US3702171A

US3702171A - Envelope with impermanent closure

Info

Publication number: US3702171A
Application number: US163269A
Authority: US
Inventors: Elliot Levine
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-07-16
Filing date: 1971-07-16
Publication date: 1972-11-07
Anticipated expiration: 1989-11-07

Abstract

AN ENVELOPE HAVING A PRESSURE-SENSITIVE TAPE-TYPE IMPERMANENT CLOSURE CONSISTING OF THREE TAPE STRIPS. EACH TAPE STRIP HAS AN AGGRESSIVELY ADHESIVE SIDE AND A LOW ADHESION SIDE. A FIRST AND A THIRD OF SAID TAPE STRIPS ARE ADHERED BY THEIR AGGRESSIVELY PRESSURE-SENSITIVE ADHESIVE SIDES TO THE REAR SURFACE OF THE ENVELOPE BODY IN ALIGNMENT. THE FIRST OF THE TAPE STRIPS IS LOCATED UNDER THE FLAP WHEN THE FLAP IS CLOSED AND RUNS PERPENDICULAR TO THE HINGE CONNECTING THE FLAP TO THE ENVELOPE BODY, TERMINATING AT THE POSITION OCCUPIED BY THE FREE EDGE OF THE FLAP WHEN THE FLAP IS CLOSED. THE THIRD OF THE TAPE STRIPS IS LOCATED ON THE REAR SURFACE OF THE ENVELOPE BODY AND EXTENDS AWAY FROM THE EDGE OF THE FIRST STRIP REMOTE FROM THE FLAP HINGE. THE THIRD TAPE STRIP HAS A PORTION EXTENDING FROM REMOTE EDGE OF THE FIRST STRIP. THIS PORTION IS NOT ADHESIVELY SECURED TO THE BACK OF THE ENVELOPE BODY AND IS REFFERED TO AS THE FREE PORTION. WHEN THE ENVELOPE IS SOLD THE FREE PORTION OF THE THIRD TAPE STRIP IS ADHESIVELY SECURED TO THE LOW ADHESION SIDE OF THE FIRST STRIP. A SECOND TAPE STRIP WHICH HAS ITS AGGRESSIVELY PRES-

SURE-SENSITIVE ADHESIVE SIDE ADHERED TO THE BACK OF THE FLAP IS PROVIDED. THE SECOND STRIP IS IN ALIGNMENT WITH THE SAID FIRST AND THIRD TAPE STRIPS AND MAY BE SLIGHTLY WIDER. IN USE THE FREE PORTION OF THE THIRD TAPE STRIP IS PEELED FROM THE LOW ADHESION SIDE OF THE FIRST STRIP, THEN THE FLAP IS FOLDED TO CLOSED POSITION AND FINALLY THE FREE PORTION IS ADHERED TO THE LOW ADHESION SIDE OF THE SECOND STRIP FROM WHICH IT CAN BE READILY PEELED AT ANY TIME THAT THE CONTENTS OF THE ENVELOPE ARE TO BE INSPECTED. THE TIP OF THE FREE PORTION HAS A PULL TAB THEREON NEITHER SIDE OF WHICH HAS A PRESSURE-SENSITIVE ADHESIVE THEREON.

Description

Nov. 7, 1972 E. LEVINE 3,702,171

ENVELOPE WITH IMPERMANENT CLOSURE Filed July 16, 1971 x 34 E I Q 3 2o 42m INVENTOR.

5? I 1 I I 524/07 Lt'V/A/E' I al al/1 Qww H6. 5

ATTORNEYS United States Patent US. Cl. 22979 8 Claims ABSTRACT OF THE DISCLOSURE An envelope having a pressure-sensitive tape-type impermanent closure consisting of three tape strips. Each tape strip has an aggressively adhesive side and a low adhesion side. A first and a third of said tape strips are adhered by their aggressively pressure-sensitive adhesive sides to the rear surface of the envelope body in alignment. The first of the tape strips is located under the flap when the flap is closed and runs perpendicular to the hinge connecting the flap to the envelope body, terminating at the position occupied by the free edge of the flap when the flap is closed. The third of the tape strips is located on the rear surface of the envelope body and extends away from the edge of the first strip remote from the flap hinge. The third tape strip has a portion extending from remote edge of the first strip. This portion is not adhesively secured to the back of the envelope body and is referred to as the free portion. When the envelope is sold the free portion of the third tape strip is adhesively secured to the low adhesion side of the first strip. A second tape strip which has its aggressively pressure-sensitive adhesive side adhered to the back of the flap is provided. The second strip is in alignment with the said first and third tape strips and may be slightly wider. In use the free portion of the third tape strip is peeled from the low adhesion side of the first strip, then the flap is folded to closed position and finally the free portion is adhered to the low adhesion side of the second strip from which it can be readily peeled at any time that the contents of the envelope are to be inspected. The tip of the free portion has a pull tab thereon neither side of which has a pressure-sensitive adhesive thereon.

velope adapted to contain thir dand fourth class mail, although not so restricted, so that the envelope can be opened for inspection without rendering the closure inr operable.

