US1100409A - Printing-press. - Google Patents

Description

R. 0. VANDERGOOK.

PRINTING PRESS.

APPLIUATION FILED 1mm, 191s.

Patented June 16, 1914.

a SHEETS-SHEET 1.

R. 0@ VANDERGOOK.

PRINTING PRESS.

APPLICATION FILED JAILB 1913.

Patented June 16, 1914.

R. 0. VANDERGOOK.

PRINTING PRESS. APPLICATION PILED J'AKB, 1913.

nonnn'r o. vnnnnncoox, or cIIIcnGo, ILLINOIS.

PRINTING-PRESS.

Specification of Letters Patent.

Patented June 16,1914.

Application filed January s, 1913. Serial No. 740,749.

T 0 all whom it may concern:

Be it known that I, Ronnn'r O. VANDER- COOK, a citizen of the United States, and a resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Printing- Presses; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification. V

This invention relates to printing presses of that class having a fixed or stationary bed andzurotative, movable roller or impression cylinder, and it embraces improvements more particularly applicable for use in connection with that class of printing presses employed in the offset and lithographing process of printing, and also improvements applicable to the kind or type of printing press set forth in an application filed by me on September 9, 1912, Serial No. 516,913.

Among the objects of my invention is to provide improved features of construction in a printing press adapted for the above mentioned ofi'set process, wherein impressions which are made from any relief plate, lithograph, photographic transfer, or. the like, are transferred to stock of varying thickness and in accordance with the .class of work being done, and to provide improvements in the arrangement and construction of the parts comprising a printing press of the type shown in said separate application.

adapted to greatly increase its capacity for' eiiicient and convenient use branches of the art.

The invention consists in the matters hereinafter described and more particularl pointed out in the appended claims.

In the drawings Figure 1 is a view in side elevation of my improved printing press; Fig. 2 is an enlarged plan view of the printing press shown in Fig. 1; Fig. 3 is a View in longitudinal section of the press taken on line 3-3 of Fig. 2; Fig. 4 is a transverse section taken on line 44 of Fig. 3, with a portion of the impression member in-section to show the construction thereof; Fig. 5 is a detail view in horizontal section, taken on line 5--5 of Fig. 1, showing the arrangement of the trip mechanism Fig. 6 is an enlarged detail view in section, taken on line 6 6 of Fig. v5; Fig. 7 is a detail view in section, taken on line 7-- 7 of Fig.- 6; Fig. 8 is an enlarged detail view in section, taken on line 8 8 of Fig. 5; Fig. 9 is an enlarged detail view in section, taken on line 99 of Fig. 5; Fig. 10 is an enlarged detail view in section, taken on line 1010 of Fig. 1; and Fig. 11 is a view in end elevation of one of the shiftable rollers.

The press embodying my invention,shown in the accompanying drawings, has a main frame comprising two stationary side frame members, which are by preference in the form of horizontal beams l of channel or I-beam construction, and transverse beams extending between and connected at their opposite ends with said horizontal channel beams 1, all forming a rigid horizontal main frame which is supported upon legs 2. Said transversebeams comprise a beam 3 located, by preference, midway between the extremities of the frame, and end beams 4:, which also extend transversely between the side frame members and are connected with the latter at or near the opposite ends thereof.

Two horizontally-disposed flat beds 5 and 5, adapted to be adjusted upwardly and downwardly with respect to each other and with respect to the main frame, are supported upon said transverse beams 3 and 4 and between the side frame or channel beam members 1 For so supporting the beds 5 and 5', devices are provided as follows: The central beam 3 is providedwith flange portions or lugs 3 projecting outward horizontally from both of its side faces and located adjacent to its lower margin.v The end beams 4, 4 are likewise provided with similar flange portions or lugs 4 extending inward horizontally from the inner faces of said beams and located in a horizontal plane are likewise provided with horizontal flange portions or lugs 5 upon their end margins corresponding with those of the transverse beams, and a plurality of jack-screws 6 ex tend through perforations in the lugs 5 (see Fig. 3), and are supported in a vertical position by the lugs 3 and 4, said jack-screws each being in screw threaded engagement with either the corresponding lug 5 or the adjacent lug on the transverse beam. Pref- ,95 of the lugs or flanges 3. The beds 5 and 5" erably the screws have threaded engagement with the corresponding lugs 5 on the bed through which thescrews extend, as shown in Fig. 3. By rotating the jack-screws 6 the beds may be adjusted up and down with respect to the rigid main frame and the tracks and impression roller or rotary impression or transfer member, hereinafter described, as required, to conform to the varying thickness of the material to be sup-J.

