US2413174A - Rotary printing press - Google Patents

Description

De@ 24 1946. c. s. CRAFTS Erm. '2,413,174

ROTARY PRINTING PRESS 3 Sheets-Sheet l Filed Dec. 2, 1945 E un f :zg A IW Dec. 24, 1946. c. s. CRAFTS ETAL 2,413,174

ROTARY PRINTING PRESS s sheets-sheet 2 Filed Dec. 2, 1945 NNN Dec. 24, 1946. c. s. CRAFTS Erm. 2,413,174

ROTARY PRINTING PRESS Filed Dec. 2, 1945 3 Sheets-Sheet 3 1s l, j??? 4 Z4 Patented Dec. 24, 1946 ROTARY PRINTING PRESS Curtis S. Crafts and Charles Alonzo Harless, Oak l Park, Ill., assignors to The Goss Printing Press Company, Chicago, Ill., a corporation of Illinois Application December 2, 1943, Serial No. 512,530

19 claims. 1

This invention is an improvement in rotary printing presses, and relates to the plate cylinder in such a press, being concerned particularly With means for exerting circumferential tension on a stereotype plate carried by theplate cylinder.

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

The invention consists in the novel parts, constructions, arrangements, combinations, and imvview taken on the line 2-2 of Fig. l;

'Fig.,3 is an enlarged fragmentary sectional if viewtaken on the line 3-3 of Fig. 1; i

Fig. 4 is an enlarged fragmentary cross section of the plate cylinder, taken on the line 4-4 of Fig. 1;

Fig. 5 is an end view partly broken away of l* the` plate cylinder of this invention;

Fig. 6 is a sectional view oi certain parts of Fig. 5 taken on the line 6-6 of Fig. 5; and

Fig. 7 is a view on a smaller scale of the por; tion of Fig. 1, looking from the right of that iigure.

With high speed printing presses, it has been'.

found desirable to hold a` stereotype plate in position on the plate cylinders by means exerting circumferential tension on the plate. With these high speed presses, there is a tendency for the plate to deform, and eventually crack, due to the continuous and successive pressure waves exerted on it in the printing operation; thereis some g tendency for the plate to become displaced, and there is also the eilect4 of centrifugal force. .All of these factors are eliminated or counteracted to a substantial degree by securing the leading edge oi the printing plate to the plate cylinder and by exerting a circumferential resilient tension on the trailing edge of the plate.

The principal object of the present invention is to provide a plate cylinder for a rotary printing'press where a resilient circumferential ten 2k sion is exerted onthe trailing edge of the plate while a torsion shaft exerts a, force on the plate against the pull of said resilient means.

Another object ofthe invention is to provide a plate cylinder where the respective longitudinal edges of the plate are engaged with hooks, one set of hooks exerting resilient tension on the trailing edge, and a second set of hooks controlled by a torsion shaft exert a force on the leading edge against the pull of the resilient hooks.

Another object oi.' the invention is to provide controlling means for the described torsion shaft which can be turned and locked in positiomto put the resilient means at the trailing edge of the plate under tension, and to hold the leading edge of the plate in place against the pull of such resilient means.

Another object of the invention is to provide a controlling means for described torsion shaft,

which means is turnable on an axis substantially perpendicular to the axis of the-plate cylinder, whereby the torsion shaft can be turned and caused'to putthe tension exerting means at the trailing edge under tension.

It will be understood that the foregoing general description and the following detailed description as well are exemplary and explanatory of the invention but are not restrictive thereof.

yReferring now to the drawings, the plate cylinder 2 is provided with a longitudinally extending recessl. The recess 4 ispartially filled by a `plate 6' which is formed with spaced recesses and is secured by bolts 8. A cover portion I0 formed integrally therewith has openings I4, opening into the respective recesses in the plate 6.

