US3641883A

US3641883A - Method and apparatus for folding a closure flap of an envelope

Info

Publication number: US3641883A
Application number: US35190A
Authority: US
Inventors: Eliot S Smithe; Herbert W Helm
Original assignee: FL Smithe Machine Co Inc
Current assignee: FL Smithe Machine Co Inc
Priority date: 1970-05-06
Filing date: 1970-05-06
Publication date: 1972-02-15
Anticipated expiration: 1989-02-15
Also published as: DE2122493A1; CA945415A

Abstract

Closure flap folding apparatus includes a transfer cylinder with rows of vacuum ports extending longitudinally along the periphery, a delivery cylinder having a plurality of rows of peripheral vacuum ports extending longitudinally thereon in spaced relation to each other and an intermediate seal fold cylinder also having vacuum ports extending longitudinally thereon. The transfer cylinder and delivery cylinder have the same diameter and are arranged to rotate in the same direction at substantially the same peripheral speed. The seal fold cylinder is positioned between the transfer cylinder and delivery cylinder and is arranged to engage a portion of the envelope transferred thereto by the transfer cylinder and retain engagement of the portion of the envelope while folding of the seal or closure flap takes place. The delivery cylinder engages the body portion of the envelope and transfers the envelope to a collecting device. The seal fold cylinder rotates at the same peripheral speed as the transfer cylinder in a direction opposite thereto and at an exact multiple of the angular velocity of the transfer cylinder, as for example, the seal fold cylinder completes four revolutions to a single revolution of the transfer cylinder. A timing device and valves are provided to exert a suction through the vacuum ports on the seal fold cylinder only when the vacuum ports are in overlying relation with the preselected portion of the envelope blank. The closure flaps may be folded forwardly in overlying relation with the opening in the envelope, rearwardly into overlying relation with the front surface of the envelope, or the envelope may be transferred through the folding device with the closure flap in an open unfolded position.

Description

United tates Patent [151 enemas Smithe et a1. Feb. 15, 1972 [54] METHOD AND APPARATUS FUR with rows of vacuum ports extending longitudinally along the FOLDING A CLOSURE FLAP OF AN periphery, a delivery cylinder having a plurality of rows of ENVELOPE peripheral vacuum ports extending longitudinally thereon in spaced relation to each other and an intermediate seal fold [72] Inventors: Eliot S. Smithe, New York, N.Y.; Herbert cylinder also having vacuum ports extending longitudinally W. Helm, l-lollidaysburg, Pa. thereon. The transfer cylinder and delivery cylinder have the same diameter and are arranged to rotate in the same direction at substantially the same peripheral speed. The seal fold cylinder is positioned between the transfer cylinder and [73] Assignee: F. L. Smithe Machine Company, Inc.,

Duncansville, Pa.

[22] Filed; May 6 1970 delivery cylinder and is arranged to engage a portion of the envelope transferred thereto by the transfer cylinder and retain PP 35,190 engagement of the portion of the envelope while folding of the seal or closure flap takes place. The delivery cylinder engages 52 us. Cl ..93/62, 270/68 the body emebpe and transfers the B3, 21/26 a collecting device. The seal fold cylinder rotates at the same [51] C] peripheral speed as the transfer cylinder in a direction op- [58] FieldoiSearch ..93/62,61;2'. 0/68 posite thereto and man exact multiple ofthe angular velocity of the transfer cylinder, as for example, the seal fold cylinder [56] References cued completes four revolutions to a single revolution of the transfer cylinder. A timing device and valves are provided to UNITED STATES PATENTS exert a suction through the vacuum ports on the seal fold 3,088,382 5/ 1963 Winkler et a1. ..93/62 cylinder only when the vacuum ports are in overlying relation 3,116,668 1/1964 Novick ..93/62 with the preselected portion of the envelope blank. The closure flaps may be folded forwardly in overlying relation with Primary Examiner Bemard Stickney the opening in the envelope, rearwardly into overlying relation Attorney-Stanley J. Price, Jr. with the front surface of the envelope, or the envelope may be transferred through the folding device with the closure flap in 57] ABSTRACT an open unfolded position.

Closure flap folding apparatus includes a transfer cylinder 12 Claims, 17 Drawing Figures I L3 a l4 L l v ,8 26 44 42 4 24 I 6 a is l a PATENTEDFEB 15 1912 3.641 .883

SHEET 2 [IF 6 PATENTEBFEB 1 5 1912 3.641 ,883

sum 3 OF 6 METHOD AND APPARATUS FOR FOLDING A CLOSURE FLAP OF AN ENVELOPE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method and apparatus for folding closure flaps and more particularly to a method and apparatus for folding closure flaps with a plurality of rotary cylinders.

2. Description of the Prior Art Envelopeand bagmaking machines include apparatus for folding the closure flap after the side and bottom flaps of the envelope blank have been folded and adhesively secured to the envelope body portion. The conventional known closure flap folding devices include belts, pressure rollers and the like which exert compressive forces on the folded envelope while conveying the envelope through the closure flap folding portion of the machine. U.S. Pat. No. 3,097,758 illustrates a typical pair of pressure rollers for engaging the envelope blank therebetween prior to the folding operation.

