Handheld pulling and pressing device and mechanical power amplifier

Abstract

The invention relates to a handheld pulling and pushing device and a mechanical force amplifier for a handheld pulling and pushing device for driving drawing and pressing tools. The handheld pulling and pushing device for driving interchangeable tools comprises a drive unit with a battery-powered electric motor, a first threaded drive with a first threaded spindle rotatably mounted on a housing body and a first threaded nut rotatably mounted on the first threaded spindle and rotationally fixed to the housing body via a bearing unit, and a coupling unit connectable to a tool holder for transmitting the tensile and compressive forces resulting from the direction of rotation of the first threaded spindle from the first threaded nut to the tool holder.In order to provide a mechanical force amplifier for a handheld pulling and pushing device, as well as a handheld pulling and pushing device that is easily and flexibly adaptable to different work processes, it is provided that the mechanical force amplifier has a connecting section for detachably fixing the mechanical force amplifier to a connection section of the housing body of the handheld pulling and pushing device and a tool connection for pulling and pushing tools.

Description

[0001] The invention relates to a hand-held pulling and pushing device and a mechanical power amplifier for a hand-held pulling and pushing device for driving pulling and pressing tools.

[0002] Hand-held pulling and pushing devices, i.e. devices that can be used by a single person in a mobile manner, such as hand-held, electric riveting and pressing devices for setting blind rivet elements, such as blind rivets and blind rivet nuts, or for carrying out punching processes and for setting punch rivets, which have a drive unit with an electric motor-driven threaded spindle of a screw drive, are known in a wide variety of designs from the prior art. The screw drive converts a rotary movement of the electric motor into a linear movement of the pulling or pressing tool in a known manner. When carrying out the setting process of a blind rivet element, for example, a pulling mandrel of the blind rivet element is moved axially.

[0003] The handheld pull and push devices described above are used, for example, in automotive workshops for carrying out repair work on vehicle bodies and for maintenance work on pipe or cable connections. Depending on the work to be performed, the pull and push devices may need to drive a wide variety of interchangeable tools, for example, with varying levels of force.

[0004] Known hand-held devices that enable the operation of both drawing and pressing tools have the disadvantage that their application possibilities are limited by the design of the device, in particular the screw drive and / or the drive unit.

[0005] Based on this, the object of the invention is to provide a mechanical force amplifier for a hand-held pulling and pushing device as well as a hand-held pulling and pushing device that can be easily and flexibly adapted to different work processes.

[0006] The invention solves this problem by a mechanical force amplifier having the features of claim 1 and by a hand-held pulling and pushing device having the features of claim 7. Advantageous further developments of the mechanical force amplifier are specified in claims 2 to 6. Furthermore, advantageous further developments of the hand-held pulling and pushing device are specified in claims 8 to 9.

[0007] The hand-held pulling and pushing device is connected via a coupling unit to a tool holder which is designed to interchangeably accommodate different pulling and pressing tools required for the respective application. When used as a pushing device, the tool holder can be designed, for example, to accommodate a rivet striker, which is used in conjunction with a rivet clamp arranged on the pushing device 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 accommodate corresponding pulling tools, whereby the pulling tools can, for example, have clamping means by means of which the tensile forces can then be transmitted.

[0008] The coupling unit is connected to the first threaded nut in such a way that both tensile and compressive forces resulting from the direction of movement of the first threaded spindle and the resulting linear adjustment of the first threaded nut are reliably transmitted to the coupling unit.

[0009] According to the invention, the pulling and pushing device is detachably connected to a mechanical force amplifier according to the invention or further developed as described below.

[0010] The pull-and-push device preferably has a switching unit that can be adjusted between a coupling position connecting the first threaded spindle to the drive unit and a decoupling position separating the first threaded spindle from the drive unit. The switching unit is understood to be a unit that is intended to connect the first threaded drive, which is decoupled from the drive unit, to the drive unit or to separate the first threaded drive, which is connected to the drive unit. The switching unit is preferably designed such that the first threaded drive can be decoupled from the drive unit manually or, particularly preferably, automatically.The switching unit enables the first screw drive to be decoupled from the drive unit, preventing the rotational movement of the electric motor from being transmitted to the first threaded spindle and thus blocking the linear adjustment of the first threaded nut and / or the coupling unit and / or the tool holder. Furthermore, by decoupling the first screw drive from the drive unit, the switching unit enables the torque of the electric motor to be tapped independently of the first screw drive, for example, by arranging a rotary shaft.

