US3494611A - Blank feeding mechanism for envelope forming machine - Google Patents

Description

BLANK FEEDING MECHANISM FOR ENVELOPE FORMING. MACHINE Filed Sept. 15, 1967 Feb. 10, 19 70 c. RICHARDS 2 Sheets-Sheet 1 INVENTOR; ROBERT C- RICHARDS BY fizmkwz 5 7%- monnevs Feb. 10,1970 RC. RlCHAl RDS 3,494,511

BLANK FEEDING MECHANISM FOR ENVELOPE FORMING MACHINE Filed Sept. 15, 1967 v 2 Sheets-Sheet a United States Patent 3,494,611 BLANK FEEDING MECHANISM FOR ENVELOPE FORMING MACHINE Robert C. Richards, Whitman, Mass., assignor to United States Envelope Company, Springfield, Mass., a corporation of Maine Filed Sept. 15, 1967, Ser. No. 667,896 Int. Cl. B65h /10, 3/08 US. Cl. 271-29 12 Claims ABSTRACT OF THE DISCLOSURE A stack of precut envelope blanks is supported in an inclined position with their forward ends uppermost. A vacuum roll, having internal vacuum means for supplying vacuum to a given portion of its circumferential surface, supports the stack at a point spaced some distance from its forward end and a dagger reciprocates between an active position wherein it supports the forward end of the stack, and an inactive position, wherein it is free of the stack, in timed relationship with movement of a pivotally mounted vacuum probe. The probe has a concave face with vacuum ports which when brought into engagement with the bottom blank of the stack forms a dimple in such blank to provide a small pocket between it and the adjacent blank. As the probe approaches the bottom blank the dagger is withdrawn, so that the probe momentarily supports the forward end of the stack, and is then returned into the pocket formed by the probe so as to be inserted between the bottom blank and the next adjacent blank. As the probe moves away from the stack in its return motion it bends the forward end portion of the lowermost blank downwardly away from the adjacent blank and a pair of counter-rotating cam segments enter the space provided between the deflected portion and the adjacent blank to urge the stack upwardly and to urge the deflected forward end portion of the lowermost blank downwardly onto the vacuum roll.

- SUMMARY OF THE INVENTION This invention relates to envelope forming machines, and deals more particularly with a mechanism for successively stripping flexible blanks from a stack of like blanks, and depositing the blanks onto a rotating vacuum roll of the machine.

' The general object of the present invention is to provide a blank feedingmechanism wherein the blanks are successively fed from the bottom of an inclined stack, in accurately indexed relationship with respect to a rotating vacuum roll around which each blank is fed as it enters the machine.

The drawings show a preferred embodiment of the invention and such embodiment will be described, but it will be understood that variouschanges may be made from the construction disclosed, and that the drawings and description are not to be construed as defining or limiting the scope of the invention, the claims forming a part of this specification being relied upon for that purpose.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational vview of a blank feeding mechanism embodying the present invention and including apair of vacuum rolls between which each envelope blank is fed after being stripped from a stack of such envelope blanks.

FIG. 2 is a vertical sectional view taken through the blank feeding mechanism of FIG. 1.

3,494,611 Patented Feb. 10, 1970 ICC FIG. 3 is a sectional view taken along the line 33 of FIG. 2.

FIG. 4 is a vertical sectional view similar to FIG. 2 showing the mechanism at approximately ninety degrees later in its cycle of operation.

FIG. 5 is a vertical sectional view similar to FIGS. 2 and 4 showing the mechanism at approximately ninety degrees (90) later in its cycle of operation from the showing of FIG. 4.

FIG. 6 is a sectional View taken on line 66 of FIG. 2.

DETAILED DESCRIPTION OF THE DRAWINGS Turning now to the drawings in greater detail, FIG. 1 shows a blank feeding mechanism 10 embodying the in vention for use in feeding envelope blanks to an envelope forming machine (not shown). A shaft 12 is driven from the envelope forming machine and carries a pulley 14 around which is entrained a timing belt 16 which rotates a vacuum roll 18 on a fixed shaft 20. The shaft 20 is preferably hollow and used as a tube for supplying vacuum to the roll 18. The vacuum roll 18 is drivingly connected to a second vacuum roll 22 which is similarly supported so that the envelope blank to be fed into the envelope forming machine passes clockwise around the upper surface of the roll 18, thence between the rolls 18 and 22, and counterclockwise around the underside of the second vacuum roll 22, as indicated by the arrow 24. Each of the vacuum rolls 18 and 22 rotates on its associated vacuum supply tube which communicates with vacuum ports, such as shown at 23, 23 in FIG. 2, distributed over a given portion of the circumferential surface thereof, the vacuum ports of the two rolls being related to one another and supplied with vacuum during given portions of each revolution of each roll for feeding the envelope blanks therebetween in a well known manner.

