US1647560A - Platen-controlling mechanism for printing machines - Google Patents

Description

Nov. 1, 1927. 1,647,560

7 C. CHISHOLM ET AL PLATEN CONTROLLING MECHANISM FOR PRINTING MACHINES Filed March 4. 1926 6 Shets-fihet 1 Nov. 1, 1927. 1,647,560 c. CHISHOLM ET AL PLATEN CONTROLLING MECHANISM FOR PRINTING MACHINES Filed March 4, 1926 SSheetS-Sheet 2 Nov. 1, 1927. 1,647,560

c. CHISHQLM ET AL PLATEN CONTROLLING MECHANISM FOR PRINTING MACHINES Filed March 4. 1926 6 Sheets Sheet s C. CHISHOLM ET AL I PLATEN CONTROLLING MECHANISM FOR PRINTING MAQHINES Noy. 1, 1927.

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Mb 2 T+ I Nov. 1, 1927. 1,647,560

c. CHISHOLM ET AL PLATEN CONTROLLING MECHANISM FOR PRINTING MACHINES Nov. 1, 1927. 1,647,560

C. CHISHOLM ET AL PLATEN CONTROLLING MECHANISM FOR PRINTING MACHINES Filed March 4, 1926 6 SheetsSheet 6 I00 I20 '25 I53 W mil/[Ill].

Patented Nov. 1, 1927.

UNITED STATES PATENT OFFICE.

CLIFTON CHISHOLM AND PETER M. COLQUI-IOU'N, OF CLEVELAND, OHIO, ASSIGNOBS TO THE AMERICAN MULTIGRAPH COMPANY, A CORPORATION OF OHIO.

ILATEN-CONTROLLING MECHANISM FOR PRINTING MACHINES.

Application filed March 4, 1926. Serial No. 92,151.

This invention relates to printing machines which are provided with mechanism for separating the printing member and platen Whenever the paper fails to feed, thus preventing smudging the platen. The invention is concerned with mechanism for automatically restoring the platen following each release thereof and before the printing surface comes into its next active position.

1n This saves the loss of time consequent on manually restoring the platen.

The general object of the invention is to provide the automatic restoring means referred to in an effective and comparatively simple form. A more particular object is to provide a restoring means suitable for embodiment on a multigraph, which has a rotary skeleton drum provided with a type carrying segment adapted to coactwith a roller platen.

Supplemental printing mechanism, such as a signature printing device or an envelope printing device, may be coupled with the multigraph and operate automatically con- 2 sequent upon the operation of the multigraph. In such case, the platen restoring mechanism of this machine may be provided with means for automatically disconnecting the supplemental printer whenever the main platen goes to idle position and reconnecting it when the main platen is restored.

Still another object of the invention is to provide a counting device so arranged that 3.3 it will count the number of sheets actually fed rather than the number of cycles of operation of the machine. In accomplishing this, we connect the counter with the platen restoring mechanism in such manner that the counter while driven by the revolution of the drum is only operated when the platen is active.

The above features, and others contributed to our invention, will be hereinafter more fully explained in connection with a description of the embodiment of the invention shown in the drawings.

In the drawings, Fig. 1 is an end elevation of a multigraph having a signature attachment and provided with our platen restoring device, this view showing the platen in idle position; Fig. 2 is a fragmentary end elevation of the platen latch, illustrating the position when the platen is idle; Fig. 3 is a fragmentary viewalso in idle position of mechanism for operating a counter for'the sheets of paper fed; Fig. 4 is an cndaelevation similar to Figure 1, but showing the parts in the position they occupy when the platen has been restored; Fig. 5, is a view of the platen latch with the platen restored; Fig. 6 1s a view of the counter operator in its active position; Fig. 7 is a diagrammatic elevation of the restoring mechanism and platen latch, illustrating'the position when the test is being made for the presence or absence of paper; Fig. 8 is a vertical section of the multigraph shown in Figs. 1 and 5 in a. plane parallel with those figures, as indicated by the line 8-8 on Fig. 10; Fig. 9 is a vertical section along the axes of the printing drum and platen; Fig. 10 is a rear eleva tion of the multigraph and signature attachment; Fig. 11 is a horizontal section through the signature attachment on the offset plane indicated by the line 11-11 on Fig. 8; Fig. 12 is a vertical cross-section of a machine adacent the controlling gearing, as indicated by the line 12-12 on Fig. 10.

