US2228094A

US2228094A - Duplicating machine

Info

Publication number: US2228094A
Application number: US274583A
Authority: US
Inventors: Wilhelm F Schoenhardt
Original assignee: Ditto Inc
Current assignee: Ditto Inc
Priority date: 1939-05-19
Filing date: 1939-05-19
Publication date: 1941-01-07
Anticipated expiration: 1958-01-07

Description

w. F. SCHOENHARDT Jan. 7, 1941.

DUPLICATING MACHINE Filed May 19, 1939 6 Sheets-Sheet l Jan. 7, 1-941. w. F.- SCHOENHARDT DUPLICATING MACHINE Filed May 19, 1959 6 Sheets-Sheet 2 a Sheets-Sheet 5 DUPLICATING MACHINE Filed May l9, 1959 w. F. VSCHOENHIARDT Jan. 7,1941

Jan. 7, 1941. w ESCHOENHARDT DUPLICATING MACHINE 6 Sheets-Sheet 4 7 Filed May 19. 1939 7, 9 w. F. ISCHOENHARDT DUPLICA'IINGv MACHINE Filed May 19, 1959 6 Sheets-Sheei: 5

Patented Jan. 7, 1941 UNITED STATES PATENT OFFICE DUTLICATKNG MACHINE of West Virginia Application May 19, 1939, Serial No. 274,583

1'7 Claims.

This invention relates to duplicating apparatus of the type in which the reading matter or other design to be duplicated is carried in reverse on a master copy such as the usual gelatin band mounted about a drum. Copy sheets are fed to the drum and pressed by an impression roller or platen into operative engagement with the band as the drum rotates for printing such copy sheets.

It is the object of the present invention to provide an improved form and arrangement of the parts in apparatus of the type described whereby improved results may be obtained. 7

The invention is directed particularly to the mechanism whereby, as the drum rotates, the

sheets are fed one at a time to the drum and brought into the proper adjusted position with respect to the design on the gelatin band for providing the desired margins on the printed sheet. The apparatus embodies mechanism whereby sheets are fed from a stack directly into position to be engaged by the gelatin band as the drum rotates. The apparatus embodies also means by which the sheets are stripped from the gelatin band and control means for the feed and stripping mechanisms whereby, at the will of the operator, a sheet may be applied to the gelatin band and caused to pass a plurality of times between the drum and the platen roller, and the platen roller may be moved into and out of operative position with respect to the drum.

It is another object of this invention to provide improved apparatus of the character described whereby to simplify the operation of feeding and positioning sheets with respect to a duplicating drum and a platen roller.

The features and advantages of the present invention will appear more fully as the description proceeds, reference being had to the accompanying drawings wherein a preferred form of the invention is shown.

In the drawings,

Fig. 1 is a View in side elevation of the improved apparatus with the end frame thereof broken away;

Fig. 2 is an enlarged fragmentary sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a top plan view of the apparatus shown in Fig. 1, with certain of the parts partially broken away so as to be shown in horizontal section;

Fig. 4 isan end view partly in section, taken substantially on the line 44 of Fig. 1; V

Fig. 5 is an enlarged view in side elevation, similar to Fig. 1, showing only a portion of the mechanism at the right-hand end of Fig. 1 and showing the parts in a changed position;

Fig. 6 is a fragmentary view similar to Fig. 5, illustrating a further changed position of the parts;

Fig. 7 is a fragmentary sectional view taken on the line 'l! of Fig. 6;

Fig. 8 is a fragmentary sectional View taken on the line 8--8 of Fig. 6;

Fig. 9 is a fragmentary sectional view taken on the line 9--9 of Fig. 6;

Fig. 10 is a fragmentary sectional View taken on the line llll 0 of Fig. 3;

Fig. 11 is a fragmentary sectional view similar to Fig. 10, showing the parts in a changed position, and

Fig. 12 is a further fragmentary view similar to Fig. 10, but showing another position of the parts.

Referring now to the several figures of the drawings, in which corresponding parts are indicated by the same reference characters, indicates a frame which in the arrangement shown comprises standards 3! and 32 oppositely arranged (see Figs. 3 and 4) supporting a drum 33 by means of two short aligned

shafts

34 and 35. The drum 33 is segmental in form as is usual in connection with gelatin-process duplicating machines, being provided with suitable mounting means of any approved type, as is indicated diagrammatically in Fig. 1, for mounting a gelatin band 36 about the face portion of the drum, the drum at the leading and rear edges of the face portion being provided with rollers 31 for engaging the gelatin band (see Figs. 1, 10 and 11). 35 The arrangement is such that the gelatin band 36 can be shifted as desired circumferentially of the segmental face portion of the drum.

