US2445271A

US2445271A - Static eliminating means

Info

Publication number: US2445271A
Application number: US583336A
Authority: US
Inventors: William C Huebner
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-03-17
Filing date: 1945-03-17
Publication date: 1948-07-13
Anticipated expiration: 1965-07-13

Description

y 13, 1948- w. c. HUEBNER sTATIC ELIIINATING EMS 2 sheets sheet 1 Filed larch 17, 1945 v INVENTOR. .7147/(201: 6175x5110,

(Zffamys y 13, 1948- w. c. HUEBNER 2,445,271

STATIC ELIIINATING MEANS Filed March 17, 1945 2 Sheets-Sheet 2 INVENTOR.

Patented July 13, 1948 UNlTED STATES PATENT orrics STATIC EIJMINATING MEANS William C. Huebner, New York. N. Y.

Application March 1?, 1945. Serial No. 588,336

1 Claim. 1

This invention relates to means for eliminating or discharging electrostatic charges from ob- Jects or materials, and particularly from travelling sheet materials such, for example. as the print-receiving paper or other webs or sheets in printing presses or apparatus.

The invention deals, for instance. with the elimination of difllculties in offsetting in printing presses and similar production problems where static charges accumulate with attracting polarities, which in printing attract ink from freshly printed sheets to the backs of succeeding sheets delivered to the pile of printed sheets. or upon the backs of webs being rewound or folded after printing; and also with elimination of the attraction of dust or other particles from the air. or from dust accumulating on parts in proximity to the charged surfaces.

An object of the invention is to provide efficient and practical means for eliminating static charges from one or both sides or surfaces of the sheets or webs, which orthodox static eliminators fail to do effectively, and to ground static charges in a practical manner, whereby a fully neutralized condition may beobtained. particularly in perfectlng printing or multicolor printing on both sides of the webs or sheets, thus assuring smoother printed images, free from spots or mottling resulting from attraction and repulsion polarities.

Another object is to eliminate effectually the clutching, clinging or binding of a plurality of surfaces, such as occurs in the unwinding of web material from a roll. or which causes sheets to draw or pull one another while they are being separated or fed from the feeding pile of sheets, thereby hindering or interfering with the feeding or correct registering or positioning of successive sheets in a printing press.

Tests and experience disclose the fact that the orthodox static eliminators commonly used. consisting of comb-like bars with spaced points. only partially ground the static charges and fall short of complete accomplishment of the desired result, particularly the complete elimination of static from both sides of sheets or webs in a way to meet exact requirements for printing in presses or apparatus of the type disclosed in patents issued to me and in pending applications, in which the ink is transferred from the printing element to print-receiving element by electronic, electromagnetic or electrostatic action, as distinguished from contact and pressure between such elements. Such orthodox or conventional static elimlnators are ordinarily held stationary with their points projecting into proximity to the surfaces of the Ill webs or sheets. but they are not adapted to actually contact with the surfaces of travelling web: or sheets, as they would thus drag across the surfaces, with the result of smearing or streaking freshly printed matter thereon, or even tearing or mutilatlng paper or analogous frail webs or sheets. Therefore, they are not adapted to function as guiding or supporting means for web; or sheets.

Another object of the invention is to provide a static eliminating device which is arranged to have rolling contact with statically charged web or sheet material and, therefore. is adapted to serve as means for supporting or guiding a sheet or web, as for instance, in its passage to or from printing rolls or for supporting or guiding a web on its way from a printing element to a winding roll for the web. folding device or other element.

Further objects and advantages of the invention will appear from the following specification of the preferred embodiments oi. the invention shown in the accompanying drawings. and the novel features of the invention are set forth in the appended claim:

In said drawings:

Figs. 1 and 2 represent respectively opposite,

end portions of a static eliminating roller or cylinder illustrating slightly difl'erent forms of a roller embodying my invention.

Fig. 3 is an end sectional elevation of the roller.

Fig. 4 is a transverse sectional elevation thereof on line --4. Fig. 1.

Fig. 5 is a plan view of aroiier of another modified construction embodying the invention.

Figs. 6 and 'l are respectively fragmentary transverse and longitudinal sections, enlarged, oi the roller shown in Fig. 5.

