US1034083A - Printing-press. - Google Patents

Description

W. M. CLARK.

PRINTING PRESS.

APPLIOA-TION FILED MAILll, 1910.

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PRINTING PRESS. APPLICATION FILED MAR. 11 1910.

Patented July 30, 1912.

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abbot/mu WILLIAM M. CLARK, 0F PHILADEBPHIA, PENNSYLVANIA, ASSIGNOR TO CLARK PRINTING PRESS COMPANY, or PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA;

PRINTING-PRESS.

Specification of Letters Patent.

Patented July 30,1912,

' Application filed March 11, 1910. Serial No. 548,661.

To all whom it may concern: I I Be it known. that 1, WILLIAM M. QLARK, a citizen. of the United States, residing at Philadelphia, in the county of Philadelphla and State of Pennsylvania, have invented new and useful Improvements in Println Presses, of which the-following is a spec cation.

My invention consists of a new and 1mproved printing press of the bed and platen type, and relates particularly to that type of bed and platen presses commonly known as job presses.

In my improvement I. use a slightly curvedpl aten, so as to-makea rolling contact with the form instead of delivering the impression at one stroke over the-whole surface of the form as in the job presses now 1n general use.

The advantages of a line contact impres; sion have long been recognized. All book, magazine and newspaper press manufacturers adopted this principle and threw out the old platen printing machines many years ago, and the demands of modern job printing make it almost imperative that job presses should also be adapted to the line contact or cylinder principle, instead of the flat platen impression, as they were Ori inally constructed almost three quarters o a century ago.

To produce a printed impression from type matter, ordinarily requires a pressure of about 150 pounds to the square inch and in view of the many small jobs of this character much in demand, the platen job press was primarily constructed. In the progress of the art, and practically in modern illustrations now largely called for in job work, a minimum pressure of 300 pounds to the square inch is required. \Vhen the whole surface of the-form or" plate must be impressed at once as in the plane platen method, the aggregate tension becomes so great that the heaviest construction and most powerful mechanism is inadequate to long withstand the sudden and enormous strain of a full form impression, occurring several hundred times an hour during the o eration of the press and which if continued would finally wreck the machine.

Therefore prudentprinters as a rule refuse to accept this class of work for job presses, fully realizing that a press employlng the platen method of impression is not able to I meet the requirements of all kinds of printing demanded, up to its full chase capacity. There are other grave difficulties encountered in the platen method quite apart from the impression.- Half-tones, tint blocks and similar matter now greatly in demand in job printing, requires a stiff andv dense printers ink to produce purity and depth of color on the printed sheet. As the sheet is 'mpressed upon the whole surface of the orm at once, it is very apt to adhere sq fast, by reason of the extreme pressure applied to produce a proper. imprint, that it can not easily be delivered, and unless the paper is unusuallytough is liable to be mutilated in quickly stripping it ofli To remedy this the mk is sometimes thinned down, but in doing so', the depth and clearness of the impression somuch desired are lost. Again the squeeze of the platen method being given all Over the surface of the plate or form at once, seems to cause the ink to appear in excess ,on. the middle tones and'on the more delicate portions, to be pressed over the lines into the spaces between as if the'ink had run. Very often the printed sheet is picked, that is, small particles-of the surface of the paper have. pulled off and white specks show in the darker portions, while it not unusually occurs that a' soft ink refuses to leave the form evenly and comes oif on the sheet mottled in appearance. In the line contact impression or cylinder method,

the sheet is separated while it is being printed and the numerous ink difiiculties which so trythe skill and patience of the pressman, in the platen impression method, mostly disappear. There is also much difference in the operation of making ready in the platen impression method, and the line contact or cylinder method. The least additional'overlay upon any portion of the platen make ready affects the whole form, often undoing the tedious work already done. In the cylinder method the impression being imparted by a line contact of the sheet with the'form, the building u of one portion of the tympan in no way a ects other portions, so that the making ready in the cylinder method is not only moresimple bu-t'more quickly and satisfactorily accomplished.

