US1087055A

US1087055A - Tripping mechanism for printing-presses.

Info

Publication number: US1087055A
Application number: US77334613A
Authority: US
Inventors: Burt F Upham
Original assignee: SOUTHGATE MACHINERY Co
Current assignee: SOUTHGATE MACHINERY Co
Priority date: 1913-06-12
Filing date: 1913-06-12
Publication date: 1914-02-10
Anticipated expiration: 1931-02-10

Description

.B'. P. UPHAM.

TRIPPING MECHANISM FOR PRINTING PRBSSES.

APPLICATION FILED MAR .17, 1910. RENEWED JUNE 12, 1913.

3 SHEETS-SHEET 1.

WITNESSES INVENTOR a J r 1 1 1g- Attorney;

B. P. UPHAM.

TEIPPING MECHANISM FOR PRINTING PBESSES.

urmonmn FILED 11.11, 1910. nnnnwnn mm: 12. 1913.

Patented Feb. 10', 1914.

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p [N VEN TOR 5M d Altorneyf WITNESSES 1%? WSW/ 3 B. F; UPHAM.

TBIPPING MECHANISM FOR PRINTING PBESSES.

APPLICATION FILED MAR. 17, 1910. RENEWED JUNE 12, 1913.

1,087,055. Patented Feb. 10, 1914.

3 SHEETS-SHEET 3.

UNITED STATES PATENT OFFICE.

BURT F. UPHAM, OI CHICAGO, ILLINOIS, ASSIGNOR TO SOUTHGATE MACHINERY COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHQQETTS.

TRIPPING MECHANISM FOR PRINTING-PRESSES.

Specification of Letters Patent.

Patented Feb. 10, 1914.

Application filed March 17, 1910, Serial No. 550,068. Renewed June 12, 1913. Serial No. 773,346.

To all whom it may concern Be it known that I, BURT F. UIHAM, a citizen of the United States, of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Tripping Mechanism for Printing-Presses; and I do hereby declare the following to be a full, clear, and eiact description of the invention, such as will enable others skilled in'the art to which it appertains to make and use the same, reference being had to the accompanying drawings. 1 This invention relates to printing presses in which a single impression cylinder is adapted to receive sheets from a plurality of feeding mechanisms, or to receive a plurality of sheets at different points of its circumference, and present such sheets to a form or forms on a coacting printing member, such as a bed or a cyllnder carrying a printing surface.

The invention is particularly applicable to, and designed for use in connection with, a press of the type shown in my Patent No. 931,099 granted August 17, 1909, in which the plate cylinder carries diametrically opposite forms and the impression cylinder has two opposite impression surfaces and sets of sheet taking devices which respectively receive sheets from two feed tables and present such sheets to the respective relative forms on the plate cylinder, so that for each rotation of the impression cylinder two sheets are printed during the normal operation of the press.

The object of the present invention is to provide novel mechanism whereby the impression may be thrown off if any of the feed mechanisms fails to properly delivera sheet to the impression cylinder, or if a sheet is improperly fed or not fed on either table, so that the related form will not print upon the blanket of the impression cylinder; and whereby the impression will be thrown on in time to cause the sheet fed by the other feed mechanism, or from the other table, to be properly printed. In other words,the press is provided with tripping mechanism so constructed that if a sheet is not properly fed on either table, whether press is fed by hand or automatically, or if the impression c linder fails to receive a sheet, the impression cylinder can be tripped away from the plate cylinder at the time feeder or feed table is provided with independent tripping mechanism by, which the throwang o of the cylinder for one form or printing section, is accomplished independently of the otherfeed table tripping mechanism, and such that the impression cylinder or one printing section thereof may continue printing, while another section of such impression cylinder will be thrown ofl impression when it comes to the printing point. Thus it is not necessary to entirely stop the printing operations of the press if either feeder fails to feed a sheet in order to prevent printing on the packing of the impression cylinder, whether the sheets are fed by hand or by automatic feeders.

