Variable Size Envelope With Single Closure Flap

The subject matter of this application is related to the subject matter of co-pending application, Ser. No. 07/005,458, filed by Wayne L. Rutkowski on Jan. 20, 1987, entitled "Dual Envelope Sheet Feed Assembly," and assigned to Avery International Corporation, the assignee of the present application is related to the subject matter of co-pending application, Ser. No. 07/270,785, filed by Tien-Tsung Chen, et al. on Nov. 14, 1988, entitled "Mailer For Laser Printer," and assigned to Avery International Corporation, the assignee of the present application; and is related to the subject matter of co-pending application, Ser. No. 07/344,615, filed by Kim Y. Kao, et al, on Apr. 27, 1989, entitled "Envelope With Single Peel-Off Backing Sheet to Facilitate Printing and Copying," and assigned to Avery International Corporation, the assignee of the present application.

The present invention relates generally to envelopes and, more particularly, to a variable size envelope with a single closure flap that may be selectively folded along two different fold lines to provide two different size envelopes, the smaller envelope being of uniform thickness to facilitate processing through automatic mechanical sheet feed printing equipment, laser printing equipment and feed through copy machines.

In the past, envelopes of variable size have been difficult to process through automatic mechanical printing equipment, laser printing equipment and copying machines because the envelopes were either too big to send through such machines when folded into a larger size, or difficult to process when folded into a smaller size. For example, German Patent No. 631,006, issued to Bassler, et al. on June 10, 1936, discloses an envelope with a closure flap which may be folded along two different lines and sealed to provide envelopes of two different sizes. However, when folded into smaller size envelopes, the envelope disclosed in this patent presents folds through two thicknesses of material and overlapping portions near the top of the envelope which lead to an envelope of uneven thickness difficult to process through automatic mechanical printing equipment, laser printing equipment and copying machines. The expanding envelope disclosed in U.S. Pat. No. 3,063,618, issued to Berkowitz on Nov. 13, 1962, presents the same problems because it is not of uniform thickness when folded and has overlapping portions.

The above problems would be solved by a variable size envelope having a single closure flap which may be selectively folded along two different fold lines to provide two different envelopes, the smaller envelope being of uniform thickness so that it may be easily processed through automatic mechanical printing equipment, laser printing equipment and copying machines.

It is an object of this invention to provide a variable size envelope which may be selectively folded to present envelopes of two different sizes.

It is still another object of this invention to provide a variable size envelope which may be folded into a smaller size envelope of uniform thickness which may be easily processed through automatic mechanical sheet feed printing equipment, laser printing equipment and feed through copy machines.

It is still another object of this invention to provide a variable size envelope that is economical to manufacture.

These and other objects and advantages are attained by a variable size envelope with a single closure flap that may be selectively folded along either of two different fold lines to provide two different sizes of envelopes. A pocket for holding papers or other documents may be formed by a single rear panel or two rear panels joined together. The height of the closure flap is preferably equal to the height of the panels so that the envelope when folded into a smaller size presents a flat envelope of uniform thickness which may be processed through automatic mechanical printing equipment, laser printing equipment and copying machines, then unfolded and later used as a larger size envelope. Adhesive strips are provided on the closure flap for the purpose of sealing the envelope. The adhesive used for the strips is preferably a stable, water-activated, or moisture-activated adhesive, which is not significantly affected by either heat or exposure to high humidity, facilitating use of the envelope during laser printing or xerographic copying. A peel-off strip of material may be used to cover sticky adhesive on the closure flap. The sticky adhesive is preferably a stable, pressure-sensitive adhesive. The strip may be peeled from the flap so that the sticky adhesive can be used to seal the envelope shut.

The various features of the present invention will be best understood together with further objects and advantages by reference to the following description of the preferred embodiments taken in conjunction with the accompanying drawings.

FIG. 1 is a rear perspective view of a variable size envelope having a central joint line provided by overlapping portions of two rear panels illustrating the principles of the present invention showing a closure flap of the envelope in an opened, unfolded position;

FIG. 2 is a rear perspective view of the envelope of FIG. 1 with the closure flap folded along an upper fold line to provide a larger size envelope;

FIG. 3 is a rear perspective view of the envelope of FIG. 1 with the closure flap folded along a lower fold line to provide a smaller size envelope;

FIG. 4 is a cross-sectional view taken in the direction of arrows IV--IV shown in FIG. 1;

FIG. 5 is a rear perspective view of another embodiment of the variable size envelope of the present invention having a rear panel attached to two side flaps showing the closure flap of the envelope in an opened, unfolded position;

FIG. 6 is a cross-sectional view taken in the direction of arrows VI--VI shown in FIG. 5;

FIG. 7 is a rear perspective view of still another embodiment of the variable size envelope of the present invention having a rear panel attached to a front panel without the use of side flaps showing the closure flap of the envelope in an opened, unfolded position; and

FIG. 8 is a cross-sectional view taken in the direction of arrows VIII--VIII shown in FIG. 7.

The following specification taken in conjunction with the drawings sets forth the preferred embodiments of the present invention in such a manner that any person skilled in the art can make and use the invention. The embodiments of the invention disclosed herein are the best modes contemplated by the inventors for carrying out their invention in a commercial environment although it should be understood that various modifications can be accomplished within the parameters of the present invention.

FIGS. 1 through 4 show an embodiment of the variable size envelope 10 of the present invention. The envelope 10 has a front panel 12 with an integrally formed closure flap 14 shown in an opened, unfolded position in FIG. 1 and two integrally formed rear panels 16 and 18. Panels 12, 16 and 18 and closure flap 14 are made of sheets of material such as paper. Panels 16 and 18 have overlapping portions 20 and 22, respectively, which are joined together by glue or some type of adhesive along a central joint line to form a pocket 24 for holding papers, documents or other materials. A bottom flap 26 is glued or sealed by some type of adhesive to the bottoms of panels 16 and 18 as shown in FIG. 1 closing the bottom of pocket 24.

Closure flap 14 has horizontal and vertical strips of glue or other adhesive 28 and 30, respectively, at the top and sides thereof as shown in FIG. 1. The vertical strips of adhesive 30 preferably extend all the way down the sides of the flap 14 to the top of pocket 24. However, the strips of adhesive 30 may extend only part of the way down the sides of flap 14 if desired. If the envelope 10 is not subjected to higher temperatures during laser printing or by the hot rollers of a xerographic copying machine, then "natural" gum adhesives may be used for the adhesive 28 and 30. However, if the envelope 10 is intended for laser printing or xerographic copying, then the relatively high temperature of a few hundred degrees Fahrenheit encountered during these operations will cause a gum adhesive to become sticky, resulting in contamination to the printer or copier. Therefore, if the envelope 10 will be used for laser printing or xerographic copying, a stable, water-activated, or moisture-activated adhesive is desirable, which is not significantly affected by either heat or exposure to high humidity. One such adhesive is available from Adhesive Consultants Corporation, 25817 Clawiter Road, Hayward, Calif. 94545, under the trade name "Adcon FS-6." The adhesive is a polyvinyl emulsion. However, other stable moisture-activated adhesives are known, and such other adhesives may be used if desired.

A peel-off strip 32 represented by dotted lines in FIG. 1 may also be used to cover a sticky adhesive such as 28 and 30 and peeled off for the purpose of adhering the flap 14 to the panels 16 and 18. The peel-off strip 32 is preferably covered by a release material such as silicone so that it may be easily removed from the sticky adhesive 28 and 30. Moreover, the sticky adhesive 28 and 30 is preferably a stable, pressure-sensitive adhesive of a type which will not flow at a temperature of a few hundred degrees Fahrenheit. Preferably, both the pressure-sensitive adhesive and water-activated adhesive will remain stable when subjected to temperatures in the range of up to about 300 to about 400 degrees Fahrenheit.

It is important to note that the invention is not intended to be limited by the type of adhesive used or by the location of the adhesive on the flap 14. For example, the entire upper half of the flap 14 may be covered by adhesive, or only one strip 28 of adhesive may be used if desired.

The flap 14 may be selectively folded along fold lines 34 and 36 to provide envelopes 10 of different sizes. FIG. 2 shows the envelope 10 after the flap 14 has been folded along fold line 34 to present a larger size envelope 10. Adhesive strips 28 and 30 are used to attach the portion of closure flap 14 above line 34 to rear panels 16 and 18 and to the portion of flap 14 below line 34. If a strip 32 is used, then the strip 32 is peeled off flap 14 and the sticky adhesive below the strip 32 is used to hold the flaps 14 in place.

