EP0720892B1 - Fastener driving tool - Google Patents

Description

The invention relates to a fastener driving tool according to the preamble of claim 1.

Such a driving tool is known from EP-A-065142.

Such driving tools have a muzzle tool an ejection channel through which fasteners are ejected can be. The ejection channel is one side-fed magazine. Across the food opening is a plunger that can be moved with a Ejection movement of a fastener from the muzzle tool pushes out. The plunger is on a working piston held in a working cylinder. The working displacement above the working piston is at a driving process filled with compressed air. For the return movement the working piston to its initial position aired. There can be a working displacement below the working cylinder with return air to drive the piston back be filled.

For controlling the air in the upper working stroke of the Piston assemblies are used. For smaller ones Series are known as "parallel valves" that arranged parallel to the working piston and directly one Trigger switch is assigned. This valve arrangement is connected to the working displacement via narrow channels, so that the efficiency is relatively low. With a parallel valve the housing can have a screw cap, which seals the working cubic space. The at air is displaced during the return movement of the working piston derived through an exhaust in the area of the handle, where it doesn't bother a user. With other driving tools So-called "head valves" are provided at which is a valve arrangement directly above the working cylinder located. Larger in the open position Flow cross sections between the working cubic space and compressed air reservoir released so that the driving process with significantly improved efficiency expires.

Conventionally there is a main valve above the cylinder intended. This has one in a valve chamber Valve piston, which is in a lower position with the Compressed air source connected inlet duct to the upper working stroke of the working cylinder shut off. In an upper one Position the valve piston shuts off an outlet channel, the through a bore in the valve piston with the working displacement connected is. For the movement between the The valve piston has a lower and upper position lower effective area, constantly from the pressure of the compressed air source is acted upon. It also has an upper effective area which can be selected using a control valve at atmospheric pressure or the pressure of the compressed air source is acted upon. The control valve is usually next to arranged the valve piston and by means of a Housing-guided valve rod can be actuated by the trigger. It but there are also device versions in which the control valve sits right next to the trigger and over a longer one Control channel is connected to the main valve.

The housing cap of these driving tools is above the main valve. It is with the device housing screwed and sealed against this. In the housing cap a valve seat element is arranged, which Drilling through the valve piston in its upper position closes and shuts off the outlet duct. Then compressed air can through the inlet duct into the working cubic space and drive the cylinder down. From the valve seat element from the outlet channel leads to an outlet opening on the Outside of the housing cap. In the lower position of the Valve piston is the compressed air source from the working cubic space separated and is the back of the working piston displaced air is discharged into the open through the outlet duct. The exhaust air flowing out of the housing cap can be a user interfere with the outflow in certain working positions can be aimed directly at his face. That is why housing caps are already attached to them from the outside Air control devices become known, which the Should influence the outflow favorably.

From DE-B-2 601 836 e.g. a valve assembly for one Generic nail gun known at extreme simple construction high impact performance with a minimum ensures air consumption and the sound pressure level of the Air outlet on the outside of the housing cap lowers.

The known head valve devices are due to the cap design made of cast metal or plastic, their sealing to the housing and any existing control equipment expensive for exhaust air.

Proceeding from this, the object of the invention is a driving tool for fasteners of the aforementioned Kind of creating that with less effort allows favorable discharge of the exhaust air.

The solution to the problem is specified in claim 1. Beneficial Refinements are contained in dependent claims 2-14.

In the driving tool according to the invention, the outlet channel at least one channel opening on the circumference of the housing cap on. The sits on the outside of the housing cap Channel opening assigned a rotatable aperture ring with at least an outlet opening. Between the housing cap and Aperture ring is a channel opening and in the circumferential direction Extending connecting channel connecting outlet extends. At the same time the cover ring is sealing between the housing cap and housing clamped. By turning the bezel ring is the outlet opening in different directions adjustable. The user can therefore in any application adjust the outlet opening so that it flows out Exhaust air does not bother. In addition, the aperture ring takes over Sealing the housing cap and housing. In contrast to The state of the art is therefore not one of the air guiding devices separate sealing element required. On top of that ensures the clamp fit of the aperture ring for fixing it on Device without additional fasteners would be required.

