Handheld pulling and pushing device
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- TKR SPEZIALWERKZEUGE GMBH
- Filing Date
- 2021-11-29
- Publication Date
- 2026-06-11
Smart Images

Figure 00000000_0000_ABST
Abstract
Description
[0001] The invention relates to a handheld pulling and pushing device for driving interchangeable drawing and pressing tools, with - a drive unit comprising a battery-powered electric motor and - a screw drive with a threaded spindle connected to the electric motor, rotatably mounted on a housing body, and a linearly adjustable threaded nut rotatably mounted on the threaded spindle and non-rotatably mounted on the housing body via a bearing unit.
[0002] Handheld pulling devices, i.e., devices that can be used mobilized by one person, such as handheld riveting tools for setting blind rivets, such as blind rivets and blind rivet nuts, which have a drive unit with an electrically driven threaded spindle of a screw drive, are known in various designs from the prior art. The screw drive converts the rotary motion of the electric motor into a linear motion of the pulling or pressing tool in a known manner. In the case of the setting process of a blind rivet, for example, a mandrel of the blind rivet is moved axially.
[0003] In addition, there are also electric pressing devices which also use a threaded drive to convert the rotary motion generated by an electric motor into a linear movement of the pressing tool, e.g. to carry out stamping processes or to set punch rivets.
[0004] DE 10 2018 124 646 A1 discloses a hand tool for forming and / or separating plastic or metal workpieces, comprising a working head and an electromechanical drive for actuating the working head. DE 44 46 503 C1 also discloses a hand tool with a basic unit comprising a housing and a drive arranged in the housing, the drive being an electrically driven threaded spindle. An electric pressing device with an electric motor and a threaded spindle engaging with a threaded nut for converting the rotary motion of the electric motor into a linear motion of a pressing tool is further disclosed in DE 10 2004 054 836 A1. A mobile, electrically operated vise for temporary mounting on a machine tool is disclosed in DE 20 2021 105 213 U1.WO 02 / 102 555 A1 discloses an electromechanical drive unit for generating linear movements via a spindle drive, wherein an electric motor, a rotatably mounted threaded spindle, and an axially displaceable nut are coupled to an actuating element. US 10,513,015 B2 describes an electrically driven crimping tool with a handheld housing, battery power supply, and an electromechanical linear drive that axially moves a crimping die to perform compression crimps. WO 2020 / 128 597 A1 discloses a drive unit with a threaded drive that can be used in various tool types, wherein the electric drive rotates a threaded spindle via a transmission unit, thus causing a nut to perform an axial movement.
[0005] The riveting and pressing devices described above are used, for example, in automotive workshops for carrying out repairs on vehicle bodies. Depending on the work to be performed, however, it is necessary to have both a pulling device and a separate pressing device available in order to perform all the required tasks. The need for at least two devices leads to increased tooling costs, especially if the tools are battery-operated rather than corded.
[0006] Based on this, the invention aims to provide a handheld pulling and pushing device suitable for driving interchangeable pulling and pressing tools.
[0007] The invention solves the problem by means of a handheld pulling and pushing device with the features of claim 1. Advantageous further developments of the invention are specified in the dependent claims.
[0008] The handheld pulling and pushing device according to the invention is characterized by a coupling unit connected to a tool holder, which is connected to the threaded nut in such a way that tensile and compressive forces resulting from the direction of rotation of the threaded spindle are transmitted from the threaded nut to the tool holder via the coupling unit.
[0009] According to the invention, the handheld pulling and pushing device is connected via a coupling unit to a tool holder, which is designed for the interchangeable reception of various pulling and pressing tools required for the respective application. For example, when used as a pushing device, the tool holder can be designed to receive a rivet setter, which, in conjunction with a rivet shank arranged on the pushing device, is used to set rivets. When used as a pulling device, the tool holder can, for example, be provided with suitable clamping devices for a blind rivet shank or have other means for transmitting tensile forces. Alternatively or additionally, the tool holder can also be designed to receive corresponding pulling tools, wherein the pulling tools have, for example, clamping means by means of which the tensile forces can then be transmitted.
[0010] The coupling unit is in turn connected to the threaded nut in such a way that both tensile and compressive forces, which result from the direction of movement of the threaded spindle and the resulting linear adjustment of the threaded nut, are reliably transmitted to the coupling unit.
