DE2453595A1 - COMPRESSED AIR PISTOL FOR DRIVING IN FASTENERS SUCH AS NAILS AND CLIPS - Google Patents

Description

Patent attorney »

DipJ.-Ing, H. Siehmann

Dipl.-PhyE Dr. K. Schweinzer

Dipl .-! Ng. Dr. M. Rau

85 NUREMBERG
Essenweinsfraße 4-6

Umberto MONACELLI, Monza / Italy

"Pneumatic gun for driving fasteners such as nails and staples. ¹¹

The present invention relates to compressed air
pistol or a compressed air device for driving loading. fasteners such as nails and staples. '

It is known that the modern pistols are for driving of fasteners, especially the nail guns and the stapling machines with a pressure— air propulsion system / which is based on the presence of a compressed air tank of larger volume (usually obtained in the pistol handle) of a cylinder open at the top, in which an actuating piston of the expulsion arm of the fastening means (this the latter individually from one with a spring-loaded

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strained. Sliding member provided magazine fed in its own guide or firing channel) is slidably received and a valve member which is displaceable between a closed position and an open position of the connection from the said container to the upper open end of the cylinder by actuation is based. ⁵

The displacement of the valve member towards the open position clearly causes the simultaneous loading high pressure on the actuating tappet, which is why with considerable force and speed against the attack with the upper part of the fastener which was recorded in the firing channel at the time. ' This fastener is thus directly driven out of the firing channel and pushed into the workpiece with force.

To apply the compressed air to the actuating piston To make the plunger faster and more effective, the valve member that makes the connection between the cylinder and the container opens and closes, usually just above the open The end of the cylinder is arranged and moved along the axis of the cylinder in such a way that the movement of the valve member in the direction of the open position, the immediate exposure of the piston to the full pressure of that contained in the container Air causes.

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Such a valve member generally consists of a piston valve provided with its own guide chamber, this is normally from the downward thrust exerted on the top of the valve by the canisters is held in the closed position, which container compressed air in the rest position of the upper end the guide chamber of the piston valve fills through a suitable line that is connected to the actuation lever Control means assigned to the pistol are provided, processing is usually effected by taking advantage of the upward thrust that is contained in the container Compressed air always exerts on an annular, peripheral edge, which is laterally opposite the upper open Cylinder end protrudes, and with which the lower valve end is provided. * When the valve is closed this is Upward thrust from the downward thrust exerted on the upper end of the valve therefore cannot cause the valve to open because the effective area of said annular edge significantly smaller than the effective area of the upper valve endes .is · '(under "effective area" is understood the area, which is exposed to the axial pressure effect of the compressed air). ' When pressing the handle, and thus to the control means associated with it, so that the connection between the container and the upper end of the Ventxlführungskanuner is interrupted and this latter, however, with an outlet in connection is set, however, the downward thrust is canceled, allowing the compressed air to so on the annular valve rim to act that the valve

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■ is raised in such a way that the compressed air is applied
is permitted on the entire lower surface of the valve. The valve therefore opens very quickly, and the compressed air reaches the cylinder just as quickly to exert the desired pressure effect on the actuating piston tappet »

One of the biggest problems that one comes across when using of piston valves of this type is the closing control. It should be noted that this Piston valves usually have the same end effective areas, which is why the compressed air is reintroduced in the upper guide chamber end of the valve is intended to bring about a state of equilibrium force, which of course is not able to bring the valve into the closed position. To do this reach, it is therefore necessary to apply an additional downward thrust to the valve, which creates the imbalance necessary to give the valve a downward movement.

In the older type of pistols, this additional thrust is provided by an intermediate between the valve and the
Shooting cap of the head, in which the valve itself is received, applied compression spring placed. Although functionally perfect, this solution has the disadvantage of causing installation dimension and cost problems.

In the case of the newer type of pistols, therefore
develops a tendency to clear this feather

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and to achieve the additional closing thrust pneumatically. For this purpose one has in the valve design worked in such a way that the upper effective area is larger than the lower effective area. In view of the fact that the piston valves of the type described normally have an axial passage are provided, which is equipped with means capable of alternating the connection between the cylinder opening and an outlet depending on the valve Opening and closing tillage has essentially worked in two directions, i.e. one has the outer upper valve diameter increased compared to the lower valve diameter, whereas the inner diameter be kept the same, or the inner upper diameter is smaller than the lower one designed, whereby the outer diameters are kept the same.

