A handheld bending device

Abstract

A handheld bending device for bending or straightening a power cable comprises a drive tool having a housing including a gripping handle, a bending guide including an arcuate guide surface having a predefined bending radius, an arm having a proximal end which is rotatably mounted to the bending guide and rotatable with respect to the bending guide about a first axis of rotation which extends in transverse direction of a bending plane and a distal end which has a supporting surface that faces the guide surface within a predefined mutual angle of the arm and the bending guide and a cable holder which is mounted to the bending guide and has a cable holder surface opposite to the guide surface under operating conditions. The guide surface, the cable holder surface and the supporting surface lie within the bending plane. The drive tool is a separate drive tool which has an output drive shaft including a second axis of rotation, which is releasably and drivably connected to the proximal end of the arm such that the first axis of rotation coincides with the second axis of rotation.

Description

[0001] A handheld bending device

[0002] The present invention relates to a handheld bending device for bending or straightening a power cable , comprising a drive tool having a housing including a gripping handle , a bending guide including an arcuate guide surface having a predefined bending radius , an arm having a proximal end which is rotatably mounted to the bending guide and rotatable with respect to the bending guide about a first axis of rotation which extends in transverse direction of a bending plane and a distal end which has a supporting surface that faces the guide surface within a predefined mutual angle of the arm and the bending guide , a cable holder which is mounted to the bending guide and has a cable holder surface opposite to the guide surface under operating conditions , wherein the guide surface , the cable holder surface and the supporting surface lie within the bending plane .

[0003] Such a handheld bending device is known from US 2016 / 0074918 . Bending or straightening a power cable can be done manually, but becomes more di f ficult with increasing diameter and sti f fness of the power cable . For example , a power cable must be inserted from outside a trans former house and pre-bent outside the trans former house and / or bent in an angle inside the trans former house . Usually, available space is very limited due to low ceilings or the like . Nevertheless , due to electri fication there is a growing demand of installing still thicker and sti f fer power cables and usually several person are working together to bend or straighten a thick power cable . Bending power cables requires special treatment since kinking must be avoided and a bending radius may not be too small . Furthermore , when a power cable is provided with a polymeric insulation sheath, bending must be performed carefully . The known handheld bending device is not suitable for bending or straightening a thick power cable in situ, since the toothed segment blade makes the handheld bending device too large to be used in compact spaces .

[0004] An obj ect of the invention is to provide an improved handheld bending device . This obj ect is accomplished with the handheld bending device according to the invention, wherein the drive tool is a separate drive tool which has an output drive shaft including a second axis of rotation, which is releasably and drivably connected to the proximal end of the arm such that the first axis of rotation coincides with the second axis of rotation .

[0005] Since the guide surface , the cable holder surface and the supporting surface lie within the bending plane , and the cable holder surface is opposite to the guide surface under operating conditions , and the guide surface faces the supporting surface within a predefined mutual angle of the arm and the bending guide , a power cable can be sandwiched between the guide surface , on the one hand, and the cable holder surface and the supporting surface , on the other hand . An advantage of the handheld bending device is that it is relatively compact and easy to operate by coupling the drive shaft of the separate drive tool and the arm to each other . The handheld bending device is operable by one person .

[0006] The housing of the drive tool and the proximal end of the arm may be located at opposite sides of the bending guide .

[0007] The proximal end of the arm may be provided with a sleeve for receiving the output drive shaft of the drive tool . The sleeve and the output drive shaft may have cooperating polygonal shapes , such as a square .

[0008] In a preferred embodiment the bending radius of the guide surface is larger than 250 mm, 300 mm, 400 mm or 500 mm in order to avoid bending a power cable to a curve below an acceptable radius .

[0009] The arc length of the guide surface within the bending plane may be smaller than 45 ° , preferably smaller than 35 ° or 30 ° . This keeps the handheld bending device compact . A larger curve of the power cable can be created by multi-step bending, i . e . a bending action can be performed in repeated steps at di f ferent positions behind each other along a power cable .

[0010] In a preferred embodiment the output drive shaft is rotatably drivable with respect to a blocking member of the drive tool , which blocking member fits to the bending guide such that when the arm is drivably connected to the output drive shaft the blocking member has a fixed position and orientation with respect to the bending guide , since a reaction force on the drive tool due to driving the arm is trans ferred via the blocking member to the bending guide . This means that an operator who operates the drive tool does not feel a reaction force , hence facilitating a bending operation .

[0011] The housing of the drive tool may be rotatable with respect to the blocking member . This provides ( de ) placing flexibility to avoid obstacles and optimi zes a holding position to an operator .

