US2351367A - Sheet feeding mechanism - Google Patents

Description

June 13, 1944. RlDER 2,351,367

SHEET FEEDING MECHAI II SM Filed Dec. 17, 1941 3 Sheets-Sheet l June. 13, 1944. E. G. RIDER 2,351,367

SHEET FEEDING MECHANISM Filed Dec. 17, 1941 3 Sheets-Sheet 2 17-11536 tlifzlzer;

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June 13, 1944. E. G. RIDER 2,351,367

SHEET FEEDING MECHANI SM Filed Dec. 1'7, 1941 3 Sheets-Sheet 3 Patented June 13, 1944 UNITED STATES PATENT OFFICE SHEET 7 Ernest G. Rider, Philadelphia, rs.

11 Claims.

The present invention relates to a paper feeding'mechanism and more particularly to means for removing one sheet at a time from a stack and delivering such sheets successively to a predetermined location.

In devices as heretofore designed to separate and remove sheets in succession from a stack of sheets it has been proposed to employ friction rollers for propelling the top sheet away from the stack; means utilizing liquid glue or adhesive in conjunction with a lifting mechanism; sticky picker cylinders controlled by cumbersome counter-weight means and, most frequently, suction devices. All such are open to objections and have many disadvantages from a practical standpoint. For example liquid adhesive is subject to temperature changes and the desired minute quantity required is practically impossible to control. Too much adhesive smears and damages the sheets, too little is ineffective, and even when temporarily adjusted will pick off part of the sheet surface. Friction rollers arranged to propel a sheet more often than cptherwise transmit pressure to the next follo'wingsheet or sheets and instead of one sheet being removed two'or more are simultaneously shifted to cause clogging of the feeding rolls. Suctipn devices frequently pick up a plurality of sheets simultaneously and require a great and continuing consumption or power.

Some of the objects of the present invention are to provide a mechanism for removing sheets from a stack without any of the previous disadvantages developing during operation; to. provide a mechanism for successively removing sheets from a stack and delivering each sheet to feeding rolls or other apparatus, such mechanism operating eillciently and continuously without soiling, crumpling or otherwise impairing the sheets for further use; to provide a sheet handling mechanism including an adhesive strip capable of adjustment while in use for varying the sheet pick-up mechanism wherein replaceable rolls of strip adhesive can be used; to provide a sheet pick-up mechanism which unfailingly engages only a single sheet; to provide a pick-up mechanism which requires no particular power requirements other than those normally attaching to the device with which the pick-up is associated; to provide a sheet feeding mechanism of extreme economy of operation while of enhanced efficiency; to provide a positive effective pick-up mechanism utilizing materials available universally at low cost for its effective engagement of the respective sheets; and to provide other improvements as will hereinafter tion showing the parts in sheet delivery position; Fig. 3 represents an end elevation of a portion of the machine to which the mechanism of the invention is attached; Fig. 4 represents an enlarged detail of the pick-up in contact with a sheet; Fig. 5 represents a sideelevation on a larger scale of a modified form of the invention including a mechanlsmgfor step-by-step control; Fig. 6 represents a perspective detail of a sheet separating device; and Fig. 7 represents another modification of sheet separating means.

Referring to the drawings one form of the present invention is shown assembled as a part of a standard sheet gluing machine, such, for example as a Stokes and Smith machine (see U. S. Patent No. 1,772,344) wherein a table l0 supports a stack of sheets I I which are to be removed one at a time for applying glue or other coating to one side thereof. The table II! is arranged for vertical travel at definite intervals through suitable intermittent motion applied to a plunger l2 upon which the table ill is mounted. Conveniently located adjacent the delivery point of the respective sheets are two coacting but relatively separable feed rolls l3 and H for directing each sheet to the stripper plates it for guiding the sheets successively under a guide roll I6 against the face of the glue applying roll il The glue or other material is contained in receptacle l8 and a roll 20 rotates in the liquid and also in contact with the roll H, which latter carries the deposited glue to the sheet. The sheets after coating are directed by a guide scraper 2i to a conveyor 22 which generally leads to a machine for applying the glued sheets to containers. The roll I3 is provided with a circumferential groove 23 which is juxtaposed with respect to'a like groove 24 in the roll H, to thus provide clearance. for a movable part presently to be described.

For the purpose of removing the sheets if from the stack one at a time, a strip 25 of material, having adhesive on one-side, is employed, the same being stretched about a blunt-ended substantially v-shaped pick-up finger 26 which is here shown as an extended part of a carrier plate 21. In the preferred form of the invention the strip 25 is wound glue side in about a hub 28 having, as an integral part, a brake drum 3|! pro vided with a v-shaped periphery. This hub 28 is mounted upon a pin 3i attached to and projecting laterally from the carrier plate 21 adjacent to the base of the pick-up finger 26. Also attached to the side of the plate 27, is a cylinder 32 having its axis alined with the brake drum 30 and housing a spring pressed plunger 33, the projecting end of which conforms to the l-shaped periphcry of the drum 30. Under the action of its and hold it against a stop 4|.

