US2241427A - Controlling of drives - Google Patents

Description

May 13, 1941. A. F. SHIELDS 1,

' CONTROLLING OF DRIVES Filed Sept. 29, 1958 s She ets-S heet 1 NTROL SHAFT DRIVER SHAFT DRIV EN SHAFT IN VENT OR. Cuber? 9- 8/1ields ATTORNEYS May 13, 1941.

A. F, SHIELDS CONTROLLING OFIDRIVES 3 Sheets-Sheet 2 J CONTROL SHAFT 4' l firgzz DRIVEN eHAF-r Dmvsa SHAFT CURVE 0F VAR\ABLE SPEED DRIVE I WITHOUT CAM couram. CURVE OF I ARlABLEZ s asm umve WITH CAM CONTROL. I g I l I J" z. I, ul l a I II 1 O I -L I, x O CURVE OF cum/s ru-zqumeo VARlABLE E-PEED omva 3 FOR spear: OF Kmves WITH CAM CONTROL E AT cuT-rmg INTERVAL v I NUMBER OF TURNS OF CONTRQI- SHAFT-5O NU MBER TufiNfi 0F CONTROL SHAFT-5O F 'l'gt4 INVENTOR. aum'mst, .Slu'eld's BY 6M W 471% ATTORNEY 5 y 1941- v A. F. SHKELDS 2,241,427

CONTROLLING OF DRIVES Filed Sept. 29, 1938 s Sheets-:Sheet s II EIIIIIIIIE 51 1 1 9 INVENTOR. Figs 11117814 shields BYMM, M 1/ 447m ATTORNEYS I Patented May 13, 1941 com-comma or DRIVES Albert F. Shields, Jamaica, N. Y., assignor to S & S Corrugated Paper Machinery Inc., Brooklyn, N. Y., a corporation of New York Application September 29, 1938, Serial No. 232,323

6 (CL ll- 230.17)

My invention relates to novel apparatus for cutting continuously moving sheet material and more particularly relates to novel means for insuring synchronous speed between the moving sheet and the transverse shearing knives during shearing. The present invention is a continuation-in-part of my copending application Serial No. 191,060, filed February 17, 1938, entitled Cutting mechanisms. The invention is described in connection with the apparatus there disclosed.

In the manufacture of corrugated sheets, the material, after it has passed through the corrugating machines, is fed at a continuous predetermined speed through a cutting mechanism which cuts the material at diflferent predetermined lengths. The cutting mechanism usually comprises a pair of knives mounted on individual rotating drums, one drum located above and one drum located below the sheet to be cut so that the knives cyclically engage and cut the sheet material.

The length of sheet cut by the knives depends, of course, upon the time taken for the knives to complete each revolution or cycle. Accordingly, in order to change the lengths of the sheets, the R. P.' M. of the knife drums is changed.

However, during the cutting interval, it is es-- sential that the speed of the knives shall be equal to or substantially in synchronism with the linear movement of the sheet material in order to prevent either bulging of the sheet which would occur if the knives move too slowly, or ripping of the sheet which would occur if the knives move too fast.

Numerous mechanisms have been proposed for securing synchronous movement with the knives in respect to the sheet material for all sizes of sheet material to becut. These have either inmind complicated and expensive gear mechanism such as specially constructed elliptical gears or expensive hydraulic transmission systems which must be carefully controlled both as to temperature and pressure and, must be constantly watched for leakage tendencies result n in ipp n i Eccentric operations employing sliding fmembers which produce eccentric movementshave also been proposed but have the further disadvantage that they have a tendency to wearin the sliding parts and requiring exact'oiling.

In accordance with the invention described in my copending application, I have materially simplified and rendered inexpensive the structure necessary for securing such synchronism by employing the principle of a kinematic or quadric chain having four turning pairs which not only is less expensive and. simpler than either the complex elliptical mechanism or the eccentric sliding principle but is more accurate and more easily adjustable and requires less maintenance. In accordance with my present invention, I incorporate a cam control system for automatically adjusting the ratio of the output speed to the input or constant speed to insure a synchronous velocity ofthe shearing knives during cutting of a continuously moving sheet for various adjustments of sheet length. The invention contemplates a cam control for the Reeves drive whereby the speed ratio thereof is changed in a desired manner to correlate and maintain synchronous cutting action when the speed of the knives is changed for cutting difierent sizes of sheets.

