US2081363A - Perforator - Google Patents

Description

May 25,1937. I t c. A. MEISEL' PERFOHAT OR Filed Sept. 27, 1933 2 Sheets-Sheet l Izwraioa- May 25, 1937. c. A. MEISEL PERFORATOR Filed Sept. 2'7, 1935 2 Sheets-Sheet 2 m\ mm 9w v 5 mw 0% Patented May 25, 1937 rsr OFFICE PERFORATOR Charles A. Meisel, Milton, Mass, assignor to Meisel Press Manufacturing Company, Boston, Mass, 2, corporationcf Massachusetts Application September 27, 1933, Serial No. 691,189

7 Claims.

5 at intervals a web of paper to make lines of weakness. Examples of its use are found in the manufacture of tickets; sales books, autographic register supplies and the like. The object is to provide a mechanism which will cut cleanly through the fibers of the material Without objectionable burr and in accurate location.

My invention will be well understood by reference to the following description of an embodiment thereof shown by way of example in the accompanying drawings, wherein- Fig. l is a diagrammatic side elevation of portions of a printing press of which the perforating mechanism forms a part;

Fig. 2 is a longitudinal section through the perforating mechanism; and

Fig. 3 is a transverse section.

Referring to Fig. 1 of the drawings, I have there shown diagrammatically portions of a printing press in which the web to passes through a printing couple embodying a plate cylinder 5 and an impression cylinder 1 and thence over guide rolls 9 which hold a portion thereof extended substantially straight for operation of the perforating mechanism proper thereon.

The particular constructional details of the illustrative form of mechanism herein illustrated will be best understood by reference to Figs. 2 and 3. The mechanism is here shown mounted on a unit frame I l which may be supportedat its ends, with provision for adjustmentas herein after appears, on suitable planed surface on the main side frames l3 and i5 of the press. The frame Il may embody the cross-bar ll adapted to extend beneath the web and provided at its upper. surface with a seat it! (see Fig.2) slanting upwardly towards the web and in the direction of its motion and adapted to receivethe knife 2l'which may be adjustably positioned on the seat by means of screws 23 and clamped in adjusted position by bolts 25. V I shall herein refer to the knife in the singular but it will be understood that it may be made of sections, and in certain instances of spaced sections, or may be a single blade extendingentirely across the width of the web. The knife presents a cutting edge 21 over which the web to passes and, as seen in Fig. 2, this edge may be serrated or otherwise formed to present a cutting edge having spaced aligned cutting portions which cooperate with the edge of a cooperating knife to form the desired pattern of perforations.

J ournalled in the frame l l at the opposite side of the web is a rotary cylinder 29, the center line of which is preferably disposed directly above the edge 21 of the lower relatively fixed knife 2| and this cylinder carries one or more cooperating knives 3i, four being herein shown. Herein the cylinder is provided with seats 33 corresponding to chords thereof on which the knives are seated, they being secured in adjusted position by the screws 35 and clamped by the bolts 31. The cylinder 2Q rotates counterclockwise, viewing Fig. 2, and the arrangement is such that the cutting edges of the knives move substantially tangent to the web to at the point where it overlies the edge 2i so that the lower and upper knives cooperate as illustrated at the lower portion of Fig. 2 to perforate the web.

The knives El preferably lie on a shear, as indicated in Fig. 2 by a showing of a portion of the leading side thereof in elevation. This means that the corner of the cutting edge at one end of the cylinder is at a certain radius and at the opposite end of the cylinder is at the same radius 25 but circumferentially displaced. The amount of displacement may be expressed in terms of the length of the body of the cylinder as a shear of a certain fraction of an inch to a foot.

The frame H (see Fig. 3) is secured on the frames is and it by the bolts 39 passing through suitably enlarged openings M which permit the frame as a whole to be swung about axis 43 in the vertical center line of the cylinder and under the center of the face of its driving gear 45 thereby to alter the inclination of the frame and therefore of the knives carried thereby relatively to the web. The range of adjustment in practice is such that such movement is practicable with the spur gear drive illustrated. An adjusting screw t1 permits a lateral adjustment transversely of the web of the frame and the entire perforating unit carried thereby. The purpose of this latter adjustment is to register intermittent perforations in the width of the web or to suit certain pattern perforations required by the particular work on the machine. The purpose of the angular adjustment described may be understood fromthe following considerations.

Since the cylinder 29 rotates in such a direction that the knife when cutting moves in the direction in which the web travels and since the knife has a certain shear, the whole perforator unit is swung at the end opposite to the drive in the direction of the web travel. If the cylinder knife were travelling at the same linear velocity as the web, then the amount of swing would equal the shear in the knife. If the surface speed of the cylinder is greater, as is preferably the case, the whole unit is swung backwards from the above position to permit the lower knife in its operation to make contact with the web at a line at right angles to the edge thereof. For perforations at right angles to the edge of the web a position of the unit directly at right angles to the web would be the limiting position as the speed of the cylinder approached infinity.

The speed of rotation of the cylinder 29 has certain theoretical limits, and the speed, the size of the cylinder and the number of knives utilized may be varied in accordance with desired conditions taking into consideration various factors hereinafter explained. In the simplest case, if the radius of the knife edge were the same as the radius of plate cylinder 5, the surface speed of the knife would be equal to the web speed which would be the lowest speed limit. Let us consider, however, a case where multiple perforations are to be made in one revolution of the plate cylinder, for example, when the plate cylinder in one revolution makes two impressions which it is desired to separate from one another and from adjacent impressions by lines of weakness and when there are two knives on the perforating cylinder. If these knives are arranged a greater circumferential distance apart than the distance between successive perforations along the actual perforated web, then if the cylinder 29 is to rotate in synchrony with the plate cylinder 5, the knives will move at a greater linear speed than the web. For example, if we had a plate cylinder H" in circumference and. desired to make two perforations 8 apart, the perforating cylinder might have two knives 10" apart and the linear speed of the knife would be 3" per revolution greater than the linear speed of the web. The knife in cutting would then actually move relative to the web facilitating the work.

