EP3703911B1 - Compressed air nail gun with safety valve assembly - Google Patents

Description

The invention relates to a pneumatic nailer which has a trigger, an attachment sensor and a trigger valve with a valve pin and a valve sleeve. When the valve pin is displaced into an actuated position relative to the valve sleeve, a control line is pressurized or vented in order to trigger a driving process. The valve pin is operated by a button that is coupled to the trigger and / or to the touch probe.

If such a compressed air rod is attached to a workpiece, the attachment sensor is displaced against the force of the spring until a muzzle tool rests or almost rests on the workpiece. A drive-in process can only be triggered when the touch-up sensor is actuated in this way. Compared to devices without an attachment probe, the pneumatic nailers offer considerably better security against unintentional triggering.

Some pneumatic nailers of the type described can be used in two different operating modes: With the so-called single triggering, the pneumatic nailer is first placed on a workpiece and the touch probe is activated. The trigger is then actuated by hand, thereby triggering a single driving process. With the so-called contact triggering, also known as "touching", the user holds the trigger down while he is applying the pneumatic nailer to the workpiece. When the workpiece is placed on the workpiece, the touch-down sensor is actuated, thereby triggering a drive-in process. The pneumatic nailer can be used repeatedly in quick succession, which enables very quick work, in particular if many fastening means have to be driven in for adequate fastening, the positioning accuracy of which is only subject to low requirements.

In certain situations, however, the contact release method increases the risk of injury. If the user keeps the manually operated trigger pressed, for example, not only when he wants to place the pneumatic nailer on one and the same workpiece at a distance of a few centimeters from the last driven fastening means, but also when he changes to another, remotely located workpiece a drive-in process can be triggered if an object or part of the body is accidentally touched by the touch probe. For example, accidents can occur if a user (in disregard of important safety regulations) climbs up a ladder with a pneumatic nailer, holds the trigger down and accidentally touches his leg with the touch probe.

Some known pneumatic nailers try to reduce this risk associated with the contact release operation by ensuring that a contact release is only possible for a short period of time after the release has been actuated or after a driving process. Once the period has elapsed, the trigger must first be released. An example of this is from the publication EP 2 767 365 B1 known. The pneumatic nailer described therein has a trigger and an attachment sensor, each of which is assigned a control valve. In addition, the known device has a safety control chamber, the pressure of which acts on a locking piston. In a certain position of the locking piston, the triggering of a driving process is prevented. The safety control chamber is ventilated via the control valve assigned to the trigger and a throttle. As a result, after the trigger has been actuated, a contact release is only possible until the pressure in the safety control chamber has exceeded a predetermined pressure threshold. The pneumatic nailer is then blocked until the trigger is released and the pressure in the safety control chamber has fallen below the pressure threshold again.

The one from the U.S. Patent No. 3,964,659 well-known pneumatic nailer, which is also in a single and in a contact release mode can be used and in which a trigger and an attachment sensor are mechanically coupled via a rocker. The rocker acts on a control valve to trigger a driving process by venting a main control line. If only the trigger and not the touch-down sensor is actuated, a control pin of the control valve is only displaced over part of its adjustment range. This half 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 full actuation of the valve pin can no longer vent the main control line, so that a contact cannot be triggered.

With some known devices, a first trip is only possible in single trip mode. For the first drive-in process, these devices must first be attached to the workpiece, which actuates the touch-down probe. A subsequent actuation of the trigger then triggers the first driving process. Then, within a short period of time, further driving processes can be carried out by contact triggering, i.e. by repeatedly lifting and placing the device on the workpiece while the trigger is continuously activated. This functionality is with the one in the publication DE 10 2013 106 657 A1 (closest prior art) described pneumatic nailer given. For this purpose, a trigger and an attachment sensor are mechanically coupled via a rocker, which acts on a control valve in order to trigger a drive-in process. With each driving process, a pressure is built up in a control chamber, which acts on a mechanical actuator. The control chamber is slowly vented through a vent opening. Depending on the pressure in the control chamber, the actuator moves into a blocking position, which prevents the contact sensor from acting mechanically on the rocker when the trigger is actuated and makes contact triggering impossible. In an exemplary embodiment shown in the cited publication, the mechanical actuator is a valve sleeve guided in an outer sleeve, in which a valve pin of a release valve is led. In the blocking position, the valve sleeve holds the valve pin and with it the rocker resting on the valve pin in a position in which the rocker is missed by the attachment sensor. Then another release is only possible after the trigger has been released and the device has been removed from the workpiece.