Means is provided for driving the drum 33, as is best shown in Figs. 1 and 3, comprising a drive 40 pulley 38 connected by means of a belt 33 with any suitable source of power, said pulley 38 being rotatably mounted upon the standard 3| of the frame by means of a short stub shaft 40. The pulley 38 is provided at one side face with a pinion 4l rigidly connected therewith in position to mesh with a large gear 42 rotatably mounted upon the short shaft 34 by means of a collar 43. The gear 42 in turn is provided on its outer face portion With a ratchet wheel 44 which is adapted to-be engaged by a pawl 45 pivotally mounted upon the adjacent face of a large gear 46 fixedly mounted upon the shaft 34 so as to rotate with the drum 33. No means is shown in the drawings for controlling the position of the pawl 45 by which power may be transmitted from the gear M to the gear 46. Control means of any approved type is to be employed as is well understood in the art for regulating the position of the pawl 55 in accordance with the requirements. Such control means are not shown since they form no part of the present invention.

Upon the opposite end of the drum from that at which the gear 46 is mounted thereon, I have provided three

cams

41, 48 and 49, rigidly mounted upon the drum so as to rotate therewith for purposes as hereinafter described.

At the rear end of the machine (see Figs. 1 and 4) I have provided extending frame bars 52 connected with parts 50 and 5! of the framework 30 for supporting a table 53 thereon, together with means for feeding the topmost sheet from a pile of copy sheets resting on the table. .At opposite sides of the table, operating mechanism is provided in connection with the feed of the sheets from the table. As is clearly shown in Fig. 4, the table 53 is preferably provided with adjustable

side margin bars

54 and 55 at opposite sides of the table for holding the sheets in evenly piled relation to each other. In the arrangement shown, the

margin bars

54 and 55 are held in frictional engagement with the table 53 by means of coiled springs 56, the arrangement being such that the margin bars are readily movable inwardly and outwardly with respect to each other to correspond with the width of the sheets being used.

The means for feeding to the drum the topmost sheet from a pile of sheets supported by the table 53 comprises means intermittently driven in timed relation to the rotation of the drum 33. This means comprises a bell-crank lever 51 pivotally mounted upon the standard 32 by means of a stub shaft 58. The bell-crank lever has a roller 59 rotatably mounted upon one of its arms in position to be engaged by the cam 49 at a predetermined point in each rotation of the drum 33. The other arm of the bell-crank lever 51 is connected by means of a link 66 with the lower end of an arm 6| which is pivotally mounted upon the adjacent frame member 52 at one side of the table 53. The arrangement is such that as the drum 33 rotates in clockwise direction to the position as shown in Fig. 1, the roller 59 and the bell-crank lever 51 are displaced in counterclockwise direction in said Fig. 1 for swinging the arm 6! also in counter-clockwise direction in said figure. A coiled spring 62 connected between a pin 65a on the movably mounted arm 6| and a collar 56a on the shaft 58 serves to swing the movably mounted arm 6! in clockwise direction as soon as the cam 49 has cleared the roller 59 for permitting such result. An eccentric stop device 66 is adjustably mounted upon the frame member 52 in position to engage the edge of the arm 6! for limiting the movement of said arm in clockwise direction in said Fig. 1.

At opposite sides of the table 53, I have provided standards 64 rising from the frame members 52 respectively for supporting a drive shaft in position across the table in upwardly spaced relation thereto. In the arrangement shown (Figs. 1, 2 and 3), the drive shaft is built up from a plurality of parts, comprising a short shaft section 66 which is journalled in a. bearing 65 carried by the upper end of one of the standards 64, and a long sleeve member 68 removably mounted at one end on said shaft section 66 so as to rotate therewith. At its inner end, the sleeve member 68 is slidably mounted upon a shaft section 69 which in turn is rotatably mounted in the side wall of a housing 79 as hereinafter described, the sleeve member 68 and the shaft section 69 being connected so as to rotate together. By this arrangement, the shaft 69 is caused normally to rotate with the shaft section 66, but the two shafts are adapted very quickly and easily to be disconnected from each other by a sliding movement of the tubular member 66 toward the housing.

The means for driving the shaft comprising the

sections

66 and 69 includes a pinion 16 operatively mounted on the shaft section 66 by clutch members 13, I4 and 15 So as to drive said shaft section in one direction, said pinion '16 being in mesh with gear teeth 11 on the upper end of the pivotally mounted arm 6|. The arrangement is such that upon a stroke of the arm 6| in counterclockwise direction in Fig. 1 the shaft is driven in clockwise direction.