and which for convenience. will be hereinafter called an impression plate. The bed 5 is adapted to support upon itsflat' upper surface a sheet of paper or other sheet material upon which an impression is to be made. I

The above-mentioned longitudinal channel members 1 have top flanges l and bottom flanges 1 projecting outward hori zontally therefrom. Upon the horizontal bottom surfaces of the top flanges 1 are attached longitudinal track plates forming downwardly facing tracks 7 7, and the bottom flanges 1 have attached thereto horizontal track plates 8, 8, forming upwardly facing tracks 8, 8, the top surfaces of which are separated vertically from said downwardly facing tracks a distance slightly greater than the diameter of rollers 16 and 17, hereinafter more particularly described. Upwardly facing tracks 9, 9 are attached to the plates 8*, 8*, laterally exterior to the tracks 7, 7 with their upper faces in a horizontal plane which is at a dlstance below the planes of the downwardly facing surfaces of the tracks 7 7 slightly less than the di-' ameter of the said rollers 16 and 17; the tracks 9, 9 being at a higher' level than the tracks 8, 8. The top flanges 1 are provided laterally exterior to the tracks 7, 7, with downwardly facing surfaces 10, 10 located in vertical alinement with the upwardly facing surface of the tracks 9, 9 and at a distance above the latter slightly greater than the diameter of said rollers. (See Fig. 4).

A rotative impression cylinder or roller 11 is adapted for rolling movement along and over the beds 5 and 5. Said impression cylinder comprises a segmental cylindrical shell or main cylindrical impression portion, provided with cylindric or annnlar bearing surfaces 11 at each end thereof. The roller and the bearing portions 11' a 1; Gear wheels 13, 13 are fixed to the ends of the impression member and have their pitch lines corresponding in diameter with that. of the cylindric surface of the impression member. Said gear wheels 13 engage toothed racks 14, 14, which have their pitch lines in the same horizontal plane with the top surfaces of said bearers or tracks 1, 1,

and are upon or integral with the portion of the channel members 1 which are located outside of and adjacent to the said bearers or tracks 1, l. A tympan 12, according to the present practice made of rubber, is mounted upon the cylinder 11 and substantially covers the cylindric surface of the same. The end margins of the said tympan are connected with the roller 11 by means of rotative shafts 12 (see Fig. 3) which are mounted within the impression roller 11 and are adapted to be .held. against rotation on their axes by means commonly employed for that urpose, such as pawls and ratchet wheels not shown) connected with the shafts 12 and impression roller 11, respectively. Said tympan is adapted to receive the impression from a plate to which ink is applied and from which impressions can be made, such as a stereotyp'ed plate or a plate having upon it a lithographic or photographic transfer or the like and which is mounted upon the bed 5, as the impression member travels over the same, and to transfer the impression thus received upon the cylindrical surface formed by the curved cylinder 11 with its tympan 12 to the paper or other substancelaid upon the bed 5, as the impression member passes thereovcr immediately after its contact with such form or late.

tub shafts or trunnions 11", 11", preferably integral With the end walls of the cylinder 11, extend outwardly therefrom. and have their axes in alinement or concentric with the longitudinal axis of'the impression member or roller 11. Said stub shafts are journaled in the hubs 15 of yokes or end frames 15, 15, comprising arms 15", 15, there being a web or frame portion 15 extending between or connecting and adapted to strengthen said arms. Said arms 15", 15 are arranged at an angle to each other, and provided at their lower extremities with stub shafts 16 and 17, respectively. Rotatively mounted upon said'stnb shafts 16 and 17 are two rollers 16 and 17. The rollers 17, 17 have rotative movement only relative to their shafts 17*, and are adapted to travel beneath and in contact with the downwardly facing tracks 7 7, during the movement of the impression member in one direction, and to travel upon the bearing sur face or tracks 8, 8, formed by the inner parts of the plates 8 8 in the movement of the impression member in the opposite direction. The rollers 16, 16, on the other hand, have laterally shifting, as well as a rotative movement relative to their shafts 16*, 16, and are adapted to travel beneath and in contact with the downwardly facing tracks 7, 7 and above the tracks 8, 8, during the passage of the impression member over the beds in one direction and to be shifted into position to travel over and in engagement with the upwardly facing tracks 9, 9, during the non-operating or return passage of the impression member over the beds. The downwardly facing tracks 7 are thus adapt ed to be engaged by the rollers 16 and'17 during the travel of the impression member in one direction along the bedsfor instance, during the movement of the impression roller from initial position, as shown in Figs. 1 and 3, toward the left or to the position shown in. Fig. 2. Said impression member is thereby held down to its work or with the tympan thereon in engagement with the impression plate, and the sheet to be printed upon, during such travel. At the beginning of the travel of the impression member in the opposite direction, or its return movement toward initial position, the roller 16 is shifted upon and longitudinally of its stub shaft 16 to a osition to engage the upwardly facing trac ( s 9, 9, so that it will be lifted by and will travel-upon the said tracks 9, 9 (see Fig. 4), while the nonshiftable roller 17 is traveling upon the up wardly facing tracks 8, 8, thereby tilting the frames 15 sufficiently to lift the impression member 11, with the same effect that is produced by the form of mechanism shown in my prior application, Serial Number 516,913, hereinbefore referred to.