The invention as applied tothe said patented press,or any press in which a plu: rality of feeds are employedto deliver sheets to the impression cylinder,embodies means whereby the impression cylinder is adapted to take a plurality of sheets around its circumference and present them successively to printing surfaces, and means whereby such cylinder may be automatically thrown off impression during part of its revolution,suflicient to prevent printing the packing of the impression cylinder in case any sheet is not properly delivered thereto ;-and then thrown on impression for the remainder of its revolution, so as to print other sheets which are properly fed thereto at another point of its circumference.

As applied to a machine of the character shown in my Patent No. 931,099 aforesaid, the invention embraces means for throwing off impression, or tripping either one of the two cylinders; one cylinder carrying two printing forms, and the other cylinder two lmpression surfaces; and the press is adapted to print continuously when both feeders are in operation, but if either feeder fails to feed a sheet the impression will be thrown off durln the time such sheet should have been printed, and the impression will be thrown on in time to enable the sheets taken from the other feeder to be properly printed; and also to enable the to work properly, the impression will remain thrown off and no printing occur until one of the feeders is again properly in operation,whereupon the impression will be antomatically thrown on at the proper time to print the sheets fed from such feeder. Thus the failure of one feeder to operate properly does not necessitate stopping the press, nor the printing operations thereof. Either feeder may be stopped, when desired, without having to stop the press, and may be again started in operation while the press is running.

On presses now in use, where automatic feeders are employed, means are usually provided whereby if anything goes wrong with a sheet of paper, the press will be stopped; this makes it necessary for the pressman to restart the press and causes much.loss of time. In a press having my tripping mechanism, stopping of the press is unnecessary,- and my invention not only saves the time of starting up the press again, but also enables the press to continue to print sheets fed from a properly operating feeder.

will now describe the invention with reference to the accompanying drawings in which Figure 1 is a diagrammatical side elevation of parts of'.'a printing press, such as that shown in my Patent No. 931,099, having two feed tables each provided with trip ping mechanism for automatically releasing novel mechanism for throwing the impression off if a sheet is not properly fed on either of the tables; and for automatically throwing the printing mechanism on impression to print the sheets properly fed from the other table, or tables. Fig. 2 is an enlarged view of the novel throw offmechanism showing the parts in on impression position. Fig. 3 is a view similar to Fig. 2 showing the position of the parts at the beginning of a throw ofl operation. Fig. 4 shows the position of such parts when the impression is thrown off Fig. 5 shows the position of parts at the beginning of a throwing on impression operation. Fig. 6 is a detail section on line 66, Fig. 5. Fig. 7 is a detail view of part of an auto matic tripping mechanism on the feed tables to control the operation of the throw off mechanism. Fig. 8 is a detail plan view of the detector shown in Fig. 7

In the drawings 3 designates a plate cylthe notch, which roller engages and inder adapted to carry diametrically oppo site plates or printing surfaces P and P; and 4 designates an impression pgeinder provided with diametrically opposi grippers 5 and 6; the grippers 5 being adapted to take sheets from a feed table 9 and present them to surface P; and the grippers 6 being adapted to take sheets from a feed table 28 and present them to surface P. The sheets are preferably transferred from feed table 28 to the grippers on cylinder 4 by means of an intermediate transfer cylinder 26 provided with grippers 27. These parts are intended and adapted to operate substantially as shown and described in my said Patent No. 931,099. Sheets may be fed on the tables 9 and 28 by hand, but preferably each table is provided with automatic sheet feeding devices which may be of any suitable character,but as that is not an essential feature of the presentinvention, such feeders are only conventionally indicated lIl the drawings.

