DE3930592A1 - Stud setting gun - with piston brake made of a specified elastomer - Google Patents

Abstract

A stud or nail setting gun with a drive piston (6) terminates its stroke by impact of the piston on a piston brake (7). The latter is made of an elastomer and is designed as a ring which is pushed in the piston guide sleeve (5) with a radial prestress until it abuts on the stud guide (8). This elastomer should have a very low recoil elasticity, pref. below 10%. The following materials are recommended as suitable: Butyl rubber (IIR), fluoro-rubber (FPM), fibre reinforced material or metal braiding. ADVANTAGE - This results in a uniform flush setting of studs and nails and eliminates the hard axial buffer impact.

Description

The invention relates to a bolt gun according to the Oberbe Handle of claim 1. Commercial bolt-setting tools, with a small propellant powder cartridge Propellant gas is generated, are used to shoot special sewing gel, also called bolts, in hard surfaces such as steel or concrete, used to construct components e.g. Profile sheets or Formwork panels directly on the respective subsurface fasten. One speaks therefore of a direct assembly. In addition to the requirements for ease of use and handling Ability to practice these devices must above all the regulation ten of the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig are enough.

The PTB writes an exit speed of the bolts from the device at a maximum of 100 m / s. To this rule To be able to meet with absolute certainty use prak table known piston setting tools as a piston Power transmission element between propellant and bolt.

Since a bolt-actuating device is generally only used to shoot bolts zen in relatively solid surfaces, this is considered safe used in device operation. Usually this is done by reversing the face of a moving part of the device, which usually also the bolt centered zen, therefore also called pin guide, is pressed against the fastening material. Doing so pushes this bolt guide into the device housing and tightens the firing pin spring of the trigger device. First when the end position is reached and the firing pin spring is full  is constantly tensioned, the bolt can be triggered. As Safety criterion against improper use of the device A contact pressure of 100 N is required. So will the device can be placed against a too soft surface this contact pressure is not normally applied because the underground gives way.

When using the known bolt gun there are but borderline cases, in which a tension of the deduction direction and triggering of the device is possible, the sub but nevertheless unsuitable for bolt setting is. This is e.g. B. the case when the bolt on a Joint is set. Then the bolt is in the fastening material hammered in too deep or even penetrated, see above that it is next to or between the substructure with a can fly out at a certain speed. This is especially true especially when the piston is in its end position is not flush with the front edge of the device, but a be right measure, e.g. B. 10 mm can emerge from the device. Because the piston punches the fastening material, e.g. B. a profile sheet of 1 mm thickness, very easily through. Virtually all of them Bolt-setting tools on the market show this Vulnerability.

Another feature of the existing bolt guns is the necessary regulation of the driving energy. The bolt set devices should be universally applicable. The regulation he follows preferably through different amounts of propellant cartridge in conjunction with an adjustable Lei Stungsdosierung on the device, e.g. B. by changing the An capture combustion chamber.

In the known bolt-actuators, the regulation is Driving energy, due to the principle, relatively imprecise, see above that an even setting of the bolts only after a short zen preliminary testing can be achieved. Another gravie  render disadvantage of the known bolt-actuators is that the piston with full driving energy on the stud can hit and destroy the device if the load servant once forgets the bolt in the setting tool introduce. This shown danger occurs with the so called empty shot. The disadvantage described applies equally in a weakened form, even with a wrong one Power dosage.

In order to counter this danger, the manufacturers build in their Devices so-called stop rings on which the piston is medium cash or immediately accumulates when its kinetic energy has not been used up with the setting of the bolt. The Plastic de formation of the stop rings is absorbed. These stop rings must be replaced after the deformation.

Another disadvantage here is that the axial and hard Braking the driving piston on the stop rings of the pistons itself and the entire device housing be relatively strong be claimed. So device parts can already after 50 to 100 empty shots experience permanent damage and then have to be replaced.

This problem is common to all manufacturers of stud setting tools ten well known, and are in patent publications Various solutions have been proposed.

