DE2604287A1 - DEVICE FOR DRIVING FASTENING MEANS - Google Patents

Description

Patent attorney DIpI.-Ing. Curt Wallach Dipl.-Ing. Öünther Koch Dipl.-Phys. Dr Tino Haibach Dipl.-Ing, Rainer Feldkamp

D-8000 Munich 2 Kaufingerstraße 8 Telephone (0 89) 24 0275 Telex 5 29 513 wakai d

Date: February 4, 1976

Our reference: I5 401 - Pk 'Ne

Harry M. Haytayan
Lincoln, Massachusetts, USA

Device for driving fasteners

The invention relates to a pneumatic device for driving fastening means.

Pneumatic devices for driving fasteners, such as nails, for example, are in the U.S. Patents 3,498,517, 3,060,441, 3,035,268, 3,060,440, 3,595,460 and 3 7II 008.

The known handheld pneumatic devices of this type were not suitable for heavy use such as driving nails or fasteners into high strength bodies such as pre-stressed Concrete with a compressive strength of 352 to 704 kp / cm and in structural steel plates with a thickness of 4.8 ram or more. the end for this reason, almost all of the high stress driving operations have been carried out using explosion actuated equipment carried out, which require a lot of time and which are expensive and dangerous to operate. Furthermore, explosion-actuated Devices for driving in fastening

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average significant recoil and noise problems.

Previous attempts to create pneumatic, heavy duty fastener driving devices have generally not been successful due to the difficulty in finding the stop force required to drive one Nail or other fastener in or through high strength bodies such as concrete and steel plates to create. Because of the problems of producing the required acceleration, these have been known pneumatic devices Kinds capable of driving high force fasteners overly complicated and required complicated ones and large valves for supplying and discharging the pneumatic fluid in order to achieve the desired acceleration and impact or to generate impact force. Furthermore, most of the known constructions of these devices have been mechanical Springs are present to support the return movement or the return stroke of the stop part. The insertion of spring elements however, has the undesirable effect that the acceleration of the impact part and that of this part on the fastening means applied impact force is limited. Most hand-held pneumatic driving devices of nails and similar fasteners have therefore been low power devices, i.e. devices that little or no acceleration time between the start of the working or driving stroke of the impact member and provide for the impact of the fastening means driven by the impact part on the workpiece. As a result, had to the known hand-held devices for driving fasteners to be very massive, so that a sufficient Energy was generated to drive fasteners with high force. This resulted in these known devices still the disadvantage of a very strong setback.

A device for driving fastening means has already been proposed (US patent application 496 453 of August 12, 1974),

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that can drive fasteners, for example nails, into high-strength structures such as prestressed concrete

with a compressive strength of 552 to 562 kp / cm and in structural steel plates with a thickness of the order of 6.35 a result that with known pneumatic devices before for driving in fasteners cannot be achieved.

The invention is based on the object of creating an improved device of the last-mentioned type which is used for applications with high performance is suitable and with a simpler structure a greater driving force per unit volume than known Devices for similar tasks results, while still providing precise control of the speed of the drive piston should be achieved so that the power output of the device can be controlled * and the available Energy is used to the maximum.

This object is achieved by the invention specified in claim 1.

Further advantageous refinements and developments of the invention emerge from the subclaims.

The device according to the invention comprises a hollow housing, a cylinder arranged in the housing, the interior of the housing in a first between the housing and the cylinder arranged chamber, which serves from air reservoir, and a second chamber divided in the cylinder, a hammer or a stop part, a piston reciprocable in the cylinder for driving the hammer via a drive or Stop stroke and a return stroke, means for arranging one Fastening means such that it engages and advances the hammer during the stop stroke an air manifold communicating with the first chamber and valve means that (a) selectively air

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from the first chamber to one or the other end of the second chamber depending on whether the piston to drive the hammer via its stop stroke or its return stroke, and the (b) selectively air in front of one side of the piston during its stop stroke or before the other side of the piston during its return stroke. the Valve devices include an extremely fast acting large orifice poppet valve to provide a fast and large Ensure supply of drive air from the air reservoir to the piston for its drive stroke, so that the available standing air output is used with the full line pressure. In the device, the return stroke of the Piston and hammer reached without the support of springs or similar energy storage devices to the one Energy transfer would be required during the drive stroke, so that essentially all of that is available and energy acting on the piston during the drive stroke is used to apply force to a fastener or other workpiece. The hammer accelerates progressing over a considerable part of its drive stroke and reaching its maximum speed while the Fastener is driven into the workpiece.

In this way, the air power is used in the device substantially with the full line pressure, so that a piston with a relatively small diameter and low weight in connection with the new type of valve control for control the air flow can be used. The device can be used for a variety of impacting and driving applications and the valve assemblies are relatively simple while still providing efficient operation.

In contrast to many known arrangements, the device described uses only a single piston for forward movement of the hammer and there is still a fail-safe operation in which an unintentional triggering

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is prevented, the device in the event of a jamming or a failure is rendered ineffective and it is not possible that several successive stop strokes are carried out unintentionally will. Despite the high performance, the noise and the kickback is largely reduced, so that the Device can be easily performed by hand.

The invention is explained in more detail below with reference to the exemplary embodiments shown in the drawing.

In the drawing show:

Fig. 1 is a side view of a preferred embodiment

shape of the device intended for driving nails;

FIG. 2 is an end view of the device of FIG

3 is a sectional view taken along line 3-3 according to FIG

Fig. 2 shows the device with the hammer withdrawn or in the ready position shows;

FIGS. 3A and 3B are enlarged views of two parts of FIG. 3

Fig. 4 is a view similar to Fig. 3 showing the hammer

shows at the end of its stop stroke;

5 is a cross-sectional view of the nail magazine along the line 5-5 of Figure 3;

FIG. 6 is a view similar to FIG. 3 of another

Embodiment of the device in the standby division;

FIG. 7 shows the device according to FIG. 6, however

the hammer is at the end of its stroke;

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Pig. 8 and 9 are enlarged fragmentary sectional views

an auxiliary exhaust control valve that is used in the Devices according to the Pigg. 3 and 6 can be used.

The ones in the Pigg. 1 and 2 shown embodiment of the device comprises a hollow housing 2, a cap part 4, a nail receiving and aligning head 6 and a magazine 8 for receiving a nail supply and for feeding into the nail receiving and aligning head 6. The cap part 4 and the head 6 are detachable attached to the upper and lower ends of the housing by means of screws 10 and 11 inserted into threaded holes in the Housing are screwed in. The magazine can be detached from the head 6 fastened by means of screws 12 which go through holes in the head and which are in threaded bores in the adjacent one Are screwed into the end of the magazine.

