DE2010940A1 - Device for cutting up fiber strands - Google Patents

Description

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Gebr. Bohler k € o. Aktiengesellschaft, .- Vienna Ifcrsohheideni von

relates to a device for trimming of fiber strands; * e.g. of, cellulose or synthetic chemical fiber strands, which has a rotating cutter head in which the individual Afeschlagmesaer are fastened interchangeably.

Me known staple fiber cut-off knives made by forging consist of a knife blade with a® cross-section, which is approximately a very acute-angled; Triangle resembles, and one. Shank part, which usually has the cross-section of a narrow rectangle. The two files form an obtuse angle, so that the shaft is clamped in the head in radial grooves, while the blade, as it rotates, lags behind by the obtuse angle. Such knives are made by forging, tempering and grinding and require a considerable amount of work and Expense. They will be expanded after some operating time, Regrinded and reinstalled for further use.

The invention is based on the object of a device for cutting off the staple fibers, in the knife for Application come in egg production cheaper and ieicliter clamped or interchangeable. According to the invention this is achieved in that the knife part and shaft part of the cutting knife run straight and an almost constant, preferably have a substantially triangular cross-section.

According to the invention, a method for manufacturing such knives is characterized in that steel is rolled into a rod with a cross-section forming the shape of an acute-angled triangle, and thicknesses that correspond to the total length of the individual knives are cut off from this. These pieces are examples catfish hardened in a salt bath, and the narrow edge is amt a liäftge Scharfgegfehiifferi that of the mm, Stmapannkopf hsrausragerideri cutting eritspriciit. pie knife will be clamped *. head so clamped that the cutting part forms a s.twnnpfen angle to the radius and thus lags behind the preheating of the "head",

BADORIQINAL

The recess provided in the clamping head for fastening the knives can be adapted to the triangular cross-section. If this recess, however, for example because of the temporary use of knives, the shaft part of a right-angled Has cross-section, also corresponds to this right-angled shape, is a plastic insert or another elastic material glued to the shaft part, its cross-section represents an acute triangle.

To the time-consuming installation and removal and Nachschleife -. To spare ■ · ■ which are carried out on special machines canoe, another device has been developed in the so-called \ ez werfklingen be used!. These are on their entire

^. * Λ Ίϊίί l'ltl'i XUJIrViULi-IJf I'llILJ

Length in brackets. ^{r have} the above-mentioned cutting knives. This device has the disadvantage that fibers often get stuck on the blade holders and cause operational interruptions. The invention is therefore based on the further object of avoiding the disadvantage of the disposable blades clamped over the entire length. According to the invention, this is achieved in that the knife blade * is only clamped in the holders over a short distance compared to its total length. The length of the blades protruding freely from the clamping head is almost half less than that of the knives clamped with a separate shank part, so that a considerable amount of high-quality material is saved. To enable this, the clamping head is provided with holders, which rise in the direction of the diameter axis of the body of the gripping head substantially he ι. In a preferred embodiment of this device, the knife blades are each provided with one or two cutting edges extending over their entire length, which, if necessary, can also be limited to the part protruding from the clamping. Blades with two cutting edges can be turned over and used twice.

Ese'erwelst is favorable if the ratio of the total length of a disposable blade to the total length of a disposable blade is less than a ic. O, [, il Further, it is advantageous if the ratio of the thickness / ur total length of the disposable blade is 0.01 to 0 _f 0J. These

009840/2091

BADiSRJQiNAt ^;

According to the invention, disposable blades are made from pre-rolled strip in the Way made that the cutting on one or both cantons formed by a cold rolling process and then "for example inductive way.hardened v / ground. Compared to the known forged and subsequently ground and tempered Knives or, compared to the knives, with continuously equal permanent, for example triangular, cross-section, in the manufacture of the disposable blades, therefore, even more important ones Benefits and cost savings. In addition, that falls in the company Installation and removal as well as regrinding away, so that the The special machines required for this have not been procured or purchased. trained professionals do not have to be hired.

Further details of the invention emerge from the following Description of exemplary embodiments shown in the drawings are shown schematically.

They show: FIG. 1 a knife holder with several pieces a possible embodiment of the knife according to the invention in view, FIG. 2 in longitudinal section, FIG. 5 a cross section through a knife and the knife holder according to the line A - B of Fig. 1, 4 shows another embodiment of the knife according to the invention in a view, FIG. 5 in a top view, FIG. 6 shows another embodiment according to the invention Device in view, FIG. 7 in longitudinal section and FIG. 8 shows a cross section through the holder, which according to FIG Line A - B of Fig. 6 is guided.