(2) Description of the prior art Third and fourth class mail is not supposed to be sealed. Accordingly, envelopes for such mail are usually impermanently closed, the closure being sufiicient to retain the contents against accidental opening, but being easily openable so that the contents can be inspected by the Post Otfice Department. Two conventional ways of impermanently closing envelopes are presently in use. The first is to provide a metal clasp on the envelope back. The clasp includes two tongues of deformable metal. The envelope flap has an opening in registry with the tongues when the flap is folded over the back of the envelope (closed), and to secure the flap to the envelope body, the tongues are inserted through the opening in the flap and then bent in opposite directions back against the closed flap. The second arrangement is to centrally connect a stiff paperboard disc to the flap and another to the envelope body clear of the closed flap but close to the first disc, the discs being held in place with eyelets. One of the discs has a string attached to its eyelet. The

3,702,171 Patented Nov. 7, 1972 string is trained alternately under and partly around each disc.

These conventional means for providing an impermanent closure for an envelope are subject to several drawbacks. The metal-type closure, for example, can only be used a few times before the tongues break off due to the bending of the same back and forth. Also, a users fingers can be easily cut on the tongues, and the tongues may rust if the envelope is exposed to a damp environment for any appreciable length of time or if wetted.

The disc-type closures are cumbersome to use and sometimes the string becomes tangled, thereby causing difficulty to be encountered in opening the envelope. Also, the discs cause extra bulk, and when a number of such envelopes are piled on top of one another, the extra bulk is very inconvenient and wastes a lot of space. Still further, when envelopes with disc-type impermanent closures are stacked, the discs and strings tend to become tangled and this creates considerable bother in separating the envelopes from one another.

Both types of closures are usually packed with the flaps extended (open), thereby occupying considerable space.

SUMMARY OF THE INVENTION (1) Purposes of the present invention It is a principal object of the present invention to provide an envelope including an impermanent closure which overcomes the disadvantages of conventional envelopes and is simple, safe and durable.

It is another object of the present invention to provide an envelope closure of the character described which is extremely easy and inexpensive to manufacture in large.

quantities and requires no special tools.

It is another object of the present invention to provide envelopes of the character described wherein the impermanent closure makes use as the attaching components of a single staple commodity which is available at low cost and which is not subject to deterioration with age or repeated usage.

It is another object of the present invention to provide an envelope of the character described wherein the impermanent closures do not add any noticeable bulk to the envelopes even when they are stacked in large quantities.

It is another object of the present invention to provide an envelope of the character described wherein the impermanent closure does not employ metal or string or discs so that it cannot rust, cut a users fingers, or become entangled.

It is another object of the present invention to provide an envelope of the character described wherein the impermanent closure may be transparent and thus does not conceal any printed matter on the envelope body or flap and does not otherwise spoil the appearance of the envelope.

It is another object of the present invention to provide an envelope of the character described which is best packed with the flap closed so as to occupy a minimum of space.

It is another object of the present invention to provide an envelope of the character described wherein the impermanent closure is much easier to attach than a metal clasp, and requires no hopped feed, raceway or clinching tools, no glue pots or glue rollers, no heating elements for drying glue, no buttons, no strings, no eyelets and no machinery to attach the latter.

It is another object of the invention to provide an envelope of the character described wherein the impermanent closure is virtually weightless, thus constituting a marked advantage both for shipping and the reduction of airmail postage.

It is another object of the invention to provide an envelope of the character described wherein the impermanent closure is so constructed that it can be disposed in a shipping position that does not permit any part of the impermanent closure to accidentally become adhered to a part of the envelope and thereby render the closure useless for its intended function.

Other objects of the invention in part will be obvious and in part will be pointed out hereinafter.

