EP3666469A1 - Compressed air nailer with a safety feature - Google Patents

Abstract

Pneumatic nailer with • a working piston, which is connected to a driving plunger for driving in a fastener and is pressurized with compressed air when triggering a driving process, • a triggering device for triggering a driving process, • a safety device controlled by a pressure in a control chamber (98), the is configured to set the pneumatic nailer from a ready-to-trigger state to a locked state, and • a control valve (56) for controlling the pressure in the control chamber (98), the control valve (56) having a control valve member (54) movable along an adjustment path, • characterized by a damper (22) which is coupled to the control valve member (54).

Description

The invention relates to a pneumatic nailer with a safety device which can set the pneumatic nailer from a ready-to-trigger state to a locked state and which is controlled by a pressure in a safety control chamber.

Such a safety device can prevent the pneumatic nailer from performing an unintentional driving-in process, as will be explained below using the example of a pneumatic nailer with a touch-down sensor. If such a pneumatic nailer is attached to a workpiece, the surface-mounted sensor is displaced against the force of a spring until a mouth tool rests on the workpiece or almost rests. A drive-in process can only be triggered when the touch-down sensor is actuated in this way. Some pneumatic rodents with surface-mounted sensors can be used in two different operating modes: In the so-called single release, the pneumatic nailer is first attached to a workpiece and the surface-mounted sensor is thereby actuated. Subsequently, a trigger of the pneumatic nailer is operated by hand, and this triggers a single driving-in process. With the so-called contact release, also referred to as "touching", the user already holds the trigger pressed while he attaches the pneumatic nailer to the workpiece. When attaching to the workpiece, the touch sensor is actuated, triggering a driving process. The pneumatic nailer can be used repeatedly in quick succession, which enables very fast working, especially if many fasteners have to be driven in for adequate fastening, and the positioning accuracy of which is only low.

In certain situations, however, the contact initiation process poses an increased risk of injury. For example, the user holds the manual trigger not only pressed when he wants to place the pneumatic nailer on the same workpiece at a distance of a few centimeters from the last fastener driven in, but also when he changes to another, remotely located workpiece, can inadvertently touch an object or Body part can be triggered with the touch sensor. For example, accidents can occur if a user (ignoring important safety regulations) climbs onto a ladder with the pneumatic nailer, keeps the trigger pressed and accidentally brushes his leg with the touch probe.

Some known pneumatic nailers seek to reduce this risk associated with the contact release operation with the aid of a safety device which only permits contact release for a short period of time after the trigger is actuated or after a driving-in operation. Once the period has passed, the trigger must be released first.

An example of this is from the publication EP 2 767 365 B1 known. The pneumatic nailer described therein has a trigger and a touch-down sensor, each of which is assigned a control valve. In addition, the known device has a safety device with a control chamber, the pressure of which acts on a locking piston. In a certain position of the locking piston, the triggering of a driving-in process is prevented. The control chamber is ventilated via the control valve assigned to the trigger and a throttle. As a result, after the trigger has been actuated, contact triggering is only possible until the pressure in the control chamber has exceeded a predetermined pressure threshold. The pneumatic nailer is then blocked until the trigger is released and the pressure in the control chamber has dropped below the pressure threshold again.

A similar functionality is offered by the from the U.S. Patent No. 3,964,659 Pneumatic nailer that has become known, which can also be used in a single and in a contact release mode and in which a trigger and a touch-down sensor are mechanically coupled via a rocker. The rocker acts on a control valve to initiate a drive-in process 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 only displaced over part of its adjustment path. This partial actuation of the control valve leads to slow ventilation of a control chamber via a small ventilation opening. The pressure prevailing in the control chamber acts on a valve sleeve that surrounds the control valve and finally shifts 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 triggering is not possible.

From the publication DE 10 2013 106 657 A1 A pneumatic nailer with a safety device has also become known, which in one exemplary embodiment has a small piston which changes the position of a rocker integrated in a triggering device. The piston is pressurized in a control chamber and moved against the force of a spring. In another exemplary embodiment, the safety device has a sleeve which is arranged around a valve pin and can be displaced against the force of a spring. The position of the sleeve is also controlled by the pressure in a control chamber. In both cases, triggering of a driving-in process is prevented when the piston or the sleeve is in a certain position. The control chamber is ventilated from the working volume with each driving process and then slowly vented through a small vent opening.

