US2406205A

US2406205A - Printing press

Info

Publication number: US2406205A
Application number: US468100A
Authority: US
Inventors: Davidson William Ward; Frank J Breman
Original assignee: DAVIDSON Manufacturing CORP
Current assignee: DAVIDSON Manufacturing CORP
Priority date: 1942-12-07
Filing date: 1942-12-07
Publication date: 1946-08-20
Anticipated expiration: 1963-08-20

Description

v Aug, 20, 1946'. x'w; DAVIDSON ETAL] 2,406,205

PRINTING- PRESS 4 Filed. Dec. 7. 1 942 5 She ets-Sh et 1 INVENTORS William Ward D l BY flan/bi 5 m HTTYS Aug 20,1946 w. w DAVIDSON tr AL r 2,406,205.

PRINTING PRESS Filed Dec. '7, 1942 5 Sheets-Sheet 2 *N v INVENTORS.

William, Ward-Davidson g BY .fia/zkJBrn/ m W. W. DAVIDSON ETAL PRINTING PRESS Aug. 20, 194

Filed Dec. "7, 1942 5Sheets-Shet 3 v INVENTORS. Wdla/n WQfiaLhI/MS /Z 1946- w. w. DAVIDSON ETAL. 5

PRINTING PRESS Filed Bed. '7, 1942 -5 Sheets-Shee't 4 Aug. 20,194.. w. w. DAVIDSON arm. 6

PRINTING PRESS 5 Sheets-Sheet 5' Filed Dec. 7, 1942 I v zdsolz P2 2012 HTTYS' may occasionally jam Patented Aug. 20, 1946 PRINTING PRESS William Ward Davidson, Evanston, and Frank J. Breman, Chicago, Ill., assignors to Davidson Manufacturing Corporation, a corporation of Illinois Application December 7, 1942, Serial No. 468,100

. 1 Under the best conditions, feeders for feeding sheets to printing presses have done a very good job of feeding the sheets against the stop fingers of the printing roll in such a way that accurate registration would result. Under adverse conditions, however, as when the sheet has a tendency to curl, thefeeders have not always functioned so Well. Quite often the registration is imperfect, and with some feeders the sheets and have to be removed by hand.

According to the present invention the printing gripper and the feeding means so cooperate that failure to obtain perfect registration is rendered virtually impossible. This is accomplished by guiding the sheet all the way into the jaws of the gripper so that there is no possibility for a curl enterthe gripper or to pull away from the stop fingers and thus produce inaccurate registration, At the same time other disturbing factors are correctedfactors which might interfere with the registration as by causing vibration of the machine or applying unstable tension to the chain carrying the printing grippers.

Additional objects and advantages of the invention will be apparent from the following description and from the drawings, in which:

Fig. Us a somewhat diagrammatic vertical sectional view of a printing press chosen for illustration of the present invention, the view being taken approximately on the line I'l of Fig. 2.

Fig. 2 is a horizontal section of the structure shown in Fig. 1, with the upper printing cylinder and certain other parts removed for the sake of clarity.

Fig, 3 is a view corresponding to Fig. 1 but taken approximately on the line 3-3 of Fig. 2.

Fig. 4 is an enlarged fragmentary sectional view corresponding to Fig. Band showing the parts at approximately the time'the sheet enters the printing gripper jaws.

6 Claims. (Cl. 101-232) to, cause the leading edge of the sheet to fail to Fig. 5 is a view corresponding to Fig, 4 but showing the parts after they have moved slightly beyond the positions shown in Fig. 4.

Fig. 6 is a fragmentary detail sectional view showing the mounting of the feed guide roll.

Fig. 7 is a vertical sectional view taken approximately on the line 1-1 of Fig. 4, showing the cooperation between the feeder stop fingers and the guide thereabove. I

Fig. 8 is a fragmentary sectional view taken approximately on the line 8-8 of 'Fig. 1, showing the cooperation of thegripper bar and the sheet discharge stop.

Fig. 9 is a fragmentary perspective view of the gripper bar. 7

Fig. 10 is a perspective view of the mounting link by which the gripper bar is secured to the chain. i

Fig, 11 is a sectional view showing the securing of the gripper bar to'the mounting link, being taken approximately on the line IIH of Fig.'8 (inverted).