In DE-PS 14 78 838 is an interception device for the Hinged piston of an internal combustion engine pin gun described the piston head side is a rubber-elastic piston interception buffer with play from one in the mouth part of the housing th sleeve is enclosed. Between piston head and interception A metallic disc or socket is arranged in the buffer. This is intended to prevent the flying piston from being caught more gently be enough. When the piston hits the buffer  perform an elastic deformation because its outside is kept smaller than the inside diameter of the Sleeve. Interposing the metallic socket or Washer should increase the life of the rubber buffer.

In this arrangement, the Piston head on a metal surface, i. H. a punch of metal on metal. Despite subsequent damping, therefore, at least least briefly generates shock waves that the piston, or the Destroy socket after a certain number of setting operations will be. Another disadvantage of this arrangement is that that with high residual energy of the flying piston, for. B. when grouting shot, this by deformation of the metallic socket and the rubber buffer is absorbed, but the full axial movement of the piston shaft guide sleeve allowed. These in turn is supported only on the mounting material, so that at the very high axial forces in the empty shot of z. B. 100 to 500 kN, this sleeve with relatively soft material, such as B. wood, penetrates deeply, or with hard material, such as e.g. B. steel, is very heavily used on compression. To The remedy is to limit the interception device introduced in such a way that between the workpiece Shoulder of the piston skirt guide sleeve and the counter shoulder of the mouth-side housing part another ring-shaped rubber-elastic interception buffer was arranged. Through this Limitation of the interception device is with correct Ab adjustment of the piston length an almost flush setting of the bolts zen additionally guaranteed, since the flying piston does not have the mouth-side housing part can run out.

A basic requirement for the proper functioning of the Intercepting device described is the right one choice of buffer material. No information is given on this makes. The term "rubbery" is very vague. Sure Lich the damping behavior of the rubber material plays a decisive role.  

By DE-PS 14 78 825 is in contrast to the vorbe written interception device one without a rubber elastic buffers revealed, thereby intercepting the flight piston hard and inelastic.

Further solutions are suggested in the publications DE-PS 16 03 918, DE-PS 16 03 852 and DE-OS 26 32 413 indicated ben. Here, however, disc springs or friction rings are used provided for buffering. Aside from the inadequate appropriate service life of these springs with the very high forces when empty shot, this axial force is also applied to the muzzle-side footprint of the device fully forwarded.

EP 02 74 919 A1 describes a device in which the piston is buffered by a hard compression damper and a downstream elastic ring or several such rings are made. This damping arrangement is arranged between the piston and the pin guide, wherein the mouth end of the piston to the hard mono blockring corresponds. Piston length, damping device and pin guide are matched so that the piston do not protrude from the face of the bolt guide can. Apart from the fact that this principle of operation in the reason set of the interception device according to DE-PS 14 78 838 ent speaks, the axial interception forces on the Fully transfer the footprint of the bolt guide. The cross cut the bolt guide is so large that a Penetration of the footprint into soft fastening material, e.g. B. wood remains low. The use of the device is there by but for certain applications, especially in narrow spaces and corners, not possible.

A second basic possibility besides the enlargement The footprint is generally all axial Braking forces no longer on the footprint, son to initiate into the housing itself. In this case, however  interception device and the device housing must be corresponding the emerging top executives overly dimensioned be nated, which makes the device unwieldy. The on The surface of the bolt guide can then be used again be kept as small as necessary.

For the sake of completeness, here is the combination of mentioned two solutions.

It is an object of the invention to provide a bolt gun to improve the above-mentioned type in such a way that no more disadvantages, a flush, the same moderate setting of the bolts and the hard axial Avoids buffer blow.

According to the invention this object is achieved in that the Driving piston with an at least partially in the radial direction piston brake that generates strong braking forces that is. In the embodiment of the invention, the pistons can Brake formed from an elastically deformable ring body be the one with radial pre-clamping in the piston guide sleeve se is introduced and in the braking position radially and axially in within the device part interacting with the driving piston le is completely encapsulated. When the piston hits this ring body is deformed more or less elastically or compresses and supports itself as a result of the com elastic deformation was even more pronounced dial on the inner wall of the piston guide sleeve over a large area starting, which causes the excess energy of the driving piston problem is freely absorbed.

The particular advantage of this solution according to the invention lies in that the trapping of the driving piston alone by the elastic ring body and without interposing a har th or metallic socket. This makes the after the prior art still possible hard buffer blow ver avoided.  