BRIEF DESCRIPTION OF THE INVENTION Generally, the invention embraces the use as an impermanent closure of a pressure-sensitive tape of the type conventionally wound in a continuous strip on rolls with an aggressively pressure-sensitive adhesive tacky side of the tape wound over and against a non-tacky low adhesion side thereof. One well-known tape of this type is sold commercially under the trademark Scotch tape. The aggressively pressure-sensitive adhesive side of the tape is capable of adhering tightly to paper or other similar surfaces. However, the low adhesion side of the tape is characterized by its ability to lightly adhere to and to be strippable from the aggressively pressure-sensitive adhesive side without tearing of the tape, without deterioration of the aggressively pressure-sensitive adhesive side and without leaving a residue of tacky adhesive on the low adhesion side.

The foregoing material is employed in the instant invention in the following general manner.

A first strip of such tape, at the time of sale, is adhered by its aggressively pressure-sensitive adhesive side to the rear surface of the envelope body. A third strip of such tape is adhered by its aggressively pressure-sensitive side to the rear surface of the envelope body in alignment with the first strip but not overlapping the first strip. The first strip is located under the tflap of the envelope when the flap is closed and the longitudinal axis of this first strip is perpendicular to the hinge connecting the flap to the envelope body. The distal edge of the first strip remote from the hinge is positioned at the free edge of the flap when the flap is closed. The third strip which, as just indicated is located on the rear surface of the envelope body, extends away from the distal edge of the first strip. The third strip has a portion running from the distal edge of the first strip. This portion is not adhesively secured to the back of the envelope and is referred to as the free portion. When the envelope is sold the free portion of the third strip is adhesively secured to the low adhesion side of the first strip.

A second tape strip has its aggressively pressure-sensitive side adhered to the back of the flap. The second tape is in alignment with the first and the third strips and preferably is slightly Wider than at least the third strip. Preferably, the widths of the first and third strips are equal to each other.

In use, the free portion of the third strip is peeled from the low adhesion side of the first strip (the position it is in at the time of sale), then the flap is folded to closed position overlying the first strip and, finally, the free portion is adhered to the low adhesion side of the second strip. The envelope is now ready for mailing. If a postal inspector desires to scrutinize the contents of the envelope, he peels the third strip from the second strip. In other words, the third strip, when the envelope is sold, is adhered to the first strip where it is out of harms way and cannot accidentally become adhered to some part of the envelope which would render the impermanent closure useless. When the envelope is to be used, the third strip is peeled from the first strip, the flap is closed and the third strip is then adhered to the second strip, thereby forming the impermanent closure.

To facilitate these peeling operations the tip of the free portion has a pull tab thereon, neither side of which is covered with a pressure-sensiive adhesive. This is accomplished in the embodiment of the invention illustrated and described by folding back the tip of the free 4 portion with the aggressively pressure-sensitive adhesive sides facing each other to leave the outer surfaces of the pull tab constituted by low adhesion sides.

The invention consists in the features of construction, combinations of elements and arrangements of parts which will be exemplified in the device hereinafter described and in which the scope of application will be indicated in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings in which is shown one of the various possible embodiments of the invention,

FIG. 1 is a rear perspective view of an envelope with an open flap and including an impermanent closure embodying the instant invention;

FIG. 2 is a view similar to FIG. 1 but showing the flap in a closed position, folded back onto the rear surface of the envelope body prior to effecting an impermanent closure; in this figure and the preceding figure the free portion of the third strip of the impermanent closure is illustrated in its disengaged position, to wit, disengaged from both the first strip and the second strip;

FIG. 3 is an enlarged fragmentary central sectional view through the flap and envelope body in the vicinity of the flap hinge and with the third strip adhered to the first strip;

FIG. 4 is a view similar to FIG. 3 but illustrating the condition of the impermanent closure after the third strip has been peeled off the first strip and is disengaged from the first and second strips, the flap being illustrated in its folded, closed position; and

FIG. 5 is a view similar to FIG. 4 but illustrating the free portion of the third strip adhered to the second strip.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now in detail to the drawings, the reference numeral 10 denotes an envelope on which there is mounted an impermanent closure 12 embodying the instant invention. Said envelope includes a rectangular body 14 which is closed at its sides and bottom and is open at its top end (as viewed in FIGS. 1 and 2) to form a mouth 16. The envelope is provided with a flap 18 hinged to the body along a fold line 20 at the top of the envelope. The flap includes a terminal (free) edge 22 remote from the fold line 20. The envelope is conventional in that it is of rectangular configuration with the fold line 20 forming one edge of the envelope when the flap is closed. The surface of the envelope onto which the flap folds in closing of the envelope will be referred to hereinafter as the back or rear surface of the envelope body 14 and the surface of the flap which faces said envelope body back when the flap is folded over will be referred to as the front surface of the flap. The surface of the flap which faces away from the envelope body in the folded over (closed) position of the flap will be referred to as the rear surface of the flap.