As ^ from the Pigg. 35 and 4 can be seen, has the upper end of the housing has an end wall 14 which serves as a poppet valve housing. For this purpose, a cylindrical bore 15 is in the End wall 14 is formed and the upper end of the bore 15 has a counterbore shown at 16. In the bore 15 is one hollow poppet valve, indicated generally by the reference numeral 17, the one being cylindrical Wall 18, the size of which results in a tight sliding fit with the bore 15, a peripheral flange I9 at the upper end of the wall 18 with a size which provides a tight sliding fit with the counterbore 16 and an upper end wall 20 comprises. The poppet valve further includes a centrally located protrusion 21 which is integrally formed with the end wall 20 and is spaced from wall 18 so that an inner annular cavity 22 is formed. The outer surfaces the wall l8 and the flange I9 are with circumferentially extending Provide grooves in which elastic sealing rings 23 which bear against the surrounding surfaces formed by the bore 15 and the counterbore 16

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and which serve to prevent leakage of the fluid, but with the poppet valve axially can move. The ring seals 23 are preferably but not necessarily made of an elastomer material and can be in the form of O-rings. The upper end wall 14 of the housing 2 is preferably with one or more channels 24 provided, which lead from the counterbore 16 to the atmosphere. The channels 24 serve as drainage lines to prevent pressure build-up in the space between the lower side of the flange 19 and the annular shoulder, which is formed by the connection of the bore 15 with the counterbore 16.

The lower end of the poppet valve is supported by a substantially rigid circular metal plate 25 and one with the plate 25 connected circular elastic sealing pad 26 completed. The latter elements are provided with central openings, to receive a banjo bolt or threaded sleeve 27 which is inserted into the lower end of a in the Projection 21 formed axial bore 28 is screwed. The poppet valve also includes a cylindrical axial extension 29, which is formed in one piece with the end wall 20 and has an internal bore which is an extension of the Bore 28 forms. The cap part has a cavity 31 with a circular cross-section in order to receive the extension 29 and the upper end of this extension has a peripheral flange or piston 32 which is sized so that a tight sliding fit in the cavity 21 results. The outer surface of the flange 32 has a circumferentially extending Groove in which another (similar to the sealing rings 23) Sealing ring 34 is arranged against the surface surrounding it of the cap part and prevents leakage of the fluid, the extension 29 at the same time can move in the axial direction in the cavity 31. A elastic sealing pad 35 is fixed in the upper end of the cavity '31 and can with the flat upper end surface the extension 29 come into engagement. The cushion 35 serves as a valve seat for the extension 29. In addition, this closes

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Cap part 4 has one or more channels or openings 36, extending from the cavity 3I to the atmosphere. The hollow extension 29, the bore 28, the cavity 31, the cushion 35 and the channels 36 together form an outlet valve, to selectively move fluid from the bottom of the poppet valve to give off to the atmosphere. Preferably, the axial dimensions of the cavity 31 * of the extension 29, the bore 15, the counterbore l6, the flange 19 and of the wall 18 selected so that when the poppet valve is moved upward, a small gap between the surfaces 37 and 38 is present when the flat upper end surface of the extension 29 is firmly pressed against the pad 35, like this is shown in FIG. The effective area of the annular top surface 37 of the poppet valve 17 is greater than that Area of the underside of the cushion 26.

The sealing pad 26 provides a permanent seal between the poppet valve and the top edge of a cylinder 40 when the poppet valve is in its lower or closed position (Fig. 3). The cylinder 40 is open formed upper and lower ends and its inner diameter is constant over its length. The lower end of the cylinder 40 is fastened in an opening which is formed in the bottom end wall of the housing 2. The cylinder 40 can be attached to the End wall 42 may be attached in various ways, such as a screw thread connection, a shrink fit or by welding or brazing. The lower end of the cylinder 2 preferably has circumferential grooves for receiving elastic wire rings 43 (similar to the sealing rings 23 and 24) which rest firmly against the surrounding surface of the end wall 42. The lower end of the cylinder 40 is closed by a plug 44 which can also be attached to the cylinder in various ways, for example by a screw thread connection, a shrink fit or by welding or brazing. Leakage of fluid between the outer surface of the plug 44 and the

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Inner surface of the cylinder 40 is elastic by another Prevents sealing ring 25, which is arranged in a circumferential groove in the plug. The stopper also has a round axial bore 46 which slidably receives a hammer or a driving part 47. The plug is with an internal groove formed around the bore 46 to receive a resilient sealing ring 48 that encompasses the outer surface of the Hammer 47 surrounds and with this with a just sufficient Force is engaged to prevent fluid leakage while at the same time the hammer is in Can move in the axial direction. The upper end of the hammer 47 is attached to a circular piston 49, the planar upper one and has lower surfaces and which is sized to be a close sliding fit with the inner one Surface of the cylinder 40 results. The piston 49 has a Circumferential groove in which an elastic sealing ring 50 is arranged which bears against the smooth inner surface of the cylinder and leakage of fluid between the Piston and cylinder prevented. An annular resilient cushion member 52 is on the inner surface of the plug 44 attached. The inner diameter of the cushion portion 52 is preferred dimensioned so that there is a considerable gap between this part and the hammer 47 to avoid any frictional forces that would prevent the hammer from moving. The cushion member 52 is preferably made of an elastomer such as e.g. made of a synthetic or natural rubber compound, but it can also be made of an elastic plastic material be made.

The outer surface of the cylinder 40 is spaced from the inner surface of the housing 2 so that a chamber 54 results, which serves as an air reservoir. Additionally the outside diameter of the cylinder 40 is smaller than the outside diameter of the poppet valve by a selected amount, so that a considerable edge portion of the cushion 26 projects in the radial direction over the cylinder, as can be seen in FIG is. Preferably, but not necessarily, has

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the top of the cylinder has an external bevel 55 to increase the amount of cushion 26 as much as possible, which protrudes from the outer edge surface of the cylinder 40.

As can be seen from Figs. 3 and 4, the housing 2 has a hollow lateral extension 57 which forms a bend chamber 58 for supplying air or other pressurized fluid to the storage chamber 5 ² J and to other parts of the device, which will be described hereinafter yet to be described. Extension 57 has an inlet port 59 which is threaded for connection to flexible tubing (not shown) leading to a regulated source of pressurized fluid such as an air compressor. The manifold chamber 58 is in direct communication with the reservoir chamber 54 via a channel 60. Part of the extension 57 of the housing is formed with a relatively thick wall section 62 which is provided with a bore 63 for receiving a control valve 64.