In order to enable the rollers 16 and 17 to be adjusted with respect to the impression roller 11 so as to take up or compensate for the wear upon said'rollers, a construction is provided as follows: The stub shafts or axle portions 16*, 16, on which the rollers 16 are mounted, are slightly offset or eccentric with reference to the portions of said shaft or axles which are supported within the extremity of the arms 15". (See Figs. 10 and 11). Each of said stub shafts is provided with a screw-threaded end extending beyond the face of the arm 15 and provided with a square head 16 adapted to be engaged and operated by means of a wrench. A nut 16 is mounted upon the screw-threaded extremity of each of the stub shafts 16, 16. By rotating any stub shaft,

by means of a wrench, and tightening the nut 16, the position of the roller and the axis of rotation of the roller may be varied with respect to the rotary impression member 11. The axis of the roller may thus be readily adjusted to compensate for the wear upon the axle or roller, or upon the bearing surfaces of the tracks, or of the bearings in the yokes or frames connected with the r0- tary impression member.

One of the yokes or end frames 15 is provided with a web 15 (Fig. 1) in which is journaled a shaft 18 to which is rigidly secured a gear wheel 19, lying in the vertical plane of the'gear wheel 13, but not meshing therewith; the wheel 13 being infixed relation to the roller 11. A crank or lever 20 is also mounted upon or connected with the shaft 18 and located upon the opposite side of the web 15 from the wheel 19. A stub shaft or counter-shaft 21 is also mounted on or journal'ed in said web, to which shaft is rigidly secured a small intermediate gear wheel 22 inter-posed between and in toothed engagement with said gear wheels 13 and 19. The crank 20 is adapted to be rotated by hand and its movement is transmitted through the medium of the several gear wheels to the rotary impression member 11, which by reason of the action of the racks 12, 12, and the gear wheels 13, 13, is caused to travel longitudinally of the main frame and over the beds. The purpose of the intermediate gear wheel 22 is to permit the crank 20 to be rotated in the same direction as that of the travel of the said impression memher, and to operatively connect the operating lever or crank 20 with the rotary im-- pression member 11. At either end of the channel members 1, 1 are provided laterally 1 9 projecting buffers 23 extending outward from the upper flanges 1 (see Fig. 2) and having pads 23 of suitable resilient ma terial secured thereon and adapted to coact with the arms 15", 15 of the yokes or de- 11o pending end frames 15, 15, and to absorb or yieldingly resist the shock due to the striking of the impression member against said hutl'ers.

Devices are provided for laterally shifting 115 the shiftable rollers 16 at opposite ends of the paths of movement of the same into engagement alternately with the downwardly and upwardly facing tracks, as follows:

Such shifting is accomplished by means of three pairs of distinctly different shifting or switch devices located upon or adjacent to the lower flanges or tracks on the main frame or channel beam members. One of such switching devices is located at each end of each of the tracks, and another at or near the middle of the same. j

The switch devices located at the left-hand end of the tracks, as illustrated in Figs. 1,

2 and 5, is made as fol-lows: This pair of switch devices is located at the end of the tracks which corresponds with the point of i The function of this pair of switch devices is to automatically shift the rollers 16 from contact with the inner downwardly facing tracks 7 outward toposition to engage the upwardly facing tracks 9. This particular device consists. of a plate 26, attached to the track plate 8, having a lateral oblique, guide shoulder or surface 25 extending obliquely across the path of the roller. The end of the track 9 'is provided with an oblique surface 25 forming with the surface 25 an oblique guide groove The guide surface 25, as the roller 16 approaches the end of its path, acts to shift the said roller into position to, en-

