EP3446833A1 - Pneumatic nail gun with safety valve assembly - Google Patents

Abstract

Pneumatic nailer (10) with €¢ a working piston (52) which is connected to a driving ram (50) for driving in a fastener and is acted upon by compressed air when a driving process is triggered, €¢ a trigger (14) and a touchdown sensor (24), the joint actuation of which can pressurize or vent a main control line (82) and thereby trigger a driving-in process, €¢ a control valve arrangement (20) which has a trigger valve (22) assigned to the trigger (14) and a touch-down sensor valve (18) assigned to the touch-down sensor (24), and €¢ a safety valve arrangement (16) which can be displaced between a blocked position and an open position by controlling the pressure in a first control chamber (60) and the pressure in a second control chamber (62), wherein €¢ the main control line (82) is connected to the control valve arrangement (20) in the open position and is not connected to the control valve arrangement (20) in the blocked position, €¢ the first control chamber (60) is connected to the trigger valve (22) in such a way that actuation of the trigger valve (22) seeks to bring the safety valve arrangement (16) into the blocked position, and €¢ in the open position, the second control chamber (62) is connected to the contact sensor valve (18) in such a way that actuation of the contact sensor valve (18) attempts to bring the safety valve arrangement (16) into the open position, at least when the trigger valve (22) is actuated.

Description

The invention relates to a Druckluftnagler having a trigger, a Aufsetzfühler and a control valve assembly. If the compressed air bearing is attached to a workpiece, the touch sensor 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 the event of unintentional contact of an object or body part with the attachment sensor, a drive-in procedure to be 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 Known pneumatic nailer, which can also be used in a single and in a contact trip operation 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 leads to a slow ventilation of a control chamber over a small ventilation opening. 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.

A further improvement in safety can be achieved if a first driving operation must always be carried out by a single trip. In this case, the device must first be attached to the workpiece for the first driving operation, 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.

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.

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 and a touchdown sensor whose joint operation can ventilate or bleed a main control line and thereby trigger a drive-in process,
• a control valve assembly having a release valve associated with the trigger and a Aufsetzfühler associated Aufsetzfühlerventil, and
• a safety valve assembly which is displaceable by controlling the pressure in a first control chamber and the pressure in a second control chamber between a blocking position and an open position, wherein
• the main control line is connected in the open position to the control valve arrangement and is not connected to the control valve arrangement in the blocking position,
• the first control chamber is connected to the trigger valve such that actuation of the trigger valve seeks to bring the safety valve assembly into the blocking position, and
• in the open position, the second control chamber is so connected to the Aufsetzfühlerventil that an actuation of the Aufsetzfühlerventils seeks to bring the safety valve assembly at least when the trigger valve in the open 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. 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 drive ram strikes a rear end of the fastener in the receptacle of the muzzle tool and drives the fastener into the workpiece.

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 until a mouth tool of the pneumatic nailer abuts the workpiece or almost rests.

The pneumatic nailer has a main control line which is vented to trigger a Eintreibvorgangs. To enable this ventilation of the main control line, the main control line is connected to the control valve arrangement in the open position of the safety valve arrangement. The driving operation can be initiated by the main control line in different ways. For example, an embodiment with a main valve and a pilot valve, which is controlled via the main control line, is known. Details will be explained for the embodiment. Conceivable, however, are other constructions with or without pilot valve. For the invention it is only important that the driving can be triggered by ventilation or venting the main control line.

The control valve assembly comprises two valves, each associated with a mechanical actuator. It is the trigger valve that is actuated by the hand-operated trigger and the Aufsetzfühlerventil that is actuated by the Aufsetzfühler, so when attaching the pneumatic nailer to a workpiece, or can be operated.

A special feature of the invention is the safety valve arrangement. This is a pressure-controlled valve arrangement with two control chambers. The pressures in the two control chambers act on the safety valve arrangement or on at least one displaceable actuator of the safety valve arrangement, so that the safety valve arrangement can be displaced between a blocking position and an open position by controlling these pressures.

