US2554114A - Shredding machine - Google Patents

Description

y 1951 AYH. MENKIN ETAL 2,554,114

SHREDDING MACHINE Filed Aug. 6, 1948 5 Sheets-Sheet l 2 flc i. I 263 y 1-951 A. H. MENKIN ETAL 2,554,114

SHREDDING MACHINE Filed Aug. 6, 194a 5 Sheets-Sheet 2 ATTORNEYS May 22, 1951 Filed Aug. 6, 19.48

A. H. M ENK|N ET AL SHREDDING MACHINE 5 Sheets$heet 3 ATTORN EYS May 22, 1951 A. H. MENKIN ET AL 2,554,114

SHREDDING MACHINE Filed Aug. e, 1948 '5 Sheets-Sheet 4 ATTORNEYS May 22, 1951 A. H. MENKIN ET AL SHREDDING MACHINE 5 Sheets-Sheet 5 Filed Aug. 6, 1948 Patented May 22, 1951 SHREDDING MACHINE Arthur H. Menkin, Elmhurst,-and Charles H. Morhardt, Baldwin, N. Y., assignors to The Shredmaster Corporation,

Delaware a corporation of Application August 6, 1948, Serial No. 42,774

Claims. (01. 164 -60) This invention relates to shredding machines more particularly of the type adapted to cut paper or other material into narrow strips.

It is among the objects of the invention to provide a machine of the above type that is neat in appearance, durable, relatively compact, easy to assemble and relatively noiseless in operation, that functions with a minimum of supervision requiring the operator only to feed material'thereto and remove the collected shredded material, that it not likely to clog or jam during the operation thereof but in the remote event of clogging or jamming may readily be cleared, that functions with a minimum of vibration, the speed of which may readily be changed Without need for special tools, that is designed to pre vent injury to the operator having but a minimum of exposed parts and that may readily be disassembled for maintenance or service.

Another object of the invention is to provide a machine of the above type which may be used for slippery material such as waxed paper and ensures positive movement of such material through the machine.

Another object is to provide a machine of the above type wherein the material to be cut may automatically be fed into the machine.

Another object is to provide a machine of the above type wherein letters and other documents may readily be cut into small segments.

According to the invention these objects are accomplished by the arrangement and combination of elements hereinafter described and particularly recited in the claims.

In the following drawings in which is shown one or more of various possible embodiments of the several features of the invention,

Fig. l is a perspective view of the machine,

Fig. 2 is a transverse sectional view taken along the line 2--2 of Fig. 1, I a

Fig. 3 is a front elevation of parts broken away,

Fig. 4 is a transverse sectional view on a larger scale taken along line 44 of Fig. 3, i

Fig. 5 is a longitudinal sectional view taken along line 5--5 of Fig. 4,

Fig. 6 is a fragmentary plan view on a smaller scale taken along line 66 of Fig. 5,

Fig. '7 is a sectional view on a larger scale taken along line l'! of Fig. 6,

Fig. 8 is an exploded perspective view showing the cutting blades, the strippers or combers and the spacing members,

Fig. 9 is asectional view on a larger scale taken along line 9-3 of Fig. 2,

the machine with Fig. 10 is a fragmentary view of another embodiment of the invention,

Fig. 11 is a fragmentary perspective view of still another embodiment of the invention,

Fig. 12 is a plan view of another embodiment of the cutting blade, and

Fig. 13 is a view similar to Fig. 12 of still another embodiment of the cutting blade.

Referring now to the drawings, the machine comprises a substantially U-shaped frame 2| preferably of cast iron, the legs 22 thereof each having a transverse flange 23 at the lower end thereof extending laterally outward therefrom, said flanges 23 mounting casters 23 whereby the machine may readily be moved. In order to prevent the legs 22 from spreading, angle irons 25 and 23 are provided extending longitudinally of the frame and affixed at each end respectively by screws 24, to transverse flanges 30 extending laterally inward from the lower ends of legs 22 and preferably integral therewith.

