US 3312126 A
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Description (OCR text may contain errors)
April 4, 1967 H. H. HERING, JR
ADJUSTABLE SPEED DRIVE 2 Sheets-Sheet l Filed June l0, 1964 mmdqod .3.10
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INVENOR Henry H` Hcrmgr:
April 4, 1967 H. H. HERING, JR v 3,312,126
ADJUSTABLE SPEED DRIVE 2 Sheets-Sheet 2 Filed June lO, 1964 C P A D m u nlllllluuuundlllllllllll|l|ou P ..mr P o Mh'oe M s Wdh PMU mf W m R Mdmw Rmk C .D PP PDmm @MSM .my Wella Huddl 10.5 .md ek MB Wm Rd 8mm... 1| I H 6 mmhlr .Mhlwdl |.5 .lain l O llllll I IFI nl hst mlww hwnswo Cmp.) P fn eh wm e ,wrm P 0 www.; 0 rHU mcmS d .MumFRAw .WMNI Umm e A oww? WMJTA @Qn nd mam@ mdn ABD .J'4 WM5 l nMEW? D b A E ecnwa l l l |-O E N W 1 5 P ,b5 sm mm@ RT T .W o EU /b. .LB o .n w OW 1%U R5 1-5 L' l5 Z L D 9 H C 0 o o 0 0 o w 0 .w n w ma 2 w w @N Ejem jiu PER CENT 0E PULL PRESS SPEED FIG. 3
D .llllllllilllilll'llllll'lw .i1|||| Illiltw D a E e e E e e P P S AW 5 5 b ID ab D 6 e E D W W R E ma l l 1 I IIIFD E @1 O O 5 p m n. u nrw 5 W T T U mw n o m Q O 6 W E M w T Rc .spN. D 2C R E P n h O w w w w o w w w w s s mo I NV ENTOR Henry H` Herngln 59W #M M Y Gitys F1a L United States Patent Otice 3,3l2,l2h Patented Apr.. 4, 1967 nois Filed June 10, 1964, Ser. No. 374,055 6 Claims. (Cl. 74--675) This invention relates to mechanisms for use in comhination with rollers. In particular, the invention is concerned with methods and means for driving rollers which are used for the transporting of material, and which must be capable of speed adjustments in the course of a continuous operation.
The instant invention will be discussed in conjunction with the operation of mechanisms used for transporting continuous webs. One particular mechanism of this type comprises la web oiset printing press wherein heat set inks are printed on web surfaces in a continuous operation. The .Webs are moved through driers subsequent to the printing operation, and thereafter, it is necessary to set the inks by cooling the web back to room temperature. In order to accomplish the cooling operation, conventional devices provide chilling rollers, and the continuous web is led over these rollers for contact with the cool surfaces thereof subsequent to movement out of the web drier.
In the operation of the chill rollers, it is necessary to provide speed control. Such speed control meets with certain diiiiculties, however, since continuous webs used in printing operationsare subject to shrinkage as a result of the printing and `drying steps. Since the exact amount of shrinkage in a .given operation is not predictable and is inconsistent throughout an operation, it is necessary to provide means which compensate for'variations in web length.
In a typical operation of the type contemplated, the chill rollers are driven through the use of connections with the drive rollers for the printing presses. The drive rollers can -be maintained at a constant speed and, therefore, variations in speed are undertaken at the chill rollers. The speed of the chill rollers is adjusted whereby web speed and the roller speed are such that rubbing and smearing will not result while the Webis passing over the chill rollers. In most instances, this can be accomplished by providing a speed in the chill rollers which exceeds the web speed by a small increment. This :arrangement provides `a small amount of tension in the web to provide better handling characteristics.
It will be apparent when considering the above remarks that the speed control of the chill rollers is a critical matter. Improper speed can result in damage to the printed surface and may actually result in tearing of the continuous web. Current installations of the type described employ plain or diiferential type P.I.V.s (suoh as speed changers built by Link Belt Co., Chicago, Illinois) in an attempt to achieve a satisfactory operation. It has Ibeen recognized, however, that the following `difculties develop when such constructions Iare employed in conventional installations:
(l) The plain P.I.V. has relatively poor speed regulation characteristics and allows a relatively great amo-unt of lash between input and output which is added to the normal gear lash experienced in the balance of the drive system. This results in an undesirably large amount of lash at the roller surface which in turn is likely to cause web breaks on rapid deceleration of the rollers due to the overhauling load condition which occurs (eg, emergency press stops).
