US2057279A - Feeding mechanism - Google Patents

Description

v Oct. .13, 1936.

w'. P. SHOMAKER FEEDING MECHANISM Filed May 7, 1936 2 Sheets-Sheet 1 INYENTOR ATTORNEY" Patented Oct. 13, 1936 UNITED STATES PATENT VOFFIQE 2,057,279 .FEEDING MECHANISM Wesley P. Shomaker, Richmond, Va.

Application May 7, 1936, Serial No. 78,298

3'Claims. ((1271-28) My invention relates to feeding mechanisms for machines into which fabric in sheet form is fed piece by piece so that it may be shaped or impressed. It particularly relates to feeding 5 mechanisms for printing machines, and it has for its special object the feeding of small sheets of paper, or envelopes, to a printing machine or other machine designed to perform some operation on the stock, such as embossing, stamping,

l printing, folding, etc. In describing my invention I shall do so as feeding envelopes to a printing press. 7

A successful mechanism of this character must be accurate in its operation, must be easily ad- 15 justable for the size of stock to be handled, must be synchronized with the press, and must be safely operable at high speed. These characteristics are possessed by my invention.

In the drawings, Figure I shows the principal 20 features of the feed mechanism in plan. Figure II shows the same in elevation and part section. Figure III shows a horizontal section through one of the principal parts of the feed mechanism.

25 In Figures I and II a hopper holds a number of envelopes 2, standing on edge. The hopper is inclined, to cause the envelopes to slide onwards toward a drum 3, against which the column of envelopes comes to rest. A cylin- 30 drical roller 51, usually of wood, is allowed to roll down the hopper and to bear against the back of the column of envelopes to hold it in shape. I

. The drum 3 is rotatably mounted on the shaft 4.

35 The shaft itself is stationary. Mounted on and keyed to a sleeve 5 which extends from the drum 3 is a gear 6. When the gear 6 is rotated, the drum 3 is rotated. Another gear I mounted on shaft 8 meshes with gear 6. Gear 1 may be 40 loose on shaft 8, and held from movement along theshaft by the collars 9 and ID. The drive shaft carries a fixed gear I2, meshing with the gear 1. On the same drive shaft II is fixed the chain sprocket l3, which is driven from 45 another chain sprocket mounted on one of the case I have chosen that the drum 3 shall make one fourth of a revolution to each impression made by the press.

In Figure III is shown a horizontal section of the drum 3, taken on line ab in Figure II, 5 with the hopper and envelopes added in plan. At each end of the drum 3 are the sprocketwheels 20 and 2|; rotatably adjustable about the same axis as the drum; and when adjusted, clamped by one or more screws to the drum 10 itself.

These sprocket-wheels 20 and 2| carry and drive the sprocket chains or belts 22 and 23. See also Figures I and II. These belts are the conveyors which. carry the envelopes to the press; and theyare driven by the sprocketwheels and 2|, and are carried at their further end by the idlers 24 and 25, which are rotatably mounted on the shaft 26. These conveyors may be steel belts or chains. I have 20 shown belts for the sake of simplicity in the drawings. Hereinafter I shall refer to them as the conveyors or conveyor belts. On the conveyors are attached cleats, or what are known in the art as pushers, 21, 2B, 29, etc., spaced 25 at regular distances apart. These pushers carry the envelopes forward at regular spaced distances apart to the feed rolls IE to the printing press. At It is a brush or other form of soft spring, supported by a bracket androd I8. The envelopes are carried against this brush, which pushes them against the pushers 21, and so brings them into proper alignment. The conveyor belts may be driven by any suitable number of sprockets on the wheels 20 and 2|. I have shown four sprockets, 30, on each wheel; and each sprocket engages through an aperture 3| in the conveyor against one of the pushers 21, etc.