Pursuant to the instant invention the impermanent closure 12 of the envelope is constituted of three

strips

24, 26 and 28. The strip 24 is hereinafter referred to as the first strip and is further denoted by the reference character I. The strip 26 is hereinafter referred to as the second strip and is further denoted by the reference character II. The strip 28 is hereinafter referred to as the third strip and is further denoted by the reference character III. Each of these strips I, II and IH (24, 26 and 28) constitutes a length of transparent pressure-sensitive adhesive tape. It has one surface (indicated by dots in the drawings) with an aggressively pressure-sensitive tacky adhesive side. The opposite surface of the tape is a low adhesion side.

Tape I is adhered by its aggressively pressure-sensitive adhesive side to the back of the envelope body so that its low adhesion side is exposed. The site of the tape is under the area which is covered by the flap when the flap is closed. The tape I extends longitudinally in a direction transverse to the fold 20. The tape runs from adjacent the edge of the rear surface of the envelope that is nearest to the fold to a tape end which is in substantial registry with the free edge 22 of the flap 18. In the preferred form of the invention, for purposes of appearance, symmetry and best mode of closure, the tape I is located at the center of the rear of the envelope body. This arrangement is used with an oblong envelope wherein the tape I extends parallel to the long edge of the envelope. However, this central position is not critical to the operation of the invention. For example, two impermanent closures may be used, in which case they would be symmetrically located on opposite sides of the center line of the envelope perpendicular to the flap fold line. Two closures would be used, for example, with envelopes having a substantial side-to-side dimension and would be used with oblong envelopes in which the fold line 20 constitutes a long side of the envelope.

In the preferred form of the invention the strip I has its longitudinal axis perpendicular to the fold line 20 although it will be understood that this particular orientation of said strip I is not critical to the proper functioning of the invention. It will be appreciated that the strip I is concealed by the flap 1-8 when the flap is closed. See, for example, FIGS. 2, 3, 4 and 5. Nevertheless, it should be pointed out that it is within the ambit of the invention to have the distal edge of the strip I extend somewhat out from under the terminal edge 22 of the flap. This arrangement merely lessens the area of adhesion between the third strip and the 'back of the envelope hereinafter to be described, and such lessening does not materially affect the efficiency of operation of the invention. The distal edge, i.e. the edge remote from the fold line 20, of the strip 1, is denoted by the reference numeral 30'.

The pressure-sensitive adhesive strips I, II, III usable in accordance with the present invention are conventional and include, as already pointed out, an aggressively tacky pressure-sensitive adhesive side and a low adhesion side on opposite surfaces of a flexible plastic web. Preferably, the force required to strip the tacky side from the low adhesion side should not exceed one-half the force required to strip the tacky side from cellophane. The tape is supplied in a standard fashion in a roll with the aggressively tacky side on the inside. In the roll the low adhesion side serves not only as one face of a permanent transparent base or carrier for the aggressively pressuresensitive adhesive coating constituting the tacky side, but also as a temporary liner, since the backing in each turn of the roll contacts and covers the adhesive surface of the overlying turn. The limited adhesion between the tacky side and the low adhesion side in the roll makes it possible to unwind the tape without too much effort and when the tape is being unwound there is not suflicient pull by the tacky side on the low adhesion side to cause delamination of tape structure which would tear the tape or strip off from the carrier web the aggressively tacky substance on the aggressively tacky side. The degree of adherency between the tacky side and the low adhesion side is sufficient to hold the tape wound in place and prevent spontaneous separation of the turns in the roll (free unwinding).

Typical conventional tapes of the aforesaid character including aggressively pressure-sensitive tacky adhesive sides and low adhesion sides as described above are sold on the open market, one such type being known as Scotch tape." Moreover, tapes of this type are described in =U.S. Pat. Nos. 2,532,011 and 2,607,711. Pressure-sensitive tape adhesive compositions are described in US. Pat. Nos. 2,156,380; 2,177,627 and 2,319,959.

