Polymer clamp

Abstract

The present invention provides a clamping device (100) formed of a flexible elongate body having first and second end portions (1, 2) for engaging with each other to form a first loop (10) around an object to be fastened The first end portion (1) comprises a lock (30) made for engagement with a tongue (40) at the second end portion (2). According to a first aspect of the invention, a radial inner wall surface of the first loop (10) has a rib portion (80) protruding radially inwards for providing a homogeneous radial compression force to the object to be fastened. According to a second aspect of the invention, the clamp (100) comprises a second loop (20) formed at a radial distance from said first loop (10) by an arch (50) extending from an intermediate portion (3) between the first and second end portions (1, 2) to the lock (30). The second loop (20) provides a receiving space for the tongue (40) extending through an opening (32) of the lock (30) such that the second end portion (2) is radially and circumferentially moveable withing the receiving space.

Description

[0001] Oetiker Schweiz AG - PMC Polymer Medical Clamp Auriga - PCA-54861

[0002] Polymer Clamp

[0003] Description

[0004] The present invention provides a polymer clamp for fixing tubes, particularly silicone / TPE / braided tubing, onto spigots, for leak proofed fluid connections. The present clamping device should be particularly suitable for the medical / pharmaceutical sector and clean-room applications. For cost efficiency and recycling reasons, it is desired to use polymer material instead of steel. Further, fewest possible clamp sizes should be able to cover a wide range of tubing diameters.

[0005] WO 2009 / 105079 A1 describes a plastic cable tie for leak-proof connection of a flexible tubing to a barbed conduit. One band end is provided with latching teeth to engage with a band lock at the other end of the cable tie. The cable tie is closed manually and / or with a pincer tool. After closing, the free end projects tangentially through the lock of the cable tie.

[0006] In some medical sector applications and for cleanroom applications, no free particles must be generated when mounting the clamp onto the tubing, in particular no cutting-off of the overhang material at the band end pushed through a lock opening at the other band end is allowed. Hence, the tangentially projecting end of the cable tie cannot be removed and may lead to an undesirable interference with other surrounding parts or the personnel.

[0007] US 4 183 120 A describes another conventional clamping device made of plastics material. Such conventional clamping devices have various disadvantages. In particular, they can lead to radial band buckling during the clamp closure process and have turned out to be insufficient in fulfilling the requirement of 360° sealing for leakage free connection of a tubing onto a spigot. Also, they are not tamper proof and in many cases not secured against sideways movement which can lead to intentional or unintentional opening of the clamp. Furthermore, to reach the strength needed, they tend to have a massive build-up of material rending it visually unpleasant and not cost-effective.

[0008] An object of the present invention is to provide clamping devices which reduce the risk of buckling during the clamp closure process and which provide a more uniform 360° compression of the clamped tubing onto the spigot.According to a first aspect, this object is achieved by the clamping device defined in claim 15. According to this claim, a radial inner wall surface of the clamping band has a rib portion which is protruding radially inwards for providing a homogeneous radial compression force to the object to be fastened. The rib portion additionally provides better slip- and seal proofing, less friction during clamp tightening, easier sliding of the tongue and a lower buckling risk.

[0009] According to a second aspect, this object is achieved by the clamping device defined in claim 1. The dependent claims relate to preferred embodiments.

[0010] According to the second aspect, the clamping device not only forms the typical first loop around the object to be fastened by locking engagement of first and second end portions of the clamp at a clamp lock but also a second loop formed radially outwards to and at a radial distance from said first loop by an arch extending from an intermediate portion between the first and second end portions to the lock. The second loop provides a receiving space for the tongue extending through an opening of the lock such that the second end portion is radially and circumferentially moveable withing the receiving space.