The known flap-folding apparatus is designed for a single type of fold as, for example, the normal forward fold of the closure flap and is not readily convertible to apparatus for providing a reverse fold of the closure flap or for permitting the envelopes to be conveyed therethrough without folding the closure flap. There is a need for apparatus that may be easily converted to provide normal or reverse folds of the closure flap or to deliver the envelopes with the closure flaps in an open, unfolded condition. There is also a need for a rotary cylindrical envelope closure flap folding device that does not exert squeezing pressure forces on the envelope.

SUMMARY OF THE INVENTION This invention relates to apparatus for folding the closure flap of an envelope which comprises a transfer cylinder with vacuum ports extending longitudinally along a portion of the cylinder periphery. A delivery cylinder is positioned in spaced parallel relation to the transfer cylinder and has a plurality of vacuum ports extending longitudinally along a portion of the cylinder periphery. The delivery cylinder and transfer cylinder rotate in the same direction at substantially the same angular velocity. A seal fold cylinder is positioned parallel to and between the delivery cylinder and the transfer cylinder. The seal fold cylinder has a diameter smaller than the transfer cylinder and vacuum ports extend longitudinally along a portion of the cylinder periphery. Drive means are provided to rotate the seal fold cylinder at an exact multiple of the angular velocity of the transfer cylinder. The seal fold cylinder vacuum ports are arranged to engage a portion of an envelope by suction while the envelope is engaged to the transfer cylinder by suction and to convey the envelope from the transfer cylinder to the delivery cylinder through a suitable guide means or folding device.

The method for folding an envelope closure flap includes engaging the leading edge of the envelope by suction on the periphery of a transfer cylinder. The transfer cylinder is rotated to a position where the envelope leading edge is adjacent to the buckle plate portion ofa folding mechanism. The closure flap of the envelope is engaged by suction to the periphery of a seal fold cylinder positioned adjacent to the transfer cylinder. The seal fold cylinder is rotated in a direction opposite to the transfer cylinder while the closure flap portion of the envelope is engaged to the periphery of the seal fold cylinder to thereby fold the closure flap into overlying relation with the rear surface of the envelope. The body portion of the envelope is engaged by suction onto the periphery of a delivery cylinder that is positioned adjacent to the seal fold cylinder and rotated in a direction opposite to the direction of the seal fold cylinder. The suction on the seal fold cylinder is released to permit the delivery cylinder to transfer the envelope with the closure flap folded into overlying relation with the rear surface of the envelope.

To obtain a reverse seal fold where the closure flap is folded rearwardly over the front surface of the envelope, only the closure flap portion of the envelope is engaged by suction to the periphery of the transfer cylinder. The transfer cylinder is rotated until the envelope body portion folds back over the closure flap and the envelope body portion is engaged by suction onto the periphery of the seal fold cylinder. The seal fold cylinder then transfers the envelope with the closure flap folded rearwardly thereon to the delivery cylinder where the front surface of the envelope and the rearwardly folded closure flap are engaged to the periphery of the delivery cylinder.

Accordingly, the principal object of this invention is to provide a rotary closure flap folding apparatus that eliminates belts, pressure rollers and the like.

Another object of this invention is to provide closure flap folding apparatus that may be easily converted from normal forward fold apparatus to reverse fold apparatus.

These and other objects and advantages of this invention will be more completely disclosed and described in the follow ing specification, the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A, 1B and 1C are schematic illustrations in elevation illustrating sequentially the manner in which the closure flap of an envelope is folded with the apparatus illustrated.

FIGS. 2A, 2B and 2C are similar to FIGS. 1A, 1B and 1C illustrating sequentially the manner in which a reverse fold is applied to a closure flap of an envelope with the apparatus illustrated.

FIGS. 3A, 3B and 3C are also similar to FIGS. 1A, 1B and 1C and illustrate the manner of delivering envelopes in an unfolded, open seal condition.

FIGS. 4A, 4B and 4C illustrate the sequential steps for folding outside side seam envelopes immediately before applying a normal fold to the closure flap.

FIG. 5 is a top plan view partially in section of the seal fold apparatus illustrated schematically in FIGS. 1-3 inclusive. Portions of the cylinders are in section to illustrate the valving mechanism to provide a suction in the vacuum ports.

FIG. 6 is a view in section taken along the line VI-VI of FIG. 5.

FIG. 7 is a view in section illustrating in detail a suitable blocking valve for applying a suction to the vacuum ports of the seal fold cylinder.

FIG. 8 is a view in section taken along the line VIIl-VlIl of FIG. 5 illustrating the valve ports for the seal fold cylinder.

FIG. 9 is a view in section taken along the line IXIX of FIG. 5 illustrating the valving for the vacuum ports along the periphery of the cylinder. Schematically illustrated in FIGS. 8 and 9 is the conduit connecting the valve ports of the delivery cylinder and the seal fold cylinder.