. A preferred form of the invention has been chosen for illustration and description, in compliance with Section 4888 of the Revised Statutes, but persons skilled in the art will readily perceive other means for accomplishing the same results, and the claims are therefore to be-construed as broadly as possible, consistent with the l prior art.

General organization and Operation In the form of the invention chosen for illustration the sheets, which have been initially separated and fed automaticallyin timed relation with the press, are fed by a conveyor board D against feeder stop fingers E. .At the proper time feeder'pressure roll H iS lO-WGIBd, and the stop fingers Eand the feed rolls coaxial therewith are rotated to. feed the sheet to the gripping and registration stop unit Q, which carries the sheet to the bite of the printing rolls I and M. As seen in Fig. 3, the printing roll I may include a lithographic plate J and a platen K. The roll M is half the diameter of the roll I and bears a blanket L which cooperates first with the plate J and thenv with the platen K. In short, the plate J, after being inked by cooperation with the dampening unit N and. inking unit 0, prints a reverse image of the matter to be printed on blanket L,,Whl0h in turn prints this matter on the underside of a sheet to be printed, the platen K pressing the sheet against the blanket L. After being printed, the sheet is turned over and dropped into a receiving box P printed-face-up. To this end the gripper unit Q is carried by chains around the guide unit S to a point where the grippers are opened by cam R to release the sheet. The grip-.

pers are again opened by cam T to receive the next sheet.

In the illustrated form of press, other orga'nizations thereof are possible but they need not be described since they are not necessary to the practicing of the presentinvention nor to the understanding of the operation thereof. Indeed, for the purpose of understanding the'invention, the roll M could be one'of the printing rolls of any printing press, and the gripping unit Q could be or evening 0f ;the two ends of the guide member Because of the relatively narrow opening ofthef gripper jaws thereis substantially nochance that the sheet will curl to such an extent wi'thinthel gripper .that it will be torn. or indented as the gripper finger closes. However, there would nevertheless be a possibility, if conventional stopf fingers were used,. 'thatimp'erfect "registration could result from having the sheet pressagainst' firmly enough to cause one of the stop fingers I slight distortion of the sheet at that 'point,'with the result that one side of the 'sheet would be" advanced slightly more than the other. 'Accord-f ing to the present invention, this danger is'com pletely overcome by having the sto shoulders 26 extend substantially all along the length of the gripper bar 21, being notched only where necessary to receive the gripper fingers 28 or other necessary cooperating parts. I a

Since the gripper bar 21 does not seat on'any part of the cylinder M butis' carried entirely by chains 46, a firm'and dependable connection between the gripper and the complete accuracy in registration. The chains themselves will seat dependably and uniformly on.

the sprockets by which they are carried. Of course, it is also desirable that the connection between the chain and the gripper bar 21 be quite simple and inexpensive. The mounting link 41 shown in Fig. and the assemblythereof shown in'Figs. 8 and 11 have been found to be very satisfactory. Although this is called amounting link for convenience, perhaps it should bementioned that it might be considered only half of the chain link since it must be paired with another link plate 48 at the opposite side of'the chain 46.

We have determined that the secret of dependable rigidity between the chain 46 and the gripper bar'21 is in avoiding any flexing of the horizontal portion 49 of'the link. According to the present invention, this isayoided by provid-, ing flanges 5| at the end of the flange 49 and by clamping the horizontal flange 49 between two legs 52 formed at the end of the gripper bar 21. The clampin pressure is applied by a screw 54 countersunk in one leg 52 and threaded into the other. a

The gripper fingers 28 are actuated by a gripper shaft 56 which is journaled in lugs 51 formed on the gripper bar 21. It is preferred that each of the gripper fingers 28 grip thev'sheets against gripper bar 2'! independently of the others, and

to this end each is provided with its own spring 58. In order that they may act independently in this manner, however, they must have some lost motion with respect to the shaft 56, and therefore eachv of them (one exception bein permissible) is provided with a suitable lost-motion means for actuating it to the open position. For example, each finger28 may be provided in its hub witha slot 59 in which a pin 6| is positioned, the pin being rigid with the shaft 56. When a grip finger 28 is at rest against a sheet, the pin 6| should be slightly spaced from the end of the slot 59 which it will engage in opening the grippers a v Sheet release When the gripper unit is passing around the cylinder M, the tension on the chain draws the tension so chain is essential for tion of the gripper bar the gripper unit is positioned along the straight.

