US3626798A

US3626798A - Apparatus for slitting lengthwise moving webs

Info

Publication number: US3626798A
Application number: US704307A
Authority: US
Inventors: Hew Mcinnes Grierson
Original assignee: Wiggins Teape Research and Development Ltd
Current assignee: Arjo Wiggins Ltd
Priority date: 1967-02-15
Filing date: 1968-02-09
Publication date: 1971-12-14
Anticipated expiration: 1988-12-14
Also published as: NO125596B; SE345490B; BE710830A; DE1611780A1; GB1156140A; JPS4842112B1; ES350494A1; FR1553539A; NL6801949A; AT288148B

Abstract

Apparatus for removing samples from a lengthwise moving web comprises at least one cutting element supported for movement towards and away from the web and actuating means which are operatively connected with support means for the cutter elements and which first effect entry of the cutting element into the web at a controlled rate and after insertion of the cutting element through the web effect transverse movements of the cutting element so that the web is slit between the longitudinal edges of the web.

Description

United States Patent Inventor Hew Mclnnes Grierson Reaconsiield, England Appl. No. 704,307 Filed Feb. 9, 1968 Patented Dec. 14, 1971 Assignee Wiggins Teape Research & Development Limited London, England Priority Feb. 15, 1967 Great Britain 7,3 10/67 APPARATUS FOR SLITTING LENGTHWISE MOVING WEBS 13 Claims, 11 Drawing Figs.

US. Cl 83/105, 73/421, 83/555, 83/564, 83/565,83/919 Int. Cl B26d 5/02, B26d 5/16 so FieldofSearch .f. 83/433, 105,432,487,919,496;497,498,499,564,428, s55, 5615;73/421; 242/564 [56] References Cited UNITED STATES PATENTS 2,837,155 6/1958 Cundiffet a1. 83/919 X 3,276,303 10/1966 Tompos 83/919 X 3,332,326 7/1967 Haas 83/498 X Primary Examiner-Frank T. Yost Attorney-Imirie and Smiley ABSTRACT: Apparatus for removing samples from a lengthwise moving web comprises at least one cutting element supported for movement towards and away from the web and actuating means which are operatively connected with support means for the cutter elements and which first effect entry of the cutting element into the web at a controlled rate and after insertion of the cutting element through the web effect transverse movements of the cutting element so that the web is slit between the longitudinal edges of the web.

Patented Dec. 14, 1971 1' Sheets-Sheet 1 Patented Dec. 14, 1971 3,626,798

4 Sheets-Sheet 3 Invenlor HEW MC GRIERsoN 111711 1&11111 y-Q: g Allornvy;

Patented Dec. 14, 1971 4' Sheets-Sheet 4 kam N Inventor All Home 1,

0 *A S R\ E mm B m BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to apparatus for removing samples from lengthwise moving webs, for example webs of paper, or of plastics or textile materials.

It is often desirable to remove samples from a web during various stages of manufacture, which samples can be used, for example, to check the web for moisture content, thickness, weight per unit area, gloss, or formation.

2. Description of the Prior Art It has been proposed in U.S. Pat. No. 2,837,l55, L. B. Cundiff et al., granted June 3, 1958 to cut lozenge-shaped samples from an unsupported portion of a lengthwise moving web by the use of a cutter device comprising one or more pairs of cutting elements which are carried by brackets rockable with a shaft mounted in bearings on opposite sides of the web, and a rotatable screw which is carried by arms also rockable with said shaft and which passes through said brackets in a manner such that on rotation thereof the threads of the screw cooperate with at least one bracket of each pair thereof to effect relative lateral movement of the cutting elements of the pair. With this proposal the cutter device is swung bodily about the axis of said shaft into and out of engagement with the web and the cutting elements are located relative to the web to effect slitting of the web by adjustable stops which are carried by said arms and engage the bearings in which the shaft is mounted. It will, therefore, be understood that although the adjustable stops limit the extent of penetration of the cutting elements through the web they do not control the entry of the cutting elements into the web and if this is not effected gently the unsupported web may be damaged and in extreme instances broken.

It has also been proposed in U.S. Pat. No. 3,276,303, Donald J. Tompos, granted Oct. 4, 1966 to cut lozengeshaped samples from a web in roll form. With this proposal the cutting device is so constructed as to rest on the surface of the roll so that the full weight of the cutter device is supported by the roll. This device is accordingly, wholly unsuitable for use with an unsupported web and cannot, therefore, be used at intermediate positions on the machine before the manufacture of the web is complete.