The means for supporting the housing 10 in position comprises a sleeve H rigidly connected at its inner end with one side wall of the housing 16 in axial alignment with the shaft section 69. At its opposite end, the sleeve ll has a releasable connection T2 with the upper end portion of the adjacent standard 64. The arrangement of the shaft comprising the

sections

66 and 69 and the connections of said shaft as above described with the housing I0 and sleeve H are such as to hold the parts strongly in operative position during the operation of the machine. When the operator desires, however, the shaft and connected parts can be very quickly and easily removed from position. For accomplishing this purpose, the sleeve 68 is first moved toward the housing I!) for disengagement from the shaft section 66, and the whole assembly is then moved toward the near side in Fig. 3 for freeing the sleeve H from the frame.

Within the housing 10, in the arrangement shown, I have provided driving connections between the shaft section 69 and a short shaft 18 which extends through the side walls of the housing 10 and has

rollers

19 and 89 fixedly mounted upon its outer end portions. The arrangement is such that when the

shaft sections

66 and 69 are driven in clockwise direction in Fig. 1 by reason of an operative stroke of the arm Si in counter-clockwise direction, the

rollers

19 and 86 are likewise driven in clockwise direction in'said Fig. 1 for moving the topmost sheet of a pile of sheets 8! (see Figs. 6 and 10) toward the left. Upon the return movement of the arm 6] by the spring 62, the free-wheeling connection as above described permits the rotation of the pinion 16 with respect to the shaft section 66 so as not to change the position of the

rollers

19 and 80.

In the arrangement as above described, the housing 10 serves as an arm for spacing the

rollers

19 and 80 from the shaft section 69, such arm etxending across above the table in spaced relation to the table, the rollers 18 and 80 being held by their own weight in operative engagement with the pile of sheets 8|. In case the operator should desire to move the

rollers

19 and 80 out of engagement with the pile of sheets, this can be accomplished by merely swinging the housing 10 and its connected parts about the shaft section 69 and the sleeve ll so as to carry the

rollers

19 and 80 upwardly and backwardly past the axis of the shaft section 66.

In Fig. 1 the roller 59 is shown in engagement with the cam 49 at the forward end of the operative stroke of the

rollers

19 and 80 for forwarding a sheet of the pile toward the left in said figure. In Fig. 5, in which the parts are shown in the changed position which they assume upon a further advance movement of the drum from the position as shown in Fig. 1, the bell-crank lever 51 has been partially returned by the spring 62 to starting position. The rollers I9 and 80, when rotated in clockwise direction in Fig. 1, move the top sheet of the pile of sheets BI into the position shown in Fig. 10. The sheet, in its advance movement, is guided between a downwardly curved guide plate 82 on the table 53 and an upper guide plate 83. The guide plate 83 is mounted upon two raised

portions

84 and 85 of the side frames 52. The upper edge of the guide plate 83 is turned up vertically, as shown as 85, so as not to interfere with the positioning of the pile of sheets 8|. The plate 82 on the table and the guide plate 83 provide a tapering throat which is adapted to direct a copy sheet over the surface of a platen roller 81 into a margin bar 8111. The plate 82 ends directly over the platen roller 8! and is tangent to that part of the roller which is engaged by the advancing gelatin band 35. The margin bar 8111 is in line with the plate 82.

The platen roller 81 is mounted upon two pivoted arms E8 and 89 (see Figs. 4, and 6). The

arms

88 and 80 are pivoted to the frames 52 by two pivot pins 90 and ill. The platen roller 81 has a shaft 92 which is journalled in the

arms

88 and 89. At the opposite ends of the

arms

88 and 89 from the shaft 92

pins

93 and 94 extend inwardly through two

slots

95 and 95 provided in the frames 52. These pins are connected to

links

91 and 98 which are, in turn, connected to two arms 99 and I00 fixed on a control shaft iii. The shaft IOI is journalled in suitable bearings I02 and I03 in the frames 52. Two collars IE4 and I 05 are fixed on the shaft Itl which is inside the bearings I02 and I03, and the arms 99 and I00 are mounted on these collars. The shaft IOI projects through the left-hand frame 52, as shown in Fig. 4, and has a sleeve I25 fixed thereon. A control lever I07 is secured to the sleeve I08 and has a handle let thereon by which the shaft IOI may be rocked to swing the platen roller 87 to and from the drum 33. A spring 03a is connected between the arm 99 and a pin 99b on the frame 52 so as to yieldingly urge the platen roller 81 toward the drum 33.

The shaft IiiI has a sleeve I00 rotatably mounted thereon at the end of the sleeve I05. This sleeve 809 carries a stripper control lever EIIJ which is provided with a handle Ill. The stripper control lever I50 is connected to a link I Hi! which leads to the stripper mechanism which will be presently described. A collar H3 is fixed on the end of the shaft I 0! to hold the sleeve H39 in place.