A common feature of the discussed prior art examples is that the pressure over time in the control chamber is significantly influenced by a gradual venting or aeration through a throttle or another small opening. The timing of the safety device achieved in this way depends on the cross section of the opening used in each case. In connection with small control chambers in particular, relatively small opening cross sections must be used, which makes the known solutions structurally complex and sensitive to contamination.

From the publication WO 2015/094504 A1 a pneumatic nailer has become known, which can be used in a contact release operation. A triggering device of the known pneumatic nailer comprises a touch-down sensor and a trigger in which a rocker is pivotably articulated. In contact release mode, when the pneumatic nailer is attached to a workpiece, the surface sensor takes a free end of the rocker with it on its way up, so that when the trigger is actuated, a control valve is actuated by the rocker, which triggers a driving-in process. A downward movement of the rocker is slowed down by a damper so that further contact trips are possible within a predetermined period of time. After the period of time has elapsed, the free end of the rocker has moved back so far that it is missed by the attachment sensor when the pneumatic nailer is again attached to a workpiece. Further releases are only possible after the trigger has been released. This known safety device has no control chamber.

Based on this, it is the object of the invention to provide a pneumatic nailer with a simple and robust safety device.

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

• einen Arbeitskolben, der mit einem Eintreibstößel zum Eintreiben eines Befestigungsmittels verbunden ist und beim Auslösen eines Eintreibvorgangs mit Druckluft beaufschlagt wird,
• eine Auslöseeinrichtung zum Auslösen eines Eintreibvorgangs,
• eine von einem Druck in einer Steuerkammer gesteuerte Sicherheitseinrichtung, die dazu ausgebildet ist, den Druckluftnagler von einem auslösebereiten in einen gesperrten Zustand zu versetzen,
• ein Steuerventil zur Steuerung des Drucks in der Steuerkammer, wobei das Steuerventil ein entlang eines Verstellwegs bewegliches Steuerventilglied aufweist, und
• einen Dämpfer, der mit dem Steuerventilglied gekoppelt ist.

The pneumatic nailer has

• a working piston which is connected to a driving plunger for driving in a fastening means and which is acted upon by compressed air when a driving-in process is triggered,
• a triggering device for triggering a driving-in process,
• a safety device controlled by a pressure in a control chamber, which is designed to put the pneumatic nailer into a locked state from a ready-to-trigger state,
• a control valve for controlling the pressure in the control chamber, the control valve having a control valve member movable along an adjustment path, and
• a damper coupled to the control valve member.

The pneumatic rodent is used to drive in fasteners such as nails, pins or clamps. For this purpose, the pneumatic nailer can have a magazine for the fastening means, from each of which a fastening means is fed to a receptacle of a mouth tool of the pneumatic nailer. When a driving action is triggered, compressed air is applied to a working piston of the pneumatic nailer. As a result, the working piston drives a driving plunger which is connected to the working piston. The driving plunger hits a rear end of the fastener in the receptacle of the mouth tool and drives the fastener into the workpiece.

The triggering device can in particular have a manually operated trigger, for example in the form of a trigger lever or slide. The triggering device can have a control valve or a plurality of control valves, which is or are actuated by the trigger and possibly by further elements of the triggering device, for example a touch-down sensor and / or a power transmission device coupled to it and / or to the trigger. When the triggering device is operated correctly, a driving-in process is triggered, provided the pneumatic nailer is in its ready-to-trigger state. If, on the other hand, the pneumatic nailer is in its locked state, it is not possible to trigger a driving-in process by actuating the triggering device.

The pneumatic nailer has a safety device which is designed to put the pneumatic nailer from the ready-to-trigger state to the secured state. An example of this change of state is the resetting of the pneumatic nailer from a contact release mode to a single release mode. Another example could be a shutdown of the pneumatic nailer, which requires a renewed start-up of the pneumatic nailer for a further driving operation, for example by pressing a reset button. To switch off the pneumatic nailer, it could be completely vented, for example.