The safety valve arrangement performs two important functions. First, it controls whether the main control line is connected to the control valve arrangement. Only if this is the case, a driving operation can be triggered by means of the control valve assembly. Thus, the safety valve arrangement prevents the triggering of a driving operation, if it is in the blocking position.

On the other hand, the position of the safety valve arrangement is decisive for whether there is a connection between the Aufsetzfühlerventil and the second control chamber or not. In the open position, this connection exists, so that an actuation of the Aufsetzfühlerventils can affect the pressure in the second control room. On the other hand, if the safety valve arrangement is in the blocking position, said connection does not exist and an actuation of the positioning sensor valve has no significant influence on the pressure in the second control chamber.

The first control chamber is connected to the trigger valve such that actuation of the trigger valve seeks to bring the safety valve assembly into the locked position. By this is meant that about the connection between release valve and the first control chamber, a force is exerted on a displaceable element of the safety valve assembly in the direction towards the blocking position. This can, depending on the design, be effected by a ventilation of the first control chamber, but also for example by a venting of the first control chamber. The connection between the trigger valve and the first control chamber may be independent of the position of the safety valve arrangement.

As a result of this solution, starting from an initial state of the pneumatic nailer, a driving-in process can be triggered only by actuating the landing sensor and the trigger in a specific sequence. If the trigger is first actuated, the connection of the trigger valve to the first control chamber effects a displacement of the safety valve arrangement into the blocking position. A subsequent actuation of the touch sensor and the associated Aufsetzfühlerventils can then no longer act on the second control chamber, so that the safety valve assembly remains in the locked position and no driving operation is triggered. If, however, the touch sensor is first actuated while the safety valve arrangement is in its open position, the pressure in the second control chamber can be influenced such that the safety valve arrangement remains in its open position when subsequently the trigger and thus the trigger valve is actuated. For this purpose, the two control chambers of the safety valve arrangement are to be designed so that the force exerted by the pressures in the two control chambers on the safety valve assembly forces, possibly including other, acting on the safety valve assembly forces hold the safety valve assembly in the open position or shift it to the open position.

As long as the pneumatic nailer is in a ground state, for example, after commissioning of the pneumatic nailer (eg by connecting the pneumatic nailer to a compressed air source) or after a break in work, it is basically not possible to initiate a driving operation by first the trigger and then, when the shutter button is pressed , the touch sensor is actuated.

The described influence of the pressure in the second control chamber by the actuation of the Aufsetzfühlerventils occurs in any case when the trigger is actuated. Optionally, the control valve arrangement can also be designed such that the action of the touch-down sensor valve on the second control chamber occurs independently of the state of the triggering valve. However, this is not necessary for the described function.

Upon actuation of the Aufsetzfühlerventils in the open position of the second control chamber is so connected to the Aufsetzfühlerventil that an actuation of the Aufsetzfühlerventils seeks to bring the safety valve assembly at least when actuated trigger valve in the open position. By this is meant that actuation of the landing feeler valve affects the pressure in the second control room to exert a force on a movable element of the safety valve assembly toward the open position. This happens at least when the trigger valve is actuated at the same time. The action of the Aufsetzfühlerventils on the second control chamber may consist of a ventilation of the second control chamber, but depending on the design of the safety valve assembly is also for example a venting of the second control chamber upon actuation of the Aufsetzfühlerventils into consideration.

In one embodiment, the safety valve assembly comprises a single actuator which is displaceable between the blocking position and the open position, wherein a pressure in the first control chamber a first force on the actuator and a pressure in the second control chamber a second, the first force opposite force the actuator exerts. As explained, the safety valve arrangement is responsible for making or separating two connections, namely on the one hand between the main control line and the trigger valve and on the other hand between Aufsetzfühlerventil and second control chamber. These functions can basically be exercised with the aid of separate actuators. The use of a single actuator is In contrast, especially easy. In particular, the two control chambers can be arranged on opposite sides of the actuator, so that the forces exerted by the respective pressures on the actuator forces are automatically directed opposite. The effects of the two forces can be measured by suitable choice of the surfaces of the actuator to which the pressures act, in particular so that with simultaneous action of both forces, the actuator remains in the open position.