The margin bar 87a is carried by two arms I i4 and H5. The arms H4 and H5 are fixed to a margin bar shaft Iiii which is journalled in the frames 52. This shaft extends through the frames 52 and at one end is provided with an arm Ii'i which connects to a spring H8 that is under tension between the arm and a pin H9 fixed on the right-hand frame member 52, as shown in Fig. 4. At the other end of the margin bar shaft i it there is provided an arm I20 which carries a roller I2I adapted to engage the cam 48 (see Figs. 3, 5-7). As illustrated best in Figs. 5 and 6, the cam 48 has a rounded nose portion i22 which strikes the roller I2I at the instant the advancinggelatin band 30 reaches the platen roller 81' asshownfin Fig. 11 and immediately swings said roller I2I in a counter-clockwise direction about the shaft H5, as viewed in these figures. The: margin bar 8M is thus moved away from the forward'edge of the copy sheet held thereby to allow the copy sheet to follow the gelatin band and be pressed against the band on the drum by the platen roller 01. The arm III, which urges the margin bar into the position shown in Figs. 5 and 10, has a flange I23 thereon which is adapted to engage an eccentrically mounted stop I24 on the frame 52. The stop I24 is adjustable so as to vary the position of the margin bar with respect to the platen roller 0!- and control the length of margin left at the advancing end of the copy sheet. The arm I20 can be adjusted on the shaft IIES by means of a slot I201; in the arm I20 and a screw I202) threaded into a collar IIfia on the shaft I I5 (see Fig. 7) for controlling the position of the cam roller I2I with respect to the margin bar 31a.

Referring now to the stripper mechanism which is shown most clearly in Figs. 1 and 3, the construction comprises a main stripping roller I25 mounted on a. shaft I25 which is journalled in the side frames 3! and 32. This shaft carries a pinion I2! that meshes with the gear 45 for rotating the roller i225 in counterclockwise direction in Fig. 1. A guide roller 528 cooperates with the roller I25 to direct the advancing edge of a copy sheet outwardly from the drum upon a receiving tray I 29. The roller I23 is carried by two arms I30, and HM. These arms are supported ,by a shaft I32 which is journalled in two studs I33 and I34 mounted on the side frames 3I and 32. The shaft I32 carries two stop mem bers I35 and I35 which are adapted to engage a cross tie rod I31 so as to limit the movement of the arms I30 and I3I and the roller 23 toward the drum. A spring E38 (see Fig. 1) is connected to one end of a lever I3 which is fixed to the shaft I32. The other end of this spring is connected to a pin 648 on the side frame 32. The purpose of the spring I35 is to urge the shaft I32 and the arms I30 and I3I to turn in a clockwise direction so as to bring the roller I28 toward the drum surface. The lever I35 carries a cam roller I4I which rides on the cam 41.

The cam 41 is so shaped as to direct the roller I28 into the path of the advancing edge of a copy sheet and then to move the roller outwardly so as to clear the advancing edge of the gelatin band. This movement of the roller I28 outwardly serves to bring the copy sheet into engagement with the rotating roller I25 and to press the sheet against the roller for stripping the sheet from the drum. It is desirable in many instances to maintain a sheet on the gelatin band for more than one rotation of the drum. The link H2 is provided with means whereby the stripping mechanism which was just described may be rendered inoperative to strip a sheet from the drum. It will be noted that the link I I2, as shown in Fig. 1, has an elongated slot I42 which receives a guide pin I43 on the side frame 32. The link H2 is bent outwardly at I44 (see Fig. 3) so as to follow the frame 32 from the front end of the machine to the rear thereof. A bar I45 is mounted on the link I I2 and extends into overlapping relationship with the spring connected end of the lever I39. Referring now to Figs. 1 and 3, if it is desired to render the stripping means inoperative, the lever H0 is pushed in a counter-clockwise direction so as to move the link II2 to the right from the position shown in Fig. 1. This will bring the screw I46 into engagement with the lever 139 and prevent the spring 138 from swinging this lever in a clockwise direction about the shaft I32. When the roller Ml rides off of the cam 41, the stripping roller 128 will still be held in the position shown in Fig. 1 and will be inoperative to engage the advancing edge of a copy sheet on the drum. Thus the sheet may be left on the drum for as many rotations thereof as are desired.

The means for holding the platen roller 81 out of contact with the drum have been previously described in detail. The operation of this means is briefly as follows: Assuming that it is desired to prevent the platen roller from engaging the drum, for any purpose such as an inspection of the design on the gelatin band, the operator may move the platen roller control lever H11 in a clockwise direction from the position shown in Figs. 1 and 3. This will swing the shaft l0! in a clockwise direction, causing the arms 99 and H10 and links 9! and 98 to turn the

arms

88 and 89 in clockwise direction and move the platen roller outwardly from the drum. It is desirable to limit the movement of the platen roller toward the drum, and for this purpose an eccentrically mounted stop I4! is provided on the frame 52 in position to engage the end of the arm 88, as is shown in Fig. 6.

