DE2037815A1 - Compressed air driven driver - Google Patents

Description

Joh. Friedrich Behrens ■

2070 Ahrensburg / Holstein July 29 , 1970

Bogenstrasse 43/45

Draokluftbe actuated β driving tool

The invention relates to a pressure air driven driving tool Sum driving in fasteners * such as nails, staples or the like with a movable back and forth in a working cylinder guided working piston and a pressurized air and pressure relief of the working piston ( controlling main control valve, aas by means of one of a

Exhaust valve operated, also responsible for compressed air construction and with the main control valve coaxially arranged servo

or pilot valve is movable.

The invention has set itself the task _t s a driving tool to provide this type of particularly high power, which can we'rden operated depending% 'with a choice of single shots or repetitively.

In the case of a single shot operation, the working piston leads to actuation " movement of the trip valve a single full reciprocating stroke. The release valve must be used to execute the next single shot to be operated again "

. . ' For repeating operation, on the other hand, the release valve only needs

/ To be depressed continuously to automatically individual with;> - get full travel shots executed in succession faster. ' ".

, '109886/0207'

moderate 'The invention provides an improved' education .and / purpose /

Design of the subject matter of the main patent

(Patent application V 19 08.150.6 of the applicant dated February 19, 1969).

According to this main patent between the servo valve and the release valve an auxiliary control valve with two each other arranged counteracting impact areas, one of which (Auslöaeventilraum) middle® of the release. » valves is controllable in such a way that when the release valve is actuated with the high pressure source and when it is not actuated Release valve is connectable to the atmosphere while the other room (Hauptyentil- or Bepetierraum) with one control channel controlled in this way by the control valve unit formed from the main control valve and the servo valve is in connection that he is with the main control valve open with the compressed air source and with the main control valve closed connected to the atmosphere.

With the driving device of the main patent »are the release valve, the main control valve, the servo or gate control valve and the auxiliary control valve in an axis outside of the working piston and its cylinder arranged »With With the help of the servo or pilot valve, it was possible to increase the impact sequence and, above all, the impact intensity of the individual beats can be increased. Still, left liese Particularly in the case of large driving tools, the arrangement should be clean left to strike with particularly great energy.

109886/0207

The invention is aimed at solving the tasks of the invention Driving device of the main patentea. According to the invention are now but both the main control valve and the auxiliary control valve arranged in the axis of the working piston and its cylinder. In this way, particularly short compressed air and exhaust air ducts and, above all, particularly large pressure air cross-sections for supplying the compressed air to the interior of the working cylinder, which makes the impact intensity significant increased and the stroke rate increased.

In a preferred embodiment of the invention, this is I. Auxiliary control valve in the housing cover of the working piston and its Cylinder arranged.

It is advisable to use the line connecting the control channel with the main valve or repetition chamber of the auxiliary control valve to switch on a delay space, which ensures that the auxiliary control valve only on the initiation of the after the working piston has carried out its full driving stroke.

An adjustable shut-off device, which is able to throttle and shut off the passage, is preferably switched into the line for connecting the control channel to the main valve or repeating valve chamber. This adjustable throttling can also be used to set the point in time at which the auxiliary control valve automatically prepares the next driving impact ataf. However, if the line ζν, τ connection of the control channel with the repetition valve chamber of the auxiliary control valve has been shut off, the repetition effect of the input device is

109886/020; - ♦ -

canceled. It then only works in single-shot mode.

The subject of the invention is also characterized by that it is extremely easy to do by changing few parts on the one hand to produce a driving tool that only works with single shots, and on the other hand a Produce a driving tool that uses both single shots

als.also repetitively works. To convert the last mentioned device designed according to the invention in a single socket device only the housing base needs to be replaced by inserting the auxiliary control valve in the new housing cover is omitted.

Further improvements and appropriate refinements of the Subjects of the invention are based on the accompanying illustration which shows an embodiment of the invention in a simplified representation. They represent:

Pig. 1 shows a section through a device designed according to the invention Driving tool omitting all parts not necessary for the invention, namely in the rest position if the release valve is not yet activated,

Fig. 2 shows the same section through the driving tool, however with activated release valve, with switched on Auxiliary control valve and when executing a working stroke by the drive piston,

3 shows the same section through the driving tool of FIGS. 1-2, but with the upward stroke of the driving piston,

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with the release valve still actuated and the auxiliary control valve switched on.

The compressed air to the working cylinder is controlled by means of a servo or pilot valve, which in the exemplary embodiment is essentially in accordance with the German patent 1 285 959 · The main control valve is formed by a sealing ring 236 on the underside a control flange 234 is attached. In the closed position shown in FIGS. 1-3, the sealing ring 236 rests against the valve seat running around it acting end face 237 of the housing 281, internally axially displaceable of the working cylinder 218 mounted and sealed is,

The cylinder 218 is provided at its upper end with a control flange 234, on the lower end face 273 of the already mentioned sealing ring 236 is attached.

The working cylinder 218 and its control flange are connected to the working cylinder 218 by means of a snap ring 282 or in some other way 234 the main control valve designed as a piston disk firmly connected, which with a piston-shaped central extension 222 engages in a sealing hole 220 in the housing cover *

In the execution example, the servo or pilot valve from the cylinder 218 to the auxiliary control pistons 223 and 222 formed by these parts are axially displaceably mounted in the housing 281,

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The invention can, however, also be carried out in a manner in which the cylinder is firmly arranged in the housing and the servo or pre-control valve is designed only in the form of a sleeve which has approximately the diameter of the working cylinder.

The auxiliary control valve generally bears the reference number 224 ^ / ^/ " ^r is designed as a differential piston and is mounted axially displaceably in the housing cover 219. Its axis coincides with the axis of the working cylinder 218. The release valve generally bears the reference number 216 and is also mounted in the housing cover The valve or release lever bears the reference number 2, 11. The connection between the release valve and the valve lever is carried out by a switch rod 200. The switch rod 200 forms a unit with the release valve 216 and has the two sealing rings 201 and 202.

With the collar 203, the shift rod 200 is in the bore of the housing with the collar 204 in the bore 209 of the socket 205 slidingly guided. With perforations 206 as well as 207 and 208 Sound 204 and socket 205 are used for air passage Mistake. The bore 209 is equipped with control edges 210 which, in cooperation with the sealing rings 201 and 202, the ' Execute valve function.

The valve lever 211 can only be actuated after the switching rod 200 has been moved by means of the safety bar 212. A Pedar 213 is provided as an intermediate member between the valve lever 211 and the safety bar. This combination can change the order in which the

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1Q9886 / 0207

Valve lever on the one hand or the safety bracket on the other can be selected for triggering the shot. "The piston 214 · consists entirely of light metal and is provided with a collar 215 on the lower impact surface. This Collar prevents the sealing body 2781 arranged in the lower part of the cylinder 218 from bulging when the Piston 214 strikes against the seal body at the end of its working stroke. The collar 215 of the piston prevents such a thing Damage to the seal body through the bores 217 of the cylinder 218.

As already mentioned, the invented item stands out from the fact that deorireßluftnagler only through the exchange of the lid 219 either as an automatic device with repeating action or as a manually operated device can only be prepared with a single shot effect. To explain the "Invention, only that housing cover is shown that is used for the automatic valve with repeating action.

This housing cover 219 has two separate ones central bores 220 and 221 provided. The control piston 222 of the main control valve 223 slides in the bore 220. The auxiliary control valve 224 is axially displaceable in the bore 221 arranged, with the help of which the repeating effect is achieved automatically. At the top is the hood 219 equipped with an extension 225 "A! Sub-area of the extension 225 is covered by a visual cover 226 concentrically enclosing it. This screw sleeve is screwed to a fine thread 227 located on the outside of the extension and in the small area

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axially adjustable. In the lower position, the bore 228 is blocked by the seal 229. In this position the device is set to single shot. In the upper position, the bore 228 is exposed. The device can then be operated with a repetitive firing sequence. The end of the extension 225 is formed by a screw cap 230. The end face 23t of this screw cap also serves as an upper limit for the axial movement of the screw sleeve 226. The cover 232 limits the socket 205 in the bore 233 and takes over the ψ for the compressed air emerging from the device Puncture of an air baffle.

The Pig. 1 puts the device in the rest position. The working piston 214 is in its upper end position. The main control valve 223 consists of a control flange 234 and a control piston 222f blocks the connection between the cylinder and the Operating compressed air line of the grip space 235 by itself the control flange 234 with its seal 236 against the Face 237 of the housing 238 lays. The workspace 276 The cylinder 218 stands above the bore 239 »space 240, - several P holes 241, hanging space 242, window 243 with the atmosphere In connection.

The hem 244 'is constantly with an operating air duct of the grip space 235 in VertoisGlHQg ₉ nnä ^ wbt over Bingkaaal 245 "Durchbrueii 206" Hlngkaasl 24β, holes 2OB ₉ liagkuagü. 247 «, bore 248. Ia äam Bawm 244 is oil® Stir & fläoh © 249 fi @ s auxiliary control valve 224 v © a ά @ τ" Brnoklnit lb _{© © iafsoblagt 9} woöüreJ this axially in Äle olb ©! ³ © te © ailag © vsrscliotoea _o fXu äi @ s © 3 end position lies dl © Stlrafläeia © 250 ü <b® Hilfssteiaefveatils 224

against the face of the screw cap 230. The sealing ring . 251 - the servo valve ^ 224 .is here in the radial "extension 252 of the bore 221 and is thus disengaged, so that the main valve roughness 253 via bores 254 with the space 244 in connection 3fceht. Her sealing ring 255 is in the hole 221 engages and blocks the connection of room 244 the annulus 279 and the bore 28O to the atmosphere. In the main valve chamber 253, the compressed air acts against the Front surfaces 257 and 258 of the control flange or control piston ", which results in a downward force. As a result, as described above, the seal 236 against the end face 237 of the housing 238 pressed in a sealing manner. ·

The switching rod 200 with the release valve 216 is duroh the compressed air directed against its collar 203 in the lower -Grenslage held. The Sealing ring 201 engaged, the sealing ring 202 disengaged in the radial expansion of the bore 209 ± consequently, the release valve chamber 259 is above the bores 260, 261, annular space 262, several bores 207t radial extension 263, bore 209f free space 256, annulus 242, window 243 with the atmosphere in connection. "

The repetition valve chamber 264 is also in communication with the atmosphere, namely via bore 265, delay chamber 266, bores 228, 267, free space 268, bore 269 _f space 240,. multiple holes 241, window 243 ·.

If set to "" Binzelechuß "is the Schrautohület 230 in ι? Ht lower position shown! Is,

ί 09886/0207,

the bore 228 covered by the sealing ring 229 and consequently the repeating valve chamber 264 blocked. A repeating sequence of shots is not possible now.

With the "Automatic" setting, the hole 228 is through the Diaphragm ring 229 exposed, whereby the repetition valve chamber 264 diverging with the atmosphere and the working chamber 276 of the Working cylinder 218 is brought into connection. The connection to the atmosphere has already been described Working cylinder 218 will be explained later.

) In Fig. 2 are both the safety bar 212 and the valve lever 211 is actuated, against the constantly downward force of the switching rod 200. The valve lever 211 is raised until its end face lies against that of the housing 238. In this position is located The sealing ring 201 is in the radial extension 263 of the bore 209 »ao that the release valve chamber 259 with the operating compressed air line of the handle area 235 via 245, 206, 246, 271, 263t 207, 262, 261, 260 is in communication. The sealing ring

^ is in the bore 209 in engagement and thereby locks the The operating compressed air passes through to the atmosphere. .

The end face 272 of the auxiliary control valve is located in the release valve chamber 259 224 pressurized with the operating compressed air. By The servo valve will act on the end faces 272 and 249 exposed to it as a result of the larger end face 272 in those in Pig. 2 position shown moves. In this position, the sealing ring 251 blocks the access of the operating compressed air to the Main valve chamber 253. Diehtring 255, which is located in the . radial extension 252 of the bore 221 is located »gives the

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t
■: ** ■ - ■

Connection to the atmosphere Via 254, 252, 279, 280, 242, 243 free. The transition to this position takes place spontaneously, so that the compressed air in the main valve chamber 253 suddenly drops to zero. This has the consequence that the constantly upward force that results from the application the end face 273 with compressed air results, the main control valve 223 opens spontaneously. The opening path is limited by the end face 274 of the control piston 222 rests against the seal 275 and thereby the working cylinder 218 shut off from the atmosphere.

After the main control valve 223 has opened, the front side of the piston 214 is acted upon by the operating compressed air in the working chamber 276 of the working cylinder 218. As a result, the working piston executes its working stroke with great acceleration. The return of the piston to the position shown in FIG. 1 is described below for the setting "single shot ¹¹ ".

In this setting, the screw sleeve 226 is in the lower position, the sealing ring 229 having the bore 228 covers. This setting is not shown in any of the figures. In this lower position of the screw sleeve 226 the Repetierventilraum 264 is self-contained, so that the automatic control is switched off for a continuous or repetitive stroke sequence. First will the pneumatic nailer is lifted from the work piece and the valve lever is no longer actuated. The holding bar 200 with ' the release valve 216, the collar 203 of which is constantly exposed to the operating compressed air, is accordingly moved with the

109886/0207 ~ ¹² ~

Valve lever 211 and the safety bracket 212 in the Pig. 1 position shown downwards. After this position has been assumed, the sealing ring 202 of the release valve 216 is the connection of the release valve space a 259 to Atmosphere over 260, 261, 262, 207, 263, 209, 256, 242, 243 free. As soon as the pressure in this space has dropped to zero, the auxiliary control valve 224 moves into the position shown in FIG Fig. 1 upwards. When the servo valve has reached this position, the sealing ring 251, which is now in the radial Extension 252 is located, connecting the main valve chamber 253 with the compressed air source of the handle aum 235 via 245, 206, 246, 208, 247, 248, 244, 252, 254 free. After the pressure in the main valve chamber 253 has been adjusted to the operating pressure of the compressed air source, the control flange moves 234 with the cylinder 218 and the control piston 222 in sealing position, in such a way that the seal 236 on the The end face 237 of the housing 238 is pressed to form a seal, so that the working space 276 is shut off from the source of operating compressed air iat. At the same time, however, the path to the atmosphere is cleared, so that the compressed air in the work area is via 239, 240, 241, 242, 243 can escape. The piston is then returned to its original position in the known manner by means of compressed air surttck moves.

With the "Automatic" setting, the screw jack 226 is located in the upper position shown in Figs. 1, 2 and 3 ■ is. The bore 228 is exposed by the sealing ring 229, so that the repeating valve chamber 264 is open. This tree is now automatically either transferred to the working area of the cylinder

109886/0207 ^{u i3-}

alleviate 276 or connected to the atmosphere from what a repeating sequence of strokes results.

Starting from FIG. 2, the valve lever 211 remains withdrawn and the safety bracket 212 pushed in, so that the switching rod 200 with the release valve 216 constantly assume the positions shown in this figure. As a result, the release valve chamber 259 is constantly connected to the operating compressed air source, and consequently the end face 272 of the auxiliary control valve 224 is acted upon by the operating compressed air; the servo valve initially takes the position according to. ₍ Fig. 2 a.

In order to move the main control valve 223 to the closed position again, the auxiliary valve 224 must be reversed, i. assume its position shown in Figure 3; for this, however, a control pulse is required, which comes from the working space 276 of the Cylinder is branched after a connection to the compressed air source has been established. This pressure pulse we 2 in the repeating valve chamber 264 via 239, 269, 268, 267, 228, 266, 265 and acts here on the forehead, | surface 277 of the servo valve 224. From the application of the End faces 249 and 277 on the one hand and the end face 272 on the other hand with compressed air results in an upward direction. Force that has a delayed effect. The delay time is determined by the size of the delay chamber 266 determined and is chosen so that the repeating valve chamber e: with full operating compressed air when the working piston 214 has definitely finished its working stroke.

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After this is the case, aioh moves the assistance control valve 224 into its position shown in FIG. 3. In this position, the sealing ring 251 is located in the radial extension 252 of the bore 221 "so that the main valve chamber 253 is connected to the compressed air source of the handle chamber _f as described above." The main control valve 223 is then shifted into its closed position, ie the working space 276 of the working cylinder is shut off by a 3-way source of operating compressed air, and at the same time connected to the atmosphere. The compressed air present in the cylinder now escapes via 239 »240, 241, 242, 243 into the atmosphere. The piston, which is pressurized with compressed air from below m gives the flowing into the atmosphere on the way to its end position Pressure creates a certain overpressure, as a result of which a pressure build-up occurs in space 269. This pressure jam lasts as long as until the piston has reached its end position. Only then can the xer pressure in the repeating valve chamber 264 via 265 »266» 228, 267, 268, 269 »240, 241, 242, 243 to the atmosphere.