In one embodiment, the pneumatic nailer on a spring which exerts a force on the actuator in the direction of the open position. It can thereby be achieved that the actuator is in the initial state of the pneumatic nailer in a defined position, namely in the open position.

In one embodiment, each actuation of the trigger valve causes venting of the first control chamber. For this purpose, an input of the trigger valve can be connected to a housing interior having compressed air and an output of the trigger valve can be in constant communication with the first control chamber via a line. As a result, the safety valve arrangement generally reaches the blocking position each time the trigger is actuated, provided that the pressure in the second control chamber does not lead to sufficiently large, oppositely directed forces.

In one embodiment, the trigger valve is actuated upon each actuation of the trigger, regardless of a position of the landing probe. The trigger thus acts directly on the trigger valve, in particular by a contact surface of the trigger acts on a valve pin of the trigger valve. A complex and possibly error-prone mechanical coupling between trigger and Aufsetzfühler, for example via a rocker, is not required.

In one embodiment, the landing feeler valve is actuated upon each actuation of the landing feeler, regardless of a position of the trigger. Again, it works So the Aufsetzfühler directly on the Aufsetzfühlerventil, for example, with an actuating surface of the Aufsetzfühlers acting on a valve pin of the Aufsetzfühlerventils. Again, can be dispensed with a complex and possibly error-prone mechanical coupling between trigger on Aufsetzfühler.

In one embodiment, the main control line is connected in the open position to an output of the Aufsetzfühlerventils and an input of the Aufsetzfühlerventils is connected to an output of the trigger valve. Trigger valve and Aufsetzfühlerventil are thus connected in series, so that both valves must be actuated to influence the pressure in the main control line. This is especially true for a ventilation of the main control line, which is intended to connect an input of the trigger valve with a housing interior leading to compressed air. In this case, the compressed air from this housing interior via the trigger valve and the Aufsetzfühlerventil is directed into the main control line, if the two valves are actuated simultaneously. As a result, it is achieved in a particularly simple manner and without additional mechanical coupling elements that a driving operation can basically only be triggered if the two valves are actuated simultaneously.

In one embodiment, a check valve is arranged in a line which connects the Aufsetzfühlerventil with the second control chamber in the open position. The check valve may be oriented so that with the aid of the Aufsetzfühlerventils only ventilation or only a vent of the second control chamber is possible. In both cases, the check valve may cause the prevailing in the second control chamber pressure is maintained regardless of the position of the Aufsetzfühlerventils.

In one embodiment, the second control chamber is vented via a throttle and connected to a storage chamber. The volume of the storage chamber and the opening cross-section the throttle can be chosen so that the pressure conditions produced by means of the Aufsetzfühlerventils in the second control chamber for a period of, for example, 0.5 seconds to 10 seconds are maintained so far that the safety valve assembly remains in the open position. Within this period then a contact triggering is possible.

In one embodiment, the safety valve assembly vented in the blocking position, the second control chamber. As a result, the pressure in the second control chamber can be reset with each response of the safety valve arrangement, that is to say whenever the safety valve arrangement reaches the blocking position. As a result, the safety valve arrangement reliably remains in the blocking position, at least as long as the pressure conditions in the first control chamber do not change.

In one embodiment, the safety valve assembly vented in the blocking position, the main control line. This safety measure counteracts the unintentional triggering of a drive-in process.

In one embodiment, the safety valve arrangement as an actuator on a locking sleeve, within which the Aufsetzfühlerventil is arranged. By this design measure, a particularly compact design can be achieved.

In one embodiment, the Aufsetzfühlerventil a fixedly arranged valve sleeve and guided therein, a displaceable valve pin, wherein the locking sleeve surrounds the valve sleeve and cooperates with this. This measure also favors a compact design.