The object of the present invention is to to create a compressed air gun with piston valve arranged in the cylinder head, in which the problem of reaching the additional pneumatic thrust necessary to close the valve on one of the previously known Species versus peculiar way is solved. ^ ■

According to the invention, this object is achieved by means of a compressed air gun of the type with in the area of the open The piston valve arranged at the end of the cylinder is released, whereby the valve is normally in the closed position by a

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nen on its end facing away from its other end facing the cylinder, exerted pneumatic Pressure dur.ch into the corresponding end of the guide chamber of the valve through a connecting cable nal compressed air introduced between the compressed air tank and the end of the guide chamber is held and being temporary by temporarily interrupting the connection between the container and the named end of the guide chamber and simultaneous connection of the latter is displaceable with an outlet in the open position, which pistol thereby is characterized in that the piston valve is exposed to substantially equal end surfaces for exposure to compressed air possesses and is provided with a central part with a changed outer diameter, which part with a corresponding middle part with a complementarily changed inside diameter of the valve guide chamber forms annular chamber in communication with said end of the guide chamber in which for said piston valve is formed a further area for exposure to compressed air, which upon recovery the connection between the container and said guide chamber end to that of said The end of the piston valve is added to generate such additional thrust that the return of the piston valve into the closed position.

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It is obvious that with such a procedure the final diameter remains unchanged, whereas an intermediate diameter remains unchanged The outer diameter is varied by the effective area of one valve end opposite the other valve end and thus the closing thrust already exerted on said valve end is an additional thrust which is sufficient to bring about the pneumatic return of the valve to the closed position.

The features of the present invention are made by. considering the following detailed description of a practical embodiment of the same better understood, which is shown in the drawing, for example.

Show it:

1 shows a side view of a compressed air gun according to the invention, partly in section;

Fig. 2 the individual part of the gun head in the rest position on a larger scale and in section;

3 shows the same view in section;

4 shows the same sectional view from FIG. 3 but in just released.

The pistol shown in the drawing (see in particular FIGS. 1 and 2) basically comprises a handle 1, a head 2 provided with an upper end cap 3, a firing channel 4 and a magazine S ₃ that can be filled with clip bars 90, the clips from one through a spring 7 loaded slide 6 are gradually pushed into the firing channel individually.

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The handle 1 is hollow inside and forms a container 8 of large volume for the to him by a suitable one Nozzle 9 fed compressed air. A feed hose is connected to this nozzle.

The head 2 is also hollow and contains inside a cylinder 10 open on both sides, which with a middle annular flange is provided which rests against an inner annular flange 12 of the head piece and by means of an O-ring 13 the head interior in a lower chamber 19 "and divided into an upper chamber which is in communication with the container 8 and represents an extension of the same.

Inside the cylinder 10, which in the vicinity of its lower end is provided with non-return valves 14, which are normally closed by an elastic ring 16, a piston 17 provided with a seal 43 is slidably received, to which a blade-shaped plunger / is attached, which extends into a firing channel 4. An inserted between the lower end of the cylinder 10 and the entrance of the firing channel 4, elastic cushion 20 has the task of acting as a stop element and buffer for the downward thrust of the piston 17 zv. works. Directly above the upper open end of the cylinder 10 there is a piston valve 21 which is movable between the closed position in FIG. 2 and the open position in FIG.

2
body / firmly connected sleeve formed guide scanner

22 is performed.

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The check valves I4 plug holes 15 in the wall of the cylinder 10 *

The guide chamber 22 is of an annular inner projection 233 in which an elastic Sealing ring 24 is included, divided into two superimposed cylindrical parts of the same diameter · ' Accordingly, the piston valve 21 contains a cylindrical upper part 25, the outer diameter of which is the same as the inner diameter of the upper part of the guide chamber 22, an internally grooved intermediate part 26, the outer diameter of which is equal to the inner diameter of the annular projection 23 and a lower part 27 * starting from an outer diameter, that of the inner diameter of the lower part of the guide chamber 22 (and thus the outer diameter of the upper part of the valve itself) is the same, gradually decreasing in diameter until it reaches an extreme value, which is slightly larger than that of the upper, open end of the cylinder 10. A sealing element 70 ensures the seal between valve and cylinder when valve 21 is in the closed position ()

Due to the described design of the valve and the guide chamber 22 is between the projection 23, the grooved part 26 and the upper end of the lower part 27 formed an annular chamber 28, which with the upper end of the guide chimney 22 through an in the valve body obtained channel 29 is in communication. A

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elastic ring 38 seals this named ring chamber against the container 8 (Fig. 2).