[0011] The second loop works as a flexible, i.e. elastically deformable, guide and protection loop for guiding and protecting the tongue during clamp tightening. The second end of the clamp, which at first sticks out from the lock opening tangentially, contacts the arch and is thereby elastically urged in a circumferential direction. Thereby, the clamp contour is adapted during tightening to guide the tongue flush alongside the arch. The arch thus works as a radial guidance of the tongue. This prevents hooking-up and entangling of the clamping band. When the arch comes into contact with the tangentially protruding tongue, the arch is elastic deformed and thereby urges the tongue to move in the circumferential direction. This assists an overall uniform circular shape of the clamping band part forming the first closed loop and thereby improves uniform 360° compression by the first loop. Additionally, the second loop prevents the tongue tip from sticking out from the overall clamping device in a tangential direction. Thereby, the arch not only protects the tongue from shearing off by external forces but also protects it from interacting with surrounding parts during transportation or the like.According to a preferred embodiment, the arch has a semi-circular shape with a smaller radius of curvature than the first loop. This gives the tongue portion protruding through the lock opening enough freedom of movement to make the tightening operation smooth and effortless. The desired arch flexibility may be supported by its composition of an arcuate main portion extending from the lock to the intermediate portion and a connecting bridge extending in the radial direction and connecting the arcuate main portion to the intermediate portion. In a most preferred embodiment, the connecting bridge has a smaller width than the arcuate main portion.

[0012] As already mentioned with respect to the first aspect of the invention, a radial inner wall surface of the first loop has a rib portion protruding radially inwards and providing a homogeneous radial compression force to the object to be fastened. Corresponding to this radial rib portion, a radial outer wall surface of the tip end of the first end portion may comprise a recessed portion or groove working as an inlet for receiving and guiding the rib portion during a closing operation of the clamping device. An extension with tapered radial width ensures in cooperation with the groove a seamless transition of the rib portion into the lock opening. Thereby, an almost stepless inner perimeter of the first loop is obtained, and friction and the risk of clamp buckling is reduced.

[0013] Moreover, a radial outer wall surface of the tongue may have a plurality of latching teeth protruding radially outwards for latching engagement with one or more locking teeth protruding radially inwards at or circumferentially adjacent to the opening of the lock. The locking teeth are arranged behind the lock opening and bounces radially up and down when the tongue is moved in a pushing direction but locks backward movement when the tongue is moved to the opposite in a pulling direction. This provides an easy and reliable locking engagement of the tongue with the lock. Preferably, the latching teeth are axially sandwiched between raised side edges or side rails. The side rails prevent tampering with a tool to open the toothing from the side. They also guide the tongue through the lock opening and prevent it from shifting sideways. Finally, they protect against the sharp edges of the locking teeth and provide an increased tensile strength to the tongue portion of the clamping band.Furthermore, the first end portion preferably comprises a first hook portion and the second end portion preferably comprises a second hook portion to be grasped during the clamp closing and tightening operation. The first hook portion has a first handle protruding radially outwards from the lock portion and the second hook portion has a second handle protruding radially outwards from the second end portion to be grasped by an operator's hand to push the tongue through the opening of the lock in a closing operation until the desired contact pressure on the object to be clamped is reached. Moreover, the first hook portion has a first pair of pincer pins protruding axially from the lock portion and the second hook portion has a second pair of pincer pins protruding axially from the second end portion. The first and second pincer pins are designed to be grasped by pincer jaws of an assembling tool to tighten the clamping device around the object to be fastened. The pincer tool defines a repeatable, user-unspecific, pre-defined closing force. In summary, this provides a relatively simple radial assembling procedure by hand and still ensures tightening of the clamp in a controlled way with a defined pressure given by an assembling tool.

[0014] The clamping device may be manufactured from a polymer material as an integral body by injection moulding. The clamping device is optimised for plastic injection moulding with focus on cost-effective production by using an optimal manufacturing process and material usage. It is also designed for sustainable use and easy recycling. There is no cutting process or other particle generation during application of the clamping device in actual use, making it safe for clean-room applications. For disposal, there is no need of cutting apart a steel clamp and separating it from the other polymer components. It can be disposed all at once.