Fig. 1

einen Druckluftnagler in einer teilweise geschnittenen Darstellung,

Fig. 2

eine vergrößerte Ansicht eines Ausschnitts mit Hauptventil und Vorsteuerventil aus Figur 1,

Fig. 3

einen Pneumatik-Schaltplan der Steuer- und Sicherheitsventilanordnung des Druckluftnaglers aus Fig. 1,

Fign. 4 bis 9

vergrößerte Darstellungen der Steuer- und Sicherheitsventilanordnung des Druckluftnaglers aus Fig. 1 in unterschiedlichen Betriebszuständen.

In one embodiment, the check valve is formed by an O-ring which is inserted into a circumferential groove of the valve sleeve. Such a check valve can be used in a confined space between the locking sleeve and valve sleeve. The invention will be explained in more detail with reference to an embodiment shown in FIGS. Show it:

Fig. 1

a compressed air nailer in a partially sectioned view,

Fig. 2

an enlarged view of a section with main valve and pilot valve off FIG. 1 .

Fig. 3

a pneumatic circuit diagram of the control and safety valve assembly of the pneumatic nailer Fig. 1 .

FIGS. 4 to 9

enlarged views of the control and safety valve assembly of Druckluftnaglers Fig. 1 in different operating states.

First, based on the Fig. 1 an overview of the structure of a pneumatic nailer 10 according to the invention given. The pneumatic nailer 10 has a lower housing part 140 with a handle 12. The lower housing part 140 is closed at the top by a housing cap 142.

On the handle 12, a control valve assembly is arranged with a trigger valve 22 which is associated with a trigger 14, and a Aufsetzfühlerventil 18 which is associated with a Aufsetzfühler 24. The Aufsetzfühler 24 is about the mouth 26 of a muzzle tool 28 by a few millimeters down over. If the pneumatic nailer 10 attached to a workpiece, the Aufsetzfühler 24 moves against the force of a spring, not shown upwards until it is flush or almost flush with the mouth 26. A slider 30, which is connected to a continuation of the Aufsetzfühlers 24 or with the Aufsetzfühler 24, always moves together with the Aufsetzfühler 24. In particular, he follows its movement relative to the housing upwards when the Druckluftnagler 10 is attached to a workpiece until he actuates the Aufsetzfühlerventil 18.

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 are based on the enlarged detail of FIG. 2 explained.

In the FIG. 2 are individual elements of the pneumatic nailer 10, which in Fig. 1 are arranged above the housing cap 142, omitted. The pilot valve 58 is clearly visible. 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 pneumatic nailer 10 is a main 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 from the guide sleeve 96 and closes a connection to a vent opening 108 which is connected to outside air. The middle O-ring 104 is not in seal, so that a 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 control line 110 is not visible over a sectional plane shown in the section Connection with the space 72, which opens into the radial bore 112 connected. 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 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 seals the upper edge of the working cylinder 54 by means of an O-ring 118 relative to the housing interior 64 , 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 main control line 82 by displacing the control piston 94 upwardly so that the middle O-ring 104 enters the seal and the upper O-ring 106 moves out of the seal. As a result, the connection of the control line 110 to the housing interior 64 is shut off and establishes a connection between the control line 110 and a vent not shown. 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 downwards. During this downward movement, the driving ram 50 connected to the working piston 52 drives a fastening means.

The interaction of the control valve assembly with the safety valve assembly is first based on the pneumatic circuit diagram of FIG. 3 explained. This shows at the top left of the main control line 82, which in the embodiment of the Pilot valve 58 leads. To the right of this, the safety valve arrangement 16 is located in a dotted rectangle. The rectangle, which is also shown dotted on the right side, summarizes the touch sensor valve 18 and the trigger valve 22 to the control valve arrangement 20.

The tripping valve 22 actuated by the trigger 14 has a first input 32, which is connected to the housing interior 64. A second input 34 of the trigger valve 22 is connected to outside air. The drawn in the unactuated position of the release valve 22 connected to the second input 34 output 36 of the trigger valve 22 is connected via a line 38 to a first input 40 of the Aufsetzfühlerventils 18. The second input 42 of the Aufsetzfühlerventils 18 is connected to outside air. In the drawn, unactuated position of the Aufsetzfühlerventils 18, the output 44 of the Aufsetzfühlerventils 18 to the second input 42 of the Aufsetzfühlerventils 18 is connected.

