US3468203A

US3468203A - Knives

Info

Publication number: US3468203A
Application number: US627978A
Authority: US
Inventors: Edouard Roger Armelin; Arthur Frederick Geor Plaskett
Original assignee: Societe dEtudes de Machines Speciales SA
Current assignee: Societe dEtudes de Machines Speciales SA
Priority date: 1966-04-15
Filing date: 1967-04-03
Publication date: 1969-09-23
Anticipated expiration: 1986-09-23
Also published as: GB1177064A; DE1561733A1; BE696420A

Description

Sept. 23, 1969 ARMELIN ET AL 3,468,203

KNIVES Filed April 3. 1967 2 Sheets-Sheet 1 I NVENTORS W ewall ATTORNEYS Sept. 23, 1969 ARMEUN ET AL 3,468,203

KNIVES Filed April 3. 1967 2 Sheets-Sheet f2 FIG.4.

INVENTORS amb, kimgup 4 1 0) AT TORNEYS United States Patent ice KNIVES Edouard Roger Armelin, London, and Arthur Frederick George Plaslrett, Orpington, England, assignors to Societe dEtudes de Machines Speciales, a French company Filed Apr. 3, 1967, Ser. No. 627,978 Claims priority, applicatligu6 Great Britain, Apr. 15, 1966,

rm. Cl: B26d 4/48 US. Cl. 83-433 Claims ABSTRACT OF THE DISCLOSURE This invention relates to improvement in knives which are primarily intended for cutting flexible web materials such as paper and cardboard.

It is frequently desired to slit a roll of such flexible web material longitudinally to form a plurality of further rolls of reduced widths. In order that this may be done, the web is unwound from an existing roll, slit as desired and rewound on to a new spindle in a series of narrower rolls.

In some instances it is desirable to slit the'web material without applying counter pressure against the slitting knife by the use of a counter knife. In such cases if a clean slit of the material is to be obtained over the whole length of the web material it has been essential to maintain a razor edge on the knife, and while it has been known to use knives which can be removed and sharpened as necessary, it has been found that this is essential more frequently than is desirable, particularly when slitting relatively strong or abrasive materials.

It is therefore an object of this invention to provide a cutting knife which remains effective for much longer usage than hitherto.

In order that this may be done, the slitting knife, which is adapted to bear on the web material during, or prior to, the rewinding operation, is provided with a vibrator. This vibrator may be actuated by for instance an electric pulse generator in order to vibrate the cutting edge of the knife at a sufliciently high frequency to cause the material of the web to disintegrate in the immediate vicinity of contact between the knife cutting edge and the web material, by virtue of one or more factors, alone or in combination; these factors being (a) the contact of the cutting edge with the web material; (b) the impact of the knife caused by the vibrations; (c) the friction caused by the vibrating knife; and (d) the heat generated at the cutting edge by the vibrations.

If desired, the slitting knife may also be provided with an auxiliary heater for raising the temperature of the cutting edge in order to assist in the disintegration or slitting of the web at the point of contact.

According to the invention there is provided apparatus for slitting flexible web material comprising a cutting edge, means for passing a web to be slit past said cutting edge in contact therewith and means for vibrating said cutting edge at a frequency in the sonic or ultrasonic range.

According to a further aspect of the invention there is provided a method of slitting flexible web material comprising progressively unwinding a roll of said material, causing the web material to contact a cutting edge which 3,468,203 Patented Sept. 23, 1969 is vibrating at a frequency in the sonic or ultrasonic range and rewinding said web material into a plurality of separate rolls of narrower width.

Two embodiments of the invention will now be described by way of example only with reference to the drlawvlilngs accompanying the provisional specification in w 1c FIGURE 1 is an end view of one embodiment;

FIGURE 2 is a sectional view on line 2-2 of FIG- URE 1;

FIGURE 3 is an end view of a second embodiment; and

FIGURE 4 is a sectional view on line 4--4 of FIG- URE 3.

Referring initially to FIGURES l and 2, there is shown a supporting framework 20 having a rotatable spindle 2 supporting a roll 1 of web which is to be slit and rewound as two

separate rolls

3, 4 on a further spindle 5 which may be driven by means such as an electric motor (not shown) to rewind the web.