The throw-0 mechanism.In the form of press illustrated-in the drawings Iprefer to throw the impression on and off by laterally shifting the impression cylinder .4; and for this purpose each trunnion 8 of such cylinder isjournaled in a slidable box 8 which is supported upon an eccentric 8 connected to a rocking arm 8 which is connected by a link 8 to a swinging lever 1 which is operated to throw the cylinder on. and off impression at the proper time as follows: The swinging lever 1 is connected to a rock shaft 1 journaled in the side frames of the press, adjacent the cylinder 4; and said rock shaft is connected at the other side of'the press to the eccentric in which the adjacent trunnion of cylinder 4 is journaled, so that when shaft 1 is rocked both ends of cylinder 4 will be similarly and simultaneously moved. This lever 1 has two arms, to one of which link 8 is ivoted, and to the other arm 1 is pivota ly connected a double ended oscillating dog 1", which normally lies in an intermediate position with its ends 1 and 1 near the notched edge of an oscillating lever -2, pivoted on the shaft 1 besides the lever 1, having a notch 2 in its periphery slightly longer than the length of the dog 1". The lever 2 has a roller 2 on its end opposite is adapted to be rocked by a cam 2 mounted on a stud 2", which can be driven by any suitable means, not shown. In the press shown there are two feed tables and the cylinder 4 carries two impression surfaces; the cam 2 therefore need make but two revolutions; one for each feed table or impression surface on the-impression cylinder; but if there were more feed tables in the machine, and more impression surfaces on the cylinder, the cam 2 should be speeded to rotate once for each feeding mechanism or impression surface on the impression cylinder. It; is intended to oscillate lever 2 once for each im ression surface on the impression cylin er, but obviously the invention does not depend upon the particular means shown in the drawings for oscillating said lever 2.

The dog 1 should be provided with some suitable means for yieldingly holding it in normal position, close to but out of en agement with the oscillating lever 2; an motion will not be imparted from lever 2 to the lever 1 unless dog 1 is thrown into engagement with notch 2. In the drawings equipoising springs 1 are shown interposed between the ends of the dog 1 and the ends of a bar 1 attached tothe arm 1 of lever 1. The m'ppin-g devices.-The end 1 of the dog 1 is shown as pivotally connected to the lower end of a rod 4 the other end of which is slidably connected to a rod 4", a spring 4 being arranged in the connection between the

rods

4, 4", so as to allow a slight relative movement of'said rods, for a purpose hereinafter explained. Rod 4 in turn is connected to one arm of a bell-crank lever 4 pivoted at its bend on the frame, or other suitable part, of the machine; and the short arm of said lever is pivotally connected by a link 4 to one arm of an oscillating lever 4 pivoted at 4 on the frame or other suitable part of the machine. The other arm of said lever 4 is connected by a link 4 to a crank arm 5 on a rock-shaft 5 above the delivery end of table 9, which shaft 5 is adapted to be rocked by any well known mechanism, (such as that hereinafter referred to,) located on the feed table 9, if a sheet is not fed up thereon at the proper time. Whenever shaft 5 is rocked motlon is imparted to the arm 5 and from it, thiough the connections described, to ,the lever 4 which in turn pulls

rods

4 and 4 upward thereby rocking dog 1 so as to throw its end 1 into engagement with the notch 2= of the oscillating lever 2, whereupon on the next upward movement of the notch 2 the lever 1 is swung upward,-(by reason of engagement of the end 1 of dog 1" with notch 2 in lever 2)-and on this upward movement of lever 1' link 8 and its connections rocks eccentric 8 so as to move cylinder 4 away from cylinder 3 and thus throw it off impression, and the impression will remain ofl' until lever 1 is moved downward again. The upward movement of lever 1, to throw off impression is indicated in Figs. 3 and 4, the latter indicating the position of parts when the impressi is ully thrown off. The cylinder when thus tripped is intended to remain oif impression only during that part of its revolution when the sheet which should have been fed on table 9 would have been printed,and the cylinder should therefore be thrown on impression before the sheet received from table 28 is brought to the printing point. For this purpose I provide means adapted to oscillate dog 1", so as to disengage its end 1 from notch' 2 and engage its end 1 therewith, so that on the return movement of lever 2 lever 1 will be returned to original position.

