US3895755A

US3895755A - Tamper proof envelope

Info

Publication number: US3895755A
Application number: US446283A
Authority: US
Inventors: Carol S Mccarthy
Original assignee: Lawrence Peska Associates Inc
Current assignee: Lawrence Peska Associates Inc
Priority date: 1974-02-27
Filing date: 1974-02-27
Publication date: 1975-07-22
Anticipated expiration: 1992-07-22

Abstract

An envelope which cannot be opened by unauthorized persons after being sealed, without exhibiting signs of such tampering. In one form, the top flap portion carries a bonding layer on its lower margin when it overlies the bottom flap and left and right side flaps, which is heat-sealable, by application of a hot ironing iron thereon, to make a permanent ''''iron-on'''' type of seal, like used on ''''iron-on'''' garment patches. Another form of the envelope uses ordinary mucilage containing a dye which changes color on application of hot steam to steam it open, so the recipient can know that someone has steamed it open.

Description

McCarthy TAMPER PROOF ENVELOPE 14 1 July 22, 1975 Primary Examiner-William I. Price I t: C 1S.MC th,A l,Md. [75] men or am 6 at y nnapo ls Assistant ExammerStephen P. Garbe Assigneel Lawrence Peska Associates, Attorney, Agent, or Firm-Richard E. Nanfeldt New York, N.Y. a part interest [22] Filed: Feb. 27, 1974 [57] ABSTRACT [21] A N 446,283 An envelope which cannot be opened by unauthorized persons after being sealed, without exhibiting signs of such tampering. In one form, the top flap portion 0.8. Carries a bonding layer on its lower margin when it Cl. r overlies the bottom fl p and left and right side flap [58] Field of Search 229/80, 83, 117/1, 1.5, which is heapsealable by application of a hot ironing 8/7 iron thereon, to make a permanent iron-on" type of seal, like used on iron-on garment patches. Another [56] References C'ted form of the envelope uses ordinary mucilage contain- UNITED ST P T ing a dye which changes color on application of hot 883,364 3/l908 Walter 229/83 steam to steam it open, so the recipient can know that l,20l,5l9 lO/l9l6 Sorensen 229/83 X someone has steamed it open. 2,032,386 3/1936 Wood 229/83 X 2,277,116 3/1942 Krueger 229/80 1 Clalm, 5 Drawing Flgures i 22 4 l y (\1 10 3 32 32 to the flapthat the paper has to be torn in order to open it, and'hence is detectable.

A further object of the invention is to provide a novel and improved envelope construction in which the adhesion of the flap with the rest of the envelope is caused by application of the iron-on principle of adhesion, which is commonly used for so-called iron-on patches for garments, slacks, elbow patches, knee patches and the like, which are secured in place by placing the patch over the tear or hole, and using a hot ironing iron to cause the patch to adhere firmly to the garment, and being so strong that it can withstand laundering, dry cleaning and other usages without coming loose.

Still a further object of the invention is to provide a novel and improved envelope construction, in which the adhesive used contains a chemical ingredient of a neutral color, but which will change color if subjected to steam or other heat being used to steam it open, so that the tampering is immediately noticed by the addressee or recipient of the letter.

Still another object of the invention is to provide a novel and improved tamper-proof envelope construction which is simple in design, looks very much like an ordinary envelope, and which can be made at low cost by mass production methods.

The above and other objects and advantages of the invention, will become apparent from the following description of a preferred embodiment thereof, as illustrated in the accompanying drawings, forming a part hereof.

IN THE DRAWINGS FIG. 1 is a face view of an envelope according to the invention, and employing a heat-seal type of bonding material, the flap being in open position.

FIG. 2 is a side elevational view of an ironing iron as used for subjecting the envelope of FIG. 1 to the heat sealing bonding sealing operation.

FIG. 3 is a face view of an envelope in which the flap has been closed and secured in closed position by heatsealing or iron-on procedure.

FIG. 4 is a face view of an envelope construction in which the adhesive material for securing the flap to the body of the envelope is a heat-sensitive two color dyecontaining adhesive which is of one color on being used to seal the envelope, and another if heat or steam is used to tamper with it.

FIG. 5 is a face view of the envelope of FIG. 4, showing how the heat-sensitive two color dye-containing adhesive of FIG. 4 changes to another color on application of heat or steam in tampering therewith to show clearly the tampering.

. In connection with the use of envelopes and other packaging for letters, manuscripts, booklets, and the like in mailing or sending by messenger, parcel post, ex-

press or other means of transportation, it is important that the contentsnot be disturbed or tampered with by unauthorized persons while this is necessary to guard against where the contents are valuable objects, such as jewelry, it is also just as important where the contents are letters, memoranda, manuscripts, song sheets, drafts or proposed lectures and the like.

The important object is to first make it very difficult for an intruder to open the package or envelope to inspect the contents, and if this is done, to make it self evident that the package or envelope has been opened, so that the sender and addressee at least know that an unauthorized person has opened the package or envelope, and also to try to ascertain or guess who it is, and to apprehend him or her. The present invention seeks to provide such an envelope or packaging means; for obtaining the above protection.

