DE1959783U - PUNCH KNIVES, HEAVY DESIGN. - Google Patents

Description

P.A.HU7WU.67

PATENT Attorney 8 MUNICH 23

- * 1 "IMTiTO riTTCMC UopoldsfraBe 33

UNTEROTTENS Swiss house Dipl.-Ing. Phone: 343958

File no. 2586

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»Behrens Aktiengesellschaft, A 1 f e 1 d / Leine

Heavy-duty punching knife

The invention relates to a profile for the production of punching knives heavy construction and one made from this profile Punching knife.

Known to be used for punching out leather _s paper _s cardboard, celluloid, asbestos ₃ rubber _s textiles and the like, punching knives _s which are bent according to the shape to be punched out. Depending on the load, weaker or stronger steel profiles are used to manufacture these punching knives.

The stamping of soft uppers _s thin rubber or textiles and paper in low layers ₃ is at the punching knife undemanding with respect to durability and position of the punching blade profile for punching level _s because the stamped out material to be cut with these ~ materials after lifting the punching blade lying on the cutting pad remain. Relatively weaker "steel profiles are for the manufacture of cutting knives for punching out these lightweight materials used. It is known that these steels are bent at bending machines _s., By the steel strip is vertically passed between three abutments which are permanently mechanically moved against each other. Such slight punching knife also referred to as steel strip _{knife 3} because the knife profile is delivered with a finished chord in greater lengths.

Heavy-duty profiles are used for punching out core leather, celluloid, asbestos, cardboard as well as paper and textiles in higher layers. When punching out these materials, it is important that the knife profile must have a certain position relative to the punching plane, depending on the material. Of particular importance are punching knives in which the cross-sectional shape formed by the knife profile widens from the cutting side to the knife back. In this position, experts speak of the "emptying position" of the punching knife. Such knives are primarily used to punch out saddle leather, which initially sticks in the punching knife, but is pushed out towards the back of the knife during the next punching. In contrast to this, for example, higher layers of paper are used for punching out punching knives, to which, for example, the envelope knives belong, in which the cross-sectional shape formed by the knife profile extends from the knife back to the cut extremity; expanded towards. In order to achieve an exact, vertical punch cut with these knives, they must be positioned in the profile to the punching plane so that about 1/3 of the knife back tends towards the inside of the shape to be punched. Finally there is a punching knife type of particularly strong construction, which must be placed vertically on the inside.

All of these knives are heavier, because they have a certain Must have profile position to the punching plane, so far still at the forge fire over the anvil after one of the punched out Form corresponding sheet metal template forged free hand. It is in other words, a distinct manual work, which requires a lot of skill and also takes a lot of time. It is coming recently added that one can hardly get labor for this physically difficult work.

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Experiments carried out> also to bend these punching knives by machine., Have repeatedly shown ₃ that it is not possible to bend steel profiles as they have been used for the production of punching knives up to now in such a way that, for example, the shape enclosed by the knife profile / shape extended to the back of the punching knife. Das.Stanzmesserprofil had to be placed at an angle to the punching plane. This is achieved, free-hand at the smith's fire over the anvil, in that the blacksmith stretches the steel on the back accordingly. If the shape to be punched is curved from the outside to the inside, such as, for example, the course in the joint of a shoe sole, the punching knife steel must be stretched here on the cut side. In some cases, certain positions of the steel profile can only be achieved by the blacksmith compressing the material in places. In all embodiments of the punching knife, it is in any case not possible to determine the position in relation to the punching plane without further ado.

It has now been found, .that a- machine production of heavy punching tools is possible :, if I _see go out from a profile whose Querschnittsfläehe already. Flank inclination of the punch knife determined on the inside. The use of such profiles was previously in the manufacture of punch knives in hand. work neither necessary nor known. After. In accordance with the invention, both profile flanks have the same inclination and this inclination already corresponds to the flank inclination of the finished punching knife on the inside. A profile designed in this way provides the prerequisites for the mechanical production of punching knives. The relevant process is not the object of the utility model, however _s erxfähnt for understanding the invention. According to this method, the profile., Whose flank inclination corresponds to the inclination of the finished punching

knife to the punching plane corresponds to curved while maintaining this plan inclination. The bending can for example take place on a worktop by means of jaws or rollers which can be moved relative to one another, one jaw of which is designed as a fork-shaped abutment. According to the invention consists in a punch blades ,, which is produced using the aforementioned profile _{s s} which is only on the outside until a Schneide.abgearbeitet of a further machined profile.

The invention accordingly relates to profiles and punch knives in which the plank on the inside of the work surface is either perpendicular or inclined in both directions.

In the drawing are two known punching knife profiles of known design and shown profiles for punching knives according to the invention.

Fig. 1 to Fig. 2 show known cross-sectional profiles for

Heavy-duty punching knife;

Pig. 3 shows a cross-sectional profile for

. position of a punch knife according to the invention with emptying position ι

Pig. 4 shows the ^: finished profile

a punching blade with ausleerender 'position; ■ "..." ■ -

Pig. 5 shows a corner profile ₃ for manufacture

a punch knife can serve ₃ in which the position for. Punch plane should be perpendicular;

Fig. Β shows a punch knife profile for a punch

knife j where the. inner. Cross sectional area increase in the direction of the cut side target.

