SE529907C2 - Rotary cutter device for slitter rewinder, contains knife units formed by rings and carriages which can be moved along rotary shaft via guide rails - Google Patents

Abstract

Two or more guide rails extend along and are joined to the rotary shaft of the cutter. Carriages are connected to and located on the inside of each of the knife rings so that each ring and the carriages inside it form a unit capable of travelling along the rails in order to adjust the positions of the knives. The knives are ring-shaped, comprise a ring or are connected to a coaxial ring, the inside of the ring facing the shaft. The positions of the knives relative to each other are adjustable.

Description

BRIEF DESCRIPTION OF THE INVENTION The object of the invention is to address the above problem complexes. The invention is characterized in that at least two guide rails connected to the shaft extend along the shaft, and that in each of said rings travel wagons are arranged, connected to the rings on the inside of the rings facing the shaft, so that each of the adjacent rings with associated carriages forms a unit, here called a crew, which can be moved on the guide rails with the carriages as vehicles and set in the desired positions for the levers.

The optimal number of guide rails is probably three, but four are also conceivable and in principle even more.

Further features of the invention appear from the dependent claims and from the following description of a preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS In the following description of a preferred embodiment, reference will be made to the accompanying drawings, of which Fig. 1 shows, in the lower part of the figure, a side view of a portion of a knife assembly according to the preferred embodiment, in Fig. 2 a view along the line II-II in Fig. 1, Fig. 3 is a view along the line III-III in Fig. 2, Fig. 4 shows a circled detail IV in Fig. 3 on a larger scale, Fig. 5 shows a cross section through a shaft and a knife mounted on the shaft including carriage holding ring included in a knife assembly according to a modified embodiment of the invention, and Fig. 6 shows four closely arranged knives on the common shaft according to F in Fig. 5 in a knife assembly according to said modified embodiment, viewed in a side view. DESCRIPTION OF A PAIR OF PREFERRED EMBODIMENTS Referring first to Fig. 1, a scissor cutting rack is generally denoted by the number l. an upper knife assembly 4, comprising an equal number of upper knives 5. The upper knives 5 and the lower knives 3 cooperate with each other in a known manner, but the upper knife assembly 4 with the upper knives 5 has only been shown schematically. The upper knife assembly 5 and the upper knives may also be designed according to the principles of the invention but need not be so. In this patent specification, only the lower knife assembly 2 according to the invention will be described in detail.

In the lower knife assembly 2 a shaft has been designated 10. The shaft 10 and thus all the lower knives 3 mounted on the shaft are rotated by a single drive motor, not shown. In the shaft 10 there are three longitudinal first grooves 11 and three longitudinal second grooves 12. The first three grooves 11 are arranged with a 120 "pitch as well as the three second grooves 12, which are arranged midway between the first grooves 11. The first grooves 11, Fig. 4, has flat bottom portions 13 on either side of a central, shallow, longitudinal center groove 15 and straight walls 14, which are perpendicular to the bottom 13, which is perpendicular to the radial direction of the shaft 10.

Recessed and screwed into the center groove 15, a guide rail 16 extends along the entire length of the knife cradle 2. A screw for anchoring the guide rail 16 in the middle groove in the bottom of said first groove 11 has been designated V17 in Fig. 4. A plurality of such screws are arranged along the length of the guide rail 16. The guide rail 16 has a pronounced waist in cross section, forming a pair of longitudinal depressions 18 in the sides of the guide rail, one on each side.

The guide rail 16 has a height above the bottom portions 13 which is slightly lower than that of the side walls 14hma. , partly, below the clamping jaw 21, a pneumatic hose 22 for pushing up the clamping jaw 21 from a lower, passive position to the higher, active clamping position shown in Fig. 2.