It is accordingly an object of my present invention to provide a novel adjustable sheet length cutting system for insuring synchronous speed of the shearingknives in cutting different lengths from a sheet moving at a continuousspeed.

Another object otmy present inventionis to provide a correlation betweenmechanism for changing the cyclic speed of shearing knives and the driving speed-thereforto insurea-predetermined speed, equalto the continuous sheet speed, of the knives during their, shearing interval. .A further object oi my present invention is to provide a novel speed ratio-adjustment mecha--- nism between the input and output'spee'ds of a Reevesdrive device.;-

'1 These and further objects ;of.;my present invention will become apparent in the; following description taken in connection with :the. draw-i ingsin which: I Figure 1 is adiagrammatic viewinyperspective of the essential elementsyoif-ga continuous sheet cutting n'etai s the synch m ous cu tin pec -ra ojcb ml o Any-pre ent ent inventions invention.

figure sa l ns is t-o eaprefe re ad us able speed mechanism nam l a fflteevesf drive, incorporating the ratiocontrol-oi mypres- I 3 in, illustrating, the synchronous-speed eiiect oi the apparatus of invention;

Figure 5 is anenl preferred embodimentoithespeed ratio control feature of the invention.-'

Figure 6 is they ze d a l'. p a

ertical sealant; vieiv are.

along B-6 of Figure through the speed-ratio control mechanism.

Figures '7, 8 and 9 illustrate the action of the cam control feature as viewed along '|'l of Figure 6, corresponding to different physical positions of the speed ratio control.

In the sheet cutting apparatus of the present invention, particularly adapted for shearing variable lengths of corrugated board in the process of manufacture, the sheet is moved at a substantially constant velocity. In cutting accurate predetermined lengths of the sheet, a pair of coacting knives are situated transversely of the moving sheet. The length of the sheet is'determined by 'the duration of the cutting cycle with respect to the velocity of the moving sheet. One sheet is cut from the moving web per cycle of rotation of the shearing knives. To insure a smooth shear and prevent buckling and tearing at the cutting edge, the knives are made to move at substantially the same or synchronous velocity with the constant speed moving sheet during the shearing interval. In accordance with my copending application referred to above, I employ a quadric chain device which is connected between the output of a Reeves drive and the shearing knives. The principle of the quadric chain mechanism to be described and as described in detail in the copending application is such that the maximum velocity imparted to the shearing knives occurs at a predetermined angular position in the rotation cycle for any given speed thereof and that the maximum velocity is substantially the same regardless of the input speed to the quadric chain. By means of a control element, the maximum cutting speed existing at a predetermined angle for a given velocity is adjusted so that the maximum speed occurs at a predetermined fixed angular position in the apparatus for substantially the whole range of speed adjustments. This predetermined angular position is chosen as the shearing interval for the knives.

when it is desired to change the length of sheet to be cut by the knives, the cyclic speed of the quadric chain cycle, and therefore the knives, is correspondingly varied; fora-shorter sheet it is speeded up, for alonger sheet, slowed down. A control shaft and indicator correspondingly per mits the operation to cause the angular position of the maximum cutting velocity imparted to the knives by the quadric chain to coincide with the shearing interval of the knives. Simultaneously therewith, the speed ratio of the Reeves drive ,is changed whereby the new length of sheet will which carries the roller drum It on which is mounted the knife ll.

The drum It carries at one end thereof a gear l8 meshing with gear l9.which is secured to and drives the knife drum carrying shaft 20 on which is mounted the drum 2| carrying the knife 22. As the drums l6 and 2| rotate in a counter-clockwise and clockwise direction respectively and the corrugated paper 23 coming from the corrugated rolls (not shown) is fed between the drums by the feed rolls 24 and 25, the cutting knives H and 22 cyclically engage and cut the strip material which is being fed forward by the feed rollers 24 and 25 driven through the sprocket and chain mechanism 26, 21 and 28 by the shaft I from the source of power.