The cross piece of the frame which forms a table portion 2'! near the mid portion thereof, has a depending skirt 28 on the front edge thereof, preferably formed integrally therewith and which extends the entire length of the cross piece. The rear edge of table portion 21 has a depending portion preferably integral therewith forming a chute 29 which is substantially the same width as table portion 2! and slopes rearwardly as shown in Fig. 2.

Each end of the cross piece adjacent table portion 21 forms a bed or base 3| and 32 respectively, substantially the width of the legs 22, base 3| being at a lower level than table portion 21 and base 32, as shown in Fig. 5. Base 3| has a longitudinal slot 33 (Figs. 3, 4) there- 'through, adjacent skirt 28 for the drive transmission to be hereinafter described.

Mounted on bed 3! and extending upwardly therefrom is a gear box 34 rigidly aflixed to bed 3| by screws 35 extending through flange 43 at the lower edge of the gear box 34 and preferably integral therewith. The gear box 34 has a removable cover plate 33 afiixed on the top thereof by screws 37, a threaded plug 38 being provided in said cover plate 36 to close the lubricant inlet. Drain plugs 33 are provided in the bottom of the gear box 33, the bed 3i having an aperture 4! therein to permit ready access to said plugs 39 to drain the oil from the gear box 34. Desirably a test plug I36 is provided threaded in an opening in side wall I l l of the gear box at a height above the bottom of the gear box below which the level of the lubricant therein 2 U should not fall. Thus if with the test plug I removed. no lubricant'flows from the opening, the gear box should be rechanged with lubricant.

The front and rear walls 43 and 44 respectively of the gear box 34, near the bottom thereof, have transversely aligned recesses 45 and 46 therein, with apertures 4! and 48 respectively therethrough. Extending through said apertures is a worm shaft journalled in ball bearings 52 and 53 near its front and rear ends respectively. Bearings 52 and 53 are seated in recesses 45 and t5 against the inturned rims 55 and 56 thereof respectively. In order to prevent axial movement of shaft 5| in its bearings and retain the hearings in their respective recesses, the

shaft 5| is threaded as at 51 and 58 and nuts 59 and BI are afiixed respectively on said threaded portions.

To prevent entry of dirt and dust into the bearings 52 and 53 and prevent leakage of oil from the gear box 3 8, a cover plate 54 is affixed to the rear wall 44 of the gear box over bearing 55 by screws 65 and a similar cover plate 6? is a'ffixed to the front wall 43 of the gear box 3 5 over bearing '52 by screws 68, the last named cover plate having an oil seal or packing I2 around opening '69 to prevent leakage of oil through aperture 59 through which the front end H of the worm shaft 5| protrudes.

Affi-xed to the front end II of worm shaft 5| over slot 33 in base 3! are a plurality of pulleys of different diameters two being illustratively shown designated by the numerals I l and T5. In order to rotate the pulleys I4 and I5 and drive worm shaft-5|, a motor M is provided positioned beneath the gear box 34 and a ffixed by bolts TI to substantially rectangular base or platform Ti Platform 18 has a pair of aligned depending cars '59 on each side thereof through which a transverse pivot rod 8| extends, rigidly afiixed at each end in angle irons and 26 pivotally to mount platform- 13. In order to limit the pivotal movement of platform 18, a transverse rod 82 is provided 25 near the free end of platform I8. bolt 5d is pivoted on rod I12 and has its threaded end 83 extending through an opening in platform '58, a pair of nuts 85 being provided screwed on the threaded end of eye bolt 85 against each face of platform I8 rigidly to clamp the latter therebetween.

The drive shaft 86 of motor M has a plurality of pulleys P thereon, illustratively two in number of different diameter, the smaller pulley on shaft 35 being aligned with the larger pulley I4 on shaft 5| and the larger pulley on shaft 86 being aligned with the smaller pulley I5 on shaft 5|. It is thus apparent that by placing the belt S'I on different pairs of aligned pulleys, either of two speeds may be selected. It is of course to be understood that a greater number of pulleys could be provided on shafts 86 and 5| to provide for a greater range of speeds. In order that a single size belt can be used for different speeds, the aligned pairs of pulleys are of such diameter that the length of the belt around each of the aligned pairs of pulleys will be the same.