DESCRIPTION OF THE PREFERRED EMBODIMENT Normal Closure Flap Fold Referring to the drawings and particularly FIGS. 1A, 1B and 1C, there is illustrated schematically closure flap folding apparatus generally designated by the numeral 10 that includes a bottom flap folding cylinder 12 and a transfer cylinder 14 positioned in parallel relation to each other. The

cylinders

12 and 14 are suitably mounted in a frame member and drivingly connected to each other by gearing, as later explained in reference to FIG. 5.

The bottom flap folding cylinder 12 has a series of vacuum ports 16 opening into the periphery of the cylinder and extending longitudinally therealong. The ports 16 are connected to a passageway 18 within the cylinder and the passageway is in turn connected through suitable valving to a source of suction or reduced pressure. The transfer cylinder 14 similarly has pairs of spaced

vacuum ports

20 and 22 opening into the cylinder periphery and extending longitudinally thereon.

Passageways

24 and 26 connect the

respective vacuum ports

20 and 22 to a vacuum source through suitable valving, as later explained. The bottom flap folding cylinder 12 is arranged to rotate in a clockwise direction as viewed in FIG. 1 and cylinder 14 is arranged to rotate in a counterclockwise direction and to engage and transfer an envelope blank from the bottom flap folding cylinder 12 to the remaining portion of the closure flap folding apparatus 10.

A delivery cylinder 28 is also mounted in the machine frame in parallel spaced relation to the transfer cylinder 14 and has a series of longitudinally extending

vacuum ports

30, 32, 34 and 36 opening into and extending around the periphery of the cylinder. The

vacuum ports

30, 32, 34 and 36 are connected respectively to

passageways

38, 40, 42, and 44 that are in turn connected to a source of suction through valving, as later explained, to progressively apply and withdraw suction to the periphery of the cylinder 28 through the longitudinally extending parallel rows of

respective ports

30, 32, 34 and 36.

A seal fold cylinder 46 is rotatably mounted in the machine frame and is positioned between the transfer cylinder 14 and the delivery cylinder 28. The seal fold cylinder 46 has a single row of vacuum ports 48 along the periphery that are arranged to engage a portion of the envelope blank and transfer the envelope blank to the delivery cylinder 28. The seal fold cylinder 46 and delivery cylinder 28 are drivingly connected in timed relation so that the angular velocity of the seal fold cylinder 46 is an exact multiple of the angular velocity of the delivery cylinder 28 as for example for each revolution of the delivery cylinder 28 the seal fold cylinder revolves four times. Bleeder valves and vacuum valves are associated with the seal fold cylinder 46 to apply a suction through the vacuum ports 48 during one portion of the revolution of the seal fold cylinder 46 and to terminate the vacuum or suction during the remaining three revolutions of the cylinder 46. The delivery cylinder 28 rotates in a counterclockwise direction, the same direction as the transfer cylinder 14. The seal fold cylinder 46 rotates in a clockwise direction, opposite to that of the delivery cylinder 28.

A buckle plate generally designated by the numeral 50 is positioned above the seal fold cylinder 46 and has a longitudinal slot 52 and guide portion 54. The slot 52 has an end wall 56 against which the envelope blank abuts when the envelope reverses direction. A suitable guide bracket 58 is positioned beneath the

cylinders

14 and 28 and a conventional delivery spiral is rotatably positioned at the downstream end from the delivery cylinder 28. The apparatus illustrated in FIGS. 1A, 1B and 1C fold the closure flap 62 of an envelope generally designated by the numeral 64 that has a rear surface 66 (FIG. 1A) and a front surface 68 (FlG. 1C).

The apparatus illustrated in FIGS. 1A, 1B and 1C folds the closure flap 62 in overlying relation with the rear surface 66 of the envelope in the following manner. The top surface 68 of the envelope 64 is engaged by suction through vacuum ports 16 to the periphery of the bottom flap fold cylinder. Upon rotation in a clockwise direction the undersurface 66 of the envelope is moved into overlying relation with the vacuum ports and 22 on the transfer cylinder 14. Suction is applied through the

ports

20 and 22 to engage the envelope to the periphery of transfer cylinder 14.

The bottom flap fold cylinder 12 and transfer cylinder 14 are so timed that the front edge or base of the envelope opposite the closure flap 62 is in overlying relation with the vacuum ports 20 so that the closure flap 62 is not engaged to the cylinder 14 by suction. Rotation of the transfer cylinder 14 rotates the transfer cylinder in a counterclockwise direction to a location where the front edge of the envelope 64 is disengaged from the transfer cylinder 14 and is conveyed upwardly in the slot 52 of buckle plate 50. As the envelope blank moves up into the slot 52 the closure flap 62 is in overlying relation with the vacuum ports 48 on the seal fold cylinder 46. Suction is applied through vacuum ports 48 in the seal fold cylinder 46 to engage the closure flap 62. Rotation of the seal fold cylinder 46 in a clockwise direction folds the closure flap 62 along a score line, as illustrated in FIG. 2.

