Handle for a screwing device and screwing device

Abstract

The invention relates to a handle for a screwing device with a connecting portion for fastening to a housing of the screwing device and with a grip portion which is designed to engage a human hand, in which the handle is provided with a measuring device for measuring a torque acting on the handle and with a torque limiting device for limiting a torque acting on the handle.

Description

[0001] The invention relates to a handle for a screwdriving device, comprising a connecting portion for attachment to a housing of the screwdriving device and a grip portion designed to engage a human hand. The invention also relates to a screwdriving device with a handle.

[0002] Maintaining a defined torque when creating a screw connection can be ensured by means of mechatronics built into the screwdriving device, in other words by means of a screwdriving device with built-in torque measurement. It is also known to provide additional torque modules that intervene directly in the mechatronics of the screwdriving device. Alternatively, to maintain a defined torque when creating a screw connection, after an initial screwing process in which only a rough torque was applied using the screwdriving device based on feel, the target tightening torque of a screw connection must be set in a second step using a torque wrench. In addition, mechanical torque limiters or clutches are available that are connected between the screwdriving device and the screw. If a defined torque is exceeded, the clutch slips.

[0003] The invention is intended to improve a handle for a screwing device and a screwing device.

[0004] According to the invention, a handle having the features of claim 1 or a screwing device having the features of claim 10 is provided for this purpose. Advantageous developments of the invention are mentioned in the subclaims.

[0005] In a handle according to the invention for a screwdriving device, for example a cordless screwdriver or an electric drill, a connecting portion for attachment to a housing of the screwdriving device and a grip portion designed to engage a human hand are provided. The handle is provided with a measuring device for measuring a torque acting on the handle and / or with a torque limiting device for limiting a torque acting on the handle.

[0006] The handle according to the invention can be attached to a housing of the screwdriving device in a very simple manner using the connecting section. This makes it very easy to detect and, if necessary, limit the torque acting on the housing of the screwdriving device and thus also on the handle when tightening a screw connection. In this way, conventional screwdriving devices can be very easily retrofitted with the handle according to the invention, so that in order to achieve a defined preload of a screw connection, in other words a defined tightening torque of a screw connection, not only special devices can be used which also have the corresponding mechatronics integrated into the machine or are compatible with torque modules. Such appropriately equipped screwdriving devices are available on the market, but are not cost-effective for many small and medium-sized companies.The handle according to the invention can be retrofitted to all types of rotary and rotary-impact screwdrivers from various manufacturers. The handle according to the invention enables the tightening of screw connections using a predefined torque, in particular using a torque previously set on the handle. Furthermore, a torque limit protects the user from injury.

[0007] The handle according to the invention is first connected to the respective screwdriving device using various adaptations, if necessary. This can be achieved, for example, by a clamp enclosing a cylindrical section of the housing, which in turn is engaged by another section of the handle. Alternatively, the handle can also be provided with a screw bolt thread and is simply screwed into a matching threaded bushing on the housing, thereby securing it. The screwdriving process with the screwdriving device is now started by holding the screwdriving device with one hand on the handle of the screwdriving device and with the other hand on the handle according to the invention.If a previously defined torque, which may be set on the handle according to the invention, is reached during the screwing-in process, a signal can be generated, for example, visually, acoustically, haptically, or a slipping can occur when the target torque is reached. According to the invention, a measuring device for measuring a torque acting on the handle and / or a torque limiting device for limiting a torque acting on the handle is provided for this purpose. The torque limiting device can, for example, comprise a compression spring mechanism, a bending rod, a slip clutch, or the like. The measuring device can, for example, comprise a bending rod or a strain gauge (SG) on a bending rod or a torsion rod.

[0008] In a further development of the invention, the torque limiting device is designed as a slip clutch or releasable mechanical lock.

[0009] A slip clutch can, for example, be implemented in the area of the connecting section so that the housing of the screwdriver rotates relative to the handle when a set torque is exceeded. For example, a mechanical lock can also be released in the manner of known torque wrenches so that the handle bends slightly when a previously set torque is reached. For example, reaching a previously set torque can also be signaled simply acoustically, haptically or visually, for example by the clicking of a mechanical lock, which is then released, by another signal, for example an electrically generated acoustic signal or even a visual signal. For example, means can also be provided to cause the handle to vibrate slightly when a preset torque is reached.

[0010] In a further development of the invention, the connecting section has the torque limiting device.

