DE2132853A1 - Electrically heated cutting device (torch knife) - Google Patents

Description

DR.-ING. DIPL-ING. G. RIEBLING? 1 PATENT ADVOCATE * ' My sign

S275-Ko / io / UJm

Please repeat in the answer

899 Lindau (Bodensee) Your message from My message from Rennerle 10 PO Box 365

3o. June 3, 1971 "SO. PARA", 63 rue Ηβποη, Lyon / France

Electrically heated cutting device (torch knife)

The invention relates to a heatable knife

especially for cutting through what can be destroyed by heat Geu / even or to form a heatable device for Shooting on plastic sheets or tapes.

The knife according to the invention is characterized in that

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Telegraph: Office hours Bank account: Pwtecheckkonto: OS 4374 patent d by agreement Bayer. Staatsbank Lindau (B) No. 1562 Munich 295

that it consists of a metal blade in which a only at one end of the blade opening longitudinal slot is formed so that the blade has two branches, the free ends of which have connecting means with an electrical power source,

The following drawing shows':

1 shows, in perspective and with parts exploded, a first embodiment of the "burning knife ¹¹ according to the invention; FIG.

FIG _e 2 is a vertical section through said knife which is assigned a ^ m guide table for a lengthwise durchzuschneidendes tissue; ,

Fig. 3 shows a bandage cutter with another Embodiment of a burning knife according to the invention;

Fig. 4 is a large scale a view of a according to Fig _o 3 cutter or internal diameter used;

5 shows, on a larger scale, a section along a line V-U (Fig. 4);

6 is a view of a third embodiment of a

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Burning knife according to the invention for shooting from thermoplastic sheets or tapes, and

7 shows a vertical section through the knife Fig. 6,

The knife shown in FIG. 1 comprises a blade generally designated 1. This reduced-thickness blade is made of a metal with high electrical resistance, such as a stud-chromium alloy. One distinguishes. (| a front edge 1a for cutting the body and a rear edge 1b opposite this. The edge 1a does not need to have a cutting edge; it can end in a rounded edge. Near this edge 1a and parallel to it is a slot 1c in the blade 1 cut out, which opens out only at one of the blade ends (lower end in Fig. 1), but ends at a certain distance from the opposite end, so that the blade divides into two branches, and also into a front 1d of less than A.

Width and a back 1e of greater width *

The free end of the rear branch 1e is firmly connected to a block of considerably greater thickness than the blade. As can be seen from the illustration, this block a rectangular profile, the major axis of which is directed obliquely to the general axis of the blade. To be more precise

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this means that, if this large axis according to FIG is assumed to be horizontal, the blade moves away from the block 2. lifts in an oblique direction from front to back, whereby the Terms "in front" and "behind" here for the edges 1a and 1b used correspond. The rear end of the block 2 is rounded and this is self-contained Provided with a hole 2a in the middle.

The free end of the branch 1d is covered with a very thick piece of metal 3 connected, which to a certain extent represents an extension downwards and in an eyelet 3a with a bore 3b ends.

The blade formed in this way is clamped between two insulating, refractory bearing halves 4, which are mutually in Are symmetrical with respect to the median longitudinal plane of the blade, In the example shown, the inside of each bearing half 4 carries a first part 4a starting from the rear Recording of block 2, then a thicker part 4b in a triangular shape, which is between block 2 and the Piece 3 inserts. Then there is a second, recessed part 4c in the form of a groove in which the aforementioned is present Piece 3 is stored. This part 4c is followed by a further part of greater thickness 4d, after which a third, recessed part Part 4e in the form of a vertical gutter with a flat bottom comes. This gutted part 4s becomes through to the front

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a last part 4f of great thickness completed · Es it follows that if the two bearing halves 4 on both sides

"The blade 1 is attached and grounded, so that the block 2 fits into the space formed around the two recesses 4a, the piece 3 in turn sliding into the passage created between the two recesses 4c. Each bearing half usually has a bore 4g , which thus corresponds to the bore 2a of the block 2 and which can receive a clamping bolt 5 (Fig _o 2) in order to establish a fixed connection between the blade and the insulating holder formed by the two bearing or holder halves 4 ".

It should be noted here that the dimensions of the recess 4c are such that even when the bolt is tightened, the piece 3 is still can slide freely in the insulating holder 4-4.

