US2097587A

US2097587A - Sheet feeding device

Info

Publication number: US2097587A
Application number: US736500A
Authority: US
Inventors: Lester V Dearing
Original assignee: AUTOMATIC UNIT CORP
Current assignee: AUTOMATIC UNIT Corp
Priority date: 1934-07-23
Filing date: 1934-07-23
Publication date: 1937-11-02
Anticipated expiration: 1954-11-02

Description

Nov. 2, 1937. L. v. DEARING SHEET FEEDING DEVICE Filed July 23, v1934 s Sheets-Sheet 1 INVENTOR. WW7

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Nov. 2, 1937. L. v. DEARING I 2,097,587

SHEET FEEDING DEY ICE 3 Sheets-Sheet 2 Filed July 23, 1934 I INVENTOR m. 7 Max/M my ATTORNEY.

Nov. 2', 1937. 1.. v. DEiARlN G 2,097,587

SHEET FEEDING DEVICE Filed July 23, 1934' 3 Sheets-Sheet .5

IN VEN TOR.

ATTORNEY.

Patented Nov. 2, 1937 SHEET FEEDING DEVICE Lester V. Bearing, Milwaukee, Wis assignor to Automatic Unit Corporation,

Wisconsin a. corporation of Application July .23, 1934, Serial No. 736,506

(rill. 271-26) ers, push fingers, or other auxiliary mechanism 14 Claims.

This invention relates to improvements in sheet feeding devices.

Sheet feeders of various types are commonly employed for removing sheets of paper, cardboard, or the like from a stack and for feeding the same one by one to a conveyor, sorting machine, printing press, or other device. Heretofore, considerable difiiculty has been encountered in satisfactorily separating the sheets during feeding, This separating is necessary because of the fact that slight adhesions between superimposed sheets of a stack are common, and these adhesions must be broken to eliminate the possibility of a plurality of sheets being picked 5 up simultaneously by the feeder, this often causing serious dimculty in the device toward which the sheets are being advanced. In order to minimize the above-mentioned trouble, it has heretofore been common to employ combers, rollers,

or push fingers in conjunction with feeding devices. These attachments are not entirely satisfactory, are complicated, and cause additional expense.

Another objection to the ordinary type of feeder resides in the fact that the suction must be adjusted to suit the requirements of the particular grade of paper. For example, if a relatively thin paper is being employed, a light suction must be used, as a strong suction will pass thru the upper sheet of the stack and result in the picking up of a plurality of sheets instead of a single one.

Still another difficulty is caused by the fact that the usual type of feeder comprises a plu- 36 rality of feeder arms mounted rigidly on a common shaft for conjoint movement. -When the stack of sheets happens to have a hump therein, which frequently occurs, one or more of the feeder arms, in moving downwardly to engage 40 the paper, will be prematurely stopped by the hump, thereby holding the other arms in a position spaced above unhumped portions of the stack. When the suction is turned on, the latter feeder arms will not function due to the fact that they are held out of contact with the stack; and, as a result, there will be crooked feeding or dropping of the sheet. This often necessitates stopping of the entire mechanism.

It is one of the objects of the present invention to provide a sheet feeding device of the type embodying suction arms, having means for causing a peeling action as the sheet is being removed from the stack to thereby break all adhesions, said peeling action eliminating the necessity of employing the beforementioned comband. eliminating the necessity of adjusting the amount of suction to suit each grade of sheet material.

A more specific object'of the invention is to provide a device as above described, in which said peeling action is accomplished by means of pivotally mounted suction feet on the ends of the suction arms, which feet are automatically movable to angular peeling position when the suction is operating.

A further object of the invention is to provide a sheet feeding device of the type embodying suction arms, wherein said arms normally move in unison but wherein they are so mounted that if one arm is temporarily held in an unnatural position due to a. hump ii -the stack of sheets, the other arms will be unaffected, thereby eliminating the before-mentioned possibility of crooked feeding or of premature dropping of the sheets.

A further object of the invention is to provide a sheet feeding device which is relatively simple in construction, having a minimum number of parts, which is efiicient in operation, and which is well adapted for the purpose described.

With the above and other objects in view, the invention consists of the improved'sheet feeding device and all its parts and combinations as set forth in the claims and all equivalents thereof.

