DE6931182U - PUNCHING DEVICE WITH A SHAPING BLADE AND METHOD FOR HEATING THE SHAPING BLADE AND PUNCHING. - Google Patents

Description

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Minnesota Mining and Manufacturing Company, Saint Paul,

Minnesota 55101 (VoSt.v.A.)

Punching device with a form cutting blade and Method of heating the shape cutting blade and

for punching out

It's hot and cold punching graphic patterns out of one paper sheet-like material and from films is known per se. ZoBo can make graphic patterns with a self-adhesive Covered materials are punched out, such as the reflective material 3M "Scotchlite", the Yinylfilm 3M « "Scotchcal" and the like, for what purpose a punching device used with multiple blades. The above materials are products of Minnesota Mining and Manufacturing Company, Saint Paul, Minnesota.

Using a heated punching blade results in a better and more even cut than using a non-heated one Punch blade as the heat on these materials together

acts with the punch blade and cuts the material more evenly. If the 3M- ⁿ Scotchlite "reflective material is used during hot punching, the heat acts on the cut edges of the material and seals them against corrosion.

In the case of the older such punching devices, the conduction heating method was used to heat the punching blades was brought into contact. After the cutting edge of the punching blade was heated by conduction to the desired temperature _s was used, the punching device for punching out a graphic pattern of a thin, cuttable material layer ·

These older bodies where the punching blades through Conduction heated have various deficiencies, for example there were restrictions on both the type of Press used together with such a punching device can be, as well as in the size of the graphic pattern formed by the die cutting blades and cut from the thin Material schioht using such a press can be punched out.

These known conduction heaters also showed operational deficiencies on. In some cases, it takes up to an hour and a half to heat the stant blades to the desired temperature required, and the heating time depends on the size and the material of the punching blades and the thermal energy supplied by the plate heat source.

Another important disadvantage of the older conduction heaters can be seen in the fact that the blunt edge of the stan blade, which is brought into contact with the heating plate, needs to be heated to a higher temperature than for that

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Cutting edge is required to reduce heat loss within the Punch blade compensate to at the cutting edge of the punch blades to maintain the predetermined temperature. Furthermore, the heat from the heating plate must be at the higher temperature be supplied in an amount equal to the heat loss is in the punching blade and when punching out.

The older Konduktionsheizeinrichtuugen could only with plate punch presses and not on punch presses where the die and the cuttable material layer be passed through the press at the same time.

These older devices still have the disadvantage that they are not suitable for the use of existing punching devices to iii to set up outstants of intricate patterns that ζ · Β · can be used in the automotive industry for decorative purposes.

The invention provides a punching device with a punching blade which is heated by electrical resistance heating can

The invention also provides a device for punching, the punching blade of which is connected to an electrical circuit and is heated by resistance heating by the electric stioa flowing through the punching blade.

In the preferred embodiment of the invention, there is Punching blade made of a material which heats to a predetermined temperature by passing an electric current through it can be so that the punching blade after heating a graphic pattern from a thin, cuttable layer of material can punch out. The punching blade is designed according to the graphic pattern and forms a conductive one Path for the electric current »The conductors of an adjustable power source are connected to the punching blade and will be supplied with electricity from the power source, which heats the punch blade to the desired temperature. When punching a cuttable

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Material layer, the power supply is changed and it is determined within which area the punching with the highest quality he follows. With the help of an Ihermo cell located near the cutting edge, the temperature range can be determined in A graphic pattern with the highest quality is punched out of a certain thin and cuttable material layer can be.

The invention will now be described in detail. In the enclosed Drawings is the

1 shows a diagrammatic position of a punching device with a punching blade, which is composed of several sections according to the invention,

2 shows a diagrammatic position of a punching device according to Fig »1, in which the cutting edges of the punching blade in a heat-insulating foam-like material are embedded, which delays the dissipation of heat,

Fig. 3 is a plan view of the device of FIG * 2 ₈ showing the embedded in the heat insulating foam-like material layer edges of the punching blade,

Figo4 shows a bottom view of the device shown in Fig.1, which are the blunt edges of the on a stiff surface attached cutting blade shows

Fig. 5 is a sectional view along the line 5-5 in Fig. 3,

6A is a circuit diagram of an electrical power supply circuit, that supplies power to several sections of a punch blade,

Figo6B is a circuit diagram of an electrical power source which the The embodiment according to FIG. 6A is supplied with power,

7A shows a position of another embodiment of the Finding in which several sections of the punching blade are connected in parallel to the power source. are,

FIG. 7B is a circuit diagram for the embodiment according to FIG Fig «7A used electrical circuit.

