DE2823284A1 - DEVICE FOR DRIVING FASTENING ELEMENTS - Google Patents

Description

Swingline Inc., 32-00 Skillman Avenue, Long Island City, New York / USA

Device for driving in fasteners

The invention relates to electrically driven driving tools for fastening means or elements, in particular Devices of this type, which have electronic control circuits for generating a plurality of rectified electronic Pulse and delivery of the same to a solenoid which actuates a driver blade for the fasteners. Each time the device is operated, this results in the delivery of an equal number of blows to each individual fastening element. Also includes means for preventing more than one fastener from advancing into the path of the driver blade provided during the driver blows triggered by a single actuation.

U.S. Patent 3,971,969 and others cited therein Electronically controlled driving devices for fastening elements are known from patents. U.S. Patent 3,971,969 relates electrically operated Kalmmer driving tools and in particular those devices that use electronically controlled circuits for generating rectified electronic pulses are equipped to operate the staple driver blade of the devices. The driver blade receives as drive energy two or more pulses containing at least two alternating current half-cycles of opposite polarity from an alternating current source correspond.

An electronic trigger circuit is described in the General Electric SCR Manual, fifth edition (1972), pp. 202-203. This reference discloses a triggered control circuit for a surge current that is a silicon controlled Rectifier, hereinafter referred to as SCR for short, controls from an alternating current source for only one half cycle, and

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teaches the disclosed circuit for solenoid actuation electrical tools can be used in which the load current only lasts for a single full half cycle must flow for a single attraction of the electromagnet regardless of the length of time during which the trigger the device is held in the on position to effect.

The invention is based on the object of providing an electronic driving device for fastening means or elements in this way control each fastener with more than one Impact of the driver blade is driven.

This object is achieved according to the invention by an electrically powered portable device for driving in fastening elements, which in combination has means for driving in the fastening elements, a coil for generating a magnetic field and one connected to the means for driving and this when the coil is acted upon axially in this moving armature having solenoid, one with the solenoid connected electronic triggered control circuit, which from an AC power source the solenoid with a predetermined Number of rectified current pulses feeds, and means for preventing the driving of each more than a fastening element with each actuation of the device, wherein the triggered control circuit

a) unilaterally or rectified controlled line means for rectifying alternating current with at least three Connections, including a gate circuit,

b) a first, the solenoid and the controlled conduction means in series with the AC power source connecting circuit,

c) switching means that can be operated at any time in relation to the periods of the alternating current,

d) a second circuit controlled by the switching means for the power supply of the gate circuit

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for establishing a conductive state of the controlled line means after actuation of the switching means during a suitably polarized half cycle and

e) a third circuit to supply the controlled line means with sufficient holding current, which should conduct at least two homopolar half-cycles of the alternating current,

includes.

In other words, there are only diodes, resistors, capacitors and a single silicon-controlled one in the circuits Rectifier (SCR) for use to apply a predetermined plurality of rectified pulses of current to the solenoid during successive homopolar AC half-cycles so that the driver blade at one Actuation of the device performs a certain number of strokes, preferably two.

The advantages that can thus be achieved are in particular that the fastening element is driven completely into the workpiece the single stroke of the driver blade requires less energy, which makes the driving process smoother The risk of wear and tear and breakage is reduced, thereby increasing the service life of the device. In addition, you can through the multiple impacts fasteners can also be driven into materials with a harder surface, what with One-shot devices was previously not possible.

According to a further embodiment of the invention, mechanical means are also provided which act on the actuating mechanism respond to the device and prevent more than one fastening element, E.g. a clip from a clip strip into which Path of the driver sheet is advanced.

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According to a further embodiment of the invention, a shock absorber device can be arranged through which the Return of the driver blade to its normal rest position is delayed and the driver blade itself prevents the penetration of the prevents the following staple in the driving path.

According to another optional embodiment of the invention, one lowers upon actuation of the trigger or switch button appealing clamping or gripping device on the first following fastener and prevents its movement into the driver path.

Each of the optionally usable mechanical means prevents more than one fastener than Result of the multiple blows being hit by the driver blade.

