the second band portion in a disconnected state, Fig. 3b is a bottom perspective view of the second end portion of the second band portion in a disconnected state Fig. 4 is a detailed perspective view of the band lock in a connected state according to the embodiment of the present invention, Fig. 5 is a cross-sectional view of the band lock detail shown in Fig. 4. DETAILED DESCRIPTION OF EMBODIMENTS FOR CARRYING OUT THE INVENTION

[0019] In the present specification, the terms "radial direction", "axial direction", and "circumferential direction" in the closed state generally relate to the overall geometric shape of the clamp, which is a ring having a constant radius and circumference. The clamp is designed to embrace a substantially axially extending pipe or hose.

[0020] As shown in Fig. 1, the clamp includes an outer clamp band 10 constituted by a first band portion 11 and a second band portion 12. The first end regions of the first and second band portions 11, 12 are connected by a threaded connecting means or tightening means 30. The second end regions of the first and second band portions 11, 12 are connected by a band lock 20.

[0021] The first end regions of the first and second band portions 11, 12 are both looped back to form first and second loops 17, 18, which are adapted to form an axial space for receiving first and second trunnions 31, 32. The first trunnion 31 has an unthreaded through hole, and the second trunnion 32 has a threaded through hole. A threaded bolt 33 extends circumferentially through the through hole of the first trunnion 31 and into the threaded through hole of the second trunnion 32. By rotating the head 34 of the threaded bolt 33 about its longitudinal axis, the connecting means 30 can draw the first and second loops 17, 18 toward each other to tighten the clamp band 10 around an object to be fastened (not shown). By rotating the bolt head 34 in the opposite rotational direction, the connecting means 30 can be released again.

[0022] The present clamp further includes four inner profile segments 13 to 16 each having a substantially V-shaped cross section, which are arranged adjacent to each other in the circumferential direction. The clamp band 10 surrounds the segments 13 to 16, and the segments 13 to 16 are adapted to surround a pipe flange (not shown) of the object to be fastened. Each of the segments 13 to 16 includes two inclined surfaces, which are configured to interact with the flanges such that the radial force exerted by the outer clamp band 10 is at least partially converted into an axial force that presses the flanges against each other.

[0023] The second end regions of the first and second band sections 11 and 12 are located on the opposite side of the first end region in the circumferential direction and are provided with band locks 20, which will be described in more detail below with reference to Figs. 2 to 5.

[0024] Fig. 2 shows the second end region of the first band portion 11, which is located radially above the inner segment 13. The second end region has a window-shaped opening 21 located in the center in the hand width direction. In the illustrated embodiment, the opening 21 is formed as a rectangular window obtained by punching out the band material with four side edges 21a to 21d. Other geometric shapes and arrangements of the opening 21 are possible and within the scope of the present invention, as long as the opening 21 is technically adapted to receive the hook member 22 in a locking engagement and form a secure band lock 20.

[0025] Figures 3A and 3B show the second end region of the second band portion 12, with a portion of it positioned radially above the other inner segment 14. The second end region has a tongue-shaped hook member 22 positioned in the center in the hand width direction. In the illustrated embodiment, the hook member 22 is formed as a rectangular lug, and this rectangular lug is first made of band material of The hook member 22 is obtained by punching out three side edges 23a to 23c, and then bending the rectangular lug twice (i.e., first bending it radially inward around the fourth side edge 23d as the first bending axis, and then folding it again around the second bending axis 23e, which is located a certain distance away from the fourth side edge 23d toward the lug tip). As a result, the hook member 22 has a curved base portion 22a that extends radially inward at an inclination angle of about 30° with respect to the circumferential direction, and a tip portion 22b that extends substantially circumferentially toward the clamp band 10. The amount by which the base portion 22a protrudes radially is controlled by the distance between the first and second bending axes 23d, 23e, and corresponds to the band thickness of the first band portion 11 in the second end region.

[0026] Other geometric shapes and arrangements of the hook member 22 are possible and within the scope of the present invention, as long as they are technically adapted to engage with the opening 21 in a locking engagement to form a secure band lock 20.

[0027] Figures 4 and 5 show details of the clamp when the band lock 20 is in the locked state. The second end region of the second band portion 12 is positioned radially outward so as to overlap the second end region of the first band portion 11. When the hook portion 22 is positioned over the opening 21, the tip portion 22b protrudes radially into the opening 21. By pulling the second end regions of the first and second band portions 11 and 12 apart, the tip portion 22b can then be locked below the second end region of the first band portion 11. This locked state is shown in Figures 4 and 5.

[0028] The hook member 22 is connected to the inner segment 13 and the first band portion 11 It is sandwiched between the second end region. Because compressive forces act on the tip portion 22b from both radial sides, the hook member 22 does not detach from the band lock 20 even when high tensile stress is applied to the clamp band 10 in the circumferential direction. This effect has been demonstrated by tests.