As with the safety devices explained at the beginning of the prior art, there is a control chamber in the invention which controls the safety device. For example, the safety device can be designed in such a way that it sets the pneumatic nailer from the ready-to-trigger state to the secured state when the pressure in the control chamber passes a predetermined pressure threshold, that is to say either exceeds or falls below this pressure threshold. Unlike the known solutions, however, the pressure in the control chamber is not, or at least, is not significantly dependent on a gradual inflow or outflow of air through a throttle or the like. Instead, the pressure in the control chamber is controlled by means of a control valve, the control valve member of which is movable along an adjustment path and is coupled to a damper.

Through this coupling, the damper influences the time course of the movement of the control valve member. With the aid of the control valve, the control chamber can be vented or vented, for example, when the control valve member reaches a predetermined position (hereinafter also referred to as the first switching point) along its adjustment path. In particular, the damper can be matched to the control valve and the processes taking place in certain work steps in such a way that this predetermined position is reached after a predetermined period of time. The predetermined period of time can begin with a specific event, for example with an actuation of a trigger and / or a touchdown sensor and / or a driving-in process.

The damper is a mechanical component that dampens movement in a specific direction by opposing the movement with a counterforce acting in the opposite direction. This counterforce can in particular be dependent on the speed of the movement, in particular essentially proportional. The movement that is damped by the damper can be generated by a force that is exerted, for example, by a spring or pneumatically. Suitable dampers are available in a wide variety of designs. They can be integrated into the pneumatic nailer in a variety of ways. For the effect according to the invention, it is only important that the movement of the control valve member is influenced in the desired manner, ie in such a way that the pressure in the control chamber is controlled in such a way that the safety device reliably relocates the pneumatic nailer from the ready-to-trigger position to the secured state in a potentially dangerous situation.

A particular advantage of the invention over the known pneumatic nailers with a control chamber is that the pressure in the control chamber can be controlled without a throttle or another, comparatively small opening cross-section. As a result, the pneumatic nailer is less susceptible to contamination, which is often difficult to avoid in harsh practical situations. In addition, the pressure in the control chamber can be brought much quicker to the value required for the correct functioning of the safety device using the control valve provided for this purpose, which can also improve the reliability of the safety device.

In one embodiment, the damper is coupled to the control valve member in such a way that it slows down a movement of the control valve member at least along a section of the adjustment path. The desired time control is achieved by slowing down the movement.

In one configuration, the triggering device has a touch-down sensor which is designed to shift the control valve member into a fully actuated position when the pneumatic nailer is attached to a workpiece. The touch-down sensor can be a mechanical component which projects beyond the front end of a muzzle tool and is held in this position, for example, by a spring, until the pneumatic nailer is attached to a workpiece. Then the surface-mounted sensor is shifted against the driving direction until a muzzle tool of the pneumatic nailer bears against the workpiece or almost bears against it. The touch sensor acts directly or indirectly on the control valve member in such a way that the control valve member is in this fully actuated position of the touch sensor is also in a fully actuated position. The pneumatic nailer can in particular be constructed in such a way that this action of the touchdown sensor on the control valve member occurs regardless of the position of a trigger. In addition, the touch-down sensor can perform further functions, for example triggering successive drive-in operations in a contact triggering operation. These additional functions can generally be performed using a separate control valve that interacts with the touch-down sensor. As will become clear from the exemplary embodiment explained in detail later, however, the different functions can be performed in particular with the aid of a control valve arrangement, in which the control valve that controls the pressure in the control chamber is integrated. In any case, the embodiment of the invention with a touch-down sensor is characterized in that the control valve with which the pressure in the control chamber is controlled is simply and reliably set to a defined position when the touch-up sensor is actuated. In particular, the control valve member can remain in this defined position until the pneumatic nailer is removed from the workpiece.

In one embodiment, the control valve member has a first switching point at which the control valve aerates or ventilates the control chamber, and the damper is coupled to the control valve member such that after the pneumatic nailer is removed from a workpiece, the control valve member starts the first switching point from the full actuated position reached after a predetermined period of time. In this embodiment, the safety device moves the pneumatic nailer from the ready-to-trigger state to the locked state after the specified period of time has elapsed. The pneumatic nailer remains in the ready-to-trigger state within the specified period of time, so that if the pneumatic nailer is set up for this purpose, in particular contact tripping is possible.