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3? Ig “7G a circuit diagram for a modification of the circuit according to the

Eige8 a plan view of another embodiment of a punching device, whose punching blades are designed as a continuous strip, and the

Iige9 a, so-pictorial representation of a going back and forth Pressing device that s> to carry out the invention Punching process can be used

1 shows a punching device in a diagrammatic representation According to the invention «In general, several punch blade sections 1G are used in known punching devices, which are each designed in such a way that they together form the desired graphic pattern · According to FIG. 1, ZoB-s- the sections 10 designed so that they together form the two concentric loops 12 and H. The punch blade sections 10 are preferably made from a flexible steel band * Although the steel band is flexible, you can use this graphic pattern can only be produced to a limited extent. As can be seen from Fig.1. sometimes several Sections 10 are provided, between which the column 15 are located. The width of column 15 is exaggerated in Mg.1 shown large to show their existence. The punch blade sections should actually meet at the crevices, so that a continuous cutting edge is generated ο

In the preferred embodiment of the invention, in each Loop provided at least one gap or a joint, which represents a non-conductive point on the punching blade. An electrically non-conductive thermal conductor, e.g. a ceramic material, can be inserted into this gap, whereby a continuous cutting edge is created. If desired, each of the concentric loops 12 and 14 (Figol) could be used as a a continuous section can be designed with only a single electrically non-conductive gap.

The punch blade sections 10 forming the loops 12 and H

and inserted into a stiff base 16 to prevent laying of sections 10 to avoid. The rigid pad 16 may be made of a non-conductive insulating material, e.g. HoIa and preferably made of plywood or hardwood. The rigid base 16 is provided with an opening for receiving the blunt Edge of the punch blade offsetting the punch blade is supported in such a way that it protrudes from one side of the rigid base 16. As shown in Figures 4 and 5, the punch blade section 10 are provided with cutouts 19, the engagement between the punching blade absohnitten 10 and the stiff base 16 improve

The cutting edge 19 of the punching blade 10 is preferably embedded in an elastic, heat-insulating splint 20 made of a foam-like material, as shown in FIGS . 2, 3 and 5. Foamed silicon rubber can be used as the heat insulation layer 20.

As shown in FIGS. 2 and 5, the heat-insulating sponge-like material 20 protrudes somewhat in the relaxed state beyond the cutting edge 19 of the blade segments 10. When the material 20 is compressed, the cutting edges protrude of the blade sections through the sponge-like material 20 »

The material layer 20 delays the radiation of heat from the blade segments 10, thereby reducing the amount of heat that must be applied to the blade sections. As the insulation material 20 protrudes beyond the cutting edge 10 of the punching blade, the insulating layer 20 also holds the heated cutting edge removed from the thin, cuttable layer of material until a graphic pattern is punched out. The insulating material layer 20 forms the passages 22 and 24 through which the cutting edges of the blade segments pass when out of the A graphic pattern is punched out of a thin, cuttable layer of material.

FIG. 3 shows a plan view of the punching device according to FIG

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the Pig 2. As shown in Fig. 3, there are two loops of the blade 12 and H in passages 22 and 24 and from insulating spongy material 20 included

Pig.4 shows a bottom view of the punching device after Pig. 1. As can be seen from Figo4, the extend blunt edges of the blade sections through the openings on the rigid base through and are held in this way on the base 16.

Pig.5 shows a section along line 5-5 in Pig.3? in which this type of attachment is shown in detail. The punch blade section 10 is on the blunt edge 21 with the cutouts 18 which hold the sections 10 in the rigid base 16. The relationship is also from Pig. 5 can be seen between the insulating material 20 in the relaxed state and the cutting edges of the Elingenabschnittes 10. The distance over which the insulating material 20 over the cutting * - Edge 19 protrudes, is shown in the Pig. 5 exaggerated large. The blunt edge 2t of the punch blades is preferably aligned with the outside 23 of the rigid pad 16.

