US425123A

US425123A - Island

Info

Publication number: US425123A
Authority: US
Publication date: 1890-04-08
Anticipated expiration: 1907-04-08

Description

(No Modl.) 6 Sheets-Sheet '1.

C. B. OOTTRELL.

OFF-SET MECHANISM FOR PRINTING MACHINES.

N0.'4-25,123. Patented Apr. 8, 1890 (No Model.) 6 SheetsSheet 2.

C. B. OOTTRELL.

OFF-SET MECHANISM FOR PRINTING MACHINES. No. 425,123. Patented Apr. 8, 1890 we HORN! m'zns cm, wow-urns, wAsHmuTqN, u. c.

(No Model.) I 6 Sheets-Sheet 3.

O. B. GOTTRELL. OPP-SET MEGHANISM FOR PRINTING MACHINES. No. 425,123.

Patented Apr. 8, 1890.

hesse a:

(No Model.)

6 Sheets-Sheet 4. C. B. OOTTRELL. OFF-SET MECHANISM FOR PRINTING MACHINES. No. 425,123.

Patented Apr. 8, 189Q.

- gwmm %%fm mine 23.-

w: NGRRIS warms 1:0,, "momma, wneumaran, u. c,

(No Model.) 6 Sheets-Sheet 5.

O. B. OOTTRELL.

OFF-SET MECHANISM FOR PRINTING MACHINES. v

No. 425,123. w Patented Apr. 8, 1890.

THE mum: PETERS co PHDTO-LIYNm, wummzmn, u. c.

(No Model.) 6 Sheets-Sheet 6. O. B. GOTTRELL.

OFF-SET MECHANISM FOR PRINTING MACHINES. No. 425,123. Patented Apr. 8 1890.

w: mums Puma co., PNOr0-uYn0.. vnsxmarou, a. c.

the right side of that figure.

UNITED STATES PATENT @EFICE.

CALVERT B. GOTTRELL, OF \VESTERLY, RHODE ISLAND.

OFFSET MECHANISM FOR PRINTING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 425,123, dated April 8, 1890,

Application filed October 11, 1889- Serial No. 326,655 (No model.)

To all whom it imty concern:

Be it known thatI, CALVERT B. COTTRELL, of WVesterly, in the county of Washington and State of Rhode Island, have invented' a new and usefullmprovement in Oifset Mechanism for Printing-lvlachines, of which the following is a specification, reference being had to the accompanying drawings.

This invention is more especially applicable to that class of printing-machines known as perfecting-machines.

The improvement relates to an automatically-shifting tympan employed on an impression-cylinder, and more especially on the second impression-cylinder of a perfectingmachine, the object being, generally, the prevention or reduction of the tendency to what is known as set-off, or transfer of ink from the tympan onto the printed sheet while the latter is receiving its second impression.

In my Letters Patent of the United States Nos. 175,036 and 17 5,037, both dated March 21, 1876, there are described and claimed automatically-shifting tympans. According to the descriptions contained in the specifications of both of those patents, the tympans are shifted a short distance during every revolution of the impression-cylinder to which they are applied; but according to the present invention the desired eifect is much better accomplished by allowing the tympan to remain stationary relatively to its cylinder during several revolutions of the cylinder, and then shifting it at once the whole distance necessary to present an entirely fresh and clean portion of the tympan on the exterior of the cylinder.

I will now proceed to describe my invention with reference to the accompanying drawings and afterward point out its novelty in the claims.

Figure 1 of the drawings represents a longitudinal vertical section of an impressioncylinder and parts of the framing of a printing-machine and of the devices and appurtenances belonging thereto involved in my invention. Fig. 2 represents an end view of the cylinderand a vertical section of those parts which are attached to the framing, taken in the line (/0 00 of Fig. 1, as viewed from Fig. 3 represents a transverse vertical section of the cylinder and its appurtenances, taken in the line 3 y of Fig. ,1, looking from the right of that figure, and also showing in dotted out=- line certain parts, the position of which is outside of said line y 1 Fig. at is a perspective view of a portion of the gearing through which the shifting of the tympan is effected by the rotary motion of the cylinder. Fig. 5

is a view corresponding with part of Fig. 1, but on a larger scale.

