US2250677A - Feed mechanism for printing presses - Google Patents

Description

July 29, 1941. c. PAULSEN FEED MECHANISM FOR PRINTING PRESSES Filed Dec. 6, 1939 4 Sheets-Sheet l INVENTOR. I C R/ST/HN PAULSEN.

ATTORNEY.

4 Sheets-Sheet 2 "Il a- C. PAULSEN Filed Dec. 6, 1959 FEED MECHANISM FOR PRINTING PRESSES INVENTOR. CHRIST/"7N PAULSEN. [1 A ATTORNEY July 29, 1941.

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FEED MECHANISM FOR PRINTING PRESSES Fla 4 CHRIS T/HN PAULSEN.

A TORNEY.

Patented July 29, 1 941 UNITED srere s PATENT FEED MECHANISM FOR, PRINTING PRESSES' Christian Paulsen, Clifton; N. J., assignor to New Era Manufacturing Company, Paterson, N. J., a corporation of New Jersey Application DeoemberB, 1939, Serial No. 307,730

20 Claims.

My invention relates to flat-bed printing presses for printing webs, and more particularly to an' improved feed mechanism that alsoregulates the tension of th printed web as such web is intermittently advanced through the press between impressions.

Heretofore it has been thegeneral practice to apply a uniform tension to the Web as the latter has been fed between impressions; However I have discovered that a steady tension is entirely inadequate for good register, particularlyat high speeds. For example, when a steady tension is applied to hold the web at the end of the feed stroke, then there is too'much tension to start the web at the beginning-of the web stroke. "Result is that the feed wheels used to advance the web-will slip slightly at every feed, andalso the extent of this slippage will not be the sam at each feed, thereby causing shortf'eeds and misregister.

The objects of my invention, among other things, 'is-to provide an improved feed mechanism for the web in'flat-bed presses that-will overcome such defects, such mechanism embodying a variable tensiondevice that is synchronized with the feed crank mechanism for advancing the web, whereby the web is left absolutely free at the-beginning of the feed stroke, and thereafter the" tension on-theweb is applied gradually with the maximumtension reached as required atthe end of the feed stroke. By my improved mechanism I am enabled to feed the web at very high speeds without the slightest slippage.

Another object of my invention is to provide means for positively clamping the web at both ends of the press against any movement at the end of each feedstroke; also for keeping the web clamped during the printing stroke while serving to strip the web away from the formas the latter rises aftermaking the impression. Such clamps are released again just before the web starts feeding for the succeeding impression, and the web is then entirely free for its forward travel. These web clamps are operatedin timed relation with the feed crank for advancing the web, and since the feed crank may be operated one, two or three times for each printing impression, I have provided improved mechanism for changing the tension and clamp devices, such chang in the feed being accomplished when'thepress is stopped in timing position.

Other objects and advantages will be hereinafter described and. particularly pointed out in the appended'claims, and I have. shown a pre-55 ferred embodiment of myinvention-in the accompanying drawings in which Fig, 1 is a side elevation of a 'flat-bed'printing press printing one color on the upper'side" of' a web and one color on the reverse side thereof with the printing heads shown on impression;

Fig. 2-is an enlarged end elevation taken'on the line 2-2 of Fig. 1;

Fig. 3 is a side elevation of the parts shown in Fig. 2;

Fig; 4 is an enlarged end-elevation-takenon the line 4-4 of Fig. 1;

Fig. 5 is a side elevation ofFig; 51ooking, from the left; 4 Fig. 6 is a detailed side-elevation of theunechzanism' for varying the tension on the Web;

Fig. '7 is an enlarged detailview of the tension setting devices;

Fig. 8 is a detailed top planof the feeding mechanism for the web shown at the-left of Fig. 1; p Fig. 9 is a side elevation of the parts shown in Fig. 8; and

Fig. 10 is a detail View, partlyin section, taken on theline Ill-Ifl-of Fig; 9.

Similar numerals refer to similar 'partsthroughout the several figures.

