NONEVERTING BOTTOM FOR THERMOPLASTIC BOTTLES

• US 3,727,783 A
• Filed: 06/15/1971
• Issued: 04/17/1973
• Est. Priority Date: 06/15/1971
• Status: Expired due to Term

• Current Assignee: Keith Stewart Carmichael
• Original Assignee: Keith Stewart Carmichael
• Inventors: Carmichael, Keith Stewart
• Primary Examiner(s): Leclair, Joseph R.
• Assistant Examiner(s): Marcus, Stephen
• Application Number:
  US05/153,268
• Time in Patent Office: 672 Days
• Field of Search: 215/1R,1C 220/3,60,70 150/.5 99/171B
• US Class Current: 215/375
• CPC Class Codes: B65D 1/0284 having a discontinuous contact surface, e.g. discrete feet

Abstract

A generally cylindrical thermoplastic bottle for bottling liquids under pressure such as beer, soda and aerosols, having a noneverting bottom under conditions of bottling and use wherein the bottom comprises at least three lobes around the bottom perimeter of the bottom on which the bottle stands, strap sections located between each lobe and a generally circular and axially aligned, recessed section defining a re-entrant cylinder of the base. To further improve eversion resistance, the bottom of the bottle can include a reinforcing ring attached to the reentrant cylinder.

Claims

1. In a generally cylindrical thermoplastic bottle, biaxially oriented at least in the generally cylindrical section, the improvement wherein the bottom configuration consists essentially of at least three lobes around the bottom perimeter of the bottle on which the bottle stands;

strap sections located between each lobe;

an axially aligned re-entrant cylinder;

anD a generally circular and axially aligned recessed section with a smooth transition of material between the lobes, straps, re-entrant cylinder, and recessed sections of the base wherein a. the strap sections begin at the generally cylindrical section of the bottle and extend downward toward the central axis of the bottle with a radius of about 0.45 to 0.7 D, including about 75* to 90* of arc and terminating in the base of the reentrant cylinder and the width of each strap is determined by the following formula;

2. The bottle of claim 1 having three lobes and three strap sections.

3. The bottle of claim 1 having four lobes and four strap sections.

4. The bottle of claim 1 having five lobes and five strap sections.

5. The bottle of claim 1 having six lobes and six strap sections.

6. The bottle of claim 1 having a reinforcing ring of thermoplastic on the interior surface of the toroidal knuckle connecting the walls of the re-entrant cylinder wherein the reinforcing ring is formed of two concentric contacting side wall sections each having a length of about 0.05 to 0.20 D.

7. The bottle of claim 1 wherein the thermoplastic is polyethylene terephthalate having an inherent viscosity of at least about 0.55.

8. The bottle of claim 7 having a shell thickness of at least 20 mils in the generally cylindrical section and 30 mils in the bottom section, prepared from a polymer having a modulus of elasticity at yield of at least about 180,000 psi, a tensile strength of at least 5,000 psi, a Poisson'"'"''"'"'s ratio of 0.35 to 0.4 and a deformation constant equal to the slope of the log (reciprocal of the strain rate) versus strain having a value of at least about 0.65.