US2740353A - Feed roll driving means for duplicating machines - Google Patents

Description

April 3, 1956 c. A. LEVIN 2,740,353

FEED ROLL DRIVING MEANS FOR DUPLICATING MACHINES Filed March 14, 1951 3 Sheets-Sheet l April 3, 1956 c. A. LEVIN 2,740,353

FEED ROLL DRIVING MEANS FOR DUPLICATING MACHINES Filed March 14, 1951 3 Sheets-Sheet 2 INVEN TOR. Carl ,2. z ez/Z'rz April 3, 1956 c. A. LEVIN 2,740,353

FEED ROLL DRIVING MEANS FOR DUPLICATING MACHINES Filed March 14. 1951 3 Sheets-Sheet 3 INVENTOR. ("GI 1.7% lee/27a FEED ROLL DRIVING MEANS FOR DUPLICATING MACHINES Carl A. Levin, Park Ridge,

porated, Chicago,

lll., assignor to Ditto, incor- Ill., a corporation of West Virginia.

This invention relates to duplicating machines of the wet process type, and in particular, {to improved means for driving the feeding and moistening rolls.

Duplicating machines of this type are provided with a drum, a pressure roll in contact therewith, and a pair of feed rolls disposed in front of the bite of the drum and pressure roll. These feed rolls serve the combined func tion of feeding a copy sheet into engagement with the drum and pressure roll, of moistening one surface of the copy sheet as it is being fed, and of positioning the copy sheet. To accomplish the positioning and feeding functions, the feed rolls are intermittently driven; the copy is fed into the bite of the feed rolls when the latter are stationary. Then when the feed rolls start to rotate, the leading edge of the copy sheet is grasped by the feed rolls and fed into engagement with the drum and pressure roll. A suitable master sheet is carried on the drum. The timing of the dwell period of the feed rolls is such that proper registration of the copy sheet and the master sheet is obtained.

Two types of intermittent driving mechanisms have heretofore been used. In one type, the'upper feed roll is positively driven from the drum or drum shaft by mutilated gearing through a major portion of each revolution of the drum. The disadvantage of this mutilated gearing is the fact that the feed rolls are accelerated up to maximum speed very rapidly. This results in shock to the mechanism and noisy operation; since the feed rolls are brought up to maximum speed in about one tooth length.

The other type of intermittent driving mechanism involves the use of a cam driven oscillating sector which serves to positively drive the upper feed roll only through a peripheral distance which is sulficient to advance the copy sheet into a position in-which the leading edge thereof is grasped by the bite of the drum and feed roll. This mechanism provides lower acceleration, resulting in smoother and quieter operation. Furthermore, it provides better registration since there is less likelihood of initial slippage between the copy sheet and the feed rolls. After United States Patent the copy sheet has been engaged by the drum, the copy sheet drags the feed rolls, and to permit this, an overrunning clutchjis interposed between the intermittent driving mechanismand the upper feed roll.

In addition to the above advantages which relate to feed roll acceleration, this sector type of mechanism avoids the accumulation of moisture in the absorbent lower feed roll since the feed rolls come to a stop almost immediately after trailing the edge of the copy sheet as passed between thefeed rolls. 'In the mutilated gearing type of mechanism, when a' short copy sheet is fed, the continued rotatibn of the upper feedroll transfers a substantial amount of solvenfto the lower feed roll which moisture is later transferred to the undersurface of subsequent copy sheets 'audthenceto the pressure roll which may later result in offsetting.

It has been found that the oscillating sector type of intermittent driving mechanism is not satisfactory for motor driven machines. This is for the reason that it "ice is very dilficult to obtain an exact balance between the moisture applied to the feed roll and the moisture removed from the feed roll by means of the copy sheet. After a motor driven machine has been run continuously for a substantial period of time,'if' the balance is not correct, an over-supply of moisture will cause slippage of the copy sheet with respect to the feed rolls, with the result that the copy sheet will not drag the feed rolls, and the remaining portion of the copy sheet will not be moistened. This slippage becomes particularly aggravated when the 'copy sheet is in the form of narrow sheets, strips, tickets and the like.

It is an object of the present invention to provide an improved feed roll driving mechanism which combines the advantages of both types of driving mechanism pointed out above, and eliminates the disadvantages of each.

Another object is to provide an improved feed roll driving mechanism which positively drives the feed roll through the greater part of each revolution of the drum.