[0015] Embodiments of the invention will now be described below in greater detail with reference to the drawings, in which:

[0016] Fig. 1 is a perspective view of the clamping device according to a first embodiment of the invention in an open state;

[0017] Fig. 2 is a perspective view of the clamping device of Figure 1 in a preclosed state;

[0018] Fig. 3 is a perspective view showing details of the clamping device of Figure 1 at the intermediate portion between the first and second end portions;Fig. 4 to 6 are side views of the clamping device in a fully open state, an intermediate state and a pre-closed state, respectively;

[0019] Fig. 7 is a perspective view showing details of the clamping device at the second end portion from the radial outer side;

[0020] Fig. 8 is a perspective view showing details of the clamping device at the first end portion from the backward direction;

[0021] Fig. 9 is a perspective view showing details of the clamping device at the second end portion from the radial inner side;

[0022] Fig. 10 is a cross-sectional view of the tongue at the second end portion;

[0023] Fig. 11 is a perspective view showing details of the clamping device at the first end portion from the frontward direction;

[0024] Fig. 12 is a perspective view of the clamping device according to a second embodiment of the invention in an open state seen from the front side;

[0025] Fig. 13 is a perspective view of the clamping device of Figure 12 seen from the rear side;

[0026] Fig. 14 is a side view of the clamping device of Figure 12;

[0027] Fig. 15 is a front view of the clamping device of Figure 12;

[0028] Fig. 16 is a top view of the clamping device of Figure 12;

[0029] Fig. 17 shows the first end portion as a detail of the clamping device in the rear side perspective view of Figure 13; and

[0030] Fig. 18 shows the first end portion as a detail of the clamping device in the front side perspective view of Figure 12.

[0031] In the present specification, the terms "radial", "axial", "tangential" and "circumferential" refer to an overall geometrical form of the clamping device which, in its closed state, is generally a ring having a certain radius and circumference. The clamping device is designed for embracing a cylindrical element such as a tubing pressed onto a spigot. The longitudinal axis of the tubing extends substantially in the axial direction which corresponds to the width direction of the band material of the clamping device. The terms "frontward" and "backward" refer to the clamp closing direction along the circumference of the clamping loop surrounding the object to be fastened.Figure 1 is a perspective side view of the clamping device 100 of the first embodiment in an open state. In this state, an object to be clamped (not shown - for example a tubing to be fastened onto a spigot) can be inserted radially into the opening formed between first and second end portions 1 , 2 of the clamping band body having substantially an elongate form. The entire clamping device 100 is formed of a polymer material by injection moulding.

[0032] The first end portion 1 comprises a lock 30 having an opening 32 through which a tongue 30 at the second end portion 2 can be pushed to bring the clamping device 100 into the pre-closed configuration shown in Figure 2. To reach the pre-closed state, the operator is provided with first and second hook portions 60, 70 provided at the first and second end portions 1 , 2, respectively. A first handle 61 extending radially from the lock 30 and a second handle 71 extending radially from a backward end of the second end portion 2 can be pulled towards each other by two fingers of the operator's hand.

[0033] In addition to the first and second handles 61 , 62, the first and second hook portions 60, 70 comprise first and second pincer pins 62, 72. The first pincer pins 62 project from the lock 30 in both axial directions. The second pincer pins 72 project from the backward end of the second end portion 2 in both axial directions. The first and second pincer pins 62, 72 can be grasped by pincer jaws of an assembling tool (not shown) to tighten the clamp by a predefined pulling force. The first and second pincer pins 62, 72 have a partially circular outer cylinder surface which allows free rotation of pincer jaws having cylindrical engagement surfaces.

[0034] By the clamp closing action, the open configuration shown in Figure 1 is transformed into the pre-closed configuration shown in Figure 2. In this state the tongue 40 is latched into the lock 30 to form a closed first loop 10 around the object to be fastened (not shown). The entire inner circumference of the first loop 10 is provided with a radial protrusion or rib 80 in the axial center portion of the clamping device 100. This radial rib 80 provides homogeneous compression forces in the radial direction along the complete inner circumference of the first loop 10.