Referring to Figures II and III, the drum,3 is pierced by four air passages or manifolds 4|], 4|, 42, and 43. These passages enter the drum 3 on the side; the near side in the drawings. From each of the air passages there branch off air tubes 45, 46, 41, and 48, opening 5 on the peripheral face of the drum 3; the several sets of air tubes being spaced apart an equal distance.

The diameter of the drum 3 is a little greater than that of the sprocket-wheels 20 and 2| to 5 give a sufiicient clearance, so that an envelope lying against the drum 3 shall not be fouled by the pushers 21, 28, 29, etc. The diameter of the drum can be made greater if desired to increase the space on the periphery between sets 5 5 of air tubes; or it may be increased to accommodate a greater number of sets of air-tubes, and therefore a greater number of envelopes per revolution.

The object of the air tubes is that by creating a suction in them this suction shall, as the drum 3 rotates, take hold of one envelope after another, and lift it from the end of the hopper i. It is desirable that the envelope be released by the air before it comes into contact with the conveyors 22 and 23; and this I bring about by suitably proportioning the air passages 40, 4|, 42, 43, and the duration of the partial vacuum which is set up therein. a I

Adjustably fixed on the stationary shaft 4, by means of a set screw 56, is the'air-valve-cover 50. To this cover is fitted at 5| a vacuum hose connection 52; the hole or port 53 passing through the cover 59. The inner face 54 of the cover 50 is exactly parallel with the face55 of the near end of the drum 3, in which face the air passages 40, 4|, 42, 43 are. The face of the drum 55 and the face of the valve-cover 54 are at a convenient distance apart to admit the sliding valve 60, which is fitted neatly between them. The valve 60 is normally stationary, with the valve-cover 50; and it is held from sideways movement with reference to the cover 50 by theshaft 4 which passes through both, and by :1. lug 6| attached to the valve and passing through the slot 62 in the valve-cover. The hole 64 in the valve through which'the shaft 4 passes is elongated to form a slot, lengthwise of the valve; and the slot 62 is lengthwise of the valve-cover. Consequently the valve can slide lengthwise between the cover and the drum 3 to the limit of these slots. A pawl or latch 65. is arranged to bear against the lug 6!, or if preferred in a notch cut in the valve 68, to hold the valve in the position shown in the drawings. A spring 66 .is arranged between the lug SI of the valve and another lug 61 on the cover 56 so that it is in compression when the valve: and cover are in the relative positions shown. The position shown is the operating position. If the latch 65 is tripped so that the lug BI and with it the valve 60 is freed, the spring 66, relieved of restraint by the" lug 6|, will open, and will force the lugs 6| and 61 apart, and in so doing will move the valve lengthwise between. valve-cover 50 and drum 3 to the limit allowed by the slots 62 and 64. The object of this movement will be stated later. 'At present it is to be: understood that the relative operating positions of valve 60 and valve-cover 50 are as shown in Figures I, II, and III.

In and passing through valve 66 is an air passage or port 70, which registers with the air port 53 in the valve-cover 59. These two ports, 53 and 10, are the same radial distance from the center of the shaft 4 as are the air passages 40, 4|, 42, and 43 in the drum 3. When the drum 3 is revolved around the shaft 4 each of the passages 40, 4|, 42, 43 is brought into registration successively with the ports 10 and 53, in the valve and valve-cover respectively, and therefore with the vacuum pump connection 52. Upon registration of the ports 10 and 53 with the air passage 46, for example, the air pressure in passage 40 is at once reduced. And so in passages 4|, 42, or 43, as they successively register with ports 10 and 53. Again for example: when passage 49 registers with ports and 53, and the air pressure is reduced in passage 40, so also will the air pressure he reduced in branch tubes 45 are in registration.

its contact with port 10 in valve 60.

air passages 45. And so also successively in branch air passages 46, 41, and 48. And when the air pressure is reduced in these branch air passages there will be a suction at the free ends of the said branch passages. (To avoid c0nfu-- sion of the several air passages shown in the drawings I will hereinafter refer to the openings 53 and 10 as valve-cover port and valve port, respectively; to the air passages 40, 4|, 42, 43, as the passages; and to the branch air passages 45, 46, 41, and 48 as the tubes.) In the drawings, in Figure III, ports 53 and 10, passage 40, and 7 If the vacuum pump. be running there will be a suction at the free ends of tubes 45.