The delivery cylinder 28 rotates in timed relation with the transfer cylinder 14 and seal fold cylinder 46 to move the

vacuum ports

30, 32, 34 and 36 into progressive overlying relation with portions of the envelope front surface 68 and move the envelope 64 downwardly in the slot 52 and between the transfer cylinder 28 and seal fold cylinder 46 with the folded closure flap 62 forming the leading edge of the envelope 64. The envelope is transferred by the delivery cylinder 28 to a conventional delivery spiral 60 where the envelope is transferred into an arcuate receiving slot 70 for delivery to a stack 72. It will thus be apparent with the above arrangement that it is now possible to apply a normal forward seal fold to closure flap 62 solely with rotating cylinders and without pressure rollers, belts, tapes and the like. This arrangement is suitable for high-speed handling and folding of envelopes and may be used with puffed or thin airmail envelopes.

Reverse Fold Referring to FlGS. 2A. 2B and 2C, the seal folding apparatus illustrated in FIGS. 1A, 1B and IC has been modified to reverse the seal fold rather than provide the normal fold previously described. Because substantially all of the apparatus illustrated in FIGS. 2A, 2B and 2C is the same as that illustrated in FIGS. 1A, 1B and 1C, similar numerals will designate similar parts. The buckle plate 50 and the guide bracket 58 are removed and another guide bracket 74 is positioned in place of buckle plate 50. The timing of the transfer cylinder 14 and the position of the

vacuum ports

20 and 22 relative to the envelope 64 is modified so that the closure flap portion 62 of the envelope is engaged by vacuum through

ports

20 and 22 to the periphery of transfer cylinder 14. The remaining portion of the envelope 64 hangs downwardly from the transfer cylinder 14 upon rotation as illustrated in FlG. 2A. Upon rotation of the transfer cylinder 14 the envelope 64 is moved upwardly toward the seal fold cylinder 46. Vacuum through ports 48 in seal fold cylinder 46 engages the rear surface 66 of envelope 64 and transfers the envelope 64 to the delivery cylinder 28, as illustrated in FlGS. 2B and 2C. ln FlG. 2B the closure flap 62 is bent rearwardly over the front surface 68 of envelope 64 and the envelope rear surface 66 is engaged by the vacuum ports 48 on the seal fold cylinder 46 adjacent the score line for the closure flap 62. Rotation of the seal fold cylinder 46 transfers the envelope 64 to the delivery cylinder 28 where the envelope front surface 68 with the closure flap 62 folded rearwardly thereon is engaged by vacuum through the

ports

30, 32, 34 and 36. The envelope with the rearwardly folded closure flap 62 is then transferred to a delivery spiral 60 and from the delivery spiral to a stack 72, as previously described.

It will be apparent by simply removing the buckle plate 50 and lower guide 58 and replacing the buckle plate 50 with a second guide means 74 and changing the timing of the transfer cylinder 14, it is possible to modify the flap-folding apparatus from a normal closure flap fold to a reverse closure flap fold. Since the folding of the envelope is accomplished by rotary cylinders and the envelopes are engaged to the cylinders by means of vacuum, high-speed folding even the reverse seal fold is possible with this apparatus. The reverse seal fold is useful where the envelopes are to be utilized in automated stuffing operations.

Open Seal Delivery For certain stuffing operations it is desirable to provide envelopes wherein the closure flap is in an open, unfolded condition. The apparatus illustrated in FIGS. 2A, 2B and 2C may be employed to transfer the envelopes through the folding apparatus without folding the closure flap 62 either in the normal seal fold or the reverse seal fold. The undersurface 66 of the envelope 64 is engaged adjacent the edge opposite the closure flap 62 by the

suction ports

20 and 22 of the transfer cylinder 14 and rotated toward the guide member 74 positioned above the seal fold cylinder 46. As illustrated in FlG. 38, when the envelope 64 is disengaged from the periphery of transfer cylinder 14 it is engaged to the periphery of seal fold cylinder 46 by means of suction through the vacuum ports 48. The seal fold cylinder 48 serves as a transfer cylinder and transfers the leading edge of the envelope 64 opposite the clo sure flap 62 to the delivery cylinder 28 where the undersurface of the envelope is engaged to the periphery of delivery cylinder 28 by suction through

vacuum ports

30, 32, 34 and 36. Rotation of the delivery cylinder 28 with the envelope secured thereto in a counterclockwise direction then transfers the envelope into a slot '70 of delivery spiral 60 from which it is positioned in a stack 72 with the closure flaps 62 in an open position.

It will be apparent with the above apparatus that it is now possible to either apply a reverse seal fold or to transfer envelopes in an open closure flap condition to the delivery spiral with the same components of seal fold apparatus. The only requirement is the relative position and timing of the seal fold cylinder 26.

