EP3083150B1 - Work device - Google Patents

Description

Technical area

The invention relates to a working device for driving a fastener into a substrate.

State of the art

Work tools for driving fasteners into substrates often comprise a guide channel for the fastener, a piston which is drivable for transmitting energy to the arranged in the guide channel fastener from a starting position in which the piston is at rest, to the fastener to drivable, and a feed device for transporting the fastening element in the guide channel. There are also tools with a feed delay device for delaying the transport of the fastener in the guide channel known.

From the WO 2005/095064 A1 For example, a portable tacker is known which comprises a spool-shaped magazine and a motor for transporting nails in the magazine in front of a drive rod. The motor does not turn until the drive rod has moved all the way back.

From the US 2011/0240709 A1 a tacker is known which comprises a magazine and a transport unit for transporting screws in the magazine into a drive-in channel. The transport unit transports the screws as soon as the tacker is pressed against a substrate.

From the EP 1 882 555 A1 a hammer tool is known, which has a transport cylinder with a transport piston for transporting nails into a drive-in channel. The transport cylinder is connected via a valve with a combustion chamber. The valve opens after or just before a percussion piston has moved completely back.

In the DE 10 2007 000 025 is a hand-held setting described, in which the piston actuates the feed device when he has moved back after a setting process behind the guide channel. However, there is a risk that the piston reciprocates and actuates the feed device several times or allows a feed multiple times, so that several fasteners may be located in the guide channel at the same time, which can lead to a clogging of the guide channel.

The object of the invention is to provide a working device, in which the risk of such a blockage is reduced.

Presentation of the invention

The object is achieved by a working device for driving a fastening element into a base, with a guide channel for the fastening element, with a piston, which is used for transmitting energy to the arranged in the guide channel fastener from a starting position in which the piston is at rest, is drivable on the fastener, with a feed device for transporting the fastener into the guide channel, and with a feed delay means for delaying the transport of the fastener in the guide channel until the piston is returned to a home operation in the starting position. This ensures that the feed of the fastener is delayed until a possibly existing reciprocating movement of the piston is completed.

According to an advantageous embodiment, the feed delay device has a release position in which it allows the transport of the fastener into the guide channel, when the piston is arranged in the starting position, and a locking position in which it blocks the transport of the fastener into the guide channel when the piston is arranged outside the initial position, on.

According to an advantageous embodiment, the working device has a detection device for querying whether the piston is arranged in the starting position.

According to an advantageous embodiment, the working device to a drive means for driving the piston to the fastener to, and a trigger whose operation triggers the driving of the piston to the fastener on.

According to an advantageous embodiment, the working device has a pressing device for querying whether the working device is pressed against a substrate, which is in a contact pressure position when the working device is pressed against a substrate. Preferably, the pressing device allows the driving of the piston on the fastener to only in the Anpressstellung. Also preferably, the drive device has a combustion chamber, which is clamped by the pressing device when the implement is pressed against a substrate. Particularly preferably, the detection device allows a collapse of the clamped combustion chamber after a drive-in until the piston is arranged in the starting position, whereas the detection device blocks the collapse of the clamped combustion chamber when the piston is not arranged in the starting position.

According to an advantageous embodiment, the feed delay device is transported from the release position to the blocking position when the implement is pressed against a substrate and / or when the combustion chamber is clamped. According to a further advantageous embodiment, the feed delay device is conveyed from the blocking position to the release position when the combustion chamber collapses.

According to an advantageous embodiment, the implement on a magazine for receiving the fastener, wherein the feed device is provided for transporting the fastener from the magazine in the guide channel.

