CN214111495U

CN214111495U - 3D printer and belt tensioning device thereof

Info

Publication number: CN214111495U
Application number: CN202022837498.0U
Authority: CN
Inventors: 刘辉林; 唐京科; 陈春; 敖丹军; 皮小园
Original assignee: Shenzhen Chuangxiang 3D Technology Co Ltd
Current assignee: Shenzhen Chuangxiang 3D Technology Co Ltd
Priority date: 2020-11-30
Filing date: 2020-11-30
Publication date: 2021-09-03
Anticipated expiration: 2030-11-30
Also published as: WO2022110449A1

Abstract

The application provides a 3D printer and belt tightener thereof, belt tightener include first synchronizing wheel, second synchronizing wheel, hold-in range, first regulating block, second regulating block and regulating part. The first synchronous wheel is connected with the second synchronous wheel through a synchronous belt, and the synchronous belt is an open type tooth-shaped synchronous belt. The first adjusting block is connected with one opening end of the synchronous belt and provided with a first adjusting hole. The second regulating block is connected with the other opening end of the synchronous belt, and a second regulating hole is formed in the second regulating block. The adjusting piece is connected with the first adjusting hole and the second adjusting hole and used for driving the first adjusting block and the second adjusting block to move in opposite directions or move back to back. The utility model discloses can realize conveniently adjusting the tensioning degree of hold-in range.

Description

3D printer and belt tensioning device thereof

Technical Field

The application relates to a 3D prints the field, especially relates to a 3D printer and belt overspeed device tensioner thereof.

Background

Three-dimensional (3D) printing, i.e., rapid prototyping, is an additive manufacturing technique, which is a digital model file based on which a Three-dimensional object is manufactured by printing layers of adhesive material using special wax, powdered metal or plastic. Fused deposition rapid prototyping (FDM), also known as hot melt deposition (hot melt deposition) technology, is one of the major 3D printing technologies. The technology comprises the steps of heating and melting hot-melt material wires, extruding the melted material wires from a spray head, depositing the material wires on a printing working platform or a previous layer of solidified material, starting solidification and forming when the temperature is lower than the solidification temperature of the material wires, and finally printing the material wires into an entity.

The structural forms adopted by the 3D printer on the market currently include a cartesian space coordinate form, a COREXY structural form, and a DELTA structural form. In the cartesian space coordinate form, if print the size great, can use two belts in a direction usually, may have two inconsistent situations of belt tensioning degree, and the belt tensioning of current 3D printer is adjusted also inconvenient, and belt tensioning degree can directly influence the printing quality of 3D printing model, how to solve above-mentioned problem, the person of skill in the art need consider.

SUMMERY OF THE UTILITY MODEL

In view of the above, in order to solve at least one of the technical problems in the prior art, an aspect of the present application is to provide a 3D printer and a belt tensioner thereof, which can conveniently adjust the tension of a synchronous belt.

The utility model provides an embodiment provides a belt tightener of 3D printer, including first synchronizing wheel, second synchronizing wheel, hold-in range, first regulating block, second regulating block and regulating part. The first synchronizing wheel is connected with the second synchronizing wheel through the synchronous belt, and the synchronous belt is an open type tooth-shaped synchronous belt. First regulating block with an open end of hold-in range is connected, first regulating block is provided with first regulation hole. The second regulating block with the other open end of hold-in range is connected, the second regulating block is provided with the second regulation hole. The adjusting piece is connected with the first adjusting hole and the second adjusting hole and used for driving the first adjusting block and the second adjusting block to move in opposite directions or move in opposite directions.

In a possible embodiment, the first adjusting block is further provided with a first positioning hole, the second adjusting block is further provided with a second positioning hole, and the belt tensioning device further comprises a fixing block, a first locking member and a second locking member. And the fixed block is provided with a third positioning hole and a fourth positioning hole. The first locking piece passes through the first positioning hole and is partially accommodated in the third positioning hole, so that the first adjusting block is fixed on the fixing block. And the second locking piece is partially accommodated in the fourth positioning hole through the second positioning hole so as to fix the second adjusting block on the fixing block.