Repeater valve chamber 264

* build. Only when the pressure has reached atmospheric pressure does the auxiliary control valve 224 switch for one new blow to its position shown in Fig. 2. This ensures that the important task of the Repetition control to switch the piston in the end positions is fulfilled.

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Claims (10)

Claims Pressurized air driving tool for driving Fasteners such as nails, staples or the like. with a working piston that can be moved back and forth in a working cylinder and one that controls the application of compressed air and pressure relief of the working piston Main control valve, which is also pressurized with compressed air by means of an actuated by a release valve and servo or pilot valve arranged coaxially with the main control valve can be moved, with naoh Patent (patent application P 19 08 150.6) between * the servo valve and the release valve, an auxiliary control valve with two opposing loading spaces is arranged, of which one space (release valve space) can be controlled by means of the release valve in such a way that it can be connected to the high pressure source when the release valve is actuated and to the atmosphere when the release valve is not actuated, while the anderr space (main valve or Repetierraum) having a λ of the group formed by the main control valve and the servo valve main control valve unit in such a manner controlled control channel in conjunction ateht that he let connected with an open main control valve to the compressed air source and closed main control valve with the atmosphere, characterized characterized in that both the main control valve (223) and the auxiliary control valve (224) are arranged in the axis of the working piston (214) and a cylinder (218). -16 V098I6 / 0207 2. driving tool according to claim 1, characterized in that the auxiliary control \ Eebtil (224) in the housing cover (219) the working piston (214) and its cylinder (218), .. is arranged. 3 · driving tool according to one of claims 1-2, characterized characterized in that within the housing (238) the upper end of the working cylinder (218) of a permanent with the compressed air supply line connected to the compressed air storage space (235), against which the k Interior of the working cylinder in the idle state of the Device is blocked by the main control piston (223) arranged coaxially to the working cylinder, which thereby with a control flange (234) is pressed onto an annular shut-off surface (237) that the Top of the control piston (223) due to larger effective area is higher with compressed air. 1 # than the radially over the annular shut-off protruding part of its underside, so that the control piston through Actuation of the release valve (216) causes pressure release its upper side is lifted from the annular shut-off surface, and thereby the access of Releases compressed air from the pressure-tight storage space (235) into the working cylinder. 4. driving tool according to claim 3 »characterized in that that the control piston & 3) and the working cylinder (218) one inside the housing in cylindrical guides fixed to the housing axially displaceable and air-tight mechanical control unit in the form of a central control 10 9 8 8 6/0207 -17- form the body, the control flange (234) in the rest and shut-off position as an annular Shut-off surface provided end face of the upper working cylinder guide is pressed, whereby compressed air inlet openings were locked, which are arranged in the upper part of the working cylinder wall so that they in the axial downward sliding of the control body caused by the pressure relief of the upper side of the control piston into the open position for the entry of compressed air from the compressed air reservoir into the working cylinder be exposed. 5. "Sintreibgerät according to claim 4, characterized in that that the control piston (223-234) from the control flange provided on its underside with a sealing ring (236) (234) and an axially fixed in the control flange plate-shaped insert part (222) on its Top has a cylindrical port set through which a central channel (239) for the known per se Ventilation of the working cylinder extends during the return stroke of the working piston (214). 6. driving tool according to any one of claims 1-5, characterized characterized in that a line (267) branches off from the outlet line (241, 242) via which, after the outlet line has been shut off (241, 242) through the main control valve (223,222) the main valve or repeater space (264) with the compressed air is supplied from the working space of the cylinder (218). -18- 109886/0207 7. driving tool according to any one of claims 1-6, characterized characterized in that in the line (267) for connection valve of the control channel (239, 240, 269) with the main j or Repetier-Raum (264) a delay room (266) switched on is. 8. tacker according to one of claims 1 - 7 »daduroh characterized in that in the line (267) for connection of the control channel (239, 240, 269) with the main valve or repeating chamber (264) an adjustable shut-off device k device (226) is switched on, which the passage to able to throttle and shut off • s 9. tacker according to one of claims 1-8, daduroh characterized in that the control port (239, 240, 269) is connected to the atmosphere via a channel (241, 242) via which the working area of the working cylinder (218) is connectable with the atmosphere. 109886/0207