CABLE PROCESSING DEVICE

Description

Technical Field

[0001] The present disclosure relates to a crimping cassette for a crimping device of a cable processing apparatus, a cable processing apparatus loaded with the crimping cassette and a loading method of a crimping cassette in a cable processing apparatus.Background Art

[0002] Cable processing apparatuses comprising a crimping device loadable with crimp cassettes are known in the art. A crimp cassette comprises part of a crimping tool, as well as a magazine (a reel) of crimp contacts or the like. The crimping tool part as a component of a crimp cassette can be arranged, typically automatically arranged, on the crimping device of the cable processing apparatus. Some crimping tools for crimping devices are divided, i. e. they have a stationary tool part and a movable tool part. The stationary and movable tool parts are configured to act together in a crimping operation of the crimping device.

[0003] The tool parts of a divided crimping tool can become misaligned, e. g. during a tool exchange operation. There is a desire to counteract such a misalignment which causes incorrect and / or unreliable crimps.

[0004] Document WO 2006 / 136930 A1 describes a crimping machine for different crimping and pressing processes having a crimping station that comprises a crimping tool. The crimping tool is formed in two parts.

[0005] Document US 2004 / 0007042 A1 describes a crimping press having a cassette that can be inserted from the rear of the press.

[0006] It is an object of the present disclosure to provide a crimp cassette and a cable processing apparatus having a crimping device loaded with the crimp cassette where positioning or alignment of the cassette inside the crimping device, as well as an alignment of the tools parts of a divided crimping tool, are improved.Brief Summary of the Disclosure

[0007] In view of the above, according to a first aspect, a crimping cassette for a crimping device of a cable processing apparatus according to claim 1 is provided.

[0008] According to a further aspect, a cable processing apparatus according to claim 4 is provided. The cable processing apparatus has a crimping device loaded with a crimping cassette according to claim 1.

[0009] According to yet a further aspect, provided is a loading method according to claim 10 of a crimping cassette in a cable processing apparatus.

[0010] Further aspects, advantages, and features of the present disclosure are apparent from the dependent claims, the description, and the accompanying drawings. The aspects discussed below may be freely combined with each other, as appropriate.

[0011] According to one aspect of the disclosure, a crimping cassette for a crimping device of a cable processing apparatus has the features of claim 1.

[0012] In the locked position, the claws are firmly clamped to the mounting part of the mounting part. When in the unlocked closed position, the mounting part is not yet released in a manner which would allow a complete detachment of the stationary tool part. However, an adjustment of the stationary tool part relative to the movable tool part in a limited adjustment range is possible in the unlocked closed position. Hence, the movable and stationary tool parts are easily aligned relative to each other.

[0013] The adjustment range, typically in a plane which is perpendicular to a crimping operation movement of the movable tool part relative to the stationary tool part, is limited to a range which is sufficient for performing an efficient alignment operation, e. g. within a range, in the two directions of the plane, of less than 10 mm or less than 2 mm. In the open position, the claws release the mounting part and allow the stationary tool part to be separated from the holding device. This allows for an easy exchange of the crimping cassette in a cable processing apparatus or by hand.

[0014] In embodiments, the crimping tool is configured to perform a tool part alignment operation in which, when the holding device is in the unlocked closed position, the movable tool part is moved towards the stationary tool part, typically to a greater extent than when performing a crimping operation, such as to mechanically shift the stationary tool part within the spatially limited adjustment range.

[0015] Corresponding shapes of the surfaces of the movable and stationary tool parts which are involved in such an alignment operation may be beneficially shaped to ensure a reliable alignment. Hence, the movable tool part and the stationary tool part may each comprise an alignment face, wherein the alignment faces are shaped such as to interact in the tool part alignment operation to self-align the stationary tool part relative to the movable tool part.

[0016] The operating device may comprise an unlocking push button and an unlocking lever coupled to each other. A linear movement of the unlocking push button may be transformed, via the unlocking lever, into a linear movement of the mandrel into the idle state. Then, an alignment operation is easily possible.

[0017] In embodiments, the crimping tool further comprises a coupling device for releaseably coupling the movable tool part with the stationary tool part. The coupling device may be fixed to the movable tool part. The coupling device may comprise a conical end face which is adapted to be engaged with a corresponding conical bore provided on the stationary tool part.