Some exemplary embodiments of the invention are explained in more detail below with reference to the schematic drawings. It shows

Fig. 1 is a side view of an electronic staple driver partially broken in the cut,

Fig. 2 is a partial section of a damper, with upward movement of a piston crown lying against it,

Fig. 3 a section along the line 3-3 of Fig. 2,

4 shows a partial section according to FIG. 2, but with the damper lifted from the piston head during downward movement,

5 shows a side view of another embodiment of a staple driving device with a clamping device in raised position,

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6 shows a partial section of a clamp clamping device in the locked position during actuation a pressure switch,

Fig. 7 is a vertical section taken substantially along the line 7-7 of Fig. 6;

Fig. 8 in axonometric representation as a decay image the assignment of a driver blade, a clamping device and the front part of a magazine,

Fig. 9 is a horizontal section taken substantially along the line 9-9 of Fig. 8, but the different Showing parts assembled, and

Figure 10 is a circuit diagram of an electronic pulse circuit.

An electric driving tool for fasteners or fasteners such as staples is powered by one of an AC power source Powered electromagnetic trigger circuit with passive cross demodulation and the possibility of pulse programming operated and controlled.

In addition to a coil, the AC circuit also includes nine other components. These nine components consist of one reverse blocking thyristor triode, e.g. a controllable silicon rectifier (SCR), and eight other components, comprising three diodes, three resistors and two capacitors.

The circuit is based on the principle of detecting the zero crossing (zero cross demodulation) for the ignition (Switching) of the SCR, but without using the known phase shift or application of the voltage comparison technique he follows. In order to obtain zero crossing values for the SCR, two passive elements are used in the circuit

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Application in which the values of the components are chosen in such a way that, through their time constants, the SCR during recurring homopolar half-cycles of the alternating current a predetermined number of times - in each case more than once - is ignited. In addition to the ignitable SCR, pure transistors are used in this trigger circuit.

By changing the electrical values of the components in the two RC elements to achieve other time constants it is possible to program the circuit to have a provides a predetermined number of half-cycle pulses. During each of these half-cycles the SCR is fired, and thereby the coil is acted upon a corresponding number of times. Therefore, when the trigger of the staple driver is actuated the circuit delivers a predetermined number of pulses and then switches off, regardless of how long the trigger is pressed. In order for the circuit to deliver a new sequence of pulses, the trigger must be released and pressed again.

The operation of the circuit according to FIG. 10 after connection to a conventional AC power source is as follows:

1. If a switch SW 1 is in position A (not actuated), one flows during the first positive half cycle from the alternating current source (110V A.C.) coming oscillation a current through the series circuit, which consists of a solenoid L, a Diode Dl and an RC loop Rl Cl consists. Although solenoid L has only approximately 2 ohms of resistance, the resistance is of Rl 680 ohms, so that only a very small current flows in the loop. The current flowing through the coil is that is, much smaller than that required for the generation of a magnetic field, around one shown in FIGS. 1 and 5 To bring plunger 26 to reciprocate. During this positive half cycle the capacitor becomes the loop Rl Cl charged and reached its full charge almost at the point in time when the oscillation of the alternating current its

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greatest amplitude reached. While the switch SWl is still in the unactuated position, a second one is on RC loop R2 C2 open.

2. During the negative half cycle, diodes Dl and D block the flow of current through the coil, and the SCR is not conductive. Loop R2 C2 is still open.

3. Is the switch SW1 activated by actuation of a trigger, e.g. a pressure switch 34 of FIG. 1 or a pressure switch of FIG. 5, brought into the working position, so is the loop R2 C2 connects to the SCR and forms another closed circuit. If the switch SWl during the positive half cycle brought into position B, no current flows through the loop R2 C2 because the diode D2 is blocked.

4. During the negative half cycle of an oscillation of the alternating current, after closing the switch SW1, current Flow through a resistor R3, the gate of the SCR, the cathode of the SCR, the loop R2 C2 and the diode D2. This Current, referred to as gate current, causes a negative current surge on the SCR, which the SCR for the next positive half cycle makes conductive.

5. During the next positive half cycle, current flows through solenoid L, diode Dl, SCR and diode D2. the Loop Rl Cl is shunted at this point, so that almost the full voltage is on the coil and through it Circle a great stream can flow. This current is sufficient to actuate the armature of the solenoid and a driver blade to give a reciprocating motion. At the same time, however, the loop provides Rl Cl for a sufficient duration a holding current to the SCR to enable it to increase during the next positive half cycle ignite.