Still another object is to provide in combination with an intermittent feed roll driving mechanism of the oscillating sector type, an auxiliary driving mechanism which will serve to extend the period during which the feed rolls are positively driven so that slippage may be prevented.

A further object is to provide auxiliary feed roll driving mechanism which can be readily disengaged when it is desired not to use the same.

A still further object of this invention is to provide improved moistening, feeding and positioning means for a wet process duplicating machine which is operative on narrow copy sheets as well as on copy sheets of standard width.

With reference now to the drawings in which like reference numerals designate like parts:

Fig. l is a side elevation of a fragmentary duplicating machine embodying my invention;

Fig. 2 is a vertical sectional view of the machine of Fig. 1 showing the relationship of the various elements referred to above;

Fig. 3 is an elevation of the auxiliary driving mechanism shown in Fig. 1, taken along line 3-3 of Fig. 1;

Fig. 4 is a detail section taken along line 4-4 of Fig. 1;

Fig. 5 is an elevation, partially in section of the opposite side of the machine from that shown in Fig. 1, showing the oscillating sector type of driving mechanism;

Fig. 6 is a vertical section taken along line 6-6 of Fig. 5; and

Fig. 7 is a detailed sectional view taken along line 77 of Fig. 6, showing the overrunning clutch.

In the drawings, which illustrate a preferred embodiment of this invention, the reference numerals 10 and 11 designate the right and left side frames, respectively, of a duplicating machine. A drum shaft 12 is suitably journaled in the side frames and carries a drum 13. Suitable means, not shown herein, are provided for driving the drum and drum shaft. The drum is provided with the usual means, not shown herein, for securing a master sheet to its surface.

A pressure roll 14, as shown in Fig. 2, is disposed below the drum for pressure engagement therewith. The pressure roll is carried in a bracket 15 which is pivoted on a shaft 16 so that it may be resiliently urged against the drum.

Disposed in front of the bite of the drum and pressure roll is a pair of feed rolls comprising upper feed roll 17 and lower feed roll 18. The upper feed roll 17 may be formed from neoprene or the like, and the lower feed roll may be formed from a sponge rubber or other absorbent material. As shown in Figs. 3 and 6 a tubular portion of a 3 shaft 19 provided for the upper feed roll 17, in which shaft are disposed right and left extensions 20 and 21, respectively. The shaft extensions are journaled in the side frames by means of ball bearing units 22 and 23, respectively.

The lower feed roll 13 is mounted in pivoted brackets 24 and 25, respectively, so that it may be resiliently urged into engagement with the upper feed roll 17.

As shown in Fig. 2 the duplicating machine is provided with a moistener 26 which includes a spray tube 27 disposed above the upper feed roll 17, a wiper 23 which en gages the upper feed roll, and mounting means 29 for partially enclosing and supporting the wiper. The wiper may be made of felt. During each revolution of the drum, a measured amount of solvent is sprayed onto the upper feed roll by the spray tube, and this solvent is uniformly distributed over the surface of the feed roll by the wiper.

A feeding throat 30 is disposed immediately in front of the bite of the feed rolls and is aligned with the usual feed tray so that a copy sheet may be directed into the bite of the feed rolls when they are stationary. Subsequent rotation of said feed rolls will cause the leading edge of the copy sheet to be fed into the bite of the drum and pressure roll, and the timing is such that proper registration with the master sheet will be obtained.

Two driving mechanisms are provided so that the feed rolls may be intermittently driven, the primary driving mechanism being disposed at the left side of the machine, and being shown in Figs. 5 and 6 and theauxiliary driving means being disposed at the right side of the machine and being shown in Figs. 1 and 3. The primary driving mechanism includes an oscillating sector 31 which ispivotally mounted on the left side frame '11 as shown in Fig. 5 by means of a pivot 32. The sector 31 is provided with teeth 33 which mesh with a pinion 34 concentrically mounted with respect to shaft extension 21. A unidirec tional driving connection is provided with the pinion 34 and the shaft extension by means of an overrunning clutch 35, shown in Figs. 6 and 7. The sector 31 is driven by a groove earn 36, mounted on the drum shaft 12 which engages a follower 37 in the form of a roller, which is carried on the sector 31. The groove cam is adjustably mounted with respect to the drum shaft by means of screws 38 and slots 39, the screws taking into a suitable flange or hub member on the drum shaft. Thus, the angular position of the groove cam with respect to the drum can be shifted in order to vary the time at which the rotation of the feed rolls is commenced, thereby regulating the registration. The groove cam is provided with a rise portion 40 and with a drop portion 41. In the position of the parts as shown in Fig. 5, the feed rolls have just commenced their rotation. Subsequent rotation of the drum and the cam in the direction indicated by the arrow will cause the sector to swing to the right with a gradually accelerated motion, thereby causing the leading edge of a copy sheet to be fed into the bite of the drum and pressure roll. The cam rise is so designed that the peripheral speed of the feed rolls at the time that the leading edge of the copy sheet is engaged by the bite of the drum and pressure roll will be equal to the peripheral speed of the drum. The provision of the cam and sector arrangement permits a gradual acceleration of the feed rolls up to this speed, thereby permitting more positive engagement of the leading edge of the copy sheet and avoiding the shock and noise inherent in other types of mechanism.

