US 2181252 A
Description (OCR text may contain errors)
Nov. 28, 1939. M. voel-:L
' SAFETY ENVELOPE Filed N0`v`. 18, 1953 JN VEN TOR.
Mmcl VCI/3m.. BY
` A TTORNEY Patented Nov. 28, 1939 UNITED STATES PATENT ori-ICE Application November 18, 1933, Serial No. 698,624 In Germany (ictober 10, 1933 3 Claims.
The present invention relates to safety- 4envelopes, particularly of the type in which cooperating adhesive surfaces are provided on the closing ap and upon -anotherportion of the enmoistened, but will firmly stick to the same ad' hesive substance, a suitable substance of this character being a solution of para rubber in gaso-v line. For convenience this substance. because of its property of adhering to itself without the necessity for moistening it, will hereinafter be l referred to as dry adhesive.
' Envelope structures heretofore in use were for the most part unsatisfactory for the use of suchv` cooperating adhesive surfaces, particularly because of` the fact that the adhesive surfaces would v,20 be apt to stick together prematurely, would be exposed to d-ust and dirt when they were out of contact with each other with the flap open, and on the contrary it was not possible to stack the envelopes, or'run them in a printing press or ,1.25 typewriter with the flap closed without the adhesive surfaces becoming stuck together. It `has been proposed'in certain instances lto place a protective strip of removable parailin paper, cloth, or the like between vthe adhesivesurfaces to prevent premature sticking, but this was-expensive and inconvenient,'and was not reliable as the strip was not a permanent part of the en` velope, and'would be apt to become displaced. vIt
is proposed in thepresent invention to provide a protective iiap for one of the adhesive surfaces which in one position protects the adhesive 'surface of the closing iiap when the latter is folded in superimposed relation and in another position exposes such adhesive surface, and which flap is further adapted to be folded into the envelope about the upper edge of the contents to retain them, and with the closing flap forms a double protective closure means.
Another object is to provide a safety envelope y which will disclose any attempt to open or tamper I with the envelope. Y, An envelope employing adire-- sive substance of the type proposed herein cainot be opened as` an ordinary gummed flap envelope can by steaming. but can be opened by employing a suitable solvent for the adhesive substance, as for instance gasoline or alcohol. -It is an object of the present invention to provide means which .will give anindication if the envelope has beenin contact with such solvent, and to this end I.
s particularly propose to provides. marking which i(Cl. 229-80) when contacted by such solvent will stain through the paper, spread or otherwise show that the envelope has been tampered wit AWith the above and other objects in view an embodiment of the invention isshown in the 5 accompanying drawing, and this embodiment will be hereinafter more fully described with reference thereto, and the invention will be nally pointed out in the claims.
lIn the drawing- 10 Fig. 1 is a plan view of the rear side of an envelope, according to one illustrated exemplary embodiment of the invention, the same being shown in its unsealed relation.
Fig. 2 is a vertical sectional view, taken along l5 the line 2--2 of Fig. 1, and showing another envelope inthe same relation adjacent thereto.
Fig. 3 is a fragmentary, plan view, with the two aps folded upwardly preparatory to inserting an enclosure, and showing one of the adhesive sur- 20 faces exposed. l
Fig.v4 is a vertical sectional view taken alongA the line l-l of Fig. 3.
Fig. 5 is a fragmentary plan view, showing the iiap at the upper edge of the back portion folded 25 into the envelope about the upper edge of the enclosure. Fig. 6 is a vertical sectional view taken along v the line 0 6 of Fig. 5, the enclosure being shown in dot-and-dash lines.
Fig. 'l is a fragmentary plan view showing the closing flap closed and sealed.
Fig. 8 is a vertical sectional viewA taken along the line 8 8 of Fig. "l, the enclosure being shown in dot-anddash lines. 35
Fig. 9 is a fragmentary plan view showing the manner in which the marking shows when the, envelope has been subjected to a solvent in an unauthorized attempt to open it.
