US2658406A - Variable speed feed mechanism - Google Patents

Description

NOV. 10, 1953 l 1 G, MC|| VA|N, JR 2,658,406

VARIABLE SPEED FEED MECHANISM Filed May 4, 1951 2 Sheets-Sheet l kdm NOV. 10, 1953 J, G MolLVAlN, j 2,658,406

VARIABLE SPEED FEED MECHANISM Filed May 4, 1951 2 Sheets-Sheet 2 /J TTOQNEYS Patented Nov. 10, 1953 VARIABLE SPEED FEED MECHANISM John Gibson Mcllvain, Jr., East Caln Township, Chester County, Pa.

Application May 4, 1951, Serial No. 224,598

(Cl. f4-394) 9 Claims. 1

This invention relates to drive mechanisms,

especially intermittenty drive mechanisms, and

still more particularly to feed mechanisms for intermittently feeding a web through a reciprocating press.

One object of the present invention is to generally improve intermittent drive mechanisms. Afmore particular object is to improve mechanisms for intermittently feeding a web at high speed. In a copending application of Frederick Auer, Serial No. 678,612, filed June 22, 1946, now Patent No. 2,548,136 and entitled Feed Mechanism, there is disclosedsuch a mechanism intended to operate in synchronism with machines requiring -a continuously moving web, a common example being the combination of a printing machine with la cutting and scoring press. A slack loop is provided between the machines and the web is kept under positive control by feed wheels which are driven through a cam and roller mechanism which causes the wheels to be accelerated, then rotated -at uniform speed, then decelerated, and then dwell briefly for the cutting operation in the press.

One object of the present invention is to generally improve the aforesaid accelerating feed mechanism. More speciiic objects are to greatly reduce the mass yof the parts which must be accelerated and decelerated. Instead of a large heart-shaped cam it is only a small diameter gear which is subjected to the variable speed drive. A

large cam is still employed to introduce the accelerating and decelerating components, but in accordance with the present improvement this cam is a stationary cam which may be fixedly secured to the frame of the machine. Thus the cam may be made as heavy and strong -as desired, instead of being minimized in mass, and so a sturdier drive is provided. In accordance with other features and objects of the invention, a number of accessory parts previously required are eliminated, and those parts which are employed remain continuously in mesh, thus affording posi- -tive control at all times.

It has been suggested to employ -a planetary drive in whichthe planet gears :are carried by `a spider-which is oscillated-by'linkage driven by a cam. A further object of the present invention is to simplify and improve such an arrangement. More speciccbjects `are to eliminate the ring gear; to `eliminate the need for the oifset cam with 'its special `drive means for rota-ting the same; to eliminate. the .spider and multiple planet gears; and to devise a more compact and simple mechanism providing a more directdrive.

The intermittentfeed wheels may be located at the entrant end of the press, and the web may be drawn by slip Wheels at the discharge end of the press. However, in the -case of webs which are largely scored and cut away this may tend to tear the weband in accordance with a further Vfeature of the invention both ends of the press are provided with intermittently operated feed wheels which exercise positive control `on the web. That, however, requires identical movement of thefeed wheels at both ends, and ithas been found that even a slight difference in backlash or lost motion in gearing or chain drives as, for example, if the feed wheels at one end are driven from the feed wheels atthe other end, is sufficient to tearthe web. The same is true if two supposedly identical accelerating cam mechanisms are provided at the ends of the press.

Afurther objectof the present invention is to help insureidentical rotation of the feed wheels, and with that object in view a symmetrical drive is provided, a` single accelerating mechanism being connected to the feed wheels at both ends of the press by gear trains made up of equal numbers of gears of like type and dimension in order thatth'e rollers may be subjected to the same probable lost motion or backlash.

To` accomplish the foregoing general objects, and such vother objects as may hereinafter appear, my invention resides in the accelerating feed elements and their relation one to another 'as are hereinafter more particularly described in the following specification. The specification is accompanied by drawings in which:

Fig. l is a small view schematically showing "a commonuse for the invention;

Fig. 2 is a side elevation of a press with feed mechanism embodying features of the invention;

Fig. 3 is an end view of the accelerating feed mechanism employedin the press of Fig. 2;

Fig. 4 is a partially sectioned plan view of the same; and

Fig. 5 i-s a partially section front elevation taken approximately in the plane of the line 5-5 `of Fig. 4.

Referring to the drawing-and more particularly to Fig. l, the apparatus comprises a-rst ma- -chine A which operates on a continuously movingweb B, and a second machine C which operates on the same web, with the web moved only intermittently, there being -a slack loop of web D `cetween the two machines. The motor E runs continuously, and drives the machines A and C, the machine C including accelerating feed mechanism to move the web intermittently.