Fig. 8 is a diagrammatic view representing a press for printing a travelling web and illustrating the application of rollers embodying the invention arranged to discharge static charges from opposite surfaces of the web. and also to serve as a. guide or supporting means for the travelling web.

Fig. 9 is a view illustrating diagrammatically the application of static eliminating rollers embodylng the invention in an apparatus of the type in which multicolor printing is effected by transferring the ink from the printing elements by electronic, electromagnetic or electrostatic action.

Fig. 10 is a diagrammatic view illustrating thev application of a static eliminating roller embodying the invention employed as a directionchanging guide for a travelling web.

Referring first to the static eliminating roller illustrated in Figs. 1-4, the roller A comprises a central supporting shaft il. a body tube or hollow cylinder ii which surrounds and is spaced and supported from the shaft by opposite sleeves I! which are mounted on the shaft at opposite ends of the body tube ii. into the ends of which the sleeves project to support the tube. These sleeves II, which are preferably made of suitable insulating material to electrically insulate the body tube Ii from the shaft, may be movable lengthwise on the shaftiand adapted to be adjusted thereon towards each other, as by securing nuts I! which are screwed on threaded portions ll of the shaft and engage the outer ends 01' the sleeves l1.

Sleeved on the body tube Ii is a series or number of relatively thin. annular disks II which are arranged transversely side by side, or face to face, on the tube, and are secured in place thereon, as by clamping rings ll adiustably mounted at the opposite ends of the body tube to engage the disks i at the opposite ends of the series. These clampin mam, which are oi metal or electrically conducting material, have central openings il into which the ends of the body tube ii are adapted to project and have inner peripheral flanges II at their outer ends which surround and bear on the sleeves II against inwardly facing peripheral shoulders I! on the sleeves. Thus, the clamping rings II are adapted to he forced towards each other over the ends oi the body tube by inward adjustment oi. the sleeves ii on the shaft "by the nuts It. so as to clamp between the rings the peripheral disks ll oi the roller and so hold the disks firmly in place on the body tube.

The peripheral disks II. which are made of suitable electrically conductive metal or material have serrated outer edges forming outwardly directed peripheral teeth or proiections II on the disks, the outer ends of which teeth or projections are preferably pointed or of minute area and are relatively closely spaced. The disks ll may be arranged in face to face contact with each other, as shown in Fig. 1, or they may be slightly spaced from each other by intervening annular spacing disks 2! alternating with the toothed disks. as shown in Fig. 2. These spacing disks are of less diameter than the toothed disks, so that the teeth of the latter project outwardly beyond the outer edges of the spacing disks, and the latter serve to space the teeth or projections of the disks II from each other axially or lengthwise of the roller. Also, as best shown in Figs. 4 and 5, the teeth or projections on adjacent disks are preferably staggered relatively to each other so that the teeth or projections 01' one disk are located eircumierentially opposite the spaces between the teeth or projections of the disks adjacent thereto. Thus, the roller or cylinder has an outer periphery composed of or formed by a multiplicity of outwardly directed, closely related teeth or projections with minute, closely spaced outer ends which, in the aggregate, form in effect an interrupted peripheral surface adapted to roll in contact with and act as a support or guide for a web or sheet without puncturing or multilating the sheet material, even though it may be of thin paper or other thin, fragile material, much the same in effect as a smooth or continuous surfaced supporting or guiding roller.

The described roller or cylinder is adapted to be mounted to rotate freely, as by means of portions I! at the outer ends of the shaft ll, forms Journals arranged to turn in suitable ball or antifriction bearing II. The roller is thus adapted to be revolved as by driving contact therewith of the travelling sheet material, and act to discharge static charges from the material without damage to the material, and the outer ends of the peripheral points or projections of the roller, being oi. such small area, will not smear the ink of a printed surface or collect the ink and smudge the surface-even if the ink is not entirely dry. The peripheral points 01' projections may be smaller than would appear from the drawings because of the scale of the latter necessary for clearness of illustration. As before stated, the disks ll forming this interrupted periphery of spaced points or projections and their and clamping rings ll are electrically conductive so that by mounting the roller with its said periphery contiguous to or in contact with the statically charged web or material and with said periphery suitably grounded, or electrically connected with a part of appropriate potential, the charges will be discharged from the web or material. As shown for this purpose, in Figs. 13. suitable contact brushes or elements 2!, 25 contact with the end clamping rings ll, one of which brushes 2!, is in electrical connection with a suitable ground conductor 21, while the other brush may be in electrical connection with a supply conductor 2! for electric current, preferably alternating current. These brushes may be, as usual, yieldingly held in contact with the clamping rings by suitable springs acting between the brushes and their supports.