[0035] The frontward part of the first end portion 1 is provided with an extension 90 having a continuously decreasing radial thickness. The radialtapering of the extension 90 towards the outer circumferential end is important to avoid a radial gap at the interface with the tongue 40 and to make the radial compression around the complete circumference as homogenous as possible. The extension 90 has some radial flexibility so that it can readily adapt to different tubing diameters. The extension 90 works as a ramp for smoothly guiding and lifting the tongue 40 at the second end portion 2 into the opening 32 of the lock 30.

[0036] The axial middle part of the extension 90 is further provided with a recessed portion working as an inlet groove 91 for the radial rib 80 during the closing operation. The inlet groove 91 extends from the frontmost part of the first end portion 1 to the opening 32 of the lock 30 and ensures a smooth entry of tongue 40 into the lock 30. The outermost end of the groove 91 has a cut-out 92 of semi-circular shape which works as an additional guidance for the tip end of the radial rib 80.

[0037] At the backward end of the lock 30 an arch 50 is integrally formed with the other parts of the clamping device 100. The arch 50 has an arcuate main portion 52 of substantially half-circular shape and extending into the backwards direction to an intermediate portion 3 (see Figure 3). The intermediate portion 3 is located circumferentially between the first and second end portions 1 , 2, at a location which is closer to the first end portion 1. As shown in Figure 3, the backward end of the arcuate main portion 52 is connected to the intermediate portion 3 by a connecting bridge 51 extending in the radial direction. The connecting bridge 51 has a smaller width than the arcuate main portion 52 to provide the arcuate main portion 52 with enhanced flexibility.

[0038] Moreover, the tongue 40 has a smaller width than the arcuate main portion 52. This reduces the risk of an unintentional side shifting of the tongue 40 out of the second loop 20 in the axial / width direction. Thus it ensures optimum protection for the tongue 40 by the arch 50 during and after the closing action as compared to conventional solutions which typically work with a single width for all clamp components.

[0039] The arch 50 forms a second loop 20 radially outwards from the first loop 10 shown in Figure 2 at a location circumferentially backwards from the lock 30. The second loop 20 provides a protected receiving space for the part of thetongue 40 that is pushed through the lock opening 32 and that should - other than usual cable clips - not be cut away in medical or clean room environment. The arcuate main portion 52 has a smaller radius of curvature than the first loop 10. Moreover, the arcuate main portion 52 is flexible but still tied to the intermediate portion 3 such that it provides a guidance for the tongue 40 from the tangential direction towards the circumferential direction. This enhances a homogenous reduction of the first loop diameter during the closing operation and thus supports the desired uniform 360° compression of the object to be fastened.

[0040] Figures 4 to 6 show side views of the clamping device at three steps of the closing operation. In the fully opened state of Figure 4, the clamping device 100 forms a radial opening through which the object to be fastened (e.g. a hose or tube of some application to be secured) can be received. By pulling the first and second handles 61 , 62 towards each other, the clamping device 100 is brought into the intermediate state of Figure 5. In this state, the tip of the tongue 40 is about to be entered into the opening 32 of the lock 30. By pulling the first and second handles 61 , 62 further, the latching teeth 41 (see Figures 2 and 7) of the tongue 40 engage with locking teeth 31 of the lock 30 and bring the clamping device 100 into the pre-closed state of Figure 6.

[0041] The pre-closed state is the state in which some (e.g. the first three) latching teeth 41 engage with the lock 30 but the clamp has not been tightened yet to reduce the diameter to correspond to that of the tubing object to be fastened. From this pre-closed state, the diameter of the first loop 10 can be further reduced by pushing the tongue 40 further into the lock 30 and approaching the first and second handles 61 , 71. In practice, the operator is pre-closing the clamping device 100 at the correct axial location of the object to be fastened. To prevent that the clamping device 100 is moving away, he will manually tighten it by his fingers.