Positioned on base 32 and extending transversely thereacross as shown in Figs. 5, 6 and 7 is a substantially L-shaped tail-stock 9|. The base 92 of the tail-stock has a pair of longitudinally aligned slots 93 and 94 therethrough on each side thereof through each of which extends a screw 95 threaded into an associated Opening 96 in base 32, the slots permitting longirigidly mounted in angle irons 25 and 7 An eye' 4 tudinal adjustment of the tail-stock when the screws 95 are loosened. In order to facilitate such adjustment, a pair of handles 91 are provided preferably integral therewith on opposite sides thereof.

Extending laterally outward from, the upright portion 98 of the tail-stock 9| are a pair of hubs 55 and |5I the latter being positioned below the former and forwardly thereof as shown in Fig. =6. The hubs 99 and IOI have openings I63 and I54 therethrough respectively, aligned with corresponding openings I05, I96 and I61, I98 in the side walls I09 and III respectively of the gear box 34.

A pair of shafts I I2 and H3 are provided positioned longitudinally of the frame 2| and extending through openings I03, I85 and Iii? and I58, I66 and I 08 respectively. As the construction and mounting of said shafts H2 and H3 are substantially identical only the former, i. e. shaft H2 will be described in detail, corresponding parts of the latter having the same reference numerals primed.

Shaft H2 has a reduced portion .I I5 adjacent side wall I09 of the gear box 3 around which a ball bearing H5 is positioned, the latter being seated against the inturned flange III of opening I05.

Shaft II2 has an encompassing collar H9 adjacent bearing H5 with a notch therein whereby the collar may be keyed to shaft I I2 in the manner hereinafter described so that collar H9 will rotate with shaft H2.

A seal ring I-2I is provided encompassing shaft H2 and collar H9 and seated in a recess I22 in side wall IE9, said seal ring being retained in said recess by screws I23. As shown in Fig; 5 the inner face I24 of collar H9 extends slightly beyond the face of seal ring I'2I The seal ring has an annular washer I25 preferably of felt, on the inner edge thereof, which abuts against collar H9 to prevent leakage of oil from the gear box and reduce the friction between the collar and seal ring.

The end of shaft H2 is journalled in a ball bearing I25, the latter encompassing the reduced portion I2"! of the shaft and seated against shoulder I 218 form-ed by said reduced portion. The bearing I25 which is positioned in opening I61 in side wall III of the gear box 34 is retained on shaft I I2 bymeans of a nut I29 threaded on the end I3I of the shaft H2.

Keyed on the portion of shafts H2 and H3 in the :gear box are meshed spur gears I32 and I33 respectively which are spacedfrom bearing H6 and H5 by means of sleeves I34 and I34 respectively.

By means-of anut I35 screwed on the threaded portion I36 of shaft H2, spur gear I 32, sleeve I 3 3, bearing H5 and collar H9 are retained against axial displacement on shaft H2.

A-lso keyed in shaft H3 is a worm gear I37 spaced by sleeve 1:88 from spur gear I33 and by sleeve -I4 I from hearing I26 positioned in opening I08 in side Wall III of the gear box. A nut I29 screwed on the threaded end I-3I" of shaft H3 prevents axial displacement of bearing I26, sleeve I41, worm gear I37, sleeve I33, spur gear I33, sleeve I34, bearing 1H6 and collar H9.

The worm gear I'B'I meshes with a worm I64 keyed on worm shaft 5I to drive shafts H2 and H3 when the worm shaftis-rotated in the manner hereinafter described.

In order to prevent the entry of dirt and dust into the gear box and also to prevent the leakage of oil therefrom, cover plates I41 and I4? are provided affixed to the gear box over the ends I3I and I3I' of shaft H2 and H3 respectively by screws I48.