In the accompanying drawings, illustrating one complete embodiment of the preferred form of the invention, in whichthe same reference numerals designate the same parts in all of the views:

Fig. 1 is a plan view of the sheet feeder, showing it mounted adjacent the end of conveying mechanism, parts beingbroken away;

Fig. 2 is a sectional view, taken on line 2-2 of Fig. 1; r

Fig. 3 is a sectional view, taken on line 3-3 of Fig. 1, showing the feeder arm elevating mechanism in a. lowered position;

Fig. 41s a similar view, showing the feeder arm elevating mechanism in a raised position;

Fig. 5 is an enlarged, sectional view, taken on line 5-5 of Fig. 1, illustrating one of the feeder arms and associated mechanism;

Fig. 6 is anenlarged, fragmentary, detail view of the outer end of one of the feeder arms, show-' ing parts in longitudinal, vertical section, the suction foot being in a lowered position;

Fig. 7 is a view similar to Fig. 6, showing the suction foot in a raised, pivoted position;

Fig. 8 is a bottom view of the portion of the feeder arm shown in Fig. 6;

Figs. 9-12 inclusive are views similar to Fig. 5,

showing various positions of the feeder arms during different stages of the feeding operation;

Fig. 13 is an elevational view, looking at the end of a pair of feeder arms, showing the position assumed by one of said arms when it encounters a hump in a stack of sheets, parts being broken away; and

Fig. 14 is a fragmentary, on line |4-|4 of Fig. 13.

Referring more particularly to the drawings, it will be seen that there is a suitable frame I6 mounted on supporting legs or posts l1. Within said frame is a table or platform l8 for supporting a stack of sheets H! of paper, cardboard, or other material to be fed onto conveyor mechanism 20 or onto any desired device, such as a printing machine or sorting machine. The platform i8 is sectional view, taken of a standard type and is so supported that it is automatically raised as the stack of sheets thereon decreases in heighth. At the front of the platform are a plurality of spaced fingers 2| which project somewhat above the platform and. which are adapted to aid in squaring the front of a stack of sheets.

A cam shaft 22 may be suitably driven, preferably in synchronism with the conveyor 20; and said cam shaft is journaled in side portions of the frame as at 23. On each side of the cam shaft is a cam 24 and another cam 25. Each of the cams 24 (see Fig. 2) is adapted to cause reciprocation of a segmental gear 26 which is pivotally mounted as at 21 and which has its lower end connected by a rod 28 with a forked slide 29, the latter embracing the cam shaft and having a cam follower 3U thereon. Coil springs 30' are adapted to cause the followers 30 to remain in constant engagement with the cam surfaces. Each segmental gear 26 engages teeth 3| mounted on the lower portion of a slide 32, the latter slide working on a track 33. A tubular supporting shaft 34 has its ends connected to the two slide members 32, and another tubular member 35 is similarly supported between the slides 32 in a position parallel to and slightly in the rear of the tubular shaft 34.

A plurality of sheet feeding arms 36 have their inner ends loosely mounted on the tubular shaft 34 as at 31. An inlettube 38 is adapted to be connected to a sourceof suction, and said tube communicates with the interior of the tubular shaft 34. Said shaft forms a header for leading the suction to av central part of the tube 35 thru a flexible connection 40. Branch suction lines 4| extend from the tube 35 to the feeder arms 36. Each of said suction lines 4| communicates with a duct 42 (see Figs. 5 and 6) extending 1ongitudinally thru each feeder arm. Projecting from the outer end of each feeder arm is a tube 43 which communicates with the duct 42 and which has its outer end portion arcuate in shape, as at 44, to telescopically receive a smaller, arcuately shaped tube 45 projecting from a suction foot 46. The tube 45 communicates with a duct 41 in the suction foot, and the duct 41 communicates with a suction chamber 48 in the bottom of the foot. Said suction chamber is closed by a plate 49 having slotted openings 50 therein (see'Fig. 8). The suction foot is pivotally connected as at 5| to a lug 52 projecting from the end of the feeder arm. It is obvious that when the suction is turned on and when the plate 49 is in contact with a sheet of paper or other material, that the force of the suction will cause a telescoping of the

tubes

44 and 45 to thereby cause pivoting of the foot to the angular position shown in Fig. '1. This pivotal movement of the .at 54, to form a hook.

An elevating bar 55 is engaged within said U-shaped portions 54 of all the feeder arms, and the ends of the elevating bar are received by rollers 56. The rollers have grooved peripheries 51 (see Fig. 1) for engagement with arms 58. Each of said arms has one end pivotally-mounted to the frame as at 59 and has a rod 60 depending from the other end thereof. Each rod 60 has its lower end connected to one arm of a bell crank lever 6| as at 62. The otherarm of the bell crank lever is connected as at 63 to one end of a rod 64. The other end of the rod 64 is connected to a forked slide 65. Each of the slides 65 embraces the cam shaft 22 adjacent the cams 25 (see Figs. 3 and 4), and each of the slides 65 carries a follower 66 which is adapted to be engaged by the cam 25 to cause movement of the arm 59 from the position shown in Fig. 3 to the elevated position shown in Fig. 4.

