DE2436217A1 - FLYING SCISSORS, IN PARTICULAR FOR WIRE OR TAPE-SHAPED CUTTING MATERIAL - Google Patents

Description

DhI.-Ing. H. MITSCHERLICH
D, pl.-Ir.l · K. GlT: ', ■ <~ ANN July 26, 1974

Or re ', nai. V /. K (') RBER
OipL-l ..;. J- S'.ü ·. !!!. · T- EVERS
8 MUNICH 22. Steinsdorfstr. 10

PATENT APPLICATION

EVG-Entwicklungs- u.Verwertungs-Gesellschaft mbH in Graz Vinzenz-Muchitsch-Straß · 36 (Styria, ö »t« rr.)

Flying scissors, especially for wire or ribbon-shaped material to be cut

The invention relates to flying scissors that are particularly suitable for wire or band-shaped material to be cut is characterized by a simple and robust structure. The scissors according to the invention can output continuously working production or processing machines for wire-like or band-like material, such as reinforcement material for reinforced concrete construction, can be used, or else are used to make coils or coils of material of this kind after passing it through a straightening machine to cut into straight pieces of the desired length. When using flying scissors, the length of the continuously moving material to be cut must be measured continuously and before or when the target length is reached

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a control pulse for the actuation of the scissors must be derived which causes the scissors to fly along with the material to be cut and this to cut in the right place.

Known flying shears, which are used in particular as tin snips, have a complicated structure and have a special control device, through which the feed speed of the scissors is adapted to the speed of the material to be cut. Other Flying scissors are temporarily clamped to the material to be cut before the cut and thereby from this during taken away from the cut. However, all of these measures require considerable effort.

The invention is concerned with the object of creating flying scissors that are driven by purely mechanical drive means a speed corresponding to the material to be cut is given and that at a relative standstill the product to be cut is operated purely mechanically.

According to the invention, this object is achieved in that the two knives of the scissors are close and transverse to the free ones End parts of two scissor beams are arranged, which are hinged on the one hand to eccentrics, which each other diametrically opposite with respect to the axis of rotation of the shaft carrying them, and on the other hand in between the eccentrics and the knives located points are connected to each other by a link, and that on which the eccentrics bearing shaft sits a cam, which is coupled to one of the two scissor bars via a scanning linkage and in the sense of a substantially uniform movement of the two knives by means of this scissor bar in Feed direction of the material to be cut during the Eccentric forced cutting movement of the same is formed.

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The relative positions of the Knife regarding the scissor beam and the side lengths of the eccentrics, the scissor beam and the handlebar formed link square be chosen so that the plane through the cutting edges of the two blades of the scissors in every instant of the cutting movement perpendicular to the feed direction of the material to be cut runs, so that optimal cutting conditions result.

The scanning linkage may consist of a lever which carries a cam follower at one end and at the other end is articulated via a link with one of the two scissor beams.

In a preferred embodiment of the invention, the cam disk has such a curve that subsequently due to the uniform feed movement during the cutting process, an ejection of the cut to length for a short time Accelerated feed movement supporting the material to be cut takes place.

The knives of the scissors can have a rectangular, in particular a square cross-section and optionally four 90 ° rotated positions can be attached to the scissor beam, so that each time a cutting edge is worn can be switched to another cutting edge.

The invention will now be explained in more detail using an exemplary embodiment with reference to the drawings. Show it: 1 and 2 are schematic side views of an inventive flying scissors from opposite directions, with the movement of the scissors in Fig. Ί with the material to be cut cam disk and the scanning rod for this have been omitted;

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Pig. 3 a partially cut through further details supplemented view of the scissors in the direction of arrows III-III in Fig. 1;

FIGS. 4 to 7 show four successive working phases the scissors only indicated in the line scheme;

8 shows the path of the cutting edges of the two knives of the scissors;

9 to 11 individual phases of movement of these knives.

The scissors according to the invention have an upper knife 1 and a lower knife 2. These two knives are in knife holders 3 and 4 attached, which in turn are supported by scissor beams 5 and 6, respectively. The scissor beam 5 is in two Arms 5a, 5b divided on both sides of the scissor beam 6 are arranged, extending the same beyond the knife holder 4 and between their free ends Carry knife holder 3. The arms 5s. and 5b of the scissor beam 5 have in the vicinity of the two knife holders 3 and 4 on their inside recesses 7a, 7b in which handlebars 8a, 8b are arranged in two spaced apart parallel axes 9, 10 on the scissor beam 5, 6 are articulated and a scissor movement of these beams and those inserted into the knife holders 3 ″ and 4 of the same Allow knife 1,2.