(2) The differential P.I.V. improves the speed regulation by the employment of .a ldifferential gear set. However, due to the yadditional reduction gearing required to improve the speed regulation, the over-all lash between input and output is increased considerably.
It is an object of this invention to provide a mechanism for controlling adjustments in the speed of rollers whereby the roller speed can be maintained in a desirable relationship with respect to material passing in contact with the rollers.
It is Ia further object of this invention to provide an improved method for utilizing adjustable speed drives whereby the relative speeds between rollers and materials carried thereby can be maintained at a critical relationship.
It is a further object of this invention to provide an adjustable speed drive system which is particularly satisfactory for use in constructions designed for the printing, drying and chilling of continuous webs.
These and other objects of this invention will appear hereinafter and for purposes of illustration but not of limitation, specific embodiments of this invention are shown in the accompanying drawing in which:
FIGURE 1 is a diagrammatic illustration of a construction employed for the printing, drying and chilling of continuous webs;
FIGURE 2 is a detail view of the adjustable speed drive mechanism of this invention; and
FIGURES 3 and 4 comprise graphic illustrations of the operation of typical systems incorporating the features of this invention.
The mechanism of this invention comprises a drive means which operates to drive rollers at infinitely variable speeds. In particular, the mechanism comprises a drive gear which is adapted to be driven by driving forces from two different sources. A first driving force is provided by separate drive rollers which are primarily responsible for the passage of a web through an apparatus in which the mechanism of this invention is employed. A second driving force is imparted to the mechanism so that the rollers with which the mechanism is associated can operate in a specis relationship with respect to the web passing in contact therewith. Any variations in web length, or due to other characteristics in the system, are compensated for so that this desired relationship can be continuously maintained.
The diagrammatic illustration of FIGURE 1 is intended to provide an example of a suitable application for the contributions of this invention. In the illustrated system, a paper roll 10 is moved .over guide rollers l2 by means of drive rollers 14 to a printing unit 16. The rollers 13 of the printing unit are adapted to form printed areas on the paper on one or both sides in accordance with conventional techniques.
A drier 20 of any conventional design is located adjacent the printing unit. As the paper web moves out of the drier, it is brought into contact with chill rollers 22. These rollers are ordinarily provided with internal passages whereby cold water can be circulated through the rollers to provide the desired setting of the ink.
Subsequent to the chill rollers, there is provided a guide roller 24 and take-up rollers 26. These latter rollers operate to pull the paper from the system and they may be adapted to transmit the printed web to a folder such as shown at 28.
In ordinary systems, the web entering the drier is wet due to the presence of printing inks thereon. During the drying and chilling operations, the paper tends to shrink and, accordingly, constant speeds of rotation for all of the drive means in the system cannot be maintained. In accordance with the techniques of this invention, means are provided for driving the chill rollers whereby shrinkage in the system can be accommodated without the danger of damage to the printed surface or to the web itself.
FIGURE 2 illustrates details of a drive mechanism which accomplishes the features of this invention. In this figure, the shaft 30 is driven through rotation of the shafts of the rollers 18 of the printing unit. The gear 32 on this shaft drives the bevel gears 34 and 36 as well as the operatively connected bevel gears 38 and 40. The bevel gears 3S and 40 are connected to additional bevel gears 42 and 44 by means of shaft 46.
The bevel gear 42 is tied to the shaft 48 and the central fitting 50 of a differential mechanism is also tied to this shaft by means of set screw 52. A pair of cylindrical arms 54 and 56 extends outwardly from the fitting 5f) and differential gear members 53 and 60 are rotatably mounted .on these arms.
A main gear 62 idles on the shaft 48 and a differential gear member 64 is tied to the gear 62. It will be apparent that rotation of shaft 48 through bevel gear 42 will cause the tting S to rotate thereby resulting in rotation of the gears 64 and 62. The gear 62 meshes with gear 66, this gear in turn meshing with gear 68 which in turn meshes with gear 70. The gears 66', 68 and 70 are tied to the shafts 72, 74 and '76, respectively, these shafts carrying the chill rollers 22. It will thus be apparent that rotation of the main drive gear 62 will result in rotation of the chill rollers.
Also idling on the shaft 4S is differential gear member 76, this gear member being tied to the gear 80. Rotation of the gear 50 is effected by means of the worm 82 which is in turn driven through D.C. moto-r 84. When the DC. motor $4 is inoperative, the worm S2 serves to lock the gear 7S in a stationary position. This Worm may cornprise a single threaded irreversible worm which is easily associated with a DC. motor. It will be apparent that rotation of the fitting 50 by means of the shaft 48 will cause the gear members 58 and 60 to rotate relative to the gear 78, even though this latter gear is held stationary.