Refer to Figure II. The drum 3 is revolving in the direction shown by the curved arrow. Passage 46 in the drum 3 is at the beginning of As the drum continues to rotate, the passage 40 and port 16 come into and pass through full registration cutting off as passage 40 finally leaves port 10. While passage 40 and port 16 are in registration there will be suction at the free ends of tubes 45; and there will also be suction from the beginning of contact until the final cut-off. The period of contact is dependent upon the diameter of the port 10 and of the passage 40. As drum 3 revolves, and as port 10 and passage 40 make contact, the suction of air at 45 will seize the first envelope, and will lift it out of the hopper. But when one lifts an envelope or a sheet of paper from a hopper or similar container it is a well known fact that the second envelope or sheet will be inclined to adhere to the first, and. so be lifted with it. So may the third be inclined to adhere to the second. This tendency is aggravated by the fact that the atmospheric pressure tends to hold the envelopes together, and to hold them against the face of the drum because of the difference in pressure between the air in the room and the air in the tubes 45. There is also the slight pressure exerted against the envelopes in the hopper by the roller 51. This holding together and lifting together has rendered many forms of feed mechanisms useless. A part of my invention is to separate the envelope to be lifted from those behind it; and to prevent the lifting of the second or of the succeeding envelopes from the hopper. I first break the even plane of the envelope to be lifted, so that it will not cling to the next one. This.I do by holding the envelope back along its central vertical line while I pull the two wings, one on each side of the central line, forward by the air suction at the tubes 45. This may be done in several ways; but I do it very simply and effectively by increasing the diameter of the drum at its center, so forming an upstanding rib 12. As the envelopes press against the drum, the tendency of the increased central diameter of the drum is to push the vertical center of the envelope back from the drum. Then just at the point of lifting the envelope, the differential in the air pressure on the two faces of the envelopes forces the two wings of the envelopes against the drum, so holding the first envelope in a broken line. This can be seen in Figure III. Now the first envelope will be held away from the second envelope on either side of the center; and the tendency to lift the second envelope will be only due to the mechanical friction between the two envelopes at their center. Above the envelopes at this point I arrange on a rod 32 the comb bracket 33. See Figures I and II. The bracket is adjustable on the rod 33. To the bracket 33 is adjustably attached the footpiece 34. Slots are cut in one edge of the foot-piece, forming toes 35. These toes are turned upward a little (see Figure II) and stand slightly clear of the face of the drum. On the foot piece 34 there is held, by screws 36, the comb 31, which is slotted along one side to form the fingers 38, which are bent to pass through the slots between the toes 35 of the foot-piece 34. The tips of the fingers 38 I allow to bear lightly against the face of the drum 3. These fingers offer a slight resistance; to the passing of an envelope; and this resistance is somewhat greater than the lifting force acting on the second, or third, or succeeding envelopes; and is therefore sufiicient to hold them down. But the greater lifting force given to the drum 3 by the vacuum tubes 45 carries the first envelope past the fingers 33, and delivers it to the grip of a belt I! which runs on crowned idlers l8 and i9; and which bears down upon the face of the drum 3. I prefer to make thebelt of rubber. When in operating position this rubber belt is a little stretched. The crowned idlers i8 and I9 are mounted with ball or roller bearings on the shafts 88 and 8!; and these shafts are dropped into slots 82 and 83 cut in the side plates 84 and 35. These slots converge as they go downwards towards the level of the drum; so that theelasticity of the stretched rubber belt pulling the shafts and BI together in the slots 82 and 83, causes the rubber belt to hug the face of the drum 3. As the drum revolves it will drive the belt H by friction; and when an envelope comes between the rubber belt and the drum there will be friction enough to cause the belt to travel on its idlers.