[0011] The handheld pulling and pushing device according to the invention allows, depending on the work to be performed, for example, in a motor vehicle workshop during bodywork repairs, the tool required for the respective operation to be positioned on the tool holder. Thus, the handheld pulling and pushing device allows both pulling and pressing operations to be carried out, such as setting blind rivets or performing punching operations. The linear adjustment of the selected tool required for the respective operation is reliably transmitted to the tool holder via the coupling unit, after the coupling unit, according to the invention, transmits both pulling and pushing forces from the threaded nut to the respective tool. The handheld pulling and pushing device therefore eliminates the need for at least two separate devices for performing pulling and pressing operations.
[0012] The design of the threaded drive for converting the rotary motion of the electric motor into a linear motion of the threaded nut, and thus of the drawing or pressing tool in operative connection with the threaded nut, is fundamentally freely selectable. For example, trapezoidal threaded spindles can be used, whose thread pitch can typically be selected in the range of 2 to 10 mm according to the forces to be achieved.
[0013] According to a particularly advantageous embodiment of the invention, the screw drive is designed as a ball screw drive or planetary screw drive. The use of such screw drives with balls or rollers as rolling elements is characterized by the fact that, unlike trapezoidal screw drives where surfaces rub against each other, they possess a particularly high efficiency. This allows the dimensions of the electric motor to be reduced in order to achieve the desired tensile forces or pressing forces, thus enabling a particularly compact design of the handheld pulling and pushing device. Typical thread pitches of ball screw drives or planetary screw drives are 5 to 10 mm.
[0014] The inventive design of the handheld pulling and pushing device provides that the tool holder is operatively connected to the threaded nut in such a way that tensile and compressive forces resulting from the direction of rotation of the threaded spindle are transmitted to the tool holder. The necessary design of the coupling unit with the threaded nut is, in principle, freely selectable.
[0015] However, according to a particularly advantageous embodiment of the invention, an adapter unit is provided for transmitting tensile and compressive forces from the threaded nut to the coupling unit. The adapter unit has a first and a second connection element, wherein the first connection element is operatively connected to a first end face of the threaded nut and the second connection element is operatively connected to a second end face of the threaded nut and the coupling unit, the end faces of the threaded nut being oriented essentially perpendicular to the longitudinal axis direction of the threaded spindle and thus to the adjustment direction of the threaded nut.
[0016] To secure the connecting elements in their position relative to the threaded nut, they are also connected to each other along the longitudinal axis of the threaded spindle, thus pre-tensioning them towards the threaded nut. This connection ensures the mutual transmission of the forces exerted on the connecting elements by the threaded nut, depending on its adjustment direction. Furthermore, the operative connection of the second connecting element to the second end face of the threaded nut and the coupling unit ensures that the coupling unit is fixed relative to the second end face of the threaded nut.
[0017] Forces acting towards the coupling unit due to a corresponding adjustment of the threaded nut result in compressive forces between the threaded nut and the coupling unit, which are transmitted via the coupling unit to the tool holder. In the case of an opposite direction of movement of the threaded nut, the compressive forces acting on the first connecting element and generated by the threaded nut are transmitted via the connection of the first connecting element to the second connecting element and thus also to the coupling unit, so that tensile forces are transmitted via the coupling unit to the tool holder in a corresponding manner.
[0018] The use of an adapter unit according to the advantageous embodiment of the invention described above ensures in a particularly reliable manner that both tensile and compressive forces are reliably transmitted from the threaded nut to the tool holder. According to a particularly advantageous embodiment of the invention, the first connecting element rests against the first end face of the threaded nut, and the second connecting element rests against a free end face of the coupling unit located against the second end face of the threaded nut, and the connecting elements are connected to each other via at least two, preferably four, tension rods.
[0019] According to this embodiment of the invention, the two connecting elements, together with the tie rods extending in the longitudinal direction of the threaded spindle, form a cage-like body that encloses the threaded nut. The first connecting element, which rests against the first end face, and the second connecting element, which rests against a free end face of the coupling unit located at the second end face, reliably ensure that tensile and compressive forces are transmitted from the threaded nut to the tool holder via the coupling unit.
