US2448934A - Slitting machine - Google Patents

Description

SLITTING MACHINE Filed April 15, 1946 H. E. VAN DERl-[QEF EI'AL LNVENTORS HENRYE. VAN DERHOEF ATTORNEYS IKALCOLM P. DAVIS Sept. 7, 1948.

Patented Sept. 7, 1948 UNITED STATES PATENT OFFICE SLITTING MACHINE Henry E. Van Derhoef, Rochester, N. Y., and Malcolm P. Davis, Sarasota, Fla., assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Application April 15, 1946, Serial No. 662,172

, l This invention relates to machines particularly designed for producing accurately-formed slits in strip material, such as cellulose nitrate, cellulose acetate, or the like. One object of our invention is to provide a machine for slitting strip material in which the slitting knives can be readily held in operative relationship. Another object of our invention is to provide a machine of the class described, in which the moving parts, insofar as possible, are enclosed, and in which the lubricating means is enclosed to prevent soiling the sheet to be slit. Another object of our invention is to provide a means for holding the slitting knives in operative relationship which entirely omits the usual use ofspringsior this purpose. A still further object of our invention is to provide a slitting machine in which the position of the slitting knives relative to the strip material can be easily and accurately adjusted to different positions relative to the width of thesheet. A still further object of our invention is to provide a slitting mechanism which can be readily set up and taken down with a minimum of difficulty in accurately aligning the parts of the machine, in setting up the machine for operation, and other objects will appear from the following specification, the novel features being particularly pointed out in the claims at the end thereof.

This slitting machine may be considered an improvement over the slitting machine construction shown in Patent 2,238,481, granted April 15, 1941, in the name of Henry E. Van Derhoei.

Coming now to the drawings wherein like reference characters denote like parts throughout:

Fig. 1 is a fragmentary front elevation and part section of a typical embodiment of a slitting machine constructed in accordance with and embodying a preferred form of our invention;

Fig. 2 is a fragmentary side elevation of the machine shown in Fig. 1 with certain parts omitted for the sake of clearness;

Fig. 3 is an enlarged detailed section showing the relationship of the circular slitting knives when the machine is set up for operation;

Fig. 4 is a fragmentary detailed section of the gear drive for the slitting knives; and

Fig. 5 is an enlarged fragmentary sectional view showing th relationship of th slitting knives and their relation to a sheet being slit.

It has been comparatively difficult to provide machines which will satisfactorily slit long strips of material with a high degree of accuracy. particularly where the material may be of a cellulose acetate or cellulose nitrate sheeting. Many materials, and particularly such acetatesheet- 4 Claims. (01. 164-61) ings, are liable to have undulations, or wrinkles, in the material as it passes through its normal path, so that it the material is slit in this wrinkled condition, it is impossible to obtain accurate dimensions between slits. Moreover, there is quite a varietyof thicknesses of material which may require somewhat different types of machines for producing the desirable clean, accurate slits in the material. The embodiment of our machine, which we are about to describe, has been particularly designed for slitting cellulose acetate, or'nitrate, sheeting of from perhaps .002 to .15 inches in thickness, although, obviously, such a machine is also useful for other types and thicknesses of material. The parts of our machine have been particularly designed to exclude all dust, oil; dirt,- and foreign matter from the sheetingwherever possible, and to avoid any lubricating materials from coming in contact with the final sheet. Where such material is to be used for photographic film, it is particularly necessary to avoid contacting the sheet with any foreign matter, and to provide a construction in which the knives themselves must be arranged to prevent the knives from producing even minute quantities of metal dust from the knives during the slitting operation. This may occur from knives which to the naked eye appear to be finely ground, but which under microscopes appear to be somewhat rough or irregular. Such irregularities may be removed by honing.