Depending upon the period of time for cutting, knife .drums l6 and 2| are placed at a slight angle with respect to the normal transverse to the paper. That is to say, if the cutting is to occur instantaneously, the knives would be substantially at right angles in the direction of travel. If, on the other hand, as is more commonly the practice, a shearing action occurs in which the knives start cutting first at one side and the cutting progresses gradually across the sheet of material, the drums are mounted at an angle with respect to the direction of the travel of the paper depending upon the helical angle of the knife. This angle compensates for the forward movement of the sheet during the cutting period so that the resulting cut is straight across the sheet.

Referring now again to the kinematic chain including the rotating link 9, connecting link II and rotating link l3 (shown in perspective in Figure 1), it will be seen that as the power from the Reeves unit 2 drives the shaft '5 and through it pinion 6 and gear I. the rotation of the shaft 8 causes a rotation of the rotating link 9. As the link 9 rotates it acts as a crank to drive the connecting link I I. Inasmuch as the distance between the pins l0 and I2 is fixed, as the crank mechanism 9 rotates, a corresponding movement of link I I at pin I2 must occur.

This movement of link H at pin l2, in turn, drives the second rotating link l3, rotating the shaft IS. The movement oflink II at pin I2 Referring to Figure 1, the driving shaft l driven from any suitable source of power drives the Reeves" drive 2 through which adjustable speeds are obtained on the output shaft 3 which is connected by a chain belt 4 to the shaft 5 determiningthe fixed center of my mechanism. Secured by any suitable means to the shaft 5 is a pinion 6 meshing with a gear I to which issecured by a keyway a shaft 8 carrying on one end of it the shaft turning link 9. At the opposite end, the turning link 9 rotates on pin 10 and which carries connecting link ll arranged to rotate'with respect to the turning link 9 on the pin Ill. The connecting link It is also rotatably mounted at its opposite end in the pin l2, through which it carries a second rotatable link I3 which in turn is fastened at its opposite end as bya keyway Il to' a knife carrying shaft I5.

and therewith link l3, (produced by the rotation of crank 9 at pin I0), is a rotation about the shaft l5 as a center. Thus the result of this quadric or double crank movement is to produce a rotation of the pin I 0 about the shaft 8' as a center and the rotation of the pin l2 about the shaft I5 as a center.

Inasmuch as the shaft 8 is rotating at a constantspeed-from power supplied by the Reeves drive, the pin ill will also rotate at a constant speed. The actual rotation of pin l0 may be resolved into two components: (1) the component in the direction of the connecting link It and (2) at right angles to this latter direction. It is this latter component which produces the actual momentary velocity of pin. l2.

By this arrangement a constant velocity of link H produces a variable velocity of link l3 during each cycle as is described in detail in my copending application Serial No. 191,060 hereinabove referred to. During each revolution of link l3, there is a time when thelink at a predetermined displacement has a linear velocity synchronous with the movement of the sheet material. This synchronous movement of the driven link I 3 and sheet at a predetermined angular displacement thereof obtains regardless of the speed of rotation of the constant speed driven link 9. The speed of the latter is changed by the Reeves. drive 2 in order to change the period of each cycle of both the driving and driven link so as to change the size of sheet cut. Notwithstanding this change in speed of the driven link l3 however, link |3 will move at synchronous speed with the sheet 23 at a predetermined angular displacement of the link l3, which in turn is fixed as the cutting position at which the knives ||-22 engage the sheet material for cutting.

As fully explained in my copending application referred to, in order to insure that the synchronous speed occurs at a predetermined angular displacement of the driven link, the adjustments of the constant speed link must be made through a predetermined arcuate path. The mechanism for accomplishing this includes the electrically controlled motor 3| which through the worm 32 and worm gear 33 drives the shaft 34 carrying for rotation therewith theworm 35. The worm 35 meshes the gear section 36 which is mounted through the arm 39 on the shaft housing 4|. As the worm gear sector 36 is turned through an angle, it in turn carries the gear 1 and the shaft 8 which is rotated about the center of shaft 5.

The gear section 35 which is attached to the common housings for both shafts 8 and 5, thereby rotates shaft 8 about shaft as a center while maintaining a fixed distance therebetween. This results in a change in the distance between the centers of shafts 8 and 5 and thereby changes the length effect therebetween so that the rate of acceleration and deceleration for each cycle is changed. This feature is fully explained in my co-pending application already referred to.