According to the invention, the punch blade segments 10 can be heated directly when they are switched into a circuit as a resistor. As can be seen from the Pig _e 1, the punching blade portions are brazed together at certain columns 15 at 26. 10 so that the punching blade continuously electrically conductive. For this purpose, e.g. Silver solder can be used because silver solder has a higher melting point than the temperature to which the punch blade section 10 are heated. On the other hand, the punching blade sections can also be mechanically connected to one another, e.g. by bolts and nuts that complete the electrical circuit.

In the embodiment according to Pig.1, the punch blade sections are 10 downstream of each other, so that an equally strong current flows through each section. The connection

dungeii of the two loops 12 and 14 to the power source advertising ■ the by soldering from reaching thick copper> ärähten 28 # means of silver solder prepared ,, The Dralitdurchmeseer eo is large f dimensioned such that no significant heating of the wires _f occurs when the Current flows through the punch blade sections. A voltage is applied to the power supply conductors 30 and 32 connected to the punching blade sections 10 so that a current flows through the blade sections 10 which heats the blade sections 10, which act as resistance, to a predetermined temperature.

In the embodiment according to FIG. 7, a circuit is closed, that through the conductor 30 to the Klingenabs oh η itt 34 and through the other blade sections of the inner grinding® 14 to conductor 28 and then the outer one of the blade sections Loop 12 leads to blade section 36 to which the conductor connected iso In this version, the are electrical non-conductive gaps 33 and 40 arranged so that all Klingenab sections of both loops 12 and 14 connected downstream are. With this interconnection, an equally strong current flows in all blade sections, so that these Circuit is preferable

After making the electrical connections, the punch blades are covered with a layer of an insulating spongy material 20, as shown in Figures 2, 3 and 5 · The passages 22 and 24 in the spongy material 20 produced in the manner that the unzerschnitiiene spongy Material is placed on the cutting edges, after which. the whole thing is passed through the press once, with the blade loops 12 and 14 penetrating the insulating material 20

Figure 6 shows the blade sections 10 as part of a electrical circuit that is closed in such a way that the punch blade sections are interconnected to form a network 42 to which a voltage is applied from a voltage source 44 · In the preferred embodiment

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the voltage source 4-4 consists of a controllable voltage source. For measuring the electrical power supplied to network 42 A 4-6 voltmeter and a 48 ammeter can be used. In this way the power supply can be regulated that a relatively constant and predetermined temperature is maintained in the blade network 42.

Pig. 6B shows a circuit in which the punch blade network 42 is shown as a resistor 50 which is connected to a Hegel transformer 52 which in turn is connected to an alternating current source 54. Ιύι the punching blade may be close to the cutting edge 19, a temperature leaders, for example, a thermocouple can be mounted 56 for measuring the temperature, so that maintained on the cutting edges 19 by Hegeln the current intensity to a predetermined temperature ·

In the embodiment described in connection with FIGS. 1-6B, the punching blade sections 10, which follow one another, are designed to form a graphic pattern with the two loops 12 and 14. The device described so far can be used, for example, for punching out graphic patterns from a thin, cuttable material, ζ .Β »a self-adhesive vinyl film with a pick of approximately 76.2 - 127 microns and a self-adhesive coating wearing. Such a thin, cuttable material is described in the American patent _{specification No. e} 2,647,848. about 101.6 "-. 152.4 Mikton and is impregnated with a polyethylene and silicon impregnation agent.

The punching blade portions 10 are by resistance heating of the flowing stream to a temperature of about 93 ⁰ G · heated With this punching process, the residence time of the cutting edge on the mounted on an impregnated paper substrate and a self-adhesive pad supporting film for punching out a graphic pattern of the vinyl film and the topping about 1/10 of a second.

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An expert can easily find the right one. Temperature, residence time, etc. _o are determined for a particular material, so that proper and smooth cut-outs can be obtained. The voltage \ ind the current strength can also be determined from the electrical resistance of the punching blade. If desired, several layers of the cuttable material can be punched at the same time with the punching device according to the invention. Ss was determined that in a vinyl film 3M "Scotchoal" 3650 the Sehneidkanten to a temperature of about 93-105 ⁰ C had to be heated.