For all: in Fig. 1 to Pig. 6 -shown. The cross-sectional profile is marked with S and the back side with R. The / inside of the punching knife to be produced was designated with I and the outside with A-. ^:

At a; Cross-sectional profile ^ as it is shown in Fig. 1 ..., the neutral - bending axisY - "- around which the steel is bent mechanically or by hand IaBt _{5 run} approximately according to the line I-II .. The -neutral . fiber laid check zwar.je the strength of the deflection slightly to the deflected side. This shift, however, is insignificant _s so that it can man.annehmen that the bending side extends approximately from the center of one to the center of the other side of the cross-sectional profile. the previously usually processed key blade profiles of this type are designed so ₃ that they decrease from the back in the direction of the cutting side in the thickness in cross section. such profiles are in Fig.! .and represented 2 of the drawing. the line I-II shown in these profiles, the perpendicular to the cutting surface extending neutral bending axis in a finished bent blade in cross-section in. the illustrated conical shape of the Profilquersehnitts and in particular that the profile is thinner on the cut side than on the back, after bending, for example, the enclosed shape becomes narrower from the cut side to the back of the knife. However, such a cross-sectional shape can not be used for cutting knives with ausleerender position., Which is why the punching knife can only be made by hand wherein _s is achieved the desired position of the punch knife by stretching or compressing the material. In any case, it was not known 3 from the shape of the punching reaming profile by means of these known profiles and the usual manufacturing processes to influence the future position of the punching knife with respect to the punching plane.

The invention can be seen in the simplest way: in the manufacture of a punching knife · _ν ; ΐη- "emptying position., Xveil a cross-line shape" is required for this _{punching knife. ,, which so far not:} usual; was.; The in.Fig .. 3 shown knife profile is used for. Manufacture of a knife with emptying point. lung. With this profile, the neutral bending axis would also run according to the drawn line Ϊ-ΙΓ. In order to achieve an emptying position of the punching knife profile, the profile on the cut side S is reinforced on both sides, namely in such a way that additional material cross-sections abc and.def are created on each side, with for clarification It is noted that the resulting profile a ~ e ~ cf should be a uniform cross-section. Since the profile be inventively exactly symmetrical _s needs. is of course the increase in material on both sides ^ _s exactly the same as that. an exact symmetry arises with respect to the axis I-II. If such a profile is now bent, the position of the bending axis I-II is retained or remains perpendicular, there. the profile is designed symmetrically to the bending axis. This has the consequence ₃ that on the inside the edge ac of the reinforcement abc maintains its inclination..Bei this side es.sich is the later inside of the punching knife _s so that you get the desired position of the punching knife profile to the punching plane _s namely a emptying position, in which the inner cross-sectional profile increases in the direction of the knife back R. This means ₃ that in a normal bend without forging work, in contrast to the profiles according to FIGS. 1 and 2, an emptying position is obtained. Fig. 4 shows schematically the. Completed cross-sectional shape of a punching knife when using a profile according to FIG. 3. On the outside of the knife, the material has been worked off at 5, so that the cutting edge 4 is the end of the original edge c «a. It is therefore readily apparent from this illustration that a certain position of the punching knife with respect to the punching plane could be achieved without manual work simply by the shape of the profile according to FIG. 3. The profile shown in Fig. 4 with

the. Cutting edge 4 _; is already part of a finished punching knife and; therefore able to work .. The ac flank inclination was ^in. This profile will receive ■ remain "that initially the full profile of FIG bent 3 and only then das.Abarbeiten was made of the material 5 This order of processing has the consequence that the... Plan inclination'a-c in relation to the axis. I ~ II remained unchanged. Proceed in the same way for the other profiles shown.. - - '_ ~ -.- -.

. "Are produced are punching blade which will have a vertical position with respect to the cutting plane, would have a profile as shown in FIG .5 find use Such profiles are useful for making:... Has already been used by heavy cutting knives However, it was not previously known _s carry out the bend in such a way that the position of the edge on the inside precisely defines the inner cross-section of the punching knife.

6 shows a cross-section of a punching knife which is intended to be used to produce such punching knives in which the cross-sectional area increases in the direction of the cut side. Such profiles for the production of punch knives were known. However, it was not known ₅ to .elect the slope of the planes in the profiles in such a way that, after bending, it corresponds to the position of the punching knife in relation to the punching plane.

Claims (2)

Sc h u. T ζ - an s ρ r ü cn e Profile harder for the production of cutting knives type _{s s} characterized in that both flanks (ac ef ₃₎ have a same inclination ;, which already Plank the inclination of the finished die-cutter blade on the inside I corresponds. 2. punching blade characterized by using a profile according to claim characterized _s that the profile is executed only on the outer side (A) to form a cutting edge (4). ■. '.