It is an object of the present invention to provide a cutter device for cutting lozenge-shaped samples from an unsupported web and which is at times so supported relative to the web that the entry of the cutting elements is controlled in a manner which ensures that the cutting elements always effect a gentle controlled entry into the web.

A further object is to provide a cutter device capable of cutting from the web a lozenge-shaped device the longitudinal axis of which extends partially across the web between the longitudinal edges of the web.

SUMMARY According to the invention there is provided apparatus for removing a lozenge-shaped sample from an unsupported lengthwise moving web, comprising a cutter device including at least one pair of cutting elements carried by support means for pivotal movement towards and away from the web, and actuating means cooperating with the cutter device and operable to effect pivotal movement of the cutting elements into and out of engagement with the web at a predetermined distance from an edge of the web and movement thereof in a direction transverse to the direction of movement of the web in a manner such that the lozenge-shaped sample is cut in the web, wherein the cutting elements are mounted one each on arms spring-biased towards each other and which are rockable about a pivot by a rotatable driving shaft which carries eccentric portions rotatable in said arms to support the weight of the arms and cutting elements, and cam means which cooperate with follower means carried by the arms to effect movement of the arms and of the cutter element in such direction transverse to the direction of movement of the web.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation of apparatus according to the invention for cutting a lozenge-shaped sample from a web,

FIG. 2 is a top plan, with some parts omitted for clarity, of FIG. 1,

FIG. 3 is a detail looking in the direction of arrow III, FIG.

FIG. 4 illustrates, in elevation, an alternative form of the apparatus,

FIG. 5 is a top plan, with some parts omitted for clarity of FIG. 4,

FIG. 6 is an elevation of a modified form of the apparatus,

FIG. 7 is a top plan of FIG. 6,

FIG. 8 illustrates the development of a cam used in the apparatus of FIGS. 6 and 7,

FIG. 9 is a section on line IX--IX, FIG. 8,

FIG. I0 illustrates the lozenge-shaped sample cut out by apparatus according to the invention,

FIG. 11 is a vector diagram. In the drawings like references indicate like or similar parts.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As will hereinafter appear, the apparatus comprises a cutter device including at least one pair of cutting elements, and actuating means which cooperate with the cutter device and which is operable to effect movement of the cutting element into and out of engagement with a web I at a predetermined distance from an edge of the web and in a direction transverse to the direction of movement of the web in a manner such that a lozenge-shaped sample is cut in the web by the cutting elements.

FIGS. 1 and 2 illustrate apparatus which is arranged to slit the web 1 and cut therefrom a lozenge-shaped sample. The apparatus comprises two cutting elements 2 arranged to be supported in a starting position thereof, shown in full lines in FIG. I, spaced from the web 1 with the tips 3 of the cutting elements engaged one with the other and facing sides thereof, see FIG. 2, divergent in a direction opposed to the direction of movement of the web I to form therebetween angles b, FIG. 2, and 0, FIG. 3. The actuating means, described below, are operable so to control movement of the cutting elements that the elements are moved from the starting position with their tips 3 engaged to pierce the web I, as shown at 4, FIG. I, and are then moved apart to form divergent slits 5, FIG. 10, of desired length, following which the cutting elements are maintained in spaced relation to form parallel slits 6 of desired length in continuation of the divergent slits 5 and are then returned to their tip engaging positions while forming convergent slits 7, in continuation of the parallel slits 6, thus forming a substantially lozenge-shaped sample, and the cutting elements are then restored to the starting position thereof. As shown in FIG. 10 the sample is shown as having the longitudinal axis 8 thereof inclined to the longitudinal edges 9 of the web I but with the apparatus as shown in FIGS. I and 2 the axis 8 is parallel with the longitudinal edges of the web.

In FIGS. 1 and 2 the cutter device comprises a unit in which the cutting elements 2 are mounted one each on a pair of arms 10 which are biased towards each other by spring plates I1 and which are supported for oscillatory movement about the axis of a pivot 12, carried by extensions 13 on a bracket 14, towards and away from the web I. The tips 3 of the cutting elements extend away from the arms I0, as shown in FIG. 1, and, also as shown in FIG. I, the portions which extend away from the arms 10 each have the form of an obtuse-angled triangle the apex of which is directed towards the web.

