Height Adjustable Food Service Support With Composite Plastic And Steel

The patent uses a composite construction combining plastic leg body with metal reinforcement elements (steel rod, metal insert with external threads) to achieve both cost reduction and structural integrity. The plastic provides economical manufacturing while the metal components provide the necessary strength to withstand side loads and creep deformation.

The patent applies metal reinforcement locally at critical stress points rather than making the entire leg from metal. The steel rod is embedded in the plastic leg body where tensile and bending stresses occur, and the metal insert is placed at the foot area where compressive loads from the nut occur, providing strength exactly where needed while maintaining overall cost effectiveness.

The patent introduces a metal insert with external threads as an intermediary between the plastic foot and the adjustment nut. This metal insert acts as a mediator that transfers the compressive loads from the nut to the plastic foot without deforming the plastic, thereby enabling height adjustment while maintaining structural integrity.

The foot assembly uses a composite structure with plastic providing the foot body and metal insert providing the load-bearing interface. This composite approach allows the plastic to be economical and easy to manufacture while the metal insert handles the mechanical stresses of height adjustment.

The patent separates the caster assembly from the leg body, allowing the caster to be independently adjustable on the steel rod. This segmentation enables height adjustment functionality to be added to fixed legs without redesigning the entire leg structure, reducing overall system complexity.

The steel rod with external threads serves multiple functions: it provides structural reinforcement for the leg, enables height adjustment through threading, and accommodates both fixed and adjustable caster configurations. This multi-functionality reduces the need for separate components and simplifies the overall design.

The patent replaces expensive zinc die casting alloys with a composite construction using economical plastic materials reinforced with strategic metal elements. This composite approach achieves comparable or superior strength and durability while dramatically reducing material and manufacturing costs.

The patent changes the material parameters from homogeneous metal alloy to composite plastic-metal construction. This parameter change allows optimization of each material's properties for its specific function while reducing overall cost, leveraging the high strength-to-weight ratio of plastic combined with the high strength of localized metal reinforcement.