The lower knives 3 consist according to known principle of circular ring-shaped cutting knives. On each such annular cutting knife 3 there is a flat, circular annular cutting surface 30 which is perpendicular to the center of rotation of the shaft 10, and which is delimited by an annular groove 29. Below the groove 29 the cutting knife 3 has an axially projecting, annular 28. in a conventional manner with an upper knife 5 assigned to each lower knife 3 in the form of a scissor cutting knife in the upper cutting assembly 4. The annular lower cutting knives 3 have a circular-cylindrical inside and are mounted on an inner ring 32, here called carriage holder ring, the outside of which has the same cylindrical shaped as the inside of the knife 3, so that the knife 3 with a good fit can be pulled on and joined to the carriage holder ring 32. At the end facing away from the cutting surface of the knife 3, the carriage holder ring 32 has an outwardly directed 33 end 33, which forms a stop for the knife 3. The flange 33 has as great an axial extent as the 28 end 28 on the opposite side of the screen blade. The knives 3 are fixed to the carriage ring rings by means of screws 38, Fig. 1. Also tightening or other conventional fastening techniques are conceivable. 10 20 25 30 35 529 907 90097 On the cylindrical inside of the carriage rings 32 there are three carriage holder grooves 35 which extend in the axial direction over the entire width of the carriage holders. The carriage holder grooves 35 have, like said first groove 1 in the shaft 10, a flat bit 36, perpendicular to the radial direction of the shaft 10, and flat side walls 37, perpendicular to the bottom 36 but narrower and shallower than the groove grooves 11. Like the grooves 11 in the shaft the carriage holder grooves 35 are provided with a 120 ° pitch in the carriage holder ring 32.

The width of the carriage carrier grooves 35 is adapted to the width of a carriage 40 with straight walls and a flat bottom arranged in each carriage holder groove 35. The carriages 40 are rotated with the respective carriage holder ring 32 by means of screws 41 and are longer than the carriage holder rings 32 are wide. Thus, on each side of each carriage holder ring 32, the carriage carriages 40 protrude with a portion 42. The carriage carriages 40 are joined to the respective carriage holder ring 32, before the carriage holder is contacted with the annular knife 3. The manufacturer forms each set, consisting of an annular knife 3. , a carriage holder ring 32 and three carriages a unit, here called carriage 44, which can be moved - ride - on the guide rails 16 The carriages 40 and the guide rails 16 are thus arranged to cooperate with each other and consist of per se known machine elements which are available on the market. .

Together, the carriages 40 and the guide rails 16 form so-called ball rail guides in that the carriages accommodate a large number of ball bearing balls 45 arranged in two ball bearing paths on each long side of each carriage. When the carriage 44 is mounted on the shaft 10, it abuts in the balls 45, Figs. 4, in two rows one above the other against roller tracks on the guide rails 16 in their side depressions 18. grooves 11 are wider than the carriages, as shown in Figs. 2-4. against the bottom 13 and so that an annular gap 49 is formed between the shaft 10 and the carriage holder ring 32.

This gap 49 is so narrow that the pneumatic expansion elements 22 during their expansion are able to push out the clamping jaws 22, so that they move over the gap 49 into contact with the carriage holder rings 32 for laterally axing the levers 3 in assumed positions.

As a carriage 44 moves along the axis H10, the balls 45 in said ball bearing tracks in each carriage 40, rolling towards the respective guide rail 16 in its side door depressions 18. The ball bearing carriages 44 can therefore be moved with great ease along the axis.

The ball rail guides have recognized great rigidity and bearing capacity in all load directions. These properties are also utilized in the heat-sensitive application to avoid the risk of jamming or drawer effects when the carriage 44 moves along the axis. In addition, the connection of the carriage 44 to the shaft 10 via the ball rail guides means that the limbs 3 are kept centered with great precision both during movement and when the limbs are fixed in their intended positions.

Normally, the knives 3 are held laterally fixed in their positions by means of the jaws 21, which are pressed against the inside 34 of each of the carriage holdings 32 by the pneumatic hoses 22, when these are connected to a pressure source. The pressure of the clamping jaws 21 'against the carriage holder rings 32, on the other hand, does not affect the setting of the knives 3 in radial direction, because the carriage holder rings SZ / knives 3 cannot move in radial LCD due to the rigidity of the system rings 3/32 - carriages 40 - guide rails 16 - shaft 10. The carriage holder rings 32 and the knives 3 are simply kept permanently centered relative to the center of rotation of the shaft 10.