Figs. 6 and 7 are diagrams representing the principal parts of two different kinds of perfecting presses, and illustrating the application of my invention to each. Fig. 8 represents the same end of the cylinder as is shown in Fig. 2, and illustrates a modification of a portion of the tympan-shifting mechanism. tional view at right angles to Fig. 8 of some of the details of that figure.

Similar letters and numerals of reference designate corresponding parts in all the figures.

A, Figs. 1, 2, 3, and S, designates the impression-cylinder-forexample,the second impression-cylinder of any perfecting-machinethe shaft A of said cylinder having its hearings in boxes A supported in the stationary side frames B, Fig. 1, of the machine. This cylinder is represented as having tympans c in four sections, each of which will be hereinafter referred to as a shifting tympan, each covering a portion of the circumference of the cylinder included between two longitudinal openings 6, the number of said openings corresponding with the number of tympans 0. Each of these tympans 0 consists of a roll of paper nearly as wide as the cylinder and of a length many times what is required to cover one of the divisions of the cylinder between two openings 6. One end of the roll is fastened to a roller (Z, and the other end to a roller j, there being two such rollers for every tympan, the said rollers, which may be termed the tympan-rollers, being within the cylinder, and their journals having bearings 61' j provided for them in the heads of the cylinder, and the roll of paper being capable of being unrolled from one roll and rolled onto the other. Between the said rollers d 3' each tympan runs from the roller (Z over a rod a, supported in the cylinder-heads; thence through one opening (2 of the cylinder over Fig. 9 is a sec the circumference of the cylinder to the next of said openings 6, over a rod or roller g, arranged in said opening; thence over and be tween the feed-rollers it i, which have their bearings h a" in the cylinder-heads,and thence to the roller The tympan-roller j, which may be called the take-up roller, as the web is taken up by it from the roller (l for the shifting of the tympan-surface outside of the cylinder, is geared at each end with the feed-roller h by friction wheels or gears 7a 7, and the said roller j is furnished inside of the cylinder with a ratchet-wheel 3' which is engaged by a spring-actuated pawl j, attached to one of the cylinder-heads for the purpose of retaining the portion of the tympan c wound upon said roller. On one end of the tympan-roller (Z, which may be termed the delivery-roller, there is within the cylinder a ratchet-wheel (1 which at all times except during the unwinding of the roll from the said roller is engaged by a pawl d, which forms part of a small lever working on a fulcrumpin (2, secured in one of the cylinder-heads. The ends of the roll of paper may be'fastened to the rollers (Z and 7' by hooks, clamps, or other suitable means.

One end of the shaft of each feed'roller h of the tympan projects outward some distance beyond the corresponding end of the cylinder, as shown in Fig. l, and also in Fig. 5, and the so projecting part has loosely fitted to it a spur-gear s, the elongated hub s of which (see Fig. 5) is fitted to turn freely in a sleeve 0, on the exterior of which is a scre\ thread of rapid pitch, which is fitted to a corresponding female screw-thread in a bushing p, which is secured by screws 1) into an annular plate A, which is secured to the cylinder concentric therewith by stud-bolts a. The spur-gear s has firmly secured to it one half of a ratchet-clutch t, the other half of which is secured to the shaft of the roller 72.. Firmly secured upon the outer end of the screw-threaded sleeve 0 is a lever 22, having two arms of equal length and having on one arm an anti-friction roller m and onthe other arm an anti-friction roller m.

C designates a spur-gear (shown dotted in Fig. 2 and in section in Fig. 1) concentric with the cylinder, but stationary at that end of the cylinder on which the gears s are situated. This gearconsists of a ring held by brackets C,

which are secured to any convenient portion of one of the side frames Bas, for instance, the cylinder-box. The several gears s belonging to the several tympans are always in gear with this stationary gear (J in readiness to drive the tympan-rollers 72 for shifting the tympans by the revolution of said gears around the stationary gear 0; but the shift ing of the tympans is only effected while the clutch t is in gear, the said gears running loose upon the shafts of their rollers at all other times.

D and E are two spur-gears concentric with the cylinder, arranged close together on the same side thereof as the spur-gear C. The outer spur-gear 1) consists simply of a toothed ring, which is held stationary by being secured to parts of the same brackets C which support the gear 0. The gear E is fitted to turn loosely on the adjacent cylinder-head, and its own hub E projects through. the outer gear or toothed ring D, as shown in Figs. 2 and -t.