gage and travel ,back upon the upwardly facing track 9, when the return movement of said roller begins. The pointed extremity of the said track 9 is sloped downwardly from the level of the top of track 9 to the level of the top of the track 8. As the impression member moves over the beds, all of the rollers are in engagement with the tracks 7, 7, and the shil'table rollers 16 are held in position for such engagement by the guide surfaces formed by the lateral, inner surfaces of the tracks 9. lVhen the impression member reaches the end of its travel the rollers 16, 16 strike the inclined or oblique guide surfaces 25, 25 of the wedge-shaped or oblique guide members 26 and are automatically shifted into a position to ride up wardlyupon the sloped en 's of the said tracks 9, when the impression member starts upon its return non-operative movementover the bed. During such return movement the shiftable rollers 16 engage and are guided or held in position for constant engagement with the track 9 by the action of the outer faces of the tracks Adjustment to the opposite or front end of the bed which corresponds with the initial position of the impression member 11, as shown in Fig. 1, is another form of switch or shifting mechanism adapted to automatically shift the rollers 16, 16 from the upwardly facing tracks 9 into position to engage the downwardly. facing tracks 7. This shifting orswitch device operates at the termination of the non-operative movement of the impression member over the beds. Each of said switch devices consists of a movable switch member 28 forming, in effect, an extension of the track 9, and provided with an inwardly facing, oblique guide surface or shoulder 28, so arranged as to act on the roller 16, in the beginning of the forward movement thereof, in a manner to shift said roller laterally from its position in line with the track 9, into position beneath and in engagement with the downwardly facing track 7.

The switch member 28 is located in an opening formed in the longitudinal strip or plate 8, and is pivoted at one end, by a horizontal pivot 28*, to said plate 8, and is vertically movable at its opposite end. The upper surface of the switch member 28 is approximately flush with the upper surface of the corresponding track 9, when the member is in raised position, as indicated in full lines in Fig. 7, and isadapted to be lowered in the position indicated in dotted lines in said Fig. 7, in which position its oblique guide surface 28" is inoperative. A spring 28 is applied to hold the switch member 28 in its elevated or operative position; said spring being adapted to permit the swinging end of said member to be depressed as the roller 16 passes from the end of the track 9, therebv preventing any jolt or jar in the passsage of the said roller from the top surface ofthe track to that of the plate 8. As shown, a rectangular, open casing 29 is attached to the bottom of the lower flange 1, and in said casing is mounted a horizontal transverse shaft 33, provided with an eccentric 28, adapted to act on the horizontal arm of a bracket 30, which is secured to the ing the same. When the shaft is rotated in the proper direction, the eccentrics thereon act to depress the switch members against the'action of their lifting springs and to hold them in their inoperative position, so that when desired, the impression member may be rotated for inspecting the impression made on its tympan, without being depressed into contact with the inked impression plate on the bed 5'.

The spring 28 is shown as having the form of a coiled spring, interposed between the switch member 28 and a bracket 28, attached to the machine frame below the flange 1. The said switch member is shown as provided with a stop-arm 28, adapted for contact with the plate 8, so asto limit the upward movement of the switch member under the action of said spring. A plate 30 provided with stop arms 30", 30 serves to limit the movement of the crank 35 in both directions.

The above described trip mechanism operates as follows: Assuming that the impression member is approaching the end of its travel in its non-operative or return movement, with the rotary impression mcmber 11 raised, in which position the shiftable rollers 16 are engaging the upwardly facing tracks 9, the said shiftable rollers upon reaching the ends of said tracks, pass over the switch members 28 and endwise beyond the same, and at the same time the rollers 16 descend to the level of the top of the lower track 8. At the commencement of a subsequent movement of the impression member in the opposite direction, or. upon its operative stroke, the shiftable rollers 16 each again strike the oblique lateral guiding edge 28 of the corresponding member 28, and are guided or shifted thereby inwardly and into engagement with the downwardly facing track 7, the roller being also brought into guiding engagement with the inner vertical faces of the track 8, by Which'they are held or guided as they move along the said downwardly facing tracks.