Means are provided for supporting a plurality of precut envelope blanks 25, 25 in an inclined stack, as indicated generally at 26, with their forward ends uppermost. Preferably, and as shown in FIG. 1, such means comprises a pair of side posts, one of which is shown at 28, a bottom post or stop 29 and a plate or other means which provides a generally smooth fiat surface 31 against which the vertically lower portion of the lowermost blank of the stack rests. The vacuum roll 18 also supports or engages part of the stack during a portion of each cycle of operation and is located between the upper end of the supporting surface 31 and the upper or forward end of the stack with its circumference approximately tangent to the surface 31. As shown by the dash-dot lines of FIG. 3, the illustrated feeding mechanism is used for feeding envelope blanks, such as shown at 25, having generally triangularly shaped forward end portions but, although, a blank with a general triangularly shaped forward end portion is shown in FIG. 3, it will be apparent that other shapes of blanks may as well be used with the feeding mechanism of this present invention.

In accordance with the present invention, a cross shaft 30 is rotatably supported above the vacuum roll 18, and is drivingly connected thereto by a second timing belt 32. The cross shaft 30 is parallel to the axis of rotation of the vacuum roll 18 and rotates in timed relationship therewith. It also carries an eccentric pin 34 which rotates in a slot 36 provided for this purpose in a crank arm 38. The crank arm 38 is pivotally supported for movement about a fixed axis, defined by a pivot pin 40, in response to the rotation of the shaft 30 and eccentric pin 34. The crank arm 38 carries a vacuum probe 42 which moves arcuately from an inactive or retracted position, such as shown in full lines in FIG. 1, toward the position of FIG. 2 wherein its forward face 43, which includes vacuum 3 I ports 45, 45, engages the lowermost blank. When the probe 42 reverses direction, as shown in FIG. 4, it pulls with it the leading or upper end portion of the lowermost alank and deflects it into the shape there depicted. It should also be noted, as shown best in FIG. 6, that the forward face 43 of the probe 42 is concave and when it :ontacts the lowermost blank 25 the vacuum applied to the blank by the probe deforms the blank to the shape of the face 43 to form a small pocket 47 between the lowermost blank and the next adjacent blank of suflicient size to loosely accommodate a dagger 48- which moves Lnto the pocket shortly after it is formed.

In further accordance with the present invention, the lagger 48 is mounted for reciprocable motion between be solid and broken line positions of FIG. 2, toward and away from the upper edge of the stack to enter the pocket 17 formed by the probe between the lowermost blank and he next adjacent blank and to thereafter maintain the ;tack in position while the probe moves from its position )f FIG. 2 to the position of FIG. 4. Preferably, and as Jest shown in FIG. 2, the dagger 48 is mounted at the free end of a lever 50, which lever is pivotally mounted it its opposite end for movement about a fixed axis deined by a pivot pin 52. Means is provided for moving he dagger 48 in timed relationship with the probe 42 that each operates sequentially on the lowermost blank. Ihis timing is such that the dagger 48 is withdrawn from :he stack shortly before the probe engages the stack. Then after the probe engages the lowermost blank and forms :he pocket 47 the dagger is moved into the pocket before :he probe is moved away from the stack. The dagger 48 remains in this latter position until just prior to the beginning of the succeeding cycle of operation when it is ifted from the stack to allow the vacuum probe 42 to :ngage another blank and form another pocket.

Turning now to a more detailed description of the neans for moving the dagger carrying lever 50, spring aiasing means indicated generally at 54 is provided for irging the lever 50 to the position shown in FIG. 2. Cam neans is provided for momentarily raising the lever 50, and with it the dagger 48, to an inactive position for pernitting the probe 42 to engage a succeeding lowermost Jlank inthe stack. As shown in FIG. 2, said means for 'aising the lever 50 comprises a rotating cam 56 carried my a secondary cross shaft 58 geared to the upper cross :haft 30 by the meshing spur gears 60 and 62 respectively best shown in FIG. 3). The cam 56 in turn cooperates vith a sliding pin 59 pivotally connected at its lower end 0 the arm 50 and having a notch so arranged that during :ach revolution of the cam 56 its finger enters the notch llld lifts the pin 59.