As can be seen from Figs. 3 and 3A can be seen, the control valve 64 comprises a control valve housing 65 which is in a bore 63 is attached by means of a dowel pin 6l. How best to do it As can be seen from FIG. 3A, the control valve housing 65 is closed at one end by a sleeve 66 which has an opening 67 forms, which leads to channel 60. A cushion 68 having an opening, which is preferably made of elastic material is made, is attached to the inner end of the sleeve 66 and serves as a valve seat for a control valve part 69. The housing 65 has at its other end a bore 70 for receiving a valve rod assembly 71 which directly connects to the valve part 69 is connected. At the inner end of the bore 70 has the valve housing 65 has a shoulder to which a further cushion 72, which also has a seal, is attached, which consists of the same material as the cushion 68 and also serves as a valve seat for the valve part 69. Between the two valve seats is the housing 65 with a side opening

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provided opening which is directly connected to one end of a channel 73 which is formed in the wall portion 62 in connection. At the opposite end of the channel 73 is connected a tube Jk which extends in the longitudinal direction of the chamber 54 and extends through the upper end wall 14 of the housing 2 and is fixed therein. The upper end of the tube * Jk communicates directly with a channel or a cavity 75 in the cap part 4, which opens into the counterbore 16 of the poppet valve housing. Looking at the control valve, it can also be seen that the housing 65 has a further opening 76 which communicates at one end with the bore and which is open to the atmosphere at the other end via a slot 77 in the side of the housing 65. The valve rod assembly 71 includes a piston 79, the size of which is such that a sliding fit in the bore 70 results.

The shape of the control valve member 69 is such that when it is moved upward against the cushion 68 it closes the opening 67, while when it is moved downward against the cushion 72 it closes the control valve chamber from the bore 70. The control valve part 69, however, cannot shut off the side opening leading to the channel 73 in any position. When the manifold inlet port 59 is connected to a source of high pressure air, the air in the manifold chamber 58 acts through port 67 to urge control valve member 69 down against cushion 72 so that air is up through control valve housing 65 into the cavity 75 of the cap part ^ _{1 flows} over the channel 73 and the pipe 7 ^ and the resulting air pressure in the cavity 75 presses the valve part 17 downwards onto the upper end of the cylinder 40.

The control valve part is moved to its upper position with the aid of a release lever 82 which is pivotable on the housing 2 is attached. For this purpose, the lower end wall 42 of the housing 2 is provided with a vertically extending hollow

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Space 83 and a side opening 84 provided with the cavity 83 is in communication. The inner end of the release lever extends through the opening 84 into the cavity 83 and points a tongue which looks into a slot 86 in the side wall of the housing 2 and which is pivotable by means of a Pivot pin 87 is attached to the housing. The outer end of the trip lever 82 springs under the outer end of the valve rod assembly 71 before. When the release lever is pulled up, i.e. pivoted counterclockwise according to Fig. 3, comes it engages with the piston rod arrangement 71 and presses it upwards so that the valve part 69 closes the opening 67 and the high pressure in the counterbore 16, the cavity 75 * the pipe 74 and the channel 73 via the opening 76 and the slot 77 can flow out to the atmosphere.

The lower end wall 42 of the housing 2 also has a circular bore for receiving an outlet or safety valve 88, which is similar to the control valve 64. As best seen in Figure 3B, the valve includes an exhaust valve housing 89 * that in the bore in the end wall 42 is secured in a suitable manner, for example by an adjusting screw 89A or by a screw connection or a friction fit is. The housing 89 is closed at one end by a threaded bushing 90 which has an opening 91. One with An apertured cushion 92, preferably made of resilient material, is at the inner end of the Bushing 90 is attached and serves as a valve seat for an exhaust valve part 93 attached to a valve rod assembly 94 is. The other end of the valve housing 89 has a bore 95 for receiving the valve rod arrangement 94. At the top At the end of the bore 95, the housing 89 e: Uie shoulder, to which a further cushion 96 provided with an opening is attached, which also acts as a seat for the valve part 9j serves. The valve part 93 has a piston 97, the one Has a sliding fit with the bore 95. The valve housing 89 has a lower side opening 95A that defines the bore 95

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connects to an outlet port 98 formed in the lower end wall 42 of the housing 2 and it is further an upper side opening 95B is provided which opens the interior space through a hole in the lower end of the cylinder 40 with a Channel 99 in the lower end wall 42 connects. The channel 99 communicates with the interior of the cylinder 40 through an opening in the cushion 52. The valve part 93 can be the opening 91 lock when it is moved up against the cushion 92 and it can lock the lower end of the bore 95 when it against the cushion 96. The valve part 93 can, however, in Do not close the upper side opening 95B leading to the channel 99 in any position. Accordingly, if the valve part 93 against the cushion 96, air from the air reservoir 54 into the lower end of the cylinder 40 via the opening 91 and the channel 99 flow in and the outlet opening 98 is closed. When the valve member 93 is brought into abutment against the cushion 92 is, the opening 9I is closed and air can out of the the lower end of the cylinder 40 via the channel 99, the bore and the outlet port 98 to flow out.

The movement of the valve part 93 is by a mechanical Linkage controlled, which is carried by the head 6. The upper end of the head 6 has a cavity 102 and a protrusion 104 which extends upwardly from the lower end wall 105 and is preferably in contact with the plug 44. The protrusion 104 has an axial bore 106 which is aligned with the hammer 47 and is of a size such that that this hammer is slidably received. The head 6 also has a lower axial extension in the form of a Foot 107 which has a bore that is an extension the bore is I06. The mentioned mechanical linkage, which controls the movement of the valve part 93, comprises a lever arm IO8, the is arranged in the cavity 102, and an actuating rod 109 which is slidably arranged in a bore 110 in the foot 107 which extends parallel to the bore 106. One end of the lever arm 108 is secured by means of a pivot pin 111

pivotally attached to the head 6. The other end of the arm

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is pivotable at the top of the StangelO9 with the help of a Pivot pin II3 attached, which is carried by the rod 109 and fits into an elongated slot 114 in the arm 108 extends. The arm I08 is pivotally connected to the valve member 93 by means of a pivot pin 115 which is attached to the the lower end of the valve rod assembly 94 is attached and into another elongated one formed in the ariii 108 Slot 116 extends.

In the absence of compressed air in the device, the weight of the rod 109 and the arm 108 is sufficient to support the valve part 95 to hold the cushion 96 when the device is as shown in Fig. 3, is held vertically. The length of the rod I09 is such that it extends outwardly over the flat floor surface II8 of the foot 107 protrudes a short distance, for example by 6 to 12 mm, when the valve part 95 rests on the cushion 96 and the rod is flush with the end surface II8 when the valve member 93 abuts the cushion 92. When compressed air is the Device is supplied, the valve part 93 remains in support against the cushion 96 "regardless of the orientation the device until the stem O9 is subjected to an upward force sufficient to the downward force To overcome force resulting from the effect of the compressed air in the chamber 5 ^ on the upper side of the valve part 93.

