Fastener driving tool

Abstract

The invention relates to a pneumatic fastener driving tool (1) for driving a fastening element (2) into an anchoring base, comprising a clamping device (18), which has a traction element winch (19), for clamping a piston-cylinder unit (10) for driving the fastening element (2) into the anchoring base. The invention proposes a freewheel (49) as a reverse rotation blocking device for the traction element winch (19) and a coupling (26) that automatically engages and disengages a screw gear (29), which rotates together with the traction element winch (19), and a spring element (32) in order to rotationally drive the traction element winch (19).

Description

[0001] Description

[0002] Setting tool

[0003] The invention relates to a setting tool for driving a fastening element, such as a nail, into an anchor base made of, for example, wood or concrete, having the features of the preamble of claim 1. The setting tool is preferably a pushing tool, but a shooting tool or another setting tool is also possible.

[0004] A setting tool for driving a nail into an anchor base is known from patent application US 2021 / 0 146 517 A1. The known setting tool has a piston-cylinder unit as an energy storage device. The piston is moved into a cylinder by an electric motor via a cable winch, thereby compressing air in the cylinder. To drive the nail into the anchor base, a cable of the cable winch is released from a cable pulley of the cable winch, whereupon the compressed air in the cylinder pushes the piston out of the cylinder, whereby the piston moves the nail axially in a driving direction.

[0005] The object of the invention is to separate an electric motor of a traction winch for tensioning an energy storage device of a setting tool for driving a fastening element into an anchor base from the energy storage device when driving the fastening element into the anchor base.

[0006] This object is achieved according to the invention by a setting tool having the features of claim 1. The setting tool according to the invention comprises a driver for driving a fastening element into an anchor base made of, for example, wood or concrete. The driver is movable along a setting axis of the setting tool. The setting tool also comprises a tensionable energy storage device for moving the driver along the setting axis from a rear end position in a driving direction to a front end position, and a tensioning device for tensioning the energy storage device.

[0007] The tensioning device comprises a traction winch with a traction pulley and a traction device that can be wound onto the traction pulley, with which the energy storage device can be tensioned. The traction winch or tensioning device comprises an electric motor to drive the traction pulley.

[0008] The fastening element is, for example, a nail.

[0009] The term "driver" refers to an element of the setting tool according to the invention that is moved by the tensioned energy storage device along the setting axis in the driving direction to drive the fastening element into the anchor base, and that moves the fastening element along the setting axis in the driving direction. The driver can also be or comprise an assembly consisting of several components. It is therefore the element that transfers energy or movement from the energy storage device to the fastening element to drive the fastening element into the anchor base, and that applies pressure or moves it in the driving direction.

[0010] The energy storage device stores energy for driving the fastener into the anchor base in basically any desired form and transfers this energy, at least in part, to the driver. The energy storage device itself or a converter converts the stored energy into movement, i.e. into kinetic energy, unless the energy storage device stores the energy as kinetic energy. Storing energy in the energy storage device is referred to here as "tensioning" and discharging or transferring energy from the energy storage device to the driver is referred to as "relaxing" the energy storage device. The energy storage device can be completely relaxed when the fastener is driven into the anchor base. In particular, the energy storage device is partially relaxed when the fastener is driven into the anchor base and remains pre-tensioned at the end of the driving process.

[0011] The energy storage device is or comprises, for example, a spring element, in particular a helical compression spring or a piston-cylinder unit as a gas spring. A spring element or a helical compression spring is mechanically tensioned. To tension the piston-cylinder unit, a piston is moved into a cylinder of the piston-cylinder unit in such a way that a gas contained in the cylinder is compressed. Other energy storage devices are possible.

[0012] A traction winch is, in particular, a cable winch with a cable as the traction means. However, traction winches with, for example, a belt, a strap, a chain or another traction means that can be wound onto a traction means pulley are also possible. The traction means pulley is, for example, a cable wheel or traction means wheel onto which the traction means is wound in a helical manner, or a cable drum or traction means drum onto which the traction means can be wound helically, or a chain wheel. “Winding up” should also be understood to mean the traction means rotating around the traction means pulley by less than one complete turn, i.e., less than 360°, for example, 180°, or even more than one complete turn, through which a tensile force is exerted on the traction means when the traction means pulley is rotated.

[0013] According to the invention, the tensioning device has a releasable coupling which, in a connected coupling state, connects the electric motor to the traction mechanism pulley such that the traction mechanism pulley can be driven in rotation by the electric motor, and which, in a released coupling state, separates the traction mechanism pulley from the electric motor such that the traction mechanism pulley can be rotated independently of the electric motor. Between the electric motor and the traction mechanism pulley, the tensioning device can have a reduction gear via which the electric motor drives the traction mechanism pulley. The coupling can be arranged between the electric motor and the reduction gear, or between the reduction gear and the traction mechanism pulley, or even within the reduction gear.