In operation of the device, the feeder arms normally start in the position shown in Fig. 9, with the suction feet in a position substantially parallel to the top sheet. At the instant that the arms are lowered to this position, a suction is automatically created in the line 38, which, thru the tubular shaft 34, line 4|], tube 35, and suction lines 4|, causes a suction in the feet 46. As soon as this suction is created, the

tubular parts

44 and 45 will telescope as shown in Fig. '1, causing the suction feet to tilt upwardly as indicated in Fig. 10. This will cause peeling movement of the end of the top sheet of the stack, causing said sheet to be drawn slightly forwardly as indicated by the numeral 61 and thereby break all adhesions. Next, the cams 25 will have traveled from the position shown in Fig. 3 to the position shown in Fig. 4, to cause raising of the elevating bar 55. This will cause a lifting of all the suction arms to the position shown in Fig. 11. Next, the cams 24 will move to the dotted line position of Fig. 2 to cause a forward movementof the slides 32, thereby carrying the suction feet to the position shown in Fig. 12 or over the end of the conveyor 20. Following this, the suction will be automatically turned off; and the sheet will be dropped onto the conveyor vanced thereby.

The earns 24 will then return to the full line position of Fig. 2, thereby drawing the arms rearwardly; and the cams 25 will move to the position shown in Fig. 3, thereby lowering the elevating bar 55 and bringing the arms to the starting position of Fig. 9. If desired, in order to facilitate the sheet feeding, blowers may be employed at the front of the stack to aid in separation of the sheets from one another. The operation of the suction may be perfectly timed with the operation of the

cams

24 and 25 thru the use of well-known automatic valves.

If a stack of sheets is carelessly placed on the platform I8 so that a hump occurs in a portion thereof, as shown in Fig. 13, then when the elevating bar is being lowered to bring the feeder arms to starting position, one or more of the suction feet will be held by the hump in the stack belts 20 and adat an elevation above the other portions of the stack. If the ordinary type of feeder arm mounting were utilized in which all of said arms are rigidly mounted on a shaft for movement in invention, the feeder arms are loosely mountedon the shaft 34; and the elevating bar 55 engages the U-shaped members 54 in such a manner that there is both lateral and vertical play. Therefore, if one of the suction feet is held in an elevated position by a hump, as shown in Figs. 13 and 14, the elevating bar can still continue downwardly to permit all of the other feet to contact the stack even tho portions of the stack may be at different elevations. This play between the elevating bar 55 and the U-shaped part 54 is clearly illustrated in Fig. 14. This is an extremely important featureof the invention, as it eliminates the possibility of the before-mentioned crooked feeding and premature dropping of the sheets.

It is desired to again emphasize the fact that the pivotal mounting of the suction feet on 'the feeder arms as shown in Figs. 6 and 7 causes a perfect peeling action to be exerted on the top sheet, as shown in Figs. 10 and 11, causing the sheet to be drawn slightly forwardly during said peeling action to break adhesions before the sheet is further elevated and moved forwardly. This eliminates the necessity of employing auxiliary combers or push fingers to aid in separating the sheets, and due to the fact that the suction foot pivots as soon as the suction is turned on, there is no need for independently regulating the suction force for each grade of material, as the front part of the sheet is moved sufiiciently far above the sheet below as soon as the suction is turned on to prevent the suction from going thru thin paperand acting upon sheets therebelow.

The invention is particularly adapted for use in connection with sorting machines but is highly advantageous as an attachment for printing presses or any other mechanism wherein accurate feeding of single sheets from a stack is required. The invention is also adapted for use in connection with other thin sheet material besides paper, as for example tin.

Although only one form of the device has been shown and described, it is obvious that various modifications may be made therein without departing from the spirit of the invention and that the suction foot may be caused to automatically pivot by means other than the force of suction. All-of such modifications and adaptations are contemplated as may come within the scope of the claims.

What I claim is:

1. In a sheet feeding device, a shaft, a plurality of feeder arms loosely mounted on said shaft for movement into engagement with sheet material, suction feet carried by said arms in which a suction is established, a common elevating means for said arms, and means for independently connecting each arm to said elevating means, said means being constructed to permit the arms to fall by gravity to contact the sheet at different elevations when the elevating means is lowered.