In further refinements, the pneumatic nailer has a main control line which has to be ventilated or triggered to trigger a driving-in process, and the control valve member has a second switching point at which the control valve ventilates or aerates the main control line. A driving process can be initiated in different ways by means of the main control line. For example, an embodiment with a main valve and a pilot valve, which is controlled via the main control line, is known. However, other constructions with or without a pilot valve are also conceivable. For the embodiment of the invention described here, it is only important that the driving-in process is triggered by venting or venting the main control line. This type of construction usually requires that the main control line is vented (if the main control line is to be ventilated to trigger a drive-in process) or that the main control line is ventilated (if the main control line is to be triggered) before another drive-in process can be triggered Is venting). This requirement is met as soon as the control valve member reaches its second switching point. The second switching point can be reached very quickly starting from the fully actuated position of the control valve member, for example when the pneumatic nailer has been removed from a workpiece by, for example, 1 mm and the touchdown sensor is still correspondingly close to its fully actuated position. In particular, the second switching point can be reached clearly before the first switching point, starting from the fully actuated position of the control valve member. As a result, a high frequency of driving operations can be achieved, particularly in a contact triggering operation.

In one embodiment, the damper is designed and coupled to the control valve member in such a way that it does not dampen a movement of the control valve member from the fully actuated position to the second switching point. By this measure the damper does not delay reaching the second switching point, which also enables fast successive contact trips.

In one configuration, a fastening of the damper has an elongated hole, so that a relative movement of two components connected via the damper is not damped by the damper over a partial distance of a possible range of motion. Such an elongated hole is a simple constructive solution to achieve undamped movement in a range of motion defined by the elongated hole.

In one configuration, a damping effect of the damper is limited to one of two possible directions of movement of the damper. For example, the damper can be designed such that it does not take effect when the control valve member is moved to a fully actuated position. It then specifically dampens only the backward movement of the control valve member, which is important for the desired timing behavior. A simple displacement of the control valve member is possible in the other direction of movement, which enables a smooth movement sequence and avoids unnecessary wear.

In one configuration, the damper has two elements which are movable relative to one another, the relative movement of which it dampens, one of the two elements being fastened and / or articulated to a part of the pneumatic nailer fixed to the housing and the other of the two elements being attached to the attachment sensor, to the control valve member or to a force transmission device, which is designed to transmit a force from the touch-down sensor to the control valve member, is attached and / or articulated. The three variants of this configuration relate to different constructive solutions for the integration of the damper in the pneumatic nailer. In the first variant, the damper dampens the relative movement between Attachment sensor and housing of the pneumatic nailer. The relative movement of the touch sensor relative to the housing is essentially straight and over a defined, relatively long distance. The desired damping of the relative movement is therefore particularly simple and robust. In the second variant, the damper dampens the relative movement between the control valve member and the housing of the pneumatic nailer. Unlike in the previous variant, the damper is thus directly on the control valve member. Such direct damping of the movement of the control valve member can be made particularly compact. In the third variant, the damper dampens the relative movement between a power transmission device and the housing of the pneumatic nailer. The force transmission device can be, for example, a rocker or a lever which is coupled to the touch-down sensor in order to act on the control valve member. This variant also enables an effective integration of a damper with a compact structure.

In one embodiment, the damper is a linear damper or a rotary damper. Both designs are suitable for the invention and are available in different versions.

In one embodiment, the damper is a fluid damper or a friction damper. In the case of a fluid damper, the damping is achieved by the flow resistance of a gas or a liquid, in the case of a friction damper by the friction between two solid bodies. Both mechanisms are suitable for the invention and are available in different versions.

In one configuration, the safety device has a safety actuator which, between a trigger position in which an actuation of the trigger device can trigger a driving-in process, and a securing position in which an actuation the triggering device cannot trigger a driving process, is displaceable, the pressure in the control chamber exerting a force on the safety actuator. An additional force acting on the safety actuator can also be generated pneumatically and / or by a spring. In particular, the safety actuator can be designed to intervene in a triggering or driving-in process in the secured position in such a way that proper actuation of the triggering device does not trigger a driving-in process.

In one embodiment, the safety actuator is shifted from the trigger position into the safety position when the pressure in the control chamber passes a predetermined pressure threshold. If the pressure in the control chamber corresponds to the predetermined pressure threshold, the force exerted by the pressure in the control chamber and the counterforce exerted on the safety actuator in another way can be in equilibrium.