I am aware that numerous inventors and as to avoid or overcome the many difficulties attending the platen impression method, but

so far as I have been able to learn, their efforts have failed to produce a press that has -met theconditions required or'the approval of'practical job pressmen, and none of these devices appears to have come into commercial use. The reasons for their failure are many and obvious. In the first place the presses devised, were slow The time consumed in the rolling action of the impression materially lessened the output, com- I pared with job presses using-a platen having a plane engaging surface. Secondly, al-

though the line contact may have been obtained more or less accurately, the bringing of the platen to a convenient position and allowing sufficient time for feeding the sheets and providing a practical inking ap paratus had not been accomplished. The platen in these devices, in its rocking'move- 'ment over the bed, lacked rigidity and the pressure applied, owing to faulty mechacomplicated, because of numerous cams,

sliding and eccentric movements, many of which were inclined to wear irregularly and would therefore be difficult to keep in adjustment. Some of the parts were weak and easily broken, sothat the machines were not only costly to build but subject to breakage and liable to soon wearout.

It is the object of my invention to overcome the numerous difliculties recited above,

to produce a press which is of a mechanical construction and arrangement of parts such that an accurate rolling contact of the platen may be readily secured under the requisite pressure, and such that a press of this type may be run at a speed sufficient to bring its output in excess of that of job presses of the' old type, and to produce a machine easy to maintain in repair, and cheap to manufacture. v

In the accomplishment of my invention I make use in the first place of an extremely simple quick acting and durable mechanism for operating the curved platen. The platen is pivoted by a shiftable pivot below the form bed. A pair of draw-bars are attached to each side of the platen at points spaced apart, and are'operated from shafts geared together in such relation that the draw-bars movethe platen to and from the form bed when the shafts are operated and rock the form over the bed under a direct pressure from the draw-bars, the draw-bars relieving each other in substantially direct equivalency as the rocking action takes place, and

a substantially uniform pressure being seproved means of adjustment of the form,

bed, whereby the pressure of the platen during an impression can be adjusted to great nicety. This means comprises a plurality of slidable wedge members between the form bed support and the bed itself, and screws associated directly with the slides for adjusting their position.

I delineate a specific embodiment of my invention in the accompanying drawings.

Figure 1 is an elevation of the left-hand side of the press; Fig. 2 is a rear elevation of the same. Fig. 3 is a vertical section on line 33 of Fig. 2 looking in the direction of arrows 3/3; Fig. 4 is a section on line 4-4 of Fig. 2, looking in the direction of arrows 4/4, opposite to arrows 3/3; Fig. 5 is a detail of one of the draw-bars of the press, Fig. 6, is a sectional view of the improved throw-ofi mechanism taken on line 11-11 on Fig. 3.

10 and 11 are respectively the right and left hand standards of the frame of the press which is made up of these'two standards and the cross-bars 13 which space them apart and connect them rigidly together. In the upper part of the frame a supporting bed 14 for the form bed performs substantially the same function as the bars 13, being rigidly cast or otherwise rigidly secured between the standards. This supporting bed 14 is located in a vertical plane near the front of the upper part of the standards 10 and 11 and supports on its front face a form bed 15 which is adapted to carry the form 16. The form bed is attached to the supporting bed by a centrally located screw or bolt 17 which passes through the supporting bed to its back and is there encircled by a compression spring, whose compression is adjusted by means of a nut 19 threaded on the end of the bolt 17.

20 is the curved platen which is provided with downwardly extending supporting arms 21 secured to a pivotal shaft 22 mounted in cycloidal ways formed in the standards 10 and 11 just below the form bed. These cycloidal ways 23 are formed with the face of the form bed and the curved face of the platen as bases, the base of the platen preferably, though not necessarily, being approximately a true are of a circle.

