GB1573035A

GB1573035A - Slitting device for lengthwise slitting of webs

Info

Publication number: GB1573035A
Application number: GB18244/77A
Authority: GB
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 1976-05-03
Filing date: 1977-05-02
Publication date: 1980-08-13
Also published as: DE2619085A1; DE2619085C3; JPS52134188A; FR2350183B1; FR2350183A1; IT1086587B; DE2619085B2

Description

(54) SLITTING DEVICE FOR LENGTHWISE SLITTING OF WEBS (71) We, BASF AKTIENGESELL SHAFT, a German Joint Stock Company of 6700 Ludwigshafen, Federal Republic of Germany, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention is based on a slitting device for mounting in a slitting apparatus and, for example, constructed on the circular springloaded cutter principle, the slitting device comprising endplates carrying a first cutter shaft and a second cutter shaft, and means for adjusting the relative position of the cutter shafts.

Slitting devices in which the actual cutting tool is formed by circular cutters which are mounted on a first cutter shaft and a second cutter shaft in such a way that they interpenetrate, have been disclosed. In practice, mainly three constructions are used which, apart from the design of the cutters, essentially differ in respect of the mounting of the cutter shafts and the adjustment of these shafts.

In a device which works on the circular spring-loaded cutter principle, a plurality of rings, chamfered on one of their outer edges at an angle of from 2" to 30 to the radius of the shaft, are provided as cutters on a first cutter shaft. An equal number of disks which are blade-shaped at their periphery and of which each is fixed to a collar, are mounted by means of the collars on a second cutter shaft. In the ready-to-use state of the slitting device, the disks of the second cutter shaft penetrate slightly into the gaps between the rings, serving as cutters, on the first cutter shaft, and are pressed, by means of axially acting spring elements, against the chamfered faces of the rings.

In order to adjust these cutter components relative to one another, the second cutter shaft is adjustable in three directions, namely: axially, to press the cutters into contact, with respect to its distance from the first cutter shaft, in order to adjust the degree of interpenetration of the cutters, by means of a worm gear which acts in either direction, and in respect of their inclination, in order to adjust the relative set of the cutter shafts, by means of eccentrically adjustable ball-andsocket bearings provided on both ends of the shaft, in order to ensure reliable contact of the cutting faces of the first and second cutters.

The adjustment of the cutter shafts is made in the slitting apparatus, as is the degree of interpenetration of the cutting edges, so that the slitting apparatus is not available for production whilst these operations are carried out. As a result, the down time of the slitting apparatus is often several hours. It is a further disadvantage that the second cutter shaft is provided, for adjustment purposes, with an eccentrically adjustable ball-andsocket bearing on both ends of the shaft.

With such bearings it is very difficult to adjust the set of the two shafts so that the point of intersection lies in the middle of both cutter shafts. Furthermore, using the slitting device described it is barely possible to fix the second cutter shaft precisely, and with adequate reproducibility, since the axial adjustment and the adjustment of the degree of interpenetration of the cutters is effected by means of one and the same adjustment drive.

As a result of these disadvantageous adjustment mechanics, and because of the poor accessibility of the parts in question, the required precision of adjustment of the cutters can only be attained with difficulty.

A further slitting device constructed on the above principle and operating by a roll-shear cut, consists essentially of two side-pieces which can be removed from the slitter. These side-pieces are kept in a precise position relative to one another by means of tie-bars, and possess cut-outs to act as bearings for the first cutter shaft and second cutter shaft. The first cutter shaft is mounted in the said cut-outs by means of bushes and is clamped by means of blocks. The second cutter shaft is provided, at both ends, with a bearing which is adjustable in respect of the separation of the two cutter shafts, and the second cutter shaft can be moved in the radial direction of the shaft by means of these bearings, using adjustment screws.

Accordingly, only the axial separation of the cutter shafts can be altered in order to adjust the degree of interpenetration of the cutters. Furthermore, no spring elements for the cutters are provided, so that the precision of the cutters and spacer rings has to conform to high standards, and their location on the cutter shafts must be very accurate.

In a device of similar construction, thin disks, again with rectangular cutting edges, are mounted as cutters on the first and second cutter shafts. The cutters act as spring elements. To adjust the force with which the cutters on the first and second cutter shafts are pressed against one another, the cutter shafts are, in this slitting device, also adjustable axially relative to one another. Here again however there is no means of achieving a relative set of the two cutter shafts, so that a uniformly good cutting action over the entire assembly of cutters on the cutter shafts is not guaranteed.