[0018] In embodiments relating to the cable processing apparatus, the cable processing apparatus further comprises a locking device for releaseably locking a loaded crimping cassette. The locking device is configured to operate the operating device of the crimping cassette.

[0019] In embodiments, the cable processing apparatus further comprises a mounting device configured to mount the moveable tool part of the crimping tool of a loaded crimping cassette.

[0020] In embodiments, the mounting device comprises a gripper which is configured and arranged to be moveable according to a gripping trajectory to grip a gripping counterpart of the moveable tool part, the gripping trajectory comprising, in a movement of the gripper to grip the gripping counterpart, a linear trajectory and a subsequent pivoting trajectory.

[0021] With a succession of a linear trajectory and a pivoting trajectory, an automated fixation and alignment operation of the tool parts relative to each other is further facilitated.

[0022] In embodiments, the gripper is arranged and shaped such as to be moved according the gripping trajectory upon applying a force to an operating face of the gripper. The force has a constant direction throughout the movement of the gripper according to the gripping trajectory. According to a further aspect, the cable processing apparatus further comprises an actuator, typically a pneumatic cylinder, to open the gripper, and a spring arrangement to close the gripper.

[0023] Thereby, with a simple linear arrangement of actuators and / or spring elements, a reliable gripping operation, involving an advanced trajectory, is possible by acting on a single face of the gripper.

[0024] In embodiments, the cable processing apparatus further comprises a lifting device adapted to lift the moveable tool part towards the mounting device. However, according to an alternative embodiment, the mounting device itself may be moveable towards the moveable tool part.

[0025] In embodiments, the cable processing apparatus further comprises a tensioning device for the mounting part adapted to apply a tensioning force to the mounting part relative to an attachment surface provided on the crimping device. Thereby, a reliable and tight fixation is possible.

[0026] According to certain aspects of the embodiment, the attachment surface is provided with at least one supporting element, typically supporting roller, adapted to lower a friction between the mounting part and the attachment surface. Thereby, a movement of the mounting part on the attachment surface, prior to tightening and / or after releasing, is facilitated.

[0027] In embodiments, the cable processing apparatus further comprises a pressure detector arranged to detect a pressing force between the movable tool part and the stationary tool part, and a stroke limiting device connected to the pressure detector, wherein the stroke limiting device is adapted to limit a stroke of the movable tool part relative to the stationary tool part upon detection of a pressing force which exceeds a predetermined maximum pressing force.

[0028] According to the invention a loading method of a crimping cassette, according to claim 10, in a cable processing apparatus according to claim 4 is provided. The loading method comprises moving the locking device towards the crimping cassette to be loaded; operating the operating device to bring the holding device into the unlocked closed position; attaching the crimping cassette to the locking device; releasing the moveable tool part from the stationary tool part; moving the moveable tool part relative to the mounting device such as to approach the moveable tool and the mounting device; and gripping the gripping counterpart of the moveable tool part.

[0029] An alignment method, acording to claim 11 is performed after the steps of the loading method, as described herein.

[0030] With the aspects and embodiments described herein, a crimping device such as a crimping press may perform any or all of the functions of lateral insertion of a crimping cassette with an intermediate position; opening a coupling device between the movable and stationary tool parts; taking over and holding the movable tool part, e. g. on a slide of the crimping device; opening the holding device in two stages (the unlocked closed position and the open position), and taking over the stationary tool part into the crimping device; aligning the tool parts, optionally by moving the tool parts together; and clamping the stationary tool part on the crimping device.Brief Description of the Drawings

[0031] The subject matter of the disclosure will be explained in more detail with reference to preferred exemplary embodiments which are illustrated in the accompanying drawings. In the drawings, like reference numerals are assigned to like or corresponding parts.