6. Because of the two diodes Dl and D3, flows during the negative half cycle between the two igniting positive ones No current through the solenoid for half cycles. During this intervening negative half-period one tries The preloaded spring of the stapler moves the anchor back to its original position bring back. When the third po-

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The half-period after moving the switch to the working position, the time constant of the loop Rl Cl is sufficient has dropped far enough that they no longer supply a holding current required for the ignition of the SCR for the third time can. If you want to bring the SCR to ignition again, the switch must be charged so that the loop Rl Cl can be switched off and then on again. 7. It should be noted that from the loop R2 C2 without Consideration of the number of ignitions only needs to be given a signal to the gate of the SCR, because after Activation of the SCR by the current surge it remains permeable during the following positive half-cycles as long as Sufficient holding current is available.

From the above it can be seen that the number of consecutive ignitions of the SCR depends is of its holding current and the gate current. The required holding current is different for different SCRs; whose Parameters are specified by the manufacturers. The time constant depends on the passive current loop Rl Cl. The gate current of the SCR is also different for different SCR and can be taken from the manufacturer's information. The time constants of the gate current are determined by the passive loop R2 C2. This results in the possibility by changing the electrical values of these RC elements to program the circuit so that it has a predetermined Number of ignitions carried out.

It has been found that a more efficient work of the driver blade of the electronic staple driver can be achieved by using a predetermined plurality of impacts as the required impact energy. With an advantageous Design is a predetermined number - preferably two - rectified pulses of the same number successive oscillations of an alternating current derived.

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28232SA

If the values of the four critical components are appropriate the following Table 1 are selected, the loop Rl Cl and the current loop R2 C2 operate in such a way that at each time the pressure switch is actuated, the SCR operates twice during two successive oscillations of the alternating current is ignited one after the other. The values of Table 1 are like those mentioned in the following description only given for explanation and not intended as the only possible j even if the combination of these values is different has proven to be very advantageous in terms of reliability and economy. In addition, the Values of the components are chosen so that when the device is operated, the number of blows is greater than two.

Table 1
Component value

Rl Cl R2 C2

In addition, the resistor used in the circuit of FIG. 10 has R3 has a resistance of 100 ohms. The resistors R1, R2 'and R3 are designed for a power of 1/4 W. Carbon film resistors with an axial line and a maximum working voltage of 250 V, but such can also be used without further ado with 1/2 W.

The diodes Dl and D3 are 3 A silicon diodes, while the Diode B2 is a 750 yuA silicon diode. All three diodes are designed for a peak reverse voltage of 200 V.

The SCR used in this application is a controllable plastic silicon rectifier with a peak reverse voltage of 200 volts and forward currents between 8 and 12 A.

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680 Ohm 10 / Uf 1,000 Ohm O ₃ 33 / if.

peak current for a half cycle (8.3 milliseconds) 100 A. The gate trigger current is between 5 and 30 mA at a temperature of 35 ° C, and the holding current at a temperature of 25 ° C in the range between 12 and 30 mA. Any of the following items are useful Motorola 2N4443, Motorola 2N6396, Unitrode R 08037580.

Preferred mechanical embodiments of the invention: Damper:

The electronic staple driver according to the present invention is a multi-impact device in which a fastener, such as a bracket, by a driver blade a predetermined number of strokes for reaching its seat in a workpiece. In a preferred embodiment of the device, each clip is received from the driver sheet two strokes. Since it is now common practice to push the staples continuously into the path of the driver blade, this must be done Apparatus be provided with means to prevent a second clamp from being moved into the path of the driver sheet during the same thing applies the second blow to the first bracket. To achieve this, a damper device is used that delays the upward and backward movement of the driver blade during the dwell time between the first and second blows. As a result, the driver blade does not return completely between the first and second blows mechanically blocks the second and all following clamps in the clamp strip in front of the path of the driver sheet until the first clamp has received its predetermined - two - blows and is completely driven into the workpiece is.

As can be seen from FIG. 1, there is a damper device 10 connected to a piston / anchor device 12 of the staple driver 8 and moves vertically in an in the cavity 14 located at the top thereof, together with and in response to the movement of the cavity 14 provided by resilient means, e.g. a compression spring 16, piston / armature device pushed upwards