The third strip III is adhered by its aggressively pressure-sensitive adhesive side to the back of the envelope body 14 in alignment with the first strip I. In a way, the third strip III constitutes an extension of the first strip I although these strips are separate physical entities. The arrangement of the third strip III is such that an intermediate portion 32 thereof is located adjacent the distal edge 30 of the first strip I. Thus, the part of the third strip III from the intermediate portion 32 in a direction away from the mouth of the envelope is tightly adhered to the rear surface of the back of the envelope body 14.

A portion 3 4 of the third strip III extending in the opposite direction from the intermediate portion 32 is referred to herein as the free portion. This free portion is capable of occupying two positions. One position is illustrated in FIG. 3. In this position the free portion overlies and is coextensive with the first strip I and is adhered by its aggressively pressure-sensitive adhesive side to the low adhesion side of said first strip I. This is the position which the strips I and III occupy when the envelope is sold. In this position the free portion of the third strip III is, in effect, lightly adhered to the low adhesion side of the first strip I whereby this free portion is, so to speak, anchored in place and is not able to firmly stick to other objects and, in so sticking, to render the impermanent closure unusable. Moreover, in this position when the envelope is sold the flap 1 8 can be folded down over the rear surface of the envelope body to cover the free portion and the first strip I although, if desired, the envelope can be shipped with the flap in open position as illustrated in FIG. 1 inasmuch as said free portion is held lightly in an out-of-the-way position.

When the envelope is used, the free portion 34 of the third strip III must be peeled off the first strip I and to facilitate this peeling, i.e. to make it easier to start the peeling, it is desirable that there be provided a tab 36 at the tip of the free portion. This tab can be formed in any suitable way, e.g. by adhering a folded paper disc to opposite sides of the tip of the free portion 34. A simple way, and the arrangement that is shown in the drawings, is to fold back the tip of the free portion so that aggressively pressure-sensitive adhesive surfaces face each other for a short distance whereby at this folded-over portion both exposed surfaces of the tip of the free portion 34 constitute low adhesion surfaces. Such tab, therefore, will not even stick lightly to the portion of the first strip I that it overlies in the position shown in FIG. 3. Thereby when a person wishes to pull the free portion 34 off the first strip I he simply grasps the tab 36 between his thumb and forefinger and pulls back on the tab in such a direction as to strip the free portion 34 from the first strip I. When the free portion is thus pulled back, it extends away from the rear surface of the envelope as illustrated in FIGS. 1, 2 and 4 and is ready for use in the further manner now to be described.

The second strip II has its aggressively pressure-sensitive tacky adhesive side adhered to the back of the flap 18 and is in alignment with the third strip III. The second strip II also overlies the first strip I and is substantially coextensive therewith when the flap is in closed position. It does not touch the first strip I because even in closed position of the flap the flap is interposed between the first and second strips I, II. Preferably, the second strip II is wider than the third strip III as can be seen most clearly in FIGS. 1 and 2.

The second strip II extends from the fold line 20 to the terminal free edge 22 of the flap 18. Inasmuch as the second and third strips II, III are in alignment, when the flap is closed and the free portion 34 has been pulled away from the first strip I, said free portion, if reapplied to the envelope, will now engage the low adhesion side of the second strip II where it will remain lightly adhered as illustrated in FIG. 5. When in this position the free portion 34 can be pulled by its tab 36 away from the low adhesion side of the second strip II thereby to release the flap and permit the contents of the envelope to be scrutinized by a Post Office ofiicial.

The manner of use of the impermanent closure is be lieved to be clear. When the envelope is shipped the three strips I, II, IH of the impermanent closure are in the positions illustrated in FIG. 3. In this position the free portion 34 of the third strip III overlies and is lightly adhesively secured to the low adhesion side of the first strip I and will not adhesively engage some other surface. When the envelope is put to use by a purchaser, the purchaser raises the envelope flap 18 and peels the free portion 34 away from the low adhesion side of the first strip I. Then he recloses the flap as shown in FIG. 4. Finally, he applies the free portion 34 to the low adhesion side of the first strip I as shown in FIG. 5. Subsequently, when the envelope is to be opened by a Post Office employee, he grasps the tab 36 and peels the free portion 34 off the first strip I.

It should be pointed out that the first strip I, the portion of the third strip III from the intermediate portion 32 and extending away from the first strip I, and the second strip 11 are all tightly and essentially permanently adhered to the underlying paper of the envelope. The only strippable connections are, firstly, that between the free portion 34 and the first strip I when the envelope is sold, and, secondly, that between the free portion 34 and the low adhesion side of the second strip II When the envelope is impermanently closed.