The recess or vertical channel 4a of each Haltarhhalf 4 knows a hole 4h. It serves to accommodate the upper end of an arm 6, which also has a corresponding bore 6a J having. A threaded pin 7 is inserted into the two opposing holes, on which the Klammuttarn 8 are screwed, so the arm 6 and the whole of the Firmly connect blade 1 and the insulating holder 4-4. Of the Pin 7 is arranged so that it can serve as a pivot axis for the arrangement 1-4-6.

In Fig. 2, a table is shown at 9 on which his

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The length of the tissue to be cut is passed by the amlYlesser can be. This table has an opening 9a through which the blade 1 is inserted obliquely, the pin 7 while rotating under this table by means of this fixed connected holders is moved.

An electromagnet 11 is provided below the table 9, against which the arm 6 rests, for example from a ferrous metal (soft iron) is made so that it can serve as a movable armature for the electromagnet can"

The device works as follows:

In order to feed the knife with heating current, one connects flexible wires 12 fed from a suitable transformer, on the one hand to the block 2, on the other hand with the eyelet 3a. In addition, the electromagnet 11 is excited so that the arm 6 is held in its position will.

The current from the wires 12 flows one after the other through the vqi their branch 1d and the rear branch 1e of the blade 1. If the parameters are set correctly, the branch 1d is raised to a relatively high temperature (e.g. in the order of 15o - 2oo ⁰ C ), while the rear branch 1 e

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only to a low temperature (e.g. 60 - 100 C) is heated «If you let a fabric made of a thermoplastic (PVC, polyamide, etc.) in Move over the table 9 in the direction of the arrow 13, the branch 1d causes a continuous longitudinal cut therein.

Ufegen the inclination of the blade 1 seeks as a result of counteraction caused by the cutting process in the tissue to climb up the same on the front branch 1 d, to the extent that it rises, it reaches areas that are

Touch were not cooled, so that the mentioned counteraction decreases during cutting, causing the tissue to sink back down. Finally the tissue swings around one Central position above the horizontal plane of the table 9.

When cutting there is no risk of the fibers in the molten state that they on the rear branch 1e of Blade 1 will stick, as the latter is a sufficient one

has a high temperature so that the fibers do not return to Jj

reach their solid state. It is further to be noted that the front branch 1d maintains its rigidity, in contrast to the flame cutting devices, their cutting edge is formed by a tensioned wire. On the other hand, since part 3 remains free in the insulating holder 4-4, the branch 1d can expand without risk of deformation frBi and remains in the direction of tissue advance, i.e. it becomes prevented from laying on the rear branch 1e.

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UIf for some reason the retroactive force in the If the cut becomes abnormally strong, the level increases up to the.

The rounded apex of the blade 1 and glides over it without it being excessively damaged in the process or, better, fed to the lower ends of the blade itself either directly or via a suitable relay, there is a certainty that in such a case the electromagnet 11 is no longer supplied with current sufficiently or not at all, so that the arrangement 1-4 -6 is not supplied with power v / at all, so that the arrangement 1-4-6 can swing freely around the pin 7 while the knife is lowered under the table, as indicated by ^{dash-dotted lines at 1 f.} Any danger one. Damage to the tissue is corrected on this lliaise.

As a modification, the electromagnet 11 can be fed via a normally closed microswitch, the one Sensory organ is assigned, which opens it as soon as the Geuiebe rises too high at branch 1d »According to a further variant, instead of the electromagnet 11, a calibrated retraction spring connected stop step to the To enable the blade to be lowered in the event of excessive reaction forces "

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Furthermore, the arrangement can also be made so that the lowering of the blade and its holder is no longer necessary by swiveling, but by sliding perpendicularly in suitable guides, whereby the holding is carried out in Working position is carried out by electromagnet, calibrated locking mechanism, etc. »

It should also be pointed out that if in Fig. ₀ 1 the two insulating parts are assumed to be symmetrical to one another,

this is not a mandatory requirement, as one f

simple flat cover for the other who can has only recesses or grooves. These parts 4 can be made of refractory ceramic, asbestos cement, etc., however, they can also be made of metal (steel) with an asbestos coating (mica or the like). In the latter case needs only the block 2 to be isolated, while the wire 12 ending at part 3 is connected to ground, so that this part does not must be isolated, preventing its movements in the holder

would be hindered. To fix the other wire ύ

12, block 2 can be lengthened a little to the rear in order to obtain a connection terminal «