[0032] In the drawings: Fig. 1is a perspective view of a crimping cassette and a crimping device of a cable processing apparatus according to an embodiment of the present disclosure; Fig. 2is a close-up view of parts of Fig. 1; Fig. 3is a schematic side view of a holding device; Fig. 4is a schematic top view of a holding device in a locked position; Fig. 5is a schematic top view of a holding device in an unlocked closed position; Fig. 6is a schematic top view of a holding device in an open position; Fig. 7is a perspective view of a locking device arranged at the crimping device; Fig. 8is a perspective view of the locking device of Fig. 7 in a state of a lever operation; Fig. 9is a perspective view of the locking device of Fig. 7 in a state of an opening lever operation; Fig. 10is a perspective view of a coupling device arranged at the crimping device; Fig. 11is an exploded view of parts of a mounting device; Fig. 12is a view showing a gripper of the mounting device in an upper position; Fig. 13is a view showing the gripper of the mounting device in an end position of linear movement; Fig. 14is a view showing the gripper of the mounting device in an end position of pivoting movement; Fig. 15shows the gripper of Figs. 12 to 14 in a first position; Fig. 16shows the gripper of Figs. 12 to 14 in a second position; Fig. 17shows the gripper of Figs. 12 to 14 in a third position; Fig. 18shows alignment faces of upper and lower tool parts of the crimping cassette; Fig. 19is a perspective view of a crimping device during an alignment operation of the upper and lower tool parts of the crimping cassette; Fig.is a close-up perspective view of parts of Fig. 19; Fig. 21is a sectional side view of the crimping device of Fig. 19 during the alignment operation; Fig. 22is a sectional side view showing a stage of a loading operation of a crimping cassette in a crimping device of a cable processing apparatus; Fig. 23is a sectional side view showing another stage of the loading operation of the crimping cassette in the crimping device of a cable processing apparatus; Fig. 24is a sectional side view showing another stage of the loading operation of the crimping cassette in the crimping device of a cable processing apparatus; Fig. 25is a sectional side view showing yet another stage of the loading operation of the crimping cassette in the crimping device of a cable processing apparatus; Fig. 26is a sectional side view showing yet another stage of the loading operation of the crimping cassette in the crimping device of a cable processing apparatus; Fig. 27is a sectional side view showing yet another stage of the loading operation of the crimping cassette in the crimping device of a cable processing apparatus; and Fig. 28is a sectional side view showing yet another stage of the loading operation of the crimping cassette in the crimping device of a cable processing apparatus. Detailed Description of the Embodiments

[0033] Fig. 1 is a perspective view of a crimping cassette 10 and a crimping device of a cable processing apparatus according to an embodiment of the present disclosure.

[0034] The crimping device comprises a mounting device 51 and a lifting device. In the embodiment of Fig. 1, the mounting device 51 is configured as a press slide, and the lifting device is configured as a lifting fork 52. A locking device is provided on the crimping device for releasably locking a loaded crimping cassette 10, as described in more detail below.

[0035] In Fig. 2 which is a close-up view of Fig. 1, a holding device of the crimping cassette 10 is shown in more detail. The holding device comprises a bracket having two claws 21a, 21b which are normally pushed together, via a spring to be described further below, into a clamping position or locked position. An unlocking push button 25 is coupled to an unlocking lever 26 to release the claws 21a, 21b and described in more detail below.

[0036] A crimping tool assembly comprises a base plate 31 on which a stationary crimp tool part is fixed. The claws 21a, 21b clamp the base plate 31. Furthermore, the crimping tool assembly comprises a coupling 35 which is configured such that a movable crimping tool part can be releasably coupled to the stationary crimp tool part. The crimp tool parts 31, comprise a crimp anvila and a crimp indentora, respectively (see also Fig. 18). In order to protect the sensitive crimp anvila and crimp indentora, the stationary and movable tool parts, are shifted in a lateral direction.

[0037] Fig. 3 shows a schematic side view of the holding device. Corresponding schematic top views of the holding device in a locked position, in an unlocked closed position, and in an open position are respectively shown in Figs. 4 to 6.

[0038] In the locked position and in the unlocked closed position, the claws 21a, 21b are pushed into a clamping or closed state by a closing spring 22. In the locked position (Fig. 4), the claws 21a, 21b are firmly clamped to a mounting part of the base plate. In the unlocked closed position (Fig. 5), the claws 21a, 21b loosely grip the mounting part for allowing an adjustment movement of the stationary tool part within a spatially limited adjustment range. In the open position (Fig. 6), the claws 21a, 21b are released from the mounting part.

