Abstract: A pair of structural members are releasably attached by providing an interlocking attachment of a boss on one member with a cavity in another member so that respective walls of the boss and cavity engage each other whereby a space is left between respectively opposed walls of the boss and cavity. A spacer is provided in the space between the opposed walls to maintain the interlocking attachment of the boss in the cavity. The spacer is maintained in position to prevent its inadvertent removal from the case by a detent which engages an indentation.

Abstract: A method of combining a transfer molding operation with a blow molding operation to form an article having wall sections of different thicknesses. The major portion of an extruded parison fed between a pair of mold sections and enclosed thereby is expanded into conformity with the cavity defined by the mold sections. An intermediate portion of the parison is directed into a cavity and displaced therefrom by opposed portions on the mold sections into a desired space to completely fill such spaced forming a wall section having a different wall thickness than the remainder of the article.

Abstract: A footstool includes a vertical base member having a lower end arranged to rest on a floor, and a support member mounted on the base member and extending outwardly therefrom to support the legs and feet of a user. The base member has two openings therethrough, and first and second surfaces arranged to face toward and away from the support member. The support member includes two male members arranged to penetrate the base member openings, and has a first surface arranged to abut the base member first surface. Each male member carries a hook-like member which is adapted to engage the base member second surface to prevent unintended separation of the base and support members.

Abstract: A freestanding ladder structure has a first base member arranged on one side of an object to be bridged, a second base member arranged on the other side of the object, and a raised platform supported above the object by two ladder members having their lower end portions engaged with the base members. The various parts and components of the ladder structure are hollow or tubular and may be conveniently formed of plastic by a well known blow molding technique. Where necessary, a reinforcing insert is arranged within a component to resist flexure or bending thereof. Some components are provided with hook members engagable with other components to prevent unintended separation of the assembled components.

Abstract: A method of and apparatus for blow molding an article having an insert permanently affixed thereto. The insert is placed on a removable member insertable through a wall of a mold section for positioning the insert in spaced relation to a mold cavity wall. An extruded parison is fed between complementary mold sections which are closed about the parison for enclosing a portion of the same. Air is introduced into the enclosed parison to expand the same into conformity with the cavity defined by the mold sections and the insert. Plastic material flows into the spacing between the insert and mold cavity wall to partially encapsulate the insert in sealed, interlocked relation to the wall of the plastic article.