The gears D and E are approximately of the same pitch, but the gear J) has one more tooth than the gear E. In the exam ple represented the gear D is supposed to have eighty teeth and the gear E to have seventy-nine. Both of these gears gear with a spur-gear 1*, (see Figs. 2 and 4,) which turns loosely on a stud F, secured in the cylinder-head.

U designates a bent lever, which hangs on a fixed fulcrum consisting of a stud-bolt 1*, (see Figs. 1 and 2,) secured in a convenient part of the side frame B on the same side of the machine as that on which the levers a are situated. This lever is shown fully in Fig. 2 and in section in Fig. .1. It has upon one arm an offset a, (see Fig. 2,) which constitutes a movable cam-surface for acting, as herein after described, on the rollers m on the inner ends of the levers n, and the extremity u* of the said arm is capable of engagement with either of two hooks 20 21 on the lower arm of an elbow-lever l V, hereinafter termed the trip-lever, which works on a fulcrum consisting of a stud bolt 19, secured in the side frame, and the other arm of which is furnished with an anti-friction roller 10, to be operated upon by a stud 9, which projects from the hub E of the spur-gear E. The outer end of roller a, to be operated upon by a cam ll, (see Fig. 52,) secured to the adjacent end of .the cylinder. The cam-lever U has applied to it apushiug-spring'w, which takes its bearing against one of the brackets (3, for the purpose of pushing it outward as far as permitted by the hook 20 or 21 of the elbow-lever W, which may be at any time engaged with the extren'iitya of the cam-lever. The trip-lever V is connected with one of the brackets C by a pulling-spring Y, to keep it in engagement with the extremity ofthc cam lever U, as shown in Fig. 2. ()n the same side of the machine as the lovers U and \V, but on the opposite side of the axis of the cylinder, there is secured to the side frame a stationary cam N, for acting, as .hereinafter described, on the rollers m at the outer ends of the lovers 11 The purpose of the cam -lever U, the lovers 0:, the screwthreaded sleeve 0, the trip-lever \V, the stud I), the gears l) E F, and the cam H is the throwing of the clutches t into gear at the proper time to produce the shifting of the tynmans after a certain number of revolutions of the cylinder has been made, and afterward to throw the said clutches outot' gear to leave the shafts of the rollers 71. free from the gears s, as will be hereinafter described.

the lever U is furnished with an anti-friction I have hereinbefore described a ratchetwheel (1 on each of the tympan-rollers cl, and a pawl d for engaging the same. This pawl d requires to be thrown out of gear from its respective ratchet-wheel prior to the operation of shifting the tympan. For the purpose ofthrowing this pawl out of gear with its ratchet, it is connected with the outer end of its respective lever 11 by means which I will now describewith reference to Figs. 2 and 3.

11 is a rod connecting the outer end of the lever 72 with one arm 12 of a rock-shaft 13,

which is supported in the ring A and the adjacent cylinder-head, another arm 14 of the said rock-shaft being connected by a rod 15 with the outer end of the pawl-lever (1 For the purpose of keeping this pawl in gear at all times, except when the pawl is intended to be thrown out of gear with its ratchet-wheel, there is coiled round its respective rod 11 a spring 16, one end of which has a bearing against a fixed guide 17, secured to the ring A, the other end of which bears against a collar 18 on the said rod. This spring 16,while strong enough to hold the pawl in gear until it is required to be thrown out, is not strong enough to overcome the friction between the bushing 19 and the screw-threaded sleeve to which the said lever 01. is attached.

In order to provide for the insertion of the tympan-rollers (Z and j into the cylinder and their removal therefrom with the roll of paper which serves as the shifting tympans, the bearings d and j for the said rolls are not made directly in the cylinder-heads, but in cap-pieces G, which are fitted to openings G, provided in the cylinder-heads, the said openings being large enough to permit the insertion of the said rollers and the roll of paper through the cylinder-heads. Each opening G is represented of a size and form to admit the roller 61 of one tympan and the roller to the next tympan. The cap-plates G are of skeleton form, having openings in them large enough to admit the arms of the attendants for the purpose of making ready the tympans for printing.

Before describing the operation of shifting the tympau I will mention that the blanket which is represented under the tympan in dotted lines in Fig. 3 may be attached to one end of the rod a, hereinbefore mentioned as one of the guides for the tympan, and at the other end to a rod 1), whichis supported in the cylinder-heads.