[0039] In order to supplement the behavior in the respective positions, a mandrel 23 is provided at the holding device. Upon operation of the unlocking push button 25, the unlocking lever 26 is pivoted and moves the mandrel 23 linearly. A back face 23a of the mandrel 23 is shaped such that when it is pushed against a corresponding face of the claws 21a, 21b, the claws 21a, 21b are tightened to the mounting part. A front surface 23b of the mandrel 23 is shaped such that when it is pushed against a corresponding face of the claws 21a, 21b, the claws 21a, 21b are spread open. In the shown embodiment, the mandrel 23 pushes against rollers 24, which in turn spread the claws 21a, 21b.

[0040] In an idle state in the unlocked closed position (Fig. 5), the mandrel substantially does not touch any of the faces on the claws 21a, 21b, thus allowing a limited spatial aligning movement of the tool parts,.

[0041] In the perspective view of Fig. 7, the locking device is shown. The locking device comprises, in addition to parts for attaching to the crimping cassette 10, elements for unlocking and opening the claws. A lever 61 is passively pivoted by a pulling force of a spring 64 at a time where the locking device is moved out as a whole (Fig. 8). Independent from the operation of the lever 61, an opening lever 62 may be actuated by a pneumatic cylinder 63 (Fig. 9).

[0042] Both the lever 61 and the opening lever 62 act on the unlocking push button 25 of the holding device. The unlocking push button 25 is then flush with the housing of the crimping cassette 10 and cannot be pushed in to such an extent that the claws 21a, 21b are opened entirely.

[0043] Fig. 10 is a perspective view of a coupling device 35 arranged at the crimping device. In Fig. 10, the coupling device 35 is fixed at the movable tool part and comprises a conical end face which is adapted to be engaged with a corresponding conical bore provided on the stationary tool part. A latch bolt 36 is provided which is pushed sidewards when the end face of the coupling device 35 is inserted into the bore. The latch bolt 36 is then reset into its initial position by a spring (not shown) and fixes the end face of the coupling device 35.

[0044] In Fig. 11, the mounting device 51 comprises a gripper 53 which is pivotable around a rotation axis 53a. A pulling rod 54 can be actuated by a pneumatic cylinder (not shown) which pushes the pulling rod 54, which in turn moves a yoke 55 at which the pulling rod 54 and the gripper 53 are fixed, into the downwards direction. Upon release of the pneumatic cylinder, this movement is counteracted by a push spring which pulls up the gripper 53 into an upper position.

[0045] The gripper 53 is inserted into the yoke 55 and has contact parts with two elements. The rotation axis 53a is one of the elements, and the rotation axis 53a allows for a rotational movement of the gripper 53. A bolt 53b, as the other one of the elements, is another contact element of the gripper 53.

[0046] Two mounting pieces each comprising a push spring and a spring holder are provided on each lateral sides of the rotation axis 53a. The mounting pieces are held within a groove on the mounting device 51 and allow for a slight linear movement of the gripper. A trajectory outline 59 is provided as an auxiliary measure to make sure that the gripper performs a linear movement in the first place. Under normal conditions, the gripper is not in contact with the trajectory outline 59; however, in the exemplary case that an irregular movement occurs which would lead to a rotary or pivoting movement of the gripper, the gripper is guided along the trajectory outline 59

[0047] When the pneumatic cylinder (not shown) is in its retracted position, the spring pulls the yoke 55 into the uppermost position (Fig. 12). The shape of the trajectory outline 59 prevents a pivoting movement of the gripper 53.

[0048] Upon moving the pneumatic cylinder outwardly, the yoke 55 is moved down. In a first stage, the mounting pieces make the gripper 53 move linearly downward (Fig. 13). At the end of the first stage, the linear movement is limited by the grooves 58. Since the rotation axis 53a is fixed, the gripper 53 moves, along the trajectory outline 59, in a pivotal manner (Fig. 14).

[0049] A gripping operation of the movable crimp tool part by the gripper is shown in an illustrative manner in Figs. 15 to 17.

[0050] Figs. 19 to 21 show a crimping press during alignment of the movable and stationary tool parts,. The base plate 31 is provided with pressure sensors 40a, 40b. In the embodiment, a third pressure sensor is provided but not shown in Figs 19 to 21. The disclosure is not limited to a particular amount of pressure sensors 40a, 40b, and in general, one, two, three, or more pressure sensors 40a, 40b can be provided, dependent on the constructive measures and / or a desired accuracy. The pressure sensors 40a, 40b help to detect when the crimp anvila and the crimp indentora touch each other and prevent an excessive pressure from being exerted to the crimp anvila and the crimp indentora.

