US3586312A - Envelope folder - Google Patents

Abstract

An envelope folder including a feed mechanism, a scoring mechanism, a folding mechanism, and a delivery mechanism. The feed mechanism includes a separator arm for separating a single envelope blank from the bottom of a stack of blanks, and for urging the envelope blank against a rotary vacuum drum. The separator arm includes rollers for rolling over the surface of the vacuum drum and the envelope blank transferred to the vacuum drum. The scoring mechanism includes scoring blades which are adjustable toward and away from each other, and which are supported at various points along their lengths. The folding mechanism comprises a pair of rollers which urge each successive envelope blank to a predetermined position, releases the envelope blank, and grasps the envelope blank again and moves it in a different direction to effect a fold on the score line on the envelope. The delivery mechanism includes a disc defining curved slots for receiving envelopes and carrying the envelopes to a stacking station, and an endless belt extending around the axle of the disc and movable toward the stacking station to gradually urge the envelopes out of their respective slots as they approach the stacking station.

Description

United States Patent David G. Summons 12" Avon Avenue. S.W., Atlanta, Ga.

[72] Inventor 30310 [2|] Appl. No. 772,769 [22] Filed Nov. 1, 1968 {45] Patented June 22,197!

[54] ENVELOPE FOLDER 5 Claims, 21 Drawing Figs.

20, ll, l2, 13

[56] References Cited UNITED STATES PATENTS 4/1953 Skow 3/ l 962 Dotzenroth Primary Examiner.loseph Wegbreit AttorneyJones and Thomas ABSTRACT: An envelope folder including a feed mechanism, a scoring mechanism, a folding mechanism, and a delivery mechanism. The feed mechanism includes a separator arm for separating a single envelope blank from the bottom of a stack of blanks, and for urging the envelope blank against a rotary vacuum drum. The separator arm includes rollers for rolling over the surface of the vacuum drum and the envelope blank transferred to the vacuum drum. The scoring mechanism includes scoring blades which are adjustable toward and away from each other, and which are supported at various points along their lengths. The folding mechanism comprises a pair of rollers which urge each successive envelope blank to a predetermined position, releases the envelope blank, and grasps the envelope blank again and moves it in a different direction to effect a fold on the score line on the envelope. The delivery mechanism includes a disc defining curved slots for receiving envelopes and carrying the envelopes to a stacking station, and an endless belt extending around the axle of the disc and movable toward the stacking station to gradually urge the envelopes out of their respective slots as they approach the stacking station.

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INVENTOR. Davld Sammons Emu-Aim ATTORNEYS PATENTEDJUNZZIHH 3586312 SHEET 5 0F 5 39 D S INVENTOR. 81 BY aVl ammons ATTORNEYS ENVELOPE FOLDER BACKGROUND OF THE INVENTION ln'the manufacture of envelopes, paper is cut to form an envelope blank, and the blank is folded, and its flaps are glued together. While various machines have been utilized to perform the folding and gluing functions, the machines presently in use are expensive, occupy an excessive amount of working space, are not adaptable to various sizes and types of envelopes, and jam frequently. Most specifically, at the feed end of the envelope folding machines previously utilized, the envelope blanks are usually arranged in a feed stack, and the bottom envelope blank is retrieved from the feed stack and processed through a path where it is scored, folded, and glued. The various feeding mechanisms utilized for retrieving the envelope blanks from the feed pile are inefi'icient in that they frequently fail to retrieve an envelope blank, or they position the envelope blank out of phase with the associated apparatus, or they feed more than one envelope blank to the apparatus at a time, or they otherwise generally malfunction to cause a jam in the folding apparatus. One of the reasons for the malfunctioning of the previously known feed apparatus is that it is sometimes difficult to slide the bottom envelope blank from the feed pile, and positively position the envelope blank on the conveyor line. While various vacuum mechanisms have been utilized in an attempt to positively grip envelope blanks, the resistance to sliding friction on the surface of vacuum drums, etc. is slight, which allows the blanks to slide or slip on the vacuum drums and become misaligned in the system.

