DE202013001537U1 - Pneumatic nailer with a manually operated release and a touch probe - Google Patents

Abstract

Pneumatic nailer with • a working piston (52) which is connected to a driving ram (50) for driving in a fastener and is pressurized with compressed air upon initiation of a driving operation, and • a triggering device having a hand-operated trigger (14) and a landing feeler (24), wherein a joint actuation of the trigger (14) and landing sensor (24) drives a first control valve (44) and can trigger a drive-in operation, characterized by? a second control valve (22) actuated upon actuation of the trigger (14) independently of actuation of the landing sensor (24), • a chamber (62) which is either vented or vented via a throttle (60) upon actuation of the second control valve (22), and • a locking piston (124) which is displaced from a rest position to a blocking position when the pressure in the chamber (62) passes a predetermined pressure threshold, and prevents the triggering of a driving operation in the blocking position.

Description

The invention relates to a Druckluftnagler with a working piston which is connected to a drive ram for driving a fastener and is applied in triggering a driving operation with compressed air, and a triggering device having a hand-actuated trigger and a touch sensor, wherein a common actuation of trigger and Aufsetzfühler controls a first control valve and can trigger a driving operation.

Such Druckluftnager are known from the prior art. The touch sensor is a mechanical component which is held by a spring in a position overhanging a nozzle tool of the pneumatic nailer. If the air rod is attached to a workpiece, the touch sensor is displaced against the force of the spring until the muzzle tool rests against the workpiece. Only with such actuated Aufsetzfühler a driving operation can be triggered. As a result, the known compressed air nailers offer a significantly improved security against unintentional release compared to devices without Aufsetzfühler.

Pneumatic nailer with a triggering device of the type described can be used in two different modes. In the so-called single release the pneumatic nailer is first attached to a workpiece and thereby actuated the landing sensor. 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, if the user wants to hold the air operated nailer on one and the same workpiece at a distance of a few centimeters from the last driven fastener, the user will not only press the manual release, but also if he changes to another, possibly remotely located, workpiece, can be triggered in an accidental contact of an object or body part with the Aufsetzfühler a driving operation. 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.

On this basis, it is the object of the invention to improve a pneumatic nailer of the type mentioned so that it can continue to be used in the contact triggering process, but offers greater security against accidental tripping.

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,
• • eine Auslöseeinrichtung, die einen handbetätigbaren Auslöser und einen Aufsetzfühler aufweist, wobei eine gemeinsame Betätigung von Auslöser und Aufsetzfühler ein erstes Steuerventil ansteuert und einen Eintreibvorgang auslösen kann,
• • ein zweites Steuerventil, das bei einer Betätigung des Auslösers unabhängig von einer Betätigung des Aufsetzfühlers angesteuert wird,
• • eine Kammer, die über eine Drossel bei Ansteuerung des zweiten Steuerventils entweder belüftet oder entlüftet wird, und
• • einen Sperrkolben, der von einer Ruhestellung in eine Sperrstellung verlagert wird, wenn der Druck der Kammer eine vorgegebene Druckschwelle passiert und der in der Sperrstellung das Auslösen eines Eintreibvorgangs verhindert.

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 triggering device having a hand-operated trigger and a touchdown sensor, wherein a joint actuation of trigger and Aufsetzfühler controls a first control valve and trigger a drive-in,
• A second control valve, which is activated independently of an actuation of the touch sensor when the trigger is actuated,
• • a chamber which is either vented or vented via a throttle when the second control valve is actuated, and
• • A blocking piston, which is displaced from a rest position to a blocking position when the pressure of the chamber passes a predetermined pressure threshold and prevents the triggering of a driving operation in the blocking 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.

When initiating a driving operation, a working piston of the pneumatic nailer is pressurized with compressed air. In this case, the working piston drives a Eintreibstößel, which is connected to the working piston. The tappet meets a rear end of the fastener in the receptacle of the muzzle tool and drives the fastener into the workpiece.