The mechanism for operatingthe platen comprlses two shafts 24 and 25, one above bars 27 and 28 connected respectively to the upper and lower cranks 26 on each side of, the machine and tothe platen 20. The upper draw bars ,27 are connected to their cranks by pin and slot connections 27. It

is to be noted that the shafts 24 and 25 are are connected. to the platen at points spaced apart, the distance between these points of,

connection being also approximately equal to the length of the platen measured along its curved face. These distances between the shafts 24cand 25 and between the points of connection of the draw- bars 27 and 28, may

be varied at will, and it may be found under certain circumstances known to me, particularly desirable to vary the distance between shafts 24: and 25.

The points of connection of the respective draw- bars 27 and 28 are constituted by the opposite eccentric ends of shafts 29 and 30 journaled transversely of the platen frame. The draw-bars are freely journaled on the eccentric ends of these shafts. On the lefthand side of the platen see Fig. 1, cranks 31 and 32 are keyed to these shafts and are connected together at their ends by link 33. The upper one of these cranks 31 which is connected to the upper shaft 29 is shorter than the lower crank 32 and is provided with an operatig handle 34. The cranks are so positioned with respect to the eccentric ends of the shafts that when the shaftsare turned by the movement of the operating handle 34, the eccentric journals of the ends of the draw-bars act to move this platen 20 toward and away from the form bed, rocking it about the pivotal shaft 22. By virtue of the making of the lower crank 32 longer than the upper crank 31, the lower shown in Fig. 1. The position of the parts when the first line of contact is made at the lower end of the platen with the form bed, is shown in. Fig. 3. In this pos1t1on the It is to be noted further that the draw-bars 27 and 28' draw-bars 28 and their respective cranks 26, coincide with the line of centers of the shaft 25 and the points of connection of the drawbars 28 to the platen, the cranks 26 pointing rearwardly from the-form bed. By proper adjustment of the draw-bars 28 the platen may be drawn to the form bed with as great pressure along the line of contact as desired. In this position the pivotalfshaft 22 of the platen is in the-same position in the cycloidal ways 23, (an inner position) as it is in the full open position of the parts of the press. After this first line of contact has been made, it is necessary that the pivotal shaft 22 move along the 'cycloidal Ways 23, to an outer position, if the platen 20 is to have a perfect rolling contact with the form bed. The platen is rolled over the form to the final line contact position shown in Fig. 4 by the pull of draw-bars 27, the drawlbars 28 relieving the lower end of the platen directly as the upper draw-bars 27 roll the platen over the form. The provision of the pin-slot connect-ions 27 insuresa positive rest for the platen, the crank pin moving along the'slot, as shoQwn in Figs. 1 and 3, and allowing the platen to rest a short while at the end of its return movement. In order to provide against binding by the lower draw-bars 28, these draw-bars are jointed at 35 and springs 36 provided on one arm of the bars which act on the other arm of the bars and biasthe knuckles of the joints downwardly, in a manner to prevent interference with the draw-bars 27 in the open position of the press as shown in Fig. 1. It will be observed that these jointed 'bars constitute in effect lost motion connections between the corresponding operating cranks and the platen.

The provision of the joint in the lower draw bars at times admits abnormal free play of the lower end of the platen. It is very desirable that the platen be positively pivoted without lost motion at all times, and that when making an impression the pres sure on the lower end of the platen be uni-' formly relieved. 37 is a shaft journaled transversely of the frame and geared to the shaft 25 to revolve at the same speed. (See Fig. 4). On this shaft is provideda heart shaped cam 38 which engages a roller 39 carried by the end of a link 10 connected to the pivotal shaft 22 of the platen. This link is supported at its outer end by a shaft 41 supported at the rear end of the press by a bracket 42 andjournaled at the other end on the shaft 37 adjacent the cam 38. In the open position of the press shown in Fig. 1, anduntil the first line contact is made, as shown in Fig. 3, the bottom of the heart shaped cam formed combinedly by its two lobes, engages the cam roller 39 on the link 40 and keeps the pivotal shaft 22 in its inner position. At this point, however, see

Fig. 3, the top of the heart s l 1aped cam comes into play and actuating 1n con unction with the draw-bars 28, allows the pivotal shaft 22 to be moved outwardly to its outer position as the platen is rolled over the form and relieves the pressure on the lower end of the platen, or the pull on the lower end, directly as the pressure or pull is applied to the upper end of the platen. The parts may readily be adjusted so that the pull on the lower end .of the platen is decreased directly as the pull on the upper end of the platen isincreased, a condition that is ideal for uniform pressure along the line of contact of the platen with the form.