With respect to scoring mechanisms, the mechanisms previously utilized are not versatile in that they are difficult to adjust to form scores that create envelopes of different sizes, and the scoring blades frequently become misaligned, bowed, or otherwise incapable of performing the desired function.

With respect to the folding mechanism, the previously utilized apparatus must be precisely adjusted and controlled to create a fold on the score line when various sizes of envelopes are folded.

With respect to the delivery mechanism, a plurality of slotted discs are normally used to individually receive each envelope delivered from the folding apparatus and deliver the envelopes individually to a stacking station. The arrangement is such that the desired high peripheral speed of the slotted disc frequently scorches, tears, or creases the envelopes as they are removed from the slots of the disc.

SUMMARY OF THE INVENTION Briefly described, the present invention comprises an envelope folder which functions to fold and stack envelopes at a high speed and with extreme accuracy. The envelope blanks are positively fed from a feed stack onto a rotating vacuum drum. A rotary scoring mechanism is utilized to score each envelope blank. The scoring mechanism is adjustable so that its scoring blades can be positioned to score the envelope blanks at virtually any position, and its structure is such that the scoring blades are supported at various positions along their respective lengths to prevent bowing or bending. The folding mechanism includes a pair of rollers normally engaging each other for receiving the envelope blanks therebetween. The rollers positively drive each envelope blank toward a holding mechanism and then release the envelope blank so that the holding mechanism maintains the envelope blank in a predetermined position, whereupon one of the rollers grasps the flap of the envelope blank adjacent the score line of the blank and pulls it in a direction generally normal to the flat plane of the blank to fold the blank at its score line. The delivery mechanism includes a plurality of slotted discs for individually receiving each envelope blank from the folding apparatus. The slots of the disc are curved inwardly of the periphery of the discs, and an endless belt extends around the axle of the discs and beyond the perimeter of the discs. The endless belt is driven at a speed which corresponds to the effective outward movement of the slots of the discs as the slots pass a stationary plane, so that the leading edge of each envelope does not bind, tear or crease as it is extracted from the slotted discs.

Thus, it is an object of this invention to provide an envelope folder which is economical to construct and operate, which is highly effective and accurate in folding and stacking envelopes, and which does not jam or otherwise malfunction in its operation.

Another object of this invention is to provide a feeding mechanism for positively feeding envelope blanks from a feed pile into a scoring and folding mechanism.

Another object of this invention is to provide a scoring mechanism which is durable, and which is adjustable to form various scoring arrangements on envelope blanks.

Another object of this invention is to provide a folding mechanism which functions to fold the flaps of envelopes on the previously created score line in spite of misalignment of the envelopes in the folding mechanism.

Another object of this invention is to provide a delivery mechanism for delivering envelopes from a folding apparatus which functions to deliver and stack envelopes without danger of tearing, scorching, creasing or otherwise damaging the envelopes.

Other objects, features and advantages of the present invention will become apparent upon reading the following specification, when taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION 'OF THE DRAWING FIG. 1 is a schematic side view of the envelope folder.

FIG. 2 is a side view, in cross section, of the receiving drum, and the manner in which the chain of the aligning conveyor cooperates with the receiving drum.

FIG. 3 is a partial front view of the envelope blank feed mechanism, and the aligning conveyor.

FIG. 4 is a partial side view of the envelope blank feed mechanism and the aligning conveyor.

FIG. 4a is a bottom view of the separator discs of the feed mechanism.

FIG. 5 is a partial top view of the scorer.

FIG. 6 is an end view, in cross section, taken along lines 6-6 of FIG. 5, of the scorer.

FIG. 7 is an end view, in cross section, taken along lines 7-7 of FIG. 5, of the scorer.

FIG. 8 is a detail showing of an arcuate scoring blade assembly.

FIG. 9 is an exploded perspective view of an arcuate scoring blade assembly.

FIG. 10 is a partial side elevational view of the envelope flap folding mechanism and the delivery mechanism.

FIG. 11 is a partial top plan view of the delivery mechanism.