When the D.C. motor 84 is operated, the gear 80 and `associated differential member 73 will be rotated and this rotation will obviously effect the speed of the main drive gear 62. If the differential member 78 were rotated in one direction, the force applied would result in an increase in the speed of the main drive 62, whereas rotation in the opposite direction would result in a decrease in the speed of this gear.
In the preferred operation of this invention, the gearing in the system is so-selected that when the D.C. motor 84 is at Zero speed, the shaft 48 will alone account for the speed of the drive gear 62. When the D.C. motor is made operative, the speed of the drive gear 62 is increased. It will be apparent that a system could be devised for providing increases and decreases through the use of a secondary drive, or decreases in speed alone could be provided for.
Where the preferred form of this invention is utilized, that is where increases in speedvalone are contemplated, certain calculations can be made to provide an efficient operation. In a system where shrinkage of the sheet occurs, the chill rollers 22 operate at a lesser speed than the press rollers 18. The maximum shrinkage possible can -be calculated, and this figure used to determine the speed of the chill rollers with the D.C. motor at zero speed. The chill rollers can be driven at a lower speed than the press rollers by appropriate gear ratios. The minimum amount of shrinkage which can occur can also be calculated and this value used to determine the speed of the chill rollers when the D.C. motor is operating at maximum speed. It will be apparent that in a system of this nature, some intermediate speed of the D.C. motor will almost always be required. The system will then operate whereby the main drive gear 62 will be rotated through the operation of the press gear drive as well as through the operation of the D.C. motor.
In a typical embodiment, gearing is selected so that when the D.C. motor is at zero speed, the chill roller surface will rotate at 95 percent of the theoretical web speed established by the prin-ting rollers. At its maximum speed, the D.C. motor will rotate at 105 percent of theoretical web speed. Accordingly, when the motor speed is varied between zero and its maximum, the roller surface speed will be varied through a range of plus or minus 5 percent of theoretical web speed.
In the operation, the speed of the D.C. motor will follow proportionally the speed of the press as the latter is sensed by the magnetic sensor head and fed back through the controller. A manual control is provided `as a biasing means for displacing the speed response curve of the DC. motor between 95 and 105 percent of press speed. See FIGURES 3 and 4.
The lower curve for 95 percent of theoretical web speed represents the speed values where all of the speed is being furnished by the press drive shaft and none by the D.C. motor, the latter being at zero speed for all 4press speeds from zero to maximum. If the press `speed is increased while tt'he biasing control is set to give 100 percent theoretical web speed, then the D.C. motor will follow the center curve, its speed remaining proportional to press speed for all values from zero to maximum, but displaced a proportional amount B from the 95 percent values. If the biasing control is changed to give 105 percent theoretical web speed, then the D.C. -motor speed will follow the upper curve, its speed still remaining proportional to press speed from zero to maximum, but displaced a proportional amount C from the 95 percent values. The proportional values B and C are thus infinitely adjustable by means of the speed selector through a range of i5 percent from the l0() percent theoretical web speed curve.
The operation of the illustrated construction includes the use of a magnetic speed sensor head 86 which detects the speed of the gear 32. Since the gear 32 is in the area of inuence of drive gears located between the shaft 30 and the shaft 48, roller speed feed-back can be sensed by this sensor. The signal produced by the sensor is fed into controller S8, and this controller provides for regulation of the speed of the D.C. motor 84 through speed selector 90 whereby the motor speed will always be proportional to the press speed. Iit will be understood that means for determining roller speed feed-back are conventional, and reference is made to specific means only for the purpose of illustrating their use in the combination of this invention.
In the .particular embodiment described, the shaft of the printing press operates to drive the .press up to percent of web speed and the press shaft furnishes about 80 percent of the power required. The D.C. motor furnishes the balance of the speed .according to its adjustable setting and the balance of the power (0-20%). If the percentage of the web speed handled by the press shaft is greater than 95 percent, then the percentage of power contributed by the press shaft will be greater and that contributed by the D.C. motor less. Therefore, if it proves practical in operation to reduce the plus or minus 5 percent of theoretical web speed as the adjustment range, then the D.C. motor and electronic gear may be made smaller.
The D.C. motor preferably has, at constant load, a speed regulation of about plus or minus 1A percent. When the speed range of the motor (0-3000 r.p.m. approximately) is applied to plus or minus 5 percent of the chill roller theoretical web speed, the regulation of the chill rollers shrinks according to the gear ratios and can be reduced by about 10 times. The roller speed lregulation will then be about 0.025 percent.