The following applies to the items shown in the drawings:

The approximately triangular cross-sections having staple fiber chopping knives Io (referred to as "knives" for short in the following text) are in the recesses of the. two-part rotatable cutter head assembled from the disk-shaped bodies 1, 2 and protrude from this. All six knives Iq. Are arranged offset from one another by the same angle W. Each knife Io is provided with a cutting edge 11 in its area protruding from the knife head or over the entire lung. The knife. Io are made of steel "co-manufactured" and either hardened over the entire "" cross-section or only in the area "of the cutting edges j _t , the 8-side surfaces 7 in the cutter head

00984072091

- 4 - 20109A0 F υ? *

Recesses for the clamping rest on the clamped knives Io and are therefore inclined towards one another in accordance with the wedge angle Vr "of the knives Io. In addition, these side surfaces 7, 8 and the end faces 9> are against which the edges of the knives Io lie and consequently also these themselves inclined with respect to the dividing plane between the two halves 1, 2 of the clamping head and with respect to the radials passing through the axis of rotation XY. This results in favorable conditions if the angles CX enclosed by the knife edges 11 and the radials are 0 to 30 °. The two disks

I and 2 of the cutter head are held together by screws 5, '25. Anyone used to hold a knife shaft Recess of one disk 2 can be located in a groove in the other disk 1 and protrudes from it Plate 6 with a rectangular cross-section made of plastic, e.g. Polyvinyl chloride, may be provided. These plates β are e.g. With the help of two countersunk screws 4 each attached to the disc 1 and ensure even pressure on the clamping surfaces the knife Io. Each knife Ιο, '35 ο "has a holding hole Ij5, '25> / whose distance b in the case of knives according to the one shown in FIG to 5 embodiment of the knife back 12 is significantly smaller than its distance a from the cutting edge 11 having Knife edge, in a provided in part 22 pin ^ hraubc 5 hooked.

In the knife shown in FIGS. 4 and 5, in the end area used for clamping on the part lo, which is triangular in cross section and made of steel, and the knife edge

II has a plate 14, also triangular in cross-section, made of plastic, for example, made of polyvinyl chloride, preferably attached by gluing, so that there the total cross-section of the knife is rectangular. As a result, this knife can be built into existing cutter heads that have rectangular recesses \ hx \ of constant width.

6, 7 and 8 show a device according to the invention in which the knives are designed as short double-edged and therefore thin disposable blades that can be used twice , and the sharks gymnastics over the edge of the disc-shaped halves of the two-part clamping head et; by the amount corresponding to the clamping length c!

009840/2091

^BATH ° Wmko cm

Piece protrude in the direction given by the clamping angle ß. The knife blades 3o are clamped in the holders of the two-part, rotatable knife blade head over a short distance c compared to their total length 1 and protrude from this. All holders have the same distances from the axis of rotation X - Y and are arranged offset from one another by the same angle Rectangle with two triangles adjoining the narrow sides. The basic bodies of the hardenable steel knife blades Jo are tempered and their cutting edges 31 , 32, which are formed and ground, for example, by cold rolling, are high-frequency hardened. The knife blades 3o could, however, also be hardened throughout, in which case they would have a Rockwell hardness of over 5o. The side surfaces 27 and 28 in the knife blade head, on which the clamped knife blades are in contact, and consequently also these themselves, are arranged at an angle to the dividing plane of the knife blade head according to the ratio of the strand feed speed to the circumferential speed. Moreover, the end faces 29 in which 3o abut the edges (cutting 31, 32) of the knife blades, and "as a consequence, this even to the passing through the axis of rotation XY radial inclined. In this case, prove Heigungswinkel (S, d) between 0 Between the two parts 21 and 22 of the knife blade head held together with the aid of screws 23, compression springs (helical springs) 20 guided in cylindrical recesses are provided whose side facing the axis of rotation XY is fastened by a protruding retaining pin 25. Each knife blade J> o has a hole 33 in an end region and is hooked into one of the retaining pins 25 with this each of which is secured against rotation with the help of a spring washer and a hexagon nut and is secured by a part 22 vo the existing hole goes through. When the effective front cutting edges 31 of the knife blades 3o located in the Moss blade head after a long period of operation ■ ″. have become blunt, the screws 23 are about a goloükort,

BATH

whereby between the adhering to the permanent magnet systems' ^ A knife blades j5o and the part 21 is a gap. As a result, the knife blades Jo can easily be turned over by hand or exchanged for new ones. The permanent magnet systems J54 serve to facilitate these assembly processes.