The actuating means comprises cyclically operable member arranged to oscillate the arms 10 about the axis of pivot I2 and to effect lateral movements of the arms following piercing of the web by the cutting elements. The actuating means comprises a rotatable driving shaft 15 carried by the extensions 13 and eccentric members 16, FIG. 1, which are rotatable by the driving shaft in slots 17 formed in the arms to effect oscillation of the arms 10 about the axis of pivot 12. The driving shaft is rotated by a handle, not shown, which may be coupled to either end of the shaft and cam elements 18 are also rotatable with the eccentric portion of the driving shaft and follower means 19 cooperate with the cam elements 18 to effect lateral movement of the arms 10 against the bias of the spring plate 11. The follower means 19 can be screwed into and out of the arms 10 to permit the tips 3 to be brought together without undue deflection of the cutting elements.

From the foregoing description, it will be understood that the pivot 12 and the driving shaft 15 are located in fixed positions relative to the web so that at all times the weight of the cutter device is taken by the bracket 14 and the entry of the tips 3 into the web is effected in a gentle, controlled, manner by the eccentric member 16 thus avoiding any sudden load on the web which might result in damage to the web.

A diverter element 20 is supported for oscillatory movement about the axis of pivot 12 and has the free end 21 thereof located beyond the cutting elements. Oscillation of the diverter element 20 is effected by the profile 22 of the cam elements 18 the profile 22 engaging the edge portion 23 of the diverter element, see FIG. 1. The diverter element is maintained in engagement with the profile 22 by a spring 24, FIG. 1, anchored to a plate 35 carried by pillars 26 depending from the bracket 14. The profile 22 raises the diverter element 20 relative to the arms 10 immediately before the cutting elements close after forming the slits 7. The diverter element, as can be seen from FIG. 1, at position 27, operates to deflect the cut out sample 28 from the plane of the web.

If the sample is being taken from a web the material of which is of low tensile strength difficulty may be experienced in the transition to the formation of the two separate slits. To accommodate this condition two further followers 29 are provided and are so adjusted as to contact the cam elements 18 in a manner such that they cause the tips 3 to part just before the tips penetrate the web. By this means two parallel slits are formed in the web in precedence to the slits 5 and the diverter element 20 strikes between these parallel slits and breaks the weak material. As the cam elements 18 rotate the control passes to the followers 19 and the operation proceeds as described above.

The cutting elements 2 are connected to the arms 10 by adapter pieces 30, FIG. 2, the shape of which is selected to determine the angles a, FIG. 1; b, FIG. 2; and c, FIG. 3 to suit the kind of material to be slit. As illustrated the angles a, b, and c are suitable for many kinds of wet paper. The angle of the cutter elements to the web is important and for a wet paper web, when the cutting elements are engaged with each other, the angles may be zr=40, b=5, and c*7%. As the cutting elements diverge angle b alters relative to the direction of movement of the web. Given correct design of the apparatus the cutting element disposition may be ideal because the width action is taken from position w as a fulcrum. This is the period when accuracy of operation is necessary to avoid mishap to the main body of the web. The converging action 77 which finishes the slitting cycle is not so critical.

The apparatus as just described may be mounted to follow some measuring instrument, either static or movable, which is used to measure a quality of the web. A sample cutout by the cutting apparatus may then be used to perform some precise laboratory measurement in order to calibrate or check the measuring instrument.

It is sometimes desirable to make checks across the width of the web with little error occurring in respect of time. This is of particular importance where conditions may vary over a short period at one spot on the machine. This is known in the papermaking art as machine direction variation." A number of samples taken simultaneously across the width of the web will permit a graph of cross-width variations to be plotted, sometimes called a cross machine profile. It has hitherto not been possible to obtain a "cross machine profile without substantial machine direction variation" confusing the results but by using apparatus as illustrated in FIGS, 4 and 5 it is now possible.