Considering another example, we may suppose with the same size of plate cylinder 2. perforating cylinder with three knives 10" apart, the perforating cylinder making two-thirds of a revolution to one revolution of the plate cylinder. The differential of linear speed would be the same as in the previous case. There is, however, a reason for the choice of three blades since if the work were to be folded in even multiples as, for instance, in the case of certain autographic register supplies, there would be a hunting action between the impressions of the plate cylinder and the perforations of the knives tending to equalize errors in indexing. This is because three, the number of knives, and two, the number of impressions, are relatively prime. Thus, in the example illustrated, four knives are shown and hunting action would take place if the plate cylinder 5 made three or five impressions per revolution. If it made six impressions per revolution, a somewhat similar hunting effect would be obtained for while four and six have the factor two in common, the remaining factors two and three are relatively prime.

To take another illustration, we may consider the case of twenty impressions by a plate cylinder to be separated by perforations and four knives widely spaced on the perforating cylinder. Such an example would occur in the case of ticket printing. There might then be five revolutions of the perforating cylinder to one revolution of the plate cylinder and in a particular instance,

the perforating cylinder being 5 in diameter and the plate cylinder 22 in circumference, the differential of linear speed is 22" for each revolution of the plate cylinder.

For best results the knife should engage the web at a suitable angle. I have herein spoken of the edge of the knife as being tangent to the web and that will be readily understood. However, the web is, of course, of finite thickness and is cut through so that we do not have a case of the upper knife edge passing over it in a direction parallel to its surface as in true geometrical tangency, in which case, of course, the size of the cylinder and the disposition of the knife would be immaterial. I consider best results are obtained by making the seats 33 such that when a knife 3| is in the cutting position shown in Fig. 2, it makes an angle of between 25 and 45 with the web and I consider about 35 as being an optimum value. The lower knife 2i may be similarly inclined.

I am aware that the invention may be embodied inother specific forms without departing from the spirit or essential attributes thereof, and I therefore desire the present embodiment to be considered in all respects as illustrative and not restrictive; reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

I claim:

1. A machine comprising printing means which in a single cycle makes a plurality of substantially duplicate impressions on a, web travelling past the same and. a mechanism comprising a rotary cylinder carrying a plurality of knives at one side of the web and a cooperating knife at the opposite side, the ratio of the number of knives to the number of impressions involving relatively prime factors.

2. A machine comprising printing means which in a single cycle makes a plurality of substantially duplicate impressions on a web travelling past the same and a perforating mechanism comprising a rotary cylinder carrying a plurality of knives at one side of the Web and a cooperating knife at the opposite side and means for rotating said cylinder to move the knife edge at a surface speed exceeding the linear speed of the web, the ratio of the number of knives to the number of impressions involving relatively prime factors.

3. Mechanism for providing spaced lines of perforations in a paper web comprising a fixed knife over which the web passes and a rotary cylinder carrying a knife, one of said knives having a cutting edge comprising spaced, aligned cutting portions which cooperate with the edge of the other knife to form a series of perforations instead of a continuous cut, said rotary cylinder carrying the edge of its knife on a path which is substantially tangent to the web at the points of cutting.

4. Mechanism for providing spaced lines of perforations in a paper web comprising a fixed knife over which the web passes and a rotary cylinder carrying a. knife, one of said knives having a cutting edge comprising spaced, aligned cutting portions which coperate with the edge of the other knife to form a series of perforations instead of a continuous out, said rotary cylinder carrying the edge of its knife on a path which is substantially tangent to the web at the points of cutting and in the direction of movement of the web, means for feeding the web and means for rotating the cylinder to move the knife edge at a greater surface speed than the web.

5. Mechanism for providing spaced lines of perforations in a paper web comprising an adjustably fixed knife inclining toward and in the direction of movement of the web to present a cutting edge to a side thereof, a rotory cylinder carrying a cooperating knife, one of said knives having its cutting edge comprising aligned cutting portions to cooperate with the edge of the other knife to form a series of perforations instead of a continuous out, said cylinder carrying the edge of its knife on a path which is substantially tangent to the web at the points of cutting, said knife at the time of contact similarly inclining toward and in the direction of movement of the web.

6. Mechanism for providing spaced lines of perforations in a paper web comprising a fixed knife presenting a cutting edge to one side of the web, a rotary cylinder at the opposite side of the web having a cooperating knife disposed along a chord thereof, one of said knives having a cutting edge comprising spaced aligned cutting portions which cooperate with the edge of the other knife to form; a series of perforations instead of a continuous cut, said cylinder carrying the edge of its knife through a path substantially tangent to the points of cutting, said chord being disposed to form an angle of between and with the web at the time when the knife edges are in opposition.

7. In a machine wherein a web is advanced at a certain linear speed, the mechanism for providing spaced lines of perforation therein comprising a rotary cylinder at one side of the web, a cooperating knife at the opposite side of the web, the edges of said knives being arranged to make contact and one comprising spaced aligned cutting portions which cooperate with the edge of the other knife to form a series of perforations instead of a cut, and means for rotating the cylinder to move the knife edge at a surface speed exceeding the linear speed of the web.

CHARLES A. MEISEL.

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