EP2923799A1 - Fastener driving tool - Google Patents

Abstract

The invention relates to a tacker comprising a handheld housing (1), a piston member received in a piston guide (2) for transferring energy from a propellant charge (3) to a fastener (4) to be driven in, and a releasably connected to the piston guide (2) The front part (6), wherein the front part (6) and the piston guide (2) parallel to a central axis (A) of the piston member are mutually displaceable, and wherein a release of the front part (6) of the piston guide (2), a relative rotation of the front part (6) and piston guide (2) by a release angle, wherein when twisting about the release angle, a torque barrier of a securing member (7) is overcome.

Description

The invention relates to a tacker according to the preamble of claim 1.

Hand-held driving devices with propellant charge are known from the prior art, in which after ignition of a pyrotechnic charge, the resulting fuel gases expand in a combustion chamber. As a result, a piston is accelerated as energy transfer means and drives a fastener into a workpiece.

In one type of such Eintreibgeräte without automatic piston recirculation of the piston is brought after a driving operation by a manual repeating movement in a start position. For this purpose, in a first portion of the repeating movement, a piston guide in the drive-in direction is pushed forward relative to a housing until a defined stop stops this movement. In a second section of the repeating movement, the piston guide is pushed in the opposite direction together with the piston to the rear in the housing until the piston guide reaches a defined rear stop. A front part of the piston guide is placed in the course of a driving operation on a workpiece and pressed by an axial stroke up to a stop, whereby a triggering of the device is released. For purposes of maintenance and cleaning of such devices, the front part of the piston guide can be dismantled, after which the piston can be removed from the piston guide as a rule.

In a previously known device, the disassembly of the front part of the piston guide takes place in that the two components are moved in the axial direction in an intermediate position at about half the axial stroke, after which a relative rotation of the components to each other and finally an axial pulling must be done. These movements correspond to a backdrop-like configuration of a guideway provided on the piston guide. An assembly takes place in the opposite way.

It is the object of the invention to provide a tacker that allows easy disassembly for maintenance purposes.

This object is achieved according to the invention for a drive-in device mentioned above with the characterizing features of claim 1. Through the torque barrier, the process of mounting and dismounting of the front part and piston guide is haptically improved. In addition, unintentional release of the components can be prevented by simple means.

A central axis in the sense of the invention is an axis at least parallel to the movement of the fastening element, which runs through a center of the piston member.

A piston member according to the invention is any means that is acted upon by the ignition of the propellant charge with kinetic energy, wherein the kinetic energy is ultimately transmitted to the fastener. Often the piston member is designed as a particular cylindrical piston.

A piston guide according to the invention is a component in which at least one rear end of the piston member is guided. In particular, the piston guide may comprise a combustion chamber, in the region of which the propellant charge is ignited and the piston member is accelerated.

A front part of the piston guide is in the context of the invention, a component facing the workpiece, which is moved in the direction of the piston guide before the initiation of the driving operation, in particular by placing and pressing on the workpiece. Preferably, a securing device of the tacker is thereby released, which prevents ignition of the propellant charge when not displaced in the direction of the piston guide front part.

In addition, in the front part, a muzzle part for receiving the fastening element, in which a front end of the piston member can retract, is generally advantageously used.

A torque barrier is understood to mean a resistance which opposes the rotation and yields when a corresponding torque is exceeded. It may be in particular a detent position of a resilient or force-loaded with a spring element of the securing member.

A securing member according to the invention is a device which prevents the front part from being detached from the piston guide in the normal operating state.

Under a fastener according to the invention is generally understood any retractable anchoring, such as nail, bolt or screw understood.

In a generally advantageous embodiment of the invention, the securing member comprises at least one preferably resiliently mounted guide member, which is arranged on one of the two, front part or piston guide. Particularly preferably, the guide member runs in this case in one of the other of the two, front part or piston guide, arranged and parallel to the central axis extending guideway. Overall, this can be a mechanically simple and safe constructed connection of the components are provided. In terms of a simple construction, the guideway is preferably located on the piston guide, which is inserted into the front part.

For easy realization of the torque barrier, a transverse web branching off in the circumferential direction from the guideway is provided in at least one axial release position, wherein the transverse web has a reduced depth relative to the guideway for forming the torque barrier. The guide member must overcome the reduced depth against a spring force, which requires a correspondingly increased torque. In a preferred detailed design of the transverse web, this can be done by means of an acoustically perceptible detent.