The outlet channel is preferably through at least one radial Outflow bore of the housing cap with the channel opening performed at the outer end. The connection channel can have a groove on the circumference of the housing cap. In the groove can open several channel openings. The outlet opening can be used for a low-noise and low-noise air outlet slit-shaped and over a peripheral portion of the Aperture ring extends. In addition, you can Air guide surface of the aperture ring can be assigned, which the exhaust air is preferred from that which is frequently turned towards the user Deflects the top of the device.

The aperture ring preferably has an L-shaped cross section, its vertical leg the circumference of the housing cap covered and his horizontal leg between sealing faces of the screw cap and housing is arranged. By pinching the horizontal leg becomes the seal between the housing cap and housing ensured. Clamping forces can suffice here allow the bezel ring to twist.

The housing cap can be designed as a flange cap, which is connected to the housing with several screws. Then the aperture ring can be outside the screw circle are located. However, the housing cap is preferred via a central threaded screw connection to the device housing connected. This facilitates a tilt-free Assembly, service and setting the clamping force for the aperture ring. In addition, the housing cap can be solid be executed so that it is like a hammer head for rework is usable. This device function is supported by the Training of the air control device favors. The cap does not need more elaborate than metal or plastic casting to be executed, but can be an inexpensive turned steel part.

The threaded screw connection preferably has an external thread on a hollow cylindrical cap shoulder of the housing cap and an internal thread at the top of the valve space on. A control channel of the control valve can be located below the housing cap in the valve compartment. Has preferred the control channel one when the housing cap is removed a linear movement from the externally accessible connecting section to the valve room. It is also preferred that the control valve or the control channel has a blind bore have introduced from the bottom of the housing is.

The valve piston can be in a hole in the device housing seal so that on a shoulder on the valve piston for an O-valve sealing ring can be dispensed with. The shoulder is formed in the device housing. As a result the main valve body is made with a simple tool will. This creates in the groove for the sealing ring No burr. In the preferred versions of the control channel or the control valve will open another avoided the top of the housing, so that a conclusion by the screwable housing cap is sufficient.

The valve piston of the main valve preferably has a piston attachment, the sealing through a bushing of the housing cap is guided and in the upper position sealing on the valve seat element is present. The socket can be sealed in the housing cap. The socket can be on top have hollow cylindrical bushing, the radial channel sections of the outlet channel. The valve seat element can be arranged in a blind hole in the housing cap be. Then the housing cap with socket or valve seat element unscrewable from the housing, whereby the valve piston remains in the valve chamber.

Fig. 1

ein Eintreibgerät mit Gehäusekappe mit zentraler Verschraubung im Querschnitt;

Fig. 2

das Eintreibgerät in Vorderansicht;

Fig. 3

Ventilkolben desselben Eintreibgerätes vergrößert in der Draufsicht (a) und im Querschnitt (b);

Fig. 4

Buchse desselben Eintreibgerätes vergrößert in Draufsicht (a), Seitenansicht (b), Unteransicht (c) und im Querschnitt (d);

Fig. 5

Gehäusekappe desselben Eintreibgerätes vergrößert in Draufsicht (a) und im Querschnitt (b);

Fig. 6

Blendenring desselben Eintreibgerätes vergrößert im Querschnitt (a), Draufsicht (b) und in Seitenansicht (c);

Fig. 7

flanschartig mittels mehrerer Schrauben an einem Gerätegehäuse fixierbare Gehäusekappe mit Blendenring in Draufsicht (a) und im Querschnitt (b).

Further details and advantages of the invention result from the following description of the attached drawings of preferred exemplary embodiments. The drawings show:

Fig. 1

a driving tool with a housing cap with a central screw connection in cross section;

Fig. 2

the driving tool in front view;

Fig. 3

Valve piston of the same driving tool enlarged in plan view (a) and in cross section (b);

Fig. 4

Socket of the same driving tool enlarged in plan view (a), side view (b), bottom view (c) and in cross section (d);

Fig. 5

Housing cap of the same driving tool enlarged in plan view (a) and in cross section (b);

Fig. 6

Aperture ring of the same driving tool enlarged in cross section (a), top view (b) and side view (c);

Fig. 7

Flange-like housing cap with diaphragm ring that can be fixed to a device housing by means of several screws in plan view (a) and in cross section (b).