As shown a rod 1 is pivotally connected to the end 1 of dog 1, and its other end is slidably engaged with a rocking guide 1, suitably pivoted to the main frame adjacent dog 1"; and an expansion spring 1 is strung on rod.1 between guide 1 and the dog 1 said spring is therefore put under compression when lever 1 is thrown upward; and consequently when the lever 2 begins to make its return stroke,(see Fig. 5) spring 1 causes dog 1 to oscillate and engage its end 1 with notch 2 in lever 2 so that upon the return stroke of this lever 2, lever 1 is rocked backward and through link 8 operates eccentric 8 and throws the cylinder 4 on impression, or toward the plate cylinder 3. If a sheet has meanwhile been properly adjusted on table 9 the dog 1 will simply return to normal position and remain out of engagement with lever 2, (see Fig. 2) until rod 4 is pulled upward again; but if a sheet has not been properly adjusted on table 9, to be taken by the grippers 5, shaft 5 will be again rocked at the proper time so as to cause end 1 of the dog 1 to again engage notch 2 of lever 2 and again throw off impression, in the manner above described, at the proper time. Thus although the cylinder is thrown off impression during the time the sheet which should have been received from table 9 would be printed, it is thrown on impression during the time that the sheet taken from table 28 is to be printed. The table 28 is similarly provided with sheet feeding devices and tripping mechanism like table 9, adapted to cause the throw off devices to operate as above described. As shown the lever 4 has a pin and slot connection with a link 4" which connects with an arm 5 on a rockshaft 5" of mechanism on table 28 similar to the tripping mechanism on table 9; and consequently if a sheet should fail to be properly positioned on table 28 the tripping mechanism thereon would through rod 4" oscillate lever 4 and through the connections therewith shift the dog 1 so as to throw its tooth 1 into engagement with notch 2 of lever 2 at such time that the cylinder 4 would be thrown of! impression during the time that the sheet that should have been received from table 28 would have been printed. Thus with the mechanisms described the cylinder 4 will be thrown off impression whenever a sheet is not properly fed to it from either table 9 (or 29), but

will be thrown on impression so as to print the sheets properly fed from the table 28 (or 9) at the proper time. If sheets should not be properly fed on either table the impres-.

sion cylinder would be kept ofl' impression; but will be automatically thrown on impression whenever sheets are again properly fed on either table, or both tables, so as to print such sheet, or sheets.

It will be seen that according to this invention the impression cylinder will be thrown off impression for a part of its revolution whenever it fails to receive a sheet from one table, but will be thrown on impression during another part of its revolution so as to properly print sheets taken from the other table, and consequently it is not necessary to stop the press when sheets are not being fed from One table; and this results in great economy of operation and greatly increased product of the press.

The spring connection 4 between the rods 4", 4, enables the dog 1 to be snapped into engagement with the notch 2 in case its end 1 (or 1 should at the moment of tripping engage the edge of lever 2 outside the notch. The

links

4 and 4" preferably have pin and slot connections with lever P as shown so that the operation of one tripping mechanism will not affect the other.

Each shaft 5 forms part of a well known automatic sheet feeding mechanism such as the Cross feeder or Dexter feeder, in which the shaft 5, and attached lever 5 will be oscillated if the detector 5" thereof fails to find a sheet properly positioned upon the table.