Carried also on the shaft 34 is a worm 42 meshing with worm gear 43 which rotates shaft 44 on the other end of which is carried an indicator 45. By means of indicator 45 the angular rotation that the motor 3| transfers to the shaft 34, for any predetermined adjustment of the Reeves drive. is made a predetermined rotation so the motor 3| is stopped when the necessary adjustment had been obtained.

I may also secure automatic adjustment of the connecting links for each change in the Reeves drive produced for different lengths of a sheet material. This is accomplished by extending the shaft 34 to shaft 48 by knuckle joint 49, and from shaft 48 to a Worm 45 which meshes with a worm gear 41 driving the shaft 50. Shaft 50 is the control shaft for the Reeves drive 2. The Reeves drive. as is well known in the art, is a mechanism whereby the output speed may be changed for a constant driving input speed by adjusting the pulley ratio for the interconnecting belt between the input and output shafts. In the Reeves drive, conical pulleys are usedso that a continuous speed ratio change can be effected. Control shaft 50 is employed to effect the internal speed ratio change between the driver shaft and driven shaft 3.

The control mechanism extending from the.

control motor 3| interconnecting the sector gear 38 and "Reeves drive speed adjustment shaft 50 is used to correlate changes in the motion of the associated cutting blade mechanism is also correspondingly varied. By properly proportioning the effect of the control shaft upon the relative speed change at shaft 3 of Reeves drive 2, the actual cutting speed of the cutting knives |'|22 may be maintained substantially constant during cutting and equal to the predetermined rate of speed of the sheet 23. An important feature of the present invention resides in the mechanism for proportioning the relative speed ratio between driver shaft and driven shaft 3, the number of control revolutions of shaft 50 serving as a reference. The invention also embraces the concept of automatically varying the speed of operation of the quadric chain mechanism or its equipment for varying the cutting speed cycle of motion so that for different adjustments of the quadric chain mechanism, the maximum speed thereof is maintained at a predetermined constant value.

Figure 2 is a plan view of Reeves drive mechanism 2 with the cover removed. Driver shaft I may be motivated by an independent constant speed source of motive power, for example a synchronous motor or driven by the corrugating machine. The sprocket wheel 28 at one end thereof is connected to the feed roll 24 driving the corrugated or similar sheet 23 as shown in Figure 1. The driven shaft 3 is operated from driver shaft in a normal Reeves drive manner as is familiar to those skilled in the art. The sprocketwheel 4 connected to shaft 3 is connected by sprocket chain 4 to the shaft 5 of the quadric chain mechanism as has already been explained. A pair of coacting conical pulleys 5|-5| is slidably keyed to. the driver shaft I; another pair of conical pulleys 5252, to driven shaft 3. A friction belt 53 interconnects the pulley sets 5| and 52 so that pulleys 5| drive pulleys 52. A pair of arms 54 extend between oppositely positioned pulleys 5| and 52 and serve to alter the speed ratio therebetween in the well known manner. Arms 54 are centrally pivoted between the driving and driven shafts and 3. By changing the angular position of the arms 54 linked to the conical pulleys as shown different relative positions of the pulley sets are effected to correspondingly change the speed ratio therebetween. Dotted positions of the pulleys show the extent of the position variation of the pulleys referred to corresponding to the dotted positions of the arms 54 connecting them. In prior speed changing adjustments for the Reeves drive 2, the control arms 54 were directly connected to the control shaft 50 or its equivalent. In accordance with the present invention I interpose a simple cam or eccentric mechanism which may be readily designed to variably control the movement of the arms 54 with respect to the rotation of control shaft 50 so as to correlate the output speed of driven shaft 3 with the speed required for driving shaft 5 of the quadric chain mechanism for the reasons already explained. A preferred embodiment of the cam mechanism interposed between control shaft 5|! and arms 54 is shown in plan view in Figure 2 by racks 56 secured to the frame 55 and coacting gears 51. The gears 5! connect to a cam or eccentric device which directly actuates arms 54 in a manner to be described in detail.