Normal FoldOutside Side Seam Envelopes Referring to FIGS. 4A, 4B and 4C, there is illustrated seal fold apparatus suitable for use with envelopes that includes a side flap folding apparatus in lieu of the transfer cylinder previously described. In the apparatus illustrated in FIGS. 4A, 4B and 4C, similar numerals will be used for similar parts. The seal fold apparatus generally designated by the numeral has a bottom flap fold cylinder 12 with a pressure roller 76 positioned in abutting relation therewith. Endless driven tapes or belts 78 are positioned around

rollers

80 and 82 and have a tensioning drive roll 84. A pair of plowshare side flap fold devices 86 are positioned above the tapes 78. The seal fold cylinder 46 has vacuum ports 48, as previously described, and the buckle plate 50 is positioned above the seal fold cylinder 46 and adjacent to the transfer cylinder 28.

As illustrated in FIG. 4A, the envelope blank 88 having a body portion 90 with a front flap 92 and a pair of side flaps 94 and 96 and a rear closure flap 98 has the front flap 92 bent rearwardly over the body portion and folded thereon as it is transferred from the bottom flap folding cylinder 12 onto the belts 78. The plowshares 86 fold the side flaps 94 and 96 into overlying relation with the bottom flap 92 to form an outside side seam type envelope. The belts 78 transfer the envelope upwardly into the slot 52 of the buckle plate 50 and the closure flap 98 is engaged to the periphery of seal fold cylinder 46 by suction through the vacuum ports 48. The seal fold cylinder 46 rotates in a clockwise direction and the delivery cylinder 28 rotates in a counterclockwise direction. The envelope body portion is engaged to the periphery of the delivery cylinder by suction through

vacuum ports

30, 32, 34 and 36 and rotation of the seal fold cylinder 46 in a direction opposite to the delivery cylinder 28 with the envelope therebetween folds the closure flap 48 into overlying relation with the side flaps 94 and 96 and bottom flap 92. The envelope is transferred in a similar manner to the spiral 60 as was discussed in reference to FIG. 1.

With this arrangement it is now possible with minor substitutions and modifications of the closure flap apparatus to provide apparatus for folding the side flaps immediately prior to folding the closure flap of the envelope into overlying relation with the side flaps as a normal closure flap fold. To modify the previously described apparatus the transfer cylinder is removed and the tapes or belts 78 with their drive means substituted therefor and the plowshares positioned thereabove.

Referring to FIGS. 59, one arrangement of the cylinders and valves in the seal fold apparatus 10 is illustrated. FIG. 5 is a top plan view with the direction of travel of the sheets being indicated by the arrows and extending from the bottom toward the top of the sheet. The cylinders of the seal fold apparatus are rotatably journaled in the envelope machine side frames 100 and 102. The bottom flap fold cylinder 12 has a main shaft 104 that is journaled in the side frames for rotation therein. Gearing 106 on drive shaft 108 is in meshing relation with a gear 110 on the bottom flap fold cylinder 104 to provide rotation thereto. The suction passageway 18 within the cylinder 12 has vacuum ports 16 connected thereto. A valve generally designated by the numeral 112 has a stationary por tion or stator 114 and a rotatable portion or rotor 116. The valve 112 is arranged to open and close the passageway 18 in preselected portions of each revolution of the bottom flap fold cylinder 12 to thereby apply and remove negative suction pressure to the periphery of the cylinder 12. FIG. 6 illustrates the bottom flap fold cylinder in section with the suction passageway 18 and the vacuum ports 16.

The transfer cylinder 14 is rotatably mounted on a shaft 118 that is suitably journaled in bearings in subframe members 120. A spur gear 122 on shaft 118 meshes with a spur gear 124 on shaft 104 of bottom flap fold cylinder 12 so that the transfer cylinder 14 is driven in timed relation with the bottom flap fold cylinder 12. The transfer cylinder 14 has a rotary valve generally designated by the numeral 126 that has a stator portion 128 and a rotor portion 130. The inlet 132 to the stator 128 supplies a suction to the pairs of

vacuum ports

20 and 22 during a preselected portion of each revolution of the transfer cylinder 14, as previously described. The location at which the arcuate opening 134 in the rotor is subjected to the vacuum through opening 132 may be changed by rotating the fixed stator 128 of valve 126.

In FIG. 7, there is illustrated one manner'of applying suction to the vacuum ports 48 of the seal fold cylinder 46 through an axial passageway 138 in the seal fold cylinder 46 (FIG. 8). A valve generally designated by the numeral 140 has a rotor portion 142 that may be suitably secured to a rotating portion of any one of

cylinders

12, 14 or 28. The rotor has an arcuate opening 144 therein and a stator 146 is positioned in overlying relation therewith. The stator has a first opening or port 148 connected to a source of vacuum such as a conventional vacuum pump (not shown) and a second port 150 suitably connected by a conduit 152 to the seal fold cylinder valve. With this arrangement, suction is applied through the seal fold cylinder vacuum ports for about one-fourth of a revolution of the cylinder to which the valve 140 is connected. Throughout the other three-fourths of a revolution, the valve port 148 is closed by the rotor 142 so that suction is not applied to the vacuum ports 48 of the seal fold cylinder 46. Since the seal fold cylinder rotates at an exact multiple of the angular velocity of the other cylinder, suction is applied through the valve ports 48 of the seal fold cylinder 46 during one of the revolutions of the seal fold cylinder 46 and suction is not present during several subsequent revolutions of the seal fold cylinder 46, depending on the multiple in the angular velocity between the respective cylinder. The above valve mechanism provides a means for periodically applying a suction through valve ports 48 in the seal fold cylinder.

