| 摘要 |
A stress failure resistant container cap for a threaded neck container in the nature of a carboy, such as large acid carboys, wherein the containers are usually large and heavy and closure caps therefor are also extremely heavy in structure. Carboys, for example, are sufficiently large that users sometimes over-tighten the cap using a wrench or similar tool. This can result in cap failures due to stress cracking due to the high torque applied to the cap. The high torque applied to the cap, and its coaction with the threads of the neck, when high or excessive torques are applied, tend to apply a strain in the corner juncture between the cap top and neck thereof. This can, and frequently has, resulted in cracking of the cap material. The strain is applied by a tendency to apply a bending force to the cap at the juncture corner. This invention teaches a construction of two-piece cap having a full large radius in the top corner whereby the top of the cap can bend when excess pressure is applied with a spring like action imparted to the cap. The cap, per se, is molded of high density or polypropylene material, or other suitable material and has interfitted therewith, and forming a component of the two-piece cap structure, a molded and assembled polyethylene cap liner fitment. The composite cap can be used in the absence of additional liners where polyethylene caps are considered suitable, or it is possible to add a separate liner for users desiring caps lined with other lining materials.
|