Briefly describing the multigraph shown, 10 and 11 indicate a'pair of end plates suitably connected together to form a rigid frame. In these end plates is mounted a main shaft 14:, which is shown as provided. with an operating crank 15. Rigidly mounted'on this main shaft are a pair of rings 16 and 17 on which reststhe printing segment 20, which is shown as having one or more hooks 21 for lockingit to the shaft.

The printing surface may be of any character desired. may have rails 23 adapted to carry grooved type (not shown). As shown, the printing surface comprises a flexible blanket 24 (Fig. 8) resting on the 'drum rails and having printing characters anchored at one end to a rail on the drum and at the other end to a movable bar 25. This bar is connected by means of a flat spring 26 with the shaft 14 and is forced by set screws 27 away from the edge of the segment to pull the blanket taut.

Between the two rings 16 and 17 of the drum, we have shown a pair of ribbon spools 28 from which extends an inked ribbon 29- overlying the printing form.

The platen comprises a roller 30 eecentrically mounted between the frame members so that it may be moved into position to coact with the printing segment or may be in position to clear the segment. As

For instance, the segment shown, the roller is mounted on a shaft 31 which has, eccentric extensions 32 and 33 (Fig. 9) journalled in suitable bushings 34 and 35 in the frame members 10 and 11. These bushings may be adjustable in the frame members to position the platen axes normally with reference to the drum. In Fig. 9, 36 illustrates a slotted arm and a locking screw tohold the bushing 32 in set position, and the bushing 35 may be similarly provided with locking mechanism if desired.

The drum and platen are geared together, thus we have shown a gear 40 mounted on the drum ring 17. This gear meshes with a pinion 41 which is loose on the shaft extension 33 and is connected with the platen by an Oldham coupling 44;

In the multigraph as described, the platen shaft 31 is given a tendency to turn in the direction to lower the platen by means of a tension spring 74 connected as hereinafter explained, but such operation is normally prevented by a latch which engages a shoulder 51 on a notched disk 52 securedto the platen shaft. This disk as shown is adjustably locked to theshaft by means of screw bolts 54 which pass through slots 55 in a disk member 56 mounted on the squared end of the shaft and rigid with it. Intermediate the collar -52 and the disk 54 is a rock arm 58 of the restoring mechanism.

All these parts although relatively adjustable are rigidly connected and operate as a unit.

The platen latch 50 above mentioned is mounted on a rock shaft 60 which rigidly carries fingers 61 adapted to test for the presence or absence of paper. These fingers stand betwen the sections of a lower section feed roller 62 and in line with spaces between the sections of an upper coacting feed roller 63. Normally when the platen is in its active position, the spring pressure of the shoulder 51 against the nose of the latch 50 holds the fingers 61 in idle position, as illustrated in Fig. 8; but, once for each rotation and just before the paper should be fed, the mechanism to be described pulls rearwardly on-the arm 58, slightly turning the platen shaft to relieve the pressure on the latch 50; then, the position of this latch becomes controlled by the presence or absence of paper between the rollers 62 and 63. If a sheet of paper is present (having been fed along,

the paper table 64 into engagement with stop fingers 65) such sheet bridges the gaps between the sleeves of the roller 63 and the fingers 61 cannot rise, so that the latch 50 is retained in the active positiorr, and this serves to retain the platen active.