As indicated in Fig. 7 to each shaft 5 is attached a segment 5 and on the shaft beside the segment is loosely mounted a sleeve 5 to which is attached a depending arm 5 which is connected to one end of a link 5 that is oscillated by suitable means, indicated, in Fig. 1, once for each sheet fed forward on the table. On the sleeve 5 is an upperarm 5 to which is pivoted a pawl 5 which is provided with a pin 5 on one side adapted to engage a notch in the upper end of an arm 5 loosely hung on sleeve 5 but normally held against the pin 5 by means of a spring 5 attached to the hub of arm 5 and to a suitable fixed point. As the arm 5 is oscillated by link 5 the pawl 5 is oscillated back and forth above the segment 5 but is normally held out of engagement therewith by a pin 5" on the pawl engaging a notch in the arm 5*, the spring 5 causing the arm 5 to normally keep in contact with the pin 5" and hold the pawl raised while the arms oscillate. To the arm 5 is attached a depending arm 5 to which a detector finger 5" is attached, which finger 5" slides back and forth upon the table 9 or 28, and its end will rest upon a sheet of paper 8 fed forward toward the end of table 9 (or 28); but if no sheet is in proper position upon the table at the time that the cylinder grippers should take it the end of the detector finger 5 which at that moment is moving toward the right (Fig. 7) will drop into a hole 9 in the table or in a metal plate or strip 9 on the end of table 9, (or 28) and will stop the arm 5 whichwas then moving to the left with pawl 5 and as pawl 5 continues to move to the left pin 5" disengages the notch in arm 5 and drops into engagement with segment 5 and causes the latter to move with arm 5 -thereby rocking shaft 5 and causing arm 5 to pull rod 4 and trip the throw-off devices as described. This sheet detecting or tripping mechanism is well known and it is unnecessary to further describe or illustrate it herein, as it is not a 'feature of the present invention.

I prefer when using automatic feeders on the tables 9 and 28 to use the present socalled Cross-feeder, but the invention is not restricted to any particular kind of automatic feeder nor to any articular kind of automatic mechanism which will cause the tripping of the throw off mechanism if a sheet fails to be properly fed to either table. Neither do I consider the invention restricted to the particular form of mechanism for throwing the cylinder on or off impression shown and described herein although said form is novel and I desire to protect such mechanism as well as the broader features of the invention herein.

Excessive throw of lever 1, in either direction may be prevented by means of a pin lattached to the frame and projecting into a slot in the edge of the lever 1; said slot and pin are so proportioned that while the pin will not prevent thenecessary oscillating movements of the lever, it will be engaged by an end of the slot and arrest the lever, if it should tend to move excessively in either direction.

What I claim is:

1. In a printing press having a printing couple and a plurality of feed tables; means for automatically throwing off impression if a sheet is not properly fed from any table during the time that such sheet should have been printed and for throwing on impression for other properly fed sheets.

2. In a printing press, an impression cylinder, a plurality of feed mechanisms, an means for automatically throwing the cylinder ofi' impression if a sheet is not properly fed thereto by any mechanism during the time that such sheet should have been printed and for throwing on impression for other properly fed sheets.

3. In a printing press, the combination of an impression cy inder, a plurality of feed tables adapted to deliver sheets to said impression cylinder, and mechanism for automatically throwing ofl' impression if a sheet is not properly fed from any table during that part of the revolution of such cylinder in which such sheet should have been printed, and for automatically throwing on impression during the remainder of the revolution so that properly fed sheets will be printed r 4. In combination, an impression cylinder, a plurality of automatic feeding mechanisms adapted to deliver sheets to said cylinder, and mechanism for automatically throwing ofi impression if a sheet is not properly fed by any mechanism during that part of the revolution of the cylinder in which such sheet should have been printed, and for automatically throwing on impression so that the properly fed sheets will be printed.

5. In combination, an impression c linder having a plurality of impression sur aces, a plurality of feed tables, and automatic mechanisms whereby the cylinder is thrown off impression if a sheet is not properly fed thereto on any table during that part of the revolution of the cylinder in which such sheet should have been printed, and automatically thrown on impression in time to print sheets that are properly fed thereto.

6. In combination, a printing machanism, a plurality of feed tables, means for throwing the impression on and off, and a tripping mechanism on each feed table whereby the throw off mechanism is tripped to throw off impression if a sheet is not properly fed on any table during that part of the cycle of operations of the press in which such sheet should have been printed, and whereby the impression is thrown on in time to print properly fed sheets, without stopping the press.