FIG. 12-17 are schematic showings of the feeding mechanism, showing the sequence in which the mechanism operates.

FIGS. l8-20 are schematic showings of the folding and delivery mechanism, showing the sequence in which the mechanism operates.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now particularly to the drawing, in which like numerals indicate like parts throughout the several views, FIG. I shows envelope folder 21 which includes feed mechanism 22, aligning conveyor 24, scoring mechanism 25, end flaps folder 26, glue applicator 28, bottom flap folder 29, top flap folder 30, transfer drum 31, and delivery mechanism 32.

As is shown in FIGS. 3 and 4, feed mechanism 22 comprises suction arm 34, separating arm 35, retaining arm 36, a pair of rotary discs 38, and feeding drum 39. Suction arm 34 has nozzle 40 attached to one of its ends, and the other of its ends is rigidly held in mounting block 41. Mounting block 41 is rigidly connected to oscillating rod 42, and flexible conduit 44 communicates with suction arm 34 and with a source of vacuum (not shown). Cam follower 45 is also connected to oscillating rod 42, and cam disc 46 engages cam follower 45. Cam disc 46 is rigidly connected to rotatable cam shaft 48. Thus, rotation of cam shaft 48 by a driving means (not shown) causes cam disc 46 to rotate, and its cam surface functions to oscillate cam follower 45 and oscillating rod 42. Mounting block 41 thus oscillates to move suction arm 34 in the direction as indicated by arrow 49 (FIG. 4).

As is shown in F165. 4 and 4a, rotary discs 38 are mounted on drive shafts 50 above feeding drum 39 and move in the directions as indicated by arrows 51. A feeding stack of envelope blanks 52 is partially supported by discs 38. Each disc 38 is broken along its periphery at 54, and the advancing edge 55 of the break in each disc 38 functions to help separate the bottom envelope from the feed pile 52 during the movement of discs 38. The envelopes comprise the usual body portion 56, end flaps 58, bottom flap 59, and sealing flap 60. Bottom flap 59 is left exposed by disc 38, and suction arm 34 is movable up to a position adjacent discs 38 into engagement with the bottom flap 59 of the bottom envelope of feeding stack 52. Thus, the vacuum source communicates through suction arm 34 to bottom flap 59 of bottom envelope 61.

Separating arm 35 includes rocker arm 62 connected intermediate its ends by pivot pin 63 to cam follower arm 64. Cam follower arm 64 is pivotally connected to rod 65, and follows the surface of cam disc 66. Rocker arm 62 includes a curved cam surface 68 which extends toward and beneath oscillating rod 42. The other end of rocker arm 62 extends toward feeding drum 39 and includes separating tongue 69 and rollers 70. Tongue 69 extends upwardly and generally about the surface of feeding drum 39, while rollers 70 extend beyond the end of separating arm 35 and are movable into rolling engagement with feeding drum 39. Tongue 69 is pointed and thus maneuverable between bottom envelope blank 61 and feeding stack 52. The cam surface 68 of rocker arm 62 is held in engagement with oscillating rod 42 by means of tension spring 71, while tongue 69 is biased toward the position as shown in FIG. 4 by tension spring 72.

Retaining arm 36 is movable toward and away from feeding stack 52 by means of cam follower arm 74. Cam follower arm 74 is similar to cam follower arm 64, in that it is L-shaped and pivotal about shaft 65. Cam follower arm 74 follows the surface of cam disc 75. Retaining arm 36 includes retaining hook 76 adjacent feeding stack 52. With the movement of retaining arm 36 by the action of its cam disc 75, retaining hook 76 is repeatedly moved toward and away from feeding stack 52, to intermittently support the bottom flap 59 of the bottom envelope 61 of feeding stack 52, and to withdraw from feeding stack 52 to allow suction arm 34 to grasp the bottom envelope 61 and move it away from feeding stack 52.