In a possible implementation manner, the fixing block is provided with a guide groove, and the first adjusting block and the second adjusting block are detachably embedded in the guide groove.

In a possible implementation manner, the guide groove is concavely formed on one side of the fixed block, and the width of the guide groove is not less than the width of the first adjusting block and the width of the second adjusting block.

In a possible embodiment, the first locking member and the second locking member are both countersunk screws, the first positioning hole and the second positioning hole are both in an ellipse-like shape, and the length of the long axis of the first positioning hole is greater than the length of the head of each countersunk screw.

In a possible implementation manner, the belt tensioning device further includes a first fastening piece and a second fastening piece respectively connected to two open ends of the synchronous belt, the first adjusting block includes a first body and a first vertical portion, the first adjusting hole is disposed in the first vertical portion, the first body is provided with a first clamping portion, the first adjusting block passes through the first clamping portion and the first fastening piece is clamped to one open end of the synchronous belt, the second adjusting block includes a second body and a second vertical portion, the second adjusting hole is disposed in the second vertical portion, the second body is provided with a second clamping portion, and the second adjusting block passes through the second clamping portion and the second fastening piece is clamped to the other open end of the synchronous belt.

In a possible implementation manner, the belt tensioning device further includes a first rotating optical axis, a second rotating optical axis and a plurality of screws, the first synchronizing wheel is rotatably sleeved on the first rotating optical axis, the second synchronizing wheel is rotatably sleeved on the second rotating optical axis, the first synchronizing wheel is provided with a first threaded hole, so that the screws can be matched with the first threaded hole to lock the first synchronizing wheel on the first rotating optical axis, and the second synchronizing wheel is provided with a second threaded hole, so that the screws can be matched with the second threaded hole to lock the second synchronizing wheel on the second rotating optical axis.

In a possible implementation manner, the first synchronizing wheel includes a first annular portion, a second annular portion, and a first wheel groove located between the first annular portion and the second annular portion, the second synchronizing wheel includes a third annular portion, a fourth annular portion, and a second wheel groove located between the third annular portion and the fourth annular portion, and the first wheel groove and the second wheel groove are disposed in cooperation with the synchronous belt.

In a possible embodiment, the width of the first annular portion is greater than the width of the second annular portion, the first threaded hole is disposed in the first annular portion, the width of the third annular portion is greater than the width of the fourth annular portion, the second threaded hole is disposed in the third annular portion, the first threaded hole and the second threaded hole are both composed of a threaded inner wall and a smooth inner wall, and the diameter of the threaded inner wall is smaller than that of the smooth inner wall.

An embodiment of this application still provides a 3D printer, includes foretell belt tensioner.

Compared with the prior art, the 3D printer and the belt tensioning device thereof can conveniently adjust the tensioning degree of the synchronous belts, are convenient for adjust the tensioning degrees of the two synchronous belts to be consistent, and avoid the influence on printing quality caused by inconsistent tensioning of the two synchronous belts in the printing process.

Drawings

FIG. 1 is a schematic diagram of a belt tensioner in one embodiment.

Fig. 2 is a schematic structural view of a portion of the belt tensioner of fig. 1 for implementing a synchronous belt tension adjustment.

Fig. 3 is a schematic structural view of a first synchronizing wheel and a second synchronizing wheel of the belt feeding tensioner shown in fig. 2.

Fig. 4 is a schematic view of a belt tensioner in another embodiment.

Fig. 5 is a schematic structural diagram of a 3D printer in an embodiment.

Description of the main elements

Belt tensioner 100

3D Printer 200

First rotating optical axis 10

Second rotating optical axis 11

A first synchronizing wheel 12

Second synchronizing wheel 13

Synchronous belt 14

First regulating block 15

Second regulating block 16

Adjusting part 17

Fixed block 18

First locking member 19

Second locking member 20

First fastener 21

Second latch 22

First screw hole 121

First annular portion 122

Second annular portion 123

First wheel groove 124

Second screw hole 131

Third annular portion 132

Fourth annular portion 133

Second wheel groove 134

Open ends

141, 142

First vertical portion 151

First body 152

Second vertical portion 161

Second body 162

Guide groove 181

Third positioning hole 182

Fourth positioning hole 183

Screw 1211

First regulation hole 1511

First positioning hole 1521

First engaging portion 1522

Second adjusting hole 1611

Second positioning hole 1621

Second engaging portion 1622

First sub guide groove 1811

Second sub-guide groove 1812

Third sub-guide groove 1813

The following detailed description will further illustrate the present application in conjunction with the above-described figures.