[0012] When the housing of the drive tool and the proximal end of the arm are located at opposite sides of the bending guide , the bending guide may be provided with a through-hole in which the blocking member fits and through which the output drive shaft extends . The blocking member and the output drive shaft may be concentrical .

[0013] The blocking member and the through-hole may be provided with cooperating external and internal splines , respectively .

[0014] In an embodiment the proximal end of the arm is rotatably mounted to the bending guide through the output drive shaft , which in turn is rotatably mounted to the bending guide through the blocking member . This means that the arm is indirectly rotatably mounted to the bending guide .

[0015] In an embodiment the cable holder is rotatably mounted to the bending guide and rotatable with respect to the bending guide about a third axis of rotation which extends parallel to the first axis of rotation, wherein the cable holder surface is opposite to the guide surface within a predefined mutual angle of the cable holder and the bending guide .

[0016] In a preferred embodiment the cable holder is located at one side edge of the bending guide , which side edge extends within the bending plane beyond the guide surface and is shaped such that upon rotating the cable holder surface and the guide surface away from each other a free distance between the cable holder surface and the bending guide increases . This facilitates to position a power cable between the cable holder surface and the bending guide such that after rotating the cable holder surface and the guide surface back towards each other the cable holder surface and the guide surface are opposite to each other and enable an operator to sandwich the power cable between the cable holder surface and the guide surface .

[0017] The cable holder may be releasably mounted to the bending guide , which provides the opportunity to apply an other cable holder of di f ferent si ze to the bending guide .

[0018] The arm may be releasably mounted to the bending guide .

[0019] In an embodiment the arm comprises a main arm part whereas the supporting surface is part of a supporting element which is rotatably mounted to the main arm part at the distal end of the arm and rotatable with respect to the main arm part about a fourth axis of rotation which extends parallel to the first axis of rotation .

[0020] In an embodiment the supporting element forms a sliding shoe and the supporting surface has a radius within the bending plane which is larger than the distance between the supporting surface and the fourth axis of rotation . This means that the supporting surface is not circular about the fourth axis of rotation .

[0021] The housing of the drive tool may have an L-shape including a first leg and a second leg, wherein the first leg extends in the same direction as the output drive shaft and the second leg is provided with the gripping handle . This means that the gripping handle may extend substantially parallel to the bending plane .

[0022] Preferably, the drive tool is provided with a controller for controlling a maximum rotation angle of the output drive shaft such that the rotation of the output drive shaft automatically stops when a predefined rotation angle is reached, since this makes a bending operation easy for an operator . Instead or in addition, the controller is suitable for controlling a maximum torque of the output drive shaft such that the rotation of the output drive shaft automatically stops when a predefined torque is reached . The latter control may be applied as a safety measure .

[0023] The controller may be configured such that after reaching the maximum rotation angle the output drive shaft is rotated in opposite direction over a predefined relieve angle . It is advantageous when after a bending operation of a power cable the output drive shaft automatically rotates in opposite direction, and therewith the arm with respect to the bending guide , in order to relieve remaining forces of the power cable onto the handheld bending device due to its flexibility and to facilitate decoupling the handheld bending device from the power cable .

[0024] Because of the relatively high flexibility of a power cable , causing a relatively high rebound ef fect after a bending action, the relieve angle is more than 15% , preferably more than 20% , of the predefined rotation angle .

[0025] In an embodiment a minimal distance between the guide surface and the supporting surface when they face each other within the predefined mutual angle of the arm and the bending guide is larger than 30 mm, preferably larger than 40 mm or 50 mm . This allows to bend a relatively thick power cable .

[0026] The bending radius of the guide surface may be larger than the distance between the first axis of rotation and the supporting surface .

[0027] The invention will hereafter be elucidated with reference to very schematic drawings showing an embodiment of the invention by way of example .

[0028] Fig . 1 is a perspective view of an embodiment of a handheld bending device according to the invention .

[0029] Fig . 2 is an exploded perspective view of the handheld bending device as shown in Fig . 1 on a smaller scale .

[0030] Fig . 3 is a similar view as Fig . 1 , showing the handheld bending device under operating conditions .

[0031] Fig . 4 is a similar view as Fig . 3 , showing the handheld bending device as seen from a di f ferent side .

[0032] Fig . 5 is side view of di f ferent parts of the handheld bending device as shown in Fig . 1 .

[0033] Figs . 1 and 2 show an embodiment of a handheld bending device 1 according to the invention . The handheld bending device 1 is suitable for bending or straightening a power cable 2 , which is illustrated in Figs . 3 and 4 .

