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 for fastening around an object of generally circular cross section, and more particularly to a screw-type clamp having a V-shaped cross section used to connect circular flanges formed on the opposing ends of two interconnected pipes. [Background technology]

[0002] An example of such a V-clamp is described in WO 2018 / 010821 A1. This type of clamp comprises at least one inner segment of a generally V-shaped cross section adapted to surround pipe flanges, a clamping band surrounding the at least one segment, loops at either end of the clamping band, a pair of trunnions surrounded by the loops, and a threaded bolt extending through the trunnions, where the at least one segment of the generally V-shaped cross section includes two inclined surfaces configured to interact with the flanges such that a radial force exerted by the clamping band is at least partially converted into an axial force pressing the flanges together.

[0003] By screwing in the threaded bolt, the two ends of the clamp band can be drawn towards each other when tightening the clamp around a fixed object such as a hose or pipe. In practice, in automobiles (or other types of machines), where there is often little assembly space, the hose or pipe is typically installed in a manner that makes it difficult or impossible to slide the clamp onto the pipe or hose as a closed (but not yet tightened) ring. Therefore, the clamp must be opened and the pipe or hose must be inserted through the clamp opening between the two free band ends.

[0004] Although threaded V-clamps such as those described in WO 2018 / 010821 or DE 102016111117 can be opened by loosening the threaded bolt from one of the trunnions, opening this type of clamp is cumbersome and time-consuming: the head of the bolt has to be reached with a screwdriver and a relatively large number of rotations are required to loosen the bolt from the threaded trunnion. There is therefore a need to provide the possibility of opening the clamp more quickly during the assembly phase.

[0005] A known solution to this problem is the so-called band lock or quick lock. For example, as disclosed in US Pat. No. 4,521,940 or US Pat. No. 5,299,344, screw clamps can be provided with a separable clamp band in two band sections. A first end of each band section is provided with a loop surrounding a pair of trunnions for engagement with a threaded bolt, while a second end region of each band section is provided with a band lock for quickly attaching the second ends of the two band sections together when assembling the clamp around the object to be fixed. The band lock comprises a hook member provided on the first band section for engaging in a hole provided in the second band section. The hook member has a tongue-shaped portion projecting radially outwardly 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] DE 102016111117 [Patent Document 3] U.S. Patent No. 4,521,940 [Patent Document 4] U.S. Patent No. 5,299,344 [Patent Document 5] DE 2619179 A1 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the screw-type clamps shown in US Patent No. 4,521,940 or US Patent No. 5,299,344 are not V-clamps, and there are no quick-lock solutions for V-clamps yet. Furthermore, the band-lock engagement of the prior art quick-locks has shown insufficient reliability in overtightening stress tests. Eventually, it was found that if the circumferential pulling force from the second band portion becomes too large, the tongue-shaped portion may deform. Then the hook member may slip out of the hole and the clamp may break.

[0008] DE 2 619 179 A1 describes a flat clamping band, the first and second ends of which are provided with holes for the insertion of hook elements provided at both ends of the band part of the band tightening means. After the clamping band has been provided around 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 clamping band. The clamp can then be tightened by means of a tightening screw. The clamping band itself is completely flat and does not have a band lock. During practical use of this prior art clamp, it eventually proved to be cumbersome to simultaneously engage the hooks of the band tightening means at both ends with the flat clamping band. [Means for solving the problem]

[0009] The present invention addresses the above problems and provides a clamp with improved band lock reliability, as defined in the accompanying claims.

[0010] Similar to the prior art, the band lock of the present invention includes first and second band portions each having a hook member and a hole at the second end region of the first and second band portions, except that the tongue-shaped tips of the hook members project 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 parts, the second band part with the hook member is positioned radially outward from the first band part with the hole, with the tongue-shaped tip of the hook member protruding radially inward from the hole of the first band part. The second end region of the first band part is thus pinched between the hook member and the remaining part of the second end region of the second band part. In other words, the hook member is locked in the radial direction by the first band part and cannot be deformed radially outward. This improved reliability of the band lock has been proven in tests. Even under high tightening stresses, the tension of the first band part acts in the circumferential direction and therefore parallel to the tip of the hook member.

[0012] This improvement is particularly important when the band lock of the invention is applied to a V-clamp. As mentioned above, such a V-clamp usually has one or more inner segments of a substantially V-shaped cross section, which are arranged 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 part is clamped between at least one inner segment and the second end region of the first band part. This restrains the hook member radially from both sides. During the stress test, the tongue-shaped tip is crushed between the V-shaped inner segment and the first band part. This radial restraint prevents the tongue from bending and escaping through the window-shaped hole of the band lock. Apart from the V-shape, other cross-sectional shapes of the inner segment are also possible, such as H-shaped or similar. The invention is equally well applicable to such other shapes, since the advantages of clamping explained above apply equally.