The safety valve assembly 16 has a first control chamber 60, a second control chamber 62, a first output 66 and a second output 68. In addition, the safety valve assembly 16 has a first input 74, a second input 76, a third input 78 and a fourth input 80th Das single actuator 98 of the safety valve assembly 16 is displaced from the open position shown in a blocking position.

The first input 74 of the safety valve assembly 16 is connected via a line 124 to the output 44 of the Aufsetzfühlerventils 18. The first output 66 of the safety valve assembly 16 is connected to the main control line 82, the second input 76 of the safety valve assembly 16 is connected to outside air. In the illustrated open position of the safety valve arrangement, the first input 74 is connected to the first output 66, so that a connection between the main control line 82 and the control valve assembly 20 is made.

The third input 78 of the safety valve assembly 16 is connected via a line 126, in which a check valve 128 is disposed, to the output 44 of the Aufsetzfühlerventils 18. The fourth input 80 of the safety valve assembly 16 is connected to outside air. The second outlet 68 of the safety valve assembly 16 is connected to a storage chamber 130 and to the second control chamber 62. In addition, there is a connection between the second control chamber 62 and the second output 68 of the safety valve arrangement and a throttle 132, via which the storage chamber 130 is vented. In the illustrated open position of the safety valve assembly 16, the third input 78 is connected to the second output 68, so that a ventilation of the second control chamber 62 via the Aufsetzfühlerventil 18 is possible.

The first control chamber 60 is connected to the output 36 of the trigger valve 22 via a line shown in dashed lines.

Is based on the ground state of the FIG. 3 first actuates the trigger valve 22, the output 36 is connected to the housing interior 64. As a result, the first control chamber 60 is vented, whereby the actuator 98 of the safety valve assembly 16 is displaced into the blocking position. Thereby, the connection between the third input 78 and the second output 68 of the safety valve assembly is interrupted, so that a subsequent actuation of the Aufsetzfühlerventils 18, the second control chamber 62 can not ventilate. In addition, the first output 66 is disconnected from the first input 74 of the safety valve assembly 16, so that the control valve assembly 20 no longer acts on the main control line 82 and a driving operation can not be triggered.

As an additional safety measure, the main control line 82 is vented by the connection produced between the first output 66 and the second input 76 of the safety valve arrangement 16 in the blocking position. If a pressure different from outside air prevails in the storage chamber 130, it becomes at the same time vented via the connection made by the safety valve assembly 16 between the second output 68 and the fourth input 80.

The triggering of a driving operation is only possible again when the trigger valve 22 is transferred by releasing the trigger 14 in its unactuated position. At this moment, the first control chamber 60 is vented via the connection made between the outlet 36 and the second inlet 34 of the trigger valve 22, so that the actuator 98 returns to its open position by the force of the spring 84.

In order to initiate a first drive-in process starting from the initial state, the touch-up sensor valve 18 must first be actuated. Thereby, a connection between the first input 40 and the output 44 of the Aufsetzfühlerventils 18 is established. In a subsequent operation of the trigger valve 22, a connection between the first input 32 and the output 36 is then made, so that compressed air via line 38 into the first control chamber 60 and simultaneously via the actuated Aufsetzfühlerventil 18, the check valve 128 and the line 126 and the in the open position existing connection between the third input 78 and the second output 68 of the safety valve assembly 16 flows into the second control chamber 62. At the same time, the forces acting on the actuator 98 by the pressures in these two control chambers thus act, which, in cooperation with the spring 84, causes the actuator 98 to remain in the drawn open position. Therefore, the ventilation of the line 124 at the same time causes ventilation of the main control line 82 and it is triggered a drive-in.

