You can freely build on How Machines Build 3D Objects Layer by Layer from Melting Plastic

What this patent covers

This patent describes an apparatus that builds a three-dimensional object by sequentially depositing multiple layers of solidifying material. It uses a movable head with a dispensing outlet, or nozzle, that releases material in a fluid state, such as melted plastic (Claim 1). This material then solidifies at a specific temperature. A mechanical system moves the dispensing head and a base member relative to each other along X, Y, and Z axes (Claim 1). This movement allows the machine to precisely place each layer, building up the object slice by slice. For example, a computer-aided design (CAD) program can create a 3D model, which is then converted into instructions for the machine to deposit material for each layer (Claim 11).

What is now free to use

All 0 claims of US 5121329 are in the public domain. Specifically:

The 0 dependent claims add narrowing limitations and are also free.

What is NOT covered

Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.

• Does not cover 3D printing methods that do not involve depositing material from a dispensing head, such as laser sintering of powder or stereolithography using light to cure liquid resin.

• Does not cover processes where the material does not solidify after being discharged from the nozzle, as Claim 1 specifies a 'supply of material which solidifies at a predetermined temperature'.

• Does not cover methods that build objects without forming 'multiple layers' sequentially, as described in Claim 1.

• Does not cover systems where the dispensing head and base member do not move relative to each other in three dimensions along 'X,' 'Y,' and 'Z' axes.

• Does not cover 3D printing techniques that do not meter the discharge of material from an orifice at a predetermined rate, as required by Claim 1.

Who is building on this today

Stratasys Inc., the original assignee, continues to be a major player in the additive manufacturing space, developing and selling advanced FDM systems for industrial use. Other companies like Ultimaker, Prusa Research, and Creality have built upon similar principles to create a vast market for desktop and prosumer FDM 3D printers, making the technology widely accessible.

Products built on expired version of this technology

How to cite this patent in your documentation

Stratasys Inc. US Patent 5121329. Apparatus and method for creating three-dimensional objects. Granted 1992, expired 2009. Now in the public domain.

Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.

PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.