TORQUE WRENCH AS POWER WRENCH

Abstract

A torque wrench such as a power wrench has a drive motor with an intermediate gearbox connected downstream of the drive motor and with a bolting gearbox connected downstream of the intermediate gearbox as a planetary gearbox with a bolting tool part on the output side, and with a housing with at least one handle in which the drive motor and the intermediate gearbox are arranged in sequence. The drive motor is non-rotatably arranged and fixed in the housing, and the intermediate gearbox is rotatably mounted in the housing and is non-rotatably connected to a ring gear of the planetary gearbox, so that, during a bolting operation, only the reaction forces occurring on the housing as a result of the drive motor have to be supported by an operator, and the reaction forces occurring as a result of the intermediate gearbox are supported by the torque support foot.

Claims

1-10. (canceled)

11. A torque wrench, comprising: a drive motor with a predetermined speed and a predetermined motor output torque; an intermediate gearbox connected downstream of said drive motor and reduces an output speed of said drive motor with a predetermined reduction ratio; a bolting gearbox connected downstream of said intermediate gearbox and having a bolting tool part on an output side, said bolting gearbox reducing an output speed of said intermediate gearbox with a predetermined reduction ratio; a housing with at least one handle, said drive motor and said intermediate gearbox are disposed in said housing in sequence; said bolting gearbox being a planetary gearbox with an external ring gear with internal toothing, said external ring gear being rotatably mounted on said housing and having a radially projecting torque support foot which, during a bolting operation, pivots against a required fixed support point and supports there reaction forces occurring on said planetary gearbox; and said drive motor being non-rotatably disposed and fixed in said housing and said intermediate gearbox being rotatably mounted in said housing and is non-rotatably connected to said external ring gear.

12. The torque wrench according to claim 11, wherein said drive motor is a pneumatic motor or a hydraulic motor or an electric motor rotating at a high speed relative to the output speed of said bolting gearbox.

13. The torque wrench according to claim 11, further comprising an energy store; and wherein said housing has a pistol grip as said at least one handle and a receptacle for said energy store for supplying energy to said drive motor being an electric motor, said receptacle is fitted on said pistol grip.

14. The torque wrench according to claim 11, wherein said external ring gear is a sun gear; wherein said radially projecting torque support foot has a connecting ring with internal toothing; and further comprising an external toothing attached to said sun gear in a partial region of said sun gear, onto which said connecting ring of said radially projecting torque support foot with said internal toothing is attachable and fixable.

15. The torque wrench according to claim 11, wherein: said planetary gearbox outputs an output polygon; and said bolting tool part is an exchangeable, attachable socket.

16. The torque wrench according to claim 11, wherein: said drive motor, said intermediate gearbox and said planetary gearbox each have an output rotary shaft and said output rotary shaft of said drive motor, said intermediate gearbox and said planetary gearbox are concentrically aligned; and said housing has an inner region being cylindrical in its basic shape.

17. The torque wrench according to claim 16, further comprising a concentric toothed disc having a central opening formed therein; further comprising an adapter ring for a rotatable mounting of said intermediate gearbox in said housing and a non-rotatable connection to said ring gear, said adapter ring is rotatably mounted on a shaft section between said drive motor and said intermediate gearbox, to said adapter ring said intermediate gearbox is non-rotatably connected and that, on an opposite region of said intermediate gearbox, said concentric toothed disc is disposed and non-rotatably connected, said concentric toothed disc has outer toothing engaging in said internal toothing of said external ring gear; and wherein said intermediate gearbox having an output pinion being guided through said central opening of said concentric toothed disc and engaging in said planetary gearbox.

18. The torque wrench according to claim 11, wherein: the predetermined reduction ratio of said intermediate gearbox is in an order of 1:10; and/or said predetermined motor output torque of said drive motor is in an order of 1 Nm and an output torque of said intermediate gearbox output torque is 10 Nm.

19. The torque wrench according to claim 11, wherein the torque wrench is configured as a shut-off wrench which automatically switches off when a presettable bolting torque is reached.

20. The torque wrench according to claim 11, wherein: the torque wrench is a power wrench; said intermediate gearbox connected downstream of said drive motor reduces the output speed of said drive motor with the predetermined reduction ratio and with a correspondingly increased intermediate gearbox output torque; said bolting gearbox reducing the output speed of said intermediate gearbox with the predetermined reduction ratio at a correspondingly increased bolting gearbox output torque which is required for a specific bolting operation; said housing is to be held by an operator at said at least one handle during the bolting process and reaction forces occurring at said housing are to be supported as rotational forces; and said intermediate gearbox is rotatably mounted in said housing and is non-rotatably connected to said ring gear in such a way that, during the bolting operation, only the reaction forces occurring on said housing as a result of said drive motor are to be supported by the operator and/or the reaction forces occurring as a result of said intermediate gearbox are additionally supported by said radially projecting torque support foot.

21. The torque wrench according to claim 13, wherein said energy store is a rechargeable battery.

22. The torque wrench according to claim 15, wherein said planetary gearbox outputs an output square.

23. The torque wrench according to claim 17, wherein to said adapter ring, said intermediate gearbox, in an intermediate gearbox housing region, is non-rotatably connected and that, on said opposite region of said intermediate gearbox, on an intermediate gearbox housing region said concentric toothed disc is disposed and non-rotatably connected.