[0014] An advantage of the invention is that the electric motor is separated from the traction roller when driving the fastening element into the anchor base and is therefore not moved by the energy storage device, whereby no energy from the energy storage device is lost for driving the electric motor when driving the fastening element into the anchor base.

[0015] Preferably, the coupling is self-releasing and automatically separates the traction roller from the electric motor when the driver reaches the rear end position when tensioning the energy storage device.

[0016] Preferably, the clutch is automatically power-shifting and disconnects the traction mechanism pulley from the electric motor when the torque is released. A torque that the clutch transmits to tension the energy storage device maintains the clutch in the connected coupling state when the energy storage device is tensioned. If the clutch is relieved of load to such an extent that it transmits no or at least only a reduced torque, it automatically transitions to the released coupling state. "Power-shifting" means that the clutch automatically transitions from the connected coupling state to the released coupling state when the torque is released. "Power-shifting" here therefore means that the clutch automatically releases when the torque is released.

[0017] Preferably, the coupling automatically enters the connecting coupling state when the driver reaches the front end position, such that the energy storage device can be tensioned again with the electric motor and the traction winch to drive a fastening element into the anchor base again.

[0018] For automatic switching of the clutch, one embodiment provides a helical gear that converts a rotation of the traction roller into a displacement that brings the clutch into the connecting clutch state in the front end position of the driver and / or into the released clutch state in the rear end position of the driver.

[0019] A further development of the invention provides a spring element for releasing the clutch, i.e., for bringing the clutch into the released clutch state, which spring element is tensioned by the helical gear when the traction mechanism is wound onto the traction mechanism pulley to tension the energy storage device, thereby releasing the clutch. A torque that the clutch transmits to the traction mechanism pulley of the traction mechanism winch when tensioning the energy storage device, preferably keeps the clutch engaged by a frictional connection within the clutch, i.e., in the connecting clutch state. If the clutch is relieved of torque in the rear end position of the driver, the spring element tensioned by the helical gear releases the clutch, i.e., the spring element tensioned by the helical gear brings the clutch into the released clutch state, whereby the traction mechanism pulley of the traction mechanism winch is separated from the electric motor.

[0020] A further development of the invention provides a spring element for engaging the clutch, i.e., for bringing the clutch into the connecting coupling state. This spring element is tensioned by the helical gear when the traction mechanism is unwound from the traction mechanism pulley, thereby engaging the clutch. A sliding lock prevents the clutch from engaging until the driver reaches its forward end position. When the driver reaches its forward end position, the sliding lock is released, whereupon the spring element, now tensioned to engage the clutch, engages the clutch, i.e., brings it into the connecting coupling state. The traction mechanism pulley can now be driven in rotation by the electric motor, the traction mechanism can be wound onto the traction mechanism pulley, and the energy storage device can thereby be tensioned.

[0021] Different spring elements or the same spring element can be used to release the clutch in the rear end position of the driver and to engage the clutch in the front end position of the driver.

[0022] After tensioning the energy storage device, and in particular during or after driving the fastening element into the anchor base, in one embodiment of the invention, the tensioning means is unwound from the tensioning means roller by a return spring, in order to subsequently tension the energy storage device by winding the tensioning means onto the tensioning means roller. The return spring is tensioned as the tensioning means is wound onto the tensioning means roller.

[0023] One embodiment of the invention comprises a claw clutch as an automatically releasing, automatically switching and / or power-switching clutch.

[0024] One embodiment of the invention features a freewheel as a reverse lock for the traction winch, preventing the traction winch from unwinding when the energy storage device is tensioned. The freewheel used as a reverse lock for the traction winch allows the electric motor for rotating the traction winch to be switched off when the energy storage device is tensioned. The freewheel used as a reverse lock prevents the traction winch from unwinding and keeps the energy storage device tensioned via the traction winch until a setting process of the setting tool is triggered. The setting process is initiated manually by a user of the setting tool.

[0025] Preferably, the freewheel of the setting tool according to the invention, used as a reverse rotation lock, locks the traction mechanism roller against rotation in a reverse direction opposite to the tensioning direction when the energy storage device is tensioned, i.e., prevents the traction mechanism from unwinding from the traction mechanism roller when the energy storage device is tensioned. It is possible for the freewheel used as a reverse rotation lock to lock the traction mechanism roller against reverse rotation even during tensioning of the energy storage device, or always.

[0026] One embodiment of the invention provides a pawl freewheel with a ratchet wheel and one or more pawls as a freewheel, i.e., a positive-locking freewheel. A force-locking or friction-locking freewheel, such as a (clamping) roller freewheel or a sprag freewheel, is also possible.