Based on this, the object of the invention is to provide a pneumatic nailer with an effective, robust and reliable safety mechanism.

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 fastener and which is subjected to compressed air when a driving process is triggered,
• a release valve which has a valve sleeve and a valve pin guided in the valve sleeve,
• a control line that is pressurized or vented to initiate a driving process through the release valve when the valve pin is moved into an actuated position relative to the valve sleeve,
• a trigger, a touch-down sensor and a button coupled to the trigger and / or to the touch-down sensor for actuating the valve pin,
• an outer sleeve in which the valve sleeve is guided, the valve sleeve being displaceable between a release position and a blocking position relative to the outer sleeve in accordance with a pressure in a safety control chamber, wherein
• the button is coupled to the trigger and / or to the touch-down sensor in such a way that it is always in a fixed, predetermined switching position relative to the outer sleeve when both the trigger and the touch-down sensor are actuated, and
• the button is arranged in the switching position so that it moves the valve pin into the actuated position when the valve sleeve is in the release position, and that it does not move the valve pin into the actuated position when the valve sleeve is in the blocking position.

The pneumatic rod 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 a fastening means is fed to a receptacle of a muzzle tool of the pneumatic nailer.

Both the drive and the control of the pneumatic nailer can be done completely pneumatically, so a supply of electrical energy is not necessary. "Venting" always means that a connection to a pressureless room, in particular to the outside air, is established. "Ventilation" always means that a connection is made to a room carrying compressed air.

The trigger can be implemented, for example, in the form of a toggle or slide switch. The attachment sensor can be a mechanical component that protrudes beyond the front end of a muzzle tool and is held in this position by a spring until the pneumatic nailer is attached to a workpiece. Then the touch probe is shifted against the direction of the spring force and against the driving direction.

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

In order to trigger a driving process, a control line must be pressurized or vented. This is done via a release valve that is actuated by moving a valve pin relative to a valve sleeve. The valve sleeve, for its part, is guided in an outer sleeve (usually arranged in a fixed position relative to a housing of the pneumatic nailer) so that it can be displaced between a release position and a blocking position. The position in which the valve sleeve is located relative to the outer sleeve depends on a pressure in a safety control chamber.

The safety control chamber thus offers the possibility of realizing a time-controlled behavior of the pneumatic nailer. For example, the pressure in the safety control chamber can be controlled in such a way that it exceeds or falls below a predetermined pressure threshold after a predetermined period of time that has elapsed since the last driving process and / or since the last actuation of the trigger.

The valve pin is actuated by means of a button that is coupled to the trigger and / or to the attachment sensor. In contrast to some of the compressed air nails explained in the introduction to the prior art, this coupling does not require a complicated, possibly fault-prone mechanism, but is designed so that the button is always in a fixed, predetermined switching position relative to the outer sleeve when both the trigger and the touch-down sensor are actuated. In particular, the sequence in which the trigger and the touch-down sensor are actuated is irrelevant.

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

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

In one embodiment, the pneumatic nailer has a safety control valve which is activated by the trigger and which controls ventilation of the safety control chamber. The pressure curve in the safety control chamber therefore depends directly on the actuation of the trigger.

In one embodiment, a connection between the safety control chamber and a ventilated housing interior is blocked by the safety control valve when the trigger is actuated. In this case, the safety control chamber is permanently and directly ventilated via the safety control valve when the trigger is not actuated. This ventilation ends when the trigger is pressed.