In each of the described compartments there is mounted a unitary assembly for exerting spring tension on the trailing edge I6 of the stereotype plate I8. This assembly comprises the plate 6 having pairs of recesses 2i. This housing is connected lwith a hook plate 22 by means of two pins 24, passing through the recesses 2|. One end of each pin 24 is secured in the housing, while the lower end passes through and loosely engages the hook plate 22, pins 24 vhaving heads 26 somewhat larger than the hole through which the pins pass. Mounted in each recess 2| and encircling each pin 24 is a strong compression spring 28 bearing against the inside of the recesses y2| and against the hook plate 22. The inner end of the hook plate projects beyond the inner wall 24' of the housing, and is rounded, as shown at 30. With the described construction, hook 22 has a limlted pivotal movementby reason of its rounded 3 end 30 and is pressed strongly outwardly by the two springs 28. The hooks 3l of the hook member extend through openings I4 in cover portion i8 and engage in recesses 32 in the trailing edge of the stereotype plate. This assembly of tension exerting means may readily be put in'vplacey or removed from the plate cylinder as a unit.

The torsion shaft and cooperating mechanism for holding the leading edge of the plate and for putting the tension exerting means at the trailing edge under tension will now be described. This mechanism comprises a. torsion shaft 38 extending longitudinally of the plate cylinder mounted in bearings 38 in their suitable recesses in the plate cylinder, the bearings being held in place by pins 40 while the outer bearings are held in place by a cover plate 42 held in place in a suitable recess in the cylinder by screw bolts 44.

In making the torsion shaft 36, it is machined under torsion, so that when in use and again put under torsion the resulting deflection will result in accurate positioning of the plate engaging hooks carried by the shaft. In other words, the hooks 52 on the finished unstressed shaft are positioned along a helix, instead of being strictly in line. -Howeven when the shaft is put under torsion in actual use, the slight successive displacements of the hooks bring the hooks into accurate axial alignment. f

Further bearings for. the shaft 36 are provided at 46, while the end of the shaft terminates in a head 48 and a projecting stud 50, stud 5l)A being loumalled in a bracket secured to the end of the plate cylinder.

'I'he shaft 36 is provided with a plurality of outwardly projecting hooks 52 rigidly secured thereto preferably being forged to the shaft, and adapted to engage in recesses 54 in the leading edge 66 of the stereotype plate, these hooks extending through openings 60 in the cover plate 42.

The mechanism for turning and locking the torsion shaft 36 for holding the leading edge of the stereotype plate will'now be described. This mechanism comprises an actuating lever or plate 62 secured to head 48 of shaft 36 by stud 64. Apertures 66 in actuating plate 62 and the head 48 provide journal bearings for the stub shafts 68 projecting from a block 10. Block is provided with a transversely extending, eccentrically mounted stub shaft 12. Shafts 68 and 12 are at right angles providing universal movement. The ends of shaft 12 are journalled in a stirrup 14 integral with arm 16, the other end of which arm is formed into an eccentric strap 18. This eccentric strap 18 engages over a, spherically curved bushing 80 being held in place by plate 8|. Bushing 88 is free on the eccentric head 82, one end 84 of which is fixed to bushing 86 journalled in recess 81, bushing 86 having a limited rotary movement by reason of the fixed pin 88 working in slot 90 of the bushing. The outer end 92 of the eccentric head 82 is journalled in a, recess 94 in the plate cylinder` and is provided with the key slot 96 for receiving a wrench for turning it. In order to lock the described parts in xed position a spring pressed plunger 98 adapted to snap into a recess in head 92 is used.

'l'he operation is as follows: A stereotype plate is put in position on the cylinder, the hooks 22 for the trailing edge being engaged in their recesses 32, while the hooks 52 for the leading edge are engaged in recesses 54, hooks 52 being -retracted far enough to allow them to slip into their tion. it is necessary to rotate torsion shaft 36 to 4 cause the hooks 52 to pull the plate against the tension exerted by the resilient hooks at the trailing edge. 'I'his is accomplished by putting a .wrench in recess 96 and turning the eccentric 82 which, referring to the lower part of Fig. 5, pushes stirrup 14 to the right, the movement of the eccentric away from the end of the cylinder being compensated for bythe movement about the stub shaft v'12. The movement of 14 to the right moves the actuating plate 62 in a counterclockwise directionvand, since the plate 62 is fixed to shaft 36, the shaft is moved in a counterclockwise direction to cause hooks 62 to exert a circumferential tension on the plate, which pulls against the tension exerted on the plate by the described resilient means engaging with the trailing edge thereof, and so the plate is put under tension. The

lshaft 36 is locked in this position by the plunger 98 snapping into the appropriate recess in head 92 of the operating eccentric, the eccentric being at about dead center in this position.

