Abstract: A closure for an open-ended container such as a tray wherein the closure element is easily inserted into the tray so as to retain the tray contents but is quickly removed therefrom to facilitate dispensing of the container contents. The container walls are formed with slots which open to the outside of the container as well as extend transversely through the walls. A locking element in the form of an elongated strip of material is inserted into the slots from the outside of the container and is retained therein in a manner such that removal without bending the strip material is substantially impeded. To remove the locking strip member from the slot, all that is required is a pulling action transversely to the container walls which will permit its withdrawal and opening of the tray-like container for dispensing of its contents.

Abstract: An unorthodox cross-sectional shape for the bobbin or mandrel upon which wire is wound makes possible high speed production of non-circular perfect layer coils.