Fig. 1

einen Ausschnitt eines Druckluftnaglers in einer schematischen Querschnittsansicht; und

Fign. 2 bis 7

einen vergrößerten Ausschnitt aus Fig. 1 in unterschiedlichen Betriebszuständen des Druckluftnaglers.

The invention is explained in more detail below on the basis of an exemplary embodiment shown in the figures. Show it:

Fig. 1

a section of a pneumatic nailer in a schematic cross-sectional view; and

Fig. 2 to 7

an enlarged section Fig. 1 in different operating states of the pneumatic nailer.

The pneumatic nailer from which in Figure 1 only a section is shown, has a compressed air connection and a working cylinder in which a working piston connected to a driving plunger is displaceably guided. At the top, the working cylinder is closed by a main valve, which is connected to a pilot valve is controlled. Insofar as the directions above and below are used now and in the following, they relate to the normal working position of the pneumatic nailer, in which the pneumatic nailer is placed on a workpiece with a horizontal surface. A magazine is used to hold a supply of fasteners, in particular nails or staples, and ends at the end of a mouth tool into which individual fasteners are inserted. These are then driven into a workpiece by the driving plunger when compressed air is applied to the working piston, controlled by the main valve and the pilot valve. These elements of the pneumatic nailer essentially correspond to the state of the art and can be designed, for example, as in the publication EP 3 257 633 B1 based on Figures 1 and 2nd described in detail.

In the Figure 1 on the other hand, a section of a housing 10 is clearly recognizable, which forms a handle 12 which is also shown in sections. A touch sensor 14 is slidably guided on the housing 10 in the vertical direction, one in Figure 1 Not shown, the lower end of the touch sensor 14 in a manner known from the prior art in its lower position protrudes beyond the mouth tool. In this lower position, which in the Figure 1 is shown, the pneumatic nailer is not attached to a workpiece. At its upper end, the touch sensor 14 has an elongated hole 16 in which a pin 18 fastened to the housing 10 is arranged. At the position of this pin 18 in the elongated hole 16, it can be clearly seen in all figures in which position the touch sensor 14 is currently.

A spring 20 is arranged between the housing 10 and the touch-down sensor 14 and presses the touch-down sensor 14 downwards. In addition, a damper 22 is arranged between the housing 10 and touch sensor 14, which in the example shown is a Has cylindrical damper housing 24 in which a damper plunger 26 is slidably guided. The damper plunger 26 protrudes from the lower end of the damper housing 24 and is attached to the touch-down sensor 14 at its free end. At the opposite, upper end, the damper 22 has a fastening section 28 which is fixedly connected to the damper housing 24. The upper, free end of this fastening section 28 is articulated with a horizontally arranged pin 30 to an elongated hole 32 formed in the housing 10. The length of the elongated hole 32 is less than the length of the elongated hole 16, in the example approximately half as large.

The damper 22 is designed in such a way that it dampens a movement of the damper tappet 26 downward, ie out of the damper housing 24, but not in the opposite direction, ie into the damper housing 24. This leads to the fact that the attachment sensor 14 can be displaced upward by the damper 22 essentially unaffected when the pneumatic nailer is attached to a workpiece. After removal of the pneumatic nailer from a workpiece, the interaction of the spring 20 with the damper 22 determines the speed at which the touch-down sensor 14 moves down again when the pin 30 is in contact with the lower end of the elongated hole 32 and for the further downward movement of the damper plungers 26 must be pulled out of the damper housing 24.

A triggering device of the pneumatic nailer comprises a trigger 36 which is pivotally mounted at its front end about a horizontal axis 34. The trigger 36 has an actuating surface 38 for actuating a valve pin 40 of a trigger valve 42. Furthermore, the triggering device comprises a force transmission element in the form of a lever 44 which is pivotally mounted at its rear end about an axis 46 arranged horizontally and fixed to the housing. The free end 48 of the lever 44 abuts an upper surface 50 of the touch sensor 14.

An actuating surface 52 arranged on the upper side of the lever 44 serves to actuate a control valve member 54 of a control valve 56 which is designed as a valve pin a main control line 58 is supplied with compressed air from a ventilated housing interior 60 via the trigger valve 42 and the control valve 56.

Figure 2 shows an enlarged section Fig. 1 . The touch sensor 14 is still in its lower end position and the trigger 36 is not actuated. The control valve member 54, which is movable along an adjustment path, is also in a lower end position, which corresponds to a completely unactuated position of the control valve 56. The valve pin 40 of the trigger valve 42 is also not actuated. It has a lower O-ring 62, which is not in the seal, and an upper O-ring 64, which is in the seal.