According to an advantageous embodiment, the feed delay device has a lever which protrudes in the blocking position in the transport path of the fastening element or abuts against the fastening element, and which is spaced in the release position of the transport path and the fastening element. Preferably, the lever has a contact surface for a non-positive and / or positive engagement with the fastening element. Also preferably, the lever is designed as a pivot lever. Particularly preferably, the lever is rotatable about a rotation axis on a housing and / or a nose of the working device, in particular mounted on the guide channel or on the magazine.

embodiments

Fig.1

einen schematischen Axialschnitt durch ein Arbeitsgerät mit kollabierten Teil-Brennkammern,

Fig. 2

einen schematischen Axialschnitt durch das Arbeitsgerät nach Fig. 1 im angepressten Zustand mit aufgespannten Teil-Brennkammern,

Fig. 3

einen schematischen Axialschnitt durch das Arbeitsgerät nach Fig. 2 während der Zündung,

Fig. 4

einen schematischen Axialschnitt durch das Arbeitsgerät nach Fig. 3 während der Rückkehr des Kolbens,

Fig. 5

einen schematischen Axialschnitt durch das Arbeitsgerät nach Fig. 4 nach der Rückkehr des Kolbens,

Fig. 6

einen schematischen Axialschnitt durch das Arbeitsgerät nach Fig. 5 während des Kollabierens der Teil-Brennkammern,

Fig. 7

eine Nase eines Arbeitsgeräts in einer Seitenansicht,

Fig. 8

eine Nase eines Arbeitsgeräts in einer Seitenansicht,

Fig. 9

eine Nase eines Arbeitsgeräts in einer Seitenansicht,

Fig. 10

eine Nase eines Arbeitsgeräts in einer Schrägansicht,

Fig. 11

eine Nase eines Arbeitsgeräts in einer Schrägansicht,

Fig. 12

eine Vorschubverzögerungseinrichtung, und

Fig. 13

eine Vorschubverzögerungseinrichtung.

The invention will be explained in more detail below with reference to embodiments with reference to the drawings. Show it:

Fig.1

a schematic axial section through a working device with collapsed partial combustion chambers,

Fig. 2

a schematic axial section through the implement after Fig. 1 in the pressed state with clamped part combustion chambers,

Fig. 3

a schematic axial section through the implement after Fig. 2 during the ignition,

Fig. 4

a schematic axial section through the implement after Fig. 3 during the return of the piston,

Fig. 5

a schematic axial section through the implement after Fig. 4 after the return of the piston,

Fig. 6

a schematic axial section through the implement after Fig. 5 during the collapse of the partial combustion chambers,

Fig. 7

a nose of a working device in a side view,

Fig. 8

a nose of a working device in a side view,

Fig. 9

a nose of a working device in a side view,

Fig. 10

a nose of a working device in an oblique view,

Fig. 11

a nose of a working device in an oblique view,

Fig. 12

a feed delay device, and

Fig. 13

a feed delay device.

Fig. 1 shows an axial section through a combustion-powered fastener setting device in the region of its combustion chamber. According to Fig. 1 the setting tool includes a cylindrically shaped combustion chamber 1 with a cylinder wall 2 and an adjoining annular bottom wall 3a, 3b. In the center of the bottom wall 3a, 3b is an opening 4a, 4b, to which a guide cylinder 5 connects, which has a cylinder wall 6 and a bottom wall 7. Within the guide cylinder 5, a piston 8 is slidably mounted, in the cylinder longitudinal direction of the guide cylinder 5. The piston 8 consists of a piston plate 9, which faces the combustion chamber 1, as well as from a centrally connected to the piston plate 9 piston rod 10, through a Through hole 11 protrudes in the bottom wall 7 to a part of the guide cylinder 5.

In Fig. 1 is the piston 8 in its returned rest position or starting position in which the setting device is not in operation. The combustion chamber 1 facing side of the piston plate 9 closes more or less with the inside of the bottom wall 3a, 3b, and the piston rod 10 projects beyond the bottom wall 7 only a little outward. The piston plate 9 tapers stepwise toward the combustion chamber 1, with the smaller diameter part coming to lie in the opening 4b and the larger diameter part in the opening 4a. The part of the piston plate 9 with a larger diameter thus beats against the bottom plate 3b, which thus serves as a stop for the piston plate 9, when the piston 8 is in its initial position. Not shown sealing rings on the outer circumference of the piston plate 9 may be provided to seal the spaces 9 on both sides of the piston plate 9 against each other. Within the combustion chamber 1 is a cylinder plate 14, which may be referred to as a combustion chamber wall. The combustion chamber wall 14 is displaceable in the longitudinal direction of the combustion chamber 1 and has on its outer peripheral edge an annular seal in order to seal the spaces in front of and behind the combustion chamber wall 14. Furthermore, the combustion chamber wall 14 has a central passage opening 16 with an annular peripheral seal.