Referring to FIG. 5, the delivery cylinder 28 is rotatably mounted on a shaft 154 and is drivingly connected through gearing 156 and 158 to the shaft 160 of seal fold cylinder 46. The seal fold cylinder 46 and delivery cylinder 28 are suitably journaled in hearings in subframes 162 and 164. The delivery cylinder is, in turn, connected by gearing 166 and 168 to a drive shaft of the envelope machine. As illustrated schematically in FlGS. 1-4, the delivery cylinder 28 has a plurality of rows of

vacuum ports

30, 32, 34 and 36 arranged in spaced relation along the periphery of the cylinder. The

vacuum ports

30, 32, 34 and .36 open into longitudinal passageways. A valve member generally designated by the numeral 170 has a rotor portion 172 and a stator portion 174. The stator 174 and rotor 172 are illustrated in FIG. 9.

The rotor 172 has a plurality of apertures 176 that are connected to

underlying passageways

38, 40, 42 and 44 in the delivery cylinder 28. Although there are a greater number of apertures 176 illustrated in FIG. 9 than the

passageways

38, 40, 42 and 44 illustrated in FIGS. 1-4, it should be understood a fewer number of passageways and vacuum ports are illustrated in schematic drawings 14 for clarity and ease in understanding the operation of the envelopefolding apparatus.

The rotor 172, in addition to apertures 176, has an arcuate slotted portion 178. The stator 174 has an arcuate slotted portion 180 on the same radius as the apertures 176 and a radially inwardly extending portion 182 that has a portion on the same radius as the slot 178 in the rotor portion 172. The stator has a port 184 connected to a suitable source of vacuum and opening into slotted portion 180. The stator has a second port 186 that is connected by means of a conduit 188 diagrammatically illustrated in FIGS. 8 and 9. A shutoff valve 190 is positioned in the conduit 183. With this arrangement, rotation of the cylinder 28 with the rotor 172 relative to the stator 174 will apply a suction through the rows of

vacuum portions

30, 32, 34 and 36 as the passageways 176 move into underlying relation with the arcuate slotted portion 180 in the stator 174. Similarly, suction is applied through vacuum ports 148 in the seal fold cylinder 46 when the arcuate slotted portion 178 is in overlying relation with the port 186 in stator 174. Thus, suction is periodically applied through the row of vacuum ports 48 in the seal fold cylinder 46 and in timed relation to the relative angular position of the parallel spaced rows of valve ports in the periphery of the delivery cylinder 28.

The arrangement illustrated in H6. 9 applies vacuum to both the delivery cylinder 28 and the seal fold cylinder 46 and is preferred. Where, however, it is desired to use separate valves for controlling the vacuum applied by the delivery cylinder 28 and the seal fold cylinder 46, a valve similar to that illustrated in FIG. 7 may be connected to any of the other cylinders and used to control the periodic suction applied through the row of valve ports 48 in the seal fold cylinder 46.

H0. 8 illustrates an adjusting mechanism for the valve on the seal fold cylinder 46. The cylinder 46 has a stator portion 192 with a port 194 to which the conduit 188 is connected. The port 194 is connected to an arcuate slotted portion 196. The seal fold cylinder 46 extends through the sleevelike stator portion 192 and has an axial passageway 138 with a radial passageway 198 that opens into the arcuate passageway 196 of stator 192. An adjusting screw 200 is suitably secured to the subframe and is arranged to rotate the stator 192 relative to the cylinder 46. It will be apparent, with the above valving arrangement that suction is applied through the various rows of valve ports in timed relation between the respective cylinders to engage and transport the envelope blanks through the envelope closure flap apparatus, as previously described.

Although the above apparatus was described with reference to folding a closure flap of an envelope, it should be understood the above apparatus may also be employed for folding various types of flaps on bags, envelopes and the like.

According to the provisions of the patent statutes, the principle, preferred construction and mode of operation of the invention have been explained, and what is considered to represent its best embodiment has been illustrated and described. However, it should be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

We claim:

1. Apparatus for folding the closure flap of an envelope comprising,

a transfer device having means to engage and convey an envelope thereon,

a delivery cylinder positioned in spaced relation to said transfer device, said delivery cylinder having a plurality of suction devices extending longitudinally along the periphery of said cylinder,

a seal fold cylinder positioned parallel to said delivery cylinder and between said delivery cylinder and said transfer device, said seal fold cylinder having a diameter smaller than said delivery cylinder, said seal fold cylinder having suction devices extending longitudinally along the periphery of said cylinder,

means to rotate said seal fold cylinder at a multiple of the angular velocity of said delivery cylinder,

means to rotate said delivery cylinder in timed relation to said seal fold cylinder,

said seal fold cylinder suction devices arranged to engage a surface of an envelope while said envelope is engaged by said transfer device and transfer said envelope to said delivery cylinder, and

said delivery cylinder suction devices arranged to engage a surface of said envelope and transfer said envelope away from said seal fold cylinder.

