EP3479963A1 - Compressed air nail gun with safety valve assembly - Google Patents

Abstract

Pneumatic nailer with €¢ a working piston which is connected to a driving ram for driving in a fastener and is pressurized with compressed air when the driving process is triggered, €¢ a release valve (22) which has a valve sleeve (44) and a valve pin (42) guided in the valve sleeve (44), €¢ a control line (82), which is pressurized or vented by the release valve (22) to trigger a driving-in process when the valve pin (42) is displaced into an actuated position relative to the valve sleeve (44), €¢ a trigger (14), a contact sensor (24) and a button (40) coupled to the trigger (14) and/or to the contact sensor (24) for actuating the valve pin (42), €¢ an outer sleeve (60) in which the valve sleeve (44) is guided, the valve sleeve (44) being displaceable relative to the outer sleeve (60) according to a pressure in a safety control chamber (62) between a release position and a blocking position, characterized in that €¢ the button (40) is coupled to the trigger (14) and/or to the contact sensor (24) in such a way that it is always in a fixed predetermined switch position relative to the outer sleeve (60) when both the trigger (14 ) and the touchdown sensor (24) are actuated, with €¢ the button (40) in the switch position is arranged such that it displaces the valve pin (42) into the actuated position when the valve sleeve (44) is in the released position and that it does not move the valve pin (42) into the shifted actuated position when the valve sleeve (44) is in the locked position.

Description

The invention relates to a pneumatic nailer having a trigger, a touch sensor and a trigger valve with a valve pin and a valve sleeve. When the valve pin is displaced relative to the valve sleeve to an actuated position, a control line is vented to initiate a drive-in operation. The valve pin is actuated by a button that is coupled to the trigger and / or the touchdown sensor.

If such a compressed air rod is attached to a workpiece, the Aufsetzfühler is displaced against the force of the spring until a muzzle tool rests against the workpiece or almost rests. Only with such actuated Aufsetzfühler a driving operation can be triggered. As a result, the pneumatic nailers offer considerably improved safety against unintentional releases compared to devices without touch sensors.

Some pneumatic nailers of the type described can be used in two different operating modes: In the so-called single release, the pneumatic nailer is first attached to a workpiece and thus the Aufsetzfühler actuated. Subsequently, the trigger is actuated by hand, thereby triggering a single drive. In the so-called contact release, also referred to as touch, the user already holds the trigger while pressing the pneumatic nailer against the workpiece. When attaching to the workpiece of the touch sensor is actuated, thereby initiating a drive-in. The compressed air nailer can be repeatedly set in rapid succession, which allows a very fast working, especially if many fasteners must be driven for a sufficient attachment to the positioning accuracy only small demands are made.

In certain situations, however, the contact triggering procedure entails an increased risk of injury. For example, not only does the user depress the hand-operated trigger when he wants to place the pneumatic nailer on one and the same workpiece a few centimeters from the last driven fastener, but also when changing to another remotely located workpiece in an accidental contact of an object or body part with the Aufsetzfühler a driving operation are triggered. For example, accidents can occur when a user (in disregard of important safety regulations) climbs a ladder with the pneumatic nailer while holding the trigger and accidentally brushing his leg with the touch probe.

Some known Druckluftnagler seek to reduce this associated with the contact tripping operation risk that a contact triggering after pressing the shutter or after a driving operation only for a short period of time is possible. Once the period has elapsed, the trigger must first be released. An example of this is from the document EP 2 767 365 B1 known. The pneumatic nailer described therein has a trigger and a Aufsetzfühler, each associated with a control valve. In addition, the known device has a safety control chamber, the pressure acting on a locking piston. In a certain position of the locking piston, the triggering of a driving operation is prevented. The safety control chamber is vented via the trigger valve associated control valve and a throttle. As a result, a contact release is possible only after the actuation of the trigger until the pressure in the safety control chamber has exceeded a predetermined pressure threshold. Thereafter, the pneumatic nailer is locked until the trigger is released and the pressure in the safety control chamber has fallen below the pressure threshold again.