If at the testing time, the paper is absent, counter-weighted ends 66 of the fingers 61 serve to raise them and this swings the latch upwardly to idle position, as shown in full lines in Fig. 7, where it is out of the notch in the collar 52, then when the platen is released there is nothing to revent it being turned to idle position and its spring causes such movemen l Such platen release as above described is claimed in Patent No. 1,148,940, of George T. Trundle,'Jr., and reference is made to that patent for a fuller description of such platen release. The restoring mechanism of the present invention has been designed with reference to that platen release, and, as stated, operates automatically to restore the platen following each movement of it to idle position. Such restoring mechanism will now be described.

The arm 58, above referred to which is rigid on the platen shaft, is shown as connected by a link 70 (Figs. 1 and 4) with an arm 71 which is pivoted at its upper end to the end frame member 11. A spring 74 connected at one end to this arm and anchored at the other end to the frame gives the of the pivot pin 72 eocentrically occupying an adjustable bushing 73 mounted in the frame plate. The main shaft 14 is provided with a cam 75 which normally coacts with a roller 76 carried by the arm 71.

To allow the platen restoring mechanism to be thrown to inoperative position, the roller 76 is mounted on a lever 77 which is pivoted to the arm 71 and is maintained either in its active position as shown in full lines in Fig. 1, or its inactive position as shown in dotted lines therein, by the spring 78 anchored at the end 79 to the lever 77 beyond the pivot and anchored at the other end to a plate 80. The plate has a slight movement for a purpose to be described, but so far as the roller 76 is concerned acts as a stationary anchorage. This spring 78 also assists in giving the platen itstendency to turn to idle position.

Now, as the crank 15 is rotated the cam 75, acting on the roller 76, will swing the arm 71 to pull the link 70 to turn the platen. If the platen is already elevated, as shown in F ig. 4. the movement of thecam 75 is mostly idle, but as the high portion of the cam engages the roller 7 6. it turns the platen collar 52 slightly but sufficiently to relieve the pressure on the latch 50. and thereupon that latch is controlled by the paperfinger 61 and remains in its active position or swings to idle position (as shown in Fig. 7). Then when the cam clears the roller, the springs 74 and 78 turn the platen down to idle position, bringing the mechanism into the position shown in Fig. 1.

It will be seen that on each rotation of the platen a test is made for the presence or absence of paper. If the paper is presentthe parts remain in normal position; if paper is absent the platen moves to idle osition,

so that no impression is made w en the glaten;

printing segment moves past .the then, after the segment has moved. eyond the platen, the platen is restored to active position and thereafter comes under the control of the paper testing mechanism acting on the next rotation and previous to the printing on that rotation.

It is sometimes desirable to restore the platen manually and for that purpose we provide two lips 59 on the disk 56. These lips are readily engaged by the operators thumb and finger and enable the platen to be raised whenever desired.

WVhile the latch 50 operates as if rigid on the rock shaft 60, it is desirable to provide an adjustment and a yielding connection and accordingly we mount the latch loose on the rock shaft, while rigidly secured to the rock shaft is a block 67 which is shown as carrying a spring 68 pressing against the latch on one side of the pivot and a set screw 69 bearing against it on the other side.

We have referred to the spring 78 as bein anchored to the plate 80 pivotally mounte on the bushing 73 carried by the frame member 11. This plate 80 is provided with an overhanging lip 82 which lies above a cam 85 on the shaft 14. This cam is shown as a hub on the side of the cam 75. The lip 82 on the plate overhangs a crank arm 91 on a suitable revolution counter supported on the end frame member 11.

Then the restoring mechanism is in the normal position as shown in Fig. 4, the plate 80 is under the control of the cam 85. Accordingly, on each rotation when the fiat face 86 of the cam 85 comes adjacent the lip 82, the spring 78 rocks the plate 80 downwardly into the position shown in Fig. 4, thus causing the operation of the revolution counter, after which the cam restores the plate 80 and a suitable spring (not shown) raises the counter crank sunk arm. Thus the counter is operated one unit for each rotation of the drum.