As can be seen from Figs. 3 to 5 can be seen, the magazine is hollow and forms an elongated channel 122 through opposite Sidewalls 124, a bottom wall 126 and a top wall 128 is delimited. Each side wall has a relative shallow upper groove IjJO and a relatively deep lower groove 131 which are separated by a rib I32. The grooves 130 serve to hold and guide the fasteners to be driven in. In this case the fasteners are Nails 134, the shafts of which are embedded in plastic sleeves 135 or are arranged with a friction fit, the plastic sleeves

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are connected to each other by connecting portions I36. The sleeves 135 and the sections I36 are considered to be continuous Strips formed. The sleeves 135 are of such a size on that they look into the grooves 1J50 extend and slide be supported by the ribs I32. Furthermore, the Sleeves 135 have an equal or slightly larger diameter than the nail heads 134 on, while the diameter of the sleeves continues -are chosen so that they give a tight fit in the bore. Furthermore, the sleeves 135 preferably have a length at least 6 rams sufficient to hold the nail straight in bore 106 during the hammer's driving stroke executes. The front end of the channel 122 is connected to an opening 138 in the foot 107, which has a cross-sectional shape similar to that of the channel 122, but without grooves corresponding to hats 131 are provided. The opening I38 has on each of its opposite sides a rib 139 corresponding to the rib I32, so that a holder for the sleeves 135 results. The row of nails is pushed towards the foot 107 with the aid of a pusher l40 which located in the channel 122 and having a rib 142 on each side that slides into the adjacent groove 131 fits. A tongue 146 on the lower side of the slider 140 is connected to one end of a tension spring 143 which revolves around a pulley 144 which is rotatably mounted on a shaft which is mounted in one of the side walls 124 extends. The other end of the spring 143 is attached to a pin 145, which is also anchored in a side wall 124. The spring 143 pushes the slide towards the foot 107. The upper one Wall 128 of the magazine ends shortly before the rear end of the magazine, so that there is an end edge 147 which acts as a stop serves for a finger 148 on the upper end of the slider 140 so that the front end of the slider is prevented from falling into the bore 106 enters and comes into contact with the hammer 47 when the last nail has been dispensed. The magazine 8 is further formed with a foot 150, the lower end surface of which flush with the lower end surface of the foot 107.

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The two feet 107 and 150 cooperate to create the device to stabilize and hold it vertically when held against a body into which a nail 1 ^ 4 is driven shall be.

The relative sizes of the openings Sj and 91 (together with the amount by which the poppet valve pad 26 protrudes above the top edge of the cylinder 40 are chosen to vary downward movement of the hammer 47 and possible inadvertent triggering of the device , when the device is connected to the compressed air source, the dimensioning is still chosen so that a quick opening of the poppet valve is ensured, an optimal utilization of the available air power is achieved and the force required to the trigger valve 64 is limited In this regard, it should be noted that the volume of air supply chamber 54 (which can be viewed as including the volume of duct 60 and manifold chamber 58) is relatively large compared to both the internal volume of cylinder 40 and the combined volume of the space above the poppet valve part

is
17fwhen this is in the lower position (FIG. 5), ie the counterbore 16, the chamber 75, the tube 74 and the channel 73 than is necessary to achieve a corresponding change in the air pressure above the TeHerventils or the air pressure below the piston 49. To avoid any possibility of the hammer 47 being inadvertently moved downward when the air pressure source is connected to the device (whereby a nail in bore 106 could be separated from the other nails and moved down far enough for the next nail would be moved into bore I06) it is essential to determine the relative flow rates (a) between manifold 58 and counterbore 16 and cavity 75, and (b) between the reservoir-

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chamber 54 and the bottom of the piston 49 to control. This The aim is through appropriate proportioning of the smallest effective Cross-sectional area of the channels connecting the manifold chamber 58 to the counterbore 16 of the poppet valve body, i.e. the Cross-sectional area of the opening 67 and the smallest effective cross-sectional area of the ducts that reach the manifold chamber 58 with the reservoir chamber 54 and the interior of the cylinder 40 under the piston 49, i.e. the cross-sectional area of the opening 91. The first-mentioned cross-sectional area is made smaller than the last-mentioned cross-sectional area. The relative Sizes of the two smallest effective cross-sectional areas mentioned above depend on the volumes of the counterbore 16 and the cavity 75 * the reservoir chamber 54 and the cylinder 40, the overlap of the poppet valve 17 over the cylinder 40, the Diameter of the piston 49 and the effective area of the top surface 37 of the poppet valve 17. In general, however Best results are achieved when the last-mentioned cross-sectional area, i.e. the opening 91, is approximately four times as large like the first-mentioned cross-sectional area, i.e. the opening 67. Typically, the diameter of the openings 67 or 9I approximately 3 * 2 or 6.4 mm, the piston 49 having a diameter of 76.5 mm and the overlap of the poppet valve 17 is approximately 3.2 mm. The compressed air inlet port 59 and cfer Channel 60 are considerably larger than openings 67 and 9I, as shown in Figs. 3 and 4 can be seen (the openings 67 and 9I in FIG shown as roughly the same as the drawings.)

In the following the operation of the device according to the Figg. 1 to 5 described. The manifold chamber 58 is compressed air at a pressure of, for example, 8.8 kp / cm by supplying the inlet opening 59 with a suitable compressed air source such as a compressor (not shown). This air passes through the opening 67 and acts the valve part 69, so that it closes the opening in the cushion 72. The air passing through the opening 67 passes