The triggering device has a hand-operated trigger, for example in the form of a tilt or push button, and a touch sensor. The touch sensor may be a mechanical component that projects beyond the front end of the muzzle 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. If this actuation of the touch probe together with an actuation of the trigger, a first control valve is actuated, whereby a driving operation can be triggered.

With a common actuation of trigger and Aufsetzfühler the first control valve is activated. If only one of the manually actuable release and the touch sensor is actuated, the first control valve will not be actuated. For a joint actuation of trigger and Aufsetzfühler it is sufficient if both the trigger and the touch sensor at a certain time both at the same time in the actuated state. This can be achieved on the one hand by a simultaneous operation, but also in any order. For example, as is typical for a single trigger, first the touchdown sensor can be actuated and then the manually operated trigger. In contact tripping operation, however, the hand-actuated trigger and then the touch sensor can be operated first.

The control of the first control valve can be achieved by a mechanical coupling of the manually operated release and the Aufsetzfühlers. For example, a control pin of the first control valve can only be displaced when the trigger and the touch sensor are actuated together, and the first control valve can thereby be activated.

The activation of the first control valve can trigger a drive-in process. This is done in the invention, when the locking piston is in its rest position. On the other hand, when the blocking piston is in its blocking position, the triggering of a driving-in process is prevented when the first control valve is activated.

In the invention, a second control valve is actuated upon actuation of the manually actuable trigger independently of an actuation of the Aufsetzfühlers. The second control valve is thus activated with each actuation of the trigger. For this purpose, for example, a control pin of the second control valve may be arranged so that it is displaced from its rest position with each actuation of the trigger.

In such a control of the second control valve, a chamber is vented via a throttle or vented. By "venting" is always meant that a connection is made to a compressed air leading room. By "venting" is always meant that a connection to a non-pressurized space, in particular to the outside air, is produced.

Whether in the invention when controlling the second control valve, ventilation or venting of the chamber takes place, depends on the design of the pneumatic nailer: In a pneumatic nailer, the chamber is vented upon actuation of the second control valve, the pneumatic nailer on a line which the chamber connects with a compressed air leading room. In a pneumatic nailer whose chamber is ventilated when the second control valve is actuated, the pneumatic nailer has a line which connects the chamber to a non-pressurized space, in particular to outside air. In both cases, the throttle and the second control valve may be located in the respective line. If the chamber is to be ventilated, the chamber is depressurized in an initial state of the pneumatic nailer. When the second control valve is actuated, air then flows via the throttle, so that the pressure in the chamber increases. If the chamber is to be vented, it is in an initial state of the pneumatic nailer under increased pressure. When the second control valve is actuated, the air in the chamber flows slowly through the throttle, so that the pressure in the chamber drops.

In both cases, the pressure in the chamber after a certain time passes a predetermined pressure threshold. In a ventilated by driving the second control valve chamber, the pressure exceeds the pressure threshold. When a chamber is vented when the second control valve is actuated, the pressure drops below the predetermined pressure threshold. In both cases, passing the predetermined pressure threshold causes the blocking piston to be displaced from a rest position to a blocking position. In the blocking position the triggering of a drive-in process is prevented.

Therefore, in the invention, a driving operation after actuation of the trigger can be triggered only as long as the pressure in the chamber has not yet passed the predetermined pressure threshold. If the trigger is thus actuated for a longer period of time and the pressure in the chamber has consequently passed the pressure threshold, actuation of the touch sensor does not trigger a driving operation, because this is prevented by the blocking piston which is then in the blocking position. It is thus prevented by a long after the actuation of the trigger takes place actuation of the Aufsetzfühlers a drive-in is triggered. As a result, most inadvertent trips, where the user accidentally pressed the shutter button for longer than necessary, can be reliably prevented.