If however, a sheet of paper has been missed, so that the platen is in the down position as shown in Fig. 1, then a pin 87 on the lever 71 engages a tongue 88 on the plate 80 and retains the plate in such position that the lip 82 cannot move downwardly sufliciently to operate the counter. Accordingly no actuation of the counter is made on that rotation of the drum.

It will be seen that the simple mechanism described makes the operation of the revolution counter dependent on the sheets fed and rather than on the number of rotations. This enables the counter to indicate accurately the number of sheets printed.

In order to make the combined cam 75 and 85 adjustable on the shaft 14, we have shown it as loose thereon but adjustably locked to the hub of the crank 15. As shown, we have provided the cam with a washer rigid with the cam which engages a notch in a pin 96 mounted in the crank hub and provided with a threaded extension having a nut 97. The tightening of this nut causes the pin to clamp the washer and thus hold the cam in its adjusted position.

To illustrate the niultigraph coupled with a supplemental printing controlled by the same platen releasing and restoring mechan sm, we have shown it as equipped with a signature-printing attachment corresponding to that shown and claimed in Patent No. 1,117,751, of R. Allen, to which reference is made for a fuller description. it comprises an eccentrically mounted roller 100 (Figs. 8 and 10) carrying a segmental printing surface 101; a roller platen ,102 adapted to coact with such printing member; a gear 103 on the platen meshing with the gear 104 on the printing member which meshes with an idler 105 meshing with the gear 40 on the main drum. The printing member 101 is inked by a roller shown as engaging a supply roller 111. This supply roller has a gear 112 meshing witha gear 113 on the roller 110, this latter ear being connected by an idler 114 with a gear 104.

The eccentric mounting of the printing member 100 is effected by reason of the internal sleeve which is eccentrically mounted on the drive shaft 121. This drive shaft carries the gear 104 above mentioned and is connected with the platen 100 by a suitable Oldham coupling 122. The eccentrio is provided with an arm 123 connected by a link 124 to an arm 125. A spring 126 acts against a link 127 connected to the arm and thus tends to maintain the segment 101 in idle position. The arm 125 carries a roller 128 adapted to occupy a cam groove 131 in a rotary member connected by gears 132 and 133 with the shaft 121. The effect of the cam groove 131 is to swing the arm 125 to turn the eccentric sleeve 120 to lower the printing member to active position. By reason of the gearing described, this action may occur once for each rotation of the main drum and at the proper time to print the signature on the sheet printed by the main drum.

The cam roller in the Allen patent referred to was provided with means whereby it might be withdrawn manually from its groove and held in such withdrawn position, thus retaining the signature attachment idle whenever desired. In our machine, withoutlnterfering with the manual release, we have provided mechanism for withdrawing the roller automatically under the control of the platen controlling mechanism, so that whenever the main platen turns to idle position on account of a sheet missing, the signature Ill-i &

attachment will also be disconnected. This is accomplished by mechanism shown in Figs. 1, 4 and 11.

The signature controlling roller 128 is shown as mounted on the end portion of a pin 140 which is slidable in a barrel 141 which in turn is slidable in a housing 129 on the arm 125. A spring 142 within the barrel tends to press the roller toward the cam. The barrel is shown in Fig. 11 as retained in its idle position by aspring 143 engaging a notch in the exterior of the barrel but manual pressure on the barrel may force it inwardly, when the spring 143 Wlll F enter the notch 144 and hold the barrel in its active position. I

The pin 140 is connected by a link 145 with a bell crank 146 which is connected by a link 147 with a pin 148 on the arm 71 of the platen restoring mechanism, so that such restoring mechanism may position or withdraw the cam roller 128. If the barrel is manually withdrawn into the position shown in Fig. 11, it is immaterial what the position of the pin 140 and the link mechanism and no engagement can take place between the roller 128 and the cam. However, if the barrel 141 be shoved into the housing 129 until the spring 143 engages the notch 144 in the barrel, the roller will be carried near enough to the cam so that it will be under the control of the platen restoring mechanism.