If the device is removed from the workpiece after this driving operation, the Aufsetzfühlerventil 18 returns to its drawn, unactuated position. Because of the check valve 128 while the prevailing in the storage chamber 130 and the second control chamber 62 pressure is initially maintained, so that the actuator 98 remains in its open position. The pressure in the second control chamber 62 and the storage chamber 130, however, gradually degrades via the throttle 132, until it finally drops below a pressure threshold. At this moment, the actuator 98 moves due to the permanently actuated trigger valve 22 in the first control chamber 60 applied pressure in its blocking position. From this point on a further contact release is not possible.

Based on FIGS. 4 to 9 constructive details are explained in more detail. It can be seen in each of these figures, the trigger 14 which is pivotally mounted about a pivot axis 86, and the slider 30 of the Aufsetzfühlers 24. This can move up and down upon actuation of the Aufsetzfühlervervils 24 to the valve pin 88 of the Aufsetzfühlerventils 18 against the force to shift a spring 134 in an actuated position. The trigger valve 22 also has a valve pin 90 which can be displaced against the force of a spring 92 to an actuated position. This is done directly by interaction with the trigger 14.

FIG. 4 shows the initial state in which Aufsetzfühlerventil 18 and trigger valve 22 are each drawn in their unactuated position. The safety valve assembly 16 has, as an actuator 98, a locking sleeve 144 which surrounds a valve sleeve 146 of the Aufsetzfühlerventils 18.

The pressurized housing interior 64 is shut off by the O-ring 148 from the leading to an input of Aufsetzfühlerventils 18 line 38. Instead, the conduit 38 is connected to outside air via the radial bore 150 and the annular gap 152 of the trigger valve 22.

The main control line 82 is also connected to the outside air, via a radial bore 154 in the locking sleeve 144, which is in its open position, a radial bore 156 in the valve sleeve 146 and an annular gap 158 of the Aufsetzfühlerventils 18. At the same time, the radial bore 156 in the valve sleeve 146 and thus also the main control line 82 is shut off from the line 38 through the seal O-ring 160 of the Aufsetzfühlerventils 18.

Above the locking sleeve 144 is the first control chamber 60 which is connected to the line 38. The pressure in this first control chamber 60 acts on the locking sleeve 144 via an annular surface 162 of the locking sleeve 144 and searches for this in the FIG. 4 to shift down to the locked position.

The second control chamber 62 is located below the locking sleeve 144 and acts on two annular surfaces 164, 166 of the locking sleeve 144 on this. The pressure in the second control chamber 62 therefore attempts the locking sleeve 144 in the drawn open position, ie in the Fig. 4 move up, relocate. A force in just this direction also exerts the spring 84 on the locking sleeve 144.

The second control chamber 62 has a relatively large volume and is therefore at the same time a storage chamber 130. About the throttle 132, the second control chamber 62 and the storage chamber 130 is connected to outside air.

FIG. 5 shows the arrangement FIG. 4 after attaching the pneumatic nailer 10 to a workpiece. For a better overview are in the FIGS. 5 to 9 only provided with the reference to these figures elements with reference numerals. One recognizes in Fig. 5 in that the slider 30 of the landing probe 24 has displaced upwardly and has moved the valve pin 88 upwardly, thereby placing the landing feeler valve 18 in the actuated position. By this measure, the O-ring 160 has moved out of the seal, so that now the line 38 is connected via the Aufsetzfühlerventil 18 and its radial bore 156 and the radial bore 154 in the locking sleeve 144 to the main control line 82. At the same time, the O-ring 188 seals the lines 124, 126 from outside air. Since the trigger valve 22 is still in its unactuated position, the conduit 38 is vented, so that actuation of the Aufsetzfühlerventils 18 has no further effect.

Subsequently, the trigger 14 and thus the trigger valve 22 is actuated, as in the FIG. 6 shown, the O-ring 148 moves out of the seal, so that the line 38 is vented. At the same time, the O-ring 168 seals this line 38 from outside air. The connected to the line 38 first control chamber 60 is also vented.