[0034] The handheld bending device 1 comprises a drive tool 3 , a bending guide 4 , an arm 5 and a cable holder 6 . The bending guide 4 has an arcuate trough-shaped guide surface 7 . The arm 5 has a proximal end 9 and a distal end 10 . The proximal end 9 is part of a rod-shaped main arm part 11 . At the distal end 10 the arm 5 is provided with a sliding shoe 12 which is rotatably mounted to the main arm part 11 . The sliding shoe 12 has a trough-shaped supporting surface 13 . The cable holder 6 is rotatably mounted to the bending guide 4 and has a trough-shaped cable holder surface 14 . The guide surface 7 , the cable holder surface 14 and the supporting surface 13 lie within a bending plane . In transverse direction of the bending plane the guide surface 7 , the cable holder surface 14 and the supporting surface 13 are concave , respectively . The bending guide 4 , the cable holder 6 , the main arm part 11 and the sliding shoe 12 may be made of a light-weight material , for example aluminium, which keeps the weight of the handheld bending device 1 relatively low .

[0035] The drive tool 3 has an L-shaped housing 15 including a first leg and a second leg . The first leg extends in the same direction as an output drive shaft 16 . The second leg is provided with a gripping handle 17 including a trigger 18 for operating the drive tool 3 and a battery 19 . The drive tool 3 is provided with a blocking member 20 having external splines 21 which fit in a through-hole 22 including cooperating internal splines in the bending guide 4 . The external splines 21 are concentrical with the output drive shaft 16 . It is noted that numerous alternatively shaped blocking members are conceivable .

[0036] The housing 15 of the drive tool 3 is rotatable with respect to the blocking member 20 and the output drive shaft 16 is rotatable with respect to the blocking member 20 . In the embodiment as shown the output drive shaft 16 is electrically driven, but alternative driving means are possible .

[0037] The proximal end 9 of the arm 5 is provided with a sleeve for receiving an end portion of the output drive shaft 16 . In this case the end portion of the output drive shaft 16 has a square shape which cooperates with a square-shaped internal wall of the proximal end 9 of the arm 5 , but numerous alternative shapes are conceivable . When the external splines 21 of the blocking member 20 are fit inside the bending guide 4 the output drive shaft 16 extends through the through-hole 22 and its end portion protrudes from the bending guide 4 . The proximal end 9 of the arm 5 is fit on the protruding portion, which means that the proximal end of the arm 5 is not directly rotatably mounted to the bending guide 4 , but the proximal end 9 of the arm 5 is rotatably mounted to the bending guide 4 through the output drive shaft 16 , which in turn is rotatably mounted to the bending guide 4 through the blocking member 20 . When the arm 5 is drivably connected to the output drive shaft 16 the blocking member 20 has a fixed position and orientation with respect to the bending guide 4 . Fig . 1 shows that the housing 15 of the drive tool 3 and the proximal end 9 of the arm 5 are located at opposite sides of the bending guide 4 . In an alternative embodiment (not shown) the arm 5 and the drive tool 3 may be located at the same side of the bending guide 4 .

[0038] The proximal end 9 of the arm 5 is rotatable with respect to the bending guide 4 about a first axis of rotation 23 . The output drive shaft 16 of the drive tool 3 has a second axis of rotation 24 . When the proximal end 9 of the arm 5 and the output drive shaft 16 are drivably connected to each other the first axis of rotation 23 and the second axis of rotation 24 coincide with each other . In an assembled condition as shown in Fig . 1 the first axis of rotation 23 and the second axis of rotation 24 are perpendicular to the bending plane .

[0039] The cable holder 6 is releasably mountable to the bending guide 4 through a pin which fits in a cooperating hole of the bending guide 4 . In an assembled condition, as shown in Fig . 1 , the cable holder 6 is rotatably mounted to the bending guide 4 and rotatable with respect to the bending guide 4 about a third axis of rotation 25 which is perpendicular to the bending plane . The sliding shoe 12 is rotatable with respect to the main arm part 11 about a fourth axis of rotation 26 which is perpendicular to the bending plane . This means that the third and fourth axes of rotation 25 , 26 are parallel to the first and second axes of rotation 23 , 24 in the assembled condition of the handheld bending device 1 .

[0040] The supporting surface 13 faces the guide surface 7 within a predefined mutual angle of the arm 5 and the bending guide 4 . Similarly, the cable holder surface 14 is opposite to the guide surface 7 within a predefined mutual angle of the cable holder 6 and the bending guide 4 . Referring to Figs . 3 and 4 , the cable holder 6 and the arm 5 are arranged such that the cable 2 can be sandwiched between the guide surface 7 , on the one hand, and the cable holder surface 14 and the supporting surface 13 , on the other hand .