Due to the provision of the overrunning clutch 35, the return stroke of the sector does not affect the continued and unidirectional rotation of the feed rolls.

The auxiliary driving mechanism, as shown in Figs. 1 and 3, includes a sector 45, a friction wheel 46 driven. thereby, and suitable gearing between the friction wheel and the upper feed roll 17. The sector may be suitably secured to the drum shaft or the drum as by set screws 47.

The friction wheel 46 is preferably formed of rubber to permit proper frictional engagement with the driving edge of the sector 45, which maybe formed of metal or other hard material.

The friction wheel 46 forms a part of an idler assembly 48, shown in Fig. 4, which is rotatably mounted on a shoulder stud 49. The latter extends outwardly from a support plate 50 to which it is suitably secured. The idler assembly includes a bushing 51 having a flange 52. A pinion 53 is riveted to the flange 52. The friction wheel 46 is confined between the flange 52 and a clamping disk 54 which is threaded onto the end of the bushing 51 so as to securely hold the friction wheel46 againstrslippage on the bushing. Thus, all of the elements of the idler assembly 48 rotate as 'a unit on the shoulder stud 49. The idler assembly is spaced from the shoulder of the shoulder stud 49 by a suitable felt lubricating washer 55, and it issecured in position on the stud by means of a washer 56 and a retaining ring 57 which snaps into an annular groove formed at the end of stud 49.

The idler pinion 53 meshes with a pinion 58 which is suitably secured to the shaft extension 20 of the upper feed roll. Thus, the upper feed roll may be intermittently rotated by the sector 45. The support plate 50 is adjustably mounted on side frame 10 by means of an eccentric bolt 60 and a screw 61 which passes through a slot 62 in the support plate and takes into the side frame 10. The eccentric bolt 60 is provided with an eccentric shoulder 63 which engages the circular edge of a cut-out portion 64 of the support plate, as shown vin Fig. l. The head of the eccentric bolt confines one end of the support plate against the frame 10. The support plate is provided with a circular opening so that it may be fitted over the bearing unit.22 to provide-a pivoted mounting. Thus, by loosening the nut 65 and the screw 61, the angular disposition of the supportplate can be regulated to a precise degree merely by changing the angular position of the eccentric shoulder 63 of bolt 60. This permits regulation of the frictional engagement of the friction wheel with the sector, and it also permits the friction wheel to be disengaged entirely from the sector when operation of the auxiliary driving means is not desired.

It will be observed that the corner edges of the sector 45 are rounded, as indicated by the reference numerals 66, so as to .minimize the shock of engagement and disengagement.

The operation of the invention has been pointed out in connection with the description of the various parts of the duplicating machine. To summarize, a copy sheet which has been positioned at the bite of the feed rolls when they are stationary, will be advanced by the feed rolls with a gradually accelerated motion so that the leading edge of the copy sheet will be fed into the bite of the printing couple. At this time, the speed of the feed rolls and of the copy sheet is equal to the drum speed. The rotation of the feed rolls during this period is controlled by the primary driving means. If it .is desired to use the secondary driving means, the support plate 50 is rocked and secured in a position so that the friction wheel 46 is engaged by sector 45. The length of the sector is such that the feed rolls will be positively driven throughout a peripheral distance which corresponds to the standard length of copy sheet which is used in straight line duplicating.

The primary driving means is preferably operative to drive positively the copy sheet at the drum speed for a short time after the leading edge has been engaged bythe printing couple, so as to provide for an overlapping of the operative positions of the cycles of the two driving mechanisms. Thus, by regulating the extent of the overlap, by adjusting the angular position of the sector, by means of the set screws 47, the total time during which the feed rolls are positively driven may be regulated to correspond with the length of the copy sheet to be duplicated-upon. However, where the length of the copy sheets varies substantially from the standard length, a different size sector may be substituted for sector 45. In the alternative, two or more overlapping or telescoping sectors may be employed to permitsubstantial variation without the necessity of substituting ditferent sectors.

