US3898900A

US3898900A - Web cutting device

Info

Publication number: US3898900A
Application number: US410156A
Authority: US
Inventors: Alfred Schmermund
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-10-31
Filing date: 1973-10-26
Publication date: 1975-08-12
Anticipated expiration: 1992-08-12
Also published as: DD108923A5; DE2351645A1; JPS5628830B2; JPS4977280A; DE2351645C2; GB1440925A; BE806331A; FR2204538A1; FR2204538B1

Abstract

A cutter device for cutting continuous webs into lengths is disclosed. Two webs are guided along respective web feed paths which are mutually convergent and have a portion in common with one another. Each web feed path is provided with respective web feeder means and the web feeder means are actuatable alternately. First and second cutter means are disposed in the respective feed paths. Further cutter means is disposed in the web feed path portion common to the respective web feed paths and downstream of the respective first and second cutter means. Each of the first and second cutter means comprises a first member rotatably displaceable relatively to a second member to bring mutually cooperable knife elements of the first and second members into cooperative action. Preferably, each of the first and second cutter means is so mounted that at least one of the first and second members of each of the respective first and second cutter means is displaceable from an inoperative position to an operative position, in which the rotatable displacement causes the cooperative action between the knife elements.

Description

United States Patent Schmermund Aug. 12, 1975 WEB CUTTING DEVICE [76] Inventor: Alfred Schmermund, 62 [57] ABSTRACT ggigg 5820 Gevelsberg A cutter device for cutting continuous webs into y lengths is disclosed. Two webs are guided along re- [22] Filed: Oct. 26, 1973 spective web feed paths which are mutually convergent and have a portion in common with one another. [2]] Appl 4l0l56 Each web feed path is provided with respective web feeder means and the web feeder means are actuat- [30] Foreign Application Priority Data able alternately. First and second cutter means are dis- Oct. 31, 1972 United Kingdom 50094 72 Posed in the respective feed P Further Cutter means is disposed in the web feed path portion com- 1521 US. Cl. 83/152; 83/303; 83/334; men to the respective Web feed Paths and downstream 3 349 of the respective first and second cutter means. Each 511 1m. 01 B26d 7/06; 826d l/56 ef the first and Seeend eutter means Comprises a first 58 Field of Search 83/285, 303, 334, 349, member retatably displaeeable relatively to a Seeend 3 5 5 5 50 member to bring mutually co-operable knife elements of the first and second members into co-operative ac- [56] References Cited tion. Preferably, each of the first and second cutter UNITED STATES PATENTS means is so mounted that at least one of the first and 7 3 ,1 w o h 3/ X second members of each of the respective first and H973 :2; 83/587 second cutter means is displaceable from an inopera- 317311281 11 1973 win? 4.11111...........IIIII"3/650 x five position to an operative position which the Primary Examiner-Willie G. Abercrombie Attorney, Agent, or Firm-Sughrue, Rothwell, Mion, Zinn & Macpeak 1 ,K \1 y,/// 2 j: 3 A 5 tatable displacement causes the co-operative action between the knife elements.

. ,WEB CUTTING DEVICE This invention relates to a web cutting device.

Various kinds of cutting devices are employed in machines for supplying webs in which goods are to be wrapped, such devices frequently being employed in machines for wrapping either groups of cigarettes directly in paper or viscose or cellulose film, or for wrapping a packet of cigarettes, i.e. a group of cigarettes in a relatively firm package, in viscose or cellulose film.

In my prior United Kingdom patent specification 1 215 047, there is disclosed a cutting device for cutting a web and employing a linearly reciprocating knife for carrying out the actual cutting operation.

In long production runs, it is of course necessary to switch over the web supply from one source to another, when the first source expires or is about to expire. For example, where reels are employed as storage means from which a web is to be fed to the cutting device, then normally two reels are in position at any given time, although only one reel at a time is used. When the first reel expires, it is necessary to switch over to the second reel. The process of switching over may give rise to difficulties where the particular cutter employed is of the rotating kind, since if such a cutter is employed to cut a web the movement of which is then stopped while the oblique edge cut by the rotary cutter remains in the vicinity of the cutter, then the clean cut at the oblique edge of the web may be snipped and spoiled upon further revolutions of the cutter.

