Injection molded screening apparatuses and methods

Patent metadata

Field	Value
Publication number	US-11638933-B2
Application number	US-202117389070-A
Country	US
Kind code	B2
Filing date	Jul 29, 2021
Priority date	May 25, 2012
Publication date	May 2, 2023
Grant date	May 2, 2023

Abstract

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.

First claim

What is claimed is:

1. A screen assembly for vibratory screening applications, the screen assembly configured to provide one or more relatively large open screening areas while having structurally stable small screen openings, the screen assembly comprising:
a continuous screen assembly screening surface comprised of a plurality of thermoplastic injection molded screen elements;
each of the plurality of thermoplastic injection molded screen elements having screen openings ranging in size from about 43 to about 1000 microns fabricated during the injection molding;
wherein the thermoplastic injection molded screen elements are assembled together to form the continuous screen assembly screening surface having an open screening area of at least about 16 percent of a total screening area.

2. The screen assembly of claim 1 , further comprising a support structure, wherein the thermoplastic injection molded screening elements are mounted to a support structure.

3. The screen assembly of claim 2 , wherein the support structure comprises a plurality of subgrid elements joined end-to-end and side-to-side.

4. The screen assembly of claim 3 , wherein the each of the subgrid elements comprises clips and clip-receiving apertures for joining adjacent subgrid elements together.

5. The screen assembly of claim 4 , wherein adjacent subgrid elements are joined end-to-end using two of the clips and two of the clip-receiving apertures.

6. The screen assembly of claim 4 , wherein adjacent subgrid elements are joined side-to-side using four of the clips and four of the clip-receiving apertures.

7. The screen assembly of claim 1 , wherein the thermoplastic injection molded screen elements comprise a material having a flexural modulus of at least about 400,000 PSI.

8. The screen assembly of claim 7 , wherein the material comprises thermoplastic polyurethane.

9. The screen assembly of claim 8 , wherein the thermoplastic polyurethane is polyester-based.

10. The screen assembly of claim 8 , wherein the thermoplastic polyurethane is polyether-based.

11. The screen assembly of claim 8 , wherein the material further comprises para-phenylene diisocyanate.

12. The screen assembly of claim 1 , further comprising a frame;
a first of the thermoplastic injection molded screen elements being attached to a first side of the frame;
a second of the thermoplastic injection molded screen elements being attached to a second side of the frame;
the frame, the first screen element, and the second screen element forming a closed structure having an enclosed internal space; and
one or more unsecured objects located within the enclosed internal space;
wherein the internal objects are configured to make collisions with one or more of the first and second screen element in response to vibration of the screening apparatus.

13. The screening apparatus of claim 12 , wherein the frame further comprises one or more internal support structures that divide the enclosed internal space into two or more enclosed internal spaces.

14. The screen assembly of claim 13 , wherein the unsecured objects further comprise two or more unsecured objects that are located in each of the two or more enclosed internal spaces.

15. The screen assembly of claim 12 , wherein the frame further comprises three internal support structures forming four internal compartments.

16. The screen assembly of claim 12 , wherein the frame further comprises two crossed internal support structures forming four internal compartments.

17. The screen assembly of claim 12 , wherein the frame further comprises four internal support structures forming eight internal compartments.

18. The screen assembly of claim 1 , further comprising a subgrid structure.

19. The screen assembly of claim 18 , wherein the screen elements are secured to the subgrid structure via laser welding.

20. The screen assembly of claim 18 , further comprising a removable plug that is configured to be attached to the screen assembly to thereby cover a portion of at least one of the screen elements.

21. The screen assembly of claim 20 , wherein the plug includes hooks that are configured to be forced through the screening element and to engage with latching structures of the subgrid structure.

22. The screen assembly of claim 20 , wherein the plug is configured to make close contact with the screen element to thereby prevent fluids and particulate matter from flowing through the portion of the screen element covered by the plug.

23. The screen assembly of claim 20 , wherein the plug is configured to be installed through a top of the subgrid structure.

24. The screen assembly of claim 20 , wherein the plug is configured to be installed through a bottom of the subgrid structure.

25. The screen assembly of claim 20 , wherein the plug has a thickness that is less than a thickness of the screen element.

26. The screen assembly of claim 20 , wherein the plug includes one or more of plastic, nylon, and thermoplastic polyurethane.

27. The screen assembly of claim 18 , wherein the screen element is configured to be removably attached to the subgrid structure using non-permanent attachment structures of the screen element and subgrid structure that allow a non-permanent attachment of the screen element to the subgrid structure.

28. The screen assembly of claim 27 , further comprising permanent attachment structures in addition to the non-permanent attachment structures,
wherein the presence of non-permanent attachment structures and permanent attachment structures allows a non-permanent attachment or a permanent attachment of the screen element to the subgrid structure.

29. The screen assembly of claim 28 , wherein the permanent attachment structures include fusion bars on the subgrid structure and cavity pockets on the screen element configured to facilitate laser welding of the screen element to the subgrid structure.

30. The screen assembly of claim 27 , wherein the non-permanent attachment structures include hooks on the screen element and hook apertures on the subgrid structure.

31. The screen assembly of claim 30 , wherein the hooks are configured to be compressed to allow hooks to be forced through respective hook apertures after entering an entrance size of each hook aperture and to expand on an exit side of a hook aperture to thereby engage the hook with the hook aperture to secure the screen element to the subgrid structure.

32. The screen assembly of claim 18 , wherein the subgrid structure is configured to be connected to neighboring subgrid structures of a subgrid structure framework.

33. The screen assembly of claim 18 , wherein the screen element is configured to be not attached to the subgrid structure at a predetermined pattern of locations to thereby allow relative motion of the screen element and subgrid structure during use in a vibratory screening machine.

34. The screen assembly of claim 1 , wherein each of the plurality of thermoplastic injection molded screen elements has screen openings ranging in size from about 43 to about 150 microns.

35. The screen assembly of claim 1 , wherein each of the plurality of thermoplastic injection molded screen elements has screen openings ranging in size from about 43 to about 100 microns.

Assignees

• Derrick Corp

Inventors

• Wojciechowski Keith
• Colgrove James R
• Stodolka Kurt
• Lipa Anthony
• Demay Alex

Classifications

• B07B1/4663

  Multi-layer screening surfaces · CPC title

• B29C45/2628

  with mould parts forming holes in or through the moulded article, e.g. for bearing cages · CPC title

• B29L2031/737

  Articles provided with holes, e.g. grids, sieves (nets B29L2028/00) · CPC title

• B29K2075/00

  Use of {PU, i.e.} polyureas or polyurethanes {or derivatives thereof}, as moulding material · CPC title

• B29C66/114

  Single butt joints · CPC title