DE6915710U - DEVICE FOR IMPACTING NAILS OR THE SAME. - Google Patents

Description

PATENTANWÄLTE 85/22/75 March 28, 1969

DR.-ING. WOLFF, H. BARTELS
DR. BRANDES, DR.-ING. HERO
STUHGART-N, LANGE STRASSE 51

Registration number. 121 746

Company Karl M. Reich / Nürtingen (Baden-Württemberg)

Device for driving nails or the like.

The invention relates to a device for driving nails or the like. by means of one in one Cylinder guided by compressed air can be acted upon piston, which with a nails or the like. collecting Plunger is connected and its impact energy at the end of its stroke from one of an elastic Material existing with a guide for the ram provided impact buffer can be received.

\ The excess impact energy that occurs when known

Devices of the type mentioned above are destroyed when the piston is braked at the end of its stroke

( must, stems from too high a blow pressure or else

from emptying the piston. With such Empty strokes of the piston, which occur when the nail supply is disturbed, affects the entire impact energy on the impact buffer. To ensure that the nails are hammered in properly, even in places with higher, for example To ensure the strength of the wood caused by branches, a certain excess pressure is required necessary .. From this it follows, however, that in places of the wood with lower strength there is always an excess Impact energy must be destroyed by the impact buffer.

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In the case of empty strikes, the impact buffers of the known devices can only be used to a small extent to destroy the Contribute impact energy, as they are completely compressed at a low impact energy of the piston and thus transfer the rest of the impact energy to the housing. However, this results in significant increases in pressure on, which can lead to the edges of the impact buffer breaking out and its complete destruction.

In a known device of the type mentioned above the impact buffer as part of the excess or complete impact energy of the piston Damping device formed. To do this, the blow buffer arranged in a cylindrical recess of a buffer piston facing the piston. This one in the cylinder limited movable buffer piston causes during its movement, which at the end of the stroke of the piston over the Impact buffer is transferred to him, a destruction of the impact energy in two ways, namely on the one hand by compression of a compressible pressure medium enclosed in an annular chamber and, on the other hand, by compression a rubber elastic body which faces its end face facing away from the piston. The damping device of this known device has, in addition to the impact buffer even more, sometimes complicated components that complicate the manufacture of the device and expensive do. The complicated structure of the known device also results from the fact that to avoid ram breaks During the destruction of the impact energy, the guide surface of the piston and the buffer piston are so long it must be chosen that tilting of the piston during braking is excluded.

The invention is based on the object of providing a device for driving nails or the like. to create that special Is expediently designed and its damping device

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is formed by a single impact buffer, which enables the piston to be guided and centered until it is fully braked and thus prevents tappet breakage even in the case of pistons with a short guide surface.

This object is achieved in a device of the type mentioned according to the invention in that the impact buffer on its side facing the piston a frustoconical projection concentric to the cylinder axis has, the thicker end facing away from the piston in a radially projecting, planar and to the cylinder axis vertical ring surface überc eht, and that in the side of the piston facing the impact buffer one in the form and size with the projection of the impact buffer coinciding with a truncated cone-shaped recess is provided, the other end of which is assigned to one of the annular surface of the impact buffer and is parallel to this annular surface is included. This ensures that in the device according to the invention, a single impact buffer is a completely reliable one Braking the piston allows. This results in a particularly expedient and cost-saving structure of the device according to the invention. The special design of the impact buffer and the piston enables that the guide surface of the piston can be chosen to be very short, since this is initially through the braking frustoconical interlocking parts is guided and centered, whereby by deforming the Sclilagbuffers already part of the impact energy is destroyed. The piston is guided and centered in this way When the parallel ring surfaces meet, the impact buffer and the piston are completely braked, without the piston jamming and thus causing the tappet to break. For the complete destruction of the impact energy Above all, the deformation of the annular flange of the impact buffer, the one on the one facing away from the piston, also contributes Front face can also be designed in the shape of a truncated cone.

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The invention is in the folgerden with reference to an embodiment of a device according to the invention shown in the drawings for driving nails or the like. explained in detail.
Show it:

1 shows a partially sectioned side view of the exemplary embodiment;

Fig. 2 is an enlarged section of the impact buffer and the piston of the Embodiment according to FIG. 1.

The one shown schematically in Fig. 1, according to the air storage principle working device 1 for driving nails or the like. has one provided with a handle 2 Housing 3 on that. are connected to one another via a magazine 4 for the nails or the like.

A cylinder 5 is arranged in the housing 3, a piston 6 in its cylinder space between a standby position and a braking position during its percussion stroke is led. In its ready position, a projection 7 of the piston 6 engages positively in a recess 8 of a rubber elastic body 9 which is arranged at one end of the cylinder in the cylinder space and holds the piston 6 in its ready position. Has on its side facing away from the projection 7 Piston 6 has a frustoconical recess 10 coaxial with the axis of the cylinder, the enlarged end of which is formed by a Ring surface 11 is included, which lies in a plane perpendicular to the axis of the cylinder.