In Fig. 3, a foundation plate is shown at 2o, which can be adjusted on a device, for example a clamp frame or with small tips, for feeding the tissue widthwise. On this plate 2o is at 21 a flat lever 22 hinged at one of its ends

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a knife generally designated 23 carries. This The knife has eyelet ends where the power leads

24 can be attached «. The opposite end

of the lever 22 is arcuate and connected by a screw

25 interspersed, which can be adjusted by zu / egg nuts 26 in their location is recorded. The screw 25 ends at its upper end in a cap 27 with an axis 28, on which an eyelet 29 fixedly connected to the movable core 3o of an electromagnet 31 is articulated. The electromagnet 31 is of the usual type with a magnetic circuit in the form of a C, with a moving core interspersed with one Surrounds coil. The entire arrangement of the electromagnet 31 is articulated at 32 on the base 2o. It is also one on the one hand at 34 on the base 2o and on the other hand, provided on the lever 22 in orphan to be explained below, hooked retraction spring 33, which the Strives to push up knife 23 and the curved end of the arcuate arm 22 against a stop 35 on the Foundation plate 2o presses.

U / ie can be seen from Fig. 4, the knife 23 has the general shape of a blade with two parallel edges 23a, 23b on the back and front, the two edges towards the tip are connected by a front edge 23 b tangent arc 23c, which is attached to the rear edge 23c connects in a vertical line. In the vicinity of the tip thus formed, an opening 23d is provided,

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whose edges are parallel to the edge 23a bzuj _o to the circular arc-shaped edge 23c · The blade usually has a longitudinal slot 23e opening into the opening 23d. As a result of the manner of the opening 23d, the branches delimited by the slit have a greater width from a certain distance from the tip into an eyelet 23f bzui serving as a connection terminal. 23g made from a more conductive

Metal manufactured as that which forms the blade itself ' %

can be «Each branch has two bores 23h and these four holes are arranged according to the corners of a rectangle.

In order to fasten the K ding β to the lever 22, the same can be seen on the lever 22 with a base 36 (FIG. 5) with pulled-through screws 37 which are connected to a counter-plate 38 arranged on the side of the blade 23 opposite the lever 22. are screwed. In order to secure the insulation, inserts 39 made of fireproof, insulating auxiliary material, such as mica, are inserted between M the base 36 and the counter plate 38. The screws 37 themselves are surrounded by insulating pipe sections 4o. Here, the base is firmly connected to an oil lug 41 into which the lower end of the spring 33 is hooked.

If the electromagnet 31 is not energized, the spring 33 holds it Knife 23 in its raised position according to FIG. 1, UJird

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the electromagnet is energized the core 3o attracted by the corresponding magnetic circuit, whereby the lever 22 pivoted and the Knife 23 is guided into the lowered position indicated by dashed lines in FIG.

The plate 2o is created in such a way that the circular arc 23c of the edge of the LYLESSER blade is then on the Path of a pulpy stretched body that the machine in question goes through ,, The altitude of the Fabric can be adjusted by a slotted table or by suitable rollers,

In order to be able to cut hems under favorable conditions, it is essential that the two on the A clamping frame or other device for spreading the tissue attached to each other symmetrically in relation to one another lie on the plane perpendicular to the longitudinal center line of the device.

_E in Fig 6 and 7 is a further embodiment of the internal diameter of the present invention ui Eder added that for welding the edges won serve two plates or strips of a non-rigid thermoplastic material. In practice, it can be sheets or strips of polyurethane or the like. Material, which have a relatively / large thickness (about Bo mm), The usually used

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Technique consists of tying the edges of the To soften both plates by heating them and then to press these edges so tightly that they are together be welded. At this point, Brenner or Heating rods used.

According to FIGS. 5 and 7, a torch knife is used for this closing according to a third embodiment of the invention used.