The operation of shifting the tympan is as follows: The shift-ing tympan having been put on each section of the cylinder, as described, the extremity 10* of the cam-lever N is brought into the inner hook 20 of the triplever XV, in which position the movable cam u will be out of the way of the rollers m of the levers n, the said levers being then in such position that the screw-threads on their surface hold the clutches tout of gear, keeping the feed-rollers 71. out of gear from the spur-gears .9. When the levers are in this position, their rollers m are in such position that they will not strike thestationary cam N in their rotation with the cylinder. The press being then started, the cylinder revolves in the direction of the arrow 23. (Shown in Figs. 2 and 3.) The gear F revolving with the cylinder in gear with the stationary gear D and the loose gear E causes the latter to turn slowly in the opposite direction to the cylinder at the rate of one tooth for each revolution of the cylinder. Aftera certain number of revolutions have been made the gear E is turned until the stud 9 on its hub comes in contact with the roller 10 on the trip-lever W and moves the said lever so far that its inner or upper hook 20 slips from under the extremity 10* of the cam-lever U and allows the said cam-lever to be forced outward by the spring into the outer or lower hook 21, as shown in Fig. 2. Then, when the portion of -a tympan which is exposed on the surface of the cylinder is clear from the web of printed paper, the roller m on its respective lever 01 comes in contact with the movable cam u on the lever U, and the said lever 71 is turned in the direction of the arrow 24. (Shown in the lower part of Fig. 2.) This movement of the lever 7%, operating through the rod 11 and through the connections hereinbefore described between the said rod 11 and the pawl 61 liberates the ratchet-wheel (1 At the same time the screw-threaded sleeve 0, turning with the lever n, to which it is attached, is caused to be screwed inward in its bushing 19, and so to push the gear 5 and the portion of the ratchet-clutch thereto attached into gear with the other portion of the said clutch on the friction-wheel k. The said gear sis always turned while the cylinder revolves, and when the ratchet-clutch comes into gear the feed-roller h turns with the said gear, and the feed-roller 2' turns with it by the friction of the tympans between them. The take-up roller j is at the same time turned by the friction between the friction-wheels '1; and Z, and thus the tympan is drawn from the roll on the roller (1 and wound upon the roller j.- The feed-rollers h and 'i turn sufficiently while the ever or of the roller .71 moves from under the cam u to a position near the cam N to move the tympan in the direction of the circumference of the cylinder a distance about or nearly equal to the distance between two openings e e, or about equal to the length of the form in that direction, and thus to present at one operation an entirely fresh and clean portion of the tympan on the exterior of the cylinder. IWhen the feed-roller it approaches the cam N, the roll on on its lever it strikes the cam 'N, and the lever n is thus turned in such direction that the screw-threaded bushing o, to which it is attached, is screwed outward in the bushing 19 and caused to ungear the clutch t, and the tympan then stops shifting. In the meantime the tympan on another section of IOL the cylinder included between. two openings 8 is shifting. \Vhen the several sections of the cylinder have clean tympans and before either feed-roller h of the ty m pans has reached the movable cam u a second time, the cam H on the cylinder comes in contact with the roll it on the cam-lever U and lifts the end 215 of the said lever into the upper or inner hook 520 of the trip-lever IV, so that the roll on on the lever 02 of the tympan will pass the said movable cam it without striking. Then the cylinder makes a number of revolutions until the pin 9 again reaches the roller 10 of the trip-lcver \V, when the cam-lever U is again tripped and the shifting operation is repeated. The number of revolutions thus made before the pin 9 again reaches the roller 10 depends upon the number of teeth in the spur-gears D E. If it be desired to shift not so often, the gears D and E should have a larger number of teeth. The frequency of the shifting may, however, be increased by putting one or more additional pins 9 in the hub E of the gear E.

