Vibratory screening machines that include stacked screening deck assemblies are provided. In some embodiments, at least one of the vibratory screening machines can include an outer frame, an inner frame connected to the outer frame, and a vibratory motor assembly secured to the inner frame for vibrating the inner frame. A plurality of screen deck assemblies can be attached to the inner frame in a stacked arrangement, each configured to receive replaceable screen assemblies. The screen assemblies can be secured to respective ones of the plurality of the screen deck assemblies by tensioning the screen assemblies in a direction that a material to be screened flows across the screen assemblies. An undersized material discharge assembly can be configured to receive materials that pass through the screen assemblies, and an oversized material discharge assembly can be configured to receive materials that pass over the screen assemblies.

Vibratory screening machines that include stacked screening deck assemblies are provided. In some embodiments, at least one of the vibratory screening machines can include an outer frame, an inner frame connected to the outer frame, and a vibratory motor assembly secured to the inner frame for vibrating the inner frame. A plurality of screen deck assemblies can be attached to the inner frame in a stacked arrangement, each configured to receive replaceable screen assemblies. The screen assemblies can be secured to respective ones of the plurality of the screen deck assemblies by tensioning the screen assemblies in a direction that a material to be screened flows across the screen assemblies. An undersized material discharge assembly can be configured to receive materials that pass through the screen assemblies, and an oversized material discharge assembly can be configured to receive materials that pass over the screen assemblies.

Disclosed embodiments include a removable support structure for a vibratory screening machine. The removable support structure is a single structure including one or more of plastic, metal, and composite materials and may be configured to provide mechanical support to one or more screening assemblies of the vibratory screening machine. The removable support structure may further be configured to be removably fastened to the vibratory screening machine. The removable support structure may be a single thermoplastic injection molded piece or may be a single injection molded piece that includes nylon, carbon, and graphite. The removable support structure may have a concave shape that is configured to mechanically support a screening assembly held under compression or may have a convex shape that is configured to mechanically support a screening assembly held under tension. A disclosed wear protective covering, made of a flexible material, provides wear protection to the removable support structure.

A disclosed screening apparatus includes a subgrid, and a screen element attached to the subgrid via laser welding at a plurality of attachment positions such that, under vibrational excitation, the screen element has a pre-determined profile of vibrational motion relative to the subgrid. The screen element may be attached at a maximal number of attachment locations to the subgrid to minimize relative motion of the screen element and the subgrid under vibrational excitation, or the screen element may be attached a sub-set of the maximal number of attachment locations to allow vibrational motion of the screen element relative to the subgrid. A disclosed method may include attaching a plurality of screen elements to a respective plurality of subgrids, attaching the plurality of subgrids to one another to form a screening pre-assembly, and cutting edges of the screening pre-assembly to form the screen assembly having a perimeter with a pre-determined shape.

A disclosed screening apparatus includes a subgrid, and a screen element attached to the subgrid via laser welding at a plurality of attachment positions such that, under vibrational excitation, the screen element has a pre-determined profile of vibrational motion relative to the subgrid. The screen element may be attached at a maximal number of attachment locations to the subgrid to minimize relative motion of the screen element and the subgrid under vibrational excitation, or the screen element may be attached a sub-set of the maximal number of attachment locations to allow vibrational motion of the screen element relative to the subgrid. A disclosed method may include attaching a plurality of screen elements to a respective plurality of subgrids, attaching the plurality of subgrids to one another to form a screening pre-assembly, and cutting edges of the screening pre-assembly to form the screen assembly having a perimeter with a pre-determined shape.

A stretching-shaft screening device for separating insects, in particular insect larvae, or worms and residual material, is disclosed, having a screen that has a first screening portion and an adjoining second screening portion, wherein the mesh size in the first screening portion is smaller than the mesh size in the second screening portion. The invention also relates to the use of a stretching-shaft screening device for separating insects, in particular insect larvae, or worms and residual material.

A disclosed screening apparatus includes a subgrid, and a screen element attached to the subgrid via laser welding at a plurality of attachment positions such that, under vibrational excitation, the screen element has a pre-determined profile of vibrational motion relative to the subgrid. The screen element may be attached at a maximal number of attachment locations to the subgrid to minimize relative motion of the screen element and the subgrid under vibrational excitation, or the screen element may be attached a sub-set of the maximal number of attachment locations to allow vibrational motion of the screen element relative to the subgrid. A disclosed method may include attaching a plurality of screen elements to a respective plurality of subgrids, attaching the plurality of subgrids to one another to form a screening pre-assembly, and cutting edges of the screening pre-assembly to form the screen assembly having a perimeter with a pre-determined shape.

Disclosed embodiments include a removable support structure for a vibratory screening machine. The removable support structure is a single structure including one or more of plastic, metal, and composite materials and may be configured to provide mechanical support to one or more screening assemblies of the vibratory screening machine. The removable support structure may further be configured to be removably fastened to the vibratory screening machine. The removable support structure may be a single thermoplastic injection molded piece or may be a single injection molded piece that includes nylon, carbon, and graphite. The removable support structure may have a concave shape that is configured to mechanically support a screening assembly held under compression or may have a convex shape that is configured to mechanically support a screening assembly held under tension. A disclosed wear protective covering, made of a flexible material, provides wear protection to the removable support structure.

Screening members, screening assemblies, methods for fabricating screening members and assemblies and methods for screening materials are provided for vibratory screening machines that incorporate the use of injection molded materials. Use of injection molded screen elements provide, inter alia, for: varying screening surface configurations; fast and relatively simple screen assembly fabrication; and a combination of outstanding screen assembly mechanical and electrical properties, including toughness, wear and chemical resistance. Embodiments of the present invention use a thermoplastic injection molded material.

Screening members, screening assemblies, methods for fabricating screening members and assemblies and methods for screening materials are provided for vibratory screening machines that incorporate the use of injection molded materials. Use of injection molded screen elements provide, inter alia, for: varying screening surface configurations; fast and relatively simple screen assembly fabrication; and a combination of outstanding screen assembly mechanical and electrical properties, including toughness, wear and chemical resistance. Embodiments of the present invention use a thermoplastic injection molded material.