In addition, from the front, the setting resistance of the Bol brake or the penetration resistance of the bolt guide acts supportive. At least for a short time is therefore when opening run of the piston between the axial form fit Bolt guide and elastic ring body of this buffer in the piston guide sleeve spatially fixed and can be by ne deformation the radial adhesion to the inside of the Piston guide sleeve and thus its fixed position on the device housing, maintained. The bolt guide can move relatively forward when the mounting mat rial, for example wood, yields. Nevertheless, the remains Ring body due to its clamping stationary with the Kol benführungshülse connected and thus forms a lock for the driving piston, which means that the same setting depth of the bolt in relation to the surface of the fastening material is achieved.

The sometimes very high buffer impact forces are thus redirected from the axial to a radial direction and the remaining, relatively low residual energy strongly ge dampens in the billiard effect transferred to the bolt guide. Due to the relative movement between the pin guide and the piston guide sleeve can, depending on the hardness of the fastening material, a more or less large gap between the pin guide and Ring bodies arise. This axial decoupling of bolts guide and ring body is absolutely necessary to the Ein penetration depth of the bolt guide into a soft surface hold ring. Would you, for example, the elastic Ring body as rubber-metal element directly on the bolts vulcanize the guide, so would the pistons when buffering guide sleeve on the radial frictional connection of the ring body coupled with the leading bolt guide. This raise then higher leading mass could then go deeper into the Un penetrate or with high kinetic energy in the Device housing open up, causing considerable damage would be caused.

Further details of the piston brake according to the invention are to ent the dependent claims and the description of figures take, which represent an example of the invention. It shows:

Figure 1 shows the schematic diagram of a bolt-firing device with the piston brake according to the invention in the on position before the bolt-setting, partially in section.

Fig. 2, the bolt gun according to Figure 1 pressed with the piston brake inventions to the invention and after the bolt, in section;

Fig. 3 is a bolt driving tool with the inventive brake with the piston head adapter part for projecting the bolt setting, in section;

Fig. 4, the bolt gun of Figure 1 after the Bol zensetzen on a joint;

Fig. 5 to Fig. 9, the piston brake in different versions.

The bolt gun 1 consists essentially of a Ge device housing 2 with a trigger 3 in the handle 4 and a piston guide sleeve 5 , a driving piston 6 , an annular body 7 and a bolt guide 8th The bolt 9 to be placed is centered in the bolt guide 8, flush with the end face of a driving piston shaft 14 . Before installation, the outer diameter 10 of the elastic ring body 7 is larger than the inner diameter 11 of the piston guide sleeve 5 . The inner diameter 12 of the ring body 7 is also larger with respect to the outer diameter 13 of the driving piston shaft 14 . As a result, the annular body can be installed or removed without any problems, despite the oversize, since the buffer material of the annular body 7 can deflect inwards during compression. The annular space 15 formed between the inner diameter of the buffer and the outer diameter of the piston must, however, be dimensioned so large that it can accommodate the buffer material displaced during compression to such an extent that the piston skirt 14 can still run with play.

When setting the bolts, the device 1 is made ready to fire via the end face 16 of the bolt guide 8 by the pressing movement via the driving piston guide sleeve 5 , by in a manner not specified, the cartridge chamber 38 in the rear part of the driving piston guide sleeve 5 is placed over the ready standing propellant powder cartridge and the firing pin Zen spring is tensioned. After trigger 3 has been released , the cartridge is fired and the driving piston 6 is moved forward. The bolt 9 is thereby driven into the fastening material 17 or the underground 18 . When the bolt-setting tool is optimally adjusted, the end position of the bolt 9 and piston 6 outlined in FIG. 2 is reached. The front edge 19 of the piston skirt 14 is flush with the front edge 28 of the device 1 or the bolt guide 8 . By varying the buffer or pin length of the bolt guide 8 or by inserting ring-shaped adapter parts 20 between the bolt guide 8 and the ring body 7 , the setting depth of the bolt 9 can be changed easily and simply in a special way of the invention without replacing the driving piston 6 .