A similar functionality offers from the U.S. Patent No. 3,964,659 become known pneumatic nailer, which also in a single and in a contact trip operation can be used and in which a trigger and a touch sensor are mechanically coupled via a rocker. The rocker acts on a control valve to initiate a drive-in operation by venting a main control line. If only the trigger and not the touch sensor is actuated, a control pin of the control valve is moved only over part of its displacement. This half actuation of the control valve results in slow ventilation of a control chamber via a small vent. The pressure prevailing in the control chamber acts on a valve sleeve, which surrounds the control valve, and finally displaces this valve sleeve into a blocking position in which a complete actuation of the valve pin can no longer vent the main control line, so that a contact release is not possible.

In some known devices, a first trip is possible only in single trip mode. For the first driving operation, these devices must therefore first be attached to the workpiece, whereby the Aufsetzfühler is actuated. A subsequent actuation of the trigger then triggers the first drive. Subsequently, further driving operations can be carried out by contact triggering within a short period of time, that is to say by repeatedly lifting off and attaching the device to the workpiece while the trigger is pressed continuously. This functionality is in the document DE 10 2013 106 657 A1 given compressed air nailer described. For this purpose, a trigger and a touch sensor are mechanically coupled via a rocker, which acts on a control valve to trigger a driving operation. With each driving operation, a pressure is built up in a control chamber which acts on a mechanical actuator. The control chamber is slowly vented through a vent. Depending on the pressure in the control chamber, the actuator comes into a blocking position, whereby a mechanical action of the touch sensor on the rocker prevents actuated trigger and a contact triggering is impossible. In an embodiment shown in said publication, the mechanical actuator is guided in an outer sleeve valve sleeve in which a valve pin of a trigger valve is guided. In the blocking position, the valve sleeve holds the valve pin and with it the rocker applied to the valve pin in a position in which the rocker is missed by the Aufsetzfühler. Then a further release is only possible after the trigger is released and the device has been removed from the workpiece.

On this basis, it is the object of the invention to provide a pneumatic nailer with an effective, robust and reliable safety mechanism available.

This object is achieved by the pneumatic nailer with the features of claim 1. Advantageous embodiments are specified in the subsequent subclaims.

• einen Arbeitskolben, der mit einem Eintreibstößel zum Eintreiben eines Befestigungsmittels verbunden ist und beim Auslösen eines Eintreibvorgangs mit Druckluft beaufschlagt wird,
• ein Auslöseventil, das eine Ventilhülse und einen in der Ventilhülse geführten Ventilstift aufweist,
• eine Steuerleitung, die zum Auslösen eines Eintreibvorgangs durch das Auslöseventil be- oder entlüftet wird, wenn der Ventilstift relativ zu der Ventilhülse in eine betätigte Stellung verlagert wird,
• einen Auslöser, einen Aufsetzfühler sowie eine mit dem Auslöser und/oder mit dem Aufsetzfühler gekoppelte Schaltfläche zur Betätigung des Ventilstifts,
• eine Außenhülse, in der die Ventilhülse geführt ist, wobei die Ventilhülse relativ zu der Außenhülse nach Maßgabe eines Drucks in einer Sicherheitssteuerkammer zwischen einer Auslösestellung und einer Sperrstellung verlagerbar ist, wobei
• die Schaltfläche derart mit dem Auslöser und/oder mit dem Aufsetzfühler gekoppelt ist, dass sie sich immer in einer fest vorgegebenen Schaltstellung relativ zu der Außenhülse befindet, wenn sowohl der Auslöser als auch der Aufsetzfühler betätigt sind, und
• die Schaltfläche in der Schaltstellung so angeordnet ist, dass sie den Ventilstift in die betätigte Stellung verlagert, wenn sich die Ventilhülse in der Auslösestellung befindet, und dass sie den Ventilstift nicht in die betätigte Stellung verlagert, wenn sich die Ventilhülse in der Sperrstellung befindet.

