EP3403787B1 - Driving tool for driving fastening means into workpieces - Google Patents

Description

The invention relates to a tacker for driving fasteners into workpieces according to the preamble of claim 1. Such a tacker is for example from the US 3,524,577 A out.

Drive-in devices of the type according to the invention are used for driving fasteners with a certain depth of penetration into workpieces. This is required, for example, when attaching plasterboard or gypsum fiber boards to wooden building components. The nail heads must not penetrate too deeply into the outer layer of cardboard and destroy it. The driving of nails with a given depth of penetration can also be desirable for aesthetic reasons, for example when planking the outside of wooden parts with wooden boards.

For this purpose Eintreibgeräte be used, which drive the nails slowly into the workpiece. The drive takes place by means of compressed air. To catch the high driving forces, the tacking devices are arranged on holding devices. Known is the attachment of Eintreibgeräten to electric motor driven bridges, which are movable along rails over a work table. Such woodworking bridges can carry other woodworking equipment such as drills, saws or milling. Also known are automatically working woodworking bridges.

The DE 20 2009 017 659 U1 describes a drive-in module for driving in particular magazine-mounted fasteners, in particular of magazines nails, in workpieces. The drive-in module has an assembly carrier for a drive-in unit, wherein the drive-in unit has a drive drive, which acts via a drive-in direction of sliding driver punch with a drive-in force on the respective fastener to be driven. The drive unit as such is by means of a Andrückantriebs to the respective Workpiece pressed and this guided slidably via an aggregate guide on the subframe in the driving direction. The Andrückantrieb has a extending in a wedge plane drive wedge, which acts to press the Eintreibaggregates to the respective workpiece on the drive-in unit. By means of the Andrückantriebes the drive-in unit is pressed against the workpiece in order to achieve a constant Eintreibtiefe. In order to further increase the compactness of the drive-in module, the drive wedge is not arranged centrally to the drive-in unit, but laterally offset from the drive plane of the drive-in unit.

The well-known drive module is still bulky and structurally complex. In particular, it requires an additional pneumatic piston drive for the pressure drive. The pressing of the Eintreibaggregates to the workpiece by means of the Andrückantriebes and subsequent driving the fastener by means of the drive-in unit requires appropriate control. The operation is energy-intensive, since the entire drive-in unit is displaced for pressing.

Also known are tacking devices that can be held by hand during use. Such hand tools drive fasteners with a quick impact stroke which is damped at the end. As a result, no great reaction forces are applied to the user. However, the fasteners are driven in different depths and inaccurately aligned in the workpiece.

On this basis, the invention is based on the object to provide a structurally and structurally less expensive tacker for driving fasteners with a certain depth of penetration into workpieces with reduced energy requirements.

The object is achieved by a tacker with the features of claim 1. Advantageous embodiments of the invention are specified in subclaims.

• einen Hauptzylinder mit einem darin verlagerbaren Kolben und einem Abdichtelement am unteren Ende mit einem ersten Durchgangsloch, durch das eine mit dem Kolben verbundene Kolbenstange abdichtend hindurch geführt ist, wobei im Hauptzylinder oberhalb des Kolbens eine mit einem ersten Lufteinlass verbundene erste Luftkammer zum Befüllen mit Luft zwecks Verlagern des Kolben nach unten und unterhalb des Kolben eine mit einem zweiten Lufteinlass verbundene zweite Luftkammer zum Befüllen mit Luft zwecks Verlagern des Kolbens nach oben vorhanden ist,
• einen Andruckzylinder, der am unteren Ende ein Mündungswerkzeug mit einem Eintreibkanal trägt, in den durch eine obere Öffnung ein unterer Abschnitt eines mit der Kolbenstange verbundenen Eintreibstößels hineinragt und der unten eine untere Öffnung für den Austritt von Befestigungsmitteln aufweist,
• ein Magazin für Befestigungsmittel, das an eine seitliche Öffnung des Eintreibkanales angeschlossen ist, um dem Eintreibkanal Befestigungsmittel zuzuführen,
• eine erste Halteeinrichtung, die ein mit der Kolbenstange verbundenes erstes Halteelement und ein mit dem Andruckzylinder verbundenes zweites Halteelement aufweist, die so ausgebildet sind, dass durch Verlagern des Kolbens in eine obere Kolbenstellung der Andruckzylinder in eine obere Andruckzylinderstellung verlagerbar ist und durch Verlagern des Kolben aus der oberen Kolbenstellung nach unten das Mündungswerkzeug auf ein Werkstück aufsetzbar ist, und
• eine erste Anschlageinrichtung, die ein mit der Kolbenstange verbundenes erstes Anschlagelement und ein mit dem Andruckzylinder verbundenes zweites Anschlagelement aufweist, die ausgebildet sind, die Verlagerung des Eintreibstößels nach unten zu begrenzen, um ein Befestigungselement mittels des Eintreibstößels aus dem Eintreibkanal mit einer bestimmten Eindringtiefe in ein Werkstück einzutreiben.

The tacker according to the invention for driving fasteners into workpieces comprises:

• a master cylinder with a piston displaceable therein and a sealing member at the lower end with a first through hole, through which a piston rod connected to the piston sealingly passes, wherein in the master cylinder above the piston connected to a first air inlet first air chamber for filling with air Displacing the piston downwardly and below the piston there is a second air chamber connected to a second air inlet for filling with air for displacing the piston upwardly,
• a pressure cylinder, which carries at the lower end an orifice tool with a drive-in channel, into which an upper opening projects through a lower section of a drive rod connected to the piston rod and which has a lower opening for the discharge of fastening means at the bottom;
• a magazine for attachment means which is connected to a side opening of the drive-in channel in order to supply fastening means to the drive-in channel,
• a first holding device which has a first holding element connected to the piston rod and a second holding element connected to the pressure cylinder, which are designed so that the pressure cylinder can be displaced into an upper pressure cylinder position by displacing the piston into an upper piston position and by displacing the piston the upper piston position down the muzzle tool is placed on a workpiece, and
• a first stopper means having a first stopper member connected to the piston rod and a second stopper member connected to the pressure cylinder adapted to limit the displacement of the drive tappet downwardly to a fastener by means of the drive tappet from the drive-in channel with a certain penetration depth To drive in the workpiece.

