Snap fit assembly for a ruggedized multi-section structure with selective embrittlement or case hardening

Patent metadata

Field	Value
Publication number	US-9738948-B2
Application number	US-201615087245-A
Country	US
Kind code	B2
Filing date	Mar 31, 2016
Priority date	Apr 17, 2015
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

Apparatus and methods associated with an enclosure or structure including two sections that are adapted with a snap-fit interlocking structure. Various embodiments of the enclosure or structures are formed with various case hardening or embrittlement processes to increase embrittlement or hardness of the enclosure or structure so as to create a structure or enclosure which has a desired fragmentation capacity while still maintaining sufficient material properties to permit snap-fit insertion of one section into another section and withstand substantial impacts. Embodiments also provide an interlocking structure that minimizes differences in fragmentation or fracturing capacity as contrasted with other portions of the structure or enclosure. An embodiment of the invention includes an enclosure where one section of the enclosure or structure has a first thickness and the second section has a second thickness, wherein the first and second thicknesses are different. In some embodiments, one section is thinner than another section.

First claim

The invention claimed is:

1. An assembly comprising:
an enclosure formed from one or more materials comprising a first and second section, said first section comprising a first wall surrounding and defining a first cavity section, said second section comprising a second wall surrounding and defining a second cavity section, said first and second sections are adapted to be assembled at a joint section of said enclosure;
wherein said first wall comprises a first and second wall side, wherein said first wall side is formed as an opposing side of said first wall from said second wall side, said first wall further comprises a first joint interface section;
wherein said second wall comprises a third wall side and fourth wall side, wherein said third wall side is formed as an opposing side of said second wall from said fourth wall side, said second wall further comprises a second joint interface section;
wherein said first joint interface section is formed to insertably receive and retain said second joint interface section;
wherein said first joint interface section (FEMALE) is formed with a first, second, and third interlocking section formed at a first end of said first wall, said first end defining a first aperture into said first cavity section, said first interlocking section forms a first rib or protrusion perpendicular to said second wall side, said first interlocking section is formed with a first inwardly tapered geometry or profile defined by a first angle extending inwardly from said first wall side and increasing in thickness from said first end to a first shoulder section of said first interlocking section, said first interlocking section is formed with said first shoulder section defining a first transition between said first interlocking section to said second interlocking section, said first shoulder formed with a shoulder wall extending perpendicularly away from said second interlocking section, said second interlocking section has a different thickness than said first or third interlocking sections wherein said second interlocking section's thickness is less than said first or second interlocking sections, said third interlocking section is formed with a second inwardly tapered geometry or profile defined by a second angle extending inwardly from said first wall side and increasing in thickness from a second transition between said second and third interlocking sections to a second shoulder formed into said first section that extends away from said third interlocking section to said second side of said first wall, wherein said first interlocking section has a chamfered or rounded edge at said first end at said first aperture to facilitate said second section insertion into said first section;
wherein said second joint interface section is formed with a fourth, fifth, and sixth interlocking section formed at a second end of said second wall defining a second aperture into said second cavity section, said second and third interlocking sections defines a first channel or recess in said second side adapted to receive and interlockably retain said fifth and sixth interlocking sections, wherein said fifth interlocking section extends away from said fourth interlocking section forming a second rib or protrusion, said fourth interlocking section further defined by a third shoulder at a third transition section between said fourth and fifth interlocking sections, said second section's third shoulder engages with said first shoulder of said first section, wherein said fourth, fifth, and sixth interlocking sections are formed having a shape or profile defined to insertably engage with said first, second, and third interlocking sections with an interference snap fit that displaces said first and second wall sections until said fifth and sixth interlocking sections snap fits into said first channel or recess,
wherein said first and second sections comprise at least one of case hardening or embrittlement process of a first hardening or embrittlement formed or created by a heat treatment, case hardening or carburizing process to impart or increase a surface hardness of said first and second sections;
wherein said fourth, fifth, and sixth interlocking sections are disposed into said first, second, and third interlocking sections so that said first section is seated against said second section with an interference snap fit such that said fifth and sixth interlocking sections has a snap fit into said first channel or recess;

wherein said first joint interface section and at least some adjacent area of said first section is formed having a lesser wall thickness than said second joint interface section and at least some adjacent area of said second section to said second joint interface area;
wherein said enclosure is formed around materials to create a fragmentation device comprising an exemplary smooth inner surface, a hexagonal patterned exemplary outer surface defined as raised portions alongside valleys within the material of body that surrounds explosive material;
wherein said process comprises different hardness factors creating hexagonal patterned exemplary outer surface that create patterns for brittleness to fracture upon explosive material projection; and
wherein said process produces alteration of said regions between said hexagonal shapes so that metal in said regions has a different hardness than metal in said hexagonal areas.

2. An assembly as in claim 1 , further comprising a first payload item disposed into said first or second cavity sections.

3. An assembly as in claim 1 , wherein said one or more materials comprises steel.

4. An assembly as in claim 1 , wherein said first joint interface structure is formed comprising a female structure.

5. An assembly as in claim 1 , wherein said second joint interface structure is formed comprising a male structure.

Assignees

• Us Navy

Inventors

• Gwaltney Josh
• Allison Lucas
• Scheid Eric
• Deshpande Nishkamraj
• Wolf Alan
• Schisler Eddie

Classifications

• F42B12/28

  the projectile wall being built from annular elements · CPC title

• C23C8/22

  of ferrous surfaces · CPC title

• F42B12/24

  with grooves, recesses or other wall weakenings {(F42B12/26, F42B12/28 take precedence)} · CPC title

• F42B33/02

  Filling cartridges, missiles, or fuzes; Inserting propellant or explosive charges {(F42B33/004 takes precedence)} · CPC title

• F42B12/22

  with fragmentation-hull construction · CPC title