US2657050A - Device for feeding sheet materials - Google Patents

Description

Oct. 27, 1953 'w; A. METCALF' 2,657,050

DEVICE FOR FEEDING SHEET MATERIALS Filed Sept. 50, 1948 Zlwwewfoo wlLLlAM A. METCALF Patented Oct. 27, 1953 William A. Me'tcail', Lancaster County,

of Pennsylvania Pa., Cork Company, Lancas West Lampeter Township, assignor to Armstrong ter, Pa., a corporation Application September 30, 1948, Serial No. 52,041

2 Claims.

My invention relates to a device for cutting or severing sheet materials and is eoncerned more particularly with a device for trimming rigid sheet materials, such as linoleum composition tiles and the like, in which a cutting die is brought I into cutting relationship with the sheet to be severed disposed upon a support such as a platen.

In the cutting of linoleum composition tiles and the like, they are sometimes severed to a proximately the desired size and are then trimmed to final dimensions; In this trimming operation, a. very minor amount of material is removed and it is necessary, therefore, to have the sheet disposed on the cutting platen in a predetermined relationship to the "die, with a very small tolerance allowable. In tile severing and trimming, it is desirable to feed the sheets at a relatively high rate-of-speed. One of the common arrangements ior feeding the sheets is a feed plate arrangement which is adapted to move the sheet from a reedin'g location to a trimming location. With sheets of linoleum composition, it has been found that inertia of the relatively heavy sheet as it is moved to trimming position causes the sheet to override the finally desired position; and, since there is but a limited tolerance in positioning, because of the small portion to be trimmed from the edges or the sheet, such improper positioning cannot be tolerated. It has been proposed to place stops on the platen to limit the forward movement of the sheets as they are fed, but it has been found that inertia of the sheet when it comes into engagement with the stops causes the sheet to rebound and thus be improperly positioned. The rough cut sheets vary in dimensions making it necessary to set the stops to properly :pos'ition sheetsof "maximum dimensions and positive positioning of the sheets between the feed plateand the stops is not possible.

It is not desirable to provide positive holding means on the upper surface of "the sheet because the die must be free for'severing around the entire periphery of the sheet closely adjacent thereto and inaddition any engagement with the upper surface which might cause marrin'g must be avoided.

it is an object of any invention to provide a device for trimming rigid sheet materials, such as linoleum tiles and the like, in which the sheet may be fed rapidly and will be properly positio'ned for trimming, even though only a minor amount of material is to be removed at the periphery of the sheet.

A further object of my invention is to provide a trimming arrangement in which movement of a sheet of material "the nature of a punch press.

the sheet to be severed is restrained without any mechanical engagement with the upper surface of the sheet to be trimmed.

According to a preferred embodiment of my invention, mechanism is provided for feeding sheets of material from a stack, over a supporting table, and onto a cutting platen, with means for creating a zone of reduced pressure at the surface of the platen tocause the sheet to be trimmed to be pressed against the platen as the sheet is moved thereover by the feeding means.

In order that my invention may be .more:.readily understood, I shall describe the same 'in conjunction with the attached drawing, .in which:

Figure 1 is a diagrammatic side elevational view, partly broken away and partly in section, illustrating one embodiment of my invention; and

Figure 2 is a top plan view of the arrangement shown in Figure 1 with the cutting head removed and with portions of the arrangement broken away and portions in section, illustrating the feeder and platen arrangement.

The device of the invention includes a cutting die 2 and a cutting platen 3 mounted in a press 4. Conventional means, not shown, are provided for reciprocating the cutting die 2 to bring it down toward the cutting platen 3 to efiectsevera-nc'e of T disposed on the cutting platen 3, the arrangement preferably being in The .press 4 'is provided with an extension 5 which supports the mechanism for holding and feeding the sheet material to be severed. In the embodiment illustrated, linoleum tiles 6 are supported in a stacker 1 which is mounted onto a guard 8 which encloses the feeding mechanism.