[0051] On an attachment surface 41 of the base plate 31, supporting rollers 42 are provided to lower a friction between a mounting part and the attachment surface 41. In the embodiment, the mounting part comprises a clamping element 43 and mounting cylinders 44. The supporting rollers 42 are optional parts and may be omitted; in particular, when using crimping contacts having a certain minimum size, the alignment may be performed without supporting rollers 42.

[0052] In an unloaded state, the supporting rollers 42 protrude slightly from the attachment surface 41 in the embodiment. A spring mechanism (not shown) bears the supporting rollers 42 such that each of the supporting rollers 42 may be pressed downwards by a load acting thereon, i. e. to be at least flush with the plane of the attachment surface 41 in the case of a sufficient load. Thereby, the stationary tool part rests entirely on the attachment surface 41 and is virtually unaffected by the supporting rollers 42.

[0053] For performing an alignment operation, the clamping element 43 is loosened, then the stationary tool part is inserted. Then, the movable tool part is lowered, and the alignment surfaces of the crimp anvila and the crimp indentora touch each other. This operation is monitored using the pressure sensors 40a, 40b. Depending on the applied forces, the optional supporting rollers 42 are pushed downwards, to make the stationary tool part rest entirely on the attachment surface 41. After the alignment is performed, the clamping element 43 is tightened.

[0054] Figs. 22-28 show different stages of a loading operation of the crimping cassette 10 in a crimping device of a cable processing apparatus.

[0055] In Fig. 22, the cassette 10 is in an initial position. In Fig. 23, the locking device of the crimping device moves outward, and the gripper 53 is opened. If present, the lifting fork 52 is lowered.

[0056] In Fig. 24, the cassette 10 is moved to the right, and the unlocking push button 25 is operated. The stationary tool part can be aligned relative using the mounting cylinders 44. In the embodiment, the alignment is performed by an aligning movement of a slit in the base plate 31 relative to a periphery of the mounting cylinder 44 and, in addition, relative to a periphery of the mounting cylinder below the clamping element 43 (cf. Fig.).

[0057] In Fig. 25, the movable tool part has been moved to the mounting device 51, and the cassette is moved further to the right. The coupling is open since the latch bolt 36 has been operated by an abutment 65.

[0058] In Fig. 26, the movable tool part is gripped by the gripper 53. Thereafter, the moveable tool part is lifted, through the lifting fork 52, to the mounting device 51. In an alternative embodiment without a lifting fork 52, the mounting device 51 is lowered towards the moveable tool part. In either case, the movable tool part is moved relative to the mounting device 51, such that the movable tool part and the mounting device 51 approach each other.

[0059] Subsequently, the locking device is moved inwards, the cassette 10 is further moved to the right and clamped, and the movable tool part is lowered (Fig. 27). Then the claws 21a, 21b are opened by pivoting the opening lever (Fig. 28), whereby the stationary tool part is released.

[0060] Subsequently, the above-described alignment process may be performed.

Claims

1. A crimping cassette (10) for a crimping device of a cable processing apparatus, the crimping cassette (10) comprising a crimping tool having a stationary tool part and a movable tool part, wherein the stationary and movable tool parts are configured to act together in a crimping operation of the crimping device, wherein the crimping cassette (10) further comprises a holding device having at least two claws (21a, 21b) for attaching to a mounting part in a mounting area of the claws (21a, 21b), the mounting part being directly or indirectly fixed to the stationary tool part, wherein the holding device has: a locked closed position in which the claws (21a, 21b) are firmly clamped to the mounting part; an unlocked closed position in which the claws (21a, 21b) loosely grip the mounting part for allowing an adjustment movement of the stationary tool part within a spatially limited adjustment range; an open position in which the claws (21a, 21b) release the mounting part such that the stationary tool part is separable from the holding device, wherein a closing spring (22) is provided and arranged such as to close the gripping of the claws (21a, 21b) in the unlocked closed position, wherein the crimping tool further comprises a coupling device (35) for releaseably coupling the movable tool part with the stationary tool part, characterized in that the crimping cassette further comprises an operating device adapted to operate the holding device at least between the locked closed position and the unlocked closed position, and in that the holding device further comprises a mandrel (23) having : a back face (23a) shaped such that when it is pushed against a corresponding face of the claws (21a, 21b), the claws (21a, 21b) are tightened, in the mounting area, to the mounting part, a front face (23b) shaped such that when it is pushed against a corresponding face of the claws, the claws are spread, wherein the mandrel (23) is moveable into an idle state in which none of the back face (23a) or the front face (23b) pushes against the claws (21a, 21b) to facilitate a tool part alignment operation in the unlocked closed position of the holding device,2. The crimping cassette (10) of claim 1, wherein in the unlocked position of the holding device, the spatially limited adjustment range is substantially in a plane which is perpendicular to a crimping operation movement of the movable tool part relative to the stationary tool part.