[0011] Characteristic of the mechanical force amplifier according to the invention (hereinafter referred to as force amplifier) ​​are a connecting section for releasably securing the mechanical force amplifier to a connection section of the housing body of the hand-held pulling and pushing device and a tool connection for pulling and pushing tools. A mechanical force amplifier is understood to be a unit designed to increase the pulling and pushing forces generated by the hand-held pulling and pushing device by mechanical means and to transmit them to a pulling or pushing tool. The force amplifier is preferably designed such that the torque generated by the drive unit of the pulling and pushing device is converted by means of the force amplifier into pulling and pushing forces that are higher than the pulling and pushing forces generated by the first screw drive.Particularly preferably, the power amplifier is connected to the drive unit of the pulling and pushing device in such a way that the torque of the drive unit is transmitted to the power amplifier and is converted by it into pulling and pushing forces.

[0012] The mechanical force amplifier allows for easy retrofitting of a handheld pull and push device limited by its original design, allowing it to be used with increased pressing force for different work processes. The force amplifier can be connected to a pull and push tool via the tool connection, so that the increased pull and push forces are transferred to the pull and push tool. Switching between the use of the pull and push forces generated by the pull and push device and the increased pull and push forces generated by the force amplifier can be easily achieved by disassembling and reassembling the force amplifier.

[0013] According to an advantageous development of the invention, the force amplifier has a coupling section for detachable connection to the first threaded spindle and / or the drive unit of the tension and compression device. Preferably, the force amplifier is connected via the coupling section to a rotary shaft of the tension and compression device connected to the drive unit. Particularly preferably, the first threaded spindle of the tension and compression device is designed as a hollow spindle for receiving the rotary shaft. The force amplifier is reliably connected via its coupling section to the first threaded spindle or, preferably, to the drive unit of the tension and compression device.

[0014] To amplify the force transmitted to the pull-and-push tool, the force amplifier can, in principle, be designed in any desired manner. However, according to an advantageous development of the invention, the force amplifier comprises a second screw drive with a second threaded spindle rotatably mounted on a base body and having the coupling section, and a second threaded nut rotatably mounted on the second threaded spindle and non-rotatably mounted on the base body via a support unit. The second threaded spindle of the force amplifier can preferably be rigidly connected to the first threaded spindle or the rotary shaft of the pull-and-push device via the coupling section.

[0015] The design of the second screw drive for converting the rotary movement of the drive unit of the hand-held pull-and-push device, in particular the rotary shaft, into a linear movement of the second threaded nut and thus of the pulling or pressing tool operatively connected to the second threaded nut is fundamentally freely selectable. The second screw drive is preferably designed such that a pulling or pressing force of 2-10 tons, preferably 4-8 tons, acts on the tool holder.

[0016] It is particularly preferred that the second 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, in contrast to trapezoidal screw drives, in which surfaces rub against each other, they have a particularly high level of efficiency. This allows the dimensions of the electric motor to be reduced in order to achieve the desired tensile forces or pressing pressures, so that the hand-held pulling and pushing device can be designed to be particularly compact. Typical thread pitches of ball screws or planetary screw drives are 5 to 10 mm. Preferably, the second threaded spindle has a pitch of 2-8 mm, particularly preferably 3-7 mm, and most preferably 4-6 mm. Particularly preferably, the second threaded spindle has a smaller pitch than the first threaded spindle of the hand-held pulling and pushing device.