[0042] After such pre-positioning of several clamps in different locations, the operator will take an assembling tool to tighten the clamping devices 100 with a repeatable, user-unspecific and pre-defined closing force one after the other. The assembling tool preferably has pincer jaws (not shown) acting on the first and second pincer pins 62, 72.Figure 7 shows the second end portion 2 from a radial outer side. The tongue 40 has latching teeth 41 projecting radially outwards for engagement with the locking teeth 31 projecting radially inwards at the backward side of the lock 30. The axial side edges of the tongue 40 are raised to form side rails 42 having approximately the same radial height as the locking teeth 31. The side rails 42 provide some protection against interaction of the locking teeth 31 with other entities than the locking teeth 31.

[0043] The backward end of the second end portion 2 shown in Figure 7 is formed by the second hook portion 70 with the radial handle 71 and the axial pincer pins 72. The corresponding first hook portion 60 with the radial handle 61 and the axial pincer pins 62 at the first end portion 1 is shown in Figure 8.

[0044] Figure 8 also shows in greater detail the locking teeth 31 which protrude from the lock main body in a circumferential direction such that they have some flexibility and can move up and down in the radial direction during contact with the latching teeth 41 when the tongue 40 is pushed through the opening 32. Other configurations, e.g., providing the locking teeth 31 contained within the lock main body, are also possible in alternative embodiments of the invention.

[0045] The arcuate main portion 52 of the arch 50 is integrally formed with the lock main body at a point radially outwards from the locking teeth 31 such that the locking teeth 31 are protected by the arcuate main portion 52 against interference from outside.

[0046] Figure 9 shows a radial inner view of the tip end of the tongue 40. A center portion in the width direction of the main clamping band (i.e. , the axial direction of the overall device) is radially raised to provide a rib 80. As can also be seen in the cross-sectional view of Figure 10, the radial height of the rib 80 is about 1 / 4 of the total height at the remaining (non center) portion of the tongue 40, and the width of the rib portion 80 is about 1 / 5 of the total width of the tongue 40.

[0047] The rib 80 protrudes radially inwards into the first loop 10 in a generally semi-circular shape. As shown in Figure 11 , a semi-circular groove 91 of complimentary shape is formed in the extension 90 at the frontward end of the first end portion 1 to facilitate smooth insertion of the tongue 40 into the lock opening 32.Figures 12 to 18 show the clamping device 100 of a second embodiment of the present invention. In the Figures, the same or equivalent structural members are designated with the same reference signs as used in the description of the first embodiment. Detailed description thereof is omitted for conciseness reasons. In the following, only the differences between the second embodiment and the first embodiment are explained.

[0048] As can be seen best in Figures 12 and 14, the tip end 43 of the tongue 40 is tapered in both the axial (or width) direction and the radial direction. This increases the flexibility of the tongue 40 at its tip end 43 and thereby alleviates smooth insertion of the tongue 40 into the opening 32 of the lock 30. No latching teeth 41 are provided at the tip end 43 which additionally reduces friction between the tongue 40 and the lock 30 during the initial part of the closing operation.

[0049] Moreover, the bottom part of the opening 32 is provided with an indentation 33 (see particularly Figure 18) which works as a centering guidance for the tip end 43 during insertion into the opening 32 and as a centering guidance for the radial rib 80 during the clamp closing interaction between the latching teeth 41 and the locking teeth 31. The indentation 33 has a generally rectangular shape in top view and a gradually increasing depth in the frontward moving direction of the tongue 40. The indentation 33 has a width which is broad enough to allow the tip end 43 and the radial rib 80 some lateral flexibility during the closing action but which is at the same time small enough to keep the tongue 40 in circumferential alignment with the first end portion 1.

[0050] As can be seen best in Figures 16 and 17, the band part which is circumferentially adjacent to the lock 30 in the frontward moving direction of the tongue 40 has a pair of radial protrusions 34 provided at lateral side portions of the clamp 100 to provide a centering channel 35 therebetween. The centering channel 35 interacts with the radial rib 80 during the clamp closing operation so as to keep the tongue 40 centered, in particular in cooperation with the groove 91 and the indentation 33.

