US 2948177 A
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Description (OCR text may contain errors)
B. A. ARVIDSON WEB CUTTING MECHANISM Filed May 29, 1956 Aug. 9, 1960 U my# z Ilm/ mw w .w NW
United States Patentv `O I Patented Aug. 9, y1960 WEB CUTTING MECHANSM Bengt A. Arvidson, Chicago, lll., assignor to Miller Wrapping & Sealing Machine Co., a corporation of Illinois Filed May 29, 1956, ser. No. 588,166
4 claims. (cl. lssi-155) This invention relates tomechanism for cutting elongated material into sheets and more particularly to a cutting mechanism having means for holding a web of material `against retrograde movement duringcutting and in addition placing the web under tension prior to cutting.
In the past, difficulty has often been experienced in cutting certain materials by means of cutter blades or scissors because of a tendency of such materials to fold about and follow the cutter rather than to be cut.v This problem has been particularly encountered in connection with material which is known in the wrapping art as limp film which is now commonly used for wrapping articles. Polyethylene and polyvinyl lms lare examples of such limp films'.
An object of this invention is to provide mechanism for cutting 'elongated material into sheets including means for holding the material against movement as it is cut.
Another object of this invention is to provide mechanism for cutting an elongated sheet of material including a knife for cutting the material and means operable in timed relation with the knife to hold theV material against retrograde movement as the knife cuts the material.
A further object of the invention is to provide mechaof fingers, each formed of spring material and extending downwardly beneath the level of the movable knife so as t`o`enga`geth material against the conveyor and :tension the material prior tocutting thereof by the knife.
An `additionalobject of theA invention is to provide `a web`cutting'mechanism. comprising, in combination, a base, yacutter including a. knife bar movably mounted on the base and adapted to carry aknife, means for supporting and intermittently advancing theY webjincludirig a plurality of laterally spacedy belts, a nger 'mounting plate adjustably mounted on -the knife bar, a plurality of laterally spaced `lingers mountedonthe 'mounting plate Aand extending to positions VVoverlying the conveyor belt, each` of ,said lingers comprising a leaf spring having *a downwardly angled mid-section and a free endextending generally parallel .to the. conveyor belt, and la pressure pad carried on 'they free endof the leaf spring positioned normally at va level beneath the loweredge of the movable knife for engagement with the web prior to said movable knife, whereby movement of the knife bar causes said lingers -to engage the web and place the web under tension prior to theV cutting of the web. by the movable knife.
The objects of the invention generally set forth together with other ancillary advantages are attained by the construction and arrangement shown by way of illustration in the accompanying drawing in which: Y
Fig. l is a vertical view in elevation `of the cutting mechanism with the knife and associated `mechanism shown in broken lines in their cutting position and with the base and web advancing mechanism shown in section; Fig. 2. is a plan view of the mechanism shown in Fig. 1
. 2 with the base and web advancing mechanism broken away;
Fig. 3 is a fragmentary side elevation of the mechanism with parts broken away and showing in broken line the lingers in initial engagement with the web; and
Fig. 4'is a view similar to Fig. V3 showing the position of the parts after the movable knife has severed the web. While this invention is susceptible of embodiment in many diiferent forms, there is shown in the drawings and will herein be described in detail an illustrative embodiment of Ithe invention with the under'sanding that the present disclosureis to be considered as an exempliiication of .the principles lof the invention and is not intended to limit the invention to the embodiment illustrated. The scope of the invention will be pointed out in the appended claims.
As shown in the drawings, a base 1 supports a belt table Z over which may extend a bel-t conveyor, indicated generally at 3, and which may be composed of a plurality of narrow, laterally spaced, endless, parallel belts 4. The belts 4 travel around a pai-r of spaced rollers mounted on the base 1, one of these rollers being indicated at 5 which may be intermittently driven to intermittently move the belt conveyor 3. As shown in Fig. 3, additional means for advancing the material 6 yand for holdingthe material during cutting comprises a feed roller 10 and a pressure roller ll'mounted on the base 1, each of which may be a continuous'. roller extending transversely of the base or may be formed of a plurality of rollers. The material 6 for purposes of description may be referred to as `a web of material although the disclosed mechanism may be used with sheet .material which-is to be cut into smaller sheets.
The belt conveyor 3 and feed and pressure roller mechanism may be of the type disclosed in Patent No.l 2,687,604 to Corley et al., dated August 31, 1954, and more particularly may be as shown in Figs. 5 and 6 of the patent. rI'he belt conveyor rollers and feed and pressure rollers may be intermittentlyfrotated. to' intermittently advance theweb of material a desired distance by a mechanism-such `asthat shown in Patent No..2,687,604.
'f A cutting'stationV indicated `generally at YC, is located between` the belt conveyor and, the lfeed nollrpllfa'nd the pressure roller '11., t A cutter isf located 'tthe cutting stationand includes a xetl, .botlomtknifez 1W a movable knife 13: mounted, for Vmovement VtowardandV away from, the fixed knife. As shown inwtheedrawings, the knife 13 may be mounted on al knife .bar `14 bywmeans of screws 15, and the knife bar '14 may beepivotally mounted at loneend by a pin v16 to a bracket 17 carriedonE the basel. The opposite end lof the knifev 15215114 may, byja pin 18, be connected to'atvertial rodf19`which maybe actuated by the knife actuator, `lFshown Vjin-Patent yNo.y 2,687,604,-'t'o'cause'v the movable knife todescend ina cutting operation when the web'fe'edfmechanism'is statiohalyl` 'Li: Y A finger-mounting-'pl'ate 20 'o verliesl`the knife-bar "14 for'amajor part ofthelengthofthe ltnifebarVv and issecured thereto by means, such as bolts 21 and 22, threadably secured in the knife bar to provide for adjustment of the finger mounting plate and the mechanism carried thereby with respect to the movable knife 13.