7. In a printing press, the combination of an impression cylinder having a plurality of impression surfaces, a feed table for each impression surface, throw ofl mechanism, and an independent tripping mechanism on each feed table, whereby the throw off mechanism is tripped to throw ofi impression when a sheet is not properly fed on any table during the time that such sheet should have been printed, and thrown on in time to print properly fed sheets.

8. In a printing press, the combination of an impression cylinder having a plurality of impression surfaces, 2. feed table for each impression surface, mechanism for throwing off and ,on impression, tripping mechanism on each feed table adapted to trip the throw ofl mechanism if a sheet is not properly fed on such table, whereby the impression is thrown off whenever a sheet is not properly fed on any table during the time that such sheet should have been printed and the impression then thrown on so that all properly fed sheets shall be printed.

9. In a printing press, the combination of an impression cylinder having a plurality of on each feed table, adapted to release .the

throw off mechanism when a sheet is not properly fed on such table, whereby when any tripping mechanism operates, the cylinder is thrown off impression for a part of its revolution during the time that the sheet that should have been fed from such table would have been printed, and is'thrown on impression for the remainder of its revolution if the other tripping mechanism is not actuated.

10. In a printing press, the combination of a plate cylinder having a plurality of printing surfaces, an impression cylinder having a plurality of impression surfaces, a plurality of feed tables respectively adapted to deliver sheets to the related impression surface on the impression cylinder, mechanism for throwing the cylinder on and of im ression during part of its revolution, an independently operating tripping mechanism on each feed table controlling the operation of said throw ofl mechanism, and whereby the throw off mechanism is tripped if a sheet is not properly fed on any table, and the impression cylinder will be thrown ofi" impression during that portion of its rotation when the unfed sheet should have been printed, without affecting the operation of the cylinder in printing sheets properly fed from the other table.

11. In a throw ofl mechanism for sheet printing presses, the combination of a cylinder, devices for moving the cylinder laterally on and off impression, a pivoted lever and connections for operating said devices, an oscillating lever pivoted beside the pivoted lever, a device whereby the levers can be locked together during one stroke of the oscillating lever; means for normally holding the locking device out of operative position, and sheet controlled tripping devices whereby said locking device is thrown into operative position.

12. In a throw off mechanism. for rinting presses, the combination of a cylinder, devices for moving the cylinder laterally on and of]? impression, a pivoted lever for operating said devices, an oscillating lever beside the first lever, devices adapted to lock the levers together, means for normally holding the locking devices out of operative position, trip devices for throwing said looking devices into operation during one stroke of the oscillating lever to throw off impression, and devices adapted to lock the levers together during the return stroke of the oscillating lever to throw the impression on.

13. In combination, an impression cylinder, and devices for moving the cylinder laterally on and off impression; with an oscillating lever, means for oscillating said lever continually during the operation of the press; a swinging lever beside the oscillating lever, connections between said swinging lever and said devices, a dog on the swinging lever adapted to be engaged with the oscillating lever, means for normally.

holding the dog out of engagement, means for engaging the dog with the oscillating lever to actuate the swinging lever and throw off impression, and means for engaging the dog with the oscillating lever on a return stroke thereof to throw on impression.

14. In combination, an impression cylinder, devices for moving the cylinder laterally, an oscillating lever, and means for oscillating said lever continually during the operation of the press, with a swinging lever beside the oscillating lever, connections between said swinging lever and said devices, a dog on the swinging lever adapted to be engaged with the oscillating lever, means for holding the dog normally out of engagement with the oscillating lever, trip ping devices adapted to cause the dog to engage the oscillating lever on one stroke to throw off impression and means for engaging the dog with the oscillating lever on a return stroke thereof to throw on impression.