[0027] The features and combinations of features, embodiments and configurations of the invention mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or drawn in a figure can be used not only in the respective combination specified or drawn, but also in principle any other combinations or individually. Embodiments of the invention are possible which do not have all the features of a dependent claim. Individual features of a claim can also be replaced by other disclosed features or combinations of features. Embodiments of the invention which do not have all the features of the exemplary embodiment, but basically any part of the identified features of the exemplary embodiment, are possible.

[0028] The invention is explained in more detail below using an embodiment shown in the drawing.

[0029] They show:

[0030] Figure 1 shows a simplified and schematic axial section of a setting tool according to the invention;

[0031] Figure 2 is a perspective view of a clamping device, a driver and an energy storage device of the setting tool from Figure 1 according to the invention;

[0032] Figure 3 shows a part of the clamping device from Figure 2 in perspective; and

[0033] Figure 4 shows another representation of part of the clamping device from Figure 2.

[0034] The setting tool 1 according to the invention shown in Figure 1 is intended for driving a fastening element 2, such as the nail shown here, into an anchor base (not shown) made of, for example, wood or concrete. It has a setting axis 3 and a housing 4 that encloses the setting axis 3 and can be understood as cylindrical with a frustoconical taper towards a front end. The housing 4 has a handle 5 for holding the setting tool 1 with one hand. The handle 5 is arranged on the housing 4 almost radially to the setting axis 3, slightly behind a longitudinal center of the housing 4.

[0035] On a front side of the handle 5, the setting tool 1 has a trigger 6 for initiating a driving process, i.e., for starting the driving of the fastening element 2 into the anchor base. The trigger 6 is an operating element of the setting tool 1, movably arranged on the front side of the handle 5, with which the driving process can be initiated with a finger, in particular an index finger of a hand grasping the handle 5 and thereby holding the setting tool 1. The front side of the handle 5 points in a driving direction 16, or in the direction in which the fastening element 2 emerges from the setting tool 1 when driven into the anchor base.

[0036] Near a front end of the housing 4, the setting tool 1 has a magazine 8 for the fastening elements 2, from which the nails forming the fastening elements 2 are individually coaxially fed onto the setting axis 3 of the setting tool by means of a magazine spring 9.

[0037] 1.

[0038] Arranged coaxially to the setting axis 3 in the housing 4 is a piston-cylinder unit 10, the piston 11 of which has a coaxial ram 12 that projects forward, i.e., in the direction of the nail that forms the fastening element 2 and is moved from the magazine 8 onto the setting axis 3. In the exemplary embodiment, the piston 11 is a hollow, cylindrical piston that is closed at its front end, which has the ram 12, and is axially displaceable in a cylinder 13 of the piston-cylinder unit 10. The cylinder 13 of the piston-cylinder unit 10 is arranged coaxially and fixedly to the housing in the housing 4 of the setting tool 1. Together with the ram 12, the piston 11 forms a driver 14 of the setting tool 1 for driving the fastening element 2 into the anchor base (not shown).

[0039] The piston-cylinder unit 10 forms a tensionable energy storage device 15 of the setting tool 1 according to the invention for driving or moving the driver 14 in the driving direction 16 along the setting axis 3 for driving in the fastening element

[0040] 2 into the anchor base (not shown). The driving direction 16, like a tensioning direction 17 opposite it, is shown in Figure 1 with an arrow. In the exemplary embodiment, the setting tool 1 with the piston-cylinder unit 10 has a gas pressure spring or a pneumatic or gas pressure energy accumulator as the energy accumulator 15, which is tensioned by a displacement of the piston 11 into the cylinder 13, whereby air or gas is compressed in the cylinder 13, the pressure of which is used to move the piston 11 to drive the fastening element 2 into the anchor base. The compression of the air or gas in the cylinder 13 of the piston-cylinder unit 10 is referred to here as "tensioning" the energy accumulator 15 and can generally also be understood as storing energy in the energy accumulator 15.

[0041] The invention is not limited to the piston-cylinder unit 10 as energy storage 15, but the setting tool 1 according to the invention can also have another energy storage, in particular a helical compression spring also arranged coaxially to the setting axis 3 as a tensionable energy storage (not shown).

[0042] To tension the energy storage device 15, i.e., to store energy in the energy storage device 15, the setting tool 1 according to the invention has a tensioning device 18, which is shown in Figure 2. The tensioning device 18 tensions the energy storage device 15 by moving the piston 11 in the tensioning direction 17 opposite the driving direction 16. The tensioning device 18 displaces the piston 11 into the cylinder 13, thereby compressing the air or gas in the cylinder 13 and thereby tensioning the energy storage device 15. This would also be possible in the same way with, for example, a helical compression spring as the energy storage device 15 (not shown). Figure 2 shows the tensioning device 18 obliquely from the side, from below, i.e., from the direction of the handle 5.Traction winches 19 and an electric motor 24 of the tensioning device 18 are therefore located above the piston-cylinder unit 10 in Figure 2, whereas in Figure 1 they are located below it, i.e. on the side of the piston-cylinder unit 10 on which the handle 5 is also arranged.

