Abstract: A molded desk top construction comprising a desk top upper member having a smooth planar surface, a lower base member supporting the upper member, the members having interlocking peripheral portions which are secured together to provide an integrated, lightweight, impact-resistant, robust desk top. The upper member is comprised of a compression-molded, melamine-covered, polyester thermoset resin. The lower portion is comprised of an injection molded acrylic-butadiene-styrene or high density polypropylene resin.

Abstract: A method and mold design for forming a molded chair seat portion and chair back support portion using air counterpressure and two different materials in an injection molding procedure. The two different materials comprise a first material having a low flexural modulus and the other material having a high flexural modulus. Other additives for tailoring the physical properties of the molded product are added to the mixture of the two materials. The air counterpressure is achieved using shop air pressure. The mold may be used to form the seat portion and the back support portion with a single stroke. An endothermic foaming agent is added to the mixture of the two materials to reduce the weight of the finished part, to reduce cycle time, and to assist in the uniform distribution of the materials that are injected into the mold cavity by the injection nozzle.

Abstract: A plastic chair which is assembled from only several unitary pieces, some of which can be identical to each other. The chair seat takes the form of a unitary seat-back shell of molded plastic material. The base structure takes the form of two molded plastic pieces having male and female connecting portions to permit joining the pieces of the base merely by fitting them together. Connecting flanges on the seat-back shell permit securing the seat to the connecting portion of the base. The base pieces are secured together by ultrasonic welding and the seat is ultrasonically welded to the base. The method of making the chair includes molding the several pieces from a colorant containing plastic and securing the pieces together. Each leg includes a plurality of webs to permit cutting the legs so a chair of a desired height is obtained while simultaneously obtaining floor engaging glides. Strengthening ribs and rigidity to the chair, and the plastic can include glass fiber reinforcing for additional strength.

Abstract: A chair seat and supporting base for the seat, each of which can be of unitary construction. The base is formed from a plastic material and has legs, the side walls of which merge smoothly into depending peripheral skirts of an upper supporting portion of the base. The legs have a plurality of vertical strengthening webs which are unexposed when the base is in its normal upright position. In addition, there is a grid-work of longitudinal and transverse walls each of which is vertical and which provide additional beam strength and rigidity to the base. Several arrangements are provided for securing a seat-back shell to different embodiments of the base. A unique glide arrangement is also disclosed which permits severing the legs at a desired height to provide chairs of different heights while providing a flat floor engaging glide that is secured against removal, for example, by ultrasonically bonding the glide to the foot of the chair leg.