The feeding arrangement shownin the drawing includes a supporting plate 9 for the sheets 6, with the lowermost sheet lying in engagement with the upper surface-of the plate '9. The plane of the upper surface ID of the plate "9 is parallel to the plane of the upper "surface H of the cutting platen 3 and the .planesare-subs'tantially common. A feeding plate "l2 overlies the supporting plate 9 and is adapted to engage the edge of the lowermost sheet 6 in the stacker I.

The feeding plate 12 is mounted on a carriage [3 which is guided in ways 14 for reciproc'atory motion, efiected through a rack and pinion t5,

the latter being suitably connected for rotation in synchronism with the movement of the cutting die 2.

Upon rotation of the pinion 15 in "a counterclockwise direction, 'as viewed in Figure '1, "the table [3 and the feeding plate l2 will move to the left as viewed in that figure. This will bring the edge of the feeding plate [2 into engagement with the edge of the lowermost sheet 6 in the stacker 1 and will move the sheet over the plate 9 and onto the platen 3. Since both the plate 9 and platen 3 have sheet supporting surfaces disposed in a substantially common plane, the sheet 6 will lie substantially fiat on the platen 3 as it is moved thereover. The rack and pinion and the actuating mechanism therefor are so constructed and arranged that upon each stroke of the press 4 the feeding plate 12 will move a sheet from the stack to cutting position on the platen 3, whereupon the die 2 will descend and trim the sheet. As the cutting die 2 is lifted the feeding plate l2 will be retracted to its normal position, as shown in Figure 1, by a clockwise movement of the pinion l5, and the feeding plate l2 will then be in a position to engage the next sheet to be fed.

Various types of feeding mechanisms may be employed such as the conventional roll feeds, chain feeds, and the like. The feed plate ar rangement shown is preferred, however, for han dling sheet materials such as linoleum and the like.

The feeder and punch press may be actuated at a high rate of speed, frequently in the order of 70 strokes per minute. The sheet material being fed may be rough cut to about 9 /8 x 9 and may be inch thick. The trimmed size of the sheets or tiles may be 9" x 9".

The surface H] of the table 9 and the surface ll of the platen 3 must be relatively smooth to 1 permit proper movement of the sheets thereover, and they soon become quite highly polished by such feeding. Since the feeding plate 12 is moving at a relatively high linear speed to feed the sheets at the desired rate, the sheets will have a tendency to move by inertia over the platen 3 after the feeding motion of the feeding plate 12 has stopped. The portion to be trimmed from the sheets is, as noted above, relatively small and, consequently, the necessity for accurate positioning of the sheets on the platen 3 for proper severance by the die 2 is obvious. It is also apparent from the foregoing description that the use of stops on the platen 3 for limiting the movement of the sheets would be ineffective because the sheets are moved with such velocity that they would rebound upon hitting the stops, and accurate positioning would be impossible where the rough cut sheets were not of uniform size permitting positive abutment of the sheet between the feed plate and the stops.

Upon severance of the sheet material, the slivers removed in the trimming operation are preferably removed from the dies by suitably arranged air jets as are commonly employed in trimming operations of this sort.

In order to restrain the free movement of the sheets and to hold them against the face ll of the cutting platen 3, there is provided a suction arrangement for creating an area or areas of reduced pressure in the face of the cutting platen. In the embodiment illustrated, this is accomplished by having a suction chamber l6 connected to a suitable pump or fan for reducing the pressure in the chamber 16. Openings H are provided in the platen 3 opening into the surface H thereof. The number, size, and disposition of the openings 11 will vary,,depending upon the nature and size of the sheets to be severed. The openings shown in Figure 2 have been found 4 acceptable for positioning a tile which has been shown in dotted lines in that figure and identified with the letter T.

Generally, it is preferred to have the platen 3 provided with an upper cutting plate I8 attached to a supporting plate 19 and to insert a separate cutting plate I8 for each die member. For example, Where 6" x 6", 9" x 9", and 12" x 12" tiles are to be trimmed, separate cutting plates IE will be provided for each side and the openings I'I will be properly arranged to effectively control the movement of the rough cut sheets to be trimmed.