[0011] In a further development of the invention, the torque limiting device is arranged in a section of the handle arranged between the connecting section and the grip section.

[0012] For example, the handle can be designed like a conventional torque wrench, so that exceeding a preset torque leads, for example, to an acoustically and haptically perceptible cracking sound in the handle.

[0013] In a further development of the invention, a torque adjustment device is provided for setting a limit value of the torque acting on the handle.

[0014] Such a torque adjustment device can be designed in a similar way to a conventional torque wrench, for example, by rotating the handle portion relative to the other portion, thereby increasing or decreasing a torque limit. However, the torque adjustment device can also be designed electronically, for example, and have input buttons and an associated display.

[0015] In a further development of the invention, the torque adjustment device is designed to adjust a slipping torque of the slipping clutch or a release torque of the releasable mechanical lock.

[0016] In a further development of the invention, a release device is provided that releases a mechanical lock depending on a torque measured by the measuring device. For example, a tactile and audible click or crack in the handle, or even the release of a bending of the handle by a small angle, can be provided.

[0017] In a further development of the invention, a display device is provided for displaying the torque measured by means of the measuring device.

[0018] Such a display device can be designed mechanically, for example by means of a bending rod, but preferably the display device is designed electronically and the measured torque can be displayed on a digital display or by means of lights.

[0019] In a further development of the invention, a signaling device is provided for setting and signaling at least one limit value of the torque applied to the handle. Such a signaling device can operate mechanically and generate a haptic and audible click or crack. The signaling device can also be optical and, for example, illuminate LEDs of different colors. The signaling device can also operate acoustically and emit a signal tone when a limit value is reached, or, for example, a continuous tone whose pitch changes as the limit value is reached.

[0020] The object underlying the invention is also achieved by a screwing device with a handle according to the invention, wherein the screwing device has a hydraulic, pneumatic or electric auxiliary drive.

[0021] In a further development of the invention, the screwing device is designed as an electric screwdriver, in particular as a cordless screwdriver.

[0022] Further features and advantages of the invention will become apparent from the description of a preferred embodiment of the invention in conjunction with the drawings. In the drawings: Fig. 1 is a schematic front view of a handle according to the invention and Fig. 2 is a schematic side view of a screwing device with a handle according to the invention.

[0023] Fig. 1 shows a handle 10 according to an embodiment of the invention. The handle 10 has a gripping portion 12, in which the handle 10 can be grasped by a human hand at a single-hand grip 14, which is cylindrical in the illustrated embodiment. The handle 10 further has a connecting portion 16, which is intended to be connected to a screwdriver. In the illustrated embodiment, the connecting portion 16 is designed in the form of a clamp, which is pushed onto a cylindrical portion of the housing of the screwdriver and then clamped. Typically, such a cylindrical portion is located directly adjacent to a drill chuck of a screwdriver or adjacent to another drive configuration of the screwdriver, see Fig. 2 . Such a cylindrical section is provided in numerous conventional screwdriving devices to attach a conventional handle with a clamp.

[0024] The handle 10 is further provided with a further section 18, which is arranged between the connecting section 16 and the grip section 12. In the illustrated embodiment, this further section 18 is rod-shaped and has a pivot point 20 for torque measurement, a schematically illustrated measuring device 44 for measuring a torque acting at the pivot point 20, a torque limiting device 46, and a display device 22 for displaying the measured and / or set torque.

[0025] The handle 10 represents merely one of several embodiments of the invention, wherein a torque is measured at the pivot point 20 by means of the measuring device 44, and the torque limiting device 46 is provided in the region of the pivot point 20, which generates a haptically and audibly perceptible click or crack when a set torque limit is exceeded. To set the torque limit at the torque limiting device 46, in the illustrated embodiment, the one-hand handle 14 is rotated relative to the further section 18. This allows a spring in the further section 18 to be tensioned or loosened, so that the releasable mechanical lock in the region of the pivot point 20 is set to a different release value, corresponding to a set target value for the torque.Within the scope of the invention, other setting options can be realized, for example by means of an electronic input device.

[0026] Fig. 2 shows a schematic representation of a screwing device 30 according to the invention with the already in Fig. 1 presented and based on the Fig. 1 explained handle 10. It can be seen that the connecting section 16 is fastened to a cylindrical section 32 of a housing 42 of the screwing device 30, wherein the cylindrical section 32 surrounds an output shaft of the screwing device 30. A drive formation 34, for example a screw socket 34, is attached to the output shaft of the screwing device 30. The screwing device 30 has an electrical auxiliary drive, in the present case an electric motor, which is Fig. 2 not visible, is connected to the output shaft and is supplied with electrical energy via a connecting cable 36. Instead of the connecting cable 36, an energy storage device in the form of a rechargeable battery can also be provided. A trigger switch 38 is provided for triggering the electric auxiliary drive of the screwing device 30.