In order to further clarify the purpose and I effect of the cam or eccentric mechanism, reference is made to the curves of Figures 3 and 4. The solid curve of Figure 3.represents the usual relation between the output speed of the driven shaft 3 with respect to the number of turns made by control shaft 50 of the usual Reeves drive arrangement. The dotted curve of Figure 3 shows the resultant speed characteristic of the driven shaft with respect to the same reference of turns of control shaft 50. In Figure 4, the same dotted curve of Figure 3 is-reproduced indicating the speed characteristic employing the cam or eccentric control device of the present invention. The solid curve in Figure 4 indicates the theoretical optimum characteristic required for the knives (l1-2l)' at the cutting interval. It is to be noted that the simplified cam control mechanism of the present invention is practically identical with the theoretically required speed characteristic and for all practical purposes is the equivalent thereto over the Wide range of operation of the apparatus. Whereas the cam control characteristic has been reproduced in ac cordance with the simple eccentric cam device to be described, it is to be understood that even greater refinement is feasible in accordance with the principle of the present invention bymere changes in the design of the control cam to be described.

Figure 5 is an enlarged detail view of the cam or eccentric control mechanism corresponding to a section of Figure '2. A portion of gear 51 is broken away to show its relation to the eccentric cam 58 connected thereto. Rack 56 is secured to the top of frame 55 as already explained. Its

position is adjustable by means of set screws 5959 positioned at opposite ends thereof of the rack 56. Bolts 60 positioned at corresponding slots in the rack 56 permit the longitudinal adjustment thereof as is evident.

Figure 6 is a vertical cross-sectional view taken along 66 of Figure 5. A nut 6| is internally threaded to coact with a correspondingly threadedportion 50' of the control shaft 50. Rotation of control shaft 50 accordingly motivates nut 6| axially of shaft 50 in a direction determined by the sense of rotation of the shaft. At opposite .ends of the elongated nut 6| projects studs 62. Gears 51 are rotatably'mounted on studs 62. A cam 58 is bolted to each of gears 51 in order to rotate therewith. The cams 58 are properly arranged to rotate about studs 62 in the same manner as gears 51. A washer 63 and bolt 64 is individual to each stud 62 to maintain the gear 51 and cam 58 arrangement rotatably positioned at both ends of nut 5 l A fork 65 is formed in the end of each arm 54. The inner edges of fork 55 are arranged to be and otherwise coact with the periphery of cam 58. Figure 7 is a cross-sectional view taken along 1--1 of Figure 6 and shows the coaction of arm 54 with cam 58. Cam 58 has been chosen as a circular disk eccentrically mounted upon stud 62. Figures 8 and 9 are similar to Figure '1. but show the angular position of cam 58 differently. Accordingly it will now be evident that by changing the angular position of cam 58, a corresponding change in theposition of the coacting arms 54 is effected. An eccentric circular cam is preferably used whenever the design features of the quadric chain or equivalent mechanism permits,

since it is the cheapest and most foolproof shape for such a cam. It is to be understood, however, that the invention is not limited to the particular circular shape illustrated, but any other shape of cam may be substituted to produce a substantial coincidence of the resultant speed characteristic and the required speed characteristic for the 'chanical reasons.

quadric chain or equivalent control mechanism as exemplified by Figure 4.

The operation of the cam speed control feature embodied in the present invention is asfollows: The rotation of control shaft 50 by means of control sprocket wheel 41 causes an axial movement of nut 6| due to the threaded coaction thereof with threads 50'. As seen in Figure 2, two similar control mechanisms are located at both sides of the conical disks corresponding to each side of the pivoted arms 54'. As is further evident from Figure 6, each top arm 54 has a corresponding arm 54 located underneath. A system of four lever arms 54 is accordingly used to control the axial and ratio variation of the Reeves drive in a preferred standard arrangement. The invention, of course, is applicable to any number of control levers used, the four arm arrangement being preferably for balancing and other me- A rod 51 rigidly interconnects the nut 6| of each set of arms with the block 66 to prevent turning of the nut and excess pressure therein in its axial movement along the control shaft 50 as is evident to those skilled in the art. Control shaft 50 contains two sets of thread portions, namely 50 and 50" as shown in Figure 2 in order that opposite sets of arms 54 shown therein acts correspondingly towards and away fromthe central axis of the belt 53 to insure properspeed changing and symmetrical positioning of the conical disks.

