THERMOFORMED SNAP CLOSURES

• US 3,786,982 A
• Filed: 11/17/1971
• Issued: 01/22/1974
• Est. Priority Date: 11/17/1971
• Status: Expired due to Term

• Current Assignee: James L. Rakes, Wayne E. Cooper
• Original Assignee: James L. Rakes, Wayne E. Cooper
• Inventors: Rakes, James L., Cooper, Wayne E.
• Primary Examiner(s): Gelak, Bernard A.
• Application Number:
  US05/199,422
• Time in Patent Office: 797 Days
• Field of Search: 24/28A,168B,28R,213,214 229/2.5,45 220/31S 150/.5
• US Class Current: 229/406
• CPC Class Codes: B65D 1/26 Thin-walled containers, e.g. formed by deep-drawing operations B65D1/165 takes precedence
• CPC Class Codes: B65D 75/22 the sheet or blank being recessed to accommodate contents containers simulating a book B65D77/006
• CPC Class Codes: Y10T 24/44274 having either discrete flaccid or thin, nonbiasing, integral, connecting hinge
• CPC Class Codes: Y10T 24/45958 Plural distinct cavities or projections
• CPC Class Codes: Y10T 24/45984 Cavity having specific shape

Abstract

An at least substantially cylindrical columnar projection thermoformed in a first sheet of a thermoformable polymeric material and an at least substantially cylindrical columnar depression thermoformed in a second sheet are employed as a snap fastener. The exterior dimensions of the columnar projection and the interior dimensions of the columnar depression permit the insertion of the columnar depression with significant frictional engagement therebetween.

Claims

1. A thermoformed container comprising first and second sheet portions of a synthetic organic thermoformable thermoplastic polymeric material, at least one of said first and second sheet portions having a thermoformed packaging cavity therein, said first sheet portion having an at least substantially cylindrical thermoformed columnar projection therein, said seecond sheet portion having an at least substantially cylindrical thermoformed columnar depression therein, the exterior dimensions of said columnar projection having a relationship with the corresponding interior dimensions of said columnar depression permitting the insertion of said columnar projection into said columnar depression with significant frictional engagement between the exterior surface of said columnar projection and the interior surface of said columnar depression, such frictional engagement being sufficient to lock said columnar projection and said columnar depression together for normal handling of said first and second sheet portions and insufficient to prevent withdrawal of said columnar projection from said columnar depression upon the application of a desired minimum separation force;

said columnar projection having a top continuous with the side wall thereof, and said columnar depression having a bottom continuous with the side wall thereof so that an at least substantially air tight chamber is formed upon the insertion of said columnar projection a desired distance into said columnar depression, whereby the buildup of the pressure of the air trapped in said chamber resists the further insertion of said columnar projection into said columnar depression and the reduction of the pressure of the air trapped in said chamber resists the withdrawal of said columnar projection from said columnar depression.

2. A container in accordance with claim 1 wherein said first and second sheet portions are portions of a single sheet.

3. A container in accordance with claim 2 wherein said columnar projection and said columnar depression are located in said single sheet equal distances on opposite sides from a fold line in said single sheet, said columnar projection extending outwardly from a first planar surface of said single sheet, and said columnar depression extending outwardly from the opposite planar surface of said single sheet.

4. A container in accordance with claim 1 wherein each of said first and second sheet portions has at least one thermoformed cavity therein.

5. A container in accordance with claim 1 wherein each of the height of said columnar projection and the depth of said columnar depression is at least five times the thickness of each of said sheet portions.

6. A container in accordance with claim 5 wherein said columnar projection is a male mold thermoformed projection and wherein said columnar depression is a female mold thermoformed depression.

7. A container in accordance with claim 1 wherein the inner diameter of said columnar depression increases from the mouth thereof to the bottom thereof.

8. A container in accordance with claim 1 wherein at least one of the inner side wall surface of said columnar depression and the outer side wall surFace of said columnar projection has a roughened surface to increase the coefficient of friction thereof.