In the preferred form of the invention, the first and third strips are of the same width. However, it may sometimes be found to be convenient to have the first strip wider than the third strip so that there is less danger of the third strip extending laterally beyond the first strip when superimposed thereon in the position shown in FIG. 3 either during manufacture or at any time prior to sale. The additional width of the first strip is, in effect, equivalent to the additional width of the second strip where such extra width is provided simply for the purpose of lessening the chance of a user applying the free portion of the third strip to the rear surface of the flap where it is not covered by the second strip.

Glue can be placed on the front surface of the flap on an envelope embodying the present invention so that a more secure sealed type of closure useful for first-class mail can be employed if desired.

As is apparent from the foregoing description, there is provided pursuant to the present invention a very simple, safe and convenient envelope including an impermanent closure which accomplishes all of the purposes above recited.

It will be understood that the drawings are merely representative and that the invention is not limited to any particular relative dimensions, i.e. ratio of dimensions, which might be picked off from the drawings. For example, in FIGS. 3, 4 and 5 the thicknesses of the paper and the pressure sensitive adhesive strips have been grossly exaggerated for the purpose of illustration and in FIGS. 1 and 2 the lengths of the strips are chosen simply for the purpose of illustration; a more accurate relationship between the lengths is seen in FIGS. 3, 4 and 5.

As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiment above set forth, it is to be understood that all matter herein described or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described the invention there is claimed as new and desired to be secured by Letters Patent:

1. An envelope including an envelope body open at one end and having a rear surface, a flap hinged to the envelope body at the open end thereof, said flap having a rear surface which faces in the same direction as the rear surface of the envelope body when the flap is folded over into closed position over the envelope body, said fiap including a terminal edge remote from the hinge connecting flap and the envelope body; and an impermanent closure for said envelope, said closure comprising three strips of pressure-sensitive adhesive tape each having an aggressively pressure-sensitive tacky adhesive side and a low adhesion side, the first of said strips being adhered on the rear surface of the envelope body by its tacky side with its low adhesion side facing away from said rear surface, said first strip being disposed to be substantially concealed by the flap in closed position, one end of said first strip being located on the rear surface of the envelope adjacent the edge of said rear surface proximate the fold between the flap and the envelope body, the other end of the first strip being adjacent and beneath the terminal edge of the flap when the flap is in closed position, the third strip being adhered by its aggressively pressure-sensitive tacky adhesive side on the rear surface of the envelope from an intermediate portion on the third strip toward an end of the third strip in a direction away from the fold between the flap and the envelope body, said intermediate portion being disposed adjacent the position occupied by the terminal edge of the flap when the flap is closed, the remainder of said third strip constituting a free portion, and the second strip having an aggressively pressure-sensitive tacky adhesive side adhered on the rear surface of the flap in alignment with the third strip and extending from the terminal edge of the flap toward the fold between the flap and the envelope body, the low adhesion side of the second strip facing away from the rear surface of the flap, whereby prior to use the free portion of the third strip may be lightly adhesively secured to the low adhesion side of the first strip and may be peeled therefrom and applied to the low adhesion side of the second strip after the flap is folded down to cover the exposed first strip.

2. An envelope as set forth in claim 1 wherein the free portion has a tip with its tacky side covered to form a pull tab for said free portion.

3. An envelope as set forth in claim 2 wherein the pull tab constitutes a folded-back portion on the tip of the third strip, the direction of fold-back being such that the aggressively pressure-sensitive tacky adhesive sides of the tip of the third strip face each other to leave at the pull tab exposed low adhesion sides.

4. An envelope as set forth in claim 1 wherein the strips are transparent.

5. An envelope as set forth in claim 1 wherein all strips extend in a direction such that their longitudinal axes are transverse to the fold between the flap and the envelope body.

6. An envelope as set forth in claim 5 wherein the longitudinal axes of the strips are perpendicular to said fold.

7. An envelope as set forth in claim 1 wherein the second strip is wider than the third strip.

8. An envelope as set forth in claim 1 wherein the first strip is wider than the third strip.

References Cited UNITED STATES PATENTS 906,121 12/1908 Dumas 22977 2,329,055 9/1943 'Kegay 229- 2,400,406 5/1946 Godoy 229-79 3,313,473 4/ 1967 Witters 229--80 3,329,331 7/1967 Morgan 229--51 W.B. 3,510,052 5/1970 Ruda 22962 FOREIGN PATENTS 1,483,501 4/1967 France 22980 DAVIS T. MOORHEAD, Primary Examiner U.S. Cl. X.R. 22980