In the modification of the device shown in Figs. 5-7, the static eliminating roller, instead of having the periphery formed as above described, by a series of serrated disks, has a solid peripheral or outer metal or the like conducting tube or portion II on which outwardly directed, spaced projections Ila are formed, as by intersecting V-shaped grooves cut or formed in the surface of said peripheral tube or portion of the roller or cylinder. These intersecting grooves form closely spaced, outwardly directed points or P ojections on the surface of the roller. The roller of this modification may be mounted and associated with the statically charged sheet or material with its periphery in rotating contiguity or contact with the surface of such material, and may be grounded or electrically connected to ef-- fect grounding or discharge of the static charges from the material as explained in connection with the first construction described.

Figs. 8, 9 and 10 indicate diagrammatically several of the various possible applications of the static eliminating rollers of this invention having outwardly directed, closely spaced, peripheral points or projections.

Fig. 8 shows at A, two such rollers rotatably mounted to contact peripherally with opposite sides or surfaces of a travelling print-receiving web I! in a printing machine for grounding the static from opposite surfaces of said web. and in the same figure two such rollers are shown at A and A rotatably mounted in position to serve as guide and supporting rollers for the web in its passage between the printing rolls oi the machine and a web winding drum 3!.

Fig. 9 shows the static eliminating rollers at A as used in a multicolor printing apparatus oi the electronic, electromagnetic or electrostatic type, between the printing elements it and I! for the first and second colors, and in rolling contact with opposite surfaces of a print-receiving web flgurealsoshowaatnfiapairol rollers in guiding relation with opposite sides 01' the web after leaving the second color printing element. In this figure 11 and 28 indicate the electric current conductors connected with the contact brushes 2! and 2! of the static eliminating rollers.

Fig. shows an application 01 the static eliminating roller in which a single roller A is arranged for turning the travelling web from movement in one direction to movementin a direction at right angles to its first direction of movement.

In all of these illustrated applications the roller functions as guide or supporting means for the material in addition to its function or discharging static charges from the material.

I claim as my invention:

Means for eliminating electrostatic charges 31, and said said static eliminating from travelling print-receiving sheet material in a printing apparatus, including a roller arranged to rotate with its periphery in conductive contlgulty with said travelling sheet, said roller comprising a central longitudinal shalt, a tube surrounding and spaced from said shaft, opposite insulating sleeves secured on said shaft and extending within opposite ends 01' said tube and supporting and insulating the tube from said shaft, a series of relatively thin electrically conductive transverse annular disks loosely sleeved on said tube approximately face to face with each other and provided around their outer edges with outwardly directed projections having closely spaced outer ends. electrically conductive clamping rings supported by said insulating sleeves at opposite ends of said series of disks, at least one oi. said sleeves being adjustable toward the other within said tube and the clamping ring supported thereby having a portion movably surrounding said tube and being adjusted axially relatively to the tube by adjustment of said adjustable sleeve for clamping said disks between said clamping rings. and an electrical conductor in electrical connection with one of said clamping rings.

WILLIAM C. HUEBNER.

REFERENCES CITED The following references are of record in the tile 0! this patent:

UNITED STATES PATENTS Number Name Date 697,173 Roesen Apr. 9, 1992 1,318,337 Wood Oct. '1, 1919 1,396,319 Bunger Nov. 8. 1921 1,660,550 Fyans Feb. 28, 1928 5 1,668,049 Clinton et al. May 1, 1928 1,968,861 Strang Aug. '1, 1934 2,012,953 Brunner et aL Sept. 3, 1935 2,096,164 Diefenbach Oct. 19, 1937 2,152,263 Knowlton Mar. 28, 1939 2,256,116 Kvropoulos Sept. 16, 1941 2,375,304 Kildufl May 6, 1945