Feeding drum 39 is rotatably supported beneath feeding stack 52 and movable in the direction as indicated by arrow 78. A plurality of apertures 79 extend through the surface of feeding drum 39. A vacuum is drawn within feeding drum 39, so that air would normally flow from the outside to the inside of the feeding drum. A valve system is utilized with feeding drum 39 so that a vacuum is exerted within feeding drum 39 as its apertures 79 travel through the arc indicated as a.

Aligning conveyor 24 is placed with its upper horizontal flight 80 positioned beneath feeding drum 39 and extending toward the remaining elements of the envelope folder. Aligning pins 82 are positioned at spaced intervals along each chain of conveyor 80. As is shown in FIGS. 2 and 3, feeding drum 39 defines spaced grooves 84 in its surface, and aligning pins 82 of the chains of conveyor 80 extend up into grooves 84 as they pass beneath feeding drum 39.

As is shown in FIG. 5, scoring mechanism 25 includes scorer 85 which comprises shaft 86, crescent-shaped scoring blade assemblies 88 and 89, fixed rectilinear scoring blade assembly 90 and movable rectilinear scoring blade assembly 91. As is shown in FIGS. 6, 7 and 9, crescent-shaped scoring blade assemblies 88 and 89 each comprises support sleeve 92 which is contractable by means of its split ring arrangement 94 into gripping relationship with shaft 86. Mounting flange 95 extends radially outwardly from sleeve 92, and boss 96 protrudes laterally from mounting flange'95. Aperture 98 is defined in mounting flange 95 a distance spaced from boss 96. A pair of crescent-shaped scoring blades 99 and 100 are connected to mounting flange 95. Blade 99 includes a pair of spaced apertures 101 and 102 which are alignable with aperture 98 and the aperture of boss 96 of mounting flange 95. Scoring blade 100 defines elongate arcuate slot 104 which is positionable adjacent aperture 98 of mounting flange 95, and indentation 105 which is slidable into abutting relationship with boss 96. Scoring blades 99 and 100 includes beveled cutting edges 106 and 107. As is shown in FIG. 8, beveled sharpened edge 106 of scoring blade 99 is tapered toward scoring blade 100 while beveled sharpened edge 107 of scoring blade 100 is tapered toward blade 99. With this arrangement, a substantially continuous cutting edge is provided by scoring blades 99 and 100, whether these blades are in complete overlapping relationship, or whether scoring blade 100 is extended beyond the limits of scoring blade 99. Scoring blades 99 and 100 are connected to mounting flange 95 by appropriate bolts 109 and 110. Scoring blade 100 is of a thickness of approximately equal to the length of boss 96, so that boss 96 functions to hold scoring blade 99 spaced from mounting flange 95. Because of slot 104, scoring blade 100 is movable radially about sleeve 92 of crescent-shaped scoring blade assembly 88. of course, once scoring blade 100 is properly positioned, its bolts 109 and 110 can be tightened to retain scoring blade 100 in a fixed position.

As is shown in FIG. 5, fixed rectilinear scoring blade assembly 90 includes support bar 111 which is maintained in spaced relationship from shaft 86 by means of support blocks 112 and 114. Connecting screws 115 extend through the ends of support bar 111 and through support block 112 and 114 into shaft 86 to rigidly connect support bar 111 to shaft 86. Scoring blade 116 is connected to support bar 111 by means of threaded screws (not shown). The sharpened edge 118 of scoring blade 116 extends slightly beyond the arcuate outer surface of support bar 111. The edges 106 and 107 of crescent-shaped scoring blades 99 and 100 extend outwardly from shaft 86 a distance equal to the extension of the edge of scoring blade 116.

As is shown in FIG. 6 movable rectilinear scoring blade assembly 91 includes support bar 120 supported at its ends by sleeves 121 and 122. The split ring arrangement 124 of sleeves 121 and 122 allows the sleeves to be contracted into frictional engagement with shaft 86, to fixedly connect support bar 120 to shaft 86. Rectilinear scoring blade 126 is connected to support bar 120 by means of screws (not shown), in such a manner that its sharpened edge 128 extends out a distance equal to the extension of the cutting edges of scoring blades 106, and 107, and 118.