The lower ends of the scissor bars 5 and 6 have openings for receiving eccentric disks 13, 14- are arranged diametrically offset from one another on a drive shaft, the eccentric disk 13 of two Share consists, namely one part 13a and 13b for each each of the two arms 5a and 5b of the scissor beam 5.

It sits securely on the shaft 15 on the scissor frame

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a worm wheel 16, which can be driven via a worm 17, around the knives 1, 2 of the scissors via the eccentric disk 13 »14- and the scissor beams 5i 6 the scissor-like To issue cutting motion.

On the drive shaft 15 also sits to derive the Movement of the scissors with the material to be cut is a cam disk 20. On a shaft 21 parallel to the shaft 15 are Two one-armed levers 22 and 23 are wedged at an angle to one another. The one-armed lever 22 carries at its free end a scanning roller 24 which is pressed against the circumference of the cam disk by a compression spring 25 supported on the scissor frame 20 is printed. The free end of the other one-armed lever 23 is connected to the scissor beam via a link 26 6 coupled.

It is assumed that the flying scissors according to the invention cooperate with a measuring device known per se, which measures the amount of material to be cut and a coupling of a known type, not shown, which sits on the shaft of the screw 17 between this and the drive motor, for the duration of one revolution of the Worm wheel 16 or the drive shaft 15 makes effective, as soon as the material to be cut through reaches the target length Has.

The processes taking place after this drive connection has been established are shown schematically in FIGS.

The flying scissors are at the start of the cutting process in their starting position shown in Fig. 4-, in which the knives 1, 2 are open and the material to be cut is unhindered can pass between the two knives. As soon as the aforementioned clutch, not shown, is engaged the worm 17 and with it the worm wheel 16 and the shaft 15 to rotate. This will make the

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two eccentric disks 13 and 14 in the direction of arrow E. set in circulation, whereby the two knives 1 and 2 moved against each other by 90 ° during the first partial rotation will.

At the same time, the one that is keyed onto the shaft 15 is also activated Cam 20 set in rotation. The one-armed lever 22 counteracts the action via the scanning roller 24 the compression spring 25 moves, whereby the shaft 21 is set in rotation and the one-armed lever 23 a Swivel movement in the direction of arrow F in Fig. 4 begins to execute.

About the handlebar 26 is the pivoting movement of the one-armed Transfer Heberls 23 to the scissors bar 6 of the lower knife 2. At the same time, the scissors bar 5 of the upper knife 1 taken from the scissor beam 6 by means of the handlebars 8a, 8b. The dimensions of the individual construction elements and the shape of the cam are chosen so that the upper and lower blades 1 and 2 are the same Speed as the strand of material to be cut move in the direction of arrow G.

As soon as the position shown in FIG. 5 rotated by 90 ° Shaft 15 is reached, the knives 1, 2 have the strand of material severed, i.e. the cut is complete.

During a further angular rotation of the shaft 15 by 90 ° Both shaft 15 and shaft 21 continue to run in the same direction (see arrows E and F in FIG Fig. 5) »but now the knives 1, 2 again from each other removed and. hence the severed material strand release «When the position according to FIG. 6 is reached, the scanning roller 24 is located at that point on the circumference of the The cam disk 20 which is farthest from the axis of the shaft 15. Therefore now return shaft 21 and the system of one-armed levers 22, 23 under the action

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the, relaxing compression spring 25 their direction of movement around and begin to run back in the direction of arrow H in Fig. 6, whereas the shaft 15 is in the original Sense of direction (see arrow E) continues to turn.

After rotating the shaft 15 by a further 90 °, the result is the intermediate position shown in Fig. 7, in which the knives 1, 2 are wide open, so that the material to be cut can still pass between them, but is already halfway back to its starting position are located.

After further rotation of the shaft 15 by 90 °, the starting position is reached according to Fig. 4 and the scissors remain in this position until a new cutting command is given will.