Detailed Description

The following description will refer to the accompanying drawings to more fully describe the present disclosure. There is shown in the drawings exemplary embodiments of the present application. This application may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. These exemplary embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Like reference numerals designate identical or similar components.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. When an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "or/and" includes any and all combinations of one or more of the associated listed items.

The following description of exemplary embodiments refers to the accompanying drawings. It should be noted that the components depicted in the referenced drawings are not necessarily shown to scale; and the same or similar components will be given the same or similar reference numerals or similar terms.

The application provides a belt tensioning device of 3D printer, including first synchronizing wheel, second synchronizing wheel, hold-in range, first regulating block, second regulating block and regulating part. The first synchronizing wheel is connected with the second synchronizing wheel through the synchronous belt, and the synchronous belt is an open type tooth-shaped synchronous belt. First regulating block with an open end of hold-in range is connected, first regulating block is provided with first regulation hole. The second regulating block with the other open end of hold-in range is connected, the second regulating block is provided with the second regulation hole. The adjusting piece is connected with the first adjusting hole and the second adjusting hole and used for driving the first adjusting block and the second adjusting block to move in opposite directions or move in opposite directions.

Above-mentioned belt tightener of 3D printer drives first regulating block and second regulating block and moves in opposite directions through twisting the regulating part, perhaps back of the body motion, and then realizes tightening up or relaxing the hold-in range.

Some embodiments of the present application are described in detail. In the following embodiments, features of the embodiments may be combined with each other without conflict.

Referring to fig. 1 and 2, an embodiment of the present application provides a belt tensioner 100 of a 3D printer, where the belt tensioner 100 is installed in the 3D printer. The belt tensioner 100 includes a first rotating optical axis 10, a second rotating optical axis 11, a first synchronizing wheel 12, a second synchronizing wheel 13, a synchronizing belt 14, a first adjusting block 15, a second adjusting block 16, an adjusting member 17, a fixing block 18, a first locking member 19, and a second locking member 20. The first synchronizing wheel 12 is rotatably sleeved on the first rotating optical axis 10, and the second synchronizing wheel 13 is rotatably sleeved on the second rotating optical axis 11. The first synchronous wheel 12 is connected with the second synchronous wheel 13 through a synchronous belt 14, and the synchronous belt 14 can be an open tooth-shaped synchronous belt. The first adjusting block 15 is connected to an open end 141 of the timing belt 14, and the first adjusting block 15 is provided with a first adjusting hole 1511. The second adjusting block 16 is connected to the other open end 142 of the timing belt 14, and the second adjusting block 16 is provided with a second adjusting hole 1611. The adjusting member 17 is connected with the first adjusting hole 1511 and the second adjusting hole 1611, and the adjusting member 17 is screwed to drive the first adjusting block 15 and the second adjusting block 16 to move in opposite directions or move in opposite directions, so as to lock or loosen the synchronous belt 14. For example, when the adjusting member 17 is screwed to drive the first adjusting block 15 and the second adjusting block 16 to move in opposite directions, the synchronous belt 14 is locked, and when the adjusting member 17 is screwed to drive the first adjusting block 15 and the second adjusting block 16 to move in opposite directions, the synchronous belt 14 is loosened. The fixing block 18 is provided with a guide groove 181, and the first adjusting block 15 and the second adjusting block 16 are detachably embedded in the guide groove 181 and can slide in the guide groove 181.

First locking member 19 may secure first adjustment block 15 to fixed block 18 and second locking member 20 may secure second adjustment block 16 to fixed block 18. First adjustment block 15 cannot slide within guide slot 181 when first locking member 19 is tightened, and first adjustment block 15 can slide within guide slot 181 when first locking member 19 is loosened. Second adjustment block 16 cannot slide within guide channel 181 when second locking member 20 is tightened, and second adjustment block 16 can slide within guide channel 181 when second locking member 20 is loosened.