In the tacker according to the invention is ensured by placing the muzzle tool with the lower end of the workpiece and driving the fastener until the effectiveness of the first stop means that the fastener is driven with a certain depth of penetration into a workpiece. Here, the lowering and placement of the necking tool is effected on the workpiece by displacing the piston down. Before placing the muzzle tool, the drive tappet moves concurrently with the muzzle tool with down. After placing the muzzle tool, the fastener is driven into the workpiece in a certain Eintreibtiefe by further moving the piston down. After driving the fastener is displaced by moving the piston up the drive tappet up and the pressure cylinder in the upper Andruckzylinderstellung. The master cylinder with the displaceable therein piston thus causes both the placement of the Andruckzylinders on and lifting the Andruckzylinders from the workpiece as well as the displacement of the driving ram for driving fasteners. An additional wedge gear and another pneumatic drive for moving the tacker are not required. As a result, the construction can be simplified, reduces the volume of construction and energy for the operation of the Eintreibgerätes be saved. The construction of the successive pressing of the muzzle tool and driving the fastener is secured, so that no special control is required for this.

The downward displacement of the piston in the master cylinder is effected by introducing pressurized air through the first air inlet into the first air chamber, preferably deaerating the second air chamber. The displacement of the piston in the master cylinder upwards is effected by introducing compressed air through the second air inlet into the second air chamber, wherein preferably the first air chamber is vented. In the upper piston position, the piston can be held by compressed air in the second air chamber. For the displacement of the piston, compressed air is preferably used from an operational compressed air network. In many cases, the operating pressure in such compressed air networks is 6 bar.

According to a preferred embodiment of the invention, the first holder device comprises a first projection projecting radially outward from the piston rod and a second projection projecting radially inwardly from the pressure cylinder, wherein the first projection is arranged below the second projection, such that in the upper piston position the first projection abuts the underside of the second projection and away from the second projection is displaced downwards, when the muzzle tool touches on the workpiece. In this embodiment, in the upper piston position is held by the abutment of the first projection on the underside of the second projection of the pressure cylinder in the upper Andruckzylinderstellung. By displacing the piston downwards, the first projection is displaced downwards so that the second projection resting against it is also lowered with the pressure cylinder. The lowering can be effected by the weight of the Andruckzylinders. When the muzzle tool touches down, the piston can be moved further down, since the first projection is not prevented by the second projection from moving further down. When displacing the piston upwards, the first projection takes with it the second projection and thus displaces the pressure cylinder back into the upper pressure cylinder position.

According to a further embodiment, the first projection and / or the second projection is a projection which extends completely or partially around the piston axis. According to a further embodiment, the first projection and / or the second projection is an annular and / or annular disk-shaped projection.

According to a further embodiment, the first projection is arranged at the bottom on a hollow cylindrical outer piston rod, which is sealingly passed through the through hole, the lower edge of the outer piston rod is the first stop element, the driving ram is connected to an inner piston rod arranged concentrically in the outer piston rod and is a compression spring in the annular space between the outer piston rod and inner piston rod and arranged in pressure cylinder and is supported with the upper end on the underside of the main piston and with the lower end at the top of the second stop element. According to a further embodiment, the compression spring is a helical spring. By the compression spring, the second projection is held in contact with the first projection during displacement of the piston from the upper piston position down until the muzzle tool touches down on the workpiece. In this way, the settling of the necking tool on the workpiece can be done very quickly. In addition, a precise alignment of the pressure cylinder can be secured to the master cylinder by the plant of the second projection on the first projection. After placing the muzzle tool on the workpiece, the compression spring is compressed when driving the fastener. When moving the piston upwards, the energy stored in the compression spring is used. In addition, compressed air is needed to move the piston up to the upper piston position. When the piston is displaced upward, the drive ram is first withdrawn in the drive-in channel and then the pressure cylinder is raised. In the following embodiment is from the beginning of the displacement of the piston upwards at the same time the drive tappet and the pressure cylinder raised, thereby saving time and more fasteners per unit time can be driven.

In this embodiment, a second holding device is provided which has a third holding element connected to the piston rod and a fourth holding element connected to the pressure cylinder, which are designed so that they hold the piston rod on the pressure cylinder on contact of the first stop element on the second stop element, so by Move the piston up the pressure cylinder is displaced upward. In addition, a third holding device is present, which has a fifth holding element on the master cylinder and a sixth holding element on the pressure cylinder, which are designed so that they can be connected to each other by displacing the Andruckzylinders up, whereby further displacement of the piston upwards further displacement of the Pressure cylinder prevents upward and the connection between the third and fourth retaining elements of the second holding device is canceled. Finally, a lifting device is provided, which is designed so that it picks up the connection between the fifth and the sixth holding element upon impact of the first holding element on the second holding element. In this embodiment, the drive-in ram is displaced upward after driving in displacing the piston upward and immediately displaced by the pressure cylinder on the piston rod holding second holding device of the pressure cylinder upwards. Only by the effectiveness of the third holding device of the pressure cylinder is held in the position then reached and repealed the further displacement of the piston up the effect of the second holding device. By the effectiveness of the third holding means of the pressure cylinder does not fall down when the piston is no longer connected to the pressure cylinder by canceling the action of the second holding means. Finally, the effect of the third holding device is canceled by means of the lifting device when the first holding element meets the second holding element. As a result, that will Settling of the muzzle tool by the third holding device is not prevented. The pressure cylinder is held by the first holding device in the upper Andruckzylinderstellung and the tacker is ready for the discontinuation of the muzzle tool before driving in another fastener.