Between the combustion chamber wall 14 and the bottom wall 3b is another partition plate 18. The partition plate 18 is also circular in shape and has an outer diameter corresponding to the inner diameter of the combustion chamber 1. On the side facing the combustion chamber wall 14, the partition plate 18 is connected to a cylindrical projection 19, which protrudes through the central passage opening 16 of the combustion chamber wall 14 and whose length corresponds to a multiple of the thickness of the combustion chamber wall 14. Said circumferential seal along the passage opening 16 nestles close to the outer circumferential surface of the cylindrical projection 19. At its upper end, the cylindrical projection 19 has an annular projection 20 projecting beyond its circumference. The outer diameter of the annular projection 20 is greater than the inner diameter of the passage opening 16. At the edge of the passage opening 16 is connected to the combustion chamber wall 14, a hollow cylindrical projection 17 which surrounds the cylindrical projection 19. The free end of the hollow cylindrical projection 17 lies opposite the lower side of the annular projection 20 and in Fig. 1 in the distance to this. A connected to the cylinder wall 2 web 2a serves as a stop for the projection 19 and thus for positioning the associated with the projection 19 partition plate 18 during clamping of the combustion chamber. The web 2a is only in Fig. 1 fully shown and in the other illustrations in Fig. 2 to 6 omitted for the sake of clarity.

At rest of the implement according to Fig. 1 is the partition plate 18 on the bottom wall 3b and the combustion chamber wall 14 on the partition plate 18. The combustion chamber. 1 is then completely collapsed. When attaching the device against an object, not shown, in which a fastener is to be driven, as will be explained later, the combustion chamber wall 14 is raised and thus moves away from the partition plate 18 and the bottom wall 3b. The combustion chamber wall 14 thus takes after a certain time on the annular projection 20, the partition plate 18 with. In this case, then the combustion chamber wall 14 and the partition plate 18 are at a predetermined distance from each other, which is determined by the position of the annular projection 20. In this case, then the combustion chamber wall 14 and the partition plate 18 form a so-called prechamber. This is a part-combustion chamber of the combustion chamber 1. This pre-chamber carries the reference numeral 21 in Fig. 2 , If the combustion chamber wall 14 is raised even further, the combustion chamber wall 14 and partition plate 18 move parallel to one another, so that between the partition plate 18 and the bottom wall 3b or piston plate 9 spans a further partial combustion chamber, which is referred to as the main chamber. This partial combustion chamber or main chamber carries the reference numeral 22 in Fig. 2 , In Fig. 2 the state is shown in which both partial combustion chambers 21 and 22 are fully clamped. Now suggests the approach 19 against the stop or ridge 2a.

For displacement of the combustion chamber wall 14 in the longitudinal direction of the combustion chamber 1 are distributed with the combustion chamber wall 14 over its circumference at equal angular intervals z. B. three drive rods 23 fixedly connected, of which only one can be seen in the drawing. The drive rods 23 are parallel to the cylinder longitudinal axis of the combustion chamber 1 and the outside of the cylinder wall 6. The drive rods 23 pass through a respective through hole 24 in the partition plate 18 and a further through hole 25a, 25b in the bottom wall 3a, 3b. This through-opening 25a, 25b is simultaneously formed as a valve opening and has a conical shape in the area 25a. The drive rods 23 and the combustion chamber wall 14 are z. B. connected in a suitable manner by means of screws, while the free ends of the drive rods 23 are connected to each other via a drive ring 28 which is concentric with the cylinder axis of the combustion chamber and the guide cylinder 5 engages around. Also, the drive ring 28 may be bolted to the drive rods 23 via screws. Between the drive ring 28 and the outside fixedly attached to the cylinder wall 6 lugs 26, passes through each one of the drive rods 23, is located on each of the drive rods 23, a compression spring 27 which is supported on the respective lug 26 and presses against the drive ring 28. These compression springs 27 are therefore anxious to always press the combustion chamber wall 14 in the direction of the bottom wall 3b.