At the knife assembly 2 according to the invention, the carriage 44 can be brought so close together that the projecting portions 42 of adjacent oak carriages 40 come into contact with each other.

A free space is thereby formed between the screws 3 which is wider than is required for a side guide 50, of e.g. a stroke similar to the shift gears used in conventional gearboxes, it must be possible to insert and grasp a knife 3 in order to move it laterally.

The lateral collar fi that the side dryer 50 exerts on the knife does not result in any inclination of the knife 2 or of the carriage holder ring 32, due to the rigidity of the system rings 3/32 - carriages 40 ~ guide rails 16 - shaft 10. On the other hand, the relatively long carriage carriages 40 a limitation, in this first embodiment of the invention, of the possibility of tightly packing the knives 2 and thus a limitation of the possibility of cutting narrower strips. The problem can be eliminated by using carriages which are shorter than carriages 40, more specifically no longer than the total axial extent of the knife 3 and the carriage holder ring 32, but on the other hand one loses strength and stability in the system. Fig. 5 and Fig. 6 illustrate a modified embodiment of the invention, where the problem is solved without the aid of shorter carriages.

According to the desiccation form of a knife assembly 2x shown in Fig. 5 and Fig. 6 according to the invention, the number of first grooves - rail grooves - and guide rails in have doubled in the axis ~ l0x. The rail grooves and the number of guide rails are thus six and have been designated 11A and 11B, respectively 16A and 16B. In each of the three rail tracks 11A there is a guide rail 16A and in each of the three rail tracks 11B fi there is a guide rail 16B. The rail grooves 11A, 11B and the guide rails 16A, 16B have the same design as the first grooves 11, 529 907 90097 and the guide rails 16 in the first embodiment, respectively. The pitch between the rail tracks / guide rails 11A / 16A is 120 °, ie the same as the pitch between the rail tracks / guide rails 11/16, and the pitch between the rail tracks / guide rails 11B / 16B is equal. The radial symmetry lines to the rail tracks / guide shoes 11A / 16A and the radial lines of symmetry to the rail tracks 11B / 16B have been designated 51A and 5B, respectively. The closest of such symmetry lines 51A and 5B form a circular angle α of each other, which amounts to 40 °. A simple calculation gives at hand that the circle segment angle ß between the nearest adjacent of said lines of symmetry 51A and 51B amounts to 80 °. "Symmetrically in each of these three circular segments there is a clamping jaw groove 12 having in identical shape to said second grooves in the shaft 10 according to the preceding embodiment. In each of the three grooves 12 there is in the same manner as before also" expander element in the form of a pneumatic hose 22 and a clamping jaw 21.

The knives included in the knife assembly 2x are of two types, designated 2A and 2B, respectively. In Fig. 5 a knife ZA is shown. In this there are three carriage holder grooves 35, each arranged in the middle of a rail groove 11A, and designed in an identical manner as the carriage holder grooves in movable formwork. In each of these carriage holder grooves there is a carriage 40 which is also of identical identity and mounted in the same way as in the previous embodiment.

In the middle of each of the three rail grooves 11A there is on the inside of the knife 2A a carriage groove 52A which is deeper and wider than the carriage holder grooves 35 and thus also deeper and wider than the carriages 40 are high and wide. On the knives 2B, the carriage receiver grooves, designated 52B, and the carriage holder grooves 35 have changed places. Incidentally, knives 2A and 2B are the same. By the inventive arrangement, the knives can be tightly packed 2A-2B-2A-2B and so on, as shown in Figs. This is made possible by the projecting parts 42 of the carriage carriages 40 in the rings 2A being inserted into the carriage receiver grooves 52B, while the protruding portions 42 of the carriage carriages 40 in the knives 2B can be inserted into the carriage receiving carriage grooves 52A in the knives 2A.

When the knives 2A, 2B are maximally tightly packed, Fig. 6, there is a gap 53 between each adjacent pair of knives, wide enough that the upper knives 5 in the upper knife assembly 4 can be brought into contact with the scissor cutting surface 30 on the respective lower knife 2A, 2B, and the side ear 50 must be able to be inserted into the slot for feeding any knife 2A, 2B laterally. It will be appreciated that the invention is not limited to the embodiment shown.