According to a further embodiment, the second holding device is a first magnetic coupling, wherein a first magnetic coupling element with the piston rod and a second magnetic coupling element is connected to the pressure cylinder. According to a further embodiment, the first magnetic coupling element is the first stop element and the second magnetic coupling element is the second stop element. According to a further embodiment, the first magnetic coupling element is circular disk-shaped and / or the second magnetic coupling element is circular disk-shaped. According to a further embodiment, the first magnetic coupling element has at least one (permanent) magnet and the second magnetic coupling element at least one ferromagnetic element or vice versa.

According to a further embodiment, the third holding device comprises a second magnetic coupling, wherein a third magnetic coupling element with the master cylinder and a fourth magnetic coupling element is connected to the pressure cylinder. In addition, the third holding device comprises a second stop device with a third stop element on the master cylinder and a fourth stop element on the pressure cylinder, which are designed so that they prevent a further displacement of the pressure cylinder upwards in the meeting. According to a further embodiment, the third magnetic coupling element is annular disk-shaped and / or the fourth magnetic coupling element is annular disk-shaped. According to a further embodiment, the third magnetic coupling element comprises at least one (permanent) magnet and / or the fourth magnetic element comprises at least one ferromagnetic component or vice versa. According to another embodiment the third stop element the underside of the sealing element and the fourth stop element a at the upper end of the pressure cylinder radially inwardly projecting, annular disk-shaped stop element. This is at the same time the fourth magnetic coupling element according to another embodiment.

According to a further embodiment, the lifting device vertically from the top of the second holding element protruding pins and the second holding element in the vertical direction until it rests on the sixth holding element displaceable, wherein the pins are displaced with their upper ends on the sixth holding elements also up to to push off the fifth holding element from the sixth holding element.

According to a further embodiment, the third magnetic coupling element is held on a vertical guide device which is formed so that the third magnetic coupling element is vertically displaceable upward starting from a lower stop position, wherein the third magnetic coupling element in the lower stop position with the fourth magnetic coupling element can be coupled and from Pin is abdrückbar away from the fourth magnetic coupling element upwards. In the lower stop position, the fourth magnetic coupling element with the third magnetic coupling element can be coupled. The pressure cylinder is then held in the position reached, so that it does not fall down when releasing the second holding device. The second magnetic coupling is disengaged by means of the pins when the first stop member meets the second stop member. The juxtaposition of the first and second stop elements to each other prevents the pressure cylinder falls after uncoupling of the second magnetic coupling device down. The piston is displaced to the upper piston position, wherein the third magnetic coupling element is taken up. When the second retaining element bears against the fourth magnetic coupling element, the piston has reached the upper piston position. According to another embodiment, the second holding device comprises at least one groove in a lower portion of the driving ram and at least one locking element on the necking tool, which engages upon engagement of the first stopper element on the second stop element in the groove and is formed so that the latching triggers when the fifth and the sixth retaining element are interconnected. In this embodiment, the piston is connected via the latching between the driving ram and locking element with the pressure cylinder. The first magnetic coupling is eliminated. According to a further embodiment, the third holding device is designed as a second magnetic coupling.

According to a further embodiment, at the bottom of the necking tool, a nail centering is present, which has a centering opening below the drive-in channel which is delimited by at least one guide element which is movable in the radial direction and is biased by a spring device in the radial direction towards the centering channel, wherein the guide element at the same time Locking element of the third holding device is. Here, a nail centering for the realization of the second holding device is used.

According to another embodiment, the nail centering comprises a centering housing, in which at least one ring of balls is arranged, between which the centering is defined, outside of the balls, an elastic snap ring, Seeger ring, O-ring or other elastic ring acts as a spring device. This nail centering is suitable for centering nails with a single nail shank and a nail head or pins. When passing the nail shank through the centering the balls are pressed against the action of the elastic ring radially slightly, so that the nail shaft is centered. As the nail head passes, the balls are pushed further apart, and after the nail head has passed, they are pressed by the elastic ring against the subsequent drive tappet. Finally, the balls snap into the groove of the drive ram. The elastic ring and the balls are designed so that a locking of the balls can take place in the groove. The detent connection is released when the piston is displaced further upwards after the impact of the sixth on the fifth support member. According to a further embodiment, the underside of the centering housing is the lower end of the muzzle tool with which the pressure cylinder is placed on the workpiece. According to a further embodiment, the underside of the centering housing is annular. As a result, imprints of the muzzle tool are avoided on the workpiece, since the centering can be placed with a large area on the workpiece. Furthermore, a driving in of the fastening means is conveyed perpendicular to the workpiece surface by large-scale investment of the centering.

According to a further embodiment, the second stop element is held by an adjusting device in the pressure cylinder, wherein the adjusting device is designed to adjust the vertical position of the second stop element in the pressure cylinder. By means of the adjusting device, the penetration depth of the fastening means in the workpiece is adjustable.

According to a further embodiment, the second stop element is a ring with an external thread, which is screwed into an internal thread of an adjusting ring, wherein the adjusting ring is held between a first and a second bearing element in the pressure cylinder, so that it rotatable in the pressure cylinder, but not displaced in the vertical direction is present, and a linear guide is present, which allows a displacement of the ring in the vertical direction, but prevents it from rotating about a vertical axis. As a result, a precise adjustment of the penetration depth is particularly easy.

According to a further embodiment, the adjusting ring on its outer circumference at different circumferential positions on first blind holes, in the through at least one slot in the pressure cylinder from the outside a pin-shaped tool can be used. By turning a tool inserted in a first blind bore, the adjusting ring is adjustable. After exhaustion of the pivoting range in the slot, the tool can be plugged into a further first blind hole to turn the adjusting ring, if necessary.