As nut 6| is moved axially of control shaft50,

gears 51 are carried therewith. A relative movement between gears 51 and fixed racks 56 takes place, causing a rotation of the gear 51 about the stud 62. Rotation of the gear 51 causes the earns 58 to rotate likewise. 58 causes the pairs of arms 54 to change their angular position and thereby change the speed ratio between the constant speed driver shaft I and driven shaft 3.

Although I have described a preferred form for carrying out my present invention, it is to be understood that modifications are feasible without departing from the broader spirit and scope of the present invention. The eccentric cam control in conjunction with the standard Reeves" drive apparatus is used to form a predetermined correlation between the cutting speed of the knives through appropriate cyclically variable driver mechanism therefor. The particular cam shapes and arrangements shown are to be considered as illustrative of the invention. Accordingly, I do not intend to be limited except as set forth by the following claims.

I claim:

1. Means for controlling the speed ratio between a driving and driven member comprising mechanism for changing the speed ratio between said driving and driven members; a control shaft; an element movable by said control shaft; a cam mounted on said element coacting with said mechanism for controlling the speed ratio changing efiect thereof; and means for rotatingsaid cam in response to a movement of said control shaft to control the speed ratio 'between said driving and driven members in a predetermined manner with respect to the operation of said control shaft.

2. Means for controlling the speed ratio between a driving and driven member comprising mechanism for changing the speed ratio between said driving and driven members; a control shaft; an element movable by said control shaft; a cam rotatably mounted on said element coacting with v The rotation of the cam said mechanism for controlling the speed ratio changing effect thereof; and means for operating said cam in response to a movement of said control shaft including a gear secured to said cam whereby a relative displacement of said element and said shaft causes a rotation of said gear and cam to control the speed ratio between said driving and driven members in a predetermined manner with respect to the operation of said control shaft.

3. Means for controlling the speed ratio between a driving and driven member comprising mechanism for changing the ratio between said driving and driven members including a lever; a rotatable control shaft having a threaded section; an element movable by said control shaft; a cam mounted on said element coacting with said lever; and means for rotating said cam in response to a rotation of said control shaft to control the speed ratio between said driving and driven members in a predeterminedmanner with respect to the operation of said control shaft.

4. Means for controlling the speed ratio between a driving and driven member comprising mechanism for changing the speed'ratio between said driving and driven members including a lever; a rotatable control shaft having a threaded section; an element having a threaded portion for coacting with said threaded shaft section; a cam mounted on said element coacting wtih said lever; and'means for operating said cam in response to a rotation of said control shaft including a gear secured to said cam whereby a relative displacement of said element and said shaft causes a rotation of said gear and .cam to control the movement of said lever to effect a predetermined speed ratio change between said driving and driven members.

5. Means for controlling the speed ratio between a driving and driven member comprising mechanism for changing the speed ratio between said driving and driven members including a lever; a rotatable control shaft having a threaded section; an element having a threaded portion for coacting with said threaded shaft section; a cam rotatably mounted on said element coacting with an end of said lever; and means for operating said cam in response to a rotation of said control shaft including a gear rotatably mounted on said 'element and secured to said cam, and a rack meshing with said gear whereby a relative displacement of said element and said shaft causes a rotation of said gear and cam to control the movement of said lever to effect a predetermined speed ratio change between said driving and driven members.

4 6. Means for controlling the speed ratio between a driving and driven member comprising mechanism for changing the speed ratio between said driving and driven members including a lever; a rotatable control shaft having a threaded section; an element having a threaded portion for coacting with said threaded shaft section; a cam rotatably mounted on said element coacting with said mechanism for controlling the speed ratio changing effect thereof; and means for operating said cam in response to a rotation of said control shaft including a gear secured to said cam, and a fixed rack meshing with said gear whereby a relative displacement of said element and said shaft causes a rotation of said gear and cam to control the movement of said lever to effect a predetermined speed ratio change between said driving and driven members.

ALBERT F. SHIELDS.

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