[0020] In the case of compressive forces resulting from movement of the threaded nut towards the coupling unit, these forces are transferred directly to the coupling unit due to the coupling unit's contact with the second end face of the threaded nut. Tensile forces result from movement of the threaded nut in the opposite direction to the coupling unit. These tensile forces are a result of a conversion of the compressive forces acting on the first connecting element, which are transferred to the second connecting element via the tension rods. The second connecting element rests against the free end face of the coupling unit opposite the second end face of the threaded nut.By using at least two, preferably four, tension rods, which are particularly preferably arranged at uniform intervals around the circumference of the threaded nut, a reliable conversion of the compressive forces acting on the first connecting element into tensile forces acting on the second connecting element and thus on the coupling unit is ensured.
[0021] The design of the coupling unit for connection to the tool holder is generally freely selectable. The coupling unit and the tool holder can even be formed as a single piece. However, a particularly advantageous embodiment provides for a detachable connection between the coupling unit and the tool holder. This design of the coupling unit allows for the attachment of adapted tool holders to the coupling unit, depending on the work to be performed. This permits the use of standardized drawing and pressing tools and further expands the application range of the pulling and pushing device.
[0022] According to the invention, the coupling unit is connected to the threaded nut in a rotationally fixed manner. This eliminates the need for a potentially separate rotationally fixed arrangement of the coupling unit on the housing body, since the rotationally fixed connection of the threaded nut to the housing body, as provided for in the invention, also ensures that the coupling unit is rotationally fixed to the housing body. The bearing unit provided for the rotationally fixed arrangement of the threaded nut can, in principle, be designed in any desired way. For example, the bearing unit could be designed as a key embedded in the threaded nut, which is supported in a corresponding guide rail on the housing body.
[0023] However, in a further development of the invention, the bearing unit is designed such that the threaded nut and / or the coupling unit, which is rotationally fixed to the threaded nut, is supported by rolling contact with the housing body. According to this embodiment of the invention, the bearing unit has at least one rolling element by which the threaded nut is supported by rolling contact with the housing body. This embodiment of the invention ensures increased efficiency by reducing losses due to friction. Furthermore, the use of a correspondingly further developed bearing unit offers a particularly simple, backlash-free mounting of the threaded nut, ensuring the reliable transmission of tensile and compressive forces.
[0024] The specific design of the bearing unit for the rolling support of the coupling unit on the housing body, for which suitable rolling elements are usually used, is generally freely selectable. However, according to a particularly advantageous embodiment of the invention, the bearing unit is designed to - a bearing roller rotatably arranged on a bearing journal projecting radially from the threaded nut or the coupling unit, supported circumferentially on two opposite sections of the housing body or - two bearing rollers, each rotatably arranged on a bearing journal projecting radially from the threaded nut or the coupling unit, and each bearing roller bearing circumferentially against one of two opposing sections of the housing body.
[0025] According to the foregoing embodiment of the invention, the bearing unit has one or two bearing rollers rotatably mounted on bearing journals that project perpendicularly from the threaded nut or coupling unit in the direction of adjustment. In the case of a single bearing roller, it is supported on the housing body by two sections arranged opposite each other perpendicular to the direction of adjustment of the threaded nut, wherein, when the threaded nut is adjusted along the longitudinal axis of the threaded spindle, the bearing roller rolls along the opposite housing body sections.
[0026] In the advantageously intended use of two bearing rollers, the threaded nut or the coupling unit has two bearing journals projecting perpendicularly from the threaded nut or the coupling unit in the direction of adjustment, on each of which a bearing roller is rotatably arranged. The two bearing rollers each bear against the housing body with a portion of their bearing area, the bearing areas being arranged opposite each other on the housing body when viewed perpendicular to the direction of adjustment of the threaded nut, thus ensuring reliable support when the threaded nut is adjusted, during which the bearing rollers roll against the housing body.
[0027] The design of the housing body for supporting the bearing unit is generally freely selectable. However, according to a particularly advantageous embodiment of the invention, the housing body has at least two, preferably four, guide rods running parallel to the threaded spindle and operatively connected to the bearing unit. The guide rods, which are connected at their ends, for example, to a bearing receptacle, form a cage-like housing body against which the bearing unit is supported. This design of the housing body, in particular the use of four guide rods evenly distributed around the circumference of the threaded spindle, offers the possibility of designing the housing body to be particularly simple, compact, and lightweight.In the case of the use of bearing rollers, in the advantageously provided use of one bearing roller, this is supported on two adjacent guide rods, and in the advantageously provided use of two bearing rollers, each bearing roller is supported on one of two guide rods arranged adjacent to each other.