After the impression is made the bottom of the heart-shaped cam again comes into play as it rotates. Momentarily due to the shape of the cam, the lower end of the curved platen is held stationary, while the upper end of the platen is moved quickly outward on the reverse movement of the draw bars connected to it. This results in a clean sepai'ation of the printed paper from the form. The jointed connections of the draw bars assist in some degree this action of the heart-shaped cam. Following this momentary rest, the pivot 22 of the platen and its lower end are moved rapidly 'inward as the upper end is moved farther out-- ward. Thus the separated printed sheet is moved with the platen quickly away from the form bed and the action of the press is made most rapid. In the fully open position the lost'motion connections of the drawbar cause a momentary pause in the movement ofthe platen when the printed sheet may be removed, and another placed, whereupon the cycle of operations is as quickly repeated.

By the mechanism just described, as greata pressure along the line of contact as desired may be obtained, it being possible to make the few-Simple parts of the mechanism in strong sturdy proportions. It isnot however always desirable to use the same pressure for all impressions of the same work, or for impressions on different kinds of work.

43 and 43 are two slides, (see Figs. 3 and 4) mounted in ways 44 in front of the support for the form bed. These slides (see Fig. 3) are provided with one plane surface side provided with screw-threads about its middle and adapted to slide in the ways 44 on the face of the support. On the opposite side the slide is provided with two inclined surfacesof substantially equalcxtent which are adapted to engage in the inclined ways 45 on the back of the form bed I 46, 46 are two screws journaled in the support parallel to the ways, 44, 44, and the threads of these screws, which are formed on enlarged portions, (see Fig. 3) project through openings 46 in the support 14 and engage the screw threads on the slides 43, 43 when the parts are in assembled position, as shown in Fig. 3. By turning these screws, which are fixedly journaled in the support, the slides may be moved up and down and the form bed adjusted to and from its support, the compression spring 17 allowing this adjustment, by distances almost infinitesimal in their measure. Adjustment of the form bed may by this means be made equivalent to the adjustment secured by the placing of a sheet of gold leaf or a sheet of thin tissue paper on the face of the platen. The provision of a plurality of slides 43 gives the form bed a foundation as rigid and as firm as it would have if cast or fixedly secured to the support.

' The press thus described can be made to produce full tint impressions and half tones of excellent quality and at a high rate of speed, it being possible to operate the press at any rate of speed desired, and at a far higher rate of speed than the press can be fed by hand. By the simple provision of automatic feeding mechanism which is well known in the art, I may increase the output of the press to a maximum.

It is, of course, evident that while I have described a form of my invention in which the platen is the rocking element and the form bed the stationary element, it may well be that a form is placed upon the movable element, and the stationary element is made to act as a platen.

While I have described the best form of my invention now known to me, I wish to have it understood that I desire to cover in the annexed claims all forms of my invention which can be given it without departing from its generic spirit.

What I claim is:

1. In a printing press, a form bed, a curved platen adapted to make a rolling contact with said bed, a pair of draw-bars connected to said platen, one of said drawbars being jointed between its nds, and said draw-bars being so timed in their operations that the first bar draws one end of the platen to the form bed, and then the other bar rocks the platen until the other end is drawn to the form bed.

2. In a printing press, a form bed, a curved platen adapted to make a rolling contact with said bed, and a pair of drawbars connected to said platen, one of said draw-bars being jointed between its ends and said joint being biased in one direction, said draw-bars being timed in their operations so that first one bar draws one end of the platen to the form bed, and then the other bar rocks said platen until the other ,end of the platen is drawn to the form bed.