In one embodiment, the safety control chamber is connected to outside air via a throttle. If the safety control chamber is ventilated, this leads to a continuous, slight flow of air that may be accompanied by an audible noise. This operating noise can indicate to a user that the pneumatic nailer is ready for operation. As soon as an inflow into the safety control chamber ends, in particular after the safety control valve has been actuated by the trigger, the pressure in the safety control chamber slowly decreases, so that if the pressure falls below a threshold in the safety control chamber, the valve sleeve moves into the blocking position and prevents further triggering.

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

In one embodiment, the button is formed on a rocker that has a fixed end and a free end, the fixed end being rotatably mounted on the trigger and the free end being carried along by the touch probe when the touch probe is actuated. This configuration is a tried and tested way of coupling the button with the trigger and the touch-up sensor. Regardless of the sequence in which it is pressed, the button is always brought into the same switch position when the trigger and the touch probe are pressed.

In one embodiment, the button is formed on the touch-down sensor and has a fixed position relative to the touch-down sensor. In this variant, the button is only linked to the touch probe and not to the trigger. If the valve sleeve is in the release position, the release valve is activated every time the attachment sensor is actuated. If the trigger is also in an actuated position, a driving process is triggered in each case.

In one embodiment, the safety control valve and the release valve are connected in series. This means that the safety control valve and the release valve must be actuated at the same time for the desired ventilation of the control line. For example, an output of the release valve can be connected directly or indirectly to the control line, while an input of the release valve is connected to an output of the safety control valve. An input of the safety control valve can be connected to a ventilated housing interior. In this case, there can be a fixed assignment to the effect that the contact sensor acts directly on the trigger valve and the trigger acts directly on the safety control valve. A mechanical coupling of the release and the touch-up sensor is not required.

In one embodiment, the safety control chamber is pressurized or deflated via the release valve and a check valve when the valve pin is moved into the actuated position relative to the valve sleeve. As a result of this measure, the pressure in the safety control chamber is "reset" at the same time as a driving-in process is triggered. With each drive-in process, a defined initial situation is created with regard to the pressure in the safety control chamber. In particular, from this point in time on, a predetermined time window can be opened for triggering further driving processes when the trigger is permanently activated.

In one embodiment, the check valve is integrated into the valve sleeve. For example, the check valve can have an O-ring which is held in a circumferential groove in the valve sleeve and which seals a radial bore in the valve sleeve arranged in the groove. By integrating the check valve in the valve sleeve, a particularly compact structure is achieved.

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

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

In one embodiment, the counter-pressure chamber has an annular space which is delimited by two seals which adjoin the valve sleeve and are spaced apart from one another in the axial direction and in the radial direction. This also contributes to a particularly compact structure. In addition, with this annular shape of the counter-pressure chamber, the valve pin can simply be guided to the outside through a central opening in the counter-pressure chamber.

Fig. 1

einen erfindungsgemäßen Druckluftnagler in einer teilweise geschnittenen Darstellung,

Fig. 2

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

Fign. 3 bis 7

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

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

Fig. 1

a pneumatic nailer according to the invention in a partially sectioned illustration,

Fig. 2

an enlarged view of a section Figure 1 which includes a main valve and a pilot valve,

Figs. 3 to 7

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

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

The compressed air rod 10 has an attachment sensor 24 which protrudes over the mouth 26 of a mouth tool 28 by a few millimeters downwards. If the pneumatic nailer 10 is placed on a workpiece, the attachment sensor 24 is displaced upwards against the force of a spring (not shown) until it is flush with the mouth 26 or only protrudes slightly beyond the mouth 26. The touch-down sensor 24 is mechanically coupled to a force transmission element 30, which moves with the movement of the touch-down sensor 24 upwards.