2. Apparatus for folding the closure flap of an envelope as set forth in claim I in which,

said transfer device includes a transfer cylinder positioned in spaced parallel relation to said delivery cylinder,

said means to engage an envelope including suction devices extending longitudinally along the periphery of said transfer cylinder.

3. Apparatus for folding the closure flap of an envelope as set forth in claim 1 which includes,

a buckle plate positioned adjacent to said seal fold cylinder,

said buckle plate having an elongated slot therein,

said buckle plate arranged to receive and support an envelope while said seal fold cylinder engages the closure flap portion of said envelope and upon rotation of said seal fold cylinder folds said closure flap into overlying relation with the rear surface of said envelope.

4. Apparatus for folding the closure flap of an envelope as set forth in claim 1 comprising,

a guide bracket positioned above said seal fold cylinder, said guide bracket arranged to guide said envelope while said envelope is engaged to said seal fold cylinder.

5. Apparatus for folding the closure flap of an envelope as set forth in claim 1 which includes,

means to rotate said delivery cylinder in a direction opposite to said seal fold cylinder.

6. Apparatus for folding the closure flap of an envelope as set forth in claim 2 which includes,

means to rotate said transfer cylinder and said delivery cylinder in the same direction and said seal fold cylinder in a direction opposite to the direction of rotation of said other cylinders.

7. Apparatus for folding the closure flap of an envelope as set forth in claim 2 which includes,

valve means associated with said seal fold cylinder and one of said other cylinders,

said valve means operable to apply a suction periodically through said vacuum ports on said cylinder periphery dependent upon the relative number of revolutions of said seal fold cylinder to said other cylinder.

8. Apparatus for folding the closure flap of an envelope as set forth in claim 7 in which,

suction is applied through said vacuum ports on said seal fold cylinder periphery during every fourth revolution of said seal fold cylinder.

9. Apparatus for folding the closure flap of an envelope as set forth in claim 1 in which,

said suction devices on said delivery cylinder include a plurality of parallel spaced rows of vacuum ports extending longitudinally along the periphery of said delivery cylinder, and

other valve means associated with said delivery cylinder and operable to progressively apply suction through said spaced rows of valve ports in said delivery cylinder periphery.

10. Apparatus for folding the closure flap of an envelope as set forth in claim 9 in which,

said other valve means includes conduit means connected to vacuum ports in said seal fold cylinder, and

means to periodically apply a suction to said valve ports in said seal fold cylinder in timed relation to the relative angular position of said parallel spaced rows of valve ports.

1 l. A method for folding a closure flap of an envelope comprising,

engaging the leading edge of an envelope by suction to the periphery of a transfer cylinder,

rotating said transfer cylinder to position said envelope leading edge adjacent a buckle plate,

engaging the closure flap of said envelope by suction to the periphery of a seal fold cylinder positioned adjacent to said transfer cylinder,

rotating said seal fold cylinder in a direction opposite to the direction of rotation of said transfer cylinder while said closure flap portion of said envelope is engaged to the periphery of said seal fold cylinder to thereby fold said closure flap into overlying relation with the rear surface of said envelope,

engaging said envelope body portion by suction onto the periphery ofa delivery cylinder positioned adjacent to the seal fold cylinder,

rotating said delivery cylinder in a direction opposite to the direction of rotation of said seal fold cylinder, and

releasing said envelope closure flap from the periphery of said seal fold cylinder to permit said delivery cylinder to transfer said envelope with said closure flap folded into overlying relation with said envelope rear surface.

12. A method for folding a closure flap of an envelope comprising,

engaging the closure flap of an envelope by suction onto the periphery of a transfer cylinder,

rotating said transfer cylinder to move said envelope between said transfer cylinder and a seal fold cylinder,

engaging the rear surface of said envelope adjacent said closure flap by suction onto the periphery of said seal fold cylinder and folding said envelope closure flap rearwardly onto the front surface of said'envelope,

rotating said seal fold cylinder in a direction opposite to the direction of rotation of said transfer cylinder and transferring said envelope to a delivery cylinder positioned adjacent thereto,

engaging said rearwardly folded closure flap and said envelope front surface by suction to the periphery of said delivery cylinder, and

rotating said delivery cylinder in a direction opposite to the direction of said seal fold cylinder to transfer said envelope with said closure flap folded into overlying relation with the front surface of said envelope.