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device 12. The damper 18 shown in Fig. 2 in the form of a hat collar is preferably made of a plastic such as Low pressure polyethylene. As can be seen from Fig. 3, there is a plurality of holes in its bottom surface for the passage of air during its movement when the device is operated. The damper 18 is loose by means of Hollow rivets 22 provided with a collar and formed as a cap attached to the plunger armature 26 of the device Piston crown 24 connected. The piston head 24 serves both as a holder and support for the compression spring 16, which the Moving device pushes upwards, as well as to close the bores 20 during the piston movement upwards. at Actuation of a trigger or push button switch 34 draws the plunger 26 into the solenoid 30. The damper 18 has such a diameter that it is fully displaceable in a cylindrically shaped inner housing 28 enclosing it is j which is located in the cavity 14 of the device and rests on the upper part of the solenoid 30. With an upward or backward movement of the damper 18 in the inner housing 28 or a similar space, regardless of whether it is integral with the device housing or, as here, designed to be used separately, there is a friction and air resistance that is not only the upward movement of the damper 18, but also that of the plunger 26 is delayed. This will help during the break between the first and the second blow exerted on the clamp - in the case of the double-pulse version of the device - the complete return of a driver blade 32 firmly connected to the plunger 26 is prevented. This has the consequence that the lower part of the driver blade 32 mechanically prevents the next staple from entering the path of the driver blade 32 to get to a first bracket Sl completely is driven into the workpiece.

The damper 18 operates as follows:

Caused during the first by pressing the trigger 34

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Pulse of the solenoid 30 moves the armature 26 into the solenoid 30. ^{As a result of inertia and friction, the damper 18 remains behind the latter by the distance of approx. 1.4 mm (0.055 t:)} left by the collar of the hollow rivets 22 of the piston crown 24, as can be seen in FIG. The gap created between the piston head 24 and the damper 18 enables air to flow in through the holes 20 in the bottom of the damper 18 so that the armature 26 is unhindered when it hits the bottom. In the pause between the blows, a compression spring 16 drives the piston head 24 upwards, the holes 20 being closed and the air in the cavity 14 being compressed. The air pressure in the cavity 14 counteracts the compression spring 16 and delays the return of the armature 26, so that the second blow occurs before the lower end of the driver blade 32 has reached the upper edge of the next bracket S2 of the staple bar. ^iv With dashed lines 33 in Fig. 1, the approximate return position of the driver blade 32 is shown in multi-lay operation between two strokes. In this way, the driver blade 32 prevents the staple S2 from entering the drive path. So that the plunger 26 can return to its starting position after the clamp S1 has been completely driven into the workpiece for driving the clamp S2, the inner housing 28 is provided at its upper end with a vent hole 36 which regulates the return movement of the damper and the compression spring 16 allows the anchor to be brought into its upwardly prestressed initial position. The device is then ready to drive in the next staple S2 when the trigger 34 is actuated again.

Clamping device:

Referring to Figs. 5 through 9, there is another mechanism of a clamp 38 to prevent entry of a second bracket S2 into the path of the driver blade 32 before the first fastening element, e.g. a clip S1, is completely inserted into the

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Workpiece has been driven. The clamping device 38 works mechanically in conjunction with the actuation of the pressure _{switch 40 3} so that when the switch 40 is pressed, a clamp presses the next following clamp S2 in the magazine 42 and this presses against a clamp guide 66 (see FIGS. 6, 7). Thereby, the staple S2 and the following it is prevented from forward movement, is released to the switch 40th When the switch 40 is released, the clamp moves upwards into its rest position (see FIG. 5), and the clamp S2 is advanced into the path of the driver blade 32 by means of a spring (not shown) located in the magazine 42.

The clamping mechanism 38 shown in detail in Fig. 6 comprises the clamp 48 and a pivot lever 44, which on and around a Pin 46 is pivotably mounted. The pivot lever 44 has two free elongated ends in the form of one projecting forward Fingers 52 and a rearwardly projecting arm 58. The finger of the pivot lever 44 penetrates an opening 50, which is pretty is arranged centrally in the terminal 48. As can be seen from FIGS. And 6, the rearwardly projecting arm 58 is the pivot lever 44 (see Figs. 5 and 6) resiliently connected to a catch 54 by resilient means such as a tension spring 56. the Notch 54 is movably connected to switch 40. At the Pressing the switch 40 from its rest position (see. Fig. 6, dash-dotted line 40) in the on position is the Notch 54 with raised. At the same time, the rearwardly projecting arm 58 is counteracted by a tension spring 56 while pivoting the clock hand raised around the pin 46. At the same time, the protruding finger 52 also pivots counterclockwise and moves due to its coupling through the opening 50 with the terminal 48, the latter down, so that this the Clamp S2 presses against a clamp guide 66. In this way, the clamp S2 is prevented from getting into the path of the driver sheet 32 to move.