Referring to Fig. 1,- the web of paper-W in' the form of a roll is rotatably mounted'on the standard II, and the web is led fromthe roll over the usual spring-tension roll 1-2; idler rollsl 3between the feed-rolls l4 rotated in unisonby the spur gear I5 driven by' any suitable mechanism. The web W below the feed-rolls l4 hangs-in'a loop to prevent snarling, and then passesupwardly around the web roll over the-idler roll 16 (Figs; 3 and 6) into the zone of the first printing'head as shown at the right of Fig. 1.

The frame ll supports the two pressunits-and the various mechanisms for controllingthe" feed of the web W as the latter passes to the left through the press as shown in Fig. 1. Power is supplied from the electric motor I8 through the belt 19 passing around the pulley 20 a-ffixedto the drive shaft 2| journalled on the far side-of the press shown in Fig. 1. The clutch for disconnecting the press and feed mechanisms from the'driveshaft 2! is indicated by the numeral- 22 (Fig. 1).

As shown in Fig. 1, the web W passes to the left to the first printing head-M for theimpression-on the top side of the web, and then to the second printing head N for the'impression on the under side of the-web. These printing head's-M-andN "are of-usual construction and in themselves constitute no part of the present invention. An outline description of one will suffice for both. Referring to the first head M, the form carrier 23 is pivotally mounted to the upright brackets 24 carried by the frame I! which support th inking mechanism [8 for inking the form rollers 25 affixed to the chains 26 passing around the sprockets 21. The form carrier 23 is connected by the link 28 to the crank 29 driven by the gear 30 meshing with the gear 3| mounted on the drive shaft 2|. In both printing heads M and N the impression is shown as on.

The web W is advanced through the press by the feed mechanisms shown at the left of Fig, 1, and such feed mechanisms comprise the under feed-roller 32 and upper pressure roller 33, the roller 32 being intermittently rotated by mechanism hereinafter to be described.

Two sets of clamps are used for holding the web at rest during impression, one set being located to hold the web before it passes to the printing head M and the other set of web clamps being positioned between the printing head N and feed rollers 32 and 33.

The first set of web clamps adjacent the printing head M are shown more particularly in Figs. 2-5 and comprise the following parts: The clamps 34 are spaced apart near the margins of the web W and have the cork pads 35 to bear on the web. The clamps 34 are secured to the lower slide bar 36 by screw bolts 3'! (Figs. 4 and to suitably space same to accommodate for different widths of the web W that maybe used. The ends of the slide bar 36 are slidably mounted on the vertical guide posts 38 mounted on the frame l1, while the clamps 34 carry the upright guide rods 39 around which are coiled the springs 49, the upper ends of which are contained in sockets M formed on the upper slide bar 42 mounted on the guide posts 38. The upper ends ofthe rods are screw-threaded where they pass through the slide bar 42 and carry the washers 43 and adjusting nuts H to adjust the length of the rods 39 between the slide bars 36 and 42 and so control the force of the springs 49 for different weights of theweb W. The upper slide bar 42 carries at each end the connecting links 45 mounted on studs 46 journalled on the cross shaft 47 carried by the brackets is supported on the frame ii. The studs are fastened to the drive levers 49 rocking on the shaft 47.

The drive link 59 for the first set of clamps 34 is' pinned to one of the drive levers 99, and extends downwardly to the connecting link 5| journalled on the pin 53 carried by the crank disk 54 mounted on the stub shaft 55 journalled in the bracket 59 (Fig. 3). This stub shaft 55 is rotated from the drive shaft 2| by an interchangeable speed gearing .mechanism hereinafter to be described.

The second set of web clamps 34 (located between the printing head N and the feed rollers 32 and 33) are of similar construction as those of the first set, and have similar actuating mechanism except that the drive link 59 is pinned to the crank disk 57 (Figs. 4 and 5) mounted on the cross-shaft 58 journalled in the frame IT. This shaft 58 carries the bevel gear 59 meshing with the bevel gear 69, mounted on the cutter drive shaft 9! (Fig. i) that is actuated in timed relation with the drive shaft 2i by any suitable mechanism (not shown).