The muzzle tool 28 has a receptacle 46, each of which is supplied with a fastening means from a magazine 48. From this position within the receptacle 46, the fastening means - for example a nail, a pin or a clamp - is driven in by a driving ram 50 which is connected to a working piston 52 of the pneumatic nailer 10. For this purpose, the working piston 52 is guided in a working cylinder 54. A main valve 56 is arranged above and sealingly closing the working cylinder 54, to the right of it a pilot valve 58 which controls the main valve 56. Details of these elements as well as the related function of the device are shown on the basis of the enlarged section of the Figure 2 explained in more detail.

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

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

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

A driving-in process is triggered by venting the control line 82 in that the control piston 94 is displaced upwards so that the middle O-ring 104 comes into the seal and the upper O-ring 106 moves out of the seal. As a result, the connection between the main control line 110 and the housing interior 64 is shut off and a connection is established between the main control line 110 and a ventilation opening (not shown). The space 114 above the main valve actuator 116 is vented via the vent opening and the main valve actuator 116 is displaced upwards against the force of the spring 120 by the pressure on its lower, outer annular surface 122 in the housing interior 64. 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 afterwards below. During this downward movement, the driving ram 50 connected to the working piston 52 drives a fastening means.

As overview in Figure 1 recognizable, is located below the pilot valve 58 is a triggering device with a triggering valve 22, a safety control valve 16 and a trigger 14. Details of the triggering device are based on the Figures 3 to 7 explained in more detail.

It can be seen there that the trigger 14 is mounted pivotably about a pivot axis 18 in a position on the housing of the pneumatic nailer 10 that is easy to grip. At the upper, rear end of the trigger 14, the latter has a button 20 which, when the trigger 14 is actuated, displaces a valve pin 32 of the safety control valve 16 upwards. This activation of the safety control valve 16 takes place each time the trigger 14 is actuated, regardless of the position of the contact sensor 24.

The force transmission element 30 of the attachment sensor 24 is movably guided on the housing of the pneumatic nailer 10 and for this purpose has an elongated hole 34 through which a guide pin 36 is passed. When the attachment sensor 24 is actuated, the force transmission element 30 is displaced from the position shown in FIG Fig. 3 Drawn starting position upwards and thereby takes the free end of a rocker 38 with it, the fixed end of which is hinged about a pivot axis 40 in the interior of the trigger 14 and near its free end. The rocker 38 is then arranged approximately parallel to a longitudinal direction of the trigger 14 and its upper side acts as a button 40 which, when the contact sensor 24 and the trigger 14 are operated together, displaces a valve pin 42 of the trigger valve 22 upwards and thus controls the trigger valve 22.

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

The counter-pressure chamber 66 surrounds a lower region of the valve sleeve 44 in an annular manner. It is delimited by an upper seal 74 and a lower seal 76, which create a seal relative to the valve sleeve 44, the upper seal 74 and lower seal 76 being spaced apart from one another in the axial direction and in the radial direction. The upper seal 74 is an O-ring which is inserted into a circumferential groove in the valve sleeve 44 and rests against the inside of the outer sleeve 60. The lower seal 76 is an O-ring inserted into a circumferential groove of a sealing disk 84 inserted into a valve block 68 and resting against the outside of the valve sleeve 44. In the radial direction further out, the counter-pressure chamber 66 comprises a free space between the closure disk 84 and the outer sleeve 60. There, two further seals 148 and 150 ensure a seal between the counter-pressure chamber 66 and the housing 68, in which the outer sleeve 60 and the closure disk 84 are inserted.

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

In the in Figure 3 As shown in the initial position of the release valve 22, the valve pin 42 is in a non-actuated position relative to the valve sleeve 44, in which an upper O-ring 128 arranged on the valve pin 42 is in a seal and a lower O-ring 130 arranged on the valve pin 42 is not in poetry. The control line 82 is therefore connected to outside air via a radial bore 132 in the outer sleeve 60, a radial bore 134 in the valve sleeve 44 and an annular gap 108 between the valve pin 42 and the valve sleeve 44.