[0028] According to an advantageous embodiment of the invention, the bearing rollers have a running surface that partially surrounds the guide rods. According to a particularly advantageous embodiment of the invention, the guide rods have a circular cross-section and the running surface of the bearing rollers has a corresponding arcuate contour.
[0029] This embodiment of the invention ensures a particularly reliable bearing arrangement for the threaded nut and / or coupling unit and its rotationally fixed arrangement relative to the threaded spindle. Relative movements of the bearing unit perpendicular to the spindle axis are reliably prevented by these designs of the bearing rollers and guide rods.
[0030] By appropriately dimensioning the guide rods, it can be reliably ensured that the bearing unit is guided along the guide rods when using the advantageously intended bearing rollers, thereby absorbing all forces transmitted circumferentially from the threaded nut to the guide rods. According to a particularly advantageous embodiment of the invention, the bearing unit has a clamping body that encompasses the guide rods engaged with the bearing rollers.
[0031] According to this embodiment of the invention, a clamping body is provided which grips the guide rods externally in the area opposite the bearing rollers. The clamping body thus provides additional protection against an increase in the distance between the guide rods in the area of the bearing unit, so that additional support, particularly in the central area of the guide rods (viewed in the longitudinal direction), can be dispensed with. The clamping body reliably prevents an increase in the distance between the guide rods due to the forces applied circumferentially when the threaded spindle is adjusted via the threaded nut.
[0032] The transmission of the motor's rotary motion to the threaded spindle can, in principle, be achieved in any manner. According to an advantageous embodiment of the invention, the drive unit comprises a gearbox connecting the electric motor and the threaded spindle. The use of a gearbox allows for the transmission of high torques with minimal installation space and weight. For example, two- or three-stage planetary gearboxes, as well as cycloidal and spur gearboxes, can be used, providing the desired gear ratios. In combination with preferably battery-powered brushless motors, optimal coordination between the electric motor gearbox, the threaded spindle, and the resulting force can be achieved.
[0033] In the simplest embodiment of the handheld pull and push device according to the invention, the electric motor can be operated such that only the direction of rotation of the threaded spindle is selectable. However, according to a particularly advantageous embodiment of the invention, the drive unit is connected to a control unit which allows for... - Control of the drawing and pressing processes and / or - trained in archiving the drawing and pressing processes.
[0034] According to this design, the use of a control unit allows for precise control of the corresponding drawing and pressing processes. For example, the control unit makes it particularly easy to set the required tensile or compressive forces, ensuring highly reliable execution of the drawing and pressing operations. The control unit can also be configured to archive the completed drawing and pressing operations, thus enabling reliable documentation of the work performed.
[0035] According to a particularly advantageous embodiment of the invention, the control unit is connected to a sensor unit for monitoring the pulling and pressing processes. The sensor unit can be configured to monitor the adjustment range, the pulling or pressing forces, the torque, or similar parameters required for carrying out the work processes and their successful completion. According to a particularly advantageous embodiment of the invention, the control unit is equipped with a display, which makes it particularly easy for the operator to operate the handheld pulling and pressing device. Furthermore, this device can also be connected to a central database via suitable wireless transmission means.
[0036] An embodiment of the invention is explained below with reference to the drawings. The drawings show: Fig. 1 a perspective view of a tension and compression device with an attached rivet bracket; Fig. 2 a perspective view of the tension and compression device of Fig. 1 without rivet bracket; Fig. 3 a perspective view of the pulling and pushing device of Fig. 2 without clamping body; Fig. 4 an enlarged perspective view of the pulling and pushing device of Fig. 3 in the area of a threaded drive and Fig. 5 a sectional view of the tension and compression device of Fig. 1.
[0037] Fig. Figure 1 shows a perspective view of a push-pull device 1 with a rivet bracket 2 attached to it. The push-pull device 1 has a drive unit 4 with an electric motor 3 and a gearbox 27 connected to the electric motor 3. The electric motor 3 drives a threaded spindle 7 of a screw drive 5 connected to the gearbox 27 via the gearbox 27, the threaded spindle 7 being rotatably mounted in a bearing receptacle 28 of a housing body 6 (see Figure 1). Fig. 2, Fig. 3, Fig. 4 to Fig. 5).