In order to understand clearly the nature of the invention and the best means for carrying it out, references may be had to the drawings, in which like numerals denote similar parts throughout the several views.

As shown, there is an envelope 10, formedof sheet material such as paper, cardboard, bristol board, sheet plastics, or other flexible material suitable for containing a letter, or other contents for mailing, delivering by messenger, or other means. Such an envelope 10 may have a main body face wall 12, with left and

right side edges

14 and 16, and front and

rear edges

18 and 20, with integral folded left and

right flap portions

22 and 24, folded under a bottom flap portion 26 to form an envelope pocket or receptacle 28, for the reception of a letter, memorandum, notice, card or other material or a pamphlet or booklet being sent to the addressee.

For closing the envelope pocket there is top flap portion 30, which is also integral with the main envelope body face wall 12, like the other flap portions mentioned, and which may be folded downwardly to overlap the borders of the remaining flap portions, in the manner shown in FIGS. 2 and 3, to close the envelope and seal in the contents.

An adhesive layer of material or glue or mucilage 32 is placed under the upper marginal areas of the bottom flap portion 26 where it overlaps the

side flaps

22 and 24, so as to be firmly secured thereto to seal the bottom of the envelope pocket. The top flap portion 30 is provided with border layers 34 of heat-seal bonding adhesive on its lower marginal surfaces where it overlaps the bottom flap portion and the two side flap portions, so as to firmly adhere to them all. This firmly seals the envelope pocket against unauthorized opening to inspect its contents, without tearing the envelope open, for, as shown in FIG. 2, an electric ironing iron 36 is heated up and used to iron the envelope top flap to firmly bond to the underlying flap portions by heat sealing, the heat causing the adhesive material to flow and meld or join the flaps together in a good seal bond.

Such iron-on bonding materials are well known in the garment repair art, being widely sold in notion and department stores for repairing tears and rips in garments, and for also attaching knee and elbow patches for greater wear and also for giving a special appearance with the present day fashions which encourage such appliques for novelty.

This bonding material may also be used for the other adhesive areas such as 32 with the other flap portions if desired, for further sealing protection, so that the iron heat seals them together also.

As shown in FIGS. 4 and 5, where the envelopes use ordinary glue or mucilage in the adhesive areas 32 to connect the bottom flap to the left and right side flaps, and such mucilage at 40A is applied as a layer along the marginal edges of the top flap portion 30A where they will overlie the marginal edge portions of the bottom and side flaps, the mucilage or adhesive will look much like ordinary adhesive which is moistened before sealing the envelope and pressed down to adhere and to seal the envelope. However, to make plain any tampering or steaming open of the envelope by unauthorized persons, the'adhesive mucilage or glue 40A contains a heat sensitive die material which changes color when steam heat is applied to the envelope to steam it open, as shown in FIG. 5 at 408. Such heat-sensitive dyes are well known in the dye and coloring arts, such as in the cloth and fabric manufacturing arts where the cloth or yarn is impregnated with liquid containing the heat sensitive dye, and at a later stage of manufacture is dipped into a hot bath or subjected to live steam, to bring out the desired color and to fix it to the fabric or yarn.

Thus the adhesive 40A of FIG. 4 would turn to some color such as red or green, when steam is applied to steam it open, and this would indicate to the recipient that the envelope had been tampered with even though additional glue or mucilage was applied to reseal the envelope. While this would not prevent tampering with the mail, it would at least let the recipient know that someone other than the sender had read the contents.

While the invention has been set forth in specific terms, it is understood that various changes may be made in size, shape, materials and arrangements without departing from the spirit and scope of the invention as claimed.

Having herein described the invention, what is claimed as new is:

l. A tamper proof envelope, which comprises:

a. a main body face wall having a left, a right, a front and a rear edge;

b. a left, a right, and a bottom flap portion integrally formed to said main body face, said left and said right flap portions folded under and sealed to said bottom flap portion forming an envelope pocket;

c. a top flap portion having a marginal edge, said top 1 flap portion integrally formed to said main body face; and

d. an integral mixture of a heat sensitive dye and an adhesive material which becomes adhesive on application of moisture, said mixture deposited as a single layer on said marginal edge of said top flap portion, said mixture forming a bond between said top flap portion and said left, said right and said bottom flap portion, said dye changing color upon the application of a heat means.

Claims

1. A tamper proof envelope, which comprises: a. a main body face wall having a left, a right, a front and a rear edge; b. a left, a right, and a bottom flap portion integrally formed to said main body face, said left and said right flap portions folded under and sealed to said bottom flap portion forming an envelope pocket; c. a top flap portion having a marginal edge, said top flap portion integrally formed to said main body face; and d. an integral mixture of a heat sensitive dye and an adhesive material which becomes adhesive on application of moisture, said mixture deposited as a single layer on said marginal edge of said top flap portion, said mixture forming a bond between said top flap portion and said left, said right and said bottom flap portion, said dye changing color upon the application of a heat means.