[0051] As can be seen best in Figures 13, 16 and 17, the lock 30 in the second embodiment is not entirely covered by the arcuate main portion 52 in the radial direction. Instead, the arch 50 is formed with a radial window 53 through whichthe lock 30 is visible from radially outside. This improves the operability of the clamping device 100, since the operator has full visual control of the state of interaction between the tongue 40 and the lock 30 during the closing operation. Additionally, the window 53 provides additional space for the operator's fingers to allow better exertion of closing force on the first handle 61 during the manual (pre-)closing operation.

[0052] Additionally, a web structure 54 forms a stable mechanical connection between the frame 56 surrounding the radial window 53 and the band material forming the first loop 10 at the first end portion 1. One such lateral web structure 54 is provided at each axial side of the band part circumferentially adjacent to the lock 30 so that the tongue 40 may pass between the two web structures 54 when being pushed though the lock 30. Each web structure 54 has an additional lateral window 55 which allows the closing operation to be visually observed from the lateral sides as well.

[0053] Finally, as can be seen best in Figure 13, the second handle 71 is provided with radially protruding corrugation ribs 73. These ribs 73 provide an anti-slippery surface for the operator's fingers during the manual (pre-)closing operation.

[0054] In summary, the present invention provides a clamping device 100 formed of a flexible elongate body having first and second end portions 1 , 2 for engaging with each other to form a first loop 10 around an object to be fastened. The first end portion 1 comprises a lock 30 made for engagement with a tongue 40 at the second end portion 2. According to a first aspect of the invention, a radial inner wall surface of the first loop 10 has a rib portion 80 protruding radially inwards for providing a homogeneous radial compression force to the object to be fastened. According to a second aspect of the invention, the clamp 100 comprises a second loop 20 formed at a radial distance from said first loop 10 by an arch 50 extending from an intermediate portion 3 between the first and second end portions 1 , 2 to the lock 30. The second loop 20 provides a receiving space for the tongue 40 extending through an opening 32 of the lock 30 such that the second end portion 2 is radially and circumferentially moveable withing the receiving space.List of Reference Signs

[0055] 1 first end portion

[0056] 2 second end portion

[0057] 3 intermediate portion

[0058] 10 first loop

[0059] 20 second loop

[0060] 30 lock

[0061] 31 locking teeth

[0062] 32 opening

[0063] 33 indentation

[0064] 34 protrusions

[0065] 35 centering channel

[0066] 40 tongue

[0067] 41 latching teeth

[0068] 42 side rails

[0069] 43 tip end

[0070] 50 arch

[0071] 51 connecting bridge

[0072] 52 arcuate main portion

[0073] 53 radial window

[0074] 54 lateral web structure

[0075] 55 lateral window

[0076] 56 window frame

[0077] 60 first hook portion

[0078] 61 first handle

[0079] 62 first pair of pincer pins

[0080] 70 second hook portion

[0081] 71 second handle

[0082] 72 second pair of pincer pins

[0083] 73 corrugation ribs

[0084] 80 radial rib

[0085] 90 extension

[0086] 91 groove

[0087] 92 cut-out

[0088] 100 clamping device / (polymer) clamp

Claims

Claims1. A clamping device (100) formed of a flexible elongate body having first and second end portions (1 , 2) for engaging with each other to form a first loop (10) around an object to be fastened, whereinthe first end portion (1 ) comprises a lock (30) made for engagement with a tongue (40) at the second end portion (2),the clamp (100) comprises a second loop (20) formed at a radial distance from said first loop (10) by an arch (50) extending from an intermediate portion (3) between the first and second end portions (1, 2) to the lock (30), and said second loop (20) provides a receiving space for the tongue (40) extending through an opening (32) of the lock (30) such that the second end portion (2) is radially and circumferentially moveable withing the receiving space.

2. The clamping device (100) of claim 1 , wherein the arch (50) is flexible and provides a guide and protection for the tongue (40), when the second end portion (2) is pushed through the opening (32) of the lock (30) for closing the clamp around the object to be fastened.