The printing-press as'here shown is so constructed that during the travel from one end to the other, when used .in printing by what is termedthe ofi'set process, the impression member or cylinder 11 makes two, or nearly two complete revolutions,-during one of which the tympan 12on the cylinder 11 receives an impression from the form, relief plate, lithographic or photographic transfer, or the like, resting on the bed 5,-

and during the other of which the impression is transferred to the stock, paper or sheet on the bed 5'. It is often necessary in order that the operator may be certain that a perfect impression has been made upon the tympan, to carry the impression member several times over the bed 5, without carrying it over the bed 5'. It is therefore desirable to rovidemeans whereby the impression memlier may be lifted to its raised position, when it reaches the point midway of the press, where its travel over the impression plate is completed, in order that it may return over the said impression plate, without traveling the entire length of the press. For this purpose a third or central pair of switch devices is used, located upon the lower flanges 1 and approximately midway between the extremities thereof, and constructed as follows: A portion of'each track 9 is omitted or removed and a laterally shiftable, horizontal switch plate 38 is mounted to slide laterally on the top of the plate 8. (See Figs. 5, 8 and 9). Said plate 38, in one position thereof, is adapted to fill the space formed by the omitted part of said track, and in the other position thereof has its outer edge inside of the pathof the rollers moving along the downwardly facing track 7 and is of a height such that its upper surface is flush with the upper surface of the said track 9. One end of the switch plate abuts against the end of the track 9 while its opposite end is provided with an outer oblique margin or guiding edge 38. (See Figs. 2 and 5). Each of said switch plates is rigidly connected with an endwise I slidable bar 39, which is seated in a groove 1 tion in dotted lines in Fig. 5. When in its inoperative position the switch plate makes the track continuous, but when in its operative position, its oblique'guiding edge is brought into the path of the roller 16 and acts to shift the same outwardly from its position beneath the downwardly facing track to a position in line with the upwardly facing track. Adjacent to the switch plates the track 9 is provided with a pivoted or swinging, outwardly. yielding switch member 40 (see Figs. 2 and 8), provided with an oblique lateral, inner margin 4:0 (see Fig.- 3) which corresponds with and faces toward the similar obliquemargin 38 of the adjacent plate 38. Each switch member 40 is pivotally attached at one end to one of the tracks 9 by means of an upright pivot pin 41, which is rigidly secured to and rotatable with the switch member, and has bearing at its lower end-in the plate 8 below the track 9 (see Fig. 8). A coiled tension spring 42 surrounds the pin 41 and has its ends secured to said plate and pin. Said pivoted switch member 40 is thus adapted to be swung outward from its normal. position, shown in Fig. 5, in which it is held by the action of said spring. Said switch member 40 isfurther provided with a downwardly inclined or sloping upper surface 43, at its swinging end,'over which the roller '16 rolls upward in the movement of the rotary impression member backward or toward its initial position, after said roller 16 has been shifted laterally outward by coming into engagement with the oblique guiding edges 38 of the switch plate 38. For simultaneously operating the two switch plates 38, 38 on opposite sides of the bed, devices are provided as follows: Pivotally connected with the inner end of one of said bars 39, is a lever 44, which is pivotally mounted at its central portion upon a lug or bracket 45 extending inwardly from the channel member 1. The opposite end of the lever 44 is pivotally connected with an endwise reciprocating bar 46 extending transversely of the frame, said bar constituting an extension of the bar 39 attached tothe switch plate 38 on the opposite side of the main frame. (See Fig. 2). By shifting the bar 46 endwise in one. direction, the 'two shiftable switch plates 38, will be simultaneously moved inwardly .into position within the path of the rollerstraveling along the tracks 7, and by shifting said bar 46 endwise in the opposite direction each switch plate will be shifted out of switching oroperative position and to its inoperative position, The

bar 46 is conveniently extended beyond the bed of the press at one side thereof, and is provided with a handle 47 to be used in the switching operation. Said extremity of the bar 46 is further provided with lateral notches 46 46, adapted to be engaged by a manually operable detent member 48, pivotally mounted on the frame and provided with a spring 49 which holds the catch member 48 normally in locking engagement with said bar, when the bar is in either of its two adjusted positions.

The central tripping or shifting mechanism above described is adapted to shift the rollers 16 from the downwardly facing to the upwardly facing tracks, thus tipping the yokes 15 and raising the impression memer or roller when said impression member has made one revolution or traveled onehalf the length of the frame. Assuming that it is desired to repeat the travel of the impression member over the bed 5, the bar 46 is shifted endwise by releasing the catch 48 and pulling outwardly upon the handle 47. This movement shifts the switch plates 38 inwardly into the path of the rollers 16, which before being shifted are in position to engage the tracks 7. As said rollers 16 approach the central shifting. mechanisms from right to left, the said rollers 16 engage the oblique margins 38 of the plates 38, and said rollers are shifted outward and in contact with the oblique inner margins -40 of the pivoted switch members 40, which latter are swung outward from the position in whichthey are shown in Figs. 2 and 5, to permit the movement of the rollers past the same, as said rollers 16 pass outward laterally from beneath the downwardly facing tracks 7 and into position to travel back toward initial position over the outer tracks- '9. The said switchmembers 40 are brought.

back to their'original positions by the action'of the springs 42 at the instant the contact between the rollers 16 and the members ceases. When the direction of the movement of the impression member or impression roller is reversed and t e return movement is begun the rollers 16 rise to the track 9 by the aid of the inclined surface 43 on the said switch member 40.