A plunger i2 runs coaxially to the axis of the cylinder 5, one end of which is in an axial bore of the calving

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is attached and in the vicinity of the piston 6 has a sealing edge 12 *. This sealing edge 12 'forms the transition between the cylindrical, fixed end of the The plunger 12 and the free end of this plunger which is provided with a flat 12 ″ and is used for driving in the nails or the like. serves and which protrudes through a cylinder base 13 arranged in extension of the cylinder 5, in which a coaxial to the axis of the cylinder guide channel for the nails or the like. is arranged.

f On the adjacent to the braking position of the piston 6

The bottom of the cylinder 5 rests on an impact buffer 15, which is centered with a guide 16 for the free end of the Plunger 12 is provided. The impact buffer 15 has

on its side facing the piston 6 a to

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Projection 17, which in shape and size with the frustoconical Recess 10 of the piston 6 matches. This frustoconical projection 17 goes on its the piston remote thicker end in a radially protruding and to the annular surface 11 of the piston 6 parallel annular surface over. This annular surface 18 forms the surface of an annular flange 19 of the impact buffer facing the piston 6 * - 15, whose outer surface 20 is on the inside of the cylinder

ders 5 is applied, the inner diameter of which is slightly expanded in this area (not shown in the drawing). This prevents the impact buffer 15 from lifting out of its position at the end of the cylinder 5. On the Side 21 of the ring flange 19 is the impact buffer 15 also frustoconical.

The guide 16 provided in the impact buffer 15 for the free end of the plunger 12 goes into a guide coaxial therewith cylindrical recess 22 into which an annular sealing sleeve 23 is cast. Shortly before the The end of the stroke of the piston 6 causes the sealing edge 12 'of the plunger 12 together with the sealing sleeve

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of the impact buffer 15 a tight seal of the pressurized cylinder chamber from the atmosphere. This ensures that the remaining air compressed in the cylinder chamber in a known manner for the Air storage provided chambers 24 can flow. The air stored in these chambers 24 causes in the In a manner known to those skilled in the art, the return stroke of the piston 6 into its ready position (FIG. 1).

In the tight seal of the cylinder chamber achieved by the sealing sleeve 23 in connection with the sealing edge 12 ^f , a short displacement of the piston before it is braked is sufficient to compress the remaining air in the cylinder chamber in the chambers 24 for the return stroke of the piston 6 enable. This creates the possibility that the sealing edge 12 'can be arranged on the plunger 12 in the vicinity of the piston 6 so that the flattened area 12 ″ can extend very far upwards In the vicinity of the path of movement of the plunger 12, the guide pin 25 and the magazine 4 for the nails or the like can be moved upwards, whereby the length of the cylinder base 13 and thus the overall height of the device 1 can be selected to be short.

Experiments have shown that as a material for the impact buffer 15 crosslinked polyurethane with a hardness of at least 42 Shore D according to DIN 53 505 is particularly suitable is what has a Young's modulus of at least 900

2
kp / cm.

When a trigger 26 provided on the handle 2 is actuated, compressed air flows in the manner known to Eachmann

in the cylinder space between the piston 6 and the rubber-elastic Body 9 a. When the pressure rises, the positive connection between the projection of the piston 6 and the rubber-elastic body 9 canceled. Thereupon the piston 6 is through the acting on it Compressed air moves in the stroke stroke from its standby position to its braking position. When hitting the Impact buffer 15, the piston 6 is initially supported by the truncated cone engaging in its frustoconical recess 10 shaped projection 17 guided and centered, initially by deforming the frustoconical projection 17 of the impact buffer 15 impact energy is used up. The remaining impact energy of the piston is at Tretten its flat annular surface 11 on the likewise "flat annular surface 18 of the impact buffer 15 by deformation of the flange 19 destroyed.

Before the piston 6 is triggered, a nail or the like stored in the magazine 4 is removed. the guide channel 14 in the Supplied in a manner known to those skilled in the art. In the stroke of the piston 6 described above, the free end of the hits in the guide channel slidably guided ram 12 on the head of the nail arranged in the guide channel 14 and drives this into a workpiece 27.

By constantly centering and guiding the piston 6 on the impact buffer when the impact energy is destroyed 15 ram breaks are avoided, since tilting of the piston 6 can not occur even with a short guide surface of the piston during the Abbrerusens.

Claims (4)

- 8 claims for protection 1. Device for driving nails or the like. by means of a piston guided by compressed air acted upon ble., the with a the nails or the like. driving ram is connected and whose impact energy at the end of its stroke can be absorbed by an impact buffer made of an elastic material and provided with a guide for the plunger, characterized in that the impact buffer (15) on its side facing the piston (6) has a side facing the cylinder axis has concentric, frustoconical projection (17) which, at its thicker end (19) facing away from the piston, merges into a radially projecting plane and an annular surface (18) perpendicular to the cylinder axis, and that in the side of the piston facing the impact buffer a shape and A frustoconical recess (10) which corresponds to the projection (17) of the impact buffer is provided, the enlarged end of which is surrounded by an annular surface (11) assigned to the annular surface (18) of the impact buffer and parallel to it. (j 2. Device according to claim 1, characterized in that that a flange (19) of the impact buffer (15) forming the annular surface (18) on its facing away from the piston (6) End face (21) is frustoconical. 3. Apparatus according to claim 1 or 2, characterized in that the guide (16) of the impact buffer (15) for the The plunger (12) merges into a concentric extension (22) in which an annular sealing sleeve (23) is arranged. 4. Device according to one of claims 1 to 3, characterized in that that the material for the impact buffer (15) crosslinked polyurethane is provided.