The operation of the sheet feeding mechanism and the margin bar is best illustrated in Figs. 10, 11 and 12. In Fig. 10, the parts are in a position where the copy sheet has been fed into the margin bar 81a and the drum 33 is advancing to engage its gelatin band 36 with the copy sheet. It is obvious that more or less margin may be left between the point of engagement of the sheet with the platen roller and the engagement of the sheet with the margin bar. This adjustment can be made by means of the eccentric stop 124. The shortness of the margin is limited only by the necessary clearance between the platen roller and the margin bar. In Fig. 11, the parts are shown at the instant when the gelatin band 36 engages the copy sheet. It is at this point that the forward end 122 of the cam 48 engages the roller l2l to move the margin bar out of the way. Since the cam 48 projects beyond the periphery of the drum, it will move the margin bar shaft enough to quickly separate the margin bar from the advancing edge of the copy sheet. In Fig. 12, the margin bar is shown in its completely retracted position corresponding to the cam position for the cam 48 illustrated in Fig. 6. The margin bar is held in this position until the roller |2I approaches the rear end of the cam 48 where the cam slopes inwardly to allow the roller I21 to gradually return the margin bar to its operative position illustrated in Fig. 10.

While I have shown and described a preferred embodiment of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as described in the appended claims, in which it is my intention to claim all novelty inherent in my inven-. tion as broadly as possible, in view of the prior art.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

I' claim:

1. A duplicating machine of the character described comprising a frame, a drum journalled therein providing an arcuate platen, a duplicating band on said platen, a platen roller movably mounted in said frame in the path of said band and adapted to press sheets against the band, a margin bar, arms carrying said bar and pivoted in the frame to swing the bar into and out of operative position in the path of the platen beyond the platen roll-er, a copy sheet table on said frame, a sheet guide on said table extending toward the drum and terminating directly over the platen roller in close proximity to the path of the platen in position to guide sheets across said roller to the margin bar and to contact the sheets with that part of the roller which lies in the path of the advancing band on the drum, sheet feeding means for advancing sheets from said table to the margin bar, and actuating means for said margin bar operable in timed relation with the drum to place the bar in position to receive a sheet riding over said guide and said platen roller until the sheet has engaged the margin bar and has been pressed by the platen roller against the duplicating band and to thereafter remove the bar from the path of the platen.

2. A duplicating machine of the character described comprising a frame, a drum journalled therein providing an arcuate platen, a duplicating band on said platen, a platen roller movably mount-ed in said frame in the path of said band and adaptedto press sheets against the band, a margin bar, arms carrying said bar and pivoted in the frame to swing the bar into and out of operative position in the path of the platen beyond the platen roller, a copy sheet table on said frame, a sheet guide on said table extending toward the drum and terminating directly over the platen roller in close proximity to the path of the platen in position to guide sheets across said roller to the margin bar and to contact the sheets with that part of the roller which lies in the path of the advancing band on the drum, said sheet guide comprising upper and lower plates directed diagonally downward and converging toward the drum, sheet feeding means for advancing sheets from said table to the margin bar, and actuating means for said margin bar operable in timed relation with the drum to place the bar in position to receive a sheet riding over said guide and said platen roller until the sheet has engaged the margin bar and has been pressed by the platen roller against the duplicating band and to thereafter remove the bar from the path of the platen.

3., A duplicating machine of the character described comprising a frame, a drum journalled therein providing an arcuate platen, a duplicating band on said platen, a platen roll-er movably mounted in said frame in the path of said band and adapted to press sheets against the band, a margin bar, arms carrying said bar and pivoted in the frame to swing the bar into and out of operative position in the path of the platen beyond the platen roller, a copy sheet table on said frame, a sheet guide on said table extending toward the drum and terminating directly over the platen roller in close proximity to the path of the platen in position to guide sheets across said roller to the margin bar and to contact the sheets with that part of the roller which lies in the path of the advancing band on the drum, sheet feeding means for advancing sheets from said table to the margin bar, and actuating means for said margin bar operable in timed relation with'the drum to place the bar in position to receive a sheet riding over said guide and said platen roller until the sheet has engaged the margin bar and has been pressed by the platen roller against the duplicating band and to thereafter remove the bar from the path of the platen, said actuating means comprising a cam fixed to the drum at one end thereof and a roller at one end of the margin bar to engage said cam.

4. A duplicating machine of the character described comprising a frame, a drum journalled therein providing an arcuate platen, a duplicating band on said platen, a platen roller movably mounted in said frame in the path of said band and adapted to press sheets against the band, manually controlled means for moving the platen roller out of the path of the band, a margin bar, arms carrying said bar and pivoted in the frame to swing the bar into and out of operative position in the path of the platen beyond the platen roller, a copy sheet table on said frame, a sheet guide on said table extending toward the drum and terminating directly over the platen roller in close proximity to the path of the platen in position to guide sheets: across said roller to the margin bar and to contact the sheets with that part of the roller which lies in the path of the advancing band on the drum, sheet feeding means for advancing sheets from said table to the margin bar, and actuating means for said margin bar operable in timed relation with the drum toplace the bar in position to receive a sheet riding over said guide and said platen roller until the sheet has engaged the margin bar and has been pressed by the platen roller against the duplicating band'and to thereafter remove the bar from the path of the platen.