[0043] In the exemplary embodiment, the tensioning device 18 has two traction winches 19, whose traction means 20 run in two tangential planes opposite one another with respect to the setting axis 3 of the setting tool 1 (Figure 2). The tangential planes are planes parallel to an axial plane of the setting axis 3 of the setting tool 1, laterally adjacent to and radially outside the piston-cylinder unit 10 and the driver 14. In the exemplary embodiment, the two tangential planes in which the traction means 20 of the two traction winches 19 run are located opposite one another with respect to the piston-cylinder unit 10. The traction winches 19 can, for example, be cable winches; in the exemplary embodiment of the setting tool 1 according to the invention, the two traction winches 19 are designed as pulley blocks with a 2:1 reduction ratio. The traction means 20 are ropes that can be wound on traction means rollers 21, which are arranged coaxially and rigidly with one another on a common, tubular hollow shaft 22.A rotation axis 23 of the two traction rollers 21 runs tangentially to the setting axis 3 of the setting device 1. In the exemplary embodiment, the traction rollers 21 are cable pulleys, but cable drums can also be used as traction rollers 21.

[0044] The hollow shaft 22 with the two traction rollers 21 is rotary-driven by the electric motor 24 via a spur gear 25 as a reduction gear, which is located on the right-hand side of the setting tool 1, as seen in the driving direction 16, in the housing 4 and the handle 5, and a claw coupling as a detachable coupling 26. The electric motor 24 is shown in Figure 2 with dashed lines so that it does not obscure the spur gear 25. The spur gear 25 is arranged in a tangential plane to the setting axis 3.

[0045] In the exemplary embodiment, the electric motor 24 and the traction rollers 21 of the traction winches 19 are located below the piston-cylinder unit 10 in the region of a transition from the housing 4 to the handle 5, as can be seen in Figure 1. "Below" or "below" refers to a peripheral region of the housing 4 in which the handle 5 is arranged. In Figures 2 to 4, the tensioning device 18 is drawn from below, i.e., viewed from the direction of the handle 5, which is why in Figures 2 to 4 the electric motor 24 and the hollow shaft 22 with the traction rollers 21 are located above the piston-cylinder unit 10 forming the energy storage device 15.

[0046] The hollow shaft 22 with the two traction rollers 21 is rotatably and axially displaceably arranged on a shaft 27 which is rotatably mounted in the housing 4 of the setting tool 1 and on which a last gear is arranged as an output gear 28 of the spur gear 25, which can be driven in rotation by the electric motor 24 via the spur gear 25.

[0047] The claw clutch forming the releasable clutch 26 is self-acting; for engagement and disengagement, it has a helical gear 29 with a spindle 30 and a nut 31, the nut thread of which is in threaded engagement with a screw thread of the spindle 30 (Figures 3 and 4). In the exemplary embodiment, the spindle 30 is a tubular hollow spindle which is coaxial with and rigid with the hollow shaft 22 and the traction rollers 21. The spindle 30, together with the hollow shaft 22 and the traction rollers 21, is rotatable and axially displaceable on the shaft 27 which is rotatably mounted in the housing 4 of the setting tool 1. "Engaging" here refers to bringing the clutch 26, designed here as a claw clutch, into a connecting coupling state, and "disengaging" refers to bringing the clutch 26 into a released coupling state.

[0048] The nut 31, which is threadedly engaged with the spindle 30, is held in a rotationally fixed manner by a spring element 32, which in the exemplary embodiment is designed as a U-shaped bow spring bent from a strip of spring sheet metal. One end of the spring element 32 is fixedly secured to the housing 4 of the setting tool 1 on a bearing block 56 of the spur gear 25, to which the electric motor 24 is also attached. The other end of the spring element 32 engages the nut 31 in a spring-loaded manner in the axial direction of the hollow shaft 22 and the shaft 27, thereby holding the nut 31 in a rotationally fixed manner.

[0049] A rotation of the traction means rollers 21 in the sense of winding the traction means 20 onto the traction means rollers 21, i.e. in a tensioning direction of the energy storage device 15, moves the nut 31 of the helical gear 29 with respect to the spindle 30 away from the traction means rollers 21 and in the direction of the output gear 28 of the spur gear 25. Conversely, a rotation of the traction means rollers 21 in the sense of unwinding the traction means 20 from the traction means rollers 21 moves the nut 31 with respect to the spindle 30 in the direction of the traction means rollers 21.