Similar. reference characters indicate corre- 40 spending parts throughout the several figures of the drawing. Y
Referring to the drawing. the envelope, according to the illustrated exemplary embodiment of .theinventiom comprises a front or address-side 46 portion III, side naps I 2-I2 bent inwardly from the side edges of the portion I 0, and a back portion il, suitably secured, as by the usual pasting methods, to the side aps. .A closing iiap I3 is 50 provided at the upper edge of the front portion I0 and vanother flap Il is provided at the upper edge of the back portion, the folds of the two flaps coinciding, and the flap I4 being of such extent as to substantially coincide with the nap I3. For
- reversely printed on this purpose it may be of exactly the same size or it may be larger. ,f
A strip of dry-adhesive I is provided on the inner side of the flap I3, and a similar strip of dryadhesive I6 is provided on ,the back portion II adjacent its upper edge, and in such relation as to be contacted by the dry-adhesive IS when the nap I4 is folded in and the closing nap t3 folded down, and to be covered by the flap Il when the latter is folded downwardly upon the outer' side of the back portion. f
Upon the inner side of the iiap I3 a marking I1 is provided, the same ing or stamping with an ink or other suitable contrastingly colored substance that is soluble in the same substance hat will dissolve the adhesive. Adhesive of the type gasoline or alcohol, and a suitable marking substance which is also soluble in these liquids is aniline ink. I-have shown the marking in the form of the words This has been tampered with, the under side of the flap Il, so that if` subjected to the solvent after sealing these letters `will stain .through the paper and be visible as shown in Fig. 9. It will be understood that the marking `may also be in the form of a design, and that it may be placed upon either or both surfaces of either or both of the flaps I3 and I4, and/or it may be placed upon .either or both of the adhesive strips I5 and Ii.
Before use and when stacked the closing flap I3 and the protective flap upon the back surface, as shown in Figs. 1 and 2, so that both adhesive strips are concealed and are out of contact lby reason of. the interposition of the protective flap I4 between them. The envelope may thus be printed upon, inserted in a typewriter, sorted, or 'otherwisehandled as an ordinary envelope, as no portion carrying the dry-adhesive strips are exposed. or. disposed in such relation as to vpremature contact each other. To insert an enclosure the flaps are turned upwardly, as indicated in Figa-3 and 4, and 'may both be grasped and spread outwardly, 4thuis widening the opening and providing, for more, convenient insertion of the enclosure than with the usual type 'of envelope. Thereupon the lnap Il is folded into the envelope over the upper edge of the enclosure.' thereby retaining and protecting it, as shown in Figs. 5 'and 6, and the closing .flap the adhesive strip I'into contact with the exposed adhesive strip I8. By slight pressure applied to the outer side ofthe ap" 'L3 Athe adhesive strips are homogeneously 'joined and the envelope is thus sealed. In this latter relation the upper edge of the enclosure -is protected by the double fold of the two aps.
I have illustrated and described a preferred and satisfactory embodimentof the invention, but it will be obvious that changesmay be made therein, Lwithin the spirit and scope thereof( as dened in the appended claims. Having thus described my invention 'what I claim and desire to secure by- Letters Patent is:
1. In an envelope, front and back portions, a closing flap carried at the Vupper' edge. of said. front portion and foldable along said edge in two being produced by printemployed herein is soluble in I4- are both folded downA guide surfaces I3 is tlien folded. down bringing o tions adapted in directions, a second ap carried at the upper edge of said back yportion and foldable in two directions respectively into contact with the inner and outer surfaces of. said back portion, both of said aps being foldable downwardly in overlying relation to the outer side which position said closing flap is adapted to overlie said second flap, an adhesive substance on the inner side of said closing flap, said side being disposed inwardly in said folded-down relation of said flap, an adhesive substance on the outer side of said back arranged to be covered by said second flap when the latter is folded downwardly upon the outer side of said back portion and to be contacted by said adhesive substance on the closing flap when said second flap is folded upon the inner side of said back portion, the adhesive substance pon said closing flap adapted to adhere to the adhesivesubstance upon said back upon contact therewith.
2. In an envelope, front and back portions, a pair of 4foldable iiaps on the upper edges of said portions, an adhesive substance upon one side of one of said flaps, the second nap being free of an adhesive on both sides and foldable about the. upper edge of the portion ofthe envelope carrying said second flap from engagement with one surface of the envelope portion to engagement with the other surface, an adhesive substance upon the outer surface of the envelope adapted to be dis' posed andconcealed beneath the second flap in the one folded position of said second ap at one side of said envelope portion and adapted to be exposed in the other folded position of said second flap at the other side of said envelope portion,' said first-mentioned adhesive substance adapted to adhere to said second-mentioned adhesive substance upon contact therewith, said flaps adapted -adhesive substance to superimposition of said' other flap thereon with said first-mentioned adhesive substance contacting with said secondmentioned adhesive substance.
3. In an envelope, front and back portions, oneA portion having an adhesive section upon one side spaced from its upper edge, a. protective section between said adhesive section and said upper edge free of an adhesive on both sides and adapted to be folded upon said adhesive section to cover it,- the ther portion having an adhesivesection upon' one side adjacent its upper edge, one of said adhesive sections adapted to be folded upon the other adhesive section, said protective section in one position adapted to be interposed between said adhesive sections, one of said adhesive sec-- another position of said protective section to be folded upon the other adhesive section Without said protective section interposed v whereby said adhesive sections contact each other,
one adhesive section adapted to adhere to thef other adhesive section upon contact therewith.