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further through the channel 73 and the pipe 74 into the chamber 75 » in which it exerts a force on the upper end of the poppet valve 17 so that it is in the position shown in FIG is pressed, in which the rubber washer 26 provides a tight seal with respect to the upper edge of the cylinder 40. Simultaneously air is fed to the air storage chamber 54 via the duct 60 and this air passes through the opening 91 of the exhaust valve 88 and presses the valve part 93 downwards against the cushion 96 in order to prevent the discharge of air from the outlet duct 98. The air entering the chamber of the exhaust valve 88 continues to pass through the channel 99 into the cylinder 40, so that a force is exerted on the underside of the piston 49, which presses the piston downward against the sealing disk 26, as shown in FIG. 3. Any between the above Air trapped at the end of the piston and the disk 26 is released to the atmosphere via the channel 28 and the openings 36. The device is now in the normal equilibrium position and cannot be triggered if the push rod I09 is not pushed upwards far enough for the valve part 93 to open the opening in the valve seat 96. If the release lever is pressed while the push rod 109 is in the position shown in Fig. 3, the position of the valve part 69 changes and the pressure acting on the upper side of the poppet valve 17 is reduced by releasing of the air from the chamber 75 via the tube 34, the inner chamber of the valve 64 and the outlet port 76 is eliminated. Corresponding moves due to the pressure in the reservoir chamber 54, the poppet valve 17 upwards, so that compressed air can act on the upper end of the piston 49. It surrenders however, no movement of the piston because of a force equilibrium state as a result of the opposing force, the pressurized air acting on the lower surface of the piston 49 and the additional static frictional forces due to the contact of the O-ring seal 50 with the cylinder 40 and the piston rod with the seal 48 (for this purpose the seals 48 and 50 are arranged so that they are commonly used with

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Fit tolerances generate a total static frictional force which is at least substantially equal to the downward force exerted on the piston, which results from the area differential between the upper and the lower surface of the piston). It should also be noted that if the diameter of the rod 47 were to be made so large that the force resulting from the area differential is considerably greater than the static frictional forces exerted by the seals, the piston 49 merely creeps towards the lower one End of cylinder moves when poppet valve is opened. When the trip lever 82 is repeatedly released and depressed, the poppet valve moves repeatedly toward and away from the cylinder 40, but the piston 49 remains stationary. In order to trigger the device, the actuating rod 109 for the safety mechanism must be pushed upwards far enough so that the valve part 93 now blocks the opening 91. When this occurs, the pressure acting on the underside of the piston 49 is largely released to the atmosphere by the outflow of air via the channel 99, the valve housing 89, the bore 95 and the opening 98. When the release lever 82 is then pressed to move the control part 69 upwards so far that the opening 67 is closed, the poppet valve 7 moves considerably upwards in the direction of the chamber 75 and the full line pressure in the reservoir chamber 54 acts on the upper end of the piston 49 * so that it moves quickly over its normal working stroke. The piston 49 does not return to its normal starting position until the actuating rod 109 is released and before the trip lever 82 is also released.

The following describes the advantages of precise control and definition of the relative sizes of the openings 67 and 91 of the control and exhaust valves. When the inlet 59 old to a compressed air source is connected, a pressure builds up on both side of the poppet valve I7. If a quick print job

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bau would occur in the reservoir chamber ^ k , the poppet valve 17 could open and the piston 49 could be pushed down a considerable distance by the pressure acting on its upper side. Because the opening 91 is made relatively large, it is possible that the air pressure on the underside of the cylinder 40 can build up very quickly, so that the piston 49 is brought almost immediately into a state of equilibrium.

When the piston 49 has a diameter of about 76.2 mm, the poppet valve lift is typically approximately 9 * 525 mm

ο and at a line pressure of approximately 8.8 kp / cm, the poppet valve opens completely within approximately 3 milliseconds. The speed at which the poppet valve opens is determined by the size of the vent in the sleeve 27 (as well as by the size of the overlap of the poppet valve with respect to the cylinder 40 and by the smallest effective cross-sectional area of the channels leading from the cavity 75 via the valve 64 to the atmosphere). The smaller the opening in the sleeve 27, the faster the poppet valve I7 opens. However, if the opening is too small, it will limit the speed of the after upward movement of the piston 49 and also can a Whistling sound is generated when the piston 49 makes its return stroke executes. When the piston 49 has a diameter of 76.2 mm has, the opening in the sleeve 27 typically has a diameter of 3.2 mm for optimal operation of the Poppet valve.

It has been found that certain design criteria must be observed for optimal operation of the device to achieve. In this regard, it will be understood that in order to utilize the air capacity at full line pressure it is essential that the poppet valve have a relatively Large opening for the rapid supply of high pressure air from the reservoir chamber 54 to the upper end of the cylinder 40 results. For example, if the piston 49 is approximately 76.2 mm in diameter, the maximum poppet valve is

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opening (i.e. the maximum gap between the poppet valve and the cylinder 40) is preferably between 7 * 62 and 12.7 mm. In order to the hammer continues to reach its maximum speed under the applied pneumatic power is the length of the Hammer 47 selected so that the hammer a predetermined Travels before driving the nail into the workpiece. This lead time changes according to the type of workpiece or body into which the nail is to be driven, but is preferably at least 50 mm. In its rest position For example, the hammer may be close to the nail in bore 106, but preferably it faces off the nail a considerable distance.

The Pigg. Figures 6 and 7 show a modified embodiment with a trip lever locking mechanism. This modified Embodiment is preferred for larger diameter hammers. In this context it should be remembered that if the release lever of the execution is pie Is according to the Pigg. J5 and is operated without the operating rod 109 far enough is pushed up to block the opening 91, the The poppet valve opens without any movement of the hammer 47, because a force equilibrium state due to the Frictional forces on the piston ring seal 50 and the hammer seal 48 occurs. However, if the hammer diameter and / or the line air pressure is increased, the | on the Top of the piston 49 acting against the force acting on the underside of the piston force so large that the Hammer is moved towards the nail in bore 106 when the trigger is pressed, even if the Actuating rod 109 was not pushed up far enough, to block the opening 91 of the exhaust valve. Therefore, in manolic cases, it may be desirable to have a release lever safety mechanism to prevent movement of the hammer 47 when the safety rod 109 is not pushed back enough to operate the exhaust valve. As a practical result, it has been found that the

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desired force balance condition is easily achieved if the hammer diameter is no greater than about 19 mm and does not exceed 20% of the diameter of the piston 49 and if the air pressure in the reservoir chamber 54 does not exceed 12.5 kgf / cm.

