GB190615063A - Improvements in Safety Envelops. - Google Patents

Abstract

15,063. Vail, R. W. July 2. Envelopes; seals.-In safety envelopes, formations in the paper of the sealing-flap and back flap are embedded in a mass of sealing-wax or plastic material, so that the paper is damaged on breaking the seal. Figs. 3 and 4 show the formations in the back flap 2 and sealing-flap 3, respectively, and Fig. 5 shows a section of the parts when sealed. Ridges 5, 9, preferably of annular contour and corrugated, are formed in the flaps to register, as shown in Fig. 5. The paper within the ridges is cut away, leaving tongues 8, 12 disposed to form a concentric series when the parts are registered. The tongues are, preferably, strengthened by corrugations 16, and one edge is, preferably, notched or cut away, as shown at 15 and turned outwards as shown at 14. When the parts are registered, a cup-shaped depression 17 is formed, Fig. 5, to receive the wax 18, which fills in the space between and under all the tongues. The wax may be impressed with an identifying initial, emblem, or mark 19. In order to prevent contact of the wax with the contents of the envelope, a protective strip or flap 20, preferably of absorbent paper or other material to which the wax adheres, is attached to the back flap 2 under the cut-away parts. Instead of providing the tongues 8, 12, the paper within the ridges may be simply perforated or provided with any suitably-shaped openings or slots ; Fig. 7 shows a lace-work of connected ribs or crosspieces 22. In such arrangements, it is preferable to give the perforated or slotted portion a convex contour, so that the wax can spread under and around all of the parts which are to be embedded in its mass. Fig. 9 shows a modification, in which an aluminium or other stiffening plate or strip 24 is fitted in the ridge 5 and secured by the flap 20 ; the inner edge of the plate 24 may be bent up to form projections 26 to be embedded in the wax.