3. In a printing press, a form bed, a curved platen adapted to make. a rolling contact with said bed, a pair of draw-bars connected to said platen, one of said drawbars being connected to one end of said platen, and the other of said draw-bars being connected to the other end of said platen, said draw-bars being so timed in the other bar rocks the platen until the other end of said platen is drawn to said bed, a movable pivot for said platen, and a heart-shaped cam which acts to shiftsaid pivot.

5. In a. printing press, a form bed, a curved platen adapted to make a rolhng contact with said bed, a pair of draw-bars connected to said platen, and timed in their operation so that first one bar draws one end of the platen to the form bed, then the other bar rocks said platen until the other end is drawn to the form bed, a shiftable pivot for said platen having inner and outer positions with respect to the bed, and means which maintains said pivot in one ofv said positions during forward movement of said platen until it contacts with the platen bed,

and thereafter permits said pivot to shift to the other of said positions. v

6. In a printing press, a form bed, a curved platen adapted to make a rolling contact with said bed, means whichcauses said platen to roll over the'bed and make printing contact therewith and which after the printing movement separates the bed and platen and maintains said part-s separated during the return movement of the platen, a shiftable pivotfor said platenat its lower end, and means which ma1nta1ns said pivot at an inher position with respect to said bed during forward movement of" the platen and until it contacts with the form bed, and thereafter permits said pivot to be moved to an outer position with respect to the form bed.

frame, cycloidal ways in said frame, a curved p1aten, a pivotal shaft for saidplaten which shaft at its inner extremity of movement during the forward movement of the platen, and until mid platen contacts with the form bed, and which thereafter permits said pi o pression o knuckle 7. In a printing press, in combmatlon, a

to move to its outer position as said platen is rolled over said bed.

8. In a printing press, a pivoted platen, draw-bars associated with said platen which move said platen to and from the form bed to make impressions, and means for throw ing ofl" t-he impressloncomprising an eccentric journal for each'draw-bar, andmeans for turnin'g'each of said journals difierent degrees, the degree of movement depending upon the distance of the journal from the pivot of the platen.

.9. In a printing press, a form bed, a pivoted platen operatively' associated with said form bed, draw-bars associated with said platen which move said platen .to and from the form bed to makeimpressions, means for throwing oil the impression comprlsing an eccentric journal for each'drawbar, and crank-arms associated with said journals for turning them, one of said crank arms being longer than another.

10. In a printing press, a form bed, a platen, twoshafts which pass transversely through" the platen 'from one side to the other, eccentric journ 'als associated with the ends of said shafts, and draw-bars connected to said journals which move the platen to and from the form bed, and means for shi-ftin "said shafts to throw the imand on. j 11. A printin press comprising a form bed, a curved p ten, a pair of draw bars one above the other 'for moving one of said first-named elements toward and from the other, operating means for said draw bars, 4

one ofsaid draw bars being jointed between points of connection to said operating means and the one of said two first named elements to which it is connected.

12. Aprinting press comprising a form bed, a curved platen, power mechanism, and a pair of draw bars connected at their ends to said power mechanism and to one of said elements, one of said bars being jointed between its ends.

13.'A printing presscomprising a form.

bed, a curved platen, power mechanism, and a pair of draw bars connected at theirends to said power mechanism and to one of said elements, one of said draw bars having a joint between its ends.

14. A prlnting press comprising a form b d, a curved platen, power mechanism, and a pair of draw'bars connected at their ends to said power mechanism and to one of said elements, one of said draw bars havin a knuckle joint biased in one direction dietween its ends. i

15.'In' a printing press, a form bed, a curved platen, a power mechanism and upper and lower draw bars connected at their ends to said power mechanism and to one of said elements, the lowermost of said draw bars-having a knuckle jo1nt between its ends.

platen, a shiftable pivot associated with l6; printing press comprising a frame a form bed, a curved platen, a shiftable pivot for the platen. cyclcidal ways in which said pivot travels, said ways entering the frame beneath said form bed, means for operating the platen to make a rolling contact with the form bed, and independent vmeans for shifting said pivot as the platen is-moved.