Claims

1. Apparatus for folding the closure flap of an envelope comprising, a transfer device having means to engage and convey an envelope thereon, a delivery cylinder positioned in spaced relation to said transfer device, said delivery cylinder having a plurality of suction devices extending longitudinally along the periphery of said cylinder, a seal fold cylinder positioned parallel to said delivery cylinder and between said delivery cylinder and said transfer device, said seal fold cylinder having a diameter smaller than said delivery cylinder, said seal fold cylinder having suction devices extending longitudinally along the periphery of said cylinder, means to rotate said seal fold cylinder at a multiple of the angular velocity of said delivery cylinder, means to rotate said delivery cylinder in timed relation to said seal fold cylinder, said seal fold cylinder suction devices arranged to engage a surface of an envelope while said envelope is engaged by said transfer device and transfer said envelope to said delivery cylinder, and said delivery cylinder suction devices arranged to engage a surface of said envelope and transfer said envelope away from said seal fold cylinder.

2. Apparatus for folding the closure flap of an envelope as set forth in claim 1 in which, said transfer device incLudes a transfer cylinder positioned in spaced parallel relation to said delivery cylinder, said means to engage an envelope including suction devices extending longitudinally along the periphery of said transfer cylinder.

3. Apparatus for folding the closure flap of an envelope as set forth in claim 1 which includes, a buckle plate positioned adjacent to said seal fold cylinder, said buckle plate having an elongated slot therein, said buckle plate arranged to receive and support an envelope while said seal fold cylinder engages the closure flap portion of said envelope and upon rotation of said seal fold cylinder folds said closure flap into overlying relation with the rear surface of said envelope.

4. Apparatus for folding the closure flap of an envelope as set forth in claim 1 comprising, a guide bracket positioned above said seal fold cylinder, said guide bracket arranged to guide said envelope while said envelope is engaged to said seal fold cylinder.

5. Apparatus for folding the closure flap of an envelope as set forth in claim 1 which includes, means to rotate said delivery cylinder in a direction opposite to said seal fold cylinder.

6. Apparatus for folding the closure flap of an envelope as set forth in claim 2 which includes, means to rotate said transfer cylinder and said delivery cylinder in the same direction and said seal fold cylinder in a direction opposite to the direction of rotation of said other cylinders.

7. Apparatus for folding the closure flap of an envelope as set forth in claim 2 which includes, valve means associated with said seal fold cylinder and one of said other cylinders, said valve means operable to apply a suction periodically through said vacuum ports on said cylinder periphery dependent upon the relative number of revolutions of said seal fold cylinder to said other cylinder.

8. Apparatus for folding the closure flap of an envelope as set forth in claim 7 in which, suction is applied through said vacuum ports on said seal fold cylinder periphery during every fourth revolution of said seal fold cylinder.

9. Apparatus for folding the closure flap of an envelope as set forth in claim 1 in which, said suction devices on said delivery cylinder include a plurality of parallel spaced rows of vacuum ports extending longitudinally along the periphery of said delivery cylinder, and other valve means associated with said delivery cylinder and operable to progressively apply suction through said spaced rows of valve ports in said delivery cylinder periphery.

10. Apparatus for folding the closure flap of an envelope as set forth in claim 9 in which, said other valve means includes conduit means connected to vacuum ports in said seal fold cylinder, and means to periodically apply a suction to said valve ports in said seal fold cylinder in timed relation to the relative angular position of said parallel spaced rows of valve ports.

11. A method for folding a closure flap of an envelope comprising, engaging the leading edge of an envelope by suction to the periphery of a transfer cylinder, rotating said transfer cylinder to position said envelope leading edge adjacent a buckle plate, engaging the closure flap of said envelope by suction to the periphery of a seal fold cylinder positioned adjacent to said transfer cylinder, rotating said seal fold cylinder in a direction opposite to the direction of rotation of said transfer cylinder while said closure flap portion of said envelope is engaged to the periphery of said seal fold cylinder to thereby fold said closure flap into overlying relation with the rear surface of said envelope, engaging said envelope body portion by suction onto the periphery of a delivery cylinder positioned adjacent to the seal fold cylinder, rotating said delivery cylinder in a direction opposite to the direction of rotation of said seal fold cylinder, and releasing said envelope closure flap from the periphery of said seal fold cylinder to permit said delivery cylinder to transfer said envelope with said closure flap folded into overlying relation with said envelope rear surface.

12. A method for folding a closure flap of an envelope comprising, engaging the closure flap of an envelope by suction onto the periphery of a transfer cylinder, rotating said transfer cylinder to move said envelope between said transfer cylinder and a seal fold cylinder, engaging the rear surface of said envelope adjacent said closure flap by suction onto the periphery of said seal fold cylinder and folding said envelope closure flap rearwardly onto the front surface of said envelope, rotating said seal fold cylinder in a direction opposite to the direction of rotation of said transfer cylinder and transferring said envelope to a delivery cylinder positioned adjacent thereto, engaging said rearwardly folded closure flap and said envelope front surface by suction to the periphery of said delivery cylinder, and rotating said delivery cylinder in a direction opposite to the direction of said seal fold cylinder to transfer said envelope with said closure flap folded into overlying relation with the front surface of said envelope.