A plurality of laterally spaced fingers Iare secured to the linger mounting plate 20 by suitable means, such as screws 26. Each lfinger is in the form off a leaf spring made of spring steel and has Ia downwardly Langled midsection 26 and a free end 27 on which a pressure pad of rubber 28 lm-ay be mounted by suitable means, such as screws 29. A continuous guard 30 overlies the mid-section 26 of each of the fingers to limit the deflection of the lingers, and this guard may =be formed as an integral p of the nger mounting plate 20. i
As shown in Figs. v1 and 2, the fingers 25 and the pressure pads 28V carried thereby are so arranged on the finger mounting plate so las to each be centered over a belt 4 when in engagement with the web.
In* operation of the mechanism With the knife bar 14Y and movable knife 13 in elevated position, `as shownv in full'v lines in Fig.V 3, the belt conveyor 3 and feed coupling formed by rollers .10 and 1'1 may be yactuated to advance the web of: material past the cutting station. Upon cornpletion of web movement, the vertical rod l19 is pulled down toilower the knife bar "14 `and knife 13 carried thereby. This movement Ialso results in lowering the fingers and prior to cutting of the web the parts will take the position shown in broken lines in Fig. 3. In the broken line position of Fig. 3, the pressure pads 12% on the fingers 25 have made contact with the .web to hold the web while the knife 213 hasnot `as yet made contact with the web. Continued downward movement of the knife bar `14 will cause flexing of the fingers 25 from their broken line position in Fig. 3 to the position shown in Fig. 4 to tension to the web prior to cutting thereof by knives vl2 and 13.
This flexing of the fingers increases the distance between the knife 13 and the pressure pads 28 so as to produce tension in the web. as well `as remove any wrinkles that may be present.
1. A web `cutting mechanism comprising, in combination, a base, a scissors-type cutter supported on said base including a fixed knife and a knife bar pivotally mounted at one end on the base adapted to carry a cooperating knife, means located forwardly of and beyond the cutter for supporting and intermittently advancing said web in- Y cluding a belt conveyor beyond the cutter having a plurality of laterally spaced belts, `a finger mounting plate adjustably mounted on said knife bar, `and a plurality of laterally spaced lingers mounted on said mounting plate -and extending rearwardly to positions overlying the belt conveyor, each of said Ifingers comprising 4a leaf spring having a downwardly angled mid-section and a free end extending generally parallel to the Ibelt conveyor and away Y tion, a base, a cutter supported on said base including a from the knife bar, anda pressure pad carried on the free end of each leaf spring normally lat la level beneath the lower edge of the movable knife for engagement with the web on said support means prior to the movable knife, whereby movement of the knife Kbar causes said fingers to engage the web and place the web under tension prior to the cuttingv of the web by the movable knife.
2. A mechanism for cutting limp lfilm material comprising,in combination, a base, a cutter supported on said base including a fixed knife land :a movably mounted knife bar adapted to carry `a cooperating knife iat opposite sides of the material path, means beyond the cutter at the same level as the fixed knife for supporting land intermittently advancing said material, a finger mounting plate adjustably mounted on said knife bar, yand -a plurality of laterally spaced fingers mounted on said mounting plate and extending rearwardly to positions overlying said means, each of said fingers comprising ya leaf spring having a downwardly -angled mid-section and a free end extending generally'parallel to said means, and a pressure fixed knife and a knife bar movably mounted Von the base adapted to carry a cooperating knife, means for supporting and intermittently advancing a web including -a conveyor, a mounting plate adjustably mounted on said knife bar, flexible straight leaf spring means mounted on said mounting plate and extending rearwardly `and downwardly to overlie the conveyor `at a level lbeneath the lower edge of the movable knife for engagement with the web prior to the mov-able knifewhereby movement of the knife bar causes said flexible means to engage the web and be flexed to place the web under tension prior to the cutting of the web `by the movable knife.
4. A web cutting mechanism comprising, in combination, a support, means for Ifeeding material onto said support, a base, :a cutter supported on said base between the support and the feed means including a fixed knife and a movably mounted knife bar `adapted to carry a cooperating knife at opposite sides of a web path, a finger mounting plate mounted for movement relative to the base and in tirned relation to the knife bar and at the same side of the web path `as the knife bar, and a plurality of laterally spaced fingers mounted on said mounting :plate Iand extending in a direction away from the cutter to overlie the support, each of said fingers comprising a leaf spring having a-downwardly angled midsection and a free end normally at a level beneath the lower edge of the movable knife for engagement with material on the support prior to cutting thereof by the movable knife, whereby the free ends of the fingers engage the material prior to engagement of the material by the movable knife and the fingers then flex to place the material under tension prior to the cutting of the material by the movable, knife.
References Cited in they file of this patent UNITED STATES PATENTS 337,270 Kelsey Mar. 2, 1886 631,475 Post Aug. 22, 1899 1,169,767 Bresnan Feb. 1, V1916 -1,417,609 Koerner May 30, 1922 1,490,230 Pollock Apr. 15, 1924 1,519,225 Townsend Dec. 16, 1924 l1,874,532 Y Holmgren Aug. 30, 1932 1,955,811V Irrnscher Apr. 24, 1934 2,022,198 Hartley Nov. 26, '1935 2,254,374 Laukhuff Sept. 2, 1941 2,364,985 Laukhuff Dee. 12, 1944 2,518,069 Roper Aug. 8, 1950 2,687,604 Corley etal Aug. 31, 1954 FOREIGN PATENTS 619,890 Great Britain Mar. 19, 1949