US2447991A

US2447991A - Resilient bearer for offset presses

Info

Publication number: US2447991A
Application number: US676516A
Authority: US
Inventors: Laszle M Stempel
Original assignee: R Hoe and Co Inc
Current assignee: R Hoe and Co Inc
Priority date: 1946-06-13
Filing date: 1946-06-13
Publication date: 1948-08-24
Anticipated expiration: 1965-08-24

Description

Aug. 24, 1948.

.Laszlu M Stamps] INVENTOR enema Au :4, 194a ww aasmsnr Banana son orrsa'r. masses Lauio u. Stempel, New York. n.1,

mesne assignmentuto R. York, N. Y., a corporation alllgnor, by Hoe k 00., Inc.,-New

of New York Application June 18, 1946, Serial No. 876,518

This invention relates to printing machinesand, more particularly to means for eliminating vibra' tion of the printing cylinders thereof.

In lithographic offset printing machines the blanket cylinder is covered with a transfer surface or blanket, of rubber or simllar'material, attached to the surface of the cylinder. A gap is left in in Figure 1 is illustrated a (Cl. 101-211) Referring more particularly to the drawings,

a blanket roller or cylinder i, comprising" a main body 2 and having bearer ring 1' formed the surface of the'cylinder at the 'pointsof attachment. During operation of the press, when this 1 gap is opposite the periphery of theopposing impression cylinder, the difference in pressure created causes vibration of the. press. Similar eifects may occur in other types of presses and cause vibration due to interruption of the surface of a plate or form-cylinder and the consequent variation in pressure between such form cylinder and the impression cylinder.

The general object of thisjinventionistoprovide means for equalizing the pressure during the revolution of the cylindera'thus smoothing out the operation of the press andpreventing wear and stress caused thereby.

This result is preferably accomplished by the provision of spring-loaded plunge'rs set into the impression cylinder at the point or points where the gaps in the surface ,ofthe blanket'cylinder are opposed totheperiphery of the-impression cylinder, and providing hardened metal rings or bearer surfaces on the ends of the blanket cylinder to be engaged by these plungers. The pressure created by the plungers, bearing against the bearer ring surface of the blanket or printing cylinder at the instant when thegapin the surface of the blanket or printing cylinder opposes the periphery of the impression cylinder, is made substantially equal to the normal pressure onthe sheet or web being printed, and hence there is no reduction in the pressure between the two cylinders while the gap is passing.

It is also an object of this invention to provide .gap 5 in the surface of the blanket or printing at each end thereof, of hardened metal or other suitable material. The

,main body of the-cylinder is covered with a blanket 4, rubber or any other suitable material, which is-wrapped around the surface of the cylinder body I and fastened thereto in a channel! formed in the cylinder body, in any suitable manner. The blanket or printing cylinder lis supported'on an axle or shaft 6 for rotation therewith. Since the ends of each of the cylinders are the same, only one end is shown in the drawing, and the other machine parts are omitted.

"As will be understood by those skilled in the art, suitable inking and plate cylinders cooperating with the blanket cylinder will be provided.

Cooperating with the above described blanket or printing cylinder l is an impression cylinder l0 having a main body ii and a surface I! formed at each end thereof. The impression cylinder is supported by a shaft i8, which shaft, as well as the shaft 8, is supported in the frame of the press in any suitable manner, not shown.

--To elimii late the vibration resulting when the cylinder i reaches the impressionpoint, or in other words, is adjacent the periphery of the a. mechanism for accomplishing the abovedescribed purposes which is simple-in construction and operation and also inexpensive.

with these and other objects in view, as may I appear from the accompanying specification, the invention consists in the various features of conll, through which pins struction and combinations of parts which-will-be" first described in connection with the accompany.-

ing drawings, showing a. resilient-bearer for print ing presses embodying the invention in a pre- 1 are embedded in or otherwise rigidly afllxed to' ferred form, and the features forming the invention will be specifically pointed out in the claims.

In the drawings: p Figure 1 is a side elevation ofone endofa printing couple embodying the presentiinven tion;

Figure couple shown in Figure 1; and

Figure 3 is a section on the line ofil ikure 1.

2 is an end elevation of the printing passage or bore ends slightly beyond I plungers impression cylinder Iii, spring-loaded plungers' are inserted into thesurface i2 of the impression cylinder ll, extending outwardly therefrom and contacting the surface of the bearer ring or sur- 'face I of the blanket cylinder during rotation of the cylinders. The plungers l3 are so located in the surface I! as to contact 3'. at the same time as the gap 5 is adjacent the surface of the cylinder ill, creating pressure between the two cylinders to offset the lack of pressure incident to the passing of the gap in the surface of the blanket cylinder.

The plungers i3. are located in bores it formed in the cylinder It, with their outer ends protrudin'g beyond the peripheral surface thereof. Openings it are formed in' the bodies of the plungers i5 extend. The pins ii are of smaller diameter than the openings I6 and the body of the cylinder ill. The difference in diameter between the openings l6 and the pins ll allows the plungers to reciprocate within the ll sufficiently to bring their outer the periphery of the impression. cylinder. A spring I1 is located within the .bore II and bears against the inner ends of the plungers i3, exerting outward pressure thereon.