Further preferably, a parallel to the guide track extending disassembly path is also provided, wherein the guide member of the guideway on the transverse track can enter the disassembly track. After entering the disassembly track, the front part can then be pulled off the piston guide, for which purpose the disassembly track preferably opens open into an edge of the piston guide.

In a particularly preferred embodiment of the invention, the axial release position is arranged at an axial end position of the guide track. This allows an intuitive and easy disassembly of the components, since the operator must push the front part against rotation only to stop against the piston guide or pull out. In a particularly preferred variant, it is provided that at each of two axial end positions of the guide track, an axial release position is provided, each with a transverse branching in the circumferential direction. As a result, the assembly and disassembly is particularly simple and intuitive, since a release in any axial end position of the front part relative to the piston guide is possible.

To obtain a low frictional resistance and a good feel, it is provided in a generally preferred detailed design that the guide member is formed as a ball. In particular, a guide track and / or disassembly track may have a part-circular cross-section corresponding to the radius of curvature of the ball.

In a simple structural realization, the guide member is held by means of a resilient retaining ring in a bore. The bore may in particular be dimensioned so that the guide member is inserted only up to a supernatant on the other side, but can not be pushed through the hole.

Generally advantageously, the securing member does not comprise any parts which are separated in a disassembly in addition to the piston guide and the front part. As a result, a possible loss of small parts such as cotter pins, spring washers or the like is avoided.

Further advantageously, a securing member described above may be provided multiple times, for example in the form of two guide paths offset by 180 °, each having a guide member. The guide members can be held resiliently in particular by means of a common spring washer.

Fig. 1

zeigt eine räumliche Gesamtansicht eines erfindungsgemäßen Eintreibgerätes.

Fig. 2

zeigt eine räumliche Ansicht einer Kolbenführung des Eintreibgerätes aus Fig. 1 mit daran verschiebbar festgelegtem Vorderteil.

Fig. 3

zeigt eine räumliche Detailansicht der Kolbenführung aus Fig. 2 bei demontiertem Vorderteil.

Fig. 4

zeigt eine räumliche Detailansicht des Vorderteils aus Fig. 2 bei demontierter Kolbenführung.

Fig. 5

zeigt eine Schnittansicht entlang einer Zentralachse A durch die Kolbenführung mit festgelegtem Vorderteil aus Fig. 2.

Fig. 6

zeigt eine Schnittansicht durch die Anordnung aus Fig. 5 entlang der Linie B - B.

Further features and advantages of the invention will become apparent from the embodiment and from the dependent claims. Hereinafter, a preferred embodiment of the invention will be described and explained in more detail with reference to the accompanying drawings.

Fig. 1

shows a general view of a Eintreibgerätes invention.

Fig. 2

shows a three-dimensional view of a piston guide of the tacker Fig. 1 with front part slidably fixed thereto.

Fig. 3

shows a detailed spatial view of the piston guide Fig. 2 with disassembled front part.

Fig. 4

shows a detailed spatial view of the front part Fig. 2 with disassembled piston guide.

Fig. 5

shows a sectional view along a central axis A through the piston guide with a fixed front part Fig. 2 ,

Fig. 6

shows a sectional view through the arrangement Fig. 5 along the line B - B.

A drive-in device according to the invention comprises a hand-guided housing 1, in which a piston member in the form of a piston (not shown) is accommodated. The piston member is located in a piston guide 2 with a combustion chamber in which the combustion gases of a pyrotechnic charge 3 expand to accelerate the piston.

The so acted upon by kinetic energy piston hits with an end-side plunger on a fastener 4, which is thereby driven into a workpiece. The fastening element 4 is inserted in a mouth part 5, which in turn is accommodated in a front part 6 of the piston guide 2. The fastening element 4 and the mouth part 5 are rotationally symmetrical about a central axis A. The central axis A is also a central axis of the piston guide 2 and the piston member.

The front part 6 is pushed over the piston guide 2 and releasably fixed by means of a securing member 7 on the piston guide. In this fixed state (see Fig. 2 . Fig. 5 and Fig. 6 ) Front part 6 and piston guide 2 can be moved by a stroke H against each other until each stop stops the shift.