Support sleeves 92 of crescent-shaped scoring blades assemblies 88 and 89 engage the bottom surface of support bar 111 of fixed rectilinear scoring blade assembly 90 and engage the bottom surface of support bar 120 of movable rectilinear scoring blade assembly 91. Also, support sleeves 121 and 122 of movable rectilinear scoring blade assembly 91 extends outwardly from shaft 86 a distance sufficient to engage the bottom surface of support bar 111 of fixed rectilinear scoring blade assembly 90. Thus, support bar 111 is supported at six places along its length: at its ends by support blocks 112 and 114; by support sleeves 121 and 122; and by the support sleeves 92 of crescent-shaped scoring blade assemblies 88 and 89. Thus, the tendency of support bars 111 and 120 to bow or otherwise bend, is virtually eliminated.

As is shown in FIG. 10, top flap folder 30 includes vacuum roller 130, pressure roller 131, and holding bracket 132. Vacuum roller 130 includes a line of apertures 134 extending through its surface, so that the vacuum applied to the inside of vacuum roller 130 draws air through apertures 134. Vacuum roller 130 rotates in the direction as indicated by arrow 135,

and a valve mechanism (not shown) is associated with vacuum roller 130 so that a vacuum is applied to vacuum 130 as its apertures 134 passed through arc b on every fourth revolution. Pressure roller 131 is normally in rolling contact with vacuum roller 130, and rotates in the direction as indicated by arrow 136. The surface of pressure roller 131 is slotted at 138, so that when slot 138 passes vacuum roller 130 the contact between vacuum roller 130 and pressure roller 131 will be relieved. Holding bracket 132 includes arcuate guide plate 139, arcuate biasing plate 140 and adjustable stop 141. The opening between guide plate 139 and biasing plate 140 is extended toward the line of contact between vacuum roller 130 and pressure roller 131 to receive envelopes passing between the rollers in the slot 142 defined between guide plate 139 and biasing plate 140.

Transfer drum 144 is positioned adjacent vacuum roller 130 and rotatable in the direction as indicated by arrow 145. Transfer drum 144 defines a plurality of holes or apertures 146 and 147 on opposite sides thereof, and a valving mechanism (not shown) functions to create a vacuum within drum 144 as apertures 146 and 147 pass through arc 0.

Delivery mechanism 32 includes a plurality of spaced slotted discs l49 rotatably mounted on axle 150. Discs 149 rotate in the direction as indicated by arrow 151, and include a series of spaced arcuate slots 152 which extend inwardly and forwardly from their peripheries, Slots 152 are progressively curved inwardly of each disc 149. Endless belts 154 extend around sheaves 155 which are rigidly connected to and driven by axle 150. Belt 154 also idles around shaft 156. Sheave 155 is chosen so that its tangential component of velocity, and thus the linear velocity of belt 154, is equal to the effective linear velocity of arcuate slots 152 as they pass the stationary plane of upper flight 158 of belt 154. With this arrangement, when a slot 152 intersects the plane of upper flight 158 of belt 154, the point of intersection on flight 158 will travel toward axle 158 of a linear velocity generally equal to the effective linear velocity of the travel of the arcuate slot 152 toward axle 156. Thus, any envelope present in an arcuate slot 152 will be urged outwardly of the arcuate slot by upper flight 158 of belt 154 without encountering any binding, shearing or drag forces 1 by the surface of belt 154.

Endless belt 160 extends across platform 161, and about intermediate driven sheave 162. The envelopes extracted from slotted discs 149 by endless belt 154 will naturally stack in a vertical arrangement on belt 160 and platform 161. The intermittent drive of sheave 162 and its belt 160 is imparted to shaft 156 by means of gear 164 surrounding shaft 156, and pawl 165 engaging gear 164. Pawl 165 is reciprocated by means of cam 166 mounted on shaft 150. The intermittent movement of belt 160 functions to move the stack of envelopes away from slotted discs 149, to create a space for the receipt of additional envelopes from delivery mechanism 32.