[0050] The coupling 26 is arranged coaxially to the hollow shaft 22 and the shaft 27 between the helical gear 29 and the output gear 28 of the spur gear 25. In the exemplary embodiment, the coupling 26 has a first coupling part 33 and a second coupling part 34, both of which are arranged coaxially to the hollow shaft 22 and the shaft 27. Both coupling parts 33, 34 have tower-shaped claws 57, 58, which are arranged on the circumferences of the coupling parts 33, 34 on the mutually facing end faces of the coupling parts 33, 34 and each protrudes in the direction of the other coupling part 34, 33. When the clutch 26 is engaged, that is, when the claw clutch is in the connecting clutch state, the claws 57, 58 of the two clutch parts 33, 34 engage between each other, whereby the two clutch parts 33, 34 are rotationally fixed to each other by the positive engagement of their claws 57, 58.When the claw clutch is engaged, i.e. in the connecting clutch state, one clutch part 33 transmits rotation and torque to the other clutch part 34. To disengage, the two clutch parts 33, 34 are moved axially apart until their claws 57, 58 disengage from each other, whereby the two clutch parts 33, 34 are rotatable relative to each other and the claw clutch is in the released clutch state.

[0051] The first coupling part 33 is rigidly arranged on the output gear 28 of the spur gear 25 and the second coupling part 34 is rigidly arranged on an end of the spindle 30 of the helical gear 29 remote from the traction means rollers 21 and facing the output gear 28.

[0052] When the traction means 20 are unwound from the traction means rollers 21, the nut 31 tensions the spring element 32 axially relative to the hollow shaft 22 and the shaft 27, engaging the claw clutch forming the releasable coupling 26. At the end of the unwinding of the traction means 20 from the traction means rollers 21, the spring element 32, via the nut 31, moves the spindle 30, together with the hollow shaft 22 with the two traction means rollers 21 and the second coupling part 34, which is arranged at the end of the spindle 30, axially relative to the first coupling part 33 such that the claws 57, 58 of the claw clutch move between one another and the claw clutch is engaged.The engaged claw clutch transmits rotation of the output gear 28 of the spur gear 25 via the spindle 30 of the helical gear 29 to the hollow shaft 22 with the traction mechanism rollers 21, such that the traction mechanism 20 for tensioning the energy storage device 15 can be wound onto the traction mechanism rollers 21 by a rotary drive of the spur gear 25 with the electric motor 24. The helical gear 29 and the spring element 32 form an engagement mechanism for automatically engaging the clutch 26 during unwinding or at the end of the unwinding of the traction mechanism 20 from the traction mechanism rollers 21.

[0053] From the traction means rollers 21, the traction means 20 run around housing-fixed deflection rollers 35 and then axially parallel to the setting axis 3 and then around axially movable deflection rollers 36 and from the axially movable deflection rollers 36 (Figure 2) back axially parallel, where the traction means 20 are fixed in the housing 4 of the setting tool 1. The movable deflection rollers 36 are rotatably mounted on two tensioning carriages 37, which are guided on both sides of the piston-cylinder unit 10 so as to be displaceable axially parallel in the housing 4. The movable deflection rollers 36 are rotatably mounted on or in the two tensioning carriages 37 about a common axis, which intersects the setting axis 3 of the setting tool 1 at a right angle.

[0054] When the traction means 20 are wound onto the traction means rollers 21, the traction means 20 pull the tensioning carriages 37 in the tensioning direction 17. Claws 38 projecting inwards from the tensioning carriages 37 in the direction of the setting axis 3 engage over the closed, front end of the piston 11, as a result of which, when the tensioning carriages 37 are pulled in the tensioning direction 17, the piston 11 is moved into the cylinder 13 and in this way tensions the energy storage device 15. The traction means 20 rotating around the movable deflection rollers 36, together with the movable deflection rollers 36 and the tensioning carriages 37, form the pulleys of the tensioning device 18 for tensioning the energy storage device 15. They reduce a tensioning force with which the traction means 20 are wound onto the traction means rollers 21 - in the exemplary embodiment 2:1.

[0055] Because the rotational axis of the movable deflection rollers 36 radially intersects the setting axis 3 of the setting device 1 and the claws 38 of the clamping slides 37 are arranged at circumferential points opposite to the setting axis 3 on the front end of the driver

[0056] 14 forming piston 11, clamping forces with which the claws 38 engage the piston 11 forming the driver 14 when tensioning the energy storage device 15 are balanced out in such a way that the piston 11 is tensioned radially to the setting axis 3 free from a tilting moment about a radial axis of the piston 11.

[0057] When the piston 11 forming the driver 14 reaches a rear end position, pins 39 projecting from the clamping slides 37 come into contact with inclined surfaces 40 of a release device 41 which extend obliquely to the setting axis 3 and which extend obliquely away from the setting axis 3 in the clamping direction. When the driver 14 reaches its rear end position, the inclined surfaces 40 of the release device 41 move the clamping slides 37 outwards away from the setting axis 3, whereby the claws 38 are disengaged from the piston 11 forming the driver 14, whereby the driver 14 is released from the energy storage

[0058] 15 is moved in the driving direction 16.