Referring to FIGS. 4 and 5, at least two units as described above with reference to FIGS. 1 to 3 are mounted each on a bracket 14, FIG. 4. slidable lengthwise of a fixed bar 31 extending transversely across the path of the web 1. The brackets 14 are retained in spaced relation lengthwise of the bar 31 by connecting links 32, FIG. 5, and the driving shafts 15 of the units are coupled for simultaneous rotation by link shafts 33. Operation of the cutting devices may be effected by manual operation of a crank 34 through a shaft 35 rotatable in the frame 36 of the machine and connected with the driving shaft 15 of the unit nearest the longitudinal edge 9 of the web I. The units are readily movable to alternative positions on the machine and manual operation is beneficial in these circumstances. When the units are permanently sited, however, the geometric movement of the cutting elements may be effected by electrical driving means, or by air or hydraulic cylinders. At web speeds up to 1,000 feet per minute manual operation is often suitable but for greater web speeds springs suddenly released may be used if the size of the samples to be taken is not too great.

When a cutting unit is positioned to follow an instrument head the width of which substantially exceeds that of a sample cutoff of the web by the unit the unit may be arranged to traverse the width of the web so that the sample taken may span the width of the web portion which passes under the instrument head, thus integrating the result between the limits of the head. A unit which traverses the web is useful in many instances for thickness measurements, and for visual inspection, but machine direction variation" cannot be entirely eliminated.

A traversing unit is described with reference to FIGS. 6 to 11, in FIGS. 6 and 7 of which the unit is supported for reciprocable movement transversely across the path of the web 1 and transversing means is operable to effect reciprocation of the unit during a web slitting operation whereby the longitudinal axis 8 of the lozenge-shaped sample 28 extends across the web, FIG. 10.

The angle at which the unit is mounted relative to the direction of movement of the web I is selected so that when the vectors of the web and unit traversing velocity are drawn, as shown in FIG. 11, the unit lies at the angle of the vector resultant.

In this embodiment of the invention the unit includes a rotatable primary shaft 37 carried in extensions 38 of the bracket 14. A gear wheel 39 is rotatable with the primary shaft 37 and meshes with a pinion 40 rotatable with the driving shaft 15 which is provided with eccentric members 16, and cam elements 18, not shown, as described above. A stationary cam 41 is mounted on a support plate 42 carried by machine frame parts 43 and a disc 44 rotatable with the primary shaft 37 is provided with at least one retractable radially extending pin 45 which is engageable with the cam 41 during movement of the unit from the starting position thereof, FIG. 7, by the traversing means thereby to effect rotation of the primary shaft 37 and one revolution of the driving shaft 15. As shown in the drawings the disc is provided with three equispaced retractable pins 45 and the ratio of the gear wheel 39 and pinion 40 is equal to the number of the pins 45, in this case the ratio is 3:1. The pins 45 are urged towards by springs 46 and shoulders or collars 47 on the pins limit the extent of outward movement of the pins.

The traversing means may comprise pneumatic or hydraulic cylinders, spring release mechanism, a cable arrangement, or any other suitable means but as shown in the drawings it consists of a nut 48 carried by the unit and threaded on a lead screw 49 rotatable in the frame parts 43 by means, not shown, applied to the end 50, FIG. 7, of the lead screw.

The unit is connected to a bracket 51 for sliding movement along a fixed bar 52 by rotation of the lead screw 49 and is pivoted at 53 to the bracket 51 so as to be angularly adjustable to conform the cutting elements 2 to the vectorial resultant, FIG. 1!, of the unit and web velocity. The bracket 51 is provided with an arcuate slot 54, FIG. 7, and a screw 55 passes through the slot an is arranged to lock the unit in an angularly adjusted position thereof.

The web slitting operation is effected as described above with reference to FIGS. 1 to 4 and occurs only over about l00 to 140 angular rotation of the driving shaft and is carried out during the period of constant traversing velocity of the unit which may travel between a and b, FIG. 7. The cam 41 is provided with an acceleration distance c, d, FIG. 8, and may continue in distance d, e during which the driving shaft 15 is rotated from its rest position to the position where web slitting commences. Distance f,-g is provided to decelerate the unit and rotate the driving shaft to its rest position, and distance, g, It provides any further deceleration which may be necessary.

On completion of the web slitting cycle the lead screw is rotated in reverse direction to return the unit to the starting position. At this time the radial pin 45 succeeding that pin which previously engaged the cam 41 during the forward movement of the unit, enters a ramp position 56 on the cam 4] which retracts the pin against its spring 46 until position d on the cam is reached.