The piston valve 21 is also provided with a central axial passage 30, which has the same outer diameter and in which an extension 31 of the cover 3 is slidably mounted inner recess 34, in which the shaft of a mushroom valve 35 is slidably received, which is pressed by a spring 36 in the direction of interaction with an O-ring 37 for sealing the connection between the lower end of the passage 30 and the holes 32. ' An O-ring or a sealing ring 39 is arranged between the cover attachment 31 and the upper end of the passage 30. "

Then a passage 40 connects the central part of the passage 30 with an annular chamber 41 ) which lies between the projection 23 of the guide chamber and the parts 25 and 26? and is sealed against the upper end of the guide chamber by means of an O-ring, 'The upper end of the guide chamber 22 can alternately either with the container 8 (FIG a piston 45, which belongs to a valve complex controlled by a manually operated trigger 47. More precisely, the piston 45 is formed in one piece by a shaft 48 with another piston 49 which is provided with a calibrated bore 50 which is received in a chamber 51, the lower end of which is provided with a submerged through passages 52

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lowering chamber 53 is in communication. ' The latter can alternately either be closed or connected to a channel 54 by means of a shaft valve 45 which can be actuated by the pusher 47. ⁵ This stem valve 55 is provided with two outer sealing rings 56 and 57 and an intermediate Lsngsnut 58, which last together with a guide chamber 59 of the movements of the valve 55 forms a passage which is always in communication with the channel 54. "Also a calibrated bore 60 causes a continuous connection between said passage and the chamber 53 · Finally, the spring 61 keeps the valve 55 in the rest position of Fig.'2. ⁴

The channel 54 is finally in communication with a chamber 62 which, depending on the position of a piston 63, is either closed or in communication with the outlet. The piston 63 is integral with a sensor element 64, which normally protrudes from the outlet opening of the firing channel by a spring 65 (FIG. ⁴ l) ί

The impact trip of those shown in the drawing With reference to FIGS. 2, 3 and 4j, the pistol is now intended to indicate three successive working phases show to be explained.

In the rest position, i.e. "when released as in Fig. 2 The pusher 47 and the sensor 64 (Fig. 1) not placed on the material to be stapled fill the container 8

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contained compressed air through the passage 50 the lower part of the chamber 51 (which is closed by the stem valve 55 and the piston 63 to the outlet) and holds due to the effective area difference (ie "the exposure of the compressed air) between the lower and the upper side of the piston 49, the piston 49 * the shaft

48 and the piston 45 in the raised position of FIG. 2. The upper end of the guide chamber 22 is therefore with the container 8 in communication, and therefore the upper end of the spool valve 21 is subjected to a large downward thrust who holds it in the closed position, whereby the— ' This thrust is only due to the weak upward thrust of the container compressed air on that annular, peripheral valve edge is insufficiently counteracted between the larger diameter circle of the lower valve part 27 and the sweeter diameter of the upper opening of the cylinder 10. "It is clear that while the compressed air is constant, the effective area difference between the two valve ends, that of the compressed air are exposed, forms such a thrust difference that keeps the valve in the closed position. at the valve 21 is in this position, the upper side of the piston is not subjected to any downward pressure, which is why the piston persists even in its rest position of Fig.2.

If the trigger 47 is pressed in this pistol position, so there will be no changes in the positions of the pistons

49 and 45 and thus the piston valve 21 and the piston 17 take place because, since the sensor 64 is still in its sunk position of Fig.1 is the piston

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63 closes the connection between the channel 54 and the outlet, ¹

If, on the other hand, the pusher 47 is pressed after the position of the sensor 04 on the material to be stapled has brought about the lifting of the piston 63 and thus the opening of the connection between the channel 54 and the outlet, the lifting of the caused by the actuation of the pusher 47 causes the Shaft valve, the air outlet from the chamber 51 through the passages 52 _f the chamber 53 > the groove 58 of the valve 55j the channel 54 and the chamber 62. ' The fact that the upward thrust but not the downward thrust is withdrawn from the piston 49 moves it downwards and thereby gently causes a corresponding movement of the piston 45 (Fig. 3). This creates the connection between the container and the upper end of the chamber. 22 is interrupted and the latter is connected to the outlet 33 through the passage 44 an initial lift-off of this valve which, on the one hand, enables the entire lower end valve surface to be exposed to the compressed air for rapid displacement of the same into the open position and, on the other hand, allows the compressed air to quickly apply its entire thrust to the top of the piston 17. ¹ This piston then moves away quickly.