[0017] According to an advantageous development of the invention, the force amplifier has a coupling element that can be connected to the tool holder for transmitting tensile and compressive forces resulting from the direction of rotation of the second threaded spindle from the second threaded nut to the tool holder. The tool holder is preferably operatively connected to the second threaded nut in such a way that tensile and compressive forces resulting from the direction of rotation of the second threaded spindle are transmitted to the tool holder. The necessary design of the coupling element with the threaded nut is fundamentally freely selectable. The coupling element is preferably designed like the coupling unit of the hand-held tensile and compressive device in order to enable a cost-effective construction for the force amplifier.

[0018] The tool holder is preferably removed from the pull-and-push device before installing the force amplifier and installed in the mechanical force amplifier after installation. The advantageously provided coupling element enables the transmission of the amplified pull and push forces to the tool holder arranged on the mechanical force amplifier and a pull and / or push tool connected to the tool holder in a simple and preferably cost-effective manner.

[0019] The support unit is preferably designed such that the second threaded nut and / or the coupling element connected to the second threaded nut in a rotationally fixed manner are supported in a rolling manner on the base body. The support unit preferably has at least one rolling element, via which the second threaded nut is supported in a rolling manner relative to the base body. This embodiment of the invention ensures increased efficiency by reducing losses due to friction. Furthermore, the use of a correspondingly developed support unit offers a particularly simple, play-free mounting of the second threaded nut, so that tensile and compressive forces are reliably transmitted.

[0020] The connection between the force amplifier and the tension and compression device can, in principle, be designed in any desired manner. According to an advantageous embodiment of the invention, the connecting section of the force amplifier has a thread or locking body for releasably securing it to the connecting section of the tension and compression device, which has a thread or locking body receptacles. A corresponding design of the connecting section enables a secure and easily releasable connection of the force amplifier to the tension and compression device without the need for additional components and / or securing elements. To release the connection between the force amplifier and the tension and compression device, it is only necessary to unscrew the thread or to release the locking connection.

[0021] The invention further solves the problem by the hand-held pulling and pushing device for driving interchangeable tools, with a drive unit having a battery-operated electric motor, a first screw drive with a first threaded spindle rotatably mounted on a housing body and a first threaded nut rotatably mounted on the first threaded spindle and non-rotatably mounted on the housing body via a bearing unit, and a coupling unit connectable to a tool holder for transmitting tensile and compressive forces resulting from the direction of rotation of the first threaded spindle from the first threaded nut to the tool holder, wherein the tensile and compressive device is detachably connected to a mechanical force amplifier according to the invention or further developed as described above.

[0022] The hand-held pulling and pushing device according to the invention enables not only the drive of mechanically driven pulling and pressing tools with the maximum force generated by the pulling and pushing device via the power amplifier, but also the drive with forces exceeding this maximum force, wherein, if necessary, it is possible to switch between an original drive by the pulling and pushing device and the increased drive via the power amplifier in a simple manner by connecting or disconnecting the power amplifier to the pulling and pushing device.

[0023] An embodiment of the invention is explained below with reference to the drawings. In the drawings: Fig.1 in a perspective view a schematic representation of a pulling and pushing device with a mechanical power amplifier arranged thereon; Fig.2 in a sectional view a schematic representation of the pulling and pushing device of Fig. 2 with the mechanical power amplifier arranged thereon; Fig. 3 in a perspective view a schematic representation of the mechanical power amplifier for the hand-held pulling and pushing device and Fig. 4 in a sectional view a schematic representation of the mechanical power amplifier of Fig.3 .

[0024] Figure 1 shows a perspective view of a schematic representation of a pulling and pushing device 1 with a drive unit 4 having an electric motor 3. By means of the electric motor 3, a first threaded spindle 7 of a first screw drive 5 is driven, wherein the first threaded spindle 7 is rotatably mounted on a housing body 6 (cf. Figure 2 ).