The present invention also provides means which is nsertable between the stack 26 and the downwardly delected forward end portion of the lowermost blank. The aid means supports and raises slightly the forward end If the stack, to aid in separating the lowermost blank rom the stack, and further deflects the forward blank )ortion toward the vacuum roll 18, all in timed relation vith the operation of the dagger 48 and the vacuum probe l2. As best shown in FIG. 3, the above-mentioned means :omprises a pair of counter-rotating segmented cams 64 ind 66 each of which is continuously driven in the direcion of the arrows associated therewith by gears 68 and '0' respectively mounted on the shaft 58. Each of the ams 64 and 66 is carried on a stub shaft, which shafts ,l'so carry a pair of gears for meshing with said gears i8 and 70 respectively.

Referring now to FIG. 4, and more particularly con ider'ing the action of the counter-rotating cams 64 and' F6, it will be noted that the leading edge 72 of the cam i6 is so arranged that after the forward portion of the dwermost blank is withdrawn or bent from the stack and noved to approximately the position shown in FIG. 4, Iythe vacuum probe 42, the leading edge portion of the am enters the space so formed between the stack and 3,494, 11 r f f the blank. The edge 72 is further arranged so as to b in the same plane as, or slightly below the plane of, the dagger 48 so that as the edge approaches the stack it will move below the blank being held by the dagger 48. Immediately behind the edge 72, the cam 66 includes an inclined surface 73 facing thestack 26 which leads from the edge 72 to another generally flat surface 75 concentric with the axis of the cam, facing the stack 26, and having an angular extent of approximately 180. This surface 75 is located above the planeofthe dagger 48 so that when it is moved into engagement with the bottom of the stack, by rotation of the cam 66, it lifts up the stack and, therefore, aids in separating the stack from the blank being fed. This is of particular advantage in cases where the blanks are die cut as such blanks often have interlocking fibers which resist the pulling of the bottommost blank from the stack in a plane parallel to the stack bottom. The lifting of the stack by the cam surface 75 separates at least some of such interlocking fibers and makes the withdrawal of the bottommost blank easier. Although FIGS. 2, 4 and 5 show only the cam 66, it should be understood that the cam 64 is a mirror image duplicate of the cam 66 and includes an inclined surface similar to the inclined surface 73 and a flat arcuate surface similar to the surface 75. In FIG. 3 this latter surface is shown at 77 on the cam 64. FIG. 5 shows the cam 66 rotated approximately ninety degrees from the position shown in FIG. 4. In this position the upper flat surface 75 engages and lifts the forward end of the stack as above described, and from this figure it will be noted that the cam also includes, below the surface 75, asurface .79 which, when the cam is in the illustrated angular position, is located close to the circumference of the vacuum roll 18 and serves to positively separate the withdrawn blank from the vacuum probe 42 and to deflect it toward and to hold f it onto the vacuum roll 18. The surface ,79 as. viewed in the horizontal section of FIG. 5 has a concave curvature generally conforming to the curvature of the circumference of the roll 18 and is concentric with the axis of the'cam 66. Again, it should be understood that the cam 64 also includes a surface similar to the'surface"7 9 of, the cam 66 for deflecting the withdrawnblank toward the vacuum roll 18.

The vacuum roll 18 is moved in timed relationship with,

the movement of the probe 42, cam 66 and dagger 48 and this timing is such that the vacuum. ports 23, 23 of the roll are presented to the forward end portion of the lowermost blank as it is moved from the stack by the probe 42 to the position of FIGJ 4. Also, at this time vacuum is applied to the ports 23, 23 so that the roll grasps the blank and pulls it from the stack. After the forward portion of the blank reaches the second vacuum roll 22 vacuum is applied to similar vacuum'ports in the roll 22, and the vacuum at its ports 23, 23 is turned off, so that the blank is transferred to the roll 22 and the re maining portion of the blank is pulled from the stack as a result of the blank passing through the nip of the two rolls 18 and 22.

After the trailing ends of each of the counter-rotating segmented cams 64 and 66 have been rotated to substan tially the positions shown in FIG; 3, the mechanism de scribed hereinabove will-have been repositioned for an other cycle of operation, so as to strip a succeeding flowermanner described hereinabove.

I claim:

1. An apparatus for feeding blanks individually from a stack of like blanks, said apparatus comprising means for supporting a stack of suchblanks', cyclically operable means for partiallyseparating' the forward portion of the lowermost blank in said stack from the next adjacent blank by bending said lowermost blank away from said stack, and means for grasping said forward end portion of said lowermost blank while said stack is displaced by said second means and for pulling said lowermost blank from said stack, a pair of cooperating segmented rotating members each having a cam surface on one side for displacing said stack from its normal position and a cam surface on the opposite side for deflecting said separated forward portion of said lowermost blank away from said stack.