Mounted on shafts H2 and H3. between end wall I09 of the gear box and upright portion 9.8 of the tail stock are a series of opposed circular cutting knives IBI and I52 respectivelywhich aresecured to their respective actuating shaft in any desired manner, keys I53 and I54 being preferably used, positioned in the keyways I55 and I56 respectively in the shafts and engaging corresponding notches I5'I in the knives as well as corresponding notches in the associated collar H9, H9. A series of spacer collars-I58; and I 59 each having a notch IBI is similarly mounted on each shaft between consecutive cutters, and each series of knives is so located with reference to the other as to be positioned opposite to the spacer collars of the opposing series with the cutting edges thereof overlapping.

The cutting knife cleaning devices or combers I52 and I63 in this mechanism which are mounted in like plurality between the knives I5I and N2 of each series, each takes the form of a substantially circular plate having an opening I68 therethrough of greater diameter than that of the associated spacer I58 or I59 and preferably encompassing said spacers respectively. As the thickness of the spacers is slightly greater than that of the cornbers, the latter will ride between the faces of the cutting knives with but a minimum of friction.

Suitably formed extension ltd and I I35 are provided on the combers IGZ and I63 respectively, preferably integral therewith and lying in the same plane therewith, each of said extensions having a substantially rectangular opening It? therein through which the supporting bars use and I69 respectively extend.

Bar M58 is affixed at one end by means of a screw I'II to the top of the gear box 34 and extends longitudinally of the shaft II2 to the tail-stock SL The other end of bar I63 has a longitudinal slot I12 therein through which a screw I'IS extends threaded into an opening I14 in the top of the upright wall 98 of the tail-stock. Thus bar I68 supports members ltl with the extensions I66 thereof in a substantially upright position.

Bar I69 is affixed at one end by screw 75 to the front wall of the gear box and extends longitudinally of the shaft II 3 to the tail stock SI. The other end of bar 169 also has a longitudinal slot I16 therein through which a screw IIIextends threaded into an opening in hub IilI of the tail stock as shown in Fig. 6. Thus bar I59 supports members I63 with the extensions I65 thereof at substantially right angles to extensions I 64. As shown in Fig. 2 the combers are so formed that at the points indicated by the numerals I78 and N9 the opposed and adjacent edge portions thereof lie within the peripheral edges of the knives between which they are positioned. From this point the edge portions are carried gradu ally outward to the points I8I and I32 where they overlap the peripheral edges of the knives.

Thus as the material is fed to the machine and cut, the strips which adhere betweenthe cutting edges of the knives are carried thereby from the point indicated by the numeral I83 to the point where they encounter the overlapping edge portions I8I and I82 of the combers. I62

6 and I63 respectively and areforced out from between the cutting edges of the knives.

-The positioning of the knife, spacer and comber elements may readily be seen in Figs. 5 and 8, the elements shown in Fig. 5 being exaggerated in thickness to facilitate a clear understanding of the machine.

In a preferred embodiment of the invention the machine is set up with elements inch in width. If it is desired to shred up to inch, knives, combers and spacers are set up on the shaft singly as shown. If it is desired to shred Te inch strips, the individual elements are placed on the shaft two at a time. If inch widths are desired, the elements are placed on the shafts three at a time and so on. This change of width may readily be accomplished by the user as desired.

Encompassing the reduced portions I9I, I9I of shafts H2 and H3 respectively and seated against shoulders I92 formed by said reduced portions are ball bearings I93, I83 respectively of diameter substantially the same as the opening I83, H54 in hubs 99 and IBI respectively so as to permit axial movement of the shafts H2 and H3 and their respective bearings I 93 and I93 in the manner hereinafter described but preventing lateral movement thereof. Bearings I 93 and I93 are retained against their associated shoulders I92 by sleeves I94 encompassing the end portion N5 of the respective shafts and retained therein each by a nut I96.