When the D.C. motor is at zero speed, if a condition of minus 5 percent of theoretical web speed were desir- Iable, then the reaction of the differential gearing would have a tendency to rotate the D.C. motor backward since presumably no current would be flowing to the motor. To elimintae this, the worm would be of the irreversible type, i.e., lead angle close to the friction angle.
The worm gear set contributes a negligible amount to fthe system lash as compared to that of the infinitely variable chain drive of a P.I.V. unit. The balance of the drive train will contribute no more than the balance of a conventional system, which is relatively small. Therefore, the over-all system lash will not be more than approximately 1/32 inch measured at fthe periphery of the furthermost 11.750 inch diameter chill roller. With a conventional system employing P.I.V.s, this figure will usually be about four times as great.
With lower inherent lash in the system, the impact felt on various shaft keys will be less under overhauling load conditions (rapid deceleration of press). As a result there Will be proportionately less system lash increase with use because of keys distorting and loosening due to the aforementioned impact.
It will 'be apparent that the description provided herein is not intended to limit the scope of this invention. There are many possible applications for the speed control arrangements described such as on letterpress chilling rollers and also on infeed roller drive systems for web offset presses. In the latter case, the system can be used with one or more webs on the web offset. Finally, applications other than in the printing art will be obvious to the skilled observer.
In the above description, fthe drive means employed provides for the use of a bevel gear type differential gear set. It will be apparent, however, that planetary differential gear set could also be used.
It will be understood that various changes and modifications may be made in the above described system which provide the characteristics of this invention without departing from the spiritthereof particularly as defined in the following claims.
That which is claimed is:
1. In an apparatus for the handling of continuous webs wherein said webs are moved through the apparatus by rollers whereby the webs can be printed on at least one surface, passed through la drier, and then to a web takeup station, and wherein chill rollers are provided between said drier and said take-up station, the 1Improvement comprising drive means for said chill rollers, said drive means including a main drive gear `operatively connected to said chill rollers whereby said chill rollers rotate in response to the `operation of said drive gear, first means for irn-l parting driving force to said drive gear in accordance with the speed of the drive rollers for the apparatus, and second means for imparting further driving force to said drive gear, each of said first and second means imparting force to said drive gear through a differential, and including a sensor adapted to sense the speed of said drive rollers for the apparatus and a controller operable in response to said sensor for regulating the driving force of said second means.
2. An apparatus in accordance with claim ll wherein said differential comprises a planetary differential gear Set.
3. An apparatus in accordance with claim 1 wherein said differential comprises a bevel type differential gear set.
4. ln an apparatus for the handling of continuous webs wherein said webs are moved through the apparatus by drive rollers and passed to a web take-up station, and wherein additional rollers are provided. between the entry end of said apparatus and said take-up station, the irnpnovement compnising 4drive means for said additional rollers, said drive means including a. main drive gear operatively connected to said additional rollers whereby said rollers rotate in response to said drive gear, first means for imparting driving force to said main drive gear by driving said drive `gear through a connection with said drive rollers, said first means operating directly proportional with the speed of said drive rollers, and second means for imparting further driving force to said drive gear, each of said first and second means imparting force to said drive gear through a differential, and wherein said second means operate to increase the speed of said drive gear beyond the speed imparted by said first means, and including a sensor adapted to sense the speed of said drive rollers for the apparatus and a controller operable in response to said sensor for regulating the driving force of said second means.
i5. An apparatus in accordance with claim i wherein said first means operates to rotate a shaft having said differential tied thereto, said drive gear bein-g operatively connected to said differential and idling on said shaft, said second means including a gear idling on said shaft and operatively connected to said differential.
6. An apparatus in accordance with claim 5 wherein said second means comprises a D C. motor `driving the gear associated therewith, and wherein said shaft is operatively connected to the drive rollers :associated with the drive rollers of said apparatus.
References Cited by the Examiner UNITED STATES PATENTS 1,594,395 8/1926 Weston 74675 2,052,255 8/1936 Shoults 226-188 2,230,715 2/1941 Cockrell 226-31 2,250,209 7/1941 Shoults et al. 226--31 2,529,161 1l/1950 Kelling et al. 226-31 2,583,580 l/1952 Ludwig 226-31 3,179,045 4/1965 Evers 101-181 3,186,273 6/1965 Tomberg 226-31 DAVID I. WILLIAMOWSKY, Primary Examiner. THOMAS C. PERRY, Examiner.