The two side plates 84 and extend, on the outside of the conveyors 22 and 23, from the hopper l to the end of the conveyors. These plates are adjustably mounted on the rods 66 and 81, along which they may be slid in a horizontal plane to adjust the conveyor to different sizes of envelopes. These plates prevent the envelopes from working ofi the sides of the conveyor.

Referring again to Figure II: the drum 3 lifts the envelope from the hopper by the air suction at the ends of the tubes 45. The envelope is quickly transferred to the grip of the rubber belt II; and the vacuum pump is disconnected from tubes 15 by the passing out of contact of port l0 and passage 40. A new high vacuum builds up in ports 53 and iii, ready for contact with the next air passage 3!, and for the lifting of the next envelope.

The first envelope being transferred to the grip of the rubber belt ll, it is carried over to and deposited upon the conveyors 22 and 23 at l9, Figure II. As the envelope is fed out from under the rubber belt II, the pushers 28 rise behind it and carry it forward with the conveyor, as at 39 and 39. It will be understood by those familiar with the art that the envelope When it leaves the grip of the belt i1 is likely to be slewed a little on, that is, not exactly square with, the conveyor. It is then carried forward against the brush 16 which aligns the envelope against the, pushers 21. It is then carried onward until it is discharged over the conveyor pulleys into thegrip of the press feed-rolls l5. By these rolls it is fed to the printing mechanisms, which are) indicated typically by the cylinder 92, in Figure I.

My feed mechanism is so designed and constructed that it may be attached to automatic machines. Such machines are stopped occasionally from one trouble or another, and while it may be necessary or convenient to allow the drive shafts to continue running. It is then desirable to stop the feed, lest good material be fed into the standing machine and destroyed. To this end the latch 65, Figure II, is mechanically or electrically connected with the operating parts of the press, for instance by a rod 93, so that whenever the machine is stopped or trouble occurs the latch 65 is tripped, the spring 66 forces the valve 60 forward the limit allowed by the slots 62 and 64, and the port 10 is thrown out of registration with port 53 and with passage 49. The vacuum is then lost in the tubes 45, and the drum 3 will no longer lift envelopes from the hopper l.

The sprocket wheels 20 and 2| are screwed or bolted at the ends of the drum 3 by any suitable adjusting means so that the pushers 21, 28, 29, etc., on the two conveyor belts may be correctly timed with the drum 3 and its tubes. 7

The hopper I is constructed with a cast iron box-like end, from which rails 58 and 59 extend as far back as may be desired.

I claim:

1. In a feed mechanism: a hopper for holding envelopes or the like in series; means for lifting the envelopes from the hopper in series; a comb consisting of spring fingers adjusted to allow the lifting of the first envelope in the series which is held by the lifting means but to hold back in the hopper envelopes behind the first envelope; and means for adjusting the resistance of the spring fingers.

2. In a feed mechanism: a hopper for holding envelopes or the like in series; a rotatable cylindrical drum the face of which is in contact with the face of the series of envelopes, and having about its periphery an annular projecting rib adapted to press upon the face of the series of envelopes, and provided with suction means on either side of its rib to hold the first envelope in the series and to lift it from the hopper; and means for rotating the drum.

3. In a feed mechanism: a hopper for holding envelopes or the like in series; a rotatable cylindrical drum the face of which is in contact with the face of the series of envelopes, and having about its periphery an annular projecting rib adapted to press back the center portion of the first envelope in the series, and provided on its face on either side of the rib with suction means to seize the first envelope in the series and to lift it from the hopper; means for rotating the drum; means for creating a partial vacuum in the suction means of the drum during part of a revolution of the drum; means for carrying the envelope forward after its release from the suction means, the said carrying means being provided with means for equally spacing the envelopes apart as it receives them from the drum; and means for aligning the envelopes with the' spacing means.

WESLEY P. SHOMAKER.

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