[0038] The threaded drive 5 has, in addition to the threaded spindle 7, a threaded nut 9 arranged on the threaded spindle 7, which is mounted to the housing body 6 in a rotationally fixed manner. The threaded nut 9 serves to drive a tool holder designed as a piston rod 10, which is adjustable in a bearing receptacle 29 in the longitudinal axis direction of the threaded spindle 7, so that punch riveting operations can be carried out by means of the pull and push device 1 via the connected riveting shank 2.
[0039] The piston rod 10 is connected to the threaded nut 9 via a detachably connected coupling unit 11, the end of which opposite the piston rod 10 rests against a second end face 14 of the threaded nut 9. To prevent the coupling unit 11 from rotating relative to the threaded nut 9, the coupling unit 11 also has projections 31 on its contact surface with the second end face 14 of the threaded nut 9, which engage in recesses 32 on the second end face 14 of the threaded nut 9.
[0040] An adapter unit 12 serves to transmit the linear motion generated by the threaded nut 9 to the coupling unit 11. This adapter unit has a first connecting element 15 abutting the first end face 13 of the threaded nut 9 facing the gearbox 27 and a second connecting element 16 abutting a circumferential flange 30 of the coupling unit 11. The first and second connecting elements 15, 16 are connected to each other by tension rods 18 designed as screws 18, which preload the connecting elements 15, 16 towards the threaded nut 9, so that the adapter unit 12 encloses the threaded nut 9 like a cage.
[0041] Compressive movements, i.e., adjustment movements of the threaded nut 9 towards the piston rod 10, are transmitted to the coupling unit 11 via the direct contact of the coupling unit 11 with the second end face 14 of the threaded nut 9. To generate tensile forces as a result of a displacement of the threaded nut 9 towards the drive unit 4, the compressive forces acting on the first connecting element 15, which rests against the first end face 13 of the threaded nut 9, are transmitted via the screws 18 to the second connecting element 16, which rests against the circumferential flange 30 of the coupling unit 11, so that the compressive forces are converted into tensile forces there.
[0042] A bearing unit 8, attached to the coupling unit 11, serves to secure the threaded nut 9 to the housing body 6 against rotation. The coupling unit 11 has a bearing journal 19 projecting from the coupling unit 11, oriented perpendicular to the threaded spindle axis, on which a bearing roller 21 is rotatably mounted. The bearing roller 21 is supported by two adjacent sections arranged relative to the threaded spindle axis against two parallel guide rods 25, so that when the threaded nut 9 is moved in the longitudinal direction of the threaded spindle 7, the bearing roller 21 rolls along the guide rods 25. The running surface 23 of the bearing roller 21 is adapted to the contour of the circular guide rods 25.The four guide rods 25 extend parallel to each other and to the axis of the threaded spindle from bearing receptacle 28 to bearing receptacle 29, forming a stable housing body 6. The bearing unit 8 is supported on this housing body 6, and thus, via the torsionally rigid connection of the coupling unit 11 to the threaded nut 9, the threaded nut 9 is supported on the threaded nut 9. The relative positions of the bearing receptacles 28 and 29 are determined by the screws 33 that secure the guide rods 25. The guide rods 25 also pass through recesses 34 in the connecting elements 15 and 16, allowing for a compact design of the tension and compression device 1.
[0043] To prevent the guide rods 25 bearing against the roller 21 from bending upwards, the bearing unit 8 also has a clamping body 26 which grips the guide rods 25 on the outside in the area of the bearing unit 8 and ensures a stable alignment of the guide rods 25 with each other.