3. The crimping cassette (10) of any one of the preceding claims, wherein the crimping tool is configured to perform a tool part alignment operation in which, when the holding device is in the unlocked closed position, the movable tool part is moved towards the stationary tool part, typically to a greater extent than when performing a crimping operation, such as to mechanically shift the stationary tool part within the spatially limited adjustment range.

4. A cable processing apparatus having a crimping device loaded with a crimping cassette according to any one of the preceding claims, the crimping cassette further comprising an unlocking push button (25) coupled to an unlocking lever (26) as an operating device operable to release the claws (21a, 21b), the cable processing apparatus comprising a locking device for releaseably locking a loaded crimping cassette, the locking device including a lever (61) passively pivoted by a tensioning force of a spring (64) as a tensioning device at a time where the locking device is moved out as a whole, and including an opening lever (62) actuatable by a pneumatic cylinder (63) as an actuator, wherein the locking device is configured to operate the operating device of the crimping cassette, and the cable processing apparatus comprising a mounting device (51) configured to mount the moveable tool part of the crimping tool of a loaded crimping cassette, wherein the tensioning device for the mounting part is adapted to apply the tensioning force to the mounting part (51) relative to an attachment surface provided on the crimping device.

5. The cable processing apparatus according to claim 4, wherein the mounting device (51) comprises a gripper (53) which is configured and arranged to be moveable according to a gripping trajectory to grip a gripping counterpart of the moveable tool part, the gripping trajectory comprising, in a movement of the gripper to grip the gripping counterpart, a linear trajectory and a subsequent pivoting trajectory.

6. The cable processing apparatus according to claim 5, wherein the gripper (53) is arranged and shaped such as to be moved according the gripping trajectory upon applying a force to an operating face of the gripper, the force having a constant direction throughout the movement of the gripper according to the gripping trajectory.

7. The cable processing apparatus according to claim 6, wherein the cable processing apparatus further comprises an actuator, typically a pneumatic cylinder (63), to open the gripper, and a spring arrangement to close the gripper.

8. The cable processing apparatus according to any one of claims 4 to 7, further comprising a lifting device (52) adapted to lift the moveable tool part towards the mounting device.

9. The cable processing apparatus according to any one of claims 4 to 8, further comprising a pressure detector (40a, 40b) arranged to detect a pressing force between the movable tool part and the stationary tool part, and a stroke limiting device connected to the pressure detector (40a, 40b), wherein the stroke limiting device is adapted to limit a stroke of the movable tool part relative to the stationary tool part upon detection of a pressing force which exceeds a predetermined maximum pressing force.

10. A loading method of a crimping cassette according to any one of claims 1 to 3 in a cable processing apparatus according to any one of claims 4 to 8, the method comprising: Moving the locking device towards the crimping cassette (10) to be loaded; Operating the operating device to bring the holding device into the unlocked closed position; Attaching the crimping cassette (10) to the locking device; Releasing the moveable tool part from the stationary tool part; Moving the moveable tool part relative to the mounting device such as to approach the moveable tool and the mounting device; Gripping the gripping counterpart of the moveable tool part.

11. The loading method of claim 10, further comprising: Bringing the holding device into the unlocked closed position; Releasing the tensioning device; Inserting the stationary tool part of the crimping tool into a tensioning area of the tensioning device; Moving the moveable tool part towards the stationary tool part slightly before the moveable tool part touches the stationary tool part; Bringing the holding device into the open position; Moving the moveable tool part towards the stationary tool part until a pressing force between the moveable tool part and the stationary tool part is reached or exceeded, such that an alignment within the adjustment range takes place between the moveable tool part and the stationary tool part; Applying a tension with the tensioning device.