In removing the plate, the plunger 98 is released and the eccentric turned in the opposite direction, to swing hooks 52 to the position shown at the right of Fig. 5, in which position the leading edge of the plate can be lifted away from the cylinder about its trailing edge as a pivot, to clear the hooks 52, after which hooks 22 are readily released.

Where two stereotype plates are used the described mechanism is in duplicate, as shown. The same mechanism may be used for a cylindrical stereotype plate.

'I'he invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may he made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages.

We 'claimas our invention:

l. In a rotary printing press, a plate cylinder for exerting circumferential tension on a stereotype plate, comprising resilient means for exerting tension on the trailing edge of the plate and means, including a torsion shaft extending longitudinally of the plate cylinder, for exerting tension on the leading edge of the plate, against the tension of said resilient means.

2. In a rotary printing press, a plate cylinder for exerting circumferential tension on a stereotype plate, comprising resilient means for exerting tension on the trailing edge of the plate, means; including a torsion shaft extending longitudinally of the plate cylinder, for exerting tension on the leading eige of the plate, against the tension of said resilient means and means for locking said torsion shaft in tension exerting position.

3. In a rotary printing press, a plate cylinder for exerting circumferential tension on a stereotype plate, comprising resilient means for exerting tension on the trailing edge of the plate, means, including a torsion shaft extending longitudinally of the plate for exerting tension on the leading edge vof the plate against the tension of said resilient means, an actuating member fixed to one end of said torsion shaft, and means for oscillating said member in a plane substantially perpendicular to the axis of the torsion shaft.

4. In a rotary printing press, a plate cylinder for exerting circumferential tension on a stereotype plate, comprising resilient means for exerting tension on the trailing edge of the plate, means including a torsion shaft extending longitudinally of the plate for exerting tension on the leading edge of the plate against the tension of said resilient means, an actuating member xed to one end of said torsion shaft, and turnable means, including an eccentric, for Oscillating said actuating member in a plane substantially perpendicular to the axis of the torsion shaft, for turning said torsion shaft back and forth about its axis.

5. In a rotary printing press, a plate cylinder for exerting circumferential tension on a stereotype plate, comprising resilient means for exerting tension on the trailing edge of the plate, means, including a torsion shaft extending longitudinally of the plate for exerting tension on the leading edge of the plate against the tension of said resilient means, an actuating member fixed to one end of said torsion shaft, and turnable means, turning on an axis substantially perpendicular to the axis of the plate cylinder, for oscillating said actuating member for turning said torsion shaft back and forth about its axis.

6. In a rotary printing press, a plate cylinder for exerting circumferential tension on a stereotype plate, comprising resilient means for exerting tension on the trailing edge of the plate, means, including a torsion shaft extending longitudinally of the plate for exerting tension on the leading edge of the plate against the tension of said resilient means, an actuating member xed to one end of said torsion shaft, means for oscillating said member in a plane substantially perpendicular to the axis of the torsion shaft and means for locking said oscillating means in fixed position.

'7. In a rotary printing press, a plate cylinder for exerting circumferential tension on a stereotype plate, comprising resilient means for exerting tension on the trailing edge of the plate, means, including a. torsion shaft extending longitudinally of the plate for exerting tension on the leading edge of the plate against the tension of said resilient means, an actuating member fixed to one endof said torsion shaft, turnable means, turning on an axis substantially perpendicular to the axis of the plate cylinder, for oscillating said actuating member for turning said torsion shaft back and forthfabout its axis and means for locking said turnable means in a xed position.

8. In a rotary printing press, a plate cylinder for exerting circumferential tension on a stereo,- type plate, comprising resilient means for exerting tension on the trailing edge of the plate, means, including a torsion shaft extending longitudinally of the plate for exerting tension on the leading edge of the plate against the tension of said resilient means, an actuating member xed to one end of said torsion shaft, turnable means, including-a spherically curved eccentric, turning on an axis substantially perpendicular to the axis of the plate cylinder, and an eccentric strap, operatively connecting said actuating member and said eccentric, whereby the torsion shaft is moved back and forth about its axis.