The present invention seeks to provide a slitting device in which the first cutter shaft and second cutter shaft can be adjusted precisely relative to one another, in the axial direction and in respect of their axial separation, preferably whilst they are outside the slitting apparatus, and the relative set of the cutter shafts, can be brought about simply, in such a way that the axes of the cutter shafts cross substantially halfway along the lengths of the shafts. It is a further aim to provide an adjustment device for the exact axial adjustment of one of the two cutter shafts, by means of which data for comparing the slitting results are obtainable.

According to the present invention a slitting device for mounting in a slitting apparatus comprises endplates carrying a first cutter shaft and a second cutter shaft, and means for adjusting the relative position of the cutter shafts, wherein each of the two cutter shafts is mounted, at one end, substantially without axial or radial play, in a normally fixed first bearing, and, at the other end, substantially without radial play, but axially displaceable, in a second bearing, the first bearing of the first cutter shaft being axially displaceable during adjustment procedures and the first and second bearings of the second cutter shaft being displaceable, during adjustment, in the direction of separation of the two cutter shafts and also adjustable to incline the second cutter shaft so as to produce a desired relative set of the two cutter shafts.

According to a further embodiment of the invention, the first cutter shaft is mounted in cut-outs of the endplates, the said one end of the first cutter shaft being supported by a roller bearing in a first bush, the first bush being axially displaceable, during adjustment procedures, in a bearing bush and fixable thereto during normal use, whilst the said other end of the first cutter shaft is supported by a movable bearing in a second bush, the cut-outs being closed by bridges detachably mounted to the endplates, and each of the bridges carrying a lockable pressure screw provided with a block for fixing the position of the bearing bush and of the second bush.

In addition, the second cutter shaft is preferably mounted, at its said one end, in a roller bearing mounted in a third bush, and is mounted, at its said other end, in a movable bearing mounted in a fourth bush, the third and fourth bushes being mounted on replaceable support members, located in cut-outs of the endplates so that the third and fourth bushes are displaceable in the direction of separation of the two cutter shafts and are turnable in order to incline the upper cutter shaft to produce the said desired relative set of the shafts.

In a further development of a slitting device according to the invention, the third and fourth bushes can be fixed in their positions on the support members by means of pressure members which act on surfaces of the third and fourth bushes and which one side and can be actuated by further lockable pressure screws.

In a preferred embodiment of a slitting device according to the invention, the bearing surfaces of the third and fourth bushes and of the support members, are cylindrical and the cylinder axes are at right angles to the axes of the cutter shafts.

Suitably a slitting device according to the invention is also characterized in that the end of a cutter shaft which is to be displaced axially is connected to the axle of an adjustment device which can be actuated by means of a pressure medium, the axle engaging with a measuring device which indicates its displacement travel.

In an advantageous embodiment of the adjustment device, the latter is a pneumatically actuated adjustment cylinder, the axle of which engages, on the one side, in the central bore of the cutter shaft which is to be displaced axially, and on the other side is connected with the measuring probe of a dial gauge for indicating the axial displacement of the cutter shaft.

The construction of the slitting device according to the invention advantageously achieves a situation where the extent of interpenetration of cutters on the first and second cutter shafts, and the inclination of one of the cutter shafts, which effects the set of the shafts, can be adjusted very accurately and reproducibly by precise and advantageously constructed bearings of the cutter shafts. A further advantage is that the axial displacement of one of the cutter shafts can be effected sensitively and accurately, whilst measuring the adjustment force and the displacement travel, so that conclusions can be drawn, from the adjustment data, in respect of the accuracy of the cutter shafts and the condition of the cutters.In addition, mounting the cutter shafts in accordance with the invention prevents them from being forced against one another, and hence damaged, when exposed to an abrupt load resulting, for example, from splices in the web. A further advantage is that as a result of using a sensitively variable gear, the speed of cutters on the first and second cutter shafts can be regulated and matched continuously. Finally, an important factor in the economics of the slitting device is that the down time of the slitting apparatus, when changing cutters, can be reduced to less than one-tenth of the conventionally required down time.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows an overall view of a slitting device according to the invention, Figure 2 shows a side view of the slitting device shown in Figure 1, Figure 3 shows a partly sectioned view of a bearing of a cutter shaft of the device shown in Figures 1 and 2, and Figure 4 shows a view in section of an adjustment member for the axial displacement of a different cutter shaft of the device shown in Figures 1 and 2.