In order to spool up the used portion of the strip 25, a rewind roller 34 is journalled on a pin 35 projecting from the face of the plate 21, and has a ratchet wheel 8' attached thereto for stepby-step operation. An operating pawl 81 is pivoted upon a rock arm '4 which pivots on the pin ll and bass spring 40 to retract the arm I.

A back lash pawl 42 is pivoted to the plate 21 in position to seat in the teeth of the ratchet wheel 86 as will be understood. The rock arm ll has an extension forming a tapered detent 43 which at certain times is engaged by an abutment lug 44 carried by a pivoted bell crank 45.

As a-means for bringing a sheet from the stack ll into position for engagement by the feed rolls II and I4, the plate 21 is attached to a rod 44 by a set screw 41. or other fastening means. The ends of the rod 46 terminate respectively in rock links 4| and 49 respectively mounted on pivots ill for operation by links II from bell cranks l2. Each of these bell cranks carries a cam roller 53 riding in the groove 84 of a side face cam II. The action of this cam 55 is to swing the plate 21 from contact position with the top sheet of the stack to a position where the feed rolls can engage the end of the sheet and deliver it to the stripper plate and gluing roll.

For moving the feed rolls I! out .of the path of a sheet as the latter is being carried by the pick-up device, the ends of the rolls I! are journalled respectively in two legs I of each of two bell cranks, which are pivoted at I1, and the other legs 58 of which terminate respectively in rollers II which ride respectively against the edges of two plate cams II. The cam surfaces are so laid out as to cause the roll it to swing away from the roll l4 as the pick-up finger 2i rises so that the end of the sheet can pass the roll I4, and as this takes place the roll ll swings back to feeding position as it engages the lower side of the sheet and brings the sheet against the roll i4 to be fed forward and away from the pick-up device. The cam rollers II are maintained in contact with the face of the plate cams I by means of follower rods 62 attached to the respective legs It and each guided by a fixed boss CI, which latter serve to maintain coil springs 84 under compression. These springs 04 encircle the re-' spective rods 62 and bear respectively against yokes I! which have pivotal connection with the bell crank legs I. As shown the side face cams 55 are formed in the plate cams II for simplified construction.

In order to prevent one or more sheets adhering to the sheet being removed by the pick-up device, a separating element 84 is provided. this,

in the present instance, being in the form of a,

saw-tooth strip fixedly mounted to project into the path of the upwardly moving edge of a picked up sheet. Thus the edge of the sheet, which is being lifted by the pick-up finger ll, brushes across the face ,of the element II but the edge of any following sheet (one improperly adhering to the lifted sheet) is engaged by the element ll and caused to drop back upon the stack of sheets.

ative position. Thus the stop 12, which is formed as a projecting part of the rock-plate ll, rests point and the arm II. The stud I8 is arranged to be withdrawn from its stop holding'position at certain selected intervals, and, in the present instance, a lever I! is located with one end beneath the head of the stud II and its other-end extending into the path of a trip tappet ll. The lever I8 is pivoted at 'll intermediate its ends. The stud I3 is mounted to be slidably guided in a vertically disposed sleeve ll, while a pin I. limits the downward movement of the stud II. The trip tappet 16 is keyed to the rock-shaft ll and therefore follows the movement of the pick-up device so that the latter becomes a control for determining the time of operation of the rewind roller 34. Thus as each sheet is removed from the stack, the pick-up device and the trip tappet 18 move down by the thickness of one sheet, and when, for example, ten sheets have been removed the trip tappet I8 strikes the lever II to raise the stud ll out of the path of the stop and consequently the spring '14 rocks the plate ll (clockwise as shown) to pull the link I down and throw the lug 44 into the path of the detent 48. Now as the pick-up plate swings upward the detent will be rocked forward by contact with the lug 44 and thereby cause the rewind ratchet to be turned preferably one tooth.

For the purpose of raising the table I. after a selected number of sheets have been removed,

connection with a pin I! fixed to the plate II. A

cam or other suitable intermittent mechanism can be employed to actuate the rod 40 in a well known manner. Thus when the stud ll releases the stop 12 the plate I. rocks to shift the control bell crankv 45 and also brings the pawl l4 back upon the ratchet wheel 83 in position to transmit motion to the shaft ll so that the pinion l2 elevates the table III the necessary distance to bring a top sheet to the normallevel of the pick-up device.

From the foregoing it will be seen that the pick-up device is intimately associated with the table elevating mechanism and in addition to lifting sheets serves to control both the feeding of the adhesive strip and the table at times determined by the selected number of removed sheets.