[0059] When the traction means 20 are wound up, a torque acts between the two coupling parts 33, 34 which is so great that it keeps the two coupling parts 33, 34 engaged by frictional engagement between their claws 57, 58, even if a spring force of the spring element 32 acts axially on the second coupling part 34 via the screw gear 29 in the sense of disengaging the claw coupling.

[0060] When the disengagement device 41 moves the two tensioning slides 37 outward upon reaching the rear end position of the driver 14 and thereby disengages the claws 38 of the tensioning slides 37 from the piston 11 forming the driver 14, the tensioning means 20 and thus also the tensioning means rollers 21 are relieved, whereby the clutch 26 becomes torque-free. The spring element 32, preloaded by the winding of the tensioning means 20 onto the tensioning means rollers 21 in the sense of disengaging the claw clutch, displaces the hollow shaft 22 with the tensioning means rollers 21, together with the helical gear 29 and the second clutch part 34 arranged on the spindle 30 of the helical gear 29, away from the output gear 28 of the spur gear 25 and thereby disengages the claws 57, 58 of the two clutch parts 33, 34 of the clutch 26.

[0061] The claw clutch forming the automatically releasing clutch 26 releases automatically when the rear end position of the driver 14 is reached by relieving the torque required to wind up the traction means 20 onto the traction means rollers 21 for tensioning the energy storage device 15.

[0062] The traction means 20 are unwound from the tensioning carriages 37 from the traction means rollers 21, which, during movement in the tensioning direction 17 when tensioning the energy storage device 15, tension return springs 42, which engage the tensioning carriage 37 via return cables 44 circulating around deflection rollers 43. If the claw clutch disengages upon reaching the rear end position of the driver 14, the return cables 44 move the tensioning carriages 37 in the driving direction 16 to the front end position, unwinding the traction means 20 from the traction means rollers 21 and thereby causing the traction means rollers 21 to rotate.

[0063] The rotation of the traction means rollers 21 during the unwinding of the traction means 20 moves the nut 31 in relation to the spindle 30 of the helical gear 29 away from the output gear 28 of the spur gear 25 and away from the coupling 26 and towards the traction means rollers 21. The spring element 32 is relaxed and preloaded in the opposite direction in the direction of engagement of the claw coupling.

[0064] Next to one of the two traction rollers 21, a roller 45 is arranged on a shaft 46, which is arranged radially to the traction roller 21 and is spring-loaded and movable radially to the traction roller 21. In its position shown in Figure 3, the roller 45 prevents the movement of the traction roller 21 axially in the direction of the clutch 26 and thereby prevents the engagement of the claws 57, 58 of the clutch 26.

[0065] Upon reaching the front end position, the tensioning slides 37 strike a releaser 47, which is movable a few millimeters parallel to the axis and, via a release cable 48, pulls the roller 45 radially far enough away from the axis of the traction mechanism roller 21 that the traction mechanism roller 21 can pass axially past the roller 45. The spring element 32 re-engages the claws 57, 58 of the clutch 26 so that the traction mechanism 20 can be wound back onto the traction mechanism rollers 21 and the energy storage device 15 can thus be tensioned again.

[0066] In the front end position, the clamping slides 37 move inwards again, whereby their claws 38 engage over the front end face of the piston 11 in such a way that the piston 11 or the energy storage device 15 can be tensioned again.

[0067] The tensioning of the energy storage device 15 is terminated before the driver 14 reaches its rear end position, before the release device 41 moves the tensioning slides 37 outward and disengages their claws 38 from the driver 14. The setting tool 1 remains with the tensioned energy storage device 15 until the trigger 6 is pulled. By pulling the trigger 6, the electric motor 24 is energized again in the tensioning direction 17. It moves the driver 14 to its rear end position, where the release device 41 moves the tensioning slides 37 outward, whereupon the energy storage device 15 moves the driver 14 in the driving direction 16.

[0068] In order to be able to switch off the electric motor 24 when the energy storage device 15 is tensioned, the tensioning device 18 has a freewheel 49 as a reverse rotation lock. A freewheel is a clutch that acts only in one direction of rotation and transmits torque only in one direction of rotation. In the setting tool 1 according to the invention, the freewheel 49 used as a reverse rotation lock prevents the traction means 20 from unwinding from the traction means rollers 21 by the tensioned energy storage device 15, which pulls on the traction means 20 via the driver 14 when it is tensioned, if and as long as the claw clutch used as the automatically releasing clutch 26 in the exemplary embodiment of the invention is engaged.

[0069] The embodiment of the invention uses a positive locking pawl freewheel 49, but non-positive clamping roller or clamping body freewheels (not shown) can also be used.