Figure 1 illustrates the overall construction of a slitting device, according to the invention, which can be removed from a slitting apparatus (shown only partially in the drawings) for the purpose of adjusting first and second cutter shafts 2, 3, respectively, and running-in cutters 4, 5 mounted on the shafts 2, 3 respectively. The first cutter shaft 2 and the second cutter shaft 3 are mounted in two endplates 7a and 7b which are held accurately positioned, relative to one another, by tie-bars 6.

The first cutter shaft 2 is mounted in the endplate 7a, without axial or radial play, in a roller or first bearing 8a contained in a bush 8 which, for the purpose of adjusting the first cutter shaft, is axially displaceable in a bearing bush 9. During operation of the slitting device, the bush 8 is fixed to the roller bearing 8a and is fixed to the bearing bush 9 by means of a screw coupling, for example by means of parts which can be screwed onto the bush 8, which is provided with an external thread at both ends, and which clamp against the bearing bush 9. The first cutter shaft 2 is held in the endplate 7b without radial play, but axially displaceable, for example by means of a needle bearing 8b, which is contained in a bush 11.

The bearing bush 9 and the bush 11 rest in cut-outs, open toward the front of the slitting device, of the endplates 7a (Figure 2) and 7b.

A bridge 12 across the open side of each cut-out is fixedly and accurately connected to the respective endplate 7a and 7b by screws and pins. A pressure screw 13 runs in a thread in each of the bridges 12 and a block 14 is fixed to the pressure screw in such a way that by turning the pressure screw 13 the block can be pressed with a recess 15 therein against the respective bush 9 or 11 in order to fix these. The pressure screws 13, and hence the blocks 14, can be secured against unintentional adjustment by means of locking nuts 16.

The mounting of the second cutter shaft 3 also comprises a roller bearing in the endplate 7a and, for example, a needle bearing in the endplate 7b. Both bearings are held in bushes 18 (Figure 3) which are located, by means of a support member 19 and a pressure member 26, one in a cut-out of each endplate 7a, 7b.

Each bush 18 used in the device illustrated is a substantially cuboid body, which is formed from a cylinder flattened on opposite sides, and which is bored through, from one flattened side 20 to the other, to receive the bearing of the second cutter shaft 3. The cylindrical faces 21 of each bush 18 are employed as guide surfaces and bearing surfaces, by means of the lower one of which each bush 18 rests displaceably on the respective support member 19, for the purpose of precisely positioning and fixing the shaft bearing. For this purpose, each support member 19 possesses a cylindrical concave curvature which matches the surface of the bush 18; at the same time, each support member 19 is replaceably mounted in a cut-out of the endplate, in such a way that the cylinder axes of the bushes 18 and of the second cutter shaft 3 are at right angles to one another.As a result, it is possible to displace the second cutter shaft 3 toward and away from the first cutter shaft 2 and, by using support members 19 of different thickness in the two endplates 7a and 7b, to set the shafts relative to one another so that the horizontal central axial planes of the two cutter shafts 2, 3 form an angle which corresponds to the relative set of the cutter shafts 2, 3. This provides a simple method of ensuring, by producing pairs of support members with identical tolerances, that the crossover point of the axes of the two cutter shafts 2, 3 lies midway of the length of the shaft.

To set the separation of the two cutter shafts 2, 3 and hence the degree of interpenetration of the cutters 4, 5, a bolt 22 provided with a fine thread is fixed to the end face of each bush 18 and is movable, by means of a nut 23, along a graduated scale corresponding to the pitch of the thread. The nut 23 is held in a slot 24 of an endplate upper part 25, which is held onto the respective endplate 7a, 7b, preferably by means of screws (Figure 2).

Each bush 18 is fixed by the respective pressure member 26, located above it and matching the upper cylindrical surface of the bush 18, each pressure member being loosely fixed to a pressure screw 27. By turning the pressure screws 27, which run in threads in the endplates, the pressure members 26 can be pressed against the upper cylindrical surfaces of the two bushes 18, and the fixed position of the latter can be secured by a locknut 28 provided for each bush. The cutouts of the endplates 7a, 7b are provided with guide bars 29 for laterally guiding the two pressure members 26 and th two support members 19.