[0029] In summary, the present invention provides a clamp, preferably a screw-type V-clamp, for securing around an object. The clamp comprises a clamp band 10 having first and second band portions 11, 12; connecting means 30 attached to the first end regions of the first and second band portions 11, 12 and suitable for tightening the clamp band 10 around an object to be secured; and a band lock 20 formed in the second end regions of the first and second band portions 11, 12 and suitable for removably attaching the first band portion 11 to the second band portion 12. The band lock 20 comprises a hook member 22 formed in the second band portion 12 and an opening 21 formed in the first band portion 11, the opening 21 being adapted to receive the hook member 22 when the second end regions of the first and second band portions 11, 12 overlap each other circumferentially in the locked configuration of the band lock 20. The tip portion 22b of the hook member 22 protrudes radially inward so that it overlaps with the second end region of the first band portion 11 in the circumferential direction. As a result, the band lock 20 will not come off even when a high tensile force is applied to the clamp band 10 in the circumferential direction. [Explanation of Symbols]

[0030] 10 Clamp Bands 11. First Band Section 12. Second Band Section 13-16 V-shaped inner segments 17. The First Loop 18. The Second Loop 20 Band Rock 21 holes / windows 21a~d Side edges of holes 22 Hook component / tan 22a Bent base 22b Tip 23a~c Cut-out side edges of hook components 23d Hook member / Uncut side edge of the first bending axis 23e Second bending axis 30 Connection means 31. First trunnion (threadless through hole) 32. Second trunnion (threaded through hole) 33 Threaded bolts 34 Bolt head

Claims

1. A clamp that is fixed around an object, A clamp band (10) having first and second band portions (11, 12), A connecting means (30) suitable for attaching to the first end regions of the first and second band portions (11, 12) and tightening the clamp band (10) around the object to be fixed, A band lock (20) is formed in the second end region of the first and second band portions (11, 12) and is suitable for removably attaching the first band portion (11) to the second band portion (12), At least one inner segment (13-16) is positioned radially between the clamp band (10) and the object to be fixed, Equipped with, The band lock (20) has a hook member (22) formed in the second band portion (12) and a hole (21) formed in the first band portion (11), and the hole is configured to receive the hook member (22) when the second end regions of the first and second band portions (11, 12) overlap each other in the circumferential direction in the locked configuration of the band lock (20). The aforementioned hook member (22) protrudes radially inward, In the locked configuration of the band lock (20), the hook member (22) of the second band portion (12) is sandwiched between the at least one inner segment (13-16) and the second end region of the first band portion (11).

2. A clamp according to claim 1, In the locked configuration of the band lock (20), the second end region of the first band portion (11) is clamped between the hook member (22) and the remaining portion of the second end region of the second band portion (12).

3. A clamp according to claim 1, The clamp comprises at least one inner segment (13-16) having a substantially V-shaped or H-shaped cross-section adapted to surround the two pipe flanges of the object to be fixed.

4. A clamp according to any one of claims 1 to 3, The hook member (22) is a clamp having a curved base portion (22a) extending radially inward and a tip portion (22b) extending substantially circumferentially.

5. A clamp according to claim 4, The amount by which the base portion (22a) protrudes radially corresponds to the band thickness of the first band portion (11) in the second end region of the clamp, at least in the locked configuration.

6. A clamp according to claim 4, A clamp in which the tip portion (22b) of the hook member (22) extends parallel to the second end region of the first band portion (11).

7. A clamp according to claim 4, The base portion (22a) is a clamp that extends radially inward at an inclination angle of 10° to 70° with respect to the circumferential direction.

8. The clamp according to claim 4 In the locked configuration of the band lock (20), the clamp is such that the tip portion (22b) is compressed between the at least one inner segment (13-16) and the second end region of the first band portion (11) to restrain the hook member (22).

9. A clamp according to any one of claims 1 to 3, The clamp is formed by punching out the band material of the second band portion (12) and leaving one side (23d) connected to the second end region of the second band portion (12), with the shape of the tongue being rectangular.

10. A clamp according to any one of claims 1 to 3, The hook member (22) is a clamp that extends circumferentially rearward from the second end region toward the first end region of the second band portion (12).

11. A clamp according to any one of claims 1 to 3, The aforementioned hole (21) is formed as a window punched out from the band material of the first band portion (11) along its outer edges (21a to d), and the shape of the window is rectangular.

12. A clamp according to any one of claims 1 to 3, The first and second band portions (11, 12) are each formed as a single band member, and their second end regions are clamps that overlap each other in the circumferential direction in the locked configuration of the band lock (20).

13. A clamp according to any one of claims 1 to 3, The aforementioned connecting means (30) A first trunnion (31) is provided on the first band loop (17) formed in the first end region of the first band portion (11), A second trunnion (32) is provided on the second band loop (18) formed in the first end region of the second band portion (12), A threaded bolt (33) extends through the first and second trunnions (31, 32) and engages with the female thread of one of the trunnions (31, 32) to bring the first and second band loops (17, 18) closer together when the clamp band (10) is tightened around the object to be fixed, A clamp having

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