An embodiment of the setting of threaded bolts 29 shows Fig. 3. Here, the head board 30 of the thread debolzens 29 was set by introducing an additional ringförmi gene adapter part 20 which is arranged axially between the ring body 7 and the bolt guide 8 . The adapter 20 consists of high-impact, in particular impact-resistant material and can be a metal or a plastic.

In Fig. 4 the case of the joint shot is shown. Due to the lack of subsurface in the joint 31 and thus very low setting resistance, the driving piston 6 runs onto the piston brake 7 with high residual energy. In this case, the force acting on the bolt guide 8 is naturally also higher, which leads to a deep penetration of the bolt guide 8 into the fastening material 17 . In no case will this penetrate, so that in a particularly advantageous embodiment of the invention the bolt 9 is intercepted in the material and can no longer emerge at high speed from the rear. The bolt-firing device 1 in the design according to the invention accordingly fulfills in a particularly advantageous manner all the criteria of bullet resistance, one of the most important requirements at all.

The relative movement between the pin guide 8 and the device housing 2 inevitably creates an annular gap 21 between the rear pin guide surface 22 and the front ring body surface 23 . The annular gap width 24 can correspond at most to the pressure path 25 of the device 1 ( FIG. 3).

Under all circumstances, the elastic ring body 7 must remain completely encapsulated when the driving piston 6 strikes and during the braking process, so that it can act as a hydraulic element and in particular is not mechanically damaged. The high forces that occur are advantageously shared on all sides by the surrounding components, the axial forces being largely deflected in a particularly advantageous manner largely in a radial direction due to the pre-compression and the suitable shape of the annular body 7 . The remaining axial forces, which still act on the rear end face 22 of the pin guide 8 and the end face 26 of the driving piston head 27 , are further reduced by the fact that, in particular through a suitable choice of material for the annular body 7, an additional strong damping takes place.

The deflection process can be reinforced in a special embodiment of the invention by special shape of the ring body 7 by the corresponding surfaces of the buffer and piston head are conical or funnel-shaped ausgebil det, so that an additional radial force is generated during the braking process. Some exemplary embodiments are outlined in FIGS. 5 to 9.

In Fig. 5, the ring body 7 has a cylindrical Puf fer 32 with a clamping bead 33 to increase the radial braking effect.

In Fig. 6 the annular body 7 is formed with a conical outer surface 34 .

Fig. 7 shows the ring body 7 as a cylindrical body with an inner cone 35 , so as to immerse the driving piston ben 6 , which is then provided with a corresponding outer surface, to increase the force in the radial direction.

The same effect as in Fig. 7 is achieved in Fig. 8 with an annular body 7 with an inner funnel 36 , which of course in turn corresponds to a corresponding outer surface of the driving piston 6 .

Fig. 9 finally shows the ring body 7 from three axially abutting discs 37 , whereby a multiple disc buffer is formed.

The elastic ring body 7 is made of an elastomer material with very low rebound resilience, values of less than 10% preferably being aimed for. Certain elastomeric rubber cards, such as butyl (IIR) or fluorine rubber (FPM), have proven to be particularly suitable materials.

The elastic ring body 7 can be made in one piece or, as in FIG. 9, from several disks, the material thickness and material properties being very variable in the multi-disk arrangement. This could be met in a particularly advantageous manner all requirements of bolt setting be extreme stress, setting depth control and setting depth accuracy.

To verify the above features of the invention, the two commercially available bolt guns 1 from different manufacturers were procured and modified so that a piston brake 7 of the type according to the invention could be installed. The devices differed in the performance and the footprint of the bolt guide 8 . As expected, the task with the more powerful device 1 with the very small footprint was more difficult to solve. It was shown in particular that the dimensioning of the ring body 7 must be handled very carefully. A cylindrical, one-piece ring buffer 7 was tested. The material and dimensions were varied. The inner diameter of the ring body 7 was 13.5 mm with an outer diameter of the piston skirt 14 of 12 mm. The outer diameter was changed between 25.5 mm and 26.5 mm with an inner diameter of the piston guide sleeve of 26.0 mm. The length of the ring body 7 was between 15 mm in the minimum and 35 mm in the maximum.

In extensive testing it was found that only certain configurations with respect to acceptable values Function and lifespan.