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As shown in Figure 7, the clamp 48 is at its lower End provided with two tongues 60 which are arranged so that they press on the top of a clip while it rests on the clip guide 66. Advantageously the tongues 60 are arranged inclined forward (see Fig. 8). The lower edges of the tongues 60 are with a horizontal surface formed, with which they rest on a bracket instead of on top. This will reduce the pressure of the clamp 48 on the Clamp increased, whereby it is pressed firmly onto the clamp guide.

The interaction of the various parts of the clamping assembly and the front end of the magazine device are shown in fig. As shown there, a sleeve 68 is provided for attachment to side walls 70 of magazine 42 and defines part of a path for the driver blade 32. The sleeve 68 and side walls 70 are through a bolt 46 acting as a joint, which extends through holes 80 aligned with one another, and by means of an aligned pin Bores 82 seated rivet, not shown, connected to one another. If necessary, they can be placed in the side walls located bores 80 and 82 be provided with inwardly projecting bearing hubs.

Arranged within the sleeve 68 is a rear driver guide 62 which is an elongated, substantially central arranged recess 72 has, further the clamp 48 and the protruding finger 52 of the pivot lever 44, which both through the opening 50 of the clamp 48 and the elongated recess 72 of the rear driver guide 62 protrudes. the Recess 72 has approximately the same width as the opening 50, but a greater length to allow movement of the finger to enable. This makes it possible to leave the rear driver guide 62 stationary while the clamp 48 is through the finger 52 is moved up and down when the device is operated. The rear driver guide 62 is through lateral Projections 76 also secured against displacement, which in

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Slits 78 of the side walls 70 fit into and rest in them. Support tabs JU projecting inwardly from the side walls 70 prevent the clamp 48 from deflecting backwards. A portion of these various parts shown in FIG. 8 is shown in the assembled position in FIG.

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Claims (1)