3. The clamping device (100) of claim 1 or 2, wherein the arch (50) has a semi-circular shape with a smaller radius of curvature than the first loop (10).

4. The clamping device (100) of any preceding claim, wherein the arch (50) has an arcuate main portion (52) extending from the lock (30) to the intermediate portion (3) and a connecting bridge (51) extending in the radial direction and connecting the arcuate main portion (52) to the intermediate portion (3), wherein the tongue (40) preferably has a smaller width than the arcuate main portion (52), and the connecting bridge (51) preferably has a smaller width than the tongue (40) and / or the arcuate main portion (52).

5. The clamping device (100) of any preceding claim, wherein the arch (50) is formed with a radial window (53) through which the lock (30) is visible from radially outside.

6. The clamping device (100) of claim 5, further comprising a web structure (54) forming a mechanical connection between a frame (56) surrounding the radial window (53) and the band material forming the first loop (10) at the first end portion (1),wherein the web structure (54) preferably has a lateral window (55) which allows the closing operation to be visually observed from a lateral side.

7. The clamping device (100) of any preceding claim, wherein a radial inner surface of the first loop (10) has a rib portion (80) protruding radially inwards for providing a homogeneous radial compression force to the object to be fastened.

8. The clamping device (100) of claim 7, wherein a radial outer surface of an extension (90) at the tip end of the first end portion (1 ) comprises a groove (91) for receiving and guiding the rib portion (80) during a closing operation of the clamping device (100).

9. The clamping device (100) of claim 7 or 8, wherein a bottom part of the opening (32) is provided with an indentation (33) which works as a centering guidance for a tip end (43) of the tongue (40) and for the rib portion (80) when the second end portion (2) is pushed through the opening (32) of the lock (30) for closing the clamp around the object to be fastened.

10. The clamping device (100) of any of claims 7 to 9, wherein a band part circumferentially adjacent to the lock (30) in the frontward moving direction of the tongue (40) has a pair of radial protrusions (34) provided at lateral side portions of the clamping device (100) to provide a centering channel (35) therebetween configured to interact with the rib portion (80) during the clamp closing operation for keeping the tongue (40) centered.

11. The clamping device (100) of any preceding claim, wherein a radial outer surface of the tongue (40) has a plurality of latching teeth (41 ) protruding radially outwards for latching engagement with one or more locking teeth (31) protruding radially inwards at or circumferentially adjacent to the opening (32) of the lock (30).

12. The clamping device (100) of any preceding claim, whereinthe first end portion (1 ) comprises a first hook portion (60) and the second end portion (1) comprises a second hook portion (70), andthe first and second hook portions (60, 70) can be grasped by a tool or an operator's hand to close the first loop (10) and bring the first and second end portions (1, 2) into locking engagement.

13. The clamping device (100) of claim 12, whereinthe first hook portion (60) has a first handle (61) protruding radially outwards from the lock portion (30) and the second hook portion (70) has a second handle (71) protruding radially outwards from the second end portion (2) to be grasped by the operator's hand to push the tongue (40) through the opening (32) of the lock (30), and / orthe first hook portion (60) has a first pair of pincer pins (62) protruding axially from the lock (30) and the second hook portion (70) has a second pair of pincer pins (72) protruding axially from the second end portion (2) to be grasped by the tool to tighten the clamping device (100) around the object to be fastened.

14. The clamping device (100) of any preceding claim, formed from a polymer material, preferably as an integral body by injection moulding.

15. A clamping device (100) formed of a flexible elongate body having first and second end portions (1 , 2) for engaging with each other to form a loop (10) around an object to be fastened, whereinthe first end portion (1 ) comprises a lock (30) made for engagement with a tongue (40) at the second end portion (2),a radial inner surface of the loop (10) has a rib portion (80) protruding radially inwards for providing a homogeneous radial compression force to the object to be fastened and,a radial outer surface of an extension (90) at the tip end of the first end portion (1) preferably comprises a groove (91) for receiving and guiding the rib portion (80) during a closing operation of the clamping device (100).

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