[0044] In an embodiment not shown here, the coupling unit 11 has two projecting bearing journals 19 in the area between two adjacent guide rods 25, each bearing journal supporting a bearing roller 21. The bearing rollers 21 are dimensioned such that each bears against only one of the two guide rods 25. Together, the two bearing rollers 21 support the coupling unit 11 against the two guide rods 25. Reference symbol list 1 Pulling and pushing device 2 rivet brackets 3 Electric motor 4 Drive unit 5 screw drive 6 Housing bodies 7 threaded spindle 8 storage units 9 threaded nut 10 Tool holder (piston rod) 11 Coupling unit 12 adapter units 13 First end face (threaded nut) 14 second end face (threaded nut) 15 First connection element (adapter unit) 16 second connection element (adapter unit) 17 free front surface 18 Pull rod (screw) 19 bearing journals 21 Bearing roller (one roller) 23 Running surface (one roller) 25 Guide rod 26 clamp bodies 27 gearboxes 28 Bearing intake 29 Storage 30 Flange (coupling unit) 31 lead 32 Exclusion 33 screw 34 recess
Claims
Handheld pulling and pushing device for driving interchangeable drawing and pressing tools, comprising a drive unit (4) with a battery-operated electric motor (3) and a threaded drive (5) with a threaded spindle (7) rotatably mounted on a housing body (6) connected to the electric motor (3) and a linearly adjustable threaded nut (9) rotatably mounted on the threaded spindle (7) and fixedly mounted to the housing body (6) via a bearing unit (8), characterized by a coupling unit (11) connected to a tool holder (10), which is connected to the threaded nut (9) in such a way that tensile and compressive forces resulting from the direction of rotation of the threaded spindle (7) are transmitted from the threaded nut (9) via the coupling unit (11) to the tool holder (10). Handheld pulling and pushing device according to claim 1, characterized in that the screw drive (5) is designed as a ball screw drive or planetary screw drive. Handheld pulling and pushing device according to claim 1 or 2, characterized by an adapter unit (12) for transmitting tensile and compressive forces from the threaded nut (9) to the coupling unit (11), with a first and second connecting element (15, 16) which are operatively connected to a first end face (13) of the threaded nut (9) and to a second end face (14) of the threaded nut (9) and the coupling unit (11). Handheld pulling and pushing device according to one or more of the preceding claims, characterized in that the first connecting element (15) abuts the first end face (13) and the second connecting element (16) abuts a free end face (17) of the coupling unit (11) abutting the second end face (14) and the connecting elements (15, 16) are connected to each other via at least two, preferably four, tension rods (18). Handheld pulling and pushing device according to one or more of the preceding claims, characterized in that the coupling unit (11) is designed for detachable connection with the tool holder (10). Handheld pulling and pushing device according to one or more of the preceding claims, characterized in that the coupling unit (11) is connected to the threaded nut (9) in a rotationally fixed manner. Handheld pulling and pushing device according to one or more of the preceding claims, characterized in that the bearing unit (8) is designed such that the threaded nut (9) and / or the coupling unit (11) connected to the threaded nut (9) is supported by rolling action on the housing body (6). Handheld pulling and pushing device according to one or more of the preceding claims, characterized in that the bearing unit (8) comprises a bearing roller (21) rotatably arranged on a bearing pin (19) projecting radially from the threaded nut (9) or the coupling unit (11) and supported circumferentially on two opposite sections of the housing body (6), or two bearing rollers (22) rotatably arranged on a bearing pin (20a, 20b) projecting radially from the threaded nut (9) or the coupling unit (11), each bearing roller bearing circumferentially against one of two opposite sections of the housing body (6). Handheld pulling and pushing device according to one or more of the preceding claims, characterized in that the housing body (6) has at least two, preferably four guide rods (25) running parallel to the threaded spindle (7) and operatively connected to the bearing unit (8). Handheld pulling and pushing device according to one or more of the preceding claims, characterized in that the bearing rollers (21, 22) have a running surface (23, 24) that partially surrounds the guide rods (25). Handheld pulling and pushing device according to one or more of the preceding claims, characterized in that the guide rods (25) have a circular cross-section and the running surface (23, 24) of the bearing rollers (21, 22) have a corresponding arc-shaped contour. Handheld pulling and pushing device according to one or more of the preceding claims, characterized in that the bearing unit (8) has a clamping body (26) encompassing the guide rods (25) which are engaged with the bearing rollers (21, 22). Handheld pulling and pushing device according to one or more of the preceding claims, characterized in that the drive unit (4) has a gearbox (22) connecting the electric motor (3) and the threaded spindle (7). Handheld pulling and pushing device according to one or more of the preceding claims, characterized in that the drive unit (4) is connected to a control unit which is designed for controlling the pulling and pressing operations and / or archiving the pulling and pressing operations. Handheld pulling and pushing device according to one or more of the preceding claims, characterized in that the control unit is connected to a sensor unit for monitoring the pulling and pressing processes.