In one embodiment, the chamber is vented or vented when not actuated trigger. If the pneumatic nailer has a chamber which is vented when the second control valve is actuated, the chamber is vented when the trigger is not actuated. If the pneumatic nailer has a chamber which is vented when the second control valve is actuated, the chamber is ventilated when the trigger is not actuated. The venting or ventilation of the chamber when not actuated trigger can be done via the second control valve, possibly also via the second control valve and the throttle. In this case, the line used in the control of the second control valve for venting or venting the chamber, in which the throttle is arranged, also be used for venting or venting the chamber when not actuated trigger.

In any case, the above-mentioned embodiment means that the desired pressure, which corresponds to an initial state of the pneumatic nailer, is established in the chamber when the trigger is not actuated. As a result, the compressed air nailer is always in its initial state after a certain time when the trigger is not actuated. If the throttle is also in the line used for venting or venting the chamber when the trigger is not actuated, this initial state is only reached again after a certain time, if the pressure in the chamber had previously passed the predetermined pressure threshold. Thus, if a user had previously pressed the trigger for a long time, so that the pressure threshold was passed, a further driving operation by pressing the Aufsetzfühlers can only be done when the trigger has remained unactuated for a certain time. Until then, the pneumatic nailer is locked. If this locked state is perceived as annoying by a user, this may in the future counteract a careless continuous actuation of the trigger and thus further improve the application security of the pneumatic nailer.

In one embodiment, an opening cross section of the throttle is dimensioned such that when operating the pneumatic nailer with a designated operating pressure of the pressure in the chamber, the predetermined pressure threshold in a period of 0.1 s to 10 s after activation of the second control valve happens. In particular, the pressure threshold can be passed in a period between 1 s and 5 s after activation of the second control valve, for example after approximately 4 s. The opening cross-section of the throttle can be adjustable, so that the period can be individually regulated. Preferably, this regulation takes place only once by the manufacturer of the pneumatic nailer and can only be changed by impermissible manipulation by a user. In any case, the pneumatic nailer is locked in time to prevent in many typical application situations a driving operation as a result of unintentional actuation of the Aufsetzfühlers.

In one embodiment, the pneumatic nailer has a valve through which the chamber is vented or vented when triggering a Eintreibvorgangs. If the chamber is vented when controlling the second control valve, it should be vented when a Eintreibvorgangs. If the chamber is vented when the second control valve is actuated, it should be ventilated when a drive-in process is triggered. As a result, the initial state is restored upon initiation of a driving operation with respect to the pressure in the chamber. This can happen very fast. If, after the drive-in operation, the trigger is still kept pressed, the pressure in the chamber approaches in the manner described at the beginning again the pressure threshold, which is passed after the predetermined period of time. Until then, a further release by pressing the Aufsetzfühlers is possible at any time, so that the Druckluftnagler is suitable without restriction for fast successive Eintreibvorgängen in the contact triggering process.

In one embodiment, when a drive-in operation is triggered, a control chamber is vented or vented as a result of the actuation of the first control valve, the valve being a check valve which connects the chamber to the control chamber. The control chamber may in particular be located in or on a pilot valve, with which a main valve, which is responsible for the ventilation of the working cylinder, is controlled. It can also be a control room in or on the main valve. To trigger a drive-in process, the pressure in the control room must be changed. This is done by venting or venting as a result of the control of the first control valve. In this embodiment, the valve which is responsible for restoring the initial state in the chamber upon initiation of a drive-in operation is a check valve which connects the chamber to the control chamber. If the pressure in the control chamber corresponds to an initial state of the pneumatic nailer, the check valve is closed so that the pressure in the chamber approaches the pressure threshold in the desired manner when the second control valve is actuated. When a drive-in process is triggered, the pressure in the control chamber changes, the check valve opens and the pressure in the chamber returns to the initial state.

In one embodiment, the check valve has an O-ring, which is arranged in an internal piercing of a sleeve and closes a bore leading from the internal pierce to an outer side of the sleeve. The sleeve may for example be a guide sleeve for a control piston of a pilot valve. The aforementioned embodiment of the check valve allows a particularly compact design.