Like it from the Pigg. 6 and 7 is the head provided with a second axially extending bore 160 in which a second actuating rod 162 is arranged is. The upper end of the operating rod 162 is pivotally connected to one end of a linkage 163 which is pivotable is attached to the head 6 with a pivot pin 164. The other end of the linkage 163 is pivotable on a lever arm Ιβ5 attached, which can be pivoted with the help of a pivot pin ΐββ is attached to the head 6. The upper end of the lever arm extends into a groove on the inner end of the trip lever 62 is formed and a side stop 167 on the Lever arm engages the inner surface of the housing 2 to pivot the lever arm clockwise to limit. A compression spring I69 acts between part of the head 6 and the lower end of the lever arm I65 to push the lever arm into the position shown in Fig. 6, in which the lower end of the actuating rod Ιβ2 is slightly above the floor surface HS of the foot I07 protrudes. The lever arm I05, the linkage 163 and the operating rod 162 form a locking mechanism for the release lever. As long as the actuating rod Ιβ2 not in the foot 107 upwards Is pressed, the spring 169 holds the lever arm in the position shown in Fig. So that the upper end of the lever arm the The release lever 82 is blocked so that it cannot be pressed in order to actuate the control valve 64. When the device however, is held on a surface into which a nail is to be driven, the operating rod 162 is driven by the same Surface printed upwards, so that the linkage 163 rotates the lever arm 165 counterclockwise (Fig. 7) as far as possible, that the upper end of this lever arm auxes engagement with the

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Release lever 82 comes and the lever arm can be freely operated to trigger the device. The spring 169 pushes the . Lever arm 1Ö5 in the position shown in Fig. 6 back when the force pushing the rod 162 upward is removed. When the trip lever 82 is released after the operating rod 162 has returned to the position shown in FIG. 6, the lever arm 165 moves under the influence of the grooved end of the trip lever 82 far enough to the trip lever to bring into its locking position. As can be seen, the actuator rods 109 and 162 are close enough against each other so that when the foot 107 is pressed on a workpiece, both rods are pushed back at the same time. Preferably the actuating rod 109 protrudes further out of the foot 107 than the actuating rod l62, in order to ensure in this way, that the latter operating rod is not pushed before the former operating rod 109 is pushed. The actuating rod 109 preferably projects so far more than the actuating rod 162 that the release lever 82 remains blocked until the actuating rod has moved upwards far enough for the valve part 95 to clear the opening 91 blocked.

In practice, the clamps on the valve part 93 of the outlet valve 88 acting air pressure the actuating rod 109 with a downward force sufficient to meet legal requirements. Typically write laws for Power-operated devices state that a force of at least 16 kp must be required to operate a safety mechanism to operate similarly to the actuating rod 109 and this requirement is easily met by the valve part 93 acting pneumatic force fulfilled. If this is desired, the required for depressing the operating rod 109 can Force by simply changing the diameter of the valve member 93 or by regulating the air pressure in the reservoir chamber 5 ^ or by a spring preload of the operating rod enlarged or reduced. Like it, for example

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in Figs. 6 and 7, a tension spring 170 can be between the linkage 108 and the head 6 are provided to permit upward movement of the actuating rod 109 and the valve assembly 71 to counteract.

Figures 8 and 9 show the operation of an auxiliary exhaust control valve, that in the devices according to Figs. 3 and can be used to further increase the speed of the piston 49 during the working stroke to control the To make energy output of the hammer 47 as large as possible. As will be understood by those skilled in the art, the affected by the Hammer during its working stroke, speed reached the energy output of the device. Because the device does not have a spring to support the piston 49 on its return stroke, the speed at which the hammer operates depends 47 is driven downward when the device is triggered, on the speed with which the poppet valve opens fully to bring full line air pressure to the top The end of the piston 49 and the rate at which the air pressure on the underside of the piston is removed becomes (the effect of friction on the hammer 47 and the Piston 49 is almost negligible during the working stroke.) During the development of the device according to the invention, noted that for certain cases when the for the exhaust air from the lower end of the cylinder 40 in front of the piston 49 offered no resistance to such air flow that the power output of hammer 47 was reduced. It is believed, that this result is due to the consumption of air power due to the movement of the piston at the beginning of the Working stroke results, which prevents the hammer from reaching its maximum acceleration. The channel 99 * the valve 88 and however, the outlet opening 98 provides a measurable resistance to air flow and by appropriate control of the size these parts the speed of the hammer is controllable, with the result that a very high impact force of the Hammer is generated on the nail in the bore 106. if

609834/0290

the piston 49, for example, has a diameter of 76.2. mm, the minimum opening, which results from the channel 99, the outlet opening 98 and the opening in the valve seat, of a diameter of approximately 6.35 now (in practice the channel 99, the outlet opening 98 and the opening be carried out in the valve seat 96 with the same diameters, but this is not absolutely necessary). Nonetheless, it has been found that if the minimum effective cross-sectional area of the exhaust path for the lower end of the cylinder 40 is variable, the energy output of the device can be further improved. Hence, like this in the Pigg. 8 and 9, the outlet opening 98 through a tapered bore serving as a valve seat

172 and a large counter bore 175 replaced. The counterbore

173 has a thread for receiving a valve body 174, which only partially fills the counterbore, so that a flow chamber 175 remains. The valve body 174 has an or several bypass outlet channels I76 and a main channel in which a valve member 178 with a tapered Valve head 179 is slidably mounted, which is dimensioned so that it is adapted to the seat in the bore 172. A compression spring 180 presses the valve head 179 against the seat 172. The valve part I78 has a through hole l82, whose Diameter is relatively small compared to the outlet valve opening 95a of the bore 172 and the channels 176.

This auxiliary valve works as follows: During the initial Part of the working stroke of the hammer 47, air is released through the bore 182. The bore 182 is dimensioned such that .that air flows out at a first rate during the initial part of the working stroke of the hammer so that the Hammer can be accelerated without loss of air performance. If the ^ mmer continues its work stroke, it builds up Air pressure on the underside of the piston 49 until finally sufficient pneumatic force is applied to the flat end surface 184 of the valve head 179 to achieve the Force of the spring I80 to overcome, whereupon the valve part

609834/0290 ^{/ #}

178 is rapidly moved away from the valve seat 182, thereby allowing air to flow out to the atmosphere at a much greater rate via the channels I76. In practice, it is preferred to design the auxiliary exhaust control valve so that it opens when the hammer 47 has moved about 40 to 80 % of its working stroke.

The described embodiments of the device result many advantages. On the one hand, a device is created that has a greater output per unit volume than known Can produce devices for the same purpose. For example, manufactured according to the invention and with an air pressure source of 8.0 kp / cm * "connected devices nails with a length of 5 cm and a shaft diameter of 3 * 9 now Drive through 25 mm thick spruce wood into prestressed concrete with a compressive strength of 562 kp / cm. Farther the device has safety devices that prevent unintentional triggering. Third, the device can not in a so-called automatic or multi-repeat mode to be triggered; Successive triggering processes cannot be carried out unless the safety operating rod has been activated beforehand I09 and the trip lever 82 are released, so that the device return to the idle state can. Fourth, the working piston 49 has a very simple structure and can be a small one because of the operating efficiency Weight and small in size, with the result that the overall size of the device is considerably smaller than that of other known devices with comparable power output. Fifth, the poppet valve is completely pneumatic actuated and results in the open state a relatively large opening for the supply of air to the piston 49 from an air storage chamber 54. Furthermore, the poppet valve has due to its Hollow construction has a low weight. It doesn't diminish only adds to the overall weight of the device, but also contributes to the extremely fast operating speed of the poppet valve. Seventh, optimum efficiency is achieved using relatively simple and reliable valve assemblies.