The pneumatic nailer has

• a working piston, which is connected to a driving ram for driving in a fastening means and is subjected to the triggering of a driving operation with compressed air,
• a trigger valve having a valve sleeve and a valve pin guided in the valve sleeve,
• a control line which is aerated or vented to initiate a drive operation by the trigger valve when the valve pin is displaced relative to the valve sleeve to an actuated position,
• a trigger, a touch probe, and a button for actuating the valve pin coupled to the trigger and / or the touch probe;
• an outer sleeve in which the valve sleeve is guided, wherein the valve sleeve is displaceable relative to the outer sleeve in accordance with a pressure in a safety control chamber between a release position and a locking position, wherein
• the button is coupled to the trigger and / or the touchdown sensor such that it is always in a fixed predetermined switching position relative to the outer sleeve when both the trigger and the touchdown sensor are actuated, and
• the button in the switch position is arranged to displace the valve pin to the actuated position when the valve sleeve is in the release position and not to displace the valve pin to the actuated position when the valve sleeve is in the locked position.

The pneumatic rodger is used to drive fasteners such as nails, pins or staples. For this purpose, the pneumatic nailer can have a magazine for the fastening means, from which in each case a fastening means is supplied to a receptacle of a necking tool of the pneumatic nailer.

Both the drive and the control of the pneumatic nailer can be done completely pneumatically, a supply of electrical energy is therefore not required. By "venting" is always meant that a connection to a non-pressurized space, in particular to the outside air, is produced. By "venting" is always meant that a connection is made to a compressed air leading room.

The trigger can be realized for example in the form of a tilt or push button. The touchdown sensor may be a mechanical component that projects beyond the forward end of a necking tool and is held in this position by a spring until the pneumatic nailer is attached to a workpiece. Then the Aufsetzfühler is displaced against the direction of the spring force and against the driving direction.

When initiating a driving operation, a working piston of the pneumatic nailer is pressurized with compressed air. The working piston drives a driving ram, which is connected to the working piston. The drive ram strikes a rear end of the fastener in the receptacle of the muzzle tool and drives the fastener into the workpiece.

To initiate a drive-in process, a control line must be vented or vented. This is done via a trigger valve, which is actuated by displacing a valve pin relative to a valve sleeve. The valve sleeve is in turn guided in a (usually arranged in a fixed position to a housing of the pneumatic nailer) outer sleeve, so that it is displaceable between a release position and a blocking position. The position in which the valve sleeve is located relative to the outer sleeve depends on a pressure in a safety control chamber.

The safety control chamber thus offers the possibility of realizing a time-controlled behavior of the pneumatic nailer. For example, the pressure in the safety control chamber can be controlled so that a predetermined pressure threshold is exceeded or fallen short of after a predetermined period of time has elapsed since the last driving operation and / or since the last actuation of the trigger.

The actuation of the valve pin by means of a button which is coupled to the trigger and / or with the touch sensor. Unlike some of the prior art pneumatic nailers, this coupling does not require a complicated, possibly interference-prone mechanism, but is designed so that the button will always be in a fixed switch position relative to the outer sleeve when both the trigger and the landing feeler are actuated. In particular, on an operating sequence of trigger and Aufsetzfühler it does not matter.

Whether a drive-in process is triggered or not, thus depends not on the effectiveness of the coupling between trigger and Aufsetzfühler, but essentially only from the position of the valve sleeve relative to the outer sleeve. The button is always in the switching position when the trigger and the touch probe are actuated together. If the valve sleeve is then in the release position, the button moves the valve pin to the actuated position. On the other hand, when the valve sleeve is in the locked position, the button does not move the valve pin to the actuated position.

Overall, the pneumatic nailer is characterized by a particularly simple and robust design.

In one embodiment, the pneumatic nailer on a triggered by the trigger safety control valve that controls a ventilation or bleeding the safety control chamber. The pressure profile in the safety control chamber thus depends directly on the actuation of the trigger.

In one embodiment, a connection between the safety control chamber and a vented housing interior is shut off by the safety control valve when the trigger is actuated. In this case, the safety control chamber is permanently and immediately vented via the safety control valve when the trigger is not actuated. This ventilation ends when the shutter button is pressed.

In one embodiment, the safety control chamber is connected via a throttle with outside air. With the safety control chamber vented, this results in a continuous, small amount of airflow that may be accompanied by an audible noise. This operating noise may indicate to a user the operational readiness of the pneumatic nailer. As soon as an influx into the safety control chamber ends, in particular after actuation of the safety control valve by the trigger, the pressure in the safety control chamber slowly decreases, so that falls below a pressure threshold in the safety control chamber, the valve sleeve enters the blocking position and prevents further triggering.