In one embodiment, the blocking piston switches the compressed air nailer completely depressurized in the blocking position. For this purpose, the blocking piston can be arranged so that it controls one or more further valves with which a central compressed air connection of the device is shut off and the interior of the pneumatic nailer is completely vented. This solution is structurally relatively expensive, but reliably prevents that another driving operation can be triggered. In addition, in particular, the complete ventilation of the pneumatic nailer does not go unnoticed, so that the user is made aware of the security reasons not optimal continuous operation of the shutter.

In one embodiment, the blocking piston in the blocking position closes a vent opening, via which a control chamber is vented when a Eintreibvorgangs. The necessary for the initiation of the driving process venting of the control room can not be done. In this way, an accidental release can be reliably prevented.

In one embodiment, the blocking piston blocks off a line which is vented or vented when the first control valve is actuated. For example, the conduit may connect to the first control valve a control room which must be vented or vented to initiate a drive-in operation. By shutting off this line with the blocking piston, the control of the first control valve no longer has the effect required to trigger a driving operation. This prevents the triggering of an unintentional drive-in process.

In one embodiment, the locking piston is designed to interrupt a frictional connection between the touch sensor and the first control valve. By this interruption, the first control valve is therefore no longer actuated when pressing the Aufsetzfühlers when the shutter button is pressed.

In particular, a mechanical coupling between the Aufsetzfühler and the first control valve can be canceled by the locking piston. This can be achieved for example by a three-part coupling between the Aufsetzfühler and the first control valve, wherein the force exerted on the Aufsetzfühler force is passed through all three parts to the first control valve. The displacement of the locking piston in the blocking position, for example, remove the middle of the three parts from its required for power transmission position. Even so, unintentional triggering can be prevented.

In one embodiment, the locking piston is biased by a spring in the blocking position. To bring the locking piston in its rest position, in which a release of the pneumatic nailer can take place, the locking piston must be displaced against the force of the spring. If there is no pressure build-up due to a malfunction of the pneumatic nailer, it is not possible to trigger the device. A biased in the blocking position locking piston is therefore particularly safe.

In one embodiment, the blocking piston in the blocking position blocks a valve element to be moved to trigger a driving operation. The necessary to trigger a driving operation movement of the valve element is thus prevented, and thus an unintentional triggering. The blocking of a valve element requires a relatively small force and accordingly allows a simple and robust construction of the locking piston. In contrast to a shut-off of a control line with the locking piston or to operate a separate valve no additional seals are required for the blocking of the existing valve element. This also favors a particularly simple and safe construction.

In one embodiment, the valve element to be moved is a control piston of a pilot control valve. The advantages described in connection with the blocking of a valve element to be moved for triggering a driving operation apply in a special way to the control piston of a pilot control valve.

In one embodiment, the valve to be moved is a main valve actuator that closes a working volume above the working piston. If movement of the main valve actuator is blocked by the blocking piston, tripping is ruled out.

In one embodiment, the locking piston is guided in a cylinder and arranged on a first side of the locking piston cylinder chamber is connected to the chamber or forms the chamber. In both cases, the cylinder space contributes to the volume of the chamber. To further increase the volume of the chamber, the locking piston can be made hollow. The larger the volume of the chamber, the less problematic a sufficient Limitation of air flow through the throttle can be achieved.

In one embodiment, a second, the first side of the locking piston opposite side of the piston is acted upon in an initial state of the pneumatic nailer with compressed air. By "initial state" is always meant a state in which the pneumatic nailer is connected to a compressed air supply and neither the touch sensor nor the trigger are actuated. By acting on compressed air second side of the piston of the locking piston is pressed into its rest position. This embodiment is particularly advantageous for a chamber to be ventilated when the second control valve is actuated. In the event of any leakage in the area of the seal of the blocking piston, the chamber is additionally ventilated via the leak, which leads to premature exceeding of the predetermined pressure threshold and thus to a blockage of the pneumatic nailer. This is advantageous for safety reasons, because the failure of the seal is noticed immediately. Otherwise, a leakage of the chamber could easily go unnoticed because of the upstream throttle and the compressed air nailer be operated despite the resulting failure of the safety mechanism according to the invention.