As already mentioned, in the area of the annular bottom wall 3a, 3b, the passage opening 25a, 25b serving as a valve opening, which widens conically outside (25a), is located. In this valve opening a valve stem 32 is sealingly inserted. This valve stem 32 is located at open valve opening 25a, 25b outside the combustion chamber 1 and below the bottom wall 3a and is blocked in this position via a guide cylinder 5 attached to the projection 33a. Between the valve stem 32 and the edge of the opening 25a is a compression spring 33b, which presses the valve stem 32 against the projection 33a. If the drive ring 28 is displaced in the direction of the bottom wall 3a, a projection 33 fastened to the drive rod engages the valve stem 32 and inserts it against the pressure of the spring 33b into the valve opening 25a, 25b to close the valve, which is the reference numeral 34 carries. This is an inlet / outlet valve. In this case, the approach 33 passes through an opening 33c present in the projection 33a.

It should also be mentioned that the partition plate 18 has a plurality of through openings 38 on the circumference, each of which can have the same distance from the cylinder axis of the combustion chamber 1. Further, at the lower end of the guide cylinder 5 are outlet ports 39 for discharging air from the guide cylinder 5 when the piston 8 is moved toward the bottom wall 7. At the lower end of the guide cylinder 5 is also a damping device 40 for damping the movement of the piston 8. If the piston 8 passes over the outlet openings 39, exhaust gas can escape from the outlet openings 39. In the cylinder wall 2 of the combustion chamber 1 are still two radial through holes 41 and 42, which are spaced apart in the axial direction. About them liquid fuel gas can be injected into the not fully clamped part-combustion chambers 21 and 22, using metering valves, which are connectable to the through holes 41 and 42. In this way, the amount of fuel gas mixture in the respective partial combustion chambers 21 and 22 can be metered.

Fig. 2 shows, as already mentioned, the setting device 10 in the clamped state of the partial combustion chambers, ie in the clamped state of the prechamber 21 and the main chamber 22. The displacement positions of the combustion chamber wall 14 and partition plate 18 are adjusted by the valve stem 32 when retracting into the valve opening 25a, 25b the approach 33 and with it the drive rods 23 stops, so that the combustion chamber wall 14 is stopped. The location of the partition plate 18 results from the fact that the projection 19 abuts against the stop 2a. The valve stem 32 is designed to be tapered. It should also be mentioned that the central projection 19 connected to the partition plate 18 is formed in its region facing the partition plate 18 as a detonator 51 for receiving an ignition device 52. This ignition device 52 is used to generate an electric spark for the purpose of igniting a fuel gas mixture in the prechamber 21. As will be described in more detail below, the ignition device 52 is located in the inner or in a central region of the Zündbügels 51, which is peripherally provided with through holes 53 through which a laminar flame front can emerge from the ignition cage 51 into the pre-chamber 21.

As Fig. 1 can also be seen, a locking and unlocking device 54 is arranged laterally next to the guide cylinder 5, which with a sensor element 55 comprehensive detection means for interrogating the displacement position of the piston 8 and the piston rod 10, so whether the piston 8 is arranged in the starting position, connected is. The locking and unlocking device 54 serves to lock the drive ring 28 and thus to lock the inlet / outlet valve 34 in the closed position. For this purpose, the locking and unlocking device 54 on a locking lever 56 which extends outside at a small distance from the cylinder wall 6 parallel to the longitudinal direction of the cylinder 5 and is pivotally mounted at its rear end on the outside of the bottom wall 3a. For this purpose, there is a bearing means 57. The bearing means 57 facing away from the end of the locking lever 54 passes through an opening 58 in the drive ring 28 and then integrally into the sensing element 55, which extends with its free end into the path of the piston rod 10 , The free end of the sensor element 55 thus comes to lie directly in front of the end face 10 a of the piston rod 10, when the piston 8 in accordance with its initial position Fig. 1 located. The locking lever 56 and the sensor element 55 may, for. B. be punched out of a sufficiently strong sheet. At the side facing away from the cylinder 5 of the locking lever 56, this has a locking edge 59, with which the locking lever 56 can engage behind the drive ring 28 when it has been moved far enough in the direction of the bottom wall 3a. Starting from the bearing device 57, therefore, the locking lever 56 initially has a relatively small width, which then increases to form the locking edge 59. With the help of a housing side mounted compression spring 60 of the locking lever 56 is pivoted so in the direction of the cylinder 5 to the bearing means 57 that the locking edge 59 out of engagement with the edge of the opening 58 and the sensor portion 55 comes with its free end in the path of the piston rod 10th lies.