Under certain circumstances, a user can recognize from the decreasing operating noise that he first has to release the trigger again before another drive-in process.

In one embodiment, the button is formed on a rocker having a fixed end and a free end, wherein the fixed end is rotatably mounted on the trigger and the free end is taken on actuation of the Aufsetzfühlers of the Aufsetzfühler. In this embodiment, it is a proven form to couple the button with the trigger and the touch sensor. Regardless of the order of operation, the button will always be brought into the same position when the trigger and touch sensor are pressed.

In one embodiment, the button is formed on the touch sensor and has a fixed position relative to the Aufsetzfühler. In this variant, the button is only coupled with the touch sensor and not with the trigger. If the valve sleeve is in the release position, the trigger valve is thus actuated by each actuation of the attachment sensor. If the trigger is also in an actuated position, a drive-in process is triggered in each case.

In one embodiment, the safety control valve and the trigger valve are connected in series. This means that for the desired ventilation of the control line, the safety control valve and the trigger valve must be actuated simultaneously. For example, an output of the trigger valve may be directly or indirectly connected to the control line, while an input of the trigger valve is connected to an output of the safety control valve. An input of the safety control valve may be connected to a ventilated housing interior. In this case, there may be a fixed allocation in that the touch sensor acts directly on the trigger valve and the trigger directly on the safety control valve. A mechanical coupling of trigger and Aufsetzfühler is not required.

In one embodiment, the safety control chamber is vented via the trigger valve and a check valve when the valve pin is displaced relative to the valve sleeve to the actuated position. By this measure, the pressure in the safety control chamber is "reset" simultaneously with the triggering of a driving operation. It is thus created with each driving operation with respect to the pressure in the safety control chamber a defined starting situation. In particular, from this point on a predetermined time window can be opened for triggering further driving operations with the shutter actuated permanently.

In one embodiment, the check valve is integrated in the valve sleeve. For example, the check valve may have an O-ring which is held in a circumferential groove of the valve sleeve and which seals a radial bore in the valve sleeve arranged in the groove. The integration of the check valve in the valve sleeve a particularly compact design is achieved.

In one embodiment, the safety control chamber on an annular space which is bounded by two seals inserted between the outer sleeve and the valve sleeve, which are spaced apart in the axial direction and in the radial direction. This measure also favors a particularly compact design. Another advantage is that the volume of the safety control chamber is unaffected by actuation of the valve pin.

In one embodiment, there is a permanently ventilated back pressure chamber, the pressure in the back pressure chamber exerting a counterforce on the valve sleeve that is directed opposite to the force exerted on the valve sleeve by the pressure in the safety control chamber. Alternatively and / or additionally, a spring can be used to exert a counterforce on the valve sleeve. The use of a permanently ventilated back pressure chamber is particularly advantageous because the force exerted by the pressure in the safety control chamber and the force exerted by the pressure in the back pressure chamber counterforce depend in the same way on the operating pressure of the pneumatic nailer. This leads to a largely independent of pressure fluctuations functioning of the safety mechanism.

In one embodiment, the back pressure chamber has an annular space bounded by two seals adjacent to the valve sleeve, which are spaced apart in the axial direction and in the radial direction. This also contributes to a particularly compact design. In addition, in this annular shape of the back pressure chamber of the valve pin can be easily passed through a central opening of the back pressure chamber to the outside.

Fig. 1

einen erfindungsgemäßen Druckluftnagler in einer teilweise geschnittenen Darstellung,

Fig. 2

eine vergrößerte Ansicht eines Ausschnitts aus Figur 1, der ein Hauptventil und ein Vorsteuerventil umfasst,

Fign. 3 bis 7

einen Ausschnitt aus Figur 1 mit einem Auslöser, einem Auslöseventil und einem Sicherheitssteuerventil in unterschiedlichen Betriebszuständen.