OPERATION When the envelope folder is in operation a stack of envelope blanks will be positioned on rotary discs 138 (FlGS. 4 and 4a) to form a feeding stack. When the apparatus is energized, rotary discs 38 and suction arm 34 function to separate bottom envelope blank 61 from the feeding stack 52. As is shown in the sequence of FIGS. 12 17 suction arm 34 moves against the bottom flap of bottom envelope blank 61, its vacuum is applied to the bottom envelope blank, and suction arm 34 is then moved in a downward direction (FIG. 13). Separating arm 35 then moves to a position so that its tongue 69 protrudes into the space between bottom envelope 61 and feeding stack 52, The movement of separating arm 35 as controlled by its cam surface 68 (FIG. 4) is such that tongue 69 moves generally parallel to the surfaces of the envelopes in the feeding stack 52 until it enters the spaced between bottom envelope 61 and feeding stack 52, whereupon it begins its downward movement toward feeding drum 39. As separating arm 35 gets closer to feeding drum 39, rollers 70 extend over the surface of bottom envelope 61, so that as rollers 70 engage feeding drum 39, bottom envelope 61 will be inserted between feeding drum 39 and rollers 70. The apertures 79 of feeding drum 39 will then allow the vacuum within feeding drum 39 to be applied to bottom envelope 61. Thus, the vacuum applied to the envelope and the pressure applied to the envelope by rollers 31 will function to positively connect bottom envelope 61 to feeding drum 39, whereupon bottom envelope 61 will be completely withdrawn from feeding stack 52 and carried around the bottom of feeding drum 39 toward aligning conveyor 24 (FIG. 16).

As the leading edge of envelope 61 is extended substantially parallel to the upper flight 80 of conveyor 24, the vacuum applied to the envelope blank will be released, and conveyor 24 will function to carry the envelope blank in a direction as indicated by arrow 81. To insure that the envelope is perfectly aligned for further processing through the envelope folder, aligning pins 82 engage the trailing edge of the envelope blank to push the envelope blank toward the next station in the envelope folder, which is the station where the scoring mechanism 25 functions to create scores in the envelope blank.

As is shown in FIG. 1, the envelope blanks are successively processed through scoring mechanism 25, end flap folder 26, glue applicator 28, bottom flap folder 29, and sealing flap folder 30. As is shown in FIGS. 18-20, the envelope 61 reaches top flap folder 50 with its body portion 56 leading its sealing flap portion 60. As the body portion 56 passes between vacuum roller and pressure roller 131, the body portion 56 is positively driven into holding bracket 132. As the score line of envelope 61 passes between vacuum roller 130 and pressure roller 131, slot 138 of pressure roller 131 functions to relieve contact between vacuum roller 130 and pressure roller 131 to release envelope 61. The vacuum within vacuum roller 130 is applied through its apertures 134, whereupon vacuum roller 130 is effective to grasp sealing flap 60 and simultaneously fold sealing flap 60 on its score line and move envelope 61 in a downward direction and out of holding bracket 132. Vacuum roller 130 functions to carry envelope 61 into engagement with transfer drum 31, whereupon openings 146 of transfer drum 31 function to grasp the body portion 56 of envelope 61 and carry envelope 61 toward delivery mechanism 32. As the envelope passes around the bottom of transfer drum 31, the vacuum exerted on the body portion 56 of the envelope is relieved and the envelopes are thrust into the slots 152 of slotted discs 149. Slotted discs 149 rotate in the direction as indicated by arrow 151, toward endless belt 160. As each slot passes upper flight 158 of endless belt 154, it is urged outwardly of its slot. The movement of upper flight 158 of belt 154 is timed so that it moves at a linear velocity equal to the effective outwardly linear velocity of the movement of each arcuate slot 152 as it passes belt 154. Thus, the bottom edge of each envelope will be urged outwardly of its respective slot 152 at a linear rate sothat no cutting, binding, scorching or drag will be felt by the bottom edge of the envelopes. As the envelopes are removed from their respective slots 152 they are stacked on endless belt 160. As the envelopes accumulate on endless belt 160, the endless belt is driven intermittently to create more space for the next envelopes.