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

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

2 an enlarged detail view 1 with the manually actuable trigger and the first and second control valve,

3 another enlarged detail view 1 with the pilot valve and the main valve,

4 a further enlarged detail of the 1 with essential elements of the pilot valve.

First, based on the 1 the most important elements of the pneumatic nailer are shown partly in an overview. The pneumatic nailer has a handle 10 , at the rear end of a central compressed air connection 12 is arranged. The handle 10 is located on a lower housing part 140 pointing upwards from a housing cap 142 is closed.

The hand-operated trigger 14 is about a pivot axis 16 pivotally mounted on the housing of the pneumatic nailer and arranged so that it by a user who uses the pneumatic nailer on the handle 10 holds, can be easily operated with the index finger. With this operation, one arrives at the top of the trigger 14 arranged button 18 in contact with a switching pin 20 a second control valve 22 , shifts the switching pin 20 upwards and thereby controls the second control valve 22 at. As this control of the second control valve 22 immediately from the firm on the trigger 14 arranged button 18 is effected, it is independent of the operation of a Aufsetzfühlers 24 ,

In the initial state of the pneumatic nailer shown in all figures is the attachment sensor 24 over the estuary 26 a muzzle tool 28 downwards by a few millimeters. If the pneumatic nailer is attached to a workpiece, the touch probe becomes 24 shifted upwards against the force of a spring, not shown, until it is flush with the mouth 26 concludes. The touch probe 24 is mechanically coupled to a power transmission element 30 that occurs during the movement of the touch sensor 24 moved upwards. The power transmission element 30 is movably guided on the housing of the pneumatic nailer and has a slot 32 on, through which the pivot axis 16 of the trigger 14 passed through.

Upon actuation of the attachment sensor 24 the force transmission element shifts 30 from the initial position drawn up and takes it with a on the power transmission element 30 attached stop pin 34 the free end of a lever 36 with, its fixed end pivoting inside the trigger 14 and hinged near its free end. The lever 36 is then approximately parallel to the longitudinal direction of the trigger 14 arranged and its top acts as a button 40 , which together with the touch sensor 24 and the trigger 14 a switch pin 42 a first control valve 44 shifted up and the first control valve 44 thus driving.

The muzzle tool 28 has a recording 46 on, each a fastener from a magazine 48 is supplied. From this position within the recording 46 is the fastener - for example, a nail, a pin or a clip - from a driving ram 50 that with a working piston 52 the pneumatic nailer is driven, driven. For this purpose, the working piston 52 in a working cylinder 54 guided. Above the working cylinder 54 and sealingly sealing this is a main valve 56 arranged, right of it a pilot valve 58 and to the right again a throttle 60 and a chamber 62 , Details of these elements and the function of the device are based on the detail enlargements of 2 to 4 explained in more detail.

Well recognizable in the 2 is the hand-operated trigger 14 with the lever mounted therein 36 and the button 18 , The switching pin 20 the second control valve 22 is in a inserted into the housing and sealed against this sleeve 66 the second control valve 22 guided. The housing of the pneumatic nailer has a housing interior 64 which is vented in the initial state of the pneumatic nailer, ie with the compressed air connection 12 connected and under operating pressure.

A second control line 68 is over an annular gap 70 with radial holes 72 the second control valve 22 connected. In the illustrated, non-actuated state of the second control valve 22 seals an upper O-ring 74 the second control valve 22 the tax pin 20 opposite the sleeve 66 so connect to a line 78 that with the housing interior 64 is connected, is locked. At the same time there is a lower O-ring 76 the second control valve 22 not in gasket, so the radial holes 72 and thus the second control line 68 over the annular gap between the switching pin 20 and the sleeve 66 are connected to outside air. In the non-actuated state of the second control valve 22 is the second control line 68 thus vented.