For a series of shot runs on copy sheets of standard width, such as may be encountered during so-called systerns operation as contrasted with straight run duplicating, the problem of slippage may not occur since evaporation during periods of inactivity will prevent over-moistening. In such a situation, the secondary driving means can be rendered inoperative by shifting the support plate 50 and the friction wheel 46 out of engagement with the sector 45.

The present invention is of utility when mutilated gearing is used for the primary driving means, provided that the mutilated drive gear is of comparatively short length. In such situations, the secondary driving means positively drivestthe feed rolls when slippage is likely to occur; at other times, the secondary driving means may be reudered inoperative so that the feed rolls will come to rest even though a short copy sheet is used.

I claim:

1. In a duplicating machine having a rotatable cooperating pressure roll providing a printing couple, the combination of a pair of intermittently driven feed rolls disposed in front of the bite of said printing couple, primary driving means'for positively drivingsaid feed rolls through a peripheral distance corresponding to the distance between the bite of said feed rolls and the bite of said printing couple and actuated by the rotation of the drum, said primary driving means embodying means providing a positive driving connection between said drum and one of said feed rolls to initiate the rotation of said feed roll as said drum passes through a predetermined angular position, and auxiliary means for driving said feed roll after a copy sheet has been fed by said feed rolls into engagement with the bite of said printing couple, said auxiliary means embodying means providing a frictional driving connection between said drum and said feed roll.

2. In a duplicating machine of the class described having a drum, a feed roll, primary and auxiliary driving means for the feed roll, said auxiliary driving means comprising a friction sector rotating with the drum and a rotatable member driven thereby to provide a frictional driving connection, together with a further driving connection between said rotatable member and said feed roll, the combination of a mounting plate on which said rotatable member and said driving connection are mounted, and means for mounting said mounting plate for pivoted movement about the axis of said feed roll, whereby the angular position of said mounting plate may be shifted to throw said rotatable member into and out of engagement with said sector.

3. Auxiliary driving means for a duplicating machine having a frame, a drum, a feed roll rotatably mounted in said frame, and primary driving means for said feed roll, comprising a friction sector rotating with said drum, a rotatable member positioned to be engaged and to be frictionally driven thereby, a driving connection between said rotatable member and said feed roll, a plate pivotally mounted on said frame for angular adjustment about the axis of said feed roll, and means for securing said plate to said frame including a bolt mounted on said frame and having a head engaging a surface of said plate for confining the plate against said frame, said rotatable member and said driving connection being rotatably mounted on said plate, and an eccentric shoulder on said bolt bearing against a portion of said plate for regulating the angular position of said plate and the engagement between said to tatable member and said sector.

4. In a duplicating machine having a drum and a cooperating pressure roll providing a printing couple, the combination of a pair of intermittently driven feed rolls disposed in front of the bite of said printing couple, primary driving means for positively driving said feed rolls through a peripheral distance corresponding to the distance between the bite of said feed rolls and the bite of said printing couple said primary driving means comprising an 0scillating sector, a pinion driven thereby, an overrunning clutch disposed between said pinion and one of said feed rollsaio provide unidirectional rotation thereof and cam means rotating with said drum to cause oscillation of said sector, said cam means having a gradually rising rise portion for imparting an accelerated motion to said sector and said feed rolls throughout a substantial portion of the time during which said feed rolls are so driven whereby a copy sheet-positioned in the bite of said feed rolls when stationary may be fed with a gradually accelerated motion into the bite of said printing couple at a speed substantially equal to the peripheral speed of said drum, and auxiliary driving means comprising a friction sector mounted on said drum, a friction wheel positioned to be engaged thereby, and means establishing a driving connection between said friction wheel and said feed roll, said sector being constructed and arranged so as to drive said feed roll at a peripheral speed substantially equal to the peripheral speed of said drum after said copy sheet has been engaged in the bite of said printing couple and throughout a period of time subsequent thereto which period terminates prior to the time that said primary driving means is again operative.