1 and 2 has a housing 1, which has a working cylinder 3 in a housing head 2, in which a working piston 4 is arranged. The working piston 4 is connected to a driving plunger 5, which led into an ejection channel 6 of a muzzle tool 7 is. On the side of the muzzle tool 7 is a linear one Magazine 8 set for fasteners, the connected to the discharge duct 6 via a feed opening is.

The housing 1 also has a handle 9 in which a Compressed air storage space 10 is provided, which has a Hose connection 11 can be connected to a compressed air source is. At the rear end, the handle 9 is over a bridge 12 connected to the magazine 8. There is also a locking lever 13, which is used to open and close the magazine 8 serves when refilling fasteners.

On the underside of the handle 9 is next to the housing head 2 a release lever 14 on a control valve carrier 15 stored. The control valve carrier 15 houses one Switch pin 16, the with a cylindrical portion Release lever 14 contacted and with a cone section concentric with one connected to the compressed air supply space 10 Sealing bush 17 is aligned in the housing 1. In the position shown gives the switching pin 16 with his Cone section the passage of the sealing bush 17 free, so that a cavity formed in the control valve carrier 15 18 is connected to the compressed air supply space. When actuated the release lever 14 by swiveling up the cone section indented into the opening of the socket 17, so that the above connection is interrupted. At the same time becomes one in a groove between the cone section and cylinder section Arranged O-ring seal (not shown) lifted from a sealing seat of the control valve carrier 15 and a connection in the area of the cylinder section 16 the cavity 18 released with the environment.

The cavity 18 is connected to a control channel which a tube 19 in crossing the compressed air storage space 10 a blind hole made from the bottom of the housing 20 has. The control channel has one with the blind hole 20 connected connecting channel 21, which is in a valve chamber 22 opens out, which is arranged above the working cylinder 3 and closed at the top by a housing cap 24 is.

A valve piston 25 is arranged in the valve chamber 22 carries an O-ring 26 on the outer circumference. As in Fig. 3 can be seen more clearly, the valve piston 25 has a External stage 27 for receiving the O-ring 26. Top the valve piston 25 has a hollow cylindrical shape Piston shoulder 28. The valve piston has a central bore 29, which extends through the piston shoulder 28. At the top, the through hole 29 has an extension 30, the one Coil spring 31 receives.

The valve piston 25 has an O-ring groove 32 in the bottom an O-ring 33 sits on the underside of the valve piston survives something.

In the position shown in FIG. 1, the valve piston is supported 25 with the underside of the O-ring 33 sealing on top of the working cylinder 3. The coil spring 31 is supported on the underside of a valve seat element 34 from that inserted into a blind bore 35 of the housing cap 24 is.

The piston shoulder 28 is guided in a bushing 36 an O-ring for sealing against the piston shoulder 37 wears. As can be seen more clearly in FIG. 4, the socket 36 has an annular groove 38 inside for the O-ring on. Outside it has an annular groove 39 for another O-ring 40 for outside sealing. On the bottom the bush 36 has radially extending grooves 41 the bushing 36 carries a hollow cylindrical bushing 42, the top with radially extending outflow grooves 43 is provided.

1, the socket 36 is supported with its upper Edge on the underside of the housing cap 24, the Outflow grooves 43 allow air to pass between the inside and outside of the socket. The outside is Bushing 36 on the O-ring 40 on a hollow cylindrical Supported cap shoulder 44 of the housing cap 24.

As can be seen better from FIG. 5, the cap attachment has 44 an external thread 45. In the upper area 45 'is the Housing cap 24 designed as a flat truncated cone 45 '. There is a short one between the truncated cone 45 'and the cap shoulder 44 Cylinder section 46, which has an annular groove 47 on the outside. Radial outflow bores are in the cylinder section 46 48 arranged that opened to the inside of the cap are and have 47 channel openings 49 in the annular groove. The housing cap 24 is a solid turned part made of metal.

1, the housing cap 24 with its hollow cylindrical Approach 44 screwed into the housing head 2. For this, it has a at the upper edge of the valve chamber 22 Internal thread 50, which cooperates with the external thread 45.

The housing cap 24 carries on the outside of the cylinder section 46 has an aperture ring 51. According to FIG. 6, the Aperture ring 51 has a leg 52 for covering the annular groove 47 and a leg 53 which engages under the cylinder section 46. The leg 53 is between the housing cap 24 and clamped the upper edge of the housing head 2 and seals the housing cap 24 towards the housing 1. The thigh 52 has a slot-shaped outlet opening 54, which extends over extends a portion of its circumference (about 45 °). The leg has at the top of the outlet opening 54 51 an air guide surface 55, which is at an acute angle to the leg 52 is inclined. The aperture ring 51 can be turned, the air guide surface 55 being used as a finger attack can be. This allows the position of the outlet opening Change 54 to the ring groove 47.

