Non-gusseted expansible envelope

• US 4,294,400 A
• Filed: 04/17/1980
• Issued: 10/13/1981
• Est. Priority Date: 04/17/1980
• Status: Expired due to Term

• Current Assignee: Westvaco Corporation (Meadwestvaco Corporation)
• Original Assignee: Westvaco Corporation (Meadwestvaco Corporation)
• Inventors: Gendron, Wilfred H.
• Primary Examiner(s): Hall, George T.
• Application Number:
  US06/141,052
• Time in Patent Office: 544 Days
• Field of Search: 229/68, 229/61, 229/75
• US Class Current: 229/67.3
• CPC Class Codes: B65D 27/00 Envelopes or like essentially-rectangular containers for postal or other purposes having no structural provision for thickness of contents with shock-absorbing properties B65D81/03; letter-cards B42D15/00
• CPC Class Codes: Y10S 493/918 Expandable

Abstract

The non-gusseted, side seamed expansible envelope of the present invention comprises a back panel, front panel and closure flap prepared from a single blank of paper or the like. The side seams are formed from a first pair of flaps foldably attached to the ends of the back panel and a second pair of flaps foldably attached to the ends of the front panel. Each of the side seam flaps are applied with diagonally oriented perforated lines that are located equidistant from the score line separating the front and back panels, and the second pair of side seam flaps are also applied with longitudinally oriented perforated lines which together with the diagonally oriented perforated lines provide the expansion characteristics of the envelope.

Claims

1. A non-gusseted expansible envelope comprising a one piece blank including a substantially rectangular rear panel, a front panel foldably attached thereto along a transverse fold line, a closure flap foldably attached to the front panel along another transverse fold line and two pairs of equally sized and shaped side seam flaps foldably attached respectively to the side edges of the front and rear panels along a pair of longitudinal fold lines, the improvement wherein the side seam flaps attached to the side edges of the front panels are each applied with longitudinal perforated lines which substantially bisect the flaps to form outer portions for the application of adhesive and to provide hinge connections which enable the side seam flaps to be folded inwardly upon themselves when the envelope is expanded.

2. The envelope of claim 1 wherein each of the side seam flaps are applied with diagonally oriented perforated lines that are located equidistant from the score line separating the front and rear panels and which begin at the longitudinal fold lines between the front and rear panels and the side seam flaps and converge toward an imaginary extension of the score line separating the front and rear panels.

3. The envelope of claim 2 wherein each of the side seam flaps are partially cut away in the region of the diagonally perforated lines to form V-shaped cutouts at the junction between the front and rear panels.

4. The envelope of claim 3 wherein a patched window is applied to the front panel.

5. The envelope of claims 3 or 4 wherein a pair of additional score lines are applied transversely of the blank parallel to the score line separating the front and rear panels and between the beginning points of the diagonally oriented score lines.

6. A method of making and expanding a non-gusseted expansible envelope from an envelope blank having inner and outer surfaces comprising an aligned rear panel, front panel and closure flap separated from one another by transverse score lines, two pairs of equally sized and shaped side seam flaps foldably attached to the front and rear panels along spaced longitudinal score lines, a pair of longitudinally arranged perforated lines in the side seam flaps foldably attached to the front panel which form inner and outer portions thereof, and two pairs of diagonally oriented perforated lines in the side seam flaps symmetrically arranged around the score line separating the front and rear panels, comprising the steps:

(a) arranging the envelope blank with its inside surface facing upwardly;

(b) folding the side seam flaps about the spaced longitudinal fold lines to lie on the inside surface of said envelope blank;

(c) applying adhesive to the side seam flaps attached to said front panels on the outer portions thereof defined by said longitudinally arranged perforated lines;

(d) folding the rear panel over into face-to-face relation with the front panel to adhere the side seam flaps together; and

,

(e) expanding the envelope by manually folding the outer portions of the perforated side seam flaps inwardly upon themselves to produce a non-gusseted expansible envelope.