US2468842A

US2468842A - Bottom feed device for paper sheets

Info

Publication number: US2468842A
Application number: US756389A
Authority: US
Inventors: Robert C Sporleder
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-06-23
Filing date: 1947-06-23
Publication date: 1949-05-03
Anticipated expiration: 1966-05-03

Description

y 1949. R. c. SPQRLEDER 2,468,842

BOTTOM FEED DEVICE FOR PAPER SHEETS Filed June 23, 1947 IN VEN TOR. Roasm C. SPOELEDEB HTrOEN- YS.

BY m M corner of the stack of paper.

Patented May 3,1949

Application June 23,- 1947, Serial No. 756,389 2 Claims. (01. 271-41) 1 This invention relates to a bottom feed device for paper sheets and has forits principal object the provision of simple, reliable means to pre-. vent double feeding of paper sheets from the bottom of a stack of such sheets and to insure the feeding of single sheets onlyin succession from said bottom. I t

Another object of the invention is the provision of animproved method of feeding single sheets only from the bottom of a stack of sheets to a duplicating device or wherever such single sheets are desired.

The desirability of delivering single sheets from the bottom of a stack to a duplicating machine or other machine for further operations on such sheetshas long been known. The stack from which delivery is made may be quite high and may contain many thousands of sheets, whereas in delivering sheets from the top of a stack, the capacity is limited and asdelivery must be made from a fixed level, the stack must be raised. Gravity keeps the bottom of a stack at a fixed leved where the bottom sheet is delivered, as in a bottom feed.

However, heretofore, no successful bottom feed device that will consistently feed only a single sheet from the bottom of a stack has been made, insofar as I am aware. The most common at tempt at preventing double feeding has been to. provide upwardly directed needles or pins that are intended to pierce the lower sheet and engage the second sheet from the bottom for holding the second sheet against movement with the first one. The first or lowermost sheet is torn loose in such instances. Apart from the fact that an objectionable tear is produced by this method Fig. 5 is a semi-diagrammatic view of a modi fled form of theinvention.

In detail, the device illustrated in the draw-' ings comprises a hopper I having side and end members for'holding a vertical stack of rectangular sheets 3 of paper therein with the corresponding edges of such sheets in alignment. While these sheets may be of any desired width and length, they are usually oblong, or about lettersize, and are fed from the stack lengthwise. In

using the words forward, forwardly, rear and rearwardly in the description, these words are used with respect to the direction of travel of the paper. Thus, the forward side of the hopper is the side that is along the leading edges of the paper that are foremost when moved from the stack, while the rear side is that side alon or system, the device soon fails to function due I and for insuring proper single feeding of sheets without objectionable mutilation of the sheets.

' Other objects and advantages will appear in the description and in the drawings. In the drawings,

Fig. 1 is a side elevational view, broken away in parts, illustrating one form of the invention. A

duplicator is diagrammatically shown.

Fig. 2 is a rear end view of the feed hopper of Fig. 1. I

Fig. 3 is an enlarged, fragmentary, semi-diagra'mmatic view of the lifting device for stopping the feeding of paper.

Fig. 4 is .an enlarged, fragmentary elevational view of one of the blade supports at the lower rear the trailing edges.

The forward and rear sides of the hopper may be rods, sheets or strips, as desired. Usually the forward side 4 is a sheet or strip of material having its lower edge terminating a very slight distance above the level of the lowermost sheet in the stack so that the lowermost sheet may pass under said lower edge. Also the lower margin 5 of said forward side may be bent slightly outwardly as seen in Fig. 1 to facilitate the dispensing of paper.

By making the sides of the hopper out of strips 6, it is seen that the stack is visible at all times if not impossible, were the sides and ends solid and imperforate. While a rear strip 1 is shown, this is not absolutely necessary. It may function to keep the stack with the edges of the sheets in alignment, but once the-stack is properly positioned, the sheets will usually-stay in alignment if rear side is used or not.

Sides 6 and ends 4, 1 are supported on a frame 8 that includes parallel side members between which is supported a power driven feed roller 9 that is below the forward portion of the stack 3 and adjacent the lower forward corner of said stack. This roller 9 supports the forward portion of the stack.

Roller 9 has a friction surface on most of its periphery as indicated in heavy black line (Fig. 1a, and a polished anti-friction segment 9 in the balance. The circumferential length of the friction surface is such as to deliver a sheet I of the rollers may be varied relatively as desired through the variable speed transmission.

Any suitable arrangement may be provided for rotating rollers 9 and 10, such as a motor 12, variable speed transmission l 3 and belts or chains [4 connecting between the transmission and the roller 9 and drum 10, respectively.

Adjacent roller 9 is a cross-roller l5 that is eccentrically supported for rotation at its ends in the frame 8. A handle IS on one end of this bar may be grasped for rotating the roller, and in one position I! of rotation, the roller will raise the stack clear of the roller 9 (Fig. 3) while in the full line position the roller will drop below the stack to allow the weight of the latter to be taken by the roller 9.