609834/0290. · ^{/ Β}

Another advantage is that the device for driving different types of fasteners or can be used for other stop operations, for example for punching holes in a plate. Farther For example, the device can be constructed to accept pre-filled disposable magazines instead of the refillable magazine 8. Furthermore, the device is relatively quiet in operation and another advantage is that the upper end of the Device can be provided with a button or a handle in the manner shown in order to put it on a workpiece to press open with sufficient force so that the actuating rod 109 (and, if necessary, then also the actuating rod Ιβ2) is depressed.

Another major benefit in terms of extension the life of the device results from the fact that the hammer 47 is made so long that its exterior "End protrudes from the end surface II8 of the foot 107 when the piston 49 reaches the cushion 52 at the end of its working stroke (Figures 4 and 7). Preferably the hammer is made long enough to be at least about 1.6 mm or more (preferably 4.8 mm) protrudes over the end surface II8 of the foot I07, before the piston 49 begins to compress the cushion 52. Driving a nail into a rigid body such as a metal plate overlying a concrete floor the end surface II8 comes into contact with the workpiece and the nail driving stroke is terminated when the end of the hammer flush with the end surface 118. However, the pneumatic force driving the hammer forces it, see further down and because the hammer is long enough to perform this movement, the hammer moves over the End surface II8, in front of the cushion 52 a braking force on the Piston 49 begins to exert. This movement of the hammer over ■ the surface II8 causes a kickback of the device away from the workpiece. This upward return of the device allows the valve

609834/0290

Part 93 of exhaust valve 88 lifts from valve seat 92 (due to the pressure differential between the relatively high pressure in chamber 54 and near atmospheric pressure in valve body 89) just enough for high pressure air from chamber 54 to pass through the interior of the valve body 89 can get into the cylinder 40 on the underside of the piston 49. In this connection it should be pointed out that because the valve part 93 has a sliding fit with the valve body 89 (typically a diameter clearance of between 0.0254 and 0.127 mm is provided), air from the chamber 54 can leak past the valve part 93 as soon as this occurs the associated valve seat 92 or 96 is lifted (the valve part 69 of the control valve 64 has a comparable sliding seat in the valve body 65 ). As a result of the exhaust valve 88 opening enough to allow air to pass from the chamber 54 into the lower end of the cylinder 40, a pneumatic force or air cushion is created on the underside of the piston which causes the piston to decelerate rapidly so that the piston only compresses the cushion 52 slightly or stops just short of this cushion. As a result, the piston does not hit the cushion 52 hard enough to exert a large tensile stress on the bolts II which hold the hail receiving or aligning head C on the housing 2. Without this Abbreniswlrkung the force exerted by the piston on the end wall part 44 and thus on the head 6 could overload the visual hoods 11 at the end of the working stroke of the hammer, so that the device could be damaged or the failure could be caused after a short period of operation. The deceleration of the hammer is very rapid and occurs almost instantaneously after the lower end of the hammer has been moved to close to the end surface II8 of the foot 107. The same feature prevents damage to the tool when held against a workpiece surface and triggered after the supply of nails has been used up. In this case the hammer strikes the workpiece surface before the piston reaches the pad 52 and causes the check of the tool, that the valve 88 opens wide enough to brake the piston,

609834/0290 ^{β /}

thus preventing the piston from destructively hitting the cushion as described above. It should be noted that the small opening of the outlet valve 88, which occurs during the upward recoil movement of the device occurs, does not cause a renewed upward movement of the piston 49 because the poppet valve 17 is still open. The piston 49 can only move up when the Operator has released the release lever 82.

Claims

609834/0290

Claims (1)