Fig. 1

ein erstes Eintreibgerät mit einer ersten und einer zweiten Magnetkupplung an einer Holzbearbeitungsbrücke in einer Perspektivansicht schräg von vorn und von der Seite;

Fig. 2

das erste Eintreibgerät mit dem Kolben in der oberen Kolbenstellung in einem Vertikalschnitt;

Fig. 3

das erste Eintreibgerät mit dem Mündungswerkzeug abgesenkt auf ein Werkstück in einem Vertikalschnitt;

Fig. 4

das erste Eintreibgerät mit gerade vollständig eingetriebenem Nagel in einem Vertikalschnitt;

Fig. 5

das erste Eintreibgerät mit vom Werkstück abgezogenem Mündungswerkzeug und magnetisch gekoppelten Haupt- und Andruckzylindern in einem Vertikalschnitt;

Fig. 6

das erste Eintreibgerät zu Beginn der mechanischen Kopplung und Auflösung der magnetischen Kopplung von Hauptzylinder und Andruckzylinder in einem Vertikalschnitt;

Fig. 7

ein zweites Eintreibgerät umfassend eine Verrastung zwischen Nagelzentrierung und Eintreibstößel mit dem Kolben in der oberen Kolbenstellung in einem Vertikalschnitt;

Fig. 8

das zweite Eintreibgerät mit auf ein Werkstück aufgesetztem Mündungswerkzeug in einem Vertikalschnitt;

Fig. 9

das zweite Eintreibgerät mit gerade vollständig in ein Werkstück eingetriebenem Nagel in einem Vertikalschnitt;

Fig. 10

das zweite Eintreibgerät mit vom Werkstück abgezogenem Mündungswerkzeug und magnetischer Kopplung von Hauptzylinder und Andruckzylinder;

Fig. 11

das zweite Eintreibgerät mit mechanischer Kopplung und aufgelöster magnetischer Kopplung von Hauptzylinder und Andruckzylinder in einem Vertikalschnitt;

Fig. 12a-c

Nagelzentrierung des zweiten Eintreibgeräts in einer teilweise geschnittenen Seitenansicht (Fig. 12a), in einer Draufsicht (Fig. 12b) und in einem Schritt entlang der Linie c-c von Fig. 12a (Fig. 12c);

Fig. 13

ein drittes Eintreibgerät umfassend eine Druckfeder mit dem Kolben in der oberen Kolbenstellung;

Fig. 14

das dritte Eintreibgerät mit auf ein Werkstück aufgesetztem Mündungswerkzeug in einem Vertikalschnitt;

Fig. 15

das dritte Eintreibgerät mit gerade vollständig in ein Werkstück eingetriebenem Nagel in einem Vertikalschnitt;

Fig. 16

das dritte Eintreibgerät bei mechanischer Kopplung von Kolben und Andruckzylinder in einem Vertikalschnitt;

Fig. 17

das dritte Eintreibgerät mit dem Kolben in der oberen Kolbenstellung in einem Vertikalschnitt.

Finally, the subject of the invention is a tacker according to one of claims 1 to 14, held on a woodworking bridge or on another displacement device or on a stationary equipment carrier. The invention will be explained in more detail with reference to the accompanying drawings of exemplary embodiments. In the drawings show:

Fig. 1

a first tacker with a first and a second magnetic coupling on a woodworking bridge in a perspective view obliquely from the front and from the side;

Fig. 2

the first tacker with the piston in the upper piston position in a vertical section;

Fig. 3

the first tacker with the muzzle tool lowered onto a workpiece in a vertical section;

Fig. 4

the first tacker with just completely driven nail in a vertical section;

Fig. 5

the first tacker with deducted from the workpiece muzzle and magnetically coupled main and Andruckzylindern in a vertical section;

Fig. 6

the first tacker at the beginning of the mechanical coupling and resolution of the magnetic coupling of master cylinder and pressure cylinder in a vertical section;

Fig. 7

a second tacker comprising a locking between nail centering and driving ram with the piston in the upper piston position in a vertical section;

Fig. 8

the second tacker with attached to a workpiece muzzle tool in a vertical section;

Fig. 9

the second tacker with just completely driven into a workpiece nail in a vertical section;

Fig. 10

the second tacker with withdrawn from the workpiece muzzle tool and magnetic coupling of master cylinder and pressure cylinder;

Fig. 11

the second tacker with mechanical coupling and resolved magnetic coupling of master cylinder and pressure cylinder in a vertical section;

Fig. 12a-c

Nail centering of the second tacker in a partially sectioned side view ( Fig. 12a ), in a plan view ( Fig. 12b ) and in one step along the line cc of Fig. 12a (Fig. 12c );

Fig. 13

a third tacker comprising a compression spring with the piston in the upper piston position;

Fig. 14

the third tacker with attached to a workpiece muzzle tool in a vertical section;

Fig. 15

the third tacker with just completely driven into a workpiece nail in a vertical section;

Fig. 16

the third tacker with mechanical coupling of piston and pressure cylinder in a vertical section;

Fig. 17

the third tacker with the piston in the upper piston position in a vertical section.

In the present application, the terms "top" and "bottom" and derived therefrom such as "above" and "below" and "vertically" and "horizontally" refer to an alignment of the tacker with the master cylinder the pressure cylinder and the lower opening of the muzzle tool at the lower end of the tacker.

According to Fig. 1 a tacker 1 is arranged on a bridge 2 above a workpiece 3. From the bridge 2, only a horizontal support is shown. Overall, the bridge is portal-shaped, wherein the two vertical posts are guided on rails on both sides of a work table in the horizontal direction displaced.

According to Fig. 1 and 2 the tacker 1 comprises a master cylinder 4 in a housing 5, a pressure cylinder 6 arranged below the housing 5, a necking tool 7 projecting downwards from the underside of the pressure cylinder 6, and a magazine 8 arranged laterally of the necking tool.

The master cylinder 4 is formed inside circular cylindrical or oval. Above the master cylinder 4 is closed by a cover 9. In a central, hexagonal recess 10 in the underside of the lid 9, the hexagonal head of a first screw 11, whose threaded shaft is passed through a central bore of the lid 9 and projects above the lid 9 sits. The first screw 11 is used for attachment to the bridge. 2

In the master cylinder 4, a piston 12 is vertically displaceable. The piston is sealed via first and second O-rings 13, 14 relative to the master cylinder 4.

From the bottom of the piston 12 is a piston rod 15 down. The piston rod 15 is connected to the piston 12 by means of a second screw 16.

At the bottom, the master cylinder 4 has a sealing element 17, which is designed as a first bottom plate. The sealing member 17 has a first in the center Through hole 18 in the form of a guide bush, through which the piston rod 15 is passed, so that it protrudes down from the sealing member 17.

On the outer circumference of the sealing member 17, a third O-ring is held in a groove, which seals this relative to the master cylinder 4.

The piston rod 15 is sealed off from the sealing element 17 by a fourth O-ring held in the sealing element 17.

Above the piston 12 is in the master cylinder 4, a first air chamber 20 and below the piston 12, a second air chamber 21 is present. The first air chamber 20 is connected to a first accessible from the outside air inlet 22 and the second chamber with an externally accessible second air inlet 23.

The pressure cylinder 6 is outside substantially box-shaped and has inside a circular or oval cross-section. At the bottom, the pressure cylinder 6 has a second bottom plate 24 with a second through-hole 25. Above the pressure cylinder 6 has an outwardly projecting flange 6.1.

The mouth tool 7 is fixed to the underside of the second bottom plate 24. It has a drive-in channel 26 which has an upper opening 27 at the top, a lower opening 28 at the lower end of the necking tool 7 and a lateral opening 29 at the side. To the side opening 29, the drum-shaped magazine 8 is connected for fastening means with its discharge opening.

A driving ram 30 protrudes with a lower portion through the second through hole 25 and the upper opening 27 into the driving channel 26. The upper portion of the driving ram 30 is fixed to the bottom of the piston rod 15. For this purpose, the driving ram 30 above an external thread 31 which is screwed into a threaded bore on the underside of the piston rod 15.

A first holding device 32 has a first holding element 33 projecting radially from the piston rod 15. This is a circular disk-shaped projection surrounding the central axis of the piston rod. The first holding element 33 has a cup-shaped formation 34 in the center, in which the lower end of the piston rod 15 is inserted. The driving ram 30 is passed through a central hole of the molding and screwed into the piston rod. A collar 35 on the outer periphery of the driving ram 30 abuts against the underside of the molding 34, so that the first holding element 33 is fixed between the piston rod 15 and the driving ram 30.

The first holding device 32 has a second holding element 36 connected to the pressure cylinder 6. The second holding element 36 is a protrusion projecting radially inwards from the pressure cylinder 6. This is designed as a circular disk, which is arranged vertically displaceable in a first extension 37 at the upper end of the pressure cylinder 6.

A first stop device 38 has a first stop element 39 connected to the piston rod and a second stop element 40 connected to the pressure cylinder 6. The first holding element 33 is at the same time the first stop element 39. The second stop element 40 is a ring which is held by an adjusting device 41 in the vicinity of the second bottom plate 24.

The adjusting device 41 comprises an adjusting ring 42, which has an internal thread 43 into which the second stop element 40 is screwed with an external thread 44. In the region of the external thread 44, the second stop element 40 has a reduced outer diameter.

The underside of the adjusting ring 42 abuts against the upper side of the second bottom plate 24. Above the collar 42 is guided on a shoulder 45 of the pressure cylinder 6. Thus, the collar 42 between shoulder 45 and second bottom plate 24 is caught so that it is not vertically displaceable, but only about the vertical axis is rotatable.

On the outer circumference of the adjusting ring 42 has a plurality of first blind holes 46, in which by a slot 47 of the pressure cylinder 6 from the outside a pin for rotating the adjusting ring 42 is used ( Fig. 1 ). The second stop element 40 has on the underside a plurality of vertical threaded bores 48 into which stud bolts 49 are screwed, which are guided axially displaceably in second bores 24. 1 of the second bottom plate 24. The second bores 24. 1 of the second bottom plate 24 and the stud bolts 49 form a linear guide 50.

By turning the adjusting ring 42, the second stop member 40 is displaced in the vertical direction, since it is prevented by the stud bolts 49 from turning with the adjusting ring 42.

Furthermore, a second holding device 51 is provided which has a third holding element 52 connected to the piston rod 15 and a fourth holding element 53 connected to the pressure cylinder 6. The second holding device 51 is a first magnetic coupling 54 which has a first magnetic coupling element 55 connected to the piston rod 15 and a second magnetic coupling element 56 connected to the pressure cylinder 6. The first magnetic coupling element 55 has permanent magnets 57, which are fastened by means of third screws 58 and first nuts 59 on the underside of the first stop element 39. The second magnetic coupling element 56 is the second stop element 40, which consists of a ferromagnetic material. By applying the first stop element 39 to the second stop element 40, the first and second magnetic coupling elements 55, 56 can be coupled together.

Furthermore, a third holding device 60 is present, which has a fifth holding element 61 on the master cylinder 4 and a sixth holding element 62 on the pressure cylinder 6. The third holding device 60 comprises a second magnetic coupling 63 which has a third magnetic coupling element 64 connected to the master cylinder 4 and a fourth magnetic coupling element 65 connected to the pressure cylinder 6. The third magnetic coupling element 64 has circular disc-shaped permanent magnets 66 which are fastened by means of fourth screws 67 at the lower ends of first rods 68, which are guided in vertical first bores 69 of the housing 5.

At the upper ends of the rods 68, first plates 71 are fixed by means of fifth screws 70, which project radially outwardly with respect to the rods 68. The first disks 71 are arranged in second extensions 72 of the first bores 69 and limit the displacement of the first rods 68 down by abutment with a shoulder at the lower end of the second extensions 72. The displacement of the first rods 68 upwards is limited by abutment of the radial with respect to the first rods 68 projecting permanent magnets 66 at the bottom of the housing 5. The fourth magnetic coupling element 65 is formed as an annular disc made of a ferromagnetic material which is attached to the upper end of the pressure cylinder 6.