In some embodiments, a guide groove 181 is concavely formed on one side of the fixed block 18, and the width of the guide groove 181 may be selected to be not less than the width of the first adjusting block 15 and the width of the second adjusting block 16, so that the first adjusting block 15 and the second adjusting block 16 can slide in the guide groove 181.

Referring to fig. 3, the first synchronizing wheel 12 and the second synchronizing wheel 13 have the same structure. The first synchronizing wheel 12 is provided with first threaded holes 121, and the number of the first threaded holes 121 can be set according to actual requirements. For example, the first synchronizing wheel 12 is provided with two first screw holes 121. The screw 1211 engages (threadedly engages) with the first threaded hole 121 to lock the first timing wheel 12 to the first rotational optical axis 10.

For example, when the screws 1211 are rotated clockwise until the bottom ends of the screws 1211 abut against the first rotating optical axis 10, the first synchronous wheel 12 can be locked to the first rotating optical axis 10, and the first synchronous wheel 12 cannot rotate relative to the first rotating optical axis 10. When the screws 1211 are rotated counterclockwise until the bottom ends of the screws 1211 are out of contact with the first rotating optical axis 10, the first synchronous wheel 12 can rotate relative to the first rotating optical axis 10.

Likewise, the second synchronizing wheel 13 is provided with second threaded holes 131, and the number of the second threaded holes 131 can be set according to actual requirements. The screw 1211 is threadedly engaged with the second threaded hole 131, and when the screw 1211 is rotated clockwise until the bottom end of the screw 1211 abuts against the second rotating optical axis 11, the second synchronizing wheel 13 can be locked to the second rotating optical axis 11, and at this time, the second synchronizing wheel 13 cannot rotate relative to the second rotating optical axis 11. When the screws 1211 are rotated counterclockwise until the bottom ends of the screws 1211 are out of contact with the second rotating optical axis 11, the second synchronizing wheel 13 can rotate relative to the second rotating optical axis 11.

In some embodiments, screw 1211 includes, but is not limited to, a screw.

The first synchronizing wheel 12 includes a first annular portion 122, a second annular portion 123, and a first wheel groove 124. The first wheel groove 124 is located between the first annular portion 122 and the second annular portion 123. The width of the first annular portion 122 is optionally larger than the width of the second annular portion 123, and the first threaded hole 121 is disposed on the first annular portion 122. The second synchronizing wheel 13 includes a third annular portion 132, a fourth annular portion 133, and a second wheel groove 134. The second race 134 is located between the third annular portion 132 and the fourth annular portion 133. The width of the third annular portion 132 is greater than the width of the fourth annular portion 133, and the second threaded hole 131 is disposed on the third annular portion 132. The timing belt 14 is disposed in cooperation with the first pulley groove 124 and the second pulley groove 134, so that the timing belt 14 can slide in the first pulley groove 124 and the second pulley groove 134.

The first and second screw holes 121 and 131 have the same structure. The first threaded hole 121 is optionally composed of a threaded inner wall and a smooth inner wall, and the diameter of the threaded inner wall is optionally smaller than that of the smooth inner wall, so that the head of the screw 1211 can be contained in the smooth inner wall, and the screw 1211 can be hidden and installed on the first synchronizing wheel 12 and the second synchronizing wheel 13.

Referring to fig. 4, the belt tensioner 100 further includes a first locking member 21 and a second locking member 22. The first adjusting block 15 includes a first vertical portion 151 and a first body 152. The first adjusting hole 1511 is disposed on the first vertical portion 151, and the first body 152 is further provided with a first positioning hole 1521 and a first engaging portion 1522. The second adjusting block 16 includes a second vertical portion 161 and a second body 162. The second adjusting hole 1611 is disposed on the second vertical portion 161, and the second body 162 is further provided with a second positioning hole 1621 and a second engaging portion 1622. The fixing block 18 includes a third positioning hole 182 and a fourth positioning hole 183. The first locking member 19 can pass through the first positioning hole 1521 and be partially received in the third positioning hole 182, so as to fix the first adjusting block 15 on the fixing block 18; the second locking member 20 can be partially received in the fourth positioning hole 183 through the second positioning hole 1621, thereby fixing the second adjusting block 16 to the fixing block 18.