[0070] In the exemplary embodiment, the output gear 28 of the spur gear 25 is part of the freewheel 49: it has a spur gearing 50 with sawtooth-shaped teeth, with which one or more - in the exemplary embodiment two - pawls 51 interact, which are pivotally mounted about pivot axes 52 fixed to the housing in such a way that they can engage with the teeth of the spur gearing 50 of the output gear 28. Pawl springs 53 urge the pawls 51 into engagement with the teeth of the spur gearing 50 of the output gear 28 in such a way that the output gear 28 cannot rotate in the unwinding direction of the traction means rollers 21. When the clutch 26 is engaged, the traction means 20 cannot be unwound from the traction means rollers 21, and the energy storage device 15 remains tensioned even when the electric motor 24 is switched off.

[0071] During rotation in the winding direction, the teeth of the spur gear 50 of the output gear 28 of the spur gear 25, due to their sawtooth shape, push the pawls 51 out of engagement such that the output gear 28 of the spur gear 25 can rotate in the winding direction. Via the engaged clutch 26, the traction rollers 21 rotate in the winding direction with the output gear 28. Due to its spur gear 50 with the sawtooth-shaped teeth, the output gear 28 of the spur gear 25 can also be considered a ratchet wheel 55 of the freewheel 49. The spur gear 50 with the sawtooth-shaped teeth can also be considered a locking gear or a circumferential locking gear.

[0072] In the exemplary embodiment, the freewheel 49 has two pawls 51 which are arranged such that they engage at two opposite points in the spur gearing 50 of the output gear 28 of the spur gear 25. The spur gearing 50 has an odd number of teeth, so that the two pawls 51 are offset from one another with respect to the teeth of the spur gearing 50 by half a number of teeth and half a tooth in the circumferential direction of the spur gearing 50. As a result, the freewheel 49 allows a maximum of one rotation by half the distance between the teeth of the spur gearing 50 in the reverse direction. This is also possible with an even or odd number of teeth on the spur gearing 50 by the engagement points of the two pawls 51 in the spur gearing 50 being offset from one another in the circumferential direction by any desired number of whole teeth and half a tooth spacing of the spur gearing 50 (not shown).With more pawls 51, the maximum reverse rotation of the traction rollers 21 can be further reduced accordingly.

[0073] When the energy storage device 15 is tensioned, the electric motor 24 is switched off shortly before the driver 14 reaches its rear end position, i.e., before the inclined surfaces 40 of the disengaging device 41 direct the tensioning slides 37 outwards, thereby disengaging their claws 38 from the piston 11 of the piston-cylinder unit 10 of the energy storage device 15 that forms the driver 14. If the trigger 6 is actuated with the driver 14 shortly before its rear end position and the energy storage device 15 tensioned, the electric motor 24 is switched on again, rotating in the winding direction. This retracts the driver 14 to its rear end position, whereby the inclined surfaces 40 of the disengaging device 41 direct the tensioning slides 37 outwards, thereby disengaging the claws 38 of the tensioning slides 37 from the piston 11 that forms the driver 14.The tensioned energy storage device 15 moves the driver 14 in the driving direction 16 into its front end position, wherein the driver 14, via its plunger 12, moves the nail brought from the magazine 8 onto the setting axis 3 or, in general, the fastening element 2 in the driving direction 16.

[0074] By separating the claws 38 of the tensioning slides 37 from the piston 11, the tensioning means 20 are relieved, whereby the clutch 26 becomes torque-free. As described above, the claws 57, 58 of the clutch 26 disengage automatically due to the torque relief, whereby the hollow shaft 22 with the tensioning means rollers 21 can rotate freely on the shaft 27. The return springs 42, which are tensioned when the energy storage device 15 is tensioned, move the tensioning slides 37 in the driving-in direction 16 to the front end position, whereby the tensioning slides 37 unwind the tensioning means 20 from the tensioning means rollers 21. By unwinding, the helical gear 29 pre-tensions the spring element 32 in the engagement direction of the clutch 26, whereby the roller 45, which rests against the end face of one of the tensioning means rollers 21, prevents engagement of the claw clutch.

[0075] In the front end position, the claws 38 of the tensioning slides 37 re-engage with the piston 11 forming the driver 14, and the tensioning slides 37 pull the roller 45 via the releaser 47 and the release cable 48 radially outside a circumference of the traction mechanism roller 21 such that the traction mechanism rollers 21 can again be displaced axially in the direction of the output gear 28 of the spur gear 25. The spring element 32, pre-tensioned in the engagement direction by the helical gear 29, engages the clutch 26, and the electric motor 24, which has been rotating in the tensioning direction since the trigger 6 was actuated, winds the traction mechanism 20 back onto the traction mechanism rollers 21, thereby re-tensioning the energy storage device 15. The electric motor 24 is switched off shortly before the driver 14 reaches its rear end position. There is no reversal of the direction of rotation of the electric motor 24; the electric motor 24 rotates exclusively in the tensioning direction.An accumulator as an electrical energy storage device 54 for supplying power to an electric motor 24 of the setting tool 1 is detachably arranged at an end of the handle 5 remote from the setting axis 3.