The third holding device 60 comprises a second stop device 73 which has a third stop element 74 on the master cylinder 4 and a fourth stop element 75 on the pressure cylinder 6. The fourth stopper member 75 is a radially inwardly projecting part of the fourth magnetic coupling member 65, and the third stopper member 74 is the lower side of the sealing member 17.

The fourth magnetic coupling element 65 limited by contact with the underside of the sealing member 17, the displacement of the pressure cylinder 6 upwards. Further it covers the first extension 37 of the pressure cylinder 6 from above and limits the displacement of the second holding member 36 upwards. Downward, the displacement of the second holding element 36 is limited by the bottom of the first extension 37.

Furthermore, a lifting device 76 with vertically aligned pins 77 is present. The pins 77 project upwardly from the top of the second support member 36.

The pins 77 engage in holes 78 of the fourth magnetic coupling element 65. When the second holding member 36 is in the lower position, the pins 77 do not project beyond the upper surface of the fourth magnetic coupling member 65 (FIG. Fig. 3 ). By moving the second holding element 36 upwards, the pins 77 are pushed out of the holes 78 at the top ( Fig. 2 ).

The flange 6.1 of the pressure cylinder 6 is attached by means of sixth screws 79 to second rods 80, which are guided in vertical third bores 81 in the housing 5. A holder 8.1 of the magazine 8 is clamped between a sixth screw 79 and the flange 6.1.

Fig. 1 and 2 show the first tacker 1 in a starting position in which the necking tool 7 is not seated on the workpiece 3. The piston 12 is held by fed into the second air chamber 21 compressed air in the upper piston position in which it rests on the cover 9. The first holding element 33 is maximally raised by the piston rod 15, so that the second holding element 36 bears against the underside of the sixth holding element 62. The third magnetic coupling member 64 is pushed by the pins 74 from the fourth magnetic coupling member 65.

According to Fig. 3 is displaced by feeding compressed air into the first air chamber 20 and venting the second air chamber 21 of the piston 12 and thus the first holding member 33 downward. With the first holding element 33, the second holding element 36 and thus the pressure cylinder 6 moves downwards until the necking tool 7 is seated with the lower end on the workpiece 3. As a result, a defined starting position for the driving in of a nail 82 or another fastening means into the workpiece 3 is given.

According to Fig. 4 After that, further compressed air is introduced into the first air chamber 20 and a nail 82 fed from the magazine 8 into the driving channel 26 is driven into the workpiece 3 until the first stop element 39 bears against the second stop element 40. Then the nail 82 is driven into the workpiece 3 in a defined drive-in depth. The penetration depth is determined by the vertical position of the second stop element 40, which is adjustable by turning the adjusting ring 42 from the outside.

With the installation of the first stop element 39 on the second stop element 40, the first magnetic coupling 51 is engaged at the same time, since the first stop element 39 is at the same time the first magnetic coupling element 52 and the second stop element 40 at the same time the second magnetic coupling element 53.

Thereafter, according to Fig. 5 moved by introducing compressed air into the second air chamber 21 and venting the first air chamber 20 of the piston 12 upwards, wherein the first magnetic coupling 51 takes the pressure cylinder 6 with upwards. Concurrently with the mouth tool 7 of the driving ram 30 is raised. The fourth magnetic coupling element 65 is coupled to the third magnetic coupling element 64 of the second magnetic coupling 63.

According to Fig. 6 the phase described above is terminated by the pins 77 striking the third magnetic coupling element 64 of the second magnetic coupling 63 and release it from the fourth magnetic coupling 65. After dissolution of the first magnetic coupling 51 falls according to Fig. 2 the pressure cylinder 6 is not back, since this is prevented by contact of the first holding element 33 on the second holding element 36 and the abutment of the second holding element 36 on the sixth holding element 62. After feeding a further nail 82 from the magazine 8 in the drive-in channel 26, the tacker 1 is ready for another driving operation.

The second tacker 1 of Fig. 7 to 12 has no first magnetic device 54 to the first tacker. By contrast, the second tacker is provided with a nail centering 80 at the lower end of the necking tool 7.

The nail centering 83 has a circular disk-shaped centering housing 84 with a vertical centering channel 85, which is aligned with the drive-in channel 26. In the centering housing 84, two concentric rings 88, 89, 90, 91 of balls 92 are arranged in two horizontal planes one above the other in chambers 86, 87 which are designed as radial ball guide channels. The balls 92 of the two stacked inner rings 88, 90 are partially in the centering 85 in, with adjacent balls 92 are supported against each other. Adjacent balls 92 of the outer rings 89, 91 and the inner rings 88, 90 abut each other at their equator.

On the outer circumference, the centering housing 84 has in each case in the equatorial plane of the upper rings 88, 89 and the lower rings 90, 91 a circumferential groove 93, 94, which extends into the chambers 86, 87 in the centering 84 in which the balls 92 are arranged , In each groove 93, 94 sits a snap ring 95, 96 which presses under elastic bias against the balls 92 of the outer ring 89, 91, which in turn push the balls of the inner rings 88, 90 until abutting each other in the centering 85, so between the balls 92 of the inner rings 88, 90 a centering opening 85 remains. In addition, O-rings 97, 98 are interposed between the balls 92 of the inner rings 88, 90 and the outer rings 89, 91 arranged to compensate for different diameters of standard balls 92 and snap rings 95, 96, so that the balls 92 of the inner rings 88, 90 abut each other.

In addition, the driving ram 30 is provided in a lower portion with circumferential, superimposed grooves 101, 102. In vertical section, the grooves 101, 102 are slightly rounded, corresponding to the outer contour of the balls 92 of the Nagelzentrierung 83. The distance between the two grooves 101, 102 corresponds to the distance of the superposed wreaths 88, 89, 90, 91 from each other.