[0013] The hook member preferably comprises a bent base portion extending radially inwardly at an inclination angle of 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 projects radially corresponds to the band thickness of the first band portion in the second end region. All of this supports smooth and reliable hook insertion into the hole of the first band portion when closing the band lock. Further, the band lock can be reopened without becoming immovable.

[0014] Preferably, the hook member is formed, for example, as a substantially rectangular tab punched out from the band material of the second band portion on three sides and 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] There may also be other hook shapes without losing the advantages of the present invention. For example, the tab may not be rectangular and / or may be offset from the central position in the width direction. Also, instead of a single tab, two or more tab-shaped members (and correspondingly two or more windows) may be provided.

[0016] The hook member may be deformed to have a bent base portion extending radially inwardly 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 invention may be applied to a screw type clamp, where a threaded bolt extends through first and second trunnions provided in first and second band loops formed in the first end regions of the first and second band portions. Instead of having trunnions, several flat supports for the bolt and nut are also known in the art, and the invention may be equally well used for those connection means. Furthermore, still other means for tightening the clamp around the object to be fixed, such as deformable ears or toothlocks, are contemplated, and the invention may be equally well used for such tightening means. [Brief description of the drawings]

[0018] Hereinafter, an embodiment of the present invention will be described in more detail with reference to 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 a second end of the first band portion in an unconnected state; FIG. 3a is a top perspective view of the second end of the second band portion in an unconnected state; FIG. 3b is a bottom perspective view of the second end of the second band portion in an unconnected state; FIG. 4 is a detailed perspective view of a band lock in a connected state according to an embodiment of the present invention; Fig. 5 is a cross-sectional view of the band lock detail shown in Fig. 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] As used herein, the terms "radial," "axial," and "circumferential" refer to the overall geometry of the clamp, which in the closed state is generally a ring having a constant radius and circumference. The clamp is designed to hug a pipe or hose that extends substantially axially.

[0020] As shown in Fig. 1, the clamp comprises an outer clamp band 10 made up of 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 or fastening 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 parts 11,12 are looped back together to form first and second loops 17,18, which are adapted to form an axial space for receiving the 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 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 towards each other to tighten the clamping band 10 around a fixed object (not shown). By rotating the bolt head 34 in the opposite rotational direction, the connecting means 30 can be released again.

[0022] The clamp further comprises four inner profile segments 13-16 of generally V-shaped cross section arranged circumferentially adjacent to one another. The clamping band 10 wraps around the segments 13-16, which are adapted to wrap around pipe flanges (not shown) of a fastening object. Each segment 13-16 includes two inclined surfaces configured to interact with the flanges such that a radial force exerted by the outer clamping band 10 is at least partially transformed into an axial force pressing the flanges against one another.

[0023] The second end regions of the first and second band portions 11, 12 are circumferentially opposite the first end regions and are provided with a band lock 20, which will be described in more detail below with reference to Figures 2 to 5.

[0024] FIG. 2 shows the second end region of the first band part 11, which is arranged radially above the inner segment 13. The second end region has a window-like hole 21 located in the middle in the hand width direction. In the illustrated embodiment, the opening 21 is formed as a rectangular window obtained by punching the band material at the four side edges 21a-d. Other geometric shapes and arrangements of the opening 21 are possible and within the scope of the invention, as long as the opening 21 is technically adapted to receive the hook members 22 in locking engagement to form a positive band lock 20.

[0025] 3A and 3B show the second end region of the second band part 12, part of which is positioned radially above the other inner segment 14. The second end region has a tongue-shaped hook member 22 positioned in the middle of the hand width direction. In the illustrated embodiment, the hook member 22 is formed as a rectangular lug, which is obtained by first punching out the band material with three side edges 23a-23c and then bending the rectangular lug twice (i.e. first bending radially inward around the fourth side edge 23d as a first bending axis and then folding back again around a second bending axis 23e located at a certain distance from the fourth side edge 23d towards the lug tip). The hook member 22 thus has a bent base part 22a extending radially inward at an inclination angle of about 30° with respect to the circumferential direction and a tip part 22b extending approximately in the circumferential direction of 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 geometries and configurations of hook members 22 are possible and within the scope of the present invention, so long as the hook members 22 are technically adapted to engage openings 21 in a locking engagement to form a positive band lock 20.

[0027] 4 and 5 show details of the clamp when the band lock 20 is in a locked state. The second end region of the second band part 12 is positioned radially outwardly so as to overlap the second end region of the first band part 11. When the hook part 22 is positioned over the opening 21, the tip part 22b projects radially into the opening 21. By pulling the second end regions of the first and second band parts 11, 12 away from each other, the tip part 22b can then be locked under the second end region of the first band part 11. This locked state is shown in FIGS. 4 and 5.