[0025] The first screw drive 5 has, in addition to the first threaded spindle 7, a first threaded nut 9 arranged on the first threaded spindle 7, which is mounted in a rotationally fixed manner on the housing body 6. The first threaded nut 9 serves to drive a tool holder designed as a piston rod 10, which is adjustably mounted in the longitudinal axis direction of the first threaded spindle 7, i.e. in the direction of the threaded spindle axis G. The piston rod 10 is connected to the first threaded nut 9 via a detachably connected coupling unit 11. A bearing unit 8, which is attached to the coupling unit 11, serves to mount the first threaded nut 9 on the housing body 6 in a rotationally fixed manner.

[0026] The hand-held pull and push device has a switching unit 13 for coupling and decoupling the first threaded drive 5 from the drive unit 4. The switching unit 13 has a sleeve 14 that is adjustable in the direction of the threaded spindle axis G. The switching unit 13 is adjustable between a coupling position connecting the first threaded spindle 7 with the drive unit 4 and a Figure 2 illustrated decoupling position separating the first threaded spindle 7 from the drive unit 3.

[0027] The first threaded spindle is designed as a hollow spindle 7 for receiving a rotary shaft 12 connected to the electric motor 3. The rotary shaft 12 is connected to the electric motor 3 in such a way that the rotary shaft 12 is rotatable independently of the switching unit 13 arranged in the coupled or uncoupled position. Furthermore, the rotary shaft 12 is arranged coaxially with the hollow spindle 7.

[0028] The switching unit 13 is arranged in the longitudinal direction of the hollow spindle 7 between the first screw drive 5 and the drive unit 4.

[0029] When the switching unit 13 is arranged in the coupling position, the torque generated by the electric motor 3 of the drive unit is transmitted via the sleeve 14 in a form-fitting manner to the hollow spindle 7 of the screw drive 5 and is converted by the screw drive 5 into a translational movement of the coupling unit 11 and of the piston rod 10 which is optionally connected to the coupling unit 11.

[0030] To adjust the switching unit 13 from the coupling position to the decoupling position, the sleeve 14 is adjusted relative to the first screw drive 5 along the threaded spindle axis G in the direction of the drive unit 4, thereby releasing the positive engagement of the sleeve 14 and the hollow spindle 7. In both positions, the torque of the electric motor 3 can be tapped via the rotary shaft 12 connected to the drive unit 4 and transmitted at the end of the rotary shaft 12 to a mechanical force amplifier 19 connected to the hand-held pull and push device 1.

[0031] The Figures 3 and 4The separately illustrated mechanical force amplifier 19 has a connecting section 20 for releasably securing the mechanical force amplifier 19 to a connecting section 21 of the housing body 6 of the hand-held pull-and-push device 1, and a tool connection 22 for pulling and pushing tools. The force amplifier 19 is connectable or connected to the rotary shaft 12 of the pull-and-push device 1 via a coupling section 23.

[0032] In addition, the force amplifier 1 has a second screw drive 24 with a second threaded spindle 26 rotatably mounted on a base body 25. To amplify the tensile and compressive forces transmitted to the piston rod 10, the second threaded spindle 26 has a smaller pitch than the hollow spindle 7 of the hand-held tensile and compressive device 1. The coupling section 23 is arranged on the second threaded spindle 26.

[0033] In addition to the second threaded spindle 26, the second screw drive 24 also has a second threaded nut 28 arranged on the second threaded spindle 26, which is mounted in a rotationally fixed manner on the base body 25 via a support unit 27. The second threaded nut 28 serves to drive the piston rod 10. The force amplifier 19 has a coupling element 29 that can be connected to the piston rod 10 and for transmitting tensile and compressive forces resulting from the direction of rotation of the second threaded spindle 26 from the second threaded nut 28 to the piston rod 10.

[0034] A change between the use of tensile and compressive forces generated by the tensile and compressive device 1 and the tensile and compressive forces increased by the force amplifier 19 can be carried out in a simple manner by disassembling and assembling the force amplifier 1, wherein the piston rod 10 is removed from the tensile and compressive device before assembly of the force amplifier 1 and is installed in the mechanical force amplifier 1 after assembly.