[0041] The handheld bending device 1 is intended to be used for bending and straightening relatively thick and sti f f power cables , for example power cables which have a diameter of 40- 100 mm . Therefore , a minimal distance between the guide surface 7 and the supporting surface 13 when they face each other within the predefined mutual angle of the arm 5 and the bending guide 4 is larger than 40 mm . In order to prevent damage when bending this type of power cables the radius of the guide surface 7 of the bending guide 4 must be relatively large , for example larger than 300 or 400 or 500 mm . Sometimes a power cable must be bent by an angle of 90 ° or larger . This would require a relatively large bending guide which would not be workable for a handheld bending device . Therefore , the arc length of the guide surface 7 within the bending plane is smaller than 35 ° or 30 ° . I f a larger bending angle of a power cable is required, the bending action can be performed in repeated steps at di f ferent positions behind each other along the power cable 2 . It is noted that the bending radius of the guide surface 7 within the bending plane is larger than the distance between the first axis of rotation 23 and the guide surface 7 .

[0042] Fig . 4 shows how the handheld bending device 1 can be mounted to the cable 2 . The bending guide 4 is rotated upwardly with respect to the cable holder 6 such that the cable 2 fits between the cable holder surface 14 and the bending guide 4 . This is caused by an arcuate side edge 27 of the bending guide 4 where the cable holder 6 is located . The arcuate side edge 27 extends within the bending plane beyond the guide surface 7 . The arcuate shape serves to create an increasing free distance between the cable holder surface 14 and the bending guide 4 upon rotating the cable holder 6 with respect to the bending guide 4 such that the cable holder surface 14 and the guide surface 7 rotate away from each other .

[0043] The drive tool 3 is provided with a controller (not shown) for controlling a maximum rotation angle of the drive shaft 16 after pressing the trigger 18 such that the rotation of the drive shaft 16 automatically stops when a predefined rotation angle is reached . The predefined rotation angle may be reached when the sliding shoe 12 reaches an end of the guide surface 6 , which condition is illustrated in Fig . 3 . The controller is also configured such that after reaching the maximum rotation angle the drive shaft 16 is rotated in opposite direction over a predefined relieve angle . Since a power cable 2 is relatively flexible , rotating the drive shaft 16 back over a relieve angle makes loosening the handheld bending device 1 from the power cable 2 after bending it relatively easy . The relieve angle may be more than 15% or 20% of the predefined rotation angle for bending the power cable 2 .

[0044] Fig . 5 shows a set of parts of the handheld bending device 1 for bending di f ferent diameters of power cables 2 . Fig . 5 shows four di f ferent possibilities for increasing diameters : a combination of the arm 5a, the bending guide 4a and the cable holder 6a' , a combination of the arm 5a, the bending guide 4a and the cable holder 6a' ' , a combination of the arm 5b, the bending guide 4b and the cable holder 6b' , a combination of the arm 5b, the bending guide 4b and the cable holder 6b' ' , respectively .

[0045] From the description above , it may be clear that the handheld bending device is a compact and handy tool for an operator to bend or straighten a power cable in situ .

[0046] The invention is not limited to the embodiment shown in the drawings and described hereinbefore , which may be varied in di f ferent manners within the scope of the claims and their technical equivalents . For example , the handheld bending device may also be suitable for other bendable elongated materials than power cables .

Claims

CLAIMS1. A handheld bending device (1) for bending or straightening a power cable (2) , comprising a drive tool (3) having a housing (15) including a gripping handle (17) , a bending guide (4) including an arcuate guide surface (7) having a predefined bending radius, an arm (5) having a proximal end (9) which is rotatably mounted to the bending guide (4) and rotatable with respect to the bending guide (4) about a first axis of rotation (23) which extends in transverse direction of a bending plane and a distal end (10) which has a supporting surface (13) that faces the guide surface (7) within a predefined mutual angle of the arm (5) and the bending guide (4) , a cable holder (6) which is mounted to the bending guide(4) and has a cable holder surface (14) opposite to the guide surface (7) under operating conditions, wherein the guide surface (7) , the cable holder surface (14) and the supporting surface (13) lie within the bending plane, wherein the drive tool is a separate drive tool (3) which has an output drive shaft (16) including a second axis of rotation (24) , which is releasably and drivably connected to the proximal end (9) of the arm (5) such that the first axis of rotation (23) coincides with the second axis of rotation (24) .

2. A handheld bending device (1) according to claim 1, wherein the housing (15) of the drive tool (3) and the proximal end (9) of the arm are located at opposite sides of the bending guide (4) .