5. A duplicating machine of the character described comprising a frame, a drum journalled therein providing an arcuate platen, a duplicating band on said platen, a platen roller movably mounted in said frame in the path of said band and adapted to press sheets against the band, manually controlled means for moving the platen roller out of the path of the band, a margin bar, arms carrying said bar and pivoted in the frame to swing the bar into and out of operative position in the path of the platen beyond the platen roller, a copy sheet table on said frame, a sheet guide on said table extending toward the drum and terminating directly over the platen roller in close proximity to the path of the platen in position to guide sheets across said roller to the margin bar and to contact the sheets with that part of the roller which lies in the path of the advancing band on the drum, sheet feeding means for advancing sheets from said table to the margin bar, and actuating means for said margin bar operable in timed relation with the drum to place the bar in position to receive a sheet riding over said guide and said platen roller until the sheet has engaged the margin bar and has been pressed by the platen roller against the duplicating band and to thereafter remove the bar from the path of the platen, said actuating means comprising a cam fixed to the drum at one end thereof and a roller at one end of the margin bar to engage said cam.

6. A duplicating machine of the character described comprising a frame, a drum journalled therein providing an arcuate platen, a duplicating band on said platen, a. platen roller movably mounted in said frame in the path of said band and adapted to press sheets against the band, a

margin bar, arms carrying said bar and pivoted in the frame to swing the bar into and out of operative position in the path of the platen beyond the platen roller, a copy sheet table on said frame, a sheet guide on said table extending toward the drum and terminating directly over the platen roller in close proximity to the path of the platen in position to guide sheets across said roller to the margin bar and to contact the sheets with that part of the roller which lies in the path of the advancing band on thedrum, said sheet guide comprising upper and lower plates directed diagonally downward and converging toward the drum, sheet feeding means 4 for advancing sheets from said table to the margin bar, and actuating means for said margin bar operable in timed relation with the drum to place the bar-in position to receive a sheet riding over said guide and said platen roller until the sheet has engaged the margin bar and has been pressed by the platen roller against the duplicating band and to thereafter remove the bar from the path of the platen, said actuating means comprising a cam fixed tothe drum at one end thereof and a roller at one end of the margin bar to engage said cam.

'7. A duplicating machine of the character described comprising a frame, a drum journalled therein providing an arcuate platen, a duplicating band on said platen, a platen roller movably mounted in said frame in the path of said band and adapted to press sheets against the band, manually controlled means for moving the platen roller out of the path of the band, a margin bar, arm-s carrying said bar and pivoted in the frame to swing the-bar into and out of operative position in the path of the platen beyond the platen roller, a copy sheet table on said frame, a sheet guide on said table extending toward the drum and terminating directly over the platen roller in close proximity to the path of the platen in position to guide sheets across said roller to the margin bar and to contactthe sheets with that part of the roller which lies: in the path of the advancing band on the drum, said sheet guide comprising upper and lower plates directed diagonally downward and converging toward the drum, sheet feeding means for advancing sheets from said table to the margin bar, and actuating means for said margin bar operable in timed relation with the drum to place the bar in position to receive a sheet riding over said guide and said platen roller until the sheet has engaged the margin bar and has been pressed by the platen roller against the duplicating band and to thereafter remove the bar from the path of the platen.

8. A duplicating machine of the character described comprising a frame, a drum journalled therein providing an arcuate platen, a duplicating band on said platen, a platen roller movably mounted in said frame in the path of said band and adapted to press sheets against the band, a margin bar, arms carrying said bar and pivoted in the frame to swing the bar into and out of operative position in the path of the platen beyond the platen roller, means to adjust the operative position of said bar toward and away from said platen roller, a copy sheet table on said frame, a sheet guide on said table extending toward the drum and terminating directly over the platen roller in close proximity to the path of the platen in position to guide sheets across said roller to the margin bar and to contact the sheets with that part of the roller which lies in the path of the advancing band on the drum, sheet feeding means for advancing sheets from said table to the margin bar, and actuating means for said margin bar operable in timed relation with the drum to place the bar in position to receive a sheet riding over said guide and said platen roller until the sheet has engaged the margin bar and has been pressed by the platen roller against the duplicating band and to thereafter remove the bar from the path of the platen.