In this position, a transverse bore 66, which is located in a sleeve 68 of the trigger valve 42, is connected to outside air via an annular gap 70 and past the lower O-ring 62. The line 72 connected to the transverse bore 66 between the release valve 42 and the control valve 56 is therefore vented. At the same time, the ventilated housing interior 60 is shut off from the transverse bore 66 and the line 72 by the upper O-ring 64 located in the seal.

The control valve member 54 is movably guided in a two-part sleeve fixed to the housing and having an inner sleeve part 74 and an outer sleeve part 76. The outer sleeve part 76 is surrounded by a safety actuator 78, which is also sleeve-shaped. The safety actuator 78 is accommodated in the housing 10 so as to be displaceable in the vertical direction. It is from a spring 80 in its in the Fig. 2 shown, upper end position pressed, which corresponds to a ready-to-trigger condition of the pneumatic nailer.

The safety actuator 54 has four O-rings: A first O-ring 82 seals against the inner sleeve part 74 in each position of the control valve member 54. Between a second O-ring 84 and a third O-ring 86, both of which are not in seal, a transverse bore 88 ends in the control valve member 54, which extends via a longitudinal bore 90 in the control valve member 54 and a further transverse bore 92 in the control valve member 54 is connected to outside air. A fourth O-ring 94 is in Fig. 2 in poetry. The control valve member 54 is pressed into its lower end position by a spring 96.

A control chamber 98 is arranged below the safety actuator 78. A pressure prevailing in this control chamber 98, like the spring 80, exerts a force on the safety actuator 78 upwards. In the position shown, the control chamber 98 is connected to outside air via a transverse bore 100 in the outer sleeve part 76 and a transverse bore 102 in the inner sleeve part 74 past the second O-ring 84 via the holes 88, 90, 92 in the safety actuator 54.

The main control line 58 is also vented, specifically via a transverse bore 104 in the safety actuator 78, past an O-ring 106 which is not in the seal and which is arranged between the outer sleeve part 76 and the safety actuator 78, a transverse bore 108 in the outer sleeve part 76 and past the third O-ring 86 through the bores 88, 90, 92 in the control valve member 54.

In Fig. 3 the pneumatic nailer was placed on a workpiece, the placement sensor 14 having reached its upper end position. The pin 18 is therefore located at the lower end of the slot 16. When the touch probe moves upwards 14 relative to the housing 10, the spring 20 and the damper 22 (only shown in FIG Fig. 1 ) pressed together. The damper tappet 16 has been pushed a bit into the damper housing 24, whereby it may have reached an upper end position within the damper housing 24. In addition, together with the damper housing 24, the fastening section 28 was pushed up so far that the pin 30 now lies against the upper end of the elongated hole 32.

On its way up, the upper surface 50 of the touch sensor 14 has taken the free end 48 of the lever 44 with it, so that the actuating surface 52 has shifted the control valve member 54 into its fully actuated position. In this position, the second O-ring 84 and the third O-ring 86 are now sealed, so that between the bores 88, 90, 92 (see Fig. 2 ) there is no longer a connection in the control valve member 54 and the transverse bore 108, 104 and the intermediate annular gap. At the same time, the fourth O-ring 94 has moved out of the seal, so that the line 72 is now connected to the main control line 58 via the transverse bore 108. Since the line 72 is still connected to outside air via the trigger valve 42, this does not yet trigger a driving-in process.

If the trigger 36 is subsequently actuated, the result in FIG Fig. 4 position shown. The valve pin 40 has been moved upwards and is now in a fully actuated position, in which the lower O-ring 62 is in the seal and the upper O-ring 64 has moved out of the seal. As a result, the line 72 is vented past the upper O-ring 64 via the bore 66 from the housing interior 60. The control chamber 98 is also ventilated, namely from the line 72 past the fourth O-ring 94, through a transverse bore 110 in the outer sleeve part 76, which forms a check valve with another O-ring 112, and through an annular gap 114 between the outer The sleeve part 76 and the safety actuator 78. The force exerted on the safety actuator 78 by the pressure in the control chamber 98 and the spring 80 is so great that it outweighs the force exerted by the pressure in the space 116 above the safety actuator 78, so that the safety actuator 78 initially remains in its upper end position. This upper end position of the safety actuator 78 can also be referred to as the release position.