The invention will be explained in more detail with reference to an embodiment shown in FIGS. Show it:

Fig. 1

a compressed air nailer according to the invention in a partially sectioned illustration,

Fig. 2

an enlarged view of a detail from FIG. 1 comprising a main valve and a pilot valve,

FIGS. 3 to 7

a section from FIG. 1 with a trigger, a trigger valve and a safety control valve in different operating states.

First, based on the Fig. 1 some important elements of Druckluftnaglers 10 shown in part überblicksartig. The pneumatic nailer 10 has a handle 12 which is fixed to a lower housing part 140, which is closed at the top by a housing cap 142.

The Druckluftnager 10 has a Aufsetzfühler 24 which projects beyond the mouth 26 of a muzzle tool 28 by a few millimeters down. If the pneumatic nailer 10 is attached to a workpiece, the Aufsetzfühler 24 is displaced upward against the force of a spring, not shown, until it is flush with the mouth 26 or only slightly beyond the mouth 26. The touch sensor 24 is mechanically coupled to a power transmission element 30, which moves with the movement of the Aufsetzfühlers 24 upwards.

The mouth tool 28 has a receptacle 46, to which a fastening means is supplied from a magazine 48 in each case. From this position within the receptacle 46, the fastening means - for example, a nail, a pin or a clip - by a driving ram 50, which is connected to a working piston 52 of the pneumatic nailer 10, driven. For this purpose, the working piston 52 is guided in a working cylinder 54. Above the working cylinder 54 and this sealingly closing a main valve 56 is arranged, to the right thereof a pilot valve 58 which controls the main valve 56. Details of these elements and the associated function of the device are based on the enlarged detail of the FIG. 2 explained in more detail.

The pilot valve 58 is best in the FIG. 2 recognizable. It has a control piston 94, which is guided in a guide sleeve 96. The lower end of the control piston 94 is sealed with a lower O-ring 100 opposite the guide sleeve 96. In the initial state of the Druckluftnaglers 10, a first control line 82 which is connected to a working volume of the pilot valve 58, vented and the control piston 94 is in the lower position shown. In this position, it is held by the force of a spring 102.

The spool 94 has a middle O-ring 104 and an upper O-ring 106 in addition to the lower O-ring 100. In the illustrated lower position of the control piston 94, the upper O-ring 106 seals the control piston 94 with respect to Guide sleeve 96 and closes a connection to a vent not shown, which is connected to outside air. The middle O-ring 104 is not in seal, so that a main control line 110 is connected via a radial bore 112 in the guide sleeve 96 and the annular gap 70 between the control piston 94 and guide sleeve 96 on the middle O-ring 104 past the housing interior 64. The main control line 110 is connected via a not visible in the sectional plane shown connection with the space 72, which opens into the radial bore 112. The housing interior 64 is vented in the initial state of the pneumatic nailer 10, that is connected to a compressed air connection, not shown, and standing under operating pressure.

The main control line 110 is connected to a space 114 above a main valve actuator 116 of the main valve 56, so that the main valve actuator 116 is acted upon by a downward force and thereby the upper edge of the working cylinder 54 by means of an O-ring 118 relative to the housing interior 64th seals. In addition, the main valve actuator 116 is acted upon by a spring 120 with a force in the direction of the shown, the working cylinder 54 occluding position.

A drive-in operation is initiated by venting the control line 82 by displacing the control piston 94 upwardly so that the center O-ring 104 enters the seal and the upper O-ring 106 moves out of the seal. Thereby, the connection of the main control line 110 is shut off to the housing interior 64 and a connection between the main control line 110 and a vent not shown is made. The space 114 above the main valve actuator 116 is vented through the vent and the main valve actuator 116 is displaced upward by the pressure prevailing at its lower, outer annular surface 122 in the housing interior 64 against the force of the spring 120. As a result, compressed air flows from the housing interior 64 into the working cylinder 54 above the working piston 52 and drives the working piston 52 after below. During this downward movement, the driving ram 50 connected to the working piston 52 drives a fastening means.

How überblicksartig in FIG. 1 can be seen, located below the pilot valve 58 is a triggering device with a trigger valve 22, a safety control valve 16 and a trigger 14. Details of the triggering device are based on the FIGS. 3 to 7 explained in more detail.