17. In a printing press,-a form bed, a platen, upper and lower draw bars for operating said platen, and means for operating said draw bars, a lost motion device associated with the upper bar, and a knuckle joint in said lower bar.

18. In a printing press, a form bed, and a said pivot.

20. In a printing press, a form bed, and a platen, a shiftable pivot associated with said platen, and means for moving said platen toward and from the form bed, and means for shifting the pivot as the elements are moved, comprising a cam, a link secured to the platen and engaged by the cam, and a guide for said link. 1

21. In a printing press, aform bed, a curved platen, a shift-able pivot for said platen, three power shafts one. above the other, operating means connecting each of the upper shafts to the platen, and means for shifting the pivot of the platen operated by the lowermost shaft.

22. A printing press comprising a form bed, a platen, a shiftabl'e pivot for said platen, two power shafts one above the other, operating means connecting the upper shaft to the platen for moving the same,

and means operable by the lower shaft for shifting the pivot.

23. In a printing pness, in combination,

a form bed, a curved platen means for rocking the platen over the 'orm bed under pressure, and means opposing the rocking action and maintaining equal pressures on the lines of contact of the platen with the bed.

24. In a printing press, in combination, aform bed, a curved platen, having a movable pivot below the lower edge of the platen, for rocking the platen over the form bed, additional and controlling means for controlling the movement of the pivot during said rolling action, which means permits movement of the pivot at a rate which insures the platens having firm contact with the' bed at all times during the rolling action.

25. In a printing press, in combination,- a form bed, a curved platen, upper draw bars for rolling the platen over the form bed, and a cam which opposes movement of the platen by the draw-bars and which releases the same commensurately with the rolling actlon.

26. In a printing press, in combination,

a form bed, a curved platen, upper draw bars for rolling the platen over the form bed, and a pressure applying cam which controlsthe pressure of the platen on the bed during movement by the bars.

27. In a printing. press, in combinationa form bed, a curved platen, upper draw-bars for rolling the platen over the form bed, and a pressure applying cam which controls the pressure of the platen on the bed during the 'movement of the bars, and which moves the a which holds the lower end of the platen stationary for a moment as the upper end of the platen is moved away from the form bed immediately after the completion of each impression.

29. In a printing press, a platen, a form bed, one of which elements is curved, means 1 for movingthe lower end of one of the elements toward the other, means for moving the upper end of the same one toward the other, and simultaneously rolling the form bed and platen on each other to make animpression, and for thereafter moving the upper end of the one away from the other, and additional means which holds the lower end of the same movable one of said elements momentarilyat rest after the impression is completed.

30. In a printing press, a form bed, a platen and'a power mechanism, upper and lower connections between the platen and the power mechanism for shifting the same to and'from the form bed, the said lower connection being a lost motion connection, and additional means for moving said platen which takes up the lost motion of said lower connection at times.

31. In a printing press, a supporting bed having recesses in its outer face, vertical rods journaled in the supporting bed and being held from vertical movement and havand having screw threads upon their rear" faces engaging with the intermediate threaded portions of the rods, whereby the wedges receive vertical movement upon the turning of the rods.

32. In a printing press, a supporting bed,

a vertical rod journaled for rotation and held from 1ongitudina1 movement in the supporting bed and having an intermediate screw threaded portion projecting through the outer face of the supporting bed, a form bed carried upon the supporting bed and having upper and lower wedges upon its rear side, and a wedge block having complemental upper and lower wedges uponits forward side slidably engaging the respective wedges of the form bed, and further having screw threads in its rear side intermeshing with the threaded intermediate portion of the. rod to receive vertical movement upon the turning of the rod.

In testimony whereof I have hereunto set my hand in presence of two subscribing witne'sses.

. WILLIAM M. CLARK. Witnesses:

RICHARD CRANKSHAW, J r., ELIZABETH V. MARTIN.

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