We claim:

1. Apparatus for removing a lozenge-shaped sample from an unsupported lengthwise moving web, comprising a cutter device including at least one pair of cutting elements, carried by support means for pivotal movement towards and away from the web, said support means comprising a pair of arms each mounting one of said cutting elements, means mounting said arms for pivotal movement towards and away from said web and for movement towards and away from each other, and actuating means cooperating with said support means and operable to effect movement of the cutting elements into and out of engagement with the web at a predetermined distance from an edge of the web and movement thereof in a direction transverse to the direction of movement of the web in a manner such that the lozenge-shaped sample is cut in the web, said actuating means including a rotatable driving shaft having eccentric portions rotatable in said arms to support the weight of the arms and cutting elements, and cam means for moving said arms towards and away from each other while the cutting elements are engaged with the web to effect movement of the cutting elements transversely to the direction of movement of the web.

2. Apparatus according to claim 1 including follower means on said arms engaging said cam means, and resilient means normally urging said arms towards each other.

3. Apparatus according to claim 2, wherein the arms are biased to cause engagement of the tips of the cutter elements in the starting and initial paper-piercing positions thereof, the cam means is operable following piercing of the web first to move the cutter elements apart against the bias thereof to form divergent slits of desired length, next to maintain the cutting elements in spaced relation to form parallel slits of desired length in continuation of the divergent slits, and thereafter to return the cutter elements to the tip engaging positions thereof while forming convergent slits in continuation of the parallel slits so that a substantially lozenge-shaped sample is cut from the web, and then to restore the cutter elements to the starting positions thereof.

4. Apparatus according to claim 3, wherein the tips of the cutting elements extend away from the arms towards the web and that portion of each cutting element which extends away from the arm on which the cutting element is mounted has the form of an obtuse-angled triangle the apex of which is directed towards the web.

5. Apparatus according to claim 3, wherein a diverter element is supported for oscillatory movement about the pivotal axis of the cutter device and has the free end thereof located beyond the cutting elements, and the actuating means includes a member arranged to effect oscillation of the diverter element in a manner such that the diverter element engages and removes the lozenge-shaped sample cut out of the web by the cutting elements.

6. Apparatus according to claim 5, wherein the member for oscillating the diverter element comprises a further eccentric member rotatable with the driving shaft, and the diverter element is spring-urged into engagement with said further eccentric member.

7. Apparatus according to claim I, wherein at least two cutter devices are mounted one each on a bracket slidable lengthwise of a fixed bar extending transversely across the path of the web, the brackets are retained in spaced relation lengthwise of the bar by connecting links, and the driving shafts of the cutter devices are coupled for simultaneous rotation by link shafts.

8. Apparatus according to claim 1, wherein the cutter device is supported for reciprocable movement transversely across the path of the web and traversing means is operable to effect reciprocation of the cutter device during a web slitting operation effected thereby whereby the longitudinal axis of the lozenge-shaped sample cut from the web extends partially across the web between the longitudinal edges of the web.

9. Apparatus according to claim 8, wherein the cutter device includes a rotatable primary shaft having a gear wheel rotatable therewith and meshing with a pinion carried by the driving shaft to effect rotation thereof, a stationary cam, and a disc rotatable with the primary shaft and provided with at least one retractable radially extending pin engageable with the stationary cam during movement of the cutter device from the starting position thereof by said traversing means thereby to effect rotation of the primary shaft and one revolution of the driving shaft.

10. Apparatus according to claim 9, wherein the disk is provided with a plurality of retractable pins and the ratio of the gear wheel and pinion is equal to the number of the pins.

11. Apparatus according to claim 9, wherein the cam includes a ramp operable to depress the pin during the return movement of the cutter device.

12. Apparatus according to claim 8, wherein the cutter device is pivotally mounted on a bracket slidable lengthwise of a fixed bar and is angularly adjustable about its pivot to conform the cutting elements to the vectorial resultant of cutter device and web velocity.

13. Apparatus according to claim 8, wherein the traversing means comprises a nut carried by the cutter device and threaded on a rotatable lead screw.

t i t i

Claims

7. Apparatus according to claim 1, wherein at least two cutter devices are mounted one each on a bracket slidable lengthwise of a fixed bar extending transversely across the path of the web, the brackets are retained in spaced relation lengthwise of the bar by connecting links, and the driving shafts of the cutter devices are coupled for simultaneous rotation by link shafts.