To achieve contact between the cutters 4 and the cutters 5, which cutters 4, 5 are constructed in the manner of a conventional slitting apparatus working on the circular spring-loaded cutter principle described at the outset, the first cutter shaft 2 is adjusted axially in the cut-outs of the endplates 7a and 7b. In order to effect axial adjustment of the cutter shaft 2 it is first necessary to release the bush 8 from the bearing bush 9 by releasing the previously referred to screw means.

The requisite displacement can then be effected by an adjustment device 30 (Figure 4) which can be actuated by means of a pressure medium and which is preferably a pneumatic adjustment cylinder. The casing of the adjustment cylinder 30, which casing consists of three parts 31, 32 and 33 boltedtogether, possesses a turned recess 34 on the end face of the part 31 of the casing, by means of which recess the adjustment cylinder is centered, when screwed onto the outside of the endplate 7b, on the flange of the bush 11 of the first cutter shaft 2. Centering can also be effected by means of at least two dowel bolts. A flexible diaphragm 35 is clamped between the part 31 and the part 32 of the casing, and a further, smaller flexible diaphragm 36 is clamped between the part 32 and the part 33 of the casing.An axle 40 is displaceably mounted in the centre of the casing parts 31, 32, 33 and its pointed end 41 engages, through an aperture in the end wall of the part 31 of the casing, in the central bore of the first cutter shaft 2, for the purpose of axially displacing the said shaft. Near the pointed end 41, this axle 40 is provided with an axial flange 43, which together with a nut 39 screwed onto the other end of the axle 40, clamps a lid 38, possessing the contour of the inner space of the case, and a spacer 37 possessing a T-profile. On the one side, the larger flexible diaphragm 35 is clamped between the lid 38 and the spacer 37, and on to other side the smaller flexible diaphragm 36 is clamped between the nut 39 and the spacer 37. As a result, the axle 40 is essentially guided in the casing parts 31, 32, 33 by means of the flexible diaphragms 35, 36.A coilspring 42 resting against the end wall of the lower part 31 of the casing, is provided on the axle 40; this spring presses against the axial flange 43 and has a return force of from 500 p to 2,000 p, preferably from 600 p to 850 p. The measuring probe 45 of a dial gauge 46 rests on the end face of the end 44 of the axle, which extends through an aperture in the part 33 of the casing. The dial gauge is carried by a holder 47 which is fixed to the end face of the part 33 of the casing. To effect the axial displacement of the first cutter shaft 2, the chamber essentially formed by the two flexible diaphragms 35, 36 in the casing is subjected to, for example, compressed air, the pressure being adjustable by means of a commercial adjustable pressurereduction valve 48 fitted with a manometer.

The axial displacement of the first cutter shaft 2 can then be read off on the dial gauge 46. With no pressure in the adjustment cylinder 30, the coilspring 42 lifts the axle 40 off the first cutter shaft 2 and brings it to its rest position.

The effective adjustment force Fs (in kilopond) of the adjustment cylinder 30 may be calculated, with theaid of the equation Fs(99.78) = [At - A2] . p - FF from the following parameters, the values shown in parentheses relating to one particular example of a slitting device according to the invention: Al = skirt surface of the large flexible diaphragm in cm2 (38.5) A2 = skirt surface of the small flexible diaphragm in cm2 (7.1) p = pressure shown on the manometer, in kp/cm2 (3.2) FF = return force of the coilspring in kp (0.7).

The flexing friction of the flexible diaphragm should be negligibly small.

As a result of being able to read the pressure and the travel, data are available, when adjusting the cutter shafts 2, 3, which can be compared with the results of the slitting operation, so that, for example, the adjustment of the cutter shaft can be optimized by a statistical evaluation. Furthermore, the pressure-dependent displacement travel of the first cutter shaft 2 provides information on the precision of the spacing dimensions of the cutters 4, 5 and on the condition of the cutters, since the force required for a particular displacement travel depends on the number of cutters on the first and second cutter shafts which simultaneously come into contact.