15. In combination, an impression cylinder, devices for moving the cylinder laterally on and off impression, and means for operating said devices comprising an oscillating lever, a swing lever beside the oscillating lever, connections between said swinging lever and said devices, a do pivoted on said swinging lever and adapted to engage the oscillating lever, means for normally holding the dog out of engagement with the oscillating lever, means whereby the dog may be thrown into engagement with the oscillating lever during one stroke thereof so as to cause the swinging lever to throw the cylinder off im ression, and means whereby the dog may e caused to engage the oscillating lever on its return stroke so as to throw the cylinder on impression.

16. In a printing press, the combination of an impression cylinder, and devices for moving the cylinder laterally on and off impression; with means for operating said devices comprising a notched oscillating lever, a swinging lever pivoted beside the oscillating lever, connections between said swinging lever and said devices; a dog pivoted on said swinging lever and adapted to be engaged with the notch in the oscillating lever, means for normally holding the dog out of engagement with the notch tripping devices whereby the dog may be thrown into engagement with the notch during one stroke of the oscillating lever so as to cause the swinging lever to throw the cylinder off impression, means for disengaging the dog from the notch when the impression is thrown ofi, and means whereby the dog may be caused to engage the oscillating lever on its return stroke so as to throw the cylinder on impression.

17. In a printing press, the combination of a plate cylinder carrying a plurality of printing surfaces, an impression cylinder having a plurality of impression surfaces, and a plurality of feed tables, and means for automatically throwing off impression if any impression surface fails to receive a sheet during that portion of the rotation of said cylinders wherein such sheet should have been printed without stopping the press, and for throwing on impression during the remainder of the rotation of the cylinders to permit the printing operation of the other impression surface to which sheets are fed.

18. In combination, an impression cylinder having a plurality of impression surfaces, a plurality of tables respectively delivering sheets to corresponding impression surfaces of said cylinder, and means for automatically throwing the cylinder ofl' impression if a sheet is not properly fed to any impression surface for that part of the revolution of such cylinder during which such sheet should have been printed, and for throwing the cylinder on impression for the remainder of its revolution to print a properly fed sheet.

19. In a printing press, the combination of an impression cylinder having a plurality of impression surfaces around its circumference, a member carrying printing surfaces co-acting with the impression cyl inder; a plurality of mechanisms feeding sheets to the impression surfaces of said cylinder, and means for automatically throwing ofi' impression if a sheet is not properly fed by any such mechanism to the impression cylinder during that part of the revolution of the impression cylinder in which such sheet should have been printed, and for throwing the cylinder on impression for the remainder of its revolution to print a properly fed sheet.

20. In a printing press, the combination of a pair of feed tables, a printing couple, one

member of said couple having a pair of impression surfaces adapted to cooperate with printing surfaces on the other member, and mechanism for automatically throwing and holding said impression member ofl' impression if a sheet is not properly fed to an impression surface thereof from either table during that portion of the rotation of said member wherein such sheet should have been printed, and for throwing said member on impression during the remainder of its rotatlon to print a sheet properly fed to another impression surface.

21. In a printing press, a plurality of feed tables, a printing surface carrier, and an impression cylinder co-acting therewith having a plurality of impression surfaces; and means for automatically throwing ofi' impression if a sheet is not properl fed to one impression surface of said cylin er from its related table during that portion of the rotary movement of said cylinder wherein such sheet should have been printed and for throwing on impression during the remainder of the rotation of said cylinder to print a sheet fed to another impression surface of said impression cylinder from another table.

22. In combination, a plurality of feed tables, a plate cylinder, and an impression cylinder co-acting therewith and having a plurality of impression surfaces; with means for automatically throwin the impression cylinder of! impression i a sheet is not properly fed to one impression surface thereof from the related table during that portion of its rotation wherein such sheet should have been printed and for throwing said impression cylinder on impression for the remainder of its rotation to print a sheet fed to another impressionsurface thereof from another table.

In testimony that I claim the foregoing as my own, I afiix my signature in presence of two witnesses.

BURT F. UPHAM.

Witnesses:

PERCY G. SHAW, FRED. G. JONES.