At the same time, alternative concepts, for example accommodating the ring body 7 in a separate sleeve or firmly connecting the ring body 7 to the bolt guide 8 , were also examined. However, as expected, these quickly proved to be unusable (material breaks) under extreme loads (empty shots).

In the solution according to the invention it was confirmed that the pre-clamping of the ring body 7 is very crucial. In al len buffers with undersize to the inner diameter of the piston guide sleeve, the axial force on the pin guide 8 was still so high that the pin guide 8 was accelerated too much forward and the relative movement to the housing was so large that material breaks in a short time occurred. Acceptable values could only be achieved from an outer ring body diameter of 26.1 mm.

This was confirmed in the same way for the material. Natural rubber (NR) with approx. 45% rebound resilience proved to be unsuitable despite considerable pre-clamping (26.2 mm diameter), since the short-term transmission shock to the bolt guide 8 was not sufficiently damped. In contrast, butyl rubber (IIR) with approx. 10% rebound resilience was extremely suitable. Even with a relatively small pre-clamp of 26.1 mm in diameter, entire series of extreme shots, i.e. empty shots and joint shots, were completed without functional defects and broken parts. The setting quality, measured by the penetration of the bolt guide 8 in wood 17 at full power of the device 1 (uncontrolled), continued to improve when the resilience was further reduced by changing the mixture of the butyl rubber. The lower limit is around 5%.

Even an extremely short ring body with a length of 15 mm functioned perfectly as a piston brake 7 in the type of installation according to the invention, a stronger pre-clamping with an outside diameter of 26.5 mm of the buffer 7 in turn providing considerably better results than with an outside diameter of only 26.1 mm.

Overall, the series of tests confirmed that we did the piston brake 7 according to the invention for a Bol zensetzgerät 1 fully. In particular, the bullet-proof function of the joint shot was guaranteed with sufficient security even with only 0.8 mm profiled sheet and full performance of the device 1 .

Claims (9)

1. Bolt gun with a driving piston which acts by means of a propellant gas optionally generated from solid, liquid or gaseous propellant on a bolt, nail or the like fastener to be set, characterized in that the driving piston ( 8 ) with an at least partially in the radial direction braking forces generating piston brake ( 7 ) is operatively connected. 2. Bolt-setting tool according to claim 1, characterized in that the piston brake ( 7 ) is formed from an elastically deformable ring body which is introduced with radial preload in the piston guide sleeve ( 5 ) and in the braking position radially and axially within the ben with the driving piston ( 6 ) interacting device parts ( 5 , 8 ) is encapsulated. 3. Bolt setting device according to claims 1 and 2, characterized in that the piston brake is formed by the elastic ring body ( 7 ) and a spacer ring ( 20 ) between the ring body ( 7 ) and a bolt guide ( 8 ), the ring body ( 7 ) and the spacer ring ( 20 ) individually or in total in their axial extent are variable. 4. Bolt-setting tool according to claims 1 to 3, characterized in that the ring body ( 7 ) is formed from an elastomer material with very little rebound resilience. 5. Bolt-setting tool according to claims 1 to 4, characterized in that the annular body ( 7 ) on its end face corresponding to the driving piston head ( 27 ) is provided with a recess verse which is conical or funnel-shaped so that the axial force transmission in Radial forces are generated braking. 6. Bolt setting device according to claim 5, characterized in that the driving piston head surface ( 27 ) opposite the annular body end face ( 26 ) corresponds to the annular body contour without play. 7. Bolt setting tool according to claims 1 to 6, characterized in that the ring body ( 7 ) is optionally formed from one piece or several disks. 8. Bolt-setting tool according to claims 1 to 7, characterized in that the ring body ( 7 ) is optionally made of butyl rubber, fluorine rubber, fiber-reinforced material, made of tallgepinsten or similar elastically deformable Ma materials low rebound resilience or mixture of such materials . 9. Bolt setting tool according to one or more of the claims vorgenann th, characterized in that the front end face ( 19 ) of the driving piston ( 6 ) in the end stop when setting bolts, nails or the same flush or almost flush with the end face ( 16 ) of the bolt guide ( 8 ) completes.