Abstract: A portable lift device that includes a portable lift column assembly having a lift column including a first end, a second end, and a length there between. The second end of the lift column has at least one column attachment system. The lift column assembly further includes a riser assembly coupled to the lift column and movable with respect to the lift column. The riser assembly includes a riser attachment device. The portable lift device also includes a platform assembly movable with the riser assembly and having a platform structure coupled to at least one platform attachment system. The at least one platform attachment-system selectively engages the riser attachment device to detachably couple the platform assembly with the riser assembly and wherein the platform structure maintains structural integrity under a predetermined load capacity. The platform assembly is movable with the riser assembly.

Abstract: An apparatus for injection molding two compatible polymeric materials, in which two or more plasticizing zones on a screw are used to simultaneously or sequentially plasticize the two materials into a common accumulation space through separate pathways. The charge comprising multiple layers of material is then injected into a closed mold by means of forward axial motion of the screw with respect to its enclosing barrel. Once inside the mold, the first material forms a skin layer, totally or partially surrounding the other material. In this way a part having a plurality of material properties may be produced in a single operation.

Abstract: An apparatus for injection molding two compatible polymeric materials, in which two substantially coaxial extrusion screws are used to plasticize the two materials into a common accumulation space. The charge comprising multiple layers of material is then injected into a closed mold by means of forward axial motion of the outer screw with respect to its enclosing barrel. Once inside the mold, the first material forms a skin layer totally or partially surrounding the other material. In this way a part having a plurality of material properties may be produced in a single operation.