Swingline Inc., 32-00 Skillman Avenue, Long Island City, New York / USA Device for driving in fasteners Claims Electrically powered portable device for driving fasteners, which in combination means for Driving in fastening elements, a coil for generating a magnetic field and one with the Means for driving connected and having these armature moving axially in the coil when it is acted upon Solenoid, an electronic triggered control circuit connected to the solenoid and operated by an AC power source, the solenoid with a predetermined number of rectified current pulses feeds, and means for preventing the driving of more than one fastener at each actuation of the device, wherein the triggered control circuit a) unidirectional controlled line means for rectifying alternating current with at least three Connections, including a gate circuit, b) a first, the solenoid and the controlled conduction means in series with the AC power source connecting circuit, c) switching means that can be operated at any time in relation to the periods of the alternating current, d) a second circuit controlled by the switching means for the power supply of the gate circuit 9 0 9 815/0642 _{0RlQlNAL 1NSPEC} ted for establishing a conductive state of the controlled line means after actuation of the switching means during a suitably polarized half cycle and e) a third circuit to supply the controlled line means with sufficient holding current, which should conduct at least two homopolar half-cycles of the alternating current, includes. 2. Apparatus according to claim 1, characterized in that as a unidirectional controlled Line means of the triggered control circuit, a silicon-controlled rectifier is provided. 3. Apparatus according to claim 2, characterized in that after actuation of the switching means the silicon controlled rectifier (SCR) during two consecutive half cycles of the alternating current is conductive. 4. Apparatus according to claim 1, characterized in that the first circuit has a first RC element and the second circuit has a second RC element. 5. Apparatus according to claim 4, dadurc'h marked net that the time constant of the second RC element is greater than that of the first RC element. 6. Apparatus according to claim 5, characterized in that the resistance of the first RC element is greater than that of the second RC element. 7. Apparatus according to claim 4, characterized in that the data of the components of the first and the 909815/0642 second RC element are selected so that the _a triggered control circuit outputs at each actuation of the switching means two unidirectional pulses to the solenoid. Method for generating and delivering a predetermined number of blows to a fastening element while being fed of at least two rectified pulses supplied by an AC power source to the solenoid an electrically powered portable driving tool for fastening elements with means for driving the same, wherein the solenoid has a coil for generating a magnetic field and one having means for driving connected and this includes when the coil is excited axially in this moving armature, gekennzei chnet by Placing the coil in series between the AC power source and a silicon rectifier, Charging the capacitor of a first RC element, Switching a second RC element to the gate of a silicon rectifier in order to supply it with control current to supply, Discharge of the capacitor of the first RC element to supply holding current to the rectifier for more than one period to the rectifier for at least two consecutive positive half-periods to make the alternating current conductive, and Prevents driving in more than one fastener with a single actuation of the device. Electrically powered device for driving fasteners with a hollow housing body having an elongated head portion for housing a moving unit comprising a solenoid, one for the solenoid -4- 9098 15/0642 matching and in this axially movable plunger and a driver blade arranged on the plunger for the fastening elements, one handle part protruding backwards from the head part, one on the head part arranged and operatively connected to the driver blade when driving in a fastening element magazine part for receiving a plurality of fastening elements and a triggered electronic control circuit for Generating a predetermined number to be issued by the fastener each time the device is actuated Having blows, as well as means for preventing the driving of more than one fastener during actuation of the device by preventing the advancement of the next fastener into the axial path of the driver blade during the driving of a first fastener by repeated blows of the driver blade is provided. 10. Electrically powered device for driving fasteners with a hollow housing body that has an elongated head section with a hollow interior for housing a moving unit comprising a solenoid and one suitable for the solenoid and axially movable therein Immersion armature, with the driver blade at its lower end and a piston head at its upper end resilient means pushing it upwards, a hollow handle part protruding backwards from the head part, the in itself a triggered electronic control circuit for the generation of a predetermined number of at each Actuation of the device receives a fastening element to be issued blows, and one arranged on the head part Magazine portion comprises, the latter receiving a plurality of fasteners, in operative connection with the driver blade stands and is provided with means to prevent the return of the driver blade between two strokes in such a way, -5- 909815/0642 that the driver blade is the advance of a second fastener prevented in its axial path as long as a first fastening element is driven, wherein these means comprise a shock absorber with a damping piston, the base of which is attached to the piston base of the plunger movable and displaceable in a cylindrical inner housing seated on the solenoid and on its inner wall is slidably disposed and at least one hole for the passage of air during the downward movement of the plunger when the device is actuated, while the inner housing has a vent hole for the controlled outlet of air during the return of the plunger. 11. Apparatus according to claim 10, characterized in that the damping piston has a plurality in its bottom of holes. 12. Apparatus according to claim 10, characterized in that the damping piston made of plastic consists. 13. Apparatus according to claim 11, characterized in that the damping piston with the piston head is connected by means of a collar provided with a hollow rivet. 14. Electrically powered device with a hollow housing body, which has an elongated head part to accommodate a movement unit, comprising a solenoid, a plunger that fits the solenoid and is axially movable therein and a driver blade arranged on the plunger for the fastening elements, one of the head part towards the rear extending handle part with a trigger and a triggered electronic control circuit for generating a predetermined number of a fastener when actuated and action of the trigger to be given blows, ^ one on the 90981 S / 0642 Head part arranged and operatively connected to the driver blade for driving in magazine part for receiving with a plurality of fastening elements and means to prevent the Advancing a second fastener into the axial path of the driver blade during the u m ra g c Driving in a first fastener V with this Means a clamp with an opening, a pivot lever pivotable about a hinge with two elongated ends in the form of a finger protruding forward and protruding through the breakthrough of the clamp and one after arm protruding at the rear to interact with the trigger, a detent fixed to the trigger to prevent the downward movement the clamp when the trigger is in the rest position and resilient means for connecting the arm of the pivot lever with the catch to hold it up against the catch and when the trigger is pressed to let the pivot lever perform a rotation, the pivoting caused by the resilient means of the arm brings it to rest on the notch, presses the clamp onto the next fastening element thereby preventing its advance into the path of the driver sheet. 15. Apparatus according to claim 14, characterized in that between the path of the driver sheet and a rear driver guide provided with an elongated aperture is disposed on the clamp. 16. Apparatus according to claim 15 »characterized in that the magazine has two side walls and a guide that runs through the joint forming bolts are interconnected. -7- 90981 S / 0642 17. Apparatus according to claim 16, characterized in that the side walls 3 are provided with support tabs to the back support of the clamp. 18. Apparatus according to claim 17, characterized in that the clamp at its lower end is provided with at least one tongue for printing against a fastening means. 19. Apparatus according to claim l8, characterized in that the lower surface of the clamp is designed for flat support on a fastening element. 20. Apparatus according to claim 19, characterized in that the tongue opposite the clamp is angled. 9098 1 5/0642