Shafts H2 and H3 each has an encompassing collar I9! with a notch I98 therein through which keys I53 and I54 respectively extends thereby affixing the collars to their respective shafts to rotate therewith, yet permitting the collars to be moved axially thereon. Abutting against each of the collars I9! respectively is a nut I99 screwed on the threaded portion Zill of the shaft adjacent collars I97 and by means of which the axial position of the collars may be determined.

Seal rings 202 and 202 are also provided, encompassing shafts H2 and H3 and their associated collars I91 respectively and seated in recesses 283 and 203' respectively in the inner face of upright portion 98, and retained in said recesses by screws 204. Each of the seal rings has an annular washer 285 preferably of felt on the inner edge thereof which engages collar I91 to reduce the friction between the seal ring and collar.

To prevent injury to the operator and also to prevent the entry of dirt and dust as well as the shredded material into the machine, which might cause jamming of the latter, suitable coverings are provided.

As shown in Figs. 1, and 3, the skirt 2% and legs 22 of the frame have a flange 2H to which a sheet metal cover 2I2 is affixed by screws 2I3. In order to provide access to the motor M and pulleys thereon, a door 2% is hingedly mounted on the sheet metal cover 2 I2 as at 2 I5. A sheet metal housing 2I6 is provided for the gear box 34, which is affixed to bed SI and is provided with a door 2!! hinged to the front wall 2I8 of the housing -2I6 as at 2I9 to provide access to pulleys I I and I5. A sheet metal housing 22I is also provided for the tail-stock 9i and is affixed to bed 32 as shown in Fig. 5.

Extending longitudinally of the machine over the portion of shafts H2 and II 3 on which the knives are mounted is a sheet metal reflector 222 afiixed at each end to housing 2I6 and 22I respectively and provided with illuminating means such as bulbs 225 to cast light on the cutting portion of the machine.

To facilitate feeding material into the machine, a table 226 is provided. As shown inF'igs. 2 and 3 the table has a substantially- L-shaped bracket 22'! afiixed therebeneath along each side edge thereof. As shown in Fig. 2 the vertical leg 228 of the bracket has an elongated slot 229 therein and a finger 23I extending longitudinally thereof having a notch 232 therein. A pair of spaced studs 233 and 234 are provided on each of the opposing walls I09 and 98 of the gear box and tail-stock respectively, extending laterally outward therefrom. Studs 233- extending through the longitudinal slot 229 of the associated brackets 22! pivotally to mount the table, the latter being retained in a horizontal position by seating studs 234 in notches 232 of fingers 23f as shown in full lines in Fig. 2.

The table 226 has an inclined lip 24? rigidly afiixed to its rear edge 243 to facilitate feeding the machine when the table is in horizontal position.

In order to safeguard the operator as he feeds the machine, a pivoted shield 249 is provided comprising a horizontal portion 25! substantially the width of the table 226, having an upturned frontedge 252 to which a knob 253 is afiixed and a. downwardly inclined rear portion 254 substantially parallel to inclined lip 24! of table 226 as shown in Fig. 2.

Rigid with portion 25I and extending obliquely upward therefrom is a plate 255 having a window 256' therein preferably of plastic or other transparent shatterproof material. The upper edge of plate 255 has a rearwardly extending flange 251' preferably integral therewith, at each end of' which is afiixed a stud 258 extending longitudinally of the plate 255.

A pair of L-shaped brackets 259 are affixed respectively on the top of the housings 256 and 22I, the upstanding leg of said brackets each having a notch 2H therein in which studs 258 may respectively be positioned pivotally to support the shield 249. In order to limit the pivotal movement of shield 229 a bracket 263 isaffixed at each edge-of'horizontal portion 251, the laterally extending arms 264 of the bracket resting on the top of housings 216' and 22I respectively when the shield is in closed position. Associated with one of said brackets 263 is an electrical switch 266 mounted in housing 2l6. The lateral extending arm 264 of bracket 263 contracts the operating plunger 26'! of the switch when the shield is in closed position to closethe switch, the latter automatically opening when arm 264 is moved away from plunger 26? by the pivoting of shield 249.