24. A method for performing a bolting operation, which comprises the steps of: providing a torque wrench, containing: a drive motor with a predetermined speed and a predetermined motor output torque; an intermediate gearbox connected downstream of the drive motor, and reduces an output speed of the drive motor with a predetermined reduction ratio; a bolting gearbox connected downstream of the intermediate gearbox and having a bolting tool part on an output side, the bolting gearbox reducing an output speed of the intermediate gearbox with a predetermined reduction ratio; a housing with at least one handle, in the housing the drive motor and the intermediate gearbox are disposed in sequence; the bolting gearbox being a planetary gearbox with an external ring gear with internal toothing, the external ring gear being rotatably mounted on the housing and having a radially projecting torque support foot which, during the bolting operation, pivots against a required fixed support point and supports there reaction forces occurring on the planetary gearbox; and the drive motor is non-rotatably disposed and fixed in the housing and the intermediate gearbox is rotatably mounted in the housing and is non-rotatably connected to the external ring gear, so that, during the bolting operation, only the reaction forces occurring at the housing due to the drive motor have to be supported by an operator and/or the reaction forces occurring due to the intermediate gearbox are additionally supported by the torque support foot; and holding the housing by the operator at the at least one handle during the bolting operation and the reaction forces occurring at the housing are to be supported as rotational forces.

Description

[0022] With the aid of a drawing, embodiments of the invention are further explained merely by way of example.

[0023] It shows:

[0024] FIG. 1 a perspective view of a torque wrench as a power wrench with a torque support foot,

[0025] FIG. 2 a side view of a similar torque wrench without a support foot,

[0026] FIG. 3 a schematic longitudinal section through a housing and a part of a bolting gearbox, and

[0027] FIG. 4 a top view onto a sun gear of the bolting gearbox.

[0028] In FIG. 1, a torque wrench 1 is shown as a cordless bolt wrench with a housing 2, with a handle 3 as a pistol grip, to the end of which is attached a receptacle 4 for a battery, for example, as an energy storage device for supplying energy to an electric motor 13 arranged in the housing 2 as a drive motor.

[0029] A bolting gearbox 5 with an outer sun gear 6 is rotatably connected to the housing 2, to which a torque support foot 7 is attached in a non-rotatable manner. As shown in FIG. 2, an external toothing 8 is attached to a section of the sun gear 6, onto which the torque support foot 7 can be fitted and fixed with an associated internal toothing.

[0030] FIG. 2 also shows that the output of the bolting gearbox 5 is designed as an output polygon, here exemplarily as an output square 9, onto which an exchangeable socket 10 can be plugged as a bolting tool part.

[0031] As can be seen from FIG. 2 in conjunction with the longitudinal section shown in FIG. 3, the housing 2 is made up of several parts and consists in particular of a stable housing inner part 11 onto which shell parts 12 are fitted and fixed to form the handle 3 and to accommodate switching, control and display elements.

[0032] In the housing inner part 11 of relevance for the invention according to FIG. 3, further generally referred to as housing 2, an electric motor 13, preferably rotating relatively quickly, with a rotary shaft 14 is arranged and shown schematically. During a bolting operation, with the design adopted here, torques in the order of approximately 1 Nm, for example, occur at the rotary shaft, in particular at an output-side shaft section 15.

[0033] The electric motor 13 is followed by a schematically shown intermediate gearbox 16, which here reduces the speed of the electric motor 13 with a reduction ratio of 10:1, whereby an intermediate gearbox output torque of approximately 10 Nm occurs at an output pinion 17 of the intermediate gearbox 16.

[0034] The intermediate gearbox 16 has an intermediate gearbox housing section 18 projecting towards the electric motor 13, which is connected to an adapter ring 19 in a non-rotatable manner. The adapter ring 19 is rotatably mounted on the shaft section 15 of the rotary shaft 14 by means of a ball bearing 20.

[0035] At the opposite end of the intermediate gearbox 16, a driver ring 21 is non-rotatably connected to the intermediate gearbox housing, to which in turn a toothed disc 22 is attached at the end. The external toothing of the toothed disk 22 engage in the internal toothing 23 of a ring gear 24 of the bolting gearbox 5 in the form of a planetary gearbox. One section of the ring gear 24 is rotatably inserted into a receiving ring part 25 at the end of the housing 2. The further structure of the bolting gearbox 5 is not relevant according to the invention and is therefore not shown further. Only in the upper area of the ring gear 24 is schematically shown a part of a planetary gear carrier 26 with a planetary gear 27, in which the output pinion 17 engages.

[0036] The thick dashed line 28 and the rotary arrows 29 and 30 are intended to illustrate that the intermediate gearbox 16 is rotatably arranged in the housing 2 and has a non-rotatable connection to the bolting gearbox 5 or the ring gear 24 and thus to the torque support foot 7, whereby the intermediate gearbox output torque is also supported by the torque support foot 7. During a bolting process, only the comparatively small motor output torque is applied to the housing 2 as a reaction force, which must be supported by an operator as a reaction force.

[0037] FIG. 4 shows a top view of the ring gear 24 with its internal toothing 23, and

[0038] FIG. 5 shows a corresponding longitudinal section. As shown, the external toothing of the toothed disk 22 engage in the internal toothing 23 for a non-rotatable connection with the intermediate gearbox 16.

TABLE-US-00001 List of reference signs 1 torque wrench 2 housing 3 handle 4 receptacle 5 bolting gearbox 6 sun gear 7 torque support foot 8 outer toothing 9 drive square 10 socket 11 internal part of the housing 12 shell parts 13 electric motor 14 rotary shaft 15 shaft section 16 intermediate gearbox 17 output pinion 18 intermediate gearbox housing area 19 adapter ring 20 ball bearing 21 driver ring 22 toothed disc 23 internal thoothing 24 ring gear 25 receiving ring part 26 planet gear carrier 27 planetary gear 28 line 29 rotary arrow 30 rotary arrow