Before driving a nail 82 corresponds to the initial position of the second tacker 1 of Fig. 7 the starting position of Fig. 2 , Also in the second tacker 1, the second magnetic coupling 63 is disengaged and the first holding member 33 abuts against the second holding member 36 and the second holding member 36 on the sixth holding member 62 at.

The settling on the workpiece 3 takes place as in the first tacker 1, although the nail centering 83 touches the workpiece 3. This is in Fig. 8 shown.

By further moving the piston 12 down a nail 82 is driven. Here, the nail shaft is centered by the rings 88, 89, 90, 91 of balls 92 so that it just penetrates into the workpiece 3. Fig. 9 shows the driving tool with driven in the predetermined Eintreibtiefe nail 82. Here also engages the lower part of the driving ram 30 in the centering 85 and in the centering 85.1. The balls 92 of the two inner rings 88, 90 engage in the two grooves 101, 102 and are held by the snap rings 95, 96, 97, 98, 99, 100 therein.

According to Fig. 10 This has the consequence that during the subsequent displacement of the piston 12 upwards over the nail centering 83, the necking tool 7 and the pressure cylinder 6 are lifted upward until the second magnetic coupling 63 engages.

By abutment of the sixth holding element 62 on the first base plate 17, the pressure cylinder 6 is prevented from moving further upwards and the driving ram 30 is pulled out of the nail centering device 83. When the first holding member 33 encounters the second holding member 36, the pins 77 release the second magnetic coupling 63. The pressure cylinder 6 is held by abutment of the first holding element 33 on the second holding element 36 and the second holding element 36 on the sixth holding element 62. This is in Fig. 11 shown.

After feeding a further nail 82 from the magazine 8 in the drive-in channel 26, the tacker 1 is ready for another driving operation. this shows Fig. 7 ,

The third tacker 1 of FIGS. 13 to 17 has in contrast to the first tacker neither a first magnetic coupling, a second magnetic coupling, nor a lifting device on. Furthermore, the second holding element 36 is not held axially displaceably on the pressure cylinder 6, but instead is fixed in an inner step 103 at the upper edge thereof.

Another difference is that the piston 12 at the bottom has a hollow cylindrical, outer piston rod 15, at the lower edge of the first holding member 33 circumferentially protrudes radially outward (piston projection). Furthermore, centrally from the piston 12 downwardly there is an inner piston rod 15.2, which is connected to the driving ram 30. In the annular space between the inner piston rod 15.2 and outer piston rod 15.1 and in the pressure cylinder 6, a compression spring 104 is arranged, which is designed as a helical spring. The compression spring 104 is supported with the upper end on the underside of the piston 12 and with the lower end on the upper side of the first stop element 40 from.

Through the first through hole 18 of the sealing member 17, the outer piston rod 15.1 is sealingly passed. The sealing member 17 has there the fourth O-ring.

According to Fig. 13 is in the initial situation in which the piston 12 is in the upper piston position, the first holding member 33 on the second holding member 36 and holds the pressure cylinder 6 on the underside of the sealing member 17 fixed. The compression spring 104 is under a bias. Here, the necking tool 7 is located at a distance above the workpiece 3. The piston is held in the upper piston position by fed into the second air chamber 21 compressed air.

According to Fig. 14 the piston 12 is displaced downward by passing compressed air into the first air chamber 20 and the second air chamber 21 is vented. At the same time, the driving ram 30 and the pressure cylinder 6 shift downwards. Due to the action of the compression spring 104 and the dead weight of the pressure cylinder 6, the second holding element 36 is held in contact with the first holding element 33. The necking tool 7 finally sits on the workpiece 3.

According to Fig. 15 On further displacement of the piston 12, the first holding element 33 is released from the second holding element 36 and the outer piston rod 15.1 telescopes into the pressure cylinder 6. Here, the driving ram 30 is moved down the driving channel 26 and drives the nail 82 in the workpiece 3 a. The Eintreibtiefe is determined by the set position of the second stop member 40, which meets the lower end of the outer piston rod 15.1 as a first stop element 39.

Thereafter, the piston 12 is displaced upward, wherein initially the necking tool 7 remains in contact with the workpiece 3 and the driving ram 30 is pulled out of the necking tool 7 until the first retaining element 33 strikes the second retaining element 36. This is in Fig. 16 shown.

Thereafter, the first holding member 33 takes the second holding member 36 and thus the pressure cylinder 6, so that the mouth tool 7 is lifted from the workpiece 3. Finally, the pressure cylinder 6 bears against the underside of the sealing element 17. This is in Fig. 17 shown. After feeding a further nail 82 from the magazine 8 in the drive-in channel 26, the tacker 1 is ready for another driving operation.

Claims (15)

1. A driving tool for driving fastening means into workpieces comprising

   - a main cylinder (4) with a piston (12) displaceable therein and a sealing element (17) on the lower end with a first through hole (18) through which a piston rod (15) connected to the piston (12) passes in a sealing manner, wherein a first air chamber (20) connected to a first air inlet for filling with air for the purpose of displacing the piston (12) downwards is present in the main cylinder (4) above the piston (12), and a second air chamber (21) connected to a second air inlet for filling with air for the purpose of displacing the piston (12) upwards is present below the piston (12), characterized by

   - a pressing cylinder (6) that carries on the lower end an outlet tool (7) with a driving channel (26) into which a lower section of a driving tappet (30) connected to the piston rod (15) projects through an upper opening (27) and that has a lower opening (28) at the bottom for discharging fastening means (79),

   - a magazine (8) for fastening means (82) that is attached to a side opening (29) of the driving channel (26) in order to supply fastening means (82) to the driving channel (26),

   - a first holding device (32) that has a first holding element (33) connected to the piston rod (15) and a second holding element (36) connected to the pressing cylinder (6) that are designed so that the pressing cylinder (6) can be displaced into an upper pressing cylinder position by displacing the piston (12) into an upper piston position and the outlet tool (7) can be placed onto a workpiece (3) by displacing the piston (12) downwards from the upper piston position,