The web-tensioning mechanism comprises the following devices best shown in Figs. 1-3, 6 and 7, :such mechanism being located adjacent the web clamps 34 for the first printing head M: Two tension plates 52 are preferably used and they are arranged between the web clamps 34 as shown in Fig. 2. These plates 62 carry felt pads 63 to bear on the web W against the supports 34 carried by the frame I1 (Figs. 6 and '7). The plates 62 are mounted on the brackets 95 journalled on the rock-shaft 66 journalled in the frame Ii. The upper ends of the brackets '65 have alined holes through which extends the rod 37 by which the plates 62 may be adjusted laterally to each other to accommodate for different widths of the web W. Midway on the shaft 68 is fastened the swinging finger G8 which is adapted to bear against the rod 61 when the shaft 66 is rocked anti-clockwise (Figs. 6 and 7) so as to exert tension on the web through the plates 62. The degree of tension of the plates 62 on the web W is determined by the different positions of the finger 68 (shown in dotted lines in Fig. 7), the position T being the maximum tension while the minimum tension is that of the position T with the tension decreasing from the T position through the T T, 'I' to the T positions according to the adjusting dial 69 (Figs. 1 and 6) on which the lever 19 pinned at TI to the frame I1 may register at the will of the operator. The lever 19 carries the drum [2 around which is atfixed the strap 13 to which is fastened the steel cable 14 that runs rearwardly over the pulleys l5 and is connected to the turn-buckle 19 by the adjustable screw bolt 18. The turn-buckle Tl carries the adjustable screw-bolt T8 to which is secured the coil spring 19 fastened at the upper end to the rock-lever 39 secured to one end of the rock-shaft 63.

The opposite end of the rock-shaft 66 carries the rock-lever 8| (Figs. 2 and 3) connected by a pair of coil springs 82 to the link 83 pivoted at 84 to the crank disk 54. The upper end of the link 83 carries the guide rod 85 that passes through a hole in the stud 85 journaled in the bracket 58. As the rock-lever 8| is raised and lowered by this mechanism the tension plates 62 are pressed against the web W under a yielding spring tension that may be varied according to the position of the finger 88 mounted on the rock-shaft 66 (Fig. 'I)

The mechanism for actuating the under feed roller 32 comprises a compound crank motion that is best shown in Figs. 1 and 840: This feedroller 32 is mounted on the shaft 87 which carries on the far end the usual friction brake hub 38 and feed gear 89. On the near end of the shaft 81 are secured the friction disk 90 and operating ring 9| together with the feed ratchet 92 that is engaged by the feed pawl 93 pinned to the pawl disk 94. The feed pinion 95 meshes with the feed rack 96 carried by the bar 91 (Fig. 1), and this feed rack 96 is connected by the link 98 to the slide 99 carried by the crank disk H39 mounted on the cross-shaft 58 that is driven from the shaft 6| through the bevel gears 59 and '6 (Fig. 8). A very slow accelerated and also a slow retarded motion is imparted to the feed-roller 32 by the mechanism shown in Figs. 8- 10: The eccentric I93 is stationary and dowelled to theframe I! while the eccentric link I94 is connected by the pin I95 to the slide 99 (Figs. 9 and 10). The slide 99 is provided with the T slot I05 and adjusting screw l0! so that the length of the feed may be adjusted to any length within the limits of the crank disk I09. As this disk I 00 rotates in the direction of the arrow (Figs. 1 and 9), the slide 99 will follow the cocentric I03 and since this eccentric is dowelled in relation to motion, the motion of the feed rack 96 will be neutralized at both the beginning as well as at the ending of each feed stroke. The critical point of action is where the pawl 93 engages the ratchet 92, which is at the very beginning of the stroke as the crank pin 99A on the slide 99 passes the line AB (Fig. 9). After passing this point in the direction of the arrow the pawl 93 has engaged the ratchet 92 and the feed roller 32 starts to rotate (anti-clockwise) with the web W held in contact with the roller 32 by the pressure of the upper feed-roller 33. As soon as the web has started its forward movement the critical point has passed for this particular feed, since the web will not slip after once it has started. Such starting of the web takes place during the first five to ten degree angular movement of the crank disk I09.