In the present case the machine A is a print, ing press, it being understood that there may be a bank of printing presses for multi-colored printing, instead of a single press as shown, and the machine C is a punch press which may be used for scoring or cutting the web. A typical problem may be to make blanks for milk containers, in which case the web is scored to mark the fold lines and is cut to mark the outlines of the blank.

Referring now to Fig. 2 of the drawing, the punch press C receives the web B as fed to it intermittently by top and bottom feed wheels I2 and I4, these being intermittently driven by speed-up mechanism generally designated S. To maintain registration and to guard against cumulative change in the size of the slack loop of web, compensating mechanism may be provided. Such mechanisms are described in greater detail in the copending application of Frederick Auer, Serial No. 678,612, now Patent No. 2,548,136 previously referred to, and the compensation may take effect either by supplying a corrective movement through differential gearing or, in the alternative, by means of a positive innite variable drive indicated at V in Fig. 1, this being disposed in the drive connection between the machines C and A.

The accelerating or speed-up mechanism S is shown-in greater detail in Figs. 3, 4 and 5 of the drawing, referring to which it will be seen that there is a rotatable input member 20 and a rotatable output member 22 disposed coaxial therewith. A sun gear 24, preferably of small diameter, is disposed on one of Said members, in this case the output member 22, While a planet gear sector 26 is carried by the other member, in this case Vthe input member 20. The planet gear sector 26 meshes with the sun gear 24 and is held against free rotation by means of an arm 28 fixed to the sector. This arm extends outwardly from the sector and may be used to oscillate the same relative to the input member 20.

For this purpose the arm 28 carries a cam follower 30 which is received in a stationary cam track 32, the said cam track extending around the axis of the rotatable members 26 and 22. The cam track 32 is so shaped as to oscillate the sector 26 during each revolution of the same about the axis of the members 20, 22, and this introduces accelerating and decelerating components into the drive from the member 26 to the member 22. In the specific case here illustrated the rotation of the output member 22 may be divided into four periods corresponding to rotation of the input member 20 as follows: acceleration for 108, uniform high velocity for 54, deceleration lfor 108, and dwell for 90. These values are given solely by way of example and are not intended to be in limitation of the invention, for it is evident that one important advantage of the present improvement is that it makes possible great flexibility in the timing cycle which may be provided.

Considering the arrangement in greater detail, in the specic arrangement here shown the input member 20 is a gear of relatively large diameter, the diameter being sufficient to make it possible to pivotally mount the gear sector 26 directly on the member 20, as indicated at 34, and for this purpose the gear may be provided with a boss 36 to increase the bearing surface. The output member 22 is a shaft, and the gear 20 is freely rotatable around the shaft 22, as is indicated in Fig. 3 by the ball bearing 38. The sun gear 24 is fixedly secured to the shaft 22, as by means of a key 40. The mechanism is mounted on the side frame 42 of the machine in such a manner that the relatively large cam 32 may be secured directly against the frame, as is clearly shown in the drawing. In Fig. 3 it will be seen that the sun gear 24 is preferably disposed between the cam 32 and the input gear 20, in which case the arm 28 may be mounted on a pivot projecting in one direction to the gear 20, while the cam roller 30 projects in the opposite direction. This arrangement has the advantage that the radius of the cam track may become less than the radius of the gear 20, as shown near the bottom of Fig. 5.

A most important 4feature of the present invention is that it readily provides a dwell period. Fig. 5 shows the cam roller 30 in the dwell portion of the cam (which in the present case is long). The dwell is obtained by a part of the cam which may be developed by tracing the motion of the cam roller when holding the sun gear 24 stationary while rolling the planet gear about the sun gear.

The present cam is laid out to accelerate the web for one-third the length of a single sheet portion of the web, to feed the web at uniform high speed for one-third the length of the sheet, to decelerate the web for one-third the length of the sheet, and to dwell for a time equivalent to one-third of the total travel time of the web. In degrees, there is acceleration for 108, uniform velocity for 54, deceleration for 108, and dwell for 90. The acceleration for 108 provides the same amount of sheet travel as the uniform high velocity provides in one-half that time or 54.

One might provide a more gradual acceleration and deceleration by eliminating the uniform velocity part of the cycle. Thus one might have acceleration, deceleration, and dwell alone. However, to obtain the desired web travel or sheet length in the same limited time, such an arrangement would require a very high maximum velocity at the top speed between acceleration and deceleration. It is primarily with a view to limiting the necessary maximum web speed that a period of uniform velocity travel is employed between the acceleration and the deceleration. However, the portion of the cycle used for uniform velocity cannot be lengthened too much because the more it is prolonged the sharper becomes the necessary acceleration and deceleration, which again is bad. Thus the cycle here employed is a compromise between a desire, on the one hand, to limit the maximum sheet velocity, and a desire, on the other hand, to provide a gradual acceleration and deceleration.