In the embodiment illustrated, the holes I! are shown passing through the platen l8, supporting plate l9, press extension 5, and also through the press bed. Identical results will be obtainedby having one relatively large opening in the press bed and press extension, this opening being suitably connected to the individual openings H in the cutting platen 3. By having the supporting plate [9 provided with intersecting grooves on its upper surface and a central opening connecting with the opening in the press extension and press bed the cutting platens will be properly supported and the openings I! will be properly connected to the pump or fan, the grooves in the supporting plate rendering it substantially universial for the various cutting platens positioned on 1 It will be clear from the foregoing that upon movement of the lowermost tile in the stack toward the left, as viewed in Figure 1, the tile will slide along the surface ll! of the plate 9 and onto the surface ll of the cutting platen 3. As soon as the tile 6 overlies one or more of the openings I! a drag will be placed upon the tile by atmospheric pressure urging the tile into en-. gagement with the surface II of the cutting platen 3 surrounding the openings I1, subatmospheric pressure existing in the openings l1. As the feeding plate I! continues its movement bringing the tile finally to a predetermined position on the platen 3, additional openings I! are closed by the tile and additional resistance to movement is built up, completely overcoming any inertia in the tile 6 which would result in improper positioning. Thus, when the feeding plate assumes its final position, the tile will be properly located with respect to the cutting die 2 and trimming may be accomplished with accuracy.

Upon completion of the trimming, the air jets for scrap removal will be actuated, the sheet T being held against movement by the suction arrangement. It will be noted from Figure 2 that the row 20 of holes I! closest to the feeding plate is not covered by'the sheet T when the same is in trimming position, This arrangement is provided so that the next oncoming sheet 6 from the stacker 1 will be drawn down into firm engagement with the surface ll so that its leading edge will engage the trailing edge of the sheet T to push the sheet T from the cutting platen.

While I have illustrated and described a preferred embodiment of my invention it will be understood the same is not limited thereto but may be otherwise embodied and practiced within the scope of the following claims.

I claim:

1. In the device for feeding rigid sheet materials such as linoleum composition tiles and the like, the combination of a support for a stack of rigid sheets to be trimmed, a stationary platen having a sheet-engaging surface which is com- F d pletely unobstructed from above and upon which said articles to be trimmed may be freely moved, reciprocatory means engageable with the end portion of a rigid sheet for feeding the same over said support and into position on the unobstructed surface of said platen with the sheet fully disposed on the platen, and means for creating a acne of reduced pressure at the surface of said stationary platen during relative motion of said sheet over said platen by said feeding means to cause said sheet to be held against said platen as said sheet is moved by said feeding means.

2. In a method of feeding a, rigid sheet material such as linoleum composition tiles and the like, the steps of moving said sheet over and relative to a platen with a surface of said sheet lying in engagement with the surface of said platen, creating a zone of reduced pressure in a limited area of the platen surface against which the sheet is positioned during said relative move- H ment to cause said sheet to be pressed against the platen by atmospheric pressure in said zone during such relative motion, maintaining said reduced pressure during movement of said sheet to final position on said platen, creating another zone of reduced pressure in an area adjacent to the rear edge of said sheet disposed upon said platen, and feeding a second sheet over said platen and in engagement therewith and into engagement with the rear edge of said first sheet, with atmospheric pressure holding said second sheet into engagement with said platen in the area adjacent to the rear edge of the first sheet to bring the second sheet into position Where its front edge will engage the rear edge of the first sheet.

WILLIAM A. METCALF.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 928,969 Harris July 27, 1909 1,182,474 Grover May 9, 1916 1,288,491 Bowen Dec. 24, 1918 1,477,920 Stewart Dec. 18, 1923 1,611,177 Fenlason Deo. 21, 1926 1,790,910 Frostad et a1. Feb. 3, 1931 1,8 %,645 Lach Feb. 23, 1932 2,313,100 Stevens Mar. 9, 1943 2,451,388 HaWes "Oct. 12, 1948 2,492,908 Von Hofe Dec. 27, 1949

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