Referring to Fig. 9, the travel from A to B is the feed stroke and the idle stroke is from B to A. The web W is at rest and the printing accomplished during the idle stroke. The web during the printing period is held by the clamps 34 to keep same from shifting and these clamps 34 also act to strip the web from the printing plate as the plate is lifting. Such clamps 34 are in operation while the crank disk I90 travels from E to F and the printing occurs between G and G The web clamps 34 are actuated in timed relation with the feed crank, and since the feed crank may be operated one, two or three times for each printing impression, a change gear box for changing the tension on the web through the plates 62 as well as the clamp mechanism is provided and is best shown in Fig. 3.

The gear box I98 (Fig. 1) comprises the following mechanism whereby a change may be made from single to double or triple feed: Referring to Fig. 3, the stub-shaft 55 is j'ournalled in the bracket 56 and the crank disk 55 is fastened to the shaft 55 by the pin H9. The sleeve III is slid-ably keyed to the shaft 55 and carries the change gears H2, H3 and H4 as well as the grooved collar H5. Complementary change gears H6, H1 and H8 are secured to the shaft II!) journalled in the bracket 56, the shaft II9 also carrying the gear I29 that meshes with the drive gear I2I mounted on the drive shaft 2| (Figs. 2 and 3). Sl-idably mounted in the bracket 59 is the push rod I22 having the handle I23, the rod l22 carrying the arm I24 that engages the grooved collar H (Fig. 3). By shifting the push rod I22 the three sets of coacting change gears are brought into cooperating relation. The gears I 13 and I H are in mesh as shown with the handle I23 in its full line position for single feed, and the gears H2 and H8 are in mesh for double feed when the handle I23 is pulled to the left (Fig, 3), while the gears H4 and H8 are in mesh for triple feed when the handle I23 is in the right-hand dotted position (Fig. 3). This change from one feed to another should be made when the press is stopped in timing position as shown in Fig. 1. A similarly constructed change gear box marked I25 is also used for the feed mechanism at the left side of Fig. 1 that is likewise changed in accordance with the proper gears in engagement as heretofore described in the box In operation and referring to Fig. 1, the printing heads M and N are shown on the impression, and in this position the operations of the feed, clamping and tension mechanisms are synchronized with the web W at rest. When the web is at rest the feed crank pin 99A is half way on the idle or return stroke (Fig. 9). When this crank pin reaches the point A the feed pawl 93 engages the ratchet 92 and the web W starts to feed. Assuming that the tension lever I9 (Fig. 1) is set with the pointer at 5 (Fig. 6), which is the maximum tension, such tension will begin to take effect when the feed crank pin 99A reaches the point T (Figs. 2 and 9). The web W at the start of the feed is entirely free and the tension is applied gradually until the crank pin 99A arrives at the point B at the end of the feed. Had the lever 'Il'l been pointed at T instead of T the crank pin 99A would reach T (Fig.9) before the tension would be applied to the advancing web, and the amount of tension at the end of the feed stroke would be proportionately less than if the pointer on the lever I9 (Fig. 6) was set at T T T or T The crank pin 84 (Fig. 2) is also shown in timing position, and the marking CD corresponds to the marking AB (Fig. 9), while the designations (T to T inclusive) correspond in the same order as on the feed crank (Fig. 9).

In both cases these markings indicate where the tension begins to take eifect, and on Fig. 7 show where the finger 68 engages the tension rod 61.

It will be seen that my adjustable feed mechanism as hereinbefore described embodies a Variable tension device that is synchronized with the feeding mechanism so as to leave the web en'- tirely free as the feed stroke begins with the ten-- sion variably and gradually applied during the feed stroke and reaching the maximum at the end of such feed stroke, while my feed mechanism also embodies means for holding the web at both ends of the press against any movement at the end of each feed stroke and at the same time the web is clamped during the printing stroke, such clamping means also serving to strip the web from the form as the latter rises after impression, and leaves the web free for the next forward feed.

I do not wish to be limited to the particular type of printing-press shown. since the same may be changed in its structural details Without sacrificing the advantages derived from the use of my improved mechanism for feeding the web therethrough.

I claim as my invention: 1. A feed mechanism for a printing unit comprising means for intermittently feeding a web to said unit, and means separate from the travelling web and cperatively connected with said feeding means for gradually applying tension directly to the Web during its forward feed.

2. A feed mechanism for a printing unit comprising means for intermittently feeding a web to said unit, means actuated by said feeding means for gradually applying tension to the web during its forward feed, and means for varying the amount of tension so applied.