reach of the chains 46, and hence the thrust of the cam R on the roller 63 can easily twist the gripper bar 21 angularly as well ,asthrust ing it downwardly Such displacement of the gripper bar Zl' can set up abnormal strains inthe chain 4B and start vibrations which mig ht c'on} ceivably, cause improper registration of the sheet.' Such irregularities are prevented in accordance with the present invention in thema'nner' seen best in Figs. l, 8"and 9. v V

The cam R is carried by a plate 68 which pro-l jects from a sliding carriage 69' whieh'slides'fe'nf a support bar 1| mounted inside the pressfrainei and spaced'therefrom'by studs 12. .'I'h'e 1115DerT surface 13 of carriage 69 forms a raceway for a roller 14 journaled at the end of shaft '56, so that this shaft is rigidly braced against outward" movement'during the time that the cam R exerts a thrust on the follower 63. -The leading. edge of the raceway or bracin surface 13 may be relieved slightly to ensure the smooth movement of the roller 14 onto the raceway I3.

Release stop the grippers before they a ain close, it isde-Q sirable to provide a stop member 8|, for obstructing the continued movement of the sheet. The stop member 8| is preferably carried by a rod 82 extending rigidlyfrom and carried by the carriage 69 Thestop member 8| is. preferably pro-i vided with resilient fingers 83, which project into; slots 84 in the gripper bar 21 on opposite sides of the central lug 51. Because the vertical Z1 is accurately det mi ei by the raceway 13, the grooves 84 neednot extend; much below the gripping face of gripper bar 21 in order for the fingers 83 to safely extendto a position where they will dependably obstruct the. continued movement of a sheet in contact with L' saidface. 1 I The carriage 69 may be moved along .the bar- 7| to a position corresponding to the length of: the sheets, so that it will cause discharge of the sheet at the earliest moment which willresultlin, proper dropping of the sheet onto the stack in the. receiver P so that there will be maximum visibility f of the sheets on the stack. The carriage is se cured by a lock nut 86 in any position. to which the carriage is adjusted. 1 a It has been found that control of the sheet is; improved by providing a guide Iwire8l looselysuspended, from the middle of a crossbar: 88 fitting'looselyin a slot in thebottom end plate 8 9 of the receptacle P. I Y- As the stack of printed sheets is removedfthe guide wire 8'l' will slip out or its; slot to avoid obstruction of the removal of the stack. While the guide wire 81 is in place there is no dangerthat the sheets will float or be blown over the end plate 89. From the foregoing it is seen, that a press} has been provided which prints with accurate." registration dependably even under. adverse conditions such as 'when the sheets ihave a warding the sheet to prevented:

r pp tively fpreven'ted.

1 ooupleone 'member of wliich is a-printing roll,

c as ycompared the simplest type of structure suitable for high grade printing heretofore know I We claim:

' 115a printing 7 press including a printing couple: one-"member of-whichisa printing roll,-

gripperxand registration stop "means having-a fixed. position with 1 respect to said 'roll at; the time 'that a sheetiheld "therebyientersthe: bite of- *thejprinting couple, means for causing the gripper-means to opento "receive a sheet, and means for feeding a sheet" against the stop meansgwhi'le, said gripper 'meansis open comprising feeder istop fingers; means for feeding a Sheetagainstthe stop-fingers in timed relation to the operati'onofl the press, means for slde=registering *the sheet before itleave's the feeder stopfingersyguide means inclined toward the "feeder stop fingers and projecting' between theffe'eder 'st'opfingers to ensure engagement of a 'shetwith saidfeeder 'stop'fingers, means for engaging the sheet adjacent the feeder stop fingers while it is'incontact therewith and forthe gripper and stop means, said stop means blocking the throat of the gripper, a table on which the sheet slides between the stopfingers and gripper and stop means',yguide 1means -'-converging toward the table to direct the leading edge of the sheet close to the; table, and with "respect-to the table and extending into close proximity with the printing couple for gripper means; having s, fixed "position with respect to- -sai'd-- rollat the time that a sheet held thereby-enters, the.; bite1: of.;-.the xiifhfill p 7 means for. causi-ngthe gripper means toopento receive a sheet, and, means for feeding .a sheet within the gripper means while said gripper means "is open comprising means for engaging the"; sheet andiorwarding the sheet to ithe gripper means; a table: on whichjthe sheet tslide's when moved toward the gripper "means, substantialh unyielding ,lgu de means, converging toward thegtable to direct the leading edge of thel sheet close. to the table,v and final guide means 'fixed withrespect to the table for causing the :sheet to bendbeyond"thetable into the opened gripper means and against;a registracausing the's'heetto bend'beyond the table to a direction'proper for-entering the opened gripper means, the 1 plane of the open gripper means intersecting the plane of saidfinal guide means whereby; passageof;the-sheet between the, final guide means-and the .grippermeans is positively "2. 'A *printing press including a printing couple one memberof-which is a, printing roll, and registration stop means having a fixedposit-ion 'with respect to saidroll 'at the time thataxsheet held thereby entersthe bite of thaprinting couple, means for causing the gripper meanstoopento receive a sheet, and means "for feeding a sheetagainst the stop means while ,said gripper means is pen comprisin'g feeder' stop fingers; means for feeding a sheet against the "stop: fingers in timed; relation ,to the, operation of the press, means for sidef-registeringthe sheet before it leaves the feeder 'stop' fingers; 'means for engaging "the sheet'ad'ja-cent-the, feeder stop fingers while, it is in contact therewith and forwarding the, sheet'to-thegripper and'stop-rneans, said stop means blocking the throat of -the gripper, ,atableon which'the sheet slides betweenthestop f fingers and-grip'perand stop means, substantiallyunyielding guide 'means' .convergingto-,