Furthermore, on the side of the cylinder 5, a trigger 61 designed as a trigger or trigger is provided which is pivotably mounted on the outside of the cylinder wall 6. For this purpose, a bearing device 62 is provided. The trigger 61 can be pivoted in the direction of the bottom wall 3a, 3b to the bearing means 62, against the compressive force of a compression spring 63. An actuating portion of the trigger 61 comes to lie outside the locking lever 56. In addition, the trigger 61 in the region of the bearing device 62 with a pointing in the direction of the bottom 7 of the cylinder 5 approach 64 z. B. integrally connected. Therefore, if the trigger 61 in Fig. 1 moved counterclockwise to the bearing means 62, the approach 64 is taken accordingly, which then acts on the cylinder 5 facing edge of the locking lever 56 and this according to the force of the spring 60 entrains or pivoted about the bearing device 57.

Hereinafter, the operation of the inventive implement according to the first embodiment with reference to the Fig. 2 to 6 be explained in more detail. Same elements as in Fig. 1 are provided with the same reference numerals and will not be described again.

Fig. 2 shows a state in which the implement has been pressed with its tip against an object into which a fastener is to be driven. The drive ring 28 is thereby displaced in the direction of the combustion chamber 1 via a front-side pressure bar, not shown, and thus biases the partial combustion chambers 21 and 22 via the drive rods 23, whereby the inlet and outlet valve 34 is also closed. The pressing bracket, the drive ring 28, the drive rods 23 and the compression springs 27 essentially form a pressing device of the working device, which is located in Fig. 2 is in a contact pressure position. Only in the Anpressstellung the pressing device allows the driving of the piston 8 to. Just before the sub-combustion chambers 21 and 22 have been fully clamped, liquid fuel gas is injected through the through-holes 41 and 42. The drive ring 28 comes to lie in the pressed-end position in front of the locking edge 59, however, the locking edge 59 can not yet engage behind the drive ring 28, since the trigger 61 has not yet been operated. The free end of the sensor element 55 therefore initially remains in the path of the piston rod 10, ie immediately before the free end face 10 a.

According to Fig. 3 Now, the trigger 61 is actuated, ie pivoted counterclockwise around the bearing axis 62, against the force of the spring 63. In this case, the locking lever 56 is pivoted about the bearing 64 counterclockwise about the bearing axis 57, so that the locking edge 59 the Drive ring 28 engages behind. At the same time, the feeler element 55 is moved out of the path of the piston rod 10 with the pivoting of the locking lever 56. In the last section of the pivoting movement of the trigger 61 and after the sensing element 55 has been moved out of the path of the piston rod 10, the ignition of the present in the partial combustion chambers 21 and 22 fuel gas mixture by means of the ignition device 52 takes place. So it is a spark through the electric igniter 52 is generated within the Zündbügels 51. The preset in each of the partial combustion chambers 21 and 22 by metering mixture of z. B. air and fuel gas begins to burn first laminar in the prechamber 21, wherein the flame front at relatively slow speed propagates radially in the direction of the passage openings 38. It pushes unburned air-fuel gas mixture before it, which passes through the passage opening 38 into the main chamber 22 and generates turbulence and precompression here. If the flame front reaches the passage openings 38 to the main chamber 22, the flames, due to the relatively small cross sections of the passage openings 38, pass as flame jets into the main chamber 22 and generate further turbulence here. The mixed turbulent air-fuel gas mixture in the main chamber 22 is ignited over the entire surface of the flame jets. It is now burning at a high speed, resulting in a large pressure increase in the main chamber 22.