For example, the carriage holder ring 32 can be eliminated and the annular blade may instead be formed with an inside facing directly against the shaft 10 or 10x in or against which the inside of the carriage 40 can be axed directly on the knife. The number of guide rails and rail tracks can also be varied, as can the number of tracks for the expander elements. The patent application is thus not limited either to what is stated in the introductory part of the description or to what is shown in the description of the embodiments, which are to serve only as illustrative examples. in

Claims (11)

10 20 25 30 35 529 907 90097 PATENT REQUIREMENTS A knife assembly (2) comprising a rotatable shaft (10) and a plurality of scissor blade knives (3) which are in the form of or comprise a ring, or are connected to a ring coaxial with a respective knife (32), the inside of which faces the shaft , which scissor blades together with said rings are slidably arranged on the shaft and adjustable at a distance from each other in desired positions along the shaft, characterized in that at least two guide rails (16) connected to the shaft extend along the shaft, and that in each of said rings (32) carriages (40) are arranged, connected to the rings on the inside of the rings facing the shaft, so that each and one of said rings with associated carriages forms a unit, here called carriage (44), which with the carriages as carriages on the guide rails can be moved on the guide rails and adjusted to the desired positions for the knives. Knife assembly according to claim 1, characterized in that the number of guide rails is more than two, preferably three. in Knife assembly according to claim 1 or 2, characterized in that the guide rails are arranged in longitudinal first groove (11) in the shaft (10). Knife assembly according to claim 3, characterized in that the carriages (40) extend into the adjacent first grooves (1 1). Knife assembly according to claim 4, characterized in that the carriages (40) are ball-bearing, comprising ball-bearing balls (45) on both sides of the carriages, which balls move in ball-bearing paths in the carriages and roll towards the sides of the guide rails (16) when the carriage ( 44) to be flattened along the axis (10). Knife assembly according to one of Claims 1 to 5, characterized in that the carriages (40) are arranged in carriage holder grooves (35) in the ring (32) whose inside faces the shaft (10). Knife assembly according to any one of claims 1-6, characterized in that the carriages (40) extend with a projecting portion »(42) past at least one side surface, preferably past both side surfaces, on the annular element (3), 32) which is part of the crew. “ Knife assembly according to any one of claims 1-7, characterized in that the carriages (40) in said carriage (44) are mounted in a carriage holder ring (32), on which the annular knife (3) is mounted. 10 15 20 529 907 90097 Knife assembly according to any one of claims 3-8, characterized in that longitudinal second grooves (12) are arranged in the shaft (10) between said first grooves (11) and that expander elements (21, 22) are arranged in said second grooves for ering xering the crew i (44) towards the shaft laterally, when the knives (3) of the crew buma have assumed the desired positions e along the shaft. Knife assembly according to claim 9, characterized in that the carriages extend in radial direction into said first groove (1 1), that the carriages are mounted in carriage holder grooves in the ring (32) whose inside faces the shaft, and that the depth of the first grooves is so adapted to the height of the carriages and the depth of the carriage holder grooves (35) that an annular gap (49) is formed between the shaft (10) and the inside of the ring (32) facing the shaft, which 'slot (49) is so thin that in the second groove (12) arranged jaw jaws (21) can be pressed out by said expander element (22), so that they move over the gap to contact with the inside of said ring facing the shaft. " Knife assembly according to one of Claims 1 to 10, characterized in that the number of grooves "(11A, 11B) in the shaft, each of which has a guide rail (16A, 16B), is greater than the number of carriage holder grooves (35) in each knife (2A, ZB) or ring, and that in each knife or ring carriage grooves (52A, 52B) are arranged in sufficient numbers, each oriented in the middle of a guide rail in the shaft, to be able to accommodate projecting end portions (42) on carriages mounted in adjacent knives or blades, so that the lcnivaxes in the unit can be tightly packed without hindrance by said projecting carriage sections.