5. In a. duplicating machine having a drum and a cooperating pressure roll providing a printing couple, the combination of a pair of intermittently driven feed rolls disposed in front of the bite of said printing couple, a moistener for said feed rolls including a wiper member engaging one of said feed rolls, primary intermittent positive drive means for positively driving said feed rolls through a peripheral distance corresponding to the distance between the bite of said feed rolls and the bite of said printing couple, auxiliary intermittent drive means for said feed rolls after rotation thereof through said peripheral distance and throughout a period of time subsequent thereto which period terminates prior to the time said primary means is again operative in order to extend that portion of the cycle of operation during which said feed roll is driven, and overrunning clutch means associated with said feed roll to permit unidirectional rotation of said feed roll at all times, said auxiliary intermittent driving means including a friction sector, and means for adjustably mounting said sector on said drum so that said portion of said cycle of operation can be regulated to accommodate sheets of different length.

6. In a duplicating machine having a drum and a coopcrating pressure roll providing a printing couple, the combination of a pair of intermittently driven feed rolls disposed in front of the bite of said printing couple, primary driving means for positively driving said feed rolls through a peripheral distance corresponding to the distance between the bite of said feed rolls and the bite of said printing couple, said primary driving means comprising an oscillating toothed sector, a pinion driven thereby, an overrunning clutch disposed between said pinion and said feed rolls to provide unidirectional intermittent rotation of said feed rolls, a groove cam rotating with said drum for causing oscillation of said sector, and auxiliary drive means comprising a friction sector rotating with the drum of said duplicating machine, a friction roller intermittently driven thereby, and a driving connection disposed between said friction roller and said feed rolls, the angular relationship between said grooved cam and said friction sector being an offset relationship so that said auxiliary drive means will impart rotation to said feed rolls after said feed rolls have been rotated through said peripheral distance by said primary driving means.

7. In a duplicating machine having a drum and drum shaft and a pressure roll cooperating with said drum to provide a printing couple, the combination of a pair of feed rolls disposed in front of the bite of the printing coupie, said feed rolls including a combined moistening and feeding roll, primary driving means therefor adapted to impart intermittent rotation thereto to advance successive copy sheets into the bite of said printing couple, overrunning clutch means disposed between-said primary driving meansand said feed roll to permit unidirectional rotation of said feed roll at times when said primary driving means is inoperative, and auxiliary driving means for establishing an intermittent driving connection betWeensaid-drum shaft and said moistening and feeding roll, the operative portion of the cycle of said auxiliary driving means commencing after said moistening and feeding roll has been rotated by said primary driving means through a peripheral distance corresponding .to the distance between the bite of said feed .rolls and the bite of said printing couple so that a given copy sheet will be engaged in the bite of-said printing couple when'said operative portion commences, and terminating after said primary driving means has become inoperative so that said moistening and feeding roll will be driven throughout a period greater than that provided by either of said driving means.

8. Driving mechanism as claimed in claim 6 including means for adjustably mounting said friction sector on said drum.

9. In a duplicating machine having a rotatable drum and a cooperating pressure roll providing a printing conple, the combination of a pair of intermittently driven feed rolls disposed in front of the bite of said printing couple, primary driving means for positively driving said feed rolls and actuated by the rotation of the drum to initiate the rotation of said feed roll as said drum passes through a predetermined angular position and to accelerate the same up to drum speed, said primary means embodying 8 a geared connection to provide an initial driving action, and embodying a first member rotating with said drum,

and auxiliary means providing a frictional drive 'forsaid' feed rolhsaidauxiliary means comprising asecondmem-w ber rotating with'saiddrum and provided with .a frictional driving =surface, a rotatable drivenelement positioned to be fr'ictionally engaged by said second member, and Ea driving :connection between said second member and said driven element, said second member being in the form of a sector angularly arranged so that it will not engage said driven element until after sai-dfeed rolls have been rotatedby said primary means through a peripheral distance corresponding ito the distance between the bite of said feed rolls and the bite of said printing couple, one

of saidmembers being vadjustably mounted withrespect to said drum, said auxiliary means providing a frictional driving connection so that the operation of the same is not dependent .upon any given .increment of adjustment, and said primary driving means providing a positivedrivingconnection so that the relative speeds of said drum and feed roll are not affected by inertia.

References Cited in the file of this patent UNITED STATES PATENTS 1,247,732 Shelton Nov. '27, 1917 2,185,682 Pittman Jan. 2, 1940 2,192,908 Harrold et a1. Mar. 12, 1940 2,268,045 Marchev Dec. 30, 1941 2,271,954 Rockhill Feb. 3, 1942 2,299,974 Grobecker Oct. 27, 1942 2,588,917 Geib Mar. 11, 1952 2,594,179 'Keil Apr. 22, 1952

Images