This high pressure is transmitted to the piston plate 9, so that it moves at high speed in the direction of the bottom wall 7, at the same time the air is forced out of the guide cylinder 5 through the outlet openings 39 to the outside. The piston plate 9 passes over the outlet openings 39 for a short time so that exhaust gas can escape through them. By extending in the direction of the arrow piston rod 10, a fastener is now set or driven into the object against which the work tool has been pressed. The combustion chamber 1, the ignition device 52 and other elements thus form a drive means for driving the piston to the fastener to.

Shortly after igniting the fuel gas mixture in Fig. 3 the trigger 61 can be released again. In the aforementioned movement of the piston rod 10 in the direction of the arrow in Fig. 3 Then the locking lever 56 and with it the sensor element 55 are pressed by the compression spring 60 in the direction of the guide cylinder 5, but the locking edge 59 is not out of engagement with the drive ring 28, since the free end of the sensor element 55 is pressed only against the circumference of the piston rod 10 and thus a pivoting of the locking lever 56 in the clockwise direction to the storage device 57 around is not possible. The drive ring 28 thus maintains its position, so that the inlet / outlet valve 34 is closed and the partial combustion chambers 21, 22 remain clamped.

Fig. 4 shows a state after setting or successful combustion of the air-fuel gas mixture in the main chamber 22, wherein the piston 8 is returned by thermal recycling to its initial position, as can be seen by the arrow shown, by cooling in the combustion chamber 1 and in Guide cylinder 5 remaining flue gas a negative pressure behind the piston 8 and behind the piston plate 9 is formed. The sensor element 55 continues to grind with its free end on the circumferential surface of the piston rod 10, so that the drive ring 28 remains locked over the locking edge 59 continues. The inlet and outlet valve 34 remains closed because the piston 8 has not quite reached its initial position.

In Fig. 5 a state is shown in which the piston 8 has been completely returned by thermal recycling to its initial position. Here, the openings 4a and 4b are completely closed by the piston plate. The free end 10a of the piston rod 10 has now been withdrawn so far into the guide cylinder 5 that this free end 10a comes to rest outside the range of the sensor element 55.

According to Fig. 6 Now, the compression spring 60 can pivot the locking lever 56 and with him the sensor element 55 in a clockwise direction about the bearing means 57, so that the locking edge 59 of the locking lever 56 comes out of engagement with the drive ring 28.

In a next step, not shown, now the drive ring 28 can be pushed away by means of the compression springs 27 of the bottom wall 3 a, 3 b, resulting in corresponding entrainment of the drive rods 23 leads. The projection 33 thus also moves away from the bottom wall 3a, 3b, so that the valve stem 32 can be led out of the valve opening 25a, 25b, namely under the action of the compression spring 33b. In the course of the displacement of the drive rods 23 in the direction of the front end of the working device, first the combustion chamber wall 14 and then the separating plate 18 are taken along accordingly, so that the entire combustion chamber 1 or the partial combustion chambers 21, 22 collapse. The burned residual gases are discharged through the inlet and outlet valve 34. This inlet and outlet valve 34 also serves to supply fresh air into the combustion chamber 1 with opposite movement of the plates 14 and 18, such as Fig. 1 lets recognize. There may also be several inlet / outlet valves and be controlled accordingly.

Fig. 7 shows a nose 100 of a working device, such as in the Fig. 1 to 6 illustrated implement. The nose 100 comprises a holder 101, which carries a guide channel designed as a pin guide 102, wherein the pin guide is displaceable in the driving direction 103 relative to the holder. A pressure bar 104 is also slidably held in the driving direction 103 on the holder 101 and can be offset from the pin guide 102 via a stop against the driving direction 103. Since the holder 101 is fixedly connected to a housing, not shown, of the working device, the bolt guide 102 serves as Anpressfühler and is together with the pressure bar 104 part of a pressing device of the working device. When the implement is pressed against a substrate, pushes the bolt guide 102 via the Anpressbügel 104, for example, the drive ring 28 to the combustion chamber 1, which is thereby clamped. In embodiments not shown, the pressing bracket extends in the driving direction beyond the bolt guide and is itself the Anpressfühler.