' 2. In a sheet feeding device, a shaft, a plurality of feederarms loosely mounted on said shaft for movement into engagement with sheet material, suction feet carried by said arms in which a suction is established, a. common elevating means for said arms independent of the shaft on which the arms are mounted, and means for independently connecting each arm to said elevating means, said means being constructed to permit the arms to fall by gravity to contact the sheet at different elevations when the elevating means is lowered.

3. In a sheet feeding device, a shaft, a plurality of feeder arms loosely mounted on said shaft for movement into engagement with sheet material, suction feet carried by said arms in which a suction is established, a common elevating means for said arms, and a hook in connection with each arm for independently connecting each arm to said elevating means, said hooks being loosely engageable with the elevating means to permit the arms to contact the sheet at different elevations.

4. In a sheet feeding device, a shaft, a plurality of feeder arms loosely mounted on said shaft for movement into engagement with sheet material, suction feet carried by said arms in which a suction is established, a common elevating means for said arms independent of the shaft on which thearms are mounted, and cam operated means for operating said elevating means.

5.. In a sheet feeding device, a shaft, a plurality of feeder arms loosely mounted on said shaftfor movement into engagement with sheet material, suction feet carried by said arms in which a suction is established, a common elevating means for said arms independent of the shaft on which the arms are mounted, cam operated means for operating said elevating means, and means for simultaneously projecting the elevating means and arms in a forward direction.

6. In a sheet feeding device, a shaft, a plurality of feeder arms loosely mounted on said shaft for movement into engagement with sheet material, suction feet carried by said arms in which a suction is established, a common'elevating means for said arms independent of the shaft on which the arms are mounted, cam operated means for opfor simultaneously projecting the elevating means and arms in a forward direction, and a common cam shaft for said two cam operated means.

7. In a sheet feeding device, a reciprocatory carriage having a transverse shaft in connection therewith, a plurality of feeder arms mounted on said shaft for vertical pivotal movement, and means for moving said carriage in a straight line to cause forward and backward movement of the feeder arms.

8. In a sheet feeding device, a reciprocatory carriage having a transverse shaft in connection therewith, a plurality of feeder arms mounted on said shaft for vertical pivotal'movement, a common elevating bar for imparting said movement to said feeder arms, rollers on the ends of said bar, pivoted levers on which said rollers are supported, means for moving said levers to cause elevating and lowering of the bar and feeder arms, and means for moving said carriage to cause forward and backward movement of the feeder arms.

9. In a sheet feeding device, a plurality of feeder arms pivotally mounted for movement into engagement with sheet material, suction feet carried by said arms in which a suction is estaberating'said elevating means, cam operated means lished, and means for elevating said arms simultaneously, said means being also movable to free the arms and to permit the latter to fall freely by gravity to contact the sheet at different elevations.

10. In a sheet feeding device, a plurality of feeder arms pivotally mounted for movement into engagement with sheet material, suction feet carried by said arms in which a suction is established, means for elevating said arms simultaneously, said means being constructed to permit the arms to fall by gravity to contact the sheet at different elevations when the elevating means is lowered, and cam operated means for operating said elevating means.

11. In a sheet feeding device, a plurality of feeder arms pivotally'mounted for movement into engagement with sheet material, suction feet carried by said arms in which a suction is established, means for elevating said arms simultaneously, said means being constructed to permit the arms to fall by gravity to contact the sheet at different elevations when the elevating means is lowered, cam operated means for operating said elevating means, and means for simultaneously projecting the elevating means and arms in a forward direction.

l2. In'a sheet feeding device, a reciprocatory carriage, a plurality of feeder arms mounted on said carriage for vertical pivotal movement, common means for causing pivotal elevating movement of all of the feeder arms, and means for moving the carriage to cause forward and backward movement of the feeder arms.

13. In a sheet feeding device, a reciprocatory carriage, a plurality of feeder arms mounted on said carriage for vertical pivotal movement, common means for causing pivotal elevating movement of all of the feeder arms, rollers in connection with said common elevating means, pivoted levers on which said rollers are supported, means for moving said levers to cause movement of the rollers and elevating of the feeder arms, and means for moving the carriage to cause forward and backward movement of the feeder arms.

14. In a sheet feeding device, a reciprocatory carriage, a plurality of feeder arms mounted on said carriage for vertical pivotal movement, common means for causing pivotal elevating movement of all of the feeder arms, rollers in connection with said common elevating means, pivoted levers on which said rollers are supported, cam operated means for moving said levers to cause movement of the rollers and elevating of the feeder arms, and cam operated means for moving the carriage to cause forward and backward movement of the feeder arms.

LESTER V. DEARING.