SUMMARY OF THE INVENTION According to the present invention there is provided a cutter device for cutting continuous webs into lengths comprising first guide means to define a first web feed path, second guide means to define a second web feed path, first web feeder means selectably operable to feed a first web along the first feed path, second web feeder means selectably operable to feed a second web along the second feed path, switch means to cause actuation of a selected one of the first and second feeder means and to cause de-actuation of the respective other one of said feeder means, first cutter means disposed in the first path, second cutter means disposed in the second path, and further cutter means disposed in a web path portion common to the first and second paths and downstream of the respective first and second cutter means, the first and second cutter means each comprising a first member rotatably displaceable relatively to a second member to bring mutually co-operable knife elements of the first and second members into cooperative action.

In principle, any kind of web may be cut by the cut ting device, paper and viscose or cellulose film for the wrapping of cigarettes merely being examples of such a kind of web.

Elongate guides may be provided to either side of each of the feed paths, to guide the travelling web in each case from rollers provided to draw the web from a supply reel to the associated auxiliary cutter.

If desired, a pair of suction roller devices, as described in my copending UK. patent application no. 50095/72 may be provided at the junction of the two feed paths upstream of the main cutter, the two roller devices defining a nip therebetween through which each web passes while being held in position by suction each roller device and a respective guide roller spaced from the roller device.

BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of this invention will now be more particularly described with reference to the accompanying drawing, in which the sole FIGURE shows a cross-section in a vertical plane through the embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Two

webs

29 and 30 are shown, which travel obliquely downwardly along mutually convergent first and second feed paths respectively, the two feed paths thereby giving the general appearance of a letter V, with a downward extension between two

suction roller devices

18 and 118. Of course, at any given time only one of the

webs

29 and 30 is fed through the cutting device, drawn by

feed rollers

1, 2 or 101, 102 respectively from respective storage bobbins or reels (not shown). It will be seen that from the two

suction roller devices

18 and 118 upwards, the cutting device is entirely symmetrical, each component of the left-hand side of the cutting device corresponding to a component symmetrically positioned on the right-hand side. Each component of the right-hand side has a similar reference numeral to its corresponding component on the left-hand side, but with added.

Overlapping the

rollers

1 and 2 and extending obliquely downwardly and to the right therefrom are guide strips 3, between which the web 29 passes towards'a first auxiliary cutter which comprises a first member 10 rigidly carrying a knife element 6 and rotatable relatively to a second member 5 carrying a stationary knife element 4, the

knife elements

6 and 4 being provided with respective mutually co-operable elongate cutting edges extending transversely of the direction of movement of the web 29. The first rotatable member 10 is rotatably mounted in bearing means rigidly carried by a bracket 34 connected to an elongate mounting member 12. The mounting member 12 is pivotally connected to a rigid support, shown only schematically, at a pivotal mounting 35. A pull rod 36 is provided to enable the member 12 to be pivoted relatively to the support about the mounting 35. Through the member 12 extends an elongate linear toothed rack member 8, the teeth being provided on the right-hand side as shown in the drawing. The teeth engage mutually co-operable teeth provided around the periphery of the first rotatable member described above, or a gear member connected thereto. An aperture 15 is provided at the lower end portion of the rack member 8, to facilitate the connection, by means of a connecting linkage, of the rack member ;8 to a magnetic actuating device to reciprocate the rack member 8 up and down relatively to the member 12 at desired times. One or more sheet metal parts 9 are provided between the

webs

29 and 30 in their approach towards the

suction roller devices

18 and 118, to provide a boundary wall for the respective feed paths. Conveyor belts l6 and 116 pass around the

roller devices

18 and 118 respectively, and also around respective guide rollers 11 and 111. The

conveyor belts

16 and 116 are permeable to air, and a plurality of apertures are provided in a rotatable outer part 17 only of the

devices

18 and 118. The purpose of the apertures is to communicate the conveyor belt with a suction chamber 14 inside the device 18, this chamber being in communication with a suction chamber 13 along which a straight portion of the conveyor belt 16 passes. Thus suction may be applied to the inner surface of part of the conveyor belt 16, to hold the travelling web 29 against the outer surface of the conveyor belt 16. Similar considerations apply to the conveyor belt 116.