Assuming that the barrel 141 has been moved into its active position, then, if the platen restoring mechanism be in the position shown in Fig. 4, the roller 128 will be in the cam groove 131 and the signature is printed in the normal manner. If however, a sheet be missing, so that the platen of the multigraph goes to idle position as shown in Fig. 1, the pin 148 pulling on the link 147 will withdraw the roller 128 from the cam groove 131 and the signature printing member is not brought to active position and its platen is not smudged.

For the sake of completeness, it may be stated that the multigraph drum is provided with a cam '150 (Fig. 12) which acts on a roller 151 connected with a yoke 152 carrying the upper feed roller 63, and at the proper time depresses that, roller into coaction with the lower feed roller 62, and at the same time through a stud 154 depresses a yoke 155 carrying the stop fingers 65. The lower feed roller 62 has a gear 157 meshing with an idler 158 which meshes with the gear 41 on the platen shaft.v At the rear of the platen roller is an ejecting roller 160 driven by a sprocket chain 161 from a gear 162 meshing with the drum gear 40. Extending between the drum and platen from front to rear of the machine are strippers 165 (Fig. 8) overlying the ejector roller 160.

Recapitulating the operation of the ma- 150 acts, to remove the stop fingers and bring the feed rollers into pinching coaction, the high part of the cam acts on the roller 76 and relieves the pressure on the platen latch 50. This latch thereupon is free to rise and the counterweights 66 on the paper fingers tend to lift these fingers, but if paper is present the fingers do not rise and the latch remains in position, so that when the cam 75 clears the roller 76, the restoring mechanism still remains in the position shown in Fig. 4. If however, no paper be present the counterweight 66 will raise the latch 50 into the positionshown in Fig. 7, and then, when the cam 75clears the roller 76, the spring 78 will swing the restoring mechanism into the position shown in Fig. 1, turning the platen to idle position.

The action described takes place before the segment 20 has come into position where it could coact with the platen, then, after the segment has traveled idly past the platen, the cam 75 again acts on the roll 76 and restores the platen, and just before the seg: ment is in position to print onthenext rotation, the operation is repeated and another test is made for the presence or absence of paper.

Each rotation of the drum is accompanied by an actuation of the counter, unless by reason of absence of the paper the platen has come to idle position, in which case the counter does not act. Likewise, in case the signature attachment has been connected by the shoving in of the barrel carrying the cam roller, its operation is controlled by the'platen mechanism and the signature printer-becomes automatically disconnected whenever the platen goes to idle position.

Should it be desired to disconnect the restoring mechanism entirely, it will only be necessary for the operator to press down on the arm 77, which normally rests against the pin, 87, so that the arm will come into the idle position shown in dotted lines in Fig. 1. In such movement the spring 78 passes to a corresponding position on the other side of the pivot of the arm 77 and holds that arm with its pin 89 resting against the front edge of the arm 71. 1

We claim:

1. The combination of a frame, a printing drum therein, a roller platen, an eccentric mounting for the platen, a spring tending to turn the mounting to move the platen to idle position, an arm on the eccentric, a lever pivoted to the frame and connected with said arm, a cam on the drum, and means carried by the lever (m eting with the cam,

Ice

' ed with the 2. The combination of a rotary printing drum, a cam movable therewith, a roller platen, an eccentric mounting for the platen, an arm on the eccentric mounting, a lever connected with said arm, an arm on the lever. a roller carried by the last mentioned arm, and a spring adapted to keep the roller in position to coact with the cam or hold it out of such position, said spring also tending to move the platen to idle position.

3. The combination, with a printing couple, of means tending to move one member thereof to idle position, a latch preventing the operation of such means, a finger connectlatch and adapted to bear against paper, means tending to move the finger across the path of a sheet of paper and concurrently move the latch to idle position, and means operating automatically consequent upon the operation of the couple for restoring said member to active position.

l. The combination of a printing member, a roller platen, an eccentric device on which the same is mounted, means tending to turn the eccentric device, a latch adapted to hold it against turning, a finger connected with said latch and adapted to bear against a sheet of paper, and means operating automatically consequent upon the operation of the printing member for restoring the platen to active position.