9. A duplicating machine of the character described comprising a frame, a drum journalled therein providing an arcuate platen, a duplicating band on said platen, a platen roller movably mounted in said frame in the path. of said band and adapted to press sheets against the band, a margin bar, arms carrying said bar and pivoted in the frame to swing the bar into and out of operative position in the path of the platen beyond the platen roller, means to adjust the operative position of said bar toward and away from said platen roller, a copy sheet table on said frame, a sheet guide on said table extending toward the drum and terminating directly over the platen roller in close proximity to the path of the platen in position to guide sheets across said roller to the margin bar and to contact the sheets with that part of the roller which lies in the path of the advancing band on the drum, said sheet guide comprising upper and lower plates directed diagonally downward and converging toward the drum, sheet feeding means for advancing sheets from said table to the margin bar, and actuating means for said margin bar operable in timed relation with the drum to place the bar in position to receive a sheet riding over said guide and said platen roller until the sheet has engaged the margin bar and was been pressed by the platen roller against the duplicating band and to thereafter remove the bar from the path of the platen.

10. A duplicating machine of the character described comprising a frame, a drum journalled herein providing an arcuate platen, a duplicating band on said platen, a platen roller movably mounted in said frame in the path of said band and adapted to press sheets against the band, a margin bar, arms carrying said bar and pivoted n the frame to swing the bar into and out of operative position in the path of the platen beyond the platen'roller, means to adjust the operative position of said bar toward and away from said platen roller, a copy sheet table on said frame, a sheet guide on said table extending toward the drum and terminating directly over the platen roller in close proximity to the path of the platen in position to guide sheets across said roller to the margin bar and to contact the sheets with that part of the roller which lies in the path of the advancing band on the drum, sheet feeding means for advancing sheets from said table to the margin bar, and actuating means for said margin bar operable in timed relation with the drum to place the bar in position to receive a sheet riding over said guide and said platen roller until the sheet has engaged the margin bar and has been pressed by the platen roller against the duplicating band and to thereafter remove the bar from the path of the platen, said actuating means comprising a cam fixed to the drum at one end thereof and a roller at one end of the margin bar to engage said cam.

11. A duplicating machine of the character described comprising a frame, a drum journalled therein providing an arcuate platen, a duplicating band on said platen, a platen roller movably mounted in said frame in the path of said band and adapted to press sheets against the band, a margin bar, arms carrying said bar and pivoted in the frame to swing the bar into and out of operative position in the path of the platen beyond the platen roller, a copy sheet table on said frame, a sheet guide on said table extending toward the drum and terminating directly over the platen roller in close proximity to the path of the platen in position to guide sheets across said roller to the margin bar and to contact the sheets with that part of the roller which lies in the path of the advancing band on the drum, sheet feeding means for advancing sheets from said table to the margin bar, and actuating means for said margin bar operable in timed relation with the drum to place the bar in position to receive a sheet riding over said guide and said platen roller until the sheet has engaged the margin bar and has been pressed by the platen roll-er against the duplicating band and to thereafter remove the bar from the path of the platen, said sheet guide comprising a plate curved downwardly from the table and terminating in a portion which is substantially tangential to the platen roller at the point where the advancing band first presses the sheets against the platen roller.

12. A duplicating machine of the character described comprising a frame, a drum journalled therein providing an arcuate platen, a duplicating band on said platen, a platen roller movably mounted in said frame in the path of said band and adapted to press sheets against the band, manually controlled means for moving the platen roller out of the path of the band, a margin bar, arms carrying said bar and pivoted in the frame to swing the bar into and out of operative position in the path of the plat-en beyond the platen roller, a copy sheet table on said frame, a sheet guide on said table extending toward the drum and terminating directly over the platen roller in close proximity to the path of the platen in position to guide sheets across said roller to the margin bar and to contact the sheets with that part of the roller which lies in the path of the advancing band on the drum, sheet feeding means for advancing sheets from said table to the margin bar, and actuating means for said margin bar operable in timed relation with the drum to place the bar in position to receive a sheet riding over said guide and said platen roller until the sheet has engaged the margin bar and has been pressed by the platen roller against the duplicating band and to thereafter remove the bar from the path of the platen, said sheet guide comprising a plate curved downwardly from the table and terminating in a portion which is substantially tangential to the platen roller at the point where the advancing band first presses the sheets against the platen roller.