Finally, there is also radial bore 56 in the working cylinder 3 to indicate that the work volume with a connect the return air chamber 57 surrounding the working cylinder. The return air chamber 57 is in the vicinity of the muzzle tool 7 via further radial bores 58 Larger cross section than the radial bores 56 with the Working displacement connected.

The device works as follows: In the starting position 1, the compressed air supply space 10 is over the cavity 18, the tube 20 and the connecting channel 21 connected to the valve chamber 22. Compressed air from the Compressed air storage space 10 thus acts on the upper side of the valve piston 25. At the same time, it lies on the underside of the valve piston 25 in the above the working cylinder 3rd protruding area. Because the pressure on the top Effective area of the valve piston 25 supported by the Coil spring 31 is greater than the pressure on the lower effective area is, the valve piston seals against pressed the upper edge of the working cylinder 3. The working displacement above the working piston 4 is over the Bore 29 of the valve piston 25 with the interior of the Bushing 36 and via the outflow grooves 43 with the interior of approach 44 connected. Via the outflow bores 48 and the annular groove 47 of the housing cap 24 and the outlet opening 54 of the aperture ring 51, it is also with the environment connected.

When the trigger lever 14 is actuated, the cavity 18 and thus the valve chamber 22 is connected to atmosphere. Consequently compressed air only acts on the lower effective area of the valve piston 25, so that this counter the action of the coil spring 31 in its upper open position in which he moved with the top of his Piston shoulder 28 sealing against the valve seat element 34 sets. This will connect the working cubic space interrupted to the atmosphere. At the same time, the movement enables of the valve piston 25 upward a flow of compressed air from the compressed air storage space 10 over the upper edge of the working cylinder 3 in the working space, so that the Working piston 4 is suddenly driven down. Here is driven by the plunger 5 from the magazine 8th tracked fastener through the muzzle tool 7 expelled.

After release of the release lever 14, this returns to his Starting position according to FIG. 1 back. As a result the upper effective surface of the valve piston 25 again with Compressed air applied. The grooves 41 of the bush 36 provide for a spread of the compressed air up to the piston attachment 28. As a result, the valve piston 25 is drawn into its lower closed position moved back and the connection of the working displacement with atmosphere restored. Compressed air is in the lowest piston position flowed through radial bores 56 into the return air chamber 57. The return air passes through the further radial bores 58 in the working space below the top ventilated working piston 4 and drives it into its Starting position according to FIG. 1 back.

It is particularly advantageous with this driving tool that the housing cap 24 can simply be screwed in and out can, the valve seat member 34 and the sealing pinched Socket 36 can be taken. In addition, the massive turned part as a face for reworking deploy. In addition, the diaphragm ring 51 enables adjustment the outlet opening 54 for the discharge of the exhaust air the piston movement upwards in a favorable for the user Direction. The aperture ring 51 causes at the same time a seal of the housing cap 24 against the housing 1.

7, a housing cap 59 can be arranged on a circle Have through holes 60 for receiving screws, with which it is flange-like above a main valve can be fixed to a housing. The housing cap 59 has a laterally projecting nose 61 that of the seal a bore of the Control valve or the control channel is used. On the bottom the housing cap 59 has a central blind hole 62 for a valve seat element and a groove 63 surrounding it, the inclusion of a silencer and the exhaust serves the exhaust air. There are radial outflow bores from the groove 63 64 led to the circumference of the housing cap 59, where they end in an annular groove 65.

A diaphragm ring 66 sits on the circumference of the housing cap 59 essentially L-shaped cross section. Its vertical Leg 67 is released at 68, so that the aperture ring on the cylindrical circumference of the housing cap 59 via a Angle is adjustable until it strikes the nose 61.

The aperture ring 66 also has a slot-shaped outlet opening 69, which extends over part of its circumference. Above the outlet opening 69 is an oblique one downwardly inclined air guide surface 70.