Specifically, when the first locking member 19 is screwed to lock the first adjusting block 15 to the fixing block 18, the first adjusting block 15 cannot slide in the guide groove 181, and when the second locking member 20 is screwed to lock the second adjusting block 16 to the fixing block 18, the second adjusting block 16 cannot slide in the guide groove 181. When the tension adjustment of the timing belt 14 is required, the first locking member 19 and the second locking member 20 are required to be released, so that the first adjusting block 15 and the second adjusting block 16 can slide in the guide groove 181.

In some embodiments, the first engaging portion 1522 and the second engaging portion 1622 include, but are not limited to, a U shape, and the first adjusting block 15 may be engaged with the open end 141 of the timing belt 14 through the first engaging portion 1522 and the first engaging member 21. The second adjustment block 16 can be engaged with the open end 142 of the timing belt 14 via the second engaging portion 1622 and the second engaging member 22.

Specifically, the open end 141 of the timing belt 14 extends into from one surface of the first engaging portion 1522 and extends from the other surface of the first engaging portion 1522, and the extending portion of the open end 141 is connected to the first locking member 21, so that the open end 141 cannot be separated from the first engaging portion 1522, and the open end 141 and the first engaging portion 1522 are locked together. The open end 142 of the timing belt 14 extends from one surface of the second engaging portion 1622 and extends from the other surface of the second engaging portion 1622, and the extending portion of the open end 142 is connected to the second locking member 22, so that the open end 142 is not separated from the second engaging portion 1622, and the open end 142 is locked to the second engaging portion 1622.

In some embodiments, the guide groove 181 includes a first sub-guide groove 1811, a second sub-guide groove 1812, and a third sub-guide groove 1813. The second sub guide groove 1812 is located between the first sub guide groove 1811 and the third sub guide groove 1813, the depth of the first sub guide groove 1811 is the same as that of the third sub guide groove 1813, and the depth of the second sub guide groove 1812 is smaller than that of the first sub guide groove 1811, so that the open ends 141 and 142 of the timing belt 14 respectively extend into one surface and the other surface of the engaging

portions

1522 and 1622. The first adjusting block 15 and the second adjusting block 16 are slidable in the second sub-guide groove 1812.

In some embodiments, the first locking member 19 and the second locking member 20 include, but are not limited to, countersunk screws, and the adjustment member 17 may include a bolt and a nut, or only a bolt, which may be a bolt with or without a handwheel. The first positioning hole 1521 and the second positioning hole 1621 may be both elliptical-like shapes, the length of the long axis of the first positioning hole 1521 is greater than the diameter of the third positioning hole 182, and therefore the first positioning hole 1521 and the third positioning hole 182 may be kept through when the tension of the synchronous belt 14 is adjusted. The length of the long axis of the second positioning hole 1621 is greater than the diameter of the fourth positioning hole 183, so that the second positioning hole 1621 and the fourth positioning hole 183 can be kept through when the tension of the timing belt 14 is adjusted.

Referring to fig. 5, an embodiment of the present application further provides a 3D printer 200, where the 3D printer 200 includes two belt tensioners 100 in the above embodiment, and the two belt tensioners 100 share the first rotating optical axis 10 and the second rotating optical axis 11. The two synchronous belts 14 of the 3D printer 200 can be tensioned and adjusted in the following manner, so that the tensioning degrees of the two synchronous belts 14 tend to be consistent to improve the 3D printing quality: a. for a belt tensioner 100, loosening the screws 1211 of the first synchronizing wheel 12 and the second synchronizing wheel 13; b. releasing the first locking member 19 from the second locking member 20; c. rotating the adjusting piece 17, testing the tension of the synchronous belt 14 by using a belt dynamometer in the rotating process, stopping rotating the adjusting piece 17 and locking the first locking piece 19 and the second locking piece 20 if the testing force is consistent with the specified force; d. a screw 1211 for locking the first synchronizing wheel 12 and the second synchronizing wheel 13; e. repeating steps a-d above adjusts another belt tensioner 100.