5. The combination of a printing member,

a rotary platen, an eccentric mounting for the same, a collar connected with the eccentric, a latch arm adapted to engage a shoulder on said collar and normally prevent the same turning, a finger connected with the latch arm and adapted to bear against a sheet of paper, a lmk connecting the said collar, and means operated by the printing member to draw on said link to restore the platen after it has been released. I 6. The combination of a printing member, a roller platen, an eccentric device on which the same is mounted, means tending to turn the eccentric device, a latch adapted to hold it against turning, a finger connected with said latch and adapted to bear against a sheet of paper, mechanism for periodically relieving-the pressure of the platen against the latch arm, and means for moving said mechanism, after the platen has been released, to restore the platen to active position.

7. The combination of a printing member, a rotary platen, an eccentric mounting for the same, a collar connected with the eccentric, a latch arm adapted to engage a shoulder, on said collar and normally prevent the same turning a finger connected with the latch arm and adapted to bear against a sheet of paper, an operating member connected to the eccentric mounting, means for moving said operating member slightly to r relieve the pressure on the latch arm, and

means for giving the operating member a greater movement to restore the platen to active position.

8. The combination, with a printing couple, of means tending to move the platen thereof to idle position, a latch for preventingsuch movement, means tending to move the latch to idle position but normally prevented, by the pressure of the means first mentioned, linkage connected with the plate'n, and a cam operated by the printing couple and adapted to move said linkage for each operation of the couple sutficiently to relieve the pressure. on the latch and'adapted to give said linkage a greater movement, after the platen is released, to restore theplaten.

9. The combination of a printing member, a rotary platen, an eccentric mounting for the same, a spring tending to turn the eccentric, a latch adapted normally to prevent the same turning, a finger connected with the latch and adapted to bear against a sheet of paper, means for periodically relieving the pressure of the spring against the latch,

and means operated by the pressure relieving means tor restoring the platen to active position.

10. In combination, a printing drum having a handle rotatable therewith, a platen, means supporting the platen to permit the same to take a printing or non-printing position, a paper controlled and spring actuated platen release for throwing the platen to non-printing position when the feed of paper fails and means for returning the platen to printing position and resetting the platen release comprising mechanism connected to the platen and to the platen release, and means movable with the handle of the printing drum and cooperable with said mechanism.

11. The combination of a rotary drum, a platen coacting therewith, constantly act-ing mechanism for moving the platen to idle position, a counter, mechanism for normally operating the counter once for each rotation of the drum, and mechanism for interrupting such operation when the platen is moved to idle position. a

12. The combination of a printing drum, a roller platen, constantly acting means adopted to move the. platen to idle position, a paper controlled latch to determine whether the platen remains active or goes to idle position, a revolution counter, mechanism for operating the same for each revolution of the printing drum, mechanism for restoring the platen, and means connected with the restoring mechanism for preventing the operation of the revolution counter when the platen is in its idle position.

13. The combination of a printing drum, a roller platen, constantly acting means adapted to move the platen to idle position, a

paper controlled latch to determine whether the platen remains active or goes to. dle position, a revolution counter, mechanism for operating the same for each revolution of the printing drum, including a cam and a member adapted to be moved thereby, restoring mechanism for restoring the platen, and means connected with the restoring mechanism for holding said member in idle position when the platen is in its idle position.

14. The combination of a main printing machine, a supplemental printing device coupled therewith, a release mechanism adapted to render idle the main couple when the paper isabsent, means whereby such operation also renders idle the supplemental printing device and means for automatically restor- 1 ing both devices.

15. The combination of a main printing device comprising a printing member and platen, a supplemental printing device cou pled therewith, means for-moving the platen of the main printing device to idle position if the paper be absent, means whereby such movement prevents the operation of the supplemental printing device, and means for automatically restoring the main platen and the supplemental printer.