9. In a rotary printing press, a plate cylinder for exerting circumferential tension on a stereotype plate, comprising resilient means for exerting tension on the trailing edge of the plate, means, including a torsion shaft extending longitudinally of the plate for exerting tension on the leading edge of the plate against the tension of said resilient means, an actuating member fixed to one end of said torsion shaft, turnable means, including a spherically curved eccentric,

6 turning on an axis substantially perpendicular to the axisl of the plate cylinder, an eccentric strap, operatively connecting said actuating member and said eccentric, whereby the torsion shaft is moved back and forth about its axis and means for locking said turnable means in fixed position.

10. In a rotary printing press, a plate cylinder for exerting circumferential tension on a stereotype plate, comprising resilient means for exerting tension on the trailing edge of the plate, a torsion shaft extending longitudinally of the cyl-- inder, projections carried by the torsion shaft and engageable with the stereotype plate, and meians for turning the torsion shaft about its ax s.

l1. In a rotary printing press, a plate cylinder for exerting circumferential tension on a stereotype plate, comprising resilient means for exerting tension on the trailing edge of the plate, a, torsion shaft extending longitudinally of the cylinder, outwardly extending hooks carried by the torsion shaft and engageable with the back of the stereotype plate and means for turning and locking the torsion shaft.

l2. In a rotary printing press, a plate cylinder for exerting circumferential tension on a stereotype plate, comprising resilient means for exerting tension on the trailing edge of the plate, and means, including a torsion shaft provided with outwardly extending hooks for engaging the leading edge of the plate, said hooks, when the shaft is not vunder torsion, being progressively displaced from axial alignment to such an extent that torsional deflection of the shaft with the hooks engaging the plate brings the hooks into substantial laxial alignment.

13. A torsion shaft for exerting a force on the edge of a stereotype plate, having outwardly extending hooks thereon for engagement with said plate, said hooks, when the shaft -is not under torsion, being progressively displaced from axial alignment to such an extent that torsional deflection of the shaft with the hooks engaging the plate brings the hooks into substantial axial alignment.

14. A torsion shaft -for exerting a force on the edge of a stereotype plate, having outwardly extending hooks thereon for engagement with said plate, said hooks, when the shaft is not under torsion, being arranged along a helix, the deection of the shaft by torsion serving to bring the hooks into substantial axial alignment.

15. In a rotary printing press, a plate cylinder for exerting circumferential tension on a curved stereotype plate, said cylinder having a recess in its surface to receive a removable plate hook assembly in substantial alignment axially of the cylinder surface, said hook assembly comprising a plate having spaced recesses extending normal to the length of the plate, a plurality of hooks pivotally mounted with respect to the recessed plate, compression springs in the recesses urging the hooks away from the recessed plate, and means for retaining the assembly in cylinder recess.

16. In a rotary printing press, a plate cylinder for exerting circumferential tension on a curved stereotype plate, said cylinder having a recess in its surface to receive a removable plate hook assembly in substantial alignment axially of the cylinder surface, said hook assembly comprising a plate having spaced recesses extending normal to the length of the plate, a plurality of hooks pivotally mounted with respect to the recessed plate, compression springs in the recesses urging the hooks away from the recessed plate, pins,

mounted in the plate recesses and encircled by said springs, said pins extending through said hooks and serving to retain them assembled to the plate, and means for retaining the assembly in cylinder recess.

17. In a rotary printing press, the combination of a plate cylinder for supporting a printing plate, resilient means carried by said cylinder for exerting tension on one edge of the plate, and movable means carried by said cylinder torsionally operated to exert aV predetermined torsional load on the other edge of the plate against the resiliency of said resilient means.

i8. In a rotary printing press, the combination of a plate cylinder for supporting a printing plate, resilient means acting on one straight edge of the plate to exert resilient tension thereon, movable means including a torsional shaft extending longitudinally of the cylinder for exerting a pull on the other straight edge of the plate against the resiliency of said resilient means. and operating means for stressing said shaft with a predetermined torsional force as said movable means engage with the said other edge of the plate.

19. In a rotary printing press the combination of a plate cylinder for supporting a printing plate, means 'for securing a parti-cylindrical printing plate thereto including a shaft carrying plate engaging hooks which project through the surface of the cylinder to engage in recesses in the concave side of the plate near an edge thereof and means for angularly moving said shaft and hooks including an arm connected thereto, an eccentric and a link connecting the eccentric and arm.

CURTIS S. CRAFTS. CHARLES ALONZO HARLESS.

Images