A trained as a nail fastener 105 is disposed in a position ready for setting behind the bolt guide and in front of a piston, not shown, of the working device, which is driven for driving the nail 105 into the ground on the nail and guided in a piston guide 106. The nail 105 is held together with other nails in a strip 107 in particular made of plastic, which is received in a magazine, not shown, and arranged by a arranged in the magazine feed device to the guide channel to, ie in Fig. 7 is transported to the viewer, so that the nails are transported one after the other into the position ready to be set.

A feed delay device, generally designated 110, comprises a lever 111, which comprises a control element 112 with a control surface 113 inclined relative to the drive-in direction 103 and is rotatably mounted on the holder 101 via a pin 114. In embodiments not shown, the lever is also designed as a pivoting lever and / or as a sliding lever, which is held, for example, as a carriage slidably on the holder. To actuate the control element 112, the pressing clip 104 has an actuating element 108 projecting in the driving direction 103.

Fig. 8 shows the nose 100 of the implement with the feed delay device 110 in a release position, so if the implement is not pressed against a substrate and the piston is in its initial position at rest and, for example, a combustion chamber, not shown, of the implement has collapsed. In favor of a better overview of the guide channel is not shown. The operating member 108 is engaged via the control surface 113 with the control member 112 of the lever 111, which is thereby held in the position shown.

Fig. 9 shows the nose 100 of the implement with the feed delay device 110 in a locked position, that is, when the implement is pressed against a substrate and, for example, the combustion chamber, not shown, of the implement is clamped. The guide channel, not shown, the pressing bracket 104 against the driving direction 103, so in the drawing to the right, moved. As a result, the actuating element 108 is disengaged from the control element 112. A spring element, not shown, for example, a torsion spring, exerts a bias on the lever 111 in a clockwise direction, so that the control element 112 in Fig. 9 moved upwards.

Fig. 10 is a perspective view of the nose 100 of the implement with the feed delay device 110 in the release position according to Fig. 8 , The strip 107 with the nails 105 is transported here from below into the guide channel, not shown. The actuator 108 is in turn via the control surface 113 in engagement with the control element 112 of the lever 111, which is thereby held in the position shown. The lever 111 has a toothed abutment surface 115 for abutment with the nail 105 or the strip 107, from which it is, however, spaced in the release position of the feed delay device 110 shown. A transport of the nail 105 in the guide channel, not shown, is therefore allowed.

Fig. 11 is a perspective view of the nose 100 of the implement with the feed delay device 110 in the locked position according to Fig. 9 , As a result, the actuating element 108 is again out of engagement with the control element 112, so that the control element 112 due to the bias of the spring element, not shown in FIG Fig. 11 has moved to the left. The contact surface 115 is now on the nail 105 and / or the strip 107, so that in the blocking position of the feed delay device 110 shown a transport of the nail 105 is locked in the guide channel, not shown. The detection device is a movement of the Anpressbügels 104 back to the position in accordance Fig. 10 free only when the piston is in its initial position at rest. This ensures that the feed of the fastener is delayed until a possibly existing reciprocating movement of the piston is completed.

Fig. 12 shows the feed delay device 110 with the lever 111 in the release position according to Fig. 8 and 10 in driving direction. The strip 107 with the nails 105 is transported here to the left in the guide channel, not shown, in which the in Fig. 12 left nail 105 is already in position ready for setting. The lever 111 comprises a contact element 116, which has the toothed contact surface 115. In the release position of the feed delay device 110 shown, the contact surface 115 is spaced from the nails 105 and the strip 107, so that a transport of the nail 105 in the guide channel, not shown, is allowed.