From a consideration of Figo 4- to 7 it can be clearly seen that the traveling movement of the flying scissors with the material to be cut and the return movement of the same through the cam disk control and the cutting process itself caused by the eccentric movements. A preferred course of the movement paths of the cutting edges two knives 1, 2 during the combined movement process is shown in Fig. 8 as a function of the angle of rotation Drive shaft 15 during one full revolution of the same shown. The path B1 of the cutting edge of the upper knife 1 runs from 0 ° to approximately 150 ° of the rotation of the shaft 15 with a close approximation linear, u.zw. the upper cutter 1 moves between the angle values 0 ° and 90 ° with a constant speed V ^ corresponding to the speed of the Material to be sliced corresponds to, and in the range from 90 ° "to over 120 ° with increased speed Vp» whereby the Ejection of the severed piece of strand of material is facilitated. The return movement of the upper knife 1 then takes place in the raised position of the same.

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The lower cutter 2 is initially lowered and approaches along the path B2 at a uniform horizontal speed the upper knife 1, which is at the cutting point corresponding to a rotation angle of 90 ° of the shaft 15 achieved. This is followed by an accelerated further movement and finally a return movement of the Lower knife in the lowered position.

9 to 11 show in an exaggerated representation the relative positions of the two cutting edges K1 and K2 of the two Knives 1 and 2 with respect to the strand of material S to be cut at the time of attack on the material to be cut (FIG. 9) Cutting through the same (FIG. 10) and during the acceleration of the severed strand piece S '(FIG. 11).

By choosing the ratio e1 / e2 of the eccentricities of the Eccentric disks 13> 14 in Fig.; 3, the penetration depths χ and y in Fig. 10 are determined so that the end of the following strand of material S is not bent will. By a suitable choice of the ratio of the effective lengths of the scissor beams 5 »6 and by a suitable choice of Articulation points 9 »10 of the links 8a, 8b, the desired paths B1, B2 of the cutting edges K1, K2 are defined with respect to one another.

The cam elevation curve can be selected according to known methods of kinematics so that the scissors run precisely with the material to be cut during the cut (in the interval between 0 and 90) and then an acceleration of the scissors serving ^{to eject the cut piece S 1.}

^{The inclination α »α 1 of} the knives 1, 2 (cf. FIGS. 9 and 10), which increases during the cutting process, results in only a small bending moment, so that a hold-down device

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- 9 - is not necessary for the food to be cut.

The illustrated embodiment can of course be structurally different within the scope of the invention modify.

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Claims (5)

- ίο - Patent claims: Flying scissors, in particular for wire or band-shaped material to be cut, characterized in that the two knives (1, 2) of the scissors are arranged close to and across the free end parts of two scissor bars (5, 6) which are hinged on the one hand to eccentrics (13 »14 ·), which are diametrically opposed to each other with respect to the axis of rotation of the shaft (15) carrying them, and on the other hand in between the eccentrics (I3, 14) and the knives (1, 2) located points (9, 10) are connected to one another by a link (8), and that on which the eccentric (13t 14 of the two scissor beams (5t 6) coupled and in the sense an essentially uniform movement of the two knives (1, 2) in the feed direction of the material to be cut during the cutting movement forced by the eccentrics (13, 14 ·) is formed. 2. Scissors according to claim 1, characterized in that the relative positions of the knives (1, 2) with respect to the Scissor beam (5t 6) and the side lengths of the Eccentrics (13t 14 ·) t the scissor beam (5t 6) and the Handlebars (8) formed handlebars are chosen so that the plane through the cutting edges of the two knives (1, 2) the scissors run perpendicular to the feed direction of the material to be cut at every moment of the son's oath. 3. Shears according to claim 1 or 2, characterized in that the scanning rod has a lever (22, 23), which carries a cam scanner (24) at one end and at the other end via a link (26) with a (6) of the two scissor beams (5t 6) is articulated. -11- 509811/0688 4. Scissors according to ^ one of claims 1 to 3 *. characterized, that the cam disc (20) one has such a curve that following the uniform Feed movement of the liesser (1, - 2) of the scissors During the cutting process, a "accelerated" function which supports the ejection of the long cut material for a short time Feed movement takes place. 5. Scissors according to one of claims 1 to 4-, characterized in that the better (I ₁ 2) rectangular, in particular have a square cross-section and optionally can be attached to the scissor beam (5, 6) in four positions rotated by 90 °. The patent attorney 50981 1/0688 Blank page