An upright shield plate 2" is also provided affixed beneath table 226 to bed portion 21 as shown in Figs. 1 and 2 to prevent the operator from touching the cutting knives when the machine is in operation and also to prevent backing up of the shredded material when the machine is functioning.

Afiixed on the table 226- on each side thereof near the free end of the table, is an adjustable paper guide, preferably comprising two L-shaped members 236 and 23?, the vertical legs 238'and 239 of which are clamped together by a wing'nut and; bolt". 2, the latter extending through a vertical slot 242 in leg 239 to permit vertical adjustment of the laterally extending'leg 2-43" of the guide. Thefoot 244 of the guide is secured to. the: table 226. by wing nut and bolt 245 the latterextending through a slot 246 in said foot to permit'lateral' adjustment of the guide on the table.

In order to energize motor M, a switch box 212 isprovided, mounted on a bracket 213 atfixed to skirt. 28 of the frame. The switch box is connected by a lead 215 to control box 216 mounted on leg 22 of the frame as shown in Fig. 2.

The switch box preferably has three buttons, i. e. start, stop and reverse, the latter button requiring constant pressure thereon for actuation thereof. As the circuit and control elements for the switch box which are. contained in the control box: are conventional, they will not be further described.

Adjustment and operation Withthe. machine assembled as heretofore. described, nuts I35 and I99 on shaft H2 and nuts I29 and I99 on shaft H3 are tightened to compress the knives'and spacers therebetween so that they are rigidly retained on. their respective shafts. As combers I52 and I63 are positioned between the knives, encompassing their associated spacers which are thicker than the combers, the combers will ride between the knives with but a minimum of friction. As comberl62 on shaft H2 and knives I52 on shaft II3, on the left side of the machine as. seenin Fig. 5, adjacent the seal rings I2l, and I2! respectively of gear box 34 are spaced therefrom by reason of the slight protrusion of collars H9 and 9' beyond the inner face of the. seal rings, therewill be no contact between the knife: and comber and their respective seal rings and hence no frictiontherebetween. This space is so small that there is little likelihood of the shredded ma.- terial jamming therein which would interfere with, the operation of the machine.

As the tail-stock 9| is movable longitudinally of the frame, accurate tolerances in the construction of the machine is not required to ensure that the space between seal rings 202 and 202., and the comber and knife adjacent thereto tating in a clockwise direction and shaft I-I3 rotating in a counterclockwise direction; As-the window 256 in the shield 249 affords a clear view of the illuminated knives, the operator may readily feed material thereto by placing the same on table 226 and moving it beneath shield 249 through the slot formed by inclined portion254 thereof and lip 241, so that it is caught by the rotating knives which will pull the material therebetween and cut the same into strips, the latter thereupon dropping down on chute 29 to slide out of the machine. To prevent accumulation of the strips beneath the machine when casters'are'used, a pivoted plate 289 is desirably provided which is aligned. with chute 2.9 to direct the strips-away from the machine. This is clearly shown in Fig. 2'.

If paper is to be shredded that is of greater widththan the cutting portion of the machine. the adjustable paper guides will cause the paper 9 to be curled over as it is fed into the machine thereby preventing such paper from getting caught in the spaces adjacent the seal rings and possibly jamming the machine.

If the machine should jam, it is merely necessary for the operator to press the stop button, then momentarily press the reverse button which will reject the material between the blades. The material may then be properly positioned in the machine and the start button again pressed.

In the eventuality that the reverse rotation should fail to clear the machine and the operator should desire manually to pull the material jammed between the knives, in order to reach the knives, he must first lift the shield 249. This will remove bracket arm 234 from safety switch plunger arm 23'! and stop the machine thereby preventing any possibility of injury.

If the operator should desire to change the speed of the machine, he need merely press the stop button, open doors 2M and 2|! and switch the belt 8! to the desired size pulleys. To facilitate such adjustment, the nuts 85 on eye bolt 34 are first loosened and the platform pivoted upwardly to slacken the belt 31. With the belt on the proper pulleys, the weight of the motor on the platform will keep the belt taut and the nuts 85 may then be tightened to retain the platform in place.