In some cases it may be desirable to provide for tripping the cam-lever U by hand to produce the shifting of the tympan at a desirable time. In such case, instead of arranging the trip-lever \V loosely on the fixed fulcrum 19, as shown and described with reference to Fig. 2,1 fasten said lever upon the inner end of a short arbor 19*, as shown in Figs. 8 and 9, which works in a fixed bearing provided in the cylinder-pocket or suitable portion of the adjacent side frame B of the machine, and on the outer end of the said arbor which projects through the outside of the said side frame I itffiX a small hand-lever \V', by which at the proper time the hooked arm of the said lever \V may be operated to trip the cam-lever in the same way as when automatically tripped by the action of the stud 9, here iubefore described. In order to prevent the trip-lever from being moved farther than it is necessary to effect the tripping of the camlever, a stop a: is provided for the hand-lever \V'. This stop :0 is represented as consisting of a pin secured in the outside of the side frame.

As it is necessary that the tripping should occur at the proper stage of the revolution of the cylinder, as hereinbefore described, some means must be provided by which the tripping at any other time is prevented, and for this purpose I provide upon the outside of the cylinder a flange or annular projection .2, (see Fig. 8,) which is concentric with the cylinder, and the external circumference of which is slightly within the radius of the outside of the cam ll. This flange or projection is in a position for the roller a of the cam-lever U to be just outside of it when the end of the said lever is engaged by the hook 20 on the trip'lever. The said flange or projection is not a complete circle, but terminates 011 each side of the cam ll, so as to leave two openings H Il between it and the said cam for the entrance of the roller 14 on the upper arm of the cam-lever U.

The operation of tripping the cam-lever by hand to produce the shifting of the tympan is as follows: The operator moves the handlever IV in a direction, and the proper distance to throw out the hook 20 of the triplever from the end of the cam-lever that is to say, until it comes in contact with the stop :0. The cam it cannot, however, then move outward to its operative position until the space H between the cam H and the flange or projection z arrives opposite the roller u on the cam-lever. The cam-lcver U will then be permitted to move a little way in the direction to throw the cam 16 outward, but the said lever will be thrown back by the cam H. The hand-lever \V must still be held against the stop-pin 0c, and when the space 1 1 reaches the roller it the said roller will pass through the said opening I1 and within the innereircumference of the flange 2, during the continued rotation of which the said lever is held with the cam 14 in the position for operating upon the levers n of the feed-rollers until the several tympans have been shifted, as hereinbet'ore described, when the cam ll comes into operation on the said roller 10' and brings the cam-lever back to the position to be engaged by the hook 20 of the trip-lever \V, the operation of the shifting being then completed. As soon as the operator sees the cam u thrown into its operative position he can release the hand-lever \V, which will be thrown back by its spring Y after all the tympaus have been shifted and the canrlever has been returned by the cam II to the position to be engaged by the hook 20 of the triplever.

The hereinbefore-deseribed means of providin g for the tylnpairsliifting mechanism by hand may be used in the same machine with the automatic mechanism herein first de scribed for operating the trip-lever or it may be used without the said automatic mechanism.

As the roll of paper on the take-up roller j increases in circumference the movementimparted to the said roller j from the feed-roller h for the taking up of the tympan as it is shifted by the said roller 7i must be diminished; otherwise there would be risk of tearing the tympan. It is to obviate this difficulty and to cause the take-up roller to take up the tympan just as fast as is necessary that I employ the friction-gears and Z between the said rollers 7L and j to drive the latter. These friction-gears are so PIOImPt-lOllOd that they will drive the take-up roller fast enough when the said roller is empty, and as the quantity of paper rolled upon it increases a slip occurs between the friction-gears; but the take-up roller is always driven fast enough to wind the tympan up tight.

The foregoing description of the construction and operation of my invention will,I believe, be sufficient to enable those skilled in ICC ITO

I have hereinbefore described a ratchetwheel (Z on each of the tympan-rollers cl, and a pawl 61 for engaging the same. This pawl 61 requires to be thrown out of gear from its respective ratchet-wheel prior to the operation of shifting the tympan. For the purpose of throwing this pawl out of gear with its ratchet, it is connected with the outer end of its respective lever n by means which I will now describewith reference to Figs. 2 and 3.

11 is a rod connecting the outer end of the lever n with one arm 12 of a rock-shaft 13, which is supported in the ring A and the adjacent cylinder-head, another arm 14 of the said rock-shaft being connected by a rod 15 with the outer end of the pawl-lever 61 For the purpose of keeping this pawl in gear at all times, except when the pawl is intended to be thrown out of gear with its ratchet-wheel, there is coiled round its respective rod 11 a spring 16, one end of which has a bearing against a fixed guide 17, secured to the ring A the other end of which bears against a collar 18 on the said rod. This spring16,while strong enough to hold the pawl in gear until it is required to be thrown out, is not strong enough to overcome the friction between the bushing 19 and the screw-threaded sleeve to which the said lever n is attached.