Although the knife blades are generally not sharpened in the device according to the invention, the operation thus much cheaper than with the known devices equipped with cut-off knives to be re-sharpened.

The invention also includes devices in which the straight knives are clamped in a different expedient manner or in which the knives have other profiles that remain the same over their entire length. For example, profiles are also suitable whose cross-sectional shapes consist of two acute-angled triangles, for example a rhombus, or for different ones . cutting materials have different suitable cutting angles and resemble a rhomboid.

BATH ORIGINAL

0 0 9 8 A 0/2091

Claims (1)

F AiW A Patent claims: Device for cutting up fiber strands, e.g. rayon or synthetic man-made fibers, which is composed of a rotatable clamping head, preferably of two disc-shaped bodies pressed against one another by bolts, and a cutting head clamped between these disc bodies up to a maximum of half their entire length, characterized in that, dass.jedes knife (lo,; 5o ) consists of a straight flat steel with a profile that remains constant over the entire length and the essentially parallel knife edges with the radius of the clamping head running through the "axis of rotation" form an "angle (c <, ß)" of 0 Include up to 20 °. 2. Apparatus according to claim 1, characterized gekennzeiuonet that the knife (lo) over the entire length have a constant profile, the cross-sectional shape of which is an acute-angled triangle. . "· J), device according to claim 1 and 2, characterized in that the side surfaces (7, 8) of the recess provided for the Einspanm ^ g in the clamping head according to the wedge angle (^) .des triangular profile are inclined to each other. 4. Apparatus according to claim 1 to 3> characterized in that the recesses provided for the clamping in the clamping head have a right-angled shape and an insert (14) consisting of an η elastic material, for example plastic, is preferably attached by gluing, which has a triangular cross-section with the acute angle (7 ^ -). 5. Apparatus according to claim 1 to 4, characterized in that a holding hole (.15) is provided in the knife, C ³ B- Sen distance (b) from the knife back (12) much smaller than the distance (a) from the cutting edge ( 11). 6. Device according to claims 1, characterized marked dinas- .. that the knives (Jo) have a constant profile over the entire length, the cross-sectional shape of which in zweispitzwiüiXi: ' Triangles terminating, the two parallel cutting edges (31,] 52) BADQRlGlNAt. 7 Device according to Claims 1 and 6, characterized in that that the ratio of the clamping distance (c) to the total length (l) of the Knife (3o) is smaller than 0.3. 8. Apparatus according to claim!., (^ Characterized in that the brackets in the direction of the knife axes opposite the outer edge of the disc-shaped clamping body approximately around the Tension required knife length (c) protrude. Device according to one or more of the preceding claims, characterized in that the knives (lo, Jo) are inclined by an angle (et) of 0 to j50 ° relative to the plane of division between the two halves of the clamping head according to the ratio of the strand feed speed to the circumferential speed . 10. Apparatus according to claim 1, 6, 7, # and B, characterized in that the ratio of the strength (s) to the total length (1) of the knife (^ o) is o, ol to o, o3. 11. Device according to one or more of the preceding Claims, characterized in that the knife (lo, 3o) remunerated and the cutting edges (11, 51, 32) of which are high-frequency hardened. 12. The device according to one or more of the preceding claims, characterized in that the consisting of hardenable steel Knife (lo, Jo) continuously to a Rockwell hardness of are hardened over 5o RC. 13. Device according to one or more of the preceding Claims, characterized in that between the two by means of screws (23) held together parts (21, 22) of the Clamping head compression springs (26) are provided and a permanent magnet system in one of these two parts (22) for each holder (27) is attached. 14. Device according to one or more of the preceding Claims, characterized in that next to each permanent magnet system (3Y) on its side facing the axis of rotation (X, Y) protruding retaining pin (5, 25) is provided. 15. The device according to one or more of the preceding claims, characterized in that through the two parts (ill, 22) passing sanding screws (24) with spring washer and nut provided ülQdQ9 8 AO / 2 O 9 1 BADORfGINAL