The knife according to Figs. 5 and 7 differs from the one * 1 and 2 in that the slot 43a of this focal knife 43 (Fig. 6) is the same distance from the two has parallel edges of the blade, so that the two branches 43b and 43c, which it defines in this blade, are the same Have cross-section. Here, too, the branches 43b and 43c end in parts, of greater thickness, which act as power supply terminals Serving eyelets 43d and 43e are firmly connected.

In order to be able to use the knife designed in this way, the m parts 43d and 43e are clamped in a suitable insulating holder in such a way that the knife protrudes perpendicularly from a work table. (Klan lays the two plates or strips 44 to be welded together on this table (Fig. 7), one of their edges is placed against one another and pressed against the knife by bringing the edges 43b and 43c of the knife so that they fit into the Grip joint A of the two plates 44. It is then sufficient to insert these plates into

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Continue in the direction of arrows 45, keeping it firm
remain pressed _{against each other o} As it passes, the knife clears the vertical surfaces of the plate edges, so that
these surfaces with each other downstream from the knife in
Direction of feed over-welded and / or grounded »Experience shows that ■ in this way a perfect weld of the two plates is produced under the only condition
that the required temperature of the diameter d, _a h _e the
this flowing current strength, the advance speed of the plates, the pressure of the same
against each other and against the knife. In particular, the same cross-section of the two branches causes a uniform temperature without
overheated areas that affect the debris
can, and without cold spots on which parts of the
Schujeissgutes could stick.

Claims

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Claims (9)

Claims 1 «Λ Burning knife for cutting foils or ribbons in one u / arm-sensitive material or to wear the Edges of thermoplastic sheets or tapes, characterized in that they are made of a metal blade (1, 23, 43) with a longitudinal slot (1c, 23e, 43a), which opens out only at one end of the blade and thus two branches (1a, 1b; 23a, 23b; 43b, 43c), the free ends of which have connection means with an electrical power source. 2. Burning knife according to claim 1, characterized in that the free ends of the branches (1a, 1b ;, 23a _f 23b; 43a, 43b) have a greater thickness than the other parts of the blade aufu / iron _e 3. Burning knife according to claim 1 or 2, characterized in that the free ends of the Branches (1a, 1b; 23a, 23b;, 43a, 43b) are made of a relatively / good conductive metal, while the rest Blade (1, 23, 43) made of a metal with high electrical power Resistance 'is made. - 16 - 109884/1670 4. Burning knife according to one of claims 1 to 3, characterized in that the slot (1c, Figs. 1 and 2) is closer to the front edge (1a) than the rear edge (1b), so that the heating is in the front Branch (1d) localized that is narrower than the posterior branch (ie) _d 5. Burning knife according to one of claims 1 to 3, characterized in that its front edge (23 b), Fig. 4) adjoins the rear edge (23a) connects via a circular arc (23c) which touches the front edge and almost perpendicular to the rear edge Edge ends, and that against the tip of the blade (23) to the slot (23e) in another opening (23d) runs out, the edges of which run parallel to those of the blade, so that the Aaste formed by the slot and the opening are relatively narrow towards the tip and wider away from this, so that the heating towards this tip localized without the parts of the branches that are further away from the tip having to be made too thick. 6. Brenrim knife according to any one of claims 1 to 3, for Welding together of the superimposed edges of thermoplastic sheets or tapes, thereby characterized in that the slot (43a, Fig, 109884/1670 4 and 5) the blade (43) divides into two branches (43b, 43c) of the same width. 7. Burning knife according to one of claims 1 to 6, characterized in that it contains an insulating holder (4, Fig. 1 and 2) in which one (1e) of the Aaste is clamped during the others (ld) are simply guided in it in a sliding manner in order to safe under the effect of uneven thermal expansion " to be able to move. 8. Device for cutting tapes or films made of thermoplastic material by means of a torch knife according to one of claims 1 to 5, characterized in that the whole torch knife (1, 4; 23, 36, 38) is pivotably mounted and in its working position against the Action of a retraction spring is held in place by an electromagnet m (11, 31) or equivalent so that it can be moved (lowered) away from the tape or film to be cut in the event of a power failure » 9. Apparatus according to claim 8, characterized in that that in their working position - 18 109884/1670 the blade (1, Fig. 1 and 2) of the knife from the front at the rear an inclined position to a plane on which the tape to be cut or the film is located emotional. 109884/1670 Blank page