By the above described construction and arrangement of parts,-with particular reference to the tracks, it will be seen that the inner laterally facing surfaces of the higher tracks 9 (see Figs. 4 and 5) serve as guides for the shiftable rollers 16 while the latter are in engagement with the downwardly facing tracks and that the oblique guide surfaces or shoulders 25*, 28*, and 38 act in the shifting operation to guide the roller 16 from one to the other of the two sets of tracks. A plurality of set-screws 50 may be provided extending inwardly through the beams 3 and 4 adapted to engage and-securely lock and retain the impression plate in osition upon or in fixed relation to the bed (see Fig. 2).

It will be ap arent that a printing press embodying the features described in the means for lifting the impression cylinder and holding the same down to its work, may be applied to many different uses and that it may be readily adapted to be used as a power machine and for a wide range of utilities, and that various automatic features, such as inking, feed and delivery mechanism, can be readily added, to suit varying conditions of the work to be done. Such a printing press is adapted to be used as a proof press, or press for printing directly from the type form, and when so used the paper on which the proof or impression is to be made will be applied over the tympan in the rotary impression member 11 in a familiar manner.

When used in printing by what is called the offset process, the impression plate, what ever may be its character, is secured upon the bed 5 at the right-hand portion of the press (with reference to the drawings) and the sheet on which the impression is to be made is laid on the bed 5, the beds being adjusted vertically to accommodate or correspond with the thickness of the plate, and so as to bring the upper surface of the sheet to be printed upon in a position to receive an impression from the tympan when both pairs of rollers are engaged with the downwardly facing tracks. The surface of the impression plate being inked, the impression member passes over it, by which operation the ink is transferred to the tympan. The impression member is then passed over the paper or other material and the inked impression upon the tympan thereby transferred to such paper or material. At the completion of the printing operation the impression member is automatically lifted by the shifting of the rollers 16 and the tilting of the yokes 15, in the manner described, and is returned to its original position without any contact'of said impression member with the sheet or the impression plate.

Among the advantages gained by the construction described, whether the press be used for the offset process or other uses, is that arising from thefeature of the depending frames on the impression member, each carryingtwo rollers, one only of which is shifted to effect the lifting of the impression member. The advantage gained from the use of this feature is due to the fact that the shifting of the single roller by cam surfaces at the ends of the tracks is accomplished in a length of travel of the impression member much shorter than would be required if both rollers were shifted. Moreover, when one only of the two rollers on each frame is shifted, I avoid the disadvantagesincident to shifting bodily the relatively heavy depending frames with the rollwithout departure from the spirit of my invention.

I claim as my invention:

1. An offset printing press comprising a frame provided with a fiat horizontal bed for supporting an impression plate, and a flat horizontal bed for supporting a sheet which receives the impression, said bedslbe ing in longitudinal alinenrent with each other, a rotative cylindric impression mem her, a tynipan on -said impression member adapted to receive an impression from the plate and to transfer the same to a sheet resting on the bed, two rollers carried on the ends of said cylinder, downwardly facing tracks engaging said rollers and acting to hold the tympan in contact with the im-- pression plate and sheet in the movement of the cylinder in one direction, and upwardly facing tracks adapted to engage said rollers and acting to maintain the tympan above the impression plate and sheet, in the movement of said cylinder in the opposite direc tion. a

2. An offset printing press comprising a bed provided with a flat horizontal surface for supporting an impression plate, and a flat horizontal sheet-supporting surface, said surfaces being in longitudinal alinement with each other, a cylindric impression member movable over said printing plate support and impression surface, a tympan on said impression member adapted to receive an impression from the impression plate and to transfer the same to the sheet, means for lifting the cylindric impression member above its impression receiving and transferring position at one extremity of its path of movement, means for lowering the cylindric impression member into its impression receiving and transferring position at the opposite extremity of its path of movement, and means shiftable into and out of operative position for lifting the cylindric impression member above its impression receiving and transferrng position at a point intermediate the opposite ends of its path of movement.