In order to provide for the insertion of the tympan-rollers (Z and 3' into the cylinder and their removal therefrom with the roll of paper which serves as the shifting tympans, the bearings d and j for the said rolls are not made directly in the cylinder-heads, but in cap-pieces G, which are fitted to openings G, provided in the cylinder-heads, the said openings being large enough to permit the insertion of the said rollers and the roll of paper through the cylinder-heads. Each opening G" is represented of a size and form to admit the roller d of one tympan and the roller j to the next tympan. The cap-plates Gr are of skeleton form, having openings in them large enough to admit the arms of the attendants for the purpose of making ready the tympans for printing.

Before describing the operation of shifting the tympan I will mention that the blanket which is represented under the tympan in dotted lines in Fig. 3 may be attached to one end of the rod a, hereinbefore mentioned as one of the guides for the tympan, and at the other end to a rod 1?, which is supported in the cylinder-heads.

The operation of shifting the tympan is as follows: The shift-ing tympan having been put on each section of the cylinder, as described, the extremity u of the cam-lever N is brought into the inner hook 20 of the triplever WV, in which position the movable cam a will be out of the way of the rollers m of the levers 'n, the said levers being then in such position that the screw-threads on their surface hold the clutches tout of gear, keeping the feed-rollers 71/ out of gear from the lower part of Fig. 2.)

'Figs. 2 and 3.) The gear F revolving with the cylinder in gear with the stationary gear D and the loose gear E causes the latter to turn slowly in the opposite direction to the cylinder at the rate of one tooth for each revolution of the cylinder. Aftera certain nunr ber of revolutions have been made the gear E is turned until the stud 9 on its hub comes in contact with the roller 10 on the trip-lever W and moves the said lever so far that its inner or upper hook 20 slips from under the extremity 16* of the cam-lever U and allows the said cam-lever to be forced outward by the spring into the outer or lower hook 21, as shown in Fig. 2. Then, when the portion of a tympan which is exposed on the surface of the cylinder is clear from the web of printed paper, the roller 'm on its respective lever 12 comes in contact with the movable cam u on the lever U, and the said lever n is turned in the direction of the arrow 24. (Shown in the This movement of the lever n, operating through the rod 11 and through the connections hereinbefore described between the said rod 11 and the pawl d liberates the ratchet-wheel (Z At the same time the screw threaded sleeve 0, turning with the lever n, to which it is attached, is caused to be screwed inward in its bushing 1;, and so to push the gear 3 and the portion of the ratchet-clutch thereto attached into gear with the other port-ion of the said clutch on the friction-wheel k. The said gear .9 is

always turned while the cylinder revolves,

and when the ratchet-clutch comes into gear the feed-roller h turns with the said gear,

,and the feed-roller 2' turns with it by the friction of the tympans between them. The take-up roller j is at the same time turned by the friction between the friction-wheels and Z, and thus the tympan is drawn from the roll on the roller (1 and wound upon the roller The feed-rollers h and 2' turn sufficiently while the lever n of the roller .h moves from under the cam u to a position near the cam N to move the tympan in the direction of the circumference of the cylinder a distance about or nearly equal to the distance between two openings 6 e, or about equal to the length of the form in that direction, and thus to present at one operation an entirely fresh and clean portion of the tympan on the exterior of the cylinder. ;When the feed-roller it approaches the cam N, the roll on on its lever 72 strikes the cam N, and the lever n is thus turned in such direction that the screw-threaded bushing 0, to which it is attached, is screwed outward in the bushing 19 and caused to ungear the clutch t, and the tympan then stops shifting. In the meantime the tympan on another section of the cylinder included between two openings 0 is shifting. \Vhen the several sections of the cylinder have clean tympans and before either feed-roller it of the tympans has reach ed the movable cam u a second time, the cam II on the cylinder comes in contact with the roll it on the cam-lever U and lifts the end of of the said lever into the upper or inner hook 20 of the trip-lever TV, so that the roll on. on the lever n of the tympan will pass the said movable cam it without striking. Then the cylinder makes a number of revolutions until the pin 9 again reaches the roller 10 of the trip-1ever \V, when the cam-lever U is again tripped and the shifting operation is repeated. The number of revolutions thus made before the pin 9 again reaches the roller 10 depends upon the number of teeth in the spur-gears I) E. If it be desired to shift not so often, the gears D and E should have a larger number of teeth. The frequency of the shifting may, however, be increased by putting one or more additional pins 9 in the hub E of the gear E.

