Abstract: A structural element, such as a section of a duckboard (e.g. a landing mat) to be removably fastened to a similar section, has one or more edges provided with male coupling formations adapted to be converted into complementary female formations by breaking off a projecting part thereof. The projecting part is generally T-shaped, with its frangible stem rising from the bottom of a preferably dovetail-shaped recess. Such an element can therefore be readily joined to another element having a mortise complementary to the head of the T or a tenon complementary to the recess.

Abstract: A nestable container or a storable-and-nestable container generally of the open-top, rectangular type, comprises along one of its walls a set-back forming a recess which lies inwardly of the remainder of the wall at a lower portion of the container. The recess is provided with means for holding an identifying card or other indicia, e.g. for disclosing the contents of the container so that the card is undamaged upon interfitting of the containers during nesting.

Abstract: A process for making synthetic resin structures in which the double wall element of a synthetic resin is molded with a channel open on one side of the element and into which a reinforcing body is fitted so that the walls of the channel flank this body. Each wall of the channel is provided with a row of openings, preferably extending in the longitudinal direction of the channel, the openings of each row registering with a respective groove formed in the reinforcement body. A cap or cover is molded over the open side of the channel so that portions of the synthetic resin of the cover can penetrate the openings and the grooves which can have a dovetail cross section.

Abstract: The invention relates to a container crate of the type that can be stacked or nested and made of molded plastic. According to the invention, the crate is divided into two compartments by an internal partition having a downwardly opening groove and containing apertures therein for ventilation. The crate has particular application for the shipment of small live animals.

Abstract: An article of furniture having a seat of a generally constant orientation but a back which can be tilted at various angles has a generally X-shaped relationship of the seat and back and, on each side a pair of horizontally spaced pins, affixed to the seat, one of which rides on the upper surface of a cooperating member of the back while the other can be selectively fitted into notches of a rack structure on the lower edge of the respective member. The upper edge or surface of these members have a cam configuration and the distance separating this edge from the bottoms of each of the respective notches is progressively increased downwardly along the rack so that the seat inclination is substantially constant for all positions in which the pins engage the notches.

Abstract: A method of moulding containers consisting of two plastic materials compatible with and sealable to each other, of differing nature and/or color, wherein the material is injected into a space provided between the walls of a mould and a counter-mould, and comprising defining within said space by means of removable separators a first and a second sub-space; injecting into said first sub-space a first one of said materials to fill it fully, injecting into the second sub-space the second material, removing said separators and continuing the injection under pressure of said second material until local interpenetration thereof.