In some cases it may prove desirable to have a somewhat more gradual acceleration and deceleration, and a somewhat higher uniform velocity to compensate, but that still would retain the idea of a compromise motion, as explained.

In the present mechanism the diameter of the Aplanet gear is twice that of the sun gear. This is done because there is a practical limit to the swing of the cam follower lever. In theory it might be carried to 180, but in practice should not be carried beyond, say and in the present case is much less than that, about '70".

The press is preferably provided with supply feed wheels at one end, and discharge feed wheels at the other end, and they are preferably driven from the accelerating mechanism by gear trains made up of equal numbers of gears of like type and dimension, in order that the supply lthe machine asser/roe .and discharge wheels maybe operatedalikeand :be subjected to-thesamefprobable llost motionor backlash. Thus 1in Figs. .4 Land15 it ,will ;beseen gears 58 and 60. Thesefin turn vdrivespindles .6.2

and 64 (Fig. 4) whichcarry spur gears Staand-53. Referring now to flig. 2 of .thedrawina .theg-spur turnmesh with gears -lll'and `lit-.which turn ,feed wheels of vcorresponding diameter. `These,gea-rs also mesh with gears 1,8 and;80 which turn'. upper feed Wheels of corresponding diameter. It Will thus be seen that the gear 44:trains are made as much alike as .possible with a view to `insuring equal Vand `simultaneous feed movement fat #both endsioi the press, andthus avoid stress or Y.tearing of thevweb even though-*the web is ,weakened by removal of large portions by :the punching action of the press itself.

The punch press'Cshotvndn Figs. 1 and2 Vmay be of conventional construction, it comprising a bolster or platen r82 reciprocated by fourvcorner rods 84 connected Vto links 86 operated byfeccentrics drivenby gears 90. These meshwith gears'92 carried o n ashaft .9.4 Which'also carries pulley B8 whichgreceives `belt it!! .leading :to .the main drive motor E previously referredito. `'One of the gears `il?, oranothergear,carriedrby the shaftgll, mesheswith the intermediateigear 96, which in turn ,meshes with Y the rlarge input v.gear 20 previously lreferred to, as is also lshown in Figs. 3 and 5.

To drive the printing press, `power -is taken from the shaftt94, and through bevelfgearingfof conventional character (notfshown) is led .tothe chain drive H12 shown in Fig. 1, which -runsto the main shaft 04 oftheline vof printingpresses. The positive infinitely variable drive V is interposed when such a drive ,isfdesired foricompensation, as previously mentioned It is believed that theconstructionv and operation of 'my improved `accelerating feed 4mechanism, as well as the advantagesthereof, .will'be apparent vfrom the-foregoing;de tailedidescription. The feed wheelsgrip theweb tightlyat .all;times, and maintain positivefcontrol oftheiveb. 'This istrue at bothl ends ofthe-press, and the-.webmay be acceleratedmoved.at Yhigh speed,;decelerated, and then causedto dwell,all inialmanner which utilizes the available time most efficiently. vThe supplyand discharge wheels 4fareoperated alike, and are subjected to the same ,probable lost motionor-backlash. Aseto the accelerating cam mechanism itse1fthe mass of the. sun gear which must be accelerated and I'decelerated is'vminimiZed. The oscillating gear sectortooisoffcom- -parativelysmall mass, and its movement is over only a comparatively small angle. The .large cam, Whichis the partof greatest massis absolutely stationaryit being boltedtothe-frame. of The input gear 2B whichcarries the gear sector is a fullcircular gearrotated at uniform speed, and `any unbalance introduced by adding the gear sector is Vreadily counterbalanced by the addition of an equivalent weight at Athe opposite side. This ispreferalblydone, although not so shown inthe drawing in order not to unduly complicate the same.

The present mechanism has the `advallltiee that there -is-nc jamming vor lockingpoint. It can even be turned in reverse direction without jamming or locking. Ithas the ,advantagesV of vrrovidir..ig-,unifolfrrl .01 .harmonic acceleration and deceleration lif desired, and of providing ya real .-dwell, and fthe ,length 0f dwell may be made whatever is needed or desired. It has-theladvan- `tage that fthepartsare simple and open so that they ,can-be beefed up asmuch as necessary,

and thus 4,can be subjected to heavy loads.