13. A duplicating machine of the character described comprising a frame, a drum journalled therein providing an arcuate platen, a duplicating band on said platen, a platen roller movably mounted in said frame in the path of said band and adapted to press sheets against the band, a margin bar, arms carrying said bar and pivoted in the frame to swing the bar into and out of operative position in the path of the platen beyond the platen roller, a copy sheet table on said frame, a sheet guide on said table extending toward the drum and terminating directly over the platen roller in close proximity to the path of the platen in position to guide sheets across said roller to the margin bar and to contact the sheets with that part of the roller which lies in the path of the advancing band on the drum, sheet feeding means for advancing sheets from said table to the margin bar, and actuating means for said margin bar operable in timed relation with the drum to place the bar in position to receive a sheet riding over said guide and said p1aten roller until the sheet has engaged the margin bar and has been pressed by the platen roller against the duplicating band and to thereafter remove the bar from the path of the platen, said sheet guide comprising a plate curved dqwnwardly from the table and terminating in a portion which is substantially tangential to the platen roller at the point where the advancing band first presses the sheets against the platen roller, and a top plate above said curved plate, said plates converging toward the plat-en roller to provide a tapered passage for directing copy sheets tangentially across the platen roller to the margin bar.

14. A duplicating machine of the character described comprising a frame, a drum journalled therein providing an arcuate platen, a duplicating band on said platen, a platen roller movably mounted in said frame in the path of said band and adapted to press sheets against the band, a margin bar, arms carrying said bar and pivoted in the frame to swing the bar into and out of operative position in the path of the platen beyond the platen roller, means to adjust the operative position of said bar toward and away from said platen roller, a copy sheet table on said frame, a sheet guide on said table extending toward the drum and terminating directly over the platen roller in close proximity to the path of the platen in position to guide sheets across said roller to the margin bar and to contact the sheets with that part of the roller which lies in the path of the advancing band on the drum, sheet feeding means for advancing sheets from said table to the margin bar, and actuating means for said margin bar operable in timed relation with the drum to place the bar in position to receive a sheet riding over said guide and said platen roller until the sheet has engaged the margin bar and has been pressed by the platen roller against the duplicating band and to thereafter remove the bar from the path of the platen, said sheet guide comprising a plat-e curved downwardly from the table and terminating in a portion which is substantially tangential to the platen roller at the point where the advancing band first presses the sheets against the platen roller.

15. A duplicating machine of the character described comprising a frame, a drum journalled therein providing an arcuate platen, a duplicating band on said platen, a platen roller movably mounted in said frame in the path of said band and adapted to press sheets against the band, manually controlled means for moving the platen roller out of the path of the band, a margin bar, arms carrying said bar and pivoted in the frame to swing the bar into and out of operative position in the path of the platen beyond the platen roller, means to adjust the operative position of said bar toward and away from said p1aten roller, a copy sheet table on said frame, a sheet guide on said table extending toward the drum and terminating directly over the platen roller in close proximity to the path of the platen in position to guide sheets across said roller to the margin bar and to contact the sheets with that part of the roller which lies in the path of the advancing band on the drum, sheet feeding means for advancing sheets from said table to the margin bar, and actuating means for said margin bar operable in timed relation with the drum to place the bar in position to receive a sheet riding over said guide and said platen roller until the sheet has engaged the margin bar and has been pressed by the platen roller 7 against the duplicating band and to thereafter remove the bar from the path of the platen, said sheet guide comprising a plate curved downwardly from the table and terminating in a portion which is substantially tangential to the platen roller at the point where the advancing band first presses the sheets against the platen roller, and a top plate above said curved plate, said plates converging toward the platen roller to provide a tapered passage for directing copy sheets tangentially across the platen roller to the margin bar.

16. In a duplicating machine of the character described, the combination of a frame, a drum rotatably mounted on said frame and cut away at one side to provide an arcuate platen, means for rotating said drum, means for holding a duplicating band wrapped about said platen, a platen roller rotatably mounted on said frame and standing normally in the path of said platen and movable outward-1y a short distance into pressure relationship with said platen for pressing a sheet against the duplicating band on the platen as the drum rotates, guiding means for directing a sheet fed thereto into position across the face of said platen roller, a margin bar movable toward and from the drum adapted when disposed inwardly to engage the leading edge of a sheet fed into position opposite to the face of said platen roller for accurately positioning the sheet for engagement with said duplicating band, and controlling means for said margin bar adapted to hold the margin bar disposed inwardly in operative stopping position until said platen is brought into pressure relationship with said platen roller and adapted thereafter to move the margin bar quickly out of the path of the platen.

1'7. In a duplicating machine of the character described, the combination of a frame, a drum rotatably mounted on said frame and cut away at one side to provide an arcuate platen, means for rotating said drum, means for holding a duplicating band wrapped about said platen, a platen roller rotatably mounted on said frame and movable toward and from the bottom face of the drum at the downwardly moving side of the drum, yielding means adapted normally to press the platen roller inwardly into position for operative engagement with said p1aten as the drum rotates, a margin bar movable toward and from the drum adjacent to said platen roller, means for holding said margin bar normally in position adjacent to the face of said platen roller, guiding means for directing a sheet fed thereto into position across the face of said p1aten roller and into engagement with said margin bar so as to be positioned thereby, and means actuated in WILHELM F. SCI-IOENHARDT.