At this point it should be apparent that the disclosed invention provides a positive feed mechanism for extracting envelopes from a feed pile of envelopes, a unique aligning mechanism for positively aligning the envelopes for subsequent scoring and folding, a versatile scoring mechanism which adapts virtually to any rectangular scoring arrangement and which resist wear and deterioration, a top flap folding mechanism which functions to fold a sealing flap of an enstack envelopes without danger of scorching, creasing, tearing or otherwise damaging the envelopes.

It will be obvious to those skilled in the art that many variations may be made in the embodiments chosen for the purpose of illustrating the present invention without departing from the scope thereof as defined by the appended claims.

lclaim:

l. in a machine of the type utilized for the manufacture of envelopes, the improvement comprising means for accommodating envelope blanks in a feed pile, separating means for separating a portion of the bottom envelope blank from the feed pile, means movable into the space between the bottom envelope blank and the feed pile to move the envelope toward a vacuum drum, and roller means movable toward engagement with the vacuum drum for positively biasing the bottom envelope blank into engagement with the surface of the vacuum drum, so that rotation of the vacuum drum withdraws the bottom envelope from the feed pile,

2. The invention of claim 1 wherein said roller means is constructed to remain in engagement with and roll over the surface of the bottom envelope blank as the vacuum drum withdraws the bottom envelope blank from the feed pile.

3. The invention of claim 1 wherein said separating means comprises a vacuum arm movable toward and away from the bottom envelope blank for applying a vacuum to the bottom envelope blank and separating the bottom envelope blank from the feed pile, and wherein said separating means further includes a retaining hook movable in a direction generally parallel to the plane of the bottom envelope blank for alternately supporting and releasing the bottom envelope blank of the feed pile adjacent in the area of the bottom envelope blank engaged by the vacuum arm.

4. The invention of claim 3 wherein said means movable into the space between the bottom envelope blank and the feed pile is constructed and arranged to move in a direction generally parallel to the planes of the envelopes of the feed pile until it enters the space between the bottom envelope blank and the feed pile and then move in a direction generally toward the vacuum drum until the envelope blank is grasped by the vacuum drum.

5. The invention of claim 1 wherein said vacuum drum is constructed and arranged to rotate in a direction such that the bottom envelope travels with the vacuum drum first in a downward direction and then around the bottom of the vacuum drum.

Claims (5)

1. In a machine of the type utilized for the manufacture of envelopes, the improvement comprising means for accommodating envelope blanks in a feed pile, separating means for separating a portion of the bottom envelope blank from the feed pile, means movable into the space between the bottom envelope blank and the feed pile to move the envelope toward a vacuum drum, and roller means movable toward engagement with the vacuum drum for positively biasing the bottom envelope blank into engagement with the surface of the vacuum drum, so that rotation of the vacuum drum withdraws the bottom envelope from the feed pile.

2. The invention of claim 1 wherein said roller means is constructed to remain in engagement with and roll over the surface of the bottom envelope blank as the vacuum drum withdraws the bottom envelope blank from the feed pile.

3. The invention of claim 1 wherein said separating means comprises a vacuum arm movable toward and away from the bottom envelope blank for applying a vacuum to the bottom envelope blank and separating the bottom envelope blank from the feed pile, and wherein said separating means further includes a retaining hook movable in a direction generally parallel to the plane of the bottom envelope blank for alternately supporting and releasing the bottom envelope blank of the feed pile adjacent in the area of the bottom envelope blank engaged by the vacuum arm.

4. The invention of claim 3 wherein said meAns movable into the space between the bottom envelope blank and the feed pile is constructed and arranged to move in a direction generally parallel to the planes of the envelopes of the feed pile until it enters the space between the bottom envelope blank and the feed pile and then move in a direction generally toward the vacuum drum until the envelope blank is grasped by the vacuum drum.

5. The invention of claim 1 wherein said vacuum drum is constructed and arranged to rotate in a direction such that the bottom envelope travels with the vacuum drum first in a downward direction and then around the bottom of the vacuum drum.

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