Hereinbefore, specific embodiments of the present application are described with reference to the drawings. However, those skilled in the art will appreciate that various modifications and substitutions can be made to the specific embodiments of the present application without departing from the spirit and scope of the application. Such modifications and substitutions are intended to be within the scope of the present application.

Claims

1. The utility model provides a belt tightener of 3D printer, includes first synchronizing wheel, second synchronizing wheel, hold-in range, first synchronizing wheel with the second synchronizing wheel passes through the hold-in range is connected, the hold-in range is the profile of tooth hold-in range of open type, its characterized in that, belt tightener still includes:

the first adjusting block is connected with one opening end of the synchronous belt and is provided with a first adjusting hole;

the second adjusting block is connected with the other opening end of the synchronous belt and is provided with a second adjusting hole;

and the adjusting piece is connected with the first adjusting hole and the second adjusting hole and used for driving the first adjusting block and the second adjusting block to move in opposite directions or move in opposite directions.

2. The belt tensioner as in claim 1, wherein the first adjustment block is further provided with a first positioning hole, the second adjustment block is further provided with a second positioning hole, the belt tensioner further comprising:

the fixed block is provided with a third positioning hole and a fourth positioning hole;

the first locking piece passes through the first positioning hole and is partially accommodated in the third positioning hole so as to fix the first adjusting block on the fixed block;

and the second locking piece is partially accommodated in the fourth positioning hole through the second positioning hole so as to fix the second adjusting block on the fixing block.

3. The belt tensioner as in claim 2, wherein the fixed block is provided with a guide groove, and the first adjusting block and the second adjusting block are detachably fitted in the guide groove.

4. The belt tensioner as claimed in claim 3, wherein the guide groove is concavely formed at one side of the fixed block, and the width of the guide groove is not less than the width of the first regulating block and the width of the second regulating block.

5. The belt tensioner of claim 2, wherein the first retaining member and the second retaining member are countersunk screws, the first positioning hole and the second positioning hole are oval-like shaped, a major axis length of the first positioning hole is greater than a diameter of the third positioning hole, and a major axis length of the second positioning hole is greater than a diameter of the fourth positioning hole.

6. The belt tensioning device according to claim 1, further comprising a first locking member and a second locking member respectively connected to two open ends of the synchronous belt, wherein the first adjusting block comprises a first body and a first vertical portion, the first adjusting hole is disposed on the first vertical portion, the first body is provided with a first locking portion, the first adjusting block is locked to one open end of the synchronous belt through the first locking portion and the first locking member, the second adjusting block comprises a second body and a second vertical portion, the second adjusting hole is disposed on the second vertical portion, the second body is provided with a second locking portion, and the second adjusting block is locked to the other open end of the synchronous belt through the second locking portion and the second locking member.

7. The belt tensioner as in claim 1, further comprising a first rotating optical axis, a second rotating optical axis, and a plurality of screws, wherein the first synchronizing wheel is rotatably disposed around the first rotating optical axis, the second synchronizing wheel is rotatably disposed around the second rotating optical axis, the first synchronizing wheel has a first threaded hole such that the screws cooperate with the first threaded hole to lock the first synchronizing wheel to the first rotating optical axis, and the second synchronizing wheel has a second threaded hole such that the screws cooperate with the second threaded hole to lock the second synchronizing wheel to the second rotating optical axis.

8. The belt tensioner as in claim 7, wherein the first synchronizing wheel comprises a first annular portion, a second annular portion, and a first wheel groove between the first annular portion and the second annular portion, and the second synchronizing wheel comprises a third annular portion, a fourth annular portion, and a second wheel groove between the third annular portion and the fourth annular portion, the first wheel groove and the second wheel groove cooperating with the timing belt.

9. The belt tensioner as in claim 8, wherein the first annular portion has a width greater than a width of the second annular portion, the first threaded hole is disposed in the first annular portion, the third annular portion has a width greater than a width of the fourth annular portion, the second threaded hole is disposed in the third annular portion, the first and second threaded holes each comprise a threaded inner wall and a smooth inner wall, the threaded inner wall having a diameter less than a diameter of the smooth inner wall.

10. A 3D printer comprising a belt tensioner according to any of claims 1 to 9.