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downwards and thereby causes the stroke of the plunger 18 into the firing channel for the impact with the one received there Clip and the subsequent expulsion of the clip itself from the firing channel into the underlying material. ' The atmospheric compressed air, which previously filled the cylinder .10 below the piston 17, is from the The cylinder itself is expelled and accumulates in the Chamber 19> where they have a pressure equal to the pressure in the Container 8 is reached when the piston 17 controls the openings 15 when it reaches the end stroke position of FIG and thus allows the compressed air to pass through the check valves 14 to the chamber 19 »'

The situation just described, i.e. the situation von Fige'Sj remains until the moment of letting go of the Pusher 47 unchanged. "By doing this, move namely, the stem valve 55 descends again and thereby closes the connection between the chamber 53 and obm the outlet (Fig. 4) j which is why the compressed air of the container re-enter through the calibrated passage 50 into the chamber 51 below the piston 49 and at the same time the underside of the same to bring back the piston itself and, accordingly, the piston 45 in the initial position (Fig. 4) required upward thrust can apply again.

By making the connection between the upper end the chamber 22 and the container 8 thus

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is, a downward thrust is again applied to the upper end of the valve 21, but this on and for is insufficient to bring about the valve closing, since the same of the upward thrust applied to the Exposure of the same lower effective area (same outside and inside diameter) to the same air pressure is due, is exactly balanced. However, the passage 29 allows the compressed air to also annular chamber 28 where the separation shoulder between parts 26 and 27 of valve 21 represents a further effective area which is added to that of the upper valve end in order to provide an additional cause downward thrust, which brings about such an imbalance that the valve displacement in the closing direction is caused (Fig.4) · While the valve 21 closes, on the other hand, the mushroom valve 35 remains temporarily under the pressure of the compressed air trapped in the upper part of the cylinder 10, which is why this Cylinder part can drain through the passage 30, the bores 32 and the outlet. While the top of the piston l8 is thus relieved, the underside of the piston is still exposed to the compressed air that is released from the chamber 19 is introduced into the lower part of the cylinder below the piston. This obviously does the immediate piston upward movement (Fig. 4), while the valve 35 to escape the atmospheric pressure air, which would otherwise counteract the piston upward movement, remains open. When the return stroke is completed, the Spring 36 returns the valve 35 to the closed position (Fig.).

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Claims (3)

Claims ■ I i «y compressed air gun for driving in fastening means, such as nails, staples and the like Compressed air tank, a cylinder having an open end to this compressed air tank, one in the called cylinder slidably received piston, which has a plunger for expelling the fastening means carries, a placed at the entrance of this open end and along the axis of said cylinder piston valve displaceable between a closed position and an open position of said open end, a guide chamber for the displacement of this piston valve, this piston valve normally being from a pneumatic thrust is held in the closed position / which thrust on the piston valve end that the facing away from the cylinder piston valve end, is exerted by compressed air, which in the corresponding The end of this guide chamber is through a connecting channel between said compressed air tank and said end of the guide chamber is inserted, and wherein this spool valve is temporarily through temporarily breaking the connection between the container and said end of the guide chamber and at the same time this last-mentioned end is slidable in connection with an outlet, characterized in that the piston valve has essentially the same end surfaces as the compressed air · expose and is provided with a central part with a changed outer diameter, which part with a corresponding middle part with complementary 509820/0398 ■ tar changed inside diameter of the valve guide chamber forms an annular chamber in communication with said end of the flow chamber in which, for said piston valve, a further surface for exposure to compressed air is formed, which at the restoration of the connection between the container and the named end of the guide chamber in the of said end of the piston valve is added to generate such an additional thrust that causes the piston valve to return to the closed position. 2. "" pistol according to claim 1, characterized in that that said central part of the piston valve consists of an annular groove Valve part and said central part of the guide chamber from an annular inner one There is projection of the guide chamber. 3. ' Pistol according to claims 1 and 2, characterized in that said piston valve has the same outer diameter and has an axial, same end diameter Passage is penetrated, one end of which is in communication with the open cylinder end and the other End displaceable on a stationary one penetrated by axial bores connected to an outlet Shank is mounted, with means for closing the connection between said axial bores and said end of the axial passage and to open this end at least temporarily 509820/0398 appealing return of the piston valve in the closed position are provided. " 4 · * Pistol according to claim 3? thereby g e k e η η-? draws that this means from an elastic pushed away from said shaft and against a sealed locking seat of said axial passage pushed valve consist '' 5 · * Pistol according to claims 1-4> characterized in that the piston valve end facing the open cylinder end has a Has outer diameter which is greater than that of said cylinder end, so that an annular, the peripheral edge of this piston valve end is always exposed to the container compressed air. 509820/0398 Blank page