3. A printing press comprising a horizontal bed, a main frame forming a support for the bed, a rotative cylindric impression member movable over the bed, a downwardly facing track located at each side of the bed, two upwardly facing tracks located at each side of the bed and below the level of the downwardly facing track, said upwardly facing tracks being arranged side by side and one above the level of the other, depending frames connected with said cylindric impression member and movabletherewith longitudinally of the bed, two rollers rotatively mounted on each of said depending frames, one of said rollers being laterally shiftable, and means acting on said shiftable roller at the ends of the path of the same for shifting said rollers into positions for alternate engagement with the downwardly facing tracks and the higher upwardly facing tracks. i

4. A printing press comprising a horizontal bed, a cylindric impression member ropending frames connected with said cylindric impression member and movable therewith longitudinally of the bed. two rollers mounted on each of said depending frames, one of said rollers being located in position for engagement with the downwardly facing track and the lower upwardly facing track, and the other roller being laterally shiftable on said frame into positions for engagement with either the downwardly facing track or the higher upwardly facing track, and means acting on the shiftable rollers at the ends of the paths of the same. for shifting said rollers into engagement in alternation with the downwardly facing tracks and the higher upwardly facing tracks.

5. A printing press comprising a horizontal bed, a rotative cylindric lmpression member movable over the bed, downwardly facing tracks located on opposite sides of the bed, depending frames connected with said cvlindric impression member and movable therewith longitudinally of the bed. two horizontal stub shafts mounted in each of said depending frames, two rollers mounted on said stub shafts, one of which is laterally shiftable, and shifting mechanism adapted to operatively engage each of the laterally shiftable rollers at opposite ends of the paths of the same for shifting the same into and out of'position for engagement with the downwardly facing tracks.

6. A printing press comprising a horizontal bed,- a rotative cylindric impression member movable over the bed, two downwardly facing tracks located one at each side of the bed and below the level of the top of the bed, two upwardly facing tracks located at 'each side of the bed, and below the level of the down'wardly facing tracks, said upwardly facing tracks being arranged side by side and one' above the level'of the other, depending frames'connected with said cylindric impression member and movable therewith longitudinally of the bed, two horizontal stub shafts on each of said depending frames, two rollers mounted on said stub shafts, one of which is laterally shiftable, and means for shifting said shiftable rollers 5 alternately into engagement with the downwardly facing and higher upwardly facing tracks, at opposite ends of the paths of the said shiftable rollers.

7. A printing press comprising a horigo zontal bed, a rotative cylindric impression member movable over the bed, two downwardly facing tracks located one at each side of the bed, depending frames operatively connected with said cylindric impression member and movable with thelatter longitudinally of the bed, two rollers rotati'vely mounted on each of said depending frames, one of which is laterally shiftable, two upwardly facing tracks located at each side of the bed, and below the level of the downwardly facing tracks, said upwardly facing tracks being arranged side by side and one above the level of the other, and means acting on the shiftable rollers to 86 bring the same alternately into engagement with the downwardly and the higher, upwardly facing tracks, comprising oblique lateral guide shoulder'svatthe ends of the upwardly facing tracks.

40 8. In a printing press, the combination with a rotative c-ylindric impression member, of a downwardly facing track, two upwardlyfacing tracks located below the level of the downwardly facing track, said upe5 wardly facing tracks bcing.arranged side by side and one above the level of the other, a depending frame connected with said impression member, two rollers mounted on said frame, one of which is laterally shift- 5 able, and shifting mechanism adapted to act on said shiftable roller at one end of its -path of movement, for shifting said roller from the position for engagement with the downwardly facing track into'position for engagement with the higher, upwardly facing track, comprising an oblique lateral guide surface extending above the lower, upwardly facing track at one end of the latter and an oblique lateral guide surface on the corresponding end of the higher, upwardly facing track.

o 9. In a printing press, the combination with a rotative cylindric impression member, of a downwardly facing track, two upwardly facing tracks located below the level of said downwardly facing track, said upwardly facingtracks being arranged side by side and one above the level of the other, a depending frame connected with said impressionmember, two rollers mounted on said frame, one of which is laterally shiftable, and shifting mechanism adapted to act on said shiftable roller at one end of its path of movement, for shifting said roller from the position for engagement with the 76 downwardly facing track into position for engagement with the higher, upwardly facing track, comprising an oblique lateral guide surface extending above the lower, upwardly facing track at one end of the 80 latter and an oblique lateral guide surface on the corresponding end of the higher, upwardly facing track; said higher, up-

wardly facing track having at its end adjacent to said oblique lateral guide surfaces an inclined top surface extending from the level of the said higher, to the level of the lower, upwardly facing track.