[0035] All features explained in connection with individual embodiments of the invention can be provided in different combinations for the mechanical force amplifier or the hand-held pull and push device in order to realize their advantageous effects, even if these have been described for different embodiments. For example, the screw drives of the pull and push device 1 and the mechanical force amplifier 19 are identical except for the differently designed threaded spindles 7, 26 in order to enable cost-effective and resource-saving production for the mechanical force amplifier. List of reference symbols

[0036] 1Pull and push device 3Electric motor 4Drive unit 5First screw drive 6Housing body 7First threaded spindle (hollow spindle) 8Bearing unit 9First threaded nut 10Tool holder (piston rod) 11Coupling unit 12Rotational shaft 13Switching unit 14Sleeve 15Adjusting element 19Mechanical power amplifier 20Connecting section 21Connecting section 22Tool connection 23Coupling section 24Second screw drive 25Base body 26Second threaded spindle 27Support unit 28Second threaded nut 29Coupling element GThreaded spindle axis

Claims

1. Mechanical force amplifier for a hand-held pulling and pushing device (1) with - a drive unit (4) having a battery-operated electric motor (3), - a first screw drive (5) with a first threaded spindle (7) rotatably mounted on a housing body (6) and a first threaded nut (9) rotatably mounted on the first threaded spindle (7) and non-rotatably mounted on the housing body (6) via a bearing unit (8), and - a coupling unit (11) connectable to a tool holder (10) for transmitting pulling and pushing forces resulting from the direction of rotation of the first threaded spindle (7) from the first threaded nut (9) to the tool holder (10), characterized by a connecting section (20) for releasably fixing the mechanical force amplifier (19) to a connecting section (21) of the housing body (6) of the hand-held pulling and pushing device (1) and a tool connection (22) for pulling and pushing tools.

2. Mechanical power amplifier according to claim 1, characterized by a coupling section (23) for detachable connection to the first threaded spindle (7).

3. Mechanical power amplifier according to claim 1 or 2, characterized by a second screw drive (24) with a second threaded spindle (26) which is rotatably mounted on a base body (25) and has the coupling section (23), and a second threaded nut (28) which is rotatably mounted on the second threaded spindle (26) and is rotationally fixed to the base body (25) via a support unit (27).

4. Mechanical power amplifier according to at least one of the preceding claims, characterized in that the second threaded spindle (26) has a smaller pitch than the first threaded spindle (7) of the hand-held pulling and pushing device (1).

5. Mechanical power amplifier according to at least one of the preceding claims, characterized bya coupling element (29) connectable to the tool holder (10) for transmitting tensile and compressive forces resulting from the direction of rotation of the second threaded spindle (26) from the second threaded nut (28) to the tool holder (10).

6. Mechanical power amplifier according to at least one of the preceding claims, characterized in that the connecting section (20) of the force amplifier (19) has a thread or locking body for releasably securing it to the connecting section (21) of the pulling and pushing device (1) which has a thread or locking body receptacles.

7. A hand-held pulling and pushing device for driving interchangeable tools, comprising - a drive unit (4) having a battery-operated electric motor (3), - a first threaded drive (5) with a first threaded spindle (7) rotatably mounted on a housing body (6) and a first threaded nut (9) rotatably mounted on the first threaded spindle (7) and non-rotatably mounted on the housing body (6) via a bearing unit (8), and - a coupling unit (11) connectable to a tool holder (10) for transmitting pulling and pushing forces resulting from the direction of rotation of the first threaded spindle (7) from the first threaded nut (9) to the tool holder (10), characterized by a mechanical force amplifier (19) according to at least one of claims 1 to 6, which is detachably connected to the pulling and pushing device (1).

8. Hand-held pulling and pushing device according to claim 7, characterized in thatthe first threaded spindle is designed as a hollow spindle (7) for receiving a rotary shaft (12) connected to the drive unit (4) and the mechanical power amplifier (1) is connected to the rotary shaft (12) via a coupling section (23).

9. Hand-held pulling and pushing device according to claim 7 or 8, characterized by a switching unit (13) adjustable between a coupling position connecting the first threaded spindle (7) to the drive unit (4) and a decoupling position separating the first threaded spindle (7) from the drive unit (4).

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