It can be seen there that the trigger 14 is mounted pivotably about a pivot axis 18 in a convenient position on the housing of the pneumatic nailer 10. At the upper, rear end of the trigger 14, this has a button 20 which displaces a valve pin 32 of the safety control valve 16 on actuation of the trigger 14 upwards. This control of the safety control valve 16 takes place with each actuation of the trigger 14, regardless of the position of the Aufsetzfühlers 24th

The power transmission element 30 of the Aufsetzfühlers 24 is movably guided on the housing of the Druckluftnaglers 10 and has for this purpose a slot 34 through which a guide pin 36 is passed. Upon actuation of the Aufsetzfühlers 24, the force transmission element 30 moves from the in Fig. 3 drawn starting position upwards and thereby takes the free end of a rocker 38, whose fixed end is pivotable about a pivot axis 40 pivotally inside the trigger 14 and near the free end. The rocker 38 is then arranged approximately parallel to a longitudinal direction of the trigger 14 and its upper surface acts as a button 40, which upon joint actuation of the Aufsetzfühlers 24 and the trigger 14 a valve pin 42 of the trigger valve 22 displaced upward and the trigger valve 22 thus activates.

The trigger valve 22 has a valve sleeve 44, in which the valve pin 42 is guided. The valve sleeve 44 in turn is guided in a fixed relative to the handle 12 arranged outer sleeve 60. In the FIG. 3 is the valve sleeve 44 relative to the outer sleeve 60 in a release position. In this release position, which corresponds to an initial state of the pneumatic nailer 10, the valve sleeve 44 is held by the pressure in a safety control chamber 62 which is vented when the safety control valve 16 is not actuated. The force exerted by the pressure in the safety control chamber 62 on the valve sleeve 44 is greater than a force exerted by the pressure in a back pressure chamber 66 on the valve sleeve 44 counterforce. The back pressure chamber 66 is always connected via a connection, not shown, with the housing interior 64 and therefore always ventilated when the Druckluftnagler 10 is connected to a compressed air supply.

The back pressure chamber 66 surrounds a lower portion of the valve sleeve 44 annular. It is defined by an upper seal 74 and a lower seal 76 which provide a seal relative to the valve sleeve 44 with the upper seal 74 and lower seal 76 axially and radially spaced from one another. The upper seal 74 is an inserted into a circumferential groove of the valve sleeve 44 O-ring, which rests against the inside of the outer sleeve 60. The lower seal 76 is an inserted into a circumferential groove of a sealing inserted into a valve block 68 closure plate 84 O-ring, which rests against the outside of the valve sleeve 44. In the radial direction further outside, the back pressure chamber 66 includes a clearance between the shutter disk 84 and the outer sleeve 60. There provide two other seals 148 and 150 for sealing the back pressure chamber 66 relative to the housing 68, in the outer sleeve 60 and shutter disk 84 are used.

The safety control chamber 62 also has an annular space defined by an upper seal 78 and a lower seal 80. These two seals 78,80 are also spaced apart in the radial and axial directions and arranged between the valve sleeve 44 and the outer sleeve 60. The safety control chamber 62 is in the outer sleeve via an axial bore 152 60, an annular gap 154 and a bore 156 in the housing 68 connected to a throttle 86, over the ventilated safety control chamber 62 constantly a small air flow escapes. Nevertheless prevails in the safety control chamber 62 in FIG. 3 shown output state operating pressure, because the safety control chamber 62 is simultaneously connected via a radial bore 88 in the outer sleeve 60 with a safety control line 90 which communicates with the housing interior 64 via the safety control valve 16. One recognizes in FIG. 3 in that the two O-rings 124, 126 of the safety control valve 16 are not in sealing, so that the connection between the safety control line 90 and the housing interior 64 is opened via a radial bore 92 in a valve sleeve 98 of the safety control valve 16.

In the in FIG. 3 shown starting position of the trigger valve 22, the valve pin 42 is relative to the valve sleeve 44 in an unactuated position in which an arranged on the valve pin 42, upper O-ring 128 in the seal and arranged on the valve pin 42, lower O-ring 130th not in seal. Therefore, the control line 82 is connected via a radial bore 132 in the outer sleeve 60, a radial bore 134 in the valve sleeve 44 and an annular gap 108 between valve pin 42 and valve sleeve 44 with outside air.