   - a first stop device (38) that has a first stop element (39) connected to the piston rod (15) and a second stop element (40) connected to the pressing cylinder (6) that are designed to limit the downward displacement of the driving tappet (30) in order to drive a fastening element (82) out of the driving channel (26) and into a workpiece (3) to a determined penetration depth by means of the driving tappet (30).
2. The driving tool according to claim 1, in which the first holding device (32) comprises a first projection (33) protruding from the piston rod (15) radially to the outside and a second projection (36) protruding from the pressing cylinder (6) radially to the inside, wherein the first projection (33) is arranged below the second projection (36) so that in the upper piston position the first projection (33) abuts the underside of the second projection (36) and can be displaced downwards away from the second projection (36) when the outlet tool (7) sits on the workpiece (3).
3. The driving tool according to claim 2, in which the first projection (33) is arranged at the bottom on a hollow cylindrical outer piston rod (15) that passes through the through hole (18) in a sealing manner, the lower edge of the outer piston rod (15.1) is the first stop element (52), the driving tappet (30) is connected to an inner piston rod (15.2) arranged concentrically in the outer piston rod (15.1), and a compression spring (104) is arranged in the ring space between the outer piston rod (15.1) and the inner piston rod (15.2) as well as in the pressing cylinder (6) and is supported with the one end on the underside of the main piston (12) and with the other end on the upper side of the second stop element (40).
4. The driving tool according to claim 1 or 2, in which a second holding device (51) is present that has a third holding element (52) connected to the piston rod (15) and a fourth holding element (53) connected to the pressing cylinder (6) that are designed so that they firmly hold the piston rod (15) on the pressing cylinder (6) when the first stop element (39) abuts the second stop element (40) so that when the piston (12) is displaced upwards the pressing cylinder (6) can be displaced upwards with it, in which a third holding device (60) is present that has a fifth holding element (61) on the main cylinder (4) and a sixth holding element (62) on the pressing cylinder (6) that are designed so that they can be connected to each other when the pressing cylinder (6) is displaced upwards, whereby the pressing cylinder (6) is held in the reached position and the connection between the third and fourth holding elements (52, 53) of the second holding device (51) is eliminated when the piston (12) is further displaced upwards, and in which a retracting device (76) is present that is designed so that it releases the connection between the fifth and the sixth holding elements (61, 62) when the first holding element (33) hits the second holding element (36).
5. The driving tool according to claim 4, in which the second holding device (51) is a first magnetic coupling (54), wherein a first magnetic coupling element (55) is connected to the piston rod (15) and a second magnetic coupling element (56) is connected to the pressing cylinder (6).
6. The driving tool according to claim 5, in which the first magnetic coupling element (55) is the first stop element (39) and the second magnetic coupling element (56) is the second stop element (40).
7. The driving tool according to one of claims 4 to 6, in which the third holding device (60) comprises a second magnetic coupling (63) that has a third magnetic coupling element (64) connected to the main cylinder (4) and a fourth magnetic coupling element (65) connected to the pressing cylinder (6), and wherein the third holding device (60) comprises a second stop device (73) that has a third stop element (74) on the main cylinder (4) and a fourth stop element (75) on the pressing cylinder (6) that are designed so that they abut each other and prevent a further upward displacement of the pressing cylinder (6).
8. The driving tool according to claim 7, in which the retracting device (76) comprises vertically aligned pins (77), the second holding element (36) can be displaced in the vertical direction until it abuts the sixth holding element (62), wherein the pins (77) can be displaced upwards with their upper ends over the sixth holding element (62) in order to push the fifth holding element (61) away from the sixth holding element (62), and the piston (12) is located in the upper piston position when the second holding element (36) abuts the sixth holding element (62).
9. The driving tool according to claim 7 and 8, in which the third magnetic coupling element (64) is held on a vertical guide device that is designed so that the third magnetic coupling element (64) can be displaced vertically upwards starting from a lower stop position, wherein the third magnetic coupling element (64) can be coupled with the fourth magnetic coupling element (65) in the lower stop position and can be pushed upwards away from the fourth magnetic coupling element (65) by means of the pins (77).
10. The driving tool according to claim 4, in which the second holding device has at least one groove (101, 102) in a lower section of the driving tappet (30) and at least one locking element (93) on the outlet tool (7) that locks into the groove (101, 102) when the first stop element (39) abuts the second stop element (40).
11. The driving tool according to claim 10, in which the outlet tool (7) has a nail centering (83) that has a centering opening (85.1) below the driving channel (26) that is limited by at least one guide element (92) movable in the radial direction that is pretensioned in the radial direction towards the centering channel (85) by at least one spring device (95, 96), wherein the guide element (92) is simultaneously the locking element of the third holding device.
12. The driving tool according to claim 11, in which the nail centering (83) comprises a centering housing (84) in which at least one circle (88 to 91) of balls (92) is arranged, between which the centering opening (85.1) is defined, wherein at least one elastic snap ring or other elastic ring acts as a spring device (95, 96) on the outside of the balls (92).
13. The driving tool according to one of claims 1 to 12, in which the second stop element (40) is held by a setting device (41) in the pressing cylinder (6), wherein the setting device (41) is designed to set the vertical location of the second stop element (40) in the pressing cylinder (6).
14. The driving tool according to claim 13, in which the second stop element (40) is a ring with an external thread (44) that is screwed into an internal thread (43) of an adjusting ring (42), wherein the adjusting ring (42) is guided between a first and a second bearing in the pressing cylinder (6) so that it can be rotated in the pressing cylinder (6) but cannot be displaced in the vertical direction, and a linear guide (50) is present which allows a displacement of the second stop element (40) in the vertical direction but hinders it from rotating about a vertical axis.
15. The driving tool according to one of claims 1 to 14, held on a woodworking bridge (2) or on another displacement device or on a stationary tool support.

Images