In the embodiment of the invention described above, the punch blade sections 10 have been held close to each other as a resistance element. However, this is only one possibility · With certain punching patterns, for example according to I ¹ Ig ₀ 7A, the proximity of the various punching blade sections 53 and 60 to one another can mean that their cutting edges are at a higher temperature than the punching blade sections 62, which are from are located further away from each other, since between the punching blade sections 58 and 60 there is a greater heat transfer. With this punching pattern, it may therefore be desirable to conduct a current with a different strength through the sections 58 and 60 than through the sections 62, so that all of the punching blade sections 58, 60 and 62 are heated to the same degree.

to do this compensation are the punch blade sections 58 held close to one another at the connection points 64 and connected in parallel to sections 60 via conductors 66 and 68, wherein the sections 60 are held close to one another at the connection points 70. This parallel connection is on the connection points 72 and 74 with the sections 62 in series switched · A stronger current therefore flows through the segments 62.

This circuit according to? Ig * 7A is shown as a basic plan in the Pig.7B, the punch blade sections 58, 60 and 62 being shown as resistors 76, 78 and 8o.

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Pig.7C shows a circuit in which the Hegel resistors 82, 84 and 86 are connected in series with the punching blade sections 59 »60 and 62 according to FIG. 3? 7A, which in FIGS. 7B and 7C by the resistors 76 _? 78 and 80 are shown (i * ig.7B and 70), so that the current intensity can be set precisely in each current branch.

Fig. 8 shows a further alternative embodiment of the invention With a separate power supply for the separated punching blades in order to generate the same temperature at the edges of the punching blades. The power for the punch blade 88 is sent to the Terminals 90 and 92 and for the punching blade 94 - supplied to terminals 96 and 98 from a second power source. The voltages can be adjusted so that a current of the desired strength flows through the two punching blades 88 and 94.

From the above it can be seen that: after Method according to the invention a punch blade by resistance heating can be heated by means of an electric current conducted through the blade. How easy it is to see shows the invention over the older such devices various advantages. For example, the device according to the invention can be used in conjunction with punch presses of various types Versions are used · A seam according to Fig. 9 can also be used. As an example of such a mess, which can be used with the method according to the invention, the "Hytronie Presse" No. 60 is cited by the United Shoe Machinery Corporation of Boston, Massachusetts (USA) *

Figure 9 shows a punching device 106 with an elongated A piece of multilayer material 108 that includes a thin, cuttable layer 109 of material from which a graphic Pattern is to be punched out, and the one with the Isoliermaterialschi Without 20 the device 106 is in contact, the thin, cuttable layer 109 of material contacting the insulating material 20 is in contact. The composite punch · « direction 106 is combined with the multilayer material 108

from left to right through the punch press 104. Here is made of the thin, cuttable material 109 punched out a graphic pattern corresponding to the arrangement of the cutting edges of the punching blades, as shown by the broken lines 110 shown

A member 112 is made of an electrically insulating material arranged separately from the punching device between the bed of the press 114 and the punching device 106 insulating member 11.2 can be attached to the rear of the punching device 106 or to the die bed 114 * As an insulating material Bakelite is preferable.

The invention enables a portable design of the punching device, and heating means need not be provided in the punch press. The device according to the invention also enables a more versatile design, since the dimensions are not entirely limited to the dimensions of the punch press and the heat transfer medium »like the heated plate of the older devices · With the device according to the invention, the punching blade can within a few minutes and not for about an hour and a half as before, so that the unproductive heating time is shortened will. Since only the punching blade is heated and not an additional heat transfer medium, thermal energy is saved.

The punching blades heated by duroh electrical resistance heating can be used for various purposes »With the punching device according to the invention, for example, from a vinyl film Punched out letters or patterns with controlled ÜM-efe.

The device according to the invention can be used, for example, with a vinyl film provided with a self-adhesive covering, for example with the ^{product sold under the trade name N} ScQ $ chcal ⁿ No. 3650. Reference is made to the pattern strips, arranged at predetermined intervals, which are attached to motor vehicles. These strips exist

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from a film with a self-adhesive covering on a paper backing · With this vinyl film, better, i.e. » Get clearer sections when the cutting blades are heated to a predetermined temperature. With this punching process Using punch blades heated by resistance heating, the material is cut through, but not the paper pad. After punching out, the excess material is peeled off from the base and removed.

