Patent US3620441A successfully refreshed from Google Patents.
US3620441A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Envelope
Assignee: Individual
•
Filing: 1969-09-26
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Granted: 1971-11-16
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Expires: 1989-09-26
Abstract
Abstract An envelope having a flap portion which is easily stripped to completely open one end, the flap having staggered perforations which tear alternately to reduce the force required to initiate as well as to continue the tear and so being particularly adaptable to high-speed opening by machine. A strippable flap is defined by specially staggered perforations for ease in opening, and a special positioning of the strippable flap makes it possible to open envelopes of different sizes on the same envelope-opening machine frequently without adjustment or only one-half of the adjustment otherwise required.
Inventors
- 👤 Daniel T Robbins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:58
CPC Classifications
B; B65; B65D; B65D27/00; B65D27/32; B65D27/34; B65D27/36
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
137 words
In an envelope having a front panel, inwardly turned side panels, an upwardly turned bottom panel secured to said side panels and an upper closure panel, the improvement comprising: a substantially triangular strippable flap in one of said side panels defined by lines of perforations converging from the adjacent end of the envelope to an apex, the apex having a continuous substantially arcuate slit defining a tab; said perforations being elongated, and the perforations in one line being staggered relative to those in the other line in the direction of opening of the flap for ease in initiating tearing; said slit having unequal extensions on either side of a curved central portions and thereby further insuring that the tearing action is started in one line of perforations before it is started in the other line of perforations.
Claim 2
Dependent Claim
137 words
In an envelope having a front panel, inwardly turned side panels, an upwardly turned bottom panel secured to said side panels and an upper closure panel, the improvement comprising: a substantially triangular strippable flap in one of said side panels defined by lines of perforations converging from the adjacent end of the envelope to an apex, the apex having a continuous substantially arcuate slit defining a tab; said perforations being elongated, and the perforations in one line being staggered relative to those in the other line in the direction of opening of the flap for ease in initiating tearing; said slit having unequal extensions on either side of a curved central portions and thereby further insuring that the tearing action is started in one line of perforations before it is started in the other line of perforations.
Claim 3
Dependent Claim
43 words
The structure of claim 1 wherein one line of perforations is less oblique than the other and the extension of said slit leading to the less oblique line of perforations is shorter than the extension leading to the more oblique line of perforations.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-15 | 1975-05-17 | 1975-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-15 | 1979-05-17 | 1979-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-15 | 1983-05-17 | 1983-11-16 | $7700.00 | Window Closed / Lapsed |