Each time the shutter button is pressed 14 becomes the switching pin 20 through the button 18 shifted upwards so that the upper O-ring 74 out of the seal and the lower O-ring 76 the switching pin 20 opposite the sleeve 66 seals. This will cause the connection of the second control line 68 shut off with the outside air. At the same time, the second control line 68 over the radial bores 72 with the line 78 connected and thus ventilated.

The switching pin 42 of the first control valve 44 is also in an inserted into the housing and sealed against this sleeve 80 guided. When the trigger is pressed together 14 and the touch probe 24 becomes the switching pin 42 of the first control valve 44 over the lever 36 driven. In the shown, not activated state of the first control valve 42 is a first control line 82 , which are used to control the pilot valve 58 serves (more in connection with the 3 and 4 ), vented, via an obliquely arranged bore 90 in the housing of the pneumatic nailer and two radial holes 86 in the sleeve 80 of the first control valve 44 , The radial bores 86 are over an annular gap between sleeve 80 and switch pin 42 of the first control valve 44 connected with outside air as long as the lower O-ring 88 of the first control valve 44 not in gasket, according to the initial condition as in the 2 shown. In the non-activated state of the first control valve 44 there is an upper O-ring 90 , which is above the radial holes 86 is arranged in seal and thus blocks a connection via a line 92 to the housing interior 64 from.

Upon actuation of the first control valve 44 succeeded the lower O-ring 88 in seal and disables the connection of the first control line 42 to the outside air. At the same time the upper O-ring moves 90 out of the seal, so the first control line 82 over the obliquely arranged hole 84 , the radial holes 86 and the line 92 with the ventilated housing interior 64 is connected.

The pilot valve 58 is best in the 3 recognizable. It has a control piston 94 on top, in a guide sleeve 96 is guided. The lower end of the control piston 94 is in an integral with the housing intermediate sleeve 98 guided and opposite this with an O-ring 100 sealed. In the initial state of the pneumatic nailer, ie with vented first control line 82 , is the control piston 94 in the lower position shown. In this position he becomes by the force of a spring 102 held.

The control piston 94 points in addition to the lower O-ring 100 a middle O-ring 104 and an upper O-ring 106 on. In the illustrated, lower position of the control piston 94 seals the upper O-ring 106 the control piston relative to the guide sleeve 96 thereby closing a connection to the vent 108 which is connected to outside air. The middle O-ring 104 is not in seal, so a main control line 110 via radial bores 112 in the guide sleeve 96 and the annular gap between the control piston 94 and guide sleeve 96 on the middle O-ring 104 over with the ventilated housing interior 64 connected is.

The main control line 110 is with a room 114 above an actuator 116 of the main valve 56 connected so that the actuator 116 is applied with a downward force and thereby the upper edge of the working cylinder 54 by means of another O-ring 118 opposite the housing interior 64 seals.

In addition, the actuator 116 from a spring 120 with a force in the direction of this, the working cylinder 54 closing position.

We the first control valve 44 operated and consequently the first control line 82 ventilated, the control piston moves 94 upwards, so that the lower O-ring 104 get into seal and the upper O-ring 106 out of the seal. This will connect the main control line 110 to the Housing interior 64 shut off and at the same time a connection to the vent 108 produced. The space 114 above the actuator 116 gets over the vent 108 vented and the actuator 116 is by the at its lower, outer ring surface 122 pending, prevailing in the housing interior pressure against the force of the spring 120 shifted upwards. As a result, compressed air flows out of the housing interior 64 in the working cylinder 54 above the working piston 52 and drives the working piston 52 downward. In this downward movement drives with the working piston 52 connected drive tappets 50 a fastener.

In the 3 right of the control piston 94 is one in a bore of the housing cap 142 horizontally guided locking piston 124 shown. He is drawn, according to the initial state of the pneumatic nailer, in a rest position in which he is in the 3 right. In this rest position is an end 126 of the locking piston 124 at a distance from the control piston 94 and collides in case of aeration of the first control line 82 not with the upward movement of the control piston 94 ,

The locking piston 124 is hollow and its interior forms together with in the 3 to the right of the O-ring 126 of the locking piston 124 located annular gap around the locking piston 124 around the chamber 62 , Inside the locking piston 124 in the chamber 62 , is a spring 128 arranged, which is the locking piston 124 with a force in its blocking position, which is shifted from the drawn rest position to the left, acted upon. In this (not shown) blocking position is the end 126 of the locking piston 124 in the path of a diameter-expanded, lower portion 130 of the control piston 94 into, so that a displacement of the triggering a Eintreibvorgangs up to moving control piston 94 is prevented.

The second control valve 22 next second control line 68 is over a throttle 60 and a slanted bore 132 with the chamber 62 connected. Therefore, aeration of the second control line 68 due to an actuation of the second control valve 22 to a slow ventilation of the chamber 62 over the throttle 60 , Exceeds the pressure in the chamber 62 a predetermined pressure threshold are those through which the spring 128 and the pressure in the chamber 62 on the locking piston 124 forces exerted in the direction towards its blocking position greater than those on the left surface of the locking piston 124 by the pressure in the housing interior 64 to the right, ie in the direction towards its rest position, exerted forces, and the locking piston 124 shifts into its blocking position. This prevents the triggering of a drive-in process as soon as the pressure in the chamber 62 exceeds the predetermined pressure threshold.

More details are best in the 4 recognizable. One recognizes there that the obliquely arranged bore 132 that over the throttle 60 is vented, on one side of the throttle 60 to the chamber 62 leads and continues on the other side up to a radial bore 134 in the guide sleeve 96 the pilot valve 58 , This radial bore 134 is associated with an inside engraving 136 in the inner bore of the guide sleeve 96 , The interior engraving 136 is located between the upper O-ring 106 and the middle O-ring 104 of the control piston 94 , In the interior engraving 136 is an O-ring 138 arranged, which forms a check valve, which is the radial bore 134 opposite the annular gap between the control piston 94 and guide sleeve 96 seals.

In the in the 4 shown initial state is the middle O-ring 104 not in seal, so the one control room 144 forming annular gap with the housing interior 64 connected and is under compressed air. The pressure in the radial bore 134 corresponds to the pressure inside the chamber 62 so the O-ring 138 in the interior engraving 136 is pressed in and the radial bore 134 closes.

When a drive-in process is triggered, the control piston becomes 94 displaced upwards and the annular gap between the control piston 94 and guide sleeve 96 is, as already explained, on the vent 108 vented. Then the pressure in the chamber 62 and thus in the radial bore 134 greater than in the annular gap between the control piston 94 and guide sleeve 96 and the O-ring 138 moves inward, causing the check valve to open and the chamber to open 62 over the oblique hole 132 and the radial bore 134 is vented. In this way, when a Eintreibvorgangs triggered automatically the unpressurized initial state in the chamber 62 Restored, so that the time window in which by triggering contact while holding the shutter button 14 further injections can be triggered, opens again.

LIST OF REFERENCE NUMBERS

10

handle

12

Compressed air connection

14

trigger

16

swivel axis

18

button

20

switch Probe

22

Second control valve

24

Aufsetzfühler

26

muzzle

28

mouth tool

30

Power transmission element

32

Long hole

34

stop pin

36

lever

38

swivel axis

40

button

42

switch Probe

44

First control valve

46

admission

48

magazine

50

driving ram

52

working piston

54

working cylinder

56

main valve

58

pilot valve

60

throttle

62

chamber

64

Housing interior

66

shell

68

Second control line

70

annular gap

72

Radial bore

74

Upper O-ring

76

Lower O-ring

78

management

80

shell

82

First control line

84

drilling

86

Radial bore

88

Lower O-ring

90

Upper O-ring

92

management

94

spool

96

guide sleeve

98

intermediate sleeve

100

Lower O-ring

102

feather

104

Middle O-ring

106

Upper O-ring

108

vent

110

Main control line

112

Radial bore

114

room

116

Main valve actuator

118

O-ring

120

feather

122

ring surface

124

blocking piston

126

The End

128

feather

130

Lower section

132

Oblique hole

134

Radial bore

136

internal groove

138

O-ring

140

Lower housing part

142

housing cap

144

control room

Claims (16)

Pneumatic nailer with • a working piston ( 52 ), with a drive tappet ( 50 ) is connected to drive in a fastener and is pressurized with the triggering of a driving operation with compressed air, and • a triggering device, the hand-actuated trigger ( 14 ) and a touch probe ( 24 ), wherein a joint actuation of triggers ( 14 ) and Aufsetzfühler ( 24 ) a first control valve ( 44 ) and can trigger a drive-in process, characterized by a second control valve ( 22 ), which is activated when the trigger ( 14 ) independent of an actuation of the touch probe ( 24 ), • a chamber ( 62 ), which have a throttle ( 60 ) when controlling the second control valve ( 22 ) is either vented or vented, and • a locking piston ( 124 ), which is displaced from a rest position to a blocking position when the pressure in the chamber ( 62 ) passes a predetermined pressure threshold, and prevents the triggering of a driving operation in the blocking position. Pneumatic nailer according to claim 1, characterized in that the chamber ( 62 ) when the shutter button is not pressed ( 14 ) is vented or ventilated. Pneumatic nailer according to claim 1 or 2, characterized in that an opening cross-section of the throttle ( 60 ) is dimensioned so that when operating the pneumatic nailer with a designated operating pressure of the pressure in the chamber ( 62 ) the predetermined pressure threshold in a period of 0.1 s to 10 s after activation of the second control valve ( 22 ) happens. Pneumatic nailer according to one of claims 1 to 3, characterized by a valve via which the chamber ( 62 ) is vented or vented when a Eintreibvorgangs. Pneumatic nailer according to claim 4, characterized in that when a Eintreibvorgangs a control room ( 144 ) as a result of the activation of the first control valve ( 44 ) is vented, wherein the valve is a check valve, the chamber ( 62 ) with the control room ( 144 ) connects. Pneumatic nailer according to claim 5, characterized in that the check valve is an O-ring ( 138 ), which is in an interior recess ( 136 ) is arranged a sleeve and one of the internal puncture ( 136 ) leading to an outside of the sleeve bore ( 134 ) closes. Pneumatic nailer according to one of claims 1 to 6, characterized in that the locking piston ( 124 ) in the blocking position, the compressed air nailer switches completely depressurized. Pneumatic nailer according to one of claims 1 to 6, characterized in that the locking piston ( 124 ) in the blocking position a vent opening ( 108 ), over which a control room ( 144 ) is vented when a Eintreibvorgangs. Pneumatic nailer according to one of claims 1 to 6, characterized in that the locking piston ( 124 ) shuts off a line which, when the first control valve ( 44 ) is vented or vented. Pneumatic nailer according to one of claims 1 to 6, characterized in that the locking piston ( 124 ) is adapted to a frictional connection between the Aufsetzfühler ( 124 ) and the first control valve ( 44 ) to interrupt. Pneumatic nailer according to claim 10, characterized by a spring ( 128 ), the locking piston ( 124 ) is biased in the locked position. Pneumatic nailer according to claim 10 or 11, characterized in that the blocking piston ( 124 ) in the blocking position blocks a valve element to be moved to trigger a driving operation. Pneumatic nailer according to claim 12, characterized in that the valve element to be moved is a control piston ( 94 ) of a pilot valve. Pneumatic nailer according to claim 12, characterized in that the valve element to be moved is a main valve actuator ( 116 ), which is a working volume above the working piston ( 52 ) closes. Pneumatic nailer according to one of claims 1 to 14, characterized in that the locking piston ( 124 ) is guided in a cylinder and on a first side of the locking piston ( 124 ) arranged cylinder chamber with the chamber ( 62 ) or the chamber ( 62 ). Pneumatic nailer according to claim 15, characterized in that a second, the first side of the locking piston ( 124 ) opposite side of the locking piston ( 124 ) is acted upon in an initial state of the pneumatic nailer with compressed air.

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