Patent claims: (1.) Device for driving fasteners with a housing, a cylinder fixed in the housing such that a first cylinder is between the side wall of the housing and forming a chamber located in the cylinder and a second chamber in the cylinder having an end wall, which closes the first end of the cylinder and has an opening in communication with the second chamber, with a hammer to drive in the fastening means, which is pulled back in the longitudinal direction through the opening between a Position and a second extended position is movable, with one connected to the hammer Piston assembly slidably disposed in the cylinder to move the hammer from its first to its second Position and vice versa, with a third chamber with an inlet for connection to a pressurized air source, the third chamber communicating with the first chamber, with a poppet valve for closing the second opposite end of the cylinder, the poppet valve including a hollow valve housing and a poppet valve member, that in the valve housing for reciprocation between a first open position in which the second chamber is open to the first chamber via the second end of the cylinder, and slidable to a second closed position is arranged in which the second chamber is closed off from the first chamber at the second end of the cylinder wherein the poppet valve member is piston members for moving the valve member into the open or closed Position corresponding to the pressure differential between the air pressure in the valve housing and the pressure in the first Has chamber, with a vent valve to the outlet of Air from the second end of the cylinder only when the poppet valve is closed, with a 609834/0290 housing leading duct, with a first control valve, the the third chamber and the channel connects to selectively (a) to block the flow of air from the third chamber to the duct and at the same time air from the poppet valve housing through the same channel, so that the reduced pressure in the valve housing causes the piston parts to Move the poppet valve part to the open position and the air pressure in the first chamber acts on the piston assembly, to bring the hammer to the extended position, or (b) to block the flow of air from the poppet housing through the duct and the flow of air from the third Chamber to allow poppet valve body through the same channel, thereby increasing the air pressure in the poppet valve body affects the piston parts so that the poppet valve is moved to the closed position, characterized by second control valve parts (88), the ver with the second chamber at the first end of the cylinder (40). are bound to selectively (a) air from the first chamber (54) into the second chamber to transfer the piston assembly (49) move hammer (47) to the retracted position; or (b) air from second chamber to atmosphere let off towards the movement of the piston assembly (49) when driving the hammer (47) in the extended position to support, 2. Apparatus according to claim 1, characterized by means (8) for the arrangement of a to be driven Fastening means (134) in the path of movement of the hammer (47). · 3. Apparatus according to claim 2, characterized by a magazine (8) for receiving a plurality of fastening means, Guide means (1O6) for the hammer (47), a feed opening through which the fastening means individually in the guide devices (106) for the Engagement with the hammer (47) can be moved when this 6 09834/0290 Hammer (47) is moved to its second extended position, and means (14o, 142, - 143, 144) for feeding the fastening means (1J54) in the guide devices (106) through the feed opening. 4. Apparatus according to claim 3 * characterized in that that a fastener outlet opening at the end of the guide remote from the second end of the cylinder Means (106) is provided and that the hammer (47) has such a length that it out of the fastening means opening protrudes when he is in its second extended position. 5. Device according to claim 3 j characterized in that that the fastener supply port (138) is arranged so that the hammer (47) is a predetermined distance must retract when moving from the retracted position to its extended position before moving with one in the guiding devices (I06) in alignment with the supply opening (I38) arranged fastening means (1 ^ 4) comes into engagement. 6. Device according to one of the preceding claims, characterized by from the housing (2) protruding means (109, 162) for mechanically actuating the first and second control valves (64, 88). 7. Device according to one of the preceding claims, characterized in that the first control valve a hollow control valve housing (65) with a first opening (67) of a second leading to the third chamber a third opening (73) leading to the channel (74, 75) opening (76, 77) leading to the atmosphere and a control valve part (69) which is movable so that selectively the first or the third opening is closed. 609834/0290 8. Apparatus according to claim 7 * characterized in that that the air pressure in the first control valve (64) biases the control valve part (69) in such a direction, that it normally closes off the third opening (76, 77). 9. Device according to one of the preceding claims, characterized by a release lever (82) for Actuation of the first control valve (64). 10. The device according to claim 9 * marked ine t by means (162, 163, I65) for releasably locking the release lever (82). 11. The device according to claim 10, characterized by means (I62) for releasing the locking devices. 12. The apparatus according to claim 11, characterized in that the devices for releasing the locking devices an actuator member (162) attached to and protruding from the housing to to actuate the release devices and that the actuating part (162) and the release devices are so connected are that the release lever (82) is released when the actuating part (162) is moved inwardly into the housing. 13. The apparatus according to claim 12, characterized by spring devices (I69) which enable an unlocking of the Counteract the release lever (82). 14. Device according to one of the preceding claims, characterized in that the second control valve (88) comprise a hollow valve housing (89, 90) attached to the Housing (2) is attached and a first to the first chamber (54) leading opening (9I), a second to the second chamber at the first end of the cylinder leading opening (95) and a 609834/0290 third opening leading to the atmosphere outside the housing (98) and that a control valve member (93) is movably mounted in the valve housing to selectively control the first and third openings (9I, 98) complete. 15. The device according to claim 14, characterized in that the air pressure in the first chamber (5 ² O biases the control valve part (93) of the second control valve in a direction in which the third opening (98) is closed. 16. The apparatus of claim I5, marked lohne t by means (I06, 108) for the mechanical displacement of the control valve part (93) of the second control valve (88) in a direction in which the first opening (9I) is closed and the third opening (98) is open. 17 · Device according to claim 16, characterized net that the facilities for mechanical displacement of the control valve part (93) of the second control valve (88) a second actuating part (109) which is fastened to the housing and protrudes therefrom, and the second operating part (109) and the control valve part (93) of the second Control valve (88) comprising connecting parts (IO8), the move the control valve part (93) in a direction in which the first opening (91) of the second control valve (88) is closed when the second actuating part (IO9) is pressed inwards into the housing. 18. The apparatus according to claim 12, characterized in that the second control valve (88) is a control valve part (93) which is normally arranged so that the second control valve part (93) includes air from the first Chamber (5 ^) forwards to the second chamber and that a second actuating part (109) is attached to the housing (2) and protrudes from this and the valve part (93) of the second control valve (88) moves so that the valve 609834/0290 ^{m /} ' til discharges air from the second chamber to the atmosphere when the second actuating part (I09) goes inwards is pressed into the housing (2). 19. The device according to claim 18, characterized in that that the first and second actuating parts (109 * I62) rods are. 20. The device according to claim 19 * gekennze lehne t by a lug (6) on the housing which forms a guide (106) for the hammer (47) and in which the rods (109, 162) are slidably arranged and protrude therefrom, 21. The device according to claim 20, characterized in that that the housing extension (6) has an end surface (II8) having a fastener outlet opening which is in communication with the guide (106) and that the rods (109, I62) normally from the end face (II8) of the housing attachment (6) protrude. 22. Device according to one of the preceding claims, characterized by a first foot section - (107) in which the hammer (47) is slidably mounted, and a second foot section (150) which is arranged at a distance from the first foot section in order to facilitate the stabilization of the device in relation to a workpiece. 25. Device according to one of the preceding claims, characterized in that the vent valve includes a vent valve-Be actuating part which is connected to the poppet valve part and movable therewith. 24. Device according to one of the preceding claims, characterized g'e denotes that the poppet valve part have first and second opposite end surfaces, one of which the second end surface for engagement with the second end 609834/0290 / - of the cylinder (4θ) is arranged so that the second chamber is closed when the poppet valve member is moved to the second closed position that the second end face is large enough to protrude in the radial direction beyond the circumference of the second end of the cylinder and that the first End face has a larger effective area than the second end face, so that when the channel opposite the third Chamber (58) is open, the air pressure in the poppet valve housing (15, l6) a greater force on the first end face exerts than the force that the air pressure in the first and second chambers exerts on the second end surface, so that the The poppet valve part closes the first chamber (54). 25. Device according to one of the preceding claims, g e characterize t by an auxiliary s control valve to control the air flow from the second control valve (88) to the atmosphere outside the housing (2), the auxiliary control valve Means (172, 179) for increasing and decreasing the amount of air released to the atmosphere corresponding to the increasing and decreasing air pressure in the second control valve (88). 2β. Device according to one of the preceding claims, characterized gekennzeichne t that the second control valve (88) leading from the first chamber to a second channel Opening (91) has that the first control valve one of the third chamber (58) to the first channel (74, 75) leading opening (67) and that the opening (91) of the second control valve (88) has a larger effective cross-sectional area than the opening (67) of the first control valve (64) having. 27. The device according to claim 26, characterized in that that the effective cross-sectional areas of the opening (67) of the first control valve (64) and the opening (91) of the 609834/0290 second control valve (88) have a ratio of approximately 1: 4. 28. Device according to one of the preceding claims, 'characterized Marked that the poppet valve part is hollow. 29. The device according to claim 28, characterized in that that the poppet valve member has a hollow body with a circular cross-section with a first outer diameter at one end and a second smaller outer diameter at the other end that an integral wall comprises one End of the hollow body terminates that an extension is formed integrally with one side of the wall that the extension formed coaxially with the hollow body and extending therefrom so that a protrusion is formed integrally with the opposite side of the viand is that the projection is located within the hollow body and extends coaxially in dfcem that a Plate is attached to the projection and the other end of the hollow body completes that the plate has a smaller one Has diameter than the outer diameter of one End of the hollow body and that a channel extends through the extension, the wall, the projection and the plate, to direct air through the valve part. 609834/0290