In some cases it may be desirable to provide for tripping the cam-lever U by hand to produce the shifting of the tympan at a desirable time. In such case, instead of arranging the trip-lever \V loosely on the fixed fulcrum 19, as shown and described with reference to Fig. 2,1 fasten said lever upon the inner end of a short arbor 19*, as shown in Figs. 8 and 9, which works in a fixed bearing pro vided in the cylinder-pocket or suitable portion of the adjacent side frame B of the machine, and on the outer end of the said arbor which projects through the outside of the said side frame I afiix a small hand-lever \V, by which at the proper time the hooked arm of the said lever W may be operated to trip the cam-lever in the same way as when automatically tripped by the action of: the stud 9, hercinbei'ore described. I11 order to prevent the trip-lever from being moved farther than it is necessary to effect the tripping of the camlever, a stop (13' is provided for the hand-lever \V'. This stop :0 is represented as consisting of a pin secured in the outside of the side frame. I

As it is necessary that the tripping should occur at the proper stage of the revolution of the cylinder, as hereinbefore described, some means must be provided by which the tripping at any other time is prevented, and for this purpose I provide upon the outside of the cylinder at flange or annular projection ,2, (see Fig. 8,) which is concentric with the cylinder, and the external circumference of which is slightly within the radius of the outside of the cam H. This flange or projection z is in a position for the roller n of the cam-lever U to be just outside of it when the end of the said lever is engaged by the hook 20 on the trip-lever. The said flange or projection is not a complete circle, but terminates on each side of the cam II, so as to leave two openings II 11 between it and the said cam for the entrance of the roller u on the upper arm of the cam-lever U.

The operation of tripping the cam-lever by hand to produce the shifting of the tympan is as follows: The operator moves the handlever \V in a direction, and the proper distance to throw out the hook 20 of the triplever from the end of the cam-leverthat is to say, until it comes in contact with the stop an. The cam it cannot, however, then move outward to its operative position until the space H between the cam H and the flange or projection z arrives opposite the roller u on the cam-lever. The cam-lever U will then be permitted to move a little way in the direction to throw the cam u outward, but the said lever will be thrown back by the cam H. The hand-lever -W" must still be held against the stop-pin a3, and when the space 11 reaches the roller u the said roller will pass through the said opening II and within the innercircumference of the flange ,2, during the continued rotation of which the said lever is held with the cam 14 in the position for operating upon the levers n of the feed-rollers until the several tympans have been shifted, as hereinbefore described, when the cam ll comes into operation on the said roller u and brings the cam-lever back to the position to be engaged by the hook 20 of the trip-lever \V, the operation of the shifting being then completed. As soon as the operator sees the cam u thrown into its operatWe position he can release the hand-lever \V, which will be thrown back by its spring Y after all the tympans have been shifted and the camlever has been returned by the cam H to the posi tion to be engaged by the hook 20 of the triplever.

The hereinbefore-described means of providing for the tympan-shiftin g mechanism by hand may be used in the same machine with the automatic mechanism herein first described for operating the trip-lever \V, or it may be used without the said automatic mechanism.

As the roll of paper on the take-up roller j increases in circumference the movement imparted to the said roller j from the feed-roller h for the taking up of the tympan as it is shifted by the said roller h must be diminished; otherwise there would be risk of tearing the tympan. It is to obviate this difiiculty and to cause the take-up roller to take up the tympan just as fast as is necessary that I employ the friction-gears 7c and Z between the said rollers 7L and j to drive the latter. These friction-gears are so proportioned that they will drive the take-up roller fast enough when the said roller is empty, and as the quantity of paper rolled upon it increases a slip occurs between the frietion gears; but the take-up roller is always driven fast enough to wind the tympan up tight.

The foregoing description of the construction and operation of my invention wili,I believe, be sufficient to enable those skilled in ICC ITO