[0076] List of reference symbols

[0077] Setting tool Setting tool 30 Spindle Fastening element 31 Nut Setting axis 32 Spring element Housing 33 First coupling part Handle 34 Second coupling part Trigger 35 Housing-fixed deflection pulley Free 36 Movable deflection pulley Magazine 37 Tensioning slide Magazine spring 38 Claw Piston-cylinder unit 39 Pin Piston 40 Inclined surface Tappet 41 Release device Cylinder 42 Return spring Driver 43 Deflection pulley Energy storage 44 Return cable Driving direction 45 Roller Tensioning direction 46 Shaft Tensioning device 47 Releaser Traction mechanism winch 48 Release cable Traction mechanism 49 Freewheel Traction mechanism pulley 50 Spur gear Hollow shaft 51 Pawl Rotation axis 52 Pivot axis Electric motor 53 Pawl spring Spur gear 54 Electrical energy storage Clutch 55 Ratchet wheel Shaft 56 Bearing block Output gear 57 Claw Screw gear 58 Claw

Claims

Claims: Setting device (1) for driving a fastening element (2) into an anchor base, comprising a driver (14) movable along a setting axis (3) and with which the fastening element (2) is movable in a driving direction (16) for driving into the anchor base, comprising a tensionable energy storage device (15) which moves the driver (14) for driving the fastening element (2) into the anchor base from a rear end position in the driving direction (16) to a front end position along the setting axis (3) and relaxes in the process, and comprising a tensioning device (18) for tensioning the energy storage device (15), comprising an electric motor (24), a traction winch (19) with a retractable traction element (20) and a traction element pulley (21) onto which the traction element (20) can be wound and which tensions the energy storage device (15) when wound onto the traction element pulley (21), characterized in that the tensioning device (18) has a detachable coupling (26),The setting device (1) according to claim 1, characterized in that the clamping device (18) has a self-disengaging clutch (26) which automatically disconnects the traction roller (21) from the electric motor (24) when the rear end position of the driver (14) is reached. The setting device (1) according to claim 1, characterized in that the clamping device has a load-switching clutch (26) which disconnects the traction roller (21) from the electric motor (24) when torque is released. Setting device (1) according to one or more of claims 1 to 3, characterized in that the clamping device (18) has a self-engaging clutch (26) which automatically enters the engaged clutch state when the driver (14) reaches its forward end position. Setting device (1) according to claim 2, characterized in that the clamping device (18) has a screw drive (29) which converts a rotation of the traction roller (21) into a displacement that moves the clutch (26) into the engaged clutch state and / or into the disengaged clutch state.Setting device (1) according to claim 5, characterized in that the screw drive (29) is driven by the traction roller (21) in a rotating manner, that the tensioning device (18) has a spring element (32) for releasing the coupling (26), which is tensioned by the screw drive (29) when the traction element (20) is wound onto the traction roller (21) and acts on the coupling (26) in the direction of releasing, and that a torque applied to the coupling (26) holds the coupling (26) against a spring force of the spring element (32) in the connecting coupling state.Setting device (1) according to claim 5 or 6, characterized in that the screw drive (29) is driven by the traction roller (21) in a rotary manner, that the tensioning device (18) has a spring element (32) for connecting the coupling (26), which is tensioned by the screw drive (29) when the traction element (20) is unwound from the traction roller (21) and acts on the coupling (26) in the direction of connecting, and that the tensioning device (18) has a releasable sliding lock for the screw drive (29), which in a locking position prevents a displacement of the screw drive (29) that would bring the coupling (26) into the connecting coupling state and which, when the front end position of the driver (14) is reached, enters a release position in which displacement of the coupling (26) by the screw drive (29) is possible.Setting device (1) according to claims 6 and 7, characterized in that the clamping device (18) has a spring element (32) for both releasing and engaging the clutch (26). Setting device (1) according to one or more of the preceding claims, characterized in that the traction roller (21) and / or at least a part of the coupling (26) is axially movable. Setting device (1) according to one or more of the preceding claims, characterized in that the setting device (1) has a return spring (42) which unwinds the traction element (20) from the traction roller (21) when the traction roller (21) is rotatable in an unwinding direction. Setting device (1) according to one or more of the preceding claims, characterized in that the clamping device (18) has a jaw coupling as a releasable coupling (26). Setting device (1) according to one or more of the preceding claims, characterized in that the clamping device (18) has a freewheel (49) as a back-rotation lock for the traction roller (21), which locks the traction roller (21) against rotation in an unwinding direction of the traction element (20) from the traction roller (21).

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