Furthermore, the position of Fig. 4 a connection between the line 72 and the main control line 58, so that when the line 72 is vented, a driving-in process is triggered at the same time.

After the pneumatic nailer is lifted off the workpiece, the pneumatic nailer gets into the in very quickly Fig. 5 Shown position, in which the touch sensor 14 has already moved a bit downwards, namely until the pin 30 rests on the lower end of the elongated hole 32 and the effect of the damper 22 begins. The downward movement of the touch sensor 14 is coupled via the lever 44 to a downward movement of the control valve member 54 because the control valve member 54 due to the force exerted by the spring 96 on the actuating surface 52 of the lever 44 and the free end 48 of the lever 44 at the upper end 50 of the Touch sensor 14 is present.

To the in Fig. 5 At the time shown, the control valve member 54 has just reached a second switching point at which the fourth O-ring 94 comes back into the seal and the third O-ring 86 moves out of the seal. As a result, the main control line 58 is shut off from the line 72 and, past the O-ring 106, through the transverse bore 108, past the third O-ring 86 and through the bores 88, 90, 92 (see Fig. 2 ) vented in the control valve member 54. The control chamber 98 is still shut off from outside air and remains under pressure, so that the safety actuator 78 remains in its release position. As a result, based on that in Fig. 5 Contact status possible at any time.

If the pneumatic nailer is not attached to the workpiece again, the touchdown sensor 14 sets its downward movement from that corresponding to the second switching point of the control valve member 54 in FIG Fig. 5 shown position under the influence of the damper 22 continues to slow. After a predetermined period of time, which can be, for example, in the range between 1 second and 5 seconds, it reaches the in Fig. 6 shown position, which is slightly above its completely unactuated position Fig. 2 lies.

In the in Fig. 6 In the position shown, the control valve member 54, which, coupled to the movement of the touch-down sensor 14, also moves downward, is immediately before a first switching point. At this first switching point, the second O-ring 84 moves out of the seal, which leads to an immediate ventilation of the control chamber 98 via the transverse bores 100 and 102, past the second O-ring 84 and through the bores 88, 90, 92 (see Fig. 2 ) leads through.

Figure 7 shows the condition of the pneumatic nailer again a short time later. At this point, the touch sensor 14 has reached its completely unactuated position and the control valve member 54 has exceeded the first switching point, so that the control chamber 98 is connected to outside air and no longer exerts any force on the safety actuator 78. The force exerted on the safety actuator 78 by the pressure in the space 116 then outweighs the force of the spring 80, so that the safety actuator 78 has shifted to its lower end position.

This lower end position is a safety position in which no further driving-in processes can be triggered, in particular not by means of triggering a contact by repositioning the pneumatic nailer on a workpiece. The pneumatic nailer is thus in a locked state. This is because regardless of the position of the valve pin 40 and the control valve member 54, the main control line 58 can no longer be vented because the transverse bore 104 through the O-ring 106 now in the seal and the two O-rings 118 which are always in the seal and 120 is cordoned off. As an additional safety measure, the O-rings 122, 124 are no longer sealed. Between these O-rings 122, 124 is a bore, not shown, which also connects the control chamber 98 and the main control line 58 to outside air.

Further triggers are only possible again if the trigger 36 is released beforehand. Then the safety actuator 78 comes back into its in Fig. 2 shown release position and the pneumatic nailer is again in a ready-to-release state.

It also shows Fig. 7 at the same time the state of the pneumatic nailer, which is established when the trigger 36 is actuated before the touchdown sensor 14 is actuated. In this case, the safety actuator 78 is shifted from the pressure built up in the space 116 to its safety position, while the control chamber 98 remains connected to outside air. For this reason, in the pneumatic nailer explained as an example, a first driving-in process must always be carried out by individual triggering.