The drive of the first cutter shaft 2 is provided in the conventional manner by an electric motor whilst the second cutter shaft 3 in the device illustrated is driven via a commercial sensitively variable gear - for example in a transmission ratio of 1:1.4 - by the first cutter shaft 2. This sensitively variable gear permits accurate matching of the cutter speeds, which is of particular importance if the diameter of the cutters 5 has altered as a result of regrinding the cutters. This advantageous embodiment of the cutter shaft drive also has an advantageous effect on the slitting quality and on the life of the cutters.

WHAT WE CLAIM IS: 1. A slitting device for mounting in a slitting apparatus and comprising endplates carrying first cutter shaft and a second cutter shaft, and means for adjusting the relative position of the cutter shafts wherein each of the two cutter shafts is mounted, at one end, substantially without axial or radial play, in a normally fixed first bearing, and, at the other end, substantially without radial play, but axially displaceable, in a second bearing, the first bearing of the first cutter shaft being axially displaceable during adjustment procedures and the first and second bearings of the second cutter shaft being displaceable, during adjustment, in the direction of separation of the two cutter shafts and also adjustable to incline the second cutter shaft so as to produce a desired relative set of the two cutter shafts.

2. A slitting device as claimed in Claim 1, wherein first cutter shaft is mounted in cutouts of the endplates, the said one end of the first cutter shaft being supported by a roller bearing in a first bush, the first bush being axially displaceable, during adjustment procedures, in a bearing bush and fixable thereto during normal use, whilst the said other end of the first cutter shaft is supported by a movable bearing in a second bush, the cutouts being closed by bridges detachably mounted to the endplates, and each of the bridges carrying a lockable pressure screw provided with a block for fixing the position of the bearing bush and of the second bush.

3. A slitting device as claimed in Claim 1 or Claim 2, wherein the second cutter shaft is mounted, at its said one end, in a roller bearing mounted in a third bush, and is mounted, at its said other end, in a movable bearing mounted in a fourth bush, the third and fourth bushes being mounted on replaceable support members located in cut-outs of the endplates so that the third and fourth bushes are displaceable in the direction of separation of the two cutter shafts and are turnable in order to incline the lower cutter shaft to produce the said desired relative set of the shafts.

4. A slitting device as claimed in Claim 3, wherein pressure members acting on the surfaces of the third and fourth bushes are provided for fixing the third and fourth bushes in their positions on the support members, each of the pressure members being actuatable by a further lockable pressure screw.

5. A slitting device as claimed in Claim 4, wherein the bearing surfaces of the third and fourth bushes and of the support members are cylindrical and the cylinder axes are at right angles to the axes of the cutter shafts.

6. A slitting device as claimed in any preceding claim wherein the end of a cutter shaft which is to be displaced axially is connected to the axle of an adjustment device which can be actuated by means of a pressure medium, the axle engaging with a measuring device which indicates its displacement travel.

7. A slitting device as claimed in Claim 6, wherein the adjustment device is a pneumatically actuated adjustment cylinder, the axle of which engages, on the one side, in the central bore of the cutter shaft which is to be displaced axially, and on the other side is connected with the measuring probe of a dial gauge for indicating the axial displacement of the cutter shaft.

8. A slitting device substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. cutters, since the force required for a particular displacement travel depends on the number of cutters on the first and second cutter shafts which simultaneously come into contact. The drive of the first cutter shaft 2 is provided in the conventional manner by an electric motor whilst the second cutter shaft 3 in the device illustrated is driven via a commercial sensitively variable gear - for example in a transmission ratio of 1:1.4 - by the first cutter shaft 2. This sensitively variable gear permits accurate matching of the cutter speeds, which is of particular importance if the diameter of the cutters 5 has altered as a result of regrinding the cutters. This advantageous embodiment of the cutter shaft drive also has an advantageous effect on the slitting quality and on the life of the cutters. WHAT WE CLAIM IS:

1. A slitting device for mounting in a slitting apparatus and comprising endplates carrying first cutter shaft and a second cutter shaft, and means for adjusting the relative position of the cutter shafts wherein each of the two cutter shafts is mounted, at one end, substantially without axial or radial play, in a normally fixed first bearing, and, at the other end, substantially without radial play, but axially displaceable, in a second bearing, the first bearing of the first cutter shaft being axially displaceable during adjustment procedures and the first and second bearings of the second cutter shaft being displaceable, during adjustment, in the direction of separation of the two cutter shafts and also adjustable to incline the second cutter shaft so as to produce a desired relative set of the two cutter shafts.