The horizontal leg 71 of the aperture ring 66 engages under the lower end face of the housing cap 59 so that he between this and the upper edge of a device housing can be pinched. The horizontal leg 71 is extends outside of the through holes 60 so that these a rotation of the aperture ring 66 does not hinder.

The annular groove 65 is on the circumference of the housing cap 59 only in the range of rotation of the vertical leg 67 of the diaphragm ring 66 extends. From the groove 63 through the outflow bores 64 exhaust air entering the annular groove 65 can only flow out through the outlet opening 69 and will therefore each derived from the rotational position of the aperture ring 66.

Claims (14)

1. A tacker for fastening means in which an apparatus housing (1) comprises a valve space (22) of a main valve, which is closed by a housing cap (24, 59) and in which a valve piston (25) is sealingly and slidingly guided coaxially above a working cylinder (3), which in a lower position blocks an inlet channel, connected to a pressurised air source, to the upper working stroke space of the working cylinder and in an upper position, by way of a sealing bearing on a valve seat element (34), blocks an outlet channel (43, 47, 48) which via a through bore (29, 30) of the valve piston (25) is connected to the working stroke space, wherein the valve piston comprises a lower effective surface which is constantly impinged by pressure of the pressurised air source, and an upper effective surface which with the help of a control valve (15, 16, 17) is selectively impinged with atmospheric pressure or pressure of the pressurised air source and wherein the outlet channel (29, 30, 43, 47, 48) comprises at least one channel opening (49) on the circumference (46) of the housing cap (24, 59), characterised in that the housing cap on the outside, allocated to the channel opening, carries a rotatable aperture ring (51, 66) with at least one outlet opening (54, 69), between the housing cap and the aperture ring there extends in the circumferential direction a connecting channel (47, 65) connecting a channel opening and outlet opening, and the aperture ring (51, 66) at the same time is sealingly clamped between the housing cap (24, 59) and the housing (1).
2. A tacker according to claim 1, characterised in that the outlet channel in the housing cap (24, 59) comprises at least one radial outflow bore (48, 64) with the channel opening (49) at the outer end.
3. A tacker according to claim 1 or 2, characterised in that the connecting channel comprises an annular groove (47, 65) on the circumference (46) of the housing cap (24, 59).
4. A tacker according to one of the claims 1 to 3, characterised in that the outlet opening (54, 69) is slot-shaped and is extended over a circumferential section of the aperture ring (51, 66).
5. A tacker according to one of the claims 1 to 4, characterised in that to the outlet opening (54, 69) there is allocated an air deflecting vane (55, 70) of the aperture ring (51, 66).
6. A tacker according to one of the claims 1 to 5, characterised in that the aperture ring (51, 66) has an L cross section, wherein the vertical arm (52, 67) is arranged on the circumference (46) of the housing cap (24, 59) and the horizontal arm (53, 71) between the end face sealing surfaces of the housing cap (24, 59) and the housing (1).
7. A tacker according to one of the claims 1 to 6, characterised in that the housing cap (24) comprises a central thread screwing (45, 50) with the apparatus housing (1).
8. A tacker according to one of the claims 1 to 7, characterised in that the housing cap (24, 59) is a turned steel part.
9. A tacker according to claim 7 or 8, characterised in that the thread screwing has an outer thread (45) on a hollow cylindrical cap shoulder (44) of the housing cap (24) and an inner thread (50) on the upper edge of the valve space (22).
10. A tacker according to one of the claims 1 to 9, characterised in that a control channel (19, 21) of the control valve opens out below the housing cap (24, 59) in the valve space (22).
11. A tacker according to claim 10, characterised in that the control channel has a section (19) with a pocket hole incorporated by the lower side of the housing, and/or has a connecting section (21) accessible by way of a straight-line movement with the housing cap (24, 59) removed.
12. A tacker according to one of the claims 1 to 11, characterised in that the valve piston (25) above has a hollow cylindrical piston shoulder (28) through which runs the through bore (29, 30) of the valve piston which sealingly and slidingly is guided in a sleeve (36) of the housing cap (24) and which in the upper position sealingly bears on the valve seat element (34).
13. A tacker according to claim 12, characterised in that the sleeve (36) is held outside sealingly in the housing cap (24).
14. A tacker according to claim 13, characterised in that the sleeve (36) above has a hollow cylindrical shoulder (42) which extends up to the lower side of the housing cap (24) and which comprises radial channel sections (43) of the outlet channel.

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