In order to slit the web material 21 a knife 6 having a cutting edge 22 is spring-loaded so as to bear tangentially on the web material 21 and slit it into the two

rolls

3 and 4 as it is rewound under the cutting edge 22 onto the spindle 5. The knife 6 is pivoted at pivot point 7 on the framework 20 and rigidly connected to a loading lever 23 which is attached to an anchored tension spring 8 in order to retain and load the cutting edge 22 in contact with the web 21. If desired any suitable means (not shown) may be incorporated in the anchorage of the spring 8, or otherwise, to adjust the pressure between the knife and the web.

The knife 6 is also provided with a vibrator 9' attached to the knife and actuated by a suitable pulse generator. The pulse generator 24 may be of any convenient form but must be capable of vibrating the knife about its pivot 7 at a frequency in at least the sonic range, although ultrasonic frequencies in excess of 20,000 c.p.s. are preferable. On such suitable form is an electronic multi-vibrator capable of generating square wave electric pulses, which may be set to any desired frequency output. If desired however, a simpler mechanical pulse generator may be used to vibrate the knife.

In operation, the web of flexible material 2 1 is rewound from the roll 1 onto spindle 5, the web 21 passing under the cutting edge 22 to divide the reel 1 into

rolls

3 and 4. In order to slit the web material 21 cleanly and to maintain the cutting edge 22 effectively sharp, the knife is vibrated at a frequency preferably in excess of 20,000 c.p.s. by the vibrator 9, thus causing the web material 21 to part under the action of the factors hereinbefore recited. This vibration extends the life of the cutting edge considerably and renders it more effective even when it would be too blunt to use were no vibrations applied to it. If desired, for certain relatively strong or tough materials, an auxiliary heater (not shown) attached to the knife may be employed to raise the temperature of the cutting edge to aid the slitting operation.

Turning to FIGURES 3 and 4, there is seen a similar arrangement, whereby a framework 20 supports

spindles

11 and 15 from which the roll 10 is to be rewound and divided into rolls 13 and 14 after passing over a support roller 12 under a cutting knife 16 again provided with a vibrator 18 actuated by a pulse generator 24. In this instance, the support roller 12 is provided with an inset groove 25 beneath the knife 16 to allow vibrations of the cutting knife to take place without damaging the cutting edge on the support roller 12 thereof. In this embodiment, furthermore, the cutting knife 16 is firmly clamped by one end 30 on the framework 20 and is constrained to vibrate within a fixed arc dictated by the depth of the groove 25 in the roller 12, bending along its length resiliently, as an alternative to being spring-loaded about a pivot as in the previous arrangement.

In alternative embodiments of the invention a plurality of knives may be used dependent upon the number of final rolls of material that it is desired to obtain.

We claim:

1. Apparatus for slitting flexible web material comprising: a framework, a web supply spindle and a Web take-up spindle rotatably supported by the framework, means for driving the web take-up spindle to unwind the web from the web supply spindle and rewind it into the form of a reel on the web take-up spindle, a knife for slitting the web as it is wound onto the web take-up spindle, said knife being pivotally mounted on said framework and being resiliently biased to bear tangentially on the reel of the web on the take-up spindle, and means for vibrating the knife at a frequency at least in the sonic range.

2. Apparatus as claimed in claim 1, wherein said resilient bias is adjustable.

3. Apparatus for slitting flexible web material comprising: a framework, a web supply spindle and a web take-up spindle rotatably supported by the framework, means for driving the web take-up spindle to unwind the web from the Web supply spindle and rewind it onto the web take-up spindle, a support roller for said web, said support roller being rotatably mounted in said framework in the path followed by the web when being rewound onto the web take-up spindle, a cutting edge for slitting the web, said cutting ede being mounted on the framework and arranged to bear on the web as it passes over the support roller, and means for vibrating the cutting edge at a frequency at least in the sonic range.

4. Apparatus as claimed in claim 3, wherein the sup port roller is provided with a groove inset therein to allow said cutting edge to vibrate without contacting said support roller.

5. Apparatus as claimed in claim 4, wherein the cutting edge is formed on a knife which is clamped at one end on said framework and which bends resiliently when vibrated.

References Cited UNITED STATES PATENTS 2,530,134 11/1950 Taylor et a1. 3,264,923 8/1966 Waitzman 83427 JAMES M. MEISTER, Primary Examiner U.S. Cl. X.R. 83-5 82