HU176524B - Powder operated nail driving device with sound absorption - Google Patents

Abstract

1534604 Silenced fastener driver tool HILTI AG 6 Aug 1976 [8 Sept 1975] 32857/76 Heading B4C A silenced explosive powered fastener driver tool comprises a piston 8 which is axially displaceable in a combustion chamber 2c between a rearward, firing position and a forward position, one or more exhaust apertures 2b communicating the combustion chamber with a first noise muffling chamber 10a which in turn communicates with at least one further noise muffling chamber 10b via one or more apertures 11a in a diaphragm 11, the last chamber (10c, as shown) having an outlet 13a for the exhaust gases, the volume of the first muffling chamber 10a being 3 to 10 times the volume swept by piston 8 between its rearward firing position and the position shown at which it begins to expose aperture 2b. As shown 3 muffling chambers 10a, 10b and 10c are separated by diaphragms 11, 12 whose apertures 11a, 12a and outlet aperture 13a are staggered relative to adjacent apertures. Preferably the total area of aperture(s) 11a in the first diaphragm is equal to or less than the total area of the apertures in the or each succeeding diaphragm, and the area of outlet aperture 13a is 2 to 10 times the area of aperture(s) 11a. Safety mechanism.-Spring 3 urges barrel 2 forwards, so that the tool has to be pressed against workpiece 4 to bring cartridge 6 into the firing position.

Description

BACKGROUND OF THE INVENTION The present invention relates to a powder gun nailer with a piston, the piston being axially displaceable between the rear firing position and the front end position, the expansion chamber having vent holes which are at least partially connected to the muffler chamber.

The known nailer devices mentioned in the introduction contain silencing chambers which exert a suffocating effect on the outgoing propellant gases, on the one hand, and on the other hand, the muffler structures are severely affected, significantly affecting the handling of the nailer devices.

Experience has shown that in known silencing chambers, only the gas flow is vortexed. This is done, for example, by the first tubular damping chamber in the downstream direction of the propellant gases, in which the propellant gases enter through the outlets. In this buffer chamber is located a second buffer chamber formed by the sleeve. The propellant gases flow through the sleeve bores to enter the second damping chamber and from there through the bore of relatively small cross-section. The propellants multiple reorientation causes said vortex, which, however, does not have any contribution corresponding hangtompítást.Ehhez that the known muffler chamber relative to the outflow of propellants the amount of relatively small in shape and can thus flowed through by the propellant gases, small holes in some circumstances ⁵ confessor na naturally they are clogged with the powder dust residues of the propellants.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a nailer having an effective silencer without the aforementioned disadvantages.

The object of the present invention is achieved by having at least two silencing chambers arranged in series and interconnected through apertures with breakthroughs, and in the flow direction the volume of the first ¹⁵ chambers is three to ten times between the rear firing position and the vent opening position. and a final chamber in the flow direction for the gases.

A large first chamber relative to the amount of propellant gas flowing out of the expansion chamber, which preferably corresponds to seven times the working space, provides for the expansion of the gases entering under high pressure, i.e. a reduction in pressure.

The gas, which is greatly expanded in the first chamber, has only a fraction of the pressure of the gases entering from the expansion chamber. Thus, the primary generation of sound as a function of gas pressure is effectively eliminated.

In addition, the pressure drop causes only a slight warming of the silencer.

Subsequent downstream flow into the second chamber and further connecting chambers, which may be substantially smaller in volume relative to the first chamber, does not result in further significant pressure reduction of the gases. These chambers primarily cause the sound waves to break, avoiding direct, i.e. straight-line, gas exits from the first chamber to the outside. The gas vent in the last chamber should have a cross-section as large as possible so that the pressure of the gases in this chamber is at atmospheric pressure, while avoiding strangulation. On the one hand, due to the requirements of good silencing and, on the other hand, the small size of the silencing parts, it has proved optimal to place three silencing chambers in a row.

Preferably, the cross-sections of the apertures of the aperture located in the first chamber are equal to or smaller than the total cross-section of all the apertures of the other apertures, in order to ensure that there is no gas suppressive pressure in the adjacent chamber.

The punctures may be of any desired shape and it is immaterial that one or more punctures are formed on the orifice or slits.

To ensure that the gases do not flow out of the first damping chamber into the open air in a straight line, the breaks in the adjacent blades are projected offset relative to one another. In this way, the gas stream is redirected multiple times from chamber to chamber, which significantly improves the damping effect in the immediate detection area of the outlet.

The invention will now be described with reference to the exemplary embodiment shown in the drawing.

The nailer shown is in the firing position. The nailer comprises a housing 1 in which an axially displaceable piston guide 2 is disposed. A compression spring 3 tensioned between the housing side lugs and the mouthpiece collar 2a screwed by the piston guide 2 ensures that the piston guide 2 is displaced forwardly, i.e. in the firing direction, in the housing 1 when the inlet is lifted from the receiving medium 4, From the range of 7 pins. Further parts of the ignition mechanism, such as the tension spring of the spike pin 7, are already known and are not shown here for simplification purposes. The housing 1 includes a discharge or inlet lb for the filling sleeve 6. In the piston guide 2, the drive piston 8 is provided with a pick-up medium 4 for filling in the nose 9, which is packed and removable.

In the working position shown, the piston rod 8 is just about to open the vent opening 2b of the piston guide 2. The propellant gases compressed in the working space 2c behind the drive piston 8 can then flow through the outlet port 2b into the first damping chamber 10a of the tubular damping body 10 and expand there.

In the example illustrated, the volume of the first damped chamber 10a is about five times the working space 2c behind the piston 8. After the pressure has been reduced in the first damping chamber 10a, the gases pass through the central opening 11a of the aperture 11 to enter the second damping chamber 10b. At this point, the gases reach the further aperture 12, and since the apertures 12a thereof are rotated against the apertures 11a, they are reversed and, in experience, begin to vortex. The gases then pass through the opening 12a into the third damping chamber 10c, and from there, after several changes of direction, exit through the outlet opening 13a of the cover 13.

In the third damping chamber 10c, the cross-section of the outlet 13a is substantially larger than, for example, the central opening 11a of the all aperture, in order to avoid any stroke.

The damping body 10 is preferably disposed in the lower hand grip and is connected to the housing 1, for example by screwing.

In principle, without affecting the damping effect, the damping body may be formed differently and, for example, positioned in the firing direction of the device body. .

Claims (4)

A gun-type nailer device with a propeller, the propeller being axially displaceable between the rear focal position and the front end position and comprising expansion chamber vent openings, which are at least partially connected to at least two silencing chambers, 10a, 10b and 10c) are arranged in series and interconnected through apertures (11a, 12a) having breakthroughs (11a, 12a) and three to ten times the volume of the first damping chamber (10a) downstream of the rear ignition position and the piston (10a). 8) the working space (2c) between the venting position (2b) and the last damping chamber (10c) in the flow direction having an outlet (13¼) for the gases. An embodiment of an angle punching device according to claim 1, characterized in that the cross-sections (1a) of the apertures (11a) associated with the first damping chamber (18a) are equal to or smaller than the apertures (12a) on all further apertures (12a). ). An embodiment of an angle punching device according to claim 1 or 2, characterized in that in the downstream direction the outlet opening (13a) of the last damping chamber (10c) is two to ten times the aperture (11) associated with the first damping chamber (10a). ) cross-sections (11a). 4. An embodiment of an angle punching device according to any one of claims 1 to 5, characterized in that the breakthroughs (11a, 12a) of the adjacent blinds (11, 12) are offset relative to one another.