If the sheets of paper are of appreciable length, one or more rollers intermediate the ends of the sheets and below the stack may be used. In ordinary letter or legal sized sheets such extra roller is not usually necessary.

Below the rear lower corner of stack 3 is a pair of spaced blades that are supported vertically with their cutting edges 26 (Fig. 4) slanted to extend across and to cut into the lower rear edges of the sheets of paper in the stack. Thus the blades will frictionally engage the second sheet from the bottom directly to the rear edge of,

such sheet, or to apoint coincident with said rear edge. The friction caused by this engagement is adequate to restrain the second sheet from moving with the lowermost one as the latter is drawn from below the stack.

Where narrow sheets are used, only one blade is required, or if wider ones are used, then two or more blades may be employed. Two is found to be adequate with standard letter-sized sheets.

Blades 25 are preferably of the wafer-type, such as conventional wafer-type safety razor blades, and said blades may be removably held in adjustable clamping members 21 that are held in adjusted position by thumb nuts 28. The angle of the cutting edges of the blades may be adjusted by loosening nuts 28'and by revolving the blades about the respective axes of the bolts carrying said nuts. It is important that this adjustment be provided inasmuch as it has been found that the angle of the cutting edges is important, and this angle may vary accordingly to the weight and character of the paper to be fed.

Above the stack of paper 3 is a'follower weight 30. This weight insures feeding of the paper to the last sheet. The rear edge of said weight is slotted as indicated at 3| to receive the blades 25 when the paper is fed to the last sheet. This weight insures the slitting of the lowermost sheet by the blades 25 so that the second sheet from the bottom will always be in frictional engagement with blades 25 no matter how much or how little paper is in the stack.

In operation, the roller 9 will draw sheets 3 in succession from below the stack and the stack will automatically fall as the sheets are withdrawn under the infiuence'of the weight of the paper and of weight 30. The rear edges of the paper sheets are slit by the knives or blades 25 as the stack lowers. This slitor slits extends through onlythe lower several sheets and is so small as to not be noticed, but it is sufiicient to cause sufiicient resistance between the blades and the second sheet from the bottom so as to prevent said second sheet from being discharged or withdrawn with the lowermost sheet.

In Fig. 5 a roller 40 is substituted for the blades 25. In this form of the invention the lower several sheets will automatically be riflied along their rear edges where they engage the roller 40. The second from the bottom sheet will engage the roller 40 and even though this roller is free to rotate, there is a small resistance between said roller and said second sheet, and'this is suflicient to prevent the second from the bottom sheet being withdrawn in many instances where it would normally follow the fast sheet.

It is to be understood that the detailed description and drawings are not to be considered restrictive of the invention but merely illustrative thereof.

I claim:

1. In a bottom feed device for a stack of paper sheets, a support for said stack includin means positioned adjacent one of the lower corners of such stack adapted to frictionally engage the second sheet from the bottom of said ,stack at a point substantially coincident with the edge of such sheet adjacent said corner for restraining movement of said second sheet in its plane upon forceably sliding the lowermost sheet in its plane from below said stack in a direction away 7 from said corner when the weight of the stack is on said lowermost sheet, said means comprising a vertically positioned wafer-type blade'having a generally upwardly directed cutting edge extending slantingly across said corner for cutting through the latter including said second sheet when said stack is positioned over said blade, and means for positioning such stack over said blade with its said corner in a position to be supported by the latter for said cutting.

2. A feed device for a stack of similar rectangular sheets of paperhaving their corresponding edges in alignment comprising, a holder for supporting said stack vertically, a movable friction element supporting said stack from below along one of said edges and adjacent one lower corner of the stack for sliding the lowermost sheet from below said stack with the edge of said sheet along said element leading upon actuation of said element, means below said stack extending across the lower opposite corner of said stack that is remote from said one lower corner and frictionally engaging the sheet immediately above said lowermost sheet for restraining movement of said 7 sheet with said lowermost sheet free from tearing said lowermost sheet, said means comprising a pair of blades having generally upwardly directed cutting edges extending slantingly across and through said opposite lower corner and through the edgeof said second sheet.

ROBERT C. SPORLEDER.

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

UNITED STATES PATENTS Number Name Date 1,291,074 Milmoe et al. Jan. 14, 1919 1,394,613 Drury Oct. 25, 1921 1,433,911 Ritchie et al. Oct. 31, 1922 1,555,378 La Bombarde Sept. 29, 1925 1,593,620 Chvojka July 27, 1926 1,594,883 Holmberg et al Aug. 3, 1926 1,739,153 Laxo et al. Dec. 10, 1929 1,971,962 Jones Aug. 28, 1934 FOREIGN PATENTS Number Country Date 708,240 France July 21, 1931