- Our invention comprises broadly providing a slitting machine inwhich there is a support carrying a horizontal trackon which one or more carriages bearing slitting knives are slidably mounted and onwhich they may be accurately adjusted by means of a hand wheel to the exact position required. The sheet material to be slit isledaround one or more rollers having contact through a considerable angle, such as 170 or 180 degrees, and since this contact causes the material to produce a part cylinder as it passes about the supporting rollers,fanyundulations or wrinkles in the material are smoothed out, and the 3 which, as shown in Fig. 2, is dovetailed in cross section or end elevation. On this track are mounted one or more carriages 3 which are preferably similar in construction, although they may be made both right and left-handed, as shown in Fig. 1. The carriage 3 is provided with brackets 4 which revolvabl support a .roller-Eas by means of ball bearings 6, these ball bearings being carried by a shaft 1, a reduced end 8 of which may carry a helical gear 9. The roller 5 may turn freely upon the shaft 1 and receives its movement from the movement of the strip material S which passes through a path which may be defined by the rollers [0, 5, 1], l2,- 113,-and The strip material S is driven at a-prede'termined number of feet per second by suitable rollers which are not shown in the present drawing, 1- though any roller frictionally engaging the sheet material S could be used for this purpose. roller 5 therefore turns at the same number of feet per minute as the strip material -S -because the roller is turned-thereby.

The shaft .8 carries one-cutting knife l 5 so that this knife will bedriventhrough the gear 9-at a rate of speed which is preferably isl-ightlysin excess to the speed (in i-eetper minute) of the sheet material S passing around the roller-5. The circular knife I 5 is fixedly mounted withrespect to the carriaget because precautions 'havebeen taken to prevent .end play in the shaft 'I...8. However, a second .stub shaft 16 is .preferably provided with slight end playwas, for instance, of an inch, sothat the cutting knife .11 may be held into contact with the icutting'knif-e because of the thrust on shaft i6 exerted by .a

helical gear I8 meshing withna helical gear 3. The angle of the tee'thofthese :helical .gearsis selected to exert thedesired pressure: on the. knife i'l against the knife t5 and :by increasing-.athe angle of the teeth, the pressure may beincreased, and by decreasing the angle of the'teeth, the pressure may be decreased. .IWBIhBVBAfOIlIid' that. a tooth angle ofapproximately20 degrees fromthe shaft it gives very :desirable results with the machine shown inythe drawings.

As indicated in Fig.'5,.the knivesglfi and ;lt1have cutting edges 20 and 2| which are substantially at right angles to the peripheries 12:2 and 23 .of these knives. Theedges are undercut, as shown, and in operation there is only a slight overlap between these edges so that .a clean cut-may be made through the sheet material, while the peripheries 22 and 23 are. at least. partially supporting the sheet material Sbeing slit.

In the present -instanoe,.athe machme is setup to slit the two edges .of the strip material ;S;; the edges E to be removed being ledqfrom theslitting knives i5 and I] over rollers 25 2 6 ,;and thence to a suitable take-up mechanism, not shown. The p s t machin :is a sokpr vided with two carriages 3, one being rightehandand the other being left-hand, the set-up being intended ,to out off the two edges E of a sheets, leaving the remaining part out {accurately to the desired-width dimension.

In order to drive thefhelicaligears L8 and 9, there is a third helical gear 21 which is, mounted to turn with, but slideon. .a shaft 28. This shaft is carried by suitable bearings 29 onthe support I in which ball bearing s 3ll-are preferably pro.- vided and one end ofthe shaft-;2 8;is provided a gear 3| which derives its power through a pine ion 32 and a main drive gear 33 1ca11-riedJoy" a shaft 34. g g

Th s a 5- 8 a d flare enc os s-en a hous- The 4 ing 35 which confines the lubricating means inside of the housing, leaving a clean exterior.

Each carriage 3 is mounted to slide on the track 2 and in order to adjust the carriage accurately to the proper position, a screw 36 is provided; this screw being pinned at 31 to the carriage and carrying a wormwheel 38 meshing with a worm 39 so that by turning the handwheel 4B, the carriage 3 may be moved along the track 2.

It should be noticed that the gear 18 is slightly smaller than the gear 9, the reason for this being that it is desirable to have one cutting knife 11 tained by 1 having a difference of one or more "teethin the'gea'r s 9 and I8 and as a result, the

two'knives l5 and vIl, turning together, do not tend to score each other by one part of one knife always striking another part of the other knife.

Since there is a constantly changing relationship between the :knives, the edges 20and 21 (which are the cutting edges) are preserved against undue wear. We have found it desirable to both grind and hone the cutting edges 20 and.2l and we have found that with such .edges, the knives will wear an extremely long time without .deteriorationzand produce clean and accurate'slits in the material. This, in part, due, no doubt, to the fact that there is. an ever-present, even, endwise thrust on the shaft I6, so that. knife 11 bears against the knife it with a substantially constant and even pressure due to the angle. of the teeth of'the gears 52 and Hi. It should :be noticed that the periphery .22 lies in substantial alignmentwith the periphery .of the roller Sand may be considered to form a continuation vof the supporting surface .of the roller 5 on which the strip material Slies as the knives slitthe.;ma.- terialto free the unwanted edge E therefrom.