With the construction herein described when material is inserted between the knives, any tendency of the shafts H2 and H3 to bow materially is prevented by reason of the double bearing support therefor in the gear box 34. If not for such dual support, the bowing might move the ends it! and i3! of the shafts out of line resulting in severe vibration which'would cause considerable noise and tend to loosen the operating parts of the machine resulting in breakdown of the latter, thus requiring-constant maintenance thereof.

When it is desired to out slippery material such as waxed paper which might not readily be caught by the smooth periphery of circular knives and pulled therethrough, the cutting knife 282 as shown in Fig. 12 or the knives 233 shown in Fig. 13 could be used. Knife 282 has a small notch 284 in the periphery thereof which would catch on the paper and pull it through and the flats 285 on knives 283 would also serve the same purpose.

In Fig. an embodiment of the machine is shown which is especially designed to cut confidential documents such as letters or other papers into small pieces. As shown in the drawing two parallel shafts 281 and 288 are provided lying in the same horizontal planes with a plurality of knives 289, spacers 290 and combers 29! on each shaft. As the construction and assembly of such machine is substantially similar to the one shown in Figs. 1 to 9, it will not be described in detail.

It is to be noted that substantially the entire periphery of the combers 29l lie within the periphery of the knives 283 and only near the top of the knives as at 292 does the sloping edge 293 of the combers extend beyond the periphery thereof.

A hopper 294 is provided with the outlet 235 thereof positioned directly over the overlapping portion 336 the knives and deflectors 296 are provided at the outlet 295 extending laterally outward and downwardly so as to extend beyond the knives.

When the paper is dropped into the hopper it will fall between the knives and initially be shredded into strips. The strips will stick in the space between the knives and be carried around until they abut against the sloping edge 293 of the combers 29! to be forced out of the space between the knives. As the strips are forced outwardly, they will abut against the deflector 296 as at 291 and curl over the top of the combers as at 298 to again pass between the cutting edges of the knives. As the strips will now not be aligned with the spaces between the knives but will be at an angle thereto, they will again be cut, but this time into smaller segments, the smaller of which will not stick between the knives but will fall downwardly. The larger segments which remain between the knives will again be forced outwardly by the combers and be deflected over the top thereof to again fall between the knives whereupon they will again be cut into still smaller segments. This procedure will be repeated until all the paper has been cut into very small segments which will be discharged from the ma chine, which segments would be almost impossible to piece together and read.

The small segments may be collected in a basket (not shown) positioned below the overlapping edges 30!] of the knives to be subsequently burned.

In Fig. 11, the machine shown in Figs. 1 to 9 has been slightly modified so that a conveyer system may readily be incorporated therewith.

To this end a plurality of cutting knives 335, combers 332 and spacers 303 are positioned on shafts 304 and 365 in the manner heretofore described, illustratively in sets of four instead of the individual elements shown in Figs. 1 to 9. Alternate sets of combers 332 on the lower shaft 365 are replaced by pulleys 323 which latter are keyed to shaft 305 by key 301. It is of course to be understood that all of the sets of combers 362 on the shaft 385 could be replaced by pulleys 306 or some intermediate arrangement could be used.

The pulleys 306 each have a continuous belt 333 therearound which encircles an idler pulley 303 mounted on a shaft 3| l, the belt being norma ly retained in taut condition in a horizontal position.

To operate the machine shown in Fig. 11, the operator need merely place the material to be shredded on the belts 3558 which will carry such material to the overlapping portion of the cutting knives, whereupon it will be drawn therethrough. As the strips of material between the cutting knives encounters the combers 332 on shafts 384 and 335, the combers will force the strips outwardly from between the knives so that it may be discharged from the machine. In the case of the strips in the spaces between the knives occupied by the pulleys, the strips will abut against the belts and be forced outwardly from between the knives in the same manner as if the combers had been used.