The two

conveyor belts

16 and 116 form between them a nip through which the travelling

web

29 or 30 as the case may be travels prior to passing between a pair of guide strips or transfer bridge members 19.

Below the guide strips 19, there is situated the main cutter, through which the

web

29 or 30 as the case may be passes to be cut into the desired lengths. The main cutter is employed to carry out the cutting except when a change of reel is desired. The main cutter is a rotary cutter, and has a stationary cutter member 32 and a rotatable cutter member 22, cutting

elements

21 and 31 being rigidly carried by the

members

22 and 32 respectively. A further conveyor belts arrangement is provided below the main cutter, the belt itself passing around the guide roller 24. A suction chamber 26 is provided to create a suction effect through apertures 27 of the chamber wall, the conveyor belt passing over the left-hand ends ofthese apertures as shown in the drawing. Again, the conveyor belt is permeable to air. The belt itself is shown at 25. The reels or bobbins (not shown) which hold a supply of the web to be cut may conveniently be of mutually similar kind.

The distance, measured along the path of the web, between the cutting point A of the first auxiliary cutter and the cutting point C of the main cutter, which is equal to the distance, similarly measured, between the cutting point B of the second auxiliary cutter and the cutting point C of the main cutter, is designed to be almost equal to the desired length of cut web, but very slightly shorter. For example, a convenient amount by which this length is shorter is l to 2 millimetres. The reason for this is to ensure that when either of the auxiliary cutters is actuated and the associated feed rollers l, 2 or 101, 102 are then stopped, the main cutter will not act on the end of a length of web cut by the auxiliary cutter. This is to avoid snipping the cut web by the main cutter and thus spoiling of the clean cut edge.

During normal operation of the cutting device, i.e. when it is not desired to effect a change of supply reel, each of the auxiliary cutters is at rest in a position in which the knife element 6 for example is displaced by about 5 anti-clockwise from its position shown in the drawing. The corresponding displacement for the knife element 106 is about 5 clockwise from its position shown in the drawing. The directions of rotation during the cutting action of the auxiliary cutters are shown by arrows.

The operation of the embodiment described above will now be set forth.

Let it initially be assumed'that the cutting device is in normal operation, the web 29 being fed by the

rollers

1 and 2 to the

auxiliary cutter

4, 6 and the

main cutter

21, 31. At this stage the auxiliary cutter is idle, since the cutting of the web into lengths is executed by the main cutter. The web 30 is at this time stationary, since it is not at present being used. It is, however, positioned in readiness for supply to the main cutter at any desired time, and in particular when the web 29 is about to expire.

The switching over from the web 29 to the web 30 being fed through the cutting device may take place either fully automatically, in which case sensing means, for example a minimum diameter sensor, are provided to sense that the web 29 is about to expire and then to start the operations necessary for the changeover, or, if desired, all these operations may be hand controlled, for example by press button switches. In either event, the procedure for switching from the web 29 to the web 30 consists of the actuation of the auxiliary cutter provided for the web 29, the deactuation of the

rollers

1 and 2 and the starting-up of the

rollers

101 and 102. It must of course be ensured that the necessary suction air supply is operative at all times when the cutting device is working.

When it is noticed, either by an operator or by automatic sensing means provided to monitor the amount of web left on the supply reel from which the web 29 is fed, that the web 29 is about to expire, or at any other time when for any reason it is desired to switch over to the web 30, the electro-magnetic arrangement connected to the aperture 15 of the rack member 8 is actuated, to raise the rack member 8 and thereby to rotate the knife member 6 in a clockwise direction in the drawing. Thereby, the auxiliary cutter shown on the left-hand side in the drawing makes an incision through the web 29. The drive to the rollers l and 2 is now stopped, either independently or by the operation of the electro-magnetic arrangement. Another electromagnetic arrangement now raises the rod 36 so that the first member 10 of the auxiliary cutter, the bearing means rotatably supporting the first member 10, the rack member 8 and the mounting member 12 are pivoted relatively to the support about the pivotal mounting 35. This brings the rotatable member 10 of the auxiliary cutter out of range of the stationary member 5, thereby avoiding the possibility of snipping the web by the auxiliary cutter. It is only necessary to pivot the member 12 about the mounting 35 through a very small distance, for example so as to bring the rotatable knife element of the auxiliary cutter to about 1 millimetre away from the stationary knife element. In an alternative arrangement, the second member 5 is displaced relative to the mounting means supporting the rotatable member 10, so as to bring the knife element 4 of the second member 5 out of range of the knife element 6 carried on the rotatable member 10. After this relative displacement between the