List of reference numbers

10th

casing

12

Handle

14

Touch sensor

16

Long hole

18th

pen

20th

feather

22

mute

24th

Damper housing

26

Damper tappet

28

Fastening section

30th

pen

32

Long hole

34

axis

36

trigger

38

Operating area

40

Valve pin

42

Trigger valve

44

lever

46

axis

48

free end

50

top surface

52

Operating area

54

Control valve member

56

Control valve

58

Main control line

60

Housing interior

62

lower o-ring

64

upper o-ring

66

Cross hole

68

Sleeve

70

Annular gap

72

management

74

inner sleeve part

76

outer sleeve part

78

Safety actuator

80

feather

82

first O-ring

84

second O-ring

86

third O-ring

88

Longitudinal bore

90

Cross hole

92

further cross hole

94

fourth O-ring

96

feather

98

Tax chamber

100

Cross hole

102

Cross hole

104

Cross hole

106

O-ring

108

Cross hole

110

Cross hole

112

another O-ring

114

Annular gap

116

room

118

O-ring

120

O-ring

122

O-ring

124

O-ring

Claims (14)

Pneumatic nailer with A working piston which is connected to a driving plunger for driving in a fastener and which is acted upon by compressed air when a driving process is triggered, A triggering device for triggering a driving-in process, • A safety device controlled by a pressure in a control chamber (98), which is designed to set the pneumatic nailer from a ready-to-trigger state to a locked state, and A control valve (56) for controlling the pressure in the control chamber (98), the control valve (56) having a control valve member (54) movable along an adjustment path, • characterized by a damper (22) which is coupled to the control valve member (54). Pneumatic nailer according to claim 1, characterized in that the damper (22) is coupled to the control valve member (54) such that it slows down a movement of the control valve member (54) at least along a portion of the adjustment path. Pneumatic nailer according to claim 1 or 2, characterized in that the triggering device has a touch sensor (14) which is designed to shift the control valve member (54) into a fully actuated position when the pneumatic nailer is attached to a workpiece. Pneumatic nailer according to claim 3, characterized in that the control valve member (54) has a first switching point at which the control valve (56) aerates or ventilates the control chamber (98), and in that the damper (22) with the control valve member (54) is coupled that after removing the pneumatic nailer from a workpiece, the control valve member (54) reaches the first switching point from the fully actuated position after a predetermined period of time. Pneumatic nailer according to claim 3 or 4, characterized in that the pneumatic nailer has a main control line (58) which has to be ventilated in order to initiate a driving process, and the control valve member (54) has a second switching point at which the control valve (56) has the main control line (56 ) vented. Pneumatic nailer according to claim 3 or 4, characterized in that the pneumatic nailer has a main control line (58) which has to be vented in order to initiate a driving process, and the control valve member (54) has a second switching point at which the control valve (56) has the main control line (58 ) ventilated. Pneumatic nailer according to Claim 5 or 6, characterized in that the damper is designed and coupled to the control valve member (54) in such a way that it does not dampen a movement of the control valve member (54) from the fully actuated position to the second switching point. Pneumatic nailer according to one of claims 1 to 7, characterized in that a fastening of the damper (22) has an elongated hole (32), so that a relative movement of two components connected via the damper (22) is not damped by the damper (22) over a partial distance of a possible range of motion. Pneumatic nailer according to one of claims 1 to 8, characterized in that a damping effect of the damper (22) is limited to one of two possible directions of movement of the damper (22). Pneumatic nailer according to one of claims 1 to 9, characterized in that the damper (22) has two relatively movable elements, the relative movement of which it dampens, one of the two elements being fastened and / or articulated to a part of the pneumatic nailer fixed to the housing and the other of the two elements on the touch sensor (14), on the control valve member (54) or on a force transmission device, which is designed to transmit a force from the touch sensor (14) to the control valve member (54), is attached and / or articulated. Pneumatic nailer according to one of claims 1 to 10, characterized in that the damper (22) is a linear damper or a rotary damper. Pneumatic nailer according to one of claims 1 to 11, characterized in that the damper (22) is a fluid damper or a friction damper. Pneumatic nailer according to one of claims 1 to 12, characterized in that the safety device has a safety actuator (78) which between a trigger position in which an actuation of the triggering device can trigger a driving-in process and a securing position in which an actuation of the triggering device does not trigger a driving-in process can trigger, is displaceable, the pressure in the control chamber (98) exerts a force on the safety actuator (78). Pneumatic nailer according to claim 13, characterized in that the safety actuator (78) is shifted from the trigger position into the safety position when the pressure in the control chamber (78) passes a predetermined pressure threshold.

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