The valve sleeve 44 has a further radial bore 144, which is closed by an O-ring 146 arranged in an outer circumferential groove around the valve sleeve 44. This arrangement with the O-ring 146 forms a check valve, via which the safety control chamber 62 can be ventilated by the trigger valve 22.

Is based on the initial state of FIG. 3 the trigger 14 is pressed, the results in FIG. 4 shown arrangement. The button 20 of the trigger 14 has displaced the valve pin 32 upwardly, thereby actuating the safety control valve 16. The two O-rings 124 and 126 are now in seal, so that the Connection of the safety control line 90 to the housing interior 64 is shut off. Consequently, the pressure in the safety control chamber 62 gradually degrades via the throttle 86. Until a predetermined pressure threshold in the safety control chamber 62 is exceeded, the valve sleeve 44 remains in its release position.

If now the compressed air nailer 10 attached to a workpiece, the results in FIG. 5 arrangement shown and the following happens: The Aufsetzfühler 24 is actuated and the power transmission element 30 of the Aufsetzfühlers 24 takes on its way up the free end of the rocker 38, so that the trained on the top of the rocker button 38 40 comes into its switching position, the relative to the outer sleeve 60 is always located in the same position and always adjusts when both the trigger 14 and the landing sensor 24 are actuated. The valve pin 42 of the trigger valve 22 is displaced relative to the valve sleeve 44 in its actuated position. As a result, the lower O-ring 130 in seal and the upper O-ring 128 moves out of the seal. Compressed air from the housing interior 64 flows past the upper O-ring 128 through the radial bore 134 in the valve sleeve 44 and through the radial bore 132 in the outer sleeve 60 in the control line 82, whereby a driving operation is triggered. At the same time, the pressure in the safety control chamber 62 is refreshed by the air flowing past the upper O-ring 128 through the check valve formed by the further radial bore 144 and the O-ring 146.

Will after the operation of the trigger 14 accordingly FIG. 4 the touch sensor 24 is not actuated for a period of, for example, four seconds or more and as a result, the pressure in the safety control chamber 62 drops below a predetermined pressure threshold, the valve sleeve 44 moves relative to the outer sleeve 60 in its in FIG. 6 shown blocking position. The control line 82 remains over the for FIG. 3 explained way continues to be connected with outdoor air.

If, based on this situation, the touch sensor 24 is actuated, the rocker 38 and with it the button 40 continues to pass exactly as for FIG. 5 explained in their switching position. However, this does not lead to the initiation of a driving operation, because the valve sleeve 44 relative to the outer sleeve 60 in its blocking position, that is retracted in comparison to its release position in the direction of actuation of the valve pin 42 into the interior of the handle 12 and the valve block 68. Therefore, the button 40, despite reaching its switching position, the trigger valve 22 is not actuated. Another driving operation can only be triggered when the trigger 14 has been released for a short time, resulting in aeration of the safety control chamber 62 and thus to a displacement of the valve sleeve 44 in its release position.

List of reference numbers used:

10

Pneumatic nailers

12

handle

14

trigger

16

Security control valve

18

swivel axis

20

button

22

release valve

24

Aufsetzfühler

26

muzzle

28

mouth tool

30

Power transmission element

32

Valve pin of the safety control valve

34

Long hole

36

guide pin

38

seesaw

40

button

42

valve pin

44

valve sleeve

46

admission

48

magazine

50

driving ram

52

working piston

54

working cylinder

56

main valve

58

pilot valve

60

outer sleeve

62

Security control chamber

64

Housing interior

66

Back pressure chamber

68

manifold

70

annular gap

72

room

74

upper seal

76

lower seal

78

upper seal

80

lower seal

82

control line

84

sealing washer

86

throttle

88

radial bore in the outer sleeve

90

Security control line

92

radial bore

94

spool

96

guide sleeve

98

valve sleeve

100

lower O-ring

102

feather

104

middle O-ring

106

Upper O-ring

108

annular gap

110

Main control line

112

radial bore

114

room

116

Main valve actuator

118

O-ring

120

feather

122

ring surface

124

O-ring of the safety control valve

126

O-ring of the safety control valve

128

Upper O-ring of the trigger valve

130

Lower O-ring of the trigger valve

132

radial bore in the outer sleeve

134

radial bore in the valve sleeve

140

lower housing part

142

housing cap

144

further radial bore of the valve sleeve

146

O-ring

148

another seal

150

another seal

152

drilling

154

annular gap

156

drilling

Claims (12)