16. The combination of a rotary printing couple, a supplemental printing device geared therewith, a platen release mechanism adapted to move the platen of the said couple to idle position when the paper is absent, and means for automatically disconnecting the operating mechanism of the supplemental device whenever said platen is moved to idle position, and means for automatically restoring the said platen and said operating mechanism.

17. The combination of a rotary printing drum, a roller platen adapted to coact therewith, a spring tending to turn said platen to idle posit-ion, a paper controlling latch for preventing such movement of the platen, mechanism for automatically restoring the platen once for each cycle of operation of the machine, a supplemental printing device coupled with the machine and adapted for automatic operation, and mechanism for disconnecting the supplemental printing device coupled with the platen restoring mechanism.

18. The combination of a rotary printing drum, a platen adapted to coact therewith, means for moving said platen to idle position if paper be absent, mechanism for automatically restoring the platen once for each cycle of operation of the machine, a supplemental printing device having a controlling cam and a coacting roller, and mechanism for withdrawing the roller from the cam when the platen-of the main printing machine goes to idle position.

19. The combination of a rotary printing drum. an eccentricall'v mounted roller platen adapted to coact therewith, means for turning said mounting to move the platen to idle position if paper be absent, mechanism for automatically restoring the platen once for each cycle of operation of the machine, a

supplemcntal printing device geared with the machine and having a controlling cam and a coacting roller, and mechanism for withdrawing the roller from the cam coupled with the platen releasing and restoring mechanism, whereby the supplemental printing device is idle when the main printing machine is idle and becomes automatically restored whenever the main platen is restored.

20. The combination of a main printing device comprising a printing member and platen, a supplemental printing couple connected therewith and having a printing member and platen, means automatically testing for the presence or absence of paper, means controlled thereby for moving the platen of the main printing device to idle position if the paper be absent, and means whereby such movement simultaneously prevents the operation of the supplemental printing device.

21. In a printing machine, a printing member, a coacting platen, means to move the platen into inactive position with reference to the printing member, a normally restrained latch blocking the action of said means, paper controlled means for tripping the latch, means controlled by the rotation of the printing member for removing the restraint on the latch whereby it may be tripped during one cycle'of operation, the same means acting on the next cycle to return the platen, to active position.

22. In a printing machine, a rotary printing member and a coacting platen, a normal-,

ly restrained latch for holding the platen in active position, means for moving the platen to inactive position, paper controlled mechanism for tripping the latch when no paper is fed, whereby the platen may be moved to inactive position, and mechanism active on each printing cycle of the machine tending to restore the platen to active position and capable of sorestoring it if it is at that time inactive, said mechanism also acting in the same cycle to release the latch, whereby if the paper is then absent the latch may be tripped and the platen moved to inactive position irrespective of whether it was active or inactive on the next preceding cycle.

23. In a printing machine the combination with a rotary segmental printing member adapted to hold a typeform, a coacting platen, means tending to move the platen away from the printing member, a latch for opposing such movement, intermittently coacting paper feeding rolls acting in advance of the printing line, paper controlled lll) means acting adjacent the paper feeding rolls for tripping the latch when no paper is fed, means active on each printing cycle and before the type form holding surface of the printing member is in registration with the platen i'or restoring the platen to active position in case it has been released by the latch on a preceding cycle, said paper controlled means acting subsequent to such restoration for again tripping the latch in case no paper is fed.

24;. A printing machine of the multigraph type, comprising a rotary drum adapted to carry a printing form and a rotary platen of materially smaller diameter, beneath the drum, and a paper controlling device in front of the platen, a spring tending to turn the platen to idle position, a latch for preventing such return, a paper finger connected with the latch, means acting periodically to relieve the pressure of the platen on the latch to enable the paper finger to test for the presence or absence of paper combined with a restoring mechanism, comprising an arm connected. with the platen support and means revolving with the drum and arranged to periodically act on the arm to restore the platen to active position.

In testimony whereof, We hereunto afiix our signatures.

CLIFTON CHISHULM. PETER M. COLQUHOUN.

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