The position and the number .of the carriages 3 will dependx-of. course, on the number of strips into which it is desirable to slit .a single sheet. The strip material S, in passing around the rollers 5, will readily bridge'the .gap between the ends of these rollers because it will be remembered that in this position the material is in the form .of a part cylinder in which the material is comparatively rigid and which supports-an even and smooth arch so that the total .distancebetween any pair ofslitting knives can be accurately determined .and maintained. 7

Our present construction particularly avoids the use .of springs which, under many instances, may work satisfactorily but which have the disadvantage of being difiicult to arrange-so that perfectly .even .axial pressure is exerted on the knives because it .is difficult first, to cut the ends of the spring in such .aumanner that they .will exert even pressure and, second, it is difficult to prevent lubrication from failing because where a machine is set with a constant spring tension for use over a long period of time, movement of the spring may be retarded by thickened lubricant, tending to prevent free movement of the spring and consequently uneven pressure upon the cutting knives. In our present slittingmachine, the pressure is obtained by the constant meshing of the .an gularly-positioned helical gear teeth, so that there is always an end thrust on theshaftltli in the direction shown by the arrow A. Thedirection and slope of the teeth .of the helical gears is ,alwaysso arranged and selected that the end thrust will cause the movable cuttingknife H to lie in firm contact with the-.relatively-fixed cutting knife l5 so that a cleanlysheared edge will result.

We claim:

1. A slitting machine comprising, in combination, a support, a track carried thereby, a carriage movably mounted on the track, a roller carried by the carriage, a shaft, a slitting knife positioned coaxially of the roller and on the shaft, a stub shaft carried by the carriage, a slitting knife carried thereby, there being axial play in the stub shaft, helical meshing gears positioned one on the shaft coaxially with the roller and the other on the stub shaft to exert an end thrust on said stub shaft to operably engage the knife on the stub shaft with the knife coaxially mounted with respect to the roller.

2. A slitting machine comprising, in combination, a support, a track carried thereby, a carriage movably mounted on the track, a roller carried by the carriage, a shaft, 9, slitting knife positioned coaxial-1y of the roller and on the shaft, said roller being mounted on said shaft for relative rotation thereto, a stub shaft carried by the carriage, a slitting knife carried thereby, there being axial play in the stub shaft, helical meshing gears positioned one on the shaft coaxially with the roller and the other on the stub shaft to exert an end thrust on said stub shaft to operably engage the knife on the stub shaft with the knife coaxially mounted with respect to the roller, means for leading strip material about the roller, the helical gear means for driving the slitting knives may thus move said knives at a peripheral speed higher than the predetermined speed of the strip material passing over said roller.

3. A slitting machine comprising, in combination, a support, a track carried thereby, a carriage movably mounted on the track, means for moving the carriage along the track to position the carriage thereon, a roller carried by the carriage, a shaft, a slitting knife positioned coaxial'ly of the roller and on the shaft, a stub shaft carried by the carriage, a slitting knife carried thereby, there being axial play in the stub shaft, helical meshing gears positioned one on the shaft coaxially with the roller and the other on the stub shaft to exert an end thrust on said stub shaft to operably engage the knife on the stub shaft with the knife coaxially mounted with respect to the roller.

4. A slitting machine as defined in claim 1 characterized by the slitting knife, arranged coaxia-lly of the roller, and the roller both being carried by a shaft parallel to the track carried. by the carriage, a shaft passing through the carriage, a gear on said last-mentioned shaft for driving the helical gears connected to the slitting knives, said shaft passing through the carriage and being carried in bearings on the support.

HENRY E. VAN DERHOEF. MALCOLM P. DAVIS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 586,808 Dittman July 20, 1897 1,024,409 Luther Apr. 23, 1912 1,534,257 Brogan Apr. 21, 1925 1,678,458 Biggert July 24, 1928 1,774,549 Finn Sept. 2, 1930 1,807,835 Finn June 2, 1931

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