A smaller size envelope 10 may be obtained by folding closure flap 14 along line 36 and by using adhesive strips 28 and 30 to adhere the flap 14 to the panels 16 and 18 as shown in FIG. 3. Note that the height h.sub.1 of closure flap 14 is preferably sized to be approximately the same size as the height h.sub.2 of the panels 16 and 18. As a result, the smaller size envelope 10 is of uniform thickness when folded as shown in FIG. 3, which facilitates passing the envelope through automatic mechanical sheet feed printing equipment, laser printing equipment and feed through copying machines or equipment. Moreover, the envelope 10 may be folded as shown in FIG. 3 without sealing or using adhesive strips 28 and 30 to attach the closure flap 14 to the panels 16 and 18. In other words, after the smaller unsealed envelope 10 has addresses or other indicia printed thereon, or has been copied, it may be unfolded and then flap 14 may be folded along line 34 and the adhesive strips 28 and 30 used to seal the larger sized envelope 10 shut. As such, the smaller sized envelope 10 provides a flat envelope of uniform thickness which may be used for the purpose of putting printing on a larger size envelope 10 that is too large to be processed by automatic mechanical printing equipment or laser printing equipment. The uniform thickness also facilitates feeding the envelope 10 through copying machines.

Preferably, h.sub.1 and h.sub.2 equal about 81/2inches and the width, W, of the envelope 10 is preferably about 93/4 inches to facilitate processing through automatic mechanical sheet feed printing equipment, laser printing equipment and feed through copy machines. As a result, the smaller envelope 10 is 81/2 inches by 93/4 inches and the size of the larger envelope 10 is about 12 inches by 93/4 inches. In addition, fold line 34 should be located at a height h.sub.3 above the top of pocket 24 that is less than half the height h.sub.1 so that flap 14 overlaps the top of pocket 24 by distance h.sub.4 when folded as shown in FIG. 2. h.sub.3 is preferably about 31/2 inches making h.sub.4 about 11/2 inches. However, it is important to point out that the dimensions h.sub.1, h.sub.2, h.sub.3, h.sub.4 and W may vary as desired to provide envelopes 10 of any desirable size. It is intended that this invention not be limited by the size of envelope 10.

FIGS. 5 and 6 show another embodiment of the variable size envelope 10 of the present invention. The envelope 10 has a single rear panel 38 that is joined to two side flaps 40 and 42 of the front panel 12 by glue or any suitable adhesive for the purpose of providing pocket 24 for holding papers, documents, etc. Alternatively, the side flaps 40 and 42 may be part of the rear panel 38 instead of the front panel 12 if desired. Note that the bottom flap 26 of the envelope 10 shown in FIGS. 1 and 2 is eliminated by the single rear panel 38 which folds upward along line 44. The remaining portions of the envelope 10 are similar to those of the embodiment shown in FIG. 1.

Still another embodiment of the variable size envelope 10 of the present invention is shown in FIGS. 7 and 8. The envelope 10 has rear panel 38 folded upward along line 44 to form pocket 24. The vertical sides of panel 38 are joined to vertical sides of front panel 12 by strips of glue or other suitable adhesive 46. The rest of the envelope 10 is similar to the embodiments shown in FIGS. 1 and 5.

The envelope 10 described above is of variable size, i.e., closure flap 14 may be selectively folded along either of lines 34 and 36 to provide larger and smaller envelopes as desired. In addition, the folding feature of the envelope 10 allows the envelope to be printed using automatic mechanical printing equipment or laser printing equipment when folded into the smaller size envelope of uniform thickness and subsequently unfolded and later used as a larger size envelope after addresses, etc. have been printed on the envelope. Copying is also simplified by the smaller size envelope 10 of uniform thickness.

The above description discloses the preferred embodiments of the present invention. However, persons of ordinary skill in the art are capable of numerous modifications once taught these principles. For instance, by way of example and not limitation, a single back panel may be folded about a vertical fold line at one side of the envelope and attached to a single flap at the opposite side of the envelope. Also, the adhesive may be attached to the back panel or panels rather than to the closure flap. Other flap designs may also be used in place of those described above. Accordingly, it will be understood by those skilled in the art that changes in form and details may be made to the above-described embodiments without departing from the spirit and size of the invention.