About this hub a security mechanism is operated in a known manner during operation of the tacker, which allows a triggering of the charge 3 only when the device is placed on a workpiece and the front part is pushed with a sufficiently large pressing force to the full stroke H.

The present invention is the releasable fixing of the front part 6 on the piston guide 2. For this purpose, a guide track 8 is formed in the outside of the piston guide 2, which has a substantially part-circular cross-section. In the guideway 8 engages a guide member 9 in the form of a ball of steel. The length of the guide track 8 corresponds to the axial stroke H, wherein both ends of the guide track are closed.

The ball 9 is resiliently held by means of a spring ring 10 from the outside in a bore 11 in the wall of the front part 6. The bore 11 has a maximum diameter which remains below the diameter of the ball 9, so that the ball 9 protrudes partially on the inside of the wall, but can not fall out.

Parallel to the guide track 8 extends a disassembly track 12, one end of which opens openly into the edge of the piston guide 2.

From each of the ends of the guide track 8 extends in the circumferential direction in each case a transverse path 13, 14 up to the parallel disassembly track 12. Each of the transverse tracks 13, 14 is of lesser depth than the disassembly track 12 and the guide track. 8

The invention now works as follows:

First, the assembled module of the front part 6 and piston guide 2, in which the piston and the mouthpiece 5 are located, removed from the tacker, possibly previously a holding member is opened. Subsequently, piston guide 2 and front part 6 are disassembled from each other to remove the piston and make cleaning and maintenance as needed.

In this case, the front part is first pulled or pushed to the stop of the ball 9 at one end of the guideway 8. Starting from this end position, the front part is rotated relative to the piston guide by a release angle of about 20 ° in the present case, wherein the ball 9 passes through a corresponding transverse path 13, 14 in the disassembly track 12. In this case, the ball is pressed over a movement section against the force of the spring ring, since the transverse web 13, 14 has a reduced depth. As a result, a torque threshold must be exceeded during rotation.

Once the ball 9 is running in the disassembly track 12, the front part 6 can be deducted from the piston guide 2.

The subsequent assembly takes place in accordance with the reverse order.

As shown in the drawings, in the present case two identical securing members 7 are provided from disassembly track 12, guide track 8, transverse tracks 13, 14 and ball 9, which are arranged offset by 180 ° to the components 2, 6. As a result, a particularly uniform and low-friction guidance of the front part 6 is ensured on the piston guide.

Claims (9)

A tacker comprising
a hand-held housing (1),
a piston member received in a piston guide (2) for transmitting energy from a propellant charge (3) to a fastener element (4) to be driven in, and
a front part (6) releasably connected to the piston guide (2),
wherein the front part (6) and the piston guide (2) parallel to a central axis (A) of the piston member are mutually displaceable, and
wherein a release of the front part (6) from the piston guide (2) comprises a relative rotation of the front part (6) and piston guide (2) by a release angle, characterized
in that a torque barrier of a securing member (7) is overcome during the rotation about the release angle. A tacker according to claim 1, characterized in that the securing member (7) comprises at least one in particular resiliently mounted guide member (9) which is arranged on one of the two, front part (6) or piston guide (2). A tacker according to claim 2, characterized in that the guide member (9) in one of the other of the two, front part (6) or piston guide (2), arranged and parallel to the central axis (A) extending guideway (8) runs. A tacker according to claim 3, characterized in that in at least one axial release position in the circumferential direction of the guideway (8) branching transverse track (13, 14) is provided, wherein the transverse web (13, 14) relative to the guide track (8) reduced depth to form the torque barrier. A tacker according to claim 4, characterized in that a parallel to the guide track (8) extending disassembly track (12) is provided, wherein the Guide member (9) of the guide track (8) via the transverse web (13, 14) in the disassembly track (12) can occur. A tacker according to claim 4 or 5, characterized in that the axial release position at an axial end position of the guide track (8) is arranged. A tacker according to claim 6, characterized in that at each of two axial end positions of the guide track (8) an axial release position, each with a circumferentially branching transverse track (13, 14) is provided. A tacker according to any one of claims 2 to 7, characterized in that the guide member (9) is formed as a ball. A tacker according to any one of claims 1 to 8, characterized in that the guide member (9) by means of a resilient retaining ring (10) is held in a bore (11).

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