10, In a printing press, the combination with a rotative cylindric impression member, of a downwardly facing track, two upwardly facing tracks located below the level of said downwardly facing track, said upwardly facing tracks being arranged side by side and one above the level of the other, a depending frame connected with said impression member, two rollers mounted on said frame, one of said rollers being laterally shiftable, and shifting mechanism for shifting said shiftable roller laterally from the position for engagement with the higher, upwardly facing track to a position for engagen'ient with the downwardly facing track, comprising a vertically movable switch member located at one end of the higher. upwardly facing track and having an oblique lateral guide surface.

11. In a printing press, the combination with a rotativc cylindric impression member, of a downwardly facing track, two upwardly facing tracks located below the level of said downwardly facingtrack, said upwardly facing tracks being arranged side by side and one above the level of the other, a depending frame connected with said imprcssion member, two rollers mounted on said frame, one of said rollers being laterally shiftable. and shifting mechanism for shifting said shiftable roller laterally from the position for engagement with the higher, upwardly facing track to a position for engagement with the downwardly facing track. comprising a vertically movable switch member located at one end of the higher. upwardly facing track and having an oblique lateral guide surface, and manually operable means for depressing said switch member into its inoperatve position.

12. In a printing press, the combination with a rotativc cylindric impression member, of a downwardly facing track, two upwardly facing tracks located below the level of said downwardly facing track, said upwardly facing tracks being arranged. side by side and one above the level of the other, a depending frame connected with said impression member, two rollers mounted on said frame, one of said rollers being laterally shiftable, and shifting mechanism for shifting said shiftable roller laterally from the position for engagement with the higher, upwardly facing track to a position for engagement with the downwardly facing track, comprising a vertically movable switch member located at one end of the higher, upwardly facing track and having an oblique lateral guide surface, and a spring applied to yieldingly support said switch member.

13. In a printing press the combination with a rotative cylindric impression member,.of a downwardly facing track, two upwardly facing tracks located below the level of said downwardly facing track, said upwardly facing tracks being arranged side by side and one above the level of the other, a depending frame connected with said impression member, two rollers mounted on said frame, one of said rollers being laterally shift-able, and shifting mechanism for shifting said shiftable roller laterally from the position for engagement with the higher, upwardly facing track to a position for engagement with the downwardly facing track, comprising a, vertically movable switch member located at one end of the higher, upwardly facing track and having an oblique lateral guide surface; said switch member being pivoted at one end to the adjacent end of the said higher, upwardly facing track, and a spring applied to yieldingly support said switch member.

14. In a printing press, the combination with a rotative cylindric impression member, of a downwardly facing track, two upwardly facing tracks located below the level of the downwardly facing track, said upwardly facing tracks being arranged side by side and one above the level of the other, a depending frame connected with said impression member, two rollers mounted on said frame, one of said rollers being laterally shiftable, shifting ends of thepath of said shiftable roller for shifting the latter into engagement alternately with the downwardly facing track and the higher, upwardly-facingtrack, and

mechanism at both shifting means intermediate the ends of said tracks adapted for shifting the shiftable roller from the position for engagement with the downwardly facing track to a position for engagement with the higher, upwardly facing track.

15. In a printing press, the combination with a. rotative cylindric impression member, of a downwardly facing track, an upwardly facing track located below, and out of alinement vertically with, the downwardly' facing track, a laterally shiftable roller in operative connection with the impression member, shifting mechanism at both ends of the path of said roller for shifting the same into engagement alternately with the upwardly and downwardly facing tracks, and shifting means for said roller intermediate the' ends of said tracks, comprising a laterally shiftable switch member provided with an oblique, lateral guide surface and a yielding, pivoted switch meinber normally forming a part of theupwardly facing track.

16. A printing press comprising a main frame provided with ahorizontal bed, a rotative cylindric impression member movable over the bed, a downwardly facing track located at each side of the bed, an upwardly facing track located at each side of the bed, said upwardly facing track being arranged below,'and out of alinement vertically with, the downwardly facing track, a laterally shiftable roller in operative connection with the opposite ends of said impression member, shiftin mechanism at both ends of the paths 0 said rollers for shifting said rollers into engagement alternatel with the upwardly and downwardly facing tracks, shifting means for said rollers, intermediate the ends of said tracks, comprising laterally shiftable switch members provided with oblique lateral guide surfaces and yielding, pivoted members normally forming parts of the upwardly facing tracks, and means connected with the laterally shiftable switch members at both sides of the machine for operating the same in unison.

In testimony that I claim the foregoing as my invention I affix my signature in the presence of two witnesses, this 6th day of January A. D. 1913'.

ROBERT O. VANDERCOOK. Witnesses:

EUGENE C. WANN, CHARLES H. Poona.

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