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

Is based on the initial state of the Figure 3 the trigger 14 is actuated, the result is in Figure 4 shown arrangement. The button 20 of the trigger 14 has shifted the valve pin 32 upwards and thereby actuated the safety control valve 16. The two O-rings 124 and 126 are now in seal, so that the Connection of the safety control line 90 to the housing interior 64 is blocked. As a result, the pressure in the safety control chamber 62 gradually decreases via the throttle 86. The valve sleeve 44 remains in its release position until the pressure falls below a predetermined pressure threshold in the safety control chamber 62.

If the pneumatic nailer 10 is now applied to a workpiece, the result in FIG Figure 5 The arrangement shown and the following happens: The attachment sensor 24 is actuated and the force transmission element 30 of the attachment sensor 24 takes the free end of the rocker 38 with it on its way up, so that the button 40 formed on the top of the rocker 38 moves into its switching position, which is always arranged in the same position relative to the outer sleeve 60 and is always set when both the trigger 14 and the contact sensor 24 are actuated. The valve pin 42 of the release valve 22 is displaced relative to the valve sleeve 44 into its actuated position. As a result, the lower O-ring 130 comes into the seal and the upper O-ring 128 moves out of the seal. Compressed air from the housing interior 64 flows past the upper O-ring 128 through the radial bore 134 in the valve sleeve 44 and through the radial bore 132 in the outer sleeve 60 into the control line 82, which triggers a driving process. At the same time, the pressure in the safety control chamber 62 is refreshed by the air flowing past the upper O-ring 128 through the check valve formed by the further radial bore 144 and the O-ring 146.

Is after actuation of the trigger 14 accordingly Figure 4 If the touchdown sensor 24 is not actuated for a period of, for example, four seconds or longer and the pressure in the safety control chamber 62 falls below a predetermined pressure threshold as a result, the valve sleeve 44 is displaced relative to the outer sleeve 60 in its internal position Figure 6 Locked position shown. The control line 82 remains on the for Figure 3 explained way still connected with outside air.

If, based on this situation, the touch-down sensor 24 is actuated, the rocker 38 and with it the button 40 continue to arrive exactly as for Figure 5 explained in their switch position. However, this does not trigger a driving-in process because the valve sleeve 44 is in its blocking position relative to the outer sleeve 60, ie, compared to its release position, it is retracted into the inside of the handle 12 or valve block 68 in the actuating direction of the valve pin 42. For this reason, the button 40 cannot actuate the release valve 22 despite having reached its switch position. A further driving process can only be triggered when the trigger 14 has been released for a short time, which leads to ventilation of the safety control chamber 62 and thus to a displacement of the valve sleeve 44 into its trigger position.

List of reference symbols used:

10

Pneumatic nailer

12th

Handle

14th

trigger

16

Safety control valve

18th

Swivel axis

20th

button

22nd

Release valve

24

Touch probe

26th

mouth

28

Muzzle tool

30th

Power transmission element

32

Safety control valve valve pin

34

Long hole

36

Guide pin

38

Seesaw

40

button

42

Valve pin

44

Valve sleeve

46

recording

48

magazine

50

Driving ram

52

Working piston

54

Working cylinder

56

Main valve

58

Pilot valve

60

Outer sleeve

62

Safety control chamber

64

Housing interior

66

Back pressure chamber

68

Valve block

70

Annular gap

72

space

74

upper seal

76

lower seal

78

upper seal

80

lower seal

82

Control line

84

Locking disc

86

throttle

88

radial bore in the outer sleeve

90

Safety control line

92

radial bore

94

Control piston

96

Guide sleeve

98

Valve sleeve

100

lower O-ring

102

feather

104

middle o-ring

106

upper O-ring

108

Annular gap

110

Main control line

112

radial bore

114

space

116

Master valve actuator

118

O-ring

120

feather

122

Ring surface

124

Safety control valve o-ring

126

Safety control valve o-ring

128

Trigger valve upper O-ring

130

Trigger valve lower O-ring

132

radial bore in the outer sleeve

134

radial bore in the valve sleeve

140

lower housing part

142

Housing cap

144

further radial bore in the valve sleeve

146

O-ring

148

further seal

150

further seal

152

drilling

154

Annular gap

156

drilling

Claims (12)