Pneumatic nailer (10) with A working piston (52), which is connected to a driving ram (50) for driving in a fastening means and is subjected to the triggering of a driving operation with compressed air, A trigger valve (22) having a valve sleeve (44) and a valve pin (42) guided in the valve sleeve (44), A control line (82) which is aerated or vented to initiate a drive operation by the trigger valve (22) when the valve pin (42) is displaced relative to the valve sleeve (44) to an actuated position, A trigger (14), a touch sensor (24) and a button (40) coupled to the trigger (14) and / or the touch sensor (24) for actuating the valve pin (42), • An outer sleeve (60) in which the valve sleeve (44) is guided, wherein the valve sleeve (44) relative to the outer sleeve (60) in accordance with a pressure in a safety control chamber (62) is displaceable between a release position and a locking position, characterized marked that The button (40) is coupled to the trigger (14) and / or to the touch sensor (24) such that it is always in a fixed predetermined switching position relative to the outer sleeve (60) when both the trigger (14) and the Aufsetzfühler (24) are actuated, wherein The button (40) is arranged in the switch position to shift the valve pin (42) to the actuated position when the valve sleeve (44) is in the release position and not to actuate the valve pin (42) Relocated position when the valve sleeve (44) is in the locked position. Compressed-air nailer (10) according to claim 1, characterized in that the pneumatic nailer (10) has a safety control valve (16) controlled by the trigger (14) which controls a ventilation or venting of the safety control chamber (62). Pneumatic nailer (10) according to claim 1 or 2, characterized in that a connection between the safety control chamber (62) and a vented housing interior (64) from the safety control valve (16) is shut off when the trigger (14) is actuated. Pneumatic nailer (10) according to one of claims 1 to 3, characterized in that the safety control chamber (62) via a throttle (86) is connected to outside air. A pneumatic nailer (10) according to any one of claims 1 to 4, characterized in that the button (40) is formed on a rocker (38) having a fixed end and a free end, the fixed end being rotatable on the trigger (14 ) is mounted and the free end is taken on actuation of the Aufsetzfühlers (24) of the Aufsetzfühler (24). Pneumatic nailer (10) according to one of claims 1 to 4, characterized in that the button (40) on the Aufsetzfühler (24) is formed and relative to the Aufsetzfühler (24) has a fixed position. Pneumatic nailer (10) according to claim 6, characterized in that the safety control valve (16) and the trigger valve (22) are connected in series. Pneumatic nailer (10) according to one of claims 1 to 7, characterized in that the safety control chamber (62) via the trigger valve (16) and a Check valve is vented or vented when the valve pin (42) is displaced relative to the valve sleeve (44) in the actuated position. Pneumatic nailer (10) according to claim 8, characterized in that the check valve is integrated in the valve sleeve (44). Pneumatic nailer (10) according to one of claims 1 to 9, characterized in that the safety control chamber (62) has an annular space bounded by two seals (78, 80) inserted between the outer sleeve (60) and the valve sleeve (44) are spaced apart in the axial direction and in the radial direction. Pneumatic nailer (10) according to any one of claims 1 to 10, characterized in that a permanently ventilated back pressure chamber (66) is present, wherein the pressure in the back pressure chamber (66) exerts a counter force on the valve sleeve (44), which of the pressure in the safety control chamber (62) is directed opposite to the force exerted on the valve sleeve (44). Compressed air nailer (10) according to one of claims 1 to 11, characterized in that the counter-pressure chamber (66) has an annular space bounded by two seals (74, 76) adjacent the valve sleeve (44), which are in the axial direction and in Radially spaced from each other.

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