Fig. 13 shows the feed delay device 110 with the lever 111 in the locked position according to Fig. 9 and 11 in driving direction. The contact element 116 rests with the toothed contact surface 115 on the strip 107, so that the teeth of the toothing engage partially in a form-fitting manner in the strip 107. The strip is thereby clamped by the force of the spring element, not shown, against a likewise not shown support element, which is for example firmly connected to the holder or the housing of the implement or the magazine. In the blocking position of the feed delay device 110 shown so is a transport of in Fig. 13 second nail 105 locked from the left in the guide channel, not shown, even if the left nail after a driving operation is no longer available and the piston has released the guide channel. In embodiments not shown, the third, fourth or fifth nail or the strip is clamped at one point between two nails. The toothing of the contact surface 115 has a Preferred direction (see Fig. 12 ), so that the strip 107, despite the blocking position manually to the right from the position shown pulled out, for example, in case of malfunction of the implement. In embodiments not shown, the contact surface is flat or gently curved and is only frictionally on the fastener or the strip.

The feed delay described is independent of how quickly a user lifts the implement from the ground again and is therefore not exposed to the user's behavior. In addition, the guide channel can be moved independently of the feed delay device, so for example, when lifting off the ground due to decoupling from the rest of the implement still pending on the ground, which may improve the Eintreibqualität. In addition, the guide channel is then a simple design wear part. Furthermore, the feed delay is independent of the type of piston drive and can also be used in implements with non-collapsing combustion chambers.

Claims (14)

1. Work tool for driving a fastening element into a surface, with a guide channel (102) for the fastening element, with a piston (8), which for transferring energy onto the fastening element arranged in the guide channel (102) is to be driven from a starting position, in which the piston (8) is at rest, onto the fastening element, with a feed device for transporting the fastening element into the guide channel (102), and with a feed delaying device (110) for delaying transport of the fastening element into the guide channel (102), until the piston (8) has gone back into the starting position after a driving procedure, characterised in that the feed delaying device (110) has a releasing position, in which it allows transport of the fastening element into the guide channel (102), if the piston (8) is arranged in the starting position, and a locking position, in which it blocks transport of the fastening element into the guide channel (102), if the piston (8) is arranged outside the starting position.
2. Work tool according to claim 1, comprising a detection device for checking whether the piston (8) is arranged in the starting position.
3. Work tool according to one of the previous claims, comprising a driving device for driving the piston (8) onto the fastening element, and a trigger, operating which triggers the piston (8) being driven onto the fastening element.
4. Work tool according to one of the previous claims, comprising a pressing device (104) for checking whether the work tool is pressed onto a surface, in which the pressing device (104) is in a pressing position, if the work tool is pressed onto a surface.
5. Work tool according to claim 4, in which the pressing device (104) allows the piston to be driven onto the fastening element only in the pressing position.
6. Work tool according to one of claims 4 to 5, in which the driving device comprises a thrust chamber, which is stretched by the pressing device (104), if the work tool is pressed onto a surface.
7. Work tool according to claims 2 and 6, in which the detection device allows the stretched thrust chamber to collapse after a driving procedure, if the piston (8) is arranged in the starting position, and locks, if the piston (8) is not arranged in the starting position.
8. Work tool according to one of the previous claims, in which the feed delaying device (110) is moved from the releasing position into the locking position, if the work tool is pressed onto a surface and/or if the thrust chamber is stretched.
9. Work tool according to one of claims 6 to 8, in which the feed delaying device (110) is moved from the locking position into the releasing position, if the combustion chamber collapses.
10. Work tool according to one of the previous claims, comprising a cartridge for taking the fastening element, in which the feed device is provided for transporting the fastening element from the cartridge into the guide channel (102).
11. Work tool according to one of the previous claims, in which the feed delaying device (110) comprises a lever (111), which in the locking position projects into the transport path of the fastening element or lies on the fastening element, and which in the releasing position is at a distance from the transport path and the fastening element.
12. Work tool according to claim 11, in which the lever (111) has a contact surface (115) for lying on the fastening element in a force fitting and/or form fitting way.
13. Work tool according to one of claims 11 to 12, in which the lever (111) is made as a spring loaded swivelling lever in particular.
14. Work tool according to one of claims 11 to 13, in which the lever (111) is housed so that it may rotate around an axis of rotation on a housing and/or a nose of the work tool, particularly on the guide channel (102) or on the cartridge.

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