members

10 and 5, the electro-magnetic arrangement connected to the rack member 8 is actuated in the opposite direction, to lower the rack member 8 relatively to the member 12 and thereby to rotatably displace the knife element 6 in the anti-clockwise direction, to return it to its original orientation relative to the member 12. The electromagnetic arrangement connected to the rod 36 is now actuated in the reverse direction, to return the entire movable assembly of the auxiliary cutter to its original position. If desired, this last step may be delayed until a further similar reel change is necessary. As mentioned above, the length of web fed to the main cutter after the auxiliary cutter has made its incision is about l or 2 millimetres shorter than the normal cutting length of the web, so that by the time when the rotatable knife element 21 of the main cutter has again reached its cutting position relative to the stationary knife element 31, the tail end of the length cut by the auxiliary cutter will have passed the stationary knife element 31, so that the main cutter will have no cutting effect on this'length of web. The main cutter isthus prevented from snipping the edge cut by the auxiliary cutter. After passing the main cutter, the cut length of web is passed to a packaging machine, which may for example be of the kind disclosed in my c o-pending U.K. patent application No. 48186/72. At the time when the

rollers

1 and 2 are disconnected from their drive, the

rollers

101 and 102 are started up, a full supply reel having been previously positioned to supply the web 30 to the

rollers

101 and 102. The cutting device now continues to operate on the web 30 instead of the web 29, thus giving an operator an opportunity to remove the left-hand reel and to fit a full reel in its place. At the time when the

rollers

101 and 102 are started up, the second

auxiliary cutter

104, 106 is, of course, in its open position, i.e. the position displaced by 5 from that shown in the drawing, as described above.

Throughout the operation of the cutting device, the rotatable member carrying the knife element 21 continues to rotate in the same sense, and for example at uniform speed, it not being necessary to stop the operation of the main cutter when a reel is changed, since it is prevented from snipping the cut web, in the manner described above.

The described embodiment is particularly suitable for use with printed webs intended to form an outer one of two wrappers surrounding a package of cigarettes, for example of the American type.

It is not essential to construct the two auxiliary cutters in the manner described above. For example, instead of a reciprocating rack member driving an oscillating knife element, a rotatable knife element actuated to rotate only in a single sense may be provided, and a single revolution drive arrangement provided to drive the rotatable knife element. A convenient arrangement based on this principle is one in which when the rotatable knife element is at rest it adopts the above mentioned open position displaced by 5 from the position of the rotatable knife element shown in the drawing, and when the single revolution drive arrangement is actuated the rotatable knife element executes one rotation only, amounting to precisely 360, so that its stationary position after the rotation is identical to that before the rotation. In this case, it is not necessary to provide an arrangement for pivoting the rotatable knife element away to a distance (for example 1 millimetre in the previously described case) from the stationary knife element, since there is no return movement of the rotatable knife element which might lead to snipping of the web passing between it and the stationary knife element. However, an equivalent pivoting arrangement may of course, if desired, be provided.

In either of the above described constructions, the position of the leading edge of the web 30 at the time when the

rollers

101 and 102 are started up, and the time of starting up itself, may be so chosen that a gap is left between the trailing edge of the last web length cut (by the auxiliary cutter 4, 6) from the web 29 and the leading edge of the new web 30. The first revolution of the main cutter after the operation of the auxiliary 6

cutter

4, 6 then causes the rotatable knife element 21 of the main cutter to pass the stationary element 31 as this gap passes the main cutter. With this arrangement, snipping of the leading edge of the new web 30 by the main cutter is avoided. A convenient way of bringing this about is to start up the

rollers

101 and 102 after a short delay from the disconnection of the drive to the,

rollers

1 and 2, the leading edge of the new web 30 of course being appropriately positioned. I

The procedure to be followed in switching from a web 30 to a web 29 is identical, each component on the right-hand side of the cutting device simply taking the place of its corresponding component of the left-hand side in the sequence of operations described above.