For example, in the disclosed mechanism two sets of feed rollers are driven from a single cam mechanism, Aand if fdesired, Athree sets or more `could b e so driven. Incidentally, when using two sets, `as `in Fig. 5, it -is not necessary that the shafts pointdiametrically opposite one another, nor `that the shafts be of equal length.

The ability-to beef up the mechanism leads ultimately to a higher speed drive. This is so because the dwell period isusually lfixed by the .needs of the particular mechanism requiring the dwell, `in this casethe punch press.

To increase the overall speed the only thing that can be done is to speed up the motion part of the cycle, and that increases the load on the accelerating mechanism.

It willbe understood that while -I have shown a gear sector for the planet, a fullgear might be employed; and conversely, while I have Vshown la vfull gear for the sun gear, a sector might be employed, particularly so when `using a lower gear ratio, say 1:1, .instead of the ratioof 2:1

.here shown. n general it willproveless expensive and more satisfactory yto employ the full sun gear even though only a `portion of the peripheryis used.

VConfipared to someprior mechanisms, it is not necessary to employ alargering gear, nor to employ multiple planetgears `with a spider, norto employ a ,separate rotatable cam with special drive mechanism for rotating the same. lThe new .drive is simple, requires a minimum number of parts, and is Kdirect, in nature. The new drive is compact in dimension, `for the input and output members have acommonaxis, yet may be dispcsedclosetooneanother in axial direction, for

Vinessence the axial dimension may be reduced to-.mlelythe sumof the thickness of the cam,

the sungear, and the input gear.

It will beiunderstood thattheinvention is not limited to Webfeed mechanism, and may be applied ,to-sheet feed mechanism, and indeed may vbe applied to vother and wholly different mechanisms Wherean intermittent motion is Wanted, For example, `in automatic rmachines employing a turretthe lturret often is turned by a Geneva gearmechanism. Such mechanisms have proved troublesome because of their abrupt acceleration, and theirshort travel time in. contrast withthe vvlong dwell time, which frequently'isfar greater than wanted. The present mechanism `may be employed todrive a turret by simply introducing agear reductionbetween thevsun gear shaft and ,the turret shaft, with a reduction. ratiocorrespending to the number of stations.

Thus the motionfromone station t0 the next isprovided bythe present mechanism, and may be apportioned. as desired `to providegradual acceleration Vand,decelerationand a limited dwell .period no greaterv than needed for the operation to be per- ,formed fat the station. Thismakes the full re- Hxnaining f timev available Yfora rmore, gradual and .therefore more satisfactory acceleration and deceleration.

It vwill be understood that While I have shown and described myvinvention ina preferredl form, changes, may beA made in the structure disclosed, withoutdeparting from ,the ,scope ofthe invention, as sought t be defined in the following claims. In the claims the reference to a sun gear is not intended to exclude the use of a sun gear sector, and the reference to a planet gear sector is not intended to exclude the use of a full planet gear. The quoted terminology is employed simply for easier recognition and consequent clarity.

I claim:

1. An accelerating feed mechanism comprising a rotatable input member, a rotatable output member coaxial therewith, a sun gear on one of said members, a planet gear sector carried by the other member and meshing with the sun gear, an arm extending from said gear sector for oscillating the same, a cam follower carried by said arm, and a stationary cam track receiving said cam follower and surrounding the axis of said rotatable members, said cam track being so shaped as to oscillate the sector during revolution of the same and to thereby introduce accelerating and decelerating components into the drive from one of said members to the other.

2. An accelerating feed mechanism comprising a rotatable input member, a rotatable output member coaxial therewith, a sun gear on the output member, a planet gear sector carried by the input member and meshing with the sun gear, an arm extending outwardly from said gear sector for oscillating the same, a cam follower carried by said arm, and a stationary cam track receiving said cam follower and surrounding the axis of said rotatable members, said cam track being so shaped as to oscillate the sector during revolution of the same and to thereby introduce accelerating and decelerating components into the drive from said input member to said output member.

3. An accelerating feed mechanism comprising a frame, a rotatable input member, a rotatable output member coaxial therewith, a sun gear on the output member, a planet gear sector carried by the input member and meshing with the sun gear, an arm iixedly related to and extending outwardly from said gear sector for oscillating the same, a cam follower carried by said arm on the side remote from the input member, and a stationary cam track receiving said cam follower and surrounding the axis of said rotatable members, said cam track being xedly secured to said frame and so shaped as to oscillate the sector during i'evolution of the same and to thereby introduce accelerating and decelerating components into the drive from said input member to said output member, said sun gear being disposed between said cam and said input member, and said cam being disposed between said sun gear and said frame.

4. An accelerating feed mechanism comprising a frame, a rotatable input member, a rotatable output member coaxial therewith a sun gear on theoutput member, a planet gear sector carried by the input member and meshing with the sun gear, an arm fixedly related to and extending outwardly from said gear sector for oscillating the same, a cam follower carried by said arm on the side remote from the input member, and a stationary cam track receiving said cam follower and surrounding the axis of said rotatable members, said cam track being xedly secured to said frame and being so shaped as to oscillate the sector during revolution of the same and to thereby introduce accelerating and decelerating components into the drive from said input member to said output member, said sun gear being disposed between said cam and said input member, and said cam being disposed between said sun gear and said frame, and said sun gear, said gear sector, and said lever all being disposed in a common plane perpendicular to the axis of the mechanism.

5. An accelerating feed mechanism comprising a frame, a rotatable input member, a rotatable output member coaxial therewith, a sun gear on the output member, a planet gear sector carried by the input member and meshing with the sun gear, an arm nxedly related to and extending outwardly from said gear sector for oscillating the same, a cam follower carried by said arm on the side remote from the input member, and a stationary cam track receiving said cam follower and surrounding the axis of said rotatable members, said cam track being ixedly secured to said frame and being so shaped as to oscillate the sector during revolution of the same and to thereby introduce accelerating and decelerating components into the drive from said input member to said output member, said sun gear being disposed between said cam and said input member, and said cam being disposed between said sun gear and said frame, an output shaft carrying said sun gear, said shaft passing through said input member, and anti-friction bearings between said input member and said output shaft.

6. A drive mechanism comprising a rotatable input member, a rotatable output member coaxial therewith, a sun gear on the output member, a planet gear sector carried by the input member and meshing with the sun gear, an arm fixedly related to and extending outwardly from said gear sector for oscillating the same, a cam follower carried by said arm, and a stationary cam track receiving said cam follower and surrounding the axis of said rotatable memu bers, said cam track being so shape-d as to oscillate the sector during revolution of the same and to thereby convert uniform rotation to nonuniform rotation, a part of said cam track being shaped to eliminate forward motion of the sun gear over a period.

7. A drive mechanism comprising a rotatable input member, a rotatable output member coaxial therewith, a sun gear on the output member, a planet gear sector carried by the input member and meshing with the sun gear, an arm fixedly related to and extending outwardly from said gear sector for oscillating the same, a cam follower carried by said arm, and a stationary cam track receiving said cam follower and surrounding the axis of said rotatable members, said cam track being so shaped as to oscillate the sector during revolution of the same and to thereby convert uniform rotation to non-uniform rotation, a part of said cam track being developed to correspond to the motion of the cam follower when the planet gear sector is rolled about the sun gear while holding the sun gear stationary, thereby providing a dwell period.

8. An accelerating feed mechanism comprising a frame, a rotatable input member, a rotatable output member coaxial therewith, a sun gear on the output member, a planet gear sector car ried by the input member and meshing with the sun gear, an arm fixedly related to and extending outwardly from said gear sector for oscillating the same, a cam follower carried by said arm on the side remote from the input mmber and a Stationary cam track receiving said cam follower and surrounding the axis of said rotatable members, said sun gear being disposed between said cam track and said input member, and said cam track being disposed between said sun gear and said frame, said cam track being xedly secured to said frame and being so shaped as to oscillate the sector during revolution of the same and to thereby convert uniform rotation to non-uniform rotation, a part of said cam track being shaped to eliminate forward motion of the sun gear ovei` a period of time.

9. An accelerating feed mechanism comprising a frame, a rotatable input member, a rotatable output member coaxial therewith, a sun gear on the output member, a planet gear sector carried by the input member and meshing with the sun gear, an arm xedly related to and extending outwardly from said gear sector for oscillating the same, a cam follower carried by said`arm on the side remote from the input member, and a stationary cam track receiving said cam follower and surrounding the axis of said rotatable members, said sun gear being disposed between said 'iii cam track and said input member, and said cam track being disposed between said sun gear and said frame, said cam track being xedly secured to said frame and being so shaped as to cscillate the sector during revolution of the same and to thereby convert uniform rotation to nonuniform rotation, a part of said cam track being developed to correspond to the motion of the cam follower When the planet gear sector is rolled about the sun gear while holding the sun gear stationary, thereby providing a dwell period.

JOHN GIBSON MCILVAIN, JUNIOR.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,080,978 Johnston Dec. 9, 1913 2,253,367 Di Prima Aug. 19, 1941 2,309,595 James Jan. 26, 1943 2,498,036 Grace Feb. 21, 1950 2,536,754 Dudley et al Jan. 2, 1951

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