In the form of the invention shown in Fig. 'l. a means is provided to move a separating member 08 into and out of operative relation to the stack of sheets. This may be used in place of the one or more separating members it, or in conjunction therewith, or may be used alone. Preferably this member II is located to coact with the sheet edges near the center thereof because here it functions to space and to slightly elevate the sheets in spaced relation while the members 68 near the sides of the sheet stack function to restrain the sheets and thus to enhance the separatiou and thus ensure an accurate pick-up of the topmost sheet only. As shown the member '8 is in the form of a saw blade but the invention isnotlimitedinthisrespectasotherformsof roughened edges or surfaces may be employed. The member 88 is pivoted at 80 to a holder Of which, illustratively only, is fixed to the shaft forming the connection between the links if and the bell cranks 52, so as to be moved in synchronism with the movement of the pick-up finger 26 by the same actuating linkage. Obviously any other actuating mechanism may be employed as desired. In the form illustrated as the links move, to the right as shown on the drawings, the plate 21 is rocked in the direction to lower the pick-up finger 28 into contact with the top sheet of a stack of sheets. The separating member 88 moves in timed synchronism with the movement of the links 5| and, in the preferred form at least, is so timed as to meet the edges of the sheets just prior to the attainment of the contact position of the pick-up finger 28. Since the member 88 is pivoted the contact of its edge with the sheet causes itto swing slightly about its pivot, which action is translated into an upward movement approximately parallel to the plane of the stack edges. As the initial contact of the member 88 with the sheets exerts a pressure against the edges, the foregoing upward movement acts as an effective means to separate the several top sheets one from another. The result is that the pick-up finger 26 can .lift the top sheet entirely free from the following sheets.

Obviously this separation is enhanced when stationary brush or other means is used at one point at the sheet edge while the movable member 88 is applied to the sheet edges at a different point on such edges.

Having thus described my invention, I claim:

1. A sheet feeding mechanism comprising a strip of material having a surface coated with adhesive, means to mount said strip in stretched condition, said means being contoured. to provide a line contact between said strip and a sheet of material, and means to shift said mounting means to deliver a sheet picked up by said strip to a selected location.

2. A sheet feeding mechanism comprising a strip of material having a surface coated with adhesive, means to mount said strip in stretched condition, said means being contoured to provide a line contact between said strip and a sheet of material, a device for changing the contact line of said strip, and means to shift said mounting means to deliver a sheet picked up by said strip to a selected location.

3. A sheet feeding mechanism comprising a support, a strip of material having a surface coated with adhesive and wound into a spool, means rotatably mounting said spool on said support, a pick-up finger holding a length of said strip in stretched condition for contact with a sheet, means to feed said strip from said spool to vary the relation with said pick-up finger, and means to shift said pick-up finger to deliver a sheet held by said strip to a'selected location.

4. A sheet feeding mechanism comprising a support, a strip of material having a surface coated with adhesive and wound into a spool,

means rotatably mounting said spool on said support, a pick-up finger holding a length of said strip in stretched condition for contact with a sheet, a tension device for maintaining said stretched condition, means to feed said strip from said spool to vary the relation with said pick-up finger, and means to shift said pick-up finger to deliver a sheet heldby said strip to a selected location.

5. A sheet feeding mechanism comprising a support, a strip of material having a surface coated with adhesive and wound into a spool, means rotatably mounting said spool on said support, a pick-up finger holding a length of said strip in stretched condition for contact with a sheet, automatically operated step-by-step means to feed said strip from said spool to vary the relation with said pick-up finger, and means to shift said pick-up finger to deliver a sheet held by said strip to a selected location.

6. A sheet feeding mechanism comprising a support, a strip of material having a surface coated with adhesive and wound into a spool, means rotatably mounting said spool on said support, a pick-up finger coacting with saidstrip to cause a portion of said strip to contact a sheet to be removed from a stack of sheets, said finger being carried by said support, means to oscillate said support, and means actuated by said support to vary the position of said strip relative to said finger, whereby fresh adhesive surfaces are brought into use at intervals.

'7. A sheet feeding mechanism comprising a movable pick-up finger for transferring a sheet of material from a sheet stack to another location,'means to stretch a strip of adhesive material about said finger for pick-up contact with said sheet, and means to vary the position of said strip relative to said finger whereby difierent sheets are engaged by different strip areas.

8. A sheet feeding mechanism comprising a movable pick-up finger for transferring a sheet of material from a sheet stack to another location, means to stretch a strip of adhesive material about said finger for pick-up contact with said sheet, and step-by-step means for feeding said strip about said finger whereby different sheets are engaged by different strip areas.

'9. A sheet feeding mechanism comprising a support for a stack of sheets, a member movable relative to said support, a strip of adhesive material carried by said member in position to cause an area of said strip to contact the top sheet of a stack on said support, and means to replace a used contact area of said strip with an unused contact area.

10. A sheet feeding mechanism comprising a support for a stack of sheets to be separated, a sheet separating device having a plurality of substantially linearly disposed teeth, and means for moving said device toward the side of said stack and angularly upwardly along the face of said stack to separate the edge portion of one or more sheets from the stack or from each other.

11. A sheet feeding mechanism comprising a support for a stack of sheets to be separated, a sheet separating device having a plurality of linearly disposed teeth, means for moving said device toward the side of said stack and angularly upwardly along the face of said stack to separate the edge portion of one or more sheets from the stack or from each other, and means to remove said top sheet when separated by said device. I

ERNEST G. RIDER.

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