, ward'the'table-to direct the leadingfedge ofthe or sheet close to the table, and'fi-nal gu'ide meansfixedwith-respectt0 the table iorcausing the shet 'to bend beyond the table into the opened gripper means and extendinginto lateral alinement'with the opening 'of said 'gripper' means whereby passage of the-sheet between the-final guide means and the gripper means ,and imperfect registration due to :sh'eetcurl "are p'os'iincluding a printinfg tion stop fixed "with respect :to, said gripper means and jful lyblocking the throat t'hereof said *finalguide means extending into lateral alinem'ent with the opening gof said gripper; means whereby passage of thesheet between the final guide means and theigripper meansis positively prevented.

4. A printing press 'inclu' chains carried bythe sprockets, a gripping and registration stopunit c'arriedby'the 'chains, and means'to feedsuccessive sheets to the. gripping and registration stop unit:for successive print ingoperations with "exact uniformity; said grippingaand registration stop unit having horizontally. slotted ends, each end being vcarried-by a side' pl'ate forming. one of the .links of the chain and having a horizontal 'fiange fitting closely into the slotted ends of said gripping and" registration stop unit, verticalgfianges ,rigid' gripper; "and'means for feeding a sheet within the, gripper means while. said gripper means Li's open-=comprisirlg 'means for engagingfithe sheet and forwarding ,the sheet to the gripper means, a table on which the sheet slides between "the stop fingers and gripper means, substantially unyielding guide means converging toward the table to direct the leading edge iofgthe sheet close to the table, -and final guide means rigid with the-table for causing "the sheet to bend beyond the table-to aK'dilLCCtiOIl'PI'OPBIVTOT extending into the openedp'grippermeans and extending-into lateral alinement' with the opening of said gripper -means whereby passage of the sheet between the finalguide means and the gripper means is positively prevented.

- "BF-In Ia printing-press oithe'typecomprising a printing "couple; sprockets .Jdriven with the couple and chains carriedibythe sprockets, the combination "therewith of" a bar carried by the chains, registrationustop means fixed in position with respect to gripper means on said bar,

the gripper means including jaws" having a limited opening, 'means ior'openingthe jaws in timed-relation 'tO'lthB operation of? the printing oup :Saif'd stop "m Po itively limitin the *travel "of a sheet'into the gripper jaws, a feed dine a printin roll; sprockets at the endsvv of 'the printing roll,

table, means for forwarding a sheet over said table into the gripper jaws in timed relation with the operation of the printing couple, fixed rigid lower guide means extending into close proximity with the path of the bar and inclined upwardly, to initially flex the sheet, rigid upper guide means in fixed relation to said table extending downwardly into close proximity with the path of the bar for directing the sheet downwardly from the lower guide into the gripper jaws and against the registration stop, said upper and lower guide means being slotted to permit passage of the gripper jaws, the feeding means and gripper jaws operating in such timed a relation that the sheet is forwarded into the .gripper jaws during the interval in which the WILLIAM WARD DAVIDSON. FRANK J. BREMAN.