The valve sleeve 146 has a radial bore 170 and an O-ring 172 closing this. The radial bore 170 and the O-ring 172 together form the check valve 128. About this check valve 128 is in the in FIG. 6 shown situation, the second control chamber 62 also vented via line 38. For this purpose, the air flows through the check valve 128 and further through an annular gap 174 formed between the valve sleeve 146 and the locking sleeve 144. This ventilation of the second control chamber 62 takes place at about the same time as the ventilation of the first control chamber 60, so that the control chambers 60, 62 forces exerted on the locking sleeve 144 approximately simultaneously take effect. By suitable dimensioning of said annular surfaces 160, 164, 166 (see Fig. 4 ) and the force of the spring 84 causes the locking sleeve 144 remains in its open position. Therefore, the ventilation of the line 38 has the further consequence that the main control line 82 is vented and a drive-in process is triggered.

Then, the device is removed from the workpiece and the Aufsetzfühler 24 relieved, the Aufsetzfühlerventil 18 returns to its inoperative position. This is in FIG. 7 shown. For a short time after the previous driving operation, a sufficiently large pressure is present in the second control chamber 62 to hold the locking sleeve 144 in its open position. In this period, a contact release can be performed at any time by pressing the Aufsetzfühlerventils 24 again, which also leads to a refresh of the pressure in the second control chamber 62 in the already outlined way, so that opens the time window for another contact activation again.

However, if no further contact release, the pressure in the storage chamber 130 and the second control chamber 62 slowly decreases by venting via the throttle 132 until the locking sleeve 144 moves down to its blocking position, as in FIG. 8 shown. As a result, the annular gap 174 is sealed by the O-ring 176 arranged on the valve sleeve 146, so that ventilation of the second control chamber 62 via the check valve 128 is no longer possible. At the same time, the likewise arranged on the valve sleeve 146 O-ring 178 closes an annular gap between the valve sleeve 146 and locking sleeve 144, through which there was previously a connection between the radial bore 156 of the valve sleeve 146 and the radial bore 154 of the locking sleeve 144. As a result, the main control line 82 is shut off from the line 38.

Furthermore, the in FIG. 8 180 space connected via a non-visible bore with outside air. Because of the two non-sealing O-rings 182, 184 of the locking sleeve 144, this leads to a venting of the main control line 82 via the radial bore 154 of the locking sleeve 144 and the second control chamber 62, which is now connected via the annular gap 186 with the space 180 ,

The locking sleeve 144 is now in their in FIG. 8 shown blocking position, as the trigger 14 remains actuated.

Will then, as in FIG. 9 shown, the Aufsetzfühler 24 and thus the Aufsetzfühlerventil 18 actuated, this has no ventilation of the main control line 82, nor ventilation of the second control chamber 62 due to the still in sealing O-rings 176 and 178.

List of reference numbers used:

10

Pneumatic nailers

12

handle

14

trigger

16

Safety valve arrangement

18

Aufsetzfühlerventil

20

Control valve assembly

22

trigger valve

24

Aufsetzfühler

26

muzzle

28

mouth tool

30

pusher

32

first input of the trigger valve

34

second input of the trigger valve

36

Output of the trigger valve

38

management

40

first input of Aufsetzfühlerventils

42

second input of Aufsetzfühlerventils

44

Output of touchdown valve

46

admission

48

magazine

50

driving ram

52

working piston

54

working cylinder

56

main valve

58

pilot valve

60

first control room

62

second control room

64

Housing interior

66

first output of the safety valve arrangement

68

second output of the safety valve arrangement

70

annular gap

72

room

74

first input of the safety valve arrangement

76

second input of the safety valve assembly

78

third input of the safety valve assembly

80

fourth input of the safety valve assembly

82

Main control line

84

feather

86

swivel axis

88

valve pin

90

valve pin

92

feather

94

spool

96

guide sleeve

98

actuator

100

lower O-ring

102

feather

104

middle O-ring

106

Upper O-ring

108

vent

110

control line

112

radial bore

114

room

116

Hauptentil actuator

118

O-ring

120

feather

122

ring surface

124

management

126

management

128

check valve

130

storage chamber

132

throttle

134

feather

140

lower housing part

142

housing cap

144

locking sleeve

146

valve sleeve

148

O-ring

150

radial bore of the trigger valve

152

Annular gap of the trigger valve

154

radial bore of the locking sleeve

156

radial bore of the valve sleeve

158

Annular gap of the touch-up sensor valve

160

O-ring

162

ring surface

164

ring surface

166

ring surface

168

O-ring

170

radial bore of the check valve

172

O-ring of the check valve

174

annular gap

176

O-ring

178

O-ring

180

room

182

O-ring

184

O-ring

186

annular gap

188

O-ring

Claims (14)