As the cylinders l and iii rotate, one of the II will contact the surface of the bearer. ring 8' each time the gap in the surface of the resiliently covered cylinder i comes opposite the the bearer surface ace-moi surface of the impression cylinder II. the plungers being so arranged and located, according to the sizes of the cooperating cylinders, as to provide for this. In the drawings the blanket cylinder is shown as one-half the diameter of the impression cylinder, and consequently only two plungers are illustrated. It is to be understood however than any number of plungers may be employed, as governed by the relative sizes of the cylinders and the number of gaps to be balanced. The bearer surfaces 3' of the blanket cylinder need not be continuous, since it isonly necessary that they be provided at the gap in the blanket cylinder where they will engage the plunger is of the impression cylinder.

The bearer surfaces and the cooperating plunger or pressure exerting mechanisms have been illustrated as applied, respectively. to the blanket cylinder and the impression cylinder. However, this application may be reversed, if desired, this being governed by the structural features of the press and the arrangement of the printing cylinder.

In the drawings, the impression cylinder II is shown as having a surface [2 formed thereon. In the preferred embodiment, this surface I! has a diameter slightly less than the diameter of the main part of the impression cylinder ll, so that the pressure between the two cylinders, l and II, is carried by the surfaces of the main bodies of said cylinders, or by the paper, at all times except when the gap 5 in the surface I is adjacent the surface II, at which time the pressure is borne by the plunger is and bearer surface I.

As will now be apparent, the invention provides for bearer surfaces attached to or embodied in one of the cylinders of a printing machine which will cooperate with plungers or other resilient pressure exerting devices associated with the other cylinder of a couple, these pressure exerting devices and cooperating surfaces being so arranged as to provide additional pressure between the two cooperating rotating cylinders at all times when the paper and the printing blanket or plate are interrupted, so as to maintain a substantially constant pressure. In this way pressure variation and consequent vibration are eliminated or reduced to a minimum. While it is preferred to utilize resilient members of the type shown and to associate the same with the impression cylinder, such members may be associated with the plate or blanket cylinders, if preferred, and other means for applying resilient pressure between the printing couples may be utilized without departing from the invention in its broader aspects.

What I claim is:

1. In a printing couple including a cylinder having a gap in the surface thereof, the combination of rigid concentric bearer means for said cylinder, and resilient means associated with the other cylinder of said couple for exerting radial pressure against said bearer-means over a restricted arc inaxial alignment a 1th the. gap when said gap is at the impression point.

2. In a printing couple having cooperating impression and printing cylinders, said printing cylinder having a ap in its surface, thecombination of rigid concentric bearer of said cylinders, and resilient means incorpomeans for one over a restricted. arc in axial rated in the other of said cylinders for exerting 1 radial pressure against said bearer meansover a restricted arc in axial alignment .with the gap when said gap is adjacent impression cylinder, whereby substantially conthe surface of 'said' able spring-loaded otherv .of said cylinders for exerting pressure- 7 bination of rigid concentric bearers for one of said cylinders, and radially movable spring-loaded plungers incorporated in the other of said cylinders for exerting pressure against said bearers when said gap is adjacent the surface of said impression cylinder.

.4. Ina printing couple having cooperating impression and printing cylinders, said printing cylinder having a gap in its surface, the combination of rigid concentric bearer means for one of. said cylinders, and resilient means for applying radial pressure against said bearer means alignment with the gap when said gap is opposite the impression cylinder whereby substantially constant spacing and pressure between the said cylinders is maintained.

i5. In a printing couple including a cylinder having a paper-engaging surface extending partially around its peripheral surface and leaving a gap therein,-the combination of rigid concentric bearers for one of said cylinders, and resilient means cooperating with said bearers overarestricted arc in axial alignment with the gal for. exerting additional pressure between said cylinders when said up reaches the impression point.

6. In a printingcouple including a cylinder having a paper-engaging surface-extending D 4- tiaily around its peripheral surface and leaving a gap therein; the combination of rigid concentric bearer means for said cylinder, and resilient means embodied inthe other cylinder of said couple cooperating with said bearer means over a restricted arc in axial alignment with the gap to increase the pressure between said cylinders when said gap reaches the impression point.

- 7. In a printing couple having cooperating impression and blanket cylinders, a blanket of rub-= her or similar resilient material covering the 'sur-' face of said blanket cylinder, and s, gap in the 8. In a printing couple having cooperating impression and blanket cylinders, a blanket of rubber or similar resilient material covering the:

surface of said blanket cylinder, and a gap in the surface of said blanket cylinder at the pointof attachment of said blanket'to said cylinder,

the combination of rigid concentric bearer sub" faces for. one ofsaid cylinders, and radially movplungers embodied in the against said bearer surfaces when said gap is diacentthe surface 9. In a printing couple comprising a pair'of cooperating"v rotatable cylinders, an impression surface on one-cylinder, aprinting surface onthe other cylinder, the said printing surface having .a, gap which periodically passes adjacent. to,the impression cylinder when the cylinders are ro-- tated, and a resiliently supported'member-inlbne of the cylinders arranged to exert pressure in a of said impression cylinder.

radial direction and to engage a bearer surface on the periphery of its cooperating cylin- UNITED STATES PATENTS der during each such passage of the gap. i t Name D W LASZLO M. STEMPEL. 421,749 Nagel Feb. 18, 1890 1 472,206 Cottrell Apr. 5, 1892 REFERENCES CITED 1,111,490 Wood Feb. 15, 1916 2,098,165 Rizgenbach Nov. 5, 1937 The following references are of record in the file of this patent: