USRE19989E

USRE19989E - swift

Info

Publication number: USRE19989E
Authority: US
Publication date: 1936-05-26

Description

May 26, 1936.

G. w. SWIFT, JR

VARIABLE SPEED CUTTING MECHANISM Original Filed Jan. -5, 1953 5 Sheets-Sheet 1 W| 52 (58$. 'HH "ll" 76 I May 26, 1936. G. w. SWIFT. JR

VARIABLE SPEED CUTTING MECHANISM Original Filed Jan.

INVENTOR- G. W. SWIFT JR VARIABLE SPEED CUTTING MECHANISM May 26, 1936.

5 Sheets-Sheet 3 Original Filed Jan; 3, 1953 y 1935- G. w. swlFT'. JR Re. 19,989

VARIQBLE SPEED CUTTING MECHANISM Original Filed Jan. 3, 19,53 5 Sheets-Sheet 4 1% A WWW May 26, 1936.

G w. SWIFT. JR

VARIABLE SPEED CUTTING MECHANISM Original Filed Jan. '5, 1953 5 Sheets-Sheet 5 BY I km Reissued May 26, 1936 PATENT oer-ice; I

VARIABLE srnsn CUTTING MECHANISM George w. Swift, Jr., Bordentown, N. J., assignor to George W. Swift, Jr., Inc., Bordentown, N. J

a corporation of New Jersey Original No. 1,997,608, dated April 16, 1935, Serial No. 649,872, January 3, 1933.

Application for reissue March 12,1936, Serial No. 68,551

17 Claims.

This invention relates more especially to that type of variable speed cutting mechanism in which cooperating cutter blades are caused to revolve continuously about spaced axes and into and out of cutting position with respect to a continuously moving web from which, during any particular run off, successive portions or sections of uniform length are to be severed. In machines of this character and type, when the machine has completed its output of sections of a particular length and it is desired to prepare the machine for an output of sections of a different length, it is usual to maintain the speed of the web constant while changing the frequency or periodicity of the cutting operations and this has led to the necessity of incorporating some device for accelerating or decelerating the linear cutting speed of the blades for the purpose of making the cutter blades travel at the same speed as the web during each cutting action.v According to the present invention, an improved construction and arrangement of parts are provided in mechanism of this character for making the peripheral speeds of the cutter blades momentarily equal to the speed of the web at each shearing operation for any "desired frequency or periodicity in the cutting operation, while at the same time making the cutting speed of the revolving cutter blades momentarily correspond to the velocity of the web while the cut is proceeding. More especiallyjthe present invention contemplates an adaptation of this device to -a duplex or multiplex cutting operation on a plurality of webs moving continuously forward at the same constant velocity and particularly in connection with the contemporaneous cutting of uniform lengths from each of the laterally parted sections formed by the longitudinal slitting of a continuous web of corrugated board. In an operation of this kind, it is of great importance to avoid excess bending of the composite board coming directly from a corrugated board machine, for the reason that the paper has not become perfectly dry, nor has the silicate of soda (which is usually employed for an adhesive) be come completely cured. To avoid these drawbacks, the present invention contemplates an improved construction, arrangement and automatic regulation of a plurality of pairs of cooperating cutter blades which operate on the laterally parted sections of the corrugated board wilho'ut unduly bending the partially dried product which would otherwise cause d stortion and a pulling away of the 'layers- Material of the above character is sometimes referred to hereinafter as slightly bendable material and the machine of the present invention is especially constructed and arranged to enable material of such character to be operated upon without undue bending. I

In the drawings which represent a preferred embodiment of my invention,

'to the line 4-4 of Figure 3.

Figure 5 is a side elevation of the machine with the differential mechanism shown in section.

Figure 6 is a fragmentary horizontal section on the line 6-45 of Figure 5.

Figure 7 is a fragmentary vertical section on the line I--1 of Figure 5.

Figure 8 is an enlarged vertical transverse section of the differential mechanism and continuous driving connections with the cutter blades shown in elevation in their relative positions during the cutting operation, parts being broken away.

Figures 9 and 10 are transverse detail sections of the cutter blades in cooperating cutting position with the elliptical gears'shown in elevation in corresponding positions under-different speed ratios for forming sections of different lengths.

Referring more especially to Figures 1 and 2 of k the drawings, the main frame of the machine I comprises a bed frame A and laterally spaced side frames B and C. Journalled in the side frames B and C as shown best in Figure 2 of the drawings, is a main drive shaft I which may be prov vided onits outerg end with a pulley 2 by means of which power may be delivered thereto. The

main drive shaft carries axially spaced

pinionsy

3, 3, which drive spur gears l, 4, on a transverse shaft 5, said spur gears 4, A, being arranged to transmit power to spur gears 5, 8, which are keyed to axially spaced shafts 1, I, said shafts I, I, be-

. ing the constant speed shafts of laterally-spaced variable speed transmission mechanisms which are arranged to drive two variable speed cutting mechanisms, said cutting mechanisms being op erable simultaneously for operating on two different continuously moving webs. As the construction and operation of the variable speed cutting mechanisms are substantially similar, a description of one will serve for both. The constant shaft i may be connected to the variable speed shaft 8 of the variable speed drive by means of an endless belt 9, of V-shaped cross-section which operates between two pairs of axially adjustable cone disks |0"-| ll and which are splined to the constantand variable speed shafts respectively. It will be understood from this description that the cone disks of each shaft may be adjusted toward and away from each other in conjunction with the corresponding cone disks on the other shaft for changing the velocity ratios at which power is transmitted. As shown best in Figure 2 of the drawings, the variable speed shaft of the Reeves drive carries a pinion l2 which meshes with the larger spur gear l3 of a compound gear, the smaller spur gear M of said compound gear being in mesh with a large spur gear l5 which is, keyed to a short shaft l6 said shaft I6 journalled in an out-rigger frame H which is spaced from the side frame B. Keyed to the shaft I6 on the outside of out-rigger frame 11 is a lower elliptical gear |9which meshes with an upper elliptical gear l9; As shown in Figure 8 of the drawings, the upper elliptical gear I9 is keyed to a tubular differential shaft 29 which is journalled on one end of a lower cutter shaft 2| and within a bearing 22 in the out-rigger frame l1. On its inner end, the tubular differential shaft 29 is providedwith an integrally formed plate or disk 23 which forms one side of a rotary cage or differential housing which rotates about the axis of the lower cutter shaft 2| with an annular channeled frame 24 .which is bolted to the inner side of out-rigger frame l1. The other side 25 of the rotary cage is journalled upon the hub of a spur gear 23 which is keyed to the lower cutter shaft 2|. Journalled in the rotary cage, are a plurality of compound planetary gears each of said planetary gears comprisinga larger spur gear 21 and a smaller spur pinion 28. The spur pinions 28 mesh with the spur gear 26 on the lower cutter shaft while the spur gears 21 mesh with and travel around an annular track gear 29 which is rotatably adjustable in the channeled frame 24 and carries an outwardly presented worm gear 39 for its adjustment in the manner hereinafter described. Journalled in the side frames 13 and C are lower and upper drums 3| and 32 which are geared together to rotate in unison by means of

spur gears

33, 33, and 34, 34, said

spur gears

33,33, being keyed to the lower cutter shaft 2|. Mounted on the drums 3| and 32, are lower and upper

helical cutter blades

35 and 36 which are thus adapted to be revolved about the spaced axes of the upper and lower cutter shafts. By means of the coordinating adjustment connections to be presently described, the lengths of the successive sections cut from the composite board may be varied at will by changing the periodicities of the cutting operation of the upper and lower cutter blades operating thereon, while at the same time, the cutting speeds of the upper and lower cutter blades may i be automatically modified to conform to the linear speed of the web by varying the setting of the cutter blades with respect to the elliptical gears.

Referring now to Figures 3 and 4 of the drawings, suitable means for adjusting the variable speed drive for varying the periodicity of the cutting operation and changing the lengths of the severed sections, may be provided as follows: Journalled in a standard 31, is a short shaft 38 to one end of which is keyed a double lobed cam 38a. In rolling contact with each lobe of said cam 38a is a cam roller 39 whichis journalled on a pin 40 which projects laterally from a cam 33a are pivotally connected at Ma to the laterally spaced adjustment levers 4| of-theReeves drive. Keyed to the outer end of the shaft 39, is a worm wheel 42 which is rotatable by a worm 43 keyed to the inner end of a shaft 44 which extends outwardly'through the side frame C and beyond a second out-rigger frame 45. Keyed to 'the outer end of the adjustment shaft 44 is a spur gear 52 which carries a graduated dial plate 53, the amount of the angular movement of said dial plate in either direction being measured by a fixed pointer arm 54. Keyed to the shaft 44 is a sprocket wheel 55 which is connected by an endless chain 56 to an upper sprocket wheel 51 keyed to a cross shaft 58. The shaft 58 is connected by bevelled pinions 59 to the upper end of a vertical shaft 60 which carries a worm BI and this worm meshes with the worm gear 39 which forms an integral portion of the internal gear 29 for adjusting the differential housing. It will be understood from this description that whenever the adjustment shaft is moved to impart a certain predetermined setting of the differential drive, this adjustment will be accompanied by the corresponding movement of the differential housing and thereby cause the planetary gears to rotate the lower cutter shaft and thus advances or retreats the upper and lower cutter blades relatively to the 'intermeshing elliptical gears. The result of this adjustment will be to vary the velocity of said blades during the cutting operation toconform to the speed of the web.

Referring again to Figures 1 and 2, my invention also contemplates a second variable speed cutting mechanism which is substantially similar in construction and arrangement to that already described. This second cutting mechanism with its variable speed drive and operating connections including variable ratio gearing and differential mechanism has been constructionally indicated on these figures of the drawings. Thus a variable speed drive 62 delivers power to a second pair of upper and

lower cutter shafts

88 and 89 through a chain ofgears comprising spur gear. 63,

compound gear

64, 35, idler 66, spur gear 61 cutter shafts, respectively. Said differentialgearing which is similar in construction to that already described in connection with the first cutting mechanism, is interposed between the driven elliptical gear 10 and the spur gear 1| and is adapted to function in the same way as the differential gearing through which the first cutting mechanism is driven. The preferred construction. shown on the drawings contemplates in the upper cutter mechanism a lower cutter blade which revolves twice for each revolution of the'u'pper cutter blade and in the lower cutter mechanism an upper cutter blade which revolves twice for each revolution of the lower cutter blade, For this purpose, the pitch diameter of the spur gears 34, 34, of the upper cutter mechanism is made twice that of "the spur gears 33, 33, the same ratio being provided for between the

gears

89, 89,

block 399.. The oppositely arranged cam blocks ings.

of the lower cutter mechanism and the gears 88, 38. At the same time, it is further preferred to same size for each cutting mechanism, each of said elliptical gears being provided with amaximum radius twice as large as its minimum radius so that the variation in the speed ratio transmission during a single complete revolution of each pair of these gears, produces'a maximum speed which is four times that of the minimum speed. Thus as shown in Figure 9 of the drawings, the elliptical gears are disposed to provide a two to one speed ratio in the transmission of power as the cutter blades come into opposition, whereas after 180 degrees of revolution, the speed ratio will become one to two. A speed ratio of one-to one is indicated in Figure 10 of the draw- Itwill be understood thereforethat with web traveling at uniform velocity past the cutter blades, the cutting speeds of the cutter blades may be variedto cut a section say 60 inches long with the arrangement shown in Figure 10; or a section 120 inches long by the arrangement shown a ,in Figure 9; or a section 30 inches long by bringing the cutter blades into conjunction when the smallest radius of the lower elliptical gear drives on the largest radius of the upper elliptical gear.

The above described cutter mechanisms arelocated one slightly above the other so that, as indicated in Fig. 3, the sectional webs of a slitted web may be fed, within the small permissible limits of bending, from a common plane to the cut-' ter mechanisms which operate respectively on the sectional webs. The two cutter mechanisms moreover are adjacently mounted as indicatedin ccreby the cut material delivered from both mechanisms passes to zones beyond both cutter mechanisms. Thus the floor space occupied the machine is markedly reduced in respect to what may be called its delivery zone,

since the blanks from the upper cutter mecha nism pass out to the space beyond the lower cutting mechanism, with the result that the two cutting mechanisms do not have to be spaced apart to afford room for blanks (which frequently are quite long) to be received between them. The

machine also afiords relatively short paths of travel for both sectional webs in passing from a. common plane to both cutter mechanisms. As

indicated in Figure l of the drawings, the second cutter mechanism is preferably arranged with the shorter radius cutter blade 11 arranged above I the longer radius cutter blade I8. This arrangement is of peculiar importance when employed for the simultaneous cutting of a plurality of webs formed by the lengthwise slitting of corrugated board coming directly from a. corrugated board machine. Thus in a machine of this character, the paper has not become perfectly dry nor has the silicate of soda, which is used as the adhesive, becomecompletely cured. In consequence, excessive bending of the composite board may cause distortion of the product and a pulling away of the layers. To avoid this drawback, the present arrangement of two pairs of cutters of unequal radii with the smaller cutting radius of the upper pair arranged belowand the small cutting radius of the lower pair arranged above, permits the cutting operations to be carried on without excessive bending of the incompletely dried board. Thus, as shown in Figures 1 and 3 of the drawings, as the webs and 9! (resulting from the previous longitudinal slitting of a continuous strip of corrugated board coming from a corrugated board machine) emerge from between the feed-rolls 15 employ two intermeshing elliptical gears of the and 15, they move at divergent angles from a common horizontal plane over feed board 14a and Bla to the upper and lower pairs of trans verse cutter blades 35, 3B, and l1, 18, respectively. By an inspection of Figure-3 of the drawings, it will be understood that by delivering the longitudinally parted sections or webs to the upper and lower pairs of cutter blades in divergent planes which deviate equally above and below their common horizontal plane of movement prior to their emergence from between the feed rolls 15,

$16, and by placing the cutter blade of each pair which has the smaller orbit of movement between said divergent planes at different distances from the feed rolls I and 16 and one behind the other in respect thereto, the amount of bending to which each web is subjected can be. reduced to such an extent as to obviate undue strain upon the undried adhesive or pulling away of the joined layers which form the corrugated board and prevent undesirable distortion of the product. As a result, the successive portions cut from the continuous webs I4 and 9| by the upper and lower pairs of-cutter blades, will be delivered in good condition over the ,upper and lower delivery feed rolls 80 and 90 respectively. i

It will be seen from theforegoing description that my present invention enables a' duplex cut-' ting operation to be carried on by one and the same machine in such a way that two 'webs (preferably derived from the longitudinally slitted continuous web coming from a corrugated board machine) may be fed at the same linear speed to different pairs of cutter blades which are constructed and arranged to operate thereon atthe same or different periodicities. By this means, the successive sections cut from one continuous web may be the same as or differentfrom those out from the other continuous web in respect to length and breadth of the resulting sheets produced thereby. Due to the above-described construction, arrangement and duplex operation of a machine of this character, a great saving in time, labor, and material may be had.

As a detail of construction, it maybe noted that a suitable rotary adjustment of the upper and lower cutter blades-about their axes, is provided as follows. The upper cutter blade drum is journalled in bearings 8|. Keyed to the journalled ends 82 of said drum is a circular flange 83 which-are integrally formed with and presented laterally from the flange 83, are two set screws 81 which impinge upon the stud or lug 86 for securing a limited movement of the upper cutter drum about its axis and a circular adjustment of the upper cutter blade with respect to the lower cutter blade. As shown in Figures 2 and 3 of the drawings, the cross shaft 5 may be connected by a horizontal sprocket chain 18a and a vertical sprocket chain 19 to the, delivery roll 80. i

As has been explained above, the cutting speed adjustment of the continuously revolving cutter blades is preferably under the control of the device for adjusting the speed ratio of the Reeves variable speed drive which transmits power to the cutting mechanism through the elliptical gears and differential mechanism. It will be In this event the upper adjustment hand-wheel 58a which is rigidly secured to the shaft 58, may be employed solely for adjusting the differential mechanism for bringing the cutting speed into conformity with the speed of the web. The

amount of this adjustment may be indicated by a dial and pointer (not shown on the drawings) similar to that described drive adjustment.

I claim:

1.. In a machine of the character described for above for the Reeves simultaneously operating upon the sections'of an advancing slitted web 'of slightly bendable material, the combination of two pairs of cooperating cutter blades, each pair oi said cutter blades being constructed to operate with a different periodicity in the cutting operation than that with which the other pair of said cutter blades operate, means for drivingeach pair of said cutter blades at yariable velocity in each 5 cycleoi their movements, and means for variably timing the cutting operation of said cutter blades within each cycle of their movements for operating both pairs'oi cutterblades at the same cutting speed, said pairs of cutter blades being arranged to sever sections of diflerent uniform lengths from each of two sectional webs moving at the same velocity past said pairs of cutter blades respectively, one-of said pairs of cutter blades being positioned to operate at a level slightly above the other pair, whereby the sectional webs of a slitted web may be fed, within small limits of bending, from a common plane to the respectivepairs of blades, said pairs of blades being adjacently mounted, whereby the cut material delivered from both pairs of blades passes into zones which are beyond both pairs of blades.

2. A machine of the character claimed in claim 1, in which said pairs of cutter blades are arranged to operate in planes divergent from and on opposite sides of a common plane in which said webs move prior to the cutting operations, the orbital paths-of the cutter blades which operate between the divergent cutting planes being disposed at difierent distances from a common line of intersection of said divergent planes with said common plane. d 3. In a machine of the character described for simultaneously operating upon the sections of an advancing slitted web of slightly bendable material, the combination of two pairs of cooperating cutter blades, each pair of said cutter blades'being constructed and arranged to operate upona web moving in a different plane of movement than the web operated upon by the other pair of said cutter blades, means for feeding said sectional webs at'the same velocity in different planes oi movement past the cutting positions of the respectivepairs of cutter blades from a plane of movement common to said webs prior to the cutting operations, a variable speed drive for varying the periodicity of the cutting operations of one pair of cutter blades with respect to the other pair of cutter blades, and operating connections between said variable speed drive and the cutter blades driven thereby, said operating connections including variable ratio gearing and difierential mechanism for oper- 'ating the last mentioned cutter blades at diflerent periodicities with a cutting speed equal to the velocity of said webs, one of said pairs of cutter biades being positioned to operate at a level slightly above the other pair, whereby the sectional webs of a slitted web may be fed, within small limits of bending, from a common plane to the respective pairs of blades, said pairs of blades being adjacently mounted, whereby the cut material delivered from both pairs of blades passes into zones which are beyond both pairs of blades.

4. In "a machine of the character described for simultaneously operating upon the sections of an advancing slitted web of slightly bendable material, the combination of two .pairs of cooperating cutter blades, said pairs of cutter blades being constructed and arranged to operate upon webs moving continuously at the same uniform velocity, and means for feeding said sectional webs at the same constant speed in diflerent planes of movement past the cutting positions of the respective pairs of cutter blades, a variable speed drive for each of said pairs of cutter blades whereby the periodicity of the cutting. operations of each pair of cutter blades may be varied in respect to'the other, and operating connections between each variable'speed drive and the cutter blades to which it is connected, said operating-- connections including'variable ratio gearing for varying the velccity of the cutting blades during each cycle of operations and difierential mechanism interposed between said variable ratio gearing and said cutter blades whereby the 'cutter' blades may be advanced or retreated relatively to said variable ratio gearing for maintaining the cutting speeds of bothpairs of cutter blades equal to the common speed of said webs and constant for all 'periodicities in thecutting operations of both pairs of cutter blades, one of said pairs of cutter blades being positioned to operate at a level slightly above'the other pair, whereby the sectional webs of a slitted web may be fed, within small limits of bending, from a common plane to the respective pairs of blades, said pairs of blades being adjacently mounted, whereby the cut -material delivered from both pairs of blades passes into zones which are be.- yond both pairs of blades.

5. A machine of the character claimed in claim 4, in which the variable speed drive for eachpair of cutter blades comprises positively con-- nected constant speed and variable speed shafts and in which said constant speed shafts for both variable speed drives are driven by the same power shaft. v i

6. A machine of the character claimed in claim 1, in which two pairs of cutter blades are constructedand arranged to operate upon webs moving in different planes of movement having equal of two cutter shafts geared together to rotate in unison, a sun gear keyed to one of said cutter shafts, a circular rack gear coaxially arranged I with respect to said cutter shaft and rotatable relatively thereto, planetary gearing interm esh-v ing between said circular rack gear and said sun gear, means, for revolving said planetary gearing about the axis of said shaft, saidmeans including variable ratio gearing for varying the velocity of the cutter shafts during each rotation and a variable speed drive for varying the periodicity of the cutting operations, and means for adjusting said circular rack for maintaining the velocity of said cutter shafts constant for different periodicities in the cutting operation.

8. In web cutting mechanism, the combination of two cutter shafts geared together to rotate in unison, a sun gear keyed to one of said cutter shafts, a circular rack gear coaxially arranged with respect to said cutter shaft and rotatable relatively thereto, planetary gearing revolvable about the axis of said cutter shaft, said planetary gearing intermeshing between said sun gear and said circular rack, a power train for revolving said planetary gearing, said power train including intermeshing elliptic gears, and a variable speed drive provided with an adjustment control connected up with said circular rack gear.

9. In web cutting mechanism, the combination of two cutter shafts geared together to rotate in unison, a sun gear keyed to'one of said cutter shafts, a sleeve 'journalled on said shaft and axially spaced from said sun gear, a circular rack gear coaxially'arranged with respect to said cutter shaft and rotatable relatively thereto, planetary gearing interengaging between said sun gear and said circular rack gear and driven by said sleeve, an elliptic gear keyed to said sleeve, a second elliptic gear meshing with the first-mentioned elliptic gear, and a variable speed drive operably connected to the second-mentioned elliptic gear. g

10. In web cutting mechanism, the combination of two cutter shafts geared together to rotate in unison, a sun gear keyed to one of said cutter shafts, a sleeve journalled on said shaft and axially spaced from said sun gear, a circular rack gear coaxially arranged with respect to said cutter shaft and rotatable relatively thereto, a planetary gearing support rotatable about the axis of said cutter shaft and relatively to said sun gear, a compound gear journalled in said planetary gearing support on an axis revolvable about the axis of said shaft, said compound gear comprising gears respectively meshing with said circular rack gear and said sun gear, an elliptic gear keyed to said sleeve, a second elliptic gear meshing with the first-mentioned elliptic gear, and variable speed power-transmitting mechanism connected to the second-mentioned elliptic gear.

11. In web cutting mechanism, the combination of two cutter shafts geared together to rotate in unison, a fixed annular housing concentrically arranged with respect to one of said cutter shafts, said fixed annular housing being provided with an inwardly presented peripheral slot, a circular rack gear rotatably mounted in said peripheral slot and coaxially arranged with respect to said cutter shaft, means for rotating said circular rack relatively to said cutter shaft, a'sun gear keyed to said cutter shaft, planetary gearing intermeshing between said circular rack and said sun gear and revolvable about said sun gear, and means including variable ratio gearing for revolving said planetary gearing.

12. In web cutting mechanism, the combination of two cutter shafts geared together to rotate in unison, cutter blades mounted on said cutter shafts respectively, a differential housing rotatable about the axis of one of said cutter shafts, said differential housing being provided with a peripheral slot, means including variable ratio gearing for rotating said differential housing, a circular rack gear slidably mounted in said peripheral slot and coaxiallyarranged with respect to said cutter shaft, means forrotating said circular rack gear in said peripheral slot and relatively to the cutter shaft with which it is concentric, a sun gear keyed to said cutter shaft. within said differential housing, and a compound gear journalled in the lateral walls of said differential housing, said compound gear comprising gears respectively meshing with said circular rack gear and said sun gear.

13. In web cutting mechanism, the combination of two cutter shafts geared together to rotate in unison, cutter blades mounted on said cutter shafts respectively, a differential housing rotatable about the axis of one of said cutter shafts, said differential housing being provided with a peripheral slot, a fixed annular housing concen-- trically arranged with respect to said cutter and provided with an inwardly presented peripheral slot in register with said peripheral slot in the train including variable ratio gearing connected to said differential housing.

l4.-I n a machine of the'character described for simultaneously operating upon the sections of an advancing slitted web'of slightly bendable material, the combination of two pairs of cooperating cutter blades arranged to operate on webs moving at the same velocity past the respective pairs of said cutter blades, one pair of said cutter blades being constructed to operate with a variable periodicity in the cutting operation with respect to the other Dair'of said cutter blades, and operating connections for varying the cutting speed of the said one pair of cutter blades during each cycle of ,their movements whereby both pairs of cutter blades may be operated at' the same cutting speed, one of said pairs of cutter blades being positioned. to operate at a level slightly above the other pair, whereby the sectionalwebs of a slitted web may be fed, within small limits of bending, from a common plane to the respective pairs of blades, said pairs of blades being adjacen'tly mounted, whereby the cut material delivered from both pairs of blades passes into zoneswhich are beyond both pairs of blades.

' 15. In a machine of the character described for simultaneously operating upon the sections of an advancing slitted web of slightly bendable material, the combination of two pairs of cooperating cutter blades, arranged to operate on said sectional webs moving at the same velocity past the respective pairs of said cutter blades,

one pair of said cutter blades being constructed 'to operate with a variable periodicity in the cut- 6 ably timed with-respect to said variable ratio gearing, one of said pairs .0! cutter blades being positioned tooperate at a level slightly above the beyond both pairs of blades.

16. In a machine of the character describedfor simultaneously operating upon the sections of an advancing slitted web of slightly bendable material, the combination of two pairs of (:0- operating cutter blades, each pair of said cutter blades being constructed to operate with a difier nt periodicity in the cutting operation than that with whichithe other pair .91 said cutter blades operate,'each pairot said cutter blades being provided with operating connections including variable ratio gearingfor transmitting power at variable velocity during each cycle of their movements, and diflerential mechanism i'or variably timing the cutting operation or said cutter blades with respect to said variable ratio gearing, one of said pairs of cutter blades being positionedto operate at a level slightly above the other pair, whereby the sectional webs of a slitted web may be i'ed, within small limits oi bending, irom a common plane to the respective jacently mounted, whereby the cut material delivered from both pairs of blades passes into zones which are beyond both pairs of blades.

17. In a machine of the character described for simultaneouslyoperating upon the sections pairs of blades, said pairs of blades being adoi! an advancing slitted web of slightly bendable material, the combination of two pairs of cutter blades, the cutter blades of each pair being movable into and out of cutting position at variable time intervals, operating connections for each pair of said cutter blades, said operating connections including variable ratio gearing \for transmitting power to said cutter blades at variable velocity during each cycle of their movements, and differential mechanism interposed between said variable ratio gearing and said cutter blades {or variably timing the, cutting operation 01' saidcutter blades with respect to said variable ratio gearing, one oi said pairs of cutter blades A being positioned to operate at a level slightly above the other pair, whereby the section webs oi! a slitted web may be fed, within small limits of bending, from a common plane to the respective L pairs of blades, saidpairs of blades being adjacently mounted, whereby the cut material delivered from both pairs of bladespasses into zones which are beyond both pairs oi blades.

GEORGE W. SWIFT; Jr.