3. A feed mechanism for a printing unit comprising means for intermittently feeding a web to said unit, and means actuated by said feeding means for initially applying tension to the web including means for gradually increasing the tension applied to the web during its forward feed.

4. A feed mechanism for a printing unit com- .prising means for intermittently feeding a web to said unit, means for applying tension to the web during its forward feed, and means for actuating said feeding means and said tension means in timed relation to free the web from said tension means when the Web starts its forward motion.

5. A feed mechanism for a printing unit comprising means for intermittently feeding a web to said unit, means for gradually applying tension to the web during its forward feed, and means for actuating said feeding means and said tension means in timed relation to free the web from said tension means when the web starts its for- Ward motion.

6. A feed mechanism for a printing unit comprising means for intermittently feeding a web to said unit, means for initially applying tension to the web including means for gradually increasing the tension applied to the web during its forward feed, and means for actuating said feeding means and said tension means in timed relation to free the web from said tension means when the web starts its forward motion.

7. A feed mechanism for a printing unit comprising means for intermittently feeding a web to said unit, means actuated by said feeding means for gradually applying tension to the web during its forward feed, and means for variably controlling the tension so applied.

8. A feed mechanism for a printing unit comprising means for intermittently feeding a web to said unit, and means for initially applying tension to the web including means for gradually increasing a variably controlled tension applied to the web during its forward feed.

9. A feed mechanism for a printing unit comprising means for intermittently feeding a web to said unit, and separate means each actuated by said feeding means for clamping the web adjacent both ends of said unit during the printing.

10. A feed mechanism for a printing unit comprising means for intermittently feeding a web to said unit, and separate means each actuated by said feeding means for clamping the web adjacent both ends of said unit during the printing, said clamping means stripping the web from said unit after impression.

11. A feed mechanism for a printing unit comprising means for intermittently feeding a web to said unit, separate means each actuated by said feeding means for clamping the web adjacent both ends of said unit during the printing, and means for releasing said clamping means before said feeding means begins its next cycle.

12. A feed mechanism for a printing unit comprising means for intermittently feeding a web to said unit, separate means each actuated by said feeding means for clamping the web adjacent both ends of said unit during the printing, said clamping means stripping the web from said unit after impression, and means for releasing said clamping means before said feeding means begins its next cycle.

13. A feed mechanism for a printing unit com prising means for intermittently feeding a web to said unit including a mechanism for forwarding said web a plurality of feeds for a printing impression, and means actuated by said feeding means for gradually applying tension to the web during each of said feeds.

14. A feed mechanism for a printing unit comprising means for intermittently feeding a web to said unit including a mechanism for forwarding said web a plurality of feeds for a printing impression, means for gradually applying tension to the web during each of said feeds, and means for varying the amount of tension so applied.

15. A feed mechanism for a printing unit comprising means for intermittently feeding a web to said unit including a mechanism for forwarding said web a plurality of feeds for a printing impression, and means actuated by said feeding means for clamping the web adjacent both ends of said unit during printing.

16. In a feed mechanism for a flat-bed printing press, means for intermittently feeding a web to the press, means for clamping the web at rest during impression, and means for gradually applying tension to the web during its forward feed between impressions.

17. In a feed mechanism for a flat-bed printing press, means for intermittently feeding a web to the press, means for clamping the web at rest during impression, means for gradually applying tension to the web during its forward feed between impressions, and means for synchronizing the operation of said clamping means and said tension means to free the web as the latter begins its forward feed.

18. In a feed mechanism for a printing press, means for intermittently feeding a web to said press, means actuated by said feeding means for applying an increasing tension on the web during its forward feed, and means for variably con trolling the tension so applied.

19. In a feed mechanism for a printing press, means for intermittently feeding a web to said press, separate means each actuated by said feeding means for clamping the web adjacent both ends of the press during impression, and means for varying the number of feeds for said web during a single impression.

20. A feeding mechanism for advancing a web of material comprising means for intermittently advancing said web and means separate from the travelling web and operatively connected with said feeding means for gradually applying tension directly to the web during the periods of its forward feed.

CHRISTIAN PAULSEN.

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