Thus by the above construction, the shredding machine may readily be supplied with a conveyor belt with resultant convenience in feeding the machine and increase in the output therefrom and this advantage may be secured without any material modification in the design of the machine.

As many changes could be made in the above construction, and many apparently widely different embodiments of this invention could be made without departing from the scope of the claims, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illusl rative and not in a limiting sense.

Having thus described our invention what we claim as new and desire to secure by Letters Patent of the United States is:

1. A shredding machine comprising a pair of parallel rotary shafts, a series of spaced circular cutting knives assembled on each of said shafts and rigidly afiixed thereon to rotate therewith the cutting knives on one of said shafts alternating with and overlapping the cutting knives on the other of said shafts, a series of stationary combers on each of said shafts between the cutting knives thereon respectively and spaced therefrom, each of said combers comprising a substantially circular plate having a central opening therethrough for the respective shaft, substantially the entire periphery of each ofv said plates lying within the periphery of said cutting knives, said plates each having an extension lying in the same plane thereof and integral therewith, said extensions protruding beyond the periphery of said cutting blades at the top thereof, means engaging said extensions to retain said combers in fixed position, a deflector plate positioned over each series of combers and means to feed material into said cutting knives at the overlapping portion thereof.

2. The combination set forth in claim 1 in which the axes of said arallel rotary shafts both lie in the same horizontal plane.

3. A shredding machine comprising a pair of parallel rotary shafts both lying in the same horizontal plane, a series of spaced circular cutting knives assembled on each of said shafts and rigidly afiixed thereon to rotate therewith, the cutting knives on one of said shafts alternating with and overlapping the cutting knives on the other of said shafts, spacers between said cutting knives having contact therewith, a series of stationary combers on each of said shafts between the cutting knives thereon respectively and spaced therefrom, each of said combers comprising a substantially circular plate having a central opening therethrough of greater diameter than that of the spacer and encompassing the latter, substantially the entire periphery of each of said plates lying within the periphery of said cutting knives, said plates each having an extension lying in the plane thereof and integral therewith, said extensions protruding beyond the periphery of the cutting blades at the top thereof, means engaging said extensions to retain said combs in fixed position, a feed hopper having an inlet positioned over the overlapping portion of said cutting knives and an inclined deflector plate positioned over each series of combers and extending longitudinally of said shafts.

4. A shredding machine comprising a pair of parallel rotary shafts, a series of circular cutting knives assembled on said shafts in alternating and overlapping relationship, spacers between said cutting knives having contact therewith, a series of stationary combers disposed between the cutting knives of one of said shafts, means disposed between the cutting knives of the other of said shafts to expel material from between said cutting knives, said means comprising a plurality of pulleys rigid with said shaft and rotating therewith, said pulleys being positioned between the cutting knives on said shaft, a belt driven by each of said pulleys, means to retain said belts in horizontal position whereby material may be placed on said belts to be fed to said cutting knives and means on said shafts for holding the cutting knives and spacers together.

5. The combination set forth in claim 4 in which bearing means are provided for each of said shafts on each side of the series of cutting knives and spacers thereon and additional bearing means are provided for each of said shafts at one end thereof.

ARTHUR H. MEN'KIN. CHARLES H. MORHARDT.

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

UNITED STATES PATENTS Number Name Date 478,023 Rohan June 28, 1892 1,178,386 Edwards Apr. 4, 1916 1,319,496 Stachowski Oct. 21, 1919 1,725,176 Bevis Aug. 20, 1929 1,747,264 Rearick Feb. 18, 1930 2,086,476 Quick et a1 July 6, 1937 2,160,999 Yoder June 6, 1939 2,202,843 Edwards June 4, 1940 2,210,018 Yoder Aug. 6, 1940 2,364,334 Wold Dec. 5, 1944 FOREIGN PATENTS Number Country Date 155,138 Germany Oct. 24, 1904 281,170 Great Britain Dec. 1, 1927 511,762 Germany Nov. 6, 1930 625,464 Germany Feb. 10, 1936

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