Made of a vinyl film with a self-adhesive covering (3M "Scotcheal" # 3650) became a decal approximately eight feet long punched out, which was intended as a tape for racing. The vinyl film was approximately 100 microns thick and was releasably connected to a base made of a silicon-impregnated paper base with a thickness of consisted of about 150 microns. Mr will have the self-adhesive covering a material was chosen that enables the vinyl film to be peeled off the paper substrate together with the self-adhesive covering. The decal or pattern can therefore be permanently attached to a motor vehicle *

The said decal was punched out using a punch blade approximately 2.1 m in length with a Approximately 2.5 cm high and approximately 760 microns thick. The punch blade sections of the approximately 2.1 m long Punch blades were connected to one another by silver solder to form a current path, similar to that shown in FIG. 3? 6B Circuit * The rod blade was plugged into a 60 Hz 3.0 volt AC power source connected with a current of 100 Ampο. An ammeter and a voltmeter were used to measure the current and voltage. Close to the cutting edge of the punch blade a thermocouple was placed.

The best results were achieved with a current of approximately 30 amps and a measured temperature of approximately 93-105 ^{0 O.} ! Therefore the predetermined temperature in the range of about 93 For this combination, the punching blade and the cuttable material - 105 ⁰ C. The temperature of the punching blade

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duroh regulating the single-gate voltage and thus the amperage to be changed. The stank blades were at these temperatures Heated for 2-3 minutes «

Is Once the predetermined temperature for a given device and a given material bekan n t, the power supply can be applied to a certain current strength to be adjusted so that need not be directly measured the temperature. With the help of this setting process, the temperature of the punching blade could be maintained at the desired predetermined value within a tolerance of a few temperature degrees «

It was found that the temperature at the cutouts by about 11 ⁰ G was higher. The heat loss from the 2.1 m long punching blade was reduced by embedding the heated punching blade in a heat-insulating sponge-like material, as already described.

A temperature sensor can of course also be arranged on the punching blade, which is switched into a feedback temperature control device ₉ which influences the input current or the input voltage in such a way that the desired temperature is maintained. Such a temperature control device is useful when the punching is carried out automatically.

Soünex claims

Claims (1)

S β μ U D. 1 »claims Stanzeinrichtuag for punching out a graphic pattern from a thin, cuttable material layer with a punching blade, which has a rear edge and is designed according to the graphic pattern, thereby characterized in that the punching blade (12, H) consists of a Material is made that; by passing an electric current through resistance heating to a a predetermined temperature can be heated and forms an electrically conductive current path for the current, and when heated to the predetermined temperature, the graphic pattern of the cutable material does not look like when the cutting edge comes into contact with the cuttable material layer, and that power supply conductors (30, 32) are connected to the punching blade and connect the punching blade to a power source connect so that an electric current can be passed through the punching blade, which the punching blade on the said predetermined temperature is heated. 2 · punching device according to claim 1, wherein the punching blade consists of a number of sections, characterized in that said sections (10) are electrical are connected to each other in such a way that the punching blade forms an electrically conductive current path 3 · punching device according to claim 1, characterized by a temperature sensor (56) which is arranged on part of the side of the punch blade and the temperature on this Indicating part of the page. 4β punching device according to claim 1, wherein the punch blade has a blunt edge, and wherein the punch means is a rigid one that receives the blunt edge of the punch blade 5. a * G - 16 - Has a base that the punching blade uses so that the « the cutting edge protrudes on one side, gekennaeicli.-net by an insulating material (20), which a lhirohlass, (22, 24) with a 'corresponding to the graphic pattern Porm, attached to one side of the rigid support, leaves the cutting edge of the punching blade intact and delayed the heat loss of the punching blade when the The punch blade has the predetermined temperature Si. Punching device according to claim 4, characterized in that that the insulating material consists of an elastic Isolienaa-; material that consists of unclaimedB; State the cutting substantially completely encloses the edge, and this in the compressed state allows the cutting edge pierces the passage.