3. A handheld bending device (1) according to claim 1 or 2, wherein the proximal end (9) of the arm (5) is provided with a sleeve for receiving the output drive shaft (16) of the drive tool (3) .

4. A handheld bending device (1) according to any one of the preceding claims, wherein the bending radius of the guide surface (7) is larger than 250 mm, preferably larger than 300 mm, 400 mm or 500 mm.

5. A handheld bending device (1) according to any one of the preceding claims, wherein an arc length of the guide surface (7) within the bending plane is smaller than 45°, preferably smaller than 35° or 30°.

6. A handheld bending device (1) according to any one of the preceding claims, wherein the output drive shaft (16) is rotatably drivable with respect to a blocking member (20) of the drive tool (3) , which blocking member (20) fits to the bending guide (4) such that when the arm (5) is drivably connected to the output drive shaft (16) the blocking member (20) has a fixed position and orientation with respect to the bending guide (4) .

7. A handheld bending device (1) according to claim 6, wherein the housing (15) of the drive tool (3) is rotatable with respect to the blocking member (20) .

8. A handheld bending device (1) according to claim 2 and to claim 6 or 7, wherein the bending guide (4) is provided with a through-hole (22) in which the blocking member (20) fits and through which the output drive shaft (16) extends.

9. A handheld bending device (1) according to claim 8, wherein the blocking member (20) and the through-hole (22) are provided with cooperating external splines (21) and internal splines, respectively.

10. A handheld bending device (1) according to any one of the claims 6-9, wherein the proximal end (9) of the arm (5) is rotatably mounted to the bending guide (4) through the output drive shaft (16) , which in turn is rotatably mounted to the bending guide (4) through the blocking member (20) .

11. A handheld bending device (1) according to any one of the preceding claims, wherein the cable holder (6) is rotatably mounted to the bending guide (4) and rotatable with respect to the bending guide (4) about a third axis of rotation (25) which extends parallel to the first axis of rotation (23) , wherein the cable holder surface (14) is opposite to the guide surface (7) within a predefined mutual angle of the cable holder (6) and the bending guide (4) .

12. A handheld bending device (1) according to claim 11, wherein the cable holder (6) is located at one side edge (27) of the bending guide (4) , which side edge (27) extends within the bending plane beyond the guide surface (7) and is shaped such that upon rotating the cable holder surface (14) and the guide surface (7) away from each other a free distance between the cable holder surface (14) and the bending guide (4) increases .

13. A handheld bending device (1) according to any one of the preceding claims, wherein the cable holder (6) is releasably mounted to the bending guide (4) .

14. A handheld bending device (1) according to any one of the preceding claims, wherein the arm (5) is releasably mounted to the bending guide (4) .

15. A handheld bending device (1) according to any one of the preceding claims, wherein the arm (5) comprises a main arm part (11) whereas the supporting surface (13) is part of a supporting element (12) which is rotatably mounted to the main arm part (11) at the distal end (10) of the arm and rotatable with respect to the main arm part (11) about a fourth axis of rotation (26) which extends parallel to the first axis of rotation (23) .

16. A handheld bending device (1) according to claim 15, wherein the supporting element (12) forms a sliding shoe and the supporting surface (13) has a radius within the bending plane which is larger than the distance between the supporting surface (13) and the fourth axis of rotation (26) .

17. A handheld bending device (1) according to any one of the preceding claims, wherein the housing (15) of the drive tool (3) has an L-shape including a first leg and a second leg, wherein the first leg extends in the same direction as the output drive shaft (16) and the second leg is provided with the gripping handle (17) .

18. A handheld bending device (1) according to any one of the preceding claims, wherein the drive tool (3) is provided with a controller for controlling a maximum rotation angle of the output drive shaft (16) such that the rotation of the output drive shaft (16) automatically stops when a predefined rotation angle is reached and / or for controlling a maximum torque of the output drive shaft (16) such that the rotation of the output drive shaft (16) automatically stops when a predefined torque is reached .

19. A handheld bending device (1) according to claim 18, wherein the controller is configured such that after reaching the maximum rotation angle the output drive shaft (16) is rotated in opposite direction over a predefined relieve angle .

20. A handheld bending device (1) according to claim 19, wherein the relieve angle is more than 15%, preferably more than 20%, of the predefined rotation angle.

21. A handheld bending device (1) according to any one of the preceding claims, wherein a minimal distance between the guide surface (7) and the supporting surface (13) when they face each other within the predefined mutual angle of the arm (5) and the bending guide (4) is larger than 30 mm, preferably larger than 40 mm or 50 mm.

22. A handheld bending device (1) according to any one of the preceding claims, wherein the bending radius of the guide surface (7) is larger than the distance between the first axis

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