[0027] To put on a Fig. 2 To tighten a screw connection (not shown) with a predefined torque, a limit value for the predefined torque is first set on the handle 10 by means of the torque limiting device 46. This is done in a manner as described in the Fig. 1 The drive design 34 is then selected to suit the screw connection to be tightened. The screwing process is then started by holding the screwing device 30 with one hand on a handle 40 of the housing 42 of the screwing device 30 and with the other hand on the one-hand grip 14 of the handle 10. If a previously defined torque, which is set on the handle 10, is reached during the screwing process, this torque acts in the handle 10, in particular in the area of the pivot point 20 of the handle 10, as can be seen from the Fig. 1 As explained above, when the set torque is reached, a signal is emitted, for example, a visual, acoustic, and / or haptic signal, such as an acoustically and haptically perceptible click or crack of a mechanically releasable lock in the area of pivot point 20, as with conventional torque wrenches.

[0028] In alternative embodiments, the achievement of the set torque, i.e., the target torque, can be signaled by the slipping of a slip clutch. The slip clutch can be provided, for example, in the area of the connecting section 16, and slipping of the slip clutch causes the handle 10 to rotate relative to the housing of the screw driver 30.

[0029] In a manner not shown, the handle 10 can be equipped with an electronic display and adjustment device. For example, a torque acting in the handle 10 can be measured using strain gauges in or on the handle 10 and displayed on the display device. Upon reaching a preset torque, in other words, a target torque, an acoustic and / or visual signal is emitted, for example.

[0030] With the handle 10 according to the invention, conventional screwing devices 30 can be equipped in a very simple manner so that they are suitable for tightening a screw connection with a predefined torque. In the handle 10 of the Fig. 1 The pivot point 20 is located away from the rotational axis of the drive shaft, which applies torque to the screw via the drive structure 34. This distance can be compensated for, or taken into account and corrected, when calculating the torque. A prototype of the handle 10 according to the invention has produced highly reliable and repeatable results when tightening screw connections with a predefined torque, which provides sufficient accuracy for the vast majority of practical applications.

[0031] The handle 10 according to the invention can be provided with an interface (not shown), in particular with a wireless interface, to transmit a measured torque in the form of a data set to a control unit and / or to supply the torque limiting device 46 with a torque setting. This makes it possible, for example, to document that a large number of screws have been tightened to the predefined torque.

Claims

1. Handle (10) for a screwing device (30) with a connecting portion (16) for fastening to a housing (42) of the screwing device (30) and with a grip portion (12) which is designed to engage a human hand, characterized in that the handle (10) is provided with a measuring device (44) for measuring a torque acting on the handle (10) and with a torque limiting device (46) for limiting a torque acting on the handle (10).

2. Handle according to claim 1, characterized in that the torque limiting device (46) is designed as a slip clutch or releasable mechanical lock.

3. Handle according to claim 2, characterized in that the connecting portion has the torque limiting device.

4. Handle according to claim 2, characterized in thatthe torque limiting device (46) is arranged in a section (18) of the handle (10) arranged between the connecting section and the grip section.

5. Handle according to at least one of claims 2 to 4, characterized in that a torque adjustment device is provided for setting a limit value of the torque acting on the handle (10).

6. Handle according to claim 5, characterized in that the torque adjustment device is designed to adjust a slipping torque of the slipping clutch or a release torque of the releasable mechanical lock.

7. Handle according to at least one of the preceding claims, characterized in that a triggering device is provided which releases a mechanical lock depending on a torque measured with the measuring device.

8. Handle according to at least one of the preceding claims, characterized in thata display device (22) is provided for displaying the torque measured by means of the measuring device (44).

9. Handle according to at least one of the preceding claims, characterized in that a signaling device is provided for setting and signaling at least one limit value of the torque acting on the handle (10).

10. A screwing device (30) with a handle according to at least one of the preceding claims, wherein the screwing device (30) has a hydraulic, pneumatic or electric auxiliary drive.

11. Screwing device (30) according to claim 10, characterized in that the screwing device (30) is designed as an electric screwdriver, in particular as a cordless screwdriver.

Images