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 (14) and a touchdown sensor (24), the joint operation of a main control line (82) can ventilate and thereby trigger a drive-in, A control valve assembly (20) having a trigger valve (22) associated with the trigger (14) and a touch probe valve (18) associated with the landing sensor (24), and • A safety valve assembly (16) which is displaceable by controlling the pressure in a first control chamber (60) and the pressure in a second control chamber (62) between a locking position and an open position, wherein The main control line (82) is connected in the open position to the control valve arrangement (20) and is not connected to the control valve arrangement (20) in the blocking position, The first control chamber (60) is connected to the trigger valve (22) in such a way that an actuation of the trigger valve (22) seeks to bring the safety valve arrangement (16) into the blocking position, • In the open position, the second control chamber (62) is so connected to the Aufsetzfühlerventil (18) that an actuation of the Aufsetzfühlerventils (18) the safety valve assembly (16) in any case when actuated trigger valve (22) to bring into the open position. Pneumatic nailer (10) according to claim 1, characterized in that the safety valve assembly (16) has a single actuator (98) which is displaceable between the blocking position and the open position, wherein a pressure in the first control chamber (60) a first force on the Actuator (98) and a pressure in the second control chamber (62) exerts a second, the first force opposite force to the actuator (98). Pneumatic nailer (10) according to claim 2, characterized by a spring (84) which exerts a force on the actuator (98) in the direction of the open position. Pneumatic nailer (10) according to one of claims 1 to 3, characterized in that each actuation of the trigger valve (22) causes aeration of the first control chamber (60). Pneumatic nailer (10) according to one of claims 1 to 4, characterized in that the trigger valve (22) is actuated each time the trigger (14) is actuated, independently of a position of the landing probe (24). A pneumatic nailer (10) according to any one of claims 1 to 5, characterized in that the landing feeler valve (18) is actuated upon each actuation of the landing feeler (24), regardless of a position of the trigger (14). Pneumatic nailer (10) according to one of claims 1 to 6, characterized in that the main control line (82) in the open position with an output (44) of the Aufsetzfühlerventils (18) is connected and that an input (40) of the Aufsetzfühlerventils (18) an output (36) of the trigger valve (22) is connected. Compressed air nailer (10) according to one of claims 1 to 7, characterized in that in a line (126) which connects the Aufsetzfühlerventil (18) in the open position with the second control chamber (62), a check valve (128) is arranged. Pneumatic nailer (10) according to one of claims 1 to 8, characterized in that the second control chamber (62) via a throttle (132) is vented and connected to a storage chamber (130). Pneumatic nailer (10) according to one of claims 1 to 9, characterized in that the safety valve arrangement (16) in the blocking position vents the second control chamber (62). Compressed air nailer (10) according to one of claims 1 to 10, characterized in that the safety valve arrangement (16) in the blocking position vents the main control line (82). Pneumatic nailer (10) according to one of claims 1 to 11, characterized in that the safety valve arrangement (16) as an actuator (98) has a locking sleeve (144), within which the Aufsetzfühlerventil (18) is arranged. Pneumatic nailer (10) according to claim 12, characterized in that the Aufsetzfühlerventil (18) has a fixed valve sleeve (146) and guided therein, a displaceable valve pin (88), wherein the locking sleeve (144) surrounds the valve sleeve (146) and with this interacts. Pneumatic nailer (10) according to claim 13, characterized in that the check valve (128) by an O-ring (172) which is inserted in a circumferential groove of the valve sleeve (146) is formed.

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