'2. An apparatus for feeding blanks individually from a stack of like blanks as defined in claim 1 further characterized by said means for separating the forward portion of said lowermost blank from the next adjacent blank of said stack comprising a vacuum probe cyclically movable toward and away from the under-surface of said lowermost blank, said probe having a concave face for engagement with said undersurface so that when said probe is brought into engagement with said lowermost blank it deforms said lowermost blank to form a pocket between said lowermost blank and the next adjacent blank, and a cyclically movable dagger operable adjacent the forward end of said stack which dagger is movable into said pocket after it is formed by said probe to restrain said next adjacent blank from moving with said lowermost blank as said lowermost blank is bent away from said next adjacent blank by said probe.

3. An apparatus for successively stripping flexible blanks from a stack of like blanks each of which has a forward end portion, said apparatus comprising support means for the blanks in said stack and including a rotatably mounted vacuum roll below the forward end portion of the lowermost blank, means including a vaccum probe mounted for cyclical motion toward and away from the underside of the forward end portion of said lowermost blank for partially deflecting said forward end portion away from said stack and downwardly toward said vacuum roll, and a pair of cooperating segmented cams, each cam having an upper surface for pushing the stack upwardly and a lower surface for deflecting the forward blank portion away from the stack.

4. Apparatus according to claim 3 further characterized by said vacuum probe having a concave face so as to form a pocket between said lowermost blank and the next adjacent blank when said probe is moved into engagement with said lowermost blank, a dagger movable relative to said stack, and means for moving said dagger in times relation to the movement of said vacuum probe, said dagger and said means for moving it being so arranged that said dagger is withdrawn from said stack as said probe approaches said lowermost blank and is then moved into said pocket to support the forward end of said stack and prevent the next adjacent blank from moving with said lowermost blank as said lowermost blank is deflected by said probe.

5. Apparatus according to claim 4 and further characterized in that said vacuum roll is continuously rotated about an axis perpendicular to the direction of movement acterized in that said cams are mounted for rotation in opposite directions about axes generally perpendicular to said stack, and said cams being driven from said cross shaft so as to rotate in timed relationship with said dagger and probe.

8. Apparatus according to claim 3 and further characterized in that said stack support means holds said blanks at an angle to the horizontal with the forward ends uppermost, said probe being so mounted on said crank arm as to move substantially tangentially with re spect to said vacuum roll toward and away from the underside of said lowermost blank between said counterrotating segmented cams, said vacuum roll having vacuum ports on a given angular portion of its circumferential surface which angular portion is so arranged as to be presented to the forward end portion of each blank after it has been partially deflected by said probe.

9. An apparatus for feeding blanks individually from a stack of like blanks each of which has a forward end portion, said apparatus comprising support means for v the blanks and including a rotatably mounted vacuum roll of said stripped blank, a cross shaft driven from said having ports on a given angular portion of its circumferential surface, a vacuum probe mounted for pivotal movement toward and away from the underside of the forward end portion of the lowermost blank for partially deflecting said forward end portion away from said stack and downwardly toward said vacuum roll, said probe having a concave face so as to form a pocket between said lowermost blank and the next adjacent blank when said probe is moved into engagement with said lowermost blank, a dagger movable in timed relationship with said probe to enter the pocket and prevent the adjacent blank from moving with the lowermost blank as the latter is deflected by said probe, and cam means insertable between said stack and the forward portion of said lowermost blank after the blank has been partially deflected for supporting the stack and further deflecting the lowermost blank toward said vacuum roll.

10. Apparatus according to claim 9 further character ized in that said cam means comprises a pair of segmented rotating cam members arranged on either side of said pivotally mounted probe, said cam members having cooperating upper cam surfaces for raising said stack slightly and cooperating lower cam surfaces for wrapping said blank around a portion of said vacuum roll.

11. Apparatus according to claim 10 further characterized in that said vacuum probe moves substantially tangentially with respect to said vacuum roll toward and away from the underside of said lowermost blank between said rotating cam members, said members rotating in opposite directions and in timed relationship with said probe and with said angular portion of said vacuum roll.

12. Apparatus according to claim 11 further characterized in that said counter-rotating cam members have lower cam surfaces which are concave in contour and conform generally to the curvature of said vacuum roll and which lower concave cam surfaces pass in close proximity to the circumference of said vacuum roll during each revolution for Wrapping the blank around a portion of said roll other than the said angular portion thereof.

References Cited UNITED STATES PATENTS 2,849,232 8/ 1958 Halahan 27129 2,954,225 9/1960 Novick 27129 3,394,930 6/ 1968 Guggisberk 27129 RICHARD E. AEGERTER, Primary Examiner

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