1. Compressed air nail gun (10) comprising:

   • a working piston (52) which is connected to a driving ram (50) for driving in a fastening means and to which compressed air is applied when a drive-in process is triggered,

   • a triggering valve (22) which has a valve sleeve (44) and a valve pin (42) guided in the valve sleeve (44),

   • a control line (82) which is filled with air or emptied of air by the triggering valve (22) in order to trigger a drive-in process when the valve pin (42) is moved into an actuated position relative to the valve sleeve (44),

   • a trigger (14), a contact sensor (24) and a switching surface (40) coupled to the trigger (14) and/or to the contact sensor (24) for actuating the valve pin (42),

   • an outer sleeve (60) in which the valve sleeve (44) is guided, wherein the valve sleeve (44) is movable relative to the outer sleeve (60) between a triggering position and a blocking position in accordance with a pressure in a safety control chamber (62), wherein

   • the switching surface (40) is coupled to the trigger (14) and/or to the contact sensor (24) in such a way that the switching surface is always in a permanently specified switching position relative to the outer sleeve (60) when both the trigger (14) and the contact sensor (24) are actuated, wherein

   • the switching surface (40) is arranged in the switching position in such a way that the switching surface moves the valve pin (42) into the actuated position when the valve sleeve (44) is in the triggering position, and

   characterised in that the switching surface does not move the valve pin (42) into the actuated position when the valve sleeve (44) is in the blocking position.
2. Compressed air nail gun (10) according to claim 1, characterised in that the compressed air nail gun (10) has a safety control valve (16) which is actuated by the trigger (14) and controls filling the safety control chamber (62).
3. Compressed air nail gun (10) according to claim 1 or 2, characterised in that a connection between the safety control chamber (62) and a housing interior (64) filled with air is blocked by the safety control valve (16) when the trigger (14) is actuated.
4. Compressed air nail gun (10) according to any one of claims 1 to 3, characterised in that the safety control chamber (62) is connected via a throttle (86) to external air.
5. Compressed air nail gun (10) according to any one of claims 1 to 4, characterised in that the switching surface (40) is formed on a rocker (38) which has a fixed end and a free end, wherein the fixed end is rotatably mounted on the trigger (14), and the free end is entrained by the contact sensor (24) upon an actuation of the contact sensor (24).
6. Compressed air nail gun (10) according to any one of claims 1 to 4, characterised in that the switching surface (40) is formed on the contact sensor (24) and has a fixed position relative to the contact sensor (24).
7. Compressed air nail gun (10) according to claim 6, characterised in that the safety control valve (16) and the triggering valve (22) are connected in series.
8. Compressed air nail gun (10) according to any one of claims 1 to 7, characterised in that the safety control chamber (62) is filled with air or emptied or air by the triggering valve (16) and a non-return valve when the valve pin (42) is moved relative to the valve sleeve (44) into the actuated position.
9. Compressed air nail gun (10) according to claim 8, characterised in that the non-return valve is integrated into the valve sleeve (44).
10. Compressed air nail gun (10) according to any one of claims 1 to 9, characterised in that the safety control chamber (62) has an annular space that is delimited by two seals (78, 80) inserted between the outer sleeve (60) and the valve sleeve (44) which are spaced from each other in the axial direction and radial direction.
11. Compressed air nail gun (10) according to any one of claims 1 to 10, characterised in that there is a continuously aerated counterpressure chamber (66), wherein the pressure in the counterpressure chamber (66) exerts a counterforce on the valve sleeve (44) which is directed in the direction opposite to the force exerted on the valve sleeve (44) by the pressure in the safety control chamber (62).
12. Compressed air nail gun (10) according to any one of claims 1 to 11, characterised in that the counterpressure chamber (66) has an annular space that is delimited by two seals (74, 76) abutting the valve sleeve (44) and which are spaced apart from one another in the axial direction and in the radial direction.

Images