I claim: i

1. A web feeding and cutting device comprising, in combination:

first guide means to define a first web feed path;

second guide means todefine a second web feed path having a portion thereof in common with said first path;

first web feeder means selectably operable to feed a first web along said first path;

second web feeder means selectably operable to feed a second web along said second path, said first and said second feeder means being actuatable alternately one with another;

main rotary cutter means disposed in said common feed path portion to sever blanks of predetermined length from a web fed along the respective one of said feed paths;

first auxiliary cutter means disposed in said first feed path;

second auxiliary cutter means disposed in said second feed path, said first and said second auxiliary cutter means each comprising a first member angularly displaceable relative to a second member to bring mutually co-operable knife elements of said first and second members into co-operative action, said first and said second auxiliary cutter means each being located at equal distances upstream of the main cutter means along the respective feed paths and each of said auxiliary cutter means being spaced apart from said main cutter means along the respective one of said feed paths by a distance less than said predetermined length, whereby on the web fed along one of said feed paths being severed by operation of the respective one of said auxiliary cutter means, the resulting cut blank is fed along said common portion without the trailing end portion of said blank being engaged by said main cutter means.

2. A device as defined in claim 1, comprising respective mounting means so mounting each of said first and said second auxiliary cutter means that at least one of said first and said second members of each of the respective said first and said second auxiliary cutter means is displaceable from an inoperative position to an operative position in which said rotatable displace ment causes said co-operative action between said knife elements.

3. A device as defined in claim 2, wherein said first member of each of said first and said second auxiliary cutter means is rotatably mounted in respective bearing means, each of said bearing means being pivotably displaceable relative to a fixed support by respective displacement means to displace the respective said first members between their inoperative and operative positions.

4. A device as defined in claim 1, wherein the respective said first members of each of said first and said second auxiliary cutter means are each coupled to respective drive means, the respective drive means each being adapted to rotate the respective said first members on each actuation of the respective said drive means.

5. A device as defined in claim 1, wherein the respective said first members of said first and said second auxiliary cutter means are each provided with gear teeth engaging co-operative gear teeth provided on a respective reciprocably displaceable elongate linear rack member, each said rack member being slidably displaceable to impart said angular displacement to the respective said first member.

6. A device as defined in claim 1, wherein each of said first and said second guide means comprises two elongate guide members extending on respectively opposite sides of the respective said web feed paths upstream of said first and said second auxiliary cutter means.

7. A device as defined in claim 1, comprising two roller devices disposed to define a nip therebetween through which each said web passes whilst being held in position against a respective one of said roller devices by suction applied to respective said webs via a plurality of orifices provided in the periphery of the respective said roller device.

Claims

1. A web feeding and cutting device comprising, in combination: first guide means to define a first web feed path; second guide means to define a second web feed path having a portion thereof in common with said first path; first web feeder meanS selectably operable to feed a first web along said first path; second web feeder means selectably operable to feed a second web along said second path, said first and said second feeder means being actuatable alternately one with another; main rotary cutter means disposed in said common feed path portion to sever blanks of predetermined length from a web fed along the respective one of said feed paths; first auxiliary cutter means disposed in said first feed path; second auxiliary cutter means disposed in said second feed path, said first and said second auxiliary cutter means each comprising a first member angularly displaceable relative to a second member to bring mutually co-operable knife elements of said first and second members into co-operative action, said first and said second auxiliary cutter means each being located at equal distances upstream of the main cutter means along the respective feed paths and each of said auxiliary cutter means being spaced apart from said main cutter means along the respective one of said feed paths by a distance less than said predetermined length, whereby on the web fed along one of said feed paths being severed by operation of the respective one of said auxiliary cutter means, the resulting cut blank is fed along said common portion without the trailing end portion of said blank being engaged by said main cutter means.

2. A device as defined in claim 1, comprising respective mounting means so mounting each of said first and said second auxiliary cutter means that at least one of said first and said second members of each of the respective said first and said second auxiliary cutter means is displaceable from an inoperative position to an operative position in which said rotatable displacement causes said co-operative action between said knife elements.