[0028] The hook member 22 is sandwiched between the inner segment 13 and the second end region of the first band portion 12. Since a compressive force acts on the tip portion 22b from both radial sides, the hook member 22 does not come off the band lock 20 even if a high tensile stress is applied to the clamp band 10 in the circumferential direction. This effect has been verified by testing.

[0029] In summary, the present invention provides a clamp, preferably a screw-type V-clamp, for fixing around an object. The clamp comprises a clamp band 10 having first and second band parts 11,12, a connection means 30 attached to first end regions of the first and second band parts 11,12 and suitable for tightening the clamp band 10 around a fixed object, and a band lock 20 formed in the second end regions of the first and second band parts 11,12 and suitable for removably attaching the first band part 11 to the second band part 12. The band lock 20 comprises a hook member 22 formed in the second band part 12 and an opening 21 formed in the first band part 11, the opening 21 being adapted to receive the hook member 22 when the second end regions of the first and second band parts 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 off even when a high tensile force is applied to the clamp band 10 in the circumferential direction. [Explanation of symbols]

[0030] 10 Clamp band 11 First Band 12 Second Band Section 13~16 V-shaped inner segment 17 First Loop 18 Second Loop 20. Band Rock 21 Holes / Window 21a~d Side edges of holes 22 Hook member / tongue 22a Bent base 22b Tip 23a-c Hook member cutout side edges 23d Uncut side edge of hook member / first bending axis 23e Second bending axis 30 Connection means 31 First Trunnion (Unthreaded Through Hole) 32 Second Trunnion (threaded through hole) 33 Threaded Bolt 34 Bolt head

Claims

1. A clamp to be secured around an object, comprising: A clamp band (10) having first and second band portions (11, 12); connecting means (30) attached to first end regions of the first and second band portions (11, 12) and suitable for tightening the clamping band (10) around the object to be fixed; a band lock (20) formed in a second end region of the first and second band portions (11, 12) and adapted to releasably attach the first band portion (11) to the second band portion (12); 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) 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 hook member (22) protrudes radially inward. A clamp characterized by:

2. 2. The clamp of claim 1, A clamp in which, in a locked configuration of the band lock (20), the second end region of the first band portion (11) is sandwiched between the hook member (22) and a remaining portion of the second end region of the second band portion (12).

3. 3. The clamp according to claim 1 or 2, The clamp further comprises at least one inner segment (13-16) arranged radially between the clamp band (10) and the object to be fixed.

4. 4. The clamp of claim 3, The at least one inner segment (13-16) of the clamp has a generally V- or H-shaped cross section adapted to surround two pipe flanges of the object to be fastened.

5. A clamp according to claim 3 or 4, A clamp in which, in a 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).

6. 6. A clamp according to any one of claims 1 to 5, The hook member (22) has a curved base portion (22a) extending radially inwardly and a tip portion (22b) extending generally in a circumferential direction.

7. 7. The clamp of claim 6, A clamp, the amount of radial projection of the base portion (22a) corresponding at least in the assembled state of the clamp to the band thickness of the first band portion (11) in the second end region.

8. 8. The clamp according to claim 6 or 7, A clamp wherein the tip portion (22b) of the hook member (22) extends parallel to the second end region of the first band portion (11).

9. A clamp according to any one of claims 6 to 8, The base portion (22a) extends radially inwardly at an inclination angle of 10° to 70°, preferably 15° to 55°, and most preferably 20° to 40° relative to the circumferential direction.

10. 10. A clamp according to any one of claims 1 to 9, The hook member (22) is formed as a tongue punched out of the band material of the second band portion (12) and remains connected to the second end region of the second band portion (12) at one side (23d), the shape of the tongue being preferably rectangular.

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

12. A clamp according to any one of claims 1 to 11, The hole (21) is formed as a window punched out of the band material of the first band portion (11) at its peripheral edges (21a-d), the shape of the window being preferably rectangular.

13. A clamp according to any one of claims 1 to 12, The first and second band portions (11, 12) are each formed as an integral band member, the second end regions of which overlap each other in the circumferential direction in the locked configuration of the band lock (20).

14. 15. A clamp according to any one of claims 1 to 14, The connection means (30) is a first trunnion (31) provided on a first band loop (17) formed in the first end region of the first band portion (11); a second trunnion (32) provided on a second band loop (18) formed in the first end region of the second band portion (12); a threaded bolt (33) extending through the first and second trunnions (31, 32) and engaging with an internal thread of one of the trunnions